Synthesis of MoS2 nanosheets for mercury speciation analysis by HPLC-UV-HG-AFS

Mercury species have aroused wide concern in the past several decades due to their high toxicity. However, it is still difficult to detect ultra-trace mercury species due to their biochemical transformation in complex samples. To establish a simpler and more sensitive method for pre-concentration and determination of trace mercury species, molybdenum disulfide (MoS₂) nanosheets with sulfur-rich characteristics and enlarged interlayer spacing were prepared by a hydrothermal method coupled with a sonication-assisted liquid exfoliation method and acted as solid-phase extraction adsorbent. The nano-MoS₂ had high adsorption capacity, fast adsorption rate and excellent selectivity towards mercury ions (Hg²⁺), methyl mercury (MeHg⁺) and ethyl mercury (EtHg⁺) in a wide pH range and complex matrices. And it could be easily regenerated by 4 mol L⁻¹ HCl and reused several times. After optimizing HPLC-UV-HG-AFS conditions, a great linearity (1.0–10.0 μg L⁻¹, R² = 0.999 for Hg²⁺, MeHg⁺ and EtHg⁺), lower detection limits (0.017, 0.037 and 0.021 ng mL⁻¹ for Hg²⁺, MeHg⁺ and EtHg⁺, respectively), relative standard deviations (<5%) and addition recoveries of the samples within 82.75–113.38% were observed. In summary, trace inorganic and organic mercury species in environmental and biological samples could be selectively enriched by the prepared nano-MoS₂ and efficiently seperated and detected by HPLC-UV-HG-AFS. The present study will help provide a better strategy for environmental monitoring and health assessment of mercury pollutants.

As-synthesized few-layered molybdenum disulfide nanosheets were used as solid-phase extraction absorbent for ultra-trace mercury speciation analysis by HPLC-UV-HG-AFS.     

Novel SrTiO3/NaTaO3 and visible-light-driven SrTiO3/NaTaO3:N nano-heterojunctions with high interface-lattice matching for efficient photocatalytic removal of organic dye

SrTiO₃/NaTaO₃ (STO/NTO) heterojunction photocatalysts were successfully constructed by decorating NaTaO₃ nanocubes with SrTiO₃ nanoparticles via a hydrothermal method. The structure of the perovskites NaTaO₃ and SrTiO₃ bear some resemblance to each other, which increases the interface lattice match for promoting the migration of photogenerated carriers between the STO/NTO interfaces. In comparison to pristine NaTaO₃ and SrTiO₃ samples, the STO/NTO composites exhibited remarkably improved capacity for the degradation of rhodamine B (RhB) under ultraviolet (UV) light (λ < 400 nm) irradiation. Furthermore, the partial replacement of O²⁻ by N³⁻ in the TaO ₆ octahedron narrowed the band gap of NaTaO₃, which significantly enhanced the photocatalytic performance of the SrTiO₃/NaTaO₃:N (STO/NTON) heterojunction under visible light (λ > 400 nm). Finally, the possible band structures of the STO/NTO and STO/NTON photocatalysts were proposed, which indicated that an n–n type heterojunction was constructed with a staggered gap for fast separation of photogenerated electron–hole pairs.

Novel SrTiO₃/NaTaO₃ and visible-light-driven SrTiO₃/NaTaO₃:N nano-heterojunctions with high interface–lattice match were synthesized for efficient photocatalytic removal of organic dye.     

超声检查和MRI在产前诊断胎儿Dandy-Walker变异型中的对比研究

目的回顾性分析胎儿头颅超声检查(US)和MRI在产前诊断胎儿Dandy-Walker变异型(DWV)中的应用价值。方法选择2011年1月至2013年9月在四川大学华西第二医院经胎儿头颅US疑诊为胎儿DWV的11例胎儿为研究对象,并同时对其进行头颅MRI检查。对疑诊为胎儿DWV者随访至引产后或生后1年,以引产后胎儿的尸检结果或随访1年后对患儿再次进行头颅MRI检查结果及其临床表现作为诊断DWV的金标准,并统计学比较胎儿头颅US及MRI产前诊断该病的正确率。本研究遵循的程序符合四川大学华西第二医院人体试验委员会制定的伦理学标准,得到该委员会批准,征得受试对象监护人知情同意,并与之签署临床研究知情同意书。结果经头颅US疑诊为胎儿DWV的11例胎儿,同时进行头颅MRI检查结果为:正常胎儿为6例,诊断为胎儿DWV为5例。根据胎儿DWV诊断的金标准,胎儿头颅MRI对胎儿DWV的产前诊断正确率显著高于头颅US,且差异有统计学意义(100.0%vs45.4%,P=0.012)。结论胎儿头颅US是产前诊断胎儿中枢神经系统疾病的首选方法。对US疑诊为胎儿DWV者进一步采取头颅MRI检查确诊,是临床诊断胎儿DWV的必要补充。     

睾丸精原细胞瘤临床病理学特点分析

目的探讨睾丸精原细胞瘤的临床病理特征。方法对6例睾丸精原细胞瘤的临床表现和组织学形态进行分析。结果 6例睾丸精原细胞瘤患者年龄25~42岁,巨检显示肿瘤呈卵圆形,最大径15cm,包膜完整,切面为灰白色;镜下均为典型精原细胞瘤的临床病理学特征;免疫组化检测显示人胎盘碱性磷酸酶(PLAP)及CD117表达阳性,1例灶性表达甲胎蛋白(AFP),1例灶性表达CD30,人绒毛膜促性腺激素(HCG),CKpan,扁豆凝集素(LCA)和Vimentin均为表达阴性。结论睾丸精原细胞瘤好发于中年男性,隐睾是高危因素,诊断主要依据典型的病理组织学特点及免疫组化检测结果。     

三种不同方式治疗儿童哮喘的疗效及不良反应研究

目的:观察规范吸入沙美特罗替卡松(SM/FP)、口服孟鲁司特及不规范用药对儿童哮喘的疗效与不良反应,指导临床治疗。方法:将哮喘患儿分A组(规范吸入SM/FP)、B组(口服孟鲁司特)和C组(不规范用药),观察患儿6个月、12个月、18个月的肺功能、临床症状、治疗费用、身高、体质量及不良反应。结果:A组、B组患儿的肺功能在治疗后6个月、12个月及18个月均较基础值明显改善(P<0.05);用药12个月、18个月后,A组的气道高反应性明显低于B组。C组患儿除观察后6个月PEF%较基础值有改善外,其余指标较基础值无好转。C组轻度咳喘发作、急诊输液及住院人次所占比例均明显高于A组、B组,差异有统计学意义(P<0.05);用药18个月时A组的急诊输液及住院人次所占比例明显低于B组,差异有统计学意义(P<0.05)。三组患儿的身高及体质量增长均在正常范围。结论:规范用药能更好控制哮喘儿童的症状,改善肺功能,减轻气道高反应性,减少不良反应;不规范用药则不能控制哮喘。     

Serum soluble programmed death-1 levels predict the spontaneous HBeAg seroclearance in chronic hepatitis B

Journal of Gastroenterology - In chronic hepatitis B virus (HBV) infection, earlier seroclearance of hepatitis B e antigen (HBeAg) is associated with more favorable outcomes. Soluble programmed...     

留守儿童主观幸福感与人格特征的研究

目的:探讨留守儿童人格特征与主观幸福感的关系,并提出培养健康人格以提高留守儿童主观幸福感.方法:以吉林市丰满区第二小学、吉林市朝鲜族实验小学两所学校的四、五、六三个年级分层随机抽取的650个小学生为对象,采用陈仲庚修订的儿童版艾森克人格问卷(EPQ),总体幸福感量表(General Well-Being Schedule)进行调查.结果:留守儿童与非留守儿童在内—外向(t=-7.760,P＜0.001)、神经质(t=11.662,P＜0.001)和精神质(t=13.647,P＜0.001)人格维度上存在显著性差异;人格维度内-外向与留守儿童的主观幸福感的各个维度呈正相关;神经质和精神质两个人格维度与留守儿童的主观幸福感呈负相关.通过留守儿童与非留守儿童主观幸福感与人格关系的回归分析表明,人格的内外向和神经质对留守儿童主观幸福感预测力最强.结论:留守儿童人格对主观幸福感的影响很大,需要监护人和教育工作者积极关注并努力培养留守儿童的健康人格.     

HIV Care Outcomes in Relation to Racial Redlining and Structural Factors Affecting Medical Care Access Among Black and White Persons with Diagnosed HIV—United States, 2017

AIDS and Behavior - Black/African American (Black) versus White persons are unequally burdened by human immunodeficiency virus (HIV) in the United States. Structural factors can influence social...     

Lipotoxic hepatocyte-derived exosomal miR-1297 promotes hepatic stellate cell activation through the PTEN signaling pathway in metabolic-associated fatty liver disease

BACKGROUNDExosomes play an important role in metabolic-associated fatty liver disease (MAFLD), but the mechanism by which exosomes participate in MAFLD still remain unclear.AIMTo figure out the function of lipotoxic exosomal miR-1297 in MAFLD.METHODSMicroRNA sequencing was used to detect differentially expressed miRNAs (DE-miR) in lipotoxic exosomes derived from primary hepatocytes. Bioinformatic tools were applied to analyze the target genes and pathways regulated by the DE-miRs. Quantitative real-time PCR (qPCR) was conducted for the verification of DE-miRs. qPCR, western blot, immunofluorescence staining and ethynyl-20-deoxyuridine assay were used to evaluate the function of lipotoxic exosomal miR-1297 on hepatic stellate cells (LX2 cells). A luciferase reporter experiment was performed to confirm the relationship of miR-1297 and its target gene PTEN. RESULTSMicroRNA sequencing revealed that there were 61 exosomal DE-miRs (P < 0.05) with a fold-change > 2 from palmitic acid treated primary hepatocytes compared with the vehicle control group. miR-1297 was the most highly upregulated according to the microRNA sequencing. Bioinformatic tools showed a variety of target genes and pathways regulated by these DE-miRs were related to liver fibrosis. miR-1297 was overexpressed in exosomes derived from lipotoxic hepatocytes by qPCR. Fibrosis promoting genes (α-SMA, PCNA) were altered in LX2 cells after miR-1297 overexpression or miR-1297-rich lipotoxic exosome incubation via qPCR and western blot analysis. Immunofluorescence staining and ethynyl-20-deoxyuridine staining demonstrated that the activation and proliferation of LX2 cells were also promoted after the above treatment. PTEN was found to be the target gene of miR-1297 and knocking down PTEN contributed to the activation and proliferation of LX2 cells via modulating the PI3K/AKT signaling pathway.CONCLUSIONmiR-1297 was overexpressed in exosomes derived from lipotoxic hepatocytes. The lipotoxic hepatocyte-derived exosomal miR-1297 could promote the activation and proliferation of hepatic stellate cells through the PTEN/PI3K/AKT signaling pathway, accelerating the progression of MAFLD.     

Abdominal paracentesis drainage attenuates intestinal inflammation in rats with severe acute pancreatitis by inhibiting the HMGB1-mediated TLR4 signaling pathway

BACKGROUND Our previous studies confirmed that abdominal paracentesis drainage(APD)attenuates intestinal mucosal injury in rats with severe acute pancreatitis(SAP),and improves administration of enteral nutrition in patients with acute pancreatitis(AP).However,the underlying mechanisms of the beneficial effects of APD remain poorly understood.AIM To evaluate the effect of APD on intestinal inflammation and accompanying apoptosis induced by SAP in rats,and its potential mechanisms.METHODS SAP was induced in male adult Sprague-Dawley rats by 5%sodium taurocholate.Mild AP was induced by intraperitoneal injections of cerulein(20μg/kg body weight,six consecutive injections).Following SAP induction,a drainage tube connected to a vacuum ball was placed into the lower right abdomen of the rats to build APD.Morphological changes,serum inflammatory mediators,serum and ascites high mobility group box protein 1(HMGB1),intestinal barrier function indices,apoptosis and associated proteins,and toll-like receptor 4(TLR4)signaling molecules in intestinal tissue were assessed.RESULTS APD significantly alleviated intestinal mucosal injury induced by SAP,as demonstrated by decreased pathological scores,serum levels of D-lactate,diamine oxidase and endotoxin.APD reduced intestinal inflammation and accompanying apoptosis of mucosal cells,and normalized the expression of apoptosis-associated proteins in intestinal tissues.APD significantly suppressed activation of the intestinal TLR4 signaling pathway mediated by HMGB1,thus exerting protective effects against SAP-associated intestinal injury.CONCLUSION APD improved intestinal barrier function,intestinal inflammatory response and accompanying mucosal cell apoptosis in SAP rats.The beneficial effects are potentially due to inhibition of HMGB1-mediated TLR4 signaling.