Dose — response relationship between noise exposure and the risk of occupational injury

Many workers worldwide experience fatality and disability caused by occupational injuries. This study examined the relationship between noise exposure and occupational injuries at factories in Korea. A total of 1790 factories located in northern Gyeonggi Province, Korea was evaluated. The time-weighted average levels of dust and noise exposure were taken from Workplace Exposure Assessment data. Apart occupational injuries, sports events, traffic accidents, and other accidents occurring outside workplaces were excluded. The incidences of occupational injury in each factory were calculated by data from the Korea Workers’ Compensation and Welfare Services. Workplaces were classified according to the incidence of any occupational injuries (incident or nonincident workplaces, respectively). Workplace dust exposure was classified as <1 or ≥1 mg/m³, and noise exposure as <80, 80-89, or >90 dB. Workplaces with high noise exposure were significantly associated with being incident workplaces, whereas workplaces with high dust exposure were not. The odds ratios (95% confidence intervals) derived from a logistic regression model were 1.68 (1.27-2.24) and 3.42 (2.26-5.17) at 80-89 dB and ≥90 dB versus <80 dB. These associations remained significant when in a separate analysis according to high or low dust exposure level. Noise exposure increases the risk of occupational injury in the workplace. Furthermore, the risk of occupational injury increases with noise exposure level in a dose-response relationship. Therefore, strategies for reducing noise exposure level are required to decrease the risk of occupational injury.     

不同方法对食源性致病菌耐药性监测研究

目的了解江苏地区食源性致病菌的常用抗菌药耐药谱,评价不同药敏方法在致病菌耐药性监测中的适用性。方法用Etest和微量肉汤稀释法,对江苏省2012-2014年食源性疾病常规监测检出的金黄色葡萄球菌、副溶血性弧菌、沙门菌菌株进行药敏鉴定。结果金黄色葡萄球菌对红霉素的耐药率最高,其次为复方磺胺甲噁唑和四环素,且有多重耐药;副溶血性弧菌除对四环素和复方磺胺甲噁唑有一定的耐药,对其他6种革兰氏阴性菌抗生素均敏感。沙门菌对萘啶酸的耐药率超过50.0%。两种方法药敏检测结果对不同抗生素符合率有差异,但符合率均80%。结论 Etest和微量肉汤稀释法有较好的一致性,但所需时间及操作要求有差异,可根据实际需要进行选择。     

The effect of meat processing methods on changes in disulfide bonding and alteration of protein structures: impact on protein digestion products

We investigated the effects of different pork preparation methods (cooked pork, emulsion-type sausage, dry cured pork, and stewed pork) on protein structures and in vitro digestion. Compared with raw meat, processed meats contained lower levels of free sulfhydryl groups (P < 0.05). Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed different protein profiles for pork products treated without or with 5% βME, which indicated different extents of disulfide bond formation. Emulsion-type sausage showed significantly higher α-helix content and lower β-sheet, β-turn, and random coil contents than cooked pork (P < 0.05). Correspondingly, emulsion-type sausage and dry-cured pork had the highest values of surface hydrophobicity (P < 0.05). Proteome data showed that the long salting and drying times used for dry-cured pork as well as long-term high-temperature cooking of stewed pork might alter the accessibility of digestive proteolytic enzymes to the protein cleavage sites.

Processing caused different levels of formation of disulfide bonds, and associated it with protein structure changes and digested products.     

Shape-controlled synthesis of magnetic Fe3O4 nanoparticles with different iron precursors and capping agents

This paper describes a modified method to prepare monodisperse Fe₃O₄ magnetic nanoparticles with different shapes (cube, octahedron, and sphere). The shape of the magnetic nanoparticles could be conveniently controlled by changing the types of precursor/capping agent and concentration of capping agent. The prepared samples were characterized using scanning electron microscopy, X-ray diffraction and vibrating sample magnetometry. Cubes and octahedra were formed using ferrous sulfate heptahydrate as an iron source, ethylene glycol as a solvent and potassium hydroxide (KOH) as a capping agent while spheres were formed by using ferric chloride hexahydrate as an iron source, ethylene glycol as a solvent and ammonium acetate as a capping agent. By varying KOH concentration (0.5 M, 1 M, 1.5 M, and 5 M), the shape was transformed from cubes to octahedra because octahedra are developed dominantly at higher concentration of KOH within the reaction mixture. The magnetic studies show superparamagnetic behavior for all samples at room temperature. The Fe₃O₄ nanoparticles show the magnetic saturation values of 87 emu g⁻¹, 85 emu g⁻¹, and 82 emu g⁻¹ for spheres, cubes, and octahedrons, respectively.

This paper describes a modified method to prepare monodisperse Fe₃O₄ magnetic nanoparticles with different shapes (cube, octahedron, and sphere).     

人感染H7N9禽流感26例临床特征与病毒基因分析研究

目的探讨人感染H7N9禽流感病毒患者的流行病学和临床特征,以及病毒分子生物学特征。方法收集湖南省2013、2014年确诊的26例人感染H7N9禽流感病毒患者的资料,对人和禽分离的H7N9病毒进行鉴定和测序分析。结果26例患者中,发热和咳嗽是最常见的起病症状,所有患者均存在肺炎;20例(76.92%)出现急性呼吸窘迫综合征(ARDS),25例(96.15%)初诊时白细胞下降或正常,发病至开始进行抗病毒治疗的平均时间为10 d。10例死亡,病死率达38.46%。患者分离的H7N9病毒株测序分析表明,发生了H7基因Gln226Leu和Gly186Val替换,PB2基因Asp701Asn突变。结论急性呼吸系统损害是人感染H7N9禽流感的主要临床表现,活禽暴露是人感染H7N9禽流感的重要危险因素,H7N9禽流感病毒基因发生了部分位点的适应性突变,更容易从禽类向人跨种传播引起人类严重疾病,需加强病原学监测。     

Tat-LK15运载siRNA沉默RGC-5神经细胞nNOS基因的实验研究

目的探讨离体条件下细胞穿透肽Tat-LK15运载小干扰RNA(small interference RNA,siRNA)沉默RGC-5视神经节细胞(retinal ganglion cell line,RGC-5)神经元型一氧化氮合酶(neuronal nitric oxide synthase,n NOS)基因的可行性,为在体条件下研究Tat-LK15运载siRNA沉默n NOS表达治疗神经病理性疼痛提供理论依据。方法 1通过凝胶阻滞分析测定Tat-LK15与siRNA的最佳交联比。流式细胞术检测Tat-LK15/FAM-siRNA以最佳交联比转染RGC-5细胞的转染效率;不同剂量Tat-LK15(1、2.5、5、10和20μg)孵育RGC-5细胞24 h,流式细胞术检测细胞凋亡率。2制备n NOS高表达的RGC-5细胞模型。3将RGC-5细胞随机分为5组:对照组、模型组、Tat-S组(Tat-LK15运载n NOS/siRNA转染模型细胞)、Lipo-S组(LipofectamineTMRNAi MAX运载n NOS/siRNA转染模型细胞)及Tat-N组(Tat-LK15运载NCsiRNA转染模型细胞),通过Q-PCR及Western blot检测各组nN OS表达水平。结果 Tat-LK15与siRNA质量比为2∶1时可完全包裹siRNA,达到最佳交联,此时其转染效率为(84.4±3.9)%。当Tat-LK15剂量为20μg(6.1μmol·L-1)时才出现一定细胞毒性,细胞凋亡率高于对照组[(10.3±1.1)%vs(7.4±0.9)%,P<0.05]。造模后RGC-5细胞nN OS表达水平明显升高(P<0.05)。与模型组相比,Tat-S组nN OS mRNA及蛋白表达水平降低(P<0.05),Tat-S组与Lipo-S组相比无差异(P>0.05)。结论Tat-LK15能高效转染siRNA,细胞毒性低,离体条件下可有效运载siRNA沉默nN OS的基因表达。     

腹腔内脏脂肪面积与2型糖尿病及血清胰岛素的相关研究

目的观察腹腔内脏脂肪面积(VA)与2型糖尿病及血清胰岛素的关系。方法 2型糖尿病患者273例,非糖尿病者122例,分为高脂肪组198例和低脂肪组197例。检测空腹血糖(FPG)、空腹胰岛素(FINS)、糖化血红蛋白(Hb A1C)、尿酸(UA)、游离脂肪酸(FFA)、血脂系列等相关指标,采用CT测定VA,计算胰岛素抵抗指数(HOMA-IR)、体质指数(BMI)。结果糖尿病组的VA显著高于非糖尿病组(P<0.05),高脂肪组的腰围、BMI、UA、FINS、TG、IR、FFA、舒张压、收缩压明显高于低脂肪组(P<0.05),HDL明显低于低脂肪组(P<0.05)。腰围、BMI、FINS、UA、IR、TG、舒张压、收缩压、FFA与腹腔内脏脂肪面积呈正相关(r=0.697、0.625、0.374、0.371、0.332、0.317、0.181、0.136、0.110,均P<0.05),HDL与VA呈负相关(r=-0.230,P<0.05)。腰围、FINS、UA为VA的独立危险因素(b=6.657、2.819、2.405,均P<0.05)。结论内脏脂肪增加伴有胰岛素水平增高,胰岛素抵抗加重,糖尿病风险增加,并出现血压、尿酸、脂肪酸、胰岛素等多项代谢指标的异常。     

7种药物有效血药浓度参考范围的探讨

目的:探讨7种药物的有效血药浓度参考范围。方法:通过咨询已经开展治疗药物监测(TDM)医院的工作人员,查询药品说明书,出版的书籍及检索相关文献,分析能够达到药物治疗目的的最低有效浓度和出现中毒反应的最小中毒浓度,作为临床TDM值的参考范围。结果:初步确定了万古霉素、卡马西平、丙戊酸钠、地高辛、环孢素、他克莫司和吗替麦考酚酯TDM监测指标及其参考范围。结论:药物TDM监测指标参考值可以为临床药师提供参考,给临床医师个体化用药提供了药物调整剂量的依据,确保药物疗效。     

黑色浅灰链霉菌次级代谢产物杀螺活性及其作用机制初步研究

目的　评价放线菌黑色浅灰链霉菌（Streptomyces nigrogriseolus XD 2⁃7）代谢产物储存稳定性及其分离纯化产物实验室杀螺活性,并初步探讨其杀螺作用机制。方法　制备黑色浅灰链霉菌发酵上清液,将其于-20 ℃、4 ℃和28 ℃无光照条件下放置10 d后,测定其72 h浸杀灭螺效果;将发酵上清液置于100 ℃水浴中煮沸30 min后恢复至室温,测定其72 h浸杀灭螺效果;用浓盐酸和氢氧化钠调节发酵上清液pH值为4.0、6.0和9.0,室温下静置12 h,再调节发酵上清液pH至7.0,测定其72 h浸杀灭螺效果。用大孔树脂、硅胶和十八烷基硅烷键合硅胶依次对黑色浅灰链霉菌发酵产物进行4次分离纯化,将最终分离纯化产物配置成10.00、5.00、2.50、1.25 mg/L和0.63 mg/L浓度药液,测定其72 h浸杀灭螺效果。各实验设立空白对照组以脱氯水处理,阳性对照组以0.10 mg/L氯硝柳胺处理。采用高效液相色谱法测定经纯化代谢产物浸泡后钉螺软体组织中三磷酸腺苷（adenosine triphosphate, ATP）和二磷酸腺苷（adenosine diphosphate, ADP）含量。结果　黑色浅灰链霉菌发酵上清液在-20 ℃、4 ℃和28 ℃无光照条件下放置10 d后,原液及稀释10、50倍药液浸杀钉螺72 h,钉螺死亡率均为100.00%（30/30）;经100 ℃煮沸30 min后,原液及稀释10、50倍药液浸杀钉螺72 h,钉螺死亡率均为100.00%（30/30）。发酵上清液在pH值为4.0、6.0条件下存储12 h后浸杀钉螺72 h,钉螺死亡率均为100.00%（30/30）;在pH值为9.0条件下存储12 h后浸杀钉螺72 h,钉螺死亡率为33.33% (10/30,[χ2] = 30.000,P < 0.05)。发酵上清液最终分离纯化产物100.00%（30/30）杀死钉螺所需最低浓度为1.25 mg/L。以0.10 mg/L和1.00 mg/L浓度最终分离纯化产物处理钉螺后,钉螺软体组织中ATP水平较对照组显著降低（F = 7.274,P < 0.05）,ADP水平与对照组差异无统计学意义（F = 2.485,P > 0.05）。结论　黑色浅灰链霉菌代谢产物中杀螺活性成分可在-20 ℃、4 ℃和28 ℃条件下稳定储存10 d,且耐热、耐酸而不耐碱,其杀螺机制可能是使钉螺能量代谢发生紊乱而死亡。     

生物可吸收支架与药物洗脱支架在急性心肌梗死治疗中的安全性和有效性Meta分析

目的系统评价生物可吸收支架(BVS)与药物洗脱支架(DES)在治疗急性心肌梗死(AMI)中的安全性和有效性。方法计算机检索PubMed、Cochrane Library、Embase、Web of Science及相关网站(www.clinicaltrials.gov)。纳入2006年1月至2020年1月关于BVS与DES治疗AMI安全性与有效性的研究。主要有效终点为靶病变血运重建,主要安全终点为明确/可能的支架内血栓形成。由两名研究者按照纳入与排除标准筛选文献,提取资料和评价文献质量。采用Stata 12.0统计软件进行Meta分析。结果最终纳入4个临床研究,其中2个为随机对照研究,2个为观察性研究,共1335例患者,其中BVS组709例,DES组626例。随访时间为12~36个月。Meta分析结果:BVS组与DES组靶病变血运重建(RR 1.59,95%CI 0.82~3.10,P=0.337)、明确/可能的支架内血栓形成(RR 1.56,95%CI 0.70~3.46,P=0.685)的差异均无统计学意义。两组靶血管心肌梗死(RR 1.05,95%CI 0.41~2.67,P=0.667)、全因死亡(RR 1.35,95%CI 0.52~3.45,P=0.871)、心原性死亡(RR 1.29,95%CI 0.59~2.80,P=0.778)、设备相关的复合终点(RR 1.37,95%CI 0.87~2.16,P=0.425)的差异均无统计学意义。结论BVS治疗AMI的安全性与有效性可能不劣于DES。