Mid-infrared Photoconductive Response in AlGaN/GaN Step Quantum Wells

AlGaN/GaN quantum structure is an excellent candidate for high speed infrared detectors based on intersubband transitions. However, fabrication of AlGaN/GaN quantum well infrared detectors suffers from polarization-induced internal electric field, which greatly limits the carrier vertical transport. In this article, a step quantum well is proposed to attempt solving this problem, in which a novel spacer barrier layer is used to balance the internal electric field. As a result, a nearly flat band potential profile is obtained in the step barrier layers of the AlGaN/GaN step quantum wells and a bound-to-quasi-continuum (B-to-QC) type intersubband prototype device with detectable photocurrent at atmosphere window (3-5 μm) is achieved in such nitride semiconductors.

Effectiveness of low-level laser therapy in patients with knee osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

To investigate the efficacy of low-level laser therapy (LLLT) treatment of knee osteoarthritis (KOA) by a systematic literature search with meta-analyses on selected studies.

DESIGN

MEDLINE, EMBASE, ISI Web of Science and Cochrane Library were systematically searched from January 2000 to November 2014. Included studies were randomized controlled trials (RCTs) written in English that compared LLLT (at least eight treatment sessions) with sham laser in KOA patients. The efficacy effective size was estimated by the standardized mean difference (SMD). Standard fixed or random-effects meta-analysis was used, and inconsistency was evaluated by the I-squared index (I(2)).

RESULTS

Of 612 studies, nine RCTs (seven double-blind, two single-blind, totaling 518 patients) met the criteria for inclusion. Based on seven studies, the SMD in visual analog scale (VAS) pain score right after therapy (RAT) (within 2 weeks after the therapy) was not significantly different between LLLT and control (SMD = -0.28 [95% CI = -0.66, 0.10], I(2) = 66%). No significant difference was identified in studies conforming to the World Association of Laser Therapy (WALT) recommendations (four studies) or on the basis of OA severity. There was no significant difference in the delayed response (12 weeks after end of therapy) between LLLT and control in VAS pain (five studies). Similarly, there was no evidence of LLLT effectiveness based on Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain, stiffness or function outcomes (five and three studies had outcome data right after and 12 weeks after therapy respectively).

CONCLUSION

Our findings indicate that the best available current evidence does not support the effectiveness of LLLT as a therapy for patients with KOA.

Salvage surgery after failure of endoscopic balloon dilatation versus surgery first for ileocolonic anastomotic stricture due to recurrent Crohn's disease

BACKGROUND

Both surgical resection and endoscopic balloon dilatation are treatment options for ileocolonic anastomotic stricture caused by recurrent Crohn's disease unresponsive to medications. Perioperative outcomes of salvage surgery owing to failed endoscopic balloon dilatation in comparison with performing surgery first for the same indication are unclear.

METHODS

An analysis of a prospectively maintained Crohn's disease database was carried out to compare perioperative outcomes of patients who had surgery for failure of endoscopic balloon dilatation with outcomes in patients who underwent resection first for ileocolonic anastomotic stricture caused by recurrent Crohn's disease between 1997 and 2013.

RESULTS

Of 194 patients, 114 (58·8 per cent) underwent surgery without previous endoscopic balloon dilatation. The remaining 80 patients had salvage surgery after one or more endoscopic balloon dilatations during a median treatment span of 14·5 months. Patients in the salvage surgery group had a significantly shorter length of anastomotic stricture (P < 0·001). Salvage surgery was associated with increased rates of stoma formation (P = 0·030), overall surgical-site infection (SSI) (P = 0·025) and organ/space SSI (P = 0·030). In multivariable analysis, preoperative endoscopic balloon dilatation was independently associated with both postoperative SSI (odds ratio 3·16, 95 per cent c.i. 1·01 to 9·84; P = 0·048) and stoma diversion (odds ratio 3·33, 1·14 to 9·78; P = 0·028).

CONCLUSION

Salvage surgery after failure of endoscopic balloon dilatation is associated with increased adverse outcomes in comparison with surgery first. This should be discussed with patients being considered for endoscopic balloon dilatation for ileocolonic anastomotic stricture due to recurrent Crohn's disease.

Immune memory responses to HBV vaccine 13-18 years after primary vaccination

The aim of this study was to evaluate the immune memory response 13-18 years after an hepatitis B virus (HBV) vaccine by performing a specific in vitro stimulation experiment. Thirty healthy volunteers who had been inoculated 13-18 years ago with the HBV vaccine were collected from the physical examination center. Peripheral blood mononuclear cells were stimulated with 50 ng/mL recombinant HBsAg. An ELISA kit was used for the detection of antibodies that were produced by these cells in vitro. It was found that even 13-18 years after inoculation with the HBV vaccine, an anamnestic antibody response still existed, and was not correlated with the serum antibody levels (r = -0.177, P = 0.377). In conclusion, our data showed that the individuals after inoculation, including those with anti-HBs <10 IU/L as well as those individuals in whom the antibody was not detected, retained immune memory, which may be the main role of memory B cells.

Upregulation of long noncoding RNA ZEB1-AS1 promotes tumor metastasis and predicts poor prognosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. Despite progress in diagnostics and treatment of HCC, its prognosis remains poor. Emerging studies showed that long noncoding RNAs (lncRNAs) have crucial regulatory roles in cancer biology. In the current study, differentially expressed lncRNAs between HCC and paired non-tumor tissues were identified using microarrays. The effects of a specific differentially expressed lncRNA (termed ZEB1-AS1) on tumor progression were investigated in vitro and in vivo. We found that ZEB1-AS1 is frequently upregulated in HCC samples, especially in metastatic tumor tissues. DNA methylation analysis shows a tumor-specific ZEB1-AS1 promoter hypomethylation. Aberrant methylation is tightly correlated with overexpression of ZEB1-AS1 in HCC. Patients with ZEB1-AS1 hypomethylation or with high ZEB1-AS1 expression have poor recurrence-free survival. Functionally, ZEB1-AS1 promotes tumor growth and metastasis, acts as an oncogene in HCC. The ZEB1-AS1 gene is located in physical contiguity with ZEB1 and positively regulates the ZEB1 expression. ZEB1 inhibition partially abrogates ZEB1-AS1-induced epithelial to mesenchymal transition (EMT) and cancer metastasis. Our results provide novel insights into the function of lncRNA-driven hepatocarcinogenesis, highlight the important role of ZEB1-AS1 and ZEB1 in HCC progression, and indicate that ZEB1-AS1 may be served as a valuable prognostic biomarker for HCC.

The arthropathic and functional impairment features of adult Kashin-Beck disease patients in Aba Tibetan area in China

OBJECT

The purpose of the study was to analyze the features of arthropathic changes and functional impairments as well as the correlations between them for adult patients suffered with Kashin-Beck disease (KBD) in Aba Tibetan area of Sichuan Province, China.

METHOD

Nine hundred and eighty-nine adult KBD patients in Aba KBD prevalence area were investigated. The arthropathic changes including arthritic pain (evaluated by visual analog pain score (VAS)), deformity, limited range of joint motion (ROM), as well as daily living and working function were examined, evaluated and analyzed.

RESULTS

Ninety-two percent of patients suffered with multiple affected joints in both upper and lower extremities. The most frequently affected joints were knee (86.1%) and hand (77.2%). The most painful joints were knee (VAS 7.1 ± 1.9) and elbow (VAS 6.8 ± 2.1). Joint deformities most frequently represented as enlargement of interphalangeal joints (93.2%). Limitation of ROM occurred most frequently in hand (76.7%) and elbow (38.4%). Multiple linear regression analysis revealed that only joint pain (regression coefficient: -0.504, 95% confidence interval (CI): -0.820-0.188, P ＜ 0.001) and ROM (regression coefficient: 0.017, 95% CI: 0.011-0.024, P ＜ 0.001) were independent risk factors affecting daily living and working function.

CONCLUSION

Most adult patients suffered with multiple affected joints in both upper and lower limbs. The elbow, hand and knee were the most frequently and severely affected joints. The pain and limited ROM were the independent risk factors of daily living and working function.

Visceral fat area is associated with a high risk for early postoperative recurrence in Crohn's disease

AIM

Mesenteric hypertrophy has been recognized as an indicator of the complicated course of Crohn's disease. The aim of this study was to investigate whether the visceral fat area (VFA) is associated with postoperative clinical and endoscopic recurrence.

METHOD

Computed tomography was used to measure the subcutaneous fat area and VFA, and the mesenteric fat index (MFI) was defined as the ratio of the VFA to the subcutaneous fat area. Associations between body mass index, subcutaneous fat area, VFA and MFI and postoperative clinical and endoscopic recurrence were investigated.

RESULTS

The factors associated with postoperative endoscopic recurrence at 6 months after surgery were a high VFA value (P = 0.019) and MFI values above the median (P = 0.008). VFA values were significantly correlated with endoscopic recurrence (r = 0.895, P = 0.040) and endoscopic lesions (r = 0.617, P < 0.0001). Additionally, MFI values correlated well with endoscopic recurrence (r = 0.918, P = 0.02) and endoscopic scores (r = 0.584, P < 0.0001). Multivariate analysis indicated that VFA values above the median (hazard ratio 2.63, 95% CI 1.03-6.74) were predictive of postoperative clinical recurrence in Crohn's disease.

CONCLUSION

A high VFA value is associated with postoperative recurrence of Crohn's disease and has clinical implications with respect to optimizing prophylaxis for each individual. However, further studies are needed to confirm the predictive role of this biomarker in a different data set.

Local structure order in Pd78Cu6Si16 liquid

The short-range order (SRO) in Pd78Cu6Si16 liquid was studied by high energy x-ray diffraction and ab initio molecular dynamics (MD) simulations. The calculated pair correlation functions at different temperatures agree well with the experimental results. The partial pair correlation functions from ab intio MD simulations indicate that Si atoms prefer to be uniformly distributed while Cu atoms tend to aggregate. By performing structure analysis using Honeycutt-Andersen index, Voronoi tessellation, and atomic cluster alignment method, we show that the icosahedron and face-centered cubic SRO increase upon cooling. The dominant SRO is the Pd-centered Pd9Si2 motif, namely the structure of which motif is similar to the structure of Pd-centered clusters in the Pd9Si2 crystal. The study further confirms the existence of trigonal prism capped with three half-octahedra that is reported as a structural unit in Pd-based amorphous alloys. The majority of Cu-centered clusters are icosahedra, suggesting that the presence of Cu is benefit to promote the glass forming ability.

Energetics of sodium–calcium exchanged zeolite A

Enthalpies of formation for sodium–calcium exchanged zeolite A.

Blockade of the T cell immunoglobulin and mucin domain protein 3 pathway exacerbates sepsis-induced immune deviation and immunosuppression

Sepsis is a life-threatening condition, but the pathophysiological basis and biomarkers for the monitoring of sepsis and as targets for therapy remain to be determined. We have shown previously that T cell immunoglobulin and mucin domain protein 3 (Tim-3), a negative immune regulator, is involved in the physiopathology of sepsis, but the underlying mechanisms remain unclear. In the present study, we showed that Tim-3 signalling modulated the response patterns of both macrophages and T helper cells in sepsis. Blockade of the Tim-3 pathway exacerbated sepsis-induced proinflammatory macrophage responses and lymphocyte apoptosis during the early phase of sepsis, and enhanced the shift to anti-inflammatory responses for both macrophages and T helper cells during the late phase of sepsis. Tim-3 signalling was found to regulate CD80 and CD86 expression on macrophages both in vivo and in vitro. Co-culture of T cells with Tim-3 knock-down macrophages led to a biased T helper type 2 (Th2) response, partially explaining how Tim-3 signalling shapes inflammation patterns in vivo. Further studies on this pathway might shed new light on the pathogenesis of sepsis and suggest new approaches for intervention.

Development of an alternating integrator for magnetic measurements for experimental advanced superconducting tokamak

A high-performance integrator is one of the key electronic devices for reliably controlling plasma in the experimental advanced superconducting tokamak for long pulse operation. We once designed an integrator system of real-time drift compensation, which has a low integration drift. However, it is not feasible for really continuous operations due to capacitive leakage error and nonlinearity error. To solve the above-mentioned problems, this paper presents a new alternating integrator. In the new integrator, the integrator system of real-time drift compensation is adopted as one integral cell while two such integral cells work alternately. To achieve the alternate function, a Field Programmable Gate Array built in the digitizer is utilized. The performance test shows that the developed integrator with the integration time constant of 20 ms has a low integration drift (<15 mV) for 1000 s.

Optical peaking enhancement in high-speed ring modulators

Ring resonator modulators (RRM) combine extreme compactness, low power consumption and wavelength division multiplexing functionality, making them a frontrunner for addressing the scalability requirements of short distance optical links. To extend data rates beyond the classically assumed bandwidth capability, we derive and experimentally verify closed form equations of the electro-optic response and asymmetric side band generation resulting from inherent transient time dynamics and leverage these to significantly improve device performance. An equivalent circuit description with a commonly used peaking amplifier model allows straightforward assessment of the effect on existing communication system architectures. A small signal analytical expression of peaking in the electro-optic response of RRMs is derived and used to extend the electro-optic bandwidth of the device above 40 GHz as well as to open eye diagrams penalized by intersymbol interference at 32, 40 and 44 Gbps. Predicted peaking and asymmetric side band generation are in excellent agreement with experiments.

Diversity and potential application of endophytic bacteria in ginger

Here, 248 endophytic bacterial strains were isolated to assess the distribution and population diversity of endophytic bacteria in ginger plants. A total of 10.4 x 10(4) to 20.2 x 10(4) CFU/g fresh weight endophytic bacteria of different growth stages were isolated. Maximum bacterium numbers were obtained at the seedling stage. A total of 107 functional strains were screened, including 17 antibacterial strains and 90 indole acetic acid-producing strains. Based on 16S rDNA sequence restriction fragment length polymorphism and 16S rDNA sequences, these 107 strains were mapped and grouped into 16 genera. Bacillus and Pseudomonas were the dominant genera; however, the bacteria belonged to a tremendous range of genera, with the highest species richness being observed at the seedling stage. Sixteen strains exhibited antimicrobial activity against Pythium myriotylum Drechsler, while 7 strains exhibited antimicrobial activity against Phyllosticta zingiberi Hori. Bacillus was the dominant antibacterial strain. Pseudomonas fluorescens, B. megaterium, and Enterobacter ludwigii produced remarkably high levels of IAA. Only a few endophytic bacterial strains were inhibited in fresh ginger juice. Most of these strains were present during seedling stage, including Roseateles depolymerans, Chryseobacterium taiwanense, E. ludwigii, Agrobacterium larrymoorei, P. fluorescens, and Bacillus amyloliquefaciens. This study indicates that the community of endophytic bacteria in ginger changes with the synthesis of antibacterial substances.

Nuclear factor erythroid 2-related factor 2 rescues the oxidative stress induced by di-N-butylphthalate in testicular Leydig cells

Aim:

This study aimed to determine whether nuclear factor erythroid 2-related factor 2 antagonized the oxidative stress induced by di- N-butylphthalate (DBP) in testicular Leydig cells.

Methods:

Mouse TM3 testicular Leydig cells were treated with Nrf2 knockdown (KD) or overexpression in the presence and absence of DBP. Oxidative profiles were examined. Nrf2 target antioxidant genes were studied, and the effects of Nrf2 inducer sulphoraphane (SFN) were tested.

Results:

DBP induced intracellular oxidative stress to a similar extent with Nrf2 KD. Expression and protein levels of Nrf2 were increased together with its target genes, namely heme oxygenase 1, nicotinamide adenine dinucleotide phosphate quinone oxidoreductase 1 and peroxiredoxin 6, following DBP stimulation. Use of SFN not only restored the intracellular oxidative toxicity but also cell proliferation and testosterone secretion in response to DBP.

Conclusion:

Increased Nrf2 activity, for example, by SFN can effectively antagonize the oxidative stress in testicular Leydig cells caused by DBP.

Conserved odontogenic potential in embryonic dental tissues

Classic tissue recombination studies have demonstrated that, in the early developing mouse tooth germ, the odontogenic potential, known as the tooth-inductive capability, resides initially in the dental epithelium and then shifts to the dental mesenchyme. However, it remains unknown if human embryonic dental tissues also acquire such odontogenic potential. Here we present evidence that human embryonic dental tissues indeed possess similar tooth-inductive capability. We found that human dental epithelium from the cap stage but not the bell stage was able to induce tooth formation when confronted with human embryonic lip mesenchyme. In contrast, human dental mesenchyme from the bell stage but not the cap stage could induce mouse embryonic second-arch epithelium as well as human keratinocyte stem cells, to become enamel-secreting ameloblasts. We showed that neither post-natal human dental pulp stem cells (DPSCs) nor stem cells from human exfoliated deciduous teeth (SHED) possess odontogenic potential or are odontogenic-competent. Our results demonstrate a conservation of odontogenic potential in mouse and human dental tissues during early tooth development, and will have an implication in the future generation of stem-cell-based bioengineered human replacement teeth.

NKG2D blockade significantly attenuates ischemia-reperfusion injury in a cardiac transplantation model

BACKGROUND

NKG2D (natural killer group 2 member D), are activating or coactivating receptor on NK cells, γδ T, and CD8(+) T cells, stimulates cytokine secretion by the former two and plays a costimulatory role for the last CD8(+) T cells.

METHODS

Male Lewis rat hearts were flushed and stored in cold Bretschneider preservation solution for 8 hours. Anti-NKG2D monoclonal antibody (mAb) was administered before transplantation into syngeneic recipients. Expressions of Troponin-T, myeloperoxidase (MPO), tumor necrosis factor (INF), (ICAM) and interleukin (IL)-17 were examined on days 1, 3, and 7 after reperfusion.

RESULTS

We observed that isografts from anti-NKG2D mAb-treated animals showed decreased cardiac troponin-T, low expression of MPO, TNF, and ICAM, and superior cardiac output. Furthermore, blockade of NKG2D significantly reduced the number of γδ T cells, which are the main source of IL-17 production.

CONCLUSION

Blockade of NKG2D significantly attenuated ischemia-reperfusion injury in a cardiac transplantation model. The effect coincided with a low expression of TNFα, ICAM and a reduced number of infiltrating IL-17-producing γδ T cells.

Efficacy and safety of enteric-coated mycophenolate sodium in patients with de novo and maintenance renal transplantation

AIMS

To evaluate the efficacy and safety of enteric-coated mycophenolate sodium (EC-MPS) in renal transplant patients treated de novo and for maintenance.

METHODS

The efficacy and safety data of EC-MPS in renal transplant patients treated de novo and for maintenance in our hospital from July 2009 to March 2013 were reviewed.

RESULTS

Thirty-one patients treated with EC-MPS de novo were included: there were 16 male and 15 female patients. The acute allograft rejection rate was 12.9% (4/31) and pneumonia occurred in 25.8% patients (8/31); the allograft survival rate was 96.7% (30/31) with a patient survival rate of 96.7% (30/31). Gastrointestinal side effects occurred in four patients (12.9%). Only one patient discontinued EC-MPS and treatment was converted to bredinin because of gastrointestinal intolerance. Thirty-nine patients receiving mycophenolate mofetil (MMF) de novo treatment served as a control group. Five (13.2%) of 38 patients developed serious acute rejection and 10 patients (26.3%) had pulmonary infection. Eight (21.1%) patients suffered abdominal distention, diarrhoea and other gastrointestinal adverse reactions; the symptoms improved significantly after treatment change to mizoribine. Compared with the MMF de novo group, the allograft function, blood cell counts and urine protein were similar in the EC-MPS de novo treatment group. The incidence of gastrointestinal side effects was obviously lower in the EC-MPS group than in the MMF group, and there was no difference in serious acute rejection and pulmonary infection between the groups. The study also included 23 renal transplantation maintenance patients who suffered from chronic diarrhoea and treatment was changed to EC-MPS treatment. This change to EC-MPS was at 77 months after transplantation. The gastrointestinal symptoms improved significantly in 21 patients after conversion. Compared with the results at 1 week, no obvious deterioration in serum creatinine, cystatin or estimated glomerular filtration rate was found at 1, 3 and 12 months after the change. In addition, there was no marked decline in blood cell counts and no significant increase in urine protein.

CONCLUSION

The outcome of EC-MPS treatment in clinical practice of de novo kidney transplant patients was good, with high patient and graft survivals. In maintenance patients it induced an improvement in gastrointestinal side effects and a stable allograft function.

Revealing of the transition from n- to p-type conduction of InN:Mg by photoconductivity effect measurement

We report evidence of the transition from n- to p-type conduction of InN with increasing Mg dopant concentration by using photoconductivity (PC) measurement at room temperature. This transition is depicted as a conversion from negative to positive PC under above-bandgap optical excitation. The n- to p-type transition in InN:Mg is further confirmed by thermopower measurements. PC detection method is a bulk effect since the optical absorption of the surface electron accumulation is negligibly low due to its rather small thickness, and thus shows advantage to detect p-type conduction. This technique is certainly helpful to study p-type doping of InN, which is still a subject of discussions.

The FEN1 E359K germline mutation disrupts the FEN1-WRN interaction and FEN1 GEN activity, causing aneuploidy-associated cancers

Polymorphisms and somatic mutations in Flap Endonuclease 1 (FEN1), an essential enzyme involved in DNA replication and repair, can lead to functional deficiencies of the FEN1 protein and a predisposition to cancer. We identified a FEN1 germline mutation which changed residue E359 to K in a patient whose family had a history of breast cancer. We determined that the E359K mutation, which is in the protein-protein domain of FEN1, abolished the interaction of FEN1 with Werner Syndrome protein (WRN), an interaction which is critical for resolving stalled DNA replication forks. Furthermore, although the flap endonuclease activity of FEN1 E359K was unaffected, it failed to resolve bubble structures, which requires the FEN1 gap dependent endonuclease (GEN) activity. To determine the etiological significance of E359K, we established a mouse model containing this mutation. E359K mouse embryonic fibroblasts (MEF) were more sensitive to DNA cross-linking agents that cause replication forks to stall. Cytological analysis suggested that the FEN1-WRN interaction was also required to for telomere stability; mutant cell lines had fragile telomeres, increased numbers of spontaneous chromosomal anomalies and higher frequencies of transformation. Moreover, the incidence of cancer was significantly higher in mice homozygous for FEN1 E359K than in wild-type mice, suggesting that the FEN1 E359K mutation is oncogenic.