全文获取类型
收费全文 | 1744284篇 |
免费 | 127000篇 |
国内免费 | 3927篇 |
专业分类
耳鼻咽喉 | 22291篇 |
儿科学 | 56688篇 |
妇产科学 | 46906篇 |
基础医学 | 247579篇 |
口腔科学 | 49418篇 |
临床医学 | 156055篇 |
内科学 | 344814篇 |
皮肤病学 | 39157篇 |
神经病学 | 136019篇 |
特种医学 | 65818篇 |
外国民族医学 | 242篇 |
外科学 | 264582篇 |
综合类 | 39487篇 |
现状与发展 | 4篇 |
一般理论 | 596篇 |
预防医学 | 127945篇 |
眼科学 | 41186篇 |
药学 | 126661篇 |
7篇 | |
中国医学 | 4523篇 |
肿瘤学 | 105233篇 |
出版年
2021年 | 14010篇 |
2019年 | 14609篇 |
2018年 | 21347篇 |
2017年 | 16141篇 |
2016年 | 17660篇 |
2015年 | 20209篇 |
2014年 | 28064篇 |
2013年 | 40186篇 |
2012年 | 56441篇 |
2011年 | 59161篇 |
2010年 | 34909篇 |
2009年 | 32558篇 |
2008年 | 54818篇 |
2007年 | 58242篇 |
2006年 | 58643篇 |
2005年 | 55863篇 |
2004年 | 53695篇 |
2003年 | 50897篇 |
2002年 | 48906篇 |
2001年 | 92182篇 |
2000年 | 93932篇 |
1999年 | 77348篇 |
1998年 | 20182篇 |
1997年 | 17701篇 |
1996年 | 17741篇 |
1995年 | 17067篇 |
1994年 | 15555篇 |
1993年 | 14316篇 |
1992年 | 57617篇 |
1991年 | 55510篇 |
1990年 | 53171篇 |
1989年 | 50969篇 |
1988年 | 46303篇 |
1987年 | 45106篇 |
1986年 | 42400篇 |
1985年 | 40160篇 |
1984年 | 29542篇 |
1983年 | 25056篇 |
1982年 | 14057篇 |
1979年 | 25639篇 |
1978年 | 17679篇 |
1977年 | 15010篇 |
1976年 | 13954篇 |
1975年 | 14639篇 |
1974年 | 17710篇 |
1973年 | 17022篇 |
1972年 | 15725篇 |
1971年 | 14506篇 |
1970年 | 13475篇 |
1969年 | 12563篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
M Vitacca M Paneroni L Bianchi E Clini A Vianello P Ceriana L Barbano B Balbi S Nava 《The European respiratory journal》2006,27(2):343-349
The present study compared four different sites and conditions for the measurement of maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) in 38 spontaneous breathing tracheotomised patients. Of the patients, 28 had chronic obstructive pulmonary disease (COPD). The four different conditions were: 1) through a cuff inflated cannula (condition A); 2) through the mouth with a deflated cannula (condition B); 3) through the mouth with a phonetic uncuffed cannula (condition C); and 4) through the mouth after stoma closure (condition D). Five trials in each condition were performed using a standardised method. The measurement of both MIP and MEP differed significantly depending on the condition of measurement. MIP taken in condition A was significantly higher when compared with conditions B, C and D. MEP in condition A was significantly higher when compared with condition B and D. In condition A the highest frequency of the best measurement of MIP and MEP was observed at the fourth and fifth effort, respectively. The same results were obtained after the selection of only COPD patients. In conclusion, respiratory muscle assessment differs significantly depending on measurement condition. Measurement through inflated cannula tracheotomy yields higher values of both maximal inspiratory and maximal expiratory pressure. 相似文献
22.
23.
S. Spinty H. Rogozinski G. T. Lealman J. E. Wraith 《Journal of inherited metabolic disease》2003,25(8):697-698
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy. 相似文献
24.
25.
26.
AIM: The innovations for disease management need to be thoroughly evaluated so that their benefits and potential downsides can be compared with the already existing approaches. Endovascular laser (EVL) treatment for varicose veins offers today several advantages over surgical standard stripping. The Italian Endovenous-laser Working Group (IEWG) is a homogeneous group of surgeons and phlebologists who have been using EVL since 1999 and has undertaken to examine EVL in a multicenter study starting from a well defined rationale, with the benefit of a single protocol to use. METHODS: In a cooperative, multicenter, clinical study, 1076 limbs in 1050 patients, mean age of 54.5 years, 241 males and 809 females affected by chronic venous insufficiency (CVI) were considered eligible for surgery and stratified by CEAP classification in a four-year period (January 1999 December 2003). Inclusion criteria were insufficiency of the great and/or small saphenous vein at various levels, beyond those accessory saphenous trunks with incompetence in the saphenofemoral junction. In all cases truncular reflux apparead up on duplex scan examination, with or without associated varicosities. All the patients underwent a surgery on the basis of the clinical assessment. All the centres involved performed treatment in conformity with the Food and Drug Administration (FDA) validated procedure, using an endo-laser venous system kit with a 810-980 nm diode. Duplex scan was performed in all patients after 36 months with very few lost to follow-up cases. RESULTS: In the immediate postoperative period the results have been impressive, with a very effective closure of incompetent great saphenous vein and the other treated varicose veins (the early occlusion rate has been 99%). Major complications have not been detected: in particular, no deep venous thrombosis (DVT) evaluated duplex ultrasound. The patients' acceptability and satisfaction regarding the procedure, have been measured by means of a questionnaire on the quality of life, and the result was 96.7%. After 36 months, the total occusion rate of saphenous trunks has been 97%. CONCLUSIONS: The first important Italian experience with EVL based on preoperative, perioperative and postoperative duplex control and which is also based on the patients' satisfaction at mid/long-term has indicated some advantages over the standard treatment with the stripping method. In terms of reduced postoperative pain, shorter sick leave, a faster resumption of the normal activities, and, in particular, the total absence of DVT, we can conclude that EVL is a good solution for all patients with anatomic and hemodinamic patterns for saphenous vein surgery. 相似文献
27.
28.
Johannes Brettschneider Axel Petzold Sigurd D Süssmuth Georg B Landwehrmeyer Albert C Ludolph Jan Kassubek Hayrettin Tumani 《Movement disorders》2006,21(12):2224-2227
We aimed to evaluate the potential of the cerebrospinal fluid (CSF) axonal damage biomarker NfH(SMI35) in the laboratory-supported differential diagnosis of parkinsonian syndromes. Patients with idiopathic Parkinson's disease (PD; n = 22), multiple-system atrophy (MSA; n = 21), progressive supranuclear palsy (PSP; n = 21), corticobasal degeneration (CBD; n = 6), and age-matched controls (n = 45) were included. CSF levels of NfH(SMI35) were measured using ELISA. Levels of CSF NfH(SMI35) were elevated in PSP compared to PD and controls (P < 0.05 each). They were also significantly higher in MSA than in PD and controls (P < 0.05 each). NfH(SMI35) differentiated PD from PSP with a sensitivity of 76.5% and a specificity of 94.4%. Axonal damage as measured by CSF NfH(SMI35) is most prominent in the more rapidly progressive syndromes PSP and MSA as compared to PD or CBD. CSF NfH(SMI35) may therefore be of some value for the laboratory-supported differential diagnosis of atypical parkinsonian syndromes. 相似文献
29.
S Dvorakova E Vaclavikova A Ryska J Cap P Vlcek J Duskova D Kodetova V Holub Z Novak B Bendlova 《Experimental and clinical endocrinology & diabetes》2006,114(4):192-196
Medullary thyroid carcinoma (MTC) is a rare form of thyroid cancer representing about 10% of all thyroid malignancies. It occurs mostly as a sporadic tumor or in association with autosomal dominant inherited cancer syndromes--multiple endocrine neoplasia (MEN) types 2A and 2B and familial MTC. Germline mutations in exons 8, 10, 11, 13, 14, 15 and 16 of the RET proto-oncogene are found in most of the familial cases. There are only a few published data reporting multiple germline mutations in the RET proto-oncogene. We have detected double germline mutations in 2 different exons on the same RET allele in two MEN 2 families. In the MEN 2A family, double germline mutation in exons 10 (Cys620Phe) and 13 (Tyr791Phe) was detected. In the MEN 2B family, beside the classical germline mutation in exon 16 (Met918Thr) a second germline mutation in exon 13 (Tyr791Phe) was found. This study revealed that MEN 2 syndromes can also be caused by double germline mutations in the RET proto-oncogene and these families can be added to small worldwide cohort of families with multiple germline mutations. 相似文献
30.
J Phua E S C Koay D Zhang L K Tai X L Boo K C Lim T K Lim 《The European respiratory journal》2006,28(4):695-702
Levels of the soluble form of the triggering receptor expressed on myeloid cells (sTREM)-1 are elevated in severe sepsis. However, it is not known whether sTREM-1 measurements can distinguish milder bacterial infections from noninfectious inflammation. The present authors studied whether serum sTREM-1 levels differ in community-acquired pneumonia, exacerbations of chronic obstructive pulmonary disease (COPD), asthma and controls, and whether sTREM-1 may be used as a surrogate marker for the need for antibiotics. Serum sTREM-1 levels in 150 patients with pneumonia, COPD and asthma exacerbations and 62 healthy controls were measured. Serum sTREM-1 levels were significantly elevated in pneumonia (median 295.2 ng x mL(-1)), COPD (280.3 ng x mL(-1)) and asthma exacerbations (184.0 ng x mL(-1)) compared with controls (83.1 ng x mL(-1)). Levels were higher in pneumonia and Anthonisen type 1 COPD exacerbations than in type 2 and 3 COPD and asthma exacerbations. The area under the receiver operating characteristics curve for sTREM-1 as a surrogate marker for the need for antibiotics was 0.77. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 were elevated predominantly in pneumonia and Anthonisen type 1 COPD exacerbations versus type 2 and 3 chronic obstructive pulmonary disease exacerbations, asthma and controls. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 has moderate but insufficient accuracy as a surrogate marker for the need for antibiotics in lower respiratory tract infections. 相似文献