Electrically-driven ultrafast out-of-equilibrium light emission from hot electrons in suspended graphene/hBN heterostructures

Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and optoelectronics.The record-high carrier mobility and ultrafast carrier dynamics of graphene make it promising as an atomically thin light emitter which can be further integrated into arbitrary platforms by van der Waals forces.However,due to the zero bandgap,graphene is difficult to emit light through the interband recombination of carriers like conventional semiconductors.Here,we demonstrate ultrafast thermal light emitters based on suspended graphene/hexagonal boron nitride(Gr/hBN)heterostructures.Electrons in biased graphene are significantly heated up to 2800 K at modest electric fields,emitting bright photons from the near-infrared to the visible spectral range.By eliminating the heat dissipation channel of the substrate,the radiation efficiency of the suspended Gr/hBN device is about two orders of magnitude greater than that of graphene devices supported on SiO2or hBN.Wefurther demonstrate that hot electrons and low-energy acoustic phonons in graphene are weakly coupled to each other and are not in full thermal equilibrium.Direct cooling ofhigh-temperature hot electrons to low-temperature acoustic phonons is enabled by the significant near-field heat transfer at the highly localized Gr/hBN interface,resulting in ultrafast thermal emission with up to 1 GHz bandwidth under electrical excitation.It is found thatsuspending the Gr/hBN heterostructures on the SiO2trenches significantly modifies the light emission due to the formation of the optical cavity and showed a~440%enhancement inintensity at the peak wavelength of 940 nm compared to the black-body thermal radiation.The demonstration of electrically driven ultrafast light emission from suspended Gr/hBNheterostructures sheds the light on applications of graphene heterostructures in photonicintegrated circuits,such as broadband light sources and ultrafast thermo-optic phase modulators.

Application of artificial synapse based on all-inorganic perovskite memristor in neuromorphic computing

Artificial synapse inspired by the biological brain has great potential in the field of neuromorphic computing and artificial intelligence.The memristor is an ideal artificial synaptic device with fast operation and good tolerance.Here,we have prepared a memristor device with Au/CsPbBr_(3)/ITO structure.The memristor device exhibits resistance switching behavior,the high and low resistance states no obvious decline after 400 switching times.The memristor device is stimulated by voltage pulses to simulate biological synaptic plasticity,such as long-term potentiation,long-term depression,pair-pulse facilitation,short-term depression,and short-term potentiation.The transformation from short-term memory to long-term memory is achieved by changing the stimulation frequency.In addition,a convolutional neural network was constructed to train/recognize MNIST handwritten data sets;a distinguished recognition accuracy of~96.7%on the digital image was obtained in 100 epochs,which is more accurate than other memristor-based neural networks.These results show that the memristor device based on CsPbBr3 has immense potential in the neuromorphic computing system.

Atomically dispersed Ni electrocatalyst for superior urea-assisted water splitting

Urea oxidation reaction(UOR) has been selected as substitution for oxygen evolution reaction ascribing to its low thermodynamic voltage as well as utilization of nickel as electrocatalyst.Herein,we report the formation of nickel single atoms(Ni-SAs) as exceptional bifunctional electrocatalyst toward UOR and hydrogen evolution reaction(HER) in urea-assisted water splitting.In UOR catalysis,Ni-SAs perform a superior catalytic performance than Ni-NP/NC and Pt/C ascribing to the formation of HOO-Ni-N_(4) structure evidenced by in-situ Raman spectroscopy,corresponding to a boosted mass activity by 175-fold at 1.4 V vs.RHE than Ni-NP/NC.Furthermore,Ni-SAs requires only 450 mV overpotential to obtain HER current density of 500 mA cm^(-2).136 mA cm^(-2) is achieved in urea-assisted water splitting at1.7 V for Ni-SAs,boosted by 5.7 times than Pt/C-IrO_(2) driven water splitting.

贝伐珠单抗在我院抗肿瘤治疗中的应用分析

目的:了解贝伐珠单抗在抗肿瘤治疗中的应用情况,以促进该药的临床合理使用。方法:回顾性收集2011年1月-2015年12月我院接受贝伐珠单抗治疗的265例肿瘤患者的病历资料,对患者的肿瘤类型、贝伐珠单抗的临床地位、治疗方案、用药次数、治疗周期进行统计和分析,计算主成分参数并进行主成分分析和聚类分析。结果:265例患者共涉及18类恶性肿瘤,以结直肠癌(48.68%)、卵巢癌(20.75%)、肺癌(9.43%)为主;贝伐珠单抗抗肿瘤治疗用于一线、二线、三线的比例分别为10.28%、26.39%、23.61%;其肿瘤治疗涉及肿瘤类型主要为结直肠癌、卵巢癌、肺癌;其抗肿瘤治疗的肿瘤类型可聚为4类,结直肠癌为一类,卵巢癌为一类,肺癌为一类,其他为一类。贝伐珠单抗与化疗药物联用方案有347例次(90.84%),贝伐珠单抗单用方案有35例次(9.16%);在贝伐珠单抗与化疗药物联用方案中,以与含氟尿嘧啶等抗代谢类药物联用(50.54%)、与含紫杉类药物联用(18.05%)、与铂类药物联用(16.50%)为主。有1例患者最多使用了69次贝伐珠单抗,有44例患者各使用了1次;有1例次治疗了51个周期,有85例次治疗了1个周期,以治疗1~4个周期最为常见。结论:贝伐珠单抗作为首个上市的抗血管生成药物,在临床恶性肿瘤(实体瘤)的治疗中具有一定的地位,已成为结直肠癌、卵巢癌和肺癌的一线治疗药物,但由于其药理作用的局限性,该药与化疗药物的联用仍是主要方向。

浙江省11家医院2010-2015年双膦酸盐类药物治疗乳腺癌骨转移相关骨损害及疼痛的利用研究

目的:了解双膦酸盐类药物在浙江省乳腺癌骨转移患者中的应用现状及趋势,为进一步促进该类药物的临床合理使用提供参考。方法:采用金额排序分析和用药频度分析方法,对抽取的浙江省11家医院2010-2015年接受双膦酸盐类药物治疗的乳腺癌骨转移患者样本处方中所使用的该类药物相关品种的使用金额、用药频度(DDDs)和日均费用(DDC)等进行统计、计算、排序及分析。结果:6年间双膦酸盐类药物的使用金额总体稳中有升(其中2011年增幅较大),2015年比2010年增加了96.26%。使用金额排前3位的品种分别是注射用唑来膦酸(进口)、注射用唑来膦酸(国产)和注射用帕米膦酸二钠,其中注射用唑来膦酸(进口)的使用金额总体基本呈上升趋势,而注射用帕米膦酸二钠的使用金额总体基本呈下降趋势。DDDs排前3位的品种分别是注射用唑来膦酸(国产)、注射用唑来膦酸(进口)和注射用帕米膦酸二钠,其中注射用唑来膦酸(国产)和注射用唑来膦酸(进口)的DDDs总体基本呈上升趋势,而注射用帕米膦酸二钠的DDDs总体基本呈下降趋势。双膦酸盐类药物各品种的B/A值介于0.33~2.00之间,其中2012-2015年注射用唑来膦酸(国产)的B/A值均为2.00,注射用唑来膦酸(进口)的B/A值均为0.50。DDC排第1、2位的品种均为注射用氯屈膦酸二钠、注射用唑来膦酸(进口)。结论:浙江省11家医院2010-2015年乳腺癌骨转移患者双膦酸盐类药物的使用金额总体稳中有升,其中疗效确切、安全性较好、价格适中的第二和第三代双膦酸盐类药物的部分品种(如注射用帕米膦酸二钠、注射用唑来膦酸等,尤其是后者)在临床使用中占优势。双膦酸盐类药物的选择与使用基本合理,但价格仍然是限制部分品种进一步广泛应用的首要因素。

基于GEO数据库的近端与远端结肠癌特征基因生物信息学研究

目的:通过分析近端与远端结直肠癌的差异基因集和其集中的关键通路,区分不同部位结肠癌的分子表达特征基因谱。方法:利用GEO数据库中高通量基因芯片数据筛选出具有结肠癌患者肿瘤部位近远端信息的芯片。采用GO基因功能注释和KEGG通路富集分析,筛选出可表征远端与近端结肠癌生物特性的特征基因簇和通路,并进行蛋白质相互作用网络可视化分析。结果:经差异基因分析后,发现不同部位结肠癌基因表达具有显著差异,且主要存在于一些重要的肿瘤相关信号通路,如Wnt信号通路,细胞外基质相关通路和免疫调控通路等。结论:本文利用生物信息学方法,从多种角度定义了近端和远端结肠癌的差异分子表达特征,为结肠癌的精准治疗提供理论依据。

Exploring the Mechanism of CircRNA-vgll3 in Osteogenically Differentiated Human Bone Marrow Mesenchymal Stem Cells

Objective:To explore the mechanism of circRNA-vgll3 in osteogenic differentiation of human bone marrow mesenchymal stem cells.Methods:BMSCs cells were transfected with circRNA-vgll3,and divided into circRNA-vgll3 high-level group,circRNA-vgll3 low-level group,and negative control group(circRNA-vgll3 not transfected)according to the amount of transfection.The proliferation and apoptosis of BMSCs osteoblasts in each group were analyzed,and the alkaline phosphatase(ALP)activity,type I collagen gray value,bone morphogenetic protein 2(BMP-2),Runx2 protein,and mRNA expression levels were detected.Results:The circRNA-vgll3 low-level group had a significant inhibitory effect on the proliferation of BMSCs osteoblasts,and the apoptosis rate of the circRNA-vgll3 low-level group was significantly higher than that of the circRNA-vgll3 high-level group(P<0.05);ALP activity,type I collagen gray value,BMP-2,Runx2 protein,and mRNA expression levels in the high-level circRNA-vgll3 group were significantly higher than those in the low-level circRNA-vgll3 group,and the difference was statistically significant(P<0.05).Conclusion:Overexpression of circRNA-vgll3 can promote the osteogenic differentiation ability of BMSCs,while low expression of circRNA-vgll3 can inhibit the osteogenic differentiation ability of BMSCs.The main mechanism of action is that circRNA-vgll3 can affect osteogenic differentiation by regulating the Runx2 protein.

白桦脂醇对宫颈癌小鼠自然杀伤细胞杀伤力及淋巴细胞增殖活性的影响

目的探究白桦脂醇对宫颈癌小鼠自然杀伤(NK)细胞杀伤力及淋巴细胞增殖活性的影响。方法通过皮下注射人宫颈癌HeLa细胞复制宫颈癌小鼠模型。将45只模型小鼠随机分为模型组、白桦脂醇组和白桦脂醇+SB203580组,每组15只。另取15只未做处理的小鼠作为对照组。白桦脂醇组和白桦脂醇+SB203580组白桦脂醇灌胃干预(100 mg/kg)。白桦脂醇+SB203580组通过腹腔注射SB203580(50 ng/kg)抑制p38通路。采用免疫组织化学染色检测细胞增殖。比较各组p38蛋白、NK细胞杀伤力及淋巴细胞增殖活性。结果白桦脂醇组和白桦脂醇+SB203580组肿瘤体积和质量小于模型组(P<0.05),并且白桦脂醇+SB203580组肿瘤体积和质量小于白桦脂醇组(P<0.05)。白桦脂醇组和白桦脂醇+SB203580组免疫组织化学染色评分、p38蛋白相对表达量低于模型组(P<0.05),并且白桦脂醇+SB203580组免疫组织化学染色评分、p38蛋白相对表达量低于白桦脂醇组(P<0.05)。白桦脂醇组和白桦脂醇+SB203580组脾脏指数、NK细胞杀伤力、淋巴细胞增殖活性高于模型组(P<0.05),并且白桦脂醇+SB203580组脾脏指数、NK细胞杀伤力、淋巴细胞增殖活性高于白桦脂醇组(P<0.05)。结论白桦脂醇通过抑制p38通路抑制宫颈癌细胞增殖,并提高NK细胞杀伤力和淋巴细胞增殖活性。

碳纳米管/石墨烯复合填充交替多层硅橡胶的结构及性能

以碳纳米管(CNTs)/石墨烯(GNs)为复合填充料,通过交替多层共挤出设备制备了一系列不同层数交替多层硅橡胶片材,获得了2^(n+1)+1层结构的多层复合硅橡胶;研究了多层结构硅橡胶微观形貌对其力学性能和介电性能的影响。扫描电镜结果表明,所制备的多层材料具有清晰、规整的连续层状结构,且随着层数增加,填料的分散状态获得改善且取向度增加;拉伸实验结果表明,多层硅橡胶的拉伸强度和断裂伸长率均有所增加,且均大于共混材料;介电性能测试结果表明,多层材料的介电常数随层数增加而增加,并且具有介电的各向异性,其在面内方向上的介电常数高于面外方向。

住院病儿使用利奈唑胺致5-羟色胺毒性相关的用药禁忌情况调查

目的调查使用利奈唑胺治疗的住院病儿存在的5-羟色胺毒性相关的用药禁忌情况。方法通过查阅中英文数据库和药品说明书,整理与利奈唑胺存在5-羟色胺毒性相关的用药禁忌的药品,回顾性收集浙江大学医学院附属儿童医院2018年1月1日至12月31日使用利奈唑胺的住院病儿的住院信息和用药信息,对用药禁忌情况进行统计分析。结果住院药房共24种药品与利奈唑胺存在5-羟色胺毒性相关的用药禁忌。全院有1 510例次使用利奈唑胺,用药禁忌发生率为24.6%。利奈唑胺在血液科的使用率和用药禁忌发生率最高,分别为42.5%和32.9%;重症监护室(ICU)次之,分别为21.0%和25.6%;其中合用例次较多的禁忌药品有氨溴特罗口服溶液、愈酚甲麻那敏糖浆、枸橼酸芬太尼注射液。结论利奈唑胺在住院病儿临床应用广泛,与氨溴特罗口服溶液、愈酚甲麻那敏糖浆、枸橼酸芬太尼注射液等多种存在5-羟色胺毒性相关的禁忌药物合用的发生率较高,这需要引起医务工作者,特别是血液科和ICU医生的足够重视。

Performance characterization of Ni60-WC coating on steel processed with supersonic laser deposition

Ni60-WC particles are used to improve the wear resistance of hard-facing steel due to their high hardness. An emerging technology that combines laser with cold spraying to deposit the hard-facing coatings is known as supersonic laser deposition. In this study, Ni60-WC is deposited on low-carbon steel using SLD. The microstructure and performance of the coatings are investigated through SEM, optical microscopy, EDS, XRD, microhardness and pin-on-disc wear tests. The experimental results of the coating processed with the optimal parameters are compared to those of the coating deposited using laser cladding.

中高温质子交换膜燃料电池催化剂研究进展

中高温质子交换膜燃料电池作为一种新型能量转换装置,具有环境友好、能量转换效率高、氢气纯度要求低等特点。催化剂作为电化学反应的核心,其性能极大影响着燃料电池的整体工作效率,目前针对中高温燃料电池催化剂的研究主要集中在电化学反应动力学较慢的阴极氧还原催化剂。磷酸掺杂的聚苯并咪唑(PA-PBI)为常用的高温质子交换膜,由于磷酸与PBI的结合力差,在长时间运行过程中磷酸容易渗透到催化剂层,造成磷酸在铂基催化剂表面的强吸附导致催化剂中毒的问题,并且氧分子在磷酸中溶解度低。基于以上问题,本文综述了铂基催化剂、非铂催化剂和非金属催化剂在中高温质子交换膜燃料电池中的应用现状,重点阐述了表面修饰、合金化、载体效应等策略对催化剂在磷酸电解液中的氧还原反应动力学的影响。最后针对目前中高温质子交换燃料电池催化剂发展方向进行了探讨和展望。

Tuberculosis in Takayasu arteritis: a retrospective study in 1105 Chinese patients

Background Tuberculosis (TB) infection has been reported to have a possible relationship with the occurrence and clinical course of Takayasu arteritis (TA). We aimed to describe the characteristics of TB in a large population of TA patients. Methods We included a total of 1105 patients with TA, who were hospitalized between January 1992 and December 2017. Comparisons of clinical features were made according to the presence of TB. Results Among the 1105 patients, 109 (9.9%) had TB, including 53 patients (48.6%) diagnosed with TB before the onset of TA, 23 (21.1%) with a concurrent diagnosis of TB and TA, and 24 patients (22.0%) who developed TB after TA. Pulmonary TB was the most frequently identified (97 patients, 89.0%). Patients with TB had more frequent involvement of the pulmonary artery and experienced more chest discomfort and constitutional symptoms but had less interventional treatment. Demographic characteristics, comorbid diseases, and use of steroids were similar between patients with and without TB. Conclusions The proportion of Chinese TA patients with TB was not low, and about half of the patients had TB before TA. Pulmonary TB was the most common. Pulmonary artery involvement and pulmonary hypertension was more frequent in TA patients with TB.

抗松针褐斑病湿地松体细胞的悬浮培养

为了获得大量的抗松针褐斑病胚性愈伤组织试验材料,完善抗性湿地松体胚发生技术,以抗松针褐斑病湿地松胚性愈伤组织为材料,探究抗性湿地松体细胞悬浮培养的较适条件,建立抗性湿地松体细胞的悬浮培养体系。研究结果显示:悬浮培养的胚性细胞较分散,利于胚性细胞充分获取营养,可产成熟体胚153个/g,而固体培养的胚性细胞产胚仅为56个/g。抗性湿地松悬浮细胞的较佳培养周期为7-9 d,较适宜的基本培养基为1/4 DCR,麦芽糖添加量为15 g/L,NAA添加量为0.5 mg/L;较佳的继代添加比为1/2;同时研究还发现不同基因型的抗性湿地松悬浮细胞在相同的培养条件下,细胞活力有一定差异,其中无性系13#-9活力最佳。

Anemia in patients with Takayasu arteritis: prevalence, clinical features, and treatment

Background Anemia is a common comorbidity of patients with Takayasu arteritis(TA). This study evaluated the prevalence, clinical characteristics, and treatment in Chinese TA patients with anemia. Methods This retrospective study included 533 consecutive patients hospitalized for TA from January 2009 to April 2018. Anemia was diagnosed on the basis of hemoglobin level, according to World Health Organization criteria. Results A total of 194 patients(36.4%) were diagnosed with anemia. Most had mild anemia(177, 91.2%). Female patients were predominant(92.8% of anemic patients). Normocytic anemia(62.9%) was the most common pattern. Anemic patients were more likely than non-anemic patients to have dizziness(29.4% vs. 21.2%), low body mass index(22.0 ± 3.6 vs. 22.9 ± 3.4 kg/m2), and active disease stage(64.9% vs. 50.1%);pulmonary involvement(12.4% vs. 26.8%), pulmonary hypertension(12.9% vs. 20.1%) and pulmonary hypertensive-target drugs(2.8% vs. 11.6%) were less common among anemic than non-anemic patients(all P < 0.05). Larger left ventricular end-diastolic diameter and lower left ventricular ejection fraction were observed in anemic patients. Over a median follow-up of four months, the increase of hemoglobin in anemic patients was associated with the use of iron supplementation. Conclusions Anemia is a very common concurrent condition in TA, especially in young, female patients. Patients with anemia are more likely to be in the active disease stage. Iron supplementation helps increase hemoglobin.

Discovery of natural products capable of inducing porcine host defense peptide gene expression using cell-based high throughput screening

Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are known for their broad-spectrum antimicrobial and immunomodulatory capabilities.Enhancing the synthesis of endogenous HDPs represents a promising antibiotic alternative strategy to disease control and prevention.Methods:To identify natural products with an ability to stimulate the synthesis of endogenous HDPs,we performed a high-throughput screening of 1261 natural products using a newly-established stable luciferase reporter cell line known as IPEC-J2/pBD3-luc.The ability of the hit compounds to induce HDP genes in porcine IPEC-J2 intestinal epithelial cells,3D4/31 macrophages,and jejunal explants were verified using RT-qPCR.Augmentation of the antibacterial activity of porcine 3D4/31 macrophages against a Gram-negative bacterium(enterotoxigenic E.coli)and a Gram-positive bacterium(Staphylococcus aureus)were further confirmed with four selected HDP-inducing compounds.Results:A total of 48 natural products with a minimum Z-score of 2.0 were identified after high-throughput screening,with 21 compounds giving at least 2-fold increase in luciferase activity in a follow-up dose-response experiment.Xanthohumol and deoxyshikonin were further found to be the most potent in inducing pBD3 mRNA expression,showing a minimum 10-fold increase in IPEC-J2,3D4/31 cells,and jejunal explants.Other compounds such as isorhapontigenin and calycosin also enhanced pBD3 mRNA expression by at least 10-fold in both IPEC-J2 cells and jejunal explants,but not 3D4/31 cells.In addition to pBD3,other porcine HDP genes such as pBD2,PG1-5,and pEP2C were induced to different magnitudes by xanthohumol,deoxyshikonin,isorhapontigenin,and calycosin,although clear gene-and cell type-specific patterns of regulation were observed.Desirably,these four compounds had a minimum effect on the expression of several representative inflammatory cytokine genes.Furthermore,when used at HDP-inducing concentrations,these compounds showed no obvious direct antibacterial activity,but significantly augmented the antibacterial activity of 3D4/31 macrophages(P<0.05)against both Gram-negative and Gram-positive bacteria.Conclusions:Our results indicate that these newly-identified natural HDP-inducing compounds have the potential to be developed as novel alternatives to antibiotics for prophylactic and therapeutic treatment of infectious diseases in livestock production.

通过电沉积及氟硅烷改性而成的三维铜镍复合超疏水表面

将Cu-Ni微纳米颗粒电沉积在铝基底上,通过1H、1H、2H、2H-全氟癸基三甲氧基硅烷(FAS-17)对其进行修饰,制备了超双疏(SAP)表面.采用扫描电子显微镜、X射线衍射、能量色散X射线光谱和傅里叶变换红外光谱对其形貌和化学成分进行了研究.结果表明,SAP表面具有三维微纳结构,最大水接触角160.0°,油接触角151.6°.进一步测试了SAP表面的机械强度和化学稳定性,结果显示该SAP表面具有优良的耐磨性、耐酸耐碱性能、自洁性和防污性能.

Advanced Power Module Packaging and Integration Structures for High Frequency Power Conversion：From Silicon to GaN

The emerging of commercial high-voltage gallium nitride(GaN) power devices provides extraordinary switching performance over silicone devices, which enables high-voltage power conversion switching at megahertz range.Such outstanding features also pose strong challenges for device packaging design since the package parasitics can significantly influence the device switching characteristics, and thus can shadow the advantages brought by GaN devices. Designers have been dealing with these challenges brought by high du/dt and high-frequency switching operation even since the silicon(Si) era when fast switching Si MOSFET is first developed and came up with lots of inspiring advanced power module packaging structures to mitigate the problems.This paper presents a review of advanced power module packaging and integration structures that are suitable for high frequency power conversion.The review covers the heritage from the high frequency Si MOSFET packaging to the state-of-the-art for GaN devices.

Prevalence and long-term prognosis in Takayasu arteritis patients with left ventricular dilatation and a decreased ejection fraction:data from 1,105 Chinese cases

Background Left ventricular dilatation and a decreased ejection fraction is one of the most serious complications in patients with Takayasu arteritis(TA).We aim to describe the prevalence,clinical features,treatment,and long-term prognosis of TA patients with this complication.