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Find video protocols related to scientific articles indexed in Pubmed.
An improved 2b-RAD approach (I2b-RAD) offering genotyping tested by a rice (Oryza sativa L.) F2 population.
BMC Genomics
PUBLISHED: 10-24-2014
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2b-RAD (type IIB endonucleases restriction-site associated DNA) approach was invented by Wang in 2012 and proven as a simple and flexible method for genome-wide genotyping. However, there is still plenty of room for improvement for the existent 2b-RAD approach. Firstly, it doesn't include the samples pooling in library preparation as other reduced representation libraries. Secondly, the information of 2b-RAD tags, such as tags numbers and distributions, in most of species are unknown. The purposes of the research are to improve a new 2b-RAD approach which possesses samples pooling, moreover to figure out the characteristic and application potentiality of 2b-RAD tags by bioinformatics analysis.
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Critical illness polyneuropathy and myopathy: a systematic review.
Neural Regen Res
PUBLISHED: 09-11-2014
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Critical illness polyneuropathy and critical illness myopathy are frequent complications of severe illness that involve sensorimotor axons and skeletal muscles, respectively. Clinically, they manifest as limb and respiratory muscle weakness. Critical illness polyneuropathy/myopathy in isolation or combination increases intensive care unit morbidity via the inability or difficulty in weaning these patients off mechanical ventilation. Many patients continue to suffer from decreased exercise capacity and compromised quality of life for months to years after the acute event. Substantial progress has been made lately in the understanding of the pathophysiology of critical illness polyneuropathy and myopathy. Clinical and ancillary test results should be carefully interpreted to differentiate critical illness polyneuropathy/myopathy from similar weaknesses in this patient population. The present review is aimed at providing the latest knowledge concerning the pathophysiology of critical illness polyneuropathy/myopathy along with relevant clinical, diagnostic, differentiating, and treatment information for this debilitating neurological disease.
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Impact of the Loess Plateau on the atmospheric boundary layer structure and air quality in the North China Plain: a case study.
Sci. Total Environ.
PUBLISHED: 09-03-2014
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The North China Plain (NCP), to the east of the Loess Plateau, experiences severe regional air pollution. During the daytime in the summer, the Loess Plateau acts as an elevated heat source. The impacts of such a thermal effect on meteorological phenomena (e.g., waves, precipitation) in this region have been discussed. However, its impacts on the atmospheric boundary layer structure and air quality have not been reported. It is hypothesized that the thermal effect of the Plateau likely modulates the boundary layer structure and ambient concentrations of pollutants over the NCP under certain meteorological conditions. Thus, this study investigates such effect and its impacts using measurements and three-dimensional model simulations. It is found that in the presence of daytime westerly wind in the lower troposphere (~1 km above the NCP), warmer air above the Loess Plateau was transported over the NCP and imposed a thermal inversion above the mixed boundary layer, which acted as a lid and suppressed the mixed layer growth. As a result, pollutants accumulated in the shallow mixed layer and ozone was efficiently produced. The downward branch of the thermally-induced Mountain-Plains Solenoid circulation over the NCP contributed to enhancing the capping inversion and exacerbating air pollution. Previous studies have reported that low mixed layer, a factor for elevated pollution in the NCP, may be caused by aerosol scattering and absorption of solar radiation, frontal inversion, and large scale subsidence. The present study revealed a different mechanism (i.e., westerly warm advection) for the suppression of the mixed layer in summer NCP, which caused severe O3 pollution. This study has important implications for understanding the essential meteorological factors for pollution episodes in this region and forecasting these severe events.
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Silver nanoparticles with an armor layer embedded in the alumina matrix to form nanocermet thin films with sound thermal stability.
ACS Appl Mater Interfaces
PUBLISHED: 07-01-2014
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In this article, we demonstrate that the Al-alloyed Ag nanoparticle-embedded alumina nanocermet films lead to excellent thermal stability, even at 500 °C for 130 h under an ambient nitrogen atmosphere. The outward diffusion of Al atoms from the AgAl bimetallic alloy nanoparticles and their easy oxidation create an armor layer to suppress the mobility of Ag atoms. Then, the AlAg particles or/and agglomerates with a uniform spherical shape favor higher dispersion concentration within the host matrix, which is beneficial both for high absorptance in the visible range and for the solid localized surface plasmon absorption features in the AgAl-Al2O3 nanocermet films. Based on the AgAl-Al2O3 absorbing layer with sound optical and microstructural stability, we successfully constructed a high-temperature-endurable solar selective absorber. The multilayer stacked absorber demonstrates a high solar absorptance of ?94.2% and a low thermal emittance of ?15% (@ 673 K) after annealing at 450 °C for 70 h in an ambient nitrogen atmosphere.
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Spatial and temporal variations of six criteria air pollutants in 31 provincial capital cities in China during 2013-2014.
Environ Int
PUBLISHED: 06-30-2014
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Long-term air pollution data with high temporal and spatial resolutions are needed to support the research of physical and chemical processes that affect the air quality, and the corresponding health risks. However, such datasets were not available in China until recently. For the first time, this study examines the spatial and temporal variations of PM2.5, PM10, CO, SO2, NO2, and 8h O3 in 31 capital cities in China between March 2013 and February 2014 using hourly data released by the Ministry of Environmental Protection (MEP) of China. The annual mean concentrations of PM2.5 and PM10 exceeded the Chinese Ambient Air Quality Standards (CAAQS), Grade I standards (15 and 40?g/m(3) for PM2.5 and PM10, respectively) for all cities, and only Haikou, Fuzhou and Lasa met the CAAQS Grade II standards (35 and 70?g/m(3) for PM2.5 and PM10, respectively). Observed PM2.5, PM10, CO and SO2 concentrations were higher in cities located in the North region than those in the West and the South-East regions. The number of non-attainment days was highest in the winter, but high pollution days were also frequently observed in the South-East region during the fall and in the West region during the spring. PM2.5 was the largest contributor to the air pollution in China based on the number of non-attainment days, followed by PM10, and O3. Strong correlation was found between different pollutants except for O3. These results suggest great impacts of coal combustion and biomass burning in the winter, long range transport of windblown dust in the spring, and secondary aerosol formation throughout the year. Current air pollution in China is caused by multiple pollutants, with great variations among different regions and different seasons. Future studies should focus on improving the understanding of the associations between air quality and meteorological conditions, variations of emissions in different regions, and transport and transformation of pollutants in both intra- and inter-regional contexts.
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Exploring the safety range via the transoral approach to the craniovertebral junction.
J Craniofac Surg
PUBLISHED: 06-11-2014
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Surgeries via the transoral approach are widely used to deal with lesions near the craniovertebral junction. For this approach, the pharyngeal tubercle is an important landmark to identify the midline. The foramen lacerum, another important anatomic area where some crucial structures pass, is close to the pharyngeal tubercle. In the current study, we measured relevant distances and angles on 120 adults without brain diseases to estimate the safety range of the transoral approach. Distances between the pharyngeal tubercle and the foramen lacerum were expressed as mean (SD) and 95% confidence interval. Angles between the straight lines, which pass through the pharyngeal tubercle and the foramen lacerum, and the sagittal plane, as well as the horizontal plane, were also presented as mean (SD) and 95% confidence interval. As regards the 95% confidence intervals of the angles and the distances, which were used to define the safety range, no differences were observed between the right side and the left side. During such surgeries, if the midline is defined as a datum line, it is less likely for surgeons to destroy adjacent structures when moving within 36.30 degrees on the sagittal plane and 45.00 degrees on the horizontal plane once they find the pharyngeal tubercle. It is also safe to move within 16.20 mm from the pharyngeal tubercle. With these data, we have successfully defined the safety range of the surgery, which may help operators choose proper instruments in surgery and avoid injuries to important structures. Moreover, operators may use these data to position the pharyngeal tubercle so as not to deviate from the midline.
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Improved methodology to obtain large quantities of correctly folded recombinant N-terminal extracellular domain of the human muscle acetylcholine receptor for inducing experimental autoimmune myasthenia gravis in rats.
Arch Med Sci
PUBLISHED: 06-07-2014
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Human myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular system. Experimental autoimmune myasthenia gravis (EAMG) is a well-established animal model for MG that can be induced by active immunization with the Torpedo californica-derived acetylcholine receptor (AChR). Due to the expensive cost of purifying AChR from Torpedo californica, the development of an easier and more economical way of inducing EAMG remains critically needed.
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Development of a PCR-RFLP assay for the detection and differentiation of canine parvovirus and mink enteritis virus.
J. Virol. Methods
PUBLISHED: 06-05-2014
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A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay has been developed to detect and differentiate between canine parvovirus (CPV) and mink enteritis virus (MEV). Eight CPV and three MEV epidemic strains isolated from 28 pathological samples from dogs and minks suspected of being infected with parvovirus were amplified by PCR using a pair of specific primers designed based on the CPV-N strain (M19296). PCR amplified a fragment of 1016bp from the genomic DNA of both MEV and CPV. The MEV-derived fragment could be digested with the restriction enzyme BSP1407I into three fragments of 102bp, 312bp and 602bp, while the fragment amplified from the CPV genomic DNA was digested into only two fragments of 414bp and 602bp. The lowest DNA concentration of CPV and MEV that could be detected using this assay was 0.004?g/ml and 0.03?g/ml, respectively. The PCR-RFLP assay developed in the present study can, therefore, be used to detect and differentiate MEV from CPV with high specificity and sensitivity.
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Poisoning of mitochondrial topoisomerase I by lamellarin D.
Mol. Pharmacol.
PUBLISHED: 06-02-2014
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Lamellarin D (Lam-D) is a hexacyclic pyrole alkaloid isolated from marine invertebrates, whose biologic properties have been attributed to mitochondrial targeting. Mitochondria contain their own DNA (mtDNA), and the only specific mitochondrial topoisomerase in vertebrates is mitochondrial topoisomerase I (Top1mt). Here, we show that Top1mt is a direct mitochondrial target of Lam-D. In vitro Lam-D traps Top1mt and induces Top1mt cleavage complexes (Top1mtcc). Using single-molecule analyses, we also show that Lam-D slows down supercoil relaxation of Top1mt and strongly inhibits Top1mt religation in contrast to the inefficacy of camptothecin on Top1mt. In living cells, we show that Lam-D accumulates rapidly inside mitochondria, induces cellular Top1mtcc, and leads to mtDNA damage. This study provides evidence that Top1mt is a direct mitochondrial target of Lam-D and suggests that developing Top1mt inhibitors represents a novel strategy for targeting mitochondrial DNA.
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Increased negative supercoiling of mtDNA in TOP1mt knockout mice and presence of topoisomerases II? and II? in vertebrate mitochondria.
Nucleic Acids Res.
PUBLISHED: 05-06-2014
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Topoisomerases are critical for replication, DNA packing and repair, as well as for transcription by allowing changes in DNA topology. Cellular DNA is present both in nuclei and mitochondria, and mitochondrial topoisomerase I (Top1mt) is the only DNA topoisomerase specific for mitochondria in vertebrates. Here, we report in detail the generation of TOP1mt knockout mice, and demonstrate that mitochondrial DNA (mtDNA) displays increased negative supercoiling in TOP1mt knockout cells and murine tissues. This finding suggested imbalanced topoisomerase activity in the absence of Top1mt and the activity of other topoisomerases in mitochondria. Accordingly, we found that both Top2? and Top2? are present and active in mouse and human mitochondria. The presence of Top2?-DNA complexes in the mtDNA D-loop region, at the sites where both ends of 7S DNA are positioned, suggests a structural role for Top2 in addition to its classical topoisomerase activities.
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Mapping topoisomerase sites in mitochondrial DNA with a poisonous mitochondrial topoisomerase I (Top1mt).
J. Biol. Chem.
PUBLISHED: 05-05-2014
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Mitochondrial topoisomerase I (Top1mt) is a type IB topoisomerase present in vertebrates and exclusively targeted to mitochondria. Top1mt relaxes mitochondrial DNA (mtDNA) supercoiling by introducing transient cleavage complexes wherein the broken DNA strand swivels around the intact strand. Top1mt cleavage complexes (Top1mtcc) can be stabilized in vitro by camptothecin (CPT). However, CPT does not trap Top1mtcc efficiently in cells and is highly cytotoxic due to nuclear Top1 targeting. To map Top1mtcc on mtDNA in vivo and to overcome the limitations of CPT, we designed two substitutions (T546A and N550H) in Top1mt to stabilize Top1mtcc. We refer to the double-mutant enzyme as Top1mt*. Using retroviral transduction and ChIP-on-chip assays with Top1mt* in Top1mt knock-out murine embryonic fibroblasts, we demonstrate that Top1mt* forms high levels of cleavage complexes preferentially in the noncoding regulatory region of mtDNA, accumulating especially at the heavy strand replication origin OH, in the ribosomal genes (12S and 16S) and at the light strand replication origin OL. Expression of Top1mt* also caused rapid mtDNA depletion without affecting mitochondria mass, suggesting the existence of specific mitochondrial pathways for the removal of damaged mtDNA.
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Unusual heat stroke caused by herbal therapy with traditional Chinese medicine.
Neurosciences (Riyadh)
PUBLISHED: 04-18-2014
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Traditional Chinese medicine (TCM) comprises a range of traditional medical practices that originate in China, including herbal medicine as a major therapy. Through its 4 natures; namely, cold, hot, warm, and cool, herbal medicine may regulate sympathetic nerves and basal metabolic rate and affect the CNS and the endocrine system. Heat stroke is a severely life-threatening heat-related illness that is most commonly seen during summer heat waves and high environmental temperatures. The intake of medications or toxins is considered one of the risk factors leading to heat stroke, as they may affect body thermoregulation. We report a case of heat stroke that was associated with herbal therapy with TCM. This case highlights the importance of paying more attention to unidentified folk prescriptions in the use of TCM.
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Predicting primary PM2.5 and PM0.1 trace composition for epidemiological studies in California.
Environ. Sci. Technol.
PUBLISHED: 04-16-2014
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The University of California-Davis_Primary (UCD_P) chemical transport model was developed and applied to compute the primary airborne particulate matter (PM) trace chemical concentrations from ? 900 sources in California through a simulation of atmospheric emissions, transport, dry deposition and wet deposition for a 7-year period (2000-2006) with results saved at daily time resolution. A comprehensive comparison between monthly average model results and available measurements yielded Pearson correlation coefficients (R) ? 0.8 at ? 5 sites (out of a total of eight) for elemental carbon (EC) and nine trace elements: potassium, chromium, zinc, iron, titanium, arsenic, calcium, manganese, and strontium in the PM2.5 size fraction. Longer averaging time increased the overall R for PM2.5 EC from 0.89 (1 day) to 0.94 (1 month), and increased the number of species with strong correlations at individual sites. Predicted PM0.1 mass and PM0.1 EC exhibited excellent agreement with measurements (R = 0.92 and 0.94, respectively). The additional temporal and spatial information in the UCD_P model predictions produced population exposure estimates for PM2.5 and PM0.1 that differed from traditional exposure estimates based on information at monitoring locations in California Metropolitan Statistical Areas, with a maximum divergence of 58% at Bakersfield. The UCD_P model has the potential to improve exposure estimates in epidemiology studies of PM trace chemical components and health.
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Mitochondrial topoisomerase I (top1mt) is a novel limiting factor of doxorubicin cardiotoxicity.
Clin. Cancer Res.
PUBLISHED: 04-08-2014
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Doxorubicin is one of the most effective chemotherapeutic agents. However, up to 30% of the patients treated with doxorubicin suffer from congestive heart failure. The mechanism of doxorubicin cardiotoxicity is likely multifactorial and most importantly, the genetic factors predisposing to doxorubicin cardiotoxicity are unknown. On the basis of the fact that mtDNA lesions and mitochondrial dysfunctions have been found in human hearts exposed to doxorubicin and that mitochondrial topoisomerase 1 (Top1mt) specifically controls mtDNA homeostasis, we hypothesized that Top1mt knockout (KO) mice might exhibit hypersensitivity to doxorubicin.
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A real-time optical tracking and measurement processing system for flying targets.
ScientificWorldJournal
PUBLISHED: 04-02-2014
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Optical tracking and measurement for flying targets is unlike the close range photography under a controllable observation environment, which brings extreme conditions like diverse target changes as a result of high maneuver ability and long cruising range. This paper first designed and realized a distributed image interpretation and measurement processing system to achieve resource centralized management, multisite simultaneous interpretation and adaptive estimation algorithm selection; then proposed a real-time interpretation method which contains automatic foreground detection, online target tracking, multiple features location, and human guidance. An experiment is carried out at performance and efficiency evaluation of the method by semisynthetic video. The system can be used in the field of aerospace tests like target analysis including dynamic parameter, transient states, and optical physics characteristics, with security control.
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Identifying PM2.5 and PM0.1 sources for epidemiological studies in California.
Environ. Sci. Technol.
PUBLISHED: 03-13-2014
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The University of California-Davis_Primary (UCD_P) model was applied to simultaneously track ? 900 source contributions to primary particulate matter (PM) in California for seven continuous years (January 1st, 2000 to December 31st, 2006). Predicted source contributions to primary PM2.5 mass, PM1.8 elemental carbon (EC), PM1.8 organic carbon (OC), PM0.1 EC, and PM0.1 OC were in general agreement with the results from previous source apportionment studies using receptor-based techniques. All sources were further subjected to a constraint check based on model performance for PM trace elemental composition. A total of 151 PM2.5 sources and 71 PM0.1 sources contained PM elements that were predicted at concentrations in general agreement with measured values at nearby monitoring sites. Significant spatial heterogeneity was predicted among the 151 PM2.5 and 71 PM0.1 source concentrations, and significantly different seasonal profiles were predicted for PM2.5 and PM0.1 in central California vs southern California. Population-weighted concentrations of PM emitted from various sources calculated using the UCD_P model spatial information differed from the central monitor estimates by up to 77% for primary PM2.5 mass and 148% for PM2.5 EC because the central monitor concentration is not representative of exposure for nearby population. The results from the UCD_P model provide enhanced source apportionment information for epidemiological studies to examine the relationship between health effects and concentrations of primary PM from individual sources.
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Source apportionment of sulfate and nitrate particulate matter in the Eastern United States and effectiveness of emission control programs.
Sci. Total Environ.
PUBLISHED: 03-11-2014
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Reducing population exposure to PM2.5 in the eastern US will require control of secondary sulfate and nitrate. A source-oriented Community Multi-scale Air Quality (CMAQ) model is used to determine contributions of major emission sources to nitrate and sulfate concentrations in the seven eastern US cities (New York City, Pittsburgh, Baltimore, Chicago, Detroit, St. Paul, and Winston-Salem) in January and August of 2000 and 2006. Identified major nitrate sources include on-road gasoline-powered vehicles, diesel engines, natural gas and coal combustion. From 2000 to 2006, January nitrate concentrations decreased by 25-68% for all the seven cities. On average, ~53% of this change was caused by emissions controls while 47% was caused by meteorology variations. August nitrate concentrations decreased by a maximum of 68% in New York City but Detroit experienced increasing August nitrate concentrations by up to 33%. On average, ~33% of the reduction in nitrate is offset by increases associated with meteorological conditions that favor nitrate formation. Coal combustion and natural gas are the dominant sources for sulfate in both seasons. January sulfate decrease from 2000 to 2006 in all cities by 4-58% except New York City, which increases by 13%. On average, ~93% of the reduction in sulfate was attributed to emission controls with 7% associated with changes in meteorology. August sulfate concentrations decrease by 11-44% in all cities. On average, emission controls alone between 2000 and 2006 would have caused 6% more reduction but the effectiveness of the controls was mitigated by meteorology conditions more favorable to sulfate production in 2006 vs. 2000. The results of this study suggest that regional emissions controls between 2000 and 2006 have been effective at reducing population exposure to PM2.5 in the eastern US, but yearly variations in meteorology must be carefully considered when assessing the exact magnitude of the control benefits.
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Solubilization of 4,4'-dibromodiphenyl ether under combined TX-100 and cosolvents.
Environ Sci Pollut Res Int
PUBLISHED: 02-21-2014
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This paper is focused on the selection of cosolvents in the remediation of contaminated soils. The aim of this study was to investigate the combined effects of Triton X-100 (TX-100) and different cosolvents on the solubilization behavior of 4,4'-dibromodiphenyl ether (BDE-15) and the washing of BDE-15 from a contaminated soil. (1)H NMR spectroscopies were used to elucidate the interactions among TX-100, cosolvents, and BDE-15 in aqueous micellar solution. Results showed that the solubility of BDE-15 was enhanced by the observed synergism among TX-100, BDE-15, and cosolvents, and the TX-100/dimethyl sulfoxide (DMSO) system exhibited the best performance in the solubilization of BDE-15. Similar synergism was further evidenced in the washing of BDE-15 from a contaminated soil. With 10 % (v/v) DMSO and 6.4 mM TX-100 solution added, considerable synergistic effect was achieved in TX-100/DMSO system, leading to the highest removal efficiency (92.9 %) of BDE-15 from the soil, relative to that of 67.3 % with TX-100 alone at the same concentration.
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Effect of adenovirus-mediated up-regulation of ?-enolase gene products on follicle-stimulating hormone receptor mRNA and luteinizing hormone receptor mRNA of granular cells from goose F1 follicles.
Res. Vet. Sci.
PUBLISHED: 02-15-2014
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Enolases are glycolytic enzymes in the glycolytic pathway. In order to evaluate the effect of ENO1 on follicle-stimulating hormone receptor (FSHR) mRNA and luteinizing hormone receptor (LHR) mRNA of primary granular cell from goose F1 follicles, the recombinant plasmid adenovirus carrying ENO1 were constructed and infected the primary culture granular cells. The granular cells were randomly divided into three groups: recombinant adenovirus infected (pAd-CMV-ENO1), empty vector infected (pAd-CMV-Null) and no virus (mock control). The expression levels of FSHR mRNA and LHR mRNA of granular cells were examined by qRT-PCR. The results showed the group pAd-CMV-ENO1 had significantly higher FSHR mRNA expression levels than the other two groups (P?
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PARP1-TDP1 coupling for the repair of topoisomerase I-induced DNA damage.
Nucleic Acids Res.
PUBLISHED: 02-03-2014
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Poly(ADP-ribose) polymerases (PARP) attach poly(ADP-ribose) (PAR) chains to various proteins including themselves and chromatin. Topoisomerase I (Top1) regulates DNA supercoiling and is the target of camptothecin and indenoisoquinoline anticancer drugs, as it forms Top1 cleavage complexes (Top1cc) that are trapped by the drugs. Endogenous and carcinogenic DNA lesions can also trap Top1cc. Tyrosyl-DNA phosphodiesterase 1 (TDP1), a key repair enzyme for trapped Top1cc, hydrolyzes the phosphodiester bond between the DNA 3'-end and the Top1 tyrosyl moiety. Alternative repair pathways for Top1cc involve endonuclease cleavage. However, it is unknown what determines the choice between TDP1 and the endonuclease repair pathways. Here we show that PARP1 plays a critical role in this process. By generating TDP1 and PARP1 double-knockout lymphoma chicken DT40 cells, we demonstrate that TDP1 and PARP1 are epistatic for the repair of Top1cc. The N-terminal domain of TDP1 directly binds the C-terminal domain of PARP1, and TDP1 is PARylated by PARP1. PARylation stabilizes TDP1 together with SUMOylation of TDP1. TDP1 PARylation enhances its recruitment to DNA damage sites without interfering with TDP1 catalytic activity. TDP1-PARP1 complexes, in turn recruit X-ray repair cross-complementing protein 1 (XRCC1). This work identifies PARP1 as a key component driving the repair of trapped Top1cc by TDP1.
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Characteristics and treatment options of elderly Chinese patients with cancer as determined by Comprehensive Geriatric Assessment (CGA).
J Geriatr Oncol
PUBLISHED: 01-08-2014
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China is experiencing a rapid increase in cancer incidence in elderly patients. In order to better understand this group, a large study of patients from multiple tertiary centers in the Beijing area was designed. This study was designed to provide insight into their unique treatment preferences, including the use of traditional Chinese medicine (TCM).
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Overexpression of OsMYB48-1, a novel MYB-related transcription factor, enhances drought and salinity tolerance in rice.
PLoS ONE
PUBLISHED: 01-01-2014
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MYB-type transcription factors (TFs) play essential roles in plant growth, development and respond to environmental stresses. Role of MYB-related TFs of rice in drought stress tolerance is not well documented. Here, we report the isolation and characterization of a novel MYB-related TF, OsMYB48-1, of rice. Expression of OsMYB48-1 was strongly induced by polyethylene glycol (PEG), abscisic acid (ABA), H2O2, and dehydration, while being slightly induced by high salinity and cold treatment. The OsMYB48-1 protein was localized in the nucleus with transactivation activity at the C terminus. Overexpression of OsMYB48-1 in rice significantly improved tolerance to simulated drought and salinity stresses caused by mannitol, PEG, and NaCl, respectively, and drought stress was caused by drying the soil. In contrast to wild type plants, the overexpression lines exhibited reduced rate of water loss, lower malondialdehyde (MDA) content and higher proline content under stress conditions. Moreover, overexpression plants were hypersensitive to ABA at both germination and post-germination stages and accumulated more endogenous ABA under drought stress conditions. Further studies demonstrated that overexpression of OsMYB48-1 could regulate the expression of some ABA biosynthesis genes (OsNCED4, OsNCED5), early signaling genes (OsPP2C68, OSRK1) and late responsive genes (RAB21, OsLEA3, RAB16C and RAB16D) under drought stress conditions. Collectively, these results suggested that OsMYB48-1 functions as a novel MYB-related TF which plays a positive role in drought and salinity tolerance by regulating stress-induced ABA synthesis.
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Microembolic signals detected with transcranial doppler sonography differ between symptomatic and asymptomatic middle cerebral artery stenoses in Northeast China.
PLoS ONE
PUBLISHED: 01-01-2014
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Although microembolus monitoring has been widely used for ischemic cerebrovascular disease, the clinical significance of microembolic signal (MES) in asymptomatic middle cerebral artery (MCA) stenosis remains unclear. We aim to investigate the frequency of MES and the value of MES in predicting ischemic stroke secondary to asymptomatic MCA stenosis. From June 2011 to December 2012, microembolus monitoring was performed in 83 asymptomatic and 126 symptomatic subjects. By comparing the demographics and risk factors between the symptomatic and asymptomatic subjects, we found that the ratio of male sexuality and smoking history differed (101/126 vs 43/83, and 88/126 vs 38/83, respectively, p<0.01). The frequency of MES was significantly higher in the symptomatic group than in the asymptomatic group (49/126 vs 2/108, p<0.01). Specifically, the frequency of MES in the symptomatic and asymptomatic groups with mild stenosis, moderate stenosis, severe stenosis and occlusion groups was 4/18 (22.22%) vs 0/30 (0), 13/31 (41.94%) vs 1/28 (3.57%), 30/62 (48.39%) vs 1/39 (2.56%), 2/15 (13.33%) vs 0/11 (0), respectively. Except for the occlusive group, the frequency of MES is correlated with stenosis degree and symptom. Two patients in the asymptomatic group were found positive for MES, and the MES number was 1 for both. During the one-year follow-up, neither of them developed ischemic stroke. In conclusion, MES detected with TCD differs between symptomatic and asymptomatic MCA stenoses. Due to the low frequency, the value of MES as a predictor of subsequent ischemic stroke in patients with asymptomatic MCA stenosis might be limited.
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Protective effect of demethylation treatment on cigarette smoke extract-induced mouse emphysema model.
J. Pharmacol. Sci.
PUBLISHED: 10-22-2013
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In the present study, we explored the effects of demethylation in a cigarette smoke extract (CSE)-induced mouse emphysema model. Animals were randomly assigned to the control group, CSE group, 5-aza-2-deoxycytidine (AZA) group, and CSE+AZA group (n = 10 per group). The mitochondrial transcription factor A (mtTFA) promoter methylation increased over 4-fold in the CSE group compared with the control group, which was reversed by AZA. The mtTFA and the cytochrome c oxidase subunit II (COX II) mRNA and protein levels were decreased approximately 3-fold in the CSE group compared with the control group, which was largely restored by AZA. Histological analysis showed that the CSE group exhibited emphysema compared with the control, which was alleviated by AZA. In addition, CSE significantly induced lung cell apoptosis and decreased lung function and lung mitochondrial COX activity, which was mostly restored by AZA. In conclusion, we for the first time provide evidence that demethylation therapy with AZA can effectively improve emphysema, lung function, lung cell apoptosis, and lung mitochondrial COX activity in a CSE-induced mouse emphysema model, which adds fresh insight into the therapeutic potential of demethylating agents in the prevention and treatment of cigarette smoke-induced emphysema.
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Differences between generalized q-sampling imaging and diffusion tensor imaging in the preoperative visualization of the nerve fiber tracts within peritumoral edema in brain.
Neurosurgery
PUBLISHED: 09-24-2013
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Diffusion tensor imaging (DTI) tractography enables the in vivo visualization of white matter tracts inside normal brain tissue, which provides the neurosurgeon important information to plan tumor resections. However, DTI is associated with restrictions in the resolution of crossing fibers in the vicinity of the tumor or in edema. We find that generalized q-sampling imaging (GQI) can overcome these difficulties and is advantageous over DTI for the tractography of the fiber bundle in peritumoral edema.
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Negative regulation of mitochondrial transcription by mitochondrial topoisomerase I.
Nucleic Acids Res.
PUBLISHED: 08-27-2013
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Mitochondrial topoisomerase I is a genetically distinct mitochondria-dedicated enzyme with a crucial but so far unknown role in the homeostasis of mitochondrial DNA metabolism. Here, we present data suggesting a negative regulatory function in mitochondrial transcription or transcript stability. Deficiency or depletion of mitochondrial topoisomerase I increased mitochondrial transcripts, whereas overexpression lowered mitochondrial transcripts, depleted respiratory complexes I, III and IV, decreased cell respiration and raised superoxide levels. Acute depletion of mitochondrial topoisomerase I triggered neither a nuclear mito-biogenic stress response nor compensatory topoisomerase II? upregulation, suggesting the concomitant increase in mitochondrial transcripts was due to release of a local inhibitory effect. Mitochondrial topoisomerase I was co-immunoprecipitated with mitochondrial RNA polymerase. It selectively accumulated and rapidly exchanged at a subset of nucleoids distinguished by the presence of newly synthesized RNA and/or mitochondrial RNA polymerase. The inactive Y559F-mutant behaved similarly without affecting mitochondrial transcripts. In conclusion, mitochondrial topoisomerase I dampens mitochondrial transcription and thereby alters respiratory capacity. The mechanism involves selective association of the active enzyme with transcriptionally active nucleoids and a direct interaction with mitochondrial RNA polymerase. The inhibitory role of topoisomerase I in mitochondrial transcription is strikingly different from the stimulatory role of topoisomerase I in nuclear transcription.
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miR-29 mediates TGF?1-induced extracellular matrix synthesis through activation of PI3K-AKT pathway in human lung fibroblasts.
J. Cell. Biochem.
PUBLISHED: 07-03-2013
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TGF?1 is very important in the synthesis and degradation of extracellular matrix, and also in the mediation of human lung fibroblasts proliferation, and miR-29 plays an important role in this process. To explore the interactions of miR-29 family members and TGF?1, the effects of transforming growth factor TGF?1 on the expression of miR-29 and whether miR-29 is involved in pro-survival signaling pathways mediated by TGF?1 were examined in human lung fibroblasts. Treatment of the human embryonic lung fibroblast cell line IMR90 with TGF?1 caused a decrease in expression of miR-29a/b/c by real-time PCR analysis. TGF?1 stimulation increased cell proliferation, colony formation and up-regulated expression of COL1A1; transfecting with miR-29a/b/c mimics reverse TGF?1-induced phenotype changes in IMR90 cells. Western blot analyses showed that TGF?1 treatment unchanged total protein expression levels of PI3K or AKT, but the expression levels of p-PI3K, p-AKT, and COL1A1 were increased; and miR-19a/b/c mimics interfering blocked phosphorylation of PI3K or AKT and decreased expression of COL1A1 after TGF?1 treatment. The results indicate that TGF?1 beta uses the PI3k-Akt pathway in these embryonic fibroblasts and miR29 blocks this activation pathway. It indicates a novel biological function of the PI3K-Akt pathway in IMR90. Elevated expression of miR-29 may play an important role in the pathogenesis of diseases related to fibrogenic reactions in human lung fibroblasts.
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Evaluation of a seven-year air quality simulation using the Weather Research and Forecasting (WRF)/Community Multiscale Air Quality (CMAQ) models in the eastern United States.
Sci. Total Environ.
PUBLISHED: 03-21-2013
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The performance of the Weather Research and Forecasting (WRF)/Community Multi-scale Air Quality (CMAQ) system in the eastern United States is analyzed based on results from a seven-year modeling study with a 4-km spatial resolution. For 2-m temperature, the monthly averaged mean bias (MB) and gross error (GE) values are generally within the recommended performance criteria, although temperature is over-predicted with MB values up to 2K. Water vapor at 2-m is well-predicted but significant biases (>2gkg(-1)) were observed in wintertime. Predictions for wind speed are satisfactory but biased towards over-prediction with 0
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Are onconeural antibodies a clinical phenomenology in paraneoplastic limbic encephalitis?
Mediators Inflamm.
PUBLISHED: 03-21-2013
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Paraneoplastic neurological syndromes (PNSs) occur in patients with cancer and can cause clinical symptoms and signs of dysfunction of the nervous system that are not due to a local effect of the tumor or its metastases. Most of these clinical syndromes in adults are associated with lung cancer, especially small cell lung cancer (SCLC), lymphoma, and gynecological tumors. The finding of highly specific antibodies directed against onconeural antigens has revolutionized the diagnosis and promoted the understanding of these syndromes and led to the current hypothesis of an autoimmune pathophysiology. Accumulating data strongly suggested direct pathogenicity of these antibodies. The field of PNS has expanded rapidly in the past few years with the discovery of limbic encephalitis associated with glutamic acid decarboxylase (GAD) 65, the voltage (VGKC-gated potassium channel) complex, the methyl (N-NMDA-D-aspartate), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), and gamma aminobutyric acid (GABA) (B) receptors, and so forth. Despite this, the clinical spectrum of these diseases has not yet been fully investigated. The clinical importance of these conditions lies in their frequent response to immunotherapies and, less commonly, their association with distinctive tumors. This review provides an overview on the pathogenesis and diagnosis of PNS, with emphasis on the role of antibodies in limbic encephalitis.
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Endothelin-1 downregulates angiotensin-converting enzyme-2 expression in human bronchial epithelial cells.
Pharmacology
PUBLISHED: 03-03-2013
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Both endothelin-1 (ET-1) and the renin-angiotensin system (RAS) are implicated in the pathogenesis and progression of chronic obstructive pulmonary disease (COPD). In the present study, we explored the interaction between ET-1 and the RAS by examining the effect of ET-1 on angiotensin-converting enzyme-2 (ACE2) expression and activity in human bronchial epithelial cells (HBEpCs).
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Novel prion protein gene mutation at codon 196 (E196A) in a septuagenarian with Creutzfeldt-Jakob disease.
J Clin Neurosci
PUBLISHED: 02-25-2013
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Creutzfeldt-Jakob disease (CJD) is a rare and rapidly progressive neurodegenerative disease of the central nervous system, which may occur in inherited, acquired (variant and iatrogenic), or spontaneous (sporadic) forms. We report a 76-year-old Chinese man with CJD found to have a novel mutation in the prion protein gene (PRNP). The 14-3-3 protein was positive in the cerebrospinal fluid; diffusion-weighted MRI revealed ribbon-like high signal intensity in the bilateral cortices; and electroencephalography showed typical periodic synchronous discharge. CJD was diagnosed based on characteristic clinical manifestations. Interestingly, a point mutation of PRNP at codon 196 (E196A: GAG?GCG) was detected. In conclusion, we identified a patient with CJD with a novel PRNP mutation, which expands the spectrum of PRNP mutations in CJD.
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Ghrelin protects human pulmonary artery endothelial cells against hypoxia-induced injury via PI3-kinase/Akt.
Peptides
PUBLISHED: 01-26-2013
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Endothelial injury and diminished NO release induced by hypoxia is thought to be a critical factor in the development of pulmonary artery hypertension (PAH). Ghrelin (Ghr) is a well-characterized hormone and has protective effects on the cardiovascular system, specifically by promoting the vascular endothelial cell function. The aim of this study was to investigate the effect of the Ghr on the hypoxia-induced injury in human pulmonary artery endothelial cells (HPAECs) and on the involved transduction pathway. Effects were investigated by treating cells with varying concentrations of Ghr in the absence or presence of inhibitors that target phosphoinositide 3-kinase (PI3K), in normoxic or hypoxic conditions for 24h. Our results indicated that the treatment with 10(-7) mol/l Ghr significantly enhanced cell viability (P<0.05, n=5) and upregulated the ratio of Bcl-2/Bax under hypoxic condition (P<0.05, n=4), as compared with the hypoxic condition alone. However, an addition of the PI3K/Akt inhibitor LY294002 inhibited these Ghr-mediated effects. Moreover, the Ghr (10(-7)mol/l) significantly increased NO secretion and eNOS phosphorylation in comparison with the hypoxia or normoxia alone group (P<0.05, n=4). Nevertheless, the treatment with LY294002 (20 ?mol/l) decreased the Ghr-induced NO release as well as the eNOS activity. In conclusion, the Ghr could inhibit hypoxia-mediated HPAECs dysfunction via the PI3K/Akt pathway, and the bcl-2/bax ratio was also involved in the protective action of the Ghr in HPAECs. As such, the Ghr demonstrates a significant potential to prevent and treat PAH affected by the endothelial dysfunction.
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Temperature effect on electrospinning of nanobelts: the case of hafnium oxide.
Nanotechnology
PUBLISHED: 06-09-2011
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Electrospinning is a convenient and versatile method for fabricating different kinds of one-dimensional nanostructures such as nanofibres, nanotubes and nanobelts. Environmental parameters have a great influence on the electrospinning nanostructure. Here we report a new method to fabricate hafnium oxide (HfO(2)) nanobelts. HfO(2) nanobelts were prepared by electrospinning a sol-gel solution with the implementation of heating and subsequent calcination treatment. We investigate the temperature dependence of the products by scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and energy-dispersive x-ray (EDX) spectroscopy. The heating temperature of spinning ambient is found to be crucial to the formation of HfO(2) nanobelts. By tuning the temperature, the morphological transformation of HfO(2) from nanowires to nanobelts was achieved. It was found that the rapid evaporation of solvent played an important role in the formation process of HfO(2) nanobelts. It is shown that nanobelts can only be obtained with the temperature higher than 50?°C and they are in the high quality monoclinic phase. A possible growth mechanism of the nanobelts based on phase separation is proposed. The enhanced photoluminescence (PL) of HfO(2):Eu(3+) nanobelts is also illustrated.
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[A simulating excorporeal experimental system for automatic drug injection based on predictive control in vascular interventional therapy].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 04-13-2011
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This paper discusses an in vitro simulating experiment for drug injection based on predictive control in vascular interventional therapy. The relationship between the model of drug injection and the pulsatile blood flow was studied. The experimental model for predictive control of drug injection was tested and verified so as to support the future animal experimental modeling with the data acquired from the in vitro simulating experiment.
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Cross-talk between apolipoprotein E and cytokines.
Mediators Inflamm.
PUBLISHED: 03-13-2011
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Apolipoprotein E (apoE) is a multifunctional glycosylated protein characterized by its wide tissue distribution. Despite its importance in lipid transport and atherosclerosis pathogenesis, apoE is associated with neurodegenerative disorders such as Alzheimers disease (AD) and Parkinson disease, and autoimmune disorders such as multiple sclerosis and psoriasis. Among others, the role of apoE in modulating inflammation and oxidation is crucial in elucidating the risk factors of the above diseases since the function of apoE is closely linked with both proinflammatory and antiinflammatory cytokines. Moreover, apoE modulates inflammatory and immune responses in an isoform-dependent manner. Correspondingly, inflammatory cytokines can either upregulate or downregulate the production of apoE in various tissue types. However, studies on the interactions between apoE and cytokines occasionally yield conflicting results, highlighting the complex roles of apoE and cytokines in various disorders. The present paper summarizes the current knowledge about the cross-talk between apoE and cytokines, with emphasis on the effects of apoE on the Th1/Th2 balance.
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Efficient fabrication of ZrO2-doped TiO2 hollow nanospheres with enhanced photocatalytic activity of rhodamine B degradation.
J Colloid Interface Sci
PUBLISHED: 03-08-2011
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ZrO(2)-doped TiO(2) hollow nanospheres with anatase phase are efficiently fabricated via functionalized negatively charged polystyrene (PS) spheres without any surfactant or polyelectrolyte. The resulting Ti(1-)(x)Zr(x)O(2) (hereafter denoted as TZ) hollow nanospheres are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Laser Raman spectroscopy (LRS), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectroscopy (XRF), nitrogen sorption, and UV-vis diffuse reflectance spectroscopy (UV-vis). The Zr(4+) incorporation decreases the anatase crystallite size, increases the specific surface area, and changes the pore size distribution. Furthermore, it induces enrichment of electron charge density around Ti(4+) ions and blueshift of absorption edges. The TZ hollow nanospheres doped with moderate ZrO(2) (molar ratio, Ti:Zr=10:1) exhibit better photocatalytic activity than the other samples for the degradation of rhodamine B in aqueous solution, which is correlated with the effect of Zr(4+) doping on the physicochemical properties in terms of surface structures, phase structures, and the electronic structures.
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Development of upland rice introgression lines and identification of QTLs for basal root thickness under different water regimes.
J Genet Genomics
PUBLISHED: 02-13-2011
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Introgression lines (ILs) are valuable materials for identifying quantitative trait loci (QTLs), evaluating genetic interactions, and marker assisted breeding. A set of 430 ILs (BC(5)F(3)) containing segments from upland tropical japonica cultivar IRAT109 in a lowland temperate japonica cultivar Yuefu background were developed. One hundred and seventy-six polymorphic markers were used to identify introgressed segments. No segment from IRAT109 was found in 160 lines. Introgressed segments of the other 270 lines covered 99.1% of the donor genome. The mean number of introgressed donor segments per individual was 3.3 with an average length of 14.4 cM. QTL analysis was conducted on basal root thickness (BRT) of the 270 ILs grown under irrigated lowland, upland and hydroponic conditions. A total of 22 QTLs affecting BRT were identified, six QTLs (qBRT3.1, qBRT3.2, qBRT6.1, qBRT8.2, qBRT9.1, and qBRT9.2) were consistently expressed under at least two environments (location and water regime), and qBRT7.2 was a new BRT QTL identified under lowland conditions. IL255 containing qBRT9.1 showed an increase of 10.09% and 7.07% BRT over cultivar Yuefu when grown under upland and lowland conditions, respectively. Using a population of 304 F(2:3) lines derived from the cross IL255×Yuefu, qBRT9.1 was validated and mapped to a 1.2 cM interval between RM24271 and RM566. The presence of qBRT9.1 explained 12% of BRT variation. The results provide upland rice ILs and BRT QTLs for analyzing the genetic basis of drought resistance, detecting favorable genes from upland rice, and rice drought resistance breeding.
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Separation and/or selective enrichment of single-walled carbon nanotubes based on their electronic properties.
Chem Soc Rev
PUBLISHED: 12-07-2010
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Single-walled carbon nanotubes (SWNTs) possess unique electronic properties that make them very promising materials for use in both nano-electronics and thin film devices. However, SWNTs are always produced as a mixture of metallic and semiconducting nanotubes, which is a major roadblock to their widespread application. This tutorial review provides a brief summary of ways of separating single-walled carbon nanotubes into metallic and semiconducting fractions. Various methods including selective growth, selective removal, selective adsorption and band structure modulation--all of which aim to produce pure SWNTs with well-defined electronic properties--are systematically discussed. The main problems in this field, the outlook for separation techniques and some views of future developments are presented.
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A core collection and mini core collection of Oryza sativa L. in China.
Theor. Appl. Genet.
PUBLISHED: 07-30-2010
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The extent of and accessibility to genetic variation in a large germplasm collection are of interest to biologists and breeders. Construction of core collections (CC) is a favored approach to efficient exploration and conservation of novel variation in genetic resources. Using 4,310 Chinese accessions of Oryza sativa L. and 36 SSR markers, we investigated the genetic variation in different sized sub-populations, the factors that affect CC size and different sampling strategies in establishing CC. Our results indicated that a mathematical model could reliably simulate the relationship between genetic variation and population size and thus predict the variation in large germplasm collections using randomly sampled populations of 700-1,500 accessions. We recommend two principles in determining the CC size: (1) compromising between genetic variation and genetic redundancy and (2) retaining the main types of alleles. Based on the most effective scheme selected from 229 sampling schemes, we finally developed a hierarchical CC system, in which different population scales and genetic diversities allow a flexible use of genetic resources. The CC, comprising 1.7% (932) of the accessions in the basic collection, retained more than 85% of both the SSR and phenotypic variations. A mini core collection, comprising 0.3% (189) of the accessions in the basic collection, retained 70.65% of the SSR variation and 76.97% of the phenotypic variation, thus providing a rational framework for intensive surveys of natural variation in complex traits in rice genetic resources and hence utilization of variation in rice breeding.
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[The advances of automatic drug infusion].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 07-24-2010
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The development of automatic drug delivery is reviewed in this paper. The control-relevance of models, the relevant algorithm, the system running and the simulation effect are introduced. The value for clinical application of each case is assessed. The new advances and high-lights of researches are discussed.
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Fine mapping a QTL qCTB7 for cold tolerance at the booting stage on rice chromosome 7 using a near-isogenic line.
Theor. Appl. Genet.
PUBLISHED: 05-12-2010
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Low temperature at the booting stage is a serious abiotic stress in rice, and cold tolerance is a complex trait controlled by many quantitative trait loci (QTL). A QTL for cold tolerance at the booting stage in cold-tolerant near-isogenic rice line ZL1929-4 was analyzed. A total of 647 simple sequence repeat (SSR) markers distributed across 12 chromosomes were used to survey for polymorphisms between ZL1929-4 and the cold-sensitive japonica cultivar Towada, and nine were polymorphic. Single marker analysis revealed that markers on chromosome 7 were associated with cold tolerance. By interval mapping using an F(2) population from ZL1929-4 x Towada, a QTL for cold tolerance was detected on the long arm of chromosome 7. The QTL explained 9 and 21% of the phenotypic variances in the F(2) and F(3) generations, respectively. Recombinant plants were screened for two flanking markers, RM182 and RM1132, in an F(2) population with 2,810 plants. Two-step substitution mapping suggested that the QTL was located in a 92-kb interval between markers RI02905 and RM21862. This interval was present in BAC clone AP003804. We designated the QTL as qCTB7 (quantitative trait locus for cold tolerance at the booting stage on chromosome 7), and identified 12 putative candidate genes.
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DNA topoisomerases and their poisoning by anticancer and antibacterial drugs.
Chem. Biol.
PUBLISHED: 01-20-2010
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DNA topoisomerases are the targets of important anticancer and antibacterial drugs. Camptothecins and novel noncamptothecins in clinical development (indenoisoquinolines and ARC-111) target eukaryotic type IB topoisomerases (Top1), whereas human type IIA topoisomerases (Top2alpha and Top2beta) are the targets of the widely used anticancer agents etoposide, anthracyclines (doxorubicin, daunorubicin), and mitoxantrone. Bacterial type II topoisomerases (gyrase and Topo IV) are the targets of quinolones and aminocoumarin antibiotics. This review focuses on the molecular and biochemical characteristics of topoisomerases and their inhibitors. We also discuss the common mechanism of action of topoisomerase poisons by interfacial inhibition and trapping of topoisomerase cleavage complexes.
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Synthesis and White-Light Emission of ZnO/HfO(2): Eu Nanocables.
Nanoscale Res Lett
PUBLISHED: 01-07-2010
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ZnO/HfO(2):Eu nanocables were prepared by radio frequency sputtering with electrospun ZnO nanofibers as cores. The well-crystallized ZnO/HfO(2):Eu nanocables showed a uniform intact core-shell structure, which consisted of a hexagonal ZnO core and a monoclinic HfO(2) shell. The photoluminescence properties of the samples were characterized. A white-light band emission consisted of blue, green, and red emissions was observed in the nanocables. The blue and green emissions can be attributed to the zinc vacancy and oxygen vacancy defects in ZnO/HfO(2):Eu nanocables, and the yellow-red emissions are derived from the inner 4f-shell transitions of corresponding Eu(3+) ions in HfO(2):Eu shells. Enhanced white-light emission was observed in the nanocables. The enhancement of the emission is ascribed to the structural changes after coaxial synthesis.
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[Prostaglandin E(2) and omeprazole in treating poisoning related acute mucosal lesion].
Zhong Nan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 11-07-2009
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To determine the effects of prostaglandin E(2) alone and the combination with omeprazole for poisoning related acute mucosal lesion.
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Adaptation of topoisomerase I paralogs to nuclear and mitochondrial DNA.
Nucleic Acids Res.
PUBLISHED: 08-31-2009
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Topoisomerase I is essential for DNA metabolism in nuclei and mitochondria. In yeast, a single topoisomerase I gene provides for both organelles. In vertebrates, topoisomerase I is divided into nuclear and mitochondrial paralogs (Top1 and Top1mt). To assess the meaning of this gene duplication, we targeted Top1 to mitochondria or Top1mt to nuclei. Overexpression in the fitting organelle served as control. Targeting of Top1 to mitochondria blocked transcription and depleted mitochondrial DNA. This was also seen with catalytically inactive Top1 mutants, but not with Top1mt overexpressed in mitochondria. Targeting of Top1mt to the nucleus revealed that it was much less able to interact with mitotic chromosomes than Top1 overexpressed in the nucleus. Similar experiments with Top1/Top1mt hybrids assigned these functional differences to structural divergences in the DNA-binding core domains. We propose that adaptation of this domain to different chromatin environments in nuclei and mitochondria has driven evolutional development and conservation of organelle-restricted topoisomerase I paralogs in vertebrates.
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Scalable synthesis of few-layer graphene ribbons with controlled morphologies by a template method and their applications in nanoelectromechanical switches.
J. Am. Chem. Soc.
PUBLISHED: 07-22-2009
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Controllable and scalable production is of great importance for the application of graphene; however, to date, it is still a great challenge and a major obstacle which hampers its practical applications. Here, we develop a template chemical vapor deposition method for scalable synthesis of few-layer graphene ribbons (FLGRs) with controlled morphologies. The FLGRs have a good conductivity and are ideal for use in nanoelectromechanics (NEM). As an application, we fabricate a reversible NEM switch and a logic gate by using the FLGRs. This work realizes both controllable and scalable synthesis of graphene, provides an application of graphene in NEM switches, and would be valuable for both the scientific studies and the practical applications of graphene.
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Genetic structure and differentiation of Oryza sativa L. in China revealed by microsatellites.
Theor. Appl. Genet.
PUBLISHED: 07-13-2009
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China is one of the largest centers of genetic diversity of Oryza sativa L. in the world. Using a genetically representative primary core collection of 3,024 rice landraces in China, we analyzed the genetic structure and intraspecific differentiation of O. sativa, and the directional evolution of SSR. The genetic structure was investigated by model-based structure analysis and construction of neighbor-joining phylogenetic tree. Comparison between genetic structure and predefined populations according to Tings taxonomic system revealed a hierarchical genetic structure: two distinct subspecies, each with three ecotypes and different numbers of geo-ecogroups within each ecotype. Two subspecies evidently resulted from adaptation to different environments. The different cropping systems imposed on the subspecies led to further differentiation, but the variation within each subspecies resulted from different causes. Indica, under tropical-like or lowland-like environments, exhibited clear differentiation among seasonal ecotypes, but not among soil-watery ecotypes; and japonica showed clear differences between soil water regime ecotypes, but not among seasonal ecotypes. Chinese cultivated rice took on evident directional evolution in microsatellite allele size at several aspects, such as subspecies and geographical populations. Japonica has smaller allele sizes than indica, and this may partly be the result of their different domestication times. Allele size was also negatively correlated with latitude and altitude, and this may be interpreted by different mutation rates, selection pressures, and population size effects under different environments and cropping systems.
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Genotypic variation in element concentrations in brown rice from Yunnan landraces in China.
Environ Geochem Health
PUBLISHED: 06-02-2009
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The mineral elements present in brown rice play an important physiological role in global human health. We investigated genotypic variation of eight of these elements (P, K, Ca, Mg, Fe, Zn, Cu, and Mn) in 11 different grades of brown rice on the basis of the number and distance coefficients of 282 alleles for 20 simple sequence repeat (SSR) markers. Six-hundred and twenty-eight landraces from the same field in Yunnan Province, one of the largest centers of genetic diversity of rice (Oryza sativa L.) in the world, formed our core collection. The mean concentrations (mg kg(-1)) of the eight elements in brown rice for these landraces were P (3,480) > K (2,540) > Mg (1,480) > Ca (157) > Zn (32.8) > Fe (32.0) > Cu (13.6) > Mn (13.2). Mean P concentrations in brown rice were 6.56 times total soil P, so the grains are important in tissue storage of P, but total soil K is 7.82 times mean K concentrations in brown rice. The concentrations of the eight elements in some grades of brown rice, on the basis of the number and distance coefficients of alleles for 20 SSR markers for the landraces, were significantly different (P < 0.05), and further understanding of the relationship between mineral elements and gene diversity is needed. There was large variation in element concentrations in brown rice, ranging from 2,160 to 5,500 mg P kg(-1), from 1,130 to 3,830 mg K kg(-1), from 61.8 to 488 mg Ca kg(-1), from 864 to 2,020 mg Mg kg(-1), from 0.40 to 147 mg Fe kg(-1), from 15.1 to 124 mg Zn kg(-1), from 0.10 to 59.1 mg Cu kg(-1), and from 6.7 to 26.6 mg Mn kg(-1). Therefore, germplasm evaluations for Ca, Fe, and Zn concentrations in rice grains have detected up to sevenfold genotypic differences, suggesting that selection for high levels of Ca, Fe, and Zn in breeding for mass production is a feasible approach. Increasing the concentrations of Ca, Fe, and Zn in rice grains will help alleviate chronic Ca, Zn, and Fe deficiencies in many areas of the world.
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Targeted constitutive activation of signal transducer and activator of transcription 3 in human hepatocellular carcinoma cells by cucurbitacin B.
Cancer Chemother. Pharmacol.
PUBLISHED: 04-01-2009
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To determine the effect of cucurbitacin B on human hepatocellular carcinoma cell growth and apoptosis, and to explore the potential mechanisms.
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Synthesis of N-doped graphene by chemical vapor deposition and its electrical properties.
Nano Lett.
PUBLISHED: 03-31-2009
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To realize graphene-based electronics, various types of graphene are required; thus, modulation of its electrical properties is of great importance. Theoretic studies show that intentional doping is a promising route for this goal, and the doped graphene might promise fascinating properties and widespread applications. However, there is no experimental example and electrical testing of the substitutionally doped graphene up to date. Here, we synthesize the N-doped graphene by a chemical vapor deposition (CVD) method. We find that most of them are few-layer graphene, although single-layer graphene can be occasionally detected. As doping accompanies with the recombination of carbon atoms into graphene in the CVD process, N atoms can be substitutionally doped into the graphene lattice, which is hard to realize by other synthetic methods. Electrical measurements show that the N-doped graphene exhibits an n-type behavior, indicating substitutional doping can effectively modulate the electrical properties of graphene. Our finding provides a new experimental instance of graphene and would promote the research and applications of graphene.
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Assessing indica-japonica differentiation of improved rice varieties using microsatellite markers.
J Genet Genomics
PUBLISHED: 01-10-2009
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To assess the indica-japonica differentiation of improved rice varieties, a total of 512 modern varieties including 301 indica and 211 japonica accessions were analyzed using 36 microsatellites. The Fst coefficients ranged from 0.002 to 0.730 among the loci with an average of 0.315. Significant differentiation was detected at 94.4% of the loci studied (P < 0.05, pairwise Fst tests), indicating that there was a high level of indica-japonica differentiation within the improved varieties. At 18 loci, about 74%-98% of the alleles of indica and japonica accessions were distributed in two ranges of amplicon length. Linkage disequilibrium analysis showed that the distribution trends were significantly nonrandomly associated. Using the differentiation trends at the 18 loci, microsatellite index (MI) was proposed for discrimination of the two subspecies. When rice accessions with MI value greater than zero were classified as indica, and those with MI value smaller than zero were classified as japonica, about 96.1% of the accessions could be classified. This result agrees with the classification based on morphological-physiological characters, indicating that this method is feasible and effective.
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[Effect of Kangai injection on hepatic fibrosis in rats].
Zhongguo Zhong Yao Za Zhi
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To investigate the inhibition role of Kangai injection (KAI) in rats with hepatic fibrosis.
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Characterization and identification of cold tolerant near-isogenic lines in rice.
Breed. Sci.
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To exploit the genetic mechanism of cold tolerance in rice, cold tolerant near-isogenic lines (NILs) were developed by backcrossing Kunmingxiaobaigu (KMXBG), reported to be the most cold-tolerant variety at the booting stage, as donor, with the cold sensitive Japanese commercial japonica variety, Towada. Comparisons of cold tolerance-related traits between five BC(6)F(5) NILs and recurrent parent Towada under cold treatment and normal temperatures at the booting stage showed that the differences between the NILs and Towada were significant only for spikelet fertility-related traits. Analyses of cold tolerance in the NILs at the budding (germination), seedling and booting stages indicated both correlated effects and differences. Lines 1913-4 and 1916-1 showed strong and stable tolerance at all three stages. Whole genome marker screening showed that the proportion of genetic background recovery was more than 98%. Seventeen markers from KMXBG were introgressed in two or more NILs, and cold tolerance genes were possibly present in these marker regions. The NILs should be excellent materials for both rice improvement and map-based cloning of cold tolerance QTLs.
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IL-17 and IL-22 in cerebrospinal fluid and plasma are elevated in Guillain-Barré syndrome.
Mediators Inflamm.
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Guillain-Barré syndrome (GBS) is an acute autoimmune-mediated inflammatory demyelinating disease that causes rapidly progressing paralysis and occasionally respiratory failure. We hypothesized that interleukin (IL)-17 and IL-22 are elevated in GBS and participate in the autoimmune inflammatory response of GBS. We used sandwich enzyme-linked immunosorbent assay (ELISA) to measure the IL-17 and IL-22 levels in the CSF, and plasma from 22 GBS patients at the acute phase and 18 healthy controls (HC). The results show that CSF and plasma levels of IL-17 and IL-22 are elevated in GBS patients compared with HC. IL-17 and IL-22 levels in CSF, respectively, are correlated with GBS disability scale scores (GDSs). Meanwhile, IL-17 and IL-22 levels in CSF, IL-22 in CSF, and plasma of GBS patients have positive correlation, respectively. The increased levels of IL-17 and IL-22 in CSF may be explained by the disruption of blood-brain barrier (BBB) and peripheral nervous system (PNS) local inflammation in GBS. Meanwhile, the elevated levels of these two cytokines in plasma suggest the activation of Th17 and Th22 cells in the systemic immune response of GBS. Our data provide preliminary evidence that GBS is associated with high levels of IL-17 and IL-22 in CSF and plasma. These cytokines display pathogenic potential and may serve as useful biomarkers for GBS.
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Investigation of surface synergetic oxygen vacancy in CuO-CoO binary metal oxides supported on ?-Al2O3 for NO removal by CO.
J Colloid Interface Sci
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The influence of CO pretreatment on the properties of CuO-CoO/?-Al(2)O(3) catalysts was investigated by SEM, TEM, XRD, LRS, XPS, TPR, and in situ FT-IR techniques. And the activities were measured by NO removal by CO. It was shown that the CuO-CoO/?-Al(2)O(3) catalysts following CO pretreatment exhibited extremely high activity and selectivity. The interaction between copper oxide and cobalt oxide upon the ?-Al(2)O(3) support before and after CO pretreatment was tentatively discussed in the view of incorporation model. According to this model, the dispersed Cu-O-Co species could be reduced to Cu-?-Co species by CO pretreatment, which was considered to be the primary active component for this reaction. FT-IR results suggested that CO was apt to adsorb on Cu(+) sites rather than Co(2+) while the NO adsorbates could convert to much more stable species with the temperature increasing. Undoubtedly, it was the surface synergetic oxygen vacancy coupled with the adjacent Cu and Co ions that guaranteed the reaction well processing over the CO pretreated samples. As a result, a possible mechanism was tentatively proposed.
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OsMIOX, a myo-inositol oxygenase gene, improves drought tolerance through scavenging of reactive oxygen species in rice (Oryza sativa L.).
Plant Sci.
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Myo-inositol oxygenase (MIOX), a unique monooxygenase, catalyzes the oxidation of myo-inositol to d-glucuronic acid. However, the protective role of MIOX in plants against oxidative stress or drought stress remains unknown. In this study, the functional characterization of MIOX obtained from the cDNA library of upland rice (Oryza sativa L. cv. IRAT109), was performed. OsMIOX was expressed predominantly in the roots and induced by drought, H?O?, salt, cold and abscisic acid. The transgenic rice lines overexpressing OsMIOX showed obviously improved growth performance in the medium containing 200 mM mannitol. Further, the survival rate of leaves from the transgenic rice lines was significantly higher than that of the wild type plants under polyethylene glycol treatment. It was discovered that the activity of ROS-scavenging enzymes and proline content, as well as the transcript levels of many ROS scavenging genes were significantly increased in transgenic plants compared to the wild type plants under drought stress conditions. Together, these data suggest that OsMIOX has a specific function in drought stress tolerance by decreasing oxidative damage.
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A kinetic clutch governs religation by type IB topoisomerases and determines camptothecin sensitivity.
Proc. Natl. Acad. Sci. U.S.A.
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Type IB topoisomerases (Top1Bs) relax excessive DNA supercoiling associated with replication and transcription by catalyzing a transient nick in one strand to permit controlled rotation of the DNA about the intact strand. The natural compound camptothecin (CPT) and the cancer chemotherapeutics derived from it, irinotecan and topotecan, are highly specific inhibitors of human nuclear Top1B (nTop1). Previous work on vaccinia Top1B led to an elegant model that describes a straightforward dependence of rotation and religation on the torque caused by supercoiling. Here, we used a single-molecule DNA supercoil relaxation assay to measure the torque dependence of nTop1 and its inhibition by CPT. For comparison, we also examined mitochondrial Top1B and an N-terminal deletion mutant of nTop1. Despite substantial sequence homology in their core domains, nTop1 and mitochondrial Top1B exhibit dramatic differences in sensitivity to torque and CPT, with the N-terminal deletion mutant of nTop1 showing intermediate characteristics. In particular, nTop1 displays nearly torque-independent religation probability, distinguishing it from other Top1B enzymes studied to date. Kinetic modeling reveals a hitherto unobserved torque-independent transition linking the DNA rotation and religation phases of the enzymatic cycle. The parameters of this transition determine the torque sensitivity of religation and the efficiency of CPT binding. This "kinetic clutch" mechanism explains the molecular basis of CPT sensitivity and more generally provides a framework with which to interpret Top1B activity and inhibition.
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Hybrid breeding in autogamous cereals.
Theor. Appl. Genet.
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Hybrid breeding in autogamous cereals has a long history of attempts with moderate success. There is a vast amount of literature investigating the potential problems and solutions, but until now, market share of hybrids is still a niche compared to line varieties. Our aim was to summarize the status quo of hybrid breeding efforts for the autogamous cereals wheat, rice, barley, and triticale. Furthermore, the research needs for a successful hybrid breeding in autogamous cereals are intensively discussed. To our opinion, the basic requirements for a successful hybrid breeding in autogamous cereals are fulfilled. Nevertheless, optimization of the existing hybridization systems is urgently required and should be coupled with the development of clear male and female pool concepts. We present a quantitative genetic framework as a first step to compare selection gain of hybrid versus line breeding. The lack of precise empirical estimates of relevant quantitative genetic parameters, however, is currently the major bottleneck for a robust evaluation of the potential of hybrid breeding in autogamous cereals.
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Mitochondrial topoisomerase I is critical for mitochondrial integrity and cellular energy metabolism.
PLoS ONE
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Mitochondria contain their own DNA genome (mtDNA), as well as specific DNA replication and protein synthesis machineries. Relaxation of the circular, double-stranded mtDNA relies on the presence of topoisomerase activity. Three different topoisomerases have been identified in mitochondria: Top1mt, Top3? and a truncated form of Top2?.
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[Experimental study on animal with automatic drug injection based on predictive control for vascular interventional therapy].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
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This paper focuses on the animal experiment of automatic drug delivery based on predictive control for vascular interventional therapy. Improvement of drug delivery system based on predictive control used in simulated experiments was put forward after the presence of time varying parameters and the characteristics of individual differences of animal had been studied. The adaptability of time varying parameters and fault tolerance of the system were also enhanced. Different injection methods were tested on animals. It is proved that higher target blood concentration can be reached while injecting during diastolic than that while injecting during systolic or injecting at a constant speed within the whole cardiac cycle. The results also showed that the improved drug injection system based on predictive control which synchronizes with the cardiac cycle could be applied to clinical trials.
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Synthesis, characterization, and catalytic performance of copper-containing SBA-15 in the phenol hydroxylation.
J Colloid Interface Sci
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A series of copper-containing SBA-15 samples were successfully synthesized via evaporation-induced self-assembly route. The resulting materials were characterized by X-ray diffraction (XRD), (29)Si MAS NMR spectroscopy, transmission electron microscopy (TEM), N(2) sorption, inductively coupling plasma-atomic emission spectrometer (ICP-AES), thermogravimetry, and differential thermal analysis (TG-DTA), Fourier-transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectra (UV-vis) and X-ray photoelectron spectroscopy (XPS). The results indicated that: (1) all the samples exhibited typical hexagonal arrangement of mesoporous structure; (2) copper ions could be incorporated into the framework of SBA-15; (3) the addition of urea in the hydrothermal stage efficiently reduced the leaching of copper and improved the thermal stability of the mesoporous materials. Catalytic performances of the obtained materials were evaluated in the hydroxylation of phenol with H(2)O(2). The catalytic tests showed that the synthesized materials exhibited high activity for this reaction and copper ions in the framework were more active than copper species in the extra-framework position. The nitric acid treatment on the samples removed the bulk CuO species, which resulted in a dramatic increase in the catalytic activity.
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Hypoglycemia-induced convulsive status epilepticus as the initial presentation of primary hepatic carcinoma.
Neurol. Sci.
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Hypoglycemia is a well-known complication of insulinoma and other non-islet-cell tumors like hepatic tumor. In the emergency unit of neurology department, hypoglycemia is an uncommon cause of convulsive status epilepticus. We report a rare case with hypoglycemia-induced convulsive status epilepticus as the initial presentation of primary hepatic carcinoma. The previously healthy 57-year-old male peasant presented with persistent unconsciousness and repeated convulsive seizures. He was later found to have hepatoma related hypoglycemia. This case highlights the importance of blood sugar test in unexplained status epilepticus in the emergency room of neurology department. Intravenous glucose infusion rather than anti-epileptic drugs might be safer and more effective in treating status epilepticus caused by hepatoma related hypoglycemia.
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Investigation of the physicochemical properties of CuO-CoO binary metal oxides supported on ?-Al2O3 and their activity for NO removal by CO.
J Colloid Interface Sci
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The dispersion and physicochemical behaviors of CuO-CoO binary metal oxides supported on ?-Al(2)O(3) were characterized by XRD, LRS, XPS, H(2)-TPR, and in situ FT-IR techniques. Their activities were evaluated by NO-CO model reaction. The results indicated that (a) for lower loadings, CuO and CoO were able to be highly dispersed on the surface of ?-Al(2)O(3) support; (b) the interaction between dispersed CuO and CoO upon ?-Al(2)O(3) was discussed in the view of incorporation model. According to this model and obtained results, the surface dispersed Cu-O-Co species were considered to exist on the surface of ?-Al(2)O(3); (c) CO or/and NO adsorption FT-IR results evidenced that the surface dispersed copper species could be reduced to lower valence by CO and the NO adsorption species converted with the increase in the temperature; (d) the surface dispersed Cu-O-Co species could be reduced to active Cu-?-Co species by CO among the mixture atmosphere. The formation of the surface synergetic oxygen vacancy (SSOV) was a crucial factor in the process of the NO-CO reaction. And a possible reaction pathway was tentatively proposed to discuss the NO-CO reaction based on all of these results.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.