全文获取类型
收费全文 | 775篇 |
免费 | 43篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 31篇 |
妇产科学 | 2篇 |
基础医学 | 105篇 |
口腔科学 | 14篇 |
临床医学 | 31篇 |
内科学 | 163篇 |
皮肤病学 | 11篇 |
神经病学 | 78篇 |
特种医学 | 83篇 |
外科学 | 76篇 |
综合类 | 123篇 |
预防医学 | 16篇 |
眼科学 | 2篇 |
药学 | 35篇 |
中国医学 | 3篇 |
肿瘤学 | 46篇 |
出版年
2021年 | 16篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 8篇 |
2015年 | 15篇 |
2014年 | 11篇 |
2013年 | 13篇 |
2012年 | 21篇 |
2011年 | 19篇 |
2010年 | 31篇 |
2009年 | 33篇 |
2008年 | 35篇 |
2007年 | 23篇 |
2006年 | 37篇 |
2005年 | 27篇 |
2004年 | 27篇 |
2003年 | 19篇 |
2002年 | 19篇 |
2001年 | 17篇 |
2000年 | 14篇 |
1999年 | 25篇 |
1998年 | 37篇 |
1997年 | 29篇 |
1996年 | 28篇 |
1995年 | 20篇 |
1994年 | 35篇 |
1993年 | 14篇 |
1992年 | 15篇 |
1991年 | 12篇 |
1990年 | 13篇 |
1989年 | 18篇 |
1988年 | 20篇 |
1987年 | 28篇 |
1986年 | 23篇 |
1985年 | 23篇 |
1984年 | 11篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1969年 | 2篇 |
1961年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有821条查询结果,搜索用时 19 毫秒
91.
Development of hatching blastocysts from immature human oocytes following in-vitro maturation and fertilization using a co-culture system 总被引:8,自引:0,他引:8
Hwu YM; Lee RK; Chen CP; Su JT; Chen YW; Lin SP 《Human reproduction (Oxford, England)》1998,13(7):1916-1921
Recently, in-vitro maturation (IVM) of immature human oocytes recovered
from non-stimulated follicles has been applied in the treatment of
infertility. However, in previous reports, very few embryos cultured in
conventional medium have reached the expanded blastocyst stage following
in-vitro maturation and fertilization (IVM/IVF). The objective of this
study was to investigate whether the developmental competence of human
embryos following IVM/IVF could be enhanced by the use of a human ampullary
cell co-culture system. Immature human oocytes were aspirated from small
follicles at Caesarean section and then cultured in medium containing human
menopausal gonadotrophin for 36 to 48 h, followed by insemination. Zygotes
were randomly cultured either in conventional culture medium alone or in
the co-culture system. Of 48 embryos cultured in conventional medium alone,
all arrested at the 2-16- cell stage on day 3 after insemination. Of 46
embryos cultured in the co-culture system, 26 embryos (56.5%) arrested at
the 2-16-cell stage. Six embryos (13%) developed to the morula stage.
Fourteen embryos (30.4%) developed to expanded blastocysts and two
blastocysts were hatching on day 7 after insemination. We conclude that
co-culture significantly enhances the development of blastocysts in embryos
resulting from IVM/IVF.
相似文献
92.
W. Herr A. Schwarting B. Wittig R. Wanitschke G. Schnitzler J. Weinerth W. Jochum U. Hake K. -H. Meyer zum Büschenfelde 《Journal of molecular medicine (Berlin, Germany)》1994,72(5):372-376
This report describes a 26-year-old patient with hemangiosarcoma of the heart and summarizes the clinicopathological features in previous reports of patients with cardiac angiosarcoma. The patient was admitted to our hospital because of a syncope and one episode of nocturnal dyspnea and hemoptysis. In his history he complained of progressive weakness and loss of weight over the past 2 months. Echocardiography and computed tomography of the chest showed inhomogeneous masses in the pericardial cavity completely surrounding the heart and involving the ascending aorta and the superior vena cava. Histological examination of the tissue obtained from the mass by fine needle technique revealed a poorly differentiated malignant tumor of mesenchymal origin. Exploratory thoracotomy followed by tumor biopsies showed an inoperable cardiac hemangiosarcoma of enormous size with multiple metastases in both lungs. Palliative tumor resection was not performed. During the postoperative course the patient still required controlled ventilation. After 3 days of cytostatic chemotherapy no regression of tumor mass was seen by chest radiography. Cardiorespiratory insufficiency was progressive, and the patient died within 3 weeks after admission. 相似文献
93.
Non-selective classical transient receptor potential (TRPC) cation channels share important roles in processes of neuronal development and function. To test the influence of TRPC6 activity on behavior, we developed a TRPC6-deficient (TRPC6−/−) mouse model in a BALB/c genetic background. Both, TRPC6−/− and wild-type (WT) mice were analyzed first for their general health and reflex status (modified SHIRPA protocol) and then in three different behavioral tests (marble-burying test, square open field and elevated star maze). No abnormalities were detected in the SHIRPA protocol. Most interestingly, TRPC6−/− mice showed no significant differences in anxiety in a marble-burying test, but demonstrated reduced exploration in the square open field and the elevated star maze. Therefore, TRPC6 channel activity may play a yet unknown role for exploration behavior. 相似文献
94.
Whybra C Kampmann C Krummenauer F Ries M Mengel E Miebach E Baehner F Kim K Bajbouj M Schwarting A Gal A Beck M 《Clinical genetics》2004,65(4):299-307
Anderson-Fabry disease (AFD) is an X-linked disorder caused by deficient activity of the lysosomal enzyme alpha-galactosidase A. The availability of enzyme replacement therapy (ERT) for this debilitating condition has led to the need for a convenient and sensitive instrument to monitor clinical effects in an individual patient. This study aimed to develop a scoring system--the Mainz Severity Score Index (MSSI)--to measure the severity of AFD and to monitor the clinical course of the disease in response to ERT. Thirty-nine patients (24 males and 15 females) with AFD were assessed using the MSSI immediately before and 1 year after commencing agalsidase alfa ERT. Control data were obtained from 23 patients in whom AFD was excluded. The MSSI of patients with AFD was significantly higher than that of patients with other severe debilitating diseases. The MSSI indicated that, although more men than women had symptoms classified as severe, overall, the median total severity scores were not significantly different between male and female patients. One year of ERT with agalsidase alfa led, in all patients, to a significant (p < 0.001) reduction in MSSI score (by a median of nine points). This study has shown that the MSSI score may be a useful, specific measure for objectively assessing the severity of AFD and for monitoring ERT-related treatment effects. 相似文献
95.
M Kruschwitz G Fritzsche R Schwarting K Micklem D Y Mason B Falini H Stein 《Journal of clinical pathology》1991,44(8):636-645
Using a newly established HTLV-1 positive T cell line as an immunogen, a new monoclonal antibody, Ber-ACT8, was produced. It reacts with in vitro activated T cells and a small subset of normal resting T cells, but not with resting B cells or any of the 29 established human permanent cell lines tested. Immunohistological analysis of a wide spectrum of human tissues showed that Ber-ACT8 reactivity is restricted to a few T cells in the peripheral blood, the extrafollicular areas of lymph nodes and tonsils, and splenic red pulp. In the gut Ber-ACT8 labelled most intraepithelial T cells and up to 50% of lamina propria T cells. The antibody also immunostained T cells present in the oral and bronchial mucosa. Double labelling on splenic cells, fresh blood lymphocytes, and in vitro activated T cells showed that most Ber-ACT8 positive cells coexpressed CD8. Ber-ACT8 did not react with any of the 14 Hodgkin's lymphomas nor any of the 172 non-Hodgkin's lymphomas tested, with the exception of 10 cases of T cell lymphomas, five of which were located in the jejunum and associated with coeliac disease, and one B cell lymphoma, and most cases of hairy cell leukaemia tested. Parallel immunostainings with Ber-ACT8, anti-TCR-beta (beta F1), and anti-TCR-delta showed that most Ber-ACT8 positive T cells carry the TCR of alpha beta type. Comparison of Ber-ACT8 with HML-1, B-ly7, and LF61 showed essentially the same reactivity and an identical molecular target. The molecular structure recognised seems to be a trimeric molecule with components of 150, 125 and 105 kilodaltons, with the Ber-ACT8 epitope localised on the 150 kilodalton chain. The 150 kilodalton molecule contains an 0-linked carbohydrate moiety of about 10 kilodaltons. Because of its very selective distribution, the trimeric antigen is a powerful reagent for the diagnosis of gut T cell-derived T cell lymphomas and other extranodal T cell lymphomas, as well as hairy cell leukaemia. 相似文献
96.
Infant rodents emit ultrasonic vocalizations when isolated from dam and littermates. Due to the context of their occurrence and the well described bidirectional modulation by substances known for their capability to influence emotionality, it was postulated that such calls reflect a negative affective state akin anxiety. Comparative studies observed pronounced differences in calling behavior between strains, which were paralleled by differences in maternal care. Therefore, it was recently hypothesized that early environmental factors may have strong impact on call production. Here, the relative contributions of genetic background, gender, and early environmental factors on calling behavior in C57BL/6JOlaHsd and C57BL/6NCrl were studied by using an embryo-transfer procedure. The results show that these sub-strains differ in the amount of calling and specific call features, like call frequency and amplitude. The embryo-transfer procedure indicated that the observed differences in the amount of ultrasonic calling are dependent on the dyadic interaction between mother and pup. Conversely, call features were primarily dependent on the genotype of the pup. Thus, call frequency and frequency modulation were solely dependent on the pup, i.e. its genotype and gender. However, there was one exception, namely call amplitude, which was solely dependent on the genotype of the mother, i.e. on early environmental factors. Furthermore, it was shown that particularly changes in call amplitude might be of high functional relevance, since a sub-strain dependent preference towards pups emitting calls with high amplitudes was observed. In total, it can be concluded that both genomic and nongenomic factors can tune calling behavior in mouse pups. 相似文献
97.
98.
99.
100.