某碳化硅制品企业工作场所职业病危害因素调查

目的识别、分析和检测某碳化硅制品企业职业病危害因素及职业卫生管理制度,为职业病防治工作提供依据。方法采用职业卫生现场调查、职业卫生检测、职业健康监护等方法对该企业工作场所职业病危害因素进行分析与评价。结果该企业主要职业病危害因素是碳化硅粉尘和噪声。经检测,粉尘时间加权平均浓度为0.3～5.9 mg/m3,超限倍数为0.9～4.6,部分岗位粉尘浓度超标;噪声强度合格率为94.1%。结论职业病危害防护设施的效果有待改善,应加强职业卫生管理和培训,落实个人防护用品管理。     

选煤厂粉尘的职业危害与控制技术

目的通过对煤矿选煤厂粉尘职业危害的调研,找出关键控制点,并提出相应的控制技术。方法运作危害分析与关键控制点(HACCP)的原理,对选煤厂的生产工艺,作业环境进行现场调研,识别各种职业危害因素,从粉尘浓度、分散度及健康损失等方面了解职业危害的严重程度,并据此找出关键控制点,提出预防控制措施。结果选煤厂装卸、破碎、筛选工种粉尘危害相对较大。选煤厂粉尘的危害主要为煤尘,煤尘游离SiO2平均含量为4.9%。各地粉尘浓度差异较大,江西煤尘的平均浓度为250.8 mg/m3。选煤厂各工种均未检出尘肺病例,选煤厂尘肺病的危害少于煤矿其他工种。结论选煤厂部分工种粉尘浓度超标,对工人的潜在危害仍然存在,除加强管理外,要从8个方面改进降尘措施。     

Effects of Turmeric Powder on Aflatoxin M1 and Aflatoxicol Excretion in Milk from Dairy Cows Exposed to Aflatoxin B1 at the EU Maximum Tolerable Levels

Due to the climatic change, an increase in aflatoxin B1 (AFB1) maize contamination has been reported in Europe. As an alternative to mineral binders, natural phytogenic compounds are increasingly used to counteract the negative effects of AFB1 in farm animals. In cows, even low dietary AFB1 concentrations may result in the milk excretion of the genotoxic carcinogen metabolite aflatoxin M1 (AFM1). In this study, we tested the ability of dietary turmeric powder (TP), an extract from Curcuma longa (CL) rich in curcumin and curcuminoids, in reducing AFM1 mammary excretion in Holstein–Friesian cows. Both active principles are reported to inhibit AFM1 hepatic synthesis and interact with drug transporters involved in AFB1 absorption and excretion. A crossover design was applied to two groups of cows (n = 4 each) with a 4-day washout. Animals received a diet contaminated with low AFB1 levels (5 ± 1 µg/kg) for 10 days ± TP supplementation (20 g/head/day). TP treatment had no impact on milk yield, milk composition or somatic cell count. Despite a tendency toward a lower average AFM1 milk content in the last four days of the treatment (below EU limits), no statistically significant differences with the AFB1 group occurred. Since the bioavailability of TP active principles may be a major issue, further investigations with different CL preparations are warranted.     

高压蒸汽灭菌法对三七细粉中3种成分含量的影响

目的探索高压蒸汽灭菌法对三七药材中3种成分含量的影响。方法采用高效液相色谱法对灭菌处理和非灭菌处理的三七药材细粉中的指标成分三七皂苷R1、人参皂苷Rg1、人参皂苷Rb1进行含量测定,记录2种处理方式各指标成分的含量变化情况。结果与结论三七药材细粉经高压蒸汽灭菌后指标成分含量显著降低,不宜采用高压蒸汽灭菌法灭菌。     

柴胡舒肝散含药血清对乳腺癌MCF-7细胞的体外抑制作用及Bcl-2与VEGF的影响

目的 探讨柴胡舒肝散含药血清对人乳腺癌MCF-7细胞株体外抑制作用及Bcl-2与VEGF的影响.方法 选取SD雌性大鼠48只,随机分为空白对照组、他莫昔芬组和柴胡疏肝散高、低剂量组.利用他莫昔芬片和不同浓度的柴胡疏肝散进行干预,留取含药血清检测MCF-7细胞凋亡,Bcl-2的蛋白表达及血清中血管内皮生长因子(VEGF)...     

血管内皮抑素转基因制剂的体外抗肿瘤作用及对大鼠大肠癌的影响

目的 研究血管内皮抑素转基因双歧杆菌口服冻干粉剂(endostatin transfected bifidobacterium oral powder prepara-tion,ETB-2)体外抗肿瘤作用及对大鼠大肠痛的影响.方法 采用MTT法检测ETB-2对人结肠癌细胞株LS-174T、人胃黏膜上皮细胞株GES-1的作用.以二甲肼(DMH)为诱发剂,观察ETB-2对大鼠大肠癌的防治作用;DMH诱癌及ETB-2灌胃时间为18周,在第33周结束实验.结果 ETB-2在体外对人结肠癌细胞株具有显著的选择性杀伤作用,体内给药可明显降低大鼠大肠癌发生率(60%:100%,P<0.01),但大肠癌平均个数及肿瘤体积指数的差异无显著性(P>0.05).结论 ETB-2对DMH诱导的大鼠大肠癌具有预防作用.     

涂覆草酸钇薄膜改善氮化铝粉耐水性及其机理

研究了表面涂覆草酸钇薄膜对氮化铝（ＡｌＮ）粉耐水性的影响。结果显示：涂膜后ＡｌＮ粉在１００℃沸水中回流４５ｍｉｎ不与水反应，温度降至７８℃时可耐水３ｈ以上；耐水时间随涂覆量增加而增加，随温度升高而下降。水分子通过薄膜的扩散过程是影响ＡｌＮ耐水性的决定因素。用Ｘ光电子能谱（ＸＰＳ）和红外光谱测定了表面草酸钇与ＡｌＮ界面形成的化学键。     

Bioceramics Based on β-Calcium Pyrophosphate

Ceramic samples based on β-calcium pyrophosphate β-Ca₂P₂O₇ were prepared from powders of γ-calcium pyrophosphate γ-Ca₂P₂O₇ with preset molar ratios Ca/P = 1, 0.975 and 0.95 using firing at 900, 1000, and 1100 °C. Calcium lactate pentahydrate Ca(C₃H₅O₃)₂⋅5H₂O and monocalcium phosphate monohydrate Ca(H₂PO₄)₂⋅H₂O were treated in an aqua medium in mechanical activation conditions to prepare powder mixtures with preset molar ratios Ca/P containing calcium hydrophosphates with Ca/P = 1 (precursors of calcium pyrophosphate Ca₂P₂O₇). These powder mixtures containing calcium hydrophosphates with Ca/P = 1 and non-reacted starting salts were heat-treated at 600 °C after drying and disaggregation in acetone. Phase composition of all powder mixtures after heat treatment at 600 °C was presented by γ-calcium pyrophosphate γ-Ca₂P₂O₇ according to the XRD data. The addition of more excess of monocalcium phosphate monohydrate Ca(H₂PO₄)₂·H₂O (with appropriate molar ratio of Ca/P = 1) to the mixture of starting components resulted in lower dimensions of γ-calcium pyrophosphate (γ-Ca₂P₂O₇) individual particles. The grain size of ceramics increased both with the growth in firing temperature and with decreasing molar ratio Ca/P of powder mixtures. Calcium polyphosphate (t _melt = 984 °C), formed from monocalcium phosphate monohydrate Ca(H₂PO₄)₂⋅H₂O, acted similar to a liquid phase sintering additive. It was confirmed by tests in vitro that prepared ceramic materials with preset molar ratios Ca/P = 1, 0.975, and 0.95 and phase composition presented by β-calcium pyrophosphate β-Ca₂P₂O₇ were biocompatible and could maintain bone cells proliferation.     

Production of Dense Cu-10Sn Part by Laser Powder Bed Fusion with Low Surface Roughness and High Dimensional Accuracy

Tin-bronze alloys with a tin content of at least 10 wt% have excellent mechanical properties, wear resistance, and corrosion resistance. Among these alloys, Cu-10Sn was investigated in this study for production with the laser powder bed fusion process with a 500W Yb:YAG laser. In particular, a design of experiment (DoE) was developed in order to identify the optimal process parameters to obtain full density, low surface roughness, and high dimensional accuracy. Samples were characterized with Archimedes’ method and optical microscopy to determine their final density. It was shown that the first method is fast but not as reliable as the second one. A first mechanical characterization was performed through microhardness tests. Finally, a set of process parameters was identified to produce fully dense samples with low surface roughness and high accuracy. The results showed that the volumetric energy density could represent an approach that is too simplified, therefore limiting the direct correlation with the physical aspects of the process.     

布拉酵母菌散剂治疗小儿消化不良性腹泻疗效观察

目的：探讨布拉酵母菌散剂治疗小儿消化不良性腹泻的临床效果。方法90例小儿消化不良性腹泻患儿随机分为两组,每组45例,分别为对照组、治疗组。对照组予抗生素及对症处理,治疗组患者在此基础上给予布拉酵母菌散剂,比较两组患者的治疗效果。结果治疗组患者治疗有效率明显高于对照组,治疗组患者平均止泻时间为（74.45±27.37）h,明显短于对照组,病程7 d所占比率为91.11%明显高于对照组,治疗组患者住院时间明显短于对照组,治疗费用明显少于对照组（P〈0.05）。所有患者均无不良反应或者过敏反应发生。结论布拉酵母菌散剂治疗小儿消化不良性腹泻疗效肯定,未发现明显的不良反应,安全有效,布拉酵母菌散剂可作为治疗小儿消化不良性腹泻的一线药物。