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Find video protocols related to scientific articles indexed in Pubmed.
[STC-1 is involved in anti-hypoxia proliferative balance of renal cancer cells by down-regulation of intracellular Ca2+ and HIF-1? levels].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 11-06-2014
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To investigate effects of stanniocalcin-1?STC-1? on proliferation balance under hypoxic condition in renal cancer cells and its mechanism. METHODS? Hypoxic model was induced on renal cancer GRC-1 cells?Group H?? the cells were treated with STC-1 protein at concentrations of 0.1 nmol/L ?H1?? 0.5 nmol/L ?H2?? 1.0 nmol/L ?H3?? or normal saline ?H0? for 48 h? respectively. Cells proliferation was measured by MTT assay; mRNA and protein expressions of hypoxia inducible factor 1??HIF-1?? and STC-1 in GRC-1 cells were detected by RT-PCR and ELISA?respectively; the intracellular levels of Ca2+ and adenosine triphosphate?ATP? were determined by fluorescence spectrophotometry and spectrophotometry?respectively. RESULTS?The expression of HIF-1??STC-1 and Ca2+ levels were increased in GRC-1 cells under hypoxia condition; STC-1 reversed these changes in a dose-effect manner. Hypoxia significantly inhibited cell proliferation and the generation of ATP in GRC-1 cells and exogenous STC-1 reversed the effects of hypoxia; ATP generation increased gradually with increasing STC-1 concentration?but the cell proliferation was reduced. CONCLUSION?Exogenous STC-1 can promote the proliferation of renal cancer cells in hypoxia condition by reducing HIF-1? expression and Ca2+ content and increased ATP production?but the progressive inhibition of HIF-1 ? hindered the renal carcinoma cell proliferation further?which indicates that STC-1 may be involved in anti-hypoxia proliferative balance of renal cancer cells.
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[Correlation analysis of survival period and CD4+ Tcell-iATP levels in liver transplant recipients].
Zhonghua Gan Zang Bing Za Zhi
PUBLISHED: 11-05-2014
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To analyze the correlation between survival time after liver transplantation and the intracellular (i)ATP levels of CD4+ T cells.
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Target-Responsive DNAzyme Cross-Linked Hydrogel for Visual Quantitative Detection of Lead.
Anal. Chem.
PUBLISHED: 11-05-2014
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Because of the severe health risks associated with lead pollution, rapid, sensitive, and portable detection of low levels of Pb(2+) in biological and environmental samples is of great importance. In this work, a Pb(2+)-responsive hydrogel was prepared using a DNAzyme and its substrate as cross-linker for rapid, sensitive, portable, and quantitative detection of Pb(2+). Gold nanoparticles (AuNPs) were first encapsulated in the hydrogel as an indicator for colorimetric analysis. In the absence of lead, the DNAzyme is inactive, and the substrate cross-linker maintains the hydrogel in the gel form. In contrast, the presence of lead activates the DNAzyme to cleave the substrate, decreasing the cross-linking density of the hydrogel and resulting in dissolution of the hydrogel and release of AuNPs for visual detection. As low as 10 nM Pb(2+) can be detected by the naked eye. Furthermore, to realize quantitative visual detection, a volumetric bar-chart chip (V-chip) was used for quantitative readout of the hydrogel system by replacing AuNPs with gold-platinum core-shell nanoparticles (Au@PtNPs). The Au@PtNPs released from the hydrogel upon target activation can efficiently catalyze the decomposition of H2O2 to generate a large volume of O2. The gas pressure moves an ink bar in the V-chip for portable visual quantitative detection of lead with a detection limit less than 5 nM. The device was able to detect lead in digested blood with excellent accuracy. The method developed can be used for portable lead quantitation in many applications. Furthermore, the method can be further extended to portable visual quantitative detection of a variety of targets by replacing the lead-responsive DNAzyme with other DNAzymes.
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[Individualized restorative designs and clinical evaluation for dental implants in the anterior esthetic zone with inappropriate conditions].
Shanghai Kou Qiang Yi Xue
PUBLISHED: 10-24-2014
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To offer individualized restorative strategies for patients receiving dental implants in the anterior esthetic zone but with inappropriate available conditions and evaluate the clinical outcomes.
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[Adsorption kinetics and mechanism of lead (II) on polyamine-functionalized mesoporous activated carbon].
Huan Jing Ke Xue
PUBLISHED: 10-24-2014
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Bagasse mesoporous carbon was prepared by microwave assisted H3 PO4 activation. Amido and imido groups were modified with ethanediamine on the channels' surface of mesoporous carbon through nitric oxidation and amide reaction. The influence of Pb(II) concentration, adsorption time on Pb(II) adsorption on the ethanediamine-modified mesoporous carbon (AC-EDA) was investigated. The adsorption kinetics and mechanism were also discussed. The results showed that AC-EDA had a great performance for Pb(II) adsorption, and more than 70% of Pb(II) was adsorbed in 5 minutes. The adsorption amount of Pb(II) on the carbon increased with the increase of solution pH in acidic conditions. It was found that AC-EDA had different binding energies on different adsorption sites for Pb(II) separation. The Pb(II) adsorption process on AC-EDA was controlled by intra-particle diffusion in the first 3 min, and then film diffusion played the important pole on the adsorption. The adsorption amount increased with the increase of temperature, indicating the adsorption was an endothermic reaction. The high adsorption energy (> 11 kJ x mol(-1)) implied that the) adsorption was a chemical adsorption. The XPS of AC-EDA before and after Pb(II) adsorption showed that the polyamine group was involved in the adsorption, and should be a main factor of the high efficient adsorption.
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[Polychlorinated biphenyls in house dust at an e-waste site and urban site in the Pearl River Delta, southern China: sources and human exposure and health risks].
Huan Jing Ke Xue
PUBLISHED: 10-24-2014
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Polychlorinated biphenyls (PCBs) were measured in house dust from an e-waste site and urban site in the Pearl River Delta, southern China. The PCB concentrations in house dust at the e-waste site ranged from 12.4 to 87 765 ng x g(-1), with an average of 10 167 ng x g(-1). There was no significant difference in the PCB concentrations between indoor and outdoor dust. The PCB homologue pattern was dominated by tri-, penta-, hexa-, and tetra-CBs, which was not similar to that in Chinese technical PCB product. There was also no significant difference in the PCB compositions between indoor and outdoor dust. PCB sources in house dust at the e-waste site were apportioned by chemical mass balance (CMB) model. The results showed that the PCBs were derived primarily from Aroclor 1262 (36.7% ), Aroclor 1254 (26.7%), Aroclor 1242 (21.4%), and Aroclor 1248 (18.5%). The daily exposure doses were 42, 17, and 2.9 ng x (kg x d)(-1) for toddlers, children/adolescents, and adults in the e-waste area, respectively. Risk assessment indicated that the hazard quotients were higher than 1 for toddlers and children/adolescents indicating adverse effects for them. The lifetime average excess carcinogenic risk for population in the e-waste area was 4.5 x 10(-5), within the acceptable range of U. S. Environmental Protection Agency. The mean concentrations of PCBs in house dust in Guangzhou was 48.7 ng x g(-1). The low PCB level is consistent with the fact that technical PCBs were not widely used in China in the past. The risks of exposure to PCBs via house dust in Guangzhou are very low.
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Sulfate ion (SO4(2-)) release from old and new cation exchange resins used in condensate polishing systems for power plants.
Water Sci. Technol.
PUBLISHED: 10-18-2014
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In this study, a dynamic cycle test, a static immersion method and a pyrolysis experiment were combined to examine the characteristics of SO4(2-) released from several new and old cation exchange resins used in condensate polishing systems for power plants. The results show that the quantity and velocity of SO4(2-) released from new and old resins tend to balance in a short time during the dynamic cycle experiment. SO4(2-) is released by 1500H (monosphere super gel type cation exchange resins) and 001 × 7 (gel type cation exchange resins) new and old cation exchange resins, the quantity of which increases according to immersion time. In the pyrolysis experiment, the quantity of SO4(2-) released from resins increases and the pH of the pyrolysis solution transforms from alkaline to acidic with an increase in temperature.
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Trifluoromethylated Nucleic Acid Analogues Capable of Self-Assembly through Hydrophobic Interactions.
Chem Sci
PUBLISHED: 10-07-2014
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An artificial nucleic acid analogue capable of self-assembly into duplex merely through hydrophobic interactions is presented. The replacement of Watson-Crick hydrogen bonding with strictly hydrophobic interactions has the potential to confer new properties and facilitate the construction of complex DNA nanodevices. To study how the hydrophobic effect works during the self-assembly of nucleic acid bases, we have designed and synthesized a series of fluorinated nucleic acids (FNA) containing 3,5-bis(trifluoromethyl) benzene (F) and nucleic acids incorporating 3,5-dimethylbenzene (M) as hydrophobic base surrogates. Our experiments illustrate that two single-stranded nucleic acid oligomers could spontaneously organize into a duplex entirely by hydrophobic base pairing if the bases were size-complementary and the intermolecular forces were sufficiently strong.
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Differential temporal expression profiles of heat shock protein genes in Drosophila melanogaster (Diptera: Drosophilidae) under ultraviolet A radiation stress.
Environ. Entomol.
PUBLISHED: 09-27-2014
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Solar UV radiation is indispensable for certain behaviors of many organisms. Nevertheless, UV-A might be expected to stress insects that possess intensive positive taxis toward UV-A light. To avoid stress hazards, organisms generally exhibit the upregulation of heat shock proteins (Hsps) expression. To gain a better understanding of the roles of the different Hsps in response to UV-A stress in the diurnal phototactic fly Drosophila melanogaster Meigen, 1830 (Diptera: Drosophilidae), we tested the temporal expression patterns of 11 DmHsps following UV-A radiation. The results indicated that each DmHsp had a differential temporal expression profile under UV-A radiation stress. Potential transcription factor-binding motifs in the promoter regions of strongly inducible DmHsps were identified; results showed these transcription factor-binding motifs were highly homologous to binding sites that have been identified for transcription factors associated with UV radiation stimuli. So DmHsps might act in a coordinated and cooperative manner at the transcriptional level to counteract UV-A radiation-based stress.
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Synergetic approach for simple and rapid conjugation of gold nanoparticles with oligonucleotides.
ACS Appl Mater Interfaces
PUBLISHED: 09-19-2014
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Attaching thiolated DNA on gold nanoparticles (AuNPs) has been extremely important in nanobiotechnology because DNA-AuNPs combine the programmability and molecular recognition properties of the biopolymers with the optical, thermal, and catalytic properties of the inorganic nanomaterials. However, current standard protocols to attach thiolated DNA on AuNPs involve time-consuming, tedious steps and do not perform well for large AuNPs, thereby greatly restricting applications of DNA-AuNPs. Here we demonstrate a rapid and facile strategy to attach thiolated DNA on AuNPs based on the excellent stabilization effect of mPEG-SH on AuNPs. AuNPs are first protected by mPEG-SH in the presence of Tween 20, which results in excellent stability of AuNPs in high ionic strength environments and extreme pHs. A high concentration of NaCl can be applied to the mixture of DNA and AuNP directly, allowing highly efficient DNA attachment to the AuNP surface by minimizing electrostatic repulsion. The entire DNA loading process can be completed in 1.5 h with only a few simple steps. DNA-loaded AuNPs are stable for more than 2 weeks at room temperature, and they can precisely hybridize with the complementary sequence, which was applied to prepare core-satellite nanostructures. Moreover, cytotoxicity assay confirmed that the DNA-AuNPs synthesized by this method exhibit lower cytotoxicity than those prepared by current standard methods. The proposed method provides a new way to stabilize AuNPs for rapid and facile loading thiolated DNA on AuNPs and will find wide applications in many areas requiring DNA-AuNPs, including diagnosis, therapy, and imaging.
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Elevated expression of nuclear protein kinase CK2? as a poor prognosis indicator in lymph node cancerous metastases of human thyroid cancers.
Asian Pac. J. Cancer Prev.
PUBLISHED: 09-18-2014
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To investigate the expression of protein kinase CK2? (CK2?) in human thyroid disease and its relationship with thyroid cancer metastasis.
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Dehydrogenative cross-coupling reaction by cooperative transition-metal and Brønsted acid catalysis for the synthesis of ?-quinolinyl ?-amino acid esters.
Org. Lett.
PUBLISHED: 09-09-2014
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A novel dehydrogenative cross-coupling (DCC) reaction between methylquinoline derivatives and N-aryl glycine esters was developed by a cooperative catalysis of copper salt and Brønsted acid, affording an efficient synthesis of ?-quinolinyl ?-amino acid esters. A plausible mechanism using a proton to activate the methylquinoline derivative and copper(II) to activate N-aryl glycine ester has been proposed.
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Variation in copper and zinc tolerance and accumulation in 12 willow clones: implications for phytoextraction.
J Zhejiang Univ Sci B
PUBLISHED: 09-04-2014
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Willows (Salix spp.) have shown high potential for the phytoextraction of heavy metals. This study compares variations in copper (Cu) and zinc (Zn) tolerance and accumulation potential among 12 willow clones grown in a nutrient solution treated with 50 ?mol/L of Cu or Zn, respectively. The results showed differences in the tolerance and accumulation of Cu and Zn with respect to different species/clones. The biomass variation among clones in response to Cu or Zn exposure ranged from the stimulation of growth to inhibition, and all of the clones tested showed higher tolerance to Cu than to Zn. The clones exhibited less variation in Cu accumulation but larger variation in Zn accumulation. Based on translocation factors, it was found that most of the Cu was retained in the roots and that Zn was more mobile than Cu for all clones. It is concluded that most willow clones are good accumulators of Zn and Cu.
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Ghrelin and obestatin levels in hypertensive obese patients.
J. Int. Med. Res.
PUBLISHED: 09-03-2014
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To investigate plasma total ghrelin and obestatin levels and the ghrelin/obestatin ratio prospectively, in hypertensive obese patients.
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Selection of DNA aptamers against epidermal growth factor receptor with high affinity and specificity.
Biochem. Biophys. Res. Commun.
PUBLISHED: 09-01-2014
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Epidermal growth factor receptor (EGFR/HER1/c-ErbB1), is overexpressed in many solid cancers, such as epidermoid carcimomas, malignant gliomas, etc. EGFR plays roles in proliferation, invasion, angiogenesis and metastasis of malignant cancer cells and is the ideal antigen for clinical applications in cancer detection, imaging and therapy. Aptamers, the output of the systematic evolution of ligands by exponential enrichment (SELEX), are DNA/RNA oligonucleotides which can bind protein and other substances with specificity. RNA aptamers are undesirable due to their instability and high cost of production. Conversely, DNA aptamers have aroused researcher's attention because they are easily synthesized, stable, selective, have high binding affinity and are cost-effective to produce. In this study, we have successfully identified DNA aptamers with high binding affinity and selectivity to EGFR. The aptamer named TuTu22 with Kd 56±7.3nM was chosen from the identified DNA aptamers for further study. Flow cytometry analysis results indicated that the TuTu22 aptamer was able to specifically recognize a variety of cancer cells expressing EGFR but did not bind to the EGFR-negative cells. With all of the aforementioned advantages, the DNA aptamers reported here against cancer biomarker EGFR will facilitate the development of novel targeted tumor cell detection, cancer cell imaging and cancer therapy.
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A cell-surface-anchored ratiometric fluorescent probe for extracellular pH sensing.
ACS Appl Mater Interfaces
PUBLISHED: 08-21-2014
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Accurate sensing of the extracellular pH is a very important yet challenging task in biological and clinical applications. This paper describes the development of an amphiphilic lipid-DNA molecule as a simple yet useful cell-surface-anchored ratiometric fluorescent probe for extracellular pH sensing. The lipid-DNA probe, which consists of a hydrophobic diacyllipid tail and a hydrophilic DNA strand, is modified with two fluorescent dyes; one is pH-sensitive as pH indicator and the other is pH-insensitive as an internal reference. The lipid-DNA probe showed sensitive and reversible response to pH change in the range of 6.0-8.0, which is suitable for most extracellular studies. In addition, based on simple hydrophobic interactions with the cell membrane, the lipid-DNA probe can be easily anchored on the cell surface with negligible cytotoxicity, excellent stability, and unique ratiometric readout, thus ensuring its accurate sensing of extracellular pH. Finally, this lipid-DNA-based ratiometric pH indicator was successfully used for extracellular pH sensing of cells in 3D culture environment, demonstrating the potential applications of the sensor in biological and medical studies.
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Salvage liver transplantation for hepatocellular carcinoma recurrence after primary liver resection.
Clin Res Hepatol Gastroenterol
PUBLISHED: 08-20-2014
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To evaluate the clinical efficacy and prognostic factors for salvage liver transplantation (SLT) for hepatocellular carcinoma (HCC) recurrence after primary liver resection.
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A label-free fluorescence strategy for sensitive detection of ATP based on the ligation-triggered super-sandwich.
Biosens Bioelectron
PUBLISHED: 08-15-2014
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In this study, a label-free fluorescence strategy for sensitive detection of ATP based on the ligation-triggered super-sandwich is reported. We designed a double-stranded DNA (ds-DNA) probe as the substrate of ATP-dependent ligation. SYBR Green I (SG I), a double-duplex DNA specific dye, was employed as the readout signal. In the absence of ATP, the ligation would not occur and the ds-DNA remained intact. Further, a weak fluorescence could be observed due to the intercalation of SG I into the grooves of the ds-DNA probe. In the presence of ATP, T4 DNA ligase would catalyse the ligation between 3'-OH and 5'-PO4 ends between ds-DNA probes. As a result, more binding sites of the SG I were generated and a fluorescence enhancement was obtained. This method showed a good sensitivity with a detection limit of 200 pM and could perfectly discriminate ATP from its analogs.
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Au@Pt Nanoparticle Encapsulated Target-Responsive Hydrogel with Volumetric Bar-Chart Chip Readout for Quantitative Point-of-Care Testing.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 08-11-2014
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Point-of-care testing (POCT) with the advantages of speed, simplicity, portability, and low cost is critical for the measurement of analytes in a variety of environments where access to laboratory infrastructure is lacking. While qualitative POCTs are widely available, quantitative POCTs present significant challenges. Here we describe a novel method that integrates an Au core/Pt shell nanoparticle (Au@PtNP) encapsulated target-responsive hydrogel with a volumetric bar-chart chip (V-Chip) for quantitative POCT. Upon target introduction, the hydrogel immediately dissolves and releases Au@PtNPs, which can efficiently catalyze the decomposition of H2 O2 to generate a large volume of O2 to move of an ink bar in the V-Chip. The concentration of the target introduced can be visually quantified by reading the traveling distance of the ink bar. This method has the potential to be used for portable and quantitative detection of a wide range of targets without any external instrument.
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Sources of halogenated brominated retardants in house dust in an industrial city in southern China and associated human exposure.
Environ. Res.
PUBLISHED: 08-06-2014
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Halogenated flame retardants (HFRs) are a class of ubiquitous pollutants in the environment and attract increasing attention. In the present study, HFR concentrations were measured in indoor and outdoor dust in an important industrial city (Dongguan) in southern China, in which their presence and associated human exposure are unknown. The HFRs were dominated by polybrominated diphenyl ethers (PBDEs) and decabromodiphenyl ethane (DBDPE), with mean concentrations of 2365 and 2441ng/g in the indoor dust, respectively, which were 2-3 order of magnitude higher the concentrations of other HFRs. However elevated tri- to hepta-BDE concentrations (869ng/g) were found in Houjie Town, a furniture manufacturing center. The mean indoor/outdoor (I/O) ratios of HFR concentrations in the dust were all larger than one (1.55-16.4), suggesting the importance of indoors sources for HFRs in indoor dust in this industrial city. Principal component analysis (PCA) showed that the correlations among the HFRs in the indoor dust probably revealed differences in their commercial applications, while most HFRs in the outdoor dust have similar sources except for phased-out BDE47 and 99. The compositions of lower brominated PBDEs varied among the towns, probably due to their different sources or influence of photo-degradation. Nevertheless, the similar composition of highly brominated congeners indicated little photo-degradation encountered in the ambient environment. The non-cancer risk associated with indoor dust ingestion is low for the general population in Dongguan, but some children in the furniture manufacturing center have significantly high risk of exposure to banned PBDEs.
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Diversity of butyrivibrio group bacteria in the rumen of goats and its response to the supplementation of garlic oil.
Asian-australas. J. Anim. Sci.
PUBLISHED: 07-23-2014
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This study aimed to investigate the diversity of the Butyrivibrio group bacteria in goat rumen and its response to garlic oil (GO) supplementation as revealed by molecular analysis of cloned 16S rRNA genes. Six wethers fitted with ruminal fistulas were assigned to two groups for a cross-over design with 28-d experimental period and 14-d interval. Goats were fed a basal diet without (control) or with GO ruminal infusion (0.8 g/d). Ruminal contents were used for DNA extraction collected before morning feeding on d 28. A total bacterial clone library was firstly constructed by nearly full-length 16S rRNA gene cloned sequences using universal primers. The resulting plasmids selected by Butyrivibrio-specific primers were used to construct a Butyrivibrio group-specific bacterial clone library. Butyrivibrio group represented 12.98% and 10.95% of total bacteria in control and GO group, respectively. In libraries, clones were classified to the genus Pseudobutyrivibrio, Butyrivibrio and others within the family Lachnospiraceae. Additionally, some specific clones were observed in GO group, being classified to the genus Ruminococcus and others within the family Ruminococcaceae. Based on the criterion that the similarity was 97% or greater with database sequences, there were 29.73% and 18.42% of clones identified as known isolates (i.e. B. proteoclasticus and Ps. ruminis) in control and GO groups, respectively. Further clones identified as B. fibrisolvens (5.41%) and R. flavefaciens (7.89%) were specifically found in control and GO groups, respectively. The majority of clones resembled Ps. ruminis (98% to 99% similarity), except for Lachnospiraceae bacteria (87% to 92% similarity) in the two libraries. The two clone libraries also appeared different in Shannon diversity index (control 2.47 and GO group 2.91). Our results indicated that the Butyrivibrio group bacteria had a complex community with considerable unknown species in the goat rumen.
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A cascade alkylarylation reaction of 2-isocyanobiphenyls with simple alkanes for 6-alkyl phenanthridines via dual C(sp3)-H/C(sp2)-H functionalizations.
Org. Biomol. Chem.
PUBLISHED: 07-05-2014
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A cascade alkylarylation reaction of 2-isocyanobiphenyls with simple alkanes for 6-alkyl phenanthridines has been developed through dual C(sp(3))-H/C(sp(2))-H functionalizations. The synthetic method has the advantages of high yields, good compatibility of functional groups and mild reaction conditions, although very unreactive alkanes were involved in the reaction. A plausible mechanism through both copper-catalyzed and DTBP mediated pathways has also been proposed.
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Label-free fluorescence strategy for sensitive detection of adenosine triphosphate using a loop DNA probe with low background noise.
Anal. Chem.
PUBLISHED: 07-03-2014
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A simple, rapid, label-free, and ultrasensitive fluorescence strategy for adenosine triphosphate (ATP) detection was developed using a loop DNA probe with low background noise. In this strategy, a loop DNA probe, which is the substrate for both ligation and digestion enzyme reaction, was designed. SYBR green I (SG I), a double-stranded specific dye, was applied for the readout fluorescence signal. Exonuclease I (Exo I) and exonuclease III (Exo III), sequence-independent nucleases, were selected to digest the loop DNA probe in order to minimize the background fluorescence signal. As a result, in the absence of ATP, the loop DNA was completely digested by Exo I and Exo III, leading to low background fluorescence owing to the weak electrostatic interaction between SG I and mononucleotides. On the other hand, ATP induced the ligation of the nicking site, and the sealed loop DNA resisted the digestion of Exo I and ExoIII, resulting in a remarkable increase of fluorescence response. Upon background noise reduction, the sensitivity of the ATP determination was improved significantly, and the detection limitation was found to be 1.2 pM, which is much lower than that in almost all the previously reported methods. This strategy has promise for wide application in the determination of ATP.
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Intrinsic autocorrelation time of picoseconds for thermal noise in water.
J Phys Chem A
PUBLISHED: 07-02-2014
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Whether thermal noise is colored or white is of fundamental importance. In conventional theory, thermal noise is usually treated as white noise so that there are no directional transportations in the asymmetrical systems without external inputs, since only the colored fluctuations with appropriate autocorrelation time length can lead to directional transportations in the asymmetrical systems. Here, on the basis of molecular dynamics simulations, we show that the autocorrelation time length of thermal noise in water is ~10 ps at room temperature, which indicates that thermal noise is not white in the molecular scale while thermal noise can be reasonably assumed as white in macro- and meso-scale systems. The autocorrelation time length of thermal noise is intrinsic, since the value is almost unchanged for different temperature coupling methods. Interestingly, the autocorrelation time of thermal noise is correlated with the lifetime of hydrogen bonds, suggesting that the finite autocorrelation time length of thermal noise mainly comes from the finite lifetime of the interactions between neighboring water molecules.
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Microfluidic approaches to rapid and efficient aptamer selection.
Biomicrofluidics
PUBLISHED: 07-01-2014
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With their advantages as molecular recognition elements, aptamers have been extensively studied and used for bioanalytical and biomedical applications. However, the process of enrichment and screening of aptamers remains a bottleneck for aptamer development. Recently, microfluidic methods have been increasingly used for rapid and efficient aptamer selection, showing their remarkable advantages over conventional methods. This review briefly introduces aptamers and their advantages. The conventional process of generating aptamers is discussed, followed by the analysis of the key obstacles to efficient aptamer selection. Microfluidic methods for highly efficient enrichment and screening of aptamers are reviewed in detail.
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The role of RhoC in epithelial-to-mesenchymal transition of ovarian carcinoma cells.
BMC Cancer
PUBLISHED: 06-19-2014
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RhoC is a small G protein/GTPase and involved in tumor mobility, invasion and metastasis. Previously, up-regulated RhoC expression is found to play an important role in ovarian carcinogenesis and subsequent progression by modulating proliferation, apoptosis, migration and invasion.
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In vitro selection of DNA aptamers for metastatic breast cancer cell recognition and tissue imaging.
Anal. Chem.
PUBLISHED: 06-16-2014
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Cancer is a major public health issue, with metastatic cancer accounting for the overwhelming majority of cancer deaths. Early diagnosis and appropriate treatment of metastatic cancer may largely prolong the survival rate and improve the quality of life for patients. In this study, we have identified a panel of DNA aptamers specifically binding to MDA-MB-231 cells derived from metastatic site-pleural effusion, with high affinity after 15 rounds of selections using the cell-based systematic evolution of ligands by exponential enrichment (SELEX) method. The selected aptamers were subjected to flow cytometry and laser confocal fluorescence microscopy to evaluate their binding affinity and selectivity. The aptamer LXL-1 with the highest abundance in the enriched library demonstrated a low K(d) value and excellent selectivity for the recognition of the metastatic breast cancer cells. Tissue imaging results showed that truncated aptamer sequence LXL-1-A was highly specific to the corresponding tumor tissue and displayed 76% detection rate against breast cancer tissue with metastasis in regional lymph nodes. Therefore, on the basis of its excellent targeting properties and functional versatility, LXL-1-A holds great potential to be used as a molecular imaging probe for the detection of breast cancer metastasis. Our result clearly demonstrates that metastatic-cell-based SELEX can be used to generate DNA ligands specifically recognizing metastatic cancer cells, which is of great significance for metastatic cancer diagnosis and treatment.
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Carbon nanoparticle-protected aptamers for highly sensitive and selective detection of biomolecules based on nuclease-assisted target recycling signal amplification.
Chem. Commun. (Camb.)
PUBLISHED: 06-06-2014
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Based on the protective properties of carbon nanoparticles for aptamers against the digestion of nuclease, we have developed a nuclease-assisted target recycling signal amplification method for highly sensitive detection of biomolecules, such as ATP and kanamycin. The high binding specificity between aptamers and targets leads to excellent selectivity of the assay.
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Monoclonal surface display SELEX for simple, rapid, efficient, and cost-effective aptamer enrichment and identification.
Anal. Chem.
PUBLISHED: 06-06-2014
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A novel method, monoclonal surface display SELEX (MSD-SELEX), has been designed for simple, rapid, efficient, and cost-effective enrichment and identification of aptamers from a library of monoclonal DNA-displaying beads produced via highly parallel single-molecule emulsion PCR. The approach was successfully applied for the identification of high-affinity aptamers that bind specifically to different types of targets, including cancer biomarker protein EpCAM and small toxin molecule aflatoxin B1. Compared to the conventional sequencing-chemical synthesis-screening work flow, MSD-SELEX avoids large-scale DNA sequencing, expensive and time-consuming DNA synthesis, and labor-intensive screening of large populations of candidates, thus offering a new approach for simple, rapid, efficient, and cost-effective aptamer identification for a wide variety of applications.
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A multifunctional nanomicelle for real-time targeted imaging and precise near-infrared cancer therapy.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 05-21-2014
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Simultaneous targeted cancer imaging, therapy and real-time therapeutic monitoring can prevent over- or undertreatment. This work describes the design of a multifunctional nanomicelle for recognition and precise near-infrared (NIR) cancer therapy. The nanomicelle encapsulates a new pH-activatable fluorescent probe and a robust NIR photosensitizer, R16FP, and is functionalized with a newly screened cancer-specific aptamer for targeting viable cancer cells. The fluorescent probe can light up the lysosomes for real-time imaging. Upon NIR irradiation, R16FP-mediated generation of reactive oxygen species causes lysosomal destruction and subsequently trigger lysosomal cell death. Meanwhile the fluorescent probe can reflect the cellular status and in?situ visualize the treatment process. This protocol can provide molecular information for precise therapy and therapeutic monitoring.
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[Effect of Kuanxiong aerosol on coronary heart disease angina patients: a multicenter randomized controlled clinical study].
Zhongguo Zhong Xi Yi Jie He Za Zhi
PUBLISHED: 05-13-2014
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To evaluate the anginal attack-relieving efficacy and safety of Kuanxiong Aerosol (KA) in patients with coronary heart disease (CHD).
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Histopathology-based prognostic score is independent prognostic factor of gastric carcinoma.
BMC Cancer
PUBLISHED: 05-10-2014
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The aim of our study was to evaluate the histological characteristics and prognosis of gastric cancer.
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Preoperative predicting score of lymph node metastasis for gastric cancer.
Tumour Biol.
PUBLISHED: 05-10-2014
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The aim of our study was to develop a new score system that might predict the probability of lymph node of gastric carcinoma. We studied the clinicopathological variables of 932 patients with gastric carcinoma admitted to the Department of Surgical Oncology at the First Hospital of China Medical University. Logistic analysis was performed to identify predictors. The hazard risk (HR) of variables obtained from logistic regression was used to construct a simple scoring system determined by an aggregate of the points assigned for each selected variable. Receiver operator characteristic (ROC) curve was created to analyze the specificity. Lymph node metastases were found in 644 (69.1 %) of 932 patients. After multivariate logistic regression analysis, tumor size, depth of invasion, and macroscopic types (P?
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A diazirine-based photoaffinity probe for facile and efficient aptamer-protein covalent conjugation.
Chem. Commun. (Camb.)
PUBLISHED: 04-02-2014
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A photo-reactive functional labelling reagent, diazirine phosphoramidite, was designed and synthesized for easy and flexible site-specific labelling of oligonucleotides with the diazirine moiety. The new reagent allows facile photo-crosslinking of oligonucleotide with its interacting partner for a variety of applications, including tertiary structure determination, molecular interaction study and biomarker discovery.
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Elevated levels of polychlorinated biphenyls in plants, air, and soils at an E-waste site in Southern China and enantioselective biotransformation of chiral PCBs in plants.
Environ. Sci. Technol.
PUBLISHED: 03-21-2014
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E-waste that contains polychlorinated biphenyls (PCBs) is moved across national boundaries, often from industrialized countries in the northern hemisphere, where the items were formerly used, to subtropical and tropical regions in southeastern Asia and Africa. As a result, there is a high likelihood that PCBs will be released into the environment from a primary source due to the elevated temperatures encountered in these low-latitude regions. In the present study, PCBs and enantiomer fractions (EFs) of chiral PCBs (PCB 84, 95, 132, 136, 149, and 183) were analyzed in air, eucalyptus leaves, pine needles, and soil at an e-waste site and a rural site in southern China. The concentrations of PCBs at the e-waste site ranged from 7825 to 76330 pg/m(3), 27.5 to 1993 ng/g, and 24.2 to 12045 ng/g in the air (gas plus particle), plant leaves, and soils, respectively. The atmospheric PCB composition profiles in the present study indicated relatively high abundances of penta- and hexa-PCBs, which were different from those previously observed in the air across China. The Clausius-Clapeyron regression analysis indicated that evaporation from local contaminated surfaces constitutes a primary emission source of PCBs in the air at the e-waste site. The chiral signatures of PCBs in the air at the e-waste site were essentially racemic (mean EFs = (0.484 ± 0.022)-(0.499 ± 0.004) in the gaseous phase) except for PCB 84 (0.420 ± 0.050), indicating that racemic sources dominate the PCB emission in the air. PCB chiral signatures in the soils ((0.422 ± 0.038)-(0.515 ± 0.016)) were similar to those in the air except for PCB 95. However, the chiral PCBs in the plants (especially the eucalyptus leaves) had significantly nonracemic residues ((0.368 ± 0.075)-(0.561 ± 0.045)) compared to those in the air and soil. This finding suggests that enantioselective biotransformation of these atropisomeric PCBs was very likely to occur in the plant leaves, possibly due to metabolism by cytochrome P-450 enzymes in leaves. To our knowledge, this is the first report on the enantioselective metabolism of chiral PCBs in plants under field conditions.
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Low junctional adhesion molecule A expression correlates with poor prognosis in gastric cancer.
J. Surg. Res.
PUBLISHED: 03-07-2014
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The aberrant expression of junctional adhesion molecule A (JAM-A), which has a close correlation with the development, progression, metastasis, and prognosis of cancer, has been frequently reported. However, neither JAM-A expression nor its correlation with clinicopathologic variables and patient survival has been defined in gastric cancers. Moreover, little is known about the role of JAM-A in gastric cancer progression. We carried out the present study to investigate the prognostic value of JAM-A expression in gastric cancer patients. Furthermore, the biological roles of JAM-A in gastric cancer progression were also investigated.
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[Effects of stanniocalcin-1 and hypoxia-inducible factor-1? on mitochondrial membrane potential stability in renal carcinoma cells].
Zhongguo Yi Xue Ke Xue Yuan Xue Bao
PUBLISHED: 03-04-2014
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To explore the effects of stanniocalcin-1(STC-1)and hypoxia-inducible factor-1?(HIF-1?)on the calcium and thus on the mitochondrial membrane potential(??m)in renal carcinoma cells.
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New strategies for prevention and treatment of splenic artery steal syndrome after liver transplantation.
World J. Gastroenterol.
PUBLISHED: 03-01-2014
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To explore a prophylactic procedure to prevent splenic artery steal syndrome (SASS), as well as a therapeutic intervention to correct it.
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The stability of herpes simplex virus 1 ICP0 early after infection is defined by the RING finger and the UL13 protein kinase.
J. Virol.
PUBLISHED: 02-26-2014
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Herpes simplex virus 1 (HSV-1)-infected cell protein 0 (ICP0) is a multifunctional protein that plays a key role in overcoming numerous facets of host innate immunity. A key function of ICP0 that requires an intact RING finger domain is that of an ubiquitin E3 ligase: ICP0 interacts with at least three ubiquitin-conjugating enzymes of which one, UbcH5a, is required for degradation of PML and SP100. A preceding report showed that ICP0 is highly unstable at very early times after infection but becomes stable at later times. We report here that (i) the degradation of ICP0 is not infected cell specific, (ii) the degradation does not require the interaction of ICP0 with either UbcH5a, UbcH6, or UbcH9, (iii) ICP0 is degraded both early and late in cells infected with a mutant lacking the UL13 protein kinase, (iv) ICP0 encoded by wild-type virus or the ?UL13 mutant is stable in cells transfected with a plasmid encoding UL13 before infection, (v) ICP0 carrying mutations in the RING finger domain is stable both early and late in infection, and, finally, (vi) in cells infected with both wild type and RING finger mutant only the wild-type ICP0 is rapidly degraded at early times. The results suggest that the stability of ICP0 is mediated by the UL13 protein kinase and that the target of proteolysis is a site at or near the RING domain of ICP0.
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Facile and rapid generation of large-scale microcollagen gel array for long-term single-cell 3D culture and cell proliferation heterogeneity analysis.
Anal. Chem.
PUBLISHED: 02-18-2014
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Microfabricated devices are suitable for single-cell analysis due to their high throughput, compatible dimensions and controllable microenvironment. However, existing devices for single-cell culture and analysis encounter some limitations, such as nutrient depletion, random cell migration and complicated fluid shear influence. Moreover, most of the single-cell culture and analysis devices are based on 2D cell culture conditions, even though 3D cell culture methods have been demonstrated to better mimic the real cell microenvironment in vivo. To solve these problems, herein we develop a microcollagen gel array (?CGA) based approach for high-throughput long-term single-cell culture and single-cell analysis under 3D culture conditions. Type-I collagen, a well-established 3D cell culture medium, was used as the scaffold for 3D cell growth. A 2 × 2 cm PDMS chip with 10?000 ?CGA units was fabricated to encapsulate thousands of single cells in less than 15 min. Single cells were able to be confined and survive in ?CGA units for more than 1 month. The capability of large-scale and long-term single-cell 3D culture under open culture conditions allows us to study cellular proliferation heterogeneity and drug cytotoxicity at the single-cell level. Compared with existing devices for single-cell analysis, ?CGA solves the problems of nutrient depletion and random cellular migration, avoids the influence of complicated fluid shear, and mimics the real 3D growth environment in vivo, thereby providing a feasible 3D long-term single-cell culture method for single-cell analysis and drug screening.
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Occurrence of brominated flame retardants (BFRs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) in agricultural soils in a BFR-manufacturing region of North China.
Sci. Total Environ.
PUBLISHED: 02-06-2014
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We investigated the occurrence of brominated flame retardants (BFRs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) in the surface soils from the largest BFR-manufacturing and vegetable farming center (Shouguang) of North China. The total concentrations of BFRs ranged from 39.9 to 8,145 ng/g dry weight with a mean of 1,947 ng/g. The BFRs were dominated by decabromodiphenylethane (deca-BDEs) and tetrabromobisphenol A (TBBPA), with means of 1127 and 672 ng/g, respectively, followed by decabromodiphenyl ethane (DBDPE) (111 ng/g) and hexabromocyclododecanes (HBCD) (37.5 ng/g). This profile was generally consistent with the BFR production and use in China, except for TBBPA. Although the lower brominated BDEs (tri- through hepta-BDEs) in the soil may originate from technical deca-BDE mixtures as trace impurities and/or from the degradation of deca-BDEs, deca-BDE was shown to be persistent in the soil. The concentrations of OCPs (44 ng/g) were significantly lower than those of BFRs and displayed a spatial distribution opposite to that of BFRs, which was concentrated in the industrial zone. PCBs (with the lowest levels) showed a relatively uniform spatial distribution because of regional diffusive sources. The mass inventories for the entire land soil (20-cm) were estimated to be 1042, 26, and 3.7 t for BFRs, OCPs, and PCBs, respectively.
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Acquired factor V inhibitor after liver transplantation.
Clin Res Hepatol Gastroenterol
PUBLISHED: 01-28-2014
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Acquired inhibitors against coagulation factor V (FV) occur rarely, the clinical symptoms vary to a great extent, from asymptomatic laboratory abnormalities to life-threatening bleeding. Coagulation factor V (FV) is a plasma-cofactor mostly existing in the plasma, and approximately 20-25% (Tracy et al. (1982), Kane (2006)) of FV exist in platelet granules. Patients' reaction is the prolonging of prothrombin time (PT) and activated partial thromboplastin time (APTT), but there is no exact reason, and that can not be corrected after normal plasma transfusion (Morris and Curris (2009), Lucia and Aguilar (2005)). We report here a case of the occurrence of FV inhibitors after orthotopic liver transplantation (OLT). With gastrointestinal bleeding, patient's haemostatic response was not achieved after using fresh frozenplasma (FFP), platelet concentrates (PC), prothrombin complex concentrates (PCC) or recombinant activated FVII (rFVIIa). After using high-dose intravenous immunoglobulin (IVIg) and change of immunosuppressant from tacrolimus (FK506) to cyclosporine, the bleeding stopped and better laboratory examination results was achieved thereafter.
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In vitro and in vivo studies on the transport of PEGylated silica nanoparticles across the blood-brain barrier.
ACS Appl Mater Interfaces
PUBLISHED: 01-17-2014
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Transport of PEGylated silica nanoparticles (PSiNPs) with diameters of 100, 50, and 25 nm across the blood-brain barrier (BBB) was evaluated using an in vitro BBB model based on mouse cerebral endothelial cells (bEnd.3) cultured on transwell inserts within a chamber. In vivo animal experiments were further performed by noninvasive in vivo imaging and ex vivo optical imaging after injection via carotid artery. Confocal fluorescence studies were carried out to evaluate the uptake of PSiNPs by brain endothelial cells. The results showed that PSiNPs can traverse the BBB in vitro and in vivo. The transport efficiency of PSiNPs across BBB was found to be size-dependent, with increased particle size resulting in decreased efficiency. This work points to the potential application of small sized silica nanoparticles in brain imaging or drug delivery.
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Expression of BAMBI and its combination with Smad7 correlates with tumor invasion and poor prognosis in gastric cancer.
Tumour Biol.
PUBLISHED: 01-05-2014
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Bone morphogenetic proteins and activin membrane-bound inhibitor (BAMBI) and drosophila mothers against decapentaplegic protein 7 (Smad7) are known to negatively regulate the transforming growth factor-? (TGF-?) signaling and play an important role in the progression of many malignant tumors. However, it remains unclear whether expression of BAMBI alone or in combination with Smad7 is associated with the progression of gastric cancer. In the present study, we investigated the expression of BAMBI and Smad7 in 276 cancer tissues and 263 tumor-adjacent tissues from gastric cancer patients, using tissue-microarray-based immunohistochemistry. The expression of BAMBI and Smad7 was significantly higher in cancer tissues than in tumor-adjacent tissues. The expression of BAMBI was significantly correlated with increased depth of invasion (P = 0.010), lymphatic invasion (P < 0.001), lymph node metastasis (P = 0.001), TNM stage (P = 0.008), and decreased differentiation (P = 0.046). The expression of BAMBI was associated with a significantly shorter overall survival (OS) (P = 0.006) and disease-free survival (DFS) (P = 0.011). The combined expression of BAMBI and Smad7 was associated with more invasion and metastasis as well as less survival time in gastric cancer patients. The univariate analysis showed that the expression of BAMBI alone or in combination with Smad7 was significantly associated with the OS and DFS. These findings suggest that BAMBI and Smad7 may cooperatively inhibit the TGF-? signaling, and thus promote the progression of gastric cancer.
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A T7 exonuclease-assisted cyclic enzymatic amplification method coupled with rolling circle amplification: a dual-amplification strategy for sensitive and selective microRNA detection.
Chem. Commun. (Camb.)
PUBLISHED: 01-03-2014
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A T7 exonuclease-assisted cyclic enzymatic amplification method (CEAM) was combined with rolling circle amplification (RCA) to develop a RCA-CEAM dual amplification method for ultrasensitive detection of microRNA with excellent selectivity.
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DSTYK kinase domain ablation impaired the mice capabilities of learning and memory in water maze test.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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DSTYK (Dual serine/threonine and tyrosine protein kinase) is a putative dual Ser/Thr and Tyr protein kinase with unique structural features. It is proposed that DSTYK may play important roles in brain because of its high expression in most brain areas. In the present study, a DSTYK knockout (KO) mouse line with the ablation of C-terminal of DSTYK including the kinase domain was generated to study the physiological function of DSTYK. The DSTYK KO mice are fertile and have no significant morphological defects revealed by Nissl staining compared with wildtype mice. Open field test and rotarod test showed there is no obvious difference in basic motor and balance capacity between the DSTYK homozygous KO mice and DSTYK heterozygous KO mice. In water maze test, however, the DSTYK homozygous KO mice show impaired capabilities of learning and memory compared with the DSTYK heterozygous KO mice.
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Androglobin knockdown inhibits growth of glioma cell lines.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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Globin family was famous for oxygen supply function of its members such as hemoglobin and myoglobin. With the progress of research, several members of this protein family have been proven to play roles in tumors including glioma. Androglobin (ADGB) is a recently identified member of globin family with very few studies about its function. In the present study, we show that ADGB plays an oncogene role in glioma. Lentiviral vector mediated ADGB knockdown inhibited the proliferation of glioma cell lines determined by MTT assay and colony formation assay. ADGB knockdown also increased the apoptosis of glioma cell line U251 assessed by flow cytometry. In addition, western blot showed that ADGB knockdown altered levels of several proteins related to proliferation, survival or apoptosis in U251 cells. These findings suggest ADGB is involved in the progression of glioma in vitro.
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A highly parallel microfluidic droplet method enabling single-molecule counting for digital enzyme detection.
Biomicrofluidics
PUBLISHED: 01-01-2014
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Although digital detection of nucleic acids has been achieved by amplification of single templates in uniform microfluidic droplets and widely used for genetic analysis, droplet-based digital detection of proteins has rarely been reported, largely due to the lack of an efficient target amplification method for protein in droplets. Here, we report a key step towards digital detection of proteins using a highly parallel microfluidic droplet approach for single enzyme molecule detection in picoliter droplets via enzyme catalyzed signal amplification. An integrated microfluidic chip was designed for high throughput uniform droplet generation, monolayer droplet collection, incubation, detection, and release. Single ?-galatosidase (?-Gal) molecules and the fluorogenic substrate fluorescein di-?-D-galactopyranoside were injected from two separated inlets to form uniform 20??m droplets in fluorinated oil at a frequency of 6.6?kHz. About 200?000 droplets were captured as a monolayer in a capture well on-chip for subsequent imaging detection. A series of ?-Gal solutions at different concentrations were analyzed at the single-molecule level. With no enzyme present, no droplets were found to fluoresce, while brightly fluorescent droplets were observed under single-enzyme molecule conditions. Droplet fluorescence intensity distribution analysis showed that the distribution of enzyme molecules under single-molecule conditions matched well with theoretical prediction, further proving the feasibility of detecting single enzyme molecules in emulsion droplets. Moreover, the population of fluorescent droplets increased as the ?-Gal concentration increased. Based on a digital counting method, the measured concentrations of the enzyme were found to match well with input enzyme concentration, establishing the accuracy of the digital detection method for the quantification of ?-Gal enzyme molecules. The capability of highly parallel detection of single enzyme molecules in uniform picoliter droplets paves the way to microdroplet based digital detection of proteins.
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Clinicopathological significance and prognostic value of lactate dehydrogenase A expression in gastric cancer patients.
PLoS ONE
PUBLISHED: 01-01-2014
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LDH-A, the enzyme responsible for transforming pyruvate into lactate, has been demonstrated to be up-regulated in many types of cancer and to give rise to more aggressive behavior by regulating proliferation and anti-apoptosis. However, its expression in gastric cancer (GC) has not been characterized thoroughly. The purpose of this study was to clarify the expression and potential impact of LDH-A in GC.
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Identification and Transcriptional Profiling of Differentially Expressed Genes Associated With Response to UVA Radiation in Drosophila melanogaster (Diptera: Drosophilidae).
Environ. Entomol.
PUBLISHED: 12-17-2013
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Ultraviolet A (UVA) radiation, the major component of solar ultraviolet (UV) radiation reaching the earths surface, leads to negative effects in insects, such as oxidative stress, photoreceptor damage, and cell death. To better understand the molecular mechanisms of insect response to UVA radiation, suppression subtractive hybridization (SSH) and real-time quantitative polymerase chain reaction approaches were combined to reveal differential transcript expression in Drosophila melanogaster Meigen, 1830 (Diptera: Drosophilidae). In this study, two subtractive cDNA libraries were constructed and sequenced, obtaining 131 high-quality unique expressed sequence tags (ESTs) that were up- or downregulated in D. melanogaster exposed to UVA radiation for 0.5 h. Of the 131 ESTs, 102 unique ESTs were differentially expressed and classified into 10 functional categories. The results showed that UVA radiation induces expression of genes related to stress and defense response and metabolism. Potential transcription factor binding motifs upstream of these genes are associated with multiple signaling pathways that may help the insect cope with the stress of UVA radiation. To our knowledge, this is the first analysis of insect response to UVA radiation at the transcriptional level. Our results reveal that UVA radiation influences the expression profiles of stress-responsive genes and provide further insights into the mechanisms of adaptive response to UVA radiation stress.
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PBX3 is overexpressed in gastric cancer and regulates cell proliferation.
Tumour Biol.
PUBLISHED: 11-11-2013
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The pre-leukemia transcription factor 3 (PBX3) is a member of the PBX family of transcription factors, which is known to increase DNA-binding/transcriptional activity of HOX proteins and regulate genes involved in development. Recently, PBX3 was reported to be involved in a variety of cancers, while its implication in gastric cancer is unclear. This study aimed to investigate its clinical significance and biological function in gastric cancer. PBX3 expression was analyzed in 90 gastric cancer specimens using immunohistochemistry. PBX3 was overexpressed in 30 cases (33.33 %). Importantly, PBX3 overexpression positively correlated with advanced invasion depth (p?=?0.0017), Clinical stage (p?=?0.0127) and grade of tumor differentiation (p?=?0.0158). PBX3 was also overexpressed in gastric cancer cell lines. Plasmid transfection was performed in AGS and SGC-7901 gastric cancer cell line with low endogenous PBX3 expression. MTT and colony formation assay were carried out to assess the role of PBX3 in proliferation. PBX3 overexpression in gastric cancer cell lines accelerated cell proliferation rate and colony formation ability, with upregulation of PCNA expression. In addition, matrigel invasion assay showed that PBX3 transfection also increased cell-invading ability. These results validate the role of PBX3 as a clinically relevant oncoprotein and establish PBX3 as a promising therapeutic target of gastric cancer.
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Tacrolimus-related seizure after pediatric liver transplantation - A single-center experience.
Pediatr Transplant
PUBLISHED: 10-25-2013
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To identify the risk factors for new-onset seizures after pediatric LT and to assess their clinical implications and long-term prognosis. The clinical and laboratory data of 27 consecutive children who underwent LT from January 2007 to December 2010 in our center were analyzed retrospectively. Patients were divided into seizures group and a non-seizures group. Pre-operative, intra-operative, and post-operative data were collected. Seizures occurred in four children, an incidence of 14.8%. All exhibited generalized tonic-clonic seizures within the first two wk after LT. Univariate analysis showed that the risk factors associated with seizures after pediatric LT included gender, pediatric end-stage liver disease score before surgery, Child-Pugh score before surgery, serum total bilirubin after surgery, and trough TAC level. Multivariate analysis showed that trough TAC level was the only independent risk factor associated with the seizures. All children who experienced seizures survived with good graft function and remained seizure-free without anti-epileptic drugs over a mean follow-up period of 33.7 ± 14.6 months. High trough TAC level was the predominant factor that contributed to seizures in the early post-operative period after pediatric LT. High PELD and Child-Pugh scores before LT and high post-operative serum Tbil may be contributory risk factors for TAC-related seizures.
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Inactivation of ?-catenin results in the reduction of postnatal body weight gain.
Brain Res. Bull.
PUBLISHED: 09-01-2013
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Arcuate nucleus of hypothalamus (ARH) is the core component in the regulation circuits of food intake and energy homeostasis. ARH projections to other parts of the hypothalamus and to extrahypothalamic areas are established in the postnatal two weeks, which is a pivotal stage for individual development. ?-Catenin, a cell adhesion protein and also the mediator of canonical Wnt signaling pathway, plays an important role in embryonic development and adult homeostasis. However, whether ?-catenin plays any roles in the development of hypothalamus is not clear. Here, we report that perinatal conditional knockout of ?-catenin by CamKII?-Cre in forebrain reduces body weight gain from P8 and dramatically shortens life span. Quantitative PCR and in situ hybridization results showed the expression of NPY mRNA in the ARH of ?-catenin CKO mice at P15 is obviously increased compared with that of littermate controls, whereas the expression of POMC mRNA is significantly decreased, which suggested the reduction of postnatal body weight gain might be due to the deficiency of food intake. Together, ?-catenin might play an important role in the regulation of food intake and postnatal body weight gain probably through affecting the development of ARH circuits.
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Single-molecule photon-fueled DNA nanoscissors for DNA cleavage based on the regulation of substrate binding affinity by azobenzene.
Chem. Commun. (Camb.)
PUBLISHED: 08-21-2013
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A pair of single-molecule photo-responsive DNA nanoscissors for DNA cleavage based on the regulation of substrate binding affinity was designed and fabricated. Compared with other DNA nanomachines, our DNA nanoscissors have the advantages of a clean switching mechanism, as well as robust and highly reversible operation.
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[NH3, N2O, CH4 and CO2 emissions from growing process of caged broilers].
Huan Jing Ke Xue
PUBLISHED: 08-17-2013
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To obtain Ammonia and greenhouse gas (GHG) emission factors of caged broilers, ammonia (NH3), methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) emissions of broilers aged 0 d to 42 days were monitored in caged broilers production systems located in Shandong province. Gas concentrations of incoming and exhaust air streams were measured by using INNOVA 1312 multi-gas monitor with multi-channel samplers. Building ventilation rates were determined by on site FANS (Fan Assessment Numeration System) measurement systems. The NH3 emission factors showed a trend of increase at the beginning and then decreased with the broiler ages. The NH3 emission rates were 8.5 to 342.1 mg x (d x bird)(-1) and the average daily emission rate was 137.9 mg x (d x bird)(-1) [48.6 g x (d x AU)(-1)] over the 42-d period. The GHGs emission rates were 19.5-351.9 mg x (d x bird)(-1) with an average of 154.5 mg x (d x bird)(-1) [54.4 g x (d x AU)(-1)] for CH4, and 2.2- 152.9 g x (d x bird)(-10 with an average of 65.9 g x (d x bird)(-1) [23.2 kg x (d x AU)(-1)] for CO2. No emission of N2O was observed. The CH4 and CO2 emission rates increased with the increase of broilers ages. The total NH3 emission over the 42 d growing period averaged (5.65 +/- 1.02) g x (bird x life cycle)(-1). The NH3 emission contribution in different growth phase to the total emission were 33.6% in growth phase 1 (0-17 day, GP1), 36.4% in GP2 (18-27 days), and 29.9% in GP3 (28-42 days), respectively. The NH3 emission in GP2 was significantly higher than emission in GP1 and GP3. CH4 and CO2 cumulative emission rates were (6.30 +/- 0.16) g x (bird(-1) x life cycle)(-1) and (2.68 +/- 0.18) kg x (bird x life cycle)(-1), respectively. The cumulative emission rates of CH4 and CO2 in GP3 were significantly higher than emission rates in GP2 and in GP1, accounting for 50% of total emissions. The results of this study could provide the data support for mitigation of gas emission from broilers production.
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Backbone-modified molecular beacons for highly sensitive and selective detection of microRNAs based on duplex specific nuclease signal amplification.
Chem. Commun. (Camb.)
PUBLISHED: 07-10-2013
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Based on backbone-modified molecular beacons and duplex-specific nuclease, we have developed a target recycling amplification method for highly sensitive and selective miRNA detection. The combination of a low fluorescence background of 2-OMe-RNA modified MB and nuclease-assisted signal amplification leads to ultrahigh assay sensitivity, and the powerful discriminating ability of MB enables the differentiation of highly similar miRNAs with one-base difference, both of which are of great significance to miRNA detection.
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Graphene oxide protected nucleic acid probes for bioanalysis and biomedicine.
Chemistry
PUBLISHED: 07-09-2013
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Recently, the binding ability of DNA on GO and resulting nuclease resistance have attracted increasing attention, leading to new applications both in vivo and in vitro. In vivo, nucleic acids absorbed on GO can be effectively protected from enzymatic degradation and biological interference in complicated samples, making it useful for targeted delivery, gene regulation, intracellular detection and imaging with high uptake efficiencies, high intracellular stability, and very low toxicity. In vitro, the adsorption of ssDNA on GO surface and desorption of dsDNA or well-folded ssDNA from GO surface result in the protection and deprotection of DNA from nucleic digestion, respectively, which has led to target-triggered cyclic enzymatic amplification methods (CEAM) for amplified detection of analytes with sensitivity 2-3 orders of magnitude higher than that of 1:1 binding strategies. This Concept article explores some of the latest developments in this field.
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Microbial recycling of glycerol to biodiesel.
Bioresour. Technol.
PUBLISHED: 07-07-2013
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The sustainable supply of lipids is the bottleneck for current biodiesel production. Here microbial recycling of glycerol, byproduct of biodiesel production to biodiesel in engineered Escherichia coli strains was reported. The KC3 strain with capability of producing fatty acid ethyl esters (FAEEs) from glucose was used as a starting strain to optimize fermentation conditions when using glycerol as sole carbon source. The YL15 strain overexpressing double copies of atfA gene displayed 1.7-fold increase of FAEE productivity compared to the KC3 strain. The titer of FAEE in YL15 strain reached to 813mgL(-1) in minimum medium using glycerol as sole carbon source under optimized fermentation conditions. The titer of glycerol-based FAEE production can be significantly increased by both genetic modifications and fermentation optimization. Microbial recycling of glycerol to biodiesel expands carbon sources for biodiesel production.
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Survivin gene expression increases gastric cancer cell lymphatic metastasis by upregulating vascular endothelial growth factor-C expression levels.
Mol Med Rep
PUBLISHED: 05-27-2013
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The aim of this study was to investigate the correlation between the expression of survivin and vascular endothelial growth factor?C (VEGF?C) in gastric cancer and the pathway by which survivin may affect gastric cancer lymphatic metastasis. The study may provide novel targets for treating gastric cancer lymphatic metastasis and distal dissemination. Survivin and VEGF?C expression in gastric carcinoma and peri?carcinoma (2 cm away from the carcinoma) tissues, obtained from 195 patients who underwent curative gastrectomy surgery (130 cases presented with lymph node metastasis and 65 cases presented without metastasis), was examined immunohistochemically using a tissue microarray. Plasmids containing survivin and VEGF?C shRNA were constructed and transfected into SGC?7901 gastric cancer cells. The expression levels of the two genes were examined using western blot analysis and qPCR, and the results were statistically analyzed. The expression levels of survivin and VEGF?C were 51.3 and 55.4%, respectively, in gastric carcinoma. Survivin and VEGF?C were located mainly in the cytoplasm of the tumor cells. The expression levels of survivin and VEGF?C were significantly higher in patients with lymph node metastasis than in those without metastasis (P=0.008 and 0.001, respectively). Patients with high expression levels of survivin and VEGF?C showed significantly less favorable survival rates compared with patients with low expression levels of those two genes (P=0.003 and 0.039, respectively). Moreover, patients with co?expression of the two genes usually had a poorer prognosis (P=0.003). However, multivariate analysis demonstrated that neither of the two genes were an independent prognostic determinant. The levels of VEGF?C expression may be regulated by survivin expression. Conversely, inhibiting VEGF?C gene expression by shRNA did not reduce survivin expression at the mRNA or protein levels. Survivin and VEGF?C were expressed in gastric cancer cells and were significantly associated with lymphatic metastasis. Survivin may be a regulator of VEGF?C expression in gastric cancer cells, and is essential in invasion and lymphatic metastasis. Moreover, survivin may be able to serve as a chemotherapy target for gastric cancer.
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Synthesis and biological evaluation of phenyl substituted polyoxygenated xanthone derivatives as anti-hepatoma agents.
Eur J Med Chem
PUBLISHED: 05-11-2013
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A series of novel derivatives of phenyl substituted tetramethoxy xanthone were synthesized and evaluated for their in vitro cytotoxicity against human hepatocellular carcinoma (HCC) and non-tumor hepatic cells. Among these derivatives, compound 6 was more potent than positive control 5-fluorouracil (5-Fu) on QGY-7703 and SMMC-7721 cells with IC50 values of 6.27 ?M, 7.50 ?M and 15.56 ?M, 14.55 ?M, respectively. Furthermore, compounds 6, 14, 16, and 29 exhibited much better selectivity toward the normal hepatic cell line QSG-7701 than 5-Fu. Additionally, compound 6 significantly induced cell apoptosis in QGY-7703 cells. Our findings suggested that these phenylxanthone derivatives may hold promise as chemotherapeutic agents for the treatment of human HCC.
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Dissipation of available benzo[a]pyrene in aging soil co-contaminated with cadmium and pyrene.
Environ Sci Pollut Res Int
PUBLISHED: 04-08-2013
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A microcosm experiment was conducted to investigate the dissipation of available benzo[a]pyrene (BaP) in soils co-contaminated with cadmium (Cd) and pyrene (PYR) during aging process. The available residue of BaP in soil was separated into desorbing and non-desorbing fractions. The desorbing fraction contributed more to the dissipation of available BaP than the non-desorbing fraction did. The concentration of bound-residue fraction of BaP was quite low across all treatments. Within the duration of this study (250 days), transformation of BaP from available fractions to bound-residue fraction was not observed. Microbial degradation was the dominant mechanism of the dissipation of available BaP in the soil. The dissipation of available BaP was significantly inhibited with the increment in Cd level in the soil. The addition of PYR (250 mg kg(-1)) remarkably promoted the dissipation of available BaP without reducing Cd availability in the soil. The calculated half-life of available BaP in the soil prolonged with the increment in Cd level; however, the addition of PYR shortened the half-life of available BaP by 13.1, 12.7, and 32.8 % in 0.44, 2.56, and 22 mg Cd kg(-1) soils, respectively. These results demonstrated that the inhibiting effect of Cd and the promoting effect of PYR on the dissipation of available BaP were competitive. Therefore, this study shows that the bioremediation process of BaP can be more complicated in co-contaminated soils.
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Outcomes in children with biliary atresia following liver transplantation.
HBPD INT
PUBLISHED: 04-06-2013
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Congenital biliary atresia is a rare condition characterized by idiopathic dysgenesis of the bile ducts. If untreated, congenital biliary atresia leads to liver cirrhosis, liver failure and premature death. The present study aimed to evaluate the outcomes of orthotopic liver transplantation in children with biliary atresia.
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Application of computer-assisted three-dimensional quantitative assessment and a surgical planning tool for living donor liver transplantation.
Chin. Med. J.
PUBLISHED: 04-06-2013
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Precise evaluation of the live donors liver is the most important factor for the donors safety and the recipients prognosis in living donor liver transplantation (LDLT). Our study assessed the clinical value of computer-assisted three-dimensional quantitative assessment and a surgical planning tool for donor evaluation in LDLT.
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Application of 1-hydroxyethylidene-1, 1-diphosphonic acid in boiler water for industrial boilers.
Water Sci. Technol.
PUBLISHED: 04-05-2013
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The primary method used for boiler water treatment is the addition of chemicals to industrial boilers to prevent corrosion and scaling. The static scale inhibition method was used to evaluate the scale inhibition performance of 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP). Autoclave static experiments were used to study the corrosion inhibition properties of the main material for industrial boilers (20# carbon steel) with an HEDP additive in the industrial boiler water medium. The electrochemical behavior of HEDP on carbon steel corrosion control was investigated using electrochemical impedance spectroscopy and Tafel polarization techniques. Experimental results indicate that HEDP can have a good scale inhibition effect when added at a quantity of 5 to 7 mg/L at a test temperature of not more than 100 °C. To achieve a high scale inhibition rate, the HEDP dosage must be increased when the test temperature exceeds 100 °C. Electrochemical and autoclave static experimental results suggest that HEDP has a good corrosion inhibition effect on 20# carbon steel at a concentration of 25 mg/L. HEDP is an excellent water treatment agent.
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Cyclic enzymatic amplification method (CEAM) based on exonuclease III for highly sensitive bioanalysis.
Methods
PUBLISHED: 04-04-2013
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Nucleic acid molecular probes (NAMPs) have been widely used in the sensing of various chemical and biological substances, as well as physical parameters. However, for traditional nucleic acid molecular probes, the stoichiometric 1:1 binding ratio limits the signal enhancement and thus the sensitivity of the assay. In order to overcome this problem, the cyclic enzymatic amplification method (CEAM) based on exonuclease III has been applied in optical and electrical detection of DNA, proteins and small molecules with excellent sensitivity, selectivity, versatility and simplicity. In this review, the working principle of CEAM is first introduced, followed by the applications of CEAM using different output signals for various analytes. Finally, experimental designs and procedures of CEAM are discussed in detail using displacing probes-based CEAM and linear molecular beacons (LMBs)-based CEAM as two examples.
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Selection of DNA aptamers against epithelial cell adhesion molecule for cancer cell imaging and circulating tumor cell capture.
Anal. Chem.
PUBLISHED: 03-29-2013
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Epithelial cell adhesion molecule (EpCAM) is overexpressed in most solid cancers and is an ideal antigen for clinical applications in cancer diagnosis, prognosis, imaging, and therapy. Currently, most of the EpCAM-based diagnostic, prognostic, and therapeutic strategies rely on the anti-EpCAM antibody. However, the use of EpCAM antibody is restricted due to its large size and instability. In this study, we have successfully identified DNA aptamers that selectively bind human recombinant EpCAM protein. The aptamers can specifically recognize a number of live human cancer cells derived from breast, colorectal, and gastric cancers that express EpCAM but not bind to EpCAM-negative cells. Among the aptamer sequences identified, a hairpin-structured sequence SYL3 was optimized in length, resulting in aptamer sequence SYL3C. The Kd values of the SYL3C aptamer against breast cancer cell line MDA-MB-231 and gastric cancer cell line Kato III were found to be 38 ± 9 and 67 ± 8 nM, respectively, which are better than that of the full-length SYL3 aptamer. Flow cytometry analysis results indicated that the SYL3C aptamer was able to recognize target cancer cells from mixed cells in cell media. When used to capture cancer cells, up to 63% cancer cell capture efficiency was achieved with about 80% purity. With the advantages of small size, easy synthesis, good stability, high binding affinity, and selectivity, the DNA aptamers reported here against cancer biomarker EpCAM will facilitate the development of novel targeted cancer therapy, cancer cell imaging, and circulating tumor cell detection.
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Synthesis of chitosan molecularly imprinted polymers for solid-phase extraction of methandrostenolone.
Carbohydr Polym
PUBLISHED: 03-18-2013
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Chitosan molecularly imprinted polymers (CHI-MIPs) for selective extraction of methandrostenolone (MA) was synthesized by cross-linking of chitosan with epichlorohydrin in the presence of MA as the template molecule. Systematic investigations of the influences of template, functional polymer, cross-linker as well as porogen concentrations on the rebinding capacity of CHI-MIPs were carried out. Adsorption and kinetic binding experiments indicated that the synthesized CHI-MIPs had high adsorption and excellent affinity to MA. Solid-phase extraction (SPE) using the prepared CHI-MIPs as adsorbent was then investigated, and the optimum loading and eluting conditions for SPE of the MA were established. The optimized SPE procedure was used to extract the MA from several spiked samples and a good sample clean-up was obtained with the average recoveries ranged from 95.97 to 101.79%.
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Structural revision of garuganin IV and 1,9-didesmethylgaruganin III through total synthesis.
J. Org. Chem.
PUBLISHED: 03-12-2013
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The chemical structures of garuganin IV and 1,9-didesmethylgaruganin III were misassigned. The structures were revised on the basis of analysis of the NMR data, and the revisions were verified through total synthesis.
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The garuganin and garugamblin diarylether heptanoids: total synthesis and determination of chiral properties using dynamic NMR.
J. Org. Chem.
PUBLISHED: 03-11-2013
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The synthesis of the garuganin and garugamblin diarylether heptanoids using an intramolecular Ullmann coupling is reported. Alkene stereoisomers, vinylogous ester regioisomers, and ?-diketone congeners are also synthesized. The chiral properties and free energies of activation for racemization of the garuganin and garugamblin diarylether heptanoids and congeners are determined using dynamic NMR methods. A combination of techniques including coalescence measurements, line shape analysis, and selective inversion experiments are used to measure racemization barriers. None of the garuganin or garugamblin diarylether heptanoids are chiral, despite their reported specific rotation values.
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