Critical behavior of quasi-two-dimensional ferromagnet Cr_(1.04)Te_(2)

The self-intercalation of Cr into pristine two-dimensional(2D) van der Waals ferromagnetic CrTe_(2),which forms chromium tellurides(Cr_(x)Te_(2)),has garnered interest due to their remarkable magnetic characteristics and the wide variety of chemical compositions available.Here,comprehensive basic characterization and magnetic studies are conducted on quasi-2D ferromagnetic Cr_(1.04)Te_(2) crystals.Measurements of the isothermal magnetization curves are conducted around the critical temperature to systematically investigate the critical behavior.Specifically,the critical exponents β=0.2399,γ=0.859,and δ=4.3498,as well as the Curie temperature T_(C)=249.56 K,are determined using various methods,including the modified Arrott plots,the Kouvel-Fisher method,the Widom scaling method,and the critical isotherm analysis.These results indicate that the tricritical mean-field model accurately represents the critical behavior of Cr_(1.04)Te_(2.A magnetic phase diagram with tricritical phenomenon is thus constructed.Further investigations confirm that the critical exponents obtained conform to the scalar equation near T_(C),indicating their self-consistency and reliability.Our work sheds light on the magnetic properties of quasi-2D Cr_(1.04)Te_(2),broadening the scope of the van der Waals crystals for developments of future spintronic devices operable at room temperature.

C-X-C chemokine receptor type 7 antibody enhances neural plasticity after ischemic stroke

Stromal cell-derived factor-1 and its receptor C-X-C chemokine receptor 4(CXCR4) have been shown to regulate neural regeneration after stroke.Howeve r,whether stromal cell-derived factor-1 receptor CXCR7,which is widely distributed in the develo ping and adult central nervous system,participates in neural regeneration remains poorly unde rstood.In this study,we established rat models of focal cerebral ischemia by injecting endothelin-1 into the cerebral co rtex and striatum.Starting on day 7 after injury,CXCR7-neutralizing antibody was injected into the lateral ventricle using a micro drug delivery system for 6 consecutive days.Our results showed that CXCR7-neutralizing antibody increased the total length and number of sprouting co rticospinal tra ct fibers in rats with cerebral ischemia,increased the expression of vesicular glutamate transporter 1 and growth-related protein 43,marke rs of the denervated spinal cord synapses,and promoted the differentiation and maturation of oligodendrocyte progenitor cells in the striatum.In addition,CXCR7 antibody increased the expression of CXCR4 in the striatum,increased the protein expression of RAS and ERK1/2 associated with the RAS/ERK signaling pathway,and im proved rat motor function.These findings suggest that CXCR7 improved neural functional recovery after ischemic stroke by promoting axonal regeneration,synaptogenesis,and myelin regeneration,which may be achieved by activation of CXCR4 and the RAS/ERK1/2 signaling pathway.

Flight parameter calculation method of multi-projectiles using temporal and spatial information constraint

The dynamic parameters of multiple projectiles that are fired using multi-barrel weapons in highfrequency continuous firing modes are important indicators to measure the performance of these weapons.The characteristics of multiple projectiles are high randomness and large numbers launched in a short period of time,making it very difficult to obtain the real dispersion parameters of the projectiles due to the occlusion or coincidence of multiple projectiles.Using six intersecting-screen testing system,in this paper,we propose an association recognition and matching algorithm of multiple projectiles using a temporal and spatial information constraint mechanism.We extract the output signal from each detection screen and then use the wavelet transform to process the output signal.We present a method to identify and extract the time values on which the projectiles pass through the detection screens using the wavelet transform modulus maximum theory.We then use the correlation of the output signals of three parallel detection screens to establish a correlation coefficient recognition constraint function for the multiple projectiles.Based on the premise of linear projectile motion,we establish a temporal and spatial constraint matching model using the projectile’s position coordinates in each detection screen and the projectile’s time constraints within the multiple intersecting-screen geometry.We then determine the time values of the multiple projectiles in each detection screen using an iterative search cycle registration,and finally obtain the flight parameters for the multiple projectiles in the presence of uncertainty.The proposed method and algorithm were verified experimentally and can solve the problem of uncertainty in projectiles flight parameter under different multiple projectile firing states.

塞来昔布联合FOLFOX4方案治疗晚期胃癌的疗效及机制研究

目的探讨塞来昔布联合FOLFOX4方案治疗人晚期胃癌的效果及可能的作用机制。方法选取2015年9月-2017年5月潍坊医学院附属医院消化科就诊的符合条件的经电子胃镜和病理证实为晚期胃癌的患者,共80例。随机分成两组,其中实验组40例,应用塞来昔布联合FOLFOX4化疗方案,对照组40例,应用FOLFOX4化疗方案。根据治疗效果的不同分为完全缓解(CR)、部分缓解(PR)、稳定(SD)和进展(PD)。参考WHO实体瘤疗效评价标准评价治疗效果。分别采用逆转录聚合酶链反应(RT-PCR)、免疫组织化学、Western blot检测治疗后胃癌组织中ABCG2、OCT-4、HIF-2α的m RNA及其蛋白表达。结果80例患者经过4周期治疗后,实验组有效率为77.5%,对照组有效率为42.5%,差异有统计学意义(P<0.05),实验组与对照组HIF-2α、ABCG2、OCT-4的m RNA和蛋白相对表达量差异均有统计学意义(P<0.05)。实验组表达减弱。结论塞来昔布联合FOLFOX4治疗晚期胃癌有效率高于FOLFOX4方案,胃癌组织中ABCG2、OCT-4、HIF-2α的m RNA和蛋白表达量降低,其机制可能通过降低HIF-2α-ABCG2和HIF-2α-OCT-4通路的表达影响胃癌的发展和转移,进而影响肿瘤的化疗抵抗、多药耐药。

Emodin induces apoptosis in human prostate cancer cell LNCaP

Aim： To elucidate effects and mechanisms of emodin in prostate cancer cells. Methods： Viability of emodin-treated LNCaP cells and PC-3 cells was measured by MTT assay. Following emodin treatments, DNA fragmentation was assayed by agarose gel electrophoresis. Apoptosis rate and the expression of Fas and FasL were assayed by flow cytometric analysis. The mRNA expression levels of androgen receptor （AR）, prostate-specific antigen （PSA）, p53, p21, Bcl-2, Bax, caspase-3, -8, -9 and Fas were detected by RT-PCR, and the protein expression levels of AR, p53 and p21 were detected by Western blot analysis. Results： In contrast to PC-3, emodin caused a marked increase in apoptosis and a decrease in cell proliferation in LNCaP cells. The expression of AR and PSA was decreased and the expression of p53 and p21 was increased as the emodin concentrations were increased. In the same time, emodin induced apoptosis of LNCaP cells through the upregulation of caspase-3 and -9, as well as the increase of Bax/Bcl-2 ratio. However, it did not involve modulation of Fas or caspase-8 protein expression. Conclusion： In prostate cancer cell line, LNCaP, emodin inhibites the proliferation by AR and p53-p21 pathways, and induces apoptosis via the mitochondrial pathway.

Esophageal mesenchymal tumors:Endoscopy,pathology and immunohistochemistry

AIM： To study the endoscopic, pathological and immunoo histochemical features of esophageal mesenchymal tumors. METHODS： Twenty-nine patients diagnosed as esophageal rnysenchymal tumors by electronic endoscopy and endoscopic ultrasound （EUS） were observed under light microscopes, and all tissues were stained by the immunohistochemical method. The expression of CD117, CD34, SMA and desmin were measured by staining intensity of cells and positive cell ratios. RESULTS： Endoscopically, esophageal gastrointestinal stromal tumors （GISTs） and leiomyomas （LMs） had similar appearances, showing submucosal protuberant lesions. They all showed low echo images originated from the muscularis propria or muscularis mucosa on EUS. Endoscopy and EUS could not exactly differentiate esophageal GISTs from LMs. Microscopically, there were two kinds of cells： spindle cell type and epitheloid cell type in esophageal GISTs. Leiomyomas and leiomyosarcornas were only of spindle cell type. One malignancy was found in five cases of esophageal GISTs, and one malignancy in 24 cases of leiomyomas and leiomyosarcomas. Using Fisher＇s exact method, the differences of malignant lesion proportion were not significant between esophageal LMs and GISTs, 1/5 vs 1/24 （P 〉 0.05）. All cases of esophageal GISTs were positive for CD117, and 3 cases were also positive for CD34. The 24 cases of leiomyomas and leiomyosarcomas were all negative for CD117 and CD34. The differences of positive rates of CD117 and CD34 were significant between esophageal GISTs and LMs, 5/5 vs 0/24, 3/5 vs 0/24 （P 〈 0.005）. All leiomyomas and leiomyosarcomas were positive for SMA, and desmin. Among 5 cases of esophageal GISTs, 2 cases were SMA positive, and 1 case was desmin positive. The differences in positive rates and expression intensity of SMA and desmin were significant between esophageal LMs and GISTs, 24/24 vs 2/5, 24/24 vs 115 （P 〈 0.005）. CONCLUSION： The most common esophageal mesenchymal tumors are leiomyomas, and esophageal GISTs are less common. Most of esophageal LMs and GISTs are benign. Endoscopy and EUS are the effective methods to diagnose esophageal mesenchymal tumors and they can provide useful information for the treatment of these tumors. However, they cannot exactly differentiate esophageal GISTs from LMs. Pathological, especially immunohistochemical features are useful to differentiate GISTs from leiomyomas.

Diabetes recurrence after metabolic surgeries correlates with re-impaired insulin sensitivity rather than beta-cell function

AIM To investigate factors causing diabetes recurrence after sleeve gastrectomy(SG)and duodenal-jejunal bypass(DJB).METHODS SG and DJB were performed on rats with diabetes induced by high-fat diet(HFD)and streptozotocin(STZ).HFD was used to induce diabetes recurrence at 4 wk postoperatively.Body weight,oral glucose tolerance test,homeostatic model assessment of insulin resistance(HOMA-IR),insulin signaling[IR,insulin receptor substrate(IRS 1,IRS2,phosphatidylinositol3-kinase and AKT in liver and skeletal muscle],oral glucose stimulated insulin secretion,beta-cell morphology(mass,apoptosis and insulin secretion),glucagon-like peptide(GLP)-1,PYY and ghrelin were compared among SG rats with common low-fat diet(SG-LFD),SG with HFD(SG-HFD),DJB rats with LFD(DJB-LFD),DJB with HFD(DJB-HFD)and shamoperation with LFD(Sham)at targeted postoperative times.RESULTS SG and DJB resulted in significant improvement in glucose tolerance,lower HOMA-IR,up-regulated hepatic and muscular insulin signaling,higher levels of oral glucose-stimulated insulin secretion,bigger betacell mass,higher immunofluorescence intensity of insulin,fewer transferase-mediated d UTP-biotin 3’nick end-labeling(TUNEL)-positive beta cells and higher postprandial GLP-1 and PYY levels than in the Sham group.The improvement in glucose tolerance was reversed at 12 wk postoperatively.Compared with the SG-LFD and DJB-LFD groups,the SG-HFD and DJB-HFD groups showed higher HOMA-IR,down-regulated hepatic and muscular insulin signaling,and more TUNEL-positive beta cells.No significant difference was detected between HFD and LFD groups for body weight,glucose-stimulated insulin secretion,betacell mass,immunofluorescence intensity of insulin,and postprandial GLP-1 and PYY levels.Fasting serum ghrelin decreased in SG groups,and there was no difference between HFD-SG and LFD-SG groups.CONCLUSION HFD reverses the improvement in glucose homeostasis after SG and DJB.Diabetes recurrence may correlate with re-impaired insulin sensitivity,but not with alterations of beta-cell function and body weight.

Three-dimensional coordinates test method with uncertain projectile proximity explosion position based on dynamic seven photoelectric detection screen

To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established.According to the relation of the dynamic seven photoelectric detection screen planes and the time values,the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.

The general public’s ability to operate automated external defi brillator: A controlled simulation study

BACKGROUND:Automated external defibrillators(AEDs)enable laypeople to provide early defi brillations to patients undergoing cardiac arrest,but scant information is available on the general public’s ability to use AEDs.This study assessed the ability of laypeople to operate AEDs,the effect of a 15-minute training,and whether skills differed by age.METHODS:From May 1 to December 31,2018,a prospective simulation study was conducted with 94 laypeople aged 18–65 years(32 aged 18–24 years,34 aged 25–54 years,and 28 aged 55–65 years)with no prior AED training.The participants’AED skills were assessed individually pretraining,post-training,and at a three-month follow-up using a simulated cardiac arrest scenario.The critical actions and time intervals were evaluated during the AED operating process.RESULTS:Only 14(14.9%)participants(eight aged 18–24 years,four aged 25–54 years,and two aged 55–65 years)successfully delivered defi brillations before training.AED operation errors were more likely to occur among the participants aged 55–65 years than among other age groups.After training,the proportion of successful defi brillations increased signifi cantly(18–24 years old:25.0%vs.71.9%,P<0.01;25–54 years old:11.8%vs.70.6%,P<0.01;55–65 years old:7.1%vs.67.9%,P<0.01).After three months,26.1%of the participants aged 55–65 years successfully delivered defi brillations,which was signifi cantly lower than that of participants aged 18–24 years(54.8%)and 25–54 years(64.3%)(P=0.02).There were no differences in time measures among three age groups in each test.CONCLUSIONS:The majority of untrained laypeople cannot effectively operate AEDs.More frequent training and refresher courses are crucial to improve AED skills.

A line laser detection screen design and projectile echo power calculation in detection screen area

A line laser with high power as the background light source for the design of a new photoelectric detection target is proposed in this paper, aiming to improve the detection ability of the traditional photoelectric detection target under low background illumination. The laser emitted pulse waveform function and the laser echo pulse response function were used to establish the mathematical model of the reflected echo power of projectile in the detection area and derive the calculation function of minimum detectable echo power in the line laser detection screen, according to information of the line laser emitted power, incident angle of projectile, duration time and detection distance of projectile passing through the line laser detection screen. Calculations and experimental results showed that the design method of line laser detection screen and calculation model of laser echo power are reasonable, and the detection ability of line laser detection screen is obviously higher than that of traditional photoelectric detection screen, especially in low background illumination;at the same time, the designed line laser detection screen was used to combine a six line laser detection screen intersection test system, based on live ammunition for shooting. The test system is stable and able to obtain the dynamic parameters of the flying projectile, verifying that the design of the line laser detection screen in new photoelectric detection target can be suitable for shooting range test applications.

Multi-area detection sensitivity calculation model and detection blind areas influence analysis of photoelectric detection target

Multi-element array photoelectric detector is the core devices to form a photoelectric detection target with a large field of view.This photoelectric detection target brings about the problem of uneven detection sensitivity distribution in the detection screen.To improve the uneven detection sensitivity of this photoelectric detection target,this paper analyzes the distribution law of the uneven detection sensitivity of the photoelectric detection target using the multi-element array photoelectric detector,dissects the main factors affecting the detection sensitivity according to the photoelectric detection principle,establishes the calculation model of detection sensitivity of the photoelectric detection target in the different detection areas and proposes a method to improve the detection sensitivity by compensating the gain of each unit photoelectric detector.The analysis of simulation and experimental results show that the proposed method of photoelectric detection target can effectively improve the output signal amplitude of the projectile under the certain detection distance,in particular,the output signal amplitude of the projectile is significantly increased when the projectile passes through the detection blind area.The experimental results are consistent with the simulation results,which verify the effectiveness of the proposed improvement method.

Weak Anti-Localization and Quantum Oscillations in Topological Crystalline Insulator PbTe

Topological crystalline insulators （TCIs） have attracted worldwide interest since their theoretical predication and have created exciting opportunities for studying topological quantum physics and for exploring spintronic appli- cations. In this work, we successfully synthesize PbTe nanowires via the chemical vapor deposition method and demonstrate the existence of topological surface states by their 2D weak anti-localization effect and Shubnikov-de Haas oscillations. More importantly, the surface state contributes ~61% of the total conduction, suggesting dom- inant surface transport in PbTe nanowires at low temperatures. Our work provides an experimental groundwork for researching TCIs and is a step forward for the applications of PbTe nanowires in spintronic devices.

在离子液体介质中对甲基苯乙烯阳离子聚合的研究

以离子液体为介质,通过密度泛函理论计算和实验分析,研究了离子液体对甲基苯乙烯(p-MeSt)的阳离子聚合的影响;考察了不同引发体系和不同离子液体对聚合的影响.通过核磁共振氢谱(1H-NMR)和傅里叶红外变换光谱(FTIR)对产物结构进行表征,凝胶渗透色谱(GPC)测定产物分子量与分布,温度记录仪跟踪测定体系温度与聚合时间的关系.结果表明,在离子液体中枯基醇(CumOH)/BF3·OEt2引发体系具有较好的引发效果;与传统分子溶剂相比,在1-丁基-3-甲基咪唑双(三氟甲烷磺酰)亚胺(缩写[Bmim][NTf2])离子液体中得到的聚合产物分子量和产率均较高(达99%),且分子量分布较窄(Mw/Mn～2.0);离子液体在阳离子聚合中仅是惰性溶剂,未直接参与反应,虽然离子液体的离子环境并不能完全抑制链转移反应,但具有稳定活性种和分散正电荷的作用,且使聚合反应更温和;离子液体回收利用实验结果表明,离子液体可多次循环利用,对产物影响不大;最终推导了离子液体中由CumOH/BF3·OEt2引发的p-MeSt阳离子聚合的基元反应机理.