Pressure-induced superconductivity in topological parent compound Bi2Te3

We report a successful observation of pressure-induced superconductivity in a topological compound Bi(2)Te(3) with T(c) of ∼3 K between 3 to 6 GPa. The combined high-pressure structure investigations with synchrotron radiation indicated that the superconductivity occurred at the ambient phase without crystal structure phase transition. The Hall effects measurements indicated the hole-type carrier in the pressure-induced superconducting Bi(2)Te(3) single crystal. Consequently, the first-principles calculations based on the structural data obtained by the Rietveld refinement of X-ray diffraction patterns at high pressure showed that the electronic structure under pressure remained topologically nontrivial. The results suggested that topological superconductivity can be realized in Bi(2)Te(3) due to the proximity effect between superconducting bulk states and Dirac-type surface states. We also discuss the possibility that the bulk state could be a topological superconductor.

A promising approach of reject water treatment using a tidal flow constructed wetland system employing alum sludge as main substrate

This study examined a novel reuse of alum sludge, an inescapable by-product of drinking water treatment process when aluminium salt is added as a coagulant, as the main medium in a laboratory-scale multi-stage constructed wetland (CW) system for reject water treatment. Such reject water is a main concern in municipal wastewater treatment plant (MWWTP) for increasing the organic and nutrient loading. A 'tidal flow' strategy was employed to enhance the wetland aeration to stimulate organic matters (OM) and ammoniacal-nitrogen (N) oxidation while the 'step feed' operation was adopted to supply the necessary amount of carbon source for denitrification. The results reveal that alum sludge acting as P adsorbent can secure the P removal. Meanwhile, high removals of N and OM can also be obtained due to the active bacteria growth on the alum sludge surface. The results show that average removal efficiencies of 65.4 +/- 12.3% for chemical oxygen demand (COD), 67.8 +/- 9.2% for five-day biochemical oxygen demand (BOD5), 33.6 +/- 17.0% for N and 99.5 +/- 0.49% for P can be achieved over a period of 190 days. This indicates that novel reuse of alum sludge as medium in CW system can provide a promising approach for reject water treatment. Therefore, it will significantly reduce the amount of pollutant feedback through reject water recycling in a MWWTP.

Estrogen enhances the functions of CD4(+)CD25(+)Foxp3(+) regulatory T cells that suppress osteoclast differentiation and bone resorption in vitro

Cross-talk has been shown to occur between the immune system and bone metabolism pathways. In the present study, we investigated the impact of CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells on osteoclastogenesis and bone resorption. Treg cells that were isolated and purified from peripheral blood mononuclear cells (PBMCs) of healthy adults inhibited both the differentiation of osteoclasts (OCs) from human embryo bone marrow cells (BMCs) and the pit formation in a dose-dependent manner. In cell cocultures, the production levels of both interleukin-10 (IL-10) and transforming growth factor-beta 1 (TGF-β1) were proportionally upregulated as the ratio of Treg cells to BMCs was increased, and the inhibition of OC differentiation and bone resorption by Treg cells was completely reversed by anti-IL-10 and anti-TGF-β1 antibodies. Treatment of BMC and Treg cell cocultures with 17β-estradiol (E2) at concentrations between 10⁻⁷ and 10⁻⁹ mol/l suppressed OC differentiation and bone resorption more efficiently than it did in cultures of BMCs alone; this enhanced suppression occurred via the stimulation of Treg cell IL-10 and TGF-β1 expression. These data suggest that Treg cells suppress OC differentiation and bone resorption by secreting IL-10 and TGF-β1. E2 enhances the suppressive effects of Treg cells on OC differentiation and bone resorption by stimulating IL-10 and TGF-β1 secretion from these cells. Therefore, Treg cell-derived IL-10 and TGF-β1 are likely involved in the regulation of E2 on bone metabolism and represent potential therapeutic targets for the treatment of postmenopausal osteoporosis (PMO).

Dynamic changes of the ecological environment quality in a river basin: a case study of the main stream of Songhua river basin

This paper reports the investigation and analysis of the status and dynamic changes of ecological environment quality in the main stream of Songhua river basin. The evaluation index system was established and the eco-environment quality in the year of 2000 and 2008 was studied in depth. Based on our research, the trend of dynamic changes of the eco-environment quality and its origins have been further discussed: In the year of 2000, the range of evaluation index covered from 0.31 to 0.47. Harbin and Yichun was relatively better than the rest of study areas. In the year of 2008, except districts of Daqing and Qitaihe, the environmental quality of Songhua river basin has entirely improved, wherein the evaluation index of the eco-environment covered from 0.31 to 0.57. Particularly, the eco-environment quality of Hegang and Shuangyashan has obtained significant improvement, whereas the improvement of Jiamusi was not obvious. According to the evaluation results, the environmental quality in the study area has an upward trend with the average growth rate 0.13% per year.

Towards the development of a novel construction solid waste (CSW) based constructed wetland system for tertiary treatment of secondary sewage effluents

This study was conducted to examine the possibility of using construction solid waste (CSW), an inevitable by-product of the construction and demolition process, as the main substrate in a laboratory scale multi-stage constructed wetland system (CWs) to improve phosphorus (P) removal from secondary sewage effluent. A tidal-flow operation strategy was employed to enhance the wetland aeration. This will stimulate aerobic biological processes and benefit the organic pollutants decomposition and nitrification process for ammoniacal-nitrogen (NH(+)(4)-N) removal. The results showed that the average P concentration in the secondary sewage effluent was reduced from 1.90 mg-P/L to 0.04 mg-P/L. CSW presents excellent P removal performance. The average NH(+)(4)-N concentration was reduced from 9.94 mg-N/L to 1.0 mg-N/L through nitrification in the system. The concentration of resultant nitrite and nitrate in the effluent of the CSW based CWs ranged from 0.1 to 2.4 mg-N/L and 0.01 to 0.8 mg-N/L, respectively. The outcome of this study has shown that CSW can be successfully used to act as main substrate in CWs. The application of CSW based CWs on improving N and P removals from secondary sewage effluent presents a win-win scenario. Such the reuse of CSW will benefit both the CSW disposal and nutrient control from wastewater. More significantly, such the application can transfer the CSW from a 'waste' to 'useful' material and can ease the pressure of construction waste solid management. Meanwhile, the final effluent from the CSW-based CWs can be used as non-potable water source in landscape irrigation, agriculture and industrial process.

Evaluation of low-cost cathode catalysts for high yield biohydrogen production in microbial electrolysis cell

As an ideal fuel due to the advantages of no pollution, high combustion heat and abundant sources, hydrogen gas can be produced from organic matter through the electrohydrogenesis process in microbial electrolysis cells. But in many MECs, platinum is often used as catalyst, which limits the practical applications of MECs. To reduce the cost of the MECs, Ni-based alloy cathodes were developed by electrodepositing. In this paper hydrogen production using Ni-W-P cathode was studied for the first time in a single-chamber membrane-free MEC. At an applied voltage of 0.9 V, MECs with Ni-W-P cathodes obtained a hydrogen production rate of 1.09 m3/m3/day with an cathodic hydrogen recovery of 74%, a Coulombic efficiency of 56% and an electrical energy efficiency relative to electrical input of 139%, which was the best result of reports in this study. The Ni-W-P cathode demonstrated a better electrocatalytic activity than the Ni-Ce-P cathode and achieved a comparable performance to the Pt cathode in terms of hydrogen production rate, Coulombic efficiency, cathodic hydrogen recovery and electrical energy efficiency at 0.9 V.

In-situ studies of cartilage microtribology: roles of speed and contact area

The progression of local cartilage surface damage toward early stage osteoarthritis (OA) likely depends on the severity of the damage and its impact on the local lubrication and stress distribution in the surrounding tissue. It is difficult to study the local responses using traditional methods; in-situ microtribological methods are being pursued here as a means to elucidate the mechanical aspects of OA progression. While decades of research have been dedicated to the macrotribological properties of articular cartilage, the microscale response is unclear. An experimental study of healthy cartilage microtribology was undertaken to assess the physiological relevance of a microscale friction probe. Normal forces were on the orderof50 mN. Sliding speed varied from 0 to 5 mm/s, and two probes radii, 0.8 mm and 3.2 mm, were used in the study. In-situ measurements of the indentation depth into the cartilage enabled calculations of contact area, effective elastic modulus, elastic and fluid normal force contributions, and the interfacial friction coefficient. This work resulted in the following findings: 1) at high sliding speed (V=1-5 mm/s), the friction coefficient was low (μ = 0.025) and insensitive to probe radius (0.8 mm 3.2 mm) despite the 4-folddifference in the resulting contact areas; 2) The contact area was a strong function of the probe radius and sliding speed; 3) the friction coefficient was proportional to contact area when sliding speed varied from 0.05mm/s-5mm/s; 4) the fluid load support was greater than 85% for all sliding conditions (0% fluid support when V=0) and was insensitive to both probe radius and sliding speed. The findings were consistent with the adhesive theory of friction; as speed increased, increased effective hardness reduced the area of solid-solid contact which subsequently reduced the friction force. Where the severity of the sliding conditions dominates the wear and degradation of typical engineering tribomaterials, the results suggest that joint motion is actually beneficial for maintaining low matrix stresses, low contact areas, and effective lubrication for the fluid-saturated porous cartilage tissue. Further, the results demonstrated effective pressurization and lubrication beneath single asperity microscale contacts. With carefully designed experimental conditions, local friction probes can facilitate more fundamental studies of cartilage lubrication, friction and wear, and potentially add important insights into the mechanical mechanisms of OA.

Overexpression of AEG-1 in renal cell carcinoma and its correlation with tumor nuclear grade and progression

The study was aimed at detecting the expression of a newly found oncogene, astrocyte elevated gene-1 (AEG-1), in renal cell carcinoma (RCC) and its correlation with histopathologic features and the survival of patients. Real-time reverse transcription-PCR and Western blot showed markedly higher expression of AEG-1 in 8 cases of RCC tissue compared with the paired normal tissue from the same patient. The expression level of AEG-1 was also increased in four RCC cell lines in contrast with normal tubular epithelial human kidney cells 2 (HK-2) at both mRNA and protein levels. Furthermore, immunohistochemistry analysis showed highly expressed AEG-1 in 96 of 102 (94.1%) cases of paraffin-embedded archival RCC tissue. Statistical analysis showed a significant correlation of AEG-1 expression with tumor grade (P <0.001), clinical staging (P = 0.003), T classification (P = 0.003) as well as metastasis classification (P=0.032). The means for survival time of low AEG-1 expression group was 76.98m<br />while high AEG-1expression group was 60.94m. Our results suggest that AEG-1 protein is overexpressed in RCC and plays an important role in tumor differentiation and progression. <br />High AEG-1 expression is closely associated with poor prognosis.

KEYWORDS

Astrocyte elevated gene-1, AEG-1, renal cell carcinoma, prognosis.

Optofluidic microcavities: Dye-lasers and biosensors

Optofluidic microcavities are integrated elements of microfluidics that can be explored for a large variety of applications. In this review, we first introduce the physics basis of optical microcavities and microflow control. Then, we describe four types of optofluidic dye lasers developed so far based on both simple and advanced device fabrication technologies. To illustrate the application potential of such devices, we present two types of laser intracavity measurements for chemical solution and single cell analyses. In addition, the possibility of single molecule detection is discussed. All these recent achievements demonstrated the great importance of the topics in biology and several other disciplines.

To investigate the role of the nervous system of bone in steroid-induced osteonecrosis in rabbits

SUMMARY

Glucocorticoid treatment frequently causes osteonecrosis of the femoral head. The precise mechanism in the pathogenesis of osteonecrosis remains highly controversial. Normal bone metabolism requires a coordinated interaction between the sensory/sympathetic nervous system and cells within the bone tissue. So we speculated that neural lesions may be involved in osteonecrosis.

OBJECTIVE

using a rabbit model, we investigated the relationship between neural factors and steroid-induced osteonecrosis of the femoral head.

METHODS

Japanese white rabbits weighing about 3.5 kg each were injected with a single intramuscular dose of methylprednisolone 4 mg/kg and then divided into three groups (groups A, B and C) consisting of 15 rabbits each. The rabbits of group A were killed after 3 days, those of group B after 1 week, and those of group C after 2 weeks. As a control group, 10 rabbits (group N) were fed under the same conditions but did not receive a steroid injection. An immunohistochemical study of the femoral heads was conducted using the monoclonal antibodies CGRP, SP, VIP, NPY and NGF. Also, using the software Image Pro Plus, the areas showing positive immunoreactivity in each group were calculated and the four groups were compared.

RESULTS

significant changes were seen in the expression of CGRP, SP, VIP and NPY nerve fibres and of NGF immunoreactivity in the subchondral bone of the femoral head and these changes were associated with the process of osteonecrosis. Furthermore, CGRP, SP, NPY and NGF (but not VIP) showed marked changes in expression 1 week after steroid administration, and this is the time when osteonecrosis is thought to occur in this model.

CONCLUSION

This study showed that osteonecrosis in rabbits is chronologically associated with changes in neural factors.

A novel allele, HLA-A*11:01:10, identified by sequence-based typing in a Chinese individual

The novel allele human leukocyte antigen (HLA)-A*11:01: 10 differs from HLA-A*11:01:10 by a synonymous nucleotide exchange at codon 146 in exon 2 (G/A). Here, we describe the identification of the novel allele HLA-A*11:01:10, which has been detected in a registered donor of the China Marrow Donor Program. The complete HLA typing results were as follows: A*02:01, *11:01:10; B*15:11, *15:18; C*03:03, *08:01; DRB1*08:02, *15:01.

Treatment of Symptomatic Intracranial Atherosclerotic Stenosis with a Normal-Sized Gateway™ Balloon and Wingspan™ Stent

The safety and performance of angioplasty using a normal-sized Gateway™ balloon and Wingspan™ stent for intracranial atherosclerotic stenosis were assessed. Seventy-two patients with intracranial stenosis (≥ 50%) were treated using an undersized (group U) or normal-sized (group N) Gateway™ balloon and a Wingspan™ stent. All patients were successfully stented. Stenosis improved from 74.2% before treatment to 23.8% immediately after treatment in group U and from 70.9% to 20.1% in group N. The two groups had similar rates of major periprocedural neurological complications (9.0% overall), none of which led to death. Residual stenosis at follow-up was 40.8% and 32.5% in groups U and N, respectively. In-stent re-stenosis (ISR) was significantly less frequent in group N (22.0%) than in group U (33.3%). It is concluded that use of a normal-sized Gateway™ balloon and Wingspan™ stent appears to be safe, to have a high rate of technical success, good immediate post-operative results and a low ISR rate.

Hepatitis B virus genotype and basal core promoter/precore mutations are associated with hepatitis B-related acute-on-chronic liver failure without pre-existing liver cirrhosis

The study was undertaken to investigate the features and clinical implications of hepatitis B virus (HBV) genotypes, basal core promoter (BCP) and precore (PC) mutations in hepatitis B-related acute-on-chronic liver failure (HB-ACLF). Samples from 75 patients with HB-ACLF and without pre-existing liver cirrhosis and 328 age-matched patients with chronic hepatitis B (CHB) were analyzed. HBV genotype and BCP/PC mutations were determined by direct sequencing. Mutations at 8 sites of the BCP/PC region were compared between the two groups of patients. A significantly higher ratio of genotype B to C was found in patients with HB-ACLF than in patients with CHB (30.7-69.3% vs 16.5-82.6%, P < 0.01). Single mutations including T1753V (C/A/G), A1762T, G1764A, G1896A and G1899A and triple mutations T1753V/A1762T/G1764A and A1762T/G1764A/C1766T (or T1768A) were more frequently detected in patients with HB-ACLF than in patients with CHB. Correspondingly, BCP/PC wild-type sequences were absent in patients with HB-ACLF in contrast to 27.1% in patients with CHB. The BCP/PC mutations were found to be associated with increased HBeAg negativity, higher alanine aminotransferase level and lower viral load. Patients with HB-ACLF infected with the PC mutant virus had a higher mortality. The findings suggest that patients with CHB infected with genotype B with BCP/PC mutations were more likely to develop HB-ACLF than those with genotype C with wild-type BCP/PC regions, and patients with HB-ACLF with the PC mutation had increased risk of a fatal outcome.

Downregulation of caspase-9 is a frequent event in patients with stage II colorectal cancer and correlates with poor clinical outcome

OBJECTIVE

 To evaluate the clinical significance of caspase-9 mRNA expression and investigate its prognostic value in stage II colorectal cancer.

METHOD

Quantitative real-time RT-PCR was used to analyse caspase-9 mRNA expression in cancer tissue and corresponding normal mucosa from 120 patients.

RESULTS

Compared with normal mucosa, the expression of caspase-9 mRNA was found to be downregulated in cancer tissue (P = 0.001). Poorly differentiated cancer showed lower mRNA expression than cancer with greater differentiation (P = 0.031). The Kaplan-Meier survival analysis demonstrated that patients with downregulated caspase-9 showed a worse overall survival (P = 0.012) and disease-free survival (P = 0.022). Cox's proportional hazards regression model confirmed that expression of caspase-9 was the strongest prognostic factor in stage II colorectal cancer.

CONCLUSION

The mRNA expression of caspase-9 can be used as an independent prognostic factor for patients with stage II colorectal cancer.