全文获取类型
收费全文 | 2126篇 |
免费 | 107篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 65篇 |
妇产科学 | 64篇 |
基础医学 | 221篇 |
口腔科学 | 16篇 |
临床医学 | 163篇 |
内科学 | 525篇 |
皮肤病学 | 11篇 |
神经病学 | 199篇 |
特种医学 | 155篇 |
外科学 | 227篇 |
综合类 | 12篇 |
一般理论 | 2篇 |
预防医学 | 82篇 |
眼科学 | 7篇 |
药学 | 205篇 |
中国医学 | 14篇 |
肿瘤学 | 264篇 |
出版年
2023年 | 12篇 |
2022年 | 38篇 |
2021年 | 34篇 |
2020年 | 36篇 |
2019年 | 51篇 |
2018年 | 57篇 |
2017年 | 37篇 |
2016年 | 29篇 |
2015年 | 54篇 |
2014年 | 72篇 |
2013年 | 78篇 |
2012年 | 152篇 |
2011年 | 163篇 |
2010年 | 89篇 |
2009年 | 73篇 |
2008年 | 109篇 |
2007年 | 103篇 |
2006年 | 103篇 |
2005年 | 90篇 |
2004年 | 115篇 |
2003年 | 86篇 |
2002年 | 83篇 |
2001年 | 49篇 |
2000年 | 65篇 |
1999年 | 37篇 |
1998年 | 22篇 |
1997年 | 16篇 |
1996年 | 16篇 |
1995年 | 20篇 |
1994年 | 15篇 |
1993年 | 14篇 |
1992年 | 29篇 |
1991年 | 26篇 |
1990年 | 33篇 |
1989年 | 21篇 |
1988年 | 24篇 |
1987年 | 13篇 |
1986年 | 16篇 |
1985年 | 16篇 |
1984年 | 18篇 |
1983年 | 12篇 |
1982年 | 7篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1976年 | 7篇 |
1975年 | 10篇 |
1974年 | 10篇 |
1973年 | 6篇 |
1969年 | 6篇 |
1967年 | 6篇 |
排序方式: 共有2240条查询结果,搜索用时 15 毫秒
1.
A R Genazzani I Lombardi G Borgioli I di Bono E Casarosa M Gambacciani M Palumbo A D Genazzani M Luisi 《Gynecological endocrinology》2003,17(2):159-168
The aim of the present study was to evaluate the effect of long-term (12 months) administration of raloxifene hydrochloride (60 mg/day) on the steroid production of the adrenal cortex and on the hypothalamic-pituitary-adrenal axis in postmenopausal women. We performed a basal evaluation, a corticotropin releasing factor (CRF) (100 microg i.v. bolus) test and a dexamethasone (DXM) (0.25 mg) suppression-adrenocorticotropic hormone (ACTH) (10 microg i.v. bolus) stimulation test in 11 postmenopausal women, before and after 3, 6 and 12 months of raloxifene treatment. Raloxifene administration significantly modified circulating levels of adrenal steroids, decreasing cortisol (-24%), dehydroepiandrosterone (DHEA) (-36%), and its sulfate (DHEAS) (-41%), and androstenedione (-29%), and increasing circulating allopregnanolone (+39%) levels. Progesterone and 17OH-progesterone levels remained unmodified, while estradiol and estrone levels showed a significant decrease (-51% for estradiol and -61% for estrone). We also observed an increase in circulating ACTH (+58%) and beta-endorphin (+120%). No modifications in the hormonal responses to CRF were observed during the treatment. DXM significantly suppressed circulating steroids at any time with a lower suppression of cortisol from the third month and a higher suppression of DHEA at 12 months. ACTH administration was associated with a significantly blunted cortisol response from the sixth month and a significantly increased response of allopregnanolone from the third month. The present data exclude a raloxifene effect on pituitary sensitivity to CRF and demonstrate a reduced adrenal sensitivity to ACTH, sustained by the opposite changes in basal cortisol and Delta5 androgens, which were reduced, and in ACTH and beta-endorphin, which were increased, as well by the reduced response of cortisol to the direct ACTH stimulus. The reduction of circulating cortisol levels and cortisol response to the ACTH challenge suggests that raloxifene protects against the neurotoxic effects of endogenous glucocorticoids. Furthermore, the progressive increase in basal allopregnanolone and its increased response to ACTH indicate that chronic raloxifene administration exerts direct effects on the pattern of adrenal enzymes, leading to specific changes in the circulating levels of this anxiolytic progesterone metabolite. The important reduction in the circulating levels of estradiol and estrone under long-term raloxifene administration may represent a further mechanism by which this molecule may exert a protective effect against breast and endometrial malignancies. 相似文献
2.
Paolo Mariotti Alfonso Fasano M Fiorella Contarino Giacomo Della Marca Marco Piastra Orazio Genovese Silvia Pulitanò Antonio Chiaretti Anna Rita Bentivoglio 《Movement disorders》2007,22(7):963-968
Status dystonicus (SD) is a life threatening disorder that develops in patients with both primary and secondary dystonia, characterized by acute worsening of symptoms with generalized and severe muscle contractions. To date, no information is available on the best way to treat this disorder. We review the previously described cases of SD and two new cases are reported, one of which occurring in a child with static encephalopathy, and the other one in a patient with pantothenate kinase-associated neurodegeneration. Both patients were admitted to an intensive care unit and treated with midazolam and propofol. This approach proved to be useful in the former while the progressive nature of the dystonia of the second patient required the combination of intrathecal baclofen infusion and bilateral pallidal deep brain stimulation. We believe that a rapid and aggressive approach is justified to avoid the great morbidity and mortality which characterize SD. Our experience, combined with the data available in the literature, might permit to establish the best strategies in managing this rare and severe condition. 相似文献
3.
Disturbances in neural circuitry including the basal ganglia and prefrontal cortex have been hypothesized to be a cause of obsessive-compulsive disorder (OCD). Because eye movements are often impaired in neurologic diseases affecting these brain areas, oculomotor functioning was assessed in 17 unmedicated patients with OCD and in 25 normal controls. As compared with control subjects, patients with OCD demonstrated low-gain (slow) pursuit eye movements and an increased frequency of square wave jerk intrusions, but no increase in anticipatory saccades. In addition, several OCD patients showed an unusual pattern of intrusive, brief epochs of high-gain (fast) pursuit lasting on the order of 50 to 130 msec. These epochs of fast pursuit moved the eyes ahead of the target being tracked, and were terminated by corrective reversal saccades. Studies of eye movement abnormalities may provide an informative neurophysiologic approach for studying disturbances in basal ganglia and frontal cortical function that have been observed in functional neuroimaging and neuropsychological studies of OCD. 相似文献
4.
The spatial and temporal pattern of expression of the protein products of immediate early genes (IEGs) c-fos, fos B, and egr-1 were mapped in medial preoptic area (MPOA) and ventral bed nucleus of stria terminalis (VBST) during maternal behavior in rats. Immunocytochemical analysis indicated significant increases in the number of cells expressing c-Fos after 2 h of pup exposure, while Fos B levels showed a delayed response, reaching maximal levels after 6 h. 相似文献
5.
6.
Biodegradable hydrogels obtained by photocrosslinking of dextran and polyaspartamide derivatives 总被引:2,自引:0,他引:2
Pitarresi G Palumbo FS Giammona G Casadei MA Micheletti Moracci F 《Biomaterials》2003,24(23):4301-4313
The functionalization of dextran with glycidyl methacrylate (GMA) leads to the formation of a derivative that generates hydrogels for irradiation at 365nm. The effects of various polymer concentrations and irradiation times on the yield and the properties of the obtained hydrogels are reported. The networks have been characterized by FT-IR spectra, dimensional analysis and swelling measurements carried out at different pH values. In vitro studies suggest that all samples undergo a partial chemical hydrolysis, whereas the incubation with dextranases causes a total degradation whose rate depends on the degree of crosslinking. In addition, aqueous solutions of functionalized dextran have been irradiated in the presence of PHG (PHEA-GMA), i.e. the copolymer obtained by the reaction of alpha,beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) with GMA. The crosslinking reaction leads to the formation of new networks containing both polymers whose properties have been investigated. To evaluate the processes which occur during UV irradiation, the sol fractions have been purified and characterized by FT-IR and 1H-NMR analyses. Finally, the suitability of hydrogels deriving from functionalized dextran, crosslinked alone or in the presence of PHG, for drug delivery systems has been investigated choosing theophylline as a model drug. 相似文献
7.
Scotto G Saracino A El-Hamed I Iannece MD Geraci S Palumbo E Cibelli DC Angarano G 《Le infezioni in medicina : rivista periodica di eziologia, epidemiologia, diagnostica, clinica e terapia delle patologie infettive》2004,12(4):245-251
In order to retrospectively evaluate the prevalence of immigrant patients affected by active tuberculosis, we analysed the clinical data of 2255 immigrant patients hospitalised during 2002 in ordinary admission or in Day Hospital in 48 Clinics of Infectious Diseases. In all, 303 patients were affected by active tuberculosis (13.4% of the total immigrant hospitalised patients); 30 patients (9.9%) were also HIV-positive. There was a considerable male gender bias (62.5%); the mean age was 29.7 years; 144 patients were from Africa (47.5%), 72 (23.7%) from Asia, 47 (15.5%) from eastern Europe and 40 (13.2%) from South America. The clinical variants were: pulmonary (57.7%), lymph node (15.8%), meningitis (13.8%), intestinal (4.2%), bone (3.3%), pleurical (2.3%), peritoneal (2.3%) and renal (0.6%). We conclude that tuberculosis is a very frequent disease among immigrants, especially of African origin. The high percentage is due to several factors, such as no vaccine prophylaxis and poor, overcrowded living conditions. It is fundamental to focus on the need to provide better health support for all subjects by setting up screening plans to estimate the real incidence of this pathology and ensure medical treatment to prevent the spread of this infection among immigrants and the local host population. 相似文献
8.
A MicroRNA signature associated with prognosis and progression in chronic lymphocytic leukemia 总被引:2,自引:0,他引:2
9.
T N Fredrickson J M Sechler G J Palumbo J Albert L H Khairallah R M Buller 《Virology》1992,187(2):693-704
The chick embryo chorioallantoic membrane was used to study the acute inflammatory response in the absence of contributions from the immune system. In preliminary experiments, lesions of wild-type cowpox virus strain Brighton (CPV-BR) and a 38K gene deletion mutant of CPV-BR (CPV-BR.D1) were compared with vaccinia virus (strains WR and Copenhagen), fowlpox virus, laryngotracheitis virus, and infectious tenosynovitis virus, and were ranked for degree of induced inflammation. The maximal and minimal inflammatory responses were observed with CPV-BR.D1 and CPV-BR viruses, respectively. CPV-BR.D1 lacks a 38K gene which encodes an anti-inflammatory 38-kDa protein that has homology to SERPINs. The kinetics and character of the inflammatory response were examined further in the wild-type CPV-BR and mutant CPV-BR.D1 infections using cell counts, electron microscopy, and assays for inflammatory cell activation. CPV-BR virus infection rapidly spread through the ectoderm, uniformly infecting all cells with the production of large amounts of virions and viral-induced cytopathic effect, but evoking little or no inflammatory response until 144 hr p.i. The CPV-BR.D1 infection, on the other hand, was rapidly contained by a dexamethasone-sensitive inflammatory response mainly of activated heterophils which was advanced by 36 hr p.i. Both infections resulted in disseminated disease with similar numbers of liver lesions and only a slight difference in the LD50, with the CPV-BR.D1 values being higher than that for CPV-BR virus. In this model, the acute inflammatory response alone is unable to prevent disseminated disease and associated mortality. 相似文献
10.
Performance of the applied biosystems ViroSeq human immunodeficiency virus type 1 (HIV-1) genotyping system for sequence-based analysis of HIV-1 in pediatric plasma samples 总被引:1,自引:0,他引:1 下载免费PDF全文