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To evaluate the associations of morning serum cortisol levels with obesity defined by different indices in Chinese rural populations. A cross-sectional study was performed including 6198 participants (2566 males and 3632 females). Serum cortisol was collected in morning and quantified by liquid chromatography‐tandem mass spectrometry. Obesity was defined by body mass index (BMI), body fat percentage (BFP), waist-to-height ratio (WHtR), waist circumference (WC), visceral fat index (VFI) and waist-to-hip ratio (WHR). Both multivariable liner regression, logistic regression and restrictive cubic splines models were used to estimate the gender-specific relationships between cortisol levels and obesity defined by different indices, respectively. After adjusting for potential confounders, serum cortisol was negatively associated with different obesity measures, except obese females defined by BFP (for instance, overall obesity defined by BMI, Quartile 4 vs. Quartile 1, odds ratio (OR) = 0.25, 95% confidence interval (CI):0.15, 0.41 in males, and OR = 0.58, 95% CI: 0.42,0.80 in females, central obesity defined by WC, OR = 0.52, 95% CI:0.39,0.69 in males and OR = 0.63, 95% CI:0.51,0.77 in females). Similarly, restrictive cubic splines showed the nonlinear relationship between high levels of cortisol and different obesity indices. Furthermore, ROC curve analysis indicated that cortisol could improve the discrimination of model with common biomarkers. Morning serum cortisol were negatively related to obesity defined by different indices in Chinese rural populations. In addition, cortisol could be as a biomarker for prediction of obesity in males.

To evaluate the associations of morning serum cortisol levels with obesity defined by different indices in Chinese rural populations.A cross-sectional study was performed including 6198 participants (2566 males and 3632 females). Serum cortisol was collected in morning and quantified by liquid chromatography-tandem mass spectrometry. Obesity was defined by body mass index (BMI), body fat percentage (BFP), waist-to-height ratio (WHtR), waist circumference (WC), visceral fat index (VFI) and waist-to-hip ratio (WHR). Both multivariable liner regression, logistic regression and restrictive cubic splines models were used to estimate the gender-specific relationships between cortisol levels and obesity defined by different indices, respectively.After adjusting for potential confounders, serum cortisol was negatively associated with different obesity measures, except obese females defined by BFP (for instance, overall obesity defined by BMI, Quartile 4 vs. Quartile 1, odds ratio (OR) = 0.25, 95% confidence interval (CI):0.15, 0.41 in males, and OR = 0.58, 95% CI: 0.42,0.80 in females, central obesity defined by WC, OR = 0.52, 95% CI:0.39,0.69 in males and OR = 0.63, 95% CI:0.51,0.77 in females). Similarly, restrictive cubic splines showed the nonlinear relationship between high levels of cortisol and different obesity indices. Furthermore, ROC curve analysis indicated that cortisol could improve the discrimination of model with common biomarkers.Morning serum cortisol were negatively related to obesity defined by different indices in Chinese rural populations. In addition, cortisol could be as a biomarker for prediction of obesity in males.

In the present study, we propose a new iterative algorithm based on discretized continuous wavelet transform (CWT) to simulate nonstationary non-Gaussian vector process for prescribed marginal probability distribution functions and the time-scale power spectral density function matrix. The algorithm is designed for a CWT pair within the wavelet analysis framework. It can be used with analytical wavelets satisfying the admissibility condition and can cope with time-dependent and time-independent coherence. The proposed algorithm is applied to generate nonstationary downburst winds and seismic ground motions at multiple sites within the wavelet analysis framework. The numerical validation analysis confirms that the proposed algorithm can lead to the simulated records matching the prescribed marginal probability distribution, marginal time-scale power spectral density function and coherence function.

Biopolymers are widely available, low-/nontoxic, biodegradable, biocompatible, chemically versatile, and inherently functional, making them highly potential for a broad range of applications such as biomedicine, food, textile, and cosmetics. 3D printing (3DP) is capable of fabricating some customized, complex material structures composed of single or multiple material constituents that cannot be achieved by conventional methodologies (e.g. internal structures design); thus, 3DP can greatly expand the application of biopolymer materials. This review presents a comprehensive survey of the latest literature in 3DP technology for materials from biopolymers such as polysaccharides and proteins. The most commonly used 3DP techniques (i.e. inkjet printing, extrusion-based printing, stereolithography, selective laser sintering, and binder jetting) in biomedical and food fields are discussed. Critical factors affecting the quality and accuracy of 3D-printed constructs, including rheological characteristics, printing parameters (e.g. printing rate, and nozzle diameter, movement rate, and height), and post-printing processes (e.g. baking, drying, and crosslinking) are analyzed. The properties and the emerging applications of 3D-printed biopolymer materials in biomedical, food, and even wider applications (e.g. wastewater treatment and sensing) are summarized and evaluated. Finally, challenges and future perspectives are discussed. This review can provide insights into the development of new biopolymer-based inks and new biopolymer-based 3D-printed materials with enhanced properties and functionality.

By comparing the safety and efficacy of 500 mg of oral levofloxacin for 3 days with those of intravenous antibiotics for 3 days in the prevention of infectious complications of ultrasound-guided transrectal prostate biopsy (TPB), we provided a safe and cost-effective infection preventive protocol for TPB in China. A total of 801 patients with indications for TPB in 12 centers were randomized into two groups from October 2011 to December 2015. Patients in the test group (n = 392) took 500 mg of oral levofloxacin for 3 days. Patients in the control group (n = 409) underwent intravenous antibiotics according to the traditional habits of the center for 3 days. All patients underwent ultrasound-guided TPB. Infectious complications were compared between the two groups. Different kinds of antibiotic were used in the control group. Comparing the two groups, the mean patient age was 70.6 ± 14.0 and 70.5 ± 14.0 years. The incidence of total infectious complications was 4.6 % (18/392) and 4.4 % (18/409) respectively, the incidence of asymptomatic bacteriuria was 3.1 % (12/392) and 2.7 % (11/409), the incidence of symptomatic urinary tract infection was 0.0 % and 0.2 % (1/409), the incidence of fever was 0.8 % (3/392) and 0.5 % (2/409), the incidence of bacteremia was 0.5 % (2/392) and 0.0 %, and the incidence of urosepsis was 0.3 % (1/392) and 1.0 % (4/409) respectively (all P > 0.05). The selection of antibacterial agents for TPB is in ca haotic condition in China. Oral levofloxacin at 500 mg once daily for 3 days is a safe, convenient, and cost-effective infection preventive protocol for TPB in China.

Passive microwave sensors have the capability to provide information on snow depth (SD), which is critically important for hydrological modeling and water resource management. However, the different algorithms used to produce SD products lead to discrepancies in the data. To determine which products might be most suitable for Northern China, this paper assesses the accuracy of the existing snow depth products in the period of 2002–2011. By comparing three daily snow depth products, including NSIDC, WESTDC and ESA Globsnow, with snow cover product and meteorological stations data, the accuracies of the different SD products are analyzed for different snow class and forest cover fraction. The results show that comparison between snow cover derived from snow depth of NSIDC, ESA GlobSnow and WESTDC with snow cover product shows that accuracy of WESTDC and ESA GlobSnow in snow cover detecting can reach 0.70. Compared to meteorological stations data below 20 cm, NSIDC consistently overestimate, WESTDC and ESA Globsnow underestimate, furthermore the product from WESTDC is superior to the others. The three products have the same tendency of significant undervaluation over 20 cm. The WESTDC is superior to the ESA Globsnow and NSIDC in non-forest regions, whereas the ESA GlobSnow estimate is superior to the WESTDC and NSIDC in forest regions. As for the prairie and alpine snow, WESTDC has smaller bias and RMSE, meanwhile Globsnow has advantages in the snow depth retrieval in tundra and taiga snow. Therefore, we should choose the more suitable snow depth products according to different needs.

This research studied the effects of a triaxial stress thermal–hydromechanical coal-containing-gas permeameter on mechanical and gas seepage characteristics under different confining pressures, different initial axial stress and different unloading speeds of the confining pressure. The results showed that in the process of unloading the confining pressure before peak strength, the strain (permeability) could be divided into three stages. As the unloading speed was increased the duration of the initial axial stress time would decrease, along with the duration of the axial stress platform. The permeability was closely related to the unloading of the confining pressure and the initial axial stress, which, when increased, would lead to accelerated strain growth. Additionally, the results of the experiment that unloaded the confining pressure after peak strength showed that strain (permeability) could be divided into two stages, and when compared to the experiment done before peak strength, the duratio...

The tensile stress and microstructure of 316L stainless steel welded joints are heterogeneous, and therefore the great risks of stress damage corrosion will be introduced. In the present study the welded joints were treated by laser shock peening (LSP) with different power density. Through residual stress test, microscopic analysis by XRD, SEM and TEM, the residual stress distribution, phase structure and microstructure were characterized, and the mechanism of LSP was discussed. The results showed that by the use of different power density, the residual tensile stress of welded joint decreased in comparison with welded sample. With the increasing of power density, these residual tensile stresses generated were superseded by the compressive residual stresses, and the maximum compressive residual stress reached about −100 MPa. By laser shock processing under different power density, the severe plastic deformation appeared in the surface layer of welded joint, high density nanocrystals and dislocation formed. However, there was difference for the plastic deformation characteristic among the three regions from weld seam, heat-affected zone, matrix zone, this should be accomplished by the interaction of the grain state, size and orientation with the laser shock peening. Moverover, the phase transformation from austenite to martensite was observed in the surface layer of welded joint, when the power density increased to 6.63 GW/cm2, while this is harmful for the improvement of stress corrosion resistance. Therefore, a specific laser power density is propitious to improve the residual compressive stress and microstructure of the weld joint, thus to gain better stress corrosion resistance.

Neovibsanin type natural products were found to display neurite outgrowth activity in PC12 cells. This suggests that such type of compounds could be promising candidates for the development of novel therapeutic agents to treat neurological diseases. In the present study rats after chronic mild stress (CMS) were treated with tricyclic neovibsanin scaffold (TCNS) to study its effect on depression. The results revealed that 15 mg/kg doses of TCNS reduced the duration of immobility in CMS model of depression. It led to a significant increase in neurite outgrowths which increased the synaptic and structural plasticity of neurons. Treatment with TCNS decreased the levels of MAO-A and caspase-3 expression both of which were found to be higher in CMS. TCNS also led to an increase in expression of heat shock protein 70 (Hsp70) in the hippocampus. These findings suggest that TCNS possesses antidepressant activity in CMS model of depression. Therefore the relief in depression by TCNS may be due to suppression of MAO-A expression and the apoptosis cascade by increased expression of Hsp70.

Autonomous navigation of Satellite and constellation has series of benefits, such as to reduce operation cost and ground station workload, to avoid the event of crises of war and natural disaster, to increase spacecraft autonomy, and so on. Autonomous navigation satellite is independent of ground station support. Many systems are developed for autonomous navigation of satellite in the past 20 years. Along them American MANS (Microcosm Autonomous Navigation System) [1] of Microcosm Inc. and ERADS [2]，[3] (Earth Reference Attitude Determination System) of Honeywell Inc. are well known. The systems anticipate a series of good features of autonomous navigation and aim low cost, integrated structure, low power consumption and compact layout. The ERADS is an integrated small 3-axis attitude sensor system with low cost and small volume. It has the Earth center measurement accuracy higher than the common IR sensor because the detected ultraviolet radiation zone of the atmosphere has a brightness gradient larger than that of the IR zone. But the ERADS is still a complex system because it has to eliminate many problems such as making of the sapphire sphere lens, birefringence effect of sapphire, high precision image transfer optical fiber flattener, ultraviolet intensifier noise, and so on. The marginal sphere FOV of the sphere lens of the ERADS is used to star imaging that may be bring some disadvantages., i.e. , the image energy and attitude measurements accuracy may be reduced due to the tilt image acceptance end of the fiber flattener in the FOV. Besides Japan, Germany and Russia developed visible earth sensor for GEO [4]、[5]. Do we have a way to develop a cheaper/easier and more accurate autonomous navigation system that can be used to all LEO spacecraft, especially, to LEO small and micro satellites? To return this problem we provide a new type of the system—CANS (Compact Autonomous Navigation System) [6].

MicroRNAs (miR) participate in cell proliferation, apoptosis and transformation, as they can regulate gene expression and intracellular signal transduction for various physiological processes. MiR-122 and miR-22 are known to be related with occurrence and progression of hepatitis B virus (HBV)-related hepatocellular cancer (HCC). This study recruited HBV-related HCC patients, whose expression levels of miR-122 and miR-22 were determined to analyze the correlation with clinical and pathological indexes.HBV-related HCC patients were enrolled, in parallel with patients suffering from benign liver disease and non-HBV-related HCC. Real-time PCR was employed to measure miR-122 and miR-22 expression levels.The relative expression levels of miR-122 and miR-22 in HBV-related HCC patients were 1.26 ± 2.73 and 5.49 ± 3.91, respectively, which were significantly lower than that in benign liver disease or non-HBV-related HCC patients (p0.05). No significant difference of serum miR-122 or miR-22 levels was found between benign liver disease and non-HBV-related HCC patients (p0.05). The miR-122 and miR-22 levels were negatively correlated with tumor size, lymph node metastasis, TNM stage, pathological type, differentiation grade, liver cirrhosis, AFP and HBV DNA, all of which were independent risk factors (p0.05).MiR-122 and miR-22 were downregulated in HBV-related HCC patients, and were related with tumor size, lymph node metastasis, TNM stage, pathological type, differentiation grade, liver cirrhosis, AFP and HBV DNA.

Starch-based superabsorbent polymers (SAPs) were produced by graft copolymerization of starch-g-acrylamide using a twin-roll mixer as reactor. This work focused on the effect of starch microstructure (amylose/amylopectin contents) from the same source (corn starch) on the graft ratio (GR), graft efficiency (GE) and Add-on (AO), as well as water absorption capability (WAC) of the SAPs, which were investigated by FTIR, NMR, gravimetric and TGA. The torque variation represented all the processing in the reactor, including compress, gelatinization, graft reaction and crosslinking. Results showed that all the starches were successfully grafted with acrylamide then crosslinked by N.N′-methylene-bisacrylamide through this technology. Both AO and GR increased with increasing amylose content. But the GE decreased with increasing amylose content, which is different from the results in the solution reaction. The higher WAC of high amylose starch-based SAP corresponds with higher AO and GR, while the higher WAC of waxy-based SAP corresponds with higher GE.

Breast cancer metastasis suppressor 1 (BRMS1) was originally identified as a metastasis suppressor gene in human breast cancer.A recent study has established an association between BRMS1 with the clinical stage and different pathology grades of prostate cancer. However, whether BRMS1 plays a role in prostate cancer has not been elucidated.In this study, we found that overexpression of BRMS1 in PC-3 cells induced apoptosis and inhibited invasion; moreover, we found that overexpression BRMS1 was associated with the suppressed expression of EMMPRIN.Taken together, our results show that BRMS1 may suppress progression and metastasis of prostate cancer through modulating EMMPRIN expression.

To study the biological characteristics of new retrograde filling materials iRoot BP plus and iRoot FS.(1) The roots were cut into 3 mm in length, and the root canals were prepared to 1 mm in diameter, followed by being filled with iRoot BP plus, iRoot FS, or mineral trioxide aggregate (MTA). The specimens were immersed in simulated body fluid (SBF). The ability of mineralization in vitro was detected through three studies. First, the mineralization of specimens was analyzed through scanning electron microscope observations and energy dispersive X-ray spectrometer. Then, the pH of SBF was monitored using pH meter. (2) The extracts were gained by immersing blocks of iRoot BP plus, iRoot FS, and MTA (8 mm diameter and 2 mm height) into dulbecco's modified eagle medium (DMEM). The effects of the extracts on proliferation of MG63 cells were detected through MTT assay. The gene expression level of alkaline phosphatase (ALP) was analyzed by quantitative real-time PCR, and the expression of ALP activity was observed by ALP activity staining.(1) The formation of minerals could be observed on the surfaces of iRoot BP plus, iRoot FS, and MTA at the end of 24 h, and there were more amounts of apatite aggregated after 14 days. The values of Ca/P ratios of apatites were 1.43, 1.39, and 1.51, respectively. (2) The pH of SBF could be raised to 8.09±0.07, 7.91±0.06, and 8.11±0.06, respectively, significantly higher than the blank. (3) The extracts of iRoot BP plus, iRoot FS, and MTA of dilutions of 1:5 and 1:10 presented no effect of proliferation of MG63 cells. (4) iRoot BP plus and iRoot FS could significantly up-regulated the levels of ALP messenger RNA expression, while there was no obvious difference in ALP staining among the iRoot BP plus, iRoot FS, MTA, and the blank.The present study shows that iRoot has displayed good mineralization capability in vitro and capability to promote differentiation and mineralization of MG63 cells, inferring that iRoot may have good bioactivity.

To explore the diagnostic values of ratios of early diastolic peak transmitral velocity(E) to late velocity(A) (E/A) and E to early diastolic peak mitral annulus velocity (E/E') for heart failure patients with preserved ejection fraction (HF-PEF).Two hundred and sixteen healthy people were divided into50 years, 50-59 years, 60-69 years, and ≥70 years groups to clarify the impact of aging on E/A and E/E'. Two hundred and two newly diagnosed consecutive in-patients with HF-PEF and 221 age- and sex-matched non-heart-failure subjects with risk factors of HF-PEF (negative controls) were enrolled.The diagnostic values and cutoff points of E/A and E/E' for HF-PEF were derived from receiver operating characteristic curve (ROC) analysis.E/A and E/E' were significantly different among age groups in healthy controls (all P0.01). Compared with50 years group, average E/A was lower and average E/E' was higher in ≥70 years group(both P0.01). E/A ratio was less than 1 in 68%(71/105), E/E' was8 cm/s in 48% (50/105)healthy people with age≥60 years. Neither E/A nor E/E' of HF-PEF patients was statistically different regarding to NYHA classification (grade Ⅱ, Ⅲ, Ⅳ), but NT-proBNP value increased in proportion to higher NYHA classification(P0.01). The area of E/E' under ROC for diagnosing HF-PEF was 0.839(P0.01), and the corresponding cutoff point was 9.5 with a sensitivity of 86% and a specificity of 69%. The areas of E/A (larger value or smaller value indicating positive) under ROC for diagnosing HF-PEF were 0.469 and 0.531, respectively(all P0.05).Aging exerts significant impacts on both E/A and E/E'. E/E' has moderate diagnostic accuracy while E/A is of limited value for diagnosing HF-PEF.

A high throughput quantitation protocol is desired to determine the replication of various recombinant oncolytic viruses in vitro. Plaque assay is the classic method for viral infectivity quantitation but is laborious and time consuming; moreover it does not report the oncolytic efficacy of a virus. In this paper, three new imaging methods for quantitating viral infectivity are derived and evaluated: fluorescence intensity, infection counts, and infection degree. Infection of oncolytic Newcastle disease virus in human tumor and normal cells was followed over a time course by plaque assay and the imaging methods. For the latter, brightfield and green channel images were acquired at various fixed locations in the cell culture, and later analyzed. One of the imaging methods was found to be highly correlated with viral titer; the other methods are complementary to plaque assay and provide additional information like oncolytic efficacy, syncytium formation etc. The new methods significantly reduce the time and material costs required by plaque assay, and provide an efficient system for quantitating and characterizing infectivity and efficacy of oncolytic viruses.

GaN has become increasingly important for microwave applications up to K a band as a result of its wide band-gap, which provides a high critical breakdown field and good thermal stability, yielding excellent potential for high power and high voltage operation. It is of major interest to understand the device structures that will lead to high efficiency, high power microwave amplifiers. In this paper, we investigate by simulation the microwave performance of InGaN/GaN Heterojunction Bipolar Transistors (HBTs), with proper device geometry to account for the effects of current crowding. We provide an analysis of both emitter-up and collector-up InGaN/GaN HBT structures, based on a distributed HBT model implemented in ADS. We simulate their performance in a fully matched Class B high power amplifier. The results show that an important issue for high power operation is the mismatch between optimum load conditions for peak output power and peak gain, To increase the output impedance, it is important to decrease base-collector capacitance, which can be achieved with a collector-up structure. Furthermore, current crowding in the emitter caused by the sheet resistance in the base becomes more important at higher power operation, and is therefore a key design consideration.

The effects of capillary bonding of Si wafers in methanol have been investigated. Wafers brought into contact in alcohol generally leads to less particle trapping at the interface, and that liquid surface tension is useful in pulling bonding wafer together. The intrusion of methanol at the interface appears to affect the bond strength of hydrophilic bonding Si wafers where the strengthening mechanism is primarily due to the escaping of H2O molecules from the interface. For hydrophobic wafers the use of methanol capillarity and dried in an inert ambient appears to prevent or minimize oxidation of the contacting surfaces. The experimental result supports the notion that such wafer pairs can indeed be heat-treated to form covalent bonds in between without resorting to high vacuum processing.

The aim of this study was to ascertain whether MG7Ag is a useful predictor of evolution of gastric dysplasia to carcinoma. A total of 1090 patients with confirmed dysplasia were stained immunohistochemically with MG7 monoclonal antibody by the ABC method. A prospective follow-up study was undertaken on 19 patients with MG7Ag positive staining and 16 with MG7 negative staining over a period of 10-78 months. The expression of MG7Ag was also compared in another two groups by conducting retrospective studies. One group showed an evolution into gastric cancer over 2-4 years, the other did not. Quantitative analysis of MG7Ag expression was carried out on the last two groups. The receiver operating characteristic curve and Youden index were used to assess the best critical value for MG7Ag. MG7Ag was found positive in 456/1090 cases (41.8%) with dysplasia. Prospective follow-up of 35 patients showed that 6/19 patients with MG7Ag positive staining developed gastric cancer, but there were no carcinomatous changes in 16 patients with MG7 negative staining. The results of MG7Ag expression in 72 cases with retrospective follow-up showed there were 24 with positive immunostaining among 34 cancerous cases (70.6%), and only 7 in 38 non-cancerous cases (18.4%) (p0.01). Image analysis showed that an average MG7Ag density index ++0.19 could be regarded as the critical value for high risk of gastric mucosa with dysplasia evolving to cancer. Positive MG7Ag expression in gastric mucosa of patients with dysplasia, especially in cases with a density index ++0.19, was an indicator of high risk of malignant change.

The process of ion cutting was used to integrate single crystalline Si layers on glass for potential active matrix flat panel display and other applications. It was found that p-Si wafers implanted at 100–150 ° C with H with a dose in the order of a few times 10 16 cm −2 could be readily bonded to glass substrates when both of the surfaces were properly treated and activated. The as-implanted Si wafer surface was converted from p type to n type. Upon bonding at room temperature, annealing (300 ° C ) and exfoliation (450 ° C ), the transferred Si layer on glass and the as-exfoliated surface of the implanted Si wafer remained n type. A highly defective region was observed near the top of the Si layer on glass, however the crystalline quality was nearly defect free in the deeper region of the layer. Annealing at sequentially higher temperatures led to the recovery of p type conductivity at ∼600–650 ° C . The type conversion and the subsequent annealing behavior observed on the samples were rationalized in terms of ion enhanced oxygen diffusion and the presence of H-related shallow donors in the Si.

We conducted this study to investigate whether glans-reconstruction with preputial flap would be more helpful for post-operative restoration of patients' sexual potency than primary closure. From 2007 to 2013 at four centres, 46 cases reconstructed with preputial flap and 59 with primary closure were selected for the investigation from 142 consecutive cases of superficial glans cancer, with the largest diameter of lesion ≤2.5 cm, who undergoing glans-preserving surgery (GPS). Subjective evaluation for patients' sexual performance was investigated using the International Index of Erectile Function-15. Objective evaluation was carried out by the Audio Visual Sexual Stimulation test with RigiScan-Plus. The degree of satisfaction for penile appearance and patients' confidence and partners' acceptability for intercourse were evaluated by 5-point scales. Patients with preputial flap reconstruction showed significant better performance in three domains (orgasmic function, intercourse satisfaction and overall satisfaction, all p < 0.05) and significantly higher ratios of appearance satisfaction (78.3% vs. 57.6%, p = 0.026) and intercourse confidence (69.6% vs. 49.2%, p = 0.035) compared with those undergoing primary closure at post-operative month 6 ends. Their sexual partners in the preputial flap group also exhibited significantly higher ratios of appearance satisfaction than in the primary closure group (67.4% vs. 42.4%, p = 0.011). Reconstruction with preputial flap contributes to a more acceptable cosmetic appearance of the penis and minimizes post-operative negative psychological impediments. Patients can benefit more from reconstruction with preputial flap than primary closure. Glans-reconstruction with preputial flap should be considered the primary reconstruction technique in GPS.

Al/Ti based metallization is commonly used for ohmic contacts to n-GaN and related compounds. We have previously reported an ohmic contact scheme specially designed for AlGaN/GaN heterostructure field-effect transistors (HFETs) [D. Qiao et al., Appl. Phys. Lett. 74, 2652 (1999)]. This scheme, referred to as the “advancing interface” contact, takes advantage of the interfacial reactions between the metal layers and the AlGaN barrier layer in the HFET structure. These reactions consume a portion of the barrier, thus facilitating carrier tunneling from the source/drain regions to the channel region. The advancing interface approach has led to consistently low contact resistance on Al0.25Ga0.75N/GaN HFETs. There are two drawbacks of the Al/Ti based advancing interface scheme, (i) it requires a capping layer for the ohmic formation annealing since Ti is too reactive and is easily oxidized when annealing is performed in pure N2 or even in forming gas, and (ii) the atomic number of Al and that of Ti are too low ...

The dependence of the Schottky barrier height of Ni/AlxGa1−xN contact on the Al mole fraction up to x=0.23 was studied. The barrier heights were measured by I–V, capacitance–voltage, and the internal photoemission method. The Al mole fractions were estimated from the AlGaN band gap energies measured by photoluminescence. In the range of x

The liquid phase oxidation of ethylbenzene catalyzed by metal phthalocyanines (CoPc, MnPc, and FePc) was investigated under atmospheric pressure of oxygen at 100° C. The catalytic activity of CoPc is higher than that of MnPc and FePc. The addition of catalytic amounts of K2Cr2O7, MnO2 or V2O5 to the catalytic system can lead to an increase in the catalytic activity or acetophenone selectivity, compared to that of the metal phthalocyanine and catalytic amounts of K2Cr2O7, MnO2 or V2O5 used alone.

A photoconductance method was used to determine the band-gap energy and, therefore, the Al mole fraction of bulk AlxGa1−xN and AlxGa1−xN/GaN heterostructures. The results are compared with those obtained by a more elaborate photoluminescence method.

A synthetic fragment 31-35 of beta-amyloid peptide was used in cultured cortical neurons to examine whether this smaller sequence could trigger apoptotic degeneration in vitro by using morphological, biochemical and flow-cytometric examinations. The results showed that: (i) neurons treated with fragment 31-35 of beta-amyloid peptide exhibited membrane blebbing, compaction of nuclear chromatin, nuclear shrinkage and nuclear fragmentation; (ii) a typical DNA ladder was revealed by agarose gel electrophoresis following fragment 31-35 of beta-amyloid peptide exposure; (iii) the internucleosome DNA fragmentation was also detected by flow-cytometric examination following fragment 31-35 of beta-amyloid peptide exposure; and (iv) the DNA fragmentation induced by fragment 31-35 of beta-amyloid peptide in the above two examinations could be blocked by co-treatment with aurintricarboxylic acid or actinomycin D. It is suggested that fragment 31-35 of the beta-amyloid peptide may be a shorter sequence of beta-amyloid peptide responsible for triggering an apoptotic process in cultured neurons.

The temperature dependence of the current–voltage characteristics of Ni–GaN Schottky barriers have been measured and analyzed. It was found that the enhanced tunneling component in the transport current of metal-GaN Schottky barrier contacts is a likely explanation for the large scatter in the measured Richardson constant.

The transport properties of the advancing interface ohmic contact to AlGaN/GaN heterostructure field-effect transistors have been investigated. We found that carrier transport across the AlGaN barrier layer is dominated by the tunneling of electrons that originate from the two-dimensional electron gas located at the AlGaN/GaN interface. The observed temperature dependence of the specific contact resistivity is different from that of the contact on highly doped bulk semiconductors, although tunneling current dominates the carrier transport in both cases.

Th1 cell-mediated adaptive immune response is very important but may not be sufficient to control Mycobacterium tuberculosis (M. tuberculosis) infection. The roles of the various T cell subsets and cytokines in the inflammatory processes are not clearly elucidated. We investigated whether Th1, Th22 and Th17 cells mediated cellular immunity at the local site of M. tuberculosis infection in patients with tuberculous pleurisy (TBP). The results showed that the cytokines IFN-γ and IL-22 but not IL-17 were elevated in tubercular pleural fluid. Following stimulation with immune-dominant peptides of early secreted antigenic target-6 (ESAT-6), culture filtrate protein-10 (CFP-10) or Bacille Calmette-Guerin, pleural fluid mononuclear cells expressed high levels of cytokines IFN-γ, IL-22 and IL-17 as revealed by mRNA and protein measurements. In addition, we showed that cytokines IFN-γ, IL-22 and IL-17 were produced in M. tuberculosis-specific immune response by distinct subsets of CD4+ T cells with the phenotype of CD45RA-CD62L-CCR7+CD27+ . Our results demonstrated for the first time that ESAT-6- and CFP-10-specific Th1, Th22 and Th17 cells existed in the patients with TBP and might play an essential role against M. tuberculosis infection. The findings of this study raised the possibility of unravelling the critical targets for therapeutic intervention in chronic inflammatory diseases such as TBP.

In present paper, a design method for natural laminar flow (NLF) airfoils with a substantial amount of natural laminar flow on both surfaces by coupling inverse design method and optimal technique is developed. The N‐factor method is used to design the target pressure distributions before pressure recovery region with desired transition locations while maintaining aerodynamics constraints. The pressure in recovery region is designed according to Stratford separation criteria to prevent the laminar separation. In order to improve the off‐design performance in inverse design, a multi‐point inverse design is performed. An optimal technique based on response surface methodology (RSM) is used to calculate the target airfoil shapes according to the designed target pressure distributions. The set of design points is selected to satisfy the D‐optimality and the reduced quadratic polynomial RS models without the 2nd‐order cross items are constructed to reduce the computational cost. The design cases indicated that...

In order to carry out the experimental investigation on control of stall flow over airfoil, two forms of the vortex generator layouts were designed. Comparison for the experimental data with and without vortex generators has been carried out, and the attention are focused on effects of stall flow over airfoil with different vortex generators layout. Experiment shows that the stall flow over airfoil is suppressed evidently by the first and second categories vortex generators, and the maximum lift coefficient is increased dramatically. The control of stall flow over airfoil with the second category vortex generator is much better than the first category vortex generator, and the smaller the inclined angle of the vortex generator is, the better the control effects of stall flow over airfoil will be.

Electrical properties and microstructures of Ta/Ti/Al and Ti/Ta/Al contacts to n-AlGaN/GaN heterostructure field-effect transistor structures were investigated using the transmission line method and transmission electron microscopy. The specific resistivity (5.3×10−7 Ω cm2) of Ta/Ti/Al contacts is much lower than that (5.1×10−4 Ω cm2) of Ti/Ta/Al contacts, for the same heterostructure and similar metallization. The contact resistivity was found to depend on the thickness of the AlGaN layer, interfacial phase, and interface roughness. The formation of interfacial phases by solid-state reactions with the metal layer during annealing appears to be essential for ohmic behavior on n-III-nitrides suggesting a tunneling contact mechanism.

Although the influence of endocrine factors is well established, the molecular and cellular mechanisms controlling coat color are not completely understood. A major mechanism for post-transcriptional regulation of gene expression is through the action of microRNAs (miRNAs), which anneal to the 3' untranslated region of mRNAs in a sequence-specific fashion and either block translation or promote transcript degradation. In this study, we investigated the expression of miRNAs in the skin of alpacas with brown vs white coat color using a microarray screen; identified potential mRNA targets for identified miRNAs among coat color genes; and subsequently determined the ability of a specific, differentially expressed miRNA (miR-25) to suppress expression of micropthalmia-associated transcription factor (MITF), a predicted miR-25 target gene that regulates genes linked to coat color. Expression of 10 different miRNA species in the skin of alpacas with brown vs white coat color was identified from microarray screens. Of the 10 alpaca skin miRNAs identified, predicted binding sites in the 3' untranslated region of RNAs encoding for known genes linked to coat color were primarily for miR-25, but sites were also identified for miR-129 and miR-377. Potential miR-25 binding sites were present in transcripts encoding for 11 coat color genes, including MITF. An inverse relationship between transcript abundance for MITF and miR-25 was observed in skin samples collected from alpacas with white vs brown coat color. Furthermore, overexpression of miR-25 in cultured melanocytes reduced MITF mRNA and protein abundance and corresponding mRNA abundance for the MITF-regulated enzymes tyrosinase and tyrosinase-related protein 1. Results support a novel functional role for miRNA-25 in the regulation of gene expression linked to coat color.

The boundary integral equations and boundary element formulation for rigid-plastic problems are derived based on the Levy-von Mises plastic stress-strain relation and on the fundamental solution obtained by using the linear quick-dropping function. A plastic compression problem in plane strain state is calculated. The results show that the calculated results are in agreement with the experimental results.

In this study, we report a simple optical reflectance method to characterize the Al mole fraction in bulk AlGaN and AlGaN/GaN heterostructures. This method is based on the concept of Fabry–Perot oscillations of a probing beam when the photon energy of the beam falls below the band-gap energy of the semiconductor. The accuracy and merits of this method in comparison with the more elaborate photoluminescence method are discussed.

The ohmic contact formation of Al/Ti on AlGaN/GaN heterostructure field effect transistors (HFETs) with and without Si implantation was investigated. Direct implantation and implantation through an AlN capping layer were studied. Compared to implantation through AlN, direct implantation is more effective in reducing the contact resistance. An Al(200 A)/Ti(1500 A) bilayer structure, called the “advancing” metallization, was used in this investigation to take advantage of consuming nearly all the top AlGaN layers for easy carrier access to the GaN layer underneath. Combining the direct implantation and the advancing metallization, low contact resistance of the order of 0.25 Ω mm (∼5.6×10−6 Ω cm2) can be readily obtained on HFET structures with an AlGaN layer about 340 A thick and with an Al fraction of at least 22%.