The corrosion behavior of 304 stainless steel in NaNO3–NaCl–NaF molten salt and vapor

Corrosion behavior of 304 stainless steel in molten NaNO₃–NaCl–NaF salt and NaNO₃–NaCl–NaF vapor has been studied at 450 °C. The results showed that the samples suffered weight loss, and surface oxides, i.e. Fe₂O₃ and FeCr₂O₄ characterized by XRD, were formed after corrosion. The surface oxide layer was about 1.1 μm in thickness after corrosion in molten NaNO₃–NaCl–NaF salt, which was relatively homogeneous and dense. Whereas, the distribution of surface oxides was not even, and a shedding phenomenon was observed after corrosion molten NaNO₃–NaCl–NaF vapor. This is mainly attributed to the existence of NO₂ and NO in the molten NaNO₃–NaCl–NaF vapor determined by thermogravimetric infrared spectroscopy, which affected the adherence between oxides and the matrix. Additionally, the corrosion rate of 304 stainless steel in molten NaNO₃–NaCl–NaF salt is almost close to that in solar salt, which demonstrates that the synergy influence of Cl⁻ and F⁻ on the rate of 304 stainless steel is not significant. This work not only enriches the database of molten salt corrosion, but provides references for the selection of alloy and molten salt in the CSP.

Surface micro-morphology of 304 SS before corrosion (a), after corrosion in molten NaNO₃–NaCl–NaF salt (b) and molten NaNO₃–NaCl–NaF vapor (c). (Local enlarged region of A1 (b-1), A2 (c-1) and A3 (c-2)).     

熊果酸对活化T细胞功能的影响

目的 研究熊果酸在体外对活化的人T细胞功能的影响,探讨其作为免疫调节药物开发的可能性和提供相关实验数据.方法 无菌采集和分离正常人外周血淋巴细胞,以不同浓度的熊果酸和PHA/PMA刺激T细胞,用MTT法检测细胞的增殖反应,ELISA法检测细胞因子IFN-γ、IL-2、GM-CSF、IL-4的峰值浓度.结果 熊果酸对淋巴细胞的活化和增殖无显著影响(P＞0.05);熊果酸抑制IFN-γ、IL-2、GM-CSF的分泌,并呈剂量依赖性(P＜0.05),而对IL-4的分泌影响较小,无统计学意义(P＞0.05).结论 熊果酸抑制活化的T细胞分泌Th1型细胞因子,抑制T细胞的功能,熊果酸有可能作为治疗某些自身免疫性疾病天然药物成分.     

Evaluating the Efficacy,Safety, and Tolerability of Serelaxin When Added to Standard Therapy in Asian Patients With Acute Heart Failure: Design and Rationale of RELAX-AHF-ASIA Trial

Background

Acute heart failure (AHF), a common and growing health concern worldwide, is associated with high risk of post-discharge rehospitalization and mortality. Existing evidence indicates potential therapeutic benefits of serelaxin in Caucasian AHF patients, but corresponding data in Asians remain scarce. RELAX-AHF-ASIA, a multinational, randomized, double-blind, placebo-controlled, phase III trial, will evaluate the effects of serelaxin on symptom relief and clinical outcomes in Asian AHF patients, with the use of novel assessments.

Catalpol Promotes the Survival and VEGF Secretion of Bone Marrow-Derived Stem Cells and Their Role in Myocardial Repair After Myocardial Infarction in Rats

Bone mesenchymal stem cells (BMSCs) transplantation has been recognized as an effective method for the treatment of myocardial infarction (MI). However, its efficacy is always restricted by the low survival of transplanted BMSCs in the ischemic myocardium. The aim of this study was to investigate the effect of catalpol pre-treatment on the survival and vascular endothelial growth factor (VEGF) secretion of BMSCs under oxygen glucose deprivation (OGD) condition and their role in myocardial repair in a rat model of MI. According to our results, pre-treatment with catalpol enhanced VEGF secretion and survival of OGD-treated BMSCs. Moreover, the apoptosis of BMSCs induced by OGD was restrained by catalpol as evidenced by increased level of B-cell lymphoma-2 (Bcl-2) and decreased levels of BCL2-associated X (Bax) and cleaved caspase-3. In vivo study suggested that the survival of transplanted BMSCs was improved by catalpol pre-treatment. The myocardial fibrosis and apoptosis was further inhibited in catalpol pre-treated BMSCs group. Cardiac function detected by echocardiography was obviously improved by catalpol pre-treated BMSCs transplantation. Finally, angiogenesis and VEGF expression in the ischemic myocardium were significantly promoted in catalpol pre-treated BMSCs group. In conclusion, catalpol pre-treatment may facilitate the survival and VEGF secretion of BMSCs and improve their therapeutic effect on MI.     

miR-20a-5p调控结核分枝杆菌诱导巨噬细胞凋亡相关基因表达的研究

目的 明确小非编码RNA(microRNA,miR-20a-5p)对结核分枝杆菌(MTB)诱导人巨噬细胞凋亡相关基因表达的调控作用。方法 构建可表达或抑制miR-20a-5p、转染miR-20a-5p抑制剂(miR-20a-5p-inhibitor,简称“miR-20a-5p-inh”)、作为慢病毒载体的阴性对照(LV1-NC)的慢病毒载体,由oligo-dT引物通过固相亚磷酰胺法合成茎环寡核苷酸,并克隆到含绿色荧光蛋白(GFP)的慢病毒载体pGLV3-GFP内,将构建的miR-20a-5p、miR-20a-5p-inh、LV1-NC转染THP-1人巨噬细胞3h,培养72h后用流式细胞仪分选出GFP+THP-1细胞,并分别采用减毒MTB菌株(H37Ra)感染8h和过氧化氢(H₂O₂)处理30min 两种方法诱导。通过实时定量PCR技术测定细胞中线粒体相关抗凋亡基因Bcl-2,以及促凋亡基因Bax、Bim和Bad的转录水平。同时,用蛋白免疫印迹法检测细胞裂解物中相关蛋白的表达。结果 慢病毒转染细胞后,在无刺激的THP-1细胞中miR-20a-5p的相对荧光强度值为12.21±1.29、miR-20a-5p-inh为9.68±1.38、LV1-NC为10.64±0.96,三者的表达差异均无统计学意义(q=1.815,P=0.385;q=2.072,P=0.602);但在H37Ra和H₂O₂的刺激后,miR-20a-5p过表达时其相对荧光强度值分别为7.20±0.53、8.55±0.82,明显高于LV1-NC (4.46±0.07、5.49±0.44)(q=50.250,P=0.007;q=1.041,P<0.01),miR-20a-5p受抑制时(1.88±0.08、1.44±0.21)明显低于LV1-NC(q=3.457,P=0.031;q=4.384,P=0.001)。在感染miR-20a-5p慢病毒的THP-1细胞中,H37Ra诱导Bcl-2的表达增加(相对荧光强度值由10.67±0.89增至14.98±0.88)(q=1.064,P=0.008),而感染miR-20a-5p-inh慢病毒时Bcl-2表达减少(由10.67±0.89降至6.49±0.47)(q=3.518,P=0.003);在miR-20a-5p过表达的THP-1细胞中Bim的转录水平减少(由1.22±0.05降至0.98±0.04)(q=1.240,P=0.011),当miR-20a-5p受抑制时Bim的转录水平增加(由1.22±0.05增至1.51±0.08)(q=2.460,P=0.021)。蛋白印迹法检测凋亡相关基因Bcl-2和Bim的蛋白表达水平,结果与基因转录水平相符。 结论 miR-20a-5p的表达水平影响MTB诱导的巨噬细胞凋亡相关基因Bcl-2和Bim的表达,并且与促凋亡基因Bim的水平呈负相关,提示miR-20a-5p可能通过调控Bim的表达而影响细胞凋亡。     

“拖尾征”锚定骨水泥椎体后凸成形术对Kummell′s病的治疗效果

目的评价"拖尾征"锚定骨水泥椎体后凸成形术(PKP)治疗老年Kummell′s病患者的临床疗效。方法回顾性分析2014年8月至2017年8月在航天中心医院行PKP术治疗的老年Kummell′s病患者的临床资料33例。依据手术方法分为2组:采用"拖尾征"锚定骨水泥PKP术治疗者为研究组(n=16);采用常规PKP术治疗者为对照组(n=17)。对比2组患者术中及术后并发症发生情况,随访24个月,对比2组患者术前、术后1 d及术后24个月时的Oswestry功能障碍指数(ODI)、视觉模拟量表(VAS)评分、Cobb′s角等指标。2组间比较采用t检验或χ~2检验。结果所有患者均顺利完成手术。研究组与对照组患者的手术时间[(55.46±7.63)和(53.56±8.54)min]和骨水泥注入量[(5.8±0.6)和(5.6±0.8)ml]比较,差异均无统计学意义(P0.05)。与对照组相比,研究组患者术后24个月时的Cobb角显著降低[(14.23°±1.85°)和(17.54°±2.02°),P0.05],而伤椎前缘高度[(1.75±0.42)和(1.39±0.61)cm]和中线高度[(1.69±0.61)和(1.35±0.34)cm]均显著增加(P0.05)。研究组术后并发症发生率显著低于对照组[6.3%(1/16)和41.2%(7/17),P0.01]。结论 "拖尾征"锚定骨水泥PKP术与常规PKP术治疗老年Kummell′s病均能取得短期良好手术效果,但长期随访发现通过"拖尾征"锚定骨水泥可有效减少骨水泥移位的发生风险。     

特发性正常压力脑积水颅内体积参数与临床症状关系的研究

目的探讨特发性正常压力脑积水(iNPH)患者术前颅内体积参数与术前临床症状严重程度及术后1年临床症状改善程度的关系。方法收集我院神经外科2016年1月至2017年2月符合国际iNPH指南诊断标准,并行脑脊液分流术的患者21例。所有患者术前行头颅磁共振扫描,并于术前及术后1年门诊复诊采用一致的临床症状指标进行评估,评估内容包括3 m计时起立行走试验(TUG)、简易精神状态量表检查(MMSE)、日本特发性正常压力脑积水分级评分(iNPHGS)与改良Rankin量表(mRS)。测量患者术前头颅影像资料中的脑室体积、脑实质体积、脑室外脑脊液体积、颅内容积,并计算相对脑室体积、脑实质比、脑室外脑脊液比、脑室内外脑脊液比,同时测量所有患者术前的Evans指数。结果iNPH患者术后无论是步态、认知功能还是排尿功能的评分较术前均有所改善(均P<0.05)。患者术前颅内体积参数(相对脑室体积、脑实质比、脑室外脑脊液比、脑室内外脑脊液比)、Evans指数与术前步态、认知功能及排尿功能的严重程度以及术后临床症状改善情况的相关性均无统计学意义(均P>0.05)。在分流术后1年随访点,mRS(17例比4例)、TUG(18例比3例)、MMSE(10例比11例)以及iNPHGS(17例比4例)有改善患者与无改善患者比较颅内体积参数的差异均无统计学意义(均P>0.05)。结论分流手术可以使iNPH患者步态、认知功能及排尿功能障碍等症状得到改善,但iNPH患者术前颅内体积参数(相对脑室体积、脑实质比、脑室外脑脊液比、脑室内外脑脊液比)、Evans指数与术前临床症状严重程度、术后1年症状改善程度无相关性,无法用于预测分流手术是否可以改善特定的临床症状。     

胃肠道类癌72例内镜下诊治与预后分析

目的 探讨胃肠道类癌的内镜下诊断、治疗、病理特点及预后情况.方法 回顾性分析山西省人民医院2004年7月至2010年7月内镜下诊治,经病理确诊并随访的胃肠道类癌72例.总结其常规内镜诊断、内镜下超声诊断、病理特点、治疗情况及预后分析.结果 共确诊并成功随访上消化道类癌26例,下消化道类癌46例,单发65例,多发7例,肿瘤大多为偏黄色广基扁平、丘状或隆起质硬结节,活动度不明显.超声内镜多表现为位于黏膜下层不均匀的低回声结节.采用内镜下黏膜切除术(EMR)或内镜下黏膜剥离术(ESD)成功治疗单发类癌51例,治愈率96.2％(51/53);EMR治愈多发类癌3例,治愈率3/7,术后随访肿瘤无复发.结论 内镜检查是发现早期类癌的重要手段,内镜下超声探查可以进一步明确病变来源及层次,并可为内镜下治疗提供依据.EMR及ESD为根治早期类癌的首选方法.     

过表达HSP20的慢病毒载体对H2O2诱导的大鼠心肌细胞凋亡的影响

目的构建过表达大鼠热休克蛋白20(HSP20)基因慢病毒载体,探讨其对H2O2诱导的大鼠H9C2心肌细胞凋亡的影响。方法构建大鼠HSP20基因pHIV-HSP20过表达质粒慢病毒,与包装质粒psPAX2、pMD2G共转染293FT细胞,检测其转染效率;包装慢病毒并转染H9C2心肌细胞;72 h后观察其转染效率,RT-PCR法检测细胞HSP20 mRNA表达,CCK-8、Hochest33258染色法检测H2O2诱导后H9C2心肌细胞凋亡情况。结果成功构建了HSP20慢病毒过表达载体,经293FT细胞包装后,其对H9C2细胞72 h的转染效率为95%;与慢性病毒组比较,H9C2细胞转染72 h后HSP20 mRNA水平显著升高,细胞活力下降,心肌细胞凋亡率明显降低(P均<0.01)。结论过表达HSP20能显著抑制H2O2诱导的H9C2心肌细胞凋亡。     

Effect of shRNA targeting survivin on ovarian cancer

Purpose

This study investigated the effect of shRNA targeting survivin on cultured ovarian cancer cells and on a murine ovarian cancer xenograft.

Methods

An RNAi plasmid for survivin was transfected into SKOV3 cells, and the effect of shRNA targeting survivin on the expression of survivin was determined. Transmission electron microscopy (TEM), flow cytometry, and TUNEL staining were used to assess apoptosis. The MTT assay was used to measure cell growth and changes in cisplatin sensitivity. SKOV3 cells were injected into nude mice, and the effect of shRNA targeting the survivin gene on tumor growth was assessed.

Results

SKOV3 cells transfected with an RNAi plasmid against survivin had increased apoptosis and slower growth. At the molecular level, these cells also had lower expression of survivin. Nude mice inoculated with SKOV3 cells developed cancers, and treatment with shRNA targeting survivin markedly inhibited the growth of these cancers with no obvious side effects.

Conclusions

Our studies of SKOV3 cells and ovarian cancer xenografts in nude mice indicate that shRNA targeting survivin has potential for the treatment of ovarian cancer.