G protein-coupled receptors (GPRs) are highly related to oncogenesis and cancer metastasis. G protein-coupled receptor 137 (GPR137) was initially reported as a novel orphan GPR about 10 years ago. Some orphan GPRs have been implicated in human cancers. The aim of this study is to investigate the role of GPR137 in human colon cancer. Expression levels of GRP137 were analyzed in different colon cancer cell lines by quantitative polymerase chain reaction and western blot analysis. Lentivirus-mediated short hairpin RNA was specifically designed to knock down GPR137 expression in colon cancer cells. Cell viability was measured by methylthiazoletetrazolium and colony formation assays. In addition, cell cycle characteristic was investigated by flow cytometry. GRP137 expression was observed in all seven colon cancer cell lines at different levels. The mRNA and protein levels of GPR137 were down-regulated in both HCT116 and RKO cells after lentivirus infection. Lentivirus-mediated silencing of GPR137 reduced the proliferation rate and colonies numbers. Knockdown of GPR137 in both cell lines led to cell cycle arrest in the G0/G1 phase. These results indicated that GPR137 plays an important role in colon cancer cell proliferation. A better understanding of GPR137's effects on signal transduction pathways in colon cancer cells may provide insights into the novel gene therapy of colon cancer.
meso-Cyano boron-pyridyl-isoindoline dyes with asymmetrical structures were synthesized through a facile two-step reaction. Broad envelopes of intense vibrational bands were observed for the main spectral bands in the absorption and emission spectra. Moderate fluorescence quantum yields were obtained in solution, with significant intensity also observed in film, powder and crystal forms. An analysis of the structure-property relationships was carried out based on X-ray crystallography, optical spectroscopy, and theoretical calculations.
The interactions between trivalent or pentavalent As/Sb and dissolved organic matter (DOM) in four regions (the river channel, the adjacent coastal area, and the northern and southern nearshore areas) of the Yangtze Estuary, China, were studied using fluorescence quenching titration combined with excitation-emission matrix spectroscopy and parallel factor analysis (PARAFAC). The As/Sb-DOM complexation characteristics were investigated using FTIR and UV absorbance spectroscopy and zeta potential analysis. Four protein-like components and one humic-like component were identified in the DOM from the Yangtze Estuary, China, by PARAFAC analysis. The tryptophan-like substance represented by component 2 was the dominant component and played an important role in the complexation between DOM and As/Sb. The results of complexation modeling demonstrated that the binding capacity of trivalent As/Sb with DOM was higher than that of pentavalent As/Sb with DOM. The DOM from the north nearshore area with the most acidic functional groups and greatest aromaticity possessed the highest binding capacity for trivalent and pentavalent As/Sb. The increase in the UV absorbance and the charge neutralization further indicated the interaction between As/Sb and DOM. The higher binding capacity of Sb(III) with DOM was mainly due to the hydroxyl and carboxyl groups. Our study demonstrates that the use of the advanced EEM-PARAFAC method in fluorescence quenching studies is very useful for evaluating the properties of DOM-pollutant interactions.
ZnO p-n homojunction light-emitting devices (LEDs) have been fabricated, and by introducing a p-type GaN as the hole-injection layer, the output power of the LEDs can reach 18.5 ?W when the drive current is 60 mA, which is almost three orders of magnitude larger than the pristine LEDs without the hole-injection layer. The improved performance can be attributed to the extra holes injected into the p-ZnO layer from the p-GaN hole-injection layer.
Hybrid plasmonic waveguides have achieved rapid advancement in plasmonics, which has given rise to remarkable field enhancement, light harvest, light-transport capabilities, bridging the gap between electronics and photonics by routing and manipulating light at sub-wavelength regions and so on. However, the development of plasmonic waveguides is hindered by lack of devices that can adjust coherent plasmonic fields. In this letter, hybridized planar multilayer insulator metal insulator metal insulator heterostructures are proposed, and it is demonstrated that their unique capabilities can be used to adjust the mode characteristics by means of varying the thickness of the insulator spacer layer inserted between two metal films, such as the shift of the surface plasmon resonance wavelength. This type of hybrid plasmonic waveguides opens up opportunities for the tunability of mode characteristics, adjustment of resonant energy transfer processes, that have a potential for designing novel optical micro/nano resonance cavities.
Porphodilactones represent the porphyrin analogues, in which the peripheral bonds of two pyrrole rings are replaced by lactone moieties. They provide an opportunity to investigate how ?-substituent orientation of porphyrinoids modulates the electronic structures and optical properties, in a manner similar to what is observed with naturally occurring chlorophylls. In this work, a comprehensive description of the synthesis, characterization, and optical properties of meso-tetrakispentafluorophenylporphodilactone isomers is first reported. The ?-dilactone moieties are found to lie at opposite pyrrole positions (trans- and cis-configurations are defined by the relative orientations of the carbonyl group when one lactone moiety is fixed), in accordance with earlier computational predictions (Gouterman, M. J. Am. Chem. Soc. 1989, 111, 3702). The relative orientation of the ?-dilactone moieties has a significant influence on the electronic structures and photophysical properties. For example, the Qy band of trans-porphodilactone is red-shifted by 19 nm relative to that of the cis-isomer, and there is a 2-fold increase in the absorption intensity, which resembles the similar trends that have been reported for natural chlorophyll f and d. An in depth analysis of magnetic circular dichroism spectral data and TD-DFT calculations at the B3LYP/6-31G(d) level of theory demonstrates that the trans- and cis-orientations of the dilactone moieties have a significant effect on the relative energies of the frontier ?-molecular orbitals. Importantly, the biological behaviors of the isomers reveal their different photocytotoxicity in NIR region (>650 nm). The influence of the relative orientation of the ?-substituents on the optical properties in this context provides new insights into the electronic structures of porphyrinoids which could prove useful during the development of near-infrared absorbing photosensitizers.
The aim of this study was to determine the frequency of axillary lymph node (ALN) metastasis of early breast cancers by evaluating the status of DARC, D6 and CCX-CKR and the levels of VEGF and MMP-9. The status of DARC, D6 and CCX-CKR and the levels VEGF and MMP-9 were evaluated in ALN- (n = 130) and ALN + (n = 88) patients with T1 breast cancer by immunohistochemical staining. For ALN, likelihood ratio ? (2)-tests were used for univariate analysis and logistic regression for multivariate analysis. Univariate analysis identified the nuclear grade, VEGF and MMP-9 expression and absence of DARC, D6 and CCX-CKR as predictors of ALN involvement. When combining the three receptors (DARC, D6 and CCX-CKR) together, tumors with multiple absence (multi-absence, any two or three loss) had a higher likelihood of being ALN positive than non-multi-absence (coexpression of any two or three) tumors (56.2 vs. 27.9 %, P < 0.001). The final multivariate logistic regression revealed nuclear grade, VEGF, MMP-9 and non-multi-absence versus multi-absence to be independent predictors of ALN involvement; the odds ratio (OR) and 95 % CI for non-multi-absence tumors versus multi-absence were 0.469 (0.233-0.943). Multi-absence was also associated with the involvement of four or more lymph nodes among ALN + tumors. Moreover, tumors with multi-absence had higher VEGF (78.1 vs. 50.0 %, P < 0.001) and MMP-9 (81.3 vs. 36.1 %, P < 0.001) expression than non-multi-absence tumors. Our data highlight that the absence of DARC, D6 and CCX-CKR in combination, which is associated with higher VEGF and MMP-9 expression, predicts the presence and extent of ALN metastasis in breast cancer.
In the title compound, C18H22O4, the cyclo-hexane and cyclo-hexa-none rings adopt normal chair and half-chair conformations, respectively. The dioxolane ring is almost planar, with an r.m.s. deviation of 0.094?(3)?Å. In the crystal, mol-ecules are connected by O-H?O hydrogen bonds, forming 21 helical chains along the a-axis direction. The chains are further connected by C-H?O hydrogen bonds.
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.
By taking semiconductors with different band-gap energies as the active layers and controlling the electron-hole recombination region through the electric field, bias-polarity dependent ultraviolet/visible switchable light-emitting devices have been realized in Au/MgO/Mg0.49Zn0.51O/MgxZn1-xO/n-ZnO structures, of which the emission bands can be switched from the ultraviolet region to the orange region by changing the polarity of the applied bias. The results reported here may provide a feasible idea to multicolor-switchable light-emitting devices.
Intrauterine devices (IUD) are the most common method of reversible birth control used worldwide. Adolescents infrequently have uterine perforation caused by IUD, hampering both the diagnosis and treatment. Herein, we report a case of uterine perforation in an 18-year-old primipara after insertion of an IUD that possessed memory function (AiMu MCu). The patient presented with vomiting and abdominal pain after insertion of an AiMu MCu IUD, was treated via laparoscopy and had a full recovery. The present case indicated that uterine perforation caused by an AiMu MCu IUD may occur as a rare complication and that uterine perforation can occur in an adolescent. Clinicians might consider a diagnosis of uterine perforation in an adolescent reporting vomiting and abdominal pain after IUD insertion. Laparoscopy could be a reasonable treatment option for such patients.
This review focuses on classifying different types of long wavelength absorbing BODIPY dyes based on the wide range of structural modification methods that have been adopted, and on tabulating their spectral and photophysical properties. The structure-property relationships are analyzed in depth with reference to molecular modeling calculations, so that the effectiveness of the different structural modification strategies for shifting the main BODIPY spectral bands to longer wavelengths can be readily compared, along with their effects on the fluorescence quantum yield (?F) values. This should facilitate the future rational design of red/NIR region BODIPY dyes for a wide range of different applications.
Although alpine meadows of Tibet are expected to be strongly affected by climatic warming, it remains unclear how soil organic C (SOC), total N (TN), ammonium N (NH4 (+)-N) , nitrate N (NO3 (+)-N), and dissolved organic C (DOC) and N (DON) respond to warming. This study aims to investigate the responses of these C and N pools to short-term experimental warming in an alpine meadow of Tibet. A warming experiment using open top chambers was conducted in an alpine meadow at three elevations (i.e., a low (4313 m), mid-(4513 m), and high (4693 m) elevation) in May 2010. Topsoil (0-20 cm depth) samples were collected in July-September 2011. Experimental warming increased soil temperature by ~1-1.4°C but decreased soil moisture by ~0.04 m(3) m(-3). Experimental warming had little effects on SOC, TN, DOC, and DON, which may be related to lower warming magnitude, the short period of warming treatment, and experimental warming-induced soil drying by decreasing soil microbial activity. Experimental warming decreased significantly inorganic N at the two lower elevations,but had negligible effect at the high elevation. Our findings suggested that the effects of short-term experimental warming on SOC, TN and dissolved organic matter were insignificant, only affecting inorganic forms.
Acute acalculous cholecystitis (AAC) is a rare complication of gastric surgery. The most commonly accepted concepts regarding its pathogenesis are bile stasis, sepsis and ischemia, but it has not been well described how to identify and manage this disease in the early stage. We report three cases of AAC in elderly patients immediately after gastric surgery, which were treated with three different strategies. One patient died 42 d after emergency cholecystectomy, and the other two finally recovered through timely cholecystostomy and percutaneous transhepatic gallbladder drainage, respectively. These cases informed us of the value of early diagnosis and proper treatment for perioperative AAC after gastric surgery. We further reviewed reported cases of AAC immediately after gastric operation, which may expand our knowledge of this disease.
Microrna-143 (miR-143) has been suggested to be a tumor suppressor, yet its role in hematological tumors has not been determined. Thus, we aimed to explore the expression and function of miR-143 in leukemia cells. miR-143 expression was assessed in bone marrow samples from 63 leukemia patients and 15 healthy controls using q-PCR, and its correlation with DNMT3A expression was determined. In addition, after lentiviral-mediated miR-143 overexpression, K562 cell proliferation was evaluated using CCK-8 analysis; cell cycle progression and apoptosis were determined using flow cytometry. The expression of Bcl-2 and pro-caspase-3 and -9 was assessed by q-PCR and western blot analysis, respectively. Leukemia patients had significantly lower relative miR-143 expression than healthy controls (P=0.004), and the expression levels of miR143 and DNMTA3A were negatively correlated (r=-0.663, P=0.001). Overexpression of miR-143 decreased DNMT3A mRNA and protein expression, and significantly reduced K562 cell proliferation at 72 and 96 h (both P ? 0.018). In addition, reduced colony formation and cell cycle progression were observed upon miR-143 overexpression. Flow cytometric analysis revealed that the early apoptosis rate was higher in the miR-143 group than the rate in the NC group. Bcl-2 mRNA expression and pro-caspase-3 and -9 protein expression were reduced in the miR-143-expressing cells. These findings suggest that miR-143 plays an important role in leukemia cell proliferation and apoptosis, possibly through silencing of DNMT3A. Further studies are necessary to determine the prognostic value and therapeutic potential of targeting miR-143.
To conduct a preliminary evaluation of the use of two-dimensional (2D) enhanced multiecho T2*-weighted angiography (ESWAN) sequence for detection and quantification of siderotic nodules (SNs) in patients with liver disease.
The synthesis and properties of phosphorus(V) 5,10,15-tris(4-methoxycarbonylphenyl)corrole (1) have been investigated, and its potential utility for bioimaging applications in living cells has been explored. As would normally be anticipated for corrole complexes, the intensity of the Q(0,0) bands of 1 is greater than those of comparable phosphorus(V) tetraphenylporphyrins, but the ?F values (0.25 for 1) are found to be comparable. A detailed analysis of the electronic structure of the complex was carried out by comparing electronic absorption and MCD spectral data to the results of TD-DFT calculations. The meso-aryl substituents, which enhance the lipophilicity of 1 and hence result in its localization in intracellular membranes during HeLa cell experiments, are predicted to result in a narrowing of the HOMO-LUMO gap and hence a red shift of the Q(0,0) bands toward the optical window in biological tissues.
Two stable core-modified rubyrins bearing one and two dithienylethene (DTE) units (1 and 2) have been synthesized. With one "closed-form" DTE unit, 1 shows aromaticity associated with its conjugated circuit of 26 ?-electrons. In contrast, rubyrin 2 containing one "open-form" DTE unit has nonaromatic properties.
Well-aligned ZnO nanowires have been prepared on sapphire substrate, and structural and optical characterizations indicate that the nanowires are of single crystalline and have relatively high luminescent quality. By employing the ZnO nanowires as an active layer, p-Zn0.68Mg0.32O:N/n-ZnO nanowire heterostructure light-emitting devices (LEDs) have been fabricated. The LEDs show pure ultraviolet emission when a forward bias is applied, while the deep-level emission frequently observed in ZnO p-n junctions is almost totally invisible. The devices can work continuously for over 27 h under the injection of a current density of 500 mA/cm2, indicating their good stability.
Sapovirus has been accepted as a major cause of acute gastroenteritis worldwide. It can affect all age groups, ranging from young adults to the elderly, while little is known about the epidemiological patterns and genetic characteristics of sapovirus infections in China.
Gastric cancer with para-aortic lymph node (PAN) involvement is regarded as advanced disease, and only chemotherapy is recommended from the guidelines. In unresectable cases, neoadjuvant chemotherapy could prolong survival if conversion to resectability could be achieved.
An orange-red [Ru(bpy)3]2+ -DNA-CU2 composite film (bpy = 2,2-bipyridine) was fabricated on an indium-tin (ITO) surface based on electrostatic interactions among [Ru(bpy)3]2+, DNA and Cu2+ by using self-standing cast methods. The photoinduced electron transfer (PET) properties of the resultant composite film mediated by DNA were studied by means of steady-state and time-resolved fluorescence spectroscopy, UV-visible absorption spectroscopy, fluorescence microscopic imaging and scan electron microscopy. The [Ru(bpy)3]2+ -DNA-Cu2+ composite film with molar ratio of 10:20:1 shows an obvious absorption band (450 nm) and an intense emission peak (lamda(em) = 595 nm), whose emission exhibits a single-exponential decay with tau = 188.6 ns and is quenched by Cu2+ via DNA-mediated PET mechanism, indicating that the quenching constant is 6.94 x 10(3) L x mol(-1) and quenching rate constant is 3.80 x 10(10) L x mol(-1) x s(-1). The increasing molar ratio of Cu2+ in composite films (10-fold) leads to an 11 nm blue-shift of the emission peak, which is dramatically weakened by Cu2+ via a static quenching mechanism. In addition, compared with the emission quenching of DNA-[Ru(bpy)2 (tatp)]2+ (tatp = 1, 4, 8, 9-tetra-aza-triphenylene) tuned by Cu2+, which is present either in solutions or in composite films, Cu2+ only quenches the emission of [Ru(bpy)3]2+ bound to DNA via an electrostatic interaction mode in composite films.
Spatiotemporal control of singlet oxygen ((1)O2) release is a major challenge for photodynamic therapy (PDT) against cancer with high therapeutic efficacy and minimum side effects. Here a selenium-rubyrin (NMe2Se4N2)-loaded nanoparticle functionalized with folate (FA) was designed and synthesized as an acidic pH-activatable targeted photosensitizer. The nanoparticles could specifically recognize cancer cells via the FA-FA receptor binding and were selectively taken up by cancer cells via receptor-mediated endocytosis to enter lysosomes, in which NMe2Se4N2 was activated to produce (1)O2. The pH-controllable release of (1)O2 specially damaged the lysosomes and thus killed cancer cells in a lysosome-associated pathway. The introduction of selenium into the rubyrin core enhanced the (1)O2 generation efficiency due to the heavy atom effect, and the substitution of dimethylaminophenyl moiety at meso-position led to the pH-controllable activation of NMe2Se4N2. Under near-infrared (NIR) irradiation, NMe2Se4N2 possessed high singlet oxygen quantum yield (??) at an acidic pH (?? = 0.69 at pH 5.0 at 635 nm) and could be deactivated at physiological pH (?? = 0.06 at pH 7.4 at 635 nm). The subcellular location-confined pH-activatable photosensitization at NIR region and the cancer cell-targeting feature led to excellent capability to selectively kill cancer cells and prevent the damage to normal cells, which greatly lowered the side effects. Through intravenous injection of FA-NMe2Se4N2 nanoparticles in tumor-bearing mice, tumor elimination was observed after NIR irradiation. This work presents a new paradigm for specific PDT against cancer and provides a new avenue for preparation of highly efficient photosensitizers.
This study was aimed to quantitatively detect the levels of microRNA-193b(miR-193b) in leukemia patients and explore its significance. Real time fluorescent quantitative PCR was used to detect the relative expression level of miR-193b. The expression changes of miR-193b in various types of leukemia were analyzed. Then the relationship among miR-193b expression, parts of laboratory index and the response to chemotherapy was analyzed as well. The results showed that miR-193b expression level in acute promyelocytic leukemia (APL) and chronic myeloid leukemia (CML) patients was not lower than that in normal group (P > 0.05). Except for APL, miR-193b expression level in acute myeloid leukemia (AML) patients was lower than that in normal group (P < 0.05). In AML (except for APL) patients, there was no correlation between white blood cell count (P > 0.05), the expression of CD34 (P > 0.05) and miR-193b expression level, but there was negative correlation between chemotherapy response and miR-193b expression level (P < 0.05). It is concluded that miR-193b expression level may be correlated with susceptibility of cells to chemotherapy in AML (except for APL) patients. miR-193b maybe become a new target in AML (except for APL) therapy.
A 2,6-distyryl-substituted boradiazaindacene (BODIPY) dye and a new series of 2,6-p-dimethylaminostyrene isomers containing both ?- and ?-position styryl substituents were synthesized by reacting styrene and p-dimethylaminostyrene with an electron-rich diiodo-BODIPY. The dyes were characterized by X-ray crystallography and NMR spectroscopy and their photophysical properties were investigated and analyzed by carrying out a series of theoretical calculations. The absorption spectra contain markedly redshifted absorbance bands due to conjugation between the styryl moieties and the main BODIPY fluorophore. Very low fluorescence quantum yields and significant Stokes shifts are observed for 2,6-distyryl-substituted BODIPYs, relative to analogous 3,5-distyryl- and 1,7-distyryl-substituted BODIPYs. Although the fluorescence of the compound with ?-position styryl substituents on both pyrrole moieties and one with both ?- and ?-position substituents was completely quenched, the compound with only ?-position substituents exhibits weak emission in polar solvents, but moderately intense emission with a quantum yield of 0.49 in hexane. Protonation studies have demonstrated that these 2,6-p-dimethylaminostyrene isomers can be used as sensors for changes in pH. Theoretical calculations provide strong evidence that styryl rotation and the formation of non-emissive charge-separated S1 states play a pivotal role in shaping the fluorescence properties of these dyes. Molecular orbital theory is used as a conceptual framework to describe the electronic structures of the BODIPY core and an analysis of the angular nodal patterns provides a reasonable explanation for why the introduction of substituents at different positions on the BODIPY core has markedly differing effects.
MgZnO heterostructure light-emitting devices (LEDs) have been fabricated from p-Mg(0.35)Zn(0.65)O/n-Mg(0.20)Zn(0.80)O structures, and the p-type Mg(0.35)Zn(0.65)O film was realized using a lithium-nitrogen codoping method. Obvious ultraviolet emission peaked at around 355 nm dominates the electroluminescence (EL) spectra of the device at room temperature, which comes from the near-band-edge emission of the n-type Mg(0.20)Zn(0.80)O film. This is the first report on MgZnO heterostructured LEDs and the shortest EL emission ever reported in ZnO-based p-n junction LEDs to the best of our knowledge.
A novel selective fluorescent chemosensor has been synthesized with a phenanthrene-fused dipyrromethene structure. Selective binding of Cu(2+) by results in a complex that displays high selectivity and sensitivity for H2S. The signal transduction occurs via reversible formation-separation of the complex and CuS. Its potential utility for biological applications was confirmed by fluorescence imaging of H2S in live cells.
DNA methylation and histone deacetylation play important roles in the occurrence and development of cancers by inactivating the expression of tumor suppressors, including p16(INK4a), a cyclin-dependent kinase inhibitor. The present study investigated the effect of epigallocatechin-3-gallate (EGCG) alone or in combination with trichostatin A (TSA) on p16(INK4a) gene expression and growth in human malignant lymphoma CA46 cells. CA46 cell viability and cell cycle were analyzed; methylation of the p16(INK4a) gene was assessed by nested methylation-specific PCR (n-MSP). p16(INK4a )mRNA and protein expression was determined by real-time quantitative PCR and western blot analyses, respectively. Both EGCG and TSA alone inhibited CA46 cell proliferation; the combined treatment (6 µg/ml EGCG and 15 ng/ml TSA) significantly reduced CA46 cell proliferation from 24 to 96 h (all P<0.001). Cells treated with 24 µg/ml EGCG or the combination treatment (6 µg/ml EGCG and 15 ng/ml TSA) had lower proliferative indices when compared to the other groups. Co-treatment with EGCG and TSA decreased p16(INK4a) gene methylation, which coincided with increased p16(INK4a) mRNA and protein expression. Thus, EGCG and TSA synergistically reactivate p16(INK4a) gene expression in part through reducing promoter methylation, which may decrease CA46 cell proliferation.
Zinc oxide (ZnO) nanocolumns have been prepared by a metal-organic chemical vapor deposition technique, and structural and optical characterization reveal that the nanocolumns have high crystalline and luminescent qualities. Au/MgO/ZnO/In structured Schottky diodes have been fabricated from the nanocolumns. An intense emission can be detected from the diodes under the drive of bias voltage, and the output power can reach 3.7 ?W. The intense emission comes from both the high crystalline and luminescent qualities of the ZnO nanocolumns, and the ideal Schottky contact formed in the Au/MgO/ZnO/In structures.
True tool use has been documented in some bird species, but to our knowledge, it has not been shown in woodpeckers. Here, we investigated the ability of Picoides major to open nuts of Juglans mandshurica by consistently inserting walnuts between tree branches in a specific position that facilitated nut opening. As seen in these birds, we showed that woodpeckers removed 96 % of the nuts of J. mandshurica from experimental seed trays and inserted each nut in a precise position that specifically allowed nut cracking. When we inserted nuts in an alternative position, woodpeckers manipulated and repositioned nuts to allow nut opening. In contrast, when we inserted the nuts in positions preferred for nut opening, woodpeckers did not alter their position and instead opened the nuts. We suggest that the origin of this behavior, as in other forms of tool use, likely requires a higher cognitive ability in these birds.
In this paper, a novel core-modified porphyrin with meso-aryl substituents and phenanthrene-fused pyrrole rings (N2S2-OR) is synthesized. Scanning tunneling microscopy (STM) has been used to probe its self-assembly behavior on a highly-oriented pyrolytic graphite (HOPG) surface. Our STM results have shown that there is an obvious solvent-dependent self-assembly for the surface-confined target molecules. In n-tetradecane, N2S2-OR assembles into a perfect alternating structure. At the 1-phenyloctane-graphite interface, disordered structures are formed and nonperiodic alternation is observed, whereas the target molecule in 1-heptanoic acid is assumed to form homogeneous close-packed monolayers with no alternating. Interestingly, such solvent-dependent supramolecular assembled behavior also involves the structural transformation of the backbone of the core-modified porphyrin derivative from saddle to reversed-saddle in these three solvents with different polarities.
ORC (origin recognition complex) serves as the initiator for the assembly of the pre-RC (pre-replication complex) and the subsequent DNA replication. Together with many of its non-replication functions, ORC is a pivotal regulator of various cellular processes. Notably, a number of reports connect ORC to numerous human diseases, including MGS (Meier-Gorlin syndrome), EBV (Epstein-Barr virus)-infected diseases, American trypanosomiasis and African trypanosomiasis. However, much of the underlying molecular mechanism remains unclear. In those genetic diseases, mutations in ORC alter its function and lead to the dysregulated phenotypes; whereas in some pathogen-induced symptoms, host ORC and archaeal-like ORC are exploited by these organisms to maintain their own genomes. In this review, I provide detailed examples of ORC-related human diseases, and summarize the current findings on how ORC is involved and/or dysregulated. I further discuss how these discoveries can be generalized as model systems, which can then be applied to elucidating other related diseases and revealing potential targets for developing effective therapies.
The efficacy and tolerability of two different schedules of paclitaxel, carboplatin, and trastuzumab (PCarH) for HER2-positive, locally aggressive (stage IIB-IIIC) breast cancers were evaluated in this phase II trial.
The concentrations of PM?.? carbon fractions in rural, urban, tunnel and remote environments were measured using the IMPROVE thermal optical reflectance (TOR) method. The highest OC1 and EC1 concentrations were found for tunnel samples, while the highest OC2, OC3, and OC4 concentrations were observed for urban winter samples, respectively. The lowest levels of most carbon fractions were found for remote samples. The percentage contributions of carbon fractions to total carbon (TC) were characterized by one peak (at rural and remote sites) and two peaks (at urban and tunnel sites) with different carbon fractions, respectively. The abundance of char in tunnel and urban environments was observed, which might partly be due to traffic-related tire-wear. Various percentages of optically scattering OC and absorbing EC fractions to TC were found in the four different environments. In addition, the contribution of heating carbon fractions (char and soot) indicated various warming effects per unit mass of TC. The ratios of OC/EC and char/soot at the sites were shown to be source indicators. The investigation of carbon fractions at different sites may provide some information for improving model parameters in estimating their radiative effects.
The synthesis and characterization of a highly photostable bromo-substituted BODIPY dye (I) fused-ring-expanded with thienopyrrole moieties is reported. The results of MTT assays and flow cytometric analyses in living HeLa cells demonstrate that I has a high singlet oxygen quantum yield (?? = 0.63) and exhibits photocytotoxicity upon irradiation in the NIR region making it potentially suitable for use in PDT.
Attachments of Acidithiobacillus ferrooxidans ATCC 23270 onto elemental sulfur, quartz and complex chalcopyrite were investigated by analysis of its extracellular polymeric substances as well as applying Langmuir and Freundlich equations. The two equations fitted the adsorption equilibrium data with significant correlation coefficient over 0.9. This indicated that bacterial attachment is complicated and involves Langmuir and Freundlich characterizations. Sulfur-grown cells showed the highest affinity for the three solid substrates. The investigated complex chalcopyrite possessed a higher maximum adsorption capacity for A. ferrooxidans than elemental sulfur or quartz. The Freundlich fitting parameters suggested that quartz had a weaker adsorption capacity and smaller adsorption areas than elemental sulfur or the complex chalcopyrite. It is not the content of total carbohydrates or proteins in EPS but their ratios that determine the affinity differences between cells and substrates.
A general strategy for constructing high-effective upconversion nanocapsules based on triplet-triplet annihilation (TTA) was developed by loading both sensitizer and annihilator into BSA-dextran stabilized oil droplets. This strategy can maintain high translational mobility of the chromophores, avoid luminescence quenching of chromophore by aggregation, and decrease the O2-induced quenching of TTA-based upconversion emission. Pt(II)-tetraphenyl-tetrabenzoporphyrin (PtTPBP) and BODIPY dyes (BDP-G and BDP-Y with the maximal fluorescence emission at 528 and 546 nm, respectively) were chosen as sensitizer/annihilator couples to fabricate green and yellow upconversion luminescent emissive nanocapsules, named UCNC-G and UCNC-Y, respectively. In water under the atmospheric environment, interestingly, UCNC-G and UCNC-Y exhibit intense upconversion luminescence (UCL) emission (?ex = 635 nm) with the quantum efficiencies (?UCL) of 1.7% and 4.8%, respectively, whereas very weak UCL emission (?UCL < 0.1%) was observed for the corresponding previous reported SiO2-coating nanosystems because of aggregation-induced fluorescence quenching of annihilators. Furthermore, application of theses upconversion nanocapsules for high-contrast UCL bioimaging in vivo of living mice without removing the skin was demonstrated under 635-nm excitation with low power density of 12.5 mW cm(-2).
This paper first reports on the condensation of DNA to a tightly packed state induced by a V-shaped di-ruthenium(II) complex [Ru2(bpy)4(mbpibH2)]Cl4 (bpy=2,2-bipyridine and mbpibH2=1,3-bis([1,10]phenanthroline[5,6-d]imidazol-2-yl)benzene), which binds to the groove of herring sperm DNA (hsDNA) with the binding constant of 2.0×10(7)M(-1) (0.05M NaCl, pH7.2). The di-Ru(II) complex is found to induce the condensation of both hsDNA to long chain-like particle clusters and originally circular plasmid pBR322 DNA to particulate structure under neutral conditions. More interestingly, the presence of NaCl has a significant impact on the condensation and decondensation of DNA upon incorporation of [Ru2(bpy)4(mbpibH2)](4+), representing tunable luminescence characteristics by NaCl. High salt concentration facilitates the decondensation of DNA-[Ru2(bpy)4(mbpibH2)](4+) adducts. The results from this study offer an effective method to control the condensation and decondensation of DNA upon incorporation of luminescent concentrators.
To evaluate the efficacy and safety of neoadjuvant chemotherapy in patients with locally advanced gastric cancer, and to analyze the relevant factors of recurrent death of gastric cancer after adjuvant chemotherapy.
Although differences in food-hoarding tactics both reflect a behavioral response to cache pilferage among rodent species and may help explain their coexistence, differentiation in cache pilfering abilities among sympatric rodents with different hoarding strategies is seldom addressed. We carried out semi-natural enclosure experiments to investigate seed hoarding tactics among three sympatric rodent species (Tamias sibiricus, Apodemus peninsulae and Clethrionomys rufocanus) and the relationship of their pilfering abilities at the inter- and intraspecific levels. Our results showed that T. sibiricus exhibited a relatively stronger pilfering ability than A. peninsulae and C. rufocanus, as indicated by its higher recovery rate of artificial caches. Meanwhile A. peninsulae showed a medium pilfering ability and C. rufocanus displayed the lowest ability. We also noted that both cache size and cache depth significantly affected cache recovery in all three species. T. sibiricus scatter-hoarded more seeds than it larder-hoarded, A. peninsulae larder-hoarded more than scatter-hoarded, and C. rufocanus acted as a pure larder-hoarder. In T. sibiricus, individuals with lower pilfering abilities tended to scatter hoard seeds, indicating an intraspecific variation in hoarding propensity. Collectively, these results indicated that sympatric rodent species seem to deploy different food hoarding tactics that allow their coexistence in the temperate forests, suggesting a strong connection between hoarding strategy and pilfering ability.
Rotavirus is a major cause of acute gastroenteritis in infants and young children, while its role as a pathogen in adults has long been underappreciated. In order to describe the epidemiological patterns and genetic characteristics of rotavirus causing sporadic acute gastroenteritis in adults, hospital-based surveillance of rotavirus infections was conducted in Shanghai, China, between June 2010 and May 2011. Stool specimens were collected from outpatients with acute gastroenteritis admitted to three local hospitals. Rotavirus was detected using a colloidal gold test device. G and P genotyping were performed by multiplex PCR assays, and the VP7 gene of G9 strains were sequenced for further genetic characterization. Of 1,479 adult diarrheal stool samples examined during the 1-year surveillance period, 138 (9.3 %) were found to be rotavirus positive. G1 appeared to be the predominant genotype (35.5 %), suggesting a shift from genotype G3 to G1 in the study population in Shanghai. Meanwhile, a high frequency of genotype G9 (27.5 %) was also observed, and G9 was also predominant (38.1 %) in the small number of children (n=123) involved in the present study. Other specificities detected in adults were G2 (12.3 %) and G3 (13.8 %). For P genotyping, only two types, P and P, were detected. P was dominant in both children and adults. Sequence and phylogenetic analysis revealed that these strains could be divided into two different groups, with clustering within G9 lineage 3 and the subcluster of Japanese and Chinese G9 strains, respectively. In comparison to the previous data, G9 strains established themselves in a short time span as an important genotype in Shanghai, China.
The process of metastases involves the dissociation of cells from the primary tumor, penetration into the basement membrane, invasion, and exiting from the vasculature to seed and colonize distant tissues. miR-200a is involved in this multistep metastatic cascade. This study aimed to test the hypothesis that miR-200a promotes metastasis through increased anoikis resistance in breast cancer.
The long noncoding MALAT1 RNA is upregulated in cancer tissues and its elevated expression is associated with hyper-proliferation, but the underlying mechanism is poorly understood. We demonstrate that MALAT1 levels are regulated during normal cell cycle progression. Genome-wide transcriptome analyses in normal human diploid fibroblasts reveal that MALAT1 modulates the expression of cell cycle genes and is required for G1/S and mitotic progression. Depletion of MALAT1 leads to activation of p53 and its target genes. The cell cycle defects observed in MALAT1-depleted cells are sensitive to p53 levels, indicating that p53 is a major downstream mediator of MALAT1 activity. Furthermore, MALAT1-depleted cells display reduced expression of B-MYB (Mybl2), an oncogenic transcription factor involved in G2/M progression, due to altered binding of splicing factors on B-MYB pre-mRNA and aberrant alternative splicing. In human cells, MALAT1 promotes cellular proliferation by modulating the expression and/or pre-mRNA processing of cell cycle-regulated transcription factors. These findings provide mechanistic insights on the role of MALAT1 in regulating cellular proliferation.
The synthesis of a novel aza-BODIPY dye functionalized with fused pyrazine rings, suitable for use as a selective colorimetric and fluorometric sensor for NH(4)(+), is outlined. In addition to significant fluorescence quenching, an obvious colorimetric change from green to red-pink is observed enabling facile "naked-eye" detection of NH(4)(+).
We present spatial light interference tomography (SLIT), a label-free method for 3D imaging of transparent structures such as live cells. SLIT uses the principle of interferometric imaging with broadband fields and combines the optical gating due to the micron-scale coherence length with that of the high numerical aperture objective lens. Measuring the phase shift map associated with the object as it is translated through focus provides full information about the 3D distribution associated with the refractive index. Using a reconstruction algorithm based on the Born approximation, we show that the sample structure may be recovered via a 3D, complex field deconvolution. We illustrate the method with reconstructed tomographic refractive index distributions of microspheres, photonic crystals, and unstained living cells.
The goal of this study was to investigate the function of phosphatidylethanolamine-binding protein 4 (PEBP4) in invasion and metastasis of non-small cell lung cancer (NSCLC). PEBP4 mRNA and protein expression in 56 cases of NSCLC tissues were detected using RT-PCR and Western blot, and the relationship between PEBP4 expression and invasion and metastasis of NSCLC was analyzed. The change in the invasive ability of human NSCLC cell line HCC827 was observed after knocking down PEBP4 expression using RNA interference. PEBP4 mRNA and protein expression in cancer tissues of patients with lymph node metastasis were significantly higher than those in patients without lymph node metastasis (p < 0.05). PEBP4 expression significantly decreased in HCC827 cells after transfection with PEBP4 siRNA (p < 0.01), and the number of HCC827 cells that migrated through Transwell chambers was significantly lower than that of non-transfected control and transfected control cells (p < 0.01). PEBP4 over-expression may promote the invasion and metastasis of NSCLC.
Ternary lead magnesium niobate-lead zirconate titanate system 0.4Pb(Mg(1/3)Nb(2/3))O(3)-0.25PbZrO(3)-0.35PbTiO(3) (40PMN-25PZ-35PT) thin film with a thickness of 1.5 ?m was grown on Pt(111)/Ti/SiO(2)/Si substrate via chemical solution deposition. X-ray diffraction and transmission electron microscopy results suggested the film obtained was highly (111)-oriented. The remanent polarization and coercive electric field of the film were found to be 25.5 ?C/cm(2) and 51 kV/cm, respectively. In addition, at 1 kHz, the dielectric constant was measured to be 1960 and the dielectric loss 0.036. The film was observed to undergo a diffuse ferroelectric-to-paraelectric phase transition at around 209°C. The leakage current appeared to depend on the voltage polarity. If the Au electrode was biased positively, the leakage current was dominated by the Schottky emission mechanism. When the Pt electrode was biased positively, the conduction current curve showed an ohmic behavior at a low electric field and space-charge-limited current characteristics at a high electric field.
We performed a retrospective study of 856 breast cancer patients in our hospital, to compare the therapeutic effect of pirarubicin with cyclophosphamide and 5-fluorouracil (CPF) with the standard epirubicin-based regimen (CEF) in adjuvant treatment of breast cancer. Patients were given cyclophosphamide and 5-fluorouracil 500 mg/m(2) each, and either pirarubicin 40 mg/m(2) or epirubicin 75-100 mg/m(2) , every 3 weeks, six cycles. A total of 233 patients used CPF and 623 patients used CEF regimen. The clinical and pathologic characteristics were well balanced between the two groups. The median follow-up time was 41 months, relapse-free survival (RFS) and overall survival (OS) were similar in both groups, p = 0.561 and p = 0.783, respectively. No treatment-related congestive heart failure or death was observed in either group. Regardless of chemotherapy regimens, only tumor size, lymph node status, and ER status were predictive factors in multivariate survival analysis. In stratified analysis, the total hazard ratio estimate for RFS was 0.876 (95% CI 0.561-1.369; p = 0.562), not in favor of either regimen, and no significant difference was observed in any subgroups between the two treatment arms. Our study verified that 3 weekly CPF gives the same efficacy and safety as the standard CEF; both CPF and CEF are the effective regimens that can be used in adjuvant chemotherapy of breast cancer.
In eukaryotes, higher order chromatin structure governs crucial cellular processes including DNA replication, transcription and post-transcriptional gene regulation. Specific chromatin-interacting proteins play vital roles in the maintenance of chromatin structure. We have identified BEND3, a quadruple BEN domain-containing protein that is highly conserved amongst vertebrates. BEND3 colocalizes with HP1 and H3 trimethylated at K9 at heterochromatic regions in mammalian cells. Using an in vivo gene locus, we have been able to demonstrate that BEND3 associates with the locus only when it is heterochromatic and dissociates upon activation of transcription. Furthermore, tethering BEND3 inhibits transcription from the locus, indicating that BEND3 is involved in transcriptional repression through its interaction with histone deacetylases and Sall4, a transcription repressor. We further demonstrate that BEND3 is SUMOylated and that such modifications are essential for its role in transcriptional repression. Finally, overexpression of BEND3 causes premature chromatin condensation and extensive heterochromatinization, resulting in cell cycle arrest. Taken together, our data demonstrate the role of a novel heterochromatin-associated protein in transcriptional repression.
The purpose of this study was to detect the methylation of the RUNX3 gene promoter in non-small cell lung cancer (NSCLC) tissue and to explore the association of this methylation with clinical features of NSCLC. In 58 samples of NSCLC tissue and normal adjacent tissue, methylation of the RUNX3 gene promoter was measured by methylation-specific polymerase chain reaction. Correlation with clinicopathological characteristics was assessed. The results demonstrated that RUNX3 gene promoter methylation was present in 26/58 (44.8%) of NSCLC tissue samples and 10/58 (17.2%) of normal tissue samples, and that the difference was statistically significant between the two groups (?(2)=10.311, p=0.001). Significantly, methylation of the RUNX3 gene promoter correlated with clinical stage, lymph node metastasis and the degree of differentiation (p<0.05) but not with age, gender, smoking history and pathological type (p>0.05). In conclusion, methylation of the RUNX3 gene promoter had a high relevance ratio in NSCLC tissue and correlated with clinical stage, lymph node metastasis and degree of differentiation; thus, this association may have clinical significance in NSCLC.
Determining the growth patterns of single cells offers answers to some of the most elusive questions in contemporary cell biology: how cell growth is regulated and how cell size distributions are maintained. For example, a linear growth in time implies that there is no regulation required to maintain homeostasis; an exponential pattern indicates the opposite. Recently, there has been great effort to measure single cells using microelectromechanical systems technology, and several important questions have been explored. However, a unified, easy-to-use methodology to measure the growth rate of individual adherent cells of various sizes has been lacking. Here we demonstrate that a newly developed optical interferometric technique, known as spatial light interference microscopy, can measure the cell dry mass of many individual adherent cells in various conditions, over spatial scales from micrometers to millimeters, temporal scales ranging from seconds to days, and cell types ranging from bacteria to mammalian cells. We found evidence of exponential growth in Escherichia coli, which agrees very well with other recent reports. Perhaps most importantly, combining spatial light interference microscopy with fluorescence imaging provides a unique method for studying cell cycle-dependent growth. Thus, by using a fluorescent reporter for the S phase, we measured single cell growth over each phase of the cell cycle in human osteosarcoma U2OS cells and found that the G2 phase exhibits the highest growth rate, which is mass-dependent and can be approximated by an exponential.
Deleterious mutations in several genes that are involved in repair of damage to DNA have been associated with an increased risk of breast cancer. Recent studies have shown sequence variants in two such genes, RAD50 and NBS1, which can be predisposed to breast cancer. The aim of this study is to elucidate the contribution of RAD50 and NBS1 germline mutations to the etiology of non-BRCA1/2 hereditary breast cancer in China. We conducted a mutational analysis of RAD50 and NBS1 in genomic DNA from 384 Chinese women with early-onset breast cancer and/or affected relatives. All the coding exons and adjacent intronic splice junction rejoins of RAD50 and NBS1 were screened using PCR-DHPLC and DNA sequencing analysis. Among all cases, no obviously deleterious mutations were observed in RAD50; one synonymous change c.102G>A at codon 34 and one single nucleotide polymorphism IVS9 + 19C>T were identified in NBS1. Furthermore, there was no remarkable difference in the allele frequency of NBS1 c.553G>C (E185Q) between cases (172/384) and controls (182/420). Our results exclude the possible role of RAD50 and NBS1 in familial breast cancer predisposition in Chinese women, and there is no evidence for the recommendation of RAD50 and NBS1 for genetic testing in China.
Seroma formation is one of the most common complications after breast cancer surgery. Various risk factors have been evaluated for their associations with the development of seromas in Western populations. However, similar data are not available in Chinese series. Therefore, we sought to investigate the potential risk factors for Chinese breast cancer patients.
Specialized complexes in eukaryotic cells recognize defined epigenetic histone marks to mediate chromatin organization. DNA replication, cell cycle progression and chromatin organization are intimately linked to one another. In addition to having roles in DNA replication initiation, the human Origin Recognition Complex (ORC) binds along with ORC-associated proteins ORCA/ LRWD1 to prominent transcriptional repressive lysine methylation marks and localizes to HP1-containing heterochromatic structures. In humans, Drosophila and Xenopus, ORC associates with HP1, and this interaction is crucial for heterochromatin organization. Further, several subunits of human ORC are required for centromere and telomere function and participate in chromosome segregation. The conserved function of ORC in replication initiation as well as in organization and maintenance of chromosome structure suggests that these cellular events are well coordinated.
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