全文获取类型
收费全文 | 2591738篇 |
免费 | 189618篇 |
国内免费 | 7586篇 |
专业分类
耳鼻咽喉 | 34312篇 |
儿科学 | 85422篇 |
妇产科学 | 71722篇 |
基础医学 | 364731篇 |
口腔科学 | 69817篇 |
临床医学 | 235322篇 |
内科学 | 517351篇 |
皮肤病学 | 62601篇 |
神经病学 | 214146篇 |
特种医学 | 100232篇 |
外国民族医学 | 736篇 |
外科学 | 387693篇 |
综合类 | 50465篇 |
现状与发展 | 5篇 |
一般理论 | 972篇 |
预防医学 | 196866篇 |
眼科学 | 56914篇 |
药学 | 188498篇 |
8篇 | |
中国医学 | 5340篇 |
肿瘤学 | 145789篇 |
出版年
2021年 | 20202篇 |
2019年 | 20785篇 |
2018年 | 29501篇 |
2017年 | 22741篇 |
2016年 | 26379篇 |
2015年 | 29682篇 |
2014年 | 40683篇 |
2013年 | 60802篇 |
2012年 | 80794篇 |
2011年 | 85079篇 |
2010年 | 51361篇 |
2009年 | 49441篇 |
2008年 | 79542篇 |
2007年 | 84431篇 |
2006年 | 86076篇 |
2005年 | 82321篇 |
2004年 | 79214篇 |
2003年 | 76529篇 |
2002年 | 73818篇 |
2001年 | 128481篇 |
2000年 | 131418篇 |
1999年 | 110589篇 |
1998年 | 31364篇 |
1997年 | 28006篇 |
1996年 | 28284篇 |
1995年 | 27462篇 |
1994年 | 25126篇 |
1993年 | 23486篇 |
1992年 | 85209篇 |
1991年 | 81619篇 |
1990年 | 78833篇 |
1989年 | 76108篇 |
1988年 | 69516篇 |
1987年 | 68033篇 |
1986年 | 63571篇 |
1985年 | 60534篇 |
1984年 | 44979篇 |
1983年 | 37972篇 |
1982年 | 22498篇 |
1981年 | 20013篇 |
1979年 | 38973篇 |
1978年 | 27457篇 |
1977年 | 23273篇 |
1976年 | 21510篇 |
1975年 | 22826篇 |
1974年 | 26800篇 |
1973年 | 25384篇 |
1972年 | 23759篇 |
1971年 | 21970篇 |
1970年 | 20198篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
K S Shiba K Kanamori H Cho N Furuhata T Harada A Shiba M Nakao 《Clinica chimica acta; international journal of clinical chemistry》1988,172(1):77-84
Proteins in normal human urine were clearly fractionated into 26 bands with molecular weights from 14,000 to 230,000 by means of one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) coupled with silver staining. The main band contained uromucoid, and the second main band had albumin. However, when urine samples from healthy persons were electrophoresed in the absence of SDS using polyacrylamide gel or agarose gel, or a cellulose acetate membrane, albumin but not uromucoid, frequently formed the main protein band. It is suggested that this is due to the complexing of uromucoid subunits to form a large molecule which cannot penetrate into the gel. In order to correctly fractionate all the proteins contained in normal human urine, it was concluded that it was best to treat a urine sample with SDS with pre-condensation, fractionate it by SDS-PAGE and stain fractionated proteins by a highly sensitive method such as silver staining. 相似文献
992.
Reevaluation of procarbazine for the treatment of recurrent malignant central nervous system tumors 总被引:1,自引:0,他引:1
Ninety-nine patients with primary recurrent malignant tumors of the central nervous system were treated with procarbazine as a single agent. Procarbazine was not given as a specified protocol, but for patients who were ineligible or refused other protocols. All patients had been treated previously with radiotherapy and 96 patients had also received previous chemotherapy. Twenty-five patients were treated at the first progression of their tumor, 47 were treated at the second progression, and 27 were treated at the third progression of their tumor. For the aggregate, the response plus stabilization rate was 27% for glioblastoma multiforme with median time to tumor progression of 30 weeks, and 28% for other anaplastic gliomas with a median time to tumor progression of 49 weeks. With respect to the percent of patients who responded or stabilized to treatment, these results are inferior to those reported previously for patients treated with procarbazine at recurrence. With respect to duration of response and stabilization, the data are comparable. 相似文献
993.
During recent decades there has been a controversial discussion if comparable plasma level profiles which are rather constant or those which show a high peak are more efficient for the cure of gonorrhoea. So far, investigations in this field were not based on the Grasso apparatus. Although the findings with cefotiam and ceftizoxime do not allow to formulate a general hypothesis without any restriction, it can be stated that on the basis of an identical area under the antibiotic level time curve, 'peak concentration' profiles are more favourable. 相似文献
994.
995.
R. P. Heaney T. M. Zizic I. Fogelman W. P. Olszynski P. Geusens C. Kasibhatla N. Alsayed G. Isaia M. W. Davie C. H. Chesnut III 《Osteoporosis international》2002,13(6):501-505
Risedronate treatment reduces the risk of vertebral fracture in women with existing vertebral fractures, but its efficacy
in prevention of the first vertebral fracture in women with osteoporosis but without vertebral fractures has not been determined.
We examined the risk of first vertebral fracture in postmenopausal women who were enrolled in four placebo-controlled clinical
trials of risedronate and who had low lumbar spine bone mineral density (BMD) (mean T-score =–3.3) and no vertebral fractures at baseline. Subjects received risedronate 5 mg (n= 328) or placebo (n= 312) daily for up to 3 years; all subjects were given calcium (1000 mg daily), as well as vitamin D supplementation (up
to 500 IU daily) if baseline serum 25-hydroxyvitamin D levels were low. The incidence of first vertebral fracture was 9.4%
in the women treated with placebo and 2.6% in those treated with risedronate 5 mg (risk reduction of 75%, 95% confidence interval
37% to 90%; P= 0.002). The number of patients who would need to be treated to prevent one new vertebral fracture is 15. When subjects were
stratified by age, similar significant reductions were observed in patients with a mean age of 64 years (risk reduction of
70%, 95% CI 8% to 90%; P= 0.030) and in those with a mean age of 76 years (risk reduction of 80%, 95% CI 7% to 96%; P= 0.024). Risedronate treatment therefore significantly reduces the risk of first vertebral fracture in postmenopausal women
with osteoporosis, with a similar magnitude of effect early and late after the menopause.
Received: 12 September 2001 / Accepted: 11 December 2001 相似文献
996.
This study examined the immunoregulatory role of recombinant interleukin 4 (IL-4), also known as B-cell stimulating factor 1, on the generation of cytotoxic effector cells from normal and leukaemic human blood mononuclear cells. When tested on cells from normal individuals, the addition of IL-4 to mixed lymphocyte cultures led to a dose-dependent proliferation of T-helper cells (CD3, 4 positive) with a concomitant decrease in phenotypic and functional cytotoxic T cells and natural killer (NK) cells. IL-4 also inhibited the interleukin-2 (IL-2)-induced generation of lymphokine-activated killer (LAK) activity when added at the beginning of mixed lymphocyte culture. When tested on mature leukaemic NK cells, IL-4 also inhibited the ability of IL-2 to induce LAK function using a short-term culture system. These results show that IL-4 acts on both normal and leukaemic cells and suggests that it acts at more than one level during the development of LAK function. 相似文献
997.
998.
Nervensch?digungen als Begleitverletzungen bei Monteggia-Frakturen sind selten und betreffen meistens den N. radialis. üblicherweise
kommt es bei frischen Frakturen zu einer spontanen neurologischen Remission, nachdem der Radiuskopf wieder reponiert wurde.
Im vorliegenden Fall erlitt ein heute 33-j?hriger Mann eine Parese des N. interosseus posterior 27 Jahre nach einer Monteggia-Fraktur,
wobei der Radiuskopf in luxierter Stellung verblieb. Nach einem Bagatelltrauma am Handgelenk beim Federballspielen kam es
zu einer L?hmung der Handgelenk- und Fingerstreckmuskulatur. Eine konservative Behandlung mittels intensiver Physiotherapie
blieb auch nach 4 Monaten erfolglos. Daraufhin wurde der Nerv exploriert. Der Profundusast zeigte sich dabei narbig adh?rent
im Bereich einer beengenden und verdickten Frohse-Arkade. Anschlie?end erfolgte eine Narbenl?sung sowie Spaltung der Arkade,
der Radiuskopf wurde im ursprünglichen verrenkten Zustand belassen. Eine v?llige Erholung des l?dierten Nerven war 9 Monate
postoperativ erreicht. 相似文献
999.
In der Behandlung von Frakturen spielt die Analgesie eine wesentliche Rolle. Es stellt sich daher die Frage, ob in der Klinik h?ufig eingesetzte Analgetika wie Tramadol oder Diclofenac negative Wirkungen auf die Knochenbruchheilung haben. 相似文献
1000.
王伏虎 《南京医科大学学报(英文版)》2002,16(2):49-64
Stroke is a debilitating disease that affects millions each year.While in many cases cerebral ischemic in jury can be limited by effectivw resuscitation or thrombolytic treatment,the injured neurons wither in a process known as delayed neuronal death(DND).Mounting evidence indicates that DND is not simply necrosis played out in slow motion but apoptosis is triggered.Of particular interest are two groups of signal proteins that participate in apoptosis-cyclin dependent kinases(CDKs) and p53-among a myriad of signaling events after an ischemic insult.Recent investigations have shown that CDKs,a family of enzymes initially known for their role in cell cycle regulation,are activated in injured neurons in DND.As for p53,new reports suggest that its up-regulation may represent a failed attempt to rescue in jured neurons,although its up-regulation was previously considered an indication of apoptosis.These observations thus rekindle an old quest to identify new neuroprotective targets to minimize the stroke damage.In this review,the author will examine the evidence that indicates the participation of CDKs and p53 in DND and then introduce pre-clinical data to explore CDK inhibition as a potential neuroprotective target.Finally,using CDK inhibition as an example,this paper will discuss the pertinent criteria for a viable neuroprotective strategy for ischemic in jury. 相似文献