556 results on '"Ping Zhou"'
Search Results
152. Adsorption of Hydrogen Isotopes on Micro- and Mesoporous Adsorbents with Orderly Structure.
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Xiao-Zhong Chu, Ya-Ping Zhou, Yu-Zhe Zhang, Wei Su, Yan Sun, and Li Zhou
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ADSORPTION (Chemistry) , *SILICON compounds , *SEPARATION (Technology) , *NONMETALS - Abstract
The equilibrium and dynamic adsorption data of H2and D2on different micro- and mesoporous adsorbents with orderly structure including 3A, 4A, 5A, Y, and 10X zeolites; carbon CMK-3; silica SBA-15; and so forth were collected. Critical effect of the nanodimension of adsorbents on the adsorption behavior of hydrogen and its isotopes is shown. The highest adsorption capacity was observed at pore size 0.7 nm, but equal or even larger isotope difference in the equilibrium adsorption was observed at larger pore sizes, whereas the largest isotope difference in the dynamic adsorption was observed at 0.5 nm. The adsorption rate of D2is larger than that of H2in microporous adsorbents, but the sequence could be switched over in mesoporous materials. Linear relationship was observed between the adsorption capacity for hydrogen and the specific surface area of adsorbents although the adsorbents are made of different material, which provides a convincing proof of the monolayer mechanism of hydrogen adsorption. The linear plot for microporous adsorbents has a larger slope than that for mesoporous adsorbents, which is attributed to the stronger adsorption potential in micropores. [ABSTRACT FROM AUTHOR]
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- 2006
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153. Generalized Two-Dimensional Correlation Analysis of NMR and Raman Spectra for Structural Evolution Characterizations of Silk Fibroin.
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Bing-Wen Hu, Ping Zhou, Isao Noda, and Qing-Xia Ruan
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NUCLEAR magnetic resonance spectroscopy , *HYDROGEN-ion concentration , *RAMAN effect , *PHYSICAL & theoretical chemistry - Abstract
Generalized two-dimensional (2D) correlation spectroscopy was used to characterize the structural evolution of silk fibroin as the pH changed from 6.8 to 4.8, demonstrating that the conformational transitions of silk fibroin are induced step by step as the pH decreases. 2D homo- and hetero-spectral correlation spectroscopy was used to establish the relationship between information extracted from NMR and Raman spectroscopy. This novel method reveals the structural evolution using two probes with different frequency scales (105-9Hz for nuclear spin motion and 1012-14Hz for molecular vibration motion), reflecting the different spatial scale sensitivity to the molecular conformational change. The transition order is identified as silk I state (helix dominant) → silk I intermediate state → silk II intermediate state → silk II state (-sheet dominant), as the pH decreases. The results may rationalize the silkworm spinning process, which undergoes the conformational transition steadily from the soluble helix state to the insoluble -sheet state as the pH decreases from the posterior to anterior glands. [ABSTRACT FROM AUTHOR]
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- 2006
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154. Cu(l) or Cu(l)-Cu(ll) Mixed-Valence Complexes of 2,4,6-Tri(2-pyridyl)-1 ,3,5-triazine: Syntheses, Structures, and Theoretical Study of the Hydrolytic Reaction Mechanism.
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Xiao-Ping Zhou, Dan Li, Shao-Liang Zheng, Xuanjun Zhang, and Tao Wu
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COORDINATION compounds , *HALIDES , *TRIAZINES , *POLYMERS , *METAL ions , *SUPRAMOLECULAR chemistry , *HYDROLYSIS - Abstract
The reactions of 2,4,6-tri(2-pyridyl)-1,3,5-triazine (tpt) with copper(l) halides under solvothermal or traditional conditions yielded two polymeric Cu(l) complexes [Cu2I2(tpt)]n (1) and [Cu3I3(tpt)]n (2), one mixed-valence Cu(l)-Cu(II) complex [Cu4Cl2I4(tpt)2] (3), and two Cu(II) complexes [CuBr(bpca)] (4) and [CuI(bpca)] (5) (bpca = bis(2-pyridylcarbonyl)-amine). Complex 1 is a zigzag chain with tpt in a bis-bipyridine-like coordination mode, whereas complex 2 with tpt chelating three Cu(l) cations is a ladderlike coordination polymer. Complex 3 is mixed-valence, with Cu(l) in a distorted tetrahedral geometry and Cu(II) in a distorted square pyramidal geometry, forming a ladderlike supramolecular chain. Complexes 4 and 5 are the products of in situ hydrolysis of tpt involving the oxidation of Cu(l). The synthesis and characterization of complex 1, 2, and 5 indicated that Cu(l) cannot promote the hydrolysis of tpt. The theoretical study shows that the main effect for hydrolysis of tpt is the electron-withdrawing effect of metal ions. [ABSTRACT FROM AUTHOR]
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- 2006
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155. pH effect on dynamic coating for capillary electrophoresis of DNA.
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Sheng-Bing Yu, Ping Zhou, Ai-Rong Feng, Xin-Cheng Shen, Zhi-Ling Zhang, and Ji-Ming Hu
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PH effect , *CAPILLARY electrophoresis , *DNA , *ATOMIC force microscopy , *FOURIER transform spectroscopy - Abstract
A buffer consisting of tris(hydroxymethyl)aminomethane, 2-( N-moropholino)ethanesulfonic acid (Mes) and EDTA with constant ion strength was used to investigate the effect of buffer pH on the dynamic coating behavior of poly( N-isopropylacrylamide) (PNIPAM) for DNA separation. The atomic force microscopy (AFM) image illustrated that PNIPAM in lower-pH buffer was much more efficient in covering a silica wafer than that in higher-pH buffer. The coating performance of PNIPAM was also quantitatively analyzed by Fourier transform IR attenuated total reflectance spectroscopy and by measuring the electroosmotic flow (EOF). These results indicated that the stability of the dynamic coating was dependent on the pH of the sieving matrix and was improved by reducing the pH to the weak-acid range. The lower pH of the sieving buffer may induce the polymer more efficiently to adsorb on the capillary wall to suppress EOF and DNA–capillary wall interaction for DNA separation. The enhanced dynamic coating capacity of PNIPAM in lower-pH buffer may be attributed to the hydrogen bonds between the hydroxyl groups of the silica surface and the oxygen atom of the carbonyl groups of PNIPAM. [ABSTRACT FROM AUTHOR]
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- 2006
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156. Size Effects in Electronic and Catalytic Properties of Unsupported Palladium Nanoparticles in Electrooxidation of Formic Acid.
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Wei Ping Zhou, Adam Lewera, Robert Larsen, Rich I. Masel, Paul S. Bagus, and Andrzej Wieckowski
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CATALYSIS , *NANOPARTICLES , *OXIDATION , *PALLADIUM - Abstract
We report a combined X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and chronoamperometry (CA) study of formic acid electrooxidation on unsupported palladium nanoparticle catalysts in the particle size range from 9 to 40 nm. The CV and CA measurements show that the most active catalyst is made of the smallest (9 and 11 nm) Pd nanoparticles. Besides the high reactivity, XPS data show that such nanoparticles display the highest core-level binding energy (BE) shift and the highest valence band (VB) center downshift with respect to the Fermi level. We believe therefore that we found a correlation between formic acid oxidation current and BE and VB center shifts, which, in turn, can directly be related to the electronic structure of palladium nanoparticles of different particle sizes. Clearly, such a trend using unsupported catalysts has never been reported. According to the density functional theory of heterogeneous catalysis, and mechanistic considerations, the observed shifts are caused by a weakening of the bond strength of the COOH intermediate adsorption on the catalyst surface. This, in turn, results in the increase in the formic acid oxidation rate to CO2(and in the associated oxidation current). Overall, our measurements demonstrate the particle size effect on the electronic properties of palladium that yields different catalytic activity in the HCOOH oxidation reaction. Our work highlights the significance of the core-level binding energy and center of the d-band shifts in electrocatalysis and underlines the value of the theory that connects the center of the d-band shifts to catalytic reactivity. [ABSTRACT FROM AUTHOR]
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- 2006
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157. Anion-Directed Assembly of Macrocycle and Helix.
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Xuanjun Zhang, Xiao-Ping Zhou, and Dan Li
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INTERMEDIATES (Chemistry) , *PROPERTIES of matter , *SOLUTION (Chemistry) , *ORGANIC compounds - Abstract
Self-assembly of the flexible ligand N,N‘-bis(3-pyridylmethyl)thiourea (bpt) with ZnCl2 and CdCl2 in the absence and presence of KSCN yielded a short series of novel complexes (1−4) with macrocyclic, helical, double-helical, and 1D polymeric structures. Different metal ions, hydrogen bonds, and counteranions play significant roles in the final crystal structures. The NCS- anion was found to favor the formation of helical structures, whereas the Cl- anion favored macrocycle formation in the present system. Photoluminescence (PL) measurement results revealed that complex 2 (Zn(bpt)(SCN)2) with a helical structure exhibits enhanced emissions compared to those of the ligand and other complexes. The anion-directed assembly as well as the interesting emissions may provide useful information for further design of metal−organic compounds with novel structures and properties. [ABSTRACT FROM AUTHOR]
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- 2006
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158. Mining and characterizing microsatellites from citrus ESTs.
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Chunxian Chen, Ping Zhou, Choi, Young A., Shu Huang, and Gmitter Jr, Fred G.
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MICROSATELLITE repeats , *CITRUS , *PLANT genetics , *CROP genetics , *PLANT gene mapping , *GENETIC polymorphisms , *GENOMICS - Abstract
Freely available computer programs were arranged in a pipeline to extract microsatellites from public citrus EST sequences, retrieved from the NCBI. In total, 3,278 bi- to hexa-type SSR-containing sequences were identified from 56,199 citrus ESTs. On an average, one SSR was found per 5.2 kb of EST sequence, with the tri-nucleotide motifs as the most abundant. Primer sequences flanking SSR motifs were successfully identified from 2,295 citrus ESTs. Among those, a subset (100 pairs) were synthesized and tested to determine polymorphism and heterozygosity between/within two genera, sweet orange ( C. sinensis) and Poncirus ( P. trifoliata), which are the parents of the citrus core mapping population selected for an international citrus genomics effort. Eighty-seven pairs of primers gave PCR amplification to the anticipated SSRs, of which 52 and 35 appear to be homozygous and heterozygous, respectively, in sweet orange, and 67 and 20, respectively, in Poncirus. By pairing the loci between the two intergeneric species, it was found that 40 are heterozygous in at least one species with two alleles (9), three alleles (28), or four alleles (3), and the remaining 47 are homozygous in both species with either one allele (31) or two alleles (16). These EST-derived SSRs can be a resource used for understanding of the citrus SSR distribution and frequency, and development of citrus EST-SSR genetic and physical maps. These SSR primer sequences are available upon request. [ABSTRACT FROM AUTHOR]
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- 2006
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159. An NMR Approach Applicable to Biomolecular Structure Characterization.
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Bing-wen Hu, Ping Zhou, Isao Noda, and Guang-zhi Zhao
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PROTEINS , *PEPTIDES , *BIOMOLECULES , *ORGANIC compounds , *POLYMERS , *MACROMOLECULES - Abstract
A generalized 2D correlation NMR (GEN2D-NMR) scheme capable of substantially reducing the experimental time for two-dimensional correlation NMR experiments is described. The experimental time used in GEN2D-NMR is shortened to less than one-tenth of that required in traditional double Fourier transform 2D-NMR (FT2D- NMIR) for a 13C-13C spin diffusion experiment for Nephila edulis spider threads. Experimentally, one needs to acquire many fewer points in GEN2D-NMR than that in FT2D-NMR in the evolution time domain. By keeping other acquisition pulse sequence and parameters the same in both methods, the GEN2D-NMR technique can produce a 2D-NMR spectrum using fewer points along the evolution time domain equivalent to that produced by the FT2D-NMR technique using more points. GEN2D- NMR would provide a significant advantage for those molecules that are difficult to highly isotropically label, such as proteins, polypeptides, and polymers, or those which become unstable in a prolonged measurement time. [ABSTRACT FROM AUTHOR]
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- 2005
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160. Characterization of phosphorus-releasing bacteria in a small eutrophic shallow lake, Eastern China
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Gen-Fu, Wu and Xue-Ping, Zhou
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FUNGUS-bacterium relationships , *RADIOACTIVE pollution of water , *PHOSPHORUS , *PROKARYOTES - Abstract
Abstract: Phosphorus contents and phosphorus-releasing bacteria were characterized in a small eutrophic lake, Eastern China. Total phosphorus and water soluable inorganic phosphate (WSIP) in water bodies were as high as the levels of hyper-eutrophic lakes. Calcium bound phosphate and organic phosphorus were 2 major forms of phosphorus existing in the sediments. Enumeration of inorganic phosphate-solubilizing bacteria (IPB) and organic phosphorus-mineralizing bacteria (OPB) with culture-dependent method showed that these bacterial groups were not very rich in the ecosystem. Molecular identification and phylogenetic analysis of the predominant IPB and OPB strains indicated that there existed various kinds of bacteria participating in the phosphorus release. Laboratory tests on phosphorus release abilities showed IPB strains could liberate more than 50μgml−1, while OPB strains produced less than 2μgml−1 WSIP every day. [Copyright &y& Elsevier]
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- 2005
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161. Mitochondria are involved in the neurogenic neuroprotection conferred by stimulation of cerebellar fastigial nucleus.
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Ping Zhou, Liping Qian, Zhou, Theresa, and Iadecola, Costantino
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MITOCHONDRIA , *DENTATE nucleus , *CEREBELLAR nuclei , *CELL nuclei , *CEREBRAL ischemia , *APOPTOSIS , *BRAIN - Abstract
Activation of neural pathways originating in the cerebellar fastigial nucleus (FN) protects the brain from the deleterious effects of cerebral ischemia and excitotoxicity, a phenomenon termed central neurogenic neuroprotection. The neuroprotection is, in part, mediated by suppression of apoptosis. We sought to determine whether FN stimulation exerts its anti-apoptotic effect through mitochondrial mechanisms. Mitochondria were isolated from the cerebral cortex of rats in which the FN was stimulated for 1 h (100 μA; 1 s on/1 s off), 72 h earlier. Stimulation of the dentate nucleus (DN), a brain region that does not confer neuroprotection, served as control. Mitochondria isolated from FN-stimulated rats exhibited a marked increase in their ability to sequester Ca2+ and an increased resistance to Ca2+-induced membrane depolarization and depression in respiration. FN stimulation also leads to reduction in the release in cytochrome c, induced either by Ca2+ or the mitochondrial toxin mastoparan. Furthermore, in brain slices, FN stimulation reduced the staurosporine-induced insertion of the pro-apoptotic protein Bax into the mitochondria, a critical step in the mitochondrial mechanisms of apoptosis. Collectively, these results provide evidence that FN stimulation protects the mitochondria from dysfunction induced by Ca2+ loading, and inhibits mitochondrial pathways initiating apoptosis. These mitochondrial mechanisms are likely to play a role in the neuroprotection exerted by FN stimulation. [ABSTRACT FROM AUTHOR]
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- 2005
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162. Extraction of Oxidized and Reduced Forms of Uranium from Contaminated Soils: Effects of Carbonate Concentration and pH.
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Ping Zhou and Baohua Gu
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URANIUM , *ACTINIDE elements , *CARBONATES , *OXIDATION , *GEOCHEMISTRY , *EARTH sciences - Abstract
Uranium may present in soil as precipitated, sorbed, complexed, and reduced forms, which impact its mobility and fate in the subsurface soil environment In this study, a uranium-contaminated soil was extracted with carbonate/bicarbonate at varying concentrations (0-1 M), pHs, and redox conditions in an attempt to evaluate their effects on the extraction efficiency and selectivity for various forms of uranium in the soil. Results indicate that at least three different forms of uranium existed in the contaminated soil: uranium(VI) phosphate minerals, reduced U(IV) phases, and U(VI) complexed with soil organic matter. A small fraction of U(VI) could be sorbed onto soil minerals. The mechanism involved in the leaching of U(VI) by carbonates appears to involve three processes which may act concurrently or independently: the dissolution of uranium-(VI) phosphate and other mineral phases, the oxidation-complexation of U(IV) under oxic conditions, and the desorption of U(VI)-organic matter complexes at elevated pH conditions. This study suggests that, depending on site-specific geochemical conditions, the presence of small quantities of carbonate/bicarbonate could result in a rapid and greatly increased leaching and the mobilization of U(VI) from the contaminated soil. Even the reduced U(IV) phases (only sparingly soluble in water) are subjected to rapid oxidation and therefore potential leaching into the environment. [ABSTRACT FROM AUTHOR]
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- 2005
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163. Influence of Hydrodynamics on the Performance of a Biofilm Airlift Suspension Reactor.
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Ping Zhou, Jiahan He, and Yi Qian
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BIOFILMS , *MICROBIAL aggregation , *HYDRODYNAMICS , *FLUID dynamics , *SUSPENSIONS (Chemistry) , *ORGANIC compounds - Abstract
Five biofilm airlift suspension (BAS) reactors filled with ceramic materials as biocarriers were used to investigate the hydrodynamics, liquid mixing, and biofilm detachment kinetics in the BAS reactor. A mathematical model was developed to describe the internal liquid circulation within the BAS reactor. The Froude number was introduced to correlate the relationship between the Froude number and superficial gas velocity at different biocarrier concentrations. The validity of the empirical model was verified over a wide range of experimental conditions and the result shows that the internal liquid circulation velocity was proportional to the square root of the reactor height and the superficial gas velocity. Because the internal liquid circulation flow rate was much larger than influent flow rate, the BAS reactor had a strong capacity to resist shock loading caused by the change in influent organic matter concentration. Shock loading resistance increased with the height of a BAS reactor. Although biofilm detachment was a very complicated process which involved many mechanisms, dimensional analysis was employed to successfully analyze the biofilm detachment kinetics. It was found that the biofilm detachment rate was proportional to the first power of the superficial gas velocity and biofilm thickness, and to the 2/3 power of the number of biocarriers in the reactor, respectively. Use of the Froude number and dimensional analysis provide an effective and accurate method to study the characteristics of the BAS reactor. [ABSTRACT FROM AUTHOR]
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- 2005
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164. FACTORS THAT EFFECT ANTIOXIDANT ACTIVITY OF C-PHYCOCYANINS FROM SPIRULINA PLATENSIS.
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Zhan-ping Zhou, Lu-ning Liu, Xiu-lan Chen, Jin-xia Wang, Min Chen, Yu-zhong Zhang, and Bai-cheng Zhou
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ANTIOXIDANTS , *CHEMICAL inhibitors , *SPIRULINA , *FREE radical reactions , *DIGESTIVE enzymes , *TRYPSIN - Abstract
Currently, antioxidants are added in the human diet to prevent free radical-induced cell damage, and there has been an explosive interest in the use of antioxidant nutritional supplements. The effects of different factors on the antioxidant activity of phycocyanins (PCs) were studied. The results showed that PCs generated hydroxyl radicals in the light, while scavenging them in the dark. When PCs were denatured by sodium dodecyl sulfate, urea and in alkaline condition, their ability to generate hydroxyl radicals disappeared and that of scavenging them greatly increased. This showed that the phycobilin moiety is the main part of PC involved in scavenging hydroxyl radicals. Trypsin hydrolysis of PCs showed that the apoprotein portion of the molecule also made a significant contribution to the antioxidant activity. [ABSTRACT FROM AUTHOR]
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- 2005
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165. Nitric oxide inhibits caspase activation and apoptotic morphology but does not rescue neuronal death.
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Ping Zhou, Liping Qian, and Iadecola, Costantino
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NITRIC oxide , *APOPTOSIS , *CELL death , *BRAIN injuries , *MEDICAL research - Abstract
Nitric oxide (NO) has been shown to inhibit apoptotic cell death by S-nitrosylation of the catalytic-site cysteine residue of caspases. However, it is not clear whether in neurons NO-mediated caspase inactivation leads to improved cell survival. To address this issue, we studied the effect of NO donors on caspase activity and cell survival in cortical neuronal culture treated with the apoptosis inducer staurosporine (STS) and camptothecin. In parallel, cell viability was assessed by the MTS assay and MAP2 staining. We found that NO donors ((±)-S-nitroso-N-acetylpenicillamine, S-nitrosoglutathione, and NONOates) dose-dependently inhibited caspase-3 and -9 activity induced by STS and camptothecin. The reduction in caspase-3 activity was, in large part, because of the blockage of the proteolytic conversion of pro-caspase-3 to active caspase-3. NO donors also inhibited the appearance of the classical apoptotic nuclear morphology. However, inhibition of both caspase activity and apoptotic morphology was not associated with enhancement of cell viability. Thus, inhibition of caspase and apoptotic morphology by NO donors does not improve neuronal survival. The data suggest that inhibition of caspase by NO unmasks a caspase-independent form of cell death. A better understanding of this form of cell death may provide new strategies for neuroprotection in neuropathologies, such as ischemic brain injury, associated with apoptosis.Journal of Cerebral Blood Flow & Metabolism (2005) 25, 348–357. doi:10.1038/sj.jcbfm.9600036 Published online 19 January 2005 [ABSTRACT FROM AUTHOR]
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- 2005
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166. Letrozole Significantly Improves Growth Potential in a Pubertal Boy With Growth Hormone Deficiency.
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Ping Zhou, Bina Shah, Prasad, Kris, and David, Raphael
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BONE densitometry , *SOMATOTROPIN , *PITUITARY hormones , *SHORT stature , *AROMATASE , *PEDIATRICS - Abstract
Clinical experience with using an aromatase inhibitor to suppress estrogen production during puberty for improvement of growth potential in adolescents with short stature is limited. This report documents treatment of such a patient with a combination of growth hormone and letrozole, a third-generation aromatase inhibitor. Our case demonstrates a favorable outcome on a short-term basis. [ABSTRACT FROM AUTHOR]
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- 2005
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167. Effect of pH and Copper(II) on the Conformation Transitions of Silk Fibroin Based on EPR, NMR, and Raman Spectroscopy.
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Xiao-Hong Zong, Ping Zhou, Zheng-Zhong Shao, Shi-Ming Chen, Xin Chen, Bing-Wen Hu, Feng Deng, and Wen-Hua Yao
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SILKWORMS , *NITROGEN , *OXYGEN , *AMINO acids , *FIBERS , *PLANT products - Abstract
Much attention has been paid to the natural mechanism of silkworm spinning due to the impressive mechanical properties of the natural fibers. Our results in the present work show that the fractional changes of the conformational components in regenerated silk fibroin (SF) extracted from Bombyx mori fibers is remarkably pH- and Cu(II)-dependent as demonstrated by Cu(II) EPR, 13C NMR, and Raman spectroscopy. Cu(II) coordination atoms in SF are changed from four nitrogens to two nitrogens and two oxygens as well as to one nitrogen and three oxygens when the pH is lowered from 8.0 to 4.0. The addition of a given amount of Cu(II) into a SF solution could induce efficiently the SF conformational fractional change from silk I, a soluble helical conformation, to silk II, an insoluble β-sheet conformation. This behavior is strikingly similar to that seen in prion protein and amyloid β-peptide. On the basis of the similarity in the relevant sequence in SF to the octapeptide PHGGGWGQ in PrP, we suggest that at basic and neutral pH polypeptide AHGGYSGY in SF may form a 1:1 complex with Cu(II) by coordination of imidazole Nπ of His together with two deprotonated main-chain nitrogens from two glycine residues and one nitrogen or oxygen from serine. Such a type of coordination may make the interaction between two adjacent β-form polypeptide chains more difficult, thereby leading to an amorphous structure. Under weakly acidic conditions, however, Cu(II)-amide linkages may be broken arid Cu(II) may switch to bind two Nτ from two histidines in adjacent peptide chains, forming an intermolecular His(Nτ-Cu(II)-His(Nτ) bridge. This type of coordination may induce β-sheet formation and aggregation, leading to a crystalline structure. [ABSTRACT FROM AUTHOR]
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- 2004
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168. Analysis of the localization of damage and the complete stress-strain relation for mesoscopic heterogeneous rock under uniaxial tensile loading.
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Xiao-ping, Zhou, Jian-hua, Wang, Yong-xing, Zhang, and Qiu-ling, Ha
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ROCK density , *CONTINUUM damage mechanics , *TENSILE architecture , *STRAINS & stresses (Mechanics) , *MESOSCOPIC phenomena (Physics) , *HETEROGENEITY , *WEIBULL distribution , *RAYLEIGH model - Abstract
The mechanical behavior of rock under uniaxial tensile loading is different from that of rock under compressive loads. A micromechanics-based model was proposed for mesoscopic heterogeneous brittle rock undergoing irreversible changes of their microscopic structures due to microcrack growth. The complete stress-strain relation including linear elasticity, nonlinear hardening, rapid stress drop and strain softening was obtained. The influence of all microcracks with different sizes and orientations were introduced into the constitutive relation by using the probability density function describing the distribution of orientations and the probability density function describing the distribution of sizes. The influence of Weibull distribution describing the distribution of orientations and Rayleigh function describing the distribution of sizes on the constitutive relation were researched. Theoretical predictions have shown to be consistent with the experimental results. [ABSTRACT FROM AUTHOR]
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- 2004
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169. Analysis of the localization of damage and the complete stress-strain relation for mesoscopic heterogeneous brittle rock subjected to compressive loads.
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Xiao-ping, Zhou, Yong-xing, Zhang, Qiu-ling, Ha, and Jian-hua, Wang
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ROCK density , *ROCK analysis , *STRAINS & stresses (Mechanics) , *CONTINUUM damage mechanics , *MICROMECHANICS , *LOCALIZATION theory , *SOLID state physics - Abstract
A micromechanics-based model is established. The model takes the interaction among sliding cracks into account, and it is able to quantify the effect of various parameters on the localization condition of damage and deformation for brittle rock subjected to compressive loads. The closed-form explicit expression for the complete stress-strain relation of rock containing microcracks subjected to compressive loads was obtained. It is showed that the complete stress-strain relation includes linear elasticity, nonlinear hardening, rapid stress drop and strain softening. The behavior of rapid stress drop and strain softening is due to localization of deformation and damage. Theoretical predictions have shown to be consistent with the experimental results. [ABSTRACT FROM AUTHOR]
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- 2004
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170. Development of the mammary gland requires DGAT1 expression in stromal and epithelial tissues.
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Cases, Sylvaine, Ping Zhou, Shillingford, Jonathan M., Wiseman, Bryony S., Fish, Jo Dee, Angle, Christina S., Hennighausen, Lothar, Werb, Zena, and Farese Jr, Robert V.
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MAMMARY glands , *EPITHELIUM , *TRIGLYCERIDES , *METABOLISM , *TISSUES - Abstract
Mammary gland development is a complex process that is dependent on interactions between the developing mammary epithelium and the surrounding stromal tissues. We show that mice lacking the triglyceride synthesis enzyme acyl CoA:diacylglycerol transferase 1 (DGAT1) have impaired mammary gland development, characterized by decreased epithelial proliferation and alveolar development, and reduced expression of markers of functional differentiation. Transplantation studies demonstrate that the impaired development results from a deficiency of DGAT1 in both the stromal and epithelial tissues. Our findings are the first to link defects in stromal lipid metabolism to impaired mammary gland development. [ABSTRACT FROM AUTHOR]
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- 2004
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171. Local expression of B7-H1 promotes organ-specific autoimmunity and transplant rejection.
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Subudhi, Sumit K., Ping Zhou, Yerian, Lisa M., Chin, Robert K., Lo, James C., Anders, Robert A., Yonglian Sun, Robert A., Lieping Chen, Yang Wang, Alegre, Maria-Luisa, Yang-Xin Fu, Zhou, Ping, Sun, Yonglian, Chen, Lieping, Wang, Yang, and Fu, Yang-Xin
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T cells , *AUTOIMMUNE diseases , *DIABETES , *TISSUES , *CELL proliferation - Abstract
A number of studies have suggested B7-H1, a B7 family member, inhibits T cell responses. Therefore, its expression on nonlymphoid tissues has been proposed to prevent T cell-mediated tissue destruction. To test this hypothesis, we generated transgenic mice that expressed B7-H1 on pancreatic islet β cells. Surprisingly, we observed accelerated rejection of transplanted allogeneic B7-Hl-expressing islet β cells. Furthermore, transgenic B7-H1 expression broke immune tolerance, as some of the mice spontaneously developed T cell-dependent autoimmune diabetes. In addition, B7-H1 expression increased CD8T cell proliferation and promoted autoimmunity induction in a T cell adoptive transfer model of diabetes. Consistent with these findings, B7-HI.Ig fusion protein augmented naive T cell priming both in vitro and in vivo. Our results demonstrate that BT-H1 can provide positive costimulation for naive T cells to promote allograft rejection and autoimmune disease pathogenesis. [ABSTRACT FROM AUTHOR]
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- 2004
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172. Overexpression of Repressive cAMP Response Element Modulators in High Glucose and Fatty Acid-treated Rat Islets.
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Yun-Ping Zhou, Marlen, Kimberly, Palma, John F., Schweitzer, Anthony, Reilly, Linda, Gregoire, Francine M., Xu, Gann G., Blume, John E., and Johnson, Jeffrey D.
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TYPE 2 diabetes , *HYPERLIPIDEMIA , *HYPERGLYCEMIA , *B cells , *GLUCOSE , *FATTY acids ,RAT anatomy - Abstract
The hyperlipidemia and hyperglycemia of the diabetic state accelerate β-cell dysfunction, yet the mechanisms are not fully defined. We used rat islet-specific oligonucleotide arrays (Metabolex Rat Islet Genechips) to identify genes that are coordinately regulated by high glucose and free fatty acids (FFA). Exposure of rat islets to FFA (125 µM for 2 days) or glucose (27 mM for 4 days) reduced glucose-stimulated insulin secretion by 70 ± 5 and 40 ± 4%, respectively, relative to control-cultured islets. These treatments also substantially reduced the insulin content of the islets. Islet Genechips analysis revealed that the mRNA levels of cAMP response element modulator (CREM)-17X and inducible cAMP early repressor were significantly increased in both 27 mM glucose- and FFA-treated islets. Removing FFA or high glucose from the culture medium restored glucose-stimulated insulin secretion and the mRNA levels of the two CREM repressors to normal. Northern blot analysis revealed a 5-fold increase in the abundance of CREM-17X mRNA and a concomitant 50% reduction in the insulin mRNA in FFA-treated islets. Transient transfection of the insulin-secreting βHC9 cells with CREM-17X suppressed rat insulin promoter activity by nearly 50%. Overexpression of CREM-17X in intact islets via adenovirus infection decreased islet insulin mRNA levels and insulin content and resulted in a significant decrease in glucose- or KCl-induced insulin secretion. Taken together, these data suggest that up-regulation of CREM repressors by either FFA or high glucose exacerbates β-cell failure in type 2 diabetes by suppressing insulin gene transcription. [ABSTRACT FROM AUTHOR]
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- 2003
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173. Periodical interfacial cracks in anisotropic elastoplastic media.
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Wan-shen, Xiao, Jian-ping, Zhou, and Guo-jin, Tang
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FOURIER transforms , *INTEGRAL equations , *ANISOTROPY , *MATERIALS analysis , *BOUNDARY value problems , *ELASTICITY , *PLASTICS - Abstract
By using Fourier transformation the boundary problem of periodical interfacial cracks in anisotropic elastoplastic bimaterial was transformed into a set of dual integral equations and then it was further reduced by means of definite integral transformation into a group of singular equations. Closed form of its solution was obtained and three corresponding problems of isotropic bimaterial, of a single anisotropic material and of a bimaterial of isotropy-anisotropy were treated as the specific cases. The plastic zone length of the crack tip and crack openning displacement (COD) decline as the smaller yield limit of the two bonded materials rises, and they were also determined by crack length and the space between two neighboring cracks. In addition, COD also relates it with moduli of the materials. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
174. Germline Inactivation of PTEN and Dysregulation of the Phosphoinositol-3- Kinase/Akt Pathway Cause Human Lhermitte-Duclos Disease in Adults.
- Author
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Xiao-Ping Zhou, Marsh, Deborah J., Morrison, Carl D., Chaudhury, Abhik R., Maxwell, Marius, Reifenberger, Guido, and Eng, Charis
- Subjects
- *
GENETIC mutation , *GENES , *SYNDROMES , *PROTEIN-tyrosine kinases , *DISEASES , *GENETICS - Abstract
Discusses the germline mutation of the PTEN gene. Dysregulation of the phosphoinositol-3-kinase/Akt pathway; Occurrence of human lhermitte-Duclos (LDD) disease in adults; Association of LDD or dysplastic gangliocytoma with Cowden syndrome.
- Published
- 2003
- Full Text
- View/download PDF
175. GATA-3: an unexpected regulator of cell lineage determination in skin.
- Author
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Kaufman, Charles K., Ping Zhou, Pasolli, H. Amalia, Rendl, Michael, Bolotin, Diana, Kim-Chew Lim, Xing Dai, Alegre, Maria-Luisa, and Fuchs, Elaine
- Subjects
- *
SKIN , *BODY covering (Anatomy) , *IMMUNE system , *HAIR follicles , *CELLS - Abstract
Applies a combination of genetics, cell biology and biochemistry to assess whether GATA-3 might orchestrate lineage determination in the skin as it does in the immune system. Defects in GATA-3-null embryonic skin; Expansion of hair shaft and hair shaft precursor cells in GATA-3-null follicles; Confirmation of biochemical defects in GATA-3-null hair follicles.
- Published
- 2003
- Full Text
- View/download PDF
176. Vortex Lattice Structure of High Temperature Superconductors.
- Author
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Shi-Ping Zhou, P., Hao-Chen Du, P., and Hong-Yin Liao, P.
- Subjects
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HIGH temperature superconductors , *TRANSITION temperature , *SUPERCONDUCTIVITY - Abstract
We study vortex lattice structure of high temperature superconductors by using the Ginzburg–Landau model. The structure of the vortex lattice is oblique at the temperatures well below the transition temperature T[sub c], where the mixed s–d state is expected to have the lowest energy. Whereas, very close to T[sub c], the d[sub x[sup 2]-y[sup 2]] wave is slightly lower in energy, and a triangular vortex lattice recovers. The coexistence and the coupling between the s- and d-waves account for the upward curvature of the upper critical field curve H[sub C2](T). [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
177. Distinct Mechanisms for Regulating the Tumor Suppressor and Antiapoptotic Functions of Rb.
- Author
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Duanduan Ma, Ping Zhou, and Harbour, J. William
- Subjects
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TUMOR suppressor proteins , *PROTEINS , *BIOCHEMISTRY - Abstract
Investigates the distinct mechanisms for the regulation of the tumor suppressor and antiapoptotic functions of the retinoblastoma protein (Rb). Immunoprecipitations and in vitro phosphorylation; Hyperphosphorylation and inactivation of ectopic Rb; Regulation of Rb apoptotic activity.
- Published
- 2003
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178. Germline Mutations in BMPR1A/ALK3 Cause a Subset of Cases of Juvenile Polyposis Syndrome and of Cowden and Bannayan-Riley-Ruvalcaba Syndromes.
- Author
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Xiao-Ping Zhou, Woodford-Richens, Kelly, Lehtonen, Rainer, Kurose, Keisuke, Aldred, Micheala, Hampel, Heather, Launonen, Virpi, Virta, Sanno, Pilarski, Robert, Salovaara, Reijo, Bodmer, Walter F., Conrad, Beth A., Dunlop, Malcolm, Hodgson, Shirley V., Iwama, Takeo, Jarvinen, Heikki, Kellokumpu, Ilmo, Kim, J.C., and Leggett, Barbara
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SYNDROMES in children , *COLON cancer risk factors , *GENETIC mutation - Abstract
Juvenile polyposis syndrome (JPS) is an inherited hamartomatous-polyposis syndrome with a risk for colon cancer. JPS is a clinical diagnosis by exclusion, and, before susceptibility genes were identified, JPS could easily be confused with other inherited hamartoma syndromes, such as Bannayan-Riley-Ruvalcaba syndrome (BRRS) and Cowden syndrome (CS). Germline mutations of MADH4 (SMAD4) have been described in a variable number of probands with JPS. A series of familial and isolated European probands without MADH4 mutations were analyzed for germline mutations in BMPR1A, a member of the transforming growth-factor b receptor superfamily, upstream from the SMAD pathway. Overall, 10 (38%) probands were found to have germline BMPR1A mutations, 8 of which resulted in truncated receptors and 2 of which resulted in missense alterations (C124R and C376Y). Almost all available component tumors from mutation-positive cases showed loss of heterozygosity (LOH) in the BMPR1A region, whereas those from mutation-negative cases did not. One proband with CS/CS-like phenotype was also found to have a germline BMPR1A missense mutation (A338D). Thus, germline BMPR1A mutations cause a significant proportion of cases of JPS and might define a small subset of cases of CS/BRRS with specific colonic phenotype. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
179. Calpains play a role in insulin secretion and action.
- Author
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Sreenan, Seamus K., Yun-Ping Zhou, Otani, Kenichi, Hansen, Polly A., Currie, Kevin P.M., Chien-Yuan Pan, Jean-Pyo Lee, Ostrega, Diane M., Pugh, William, Horikawa, Yukio, Cox, Nancy J., Hanis, Craig L., Burant, Charles F., Fox, Aaron P., Bell, Graeme I., Polonsky, Kenneth S., Sreenan, S K, Zhou, Y P, Otani, K, and Hansen, P A
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- *
CALPAIN , *INSULIN , *PHYSIOLOGY - Abstract
Studies of the genetic basis of type 2 diabetes suggest that variation in the calpain-10 gene affects susceptibility to this common disorder, raising the possibility that calpain-sensitive pathways may play a role in regulating insulin secretion and/or action. Calpains are ubiquitously expressed cysteine proteases that are thought to regulate a variety of normal cellular functions. Here, we report that short-term (4-h) exposure to the cell-permeable calpain inhibitors calpain inhibitor II and E-64-d increases the insulin secretory response to glucose in mouse pancreatic islets. This dose-dependent effect is observed at glucose concentrations above 8 mmol/l. This effect was also seen with other calpain inhibitors with different mechanisms of action but not with cathepsin inhibitors or other protease inhibitors. Enhancement of insulin secretion with short-term exposure to calpain inhibitors is not mediated by increased responses in intracellular Ca2+ or increased glucose metabolism in islets but by accelerated exocytosis of insulin granules. In muscle strips and adipocytes, exposure to both calpain inhibitor II and E-64-d reduced insulin-mediated glucose transport. Incorporation of glucose into glycogen in muscle also was reduced. These results are consistent with a role for calpains in the regulation of insulin secretion and insulin action. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
180. Assessment of traffic related air pollution in urban areas of Macao.
- Author
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Dong-quan, He, Zhong-ping, Zhou, Ke-bin, He, Yang, Liu, Ji-ming, Hao, Zhi-shi, Wang, and Yu-hua, Deng
- Subjects
- *
AIR pollution , *URBAN ecology , *ENVIRONMENTAL impact analysis - Abstract
Abstract: A method that enables the user to assess air pollution originated from vehicle emission in the urban center was described by taking Macao as an example. The method involved the use of mathematical models for the calculation of urban pollutant emissions and concentrations, of which a revised MOBILE5 was adopted to calculate the emission factors and two dispersion models of CAR and OSPM were used to calculate the long term and short term concentrations within street canyons, respectively. The results show consistency with the monitoring data, and some conclusions of controlling vehicle emissions are given based on the calculation results. [ABSTRACT FROM AUTHOR]
- Published
- 2000
181. Overexpression of Bcl-XL in beta-cells prevents cell death but impairs mitochondrial signal for...
- Author
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Yun-Ping Zhou and Pena, John C.
- Subjects
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PANCREATIC beta cells , *INSULIN , *HYPERGLYCEMIA , *SECRETION - Abstract
Studies the effects of Bcl-XL in the pancreatic beta cell by producing two cell lines using different forms of the rat insulin promoter. Observation of glucose intolerance; Reduction in glucose-induced insulin secretion and hyperglycemia due to overexpression of Bcl-XL and defect in mitochondrial nutrient metabolism.
- Published
- 2000
182. Applicability of municipal solid waste incineration (MSWI) system integrated with pre-drying or torrefaction for flue gas waste heat recovery.
- Author
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Xing, Zhou, Ping, Zhou, Xiqiang, Zhao, Zhanlong, Song, Wenlong, Wang, Jing, Sun, and Yanpeng, Mao
- Subjects
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SOLID waste , *WASTE gases , *FLUE gases , *HEAT recovery , *INCINERATION , *WASTE heat , *ENERGY consumption , *SPECIFIC heat - Abstract
A system based on pre-drying and torrefaction of raw municipal solid waste (MSW) is proposed in this study to minimize the amount of pollutants and improve the efficiency of the system by recovering flue gas waste heat as heat source for the pre-drying or torrefaction stage. A steady-state model integrated with the mass residual rate and energy coefficient of this novel system is established to evaluate the effect of pretreating solid waste on the performance of the municipal solid waste incineration (MSWI) system comprehensively. Thermodynamic calculation results show that the low heating value (LHV) of the MSW is increased to approximately 9000 kJ/kg at a torrefaction temperature of 533 K for 30 min; the combustion flue gas temperature is approximately 1150 K, thereby satisfying the incineration temperature requirement. Further, pre-drying is conducive for improving the energy utilisation rate; for torrefaction, when the mass residual rate of MSW is greater than 39.25%, the energy coefficient of the pretreatment exceeds 1. For the pre-processing method involving torrefaction, the mass loss and LHV improvement after torrefaction should be considered to select the appropriate torrefaction conditions. This study supplies effective and feasible reference for developing higher performance MSWI system with pre-drying or torrefaction as the pretreatment. • Proposed a model to describe municipal solid waste incineration system. • Suggested a model to predict the specific heat of flue gas. • Posed a method to predict the specific heat of municipal solid waste in China. • Pre-drying of municipal solid waste could optimize its' incineration. • The impacts of torrefaction depend on operating condition. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
183. Network-based screen in iPSC-derived cells reveals therapeutic candidate for heart valve disease.
- Author
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Theodoris, Christina V., Ping Zhou, Lei Liu, Yu Zhang, Tomohiro Nishino, Yu Huang, Kostina, Aleksandra, Ranade, Sanjeev S., Gifford, Casey A., Uspenskiy, Vladimir, Malashicheva, Anna, Sheng Ding, and Srivastava, Deepak
- Subjects
- *
GENETIC regulation , *THERAPEUTICS , *CELLS , *DISEASES , *STEM cells - Abstract
The article presents the discussion on determining the gene-regulatory networks driving human disease allowing the design of therapies targeting the core disease. Topics include In silico correlation of disease network dysregulation with pathways affected by molecules in surrogate cell types; and mapping the architecture of the dysregulated network in disease-relevant cells differentiating from patient-derived induced pluripotent stem cells (iPSCs).
- Published
- 2021
- Full Text
- View/download PDF
184. Crystal structures of [18]aneN[sub6]H[sub2]K[Co(CN)[sub6]].4H[sub2]O, [16]aneN[sub4]H[sub2]K[Co(CN)[sub6]] and [12]aneN[sub4]H[sub3][Co(CN)[sub6]]2H[sub2]O. Inisght into the electrostatic and hydrogen-bonding interaction in self-assembling supercomplexes.
- Author
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Ping Zhou, Feng Xue, Au-Yeung, Steve C.F., and Xiao-Ping Xu
- Subjects
- *
COMPLEX compounds , *CRYSTALS - Abstract
Studies the crystal structures of three self-assembling supercomplexes. Lamella derived from chain-like arrangement of rings; Electrostatic and hydrogen bonding interactions; Binding of metal cyanide anions by polyammonium macrocyclic cations.
- Published
- 1999
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185. Charged top-pion production associated with the bottom quark pair as a probe of the topcolor-assisted technicolor model at the LHC.
- Author
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Guo-Li Liu and Ping Zhou
- Subjects
- *
PIONS , *QUARKS , *PARTICLES (Nuclear physics) , *HADRON colliders , *PARTONS - Abstract
The topcolor-assisted technicolor (TC2) model predicts the existence of the charged top-pions (πt±), whose large couplings with the third generation fermions will induce the charged top-pion production associated with the bottom and antibottom quark pair at the CERN Large Hadron Collider (LHC) through the parton processes cb¯ → πt+bb¯ and ud¯(cs¯) → πt+bb¯. In this report, we examine these productions and find that, due to the small standard model backgrounds, their production rates can exceed the 3σ sensitivity of the LHC in a large part of parameter space, so these processes may serve as a good probe of the TC2 model. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
186. Asymmetric fluorination of enolates with nonracemic N-fluoro-2,10-camphorsultams.
- Author
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Davis, Franklin A., Ping Zhou, Murphy, Christopher K., Sundarababu, Gajendran, Hongyan Qi, Wei Han, Przeslawski, Robert M., Bang-Chi Chen, and Carroll, Patrick J.
- Subjects
- *
ENOLS , *FLUORINATION , *BIOSYNTHESIS - Abstract
Provides information on a study of the assymmetric fluorination of enolates with nonracemic N-fluoro-2,10-camphorsultams. Methodology used to conduct the study; Detailed information on the synthesis and structure of N-fluoro-2,10-camphorsultams; Results of the study; Discussion on the results.
- Published
- 1998
- Full Text
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187. Role of prostaglandins in renal medullary circulation: Response to different vasoconstrictors.
- Author
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Parekhc, Niranjan and Ai-Ping Zhou
- Subjects
- *
PROSTAGLANDINS , *BLOOD flow - Abstract
Investigates the effects of renal prostaglandins and their interaction with different vasoactive agents in regulating regional renal blood flow. Comparison of the effects of different pressor hormones and a nitric oxide inhibitor under control conditions; Mean arterial pressure; Mechanisms involved in the papillary necrosis found in analgesic nephropathy.
- Published
- 1996
188. Three-Dimensional Photon Control in Membrane-Stack Photonic Crystals.
- Author
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Xing-Ping, Zhou and Jing, Shu
- Subjects
- *
PHOTONIC crystals , *WAVEGUIDES , *PLANE wavefronts , *PHENOMENOLOGICAL theory (Physics) , *LIGHT scattering - Abstract
We design two novel waveguides in membrane-stack photonic crystals and obtain their dispersion characteristics by the three-dimensional (3D) plane wave-expansion method. The 3D photon control phenomena are demonstrated, in which light is incident on the crystal and is bent both horizontally and vertically. Then light is split into two and is finally emitted from the other side of the crystal. A 3D splitter is realized. We also present a nanocavity to trap photons. With waveguides of different directions and nanocavities, the arbitrary 3D photon manipulation has been demonstrated. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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- View/download PDF
189. Prognosis and Clinicopathological Characters of Adult TFEB-Altered Renal Cell Carcinoma: A Single Center Experience of 18 Cases.
- Author
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Jie Wu, Chuan-Zhen Cao, Hong-Lei Cui, Gan Du, Hong-Zhe Shi, Jing Liang, Lei Guo, Yi-Cheng Wang, Jin Zhang, Ai-Ping Zhou, Chang-Ling Li, Shan Zheng, and Jian-Zhong Shou
- Subjects
- *
RENAL cell carcinoma , *METASTASIS , *CANCER immunotherapy , *IMMUNOHISTOCHEMISTRY , *FOLLOW-up studies (Medicine) - Abstract
TFEB-altered RCC is a rare entity whose therapeutic implications and long-term survival remain unclear, especially for metastatic cases. In this study, we reported the clinicopathologic and radiological features of eighteen novel TFEB-altered RCC cases and found that TFEB-altered RCC exhibited mixed morphological and radiological characteristics. For metastatic TFEB-altered RCC, immunotherapy-based drug combinations could be a promising treatment strategy. Introduction: TFEB-altered renal cell carcinoma (RCC) is a rare entity characterized by the rearrangement of the TFEB gene or TFEB amplified. The therapeutic implications and long-term survival of TFEB-altered RCC remain unclear, especially for metastatic cases. Materials and Methods: The current study initially enrolled 7604 consecutive RCC patients at our center and a total of 248 patients were selected for FISH and immunohistochemistry (IHC) analysis. Eventually, eighteen TFEB-altered RCC patients were identified. We then reported the clinical, morphological, IHC, and radiological features of these cases. Results: The median age at initial diagnosis was 45 years, ranging from 18 years to 66 years. The majority of the TFEB-altered RCC patients were male (61.1%), with localized disease (T1-2N0M0, 77.8%). The median split TFEB fluorescent signal was 24%, ranging from 15%-80%. The morphological characteristics of TFEB-altered RCC were variable, with acinar, papillary, solid, or nest patterns. IHC and magnetic resonance imaging features of TFEB-altered RCC were nonspecific. Nine patients with localized disease received partial nephrectomy and five patients with localized disease received radical nephrectomy. During the median follow-up of 67 months, no signs of recurrence or metastasis were found in these patients. Two patients had distant metastasis and received axitinib plus PD-1 immunotherapy. One of them died at 40-month follow-up and another still alive at 88-month follow-up. Conclusion: TFEB-altered RCC is an extremely rare variant, exhibited mixed morphological characteristics. The radiological feature lack specificity, resembling clear cell RCC or papillary RCC. Genetic analyses including FISH analysis is crucial in the diagnosis of TFEB-altered RCC. For localized TFEB-altered RCC, both radical nephrectomy and partial nephrectomy conferred satisfactory prognosis. For metastatic TFEB-altered RCC, immunotherapy-based drug combinations could be a promising treatment strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
190. Spatiotemporal Transcriptome Analysis Reveals Activation of the AP1 Pathway in the Ovarian Microenvironment during the Transition from Premenopause to Postmenopause.
- Author
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Wendi Pei, Xiaomin Cao, Puyao Zhang, Lin Fu, Ping Zhou, Ye Liu, Yong Fan, Fengqin Xu, Canhui Cao, and Yang Yu
- Subjects
- *
PERIMENOPAUSE , *HORMONE regulation - Published
- 2024
- Full Text
- View/download PDF
191. Discovery and timing of pulsar J2016+3711 in supernova remnant CTB 87 with FAST.
- Author
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(劉前程), Qian-Cheng Liu, (鍾文娟), Wen-Juan Zhong, (陳陽), Yang Chen, (王培), Pei Wang, (周平), Ping Zhou, (岳友嶺), You-Ling Yue, and (李菂), Di Li
- Subjects
- *
SUPERNOVA remnants , *PULSARS , *MAGNETIC dipoles , *RADIO telescopes , *ACTINIC flux , *SURVEILLANCE radar , *RADIO technology - Abstract
We report on our discovery of the radio pulsar, PSR J2016+3711, in supernova remnant (SNR) CTB 87, with a ∼10.8σ significance of pulses, which confirms the compact nature of the X-ray point source in CTB 87. It is the first pulsar discovered in SNRs using Five-hundred-meter Aperture Spherical radio Telescope (FAST). Its integrated radio pulse profile can be well described by a single component, with a width at 50 per cent of the peak flux density of about 28.1○ and an effective width of about 32.2○. The mean flux density at 1.25 GHz is estimated to be about 15.5 |$\mu$| Jy. Combined with the non-detection of the radio pulse at lower frequencies, the radio spectral index of the pulsar is constrained to be ≲2.3. We also present the timing solution based on 28 follow-up FAST observations. Our results reveal a period of 50.81 ms, period derivative of 7.2 × 10−14 s s−1, and dispersion measure of 428 pc cm−3. The strength of the equatorial surface magnetic dipole magnetic field is inferred to be about 1.9 × 1012 G. Using the ephemeris obtained from the radio observations, we searched Fermi -LAT data for gamma-ray pulsations but detected no pulsed signal. We also searched for radio pulses with FAST towards the X-ray counterpart of the gamma-ray binary HESS J1832−093 proximate to SNR G22.7−00.2 but found no signal. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
192. Durability of glass fiber reinforced thermoplastic polypropylene composite bars under the coupling effect of seawater and sea sand concrete environment and sustained bending.
- Author
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Shaoce Dong, Xiao Qi, Jingwei Tian, Ping Zhou, Chenggao Li, and Guijun Xian
- Subjects
- *
GLASS fibers , *THERMOPLASTIC composites , *ARTIFICIAL seawater , *BENDING stresses , *DURABILITY - Abstract
The long-term interfacial shear strength (IFSS) and flexural strength of GFPP bars under the coupling effect of bending and immersion in the simulated seawater and sea sand concrete (SWSC) solution were studied by an acceleration experiment. Three temperatures and three bending stress levels (0%, 9.8%, and 29.4% of the maximum flexural strain of GFPP bars) were used to accelerate the experiment. Results indicate that the degradation of mechanical properties of GFPP bars is relatively sensitive to the immersion temperature. Low bending stress did not accelerate the degradation of GFPP bars compared with unbent GFPP bars while high bending stress dramatically accelerated the degradation. Microscopic tests found there is corrosion of glass fibers and debonding between glass fibers and polypropylene but no obvious chain breaks of polypropylene occurred. Based on the Arrhenius theory, long-term stable retention rates of the IFSS of GFPP bars with zero and low bending stress immersed in the simulated SWSC solution are 42.4% and 52.3%. Highlights • Low-stressed GFPP bars degraded similarly or even slower than unbent GFPP bars. • GFPP bars degraded mainly due to interfacial debonding and fiber corrosion. • Long-term IFSS of GFPP bars under a coupling effect was predicted. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
193. Multi-surrogate framework with an adaptive selection mechanism for production optimization.
- Author
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Jia-Lin Wang, Li-Ming Zhang, Kai Zhang, Jian Wang, Jian-Ping Zhou, Wen-Feng Peng, Fa-Liang Yin, Chao Zhong, Xia Yan, Pi-Yang Liu, Hua-Qing Zhang, Yong-Fei Yang, and Hai Sun
- Abstract
Data-driven surrogate models that assist with efficient evolutionary algorithms to find the optimal development scheme have been widely used to solve reservoir production optimization problems. However, existing research suggests that the effectiveness of a surrogate model can vary depending on the complexity of the design problem. A surrogate model that has demonstrated success in one scenario may not perform as well in others. In the absence of prior knowledge, finding a promising surrogate model that performs well for an unknown reservoir is challenging. Moreover, the optimization process often relies on a single evolutionary algorithm, which can yield varying results across different cases. To address these limitations, this paper introduces a novel approach called the multi-surrogate framework with an adaptive selection mechanism (MSFASM) to tackle production optimization problems. MSFASM consists of two stages. In the first stage, a reduced-dimensional broad learning system (BLS) is used to adaptively select the evolutionary algorithm with the best performance during the current optimization period. In the second stage, the multi-objective algorithm, non-dominated sorting genetic algorithm II (NSGA-II), is used as an optimizer to find a set of Pareto solutions with good performance on multiple surrogate models. A novel optimal point criterion is utilized in this stage to select the Pareto solutions, thereby obtaining the desired development schemes without increasing the computational load of the numerical simulator. The two stages are combined using sequential transfer learning. From the two most important perspectives of an evolutionary algorithm and a surrogate model, the proposed method improves adaptability to optimization problems of various reservoir types. To verify the effectiveness of the proposed method, four 100-dimensional benchmark functions and two reservoir models are tested, and the results are compared with those obtained by six other surrogate-model-based methods. The results demonstrate that our approach can obtain the maximum net present value (NPV) of the target production optimization problems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
194. Failure mechanism and bearing capacity analysis of steel fiber steel reinforced concrete(SFSRC) beams.
- Author
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Xu, Chao, Wu, Kai, Cao, Ping zhou, Sun, Yu yong, and Yang, Ding guo
- Subjects
- *
FIBER-reinforced concrete , *COMPOSITE construction , *STEEL analysis , *BEARING steel , *FAILURE mode & effects analysis , *INTERFACIAL bonding - Abstract
In order to put forward the failure mechanism and calculation method of bearing capacity of Steel Fiber and Steel Reinforced Concrete (SFSRC) composite beams, the mechanical performance tests of 33 SFSRC specimens were carried out with steel fiber content, shear span ratio, stirrup ratio and longitudinal reinforcement configuration as variables, and the failure mechanism of specimens under three different failure modes of shear failure, bending failure and interface slip failure is revealed, the typical load deflection curves of three failure modes are summarized. According to the theory of crack strength enhancement of steel fiber, a formula for calculating the anti slip strength of the interface between steel and steel fiber concrete is proposed. By means of regression analysis, the distribution coefficients of steel fiber reinforced concrete, steel shape and reinforcement of composite beams are determined, and the calculation formula of shear strength of composite beams is proposed. Based on the interface failure mechanism of specimens, the bond influence coefficient is introduced, and the bearing capacity calculation formula of composite beam with normal section bending failure and interface slip failure are proposed. Through comparison and verification, the calculation results of the above formula are in good agreement with the test results. • Research on Steel Fibers Steel Reinforced Concrete composite beams under four point bending. • The failure mechanisms corresponding to the three failure modes were revealed. • The formulas for calculating the interfacial bonding strength were proposed based on the interfacial bonding failure mechanism. • The section steel and SFRC in the rebar-free composite beams were in good agreement before the specimens entered the failure stage. • The calculated method for predicting the bearing capacity of SFSRC beams are proposed and correctness has been verified. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
195. Clinical features of isolated superior mesenteric artery dissection in the emergency department: a single center retrospective study.
- Author
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Xiang-Min Li, Guo-Qing Huang, Li-Ping Zhou, Xiao-Ye Mo, Ai-Min Wang, and Fang-Jie Zhang
- Subjects
- *
MESENTERIC artery , *HOSPITAL emergency services , *LIVER function tests , *ABDOMINAL pain , *AORTIC dissection - Abstract
Isolated superior mesenteric artery dissection (ISMAD) is a relatively rare disease and often lacks specificity in its clinical presentation, diagnosing it in emergency departments quickly and accurately is a challenge. The study was conducted to understand the basic characteristics of ISMAD including age of onset, risk factors, gender difference and whether D-dimer can be used as a biomarker for its detection. We retrospectively analyzed patients with ISMAD admitted to the emergency department of Xiangya Hospital of Central South University from September 1, 2017 to September 30, 2020. The data included the patient's basic information and the first laboratory test results after admission, including routine blood, liver function, renal function and coagulation function tests. Statistical analysis of results was done using GraphPad Prism 5. There were a total of 17 (15 male and 2 female) patients with a mean age of 52.53 ± 7.11 years diagnosed with ISMAD. Out of these, 7 (41%) patients had history of hypertension, 7 (41%) had history of smoking and/or alcohol intake, and almost all patients experienced significant abdominal pain and fullness. Four patients (24%) were initially misdiagnosed. The laboratory test results of renal, liver function tests and myocardial enzymology were in their normal ranges. In coagulation results, the positive rates of fibrinogen degradation products (FDP) and D-dimer were 29% and 35%, respectively. We compared these ISMAD results with our previous results for acute aortic dissection (AAD). D-dimer and FDP levels were lower in the ISMAD than in the AAD patients (P = 0.0004, P = 0.0325, respectively), and negative rates of D-dimer and FDP in ISMAD (65%, 71%) were higher than in AAD patients (14%, 24%) (P < 0.0001, P = 0.0003, respectively). In our study, ISMAD mostly occurred in middle-aged male patients with known hypertension or active smoking status. Misdiagnosis was common (24% of cases). Since D-dimer and FDP levels proved to be of limited diagnostic value, an abdominal Computed Tomography (CT) scan should be conducted in patients with unclear abdominal pain at an early stage of their diagnostic workup. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
196. Cracking behavior and energy consumption of Steel Fiber Concrete Encased Steel beams.
- Author
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Xu, Chao, Wu, Kai, Cao, Ping zhou, Lin, Shi-qi, and Chen, Zhuo
- Subjects
- *
STEEL , *CONSUMPTION (Economics) , *REINFORCING bars , *CONCRETE beams , *FIBERS , *REINFORCED concrete , *ENERGY consumption - Abstract
Steel Fiber Concrete Encased Steel (SFCES) beams were subjected to bending to investigate the effect of steel fibers on the behavior of Steel Reinforced Concrete beams with or without steel reinforcement. 18 SFCES beams reinforced with steel fibers, steel reinforcement, or both were cast. The parameters considered in the experiment were (a) the volume percentage of steel fiber (0%, 1%, and 2%), (b) the shear span to depth ratio(s/d = 2.5 and 3.5), (c) the stirrups spacing (180 mm and 360 mm), and (d) the presence or absence of longitudinal reinforcement (2Φ8+2Φ10).The cracking load, crack development, energy dissipation capacity, and ductility of the specimens were investigated. The results illustrate that the cracking load F c , the total energy consumption, and the energy ductility increase with increasing steel fiber volume, and the average improvement with a steel fiber volume increase of 1% can reach 36.5%, 21.2%, and 28.67%, respectively. However, this strengthening effect of steel fibers was weakened due to the addition of steel reinforcement. The influence of the steel fiber volume and reinforcement configuration on each stage of energy consumption was mainly concentrated in the elastic (E 1 ) and failure stages (E 3 ). Finally, mathematical equations were proposed to predict the cracking load and crack width of the SFCES specimens, which were verified by comparing the predictions with the experiment results. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
197. Reactions of H2S with AgCl within a Porous Coordination Network.
- Author
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Xiao-Ping Zhou, Zhenqtao Xu, ZeIler, Matthias, Allen O. Hunter, Stephen Sin Yin Chui, Chi-Ming Che, and Jianhua Lin
- Subjects
- *
SILVER sulfide , *METALLIC composites , *EUROPIUM , *CHALCOGENIDES , *CHARGE transfer , *OXIDATION-reduction reaction - Abstract
A silver(I) sulfide species Is now imbedded in a porous coordination network. Such a composite system builds on the molecule tetrakis(methylthio)-1 4-benzenedicarboxate that holds out the hard carboxylate to europium(lll) to form a host net, while taking on AgCl using its soft sulfur side arms. AgCI is then treated with H2S to form the dark-colored Ag2S species, while leaving the hard host net intact and upstanding. This hard-soft duality serves to conjoin the rich electronic flavors of metal chalcogenides and the flexible textures of coordination nets. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
198. Poly[μ8-4,4'-bipyridine-2,2',6,6'-tetracarboxylato-dilead(II)].
- Author
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Su-Ping Zhou, Xu-Xian Wu, Chao Zu, Zi-Lu Chen, and Fu-Pei Liang
- Subjects
- *
ORGANIC compounds , *CRYSTALS , *ANIONS , *LIGANDS (Chemistry) , *CRYSTALLOGRAPHY - Abstract
The article discusses the crystal structure of the metal-organic compound, Poly[µ8-4,4'-bipyridine-2,2',6,6'-tetracarboxylato-dilead(II) ([Pb2(C14H4N2O8)]n). The 4,4'-bipyridine-2,2',6,6'-tetracarboxylate (BPTCA4-) anion's geometric centre is positioned on the inversion centre. The centrosymmetric BPTCA4- ligand also acts as a three-dimensional metal-organic framework.
- Published
- 2010
- Full Text
- View/download PDF
199. Giant electric-field-induced magnetization in a magnetoelectric composite at high frequency.
- Author
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Jian-Ping Zhou, Yang-Yang Guo, Zengzhe Xi, Peng Liu, Shuyu Lin, Gang Liu, and Huai-Wu Zhang
- Subjects
- *
MAGNETIC fields , *ELECTRIC fields , *ELECTROMAGNETIC fields , *HYSTERESIS loop , *RESONANCE - Abstract
Electric-field-induced magnetization (EIM) characteristics are investigated in a small 0.68[Pb(Mg1/3Nb2/3)O3]0.32PbTiO3/Terfenol-D bilayered composite by using double coils in a wide frequency range of 10–700 kHz. The EIM behaviors are strongly dependent on driving electric field frequency, bias magnetic field, and angle θ between the bias magnetic field and polarization direction. The magnetoelectric coefficient at electromechanical resonance frequency of 185 kHz reaches up to 3.1×10-7 s/m, which is ∼60 times higher than the values at nonresonance frequency. The EIM variations with the bias magnetic field exhibit hysteresis, forming EIM hysteresis loops caused by the magnetostrictive hysteresis from Terfenol-D. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
200. In Situ Formed Guanidinium Cations as Templates To Direct Fabrication of Honeycomb-like CuCN Networks.
- Author
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Shi-Hong Lin, Xiao-Ping Zhou, Seik Weng Ng, and Dan Li
- Subjects
- *
GUANIDINE , *CATIONS , *CHEMICAL templates , *CHEMICAL reactions , *SOLVENTS , *ACETONITRILE - Abstract
The solvothermal reaction of CuSCN and 1,2-bis(diphenylphosphino)ethane (dppe) in mixed solvents acetonitrile/ n-hexane/(methanol or ethanol) gave a honeycomb-like guanidinium cyanocuprate [C(NH 2) 3)]·[Cu 2(CN) 3]. The in situ formed cations C(NH 2) 3+act as templates to direct the formation of the CuCN network in which multiple weak N−H····N/C hydrogen interactions potentially exist between the cations C(NH 2) 3+and the {CuCN} 6rings. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
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