全文获取类型
收费全文 | 642923篇 |
免费 | 33323篇 |
国内免费 | 759篇 |
专业分类
耳鼻咽喉 | 8452篇 |
儿科学 | 20450篇 |
妇产科学 | 14888篇 |
基础医学 | 107888篇 |
口腔科学 | 16417篇 |
临床医学 | 55588篇 |
内科学 | 123433篇 |
皮肤病学 | 15483篇 |
神经病学 | 43036篇 |
特种医学 | 22232篇 |
外国民族医学 | 54篇 |
外科学 | 92061篇 |
综合类 | 8204篇 |
现状与发展 | 2篇 |
一般理论 | 142篇 |
预防医学 | 49806篇 |
眼科学 | 14559篇 |
药学 | 49129篇 |
1篇 | |
中国医学 | 1659篇 |
肿瘤学 | 33521篇 |
出版年
2021年 | 6269篇 |
2019年 | 6556篇 |
2018年 | 10244篇 |
2017年 | 6740篇 |
2016年 | 7296篇 |
2015年 | 8076篇 |
2014年 | 10233篇 |
2013年 | 15205篇 |
2012年 | 23887篇 |
2011年 | 26290篇 |
2010年 | 14404篇 |
2009年 | 11907篇 |
2008年 | 22794篇 |
2007年 | 24980篇 |
2006年 | 23894篇 |
2005年 | 23196篇 |
2004年 | 21953篇 |
2003年 | 20993篇 |
2002年 | 20187篇 |
2001年 | 25675篇 |
2000年 | 26725篇 |
1999年 | 21710篇 |
1998年 | 5685篇 |
1997年 | 4634篇 |
1996年 | 4678篇 |
1995年 | 4338篇 |
1992年 | 15485篇 |
1991年 | 16728篇 |
1990年 | 16729篇 |
1989年 | 16267篇 |
1988年 | 14847篇 |
1987年 | 14694篇 |
1986年 | 13696篇 |
1985年 | 13100篇 |
1984年 | 9734篇 |
1983年 | 8247篇 |
1982年 | 4291篇 |
1979年 | 9201篇 |
1978年 | 6542篇 |
1977年 | 5309篇 |
1976年 | 5670篇 |
1975年 | 6822篇 |
1974年 | 7668篇 |
1973年 | 7432篇 |
1972年 | 6818篇 |
1971年 | 6551篇 |
1970年 | 6104篇 |
1969年 | 5710篇 |
1968年 | 5380篇 |
1967年 | 4807篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
181.
182.
183.
OBJECTIVE: This study was conducted to compare an otolaryngologist's experience with a cohort of epilepsy patients implanted with a vagal nerve stimulator (VNS) to previously published data. METHODS: Demographics, preoperative seizure frequency, medications, and complications were retrospectively collected from patients implanted by the senior author. Postoperative medications and seizure frequency were obtained from referring neurologists. RESULTS: Seventeen patients were implanted over a 24-month period. Average age was 28.3 years. Patients presented with petit mal (n = 3), tonic-clonic (n = 6), complex partial (n = 5), and grand mal (n = 8) seizures. Mean follow-up postimplantation was 13.5 months. Most patients had at least a 50% reduction of seizure frequency, with 3 patients being seizure free. There were no postoperative infections. One patient had left vocal cord immobility. The most common side effect was voice disturbance during device activation. CONCLUSION: Otolaryngologists are well equipped to perform VNS implantation and to diagnose and treat possible laryngeal side effects. EBM rating: C-4. 相似文献
184.
S. V. Terent’eva E. N. Komarova T. N. Sapozhnikova A. T. Teplyakov E. A. Ivanovskaya T. I. Andreeva 《Pharmaceutical Chemistry Journal》2006,40(12):694-696
A rapid procedure for determining angiotensin II in the blood by inverse voltammetry using a TA-2 device (Tekhnoanalit Company,
Tomsk) with a graphite electrode has been developed. The results of analyses using the proposed technique agree with the clinical
data. The rapid analytical procedure favors optimization of cardiotropic drug therapy.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 12, pp. 54–56, December, 2006. 相似文献
185.
186.
Adalberto Parra Jorge Ramírez-Peredo Rocío Hidalgo Amelia Morales-Toquero Gabriela Velásquez-Ramírez Alejandro Ruiz-Argüelles Guillermo J Ruiz-Argüelles 《Biology of blood and marrow transplantation》2006,12(5):566-572
We compared the functional status of the hypothalamic dopaminergic tone in patients given an allogeneic hematopoietic stem cell transplantation (allo-HSCT) with chronic graft-versus-host disease (GVHD) with that observed in patients with allo-HSCT without chronic GVHD and in healthy controls. The effect of acute dopaminergic blockade with intravenous metoclopramide on serum prolactin (PRL) concentrations was evaluated. Twenty volunteers, 20 to 52 years of age, seronegative for both hepatitis C virus and the human immunodeficiency virus, were studied: (1) 10 clinically healthy men (group 1), and (2) 9 patients with leukemia, and 1 patient with refractory aplastic anemia who underwent allo-HSCT, 5 of whom (3 men and 2 women) developed chronic GVHD (group 2), and 5 (3 men and 2 women) who did not develop chronic GVHD (group 3). Serum PRL concentrations were measured both fasting and after intravenous administration of metoclopramide (10-mg bolus). The area under the PRL curve was calculated. Patients in group 2 were older than those in groups 1 and 3 (P<.018), but their body mass index was similar. Fasting serum PRL concentrations were similar among the 3 groups; however, group 2 had higher PRL concentrations throughout the test (P<.001) and a greater area under the PRL curve than groups 1 and 3 (P<.001), without differences between the last 2 groups. The differences remained significant after adjustment for age (P<.01). Our results in a small group of patients with chronic GVHD after allo-HSCT suggest the existence of an increased functional level of their hypothalamic dopamine tone, which would favor a tendency toward a diminished endogenous production, release of pituitary PRL, or both. This could represent an adaptive mechanism aiming to maintain circulating PRL concentrations within a physiological range. 相似文献
187.
Effect of leptin on the regulation of placental hormone secretion in cultured human placental cells.
Raquel Coya Pedro Martul Jaime Algorta Ma Angeles Aniel-Quiroga Ma Angeles Busturia Rosa Se?arís 《Gynecological endocrinology》2006,22(11):620-626
Placenta is an important source of leptin during pregnancy that contributes to the high plasma leptin levels in pregnant women. Leptin and its functional receptors are synthesized in trophoblast cells that, in turn, secrete gestational hormones supporting a paracrine or autocrine role for leptin in the endocrine activity of the placenta. In the present study we examined the effect of leptin on in vitro release of gestational hormones (human chorionic gonadotropin (hCG), human placental lactogen (hPL), progesterone, estrogens and testosterone) by human term placental cells in culture. Placentas at term were obtained immediately after delivery from mothers with uncomplicated pregnancies. Progesterone, hCG, hPL, estradiol, estrone, estriol and testosterone levels were measured by different assays in culture media of cells maintained in monolayer culture after incubation for 12, 24, 48 or 72 h with leptin or placebo. Incubation with leptin did not modify hCG, hPL, progesterone, estriol and estrone secretion for any of the doses and times assayed. However, leptin led to a dose-dependent decrease in estradiol release. This effect was observed when treatment with recombinant human leptin spanned from 12 to 72 h. At this time an increase in testosterone levels was observed in leptin-treated cells versus placebo. These results indicate that leptin can be considered a gestational hormone implied in the endocrine function of the placenta, with an important role in control of the production of steroid reproductive hormones in placental cells in vitro. 相似文献
188.
189.
Hugo Maia Julio Casoy Tania Correia Luís Freitas Kleber Pimentel Célia Athayde Elsimar Coutinho 《Gynecological endocrinology》2006,22(10):547-551
OBJECTIVES: To determine whether aromatase expression in the eutopic endometrium and adenomyotic foci is affected by previous use of oral contraceptives containing gestodene, and to determine whether changes in cyclooxygenase-2 (COX-2) expression occur in adenomyosis during the menstrual cycle. PATIENT AND METHODS: This was a retrospective cohort study carried out in paraffin-embedded endometrial tissue obtained from patients with a histological diagnosis of adenomyosis obtained during the proliferative (n = 25) and luteal (n = 10) phases of the menstrual cycle and following the use of continuous oral contraception with gestodene/ethinyl estradiol (n = 7). COX-2 and aromatase expression were measured in both eutopic endometrium and adenomyotic foci using immunohistochemical methods. RESULTS: Aromatase expression was detected in 80% of the endometrial slices by immunohistochemistry. In positive cases, aromatase was mainly detected in the stromal cells of the eutopic endometrium, whereas in the adenomyotic foci this expression was negative in the majority of the cases. Oral contraceptives containing gestodene, on the other hand, were effective in suppressing aromatase expression in both eutopic and ectopic endometrium. COX-2 expression was detected by immunohistochemistry in the glandular epithelium of both eutopic endometrium and adenomyotic foci and there were no significant changes in its intensity throughout the menstrual cycle. CONCLUSION: Aromatase expression in the eutopic endometrium and adenomyotic foci is suppressed by oral contraceptives containing gestodene. Increased aromatase activity may be responsible for the persistent COX-2 expression during the luteal phase. 相似文献
190.
Riitta Suhonen Maritta V?lim?ki Jouko Katajisto Helena Leino-Kilpi 《Journal of Professional Nursing》2006,22(4):253-261
The purposes of this study were to examine how hospital patients' backgrounds and clinical illness are related to their perceptions of the individualized care they receive and to test the sensitivity of the Individualized Care Scale (ICS). Cross-sectional explorative survey data were obtained using questionnaires completed by 861 (response rate = 88%) predischarge hospital patients from six hospitals in Southern Finland in 2004. Self-administered questionnaires included the ICS as well as the 15D, a measure of health-related quality of life, and gathered information about the patients' backgrounds. Based on association tests, younger age, poorer state of health, and higher level of education were associated with more critical perceptions of individualized care. Using simultaneous regression analysis and presenting the results from stronger to weaker, we found age to be the strongest predictor of patients' positive perceptions of the individualized care they received. This was followed by health-related quality of life (HRQoL) as measured by the 15D, vocational education, and type of admission. The ICS was found to be a valid tool for the measurement of individualized care in hospitals. The self-reported patient data from this survey suggest that some patient characteristics are associated with the patients' perceptions about the individualized care they receive. There is now a need to consider how these characteristics can be taken into account in nursing care delivery to increase individualized care for hospital patients. The results also support use of the ICS in the measurement of individualized care in hospitals. 相似文献