全文获取类型
收费全文 | 2221811篇 |
免费 | 166915篇 |
国内免费 | 7369篇 |
专业分类
耳鼻咽喉 | 29689篇 |
儿科学 | 71194篇 |
妇产科学 | 59992篇 |
基础医学 | 308482篇 |
口腔科学 | 62005篇 |
临床医学 | 199543篇 |
内科学 | 440981篇 |
皮肤病学 | 52150篇 |
神经病学 | 177100篇 |
特种医学 | 90388篇 |
外国民族医学 | 472篇 |
外科学 | 343446篇 |
综合类 | 49382篇 |
现状与发展 | 3篇 |
一般理论 | 656篇 |
预防医学 | 168831篇 |
眼科学 | 48847篇 |
药学 | 165068篇 |
10篇 | |
中国医学 | 4554篇 |
肿瘤学 | 123302篇 |
出版年
2018年 | 22459篇 |
2017年 | 17768篇 |
2016年 | 20934篇 |
2015年 | 23315篇 |
2014年 | 32225篇 |
2013年 | 47881篇 |
2012年 | 61173篇 |
2011年 | 65324篇 |
2010年 | 39924篇 |
2009年 | 38468篇 |
2008年 | 61000篇 |
2007年 | 65130篇 |
2006年 | 66590篇 |
2005年 | 63894篇 |
2004年 | 61154篇 |
2003年 | 59345篇 |
2002年 | 56863篇 |
2001年 | 112348篇 |
2000年 | 115715篇 |
1999年 | 96599篇 |
1998年 | 26854篇 |
1997年 | 23888篇 |
1996年 | 24660篇 |
1995年 | 24260篇 |
1994年 | 22433篇 |
1993年 | 21131篇 |
1992年 | 77171篇 |
1991年 | 74828篇 |
1990年 | 72641篇 |
1989年 | 69725篇 |
1988年 | 63906篇 |
1987年 | 62616篇 |
1986年 | 59033篇 |
1985年 | 56420篇 |
1984年 | 42057篇 |
1983年 | 35386篇 |
1982年 | 21064篇 |
1981年 | 18650篇 |
1980年 | 17650篇 |
1979年 | 37822篇 |
1978年 | 26598篇 |
1977年 | 23004篇 |
1976年 | 20653篇 |
1975年 | 22313篇 |
1974年 | 26102篇 |
1973年 | 25092篇 |
1972年 | 23490篇 |
1971年 | 21837篇 |
1970年 | 19999篇 |
1969年 | 18991篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
K Thomsen B J Riis J S Johansen C Christiansen P R?dbro 《Gynecological endocrinology》1987,1(2):169-175
Bone turnover before and after withdrawal of estrogen/gestagen treatment was studied in a randomized trial with 110 healthy female volunteers, who had passed a natural menopause 6 months to 3 years before the start of the study. Urinary excretion of intravenously injected 99m-technetium diphosphonate was measured as an index of bone turnover; plasma bone Gla protein and serum alkaline phosphatase were measured as indices of bone formation; and fasting urinary excretion of hydroxyproline and calcium were measured as estimates of bone resorption. During 2 years of hormone treatment, all variables decreased highly significantly (p less than 0.001) to a constant low level. Three months after withdrawal all variables increased highly significantly (p less than 0.001) towards, but not above, pretreatment and placebo levels. We conclude that withdrawal of estrogen/gestagen replacement therapy in postmenopausal women increases bone turnover, but not in excess of pretreatment values. This indicates that bone loss (after withdrawal) is similar to that seen in the placebo group and that a rebound phenomenon is unlikely. 相似文献
992.
993.
The authors report the results of the Patterns of Care for Brachytherapy in Europe (PCBE) throughout France. Responses were obtained for 91% of the Radiation Oncology departments, which have declared using brachytherapy for 67, and gave detailed data for 49 ones. The equipments and treated tumours were recorded. LDR brachytherapy remained the most often used (53.5%), followed by HDR (28%). PDR represented 5.5% and permanent implants 11%. The authors discuss the development of new equipment, with an aggregation of the structures, and an increase of the PDR and prostate implants use. 相似文献
994.
D. Besch I. El-Araj J. Mielke V. Herzau 《Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft》2005,102(10):1000-1002
Ohne Zusammenfassung 相似文献
995.
Regula E Egli Thomas L Kash Kevin Choo Valentina Savchenko Robert T Matthews Randy D Blakely Danny G Winder 《Neuropsychopharmacology》2005,30(4):657-668
The bed nucleus of the stria terminalis (BNST) and its adrenergic input are key components in stress-induced reinstatement and maintenance of drug use. Intra-BNST injections of either beta-adrenergic receptor (beta-AR) antagonists or alpha2-adrenergic receptor (alpha2-AR) agonists can inhibit footshock-induced reinstatement and maintenance of cocaine- and morphine-seeking. Using electrophysiological recording methods in an in vitro slice preparation from C57/Bl6j adult male mouse BNST, we have examined the effects of adrenergic receptor activation on excitatory synaptic transmission in the lateral dorsal supracommissural BNST (dBNST) and subcommissural BNST (vBNST). Alpha2-AR activation via UK-14,304 (10 microM) results in a decrease in excitatory transmission in both dBNST and vBNST, an effect predominantly dependent upon the alpha2A-AR subtype. Beta-AR activation via isoproterenol (1 microM) results in an increase in excitatory transmission in dBNST, but not in vBNST. Consistent with the work with receptor subtype specific agonists, application of the endogenous ligand norepinephrine (NE, 100 microM) elicits two distinct effects on glutamatergic transmission. In dBNST, NE elicits an increase in transmission (62% of dBNST NE experiments) or a decrease in transmission (38% of dBNST NE experiments). In vBNST, NE elicits a decrease in transmission in 100% of the experiments. In dBNST, the NE-induced increase in synaptic transmission is blocked by beta1/beta2- and beta2-, but not beta1-specific antagonists. In addition, this increase is also reduced by the alpha2-AR antagonist yohimbine and is absent in the alpha2A-AR knockout mouse. In vBNST, the NE-induced decrease in synaptic transmission is markedly reduced in the alpha2A-AR knockout mouse. Further experiments demonstrate that the actions of NE on glutamatergic transmission can be correlated with beta-AR function. 相似文献
996.
Adjuvant radiotherapy in carcinomas of the uterine cervix: the prognostic value of hemoglobin levels
K. Münstedt P. Johnson M.K. Bohlmann M. Zygmunt R. von Georgi† & H. Vahrson 《International journal of gynecological cancer》2005,15(2):285-291
Anemia has been associated with a poorer treatment response and reduced survival in women undergoing primary radiotherapy (RT) or radiochemotherapy for advanced cervical carcinoma. This study aimed to determine the influence of anemia on outcome in patients with cervical carcinoma undergoing adjuvant RT. Medical records were reviewed for 183 cervical cancer patients who had received adjuvant RT because of risk factors after radical surgery (n= 109) or inadequate primary surgery (simple hysterectomy; n= 74). Kaplan-Meier and Cox regression analyses were used to study hemoglobin levels before and during adjuvant RT in relation to recurrence-free and overall survival. Hemoglobin values > or =11 g/dL were considered normal, while those <11 g/dL indicated anemia. Hemoglobin levels before RT influenced significantly overall survival and recurrence-free survival across the whole group (overall survival--log rank(all patients)= 7.5; df = 1; P= 0.006). However, subgroup analysis showed that the observed difference was mainly due to the group of women who had undergone inadequate primary surgery (overall survival--log rank(inadequate surgery)= 10.8; df = 1; P= 0.001). Multifactorial regression analyses comparing hemoglobin before RT with grading and tumor stage confirmed the prognostic value of hemoglobin values. Maintaining normal hemoglobin values before and during adjuvant RT seems to be important, especially in patients who have had inappropriate simple hysterectomy, which may resemble a therapeutic situation. 相似文献
997.
I Kandarakis D Cavouras D Nikolopoulos A Episkopakis N Kalivas P Liaparinos I Valais G Kagadis K Kourkoutas I Sianoudis N Dimitropoulos C Nomicos G Panayiotakis 《Applied radiation and isotopes》2006,64(4):508-519
The aim of this study was to examine the angular distribution of the light emitted from radiation-excited scintillators in medical imaging detectors. This distribution diverges from Lambert's cosine law and affects the light emission efficiency of scintillators, hence it also affects the dose burden to the patient. In the present study, the angular distribution was theoretically modeled and was used to fit experimental data on various scintillator materials. Results of calculations revealed that the angular distribution is more directional than that predicted by Lambert's law. Divergence from this law is more pronounced for high values of light attenuation coefficient and thick scintillator layers (screens). This type of divergence reduces light emission efficiency and hence it increases the incident X-ray flux required for a given level of image brightness. 相似文献
998.
Local mucosal immunoglobulin E production: does allergy exist in non‐allergic rhinitis? 总被引:2,自引:0,他引:2
In this review, we critically evaluate the evidence for local IgE production in allergic rhinitis mucosa and the concept of local allergy in non-atopic idiopathic rhinitis. Significantly, fewer studies have focused on the disease pathways associated with non-allergic rhinitis compared with their allergic counterparts. Recently, there's been a revival of the hypothesis concerning the existence of local tissue-specific allergic disease confined to the nasal mucosa of some systemically non-atopic rhinitis subjects. Providing the evidence for local mucosal IgE production in allergic rhinitis is a pre-requisite to reviewing its existence in non-allergic rhinitis. In addition, practical and theoretical approaches useful in the detection of allergy in non-allergic rhinitis will be discussed. Furthermore, successful therapeutic regimens used in the treatment of non-allergic rhinitis will be examined as these could provide an insight into the underlying pathophysiology of this common but poorly understood disease. 相似文献
999.
Williamson Kathleen A.; Hever Ann M.; Rainger Joe; Rogers R. Curtis; Magee Alex; Fiedler Zdenek; Keng Wee Teik; Sharkey Freddie H.; McGill Niolette; Hill Clare J.; Schneider Adele; Messina Mario; Turnpenny Peter D.; Fantes Judy A.; van Heyningen Veronica; FitzPatrick David R. 《Human molecular genetics》2006,15(12):2030
Table 1 相似文献
1000.