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1.
Objectives. We examined the associations of pregnancy desire (ambivalence or happiness about a pregnancy in the next year) and recent pregnancy attempts with hopelessness and self-worth among low-income adolescents.Methods. To evaluate independent associations among the study variables, we conducted gender-stratified multivariable logistic regression analyses with data derived from 2285 sexually experienced 9- to 18-year-old participants in the Mobile Youth Survey between 2006 and 2009.Results. Fifty-seven percent of youths reported a desire for pregnancy and 9% reported pregnancy attempts. In multivariable analyses, hopelessness was positively associated and self-worth was negatively associated with pregnancy attempts among both female and male youths. Hopelessness was weakly associated (P = .05) with pregnancy desire among female youths.Conclusions. The negative association of self-worth and the positive association of hopelessness with pregnancy attempts among young men as well as young women and the association of hopelessness with pregnancy desire among young women raise questions about why pregnancy is apparently valued by youths who rate their social and cognitive competence as low and who live in an environment with few options for material success.Rates of adolescent pregnancy and childbearing in the United States are among the highest in the developed world.1 Each year, approximately 750 000 women younger than 20 years become pregnant,2 and about 400 000 give birth.3 In the United States, adolescent pregnancy rates are about two thirds higher among non-White young women than among White young women, and childbearing rates are approximately one third higher2; 57% of births to adolescents in 2010 were to African American or Hispanic/Latino mothers.3 Surveillance data for 9th- to 12th-grade US students show that Blacks and Hispanics are more likely than Whites to engage in risk behaviors associated with pregnancy (e.g., vaginal intercourse at an early age, nonuse of hormonal contraceptives).4Race and ethnicity do not, in themselves, explain adolescent pregnancy risk. Kirby identified more than 100 antecedents of adolescent pregnancy, primarily related to the types of physical and social environments in which minority youths in the United States are disproportionately represented.5 He concluded that most risk factors, including poor school performance6 and residence in a socioeconomically disadvantaged neighborhood,7–9 reflected dysfunction, disadvantage, or disorganization. Offspring of adolescent parents or sisters of women who began childbearing in adolescence are at high risk for adolescent parenthood, suggesting a cultural or intergenerational component.8–10 Family quality, especially parent characteristics and relationships9,11–16; the quality of relationships with one’s school, residential community, and peers6,7,9,12,14; and substance use and mental health,9,17–22 are associated with pregnancy or pregnancy risk behaviors among both female and male adolescents.Youths who live in challenging social and physical environments typically have negative psychological and cognitive responses to their surroundings (e.g., low self-worth and hopelessness).23,24 Although the evidence is mixed,20–22,25,26 it is generally assumed that poor self-image, poor self-worth, and poor self-esteem in girls are associated with pregnancy or pregnancy risk markers, including early age at first vaginal intercourse and an inability to negotiate condom use. Hopelessness reflects negative expectations about future desired or valued outcomes and helplessness with respect to one’s ability to change the odds that negative outcomes will occur.27 Hopelessness has been identified as a risk marker for youth violence and self-harm and poor adult social trajectories.24,28–31 In industrialized countries, adolescent pregnancy (and the decision to continue a pregnancy) may be a consequence of a lack of hope and the perception of too few positive life options,32,33 although only a limited number of studies have directly examined hopelessness and pregnancy risk.Kogan et al. examined a related phenomenon, conventional future orientation, and found associations with decreased sexual risk taking at age 16 and avoidance of pregnancy at age 19 years.34 A 2013 study of Mobile Youth Survey (MYS) participants showed that having a positive feeling about the future was marginally associated with older age at first intercourse, a risk factor for adolescent pregnancy.35 Neither study examined female and male youths separately. Despite the health, social, and economic burdens associated with pregnancy involvement among boys,9,36,37 little is known about the psychological or cognitive correlates of adolescent paternity risk.Adolescent pregnancy and childbearing disproportionately occur among historically marginalized youths and present significant, and often lifelong, social and health risks to parents and their offspring.37 Many known antecedents, including poverty, neighborhood quality, and quality of the parental relationship, may be intractable. However, learned cognitive factors such as hopelessness and low self-worth may be modifiable.27Because of our overarching interest in identifying potentially intervenable correlates of pregnancy involvement among high-risk youths, we examined the hypotheses that hopelessness is positively associated and self-worth is negatively associated with 2 known risk markers of adolescent pregnancy: pregnancy attempts and pregnancy desire.15,26,38–42 Our analyses involved a cross-sectional sample of adolescent female and male participants in the MYS,43 a study of primarily African American and impoverished young people with little variation in their social risk for pregnancy. Because there may be gendered cultural meanings or consequences associated with early pregnancy and parenting (especially in communities where rates of adolescent pregnancy are disproportionately high) and because the psychological or cognitive correlates of pregnancy risk may vary according to gender,21,22 we examined female and male youths separately.  相似文献   
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3.
In the present study, some new amides of 5-amino-3-methylisoxazole-4-carboxylic acid were obtained. All new structures possessed markedly different groups of electron acceptor character, different spatial structure and they contained nitrogen heteroatom, enabling formation of salts and, at the same time, higher biological availability. They were examined for immunomodulating activity in comparison with cyclosporine A (CsA). We investigated effects of the compounds on the lipopolysaccharide (LPS)-induced production of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) by human peripheral blood cells. Some compounds exhibited suppressory action which corresponded with increasing electronoacceptor nature of the amide substituent. Two compounds, characterized by flat aromatic rings, demonstrated quite different properties. Much higher activity was expressed by compounds which contained -NH group, the group which conditioned immunostimulatory activity in other compounds described previously.  相似文献   
4.
5.
IL-12 is a cytokine detected in active lesions in multiple sclerosis (MS) and promotes the acquisition of a Th1 cytokine profile by CD4+ T cells. Autoreactive T cells recovered from the central nervous system of animals with experimental autoimmune encephalomyelitis (EAE), a disease model for MS, display this phenotype. We demonstrate that human central nervous system-derived microglia, but not astroglia, can produce IL-12 in vitro. Under basal culture conditions, human adult microglia do not express detectable levels of IL-12, although these cells show some degree of activation as assessed by expression of the immunoregulatory surface molecules HLA-DR and B7 as well as low levels of TNF-alpha mRNA. Following activation with LPS, IL-12 p40 mRNA and p70 protein can be readily detected. IL-12 production is preceded by TNF-alpha production and is inhibited by recombinant soluble human TNF receptor (II)-IgG1 fusion protein (shu-TNF-R). These data indicate regulation of IL-12 by an autocrine-dependent feedback loop, providing an additional mechanism whereby shu-TNF-R, now used in clinical trials in MS, may be exerting its effect.  相似文献   
6.
The objective of this review is to summarize the data about metabolic side effects of atypical antipsychotics in children. Original research articles about side effects of atypical antipsychotics used in children were reviewed. The data was obtained mainly through Medline searches, identifying articles focusing on the use of atypical antipsychotics in children. Forty studies that addressed the issue of metabolic side effects were selected. The use of atypical antipsychotics in children has been consistently associated with weight gain and moderate prolactin elevation, while only a few case reports address the issue of glucose dysregulation and dyslipidaemia. The risk of weight gain and hyperprolactinaemia might be higher in younger children. Other risk factors have also been associated with antipsychotic-induced metabolic disturbances. These changes seem to be reversible, at least in some cases. Metabolic side effects of atypical antipsychotics could lead to serious complications in children who are prescribed these medications. Serious considerations should be given before initiating treatment and consistent clinical monitoring is essential. More research is needed, especially regarding glucose dysregulation and dyslipidaemia.  相似文献   
7.
世界卫生组织估计,全球每年5700万例死亡中有25%是由微生物引起。研究报道有1415种传染性生物可使人类致病。种间传染病占所有已知传染性疾病的61%,但人类作为初始病原者仅占3%。在175个被认为是新的传染性生物中,有75%可致人畜共染。尽管不同物种间病因和治疗方法相似,但种间传染病及其对人类和动物健康的影响并未以整合的方式监测、预防和治疗。种间传染病中,一个药物的有效性和耐药在同一种系的不同物种间彼此相似。因此,在同一自然环境下包含多个物种的随机对照试验有效、可靠,并可减少所需志愿者的人数。"同一个健康"基于系统方法和多学科的共同努力,地方、国家和全球协作,以达到人、动物和环境的最佳健康状态。系统评价和Meta分析迄今一直是独立和学科导向的。必须搜集种间传染病的诊断准确性和(药物)治疗有效性的(研究)结果,因为临床前实验结果来自于实验动物。Cochrane协作网是建立种间传染病系统评价小组平台的选择之一,通过无偏倚的诊断实验和药物效能(结果)的Meta分析以支撑系统方法与同一个健康(理念)。  相似文献   
8.
Our previous studies showed, that the,TPQRGDVYT, QRGDVYT and RGDVYT fragments, located in the beta164-172 loop of HLA-DQ, strongly suppress the humoral and cellular immune response, while their shorter analogs, RGDV, RGDVY, and QRGDVY, show only weak stimulatory activity in respect to humoral immunological response. The fragments contain the RGDVY sequence that is analogous to thymopentin (pentapeptide RKDVY, an immune system activator) as well as the RGD sequence, known for its importance for cellular association phenomena. Based on the crystal structure of HLA-DR1, we also designed and synthesized a cyclic analog C*RGDVYC* (where C* indicates Cys participating in disulfide bridge) with restricted conformation, which strongly suppresses both humoral and cellular immune response. In the present study we synthesized and tested the immunological properties of the linear and cyclic HLA-DP and HLA-DR counterparts of all the above HLA-DQ fragments. Although the results show that the linear HLA-DP fragments possess moderate immunosuppressory potency, their conformationally restricted analog, C*QGDVYC*C shows a considerable suppression of both humoral and cellular immune response. The nonapeptide fragment of HLA-DR, VPRSGEVYT and particularly its cyclic analog C*SGEVYC*, are strong suppressors of the humoral response.  相似文献   
9.
The receptor-mediated axonal transport of [125I]-labeled neurotrophins by afferent and efferent neurons of the vagus nerve was determined to predict the responsiveness of these neurons to neurotrophins in vivo. [125I]-labeled neurotrophins were administered to the proximal stump of the transected cervical vagus nerve of adult rats. Vagal afferent neurons retrogradely transported [125I]neurotrophin-3 (NT-3), [125I]nerve growth factor (NGF), and [125I]neurotrophin-4 (NT-4) to perikarya in the ipsilateral nodose ganglion, and transganglionically transported [125I]NT-3, [125I]NGF, and [125I]NT-4 to the central terminal field, the nucleus tractus solitarius (NTS). Vagal afferent neurons showed minimal accumulation of [125I]brain-derived neurotrophic factor (BDNF). In contrast, efferent (parasympathetic and motor) neurons located in the dorsal motor nucleus of the vagus and nucleus ambiguus retrogradely transported [125I]BDNF, [125I]NT-3, and [125I]NT-4, but not [125I]NGF. The receptor specificity of neurotrophin transport was examined by applying [125I]-labeled neurotrophins with an excess of unlabeled neurotrophins. The retrograde transport of [125I]NT-3 to the nodose ganglion was reduced by NT-3 and by NGF, and the transport of [125I]NGF was reduced only by NGF, whereas the transport of [125I]NT-4 was significantly reduced by each of the neurotrophins. The competition profiles for the transport of NT-3 and NGF are consistent with the presence of TrkA and TrkC and the absence of TrkB in the nodose ganglion, whereas the profile for NT-4 suggests a p75 receptor-mediated transport mechanism. The transport profiles of neurotrophins by efferent vagal neurons in the dorsal motor nucleus of the vagus and nucleus ambiguus are consistent with the presence of TrkB and TrkC, but not TrkA, in these nuclei. These observations describe the unique receptor-mediated axonal transport of neurotrophins in adult vagal afferent and efferent neurons and thus serve as a template to discern the role of specific neurotrophins in the functions of these visceral sensory and motor neurons in vivo. J. Comp. Neurol. 393:102–117, 1998. Published 1998 Wiley-Liss, Inc.
  • 1 This article is a US government work and, as such, is in the public domain in the United States of America.
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