全文获取类型
收费全文 | 16815篇 |
免费 | 1040篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 579篇 |
儿科学 | 937篇 |
妇产科学 | 620篇 |
基础医学 | 1384篇 |
口腔科学 | 928篇 |
临床医学 | 1310篇 |
内科学 | 3414篇 |
皮肤病学 | 485篇 |
神经病学 | 1203篇 |
特种医学 | 591篇 |
外科学 | 3253篇 |
综合类 | 154篇 |
一般理论 | 1篇 |
预防医学 | 845篇 |
眼科学 | 493篇 |
药学 | 839篇 |
中国医学 | 62篇 |
肿瘤学 | 794篇 |
出版年
2024年 | 59篇 |
2023年 | 251篇 |
2022年 | 241篇 |
2021年 | 483篇 |
2020年 | 361篇 |
2019年 | 424篇 |
2018年 | 752篇 |
2017年 | 594篇 |
2016年 | 752篇 |
2015年 | 682篇 |
2014年 | 961篇 |
2013年 | 1248篇 |
2012年 | 1228篇 |
2011年 | 1269篇 |
2010年 | 863篇 |
2009年 | 566篇 |
2008年 | 708篇 |
2007年 | 723篇 |
2006年 | 701篇 |
2005年 | 674篇 |
2004年 | 602篇 |
2003年 | 542篇 |
2002年 | 511篇 |
2001年 | 431篇 |
2000年 | 358篇 |
1999年 | 294篇 |
1998年 | 132篇 |
1997年 | 86篇 |
1996年 | 82篇 |
1995年 | 63篇 |
1994年 | 48篇 |
1993年 | 44篇 |
1992年 | 103篇 |
1991年 | 71篇 |
1990年 | 76篇 |
1989年 | 80篇 |
1988年 | 48篇 |
1987年 | 55篇 |
1986年 | 42篇 |
1985年 | 46篇 |
1984年 | 43篇 |
1979年 | 33篇 |
1977年 | 37篇 |
1974年 | 34篇 |
1973年 | 42篇 |
1971年 | 37篇 |
1970年 | 31篇 |
1969年 | 34篇 |
1968年 | 34篇 |
1967年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 28 毫秒
41.
I Patty S Benedek G Deák T Jávor P Kenéz F Morón L Nagy L Simon F Tárnok G Mózsik 《International journal of tissue reactions》1983,5(3):301-307
The effects of vitamin A were studied on the basal and maximal gastric secretory responses of 12 patients; and on healing in 60 patients with chronic gastric ulcer. The effect of vitamin A on ulcer healing was evaluated by a multiclinical, multicentre, randomized, prospective study in which the patients were divided into three groups. In group A the patients were treated with antacids only; in group B the patients were given antacids plus vitamin A (in doses of 3 X 50.000 U orally); and in group C the patients received antacids, vitamin A plus cyproheptadine (in doses of 3 X 4 mg orally). The treatment lasted four weeks. At the beginning and the end of treatment endoscopies were performed and ulcer sizes were measured planimetrically. Various other parameters such as ulcer index, antacid consumption and laboratory parameters were also evaluated during the four-week treatment. It was observed that: (i) vitamin A (given in doses of 100.000 U i.m.) decreased neither basal nor maximal gastric secretory responses; (ii) the number of patients with completely healed gastric ulcer was significantly higher (P less than 0.05) in groups B and C than in group A; (iii) the extent of ulcer reduction was significantly higher (P less than 0.01) in groups B and C than in group A; (iv) no significant changes were observed in ulcer index and antacid consumption during the four-week treatment in the different groups of patients; (v) the reduction of ulcer size was significantly greater (P less than 0.01) in the group treated with antacids plus vitamin A than in the group treated with antacids only, at two weeks of treatment.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
42.
Summary The purpose of the study was to analyse the effect of arm-shoulder fatigue on manual performance. Ten experienced carpenters performed three standardized tasks (nailing, sawing and screwing). Electromyographic activity was recorded from six arm-shoulder muscles and the performances were video-filmed. After 45 min of standardized arm-cranking (arm-shoulder-fatiguing exercise of approximately 70%–80% maximal oxygen consumption), the tasks were repeated. The number of work movements and the time taken for each task were recorded and the quality of the work performed was compared. After the fatiguing exercise, only nailing was perceived as being harder and more mistakes were made during nailing and sawing. Movement performance was not influenced during nailing but was slightly slower during sawing and faster during screwing. However, there were increased mean EMG amplitudes in the upper trapezius and biceps muscles during nailing, in the upper trapezius, anterior deltoid and infraspinatus muscles during sawing and in the anterior deltoid muscle during screwing. Of the muscles studied the upper trapezius and anterior deltoid muscles increased their activity most after the arm-shoulder-fatiguing exercise. 相似文献
43.
International Urology and Nephrology - To evaluate the effect of masturbation on the spontaneous expulsion of distal ureteral stones 5–10 mm in size. A total of 128 men with distal... 相似文献
44.
Ahmet Tektemur Ebru Etem Önalan Nalan Kaya Tektemur Serap Dayan Cinkara Ayten Kılınçlı Çetin İbrahim Tekedereli Tuncay Kuloğlu Gaffari Türk 《Andrologia》2021,53(2):e13954
Male infertility is a global health problem, and the underlying molecular mechanisms are not clearly known. Ion channels and microRNAs (miRNAs), known to function in many vital functions in cells, have been shown to play a significant role in male infertility through changes in their expressions. The study aimed to evaluate the alterations of testicular and/or spermatozoal potassium voltage-gated channel subfamily J member 11 (KCNJ11), Cystic fibrosis transmembrane conductance regulator (CFTR), miR-let-7a and miR-27a expressions in carbamazepine-related male infertility. Here, we showed that carbamazepine reduced sperm motility, increased abnormal sperm morphology, and impaired hormonal balance as well as increased relative testis weight and decreased relative seminal vesicle weight. On the other hand, downregulated KCNJ11 and upregulated miR-let-7a expressions were determined in testis (p < .05). Also, downregulated KCNJ11 and upregulated CFTR and miR-27a expressions were found in spermatozoa (p < .05). Interestingly, altered testicular KCNJ11 and miR-let-7a expressions were correlated with decreased sperm motility and elevated sperm tail defect. Besides, spermatozoal CFTR and miR-27a expressions positively correlated with sperm tail defects. The results indicated a significant relationship between ion channel and/or miRNA expression alterations and impaired sperm parameters due to carbamazepine usage. 相似文献
45.
46.
Sexuality and Disability - This study was carried out to determine the reproductive health, sexual function and sexual satisfaction levels of women with disabilities. The sample of the study was... 相似文献
47.
Jastrzebska M Torbus-Lisiecka B Pieczul-Mróz J Chełstowski K Naruszewicz M 《Materia medica Polona. Polish journal of medicine and pharmacy》1997,29(1-4):3-7
The concentrations of fibrinogen (Fb) and the activities of factor VII (F VIIC) and antithrombin III (AT III) both in men less than 55 years old with a history of myocardial infarction (MI) and with normolipemia (MI-NLP) or hyperlipoproteinemia (MI-HLP) and in their sons have been measured. A significantly higher levels of Fb were found in both MI groups. Significantly higher levels of F VIIC and AT III were found only in the MI-NLP group. No lipid or haemostatic disorders were noted in sons. Furthermore, a positive correlation between the level of F VIIC and triglycerides (TG) or total cholesterol (TCh) in the patients and sons was revealed. A positive correlation was found between: (a) Fb levels in MI-HLP patients and in their sons; (b) TG levels in MI-HLP patients and in their sons; and (c) AT III activity in MI patients and in their sons. Fibrinogen appears to be associated with ischemic heart disease more closely than factor VII, the latter being strongly linked with hypertriglyceridemia. Elevated activities of AT III may reflect the haemostatic response to the prothrombotic state in IHD on the one hand whereas they may contribute to the development of IHD on the other. 相似文献
48.
M. H. özörnek P. Bielfeld J. S. Krüssel M. Moustafa B. Mikat-Drozdzynski U. Koldovsky U. Kuhn 《Journal of assisted reproduction and genetics》1995,12(9):590-593
Purpose
The aim of our study is to elucidate whether human oocyteslembryos secrete IFN
and/or IL-10 and whether the fertilization process depends on the balance between these cytokines.Methods
A total of 142 embryo culture media from 24 patients were collected and the cytokine levels were tested with ELISA.Results
IFN
and IL-10 were detectable in 40.1% and 29.6% of culture media respectively. The difference of IFN
and IL-10 levels in media from fertilized oocytes between day 1 and day 2 are significant (0.46 vs. 1.47 and 34.2 vs. 12.7, respectively). However there was no significant difference between the IFN
levels of the media from fertilized and nonfertilized oocytes 0.46 vs. 0.85 at day 1 and 1.47 vs. 1.49 at day 2, as well as IL-10 levels 34.2 vs. 30.9 at day 1 and 12.7 vs. 9.58 at day 2 respectively.Conclusions
Human preimplantation embryos secrete the cytokines IFN
and IL-10. No effect of these cytokines on fertilization process could be shown.Presented at the IXth World Congress on In Vitro Fertilization and Alternate Assisted Reproduction, April 3–7, 1995, Vienna, Austria. 相似文献
49.
50.
Kiriş T Karasu A Yavuz C Erdem T Unal F Hepgül K Baloğlu H 《Acta neurochirurgica》1999,141(12):1323-1329
The constant release of nitric oxide (NO) is essential to maintain basal cerebrovascular tone. Oxyhaemoglobin, liberated by lysis of red blood cells after subarachnoid haemorrhage binds NO and prevents its entry into vascular smooth muscle cells. While endothelium-dependent vasoconstriction is preserved, decreased levels of NO inhibit endothelium-dependent relaxation and may cause vasospasm. S-nitrosothiols are potent vasodilators and precursors of NO. The authors' aim was to determine whether S-nitroso-N-acetylpenicillamine (SNAP), a stable S-nitrosothiol compound, could reverse vasospasm in an experimental vasospasm model in rabbit. Experimental subarachnoid haemorrhage (SAH) was induced in 37 New Zealand white rabbits. The animals were divided into four groups. Control (no SAH), SAH only, SAH plus saline and SAH plus SNAP. SNAP (15 micrograms/kg/min) or 0.09% saline (equal volume) was infused 46 hours after induction of SAH. All animals were killed by perfusion fixation 48 hours after SAH occurred. Basilar arteries were removed, sectioned and their cross sectional areas were evaluated in a blind manner, by light microscopy and by using computer assisted morphometry. Experimental SAH elicited vasospasm in all animals of SAH only and SAH plus saline group. In animals treated with SNAP, arterial narrowing was markedly attenuated without producing systemic hypotension. This widening achieved statistical significance when compared to the arteries of the SAH only and SAH plus saline group (p < 0.01). This study indicates that the NO donor SNAP is a potentially useful drug to reverse cerebral vasospasm due to SAH. 相似文献