全文获取类型
收费全文 | 39993篇 |
免费 | 3091篇 |
国内免费 | 100篇 |
专业分类
耳鼻咽喉 | 329篇 |
儿科学 | 1221篇 |
妇产科学 | 832篇 |
基础医学 | 5134篇 |
口腔科学 | 459篇 |
临床医学 | 4492篇 |
内科学 | 7993篇 |
皮肤病学 | 922篇 |
神经病学 | 3716篇 |
特种医学 | 1321篇 |
外国民族医学 | 1篇 |
外科学 | 5358篇 |
综合类 | 558篇 |
一般理论 | 79篇 |
预防医学 | 4000篇 |
眼科学 | 1015篇 |
药学 | 2735篇 |
中国医学 | 34篇 |
肿瘤学 | 2985篇 |
出版年
2023年 | 325篇 |
2022年 | 460篇 |
2021年 | 919篇 |
2020年 | 598篇 |
2019年 | 967篇 |
2018年 | 1044篇 |
2017年 | 777篇 |
2016年 | 853篇 |
2015年 | 898篇 |
2014年 | 1256篇 |
2013年 | 1834篇 |
2012年 | 2739篇 |
2011年 | 2778篇 |
2010年 | 1478篇 |
2009年 | 1336篇 |
2008年 | 2345篇 |
2007年 | 2433篇 |
2006年 | 2411篇 |
2005年 | 2407篇 |
2004年 | 2230篇 |
2003年 | 2107篇 |
2002年 | 2049篇 |
2001年 | 484篇 |
2000年 | 376篇 |
1999年 | 430篇 |
1998年 | 442篇 |
1997年 | 419篇 |
1996年 | 357篇 |
1995年 | 341篇 |
1994年 | 278篇 |
1993年 | 285篇 |
1992年 | 317篇 |
1991年 | 279篇 |
1990年 | 254篇 |
1989年 | 247篇 |
1988年 | 220篇 |
1987年 | 211篇 |
1986年 | 199篇 |
1985年 | 232篇 |
1984年 | 234篇 |
1983年 | 238篇 |
1982年 | 267篇 |
1981年 | 285篇 |
1980年 | 226篇 |
1979年 | 177篇 |
1978年 | 190篇 |
1977年 | 197篇 |
1976年 | 132篇 |
1975年 | 138篇 |
1974年 | 150篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
Attitudes to childhood in general and towards one's own childhood in particular are compared in a survey of 152 Australian and New Zealand child psychiatric and paediatric trainees. Results confirm the findings of Enzer et al that paediatricians view childhood more positively than do child psychiatrists. Although there is a significant difference between the two groups on measures of their perceptions of the parenting they received with child psychiatrists rating their own parents as less caring than do paediatricians, there is no relationship between attitudes to childhood and perceptions of the parenting they received. Implications of these findings are examined, both in terms of motivation for choosing one or other specialty and for the working relationship between the two professions. 相似文献
122.
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
123.
The gustatory and olfactory basis of learned alcohol aversions was examined by testing rats with either gustatory neocortex ablations, olfactory bulb ablations, or a combination of both ablations. In the first experiment operated rats were compared with control rats in the acquisition of a learned alcohol aversion. In the second experiment, the effect of ablations on preoperatively-learned alcohol aversions was examined. Rats lacking gustatory neocortex learned and retained alcohol aversions normally although these rats extinguished the aversions faster than normal rats. Olfactory bulb ablation alone failed to disrupt normal aversion learning but completely eliminated retention of a previously acquired aversion. Combination ablations produced severe deficits both in acquisition and retention of learned alcohol aversions. The results indicate that, besides having gustatory qualities, the odor quality of alcohol is important in determining the associative and memorial characteristics of alcohol. 相似文献
124.
Induction of islet cytodifferentiation by fetal mesenchyme in adult pancreatic ductal epithelium. 总被引:4,自引:0,他引:4
Recombinant tissue consisting of adult ductal epithelium isolated from pancreas and fetal mesenchyme was transplanted subcutaneously in the inguinal region of nude mice or epididymal fat pads of rats with a tissue chamber device for short-term (8-day) or long-term (6- to 12-wk) duration. We found that recombinant tissue underwent morphogenesis and cytodifferentiation, thereby forming islets that contained cells immunocytochemically positive for insulin and glucagon. Islet cytodifferentiation occurred in approximately 20% of the recombinants. In recombinants that developed into islets, the tissue was always in close association with an extracellular matrix, nerves, and blood vessels. Controls consisting of mesenchyme alone or duct epithelium alone showed no evidence of morphogenesis of cytodifferentiation. Pancreatic rudiments were also implanted to serve as positive controls. This is the first demonstration of islet cytodifferentiation from adult duct epithelium. 相似文献
125.
Augusto Giussani Adeseye M Arogunjo Marie Claire Cantone Federico Tavola Ivan Veronese 《Applied radiation and isotopes》2006,64(6):639-644
The intestinal absorption of molybdenum in healthy human volunteers has been measured by simultaneous oral and intravenous administration of the stable isotopes 95Mo and 96Mo, and the results were analysed using the convolution integral technique. The results showed that molybdenum ingested in liquid form was rapidly and totally absorbed into the circulation under ordinary intake regimes. The rates and extent of absorption were lower for composite meals, and also for increasing levels of administration. This information can be helpful in the application of the new ICRP model of the human alimentary tract. 相似文献
126.
127.
128.
Lawrence G. Raisz MD 《Clinical reviews in bone and mineral metabolism》2006,4(2):123-127
Prostaglandins, particularly PGE2, have been shown to stimulate bone formation in a number of circumstances. Endogenous prostaglandins may be important in
heterotopic ossification and fracture healing. The major source of prostaglandins in bone is the inducible form of cyclooxygenase
(COX)-2 and inhibition of COX-2 may impair bone formation. Recent studies using selective agonists for the prostaglandin EP2
and EP4 receptors, which stimulate cAMP in bone cells, have suggested that these might be used clinically to accelerate bone
formation, particularly when used locally. 相似文献
129.
Dr. Joseph A. Kuhn MD Lawrence D. Wagman MD John A. Lorant MD Fredrick W. Grannis MD Mordecai Dunst MD William R. Dougherty MD Daniel I. Jacobs MD 《Annals of surgical oncology》1994,1(4):353-359
Background: A radical forequarter amputation with partial chest wall resection (one to four ribs) has been reported for benign and malignant
lesions involving the shoulder and chest wall region. Concerns about reconstruction and postoperative pulmonary function have
previously limited more extensive chest wall resections. The current report describes the first case in which a complete unilateral
anterior and posterior chest wall resection and pneumonectomy (hemithoracectomy) accompany a forequarter amputation. A novel
reconstructive technique used the full circumference of the forearm tissue with an intact ulna as a free osseomyocutaneous
flap.
Methods: In this case, a 21-year-old patient presented with an extensive recurrent desmoid tumor that involved the shoulder, brachial
plexus, subclavian vein, and chest wall from the lateral sternal border to the midportion of the scapula and down to the eighth
rib. The operative technique involved removal of the entire right hemithorax from the midline sternum to the transverse process
posteriorly, down to the ninth rib inferiorly. Due to the absence of a rigid hemithorax, the uninvolved ipsilateral lung was
also removed. The forearm flap was prepared before final separation of the specimen and division of the subclavian vessels.
Results: Postoperatively, the patient maintained excellent oxygenation without atelectasis or fever and was extubated on the 15th
postoperative day. As expected after pneumonectomy, significant decreases from preoperative to immediate postoperative values
were noted for the vital capacity (VC) (from 4.87 L to 1.29 L), forced 1-s expiratory volume (FEV1) (from 3.77 L to 1.02 L),
and inspiratory capacity (IC) (3.33 1 to 0.99 1). Rehabilitation included a specially designed external prosthesis to provide
cosmesis and prevent scoliosis. By the 15th postoperative week the patient had returned to normal social and physical activities,
with a gradual improvement in all respiratory parameters: VC 1.52 L, FEV1 1.29 L, IC 1.04 L. There has been no evidence of
tumor recurrence at 1 year.
Conclusions: This report provides evidence that a complete hemithoracectomy, pneumonectomy, and forequarter amputation can be safely performed
for selective tumors involving the shoulder region with extensive chest wall invasion. Reconstruction may be achieved with
an extended forearm osseomyocutaneous free flap with an excellent functional outcome.
Presented at the 46th Annual Cancer Symposium of The Society of Surgical Oncology, Los Angeles, California, March 18–21, 1993. 相似文献
130.
E. Eric Muirhead David H. P. Streeten Bennie Brooks Edward T. Schroeder Lawrence W. Byers 《Blood pressure》1992,1(3):138-148
A new syndrome is described in a patient with advanced renal insufficiency. This consists of severe and persistent hypotension causing weakness but associated with a clear mental status. Also present is evidence for decreased vascular reactivity. The hypotension was not orthostatic. The hypotension was associated with a circulating vasodepressor substance having the characteristics of medullipin I. The medullipin appears to have been derived from the remaining right kidney. Hypotension existed despite the presence of major prohypertensive mechanisms, including an endstage kidney, hyperreninemia and hyperaldosteronemia. It is likely that hypotension due to hypermedullipinemia is an entity occurring in the human being. 相似文献