全文获取类型
收费全文 | 6526篇 |
免费 | 493篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 208篇 |
妇产科学 | 143篇 |
基础医学 | 976篇 |
口腔科学 | 97篇 |
临床医学 | 705篇 |
内科学 | 1252篇 |
皮肤病学 | 164篇 |
神经病学 | 698篇 |
特种医学 | 163篇 |
外科学 | 639篇 |
综合类 | 52篇 |
一般理论 | 11篇 |
预防医学 | 674篇 |
眼科学 | 114篇 |
药学 | 412篇 |
中国医学 | 9篇 |
肿瘤学 | 662篇 |
出版年
2024年 | 7篇 |
2023年 | 94篇 |
2022年 | 146篇 |
2021年 | 302篇 |
2020年 | 209篇 |
2019年 | 269篇 |
2018年 | 263篇 |
2017年 | 222篇 |
2016年 | 240篇 |
2015年 | 231篇 |
2014年 | 310篇 |
2013年 | 390篇 |
2012年 | 591篇 |
2011年 | 548篇 |
2010年 | 273篇 |
2009年 | 279篇 |
2008年 | 419篇 |
2007年 | 406篇 |
2006年 | 362篇 |
2005年 | 337篇 |
2004年 | 283篇 |
2003年 | 246篇 |
2002年 | 229篇 |
2001年 | 31篇 |
2000年 | 22篇 |
1999年 | 19篇 |
1998年 | 33篇 |
1997年 | 19篇 |
1996年 | 19篇 |
1995年 | 15篇 |
1994年 | 19篇 |
1993年 | 20篇 |
1992年 | 11篇 |
1991年 | 11篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 14篇 |
1987年 | 7篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1980年 | 9篇 |
1979年 | 5篇 |
1969年 | 6篇 |
1958年 | 3篇 |
1954年 | 3篇 |
1926年 | 3篇 |
排序方式: 共有7038条查询结果,搜索用时 343 毫秒
11.
Withdrawal of bromocriptine after long-term therapy for macroprolactinomas; effect on plasma prolactin and tumour size 总被引:1,自引:0,他引:1
The present study describes the effect on plasma prolactin values and tumour size of bromocriptine withdrawal in 12 patients who had been treated for macroprolactinomas for a period of 3.5-7 (mean 4.9) years. Pretreatment plasma prolactin values ranged from 12,000 to 210,000 (mean: 66,000) mU/l. Immediately before bromocriptine withdrawal plasma prolactin values were in the normal range (less than 350 mU/l for men; less than 450 mU/l for women). Bromocriptine treatment was associated with tumour reduction in all cases. The following observations were made upon withdrawal of bromocriptine: (1) In 11 patients hyperprolactinaemia redeveloped although plasma prolactin levels remained below 600 mU/l in two of these patients during a follow-up period of 1 year. In the other nine patients bromocriptine treatment was reinstituted after 4-12 weeks. (2) Hyperprolactinaemia was associated with tumour reexpansion in one case and increased density of the tumour in two cases. (3) In one patient plasma prolactin remained undetectable during a follow-up period of 1 year and no tumour re-expansion was found. It is concluded that tumour regrowth is uncommon and of small extent after cessation of long-term bromocriptine treatment for macroprolactinomas. 相似文献
12.
Questionable dietary remedies for cancer decreased quality of life and did nothing to improve cancer outcomes in patients with extensive disease. 相似文献
13.
Femke M van de Water Johanna M Boleij Janny G P Peters Frans G M Russel Rosalinde Masereeuw 《European journal of pharmaceutical sciences》2007,30(1):36-44
The activity of P-glycoprotein (Pgp/MDR1/ABCB1) and multidrug resistance proteins (MRP/ABCC) influence the pharmacokinetics and bioavailability of many drugs. Few suitable cell lines for the study of drug transport exist. Additional non-human cell lines may help clarify species differences and contribute to the current knowledge of drug transport. The aim of the present study was to characterize three rat epithelial cell lines for transporter expression and activity. Transporter expression was assessed in intestinal IEC-6 and renal GERP and NRK-52E cells using RT-PCR and Western blot analysis. Pgp and Mrp transport activity were analyzed by measuring calcein accumulation and glutathione-S-bimane efflux, respectively. The three cell lines showed Pgp expression and Pgp-dependent transport, both decreasing with culture time after reaching confluency. Besides Pgp, cells expressed Mrp1, Mrp3, Mrp4, and Mrp5, while Mrp2 and Mrp6 were absent. In addition, they showed temperature- and Mrp-dependent efflux of glutathione-S-bimane. Exposure to a panel of different inhibitors showed that this efflux was probably mediated by Mrp4. In conclusion, the three rat epithelial cell lines investigated showed Pgp and Mrp expression and transport. Mrp dependent transport was most likely mediated by Mrp4. In future, these cell lines may be used as in vitro models to study drug transport. 相似文献
14.
Menno van Gameren Maarten Witsenburg Johanna J M Takkenberg Derize Boshoff Luc Mertens Anton M van Oort Dani?l de Wolf Matthias Freund Narayanswani Sreeram Regina B?kenkamp Melle D Talsma Marc Gewillig 《European heart journal》2006,27(22):2709-2715
AIMS: Stenting has become an established interventional cardiology procedure for congenital heart disease. Although most stent procedures are completed successfully, complications may occur. This multicentre study evaluated early complications after stenting in patients with congenital heart disease, including potential risk factors. METHODS AND RESULTS: In this combined Dutch-Belgian retrospective study, 309 consecutive patients had undergone 366 catheterizations and received 464 stents in 13 different anatomical positions (418 sites). Seventy-two stenting-related complications (19%) occurred, of which 24 (5.7%) were major. Seven procedure-related deaths were documented (2.3%). Stent malpositioning and embolization were most common (7.7%). The use of non-premounted stents tended to be associated with higher complication rates. Centre inexperience with stenting and stenting of native vs. post-surgical stenosis tended to be associated with increased major complication rates. CONCLUSION: After stenting, complications are common for congenital heart disease. The vast diversity of stenotic sites combined with relatively small patient populations makes these procedures sensitive to complications. Combining operator experience may reduce the risks of stenting in congenital heart disease. The availability of premounted stents for greater vessel diameters will likely reduce incidences of stent migration and embolization. 相似文献
15.
Robert J van Thiel Sofie R Koopman Johanna J M Takkenberg Arend Derk Jan Ten Harkel Ad J J C Bogers 《European journal of cardio-thoracic surgery》2005,28(2):229-233
OBJECTIVE: To determine occurrence, causes and associated mortality of postoperative metabolic alkalosis in pediatric cardiac surgery. METHODS: We retrospectively analyzed clinical and biochemical variables of 186 consecutive cardiac operations other than ductal ligations on children less than 2 years old during the years 1999 and 2000. Metabolic alkalosis was defined as a pH>7.48 corrected for PCO2, with a base excess > or =5 on two or more consecutive measurements during an 8h period. RESULTS: Median age was 15 weeks [range 2 days-95 weeks] and median weight 4.5 kg [range 2.1-15.7 kg]. In 157 cases, cardiopulmonary bypass was used. In 92 [49%] procedures, metabolic alkalosis occurred with the highest corrected pH 24.3h after operation. Multivariate regression analysis associated age [P<0.001], cardiopulmonary bypass [P<0.001] and preoperative ductal dependency [P=0.04] with postoperative metabolic alkalosis. Of the surgical procedures the arterial switch for transposition of the great arteries [n=19] was strongly associated with metabolic alkalosis [100%, P<0.001]. Hemodilution appeared to enhance the development of alkalosis: those who experienced alkalosis had been hemodiluted to a greater extent [P=0.007]. Nearly 95% of patients experienced some increase in bicarbonate, but patients with metabolic alkalosis experienced more than those without [5.9 versus 3.5 mmol/l, P<0.001]. There were four postoperative deaths, only one coincidental with metabolic alkalosis. CONCLUSIONS: Metabolic alkalosis has a high incidence after pediatric cardiac surgery, strongly associated with younger age, cardiopulmonary bypass, preoperative ductal dependency and perioperative hemodilution. Early recognition allows for timely therapeutic intervention. 相似文献
16.
Nixie G. Raymond Johanna T. Dwyer Patricia Nevins Paul Kurtin 《Pediatric nephrology (Berlin, Germany)》1990,4(2):145-151
Children with mild to moderate renal insufficiency may be at an increased risk for developing glomerulosclerosis and subsequent renal failure. Low protein diets (LPD) have been shown to delay the progression of renal insufficiency in laboratory animals and may be of benefit in adult humans. The nutritional costs of a LPD in adults are reportedly minimal. We review the protein and caloric requirements of growing children and discuss the potential harmful effects and benefits of an LPD in this population. We also discuss dietary adherence and the difficulty of designing an LPD for children. We conclude that the protein content of a typical American diet can safely be reduced to, but not below, the recommended daily allowance for protein if diets are carefully planned, patients and their parents extensively counseled, and if dietary supplements are given to help meet the caloric and vitamin-mineral nutrient needs of growing children. In addition, ongoing nutritional assessment, counseling, and frequent monitoring of growth, diet and biochemical indicators of protein status are essential for maintaining the health of these children. 相似文献
17.
A Lusinchi P Wibault P Marandas I Kunkler F Eschwege 《International journal of radiation oncology, biology, physics》1989,17(2):273-277
One hundred and ninety-three T1 or T2 tumors of the tonsillar region have been treated by exclusive external irradiation between 1970 and 1982. Seventy-five percent of these tumors were classified as T2. There was no relationship between T and N stages. The nodal involvement was essentially linked to the macroscopic appearance of the tumor (superficial or nodular) and to the histology. The 5-year survival rate of the whole population was 58%. N stage and macroscopic appearance only influenced the survival. The local control was 88% for T1, 79% for T2. The main prognostic factors for local control were the histological type, with a 93% local control rate for poorly differentiated tumors versus 73% for well differentiated ones, and the macroscopic appearance, with a 83% local control rate for nodular tumors versus 75% for superficial ones. Superficial tumors spreading forward the anterior pilar have a higher local failure rate. All the patients' charts have been reviewed, and we observed a high percentage of marginal recurrences. The technique of irradiation, above all in case of a superficial tumor, must take into account the possibility of "geographic miss" and keep large safety margins. 相似文献
18.
Sarr O Myrick A Daily J Diop BM Dieng T Ndir O Sow PS Mboup S Wirth DF 《Parasitology research》2005,97(2):136-140
To determine the predictive value of chloroquine (CQ) resistance markers in Senegal, Plasmodium falciparum DNA polymorphisms in pfmdr1and pfcrt were examined in relation to clinical outcome. Despite CQ treatment, 17% of patients had parasitemia after 28 days. Examination of molecular markers of CQ resistance revealed that 64% of all isolates had the T76 resistant allele at the pfcrt locus, while 30% carried the Y86 resistant allele at the pfmdr1 locus. The pfcrt T76 allele was present not only in all in vivo resistant isolates, 89% of in vitro resistant isolates, but also in 35% of in vitro sensitive isolates. The pfmdr1 N86Y polymorphism did not correlate with in vitro or in vivo CQ resistance. Our data suggest that the pfcrt T76 allele alone is required but not a sufficient predictor for in vivo CQ resistance. 相似文献
19.
Manfred L'Age Johanna Stehr Peter Wahl 《Journal of molecular medicine (Berlin, Germany)》1963,41(13):659-662
Zusammenfassung Das Verhalten der Unveresterten Fettsäuren an Gesunden und Diabetikern und am epididymalen Fettgewebe der Ratte unter N1-n-Butylbiguanid wurde untersucht. Normalpersonen mit und ohne Biguanid reagieren bei Blutzuckerabfall mit einem Anstieg der UFS, der unter Biguanid signifikant höher ist. Diabetiker zeigen einen geringfügigen Abfall der UFS nach Biguanid. Unter Biguanidkonzentrationen, die der therapeutischen Serumkonzentration entsprechen (5/ml), werden vom Fettgewebe in Gegenwart von Glucose vermehrt UFS utilisiert. Bei hohen Konzentrationen (100 bis 1000/ml) tritt ein Wirkungsumschlag ein, die Fettsäureutilisation wird gehemmt.Teile dieser Arbeit sind in den Dissertationen vonM. L'age undJ. Stehr enthalten. 相似文献
20.
A. Fleckenstein E. Gerlach Johanna Janke P. Marmier 《Pflügers Archiv : European journal of physiology》1960,271(1):75-104
Ohne ZusammenfassungMit 7 TextabbildungenDie vorliegenden Studien am Physiologischen Institut Freiburg i. Br. wurden durch einen Bundeszuschuß des Ministeriums für Atomkernenergie und Wasserwirtschaft (Bonn) ermöglicht. Die Untersuchungen in Zürich wurden aus Mitteln des Schweizer Nationalfonds getragen. Den genannten Institutionen gilt unser besonderer Dank. Vorläufige Mitteilungen über die Methode und die hier dargestellten Ergebnisse wurden bereits früher gegeben [siehe Fleckenstein, A. E. Gerlach, u. J. Janke gemeinsam mit P. Marmier: Naturwissenschaften 46, 365 (1959); Pflügers Arch. ges. Physiol. 270, 20 (1959); P. Marmier gemeinsam mit E. Gerlach, J. Janke u. A. Fleckenstein: Pflügers Arch. ges. Physiol. 270, 19 (1959); A. Fleckenstein: University of London Special University Lectures in Physiology 26–28. Oct. 1959: The turnover rates of high energy phosphate compounds during activity and rest as indicated by the oxygen exchange with H2O18. Bericht von E. Gerlach sowie von J. Janke vor der Freiburger Med. Ges. vom 24. 11. 1959, vgl. Klin. Wschr. 38, 341–342 (1960)]. 相似文献