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OBJECTIVE: This paper evaluated harness sizing schemes and anthropometric criteria for harness design applications. BACKGROUND: Updated harness sizing systems are needed to accommodate diverse populations in the current workforce. METHOD: Three-dimensional torso scan data and human-harness interfaces from 108 women and 108 men were digitally captured. Abounding box approach was employed to quantify the effect of torso shape and size on fall harness fit. RESULTS: A logistic regression model with eight equations was developed and tested to classify more than 96% of participants to the best-fitting size. CONCLUSION: Study outcomes suggested an alternative system of two sizes for women and three sizes for men over the current four-size unisex system. In addition, thigh strap angle and back D ring location could be utilized along with current harness static fit test criteria to further enhance postfall harness fit predictions. APPLICATION: This research could help reduce the risk of worker injury resulting from poor fit, improper size selection, or failure to don the harness properly. 相似文献
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作为电子文档长期保存格式的PDF/Archive(PDF/A)经中国国家标准化管理委员会批准已成为正式的中国国家标准,并于2009年9月1日起正式实施的公告发布之后,PDF文档格式的使用将会越来越普遍.它已经从单一功能的小范围的个人使用者上升为需要对PDF文档进行综合处理的政府、企业、个人等类型的用户。其实市面上已有一款功能强大的PDF电子文档套件的产品能实现对PDF文档的综合处理, 相似文献
95.
"99%下载门"说的就是在IE浏览器或其他下载软件下载网络资源时,进行到99%时就停了,不能结束下载的问题.关于这类问题相信不少朋友都遇到过,那么出现这种情况主要是由什么原因引起的?有什么切实可行的解决办法呢?下面就一起来讨论讨论. 相似文献
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To increase the pH optimum of glucoamylase (GA), five mutations-S411G,
S411A, S411C, S411H and S411D--were designed to destabilize the carboxylate
ion form of Glu400, the catalytic base, by removing or weakening the
hydrogen bond between Ser411 and Glu400, and thereby raising its pK. The
substitution of alanine, histidine and aspartate were also designed to
study the additional effects of polarity and both positive and negative
charges, respectively. S411G GA had catalytic efficiencies like those of
wild-type GA for isomaltose, maltose and maltoheptaose hydrolysis at pH
4.4, while S411A and S411C GAs had 54- 74% and S411H and S411D GAs had only
about 6-12% of wild-type catalytic efficiencies. All five mutations
increased the pH optimum in the enzyme- substrate complex, mainly by
raising pK1 values. S411A is the best performing and most industrially
promising of the pH mutants isolated to date. S411A GA increased the pH
optimum by 0.8 units for both maltose and maltoheptaose hydrolysis while
maintaining a high level of activity and catalytic efficiency. In
hydrolysis of 28% DE 10 maltodextrin, S411A GA had a pH optimum of 7
compared with pH 5.6 for wild-type GA, and had higher initial rates of
glucose production than wild-type GA at all pH values tested above pH 6.6.
相似文献
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MJ Lo SW Wang MM Kau JJ Chen YH Chen VS Fang LT Ho PS Wang 《Canadian Metallurgical Quarterly》1998,46(9):444-452
BACKGROUND: We investigated the direct effects of propylthiouracil (PTU) on corticosterone secretion both in vivo and in vitro. METHODS: Male rats were divided into 4 groups and then injected subcutaneously with saline, PTU, PTU plus thyroxine (T4), or T4 once daily for 2 weeks. After 2 weeks, rats were decapitated or received adrenocorticotropic hormone (ACTH), intravenously. Zona fasciculata-reticularis (ZFR) cells from normal, saline-, PTU-, PTU plus T4-, or T4-treated rats were incubated with ACTH, forskolin, 8-Br-cAMP, deoxycorticosterone (DOC) +/- PTU (1, 2, or 5 mg/mL) at 37 degrees C for 2 hours. Corticosterone concentrations in plasma and cell media, and 3':5'-cyclic adenosine monophosphate (cAMP) production in ZFR cells were determined by radioimmunoassay. The effects of PTU on the activities of steroidogenic enzymes in ZFR cells were measured by the amounts of intermediate steroidal products separated by thin-layer chromatography. RESULTS: The basal and ACTH-stimulated levels of plasma corticosterone in PTU-treated rats were lower as compared to saline-treated animals. Both basal and ACTH-stimulated corticosterone secretion were inhibited by PTU > 2 mg/mL in rat ZFR cells. The cAMP production induced by forskolin was lower in PTU, PTU plus T4, or T4-treated rats than in saline-treated animals. Chronic administration of PTU or PTU plus T4 inhibited the 3 beta-hydroxysteroid dehydrogenase, 21 beta-hydroxylase, and 11 beta-hydroxylase activities. Administration of PTU (1, 2, and 5 mg/mL) suppressed the basal, ACTH, 8-Br-cAMP, forskolin, and DOC-stimulated corticosterone secretion in rat ZFR cells. Likewise, PTU > 2 mg/mL inhibited the ACTH and 8-Br-cAMP-stimulated levels of intracellular cAMP in rat ZFR cells. CONCLUSIONS: These results suggest that PTU counteracts both basal and ACTH-induced adrenal steroidogenesis through their attenuation of the activity of 11 beta-hydroxylase and cAMP production in rat ZFR cells. 相似文献