首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   506篇
  免费   60篇
耳鼻咽喉   18篇
儿科学   9篇
妇产科学   21篇
基础医学   70篇
口腔科学   14篇
临床医学   96篇
内科学   70篇
皮肤病学   3篇
神经病学   26篇
特种医学   9篇
外科学   53篇
综合类   11篇
一般理论   2篇
预防医学   55篇
眼科学   7篇
药学   70篇
肿瘤学   32篇
  2021年   6篇
  2019年   5篇
  2018年   7篇
  2015年   8篇
  2014年   7篇
  2013年   14篇
  2012年   19篇
  2011年   24篇
  2010年   9篇
  2009年   9篇
  2008年   15篇
  2007年   28篇
  2006年   11篇
  2005年   16篇
  2004年   8篇
  2003年   13篇
  2002年   10篇
  2001年   8篇
  2000年   10篇
  1999年   13篇
  1998年   8篇
  1994年   10篇
  1993年   4篇
  1992年   19篇
  1991年   14篇
  1990年   25篇
  1989年   9篇
  1988年   27篇
  1987年   7篇
  1986年   10篇
  1985年   16篇
  1984年   14篇
  1983年   12篇
  1982年   11篇
  1981年   5篇
  1980年   6篇
  1979年   10篇
  1978年   6篇
  1977年   4篇
  1976年   4篇
  1975年   6篇
  1974年   8篇
  1973年   6篇
  1972年   9篇
  1970年   5篇
  1969年   12篇
  1968年   7篇
  1967年   7篇
  1966年   16篇
  1964年   4篇
排序方式: 共有566条查询结果,搜索用时 9 毫秒
1.
PURPOSE: To discuss injury research as a phenomenon of concern in nursing science. ORGANIZING CONSTRUCT: Injury is defined as the physical damage that results when the human body is briefly subjected to intolerable levels of energy. It is the leading cause of death in the first 4 decades of life in high-income nations and is second only to infectious diseases as a leading cause of death in low- and middle-income nations. METHODS: Review and discussion of relevant scientific and theoretical literature in both injury and nursing science. FINDINGS: Nurse scientists can apply unique perspectives to increase understanding of injury and its consequences. Fertile areas for nursing inquiry include identifying people at risk, developing models to explain the association between risk-taking and injury, testing interventions to prevent and limit injury, and creating and refining interventions that are culturally relevant to subpopulations most at risk for injury. CONCLUSIONS: The mandate to improve global heath should lead to nursing inquiry about this phenomenon, including developing and testing interventions to prevent and reduce injury.  相似文献   
2.

Background  

Lag screw cut-out failure following fixation of unstable intertrochanteric fractures in osteoporotic bone remains an unsolved challenge. This study tested if resistance to cut-out failure can be improved by using a dual lag screw implant in place of a single lag screw implant. Migration behavior and cut-out resistance of a single and a dual lag screw implant were comparatively evaluated in surrogate specimens using an established laboratory model of hip screw cut-out failure.  相似文献   
3.
One of the first to permit multiple diagnoses, this new TMD classification scheme offers guidelines for clinicians and those conducting clinical field studies. The scheme was applied to a TMD population, with control subjects.  相似文献   
4.
Extracellular pH may affect the sensitivity of cancer cells to chemotherapy agents. In an attempt to maximize the conditions for chemotherapy treatment of transitional cell carcinoma we tested the effect of pH on sensitivity of MGH-U3 transitional cell carcinoma cell line to thiotepa, doxorubicin, and mitomycin c in vitro. The toxicity of each agent tested varied with pH. There was no variation in cell growth in response to pH alone. The cytotoxic activity of thiotepa was markedly enhanced when cells were treated with a diluent pH of 5.5. Significant differences were also observed after treatment with doxorubicin and mitomycin c with a diluent pH of 7.0. This in vitro assay may be useful for clinical application of pH modulation during intravesical chemotherapy.  相似文献   
5.
Kidney and pancreas transplantation in 2005 improved in quantity and outcome quality, despite the increasing average age of kidney graft recipients, with 56% aged 50 or older. Geography and ABO blood type contribute to the discrepancy in waiting time among the deceased donor (DD) candidates. Allocation policy changes are decreasing the median times to transplant for pediatric recipients. Overall, 6% more DD kidney transplants were performed in 2005 with slight increases in standard criteria donors (SCD) and expanded criteria donors (ECD). The largest increase (39%) was in donation after cardiac death (DCD) from non‐ECD donors. These DCD, non‐ECD kidneys had equivalent outcomes to SCD kidneys. 1‐, 3‐ and 5‐year unadjusted graft survival was 91%, 80% and 70% for non‐ECD‐DD transplants, 82%, 68% and 53% for ECD‐DD grafts, and 95%, 88% and 80% for living donor kidney transplants. In 2005, 27% of patients were discharged without steroids compared to 3% in 1999. Acute rejection decreased to 11% in 2004. There was a slight increase in the number of simultaneous pancreas‐kidney transplants (895), with fewer pancreas after kidney transplants (343 from 419 in 2004), and a stable number of pancreas alone transplants (129). Pancreas underutilization appears to be an ongoing issue.  相似文献   
6.
It has been hypothesized that the negative symptoms of schizophrenia are related to structural brain abnormalities and respond poorly to treatment with neuroleptics and other drugs since they are persistent, if not irreversible. Because this issue has important clinical and theoretical implications, the authors reviewed the relevant literature on the effect of neuroleptics, L-dopa, and other psychotropic agents on these symptoms. Contrary to the above conclusions, several large scale, controlled studies of the therapeutic effects of conventional neuroleptics have reported clinically relevant improvement in negative symptoms in a significant proportion of schizophrenics. The improvement tended to occur early in the course of treatment and was most notable in those patients with relatively shorter durations of illness. A specific class of neuroleptic drugs not studied in these earlier large scale trials, the diphenylbutylpiperidines, has been suggested to be particularly likely to ameliorate negative symptoms, possibly because of their significant calcium channel blocking action. A review of the clinical studies comparing this group of neuroleptics with those from different classes supports the suggestion that they can produce greater improvement in anergia and emotional withdrawal. Six open and four controlled trials of L-dopa treatment of negative symptoms with L-dopa alone or in combination with neuroleptics. As with neuroleptics alone, improvement tended to be greater in those with a shorter duration of illness. The available evidence suggests that negative symptoms, at least in less chronic schizophrenic patients, may be partially responsive to currently available pharmacological intervention in a significant proportion of schizophrenics.  相似文献   
7.
This study investigated central anticholinergic drug effects on: (1) the Randt Memory Test, a relatively new instrument which measures the acquisition and recall of verbal and pictorial information; (2) the averaged photopalpebral reflex (PPR), an electrophysiological parameter, the validity of which needs to be further investigated in pharmacological research and; (3) mood as measured by a 16-item visual analogue scale. Atropine (1 mg and 2 mg), pirenzepine (20 mg) and a placebo were administered intramuscularly in a double-blind cross-over trial in eight healthy volunteers. There were no inter-treatment differences on the Randt Memory Test. This finding is seemingly in contrast to those reported by some authors using other memory tests. In contrast to the reported effects of some benzodiazepines, the anticholinergics used in the present study did not prolong the latencies of the PPR, but reduced the amplitudes. Visual analogue scales indicated central effects for both pirenzepine and atropine. This implies pirenzepine's penetration of the blood-brain barrier and a physiological function for central muscarinic-1-receptors. The significant anticholinergic effects were exclusive to the "alertness" factor.  相似文献   
8.
Expression of the intermediate filament protein vimentin, and loss of the cellular adhesion protein uvomorulin (E-cadherin) have been associated with increased invasiveness of established human breast cancer cell linesin vitro andin vivo. In the current study, we have further examined these relationships in oncogenically transformed human mammary epithelial cells. A normal human mammary epithelial strain, termed 184, was previously immortalized with benzo[a]pyrene, and two distinct sublines were derived (A1N4 and 184B5). These sublines were infected with retroviral vectors containing a single or two oncogenes of the nuclear, cytoplasmic, and plasma membrane-associated type (v-ras H, v-ras Ki, v -mos, SV40T and c -myc). All infectants have been previously shown to exhibit some aspects of phenotypic transformation. In the current study, cellular invasiveness was determinedin vitro using Matrigel, a reconstituted basement membrane extract. Lineage-specific differences were observed with respect to low constitutive invasiveness and invasive changes after infection withras, despite similarras-induced transformation of each line. Major effects on cellular invasiveness were observed after infection of the cells with two different oncogenes (v-ras H + SV40T and v -ras H + v -mos). In contrast, the effects of single oncogenes were only modest or negligible. All oncogenic infectants demonstrated increased attachment to laminin, but altered secretion of the 72 kDa and 92 kDa gelatinases was not associated with any aspect of malignant progression. Each of the two highly invasive double oncogene transformants were vimentinpositive and uvomorulin-negative, a phenotype indicative of the epithelial-mesenchymal transition (EMT) previously associated with invasiveness of established human breast cancer cell lines. Weakly invasive untransformed mammary epithelial cells in this study were positive for both vimentin and uvomorulin, suggesting that uvomorulin may over-ride the otherwise vimentin-associated invasiveness.  相似文献   
9.
Diverting the fecal stream has been considered to benefit the course of Crohn's disease. Clinical signs and symptoms have not, however, been distinguished previously from the objective inflammatory changes in the distal segment. We reviewed the course of 16 consecutive patients with Crohn's disease in whom sigmoidoscopy showed normal mucosa at the time of diversion and who underwent an ileostomy or colostomy, the rectal segment being left in place. As early as 3 months after diversion, all 16 patients showed progressive friability, ulceration, and exudation in the retained rectum. Stricture occurred in four and lead to abdominoperineal resection in three. Four of eight patients with only moderate inflammation on sigmoidoscopy underwent reanastomosis which was followed by a return to a normal-appearing rectal mucosa. The rectal segment inflammed after diversion rarely shows the histological characteristics of Crohn's disease when resected. This leads us to suspect that the disorder of nonspecific "diversion colitis" might account for this phenomenon entirely, or at least it may accelerate the Crohn's disease process. Continuity of the intestinal tract should be maintained in the course of Crohn's disease surgery if feasible. If a diversion is clinically warranted, reanastomosis should be considered as early as possible despite progressive inflammation of the rectal mucosa.  相似文献   
10.
A comprehensive perspective is essential to properly manage medical services for patients with multiple needs. For optimum care, all service aspects must be coordinated and a program format developed to meet individually identified needs. The Gundersen Clinic in LaCrosse, Wisconsin, has designed and implemented comprehensive care programs for two very different patient populations: children with special health and education problems, and the elderly. Many important aspects of a comprehensive care program are examined here, including ease of accessibility and follow-through, cost consciousness, staffing and space considerations, the administrative structure, marketing techniques, and evaluation procedures.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号