全文获取类型
收费全文 | 2060篇 |
免费 | 116篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 165篇 |
妇产科学 | 37篇 |
基础医学 | 251篇 |
口腔科学 | 60篇 |
临床医学 | 195篇 |
内科学 | 447篇 |
皮肤病学 | 28篇 |
神经病学 | 67篇 |
特种医学 | 477篇 |
外科学 | 185篇 |
综合类 | 34篇 |
预防医学 | 69篇 |
眼科学 | 17篇 |
药学 | 91篇 |
中国医学 | 3篇 |
肿瘤学 | 64篇 |
出版年
2021年 | 8篇 |
2020年 | 10篇 |
2019年 | 8篇 |
2018年 | 17篇 |
2017年 | 11篇 |
2016年 | 25篇 |
2015年 | 30篇 |
2014年 | 26篇 |
2013年 | 58篇 |
2012年 | 39篇 |
2011年 | 39篇 |
2010年 | 76篇 |
2009年 | 62篇 |
2008年 | 53篇 |
2007年 | 49篇 |
2006年 | 46篇 |
2005年 | 39篇 |
2004年 | 35篇 |
2003年 | 38篇 |
2002年 | 44篇 |
2001年 | 33篇 |
2000年 | 40篇 |
1999年 | 37篇 |
1998年 | 134篇 |
1997年 | 118篇 |
1996年 | 127篇 |
1995年 | 91篇 |
1994年 | 74篇 |
1993年 | 81篇 |
1992年 | 32篇 |
1991年 | 31篇 |
1990年 | 32篇 |
1989年 | 67篇 |
1988年 | 51篇 |
1987年 | 62篇 |
1986年 | 53篇 |
1985年 | 59篇 |
1984年 | 37篇 |
1983年 | 40篇 |
1982年 | 34篇 |
1981年 | 21篇 |
1980年 | 38篇 |
1979年 | 23篇 |
1978年 | 22篇 |
1977年 | 21篇 |
1976年 | 25篇 |
1975年 | 32篇 |
1974年 | 8篇 |
1972年 | 11篇 |
1969年 | 10篇 |
排序方式: 共有2198条查询结果,搜索用时 15 毫秒
81.
Corzo D; Yunis JJ; Salazar M; Lieberman JA; Howard A; Awdeh Z; Alper CA; Yunis EJ 《Blood》1995,86(10):3835-3840
Genes of the major histocompatibility complex (MHC) have been associated with susceptibility to drug-induced adverse reactions. We previously found that clozapine-induced agranulocytosis (CA) is associated with the HLA-DRB1*0402, DRB4*0101, DQB1*0302, DQA1*0301 haplotype in Ashkenazi Jewish patients and with the HLA-DRB1*1601, DRB5*02, DQB1*0502, DQA1*0102 haplotype in non-Jewish patients. In the present study, we tested the hypothesis that the variants of the heat- shock protein 70 (HSP-70) encoded by the HSP-70 loci located within the MHC region and known to be involved in apoptosis and regulation of cell proliferation could play an important role in molecular mechanisms of CA. First, we analyzed HSP70-2 polymorphism in risk-associated haplotypes from HLA homozygous cells and normal individuals and confirmed that the HSP70-2 9-kb variant was associated invariably with DR4 (HLA-DRB1*0402, DQB1*0302) and DR2 (HLA-DRB1*01601, DQB1*0502, DQA1*0102 and HLA-DRB1*1501, DQB1*0602) haplotypes, which were the haplotypes found increased in Jewish and non-Jewish patients with CA, respectively. The 9.0-kb variant was also found to be associated with HLA-B44, DRB1*0401 and HLA-B44, DRB1*07 haplotypes. Second, in patients with CA (12 Ashkenazi Jewish and 20 non-Jewish patients), HSP70-1 A and HSP70-2 9.0-kb variants were associated with the MHC haplotypes found by us to be markers of susceptibility to CA. The clozapine-treated control group had an excess number of HSP70-1 C and HSP70-2 8.5-kb variants, consistent with genetic resistance to CA associated with those variants. This finding supports our hypothesis that a dominant gene within the MHC region (marked by HSP70-1 and HSP70-2), but not necessarily HLA, is associated with CA in two different ethnic groups. 相似文献
82.
Jelinek J; Fairbairn LJ; Dexter TM; Rafferty JA; Stocking C; Ostertag W; Margison GP 《Blood》1996,87(5):1957-1961
A human O6-alkylguanine-DNA-alkyltransferase (ATase) cDNA-containing retrovirus was used to infect murine long-term primary bone marrow cultures. High levels of ATase expression were obtained, and colony- forming cells of the granulocyte-macrophage lineage from the cultures transduced with the human ATase retrovirus were three times more resistant to the alkylating agent, N-methyl-N-nitrosourea (MNU), than control cultures. Furthermore, expression of the human ATase protected long-term hematopoiesis, measured as the output of progenitor cells to the nonadherent fraction of the culture, against the cytotoxic effects of repeated exposures to MNU. These results clearly show that a human ATase cDNA-containing retrovirus can be used to infect long-term primary bone marrow cultures and that this attenuates their sensitivity to nitrosoureas. 相似文献
83.
84.
85.
J Tang DJ Humes E Gemmil NT Welch SL Parsons JA Catton 《Annals of the Royal College of Surgeons of England》2013,95(5):323-328
Introduction
The high mortality and morbidity associated with resection for oesophagogastric malignancy has resulted in a conservative approach to the postoperative management of this patient group. In August 2009 we introduced an enhanced recovery after surgery (ERAS) pathway tailored to patients undergoing resection for oesophagogastric malignancy. We aimed to assess the impact of this change in practice on standard clinical outcomes.Methods
Two cohorts were studied of patients undergoing resection for oesophagogastric malignancy before (August 2008 – July 2009) and after (August 2009 – July 2010) the implementation of the ERAS pathway. Data were collected on demographics, interventions, length of stay, morbidity and in-hospital mortality.Results
There were 53 and 55 oesophagogastric resections undertaken respectively for malignant disease in each of the study periods. The median length of stay for both gastric and oesophageal resection decreased from 15 to 11 days (Mann– Whitney U, p<0.001) following implementation of the ERAS pathway. There was no significant increase in morbidity (gastric resection 23.1% vs 5.3% and oesophageal resection 25.9% vs 16.7%) or mortality (gastric resection no deaths and oesophageal resection 1.8% vs 3.6%) associated with the changes. There was a significant decrease in the number of oral contrast studies used following oesophageal resection, with a reduction from 21 (77.8%) in 2008–2009 to 6 (16.7%) in 2009–2010 (chi-squared test, p<0.0001).Conclusions
The introduction of an enhanced recovery programme following oesophagogastric surgery resulted in a significant decrease in length of median patient stay in hospital without a significant increase in associated morbidity and mortality. 相似文献86.
87.
Johansson S Wennergren G Aberg N Rudin A 《The Journal of allergy and clinical immunology》2007,120(2):308-314
BACKGROUND: Levels of the Clara cell 16-kd protein (CC16) are lower in plasma and bronchoalveolar lavage fluid from adults with asthma relative to those seen in healthy control subjects, and CC16 inhibits the T(H)2 cytokine production from murine T cells. OBJECTIVE: We sought to determine the plasma levels of CC16 in infants and to investigate whether CC16 might inhibit the T(H)2 cytokine production from neonatal T cells. METHODS: Cord blood and blood samples at 4, 18, and 36 months of age were taken from 64 children prospectively, and CC16 levels were analyzed in plasma. Cord monocyte-derived dendritic cells (DCs) were pulsed with birch allergen extract alone or together with CC16 or prostaglandin D(2) receptor inhibitors, after which autologous naive CD4(+) T cells were added to the DCs. The production of IL-5, IL-13, and IFN-gamma was measured by means of ELISA and flow cytometry. RESULTS: The plasma levels of CC16 in children peaked at 4 months. CC16 did not directly affect the cytokine production from human T(H)2 cells. However, CC16 inhibited birch pollen extract-stimulated T(H)2 differentiation of naive T cells through the DC. Inhibition of the prostaglandin D(2) receptors did not consistently result in suppressed T(H)2 differentiation. CONCLUSION: The production of CC16 seems to peak early in life, and CC16 has an inhibitory effect on T(H)2 cell differentiation from human infants by affecting DCs. CLINICAL IMPLICATIONS: CC16 is an immunoregulatory protein, and its inhibitory effect on T(H)2 cell differentiation might be of importance in the pathogenesis of allergy in infants. 相似文献
88.
Farah Rahman Sean T. H. Liu Sarah Taimur Samantha Jacobs Timothy Sullivan Dallas Dunn Emily Baneman Risa Fuller Judith A. Aberg Nicole Bouvier Meenakshi M. Rana 《Clinical transplantation》2020,34(12):e14089
Solid organ transplant (SOT) recipients may be at higher risk for poor outcomes with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Convalescent plasma is an investigational therapy that may benefit immunosuppressed patients by providing passive immunity. Convalescent plasma was administered to hospitalized patients with coronavirus disease-2019 (COVID-19) at an academic transplant center in New York City. Eligible patients were hospitalized and required to have positive nasopharyngeal polymerase chain reaction (PCR) diagnosis of SARS-CoV-2 infection, be at least 18 years old, and have either dyspnea, blood oxygen saturation ≤ 93% on ambient air, respiratory frequency ≥ 30 breaths/min, partial pressure of arterial oxygen to fraction of inspired oxygen ratio < 300, or lung infiltrates > 50%. Thirteen SOT recipients received convalescent plasma from April 9, 2020, to May 17, 2020. The median time from symptom onset to plasma infusion was 8 days. Eight of 13 patients (62%) had de-escalating oxygenation support by day 7 post-convalescent plasma. Nine (69%) patients were discharged, 1 (7%) patients remain hospitalized, and 3 (23%) patients died. This series supports the need for additional studies on convalescent plasma use in SOT recipients with COVID-19 to better determine efficacy and identify patients who are likely to benefit. 相似文献
89.
90.
巨噬细胞迁移抑制因子最初是由于能抑制体外巨噬细胞随机迁移而被发现,现在它作为一种重要的调节因子参与一系列炎症性疾病过程.我们最近发现,巨噬细胞迁移抑制因子的缺失使一些由炎症介质诱发的白细胞-内皮细胞相互作用减弱,提示巨噬细胞迁移抑制因子在炎症反应中起作用的机制之一是促进白细胞聚集.…… 相似文献