Charge Transfer Effects in Naturally Occurring van der Waals Heterostructures (PbSe)_{1.16}(TiSe_{2})_{m} (m=1, 2)

van der Waals heterostructures (VDWHs) exhibit rich properties and thus has potential for applications, and charge transfer between different layers in a heterostructure often dominates its properties and device performance. It is thus critical to reveal and understand the charge transfer effects in VDWHs, for which electronic structure measurements have proven to be effective. Using angle-resolved photoemission spectroscopy, we studied the electronic structures of (PbSe)_{1.16}(TiSe_{2})_{m} (m=1, 2), which are naturally occurring VDWHs, and discovered several striking charge transfer effects. When the thickness of the TiSe_{2} layers is halved from m=2 to m=1, the amount of charge transferred increases unexpectedly by more than 250%. This is accompanied by a dramatic drop in the electron-phonon interaction strength far beyond the prediction by first-principles calculations and, consequently, superconductivity only exists in the m=2 compound with strong electron-phonon interaction, albeit with lower carrier density. Furthermore, we found that the amount of charge transferred in both compounds is nearly halved when warmed from below 10 K to room temperature, due to the different thermal expansion coefficients of the constituent layers of these misfit compounds. These unprecedentedly large charge transfer effects might widely exist in VDWHs composed of metal-semiconductor contacts; thus, our results provide important insights for further understanding and applications of VDWHs.

Inhibition of the Effect of High Glucose on the Expression of Smad in Human Peritoneal Mesothelial Cells

Objective

As high glucose (HG) concentration in peritoneal dialysis (PD) solution is thought to contribute to peritoneal fibrosis, and angiotensin II receptor blockers (ARBs) may have a key role in preventing fibrosis as they may inhibit the TGF- ß1–Smad pathway, the aims of this in vitro study were to investigate 1) if HG affects the expression of Smad in human peritoneal mesothelial cells (HPMCs) and 2) if ARB (losartan) can inhibit this effect.

Methods

HPMCs, obtained from non-renal patients undergoing elective abdominal surgery, were stimulated by HG solutions with different concentrations (1.5%, 2.5%, 4.25%) of dextrose and mannitol, and by solutions containing combination with dextrose and losartan. The supernatant was assayed for TGF- ß1 by ELISA and cells were collected for the analysis of Smad family by RT-PCR and Western Blot.

Results

1) HG up-regulated the expression of Smad2 on both gene and protein levels, especially in 2.5% and 4.25% dextrose groups (P&0.05), and also stimulated the expression of Smad4 in 4.25% dextrose group. However, the expression of Smad3 was not affected. 2) High osmolality as such (using mannitol) did not affect the TGF-ß1-Smad signaling pathway. 3) Losartan inhibited the expression of Smad2 on the gene level but not on the protein level. 4) HG up-regulated the level of TGF- ß1 with increasing dextrose concentration, while losartan partially inhibited this effect of HG on releasing of TGF-ß1.

Conclusion

A high glucose solution up-regulated the expression of Smad2 and Smad4, suggesting that the TGF- ß1-Smad pathway could be involved in the fibrosis of the peritoneum during PD. As losartan inhibited the expression of Smad2 on the gene level and reduced the concentration of TGF- ß1 in our study, the results of this in vitro study suggest that the use of angiotensin II receptor blockers might represent a possible way to prevent and treat peritoneal fibrosis in PD patients. However, further studies in vivo are needed to confirm this hypothesis.

Dietary Intake is Positively Associated with Cognitive Function of a Chinese Older Adults Sample

OBJECTIVE

The relationship between cognitive function and dietary intake in older adults was under-studied in China. This study examined this relationship in a Chinese sample while controlling for the effects of sleep quality and socio demographic confounders.

METHODS

The sample consisted of 340 Chinese older adults (age > 60) who were randomly selected from Wuhan city in central China. Cognitive function was assessed by the Mini-mental State Examination [MMSE], sleep quality by the Pittsburgh Sleep Quality Index [PSQI], and dietary intake by frequencies of intake of meat products, fruits, fish/seafood/aquatic products, nuts and mushroom/algae over the past year. First, confirmatory factor analysis (CFA) was conducted to evaluate the measurement properties of cognitive function, dietary intake, and sleep quality. Second, structural equation modeling (SEM) was conducted to examine the relations of cognitive function, dietary intake, and sleep quality.

RESULTS

Dietary intake was found to be positively related to cognitive function. Older age, lower education status, monthly income, and living alone or without a spouse were significantly associated with poorer cognitive function. SES status had an indirect effect on cognitive function via dietary intake.

CONCLUSION

Dietary intake may be critical to maintain normal cognitive function of older adults in China.

Base-promoted hydrolytic dehydrogenation of ammonia borane catalyzed by noble-metal-free nanoparticles

Noble-metal-free CuCoMo catalysts exhibited ultra-high catalytic performance toward the hydrolytic dehydrogenation of ammonia borane under the assistance of a base.

Metal–organic framework immobilized RhNi alloy nanoparticles for complete H2 evolution from hydrazine borane and hydrous hydrazine

MOF immobilized RhNi alloy NPs with size of 2.8 nm have been fabricated via a reduction rate controlled method and applied as efficient catalyst for complete H₂ evolution from hydrazine borane and hydrous hydrazine.

Optomechanical properties of GaAs/AlAs micropillar resonators operating in the 18 GHz range

Recent experiments demonstrated that GaAs/AlAs based micropillar cavities are promising systems for quantum optomechanics, allowing the simultaneous three-dimensional confinement of near-infrared photons and acoustic phonons in the 18-100 GHz range. Here, we investigate through numerical simulations the optomechanical properties of this new platform. We evidence how the Poisson's ratio and semiconductor/vacuum boundary conditions lead to very distinct features in the mechanical and optical three-dimensional confinement. We find a strong dependence of the mechanical quality factor and strain distribution on the micropillar radius, in great contrast to what is predicted and observed in the optical domain. The derived optomechanical coupling constants g₀ reach ultra-large values in the 10⁶ rad/s range.

Study on the expression and mechanism of plasma microRNA-21 in patients with ischemic cardiomyopathy

OBJECTIVE

To investigate the expression and mechanism of plasma microRNA-21 in patients with ischemic cardiomyopathy (ICM).

PATIENTS AND METHODS

56 cases of ICM patients were selected in our hospital from February 2010 to March 2016 as the observation group, and 60 cases of healthy patients were selected as control group. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of microRNA-21 in two groups. Then, differences of the total cholesterol (TC), triglycerides (TG), left ventricular ejection fraction (LVEF), high and low density lipoprotein cholesterol (HDL-C, LDL-C), left ventricular end-diastolic volume (LVEDV), N terminal B type brain natriuretic peptide (NT-proBNP) and other clinical indicators of the two groups, were compared. The correlation between the plasma microRNA-21 level and the clinical indices was analyzed, and the value of microRNA-21 in the diagnosis and treatment of ICM was evaluated.

RESULTS

The levels of LDL-C, HDL-C and LVEF in the observation group were lower than those in the control group (p<0.05). Plasma microRNA-21, TG, NT-proBNP and LVEDV were higher than those in the control group; the difference was statistically significant (p<0.05). Logistic regression analysis showed that the plasma microRNA-21 level was positively correlated with NT-proBNP and LVEDV (p<0.05).

CONCLUSIONS

The expression of microRNA-21 in plasma of patients with ICM was significantly increased. And the expression of micro RNA-21 in plasma was positively correlated with NT-proBNP and LVEDV. Through the ventricular remodeling in ICM patients, it can be used as a new target for the diagnosis and treatment of ICM and a new biomarker for risk assessment.

[A randomized controlled clinical trial of acoustic resonance combined with systemic steroid therapy for sudden hearing loss]

Objective:To study the short-term and long-term therapeutic effect of acoustic resonance combined with systemic steroid therapy in treatment of Sudden hearing loss (SHL).Method:Clinical data of 128 patients with SHL were analyzed in the randomized controlled trial. Patients were divided into study group (68 cases) and control group (60 cases). Patients in control group received steroid therapy and conventional drug therapy, while study group received acoustic resonance therapy combined with systemic steroid therapy and conventional drug therapy.Result:The total effective rate of study group and control group was 66.18% and 65.00% respectively at the end of treatment; the total effective rate of study group and control group was 72.06% and 70.00% 4 weeks after treatment; the total efficiency of study group and control group was 73.53% and 68.33% respectively 8 weeks after treatment. The total effective rate of study group was not significantly higher than that of the control group in the three periods (P> 0.05). But the PTA significantly improved in study group 4 weeks and 8 weeks after treatment [(43.87±16.73)dB, (40.96±17.11)dB], while the PTA of control group is (50.89±18.41)dB, (48.93±17.84)dB (P< 0.05), and no serious adverse events were happened during treatments and after treatments.Conclusion:Acoustic resonance combined with systemic steroid therapy can significantly improve the therapeutic effect of SHL with no obvious side effects, which is worth clinical promotion.

[Effects of tetrahydrobiopterin on the angiogenesis in hepatocellular carcinoma]

Objective: To investigate the effect and mechanism of tetrahydrobiopterin (BH4) on the angiogenesis in hepatocellular carcinoma (HCC). Methods: BALB/c-nu mice were subcutaneously injected with HepG-2 cells and randomly divided into control and BH4 groups. The BH4 group and control group received 20 mg/kg BH4 or saline by intraperitoneal injection daily for two weeks, respectively. The level of BH4 was measured by high performance liquid chromatography (HPLC), the level of nitric oxide (NO) was measured by Griess test array, the transcriptional level of K-ras was measured by quantitative RT-PCR, and the protein expressions of guanosine triphosphate cyclohydrolase Ⅰ(GTPCH), endothelial nitric oxide synthase (eNOS), phospho-Akt and Akt were determined by Western blot. Results: BH4 level in the tumor tissues of BH4 group was (0.24±0.02) μg/ml, significantly higher than the (0.17±0.01) μg/ml in the control group (P<0.01). The level of NO in the tumor tissues of BH4 group was (51.44±2.90) mmol/L, significantly higher than the (24.77±0.54) mmol/L in the control group (P<0.01). The tumor volume of BH4 group was (191.05±8.70) mm3, significantly higher than the (103.10±5.03) mm3 in the control group (P<0.01). The expressions of CD34, K-ras, phospho-eNOS, phospho-Akt and GTPCH were significantly up-regulated in the tumor tissues of BH4 group when compared with those of the control group (P<0.01). Conclusions: BH4 recognized as an essential cofactor of eNOS can increase tumor-produced NO by activating the wild-type Ras-PI3K/Akt pathway, thus induces angiogenesis. This might provide a novel and promising way to control the progression of hepatocellular carcinoma through targeting BH4 synthesis pathway and inhibiting angiogenesis.

Facile Synthesis of Platinum-Cerium(IV) Oxide Hybrids Arched on Reduced Graphene Oxide Catalyst in Reverse Micelles with High Activity and Durability for Hydrolysis of Ammonia Borane

Highly dispersed Pt-CeO₂ hybrids arched on reduced graphene oxide (Pt-CeO₂ /rGO) were facilely synthesized by a combination of the reverse micelle technique and a redox reaction without any additional reductant or surfactant. Under a N₂ atmosphere, the redox reaction between Ce³⁺ and Pt²⁺ occurs automatically in alkaline solution, which results in the formation of Pt-CeO₂ /rGO nanocomposites (NCs). The as-synthesized Pt-CeO₂ /rGO NCs exhibit superior catalytic performance relative to that shown by the free Pt nanoparticles, Pt/rGO, Pt-CeO₂ hybrid, and the physical mixture of Pt-CeO₂ and rGO; furthermore, the nanocomposites show significantly better activity than the commercial Pt/C catalyst toward the hydrolysis of ammonia borane (NH₃ BH₃ ) at room temperature. Moreover, the Pt-CeO₂ /rGO NCs have remarkable stability, and 92 % of their initial catalytic activity is preserved even after 10 runs. The excellent activity of the Pt-CeO₂ /rGO NCs can be attributed not only to the synergistic structure but also to the electronic effects of the Pt-CeO₂ /rGO NCs among Pt, CeO₂ , and rGO.

Highly Anisotropic and Twofold Symmetric Superconducting Gap in Nematically Ordered FeSe_{0.93}S_{0.07}

FeSe exhibits a novel ground state in which superconductivity coexists with a nematic order in the absence of any long-range magnetic order. Here, we report on an angle-resolved photoemission study on the superconducting gap structure in the nematic state of FeSe_{0.93}S_{0.07}, without the complications caused by Fermi surface reconstruction induced by magnetic order. We find that the superconducting gap shows a pronounced twofold anisotropy around the elliptical hole pocket near Z (0, 0, π), with gap minima at the end points of its major axis, while no detectable gap is observed around Γ (0, 0, 0) and the zone corner (π, π, k_{z}). The large anisotropy and nodal gap distribution demonstrate the substantial effects of the nematicity on the superconductivity and thus put strong constraints on current theories.

Erratum: Structural and Electronic Properties of Germanene on MoS_{2} [Phys. Rev. Lett. 116, 256804 (2016)]

This corrects the article DOI: 10.1103/PhysRevLett.116.256804.

Structural and Electronic Properties of Germanene on MoS_{2}

To date germanene has only been synthesized on metallic substrates. A metallic substrate is usually detrimental for the two-dimensional Dirac nature of germanene because the important electronic states near the Fermi level of germanene can hybridize with the electronic states of the metallic substrate. Here we report the successful synthesis of germanene on molybdenum disulfide (MoS_{2}), a band gap material. Preexisting defects in the MoS_{2} surface act as preferential nucleation sites for the germanene islands. The lattice constant of the germanene layer (3.8±0.2  Å) is about 20% larger than the lattice constant of the MoS_{2} substrate (3.16 Å). Scanning tunneling spectroscopy measurements and density functional theory calculations reveal that there are, besides the linearly dispersing bands at the K points, two parabolic bands that cross the Fermi level at the Γ point.

[Fine needle aspiration cytology of thyroid nodules: a cytopathologic study of 2 043 cases]

OBJECTIVE

To evaluate the clinical value of thyroid fine needle aspiration cytology(FNAC) and the Bethesda system for reporting thyroid cytopathology(TBSRTC).

METHODS

FNAC was performed for 2 043 cases and cytopathological data were retrospectively analyzed. Cytopathological diagnoses according to TBSRTC were classified as non-diagnostic, benign, atypia of undetermined significance/follicular lesion of undetermined significance(AUS/FLUS), follicular neoplasm/suspicious for follicular neoplasm(FN/SFN), suspicious for malignancy(SM) and malignancy. The results of 234 FNAC samples in which surgery was performed were compared with the histological diagnoses.

RESULTS

Of the 2 043 FNAC samples, 15.7%(320/2 043)were non-diagnostic, 51.2%(1 047/2 043)were benign, 16.6%(339/2 043) were AUS/FLUS, 2.3%(46/2 043)were FN/SFN, 8.6%(176/2 043)were SM and 5.6%(115/2 043)were malignant. In 234 cases, there was follow-up histology. Rates of malignancy were as follows: non-diagnostic, 18.2%(2/11); benign(2.2%, 1/45); AUS/FLUS(25.6%, 10/29); FN/SFN(12.1%, 10/39); SM(91.8%, 56/61); malignant(100.0%, 45/45). The sensitivity, specificity, false positive rate, false negative rate and overall accuracy of FNAC in the diagnosis of thyroid nodules was 87.1%(101/116), 95.3%(102/107), 4.7%(5/107), 12.9%(15/116), 91.0%(203/223).

CONCLUSIONS

FNAC is a reliable diagnostic method for evaluation of thyroid disease. TBSRTC is a accurate and effective reporting system for cytopathological diagnoses, so it is worthy of being widely popularized in clinical application.

No causal effect of serum urate on bone-related outcomes among a population of postmenopausal women and elderly men of Chinese Han ethnicity--a Mendelian randomization study

SUMMARY

We conducted a Mendelian randomization analysis to assess the effect of serum uric acid on bone-related outcomes using a weighted urate transporter genetic risk score as the instrumental variable. The results showed no significance. Our study identified no evidence of a causal role between uric acid and bone-related outcomes.

INTRODUCTION

Observational studies have associated elevated levels of serum uric acid (SUA) with increasing bone mineral density (BMD) and a lowered prevalence of osteoporotic fractures (OFs) in postmenopausal women and elderly men. However, due to unmeasured confounding variables, these observational studies have not provided insight into the causal relationship between SUA and bone-related outcomes. Our aim was to evaluate the effect of SUA on bone-related outcomes using Mendelian randomization.

METHODS

We recruited 1322 Chinese Han individuals (214 elderly men and 1108 postmenopausal women) from the Shanghai area in China. Mendelian randomization using a two-stage least-squares regression method was conducted with SUA as the exposure variable, a weighted urate transporter genetic risk score as the instrumental variable, and all-site BMD, bone turnover markers, and levels of 25-hydroxyvitamin D3 [25(OH)D], serum calcium (Ca), serum phosphorus (P), and parathyroid hormone (PTH) as outcome variables.

RESULTS

Strong associations between SUA and bone-related outcomes were observed in an ordinary observational analysis (lumbar spine: beta = 0.122, p < 0.0001; hip: beta = 0.104, p < 0.0001; femoral neck: beta = 0.108, p < 0.0001). However, the Mendelian randomization analysis showed no evidence for a causal association of SUA with BMD (lumbar spine: beta = 0.385, p = 0.257; hip: beta = 0.191, p = 0.499; femoral neck: beta = 0.194, p = 0.533). Similar results were found between SUA and other bone-related phenotypes.

CONCLUSIONS

Our study identified no evidence of a causal role between SUA and bone-related outcomes, although strong associations in an observational analysis were observed in a population of postmenopausal women and elderly men.

Core–shell Co@SiO2 nanosphere immobilized Ag nanoparticles for hydrogen evolution from ammonia borane

Silver nanoparticles anchored on core–shell Co@SiO₂ nanospheres (Co@SiO₂/Ag) have been facilely prepared by using an in situ generated approach, and exhibited higher catalytic activity than their monometallic counterparts for the hydrolysis of AB.

Ruthenium nanoparticles confined in SBA-15 as highly efficient catalyst for hydrolytic dehydrogenation of ammonia borane and hydrazine borane

Ultrafine ruthenium nanoparticles (NPs) within the mesopores of the SBA-15 have been successfully prepared by using a “double solvents” method, in which n-hexane is used as a hydrophobic solvent and RuCl₃ aqueous solution is used as a hydrophilic solvent. After the impregnation and reduction processes, the samples were characterized by XRD, TEM, EDX, XPS, N₂ adsorption-desorption, and ICP techniques. The TEM images show that small sized Ru NPs with an average size of 3.0 ± 0.8 nm are uniformly dispersed in the mesopores of SBA-15. The as-synthesized Ru@SBA-15 nanocomposites (NCs) display exceptional catalytic activity for hydrogen generation by the hydrolysis of ammonia borane (NH₃BH₃, AB) and hydrazine borane (N₂H₄BH₃, HB) at room temperature with the turnover frequency (TOF) value of 316 and 706 mol H₂ (mol Ru min)⁻¹, respectively, relatively high values reported so far for the same reaction. The activation energies (E_a) for the hydrolysis of AB and HB catalyzed by Ru@SBA-15 NCs are measured to be 34.8 ± 2 and 41.3 ± 2 kJ mol⁻¹, respectively. Moreover, Ru@SBA-15 NCs also show satisfied durable stability for the hydrolytic dehydrogenation of AB and HB, respectively.

Evolutionary analysis of the ubiquitin gene of baculovirus and insect hosts

Baculovirus is the only virus that has been found to encode the ubiquitin protein. In this study, ubiquitin sequences from 16 insects and 49 viruses were collected and compared. The resulting sequences were aligned with virus genomes. Then MAGE 5.0, k-estimated software, as well as other software programs were used for systemic evolutionary, selection pressure, and evolutionary distance analysis. The results of the pairwise ratio of non-synonymous to synonymous substitution values and evolutionary distances showed that ubiquitin from baculovirus and insect hosts have been under purifying selection during evolution and are thus evolutionarily conserved. Moreover, genes from insect hosts were more conserved than those in baculovirus. Analysis of the non-synonymous to synonymous substitution rates at each site and entropy calculations revealed the evolutionary status of every site in the ubiquitin genes of baculovirus and their hosts. Genome locations and phylogenetic trees indicated that granuloviruses and non-photosynthetic vegetation evolved, and granulovirus evolution was more similar to that of insect hosts. Our results suggest that the ubiquitin gene in baculovirus may have been acquired through horizontal transfer from the host.

Methanolysis of ammonia borane by shape-controlled mesoporous copper nanostructures for hydrogen generation

Diverse mesoporous CuO nanostructures have been prepared by a facile and scaleable wet-chemical method and reduced to mesoporous Cu nanostructures by using the reductant ammonia borane (AB). These mesoporous Cu nanostructures have been applied as a catalyst for hydrogen generation from the methanolysis of AB. The catalytic results show that the reaction rate and the amount of hydrogen evolution significantly relied on their morphologies. Compared with the nanosheet-like, bundle-like and dandelion-like Cu, the flower-like Cu nanostructures exhibit the highest catalytic activity with a total turnover frequency (TOF) value of 2.41 mol H2 mol catalyst(-1) min(-1) and a low activation energy value of 34.2 ± 1.2 kJ mol(-1) at room temperature. Furthermore, the flower-like Cu nanostructures have also shown excellent activity in recycling tests. The low cost and high performance of Cu nanocatalysts may offer high potential for its practical application in hydrogen generation from the methanolysis of AB.

Effects of Herceptin on circulating tumor cells in HER2 positive early breast cancer

The objective of this study was to determine the changes in peripheral blood circulating tumor cells in HER2-positive early breast cancer before and after Herceptin therapy, and to explore the effects of the HER2 gene and Herceptin on circulating tumor cells. CK19 mRNA expression in peripheral blood was evaluated by qRT-PCR as an index of circulating tumor cells in 15 cases of HER-2-positive breast cancer and 18 cases of HER2-negative breast cancer before, and after chemotherapy as well. Ten cases of HER2-positive breast cancer continued on Herceptin therapy for 3 months after chemotherapy, and their peripheral blood was again drawn and assayed for CK-19 mRNA expression. Preoperatively, all cases of HER2-positive cancer were positive for CK19 mRNA in peripheral blood, but 6 cases of HER2-negative breast cancer were positive (33.3%), where there was a substantial difference between the two groups. After 6 cycles of adjuvant chemotherapy, CK19 positive rates in cases of HER2-positive and -negative breast cancer reduced by 93.3 and 11.1%, respectively, with a significant difference still existing. After 3 months of Herceptin therapy, expression of CK19 mRNA declined considerably in 10 cases of HER2 positive breast cancer (113.66 ± 88.65 vs 63.35 ± 49.27, P = 0.025). HER-2 gene expression closely correlated with circulating tumor cells in peripheral blood of early breast cancer patients. Moreover, Herceptin, a monoclonal antibody for HER2, can reduce the number of circulating tumor cells, which can be an early predictive factor for Herceptin therapy effectiveness against breast cancer.

miR-15b regulates cisplatin resistance and metastasis by targeting PEBP4 in human lung adenocarcinoma cells

MicroRNAs (miRNAs) have been identified as important posttranscriptional regulators involved in various biological and pathological processes of cells, but their association with tumor chemoresistance has not been fully understood. We detected miR-15b expression in two lung adenocarcinoma cell lines, A549 and A549/CDDP, and then investigated the effects of miR-15b on the metastasis and the chemosensitivity of cancer cells, using both gain- and loss-of-function studies. The correlation between miR-15b level and chemoresistance was further investigated in clinical lung adenocarcinoma specimens. miR-15b was significantly upregulated in cisplatin-resistant lung adenocarcinoma A549/CDDP cells compared with parental A549 cells. miR-15b regulates epithelial-mesenchymal transition (EMT) and cisplatin resistance in vitro and modulates response of lung adenocarcinoma cells to cisplatin in vivo. Further studies identified phosphatidylethanolamine-binding protein 4 (PEBP4) as a direct and functional target of miR-15b. Small-interfering RNA-mediated PEBP4 knockdown revealed similar effects as that of ectopic miR-15b expression, whereas overexpression of PEBP4 attenuated the function of miR-15b in lung adenocarcinoma cells. Increased miR-15b expression was also detected in tumor tissues sampled from lung adenocarcinoma patients treated with cisplatin-based chemotherapy and was proved to be correlated with low expression of PEBP4, decreased sensitivity to cisplatin and poor prognosis. Our results suggest that upregulation of miR-15b could suppress PEBP4 expression and in turn contribute to chemoresistance of lung adenocarcinoma cells to cisplatin.

Sirenomelia with upper limb malformation: a case report and review of the literature

Sirenomelia sequence is a rare lethal pattern of congenital anomalies characterized by fusion of the legs and a variable combination of visceral abnormalities. Some cases accompanied with rare malformations have been reported. In this article, the authors report a case of sirenomelia with upper limb malformations and a review of the literature.

Selective termination in discordant twin pregnancy with early onset preeclampsia: case report

OBJECTIVE

To study the effectiveness of selective termination for discordant twins in treating early onset preeclampsia.

MATERIALS AND METHODS

After literature review, ethical review, and discussion with the couple, one patient with early onset preeclampsia complicated with a lethal condition in one twin, was performed selective termination by intracardiac injection of potassium chloride at 27 weeks' and four days' gestation in an effort to reverse preeclampsia and prolong the pregnancy.

RESULTS

The clinical manifestation of preeclampsia was alleviated in this patient. At 29 weeks, the stillborn fetus was delivered because of spontaneous preterm labor. A live birth was achieved five days later. All procedures allowed continuation of the pregnancy for an additional two weeks and one day of the remaining fetus.

CONCLUSION

Selective termination may be an option for treating early onset preeclampsia in discordant twins, instead of termination of whole pregnancy.

The Pekin duck programmed death-ligand 1: cDNA cloning, genomic structure, molecular characterization and mRNA expression analysis

Programmed death ligand-1 (PD-L1) plays an important role in the attenuation of adaptive immune responses in higher vertebrates. Here, we describe the identification of the Pekin duck PD-L1 orthologue (duPD-L1) and its gene structure. The duPD-L1 cDNA encodes a 311-amino acid protein that has an amino acid identity of 78% and 42% with chicken and human PD-L1, respectively. Mapping of the duPD-L1 cDNA with duck genomic sequences revealed an exonic structure of its coding sequence similar to those of other vertebrates but lacked a noncoding exon 1. Homology modelling of the duPD-L1 extracellular domain was compatible with the tandem IgV-like and IgC-like IgSF domain structure of human PD-L1 (PDB ID: 3BIS). Residues known to be important for receptor binding of human PD-L1 were mostly conserved in duPD-L1 within the N-terminus and the G sheet, and partially conserved within the F sheet but not within sheets C and C'. DuPD-L1 mRNA was constitutively expressed in all tissues examined with highest expression levels in lung and spleen and very low levels of expression in muscle, kidney and brain. Mitogen stimulation of duck peripheral blood mononuclear cells transiently increased duPD-L1 mRNA expression. Our observations demonstrate evolutionary conservation of the exonic structure of its coding sequence, the extracellular domain structure and residues implicated in receptor binding, but the role of the longer cytoplasmic tail in avian PD-L1 proteins remains to be determined.

One-pot synthesis of core-shell Cu@SiO2 nanospheres and their catalysis for hydrolytic dehydrogenation of ammonia borane and hydrazine borane

Ultrafine copper nanoparticles (Cu NPs) within porous silica nanospheres (Cu@SiO₂) were prepared via a simple one-pot synthetic route in a reverse micelle system and characterized by SEM, TEM, EDX, XRD, N₂ adsorption-desorption, CO-TPD, XPS, and ICP methods. The characterized results show that ultrafine Cu NPs with diameter of around 2 nm are effectively embedded in the center of well-proportioned spherical SiO₂ NPs of about 25 nm in diameter. Compared to commercial SiO₂ supported Cu NPs, SiO₂ nanospheres supported Cu NPs, and free Cu NPs, the synthesized core-shell nanospheres Cu@SiO₂ exhibit a superior catalytic activity for the hydrolytic dehydrogenation of ammonia borane (AB, NH₃BH₃) and hydrazine borane (HB, N₂H₄BH₃) under ambient atmosphere at room temperature. The turnover frequencies (TOF) for the hydrolysis of AB and HB in the presence of Cu@SiO₂ nanospheres were measured to be 3.24 and 7.58 mol H₂ (mol Cu min)⁻¹, respectively, relatively high values for Cu nanocatalysts in the same reaction. In addition, the recycle tests show that the Cu@SiO₂ nanospheres are still highly active in the hydrolysis of AB and HB, preserving 90 and 85% of their initial catalytic activity even after ten recycles, respectively.

Cyclic mechanical stress modulates neurotrophic and myelinating gene expression of Schwann cells

OBJECTIVES

This study aimed to investigate the response of Schwann cells to cyclic compressive and tensile stresses of different durations of stimulation.

MATERIALS AND METHODS

RSC96 cells were subjected to cyclic tensile stress or compressive stress; for either, cells in five groups were treated for 0, 1, 2, 24 and 48 h respectively. Enzyme-linked immunosorbent assay was conducted to detect secretion of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 and neurotrophin-4 in the culture medium. Real-time PCR was conducted to quantify mRNA expression of neurotrophins including NGF, BDNF, neurotrophin-3 and neurotrophin-4, and myelin-related genes including Sox10, Krox20, neuregulin 1, NCAM, N-cadherin, P0, MAG and MBP. Immunofluorescent staining was performed to visualize Krox20 and F-actin in the tensile groups.

RESULTS

Within 24 h, cells treated with cyclic tensile stress expressed and secreted significantly more BDNF, while cyclic compression down-regulated BDNF expression. Cells treated with both tensile and compressive stress down-regulated expression of NRG1, NCAM, Krox20 and Sox10 at all time points. Expression of N-cadherin was not affected by either stretch or compression. F-actin was down-regulated by tensile stress.

CONCLUSIONS

Both tensile and compressive loading down-regulated expression of several important myelin-related Schwann cells genes and thus facilitated demyelination. Tensile stress meanwhile promoted secretion of BDNF by Schwann cells within 24 h, which may contribute to maintenance and repair of damaged axons. These effects of mechanical stress might have been mediated by the actin cytoskeleton.

Tumour-initiating capacity is independent of epithelial-mesenchymal transition status in breast cancer cell lines

Background:

Epithelial–mesenchymal transition (EMT) and cancer stem cells (CSCs) are considered to be crucial for cancer biology. The purpose of this study was to determine whether EMT directly led to the acquisition of tumour-initiating capacity in breast cancer cell lines.

Methods:

Epithelial–mesenchymal transition was induced in five breast cancer cell lines and one normal breast cell line by EMT-related cytokine stimulation. Mesenchymal–epithelial transition (MET) was induced by stably overexpressing miR-200c in three mesenchymal-like breast cancer cell lines. Molecular expression and cell function analysis were performed to evaluate the effect of EMT or MET on tumour-initiating capacity and other biological characteristics.

Results:

The induction of EMT did not enhance tumour-initiating capacity but, instead, conferred a CD44⁺/CD24^−/low phenotype as well as cell proliferation, migration, and resistance to doxorubicin and radiation on breast cancer cell lines. Furthermore, MET did not lead to inhibition or loss of the tumour-initiating capacity in mesenchymal-like breast cancer cell lines, but it markedly attenuated other malignant properties, including proliferation, invasion, and resistance to therapy.

Conclusions:

Epithelial–mesenchymal transition does not alter tumour-initiating capacity of breast cancer cells but some other biological characteristics. Therefore, EMT and tumour-initiating capacity may not be directly linked in breast cancer cell lines.

Clinical and cytogenomic studies in a case of infertility associated with a nonmosaic dicentric Y chromosome

In this study, a short stature male with infertility is reported. Semen analysis and serum concentrations of FSH, LH, T and PRL were estimated. Chromosome analysis was performed on lymphocytes obtained from both the male and his parents. Cytogenomic studies were performed by fluorescent in situ hybridisation and the CytoScan(™)  HD array analysis to detect Y chromosomal rearrangements and copy number mutations. Semen analysis showed severe oligozoospermia. Numerous spermatogenic cells were observed in the semen, and approximately 60% of the cells examined in semen were primary spermatocytes, showing spermatogenic arrest at the primary spermatocyte level. Cytogenomic studies of blood revealed his karyotype which was 46,X,i(Y) (p11.32) (Yqter→Yp11.32::Yp11.32→Yqter).ish (DYZ3++, SRY++, SHOX-). array (PLCXD1→SHOX) ×1,(SRY →GOLGA2P3Y)×2, (DHRSX→ ASMT, SPRY3 →IL9R)×3. The rearrangement Y chromosome is de novo. This is the first case reported with a nonmosaic 46,X, i (Y) (p11.32), which will be useful to estimate the infertility phenotype-molecular karyotype correlation. Haploinsufficiency of short stature homeobox-containing gene is primarily responsible for the short stature. Aberrations in pseudoautosomal region 1 on the rearranged Y chromosome may result in the deficiency of X-Y pairing or recombination, ultimately lead to the spermatogenic failure.

Kinetic modeling of inherent mineral catalyzed NO reduction by biomass char

The evolution of rice straw char reactivity during reaction with NO was examined in differential reactor at 900 and 1000 °C. Original and acid-washed rice straw chars were used. Surface area and mineral content of char samples with different conversion were analyzed. The reactivity of the acid-washed char increased until conversion Xchar = 20%, remained constant, and then decreased continuously to zero. The reactivity of the original char decreased continuously to zero throughout the reaction, with a faster decrease at 1000 °C. Mineral transformation during original char reaction was obvious. Concentration of acid-soluble K decreased about 56% and 90% at 900 and 1000 °C. Ca and Mg released little to gas phase, but reacted with SiO2 in a small amount. The evolution of the acid-washed char reactivity correlated well with the development of surface area and was well predicted by random pore model. The reactivity of the original char depended not only on the development of surface area, but also on transformation of inherent minerals, mainly K. A two-reaction model was built which well predicted inherent K transformation. A modified random pore model was developed, which successfully simulated inherent mineral catalyzed char-NO reaction.

Uterine contractility in intrahepatic cholestasis of pregnancy

This study aims to compare uterine activity in intrahepatic cholestasis of pregnancy (ICP) patients vs normal pregnancies, and to determine the relevance of ICP and excessive uterine activity. A total of 59 patients with ICP and 89 with normal pregnancies were selected. Liver function, total bile acids and uterine activity were evaluated; uterine contraction parameters were compared at the specified range of gestational age. Uterine contraction frequency was significantly higher in the third trimester patients with ICP. Aspartate transaminase (AST) appeared to correlate with contraction frequency (r = 0.357, p = 0.006) and Montevideo units (MVUs) (r = 0.349, p = 0.007). For each 50 U/l increase in AST, the hazard ratio of excessive uterine activity was increased by 1.31-fold (95% CI = 1.034-1.663, p = 0.025). The present study demonstrates that third trimester uterine contractility increases in patients with ICP. These findings should be of note, given what is known about obstetric cholestasis, and should prompt further research.

Conjoined twins: three cases in one tertiary medical center and literature review

Conjoined twins are so rare that most obstetricians will not be personally exposed to such cases during their professional lifetimes. The authors report three cases including one of dicephalic parapagus conjoined twins and two thoracopagus conjoined twins in the present tertiary medical center, and discuss the diagnosis and management details. They also review the incidence, embryological, diagnostic, obstetrical, and prognostic aspects of conjoined twins. Regular antenatal visits and serial ultrasound scanning are crucial for early diagnosis of conjoined twins, optimal obstetric management and perinatal preparation still remain challenging, and multidisciplinary cooperation is urgently needed.

Phylogenetic analyses of vector mosquito basic helix-loop-helix transcription factors

Basic helix-loop-helix (bHLH) transcription factors play critical roles in the regulation of a wide range of developmental processes in higher organisms and have been identified in more than 20 organisms. Mosquitoes are important vectors of certain human diseases. In this study, Aedes aegypti, Anopheles gambiae str. PEST and Culex quinquefasciatus genomes were found to encode 55, 55 and 57 bHLH genes, respectively. Further phylogenetic analyses and OrthoDB and Kyoto encyclopedia of genes and genomes orthology database searches led us to define orthology for all the identified mosquito bHLHs successfully. This provides useful information with which to update annotations to 40 Ae. aegypti, 55 An. gambiae and 38 C. quinquefasciatus bHLH genes in VectorBase. The mosquito lineage has more bHLH genes in the Atonal, neurogenin (Ngn) and Hes-related with YRPW motif (Hey) families than do other insect species, suggesting that mosquitoes have evolved to be more sensitive to vibration, light and chemicals. Mosquito bHLH genes generally have higher evolutionary rates than other insect species. However, no pervasive positive selection occurred in the evolution of insect bHLH genes. Only episodic positive selection was found to affect evolution of bHLH genes in 11 families. Besides, coding regions of several Ae. aegypti bHLH motifs have unusually long introns in which multiple copies of transposable elements have been identified. These data provide a solid basis for further studies on structures and functions of bHLH proteins in the regulation of mosquito development and for prevention and control of mosquito-mediated human diseases.

Gene profile identifies zinc transporters differentially expressed in normal human organs and human pancreatic cancer

Deregulated expression of zinc transporters was linked to several cancers. However, the detailed expression profile of all human zinc transporters in normal human organs and in human cancer, especially in pancreatic cancer is not available. The objectives of this study are to investigate the complete expression patterns of 14 ZIP and 10 ZnT transporters in a large number of normal human organs and in human pancreatic cancer tissues and cell lines. We examined the expression patterns of ZIP and ZnT transporters in 22 different human organs and tissues, 11 pairs of clinical human pancreatic cancer specimens and surrounding normal/benign tissues, as well as 10 established human pancreatic cancer cell lines plus normal human pancreatic ductal epithelium (HPDE) cells, using real time RT-PCR and immunohistochemistry. The results indicate that human zinc transporters have tissue specific expression patterns, and may play different roles in different organs or tissues. Almost all the ZIPs except for ZIP4, and most ZnTs were down-regulated in human pancreatic cancer tissues compared to the surrounding benign tissues. The expression patterns of individual ZIPs and ZnTs are similar among different pancreatic cancer lines. Those results and our previous studies suggest that ZIP4 is the only zinc transporter that is significantly up-regulated in human pancreatic cancer and might be the major zinc transporter that plays an important role in pancreatic cancer growth. ZIP4 might serve as a novel molecular target for pancreatic cancer diagnosis and therapy.

Complete and repeatable inactivation of HIV-1 viral particles in suspension using a photo-labeled non-nucleoside reverse transcriptase inhibitor

A method is described for achieving repeatable, complete inactivation of HIV, based on photo-inactivation of HIV reverse transcriptase (RT) with a non-nucleoside reverse transcriptase inhibitor (NNRTI), photoactive 4-[[4-[(4-azido-2,6-dimethylphenyl) amino]-2-pyrimidinyl]amino]benzonitrile (PA-DAPYa). These results show that PA-DAPYa inactivated completely a suspension of cell-free HIV-1 viral particles in a dose and time-dependent manner. Using an ELISA assay for p24, it is demonstrated that a 500nM concentration of PA-DAPYa is able to inactivate 500 TCID50 of HIV viral particles in suspension when irradiated with non-microbicidal wavelength UV light for 30min. No active p24 was detected on days 7, 14, and 21 days after culturing the inactivated HIV in peripheral blood mononuclear cells (PBMCs). Several batches of large quantities of HIV viral particles were demonstrated to be inactivated completely and repeatedly by this method. Therefore, a reliable method has been developed to inactivate HIV viral particles in a reproducible manner using an optimal concentration of PA-DAPYa and duration of UV exposure time of the treated particles. The inactivation of viral particles in suspension allows for large-scale production of an injectable formulation of inactivated HIV viral particles for vaccine development which should preserve the conformational and antigenic integrity of viral surface proteins.