全文获取类型
收费全文 | 1338篇 |
免费 | 80篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 71篇 |
妇产科学 | 30篇 |
基础医学 | 166篇 |
口腔科学 | 45篇 |
临床医学 | 102篇 |
内科学 | 297篇 |
皮肤病学 | 24篇 |
神经病学 | 35篇 |
特种医学 | 419篇 |
外科学 | 86篇 |
综合类 | 39篇 |
预防医学 | 23篇 |
眼科学 | 6篇 |
药学 | 40篇 |
1篇 | |
肿瘤学 | 30篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 9篇 |
2017年 | 14篇 |
2016年 | 10篇 |
2015年 | 13篇 |
2014年 | 30篇 |
2013年 | 32篇 |
2012年 | 15篇 |
2011年 | 20篇 |
2010年 | 34篇 |
2009年 | 51篇 |
2008年 | 21篇 |
2007年 | 37篇 |
2006年 | 29篇 |
2005年 | 26篇 |
2004年 | 17篇 |
2003年 | 20篇 |
2002年 | 10篇 |
2001年 | 21篇 |
2000年 | 10篇 |
1999年 | 17篇 |
1998年 | 78篇 |
1997年 | 80篇 |
1996年 | 80篇 |
1995年 | 64篇 |
1994年 | 42篇 |
1993年 | 59篇 |
1992年 | 7篇 |
1991年 | 12篇 |
1990年 | 25篇 |
1989年 | 54篇 |
1988年 | 42篇 |
1987年 | 47篇 |
1986年 | 52篇 |
1985年 | 68篇 |
1984年 | 35篇 |
1983年 | 29篇 |
1982年 | 29篇 |
1981年 | 31篇 |
1980年 | 37篇 |
1979年 | 5篇 |
1978年 | 18篇 |
1977年 | 23篇 |
1976年 | 21篇 |
1975年 | 20篇 |
1914年 | 1篇 |
排序方式: 共有1422条查询结果,搜索用时 15 毫秒
941.
DC Whitcomb RA Preston CE Aston MJ Sossenheimer PS Barua Y Zhang A Wong- Chong GJ White PG Wood LK Gates Jr C Ulrich SP Martin JC Post GD Ehrlich 《Gastroenterology》1996,110(6):1975-1980
BACKGROUND & AIMS: Hereditary pancreatitis (HP) is an autosomal- dominant disorder with incomplete penetrance characterized by recurrent bouts of severe epigastric pain with onset usually at 5-10 years of age. A genetic linkage study was designed to identify the HP gene. METHODS: A 500-member pedigree was constructed from a U.S. kindred centered in eastern Kentucky and western Virginia. A genome-wide search strategy was employed using a 36-member subset of this family to determine the genetic locus for HP. Testing for linkage to microsatellite loci was performed at 20-cM intervals. RESULTS: Linkage was established between the HP phenotype and chromosome 7q in this subset of the family. Modeled as an autosomal dominant disorder with 80% penetrance, a maximal multipoint logarithm of the odds score of 4.3 was obtained using a four-point analysis consisting of markers D7S684, D7S661, D7S505, and the HP locus. Two microsatellite markers, D7S661 and D7S505, that correspond to the 7q35 region of chromosome 7 spanning a 6-cM region did not evidence obligate recombinations with HP. The centromeric and telomeric limits are defined by recombinations at D7S684 and D7S483, respectively, which generates a 19-cM locus for HP. Utilizing family members from the extended pedigree, a break in the high-risk haplotype between D7S684 and D7S661 was observed, which suggests it may be possible to exclude an additional 8 cM from the HP locus. A maximal pairwise logarithm of the odds score of 4.73 at a recombination fraction of theta at D7S684 was obtained with the addition of these extended family members. CONCLUSIONS: Linkage of HP to 7q35 represents a major advancement in our understanding of the genetic basis of this disorder. (Gastroenterology 1996 Jun;110(6):1975-80) 相似文献
942.
Clift RA; Bianco JA; Appelbaum FR; Buckner CD; Singer JW; Bakke L; Bensinger WI; Bowden RA; McDonald GB; Schubert M 《Blood》1993,82(7):2025-2030
This study evaluated the effect of pentoxifylline (PTX) on the incidence of regimen-related toxicity in patients receiving allogeneic marrow transplants from related donors. All patients received a regimen of methotrexate and cyclosporine as prophylaxis against acute graft- versus-host disease (GVHD). Patients were randomized to receive PTX or a placebo for 70 days and the outcome was examined in a blinded fashion. Forty-four patients were evaluate in each study arm. PTX had no significant effect on engraftment, the incidence of GVHD, venocclusive disease of the liver, infection, the need for oxygen, posttransplant survival, or the duration of hospitalization. Patients receiving PTX were significantly more likely to develop major elevations of serum creatinine levels. PTX was poorly tolerated and induced significantly more vomiting than the placebo. PTX as administered in this randomized study was associated with significant toxicity and offered no benefit in reducing transplant-related morbidity or mortality. 相似文献
943.
We have previously demonstrated that interleukin-4 (IL-4) induces tyrosine phosphorylation of a protein closely related or identical to the c-fes proto-oncogene product (FES) and association of this protein with the IL-4 receptor alpha chain (IL-4R alpha). IL-4 is known to induce association of phosphatidylinositol-3 (PI3) kinase with the IL- 4R alpha. Since FES contains the consensus motifs for PI3 kinase binding, we tested the possibility that FES may associate with PI3 kinase upon IL-4 stimulation. We demonstrate herein that IL-4 stimulation induced rapid association of FES or a related protein with PI3 kinase in mouse T-cell lines. We also show an association of human FES (hFES) with the src homology 2 (SH2) domain of PI3 kinase in a COS7 cell expression system. The in vitro PI3 kinase assay using COS7 cells suggested that hFES partly contributes to the association between the hIL-4R alpha and PI3 kinase. We have further identified the important region in the cytoplasmic domain of the hIL-4R alpha for association of tyrosine-phosphorylated hFES with the hIL-4R alpha and SH2 domain of PI3 kinase using a COS7 cell expression system. These results suggest that FES or a related protein/PI3 kinase pathway may play a role in the pleiotropic effects of IL-4. 相似文献
944.
Nash RA; Etzioni R; Storb R; Furlong T; Gooley T; Anasetti C; Appelbaum FR; Doney K; Martin P; Slattery J 《Blood》1995,85(12):3746-3753
The pharmacokinetics, safety, and efficacy in marrow transplantation of FK506-based immunosuppression for graft-versus-host disease (GVHD) prophylaxis was evaluated in an open label pilot study of 18 patients. Patients more than 12 years of age (median, 35 years; range, 15 to 50 years) with advanced hematologic malignancies receiving HLA-matched sibling marrow grafts were randomized to receive FK506 alone, FK506 and methotrexate (MTX), or FK506 and methyl-prednisolone. Of 17 evaluable patients, all had evidence of sustained marrow engraftment. The median time to an absolute neutrophil count of greater than 500/microL was 15 days for patients receiving FK506 alone or FK506 plus methylprednisolone and 23 days for FK506 plus short MTX. Pharmacokinetic studies did not show any significant difference in clearance of FK506 when administered alone or in combination with methylprednisolone or MTX. The mean bioavailability after oral administration in these same three groups was 0.49 +/- 0.1, 0.27 +/- 0.12, and 0.16 +/- 0.08, respectively (P = .003). The decrease in bioavailability may have resulted from an exacerbation of radiation- induced gastroenteritis by MTX. The most significant adverse effect associated with the administration of FK506 was nephrotoxicity, which occurred in 14 of 18 patients (78%). The mean glomerular filtration rate, determined by clearance of (99MTc)DTPA, decreased to 56% (+/- 18%) of the pretransplant baseline level by week 8 (P = .002). Eight of 18 patients (44%) developed grades II-IV acute GVHD, predominantly of the skin and gastrointestinal tract. The actuarial probability of transplant-related mortality during the first 100 days was 24%. The actuarial probability of 1-year disease-free survival was 39%. In conclusion, although bioavailability of FK506 may be affected in patients receiving MTX, this study suggests that FK506 may have a role in the management of patients after allogeneic marrow transplantation. 相似文献
945.
Graft failure following bone marrow transplantation for severe aplastic anemia: risk factors and treatment results 总被引:5,自引:2,他引:5
Champlin RE; Horowitz MM; van Bekkum DW; Camitta BM; Elfenbein GE; Gale RP; Gluckman E; Good RA; Rimm AA; Rozman C 《Blood》1989,73(2):606-613
Graft failure was analyzed in 625 patients receiving allogeneic bone marrow transplants from HLA-identical sibling donors as treatment for severe aplastic anemia. Sixty-eight (11%) had no or only transient engraftment. Second bone marrow transplants were successful in achieving extended survival in 16 of 27 patients with transient initial engraftment but in none of ten patients with no sign of engraftment after the first transplant. The major factors associated with a reduced risk of graft failure were use of radiation for pretransplant immunosuppression and use of cyclosporine rather than methotrexate or T- cell depletion of the donor bone marrow for prophylaxis against graft-v- host disease (GVHD). Among 266 patients prepared for transplantation with cyclophosphamide alone, the risk of graft failure was increased in patients who received previous transfusions and reduced in those who received corticosteroids for previous therapy. Neither cell dose nor administration of donor buffy coat cells affected the probability of engraftment. Although use of radiation in conditioning reduced graft failure, survival was not improved. Posttransplant treatment with cyclosporine and avoidance of pretransplant blood transfusions were associated with improved survival. 相似文献
946.
Acute nonlymphocytic leukemia following etoposide and cisplatin combination chemotherapy for advanced non-small-cell carcinoma of the lung 总被引:1,自引:1,他引:1
Ratain MJ; Kaminer LS; Bitran JD; Larson RA; Le Beau MM; Skosey C; Purl S; Hoffman PC; Wade J; Vardiman JW 《Blood》1987,70(5):1412-1417
Combination chemotherapy is frequently used in the therapy of advanced non-small-cell lung cancer (NSCLC), but late complications are rarely recognized because of the short survival of most patients. Of 119 patients with advanced NSCLC treated with cisplatin and other drugs, four patients developed acute nonlymphocytic leukemia (ANLL). All four patients received etoposide and cisplatin with or without vindesine. Leukemia was diagnosed at 13, 19, 28, and 35 months after start of treatment. Three patients had morphologic and/or cytogenetic features of acute leukemia with significant monoblastic involvement; the fourth patient had trilineage dysplasia and cytogenetic abnormalities more commonly associated with therapy-related leukemia. Detailed analysis of the subgroup who survived longer than 1 year (24 patients) suggests that high cumulative doses of etoposide are leukemogenic; the median etoposide dose was 6,795 mg/m2 (first year only) in the four leukemic patients compared with 3,025 mg/m2 in the 20 nonleukemic patients (P less than .01). The rate of ANLL was 0.30 per person-year after the first year (95% confidence limits 0.11 to 0.90), with a cumulative risk of 15% +/- 11% at 2 years, and 44% +/- 24% at 2.5 years. We conclude that high doses of etoposide are potentially leukemogenic, and can induce a syndrome with features of acute monoblastic leukemia de novo that is distinct from other secondary leukemias. 相似文献
947.
Dorsal cortical regions subserving visually guided saccades in humans: an fMRI study 总被引:5,自引:17,他引:5
Luna B; Thulborn KR; Strojwas MH; McCurtain BJ; Berman RA; Genovese CR; Sweeney JA 《Cerebral cortex (New York, N.Y. : 1991)》1998,8(1):40-47
Neurophysiological studies in non-human primates have identified
saccade-related neuronal activity in cortical regions including frontal
(FEF), supplementary (SEF) and parietal eye fields. Lesion and neuroimaging
studies suggest a generally homologous mapping of the oculomotor system in
humans; however, a detailed mapping of the precise anatomical location of
these functional regions has not yet been achieved. We investigated dorsal
frontal and parietal cortex during a saccade task vs. central fixation in
10 adult subjects using functional magnetic resonance imaging (fMRI). The
FEF were restricted to the precentral sulcus, and did not extend anteriorly
into Brodmann area 8, which has traditionally been viewed as their location
in humans. The SEF were located in cortex along the interhemispheric
fissure and extended minimally onto the dorsal cortical surface. Parietal
activation was seen in precuneus and along the intraparietal sulcus,
extending into both superior and inferior parietal lobules. These findings
localize areas in frontal and parietal cortex involved in saccade
generation in humans, and indicate significant differences from the macaque
monkey in both frontal and parietal cortex. These differences may have
functional implications for the roles these areas play in visuomotor
processes.
相似文献
948.
Summary: Twenty-one women with primary glomerulonephritis and a history of a poor outcome in previous pregnancies were randomized to receive heparin, 15 000 units subcutaneously and dipyridamole, 400 mg daily ( n = 10) or no treatment ( n = 11) from 14 weeks of gestation. the women were well matched in terms of the type of underlying glomerulonephritis and previous pregnancy complications. the treated group showed a significantly lower incidence of hypertension ( P <0.03) and of overall maternal complication ( P <0.03). the days spent in hospital prior to delivery were 18 in the treated group and 27 in the control group ( P <0.01). In all other parameters which were measured the outcome was better in the treated group although these did not achieve statistical signficance. In the control group the pregnancy complications were similar to those in previous pregnancies but very few complications occurred in treated patients. Heparin and dipyridamole were used because of the activation of coagulation in preeclampsia and because of the prominence of fibrin in renal and uterine vessels in pre-eclampsia. As heparin suppresses both the action and the production of endothelin, the benefit of treatment could have reflected endothelin inhibition. 相似文献
949.
950.