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OBJECTIVE: The rate of cannabis use by women has been increasing in recent decades. This study examined the etiology of cannabis use and abuse among women and the possible role of genetic risk factors. METHOD: Unselected individual twins (N=1,934) from female-female pairs ascertained through a population-based registry, including both members of 485 monozygotic pairs and of 335 dizygotic pairs, were interviewed by telephone to assess lifetime cannabis use, heavy use, abuse, and dependence as defined by DSM-IV criteria. Biometric model fitting was performed with the Mx computer package. RESULTS: The prevalences of lifetime cannabis use, heavy use, abuse, and dependence were 47.9%, 6.7%, 7.2%, and 2.2%, respectively. Model fitting suggested that twins' resemblance for liability to cannabis use was due to both genetic and familial-environmental factors, while twins' resemblance for heavy cannabis use and abuse and symptoms of dependence resulted solely from genetic factors, with heritabilities ranging from 62% to 79%. The frequency of adolescent social contact between co-twins, which was greater among monozygotic than among dizygotic twins, predicted the twins' resemblance in cannabis use. However, further analyses suggested that the heritability of cannabis use was at most modestly inflated by such social factors. CONCLUSIONS: In women, genetic risk factors have a moderate impact on the probability of ever using cannabis and a strong impact on the liability to heavy use, abuse, and, probably, dependence. By contrast, the family and social environment substantially influences risk of ever using cannabis but plays little role in the probability of developing heavy cannabis use or abuse. 相似文献
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Histochemical and immunohistochemical studies on the origin of the blue marlin heater cell phenotype
The superior rectus muscle fibers of marlins, swordfish, sailfish and spearfish are modified for heat production at the expense of contractile ability. Although 'heater cells' are a muscle derivative (Block, 1986, 1991), the myoblast origin and developmental pathway of these thermogenic cells is unknown. To gain insight into heater cell origins, we characterized blue marlin superior rectus muscle and its heater tissue derivative with histochemical and immunological techniques. We specifically employed myosin ATPase and succinate dehydrogenase histochemical assays, and myosin heavy chain immunohistochemistry. Results revealed that marlin superior rectus muscles contain at least six distinct fiber types, and suggested the presence of both twitch and tonic fibers. Immunological results indicate that myosin is present within the thermogenic cells but not in myofibrillar lattices. The antibodies that recognized myosin in heater cells also labeled myosin in the twitch fibers of swimming muscle. In contrast, antibodies that labeled histologically defined tonic fibers did not label heater cells. These results suggest that heater cells and twitch fibers express the same myosin isoform, and establish a phenotypic connection between heater cells and twitch fibers. This conclusion is discussed in the context of the muscle-to-heater trajectory and the muscle fiber-type origin of heater cells. 相似文献
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The endoscopic placement of percutaneous gastrostomy tubes has been an accepted technique for several years but has traditionally been performed by gastroenterologists and general surgeons. Fluoroscopically guided tube placement is now performed by radiologists. Head and neck surgeons have been slow to adopt the responsibility for placing percutaneous gastrostomy tubes despite the fact that most are proficient in both rigid and flexible esophagoscopy and trained in the Seldinger technique. We report on 41 percutaneous endoscopic gastrostomies performed in 39 patients by the Head and Neck Service at Stanford Medical Center between July 1, 1992, and August 30, 1995. There were 28 (71.8%) male and 11 (28.2%) female patients. Eleven (28.2%) procedures were performed in patients at the time of major head and neck resections. Another seven (17.9%) patients underwent percutaneous gastrostomy tube placement at the time of their initial staging panendoscopy before receiving chemotherapy and radiation. Fifteen (38.5%) procedures were performed for severe postsurgical dysphagia. Six (15.4%) patients had neurologic dysfunction, and this procedure was often performed in conjunction with tracheostomy. There were no major complications. Two patients had to undergo intraoperative tube replacement at 7 months and 18 months for chronic infection and tube damage, respectively. The only other complication was local irritation at the surgical site, which occurred in 2 (5.1%) patients. Our experience with percutaneous gastrostomy tube placement confirms that this is a procedure that can be safely performed by head and neck surgeons and should be part of otolaryngology-head and neck surgery training. The ability to provide comprehensive care of head and neck cancer patients as well as a means of supplemental feeding in conjunction with performing tracheostomy in neurologically impaired patients will no doubt improve the service that our specialty can provide. 相似文献
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Histological and histochemical techniques have been employed to determine the structure and autonomic innervation of paraganglia located in the human pelvis. In foetal and early postnatal tissues, paraganglia formed rounded cellular masses which were frequently in company with the autonomic nerves and ganglia of the urinary bladder and other pelvic viscera. The constituent cells contained only small amounts of cholinesterase and were unrelated to enzyme positive autonomic nerves; acetylcholinesterase containing nerves were occasionally observed in the capsule and the fibrous septa of the pelvic paraganglia. In early postnatal specimens, pelvic paraganglia frequently contained single or multiple "pacinian-like" corpuscles, each possessing a central region which was rich in both acetyl and pseudocholinesterase. These structures were rarely observed within autonomic ganglia and were absent 4 1/2 years post partum. By means of a histochemical technique, pelvic paraganglia were found to contain catecholamine which was attributed to the presence of relatively large quantities of noradrenaline. These observations have been discussed with particular reference to the results of other studies on the autonomic innervation of paraganglia. 相似文献
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在酸性条件下,利用金属离子、碘离子和亚甲蓝形成一种三元缔合物[MIn+1]-[MB]+,该缔合物极易溶于甲苯,通过N2能浮选于甲苯中,分光光度法测定,据此建立了复杂基质样品中痕量重金属银、铜、镉、铅的检测新方法。考查了溶液pH值、KI和亚甲蓝溶液用量以及有机溶剂等对浮选的影响,讨论了共存离子的干扰情况。Cu,Pb,Cd和Ag的检出限分别为0.9,0.8,0.5和0.4ng/mL。本法用于高浓度盐溶液和工业硫酸样品中痕量Cu,Cd,Pb,Ag的分析,实测样品的回收率为80%~93%,相对标准偏差小于5%。 相似文献
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T Terasaki K Shimada H Wakabayashi M Tanaka A Watanabe 《Canadian Metallurgical Quarterly》1996,11(10):928-940
To investigate pathophysiological diversities in the repairing process of gastric ulcer, distribution density of basic fibroblast growth factor (bFGF)-positive fibroblasts and myofibroblasts and vascular endothelial cells, mucosal haemoglobin content, PAS-positive mucus amount and glandular index were compared in the peripheral region of an open ulcer (the unhealed group; n = 17), the central region of a red scar (the red scar group; n = 32) and the central region of the white scar (white scar group; n = 32). Density of bFGF-positive fibroblasts and myofibroblasts and vascular endothelial cells was highest in the unhealed group, followed by the red scar group, while the white scar group showed a low value close to control. Mucosal haemoglobin content was high in the red scar and unhealed groups. PAS-positive mucus amount in the unhealed and red scar groups showed lower values compared with that in the white scar group. Glandular index in the unhealed group was the lowest, followed by the red scar group, while the white scar group neared control values. Statistically significant correlations were observed between the density of bFGF-positive "fibroblasts and myofibroblasts' and density of bFGF-positive vascular endothelial cells, between the density of bFGF-positive vascular endothelial cells and mucosal haemoglobin content and between the PAS-positive mucus amount and glandular index. Discriminant analysis demonstrated that the unhealed group could be distinguished from the red and white scar groups, based on glandular index, density of bFGF-positive "fibroblasts and myofibroblasts', mucosal haemoglobin content and PAS-positive mucus amount, while the red scar group could be discriminated from the white scar group based on the density of bFGF-positive "fibroblasts and myofibroblasts', density of bFGF-positive vascular endothelial cells, glandular index, haemoglobin content and PAS-positive mucus amount. The white scar group was difficult to discriminate from control. Our present results show that the recovery of glandular formation and mucus production continues throughout the repairing process, whereas the acceleration of angiogenesis and granulation formation is observed only in unhealed ulcers and at the red scar stage. 相似文献
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Continuous weighing of kaolin during carbochlorination has been used to show the superiority of NaCl as a catalyst for increasing
the reaction rate and selectivity at 625° to 650 °C, and the possibility of using different types of carbon as a reductant.
Initial distribution of NaCl in the kaolin was found to be of importance. A reaction mechanism involving the formation of
NaAlCl4 and alumina solubility in this salt is used to explain the effect of reactor configuration and kaolin particle geometry. 相似文献
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在宝钢炼钢现场使用SPC(统计过程控制)的探讨 总被引:1,自引:0,他引:1
对宝钢炼钢现场推进SPC过程中遇到的一些问题进行了讨论,包括SPC的使用场合和控制对象、SPC控制图类型的选取、SPC的正确计算与分析、过程评价以及SPC的自动化等.并指出了其中的注意要点,阐述了作者的认识. 相似文献
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LP Krustev TA Tashev AA Popov JZ Apostolov BJ Borov MS Stefanova 《Canadian Metallurgical Quarterly》1976,20(6):597-603
The subjection of rats with body weight 150 +/- 10 g to complete starvation for a period of four days leads to a diminution of total protein, total lipids, blood sugar, body weight and liver weight. Lipid dystrophy develops in the liver, as well as deposition of lipofuscin-like pigment and atrophy. Lipid dystrophy and desposition of pigment increase during the first three days and abruptly decrease during the fourth. Atrophy is a progressive process. The delineation of three phases in the atrophic - dystrophic process is possible with the application of histological, enzyme-histochemical, morphometric, biochemical and electron microscopic methods: Phase I (first 24 hours) - a common adaptive phase. It engages both the liver, which must utilize the increased nutrients from the organism depots and the homeostatic mechanisms of the organism as a whole. Phase II - (second and third 24 hours) - alterative-restorative, manifested markedly at the liver parenchimal level and especially by autophagic lysosome function. Phase III - (fourth 24 hours) - alterative. Exhaustion of adaptive-restorative liver process (and the hepatocyte in particular), and the organism as a whole as well. 相似文献
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The female form of the SVIB was administered to 203 freshmen and sophomore female students in an introductory course in the University of Florida's College of Health Related Services. 29 scales were scored, intercorrelated, and factor analyzed. 9 factors resulted with loadings of ±.35 or more. The factors are discussed in terms of implications for female vocational interest and compared with previous factor analytic studies with the male form of the Blank. Groupings of occupations are presented, also, based on the factor structure of the female interests. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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文中研究了在NaCl-KCl-CuO体系中采用熔盐电解法直接制取铜粉的方法.基本反应条件为:电解温度740~820 ℃;槽电流12~15 A;阴极电流密度110~140 mA/cm2;槽电压2.2~3.2 V;电解时间1.5~3.5 h.对阴极电解产物进行了X射线衍射(XRD)及铜粉粒度分析,同时用扫描电镜(SEM)及能谱仪(EDS)对产物的形貌及元素含量进行了分析.结果表明:在上述条件下可以得到铜粉末,产物纯度在98 %以上且平均粒度为0.91 μm. 相似文献
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MG Shubich LL Goriacheva VI Dudetski? NM Lutsenko GM Mogil''naia 《Canadian Metallurgical Quarterly》1977,11(3):40-44
The histochemical study of the stomach, small and large intestines and pancreas of rats flown aboard the biosatellite Cosmos-605 as well as of synchronous and vivarium controls demonstrated a significant decline in the mucine producing capacity of epithelial cells of the stomach of the flight rats on the R + 1 day. The study showed an increased content of sialo- and sulphosaccharides in goblet cells of cryptae of large intestine and a reduced content of free cation protein in the acinar cells of the pancreas of flight rats. The changes were transient and disappeared by the R + 26 day. 相似文献
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D Elise 《Canadian Metallurgical Quarterly》1997,66(3):489-517
While the concept of primary femininity advances our understanding of the girl's developmental experience, a number of contradictions and problematic assumptions are at the present time contained within this concept. I propose that we use the phrase "primary sense of femaleness" to refer to the girl's earliest sense of self deriving from the mental representation of her body. In addition, I argue that the concepts of a primary sense of femaleness and of a bisexual matrix are not mutually exclusive; an early sense of self located in a female body can co-exist with the fantasy of potential unlimited by gender. Finally, I examine the role of the mother as ego ideal for the girl. 相似文献