全文获取类型
收费全文 | 33601篇 |
免费 | 1887篇 |
国内免费 | 297篇 |
专业分类
耳鼻咽喉 | 558篇 |
儿科学 | 682篇 |
妇产科学 | 871篇 |
基础医学 | 5544篇 |
口腔科学 | 1013篇 |
临床医学 | 2940篇 |
内科学 | 6301篇 |
皮肤病学 | 865篇 |
神经病学 | 3050篇 |
特种医学 | 1445篇 |
外科学 | 4273篇 |
综合类 | 1045篇 |
一般理论 | 4篇 |
预防医学 | 1843篇 |
眼科学 | 874篇 |
药学 | 2602篇 |
4篇 | |
中国医学 | 219篇 |
肿瘤学 | 1652篇 |
出版年
2023年 | 168篇 |
2022年 | 305篇 |
2021年 | 509篇 |
2020年 | 377篇 |
2019年 | 425篇 |
2018年 | 503篇 |
2017年 | 474篇 |
2016年 | 507篇 |
2015年 | 672篇 |
2014年 | 775篇 |
2013年 | 1069篇 |
2012年 | 1502篇 |
2011年 | 1767篇 |
2010年 | 1190篇 |
2009年 | 1100篇 |
2008年 | 1558篇 |
2007年 | 1751篇 |
2006年 | 1633篇 |
2005年 | 1571篇 |
2004年 | 1504篇 |
2003年 | 1437篇 |
2002年 | 1430篇 |
2001年 | 789篇 |
2000年 | 754篇 |
1999年 | 726篇 |
1998年 | 420篇 |
1997年 | 408篇 |
1996年 | 318篇 |
1995年 | 251篇 |
1994年 | 276篇 |
1993年 | 217篇 |
1992年 | 404篇 |
1991年 | 389篇 |
1990年 | 340篇 |
1989年 | 325篇 |
1988年 | 309篇 |
1987年 | 268篇 |
1986年 | 270篇 |
1985年 | 280篇 |
1984年 | 194篇 |
1983年 | 187篇 |
1982年 | 156篇 |
1979年 | 163篇 |
1978年 | 150篇 |
1975年 | 156篇 |
1932年 | 141篇 |
1931年 | 138篇 |
1930年 | 166篇 |
1928年 | 149篇 |
1926年 | 138篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Dr. Lutz Lindemann-Sperfeld Klaus-Dieter Rudolf Michael Steen Ivan Marintschev Wieland Otto 《Trauma und Berufskrankheit》2003,5(2):198-207
Complex injuries of the foot are often overlooked, especially in the multiple injured patient, and they then lead to major loss of function. When the mechanism of injury suggests involvement of the foot, a clinical examination of the lower extremities should be included in the primary diagnostic procedures implemented in the multiply injured patient, followed by radiological examination once the patient's condition is stable. The condition of the soft tissues is of decisive importance in the prognosis of complex foot injuries, regardless of whether the damage to the foot is one component of a polytrauma or an isolated injury, which can also be life threatening. The diagnostic examinations selected should be adapted to the severity of the injuries in the particular multiply injured patient. Successful therapy involves stable internal fixation of injuries to bones and joints, though the external fixation options should be considered in the first instance, and carefully selected methods of temporary and definitive soft tissue reconstruction. The aim of treatment is the best possible reconstruction of the foot as a functional weight-bearing unit with intact soft tissue cover and a natural form. Good results can be achieved when there is close interdisciplinary cooperation between trauma (orthopedic) and plastic surgeons. Patient with severe injuries of this kind should be transferred to a trauma center as the first step toward this end. 相似文献
52.
The results from a cohort study on the incidence of cancer and the mortality in a cohort of 2391 male workers producing magnesium metal are presented. The study population was restricted to employees with more than one year of work experience in the study plant between 1951 and 1974 and the cohort was observed from 1953 to 1984. Altogether 152 new cases of cancer were observed versus 132.6 expected. Six cases of cancer of the lip were found against 2.3 expected, 21 of stomach cancer against 12.8 expected, and 32 of lung cancer against 18.2 expected. A possible causal relation between exposure to factors in the work environment and the development of cancer is discussed. 相似文献
53.
Baucke van Minnen Boudewijn Stegenga M Barbara M van Leeuwen Theo G van Kooten Rudolf R M Bos 《Journal of oral and maxillofacial surgery》2007,65(2):218-222
PURPOSE: Surgical closure of oroantral communications (OACs) has several disadvantages. An animal study was performed to test whether OACs can be closed nonsurgically with a biodegradable polyurethane (PU) foam. MATERIALS AND METHODS: In 6 rabbits, an OAC was created on both sides of the maxilla. Three rabbits were used to evaluate the animal model by applying a surgical treatment on 1 side and by leaving the other defects untreated. In the 3 other rabbits, OACs were closed with PU foam. Wound healing was evaluated clinically and histologically. RESULTS: The surgically treated defects healed without complications. The untreated defects showed complicated and delayed healing. Healing of the foam-treated OACs was dependent on the type of foam that was used. CONCLUSIONS: The rabbit is a suitable animal model for OAC investigations. It is possible to close an OAC with a biodegradable PU foam. Further research is needed to show the most suitable composition of the PU for this purpose. 相似文献
54.
C. Lang J. Reichwein H. Iro T. Treig 《European archives of psychiatry and clinical neuroscience》1989,239(3):188-193
Summary In a 66-year-old woman signs and symptoms of bilateral opercular syndrome (Foix-Chavany-Marie-syndrome) developed progressively over a period of more than 10 years. Facio-linguo-velo-pharyngeo-masticatory diplegia with automatic-vol-untary dissociation was accompanied by motor aphasia and oral apraxia leading to a state of almost complete anarthria. Although it initially resembled the anterior biopercular syndrome there are also features indicating involvement of the posterior opercula. Although the aetiology remains obscure without pathological data, a bilateral focal brain atrophy is assumed. This is probably the first case documented by MRI and SPECT.Supported by the Hirnliga, Heidelberg, Federal Republic of Germany 相似文献
55.
Ernst Heinrich; Ohshima Hiroshi; Bartsch Helmut; Mohr Ulrich; Reichart Peter 《Carcinogenesis》1987,8(12):1843-1845
In order to evaluate the effect of concurrent administrationof areca nut and sodium nitrite, a long-term feeding study wasconducted with 120 Syrian hamsters. The animals were dividedinto four treatment groups, each consisting of 15 males and15 females, and received 2 g/kg diet of sodium nitrite (groupI), 20 g/kg diet of powdered areca nut (group II), 2 g/kg dietof sodium nitrite plus 20 g/kg diet of areca nut (group III)or powdered diet only (group IV) throughout their lifetime.Urine samples from all groups were analysed for N-nitrosonipecoticacid (NNIP), a major urinary metabolite of areca-nut-derivednitrosamines. NNIP was only detected in the urine of hamstersfed nitrite plus areca nut (concentration: 1.9±0.9 ng/mlurine), indicating that areca nut alkaloids underwent in vivonitrosation to form arecanut-specific nitrosamines. The totaltumour response was not significantly elevated in groups IIand III. Hamsters of group III had a markedly, but also insignificantlyhigher frequency of malignant tumours than those of the othergroups, with a statistically significant increase in malignantlymphomas in the males. Although limited by the low number ofanimals per group, these results indicate that exposure to nitritetogether with areca nut constituents appears to enhance therisk of developing malignancies. 相似文献
56.
57.
M. Ito T. F. Lang M. Jergas M. Ohki M. Takada T. Nakamura K. Hayashi H. K. Genant 《Calcified tissue international》1997,61(2):123-128
This study examined trabecular bone mineral density (BMD) in Japanese women with and without spinal fracture, and compared
the results to American women with and without fracture. The quantitative computed tomography (QCT) systems used at the University
of California, San Francisco (UCSF) and at Nagasaki University were cross-calibrated. Normative BMD was assessed with the
K2HPO4 liquid phantom in 538 Americans aged 20–85 years, and with the B-MAS200 phantom in 577 Japanese aged 20–83 years. These BMD
were adjusted for use with the Image Analysis solid phantom using the result of cross-calibration. The trabecular BMD in 111
postmenopausal American women (55 with fracture), and in 185 postmenopausal Japanese women (67 with fracture) were compared
for investigation of the difference in BMD values relative to fracture status. The absolute BMD values in Japanese were lower
than those in Americans, and the differences were greater with advancing age. The magnitude of the BMD difference was 8.6,
20.5, 38.1 mg/cm3 in women aged 20–24 years, 40–44 years, 60–64 years, respectively. In premenopausal women, BMD began to decrease at the age
of 20 in Japanese, whereas the peak bone mass was maintained until the age of 35 in the American women. In immediate postmenopausal
women, BMD significantly decreased in both populations. In later postmenopausal women, BMD significantly decreased with age
in the Japanese women but decreased less rapidly in the American women. The aging decrease of BMD was 1.4% and 2.2% per year
in the later postmenopausal American and Japanese women, respectively. The fracture threshold is considered to be lower in
Japanese women. However, the BMD difference between American and Japanese women with fracture was similar to that without
fracture. The Z-scores of fracture subjects versus controls were 2.9 in American and 1.8 in Japanese women. In conclusion,
Japanese women were found to have a lower BMD and lower fracture threshold than American women. The significant decrease of
spinal trabecular BMD in late postmenopause is potentially responsible for the higher prevalence of spinal fracture in Japanese
women.
Received: 18 December 1995 / Accepted: 23 September 1996 相似文献
58.
59.
Expression of cell-matrix molecules and integrin receptors in human liver grafts during chronic rejection 总被引:1,自引:0,他引:1
Ken Hoshino Bjorn Nashan Gustav Steinhoff Rudolf Pichlmayr K. Hoshino 《Transplant international》1994,7(S1):637-640
Abstract The inflammatory response of immune cells to target cells and cell-matrix molecules is regulated by several receptor-ligand molecules. As fibrosis develops in ongoing chronic rejection after liver transplantation, it is of interest to analyze patterns of integrin receptors and cell-matrix molecules in order to study the relation between immune cells and the stromal and parenchymal cells. In the present study, we demonstrated the expression of these molecules in chronic rejected human liver grafts using immunohistochemical techniques. The results showed a differential expression and induction of integrin receptors and cell-matrix molecules on resident liver cells, especially on sinusoids, reflecting a state of chronic inflammation and a specific interaction between integrin receptors and cell-matrix molecules. The patterns of induced integrin receptors on graft-infiltrating cells was closely related to the local production of cell-matrix molecules and reflected the final sequence of a stepwise progress of the inflammatory reaction. 相似文献
60.
P D Clouston C B Saper T Arbizu I Johnston B Lang J Newsom-Davis J B Posner 《Neurology》1992,42(10):1944-1950
We studied nine patients with a subacute onset of a pancerebellar syndrome. Six had known cancer (three small-cell carcinoma of the lung [SCLC], one metastatic small-cell carcinoma, one small-cell carcinoma of the prostate, and one non-Hodgkin's lymphoma). Six of eight who had neurophysiologic testing, including the three patients without detectable cancer, had coexistent Lambert-Eaton myasthenic syndrome (LEMS). In two of the patients, LEMS was discovered only by neurophysiologic testing. We looked for anti-Purkinje cell autoantibodies in all patient's sera and in four patients' CSF. We also looked for autoantibodies to voltage-gated calcium channels (VGCCs) in seven patients' sera and two patients' CSF, using the 125I-omega-conotoxin radioimmunoassay. We were unable to detect anti-Purkinje cell autoantibodies in any patients' serum or CSF. However, there were raised titers of anti-VGCC autoantibodies in five of seven patients' serum, including one patient with SCLC who did not have LEMS, and in the CSF of one of two patients. We conclude that the frequency of presentation of a pancerebellar syndrome with LEMS is higher than expected by chance and is usually associated with cancer. In some of these patients, LEMS may be clinically occult. The presence of LEMS and raised titers of anti-VGCC autoantibodies in some patients with subacute cerebellar degeneration is suggestive of an autoimmune etiology even though anti-Purkinje cell antibodies could not be detected. Anti-VGCC autoantibodies are not confined to LEMS. They may be found at high titer in CSF as well as serum. 相似文献