全文获取类型
收费全文 | 453篇 |
免费 | 23篇 |
国内免费 | 22篇 |
专业分类
儿科学 | 34篇 |
妇产科学 | 3篇 |
基础医学 | 45篇 |
口腔科学 | 7篇 |
临床医学 | 65篇 |
内科学 | 78篇 |
皮肤病学 | 1篇 |
神经病学 | 7篇 |
特种医学 | 169篇 |
外科学 | 16篇 |
综合类 | 11篇 |
预防医学 | 15篇 |
眼科学 | 4篇 |
药学 | 29篇 |
肿瘤学 | 14篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 6篇 |
2014年 | 9篇 |
2013年 | 15篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2010年 | 11篇 |
2009年 | 8篇 |
2008年 | 2篇 |
2007年 | 14篇 |
2006年 | 4篇 |
2005年 | 11篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 6篇 |
1998年 | 30篇 |
1997年 | 27篇 |
1996年 | 39篇 |
1995年 | 22篇 |
1994年 | 18篇 |
1993年 | 26篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 13篇 |
1989年 | 22篇 |
1988年 | 24篇 |
1987年 | 25篇 |
1986年 | 10篇 |
1985年 | 17篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 20篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 9篇 |
1976年 | 18篇 |
1975年 | 7篇 |
排序方式: 共有498条查询结果,搜索用时 15 毫秒
411.
SB van der Meer PP Forget RH Kuijten JW Arends 《Acta paediatrica (Oslo, Norway : 1992)》1992,81(2):137-140
In this study we investigated the presence of gastroesophageal reflux in children with recurrent abdominal pain and its possible relationship to food intolerance-associated duodenal inflammation. Twenty-four-hour intra-esophageal pH monitoring, an endoscopic duodenal biopsy and a small bowel 51Cr-EDTA permeability test were performed in 25 children with recurrent abdominal pain. In 14 cases (56%) the pH monitoring was abnormal, pointing to the presence of pathological gastroesophageal reflux. Treatment of gastroesophageal reflux in the latter patients resulted in resolution or improvement of abdominal pain in 10 cases (71%). Gastroesophageal reflux did not appear to be associated with either intestinal permeability to 51Cr-EDTA or duodenal biopsy findings. We conclude that pathological gastroesophageal reflex is a frequent finding in children with recurrent abdominal pain, that it is unrelated to duodenal inflammation and that there might be a causal relationship between pathological gastroesophageal reflux and recurrent abdominal pain in children. 相似文献
412.
S Bailey R Skinner HH Lucraft RH Perry N Todd AD Pearson 《Archives of disease in childhood》1996,75(3):181-185
The records of 38 patients under 25 years of age presenting with pineal tumours between 1968 and 1993, identified from the Northern Region Children's and Young Adults' Malignant Disease Registry, were analysed retrospectively with regards to clinical presentation, diagnostic approach, treatment strategy, and outcome. The overall five year survival was 45%. Fifteen patients had a histological diagnosis: six with germinomas, three with teratomas, three with astrocytomas, and three with pinealoblastomas. One patient had a definitive diagnosis of teratoma made on the basis of raised tumour markers (alpha fetoprotein). Treatment consisted of surgery (87%) (ventriculoperitoneal or atrial shunt and/or biopsy), and/or radiotherapy (82%), and/or chemotherapy (26%). Those patients with a tissue diagnosis appeared to have a more favourable outcome, especially after 1976 when treatment was determined by tumour type (five year survival for those with a tissue diagnosis was 91% v 51% for those without, 95% confidence intervals 74 to 100% and 26 to 75%). This study suggests that tissue diagnosis allows more appropriate treatment to be delivered for children with pineal tumours resulting in improved survival. Referral to a centre with neurosurgery, radiotherapy, neuropathology, and paediatric oncology collaboration is essential. 相似文献
413.
Influence of HLA-A2 on the effectiveness of platelet transfusions in alloimmunized thrombocytopenic patients 总被引:1,自引:0,他引:1
Platelet transfusions from donors selectively mismatched for cross- reactive and certain non-cross-reactive HLA antigens were found to be more effective in HLA-A2 negative than in HLA-A2 positive, alloimmunized thrombocytopenic patients. The two groups of patients responded equally well to platelets matched for antigens of the HLA-A and B loci. Certain alloimmunized patients negative for HLA-A2 continued to respond satisfactorily to platelets selectively mismatched for non-cross-reactive HLA antigens as long as platelets containing HLA- A2 were avoided. The data indicate that platelet transfusion support can be provided within a broader range of donor-recipient HLA antigenic disparity to HLA-A2 negative alloimmunized patients than to those who are positive for this antigen. 相似文献
414.
海南粗榧新碱衍生物HH07A的抗肿瘤作用 总被引:3,自引:0,他引:3
用细胞生长曲线测定法及软琼脂集落形成分析法研究了HH07A对几种肿瘤及正常细胞生长的影响。结果表明,1.5ug·ml-1及3μg·ml-1HH07A能分别明显抑制L1210和HL-60细胞的生长。3种肿瘤细胞对HH07A的敏感性依次为L1210>KB>HL-60,而正常小鼠粒系祖细胞GM-CPC对药物的敏感性则低于前三者,且HH07A3.5μg·ml-1对HL-60细胞无分化诱导作用。HH07A对腹水型L1210白血病小鼠、S180小鼠均有较明显的治疗作用,使L1210荷瘤小鼠、S180荷瘤小鼠存活时间延长。也能抑制S180实体瘤的生长。 相似文献
415.
Inflatable artificial urinary sphincters provide excellent voluntary continence. Eighty-four consecutive patients underwent implantation of artificial urinary sphincters for intractable urinary incontinence; 33 patients had 58 episodes of sphincter malfunction, and eight patients had eight complications involving a functional prosthetic sphincter. Retrospective analysis was performed to determine the value of plain radiography of the pelvis in patients with sphincter malfunction or complication. The cause of malfunction in the majority of patients was a system leak and subsequent loss of hydraulic fluid (31 occurrences; 53%). Plain radiography permitted correct identification of all instances of fluid leakage in patients with opacified prostheses. Plain radiographs were of no value in examining patients with nonopacified prostheses or the complications of cuff erosion or wound infection. Due to the low cost and noninvasive nature of plain radiography of the pelvis, we conclude that it should be used as the initial diagnostic modality in patients with previously opacified but currently dysfunctional artificial urinary sphincters. 相似文献
416.
417.
White American, Hispanic, and African American women were surveyed in public health and low‐income clinics in Los Angeles, California, and Seattle, Washington, to determine if they delayed seeking prenatal care because of battering during their pregnancies. Nursing staff in the clinics attempted to enroll in the study all pregnant women from these groups who presented themselves for care; no other criteria were used, other than the ability to read either English or Spanish. Results were obtained from 162 White Americans, 208 Hispanics, and 132 African Americans. Although the incidence of abuse was not significantly different among the ethnic groups, battered women sought prenatal care 6.5 weeks later than the nonabused sample, with a similar delay in each ethnic group. Twenty‐one percent of the women reported physical harm during the pregnancy, and 13.7% stated that they had delayed care because of injuries. 相似文献
418.
419.
Immune response gene function correlates with the expression of an Ia antigen. II. A quantitative deficiency in A(e):E(a), complex expression causes a corresponding defect in antigen-presenting cell function 下载免费PDF全文
LA Matis PP Jones DB Murphy SM Hedrick EA Lerner CA Janeway JM McNicholas RH Schwartz 《The Journal of experimental medicine》1982,155(2):508-523
A series of experiments were performed to explore the role of complementing major histocompatability complex (MHC)-linked immune response Ir genes in the murine T cell proliferative response to the globular protein antigen pigeon cytochrome c. The functional equivalence of I-E-subregion-encoded, structurally homologous E(a) chains from different haplotypes bearing the serologic specificity Ia.7 was demonstrated by the complementation for high responsiveness to pigeon cytochrome c of F(1) hybrids between low responder B 10.A(4R) (I-A (k)) or B 10.S (I-A(8)) mice and four low responder E(a)- bearing haplotypes. Moreover, this Ir gene function correlated directly with both the ability of antigen-pulsed spleen cells from these same F(1) strains to stimulate pigeon cytochrome c-primed T cells from B10.A or B10.S(9R) mice, and with the cell surface expression of the two-chain Ia antigenic complex, A(e):E(a), bearing the conformational or combinatorial determinant recognized by the monoclonal anti-Ia antibody, Y-17. The B 10.PL strain (H-2(u)), which expresses an Ia.7-positive I-E- subregion-encoded E(a) chain, failed to complement with B10.A(4R) or B10.S mice in the response to pigeon cytochrome c. However, (B10.A(4R) × B10.PL)F(1) and (B10.S × B10.PL)F(1) mice do express A(k)(e):E(u)(a) and A(8)(e):E(u)(a) on their cell surface, although in reduced amounts relative to A(k,s)(e):E(k,d,p,r)(a) complexes found in corresponding F(1) strains. This quantitative difference in Ia antigen expression correlated with a difference in the ability to present pigeon cytochrome c to B 10.A and B 10.S(9R) long-term T cell lines. Thus, (B10.A(4R) × B10.PL)F(1) spleen cells required a 10-fold higher antigen dose to induce the same stimulation as (B10.A(4R) × B10.D2)F(1) spleen cells. In addition, the monoclonal antibody, Y-17, which reacts with A(e):E(a) molecules of several strains, had a greater inhibitory effect on the proliferative response to pigeon cytochrome c of B10.A T cells in the presence of (B10.A(4R) X B10.PL)F(1) spleen cells than in the presence of (B10.A(4R) X B10.D2)F(1) spleen cells. These functional data, in concert with the biochemical and serological data in the accompanying report, are consistent with the molecular model for Ir gene complementation in which appropriate two-chain Ia molecules function at the antigen-presenting cell (APC) surface as restriction elements. Moreover, they clearly demonstrate that the magnitude of the T cell proliferative response is a function of both the concentration of nominal antigen and of the amount of Ia antigen expressed on the APC. Finally, the direct correlation of a quantitative deficiency in cell surface expression of an Ia antigen with a corresponding relative defect in antigen-presenting function provides strong independent evidence that the I-region-encoded Ia antigens are the products of the MHC-linked Ir genes. 相似文献
420.
ES Perry ; RH Moore ; TA Berger ; LC Billups ; DA Maybee ; KF Salata ; LE Lippert 《Transfusion》1996,36(4):318-321
BACKGROUND: Reticulocytes are important in the phenotyping of transfused patients. Reticulocytes can persist in blood units for the shelf life of the unit. STUDY DESIGN AND METHODS: Temperature dependence of reticulocyte persistence was examined in vitro at 4, 24, and 37 degrees C by using thiazole orange staining and flow cytometric analysis. Two-color flow cytometric analysis was used to evaluate the persistence of donor reticulocytes in transfused patients. RESULTS: Flow cytometric analysis using thiazole orange demonstrated that persistence of reticulocytes in units of stored CPDA-1 blood was temperature-dependent. Reticulocytes disappeared over 13 and 6 days at 24 degrees C and 37 degrees C, respectively, but at 4 degrees C the reticulocyte count changed little over 35 days. Two-color flow cytometric analysis of reticulocyte antigens was used to follow donor reticulocytes in 14 transfusion events in nine different patients. Donor reticulocytes persisted through 24 hours in 75 percent of the patients and were detectable at 48 hours in three patients. CONCLUSION: This study demonstrates that reticulocytes persist during refrigerated storage; they are detectable in the circulation of most recipients for the first 24 hours after transfusion and in the circulation of a few recipients after 48 hours. These findings may have relevance for separation techniques based on reticulocyte density in samples drawn shortly after transfusion and for evaluation of reticulocyte counts in patients with hematologic abnormalities. 相似文献