全文获取类型
收费全文 | 8707篇 |
免费 | 557篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 237篇 |
妇产科学 | 173篇 |
基础医学 | 1310篇 |
口腔科学 | 139篇 |
临床医学 | 1091篇 |
内科学 | 1585篇 |
皮肤病学 | 161篇 |
神经病学 | 893篇 |
特种医学 | 261篇 |
外科学 | 777篇 |
综合类 | 129篇 |
一般理论 | 12篇 |
预防医学 | 1001篇 |
眼科学 | 170篇 |
药学 | 649篇 |
中国医学 | 8篇 |
肿瘤学 | 648篇 |
出版年
2024年 | 10篇 |
2023年 | 69篇 |
2022年 | 110篇 |
2021年 | 167篇 |
2020年 | 156篇 |
2019年 | 188篇 |
2018年 | 205篇 |
2017年 | 183篇 |
2016年 | 229篇 |
2015年 | 267篇 |
2014年 | 316篇 |
2013年 | 442篇 |
2012年 | 631篇 |
2011年 | 774篇 |
2010年 | 369篇 |
2009年 | 375篇 |
2008年 | 560篇 |
2007年 | 583篇 |
2006年 | 553篇 |
2005年 | 576篇 |
2004年 | 490篇 |
2003年 | 507篇 |
2002年 | 483篇 |
2001年 | 87篇 |
2000年 | 61篇 |
1999年 | 83篇 |
1998年 | 116篇 |
1997年 | 85篇 |
1996年 | 66篇 |
1995年 | 64篇 |
1994年 | 66篇 |
1993年 | 52篇 |
1992年 | 32篇 |
1991年 | 33篇 |
1990年 | 39篇 |
1989年 | 23篇 |
1988年 | 24篇 |
1987年 | 24篇 |
1986年 | 14篇 |
1985年 | 19篇 |
1984年 | 20篇 |
1983年 | 9篇 |
1982年 | 21篇 |
1981年 | 13篇 |
1980年 | 11篇 |
1979年 | 11篇 |
1978年 | 17篇 |
1977年 | 12篇 |
1976年 | 7篇 |
1975年 | 8篇 |
排序方式: 共有9293条查询结果,搜索用时 15 毫秒
21.
Kallol Ray Chaudhuri Pablo Martinez-Martin Anthony H V Schapira Fabrizio Stocchi Kapil Sethi Per Odin Richard G Brown William Koller Paolo Barone Graeme MacPhee Linda Kelly Martin Rabey Doug MacMahon Sue Thomas William Ondo David Rye Alison Forbes Susanne Tluk Vandana Dhawan Annette Bowron Adrian J Williams Charles W Olanow 《Movement disorders》2006,21(7):916-923
Nonmotor symptoms (NMS) of Parkinson's disease (PD) are not well recognized in clinical practice, either in primary or in secondary care, and are frequently missed during routine consultations. There is no single instrument (questionnaire or scale) that enables a comprehensive assessment of the range of NMS in PD both for the identification of problems and for the measurement of outcome. Against this background, a multidisciplinary group of experts, including patient group representatives, has developed an NMS screening questionnaire comprising 30 items. This instrument does not provide an overall score of disability and is not a graded or rating instrument. Instead, it is a screening tool designed to draw attention to the presence of NMS and initiate further investigation. In this article, we present the results from an international pilot study assessing feasibility, validity, and acceptability of a nonmotor questionnaire (NMSQuest). Data from 123 PD patients and 96 controls were analyzed. NMS were highly significantly more prevalent in PD compared to controls (PD NMS, median = 9.0, mean = 9.5 vs. control NMS, median = 5.5, mean = 4.0; Mann-Whitney, Kruskal-Wallis, and t test, P < 0.0001), with PD patients reporting at least 10 different NMS on average per patient. In PD, NMS were highly significantly more prevalent across all disease stages and the number of symptoms correlated significantly with advancing disease and duration of disease. Furthermore, frequently, problems such as diplopia, dribbling, apathy, blues, taste and smell problems were never previously disclosed to the health professionals. 相似文献
22.
Purpose. This paper compares unsteady-state and steady-state methods for estimating dermal absorption or analyzing dermal absorption data. The unsteady-state method accounts for the larger absorption rates during short exposure times as well as the hydrophilic barrier which the viable epidermis presents to lipophilic chemicals.
Methods. Example calculations for dermal absorption from aqueous solutions are presented for five environmentally relevant chemicals with molecular weights between 50 and 410 and log10Kow between 0.91 and 6.8: chloromethane, chloroform, chlordane, 2,3,7,8-TCDD, and dibenz(a,h)anthracene. Also, the new method is used to evaluate experimental procedures and data analyses of in vivo and in vitro permeation measurements.
Results. In the five example cases, we show that the steady-state approach significantly underestimated the dermal absorption. Also, calculating permeability values from cumulative absorption data measured for exposure periods less than 18 times the stratum corneum lag time will overestimate the actual permeability.
Conclusions. In general, steady-state predictions of dermal absorption will underestimate dermal absorption predictions which consider unsteady-state conditions. Permeability values calculated from data sets which include unsteady-state data will be incorrect. Strategies for analyzing in vitro diffusion cell experiments and confirming steady state are described. 相似文献
23.
24.
Steven D. Leach M.D. Annette I. LaMorte M.D. Lawrence D. True M.D. Stuart D. Flynn M.D. Peter E. Schwartz M.D. C. Elton Cahow M.D. Barbara K. Kinder M.D. 《World journal of surgery》1990,14(3):335-340
Syndromes involving peptide or nonsex steroid hormone secretion due to aberrantly located tumors are rare. We report a collected series of 16 patients with ectopic hormone production from ovarian neoplasms, including 3 patients recently encountered at our institution as well as 13 additional cases identified in the recent literature. These tumors included 2 insulin-producing ovarian carcinoids, 1 ACTH-producing pituitary adenoma within a benign ovarian cystic teratoma, 2 cortisol-producing ovarian neoplasms, 8 gastrin-producing ovarian cystadenomata or cystadenocarcinomata, and 3 thyroxine-producing ovarian strumal carcinoids. All patients presented with syndromes of hormone excess. Only 62% of all tumors were localized preoperatively. Following ovarian resection, 87% of patients remained disease-free with a median follow-up period of 1.5 years. In addition to ovariectomy, 8 additional unnecessary ablative procedures were performed in 7 patients. These included distal pancreatectomy, pancreaticoduodenectomy, adrenalectomy, total gastrectomy, selective vagotomy, and subtotal thyroidectomy. Failure to localize the ovarian neoplasm preoperatively was associated with a significantly higher risk of subsequent unnecessary ablative procedures. Because of the potential for the ovary to act as a source of aberrant hormone secretion, we recommend complete preoperative evaluation of the pelvis in female patients presenting with nonlocalizable endocrine tumors.
Presented at the International Association of Endocrine Surgeons in Toronto, Ontario, Canada, September, 1989. 相似文献
Resumen Los síndromes relacionados con la secreción de péptidos o de hormonas esteroideas no sexuales por tumores de ubicación aberrante ocurren infrecuentemente. En este artículo reportamos una serie de 16 pacientes con producción hormonal ectópica por neoplasmas ováricos, la cual incluye 3 pacientes vistos recientemente en nuestra institución y 13 identificados en la literatura médica de los últimos años. El grupo incluye 2 carcinoides ováricos productores de insulina, 1 adenoma pituitario productor de ACTH, 2 neoplasmas ováricos productores de cortisol, 8 cistadenomas o cistadenocarcinomas ováricos productores de gastrina, y 3 carcinoides ováricos estrumales productores de tiroxina. Todas las pacientes se presentaron con síndromes de exceso hormonal. En sólo el 62% de los tumores se pudo establecer la ubicación anatómica en la fase preoperatoria. Después de realizada la resección del ovario, 87% de las pacientes permanecieron libres de enfermedad en el período de seguimiento, que fue de 1.5 años en promedio. Además de la resección ovárica, se practicaron otros 8 procedimientos adicionales innecesarios en 7 pacientes. Estos incluyeron pancreatectomía distal, pancreatoduodenectomía, adrenalectomía, gatrectomía total, vagotomía selectiva, y tiroidectomía subtotal. La falla en la localización preoperatoria del neoplasma ovárico apareció asociada con un riesgo aumentado de ulteriores procedimientos quirúrgicos innecesarios. En vista de la potencialidad del ovario de actuar como fuente de secreción hormonal aberrante, nosotros recomendamos una completa evaluación de la pelvis en las pacientes femeninas en quienes se diagnostiquen tumores endocrinos no localizables.
Résumé Les syndromes concernant la sécrétion d'hormones peptidique ou stéroïde nonsexuelle due à des tumeurs ectopiques sont rares. Nous rapportons une série de 16 patientes avec une production d'hormone ectopique provenant de néoplasmes ovariens, comprenant 3 patientes récemment soignées dans notre établissement ainsi que 13 cas supplémentaires relevés dans la littérature récente. Ces tumeurs comprennent 2 tumeurs carcinoïdes ovariennes productrices d'insuline, 1 adénome hypophysaire producteur d'ACTH à l'intérieur d'un tératome cystique ovarien bénin, 2 néoplasmes ovariens producteurs de cortisol, 8 cystadénomes ou cystadénocarcinomes ovariens producteurs de gastrine, et 3 carcinoïdes ovariens strumaux producteurs de thyroxine. Toutes les patientes avaient des syndromes d'hyperproduction hormonale. Soixante-deux pour cent seulement des tumeurs avaient été localisées en préopératoire. Après ovariectomie, 87% des patientes étaient apparamment sans récidive avec un suivi médian d'un an et demi. Cependent, outre l'ovariectomie, 8 interventions supplémentaires non nécessaires ont été accomplis chez 7 patientes. Celles-ci comprenaient: pancréatectomie distale, duodénopancréatectomie, surrénalectomie, gastrectomie totale, vagotomie sélective, et thyroïdectomie subtotale. L'impossibilité de localiser le néoplasme ovarien en période préopératoire était associée à un risque notoirement plus grand de faire une résection inutile. Compte tenu de la possibilité pour l'ovaire de se comporter en producteur de sécrétion ectopique d'hormone, nous recommandons un examen complet préopératoire du bassin chez les femmes se présentant avec des tumeurs endocrines non localisables.
Presented at the International Association of Endocrine Surgeons in Toronto, Ontario, Canada, September, 1989. 相似文献
25.
26.
27.
Diagnosis of scaphoid fractures:A prospective multicenter study of 1,052 patients with 160 fractures
Bo Munk Johnny Fr kj r Claus Falck Larsen Hans Gad Johannsen Lars Lundager Rasmussen Annette Edal Lilla Demeney Rasmussen 《Acta orthopaedica》1995,66(4):359-360
In a prospective multicenter study of 1,052 patients with clinical signs of a scaphoid fracture, mammo-graphic films and fine intensifying screens were used at the radiographic examination. 5 standardized projections including 3 special projections focused on the scaphoid were taken. 150 fractures were diagnosed at the first examination but in 10 cases the fracture was first diagnosed at a second radiographic examination after 10-14 days.
The second examination still seems mandatory despite the use of high quality radiographs with optimal spatial resolution and contrast, and the value of supplementary special projections. 相似文献
The second examination still seems mandatory despite the use of high quality radiographs with optimal spatial resolution and contrast, and the value of supplementary special projections. 相似文献
28.
29.
Jürgen Vogt Torsten Schwarz Daniel Gras Johannes Sperzel Philippe Ritter Willem de Voogt Jean-Pierre Cebron Martin Seifert Bruce Tockman Bernd Schubert Eric Johnson Annette Doelger Thierry Pochet Elisabeth Mouton Christian Butter 《Journal of interventional cardiac electrophysiology》2007,19(1):61-68
Introduction Failure to enter the coronary sinus (CS) with a guiding catheter and entering its tributaries remains challenging in left
ventricle (LV) pacing lead implants for cardiac resynchronization therapy (CRT). A dual telescoping catheter system (8F outer/6F
inner) is designed to provide the ability to adjust the catheter curve size, shape and/or reach to the patients’ anatomy avoiding
the need for catheter change.
Methods Five different designs for CS cannulation were randomly tested in 64 patients scheduled for CRT device implant.
Results In 33 consecutive patients three adaptable telescoping guiding catheter systems were tested per patient, the adaptable catheters
had higher overall cannulation success rates (68, 63 and 62%) compared to the fixed shape catheter (46%) and an greater cannulation
success rate when the CS location was not known (70, 53 and 72% vs 33% for the fixed shape). In a second group of 31 CRT patients
the two telescoping catheters had similar high levels of success (71–80%), with or without using the inner catheter.
Conclusions The telescopic system is adaptable to a wide range of anatomical variations in patients and can result in a higher CS cannulation
success rate due to its adjustability in the RA in search for the CS ostium. On top of this the inner catheter allows for
sub-selecting the CS tributaries. 相似文献
30.
Preclinical evaluation of coronary vascular function after cardioplegia with HTK and different antioxidant additives. 总被引:10,自引:0,他引:10
Cornelia Schr?der Anke Heintz Annette Pexa Ursula Rauen Andreas Deussen 《European journal of cardio-thoracic surgery》2007,31(5):821-826
OBJECTIVE: Due to limited resources, improvement of preservation solutions is still of great importance in cardiac transplant surgery. New additives with antioxidant properties were tested with respect to coronary function of isolated rat hearts. METHODS: Bretschneider HTK solution containing none or an antioxidant additive (deferoxamine, trolox or LK 616) was used for 8h cold cardioplegia. After reperfusion with Krebs-Henseleit buffer (KHB), we assessed vascular dilator capacity (bradykinin, adenosine triphosphate, reactive hyperemia), myocardial function (left ventricular developed pressure, heart rate, oxygen consumption) and release of biochemical markers (aspartate aminotransferase, creatine kinase, lactate dehydrogenase, troponin, adenosine). RESULTS: Bradykinin- and adenosine triphosphate-induced vasodilations were largely reduced in hearts stored 8h in traditional HTK as compared to unstored controls. Storage in HTK+LK 616 significantly improved bradykinin-induced vasodilation. Vasodilation toward ATP was best preserved in hearts stored in HTK+deferoxamine. Deferoxamine and trolox, both improved reactive hyperaemic response during reperfusion. Left ventricular pressure development was significantly reduced after 8h cardioplegia, but no difference existed between different cardioplegia groups. Release of biochemical markers of tissue injury was similar in all cardioplegia groups. After storage in HTK+LK 616 (100 microM), however, heart marker release was slightly augmented as compared to HTK. CONCLUSIONS: Despite similar myocardial function and marker release, coronary vascular function after cardioplegic storage may profit by addition of iron chelators (or antioxidants) to traditional HTK solution. 相似文献