Search

In this article, a sheet model is utilized to model and simulate hot electron transport properties in vacuum gap. Based on this model, emitted electrons with constant initial velocities and Maxwell–Boltzmann distribution are considered. Numerical analyses of the potential, electric field, current density, velocity, and phase-space distribution are also performed. The accuracy of this model is verified by comparing with analytical results. Furthermore, we studied the velocity distribution of the emitted electrons at any position in the interelectrode gap and observed a significant change in the distribution.

The central deformation extent of the thick plate can be improved and the approaching uniform deformation will be realized by the snake/gradient temperature rolling (SGTR). At present, the existing rolling force analytical models cannot be directly used for SGTR because of the great difference with the synchronous rolling. The rolling force model should be established so as to meet the production demand of the SGTR with different roll diameters. The thick plate is divided into three layers according to the numerical results of the short-term ultra-fast cooling for the thick plate. The deformation region is simplified into different zones and layers according to the temperature gradient and neutral point position. The traditional von Mises yield criterion was optimized by the introduced coefficients c1 and c2 according to the slip line field theory to correct the deviation caused by the uniform and shear stress assumption. The specific pressure equation is established by the slab method. The deformation region with different composition cases is analyzed, and the rolling force and torque analytical models are established according to the boundary conditions on this basis. The short-term ultra-fast cooling and rolling process were simulated by ANSYS software. The deformation resistance gradient produced by short-term ultra-fast cooling and roll diameter ratio are the main factors to affect the rolling force, while the roll offset has little effect on the rolling force because of its small proportion in the deformation region. The position of neutral points not only affects the rolling torque, but also changes its direction in certain conditions. The model precision was analyzed, and the rolling force calculated by the established analytic model is in good agreement with the numerical method, which serves as a theoretical basis for the rolling mill design and process parameter setting.

Background High levels of thymidylate synthase (TS) and dihydrofolate reductase (DHFR) expression in tumour tissues are an indicator of ineffective responses to pemetrexed-based chemotherapy in various tumours, including non-small cell lung cancer (NSCLC). However, tumour tissues are highly heterogeneous, so a single biopsy may not reflect genetic alterations during disease progression. This study investigated the potential use of plasma TS and DHFR mRNA levels as biomarkers for predicting sensitivity to pemetrexed-based chemotherapy. Methods Plasma samples were obtained from 245 patients with advanced NSCLC and 30 healthy donors. Total RNA was extracted from the plasma samples, and TS and DHFR mRNA levels were determined via real-time PCR. TS and DHFR mRNA levels between cancer patients and healthy controls were compared. The association between plasma TS and DHFR mRNA levels and tumour response to pemetrexed/cisplatin chemotherapy was analysed. Results The plasma TS and DHFR mRNA levels decreased in patients with advanced NSCLC compared with healthy controls. Moreover, plasma TS and DHFR mRNA levels negatively correlated with tumour response to pemetrexed/cisplatin chemotherapy in patients with advanced NSCLC. Overall survival time was prolonged in patients with low TS mRNA expression compared with those with high TS mRNA expression, although the difference was not statistically significant. Conclusions Low expression levels of plasma TS and DHFR mRNA confer increased tumour sensitivity to pemetrexed/cisplatin chemotherapy in patients with advanced NSCLC. The results suggested that plasma TS and DHFR mRNA levels are promising biomarkers for choosing patients who are likely to respond and benefit the most from pemetrexed-based chemotherapy.

Purpose – This paper highlights the interaction between innovation and financial structure under duopoly with a monopoly debater. Design/methodology/approach – By game-theory approaches, we characterize effects of debt levels on innovative investment with limited liability effect. Findings – This paper argues that higher debt levels increase both innovative investment and output. Both higher debt rate and higher debt levels act as commitment to reduce opponent firms’ net profits. Net profit for unit debt is reduced with higher debt level and higher debt rate. Originality/value – This study extends Brander and Lewis’s (1986) to innovative situation and no interior point solution is restricted.

By establishing a two-stage model, this paper captures the optimal strategies for clean technology to advance green transition upon various scenarios. Based on theoretical analysis, we conclude that carbon taxes could stimulate innovation and green transition as well as subsidies when technology is mature. On the other hand, the effectiveness of carbon taxes decreases with immature technology. Meanwhile, both energy price fluctuation and innovation risk deter the development of clean technology, while the negative effects are much more significant at the second stage than those at the first stage. In addition, subsidies in both periods show much more significant impacts on the second stage than those on the first stage, while firms face more uncertainty and risk in the first stage. To advance green transition efficiently, the optimal incentive strategy is to allocate more subsidies in the first stage instead of in the second stage.

The snake rolling can keep the plate shape well, and the larger shear strain produced by the snake rolling is conducive to the deformation penetrating into the center of the heavy plate. So it provides a new method for producing the high-performance heavy steel plate. However, there is little research on the plate curvature modeling which is the key to achieve the snake rolling process. The deformation region was divided into four different zones at most which was depended on the positions of the two neutral points, and this number could be dropped to three or two in some other conditions. It was divided into three different cases according to the neutral point position: I, II, III and IV; I, II and IV; II and IV. The unit pressure and the accumulated shear strain deviation between the top and bottom portions of the plate with every case were established, and the plate curvature caused by shear strain was calculated on this basis. The plate curvature caused by the axial strain was also calculated according to the flow criterion. The approximations are corrected by a fitting coefficient E. The homogeneity coefficient E was introduced during the plate curvature modeling process to make the model more accurate. Then the total plate curvature model was established. The simulation of snake rolling process is carried out by using ANSYS LS-DYNA, and the plate curvature results are compared with the theoretical method. The results showed that the maximum and minimum relative error of the model was 11.61% and 0.28% compared to the simulation method, which can be applied for the online plate curvature control application with the effect of some self-learning methods. The plate curvature affecting law with the different process parameters (roll offset, roll speed ratio, rolling reduction, plate thickness and so on) was obtained in this paper. The research about the plate curvature modeling will provide important references for the heavy steel plate snake rolling production.

The grains in the center of the heavy steel plate can be refined by the snake/gradient temperature rolling, and the deformation penetration, the microstructure, and the properties of the steel plate will be improved. The existing rolling mechanical models are not suitable for the snake/gradient temperature rolling, so it is necessary to establish the mechanical parameters model of the snake/gradient temperature rolling to instruct production. The yield criterion of rolled material was modified based on the idea of equivalent flow stress. The element stress analyses were carried out based on the uniform normal stress and nonuniform shear stress in the vertical sides of each slab. Then the equilibrium equation of the unit pressure based on the slab method was established on this basis. The deformation region was divided into three layers (the top layer, the bottom layer, and the central layer) and maximum four zones (back slip zone, front slip zone, cross shear zone, and reverse deflection zone) according to the temperature distribution and position of the neutral point, and then the 12 zones were formed during the snake/gradient temperature rolling. The boundary conditions of the existence of the back slip zone, the front slip zone, and the cross shear zone were established according to the relationship between the threading angle and the neutral angle. The accurate mechanical parameters model of the rolling force and rolling torque of the snake/gradient temperature rolling with the same roll diameters was set up on this basis. The ANSYS software has been used in the rolling process simulation by many scholars, and the calculating precision has been verified. So the rolling processes were simulated by the ANSYS software to validate the model precision. The results show that the maximum relative deviation of the rolling force analytic model is less than 7% compared with the numerical method, and the maximum relative deviation of the rolling torque analytic model is less than 11% compared with the measured results. The mechanical parameters model can accurately predict the rolling force and rolling torque during the snake/gradient temperature rolling with the same roll diameters, so as to provide a theoretical basis for the design of rolling mill and the setup of the process parameters.

To detect the expression of miRNA in de novo and complete response SAA patients and predict the targets of the miRNAs.The expression profiles of miRNA from bone marrow mononuclear cells of the SAA patients with de novo and CR were detected by miRNA microarray.Totally 35 up-regulated and 37 down-regulated miRNA were identified in CR SAA patients in comparison with de novo SAA patients. Furthermore, by predicting the targets of the differentlly expressed miRNA, it was found that some targets associated with T cell receptor signaling pathway and cell adhesion molecules.Some miRNA may be involved in the pathogenesis of SAA.

To explore the clinical characteristic, therapeutic efficacy and prognosis of patients with hepatitis-associated aplasitc anemia (HAAA).the clinical data and labrotatory examination results of 30 cases of HAAA were analyzed retrospectively, the 6-month response ratio and overall survival (OS) were assessed.HAAA most commonly occured in males, with the occurence rate of males and females was 4:1, the median onset age was 16 (4-43) years old, HAAA oriented focus on sever aplastic anemia (SAA)(4 cases,13%) and very sever aplastic anemia (VSAA)(22 cases,73%). Aplastic anemia (AA) could be seen on occurence of hepatitis (accompanied aplastic anemia) (7 cases,23%), or after the onset of hepatits (delayed aplastic anemia) (23 cases,77%), but more often occured in the latter. Statistical analysis showed that when compared with the patients of delayed aplastic anemia, patients accompanied aplastic anemia possesses lower levels of glutamic-pyruvic transaminase(ALT), aspertate aminotransferase (AST) and total bilirubin (TBIL)(P=0.042,0.012,0.001), and possessed a more obvious lymphoid cell disorder when AA occured, with more lower peripheral blood CD19HAAA more often occur in young male, HAAA is mainly SAA and VSAA and mostly non-A-C hepatitis associated aplastic anemia, patients usually have a high incidence of early infection. Patients acompanied with aplastic anemia possess more obvious immunological derangement; the treatment efficacy for HAAA is poor, patients who haven't obtained 6-month response indicate a sinister prognosis, allogeneic hematopoietic stem cell transplantion is a better choice for these patients.

To investigate the clinical characteristics and gene mutations of patients with Gilbert syndrome complicated with myeloproliferative neoplasms (MPN).Peripheral blood samples from 1 patient with Gilbert syndrome complicated with MPN and his son were collected to analyse all exon mutations of UGT1A1 gene.The patient with leukocytosis, thrombocythemia, mild anemia and positive JAK2/V617F mutation was initially diagnosed as MPN. The hyperbilirubinemia suggested concurrent disease. Further gene evaluation disclosed a insertion mutation in the (TA)It is a first report case of MPN complicated with Gilbert syndrome that can highlight the differential diagnosis for hyperbilirubinemia.

Whether or not uniportal video-assisted thoracoscopic surgery (VATS) is beneficial for spontaneous pneumothorax remains inconclusive. This meta-analysis aimed to summarize the available evidence to assess the feasibility and advantages of uniportal VATS for the treatment of spontaneous pneumothorax compared with three-port VATS.Eligible publications were identified by searching the Cochrane Library, PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang Data databases and CQVIP. Odds ratios (OR) and standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated to compare dichotomous and continuous variables, respectively.This meta-analysis was based on 17 studies and included a total of 988 patients with spontaneous pneumothorax. No death was reported during the perioperative period. Compared with three-port VATS groups, there was a statistically significant difference in uniportal VATS groups regarding postoperative hospital stay (SMD= -0.58; 95% CI: -1.04 to -0.12; P=0.01), paresthesia (OR=0.13; 95% CI: 0.07 to 0.24; P0.00001), visual analogue pain score (VAS) at 24 hours (h) (SMD= -0.87; 95% CI: -1.07 to -0.68; P0.00001), VAS at 72 h (SMD= -0.49; 95% CI: -0.68 to -0.30; P0.00001), and patients satisfaction scale (PSS) at 24 h (SMD= -0.81; 95% CI: -1.21 to -0.41; P0.0001), PSS at 48 h (SMD= -0.69; 95% CI: -1.08 to -0.29; P=0.0007). However there was no statistically significant difference on the recurrence (OR=0.79; 95% CI: 0.42 to 1.46; P=0.45), operative time (SMD= -0.23; 95% CI: -0.21 to 0.67; P=0.31), length of postoperative drainage (SMD= -0.17; 95% CI: -0.40 to -0.07; P=0.16), VAS at 48 h (SMD= -0.40; 95% CI: -1.47 to 0.67; P=0.46), and PSS at 72 h (SMD= -0.13; 95% CI: -0.52 to -0.25; P=0.50).The results for mortality, recurrence, operative time, and length of postoperative drainage were similar between uniportal and three-port VATS. Uniportal VATS resulted in reduction in postoperative pain and paresthesia as well as an improvement in patients' satisfaction. This meta-analysis indicated that using uniportal VATS to treat spontaneous pneumothorax was safe and feasible, and it may be a better alternative procedure because of its advantage in reducing postoperative pain and paresthesia.

Expanded graphite (EG) was prepared by microwave irradiation and evaluated as adsorbent for the removal of disperse blue 2BLN (DB) from aqueous solution by the batch adsorption technique under different conditions of initial pH value, adsorbent dosage, initial dye concentration and contact time. The experimental data were analyzed considering pseudo-first-order, pseudo-second-order and intra-particle diffusion approaches. The adsorption kinetics at room temperature could be expressed by the pseudo second order model very well. The results indicate that the adsorption rate is fast enough and more than eighty percent of the adsorbed DB can be removed in the first 15 min at room temperature, which makes the process practical for industrial application.

The expanded graphite (EG) was prepared after microwave irradiation treatment of the expandable graphite in a domestic microwave oven at 1000 W for 60 s. The adsorption of methyl orange (MO) from aqueous solution onto EG was investigated at initial concentrations and contact time, different pH values, adsorbent dosage, temperatures for the removal of dye. The results confirmed that the adsorption isotherm data fitted to Langmuir isotherm with monolayer adsorption capacity of 13.37 mg/g. The results suggested that the EG would be an excellent adsorbent for the removal of MO by adsorption process.

To investigate the abnormalities of iron metabolism, the prevalence and risk factors of iron overload and clinical characteristics of patients with aplastic anemia (AA).A cross-sectional study was conducted on 520 newly diagnosed AA patients.Iron overload was observed in 66(13%) of 520 AA patients,in which a higher prevalence of iron overload was seen not only in patients with infections(19/86, 22%)than those without infections (47/434, 11%, P0.01), but also in patients with hepatitis associated AA(HAAA) (6/22, 19%) than the idiopathic cases (60/488, 12%, P0.05). Excluded the patients with infections and/or HAAA, 43 of 405(11%)cases had iron overload, including 14 of 248(6%) cases without history of blood transfusion and 29 of 157 patients (18%, P0.01) with transfusion. In univariate analysis, higher levels of serum ferritin (SF), serum iron (SI) and transferrin saturation (TS) were mainly observed in adult male patients with severe AA (SAA) and significantly upward with increasing blood transfusion (P0.01). No differences of soluble transferrin receptor (sTfR) were observed between adults and children, males and females, hepatitis and idiopathic AA. However, patients with infections had significantly lower level of sTfR (0.50 mg/L) than cases without infections (0.79 mg/L, P0.01). The level of sTfR in SAA patients (0.70 mg/L) was only half of that in non-SAA (NSAA) (1.36 mg/L, P0.01). Patients with increasing blood transfusion had significantly downward levels of sTfR (P0.01). In multivariate analysis, more than 8 U blood transfusion (OR=10.52, P0.01), adults (OR=3.48, P0.01), males (OR=3.32, P0.01) and infections (OR=2.09, P0.01) were independent risk factors.AA patients had higher iron burden and were high-risk populations occurring iron overload. The iron overload occurred in 18% of patients with blood transfusion and in 6% of patients without transfusion.

Background The -493G/T polymorphism in the microsomal triglyceride transfer protein (MTP) gene is associated with lower serum low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) levels and longevity in several populations, but the results are inconsistent in different racial/ethnic groups. The current study was to investigate the plausible association of MTP -493G/T polymorphism with serum lipid levels and longevity in Zhuang long-lived families residing in Bama area, a famous home of longevity in Guangxi, China. Methods The MTP -493G/T was genotyped by PCR-restriction fragment length polymorphism in 391 Bama Zhuang long-lived families (BLF, n = 1467, age 56.60 ± 29.43 years) and four control groups recruited from Bama and out-of-Bama area with or without a familial history of exceptional longevity: Bama non-long-lived families (BNLF, n = 586, age 44.81 ± 26.83 years), Bama non-Zhuang long-lived families (BNZLF, n = 444, age 52.09 ± 31.91 years), Pingguo long-lived families (PLF, n = 658, age 50.83 ± 30.30 years), and Pingguo non-long-lived families (PNLF, n = 539, age 38.74 ± 24.69 years). Correlation analyses between genotypes and serum lipid levels and longevity were then performed. Results No particularly favorable lipoprotein and clinical phenotypes were seen in BLF as compared to general families in the same area. Instead, the levels of total cholesterol (TC), TG, LDL-C, and the prevalence of dyslipidemia were significantly higher in the three Bama families as compared to the two non-Bama families (P P > 0.05 for all), but the TT genotype tended to enrich in the three long-lived cohorts from both areas. In addition, the individuals harboring TT genotype exhibited lower LDL-C and TC levels in the overall populations and Bama populations with a region- and sex-specific pattern. Multiple linear regression analyses unraveled that LDL-C levels were correlated with genotypes in Bama combined population, BNLF, and the total population (P P Conclusions MTP -493G/T polymorphism may play an important role in fashioning the serum lipid profiles of Bama populations, despite no direct association between MTP -493G/T and longevity was detected.