全文获取类型
收费全文 | 915篇 |
免费 | 33篇 |
国内免费 | 78篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 42篇 |
妇产科学 | 7篇 |
基础医学 | 93篇 |
口腔科学 | 15篇 |
临床医学 | 154篇 |
内科学 | 188篇 |
皮肤病学 | 22篇 |
神经病学 | 8篇 |
特种医学 | 288篇 |
外科学 | 46篇 |
综合类 | 21篇 |
预防医学 | 33篇 |
眼科学 | 1篇 |
药学 | 77篇 |
肿瘤学 | 29篇 |
出版年
2023年 | 3篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 11篇 |
2013年 | 17篇 |
2012年 | 15篇 |
2011年 | 10篇 |
2010年 | 22篇 |
2009年 | 35篇 |
2008年 | 17篇 |
2007年 | 63篇 |
2006年 | 7篇 |
2005年 | 19篇 |
2004年 | 8篇 |
2003年 | 13篇 |
2002年 | 11篇 |
2001年 | 17篇 |
2000年 | 14篇 |
1999年 | 20篇 |
1998年 | 66篇 |
1997年 | 72篇 |
1996年 | 50篇 |
1995年 | 63篇 |
1994年 | 36篇 |
1993年 | 35篇 |
1992年 | 18篇 |
1991年 | 20篇 |
1990年 | 16篇 |
1989年 | 35篇 |
1988年 | 35篇 |
1987年 | 23篇 |
1986年 | 26篇 |
1985年 | 43篇 |
1984年 | 19篇 |
1983年 | 12篇 |
1982年 | 26篇 |
1981年 | 14篇 |
1980年 | 24篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 14篇 |
1976年 | 15篇 |
1975年 | 9篇 |
1974年 | 3篇 |
1969年 | 1篇 |
排序方式: 共有1026条查询结果,搜索用时 31 毫秒
41.
The glycoprotein (GP) Ib-IX complex mediates platelet aggregation in response to high shear forces by binding von Willebrand factor (vWF) in the plasma. We investigated the possibility that the complex could mediate a similar phenomenon if expressed in nonhematopoietic cells. When agitated on a tabletop shaker, CHO and L cells expressing the full complex formed large aggregates in the presence of vWF and the modulator ristocetin. When the rate of agitation was increased, aggregation occurred without added ristocetin and appeared to require only the application of a physical force. The aggregation was homophilic and temperature-dependent and required a functional ligand- binding subunit of the GP Ib-IX complex, GP Ib alpha. Posttranslational tyrosine sulfation of GP Ib alpha was required for aggregate formation and stability. Thus, aggregation of cells expressing the GP Ib-IX complex is a unique example of a ligand-receptor interaction induced by mechanical forces and demonstrates an important biological role for sulfation of tyrosine residues. 相似文献
42.
Genetic and non‐genetic factors that increase the risk of non‐syndromic cleft lip and/or palate development 下载免费PDF全文
43.
In this case, a male patient presented with a clinically and radiographieally unstable slipped capital femoral epiphysis (SCFE) as well as slipped calcaneal epiphysis years. Subsequent thorough at the age of 23 work-up revealed that he had some features of rickets and labo- ratory test demonstrated he had hypophos- phatemia (2.3mg/dl), normocalcemia, normal vi- tamin D metabolite levels, and secondary hy- perparathyroidism. 相似文献
44.
Jane E Sarginson JF William Deakin Ian M Anderson Darragh Downey Emma Thomas Rebecca Elliott Gabriella Juhasz 《Neuropsychopharmacology》2014,39(12):2857-2866
There is increasing evidence that genetic factors have a role in differential susceptibility to depression in response to severe or chronic adversity. Studies in animals suggest that nitric oxide (NO) signalling has a key role in depression-like behavioural responses to stress. This study investigated whether genetic variation in the brain-expressed nitric oxide synthase gene NOS1 modifies the relationship between psychosocial stress and current depression score. We recruited a population sample of 1222 individuals who provided DNA and questionnaire data on symptoms and stress. Scores on the List of Life-Threatening Experiences (LTE) questionnaire for the last year and self-rated current financial hardship were used as measures of recent/ongoing psychosocial stress. Twenty SNPs were genotyped. Significant associations between eight NOS1 SNPs, comprising two regional haplotypes, and current depression score were identified that survived correction for multiple testing when current financial hardship was used as the interaction term. A smaller three-SNP haplotypes (rs10507279, rs1004356 and rs3782218) located in a regulatory region of NOS1 showed one of the strongest effects, with the A-C-T haplotype associating with higher depression scores at low adversity levels but lower depression scores at higher adversity levels (p=2.3E-05). These results suggest that NOS1 SNPs interact with exposure to economic and psychosocial stressors to alter individual''s susceptibility to depression. 相似文献
45.
Bishop JF; Matthews JP; Young GA; Szer J; Gillett A; Joshua D; Bradstock K; Enno A; Wolf MM; Fox R 《Blood》1996,87(5):1710-1717
High-dose cytarabine (ara-c) may overcome cytarabine resistance in leukemic blasts. It has been used as a successful salvage and in postremission therapy but not as initial induction treatment. Patients aged 15 to 60 years, presenting with newly diagnosed acute myeloid leukemia (AML) were randomized to receive either high-dose cytarabine, 3 g/m2 12 hourly on days 1, 3, 5, and 7 for 8 doses, daunorubicin 50 mg/m2 days 1 to 3, etoposide 75 mg/m2 days 1 to 7, (HIDAC-3-7) or standard dose cytarabine 100 mg/m2 continuous intravenous infusion for 7 days with daunorubicin and etoposide at the same dose and schedule as above (7-3-7). Patients could receive a second or third induction course if complete remission (CR) was not achieved. All patients received the same postinduction consolidation therapy (5-2-5) for 2 courses. Eligible patients had no prior chemotherapy or myelodysplastic disease. Patients have been followed for a median of 4.5 years. Of 301 patients treated, complete response (CR) was achieved in 71% with HIDAC- 3-7 and 74% with 7-3-7. For patients in CR, the estimated median remission duration was 45 months with HIDAC-3-7 and 12 months with 7-3- 7 (P = .0005 univariate analysis, P = .0004 multivariate analysis). The estimated percentage of patients relapse free 5 years after achieving a CR was 49% on HIDAC-3-7 and 24% on 7-3-7. Patients in CR tended to survive longer with HIDAC-3-7 but there were no overall survival differences between the two arms. HIDAC-3-7 was associated with significantly more toxicity in induction with more leukopenia, thrombocytopenia, nausea, and vomiting and eye toxicity (all P < .001) but a similar incidence of severe central nervous system and cerebellar toxicity compared to 7-3-7. The consolidation treatment was the same in both arms but caused significantly more leukopenia and thrombocytopenia in patients previously treated with HIDAC-3-7 induction (P < .0001). We conclude that a dose-effect exists for cytarabine in AML and that HIDAC- 3-7 prolongs remission duration and disease-free survival and is tolerable when used as initial induction therapy in patients with de novo AML. 相似文献
46.
Yves?JF?GarinEmail author Pascale?Meneceur Francine?Pratlong Jean-Pierre?Dedet Francis?Derouin Frédéric?Lorenzo 《BMC infectious diseases》2005,5(1):18
Background
Leishmaniases are among the most proteiform parasitic infections in humans ranging from unapparent to cutaneous, mucocutaneous or visceral diseases. The various clinical issues depend on complex and still poorly understood mechanisms where both host and parasite factors are interacting. Among the candidate factors of parasite virulence are the A2 genes, a family of multiple genes that are developmentally expressed in species of the Leishmania donovani group responsible for visceral diseases (VL). By contrast, in L. major determining cutaneous infections (CL) we showed that A2 genes are present in a truncated form only. Furthermore, the A2 genomic sequences of L. major were considered subsequently to represent non-expressed pseudogenes [1]. Consequently, it was suggested that the structural and functional properties of A2 genes could play a role in the differential tropism of CL and VL leishmanias. On this basis, it was of importance to determine whether the observed structural/functional particularities of the L. major A2 genes were shared by other CL Leishmania, therefore representing a proper characteristic of CL A2 genes as opposed to those of VL isolates. 相似文献47.
Platelet-melanoma cell interaction is mediated by the glycoprotein IIb- IIIa complex 总被引:3,自引:0,他引:3
A human malignant melanoma cell line (M3Dau) was observed by electron microscopy to interact directly with human platelets and induced platelet aggregation. Fab fragments of a monoclonal antibody MoAb (LYP18), directed against the platelet glycoprotein (GP) IIb-IIIa complex, inhibited platelet-melanoma interactions and platelet-platelet aggregation. M3Dau melanoma cells bind LYP 18 and synthesize IIb-IIIa- like GPs. When the melanoma cells were preincubated with LYP 18, tumor- platelet interaction did not occur, suggesting that the interaction may be mediated by the IIb-IIIa-like GPs present on the melanoma cell surface. Glanzmann's thrombasthenic platelets, lacking GPIIb and IIIa, did not interact with melanoma cells, indicating that the platelet GPIIb-IIIa complex is also necessary for the platelet-melanoma cell interaction. This work demonstrates the importance of the IIb-IIIa-like GPs, present on M3Dau melanoma cells, in mediating tumor-platelet interactions. 相似文献
48.
Metabolic activity of phagocytosing granulocytes in chronic granulocytic leukemia: ultrastructural observation of a degranulation defect 总被引:4,自引:0,他引:4
Cramer E; Auclair C; Hakim J; Feliu E; Boucherot J; Troube H; Bernard JF; Bergogne E; Boivin P 《Blood》1977,50(1):93-106
The functional capacities of granulocytes in patients with chronic granulocytic leukemia are still a subject of controversy, probably due to the heterogeneity of the abnormalities observed from patient to patient. For a better definition of these abnormalities, 14 patients with untreated chronic granulocytic leukemia were studied. The patients were divided into three groups on the basis of the functional activities of their phagocytosing granulocytes. In four patients (group I), the granulocytes were normal in respect to particle ingestion, nitroblue tetrazolium (NBT)-stimulated reduction, cyanide-insensitive oxygen (O2) consumption, superoxide anion (O2-)-stimulated production, hydrogen peroxide (H2O2) production, and iodination. They also had a normal myeloperoxidase (MPO) content. In four patients (group III), the granulocytes were significantly defective in all of these activities. In the six remaining patients (group II), all the initial metabolic steps of the phagocytosing granulocytes (ingestion, NBT reduction, O2 consumption, O2-production, H2O2 production) were normal, as were the MPO content of the granulocytes, while iodination was strikingly decreased. These metabolic features suggested a degranulation defect which was observed ultrastructurally in the only patient studied among these six. The phagocytosing granulocytes of this patient did not degranulate and no deposits of MPO activity were seen in the phagosomes. 相似文献
49.
50.
TCR gamma delta bearing lymphocyte clones with lymphokine-activated killer activity against autologous leukemic cells 总被引:1,自引:0,他引:1
Activated T lymphocytes with the T-cell receptor (TCR) gamma delta (CD3+ and TCR delta 1+) exhibit strong cytotoxic activity against the standard natural killer (NK) and lymphokine-activated killer (LAK) sensitive target cells. In order to test the cytotoxic activity of gamma delta T lymphocytes against autologous leukemic cells, 84 clones of gamma delta T lymphocytes were obtained from the peripheral blood of three acute lymphoblastic leukemia (ALL) patients. Forty-four of these T-cell clones were active against an LAK-sensitive cell line and the other 40 were active against K562, an NK target cell line. In each of the three patients, cytotoxic clones against autologous leukemic cells were obtained. Among the 84 clones, ten were able to kill autologous tumor cells, including eight that lyse the LAK-sensitive target and two with NK activity. The clones were highly cytotoxic, stable, and easily expanded in large quantity. 相似文献