Terahertz high-sensitivity SIS mixer based on Nb–AlN–NbN hybrid superconducting tunnel junctions

The terahertz band,a unique segment of the electromagnetic spectrum,is crucial for observing the cold,dark universe and plays a pivotal role in cutting-edge scientific research,including the study of cosmic environments that support life and imaging black holes.High-sensitivity superconductor–insulator–superconductor(SIS)mixers are essential detectors for terahertz astronomical telescopes and interferometric arrays.Compared to the commonly used classical Nb/AlO_(x)/Nb superconducting tunnel junction,the Nb/AlN/NbN hybrid superconducting tunnel junction has a higher energy gap voltage and can achieve a higher critical current density.This makes it particularly promising for the development of ultra-wideband,high-sensitivity coherent detectors or mixers in various scientific research fields.In this paper,we present a superconducting SIS mixer based on Nb/AlN/NbN parallel-connected twin junctions(PCTJ),which has a bandwidth extending up to490 GHz–720 GHz.The best achieved double-sideband(DSB)noise temperature(sensitivity)is below three times the quantum noise level.

Key technology and application of AB_(2) hydrogen storage alloy in fuel cell hydrogen supply system

At present,there is limited research on the application of fuel cell power generation system technology using solid hydrogen storage materials,especially in hydrogen-assisted two-wheelers.Considering the disadvantages of low hydrogen storage capacity and poor kinetics of hydrogen storage materials,our primary focus is to achieve smooth hydrogen ab-/desorption over a wide temperature range to meet the requirements of fuel cells and their integrated power generation systems.In this paper,the Ti_(0.9)Zr_(0.1)Mn_(1.45)V_(0.4)Fe_(0.15) hydrogen storage alloy was successfully prepared by arc melting.The maximum hydrogen storage capacity reaches 1.89 wt% at 318 K.The alloy has the capability to absorb 90% of hydrogen storage capacity within 50 s at 7 MPa and release 90% of hydrogen within 220 s.Comsol Multiphysics 6.0 software was used to simulate the hydrogen ab-/desorption processes of the tank.The flow rate of cooling water during hydrogen absorption varied in a gradient of(0.02 t x)m s^(-1)(x=0,0.02,0.04,0.06,0.08,0.1,0.12).Cooling water flow rate is positively correlated with the hydrogen absorption rate but negatively correlated with the cost.When the cooling rate is 0.06 m s^(-1),both simulation and experimentation have shown that the hydrogen storage tank is capable of steady hydrogen desorption for over 6 h at a flow rate of 2 L min^(-1).Based on the above conclusions,we have successfully developed a hydrogen-assisted two-wheeler with a range of 80 km and achieved regional demonstration operations in Changzhou and Shaoguan.This paper highlights the achievements of our team in the technological development of fuel cell power generation systems using solid hydrogen storage materials as hydrogen storage carriers and their application in twowheelers in recent years.

腹内压监测与床旁超声监测对ICU病人早期肠内营养效果的Meta分析

目的:系统评价腹内压监测与床旁超声监测胃残余量对重症监护室(ICU)病人早期肠内营养的应用效果。方法:计算机检索PubMed、EMbase、the Cochrane Library、Web of Science、中国生物医学文献数据库、中国知网、万方数据库、维普数据库中关于ICU病人使用腹内压监测或床旁超声监测胃残余量指导下进行早期肠内营养的随机对照试验,检索时限为建库至2024年1月。由2名研究人员依据纳入、排除标准筛选文献,提取资料并评价文献质量,使用RevMan 5.4、Stata 17.0和ITC软件进行Meta分析。结果:最终纳入27篇文献。Meta分析结果显示,腹内压监测与床旁超声监测胃残余量均能降低病人呕吐、腹胀、腹泻发生率,改善病人的血清清蛋白水平,提高7 d肠内营养目标热量达标率。腹内压监测与床旁超声监测胃残余量对早期肠内营养病人应用效果(除血清清蛋白水平)间接比较的Meta分析结果显示,差异无统计学意义(P>0.05)。结论:现有证据表明,腹内压监测与床旁超声监测均可改善病人呕吐、腹胀、腹泻发生率,提高血清清蛋白水平和7 d肠内营养目标热量达标率,且两种方法的效果(除血清清蛋白水平)差异无统计学意义。临床实践可根据科室实际情况以及病人病情进行选择。

体外模型的发展及其在鲸豚研究中的应用

体外补充替代模型"细胞系"为生命科学研究提供了新的平台,在一定程度上突破了科学研究中伦理、法律、动物福利和动物保护等的限制,从细胞和分子视角更深层次地揭示复杂生命体的生物效应和调控机制。尤其对于濒危动物,细胞系的建立与超低温冷冻技术相结合,既可以保存濒危动物具有生物表达活性的遗传种质,又可以提供体外保育研究的新平台(如动物毒理学实验),对动物保护意义重大。目前细胞培养体系已作为多功能平台被应用于鲸豚类细胞遗传学、病毒学和毒理学的相关研究中,但从物种和组织来源以及细胞类型来看,能长期稳定传代的鲸豚类细胞系仍较单一。优化细胞培养条件,运用鲸豚类体外细胞揭示更多的生命机制问题,仍是当前鲸豚类体外细胞模型研究所面临的挑战。本文对动物体外模型及其在鲸豚研究中的应用进行了概述,以期推动该技术在鲸豚保育研究中的创新和发展。

应用于风力发电系统中的撬棒阻值整定新方法

在电网发生电压跌落故障的情况下,双馈异步发电机(Doubly-Fed Induction Generator,DFIG)多采用撬棒保护电路以实现低电压穿越(Low Voltage Ride Though,LVRT),而撬棒阻值的选择对机组的LVRT效果影响很大。从DFIG在电压跌落故障下的暂态数学模型出发,运用空间矢量分析和拉普拉斯变换的方法,推导出风电机组在电压跌落故障下的暂态电流时域表达式、转子侧故障电流的计算式。由此提出一种切合工程实际的撬棒阻值整定方法,解决了投入撬棒保护电路后转子侧出现过电流和直流母线过电压的问题。算例及仿真实验数据均表明,采用该方法可有效抑制暂态故障分量,显著提高风力发电系统的LVRT水平。

锂硫电池用高度环化硫化聚丙烯腈的制备

硫化聚丙烯腈因其不溶解机制和有效缓解锂硫电池中多硫化物“穿梭效应”,被认为是具有吸引力的锂硫电池正极候选材料。硫化聚丙烯腈的导电聚合物骨架具有优异的电子导电性,同时共轭主链能有效解决充放电过程中硫正极体积变化引起的正极结构坍塌问题。因硫化聚丙烯腈的固-固反应机理,有效克服了传统硫正极在醚类电解液中多硫化物溶解及穿梭效应的问题,具有高正极活性物质利用率、出色的循环稳定性和结构稳定性等优势。有许多研究工作致力于通过硫化促进剂来提高硫化聚丙烯腈的硫含量,进而提高材料的能量密度。其中,硫化聚丙烯腈主链的环化度与循环稳定性的关系引起了我们的关注。在该研究工作中,通过在硫化过程中引入无水硫酸铜和正乙基正苯基二硫代氨基甲酸锌(ZDB)合成了SPAN-C-V复合材料。无水硫酸铜和ZDB的共同引入降低了聚丙烯腈环化反应的起始温度,同时提高了产物SPAN-C-V内碳碳双键的含量,在提高了材料硫含量的同时提高了其环化度。以SPAN-C-V为正极活性物质所组装的锂硫电池展现出良好的循环稳定性和倍率性能:在0.2 C(1 C=600 mAh·kg^(-1))下循环100次后的可逆容量为601 mAh·kg^(-1),容量保持率为93%。该工作对于硫化聚丙烯腈材料的发展提供了参考。

Establishment of model of visceral pain due to colorectal distension and its behavioral assessment in rats

AIM： To establish a visceral pain model via colorectal distension （CRD） and to evaluate the efficiency of behavioral responses of CRD by measuring the score of abdominal withdrawal reflex （AWR） in rats. METHODS： Thirty-eight male SD rats weighing 180-240g were used to establish the visceral pain model. The rat was inserted intra-anally with a 7 cm long flexible latex balloon under ether anesthesia, and colorectal distensions by inflating the balloon with air were made 30 min after recovering from the anesthesia. Five AWR scores （AWR0 to AWR4） were used to assess the intensity of noxious visceral stimuli. It was regarded as the threshold of the minimal pressure （kPa）. For abdominal flatting was induced by colorectal distension. RESULTS： A vigorous AWR to distension of the descending colon and rectum was found in 100% of the awake rats tested. The higher the pressure of distension, the higher the score of AWR. The distension pressures of 0, 2.00, 3.33, 5.33 and 8.00 kPa produced different AWR scores （P〈0.05）. The pain threshold of AWR was constant for up to 80 min after the initial windup （first 1-3 distensions）, the mean threshold was 3.69±0.35 kPa. Systemic administration of morphine sulfate elevated the threshold of visceral pain in a dosedependent and naloxone reversible manner. CONCLUSION： Scoring the AWR during colorectal distensions can assess the intensity of noxious visceral stimulus. Flatting of abdomen （AWR 3） to CRD as the visceral pain threshold is clear, constant and reliable. This pain model and its behavioral assessment are good for research on visceral pain and analgesics.

Trigeminal extracranial thermocoagulation along with patientcontrolled analgesia with esketamine for refractory postherpetic neuralgia after herpes zoster ophthalmicus:A case report

BACKGROUND Primary trigeminal neuralgia can achieve satisfactory results through clinical treatment and intervention.The pathogenesis of neuralgia caused by varicellazoster virus infection of the trigeminal nerve is more complex,and it is still difficult to relieve the pain in some patients simply by drug treatment or surgical intervention.CASE SUMMARY A 66-year-old woman was hospitalized with herpetic neuralgia after herpes zoster ophthalmicus(varicella-zoster virus infects the ophthalmic branch of the trigeminal nerve).On admission,the patient showed spontaneous,electric shocklike and acupuncture-like severe pain in the left frontal parietal region,and pain could be induced by touching the herpes area.The numerical rating scale(NRS)was 9.There was no significant pain relief after pulsed radiofrequency and thermocoagulation of the ophthalmic branch of the trigeminal nerve.Combined with patient-controlled intravenous analgesia(PCIA)with esketamine,neuralgia was significantly improved.The patient had no spontaneous pain or allodynia at discharge,and the NRS score decreased to 2 points.The results of follow-up 2 mo after discharge showed that the NRS score was≤3,and the Pittsburgh Sleep Quality Index score was 5 points.There were no adverse reactions.CONCLUSION Trigeminal extracranial thermocoagulation combined with esketamine PCIA may be a feasible method for the treatment of refractory herpetic neuralgia after herpes zoster ophthalmicus.

高γ-氨基丁酸发芽糙米的循环加湿生产工艺研究

探索生产高含量γ-氨基丁酸(gamma-aminobutyric acid,GABA)发芽糙米的循环加湿工艺的最优条件。采用单因素试验和正交试验,对循环加湿生产工艺的发芽温度、CaCl_(2)浓度、纤维素酶浓度、谷氨酸钠浓度和发芽时间条件进行筛选,高效液相色谱(high performance liquid chromatography,HPLC)法检测发芽糙米中GABA含量。当循环加湿工艺的发芽温度为40℃、CaCl_(2)浓度为1.0 mg/mL、纤维素酶浓度为0.96 mg/mL、谷氨酸钠浓度为0.8 mmol/L、发芽时间为63 h时,发芽糙米的GABA含量最高,达同品种未发芽糙米GABA含量的近5倍。结果表明,循环加湿工艺可以大幅度提高发芽糙米的GABA含量。

苓术菟丝子丸抑制IKKβ/NF-κB/MCP-1通路减少阿霉素诱导的大鼠肾性蛋白尿

目的探讨苓术菟丝子丸对阿霉素肾病蛋白尿的影响及机制。方法将36只雄性SD大鼠纳入实验。随机分为6组(6只/组)。包括空白、模型组和PDTC(NF-κB抑制剂)组(100 mg/(kg·d)),以及苓术菟丝子丸低、中、高剂量组(14、28、56 g/(kg·d))。除空白组外的大鼠均用阿霉素造成肾病模型。造模成功后,连续用药6周。记录一般生命体征;收集检测24 h尿蛋白,血浆白蛋白(Alb)、血肌酐(Scr)、尿素氮(BUN)和C反应蛋白(CRP);HE、Masson、PAS染色,透射电镜观察肾病理形态变化;ELISA检测血清IL-6、TNF-α水平;Western Blot检测IKKβ/NF-κB/MCP-1通路相关蛋白。结果模型组大鼠生存状态差。Alb降低,24 h尿蛋白升高。肾小管广泛肿胀,肾小球足突融合;大量纤维沉积,基底膜增厚。血清IL-6、TNF-α和CRP升高;肾p-IKKβ、p-NF-κB、MCP-1表达水平,及p-IKKβ/IKKβ、p-NF-κB/NF-κB比值升高,nephrin、podocin表达减少(P<0.05)。给药组除高剂量组外,大鼠一般状况良好。体重升高,24 h尿蛋白降低,Alb升高。肾小管肿胀减轻,肾小球足突融合改善。肾小管、小球纤维化减少,基底膜无增厚。血清IL-6、TNF-α和CRP降低;肾p-IKKβ、p-NF-κB、MCP-1表达水平,及p-IKKβ/IKKβ、p-NF-κB/NF-κB比值减少,nephrin、podocin表达增多(P<0.05)。结论苓术菟丝子丸减少阿霉素肾病大鼠24 h尿蛋白,降低血清炎性因子,其作用机制可能与抑制IKKβ/NF-κB/MCP-1信号通路有关。

基于网络药理学探讨苓术菟丝子丸治疗肾性蛋白尿的作用机制

目的:运用网络药理学方法,初步探讨苓术菟丝子丸治疗肾性蛋白尿的作用机制。方法:通过中药系统药理学数据库与分析平台获取苓术菟丝子丸组方药物的活性成分及其靶点,利用人类孟德尔遗传综合数据库、GeneCards数据库获取肾性蛋白尿的靶点,将获得的数据集进行Venn分析得到苓术菟丝子丸作用于肾性蛋白尿的靶点。通过String数据库构建蛋白互作网络,并在Cytoscape软件中进行可视化处理。利用DAVID数据库进行基因本体(gene ontology,GO)功能富集分析及京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)通路富集分析。结果:苓术菟丝子丸作用于肾性蛋白尿的活性成分有138个,共同作用的靶点有75个。GO功能富集分析共查询到93个条目;KEGG通路富集分析共查询到119个条目,其中包括肿瘤信号通路、细胞凋亡过程、肿瘤坏死因子信号通路等。结论:本研究通过网络药理学预测了苓术菟丝子丸治疗肾性蛋白尿的作用机制,可为进一步的研究提供参考。

蓝莓发酵原浆冻干粉对小鼠免疫功能的影响研究

该文依据相关标准检测蓝莓发酵原浆的功效成分。将SPF级雄性Balb/c小鼠随机分为对照组、蓝莓发酵原浆冻干粉低、中、高剂量组(0.75、1.50 g/kg bw和2.25 g/kg bw),连续灌胃30 d,进行免疫器官脏器指数测定、脾淋巴细胞转化实验、迟发型变态反应实验、血清溶血素测定、抗体生成细胞检测、腹腔巨噬细胞吞噬鸡红细胞实验、碳廓清实验和NK细胞活性测定。结果表明:中剂量组和高剂量组小鼠足跖厚度的差值显著高于空白对照组(P<0.05),各剂量组的小鼠抗体积数均显著高于空白对照组(P<0.05),中剂量组和高剂量组的溶血空斑数显著高于空白对照组(P<0.05),说明蓝莓发酵原浆冻干粉具有增强免疫力的功能。实验结果可为蓝莓的开发利用提供依据。

Establishment of NOD/SCID mouse models of human hepatocellular carcinoma via subcutaneous transplantation of histologically intact tumor tissue

Hepatocellular carcinoma （HCC） is one of the most deadly human cancers, but it is very difficult to establish an animal model by using surgical specimens. In the present experiment, histologically intact fresh surgical specimens of HCC were subcutaneously transplanted in non-obese diabetic/severe combined immunodeficienccy （NOD/SCID） mice. The biological characteristics of the original and the corresponding transplanted tumors and cell lines were investigated. The results showed that 5 new animal models and 2 primary cell lines were successfully established f^om surgical specimens. Hematoxylin-eosin staining showed that xenografts retained major histological features of the original surgical specimens. The two new cell lines had been cultivated for 3 years and successively passaged for more than 100 passages in vitro. The morphological characteristics and biologic features of the two cell lines were genetically similar to the original tumor. The subcutaneous transplant animal models with histologically intact tumor tissue and primary cell lines could be useful for in vivo and in vitro testing of anti-cancer drugs and be ideal models to study various biologic features of HCC.

从《黄帝内经》理论探讨尿毒症皮肤瘙痒的中医治疗

中医认为皮肤瘙痒多因外感热毒风邪或血虚生风所致,因此在治疗尿毒症皮肤瘙痒时,一定要结合风药的运用,驱除内外邪风,使气血归于平和,才能从根本上解除瘙痒。肺主皮毛,皮肤瘙痒与肺也密切相关。另外,调畅患者情志,减缓其焦虑的心理也尤为重要。

Computed tomography-guided chemical renal sympathetic nerve modulation in the treatment of resistant hypertension: A case report

BACKGROUND Resistant hypertension(RH)has always been a difficult problem in clinical diagnosis and treatment.At present,there is no recognized safe and effective minimally invasive treatment.CASE SUMMARY An 80-year-old woman was admitted to hospital due to trigeminal neuralgia(TN).The patient had a history of RH for more than 10 years and her blood pressure(BP)was not well-controlled.Before the treatment for TN,we decided to perform chemical renal sympathetic denervation with ethanol in the Pain Department of our hospital.One year after the operation,she stopped taking antihypertensive drugs,and her BP was satisfactorily controlled within 4 years after surgery.CONCLUSION Computed tomography-guided chemical renal sympathetic modulation may be a feasible method for the treatment of RH.

Mortality in patients with COVID-19 requiring extracorporeal membrane oxygenation:A meta-analysis

BACKGROUND Coronavirus disease 2019(COVID-19)has become a worldwide pandemic and significant public health issue.The effectiveness of extracorporeal membrane oxygenation(ECMO)in treating COVID-19 patients has been called into question.AIM To conduct a meta-analysis on the mortality of COVID-19 patients who require ECMO.METHODS This analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes 2020(PRISMA)and has been registered at the International Prospective Register of Systematic Reviews(number CRD42020227414).A quality assessment for all the included articles was performed by the Newcastle-Ottawa Scale(NOS).Studies with tenor more COVID-19 patients undergoing ECMO were included.The random-effects model was used to obtain the pooled incidence of mortality in COVID-19 patients receiving ECMO.The source of heterogeneity was investigated using subgroup and sensitivity analyses.RESULTS We identified 18 articles with 1494 COVID-19 patients who were receiving ECMO.The score of the quality assessment ranged from 5 to 8 on the NOS.The majority of patients received veno-venous ECMO(93.7%).Overall mortality was estimated to be 0.31[95%confidence interval(CI):0.24-0.39;I2=84.8%]based on random-effect pooled estimates.There were significant differences in mortality between location groups(33.0%vs 55.0%vs 37.0%vs 18.0%,P<0.001),setting groups(28.0%vs 34.0%,P<0.001),sample size(37.0%vs 31.0%,P<0.001),and NOS groups(39.0%vs 19.0%,P<0.001).However,both subgroup analyses based on location,setting,and sample size,and sensitivity analysis failed to identify the source of heterogeneity.The funnel plot indicated no evident asymmetry,and the Egger’s(P=0.95)and Begg’s(P=0.14)tests also revealed no significant publication bias.CONCLUSION With more resource assessment and risk-benefit analysis,our data reveal that ECMO might be a feasible and effective treatment for COVID-19 patients.

Id4 promotes cell proliferation in hepatocellular carcinoma

Background: Hepatocellular carcinoma(HCC) is a common malignant tumor in the world, especially in China. As a member of the inhibitor of differentiation(Id) family, Id4 has been reported to function in many cancer types, but relatively little is known about its role in HCC. The purpose of this study was to investigate the potential relationship between Id4 and HCC development and the underlying mechanism involving the function of Id4 in HCC.Methods: We used quantitative real?time polymerase chain reaction and Western blotting to examine the RNA and protein expression of Id4. In addition, we used Cell Counting Kit?8 assay and colony formation assay to identify the function of Id4 in the regulation of cell proliferation in human HCC.Results: We found that the expression of Id4 protein was up?regulated in tumor tissues from HCC patients. Over?expression of Id4 promoted HCC cell proliferation, clonogenicity in vitro, and tumorigenicity in vivo. Id4 knockdown experiments showed that silencing Id4 blocked the proliferation and colony formation ability of HCC cells in vitro. Furthermore, overexpression of CCAAT/enhancer?binding protein β inhibited Id4 expression in HCC cells.Conclusion: Id4 may be developed as a potent therapeutic agent for the treatment of HCC, but more details about the underlying mechanisms of action are needed.

一种改进型频率正反馈孤岛检测方法研究

针对传统孤岛检测算法的检测时间较长问题,提出一种改进型频率正反馈孤岛检测方法。即以缩短孤岛检测时间为目的,在逆变器输出角频率时加入正反馈增益系数A和B,加快频率的偏移速率。探讨了A和B取不同值时逆变器输出电压角频率对应的反馈强度和检测效果。同时通过分析成功检测孤岛现象的临界条件,确定了有效缩短检测时间的A、B值。仿真得出的结论与理论分析结果相符合,从而验证了所提方法的有效性。

从肝脾肾论治纯红细胞再生障碍性贫血肾阳虚证的单病例随机对照试验

目的观察右归丸合补中益气汤治疗纯红细胞再生障碍性贫血肾阳虚证的疗效。方法采用单病例随机对照试验,观察右归丸合补中益气汤对纯红再障患者血红蛋白、中医证候及生活质量的影响。结果右归丸合补中益气汤可显著促进纯红再障贫血患者血红蛋白增长,明显降低肾阳虚证候积分,提高日常生活活动能力评分。结论右归丸合补中益气汤治疗肾阳虚型纯红再障有明显临床疗效,可改善肾阳虚临床症状及生活质量。

一种光伏并网逆变器的相位补偿控制方法研究

并网逆变器在光伏并网系统中占据核心的地位,其控制效果会对整个系统的性能产生极大的影响。提出一种带相位补偿的光伏并网逆变器控制方法,将滤波电感输出的正弦半波电流作为电流闭环控制的反馈量,通过幅值反向函数将此正弦半波变成为正弦全波,然后与设定的交流电流参考值相减,得到反馈量与参考量之间的偏差,将此偏差作为控制电路的参数,计算出相位补偿角θ,因此就能消去系统中固有的相位差,实现并网电流和电网电压相位同步,电能质量有明显改善。仿真、实验得出的结论与理论相符合。