Pressure-Induced Electronic Transition in Black Phosphorus.

In a semimetal, both electrons and holes contribute to the density of states at the Fermi level. The small band overlaps and multiband effects engender novel electronic properties. We show that a moderate hydrostatic pressure effectively suppresses the band gap in the elemental semiconductor black phosphorus. An electronic topological transition takes place at approximately 1.2 GPa, above which black phosphorus evolves into a semimetal state that is characterized by a colossal positive magnetoresistance and a nonlinear field dependence of Hall resistivity. The Shubnikov-de Haas oscillations detected in magnetic field reveal the complex Fermi surface topology of the semimetallic phase. In particular, we find a nontrivial Berry phase in one Fermi surface that emerges in the semimetal state, as evidence of a Dirac-like dispersion. The observed semimetallic behavior greatly enriches the material property of black phosphorus and sets the stage for the exploration of novel electronic states in this material.

Expression of aquaporins 1 and 3 in degenerative tissue of the lumbar intervertebral disc.

Lumbar intervertebral disc degeneration is induced by multiple factors, but few studies have examined the effects of aquaporins on this process. We compared the expression levels of aquaporins 1 and 3 in normal and degenerative lumbar intervertebral discs. Fifteen normal and 15 degenerative lumbar intervertebral disc tissues were excised from lumbar burst fracture patients during orthopedic operations at the Dali College subsidiary hospital. Tissues were stained with hematoxylin-eosin and the expression levels of aquaporins 1 and 3 were measured by immunohistochemistry. Hematoxylin-eosin-staining results illustrated that the structures of the intervertebral disc tissues from the control group were clear, with distinct collagen fiber shapes and slight edema but without mucoid degeneration. Structures of the intervertebral disc tissues from the disease group were obscure and disordered with hyperplastic collagen fibers and tissues of severe inflammatory edemas with necrosis mucoid degeneration. Immunohistochemistry results demonstrated that the average absorbances of aquaporins 1 and 3 in the disease group were significantly lower than those in the control group (P < 0.01), suggesting that the reduction of aquaporins 1 and 3 may be a factor resulting in lumbar intervertebral disc degeneration.

Resveratrol prevents renal lipotoxicity and inhibits mesangial cell glucotoxicity in a manner dependent on the AMPK-SIRT1-PGC1α axis in db/db mice.

AIMS/HYPOTHESIS: Many of the effects of resveratrol are consistent with the activation of AMP-activated protein kinase (AMPK), silent information regulator T1 (SIRT1) and peroxisome proliferator-activated receptor (PPAR)γ co-activator 1α (PGC-1α), which play key roles in the regulation of lipid and glucose homeostasis, and in the control of oxidative stress. We investigated whether resveratrol has protective effects on the kidney in type 2 diabetes. METHODS: Four groups of male C57BLKS/J db/m and db/db mice were used in this study. Resveratrol was administered via gavage to diabetic and non-diabetic mice, starting at 8 weeks of age, for 12 weeks. RESULTS: The db/db mice treated with resveratrol had decreased albuminuria. Resveratrol ameliorated glomerular matrix expansion and inflammation. Resveratrol also lowered the NEFA and triacylglycerol content of the kidney, and this action was related to increases in the phosphorylation of AMPK and the activation of SIRT1-PGC-1α signalling and of the key downstream effectors, the PPARα-oestrogen-related receptor (ERR)-1α-sterol regulatory element-binding protein 1 (SREBP1). Furthermore, resveratrol decreased the activity of phosphatidylinositol-3 kinase (PI3K)-Akt phosphorylation and class O forkhead box (FOXO)3a phosphorylation, which resulted in a decrease in B cell leukaemia/lymphoma 2 (BCL-2)-associated X protein (BAX) and increases in BCL-2, superoxide dismutase (SOD)1 and SOD2 production. Consequently, resveratrol reversed the increase in renal apoptotic cells and oxidative stress, as reflected by renal 8-hydroxy-deoxyguanosine (8-OH-dG), urinary 8-OH-dG and isoprostane concentrations. Resveratrol prevented high-glucose-induced oxidative stress and apoptosis in cultured mesangial cells through the phosphorylation of AMPK and activation of SIRT1-PGC-1α signalling and the downstream effectors, PPARα-ERR-1α-SREBP1. CONCLUSIONS/INTERPRETATION: The results suggest that resveratrol prevents diabetic nephropathy in db/db mice by the phosphorylation of AMPK and activation of SIRT1-PGC-1α signalling, which appear to prevent lipotoxicity-related apoptosis and oxidative stress in the kidney.

Room-temperature ferromagnetism of Cu-doped ZnO films probed by soft X-ray magnetic circular dichroism.

We report direct evidence of room-temperature ferromagnetic ordering in O-deficient ZnO:Cu films by using soft x-ray magnetic circular dichroism and x-ray absorption. Our measurements have revealed unambiguously two distinct features of Cu atoms associated with (i) magnetically ordered Cu ions present only in the oxygen-deficient samples and (ii) magnetically disordered regular Cu2+ ions present in all the samples. We find that a sufficient amount of both oxygen vacancies (V(O)) and Cu impurities is essential to the observed ferromagnetism, and a non-negligible portion of Cu impurities is uninvolved in the magnetic order. Based on first-principles calculations, we propose a microscopic "indirect double-exchange" model, in which alignments of localized large moments of Cu in the vicinity of the V(O) are mediated by the large-sized vacancy orbitals.

Ferromagnetism in dilute magnetic semiconductors through defect engineering: Li-doped ZnO.

We demonstrate, both theoretically and experimentally, that cation vacancy can be the origin of ferromagnetism in intrinsic dilute magnetic semiconductors. The vacancies can be controlled to tune the ferromagnetism. Using Li-doped ZnO as an example, we found that while Li itself is nonmagnetic, it generates holes in ZnO, and its presence reduces the formation energy of Zn vacancy, and thereby stabilizes the zinc vacancy. Room temperature ferromagnetism with p type conduction was observed in pulsed laser deposited ZnO:Li films with certain doping concentration and oxygen partial pressure.

Handedness in a Chinese population: biological, social, and pathological factors.

A questionnaire survey of 4143 Chinese was conducted. Social pressure for right-handed writing and eating was effective on these two target skills but showed little indirect influence on hand use in other activities. Neither primiparous birth nor birth to older mothers affected handedness. Twinning, however, seemed to be associated with both decreased right-handedness and lower intelligence.

Intraspinal schwannoma and neurogenic bladder.

Most lumbar intradural schwannomas present initially as radiculopathies with sensory disturbances. However, neurogenic bladder dysfunction may be one of the earliest manifestations and can cause long-term disability. We present the case of a patient with a L3-4 schwannoma (newly diagnosed owing to recurrent urinary retention and urinary tract infection) who finally underwent surgical resection. Improvement of bladder sensation was documented by urodynamic study and the patient was subsequently weaned off her Foley catheter with satisfactory outcome.

Molecular structure of fluoxetine hydrochloride, a highly selective serotonin-uptake inhibitor.

Fluoxetine, a selective inhibitor of serotonin uptake, is clinically useful in treating depression and may be useful for management of a variety of other psychiatric and metabolic derangements. Using X-ray crystallography, we have determined the three-dimensional structure of fluoxetine hydrochloride. A total of 2394 unique reflections were measured, and full-matrix least-squares refinement of all non-hydrogen coordinates and thermal parameters gave a final discrepancy index of 0.074 for 1759 observed reflections. In the solid state, the planes defined by the two aromatic rings are skewed, precluding the possibility of intramolecular ring-ring interactions. The methylene units of the methylpropanamine moiety adopt the anticipated conformational relationships to minimize torsional strain. An exact antiperiplanar relationship exists between N11 and C3; the N11-C1-C2-C3 dihedral angle is -180 degrees. The C1-C2-C3-O4 dihedral angle is 60.6 degrees, indicating that the propanamine side-chain folds toward the phenoxy moiety rather than adopting a fully extended conformation. This folded three-dimensional relationship may be necessary for high-affinity interaction with the serotonin-uptake carrier and confers considerable structural homology between this portion of fluoxetine and the phenylcyclohexylamine substructure of sertraline and EXP-561. However, the nature of substituents on the phenoxy portion of fluoxetine is also critical in determining potency and selectivity in this series of compounds.

A remarkable rate acceleration of the Baylis-Hillman reaction.

Treatment of alpha-naphthyl acrylate with both aliphatic and aromatic aldehydes in the presence of DABCO (30 mol%) afforded the desired (alpha-methylene-beta-hydroxy)esters with reasonable chemical yields (51-88%) within 20 min.

Exploring implicit personality theories with indigenous or imported constructs: the Chinese case.

This study is concerned with the relation between indigenous and imported constructs of personality perception. A pool of Chinese personality descriptors was used by Chinese Ss to rate a variety of target persons. These same Ss then rated the same target persons using the (translated) personality descriptions first isolated by Tupes and Christal (1961) from Americans. Five factors of personality perception were then derived from both the emic Chinese descriptors and the imported American descriptors. The interrelations among these factors were examined to address the basic question of how adequately the factors gleaned from these foreign materials represented Chinese perceptual space. Of the 5 Chinese factors, 4 could be adequately explained by varying combinations of the 5 imported factors. Furthermore, there was a 1-to-1 relation of imported to indigenous factors for only 2 of the 5 indigenous factors, whereas the others were multiply determined. The implications of these results are discussed with respect to the widespread use of foreign instrumentation and the models of man that may or may not be constructed in consequence.

Amperometric glucose enzyme electrode by immobilizing glucose oxidase in multilayers on self-assembled monolayers surface.

A novel and robust amperometric enzyme electrode for the determination of glucose was constructed by immobilizing glucose oxidase (GOD) and Os(bpy)(2)Cl-poly(4-vinyl)pyridine (Os-PVP) complex multilayers on thiol self-assembled monolayers surface. The apparent Michaelis-Menton constant K(m)' increased with increasing the number of Os-PVP/GOD multilayers. The concentration range of linear response and detection limit were 0.1-10 and 0.05 mM, the interference of ascorbic acid and uric acid were eliminated by the presence of SAMs and the enzyme electrodes were stable over 3 weeks. The preparation technique may be useful for controlling the performance of multilayer enzyme electrodes by changing the enzyme content.

Antioxidative effects of cichorium intybus root extract on LDL (low density lipoprotein) oxidation.

The water extract of Cichorium intybus (WECI) showed a remarkable antioxidative effect on LDL, and inhibitory effects on the production of thiobarbituric acid reactive substance and the Degradation of fatty acids in LDL. Vitamin E and unsaturated fatty acids in LDL were protected by adding WECI from the effects of metal catalyzed LDL oxidation. From the results obtained, we conclude that LDL oxidation is inhibited in vitro by the addition of WECI, and that LDL is protected by WECI from oxidative attack, as shown by agarose gel electrophoresis.

Effects of environmental endocrine disruptors on the sex differentiation in Korean rockfish, Sebastes schlegeli.

The effects of estradiol-17beta, methyltestosterone, tributyltin, bisphenol A and 2,4-dinitrophenol on sex differentiation were investigated in the Korean rockfish, Sebastes schlegeli. The 51 day-old fry with undifferentiated gonads were fed with food containing the chemicals at 0.05, 0.5, 5, 50 and 100 micro/g diet for 29 days. Sex ratio and gonadal abnormality after the chemical treatment were determined by histological examination of gonads. In control group, the sex ratio of fry was 1:1.3 (female:male), and more males than females appeared. The sex of fry fed with estradiol-17beta at 5, 50 and 100 micro/g diet was all females. Feminization of the fry was induced by exogenic estradiol-17beta. In the methyltestosterone group, sex ratio of fry was 1:10.2 in 0.05 micro/g diet, 1:2.4 in 0.5 micro/g diet, 1:3.1 in 5 micro/g diet, 1:1.2 in 50 micro/g diet and 1:2.3 in 100 micro/g diet. Masculinization of the fry was induced by methyltestosterone at the lowest concentration. Furthermore, intersex of the fry was observed. The number of intersex fry was 23.3, 25.0 and 35.3 at 0.5, 5 and 50 micro/g diet of methyltestosterone, respectively. Sex ratio of bisphenol A group showed no difference with that of the control. The sex of fry fed with 2,4-dinitrophenol at 5, 50 and 100 micro/g diet was all females. 2,4-dinitrophenol should be considered as a new member of endocrine disruptors. In tributyltin group, the sex ratio of fry at 100 micro/g diet of tributyltin was 5.4:1. Tributyltin induced the feminization of the fry at the highest dose. Tributyltin showed an estrogenic effect in the Korean rockfish in contrast to an androgenic effect in gastropods.

Safety of transorally-inserted anvil for esophagojejunostomy in laparoscopic total gastrectomy.

BACKGROUND: To assess the safety of transorally-inserted anvil (TOA) for use during esophagojejunostomy (EJ) reconstruction during laparoscopic total gastrectomy (LTG). METHODS: Between March 2009 and December 2011, 39 consecutive open total gastrectomies (OTGs) and 36 LTGs using TOA for gastric cancer were comparatively evaluated. We investigated postoperative complications, using the Clavien-Dindo classification. To evaluate the effect of a learning period in using TOA for LTG, we also investigated shifts in the patterns of complications and changes in total operation time over the course of the study. RESULTS: The patient characteristics at baseline were not different between both groups, except for the extent of lymphadenectomy (P < 0.001) and depth of tumor invasion (P = 0.003). Multivariate analysis revealed that TOA usage elevated the occurrence of infectious complications significantly (OR = 3.32, P = 0.042), but was not associated with EJ-related complications. TOA usage did not need a learning period for the length of time required to complete the operation, or the likelihood of developing an EJ-related or infectious complication. CONCLUSIONS: TOA use for EJ during LTG is relatively simple and easy enough not to require a learning period for surgeons. This procedure did not elevated the occurrence of EJ-related complications compared to circular stapling in open surgery, but it does require special prevention efforts to avoid infectious complications.

The clinical outcome of end-stage renal disease patients who return to peritoneal dialysis after renal allograft failure.

BACKGROUND: With the increased numbers of kidney transplantations, more patients return to dialysis after graft loss (DAGL). The aim of this study was to investigate the safety and efficacy of peritoneal dialysis (PD) after graft loss compared with transplant-naive PD patients (TN-PD). METHOD: This study was conducted on 715 patients who started PD between 1988 and 2009, including 47 who started PD after allograft loss (DAGL-PD) and 668 in the (TN-PD) group. RESULT: The mean ages were 40.8 ± 10.7 in DAGL-PD group and 51.03 ± 14.20 in TN-PD group (P < .01). The most common cause of end-stage renal disease in DAGL was primary glomerulonephritis (76.6%), but it was diabetes mellitus (38.9%) in the TN-PD group (P < .05). Patient survival rates at 1, 5, and 10 years were not different: 100%, 86%, and 57% versus 91%, 70%, and 62%, respectively. PD survival rate at 1, 5, and 10 years did not show significant differences: 98%, 95%, and 88% versus 95%, 80%, and 66%, respectively. The most common causes of death in both groups were infection (DAGL, 26.7%; TN-PD, 24.5%) followed by cardiovascular disease (DAGL, 20.0%; TN-PD, 19.6%); the distribution of causes did not differ significantly (P > .05). CONCLUSION: The clinical outcomes of PD in DAGL group were comparable with those of TN-PD patients. Therefore, PD could be considered as a dialysis modality for patients who experience allograft failure.