全文获取类型
收费全文 | 1009篇 |
免费 | 105篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 36篇 |
妇产科学 | 22篇 |
基础医学 | 133篇 |
口腔科学 | 65篇 |
临床医学 | 115篇 |
内科学 | 236篇 |
皮肤病学 | 16篇 |
神经病学 | 75篇 |
特种医学 | 90篇 |
外科学 | 97篇 |
综合类 | 34篇 |
一般理论 | 1篇 |
预防医学 | 83篇 |
眼科学 | 34篇 |
药学 | 33篇 |
中国医学 | 1篇 |
肿瘤学 | 43篇 |
出版年
2023年 | 7篇 |
2022年 | 7篇 |
2021年 | 8篇 |
2020年 | 12篇 |
2019年 | 20篇 |
2018年 | 26篇 |
2017年 | 9篇 |
2016年 | 17篇 |
2015年 | 19篇 |
2014年 | 23篇 |
2013年 | 37篇 |
2012年 | 33篇 |
2011年 | 32篇 |
2010年 | 38篇 |
2009年 | 29篇 |
2008年 | 35篇 |
2007年 | 36篇 |
2006年 | 36篇 |
2005年 | 43篇 |
2004年 | 32篇 |
2003年 | 26篇 |
2002年 | 23篇 |
2001年 | 29篇 |
2000年 | 29篇 |
1999年 | 37篇 |
1998年 | 30篇 |
1997年 | 30篇 |
1996年 | 27篇 |
1995年 | 17篇 |
1994年 | 17篇 |
1993年 | 15篇 |
1992年 | 15篇 |
1991年 | 11篇 |
1990年 | 26篇 |
1989年 | 23篇 |
1988年 | 15篇 |
1987年 | 14篇 |
1986年 | 26篇 |
1985年 | 16篇 |
1984年 | 23篇 |
1983年 | 27篇 |
1982年 | 19篇 |
1981年 | 17篇 |
1980年 | 12篇 |
1979年 | 10篇 |
1978年 | 7篇 |
1977年 | 11篇 |
1975年 | 9篇 |
1973年 | 6篇 |
1972年 | 6篇 |
排序方式: 共有1117条查询结果,搜索用时 15 毫秒
81.
AIM: To describe the health of farmers in Southland. METHODS: Coss-sectional study of a random sample of farmers in Southland. RESULTS: 586 individuals were interviewed from 286 farms with a response rate of 65.4%. The prevalence of at least one injury in the last twelve months which prevented normal farm work was 17.1%. Low back pain was common with 54.6% reporting such an episode in the last twelve months. Noise-induced hearing loss was prevalent among men with 28.7% of those 45 years and over being affected. Levels of asthma appeared low with a point prevalence of 6.8%, with 4.6% on medication.There were 19.3% of male farmers who were obese. The prevalence of alcohol use disorder among men aged 15-24 years was 57.4%, and 39.0% among farm workers. Similarly, 32.0% of men in this age-group smoked, with 35.6% of farm workers being smokers. CONCLUSIONS: Farmers experienced high levels of injury, low back pain and noise-induced hearing loss. Community intervention programmes to prevent injury remain a priority for farmers, although lifestyle factors should also be addressed, particularly among farm workers. 相似文献
82.
83.
Familial hypercholesterolaemia (FH), an autosomal dominantly inherited disorder characterised by elevated plasma low-density lipoprotein (LDL) cholesterol levels, tendon xanthomata and premature ischaemic heart disease, is amenable to treatment with modern medication. The clinical and biochemical details of 1 031 patients with FH were analysed. FH is the most common monogenic disorder of lipoprotein metabolism presenting to the Lipid Clinic at Groote Schuur Hospital, accounting for about 20% of consultations. The hospital classified 55% of the FH patients as white, 43% as coloured, 1.5% as Asian and 0.5% as black. In the FH cohort (whose mean age at presentation was 44 years), 80% had tendon xanthomata, 36% had arcus cornealis, and 14% had xanthelasma. Tendon xanthomata was present in almost 90% of patients by the age of 50 years. Arcus cornealis was present in about 45% by the age of 40 years, further increasing in frequency with age. Cardiovascular complications included ischaemic heart disease (43%), stroke (1.5%), transient ischaemic attacks (1.3%), and peripheral vascular disease (3.7%). The mean age of death was 55 (+/-13) years; 51 ( +/-10) years in men and 61 ( +/-12) years in women. In 46% of the cohort, a defective gene was identified by testing for locally prevalent mutations. 相似文献
84.
R S Knight A R Fielder J L Firth 《Journal of neurology, neurosurgery, and psychiatry》1986,49(3):243-250
Five patients with serious ocular complications of benign intracranial hypertension are described. Optic nerve sheath fenestration resulted in resolution of papilloedema with, in three instances, improvement in vision. Benign intracranial hypertension may not always be benign for vision and fenestration operations may prevent or reverse visual deterioration by an effect on the optic nerve rather than by reducing intra-cranial pressure. 相似文献
85.
86.
Risk management requires detailed understanding of circumstances affecting risk. Management of multiple risks necessitates different strategies to minimise different risks. Multi-agency work requires presentation in accessible formats. Limitations of existing procedures are discussed. The Concise Risk Assessment Format summarises key information, differentiating history, risk and protective circumstances , and management recommendations/requirements for a number of either disparate or related types of risk. Standardised risk assessment information can be incorporated. The Format allows information to be readily contributed, shared, and updated between parents, young people and multiple agencies. 相似文献
87.
Mixed lymphocyte reactivity and cell-mediated lympholysis to trinitrophenyl-modified autologous lymphocytes in C57BL/10 congenic and B10.A recombinant mouse strains 下载免费PDF全文
GM Shearer EC Lozner TG Rehn A Schmitt-Verhulst 《The Journal of experimental medicine》1975,141(4):930-934
Cell-mediated lympholysis (CML) to trinitrophenyl (TNP)-modified autologous splenic lymphocytes has been recently reported in the mouse (1). Both the sensitization and effector phases of this phenomenon were shown to be T-cell mediated. Effector cell specificity studies indicated that modification of the target cells is a necessary but insufficient requirement for cytolysis, and suggested that altered cell surface components controlled by genes mapping in the mouse major histocompatibility H-2 complex (MHC) are important in the specificity of the cytotoxic reaction (1). In allogeneic models the generation of cytotoxic effector cells has been shown to be preceded or accompanied by immunogen- induced proliferation of responding lymphocytes, i.e. a mixed lymphocyte reaction (MLR) (2-5), although the generation of effectors may not necessarily always be the consequence of extensive cell proliferation (5). If the induction of cytotoxic effector lymphocytes by modified syngeneic spleen cells is characteristic of sensitization with cellular alloantigens, one would expect to find that sensitization with TNP-modified autologous cells would also induce thymidine incorporation by the responding cells in the culture. The present report demonstrates that both stimulation of thymidine incorporation and generation of cytotoxic effector cells are part of the in vitro response to TNP-modified autologous lymphocytes. However, the MLR to TNP- modified autologous cells consistently appeared to be less pronounced when compared with an allogeneic MLR, whereas the cytotoxic activity of the effector cells generated by sensitization against TNP-modified autologous cells was frequently as high as that detected against H-2 alloantigens. These two components of reactivity to “modified self” are verified in several C57BL/10 congenic and B10.A recombinant mouse strains. 相似文献
88.
89.
JB Gorlin ; EC Vamvakas ; E Cooke ; D Galacki ; R Geha ; D Humphreys ; P Kent 《Transfusion》1996,36(10):879-885
Background: Recruitment of progenitors during a large-volume collection, as defined by increasing relative and absolute numbers of progenitors (colony-forming units-granulocyte-macrophage [CFU-GM] of CD34+ cells), has been reported previously. Study Design and Methods: To ascertain whether intra-apheresis recruitment occurs in pediatric patients who have undergone mobilization with chemotherapy and granulocyte-colony-stimulating factor (G-CSF), each hour's portion of a 4-hour leukapheresis was collected into separate bags, and assessed by complete blood count, CFU-GM, and CD34+ cell assays. Seven pediatric patients (median age, 7; range, 2–19) were studied in connection with 2 to 4 collections each, for a total of 21 collections (with hourly samples). The collections lasted for 4 hours, at an inlet rate of 1 to 3 mL per kg per minute, for daily processing totals of 5 to 12 blood volumes. (One blood volume [mL] is estimated by the patient's weight in kg × 70 mL/kg.) Smaller (younger) patients had inlet rates exceeding 2 mL per kg per minute, and larger (older) patients had rates of 1 to 1.5 mL per kg per minute. CFU-GM and CD34+ cell counts obtained each hour of the collection and divided by the first hour's value were compared by nonparametric repeated-measures ANOVA. Results: Second-, third- and fourth-hour CD34+ progenitor cell counts were arithmetically higher than first-hour counts, but the trend did not reach significance (p = 0.1561). Second-hour counts were higher than first-hour counts in the overall analysis (mean ± standard error [SE], 1.00 and 1.39 ± 0.1, respectively; p = 0.0525) and in children older than 5 years (1.00 vs. 1.70 ± 0.30, respectively; p = 0.0259), but not in children younger than 5 years (p = 0.8125). CFU-GM counts did not differ among the 4 hours of collection (p = 0.1717) or between the first and second hour (p = 0.9587). Conclusion: In larger (older) patients, from whom fewer blood volumes were collected, there is a trend toward intra-apheresis recruitment, although less than reported previously. In the smaller (younger) patients, from whom more blood volumes were collected, no trend was observed. Lack of (or submaximal) prior mobilization in previously reported studies may have facilitated intracollection recruitment. Alternatively, the larger number of blood volumes collected from the smaller (younger) patients may have masked intra-apheresis recruitment. The study documents the feasibility of large-volume, 4-hour leukapheresis in pediatric patients. 相似文献
90.
A systematic comparison of feedback and staff discussion in changing the ward atmosphere 总被引:1,自引:0,他引:1
The efficacy of therapeutic programmes depends on several characteristics of the treatment environment. For this reason therapists are increasingly directing their efforts towards changing the social characteristics of treatment units. This study aimed to promote change in social climate by providing nursing staff with structured information about their unit. The 'real' and 'ideal' social climate of the unit was defined and assessed using the Ward Atmosphere Scale. All staff were asked to complete it during an assessment period. Feedback about their perception of the unit was provided to staff in two ways. One group of staff received written feedback only; a second group received in addition the opportunity to discuss the feedback and strategies for reducing the real-ideal discrepancies in four once-monthly meetings. The effect of the feedback on the social climate of the unit was ascertained by further assessment using the WAS and from interviews with all staff. The evaluation suggested that the feedback had contributed to changes in several procedures in the unit and to a reduction in the real-ideal discrepancies for the systems maintenance elements. The effect was greater for the group of staff who had the opportunity to discuss the feedback in a formal setting. 相似文献