全文获取类型
收费全文 | 1606篇 |
免费 | 148篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 57篇 |
妇产科学 | 17篇 |
基础医学 | 189篇 |
口腔科学 | 50篇 |
临床医学 | 168篇 |
内科学 | 206篇 |
皮肤病学 | 26篇 |
神经病学 | 476篇 |
特种医学 | 176篇 |
外科学 | 152篇 |
综合类 | 30篇 |
预防医学 | 64篇 |
眼科学 | 30篇 |
药学 | 65篇 |
中国医学 | 1篇 |
肿瘤学 | 50篇 |
出版年
2023年 | 9篇 |
2021年 | 18篇 |
2020年 | 15篇 |
2019年 | 25篇 |
2018年 | 18篇 |
2017年 | 18篇 |
2016年 | 26篇 |
2015年 | 25篇 |
2014年 | 36篇 |
2013年 | 48篇 |
2012年 | 65篇 |
2011年 | 58篇 |
2010年 | 60篇 |
2009年 | 70篇 |
2008年 | 54篇 |
2007年 | 53篇 |
2006年 | 60篇 |
2005年 | 47篇 |
2004年 | 44篇 |
2003年 | 40篇 |
2002年 | 50篇 |
2001年 | 45篇 |
2000年 | 53篇 |
1999年 | 53篇 |
1998年 | 44篇 |
1997年 | 54篇 |
1996年 | 61篇 |
1995年 | 48篇 |
1994年 | 44篇 |
1993年 | 50篇 |
1992年 | 35篇 |
1991年 | 39篇 |
1990年 | 30篇 |
1989年 | 37篇 |
1988年 | 28篇 |
1987年 | 32篇 |
1986年 | 34篇 |
1985年 | 34篇 |
1984年 | 21篇 |
1983年 | 22篇 |
1982年 | 26篇 |
1981年 | 14篇 |
1980年 | 11篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 20篇 |
1976年 | 11篇 |
1975年 | 13篇 |
1971年 | 9篇 |
1969年 | 7篇 |
排序方式: 共有1760条查询结果,搜索用时 15 毫秒
81.
Retrovirally marked CD34-enriched peripheral blood and bone marrow cells contribute to long-term engraftment after autologous transplantation 总被引:16,自引:17,他引:16
Dunbar CE; Cottler-Fox M; O'Shaughnessy JA; Doren S; Carter C; Berenson R; Brown S; Moen RC; Greenblatt J; Stewart FM 《Blood》1995,85(11):3048-3057
We report here on a preliminary human autologous transplantation study of retroviral gene transfer to bone marrow (BM) and peripheral blood (PB)-derived CD34-enriched cells. Eleven patients with multiple myeloma or breast cancer had cyclophosphamide and filgrastim-mobilized PB cells CD34-enriched and transduced with a retroviral marking vector containing the neomycin resistance gene, and CD34-enriched BM cells transduced with a second marking vector also containing a neomycin resistance gene. After high-dose conditioning therapy, both transduced cell populations were reinfused and patients were followed over time for the presence of the marker gene and any adverse effects related to the gene-transfer procedure. All 10 evaluable patients had the marker gene detected at the time of engraftment, and 3 of 9 patients had persistence of the marker gene for greater than 18 months posttransplantation. The marker gene was detected in multiple lineages, including granulocytes, T cells, and B cells. The source of the marking was both the transduced PB graft and the BM graft, with a suggestion of better long-term marking originating from the PB graft. The steady- state levels of marking were low, with only 1:1000 to 1:10,000 cells positive. There was no toxicity noted, and patients did not develop detectable replication-competent helper virus at any time posttransplantation. These results suggest that mobilized PB cells may be preferable to BM for gene therapy applications and that progeny of mobilized peripheral blood cells can contribute long-term to engraftment of multiple lineages. 相似文献
82.
83.
The brainstem and basal ganglia are important in the pathophysiology of Parkinson's disease (PD). Reliable and sensitive detection of neural activity changes in these regions should be helpful in scientific and clinical research on PD. In this study, we used resting state functional MRI and amplitude of low frequency fluctuation (ALFF) methods to examine spontaneous neural activity in 109 patients with PD. We examined activity in two frequency bands, slow‐4 (between 0.027 and 0.073 Hz) and slow‐5 (0.010–0.027 Hz). Patients had decreased ALFF in the striatum and increased ALFF in the midbrain, and changes were more significant in slow‐4. Additionally, changes in slow‐4 in both basal ganglia and midbrain correlated with the severity of the parkinsonism. The ALFF in the caudate nucleus positively correlated with the dose of levodopa, while the ALFF in the putamen negatively correlated with the disease duration in both slow‐4 and slow‐5 bands. In addition, the ALFF in the rostral supplementary motor area negatively correlated with bradykinesia subscale scores. Our findings show that with a large cohort of patients and distinguishing frequency bands, neural modulations in the brainstem and striatum in PD can be detected and may have clinical relevance. The physiological interpretation of these changes needs to be determined. Hum Brain Mapp 35:5815–5833, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
84.
We investigated the potential of two terrestrial biomass invasive species in the United-Kingdom as lignocellulosic biofuel feedstocks: Japanese Knotweed (Fallopia japonica) and Rhododendron (Rhododendron ponticum). We demonstrate that a pretreatment technique using a low-cost protic ionic liquid, the ionoSolv process, can be used for such types of plant species considered as waste, to allow their integration into a biorefinery. N,N,N-Dimethylbutylammonium hydrogen sulfate ([DMBA][HSO4]) was able to fractionate the biomass into a cellulose-rich pulp and a lignin stream at high temperatures (150–170 °C) and short reaction times (15–60 minutes). More than 70–80% of the subsequent cellulose was hydrolysed into fermentable sugars, which were fermented into the renewable energy vector bioethanol.Japanese Knotweed (Fallopia japonica) and Rhododendron (Rhododendron ponticum), two invasive species in the UK that are an environmental threat and economic burden, can be integrated into a flexible ionic liquid based biorefinery process to produce bioenergy and chemicals. 相似文献
85.
86.
Period of susceptibility for cross-modal plasticity in the blind 总被引:9,自引:0,他引:9
Cross-modal plasticity in blind subjects contributes to sensory compensation when vision is lost early in life, but it is not known if it does so when visual loss occurs at an older age. We used H2(15)O positron emission tomography to identify cerebral regions activated in association with Braille reading, and repetitive transcranial magnetic stimulation to induce focal transient disruption of function during Braille reading, in 8 subjects who became blind after age 14 years (late-onset blind), after a lengthy period of normal vision. Results were compared with those previously reported obtained from congenitally and early-onset blind subjects. As shown by H2(15)O positron emission tomographic scanning, the occipital cortex was strongly activated in the congenitally blind and early-onset blind groups but not in the late-onset blind group. Occipital repetitive transcranial magnetic stimulation disrupted the Braille reading task in congenitally blind and early-onset blind subjects but not in late-onset blind subjects. These results indicate that the susceptible period for this form of functionally relevant cross-modal plasticity does not extend beyond 14 years. 相似文献
87.
目的:观察开道散合扶正和胃合剂治疗上消化道癌性狭窄的临床疗效。方法:对40例患者采用口服开道散、扶正和胃合剂联合胃镜下癌灶内注射5-氟脲嘧啶注射液及鸦胆子乳剂方法治疗上消化道癌性狭窄。结果:治疗后无瘤灶消失病例,34例患者肿瘤缩小达50%以上,完全缓解0例,部分缓解34例,稳定4例,进展2例,有效率为85.0%。治疗后患者吞咽困难有了较明显的改善,显效7例,有效31例,无效2例,总有效率95.0%。治疗后所有患者的卡氏评分均有所升高,与治疗前比较,差异有显著性意义(P〈0.05),提示治疗后患者的生活质量有所改善。结论:开道散合扶正和胃合剂治疗上消化道癌性狭窄疗效满意,能使实体瘤缩小、吞咽困难改善、生活质量提高。 相似文献
88.
Hemilaminectomy with diskectomy, the original surgical option to address intervertebral disk herniation, was superseded by open microdiskectomy, a less invasive technique recognized as the surgical benchmark with which minimally invasive spine surgery techniques have been compared as they have been developed. These minimally invasive surgical techniques for patients with herniated nucleus pulposus and radiculopathy include laser disk decompression, arthroscopic microdiskectomy, laparoscopic techniques, foraminal endoscopy, and microendoscopic diskectomy. Each has its own complications and requires a long learning curve to develop familiarity with the technique. Patient selection, and especially disk morphology, are the most important factors in choice of technique. The optimal candidate has a previously untreated single-level herniation with limited migration or sequestration of free fragments. 相似文献
89.
Patients with obstructive jaundice frequently suffer postoperative complications. We have investigated
the relationship of obstructive jaundice to the neutrophil oxidase response and the “priming” of the
response by the cytokines TNFα, interleukin-1 (IL-1), IL-6, and IL-8. On stimulation with f-met-leuphe
(fmlp), the respiratory burst in neutrophils from jaundiced patients was greatly increased compared
with controls (p < 0.01), jaundiced patients having the highest respiratory burst levels were those with
the poorest prognosis. Neutrophils from controls were primed by all the cytokines tested, whereas
“jaundiced” cells were primed only by IL-1, and not by TNFα, IL-6, or IL-8, which in fact produced
slight inhibition. We conclude that neutrophils from obstructive jaundiced patients have raised oxidative
responses which may be due to “pre-priming” in vivo by cytokines, such as IL-6, IL-8, or TNFα. This exaggeration of the oxidative response in circulating neutrophils may contribute to the peri-operate
complications of patients with obstructive jaundice. 相似文献
90.