全文获取类型
收费全文 | 85970篇 |
免费 | 4871篇 |
国内免费 | 2006篇 |
专业分类
耳鼻咽喉 | 1578篇 |
儿科学 | 4577篇 |
妇产科学 | 1470篇 |
基础医学 | 3994篇 |
口腔科学 | 904篇 |
临床医学 | 8589篇 |
内科学 | 13360篇 |
皮肤病学 | 1070篇 |
神经病学 | 3829篇 |
特种医学 | 3290篇 |
外国民族医学 | 23篇 |
外科学 | 11865篇 |
综合类 | 15326篇 |
现状与发展 | 3篇 |
一般理论 | 1篇 |
预防医学 | 4666篇 |
眼科学 | 1062篇 |
药学 | 6863篇 |
80篇 | |
中国医学 | 2937篇 |
肿瘤学 | 7360篇 |
出版年
2024年 | 830篇 |
2023年 | 1282篇 |
2022年 | 2662篇 |
2021年 | 3236篇 |
2020年 | 3028篇 |
2019年 | 2619篇 |
2018年 | 2650篇 |
2017年 | 2379篇 |
2016年 | 2991篇 |
2015年 | 2898篇 |
2014年 | 6382篇 |
2013年 | 5858篇 |
2012年 | 5761篇 |
2011年 | 6242篇 |
2010年 | 5401篇 |
2009年 | 4751篇 |
2008年 | 4577篇 |
2007年 | 4357篇 |
2006年 | 3824篇 |
2005年 | 3228篇 |
2004年 | 2678篇 |
2003年 | 2287篇 |
2002年 | 1873篇 |
2001年 | 1744篇 |
2000年 | 1359篇 |
1999年 | 1149篇 |
1998年 | 919篇 |
1997年 | 700篇 |
1996年 | 574篇 |
1995年 | 548篇 |
1994年 | 457篇 |
1993年 | 360篇 |
1992年 | 359篇 |
1991年 | 299篇 |
1990年 | 265篇 |
1989年 | 213篇 |
1988年 | 204篇 |
1987年 | 213篇 |
1986年 | 176篇 |
1985年 | 253篇 |
1984年 | 205篇 |
1983年 | 91篇 |
1982年 | 162篇 |
1981年 | 125篇 |
1980年 | 126篇 |
1979年 | 111篇 |
1978年 | 73篇 |
1977年 | 66篇 |
1976年 | 40篇 |
1973年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
VRK1 is a novel human putative serine/threonine kinase, and is located on chromosome 14 at band q32 where an autosomal recessive
congenital microphthalmia (CMIC) is mapped. We isolated a polymorphic dinucleotide CA repeat marker from a genomic clone containing
the human VRK1 gene. This polymorphism will be useful in genetic studies of disorders localized at the 14q32 region, such as CMIC.
Received: October 8, 1998 / Accepted: October 16, 1998 相似文献
92.
Martin Griebe Michael Daffertshofer Mark Stroick Magdalena Syren Parviz Ahmad-Nejad Michael Neumaier Juergen Backhaus Michael G. Hennerici Marc Fatar 《Neuroscience letters》2007
Biological markers play an evolving role in the diagnosis of Alzheimer disease (AD). We compare conventional measurements of cerebrospinal fluid (CSF) tau and β-amyloid1–42 proteins to a novel approach – Fourier transformed infrared (FT-IR) spectroscopy – a simple technique derived from chemical and physical sciences that characterizes intramolecular bonds. For automatic diagnostic analysis, we developed an artificial neural network (ANN). We examined 71 patients with a clinical diagnosis of AD and 66 controls. β-Amyloid1–42 was decreased (sensitivity 80% and specificity 78%); tau was elevated (sensitivity 76% and specificity 88%) in CSF of AD patients. The combined tau/β-amyloid1–42 quotient was able to distinguish healthy from diseased subjects with 99% sensitivity and 86% specificity. The ANN could separate FT-IR spectroscopy data with 88.5% sensitivity and 80% specificity. FT-IR spectroscopy proved to be cost-effective and simple to perform. Diagnostic sensitivity and specificity is in the range of CSF tau and β-amyloid1–42 protein analysis. Larger sample numbers for ANN training and validation could increase diagnostic accuracy and thus prove to be a useful screening tool. 相似文献
93.
Respiratory failure from pulmonary hypoplasia continues to be the major cause of death in newborn infants with diaphragmatic hernia. Recent investigations have suggested that postnatally induced pulmonary injury can result from excessive positive or negative intrathoracic pressure and contribute to the respiratory deterioration. Therefore, the method of thoracic drainage on the side of the diaphragmatic hernia is critical in controlling and maintaining normal intrathoracic pressure in both intrathoracic spaces. No chest tube or an ipsilateral chest tube connected to water seal, can result in either excessive negative or positive intrathoracic pressure and, therefore, both methods should be avoided. Recently, we employed a "balanced" intrathoracic drainage system which maintains the ipsilateral intrathoracic pressure within the normal physiologic range of +2 to -8 cm H2O regardless of the degree of pulmonary hypoplasia, presence of an ipsilateral pulmonary air leak, straining by the infant, or mechanical ventilation. This system is simple, requires no suction apparatus, and is easily assembled with equipment readily available within the hospital. This technique has been utilized in 18 newborn infants with diaphragmatic hernia and pulmonary hypoplasia. There have been no complications which specifically could be related to the balanced drainage system. 相似文献
94.
Corticosteroid therapy in biliary atresia 总被引:4,自引:0,他引:4
Sixteen patients with biliary atresia had 44 steroid courses for treatment of cholangitis or diminution of bile flow following Kasai hepatic portoenterostomy operations. A "blast" type (high dose/short duration) steroid administration was employed to potentiate the choleretic and anti-inflammatory effect. There was a significant augmentation of bile flow and a reduction in maximum temperature, serum bilirubin, and alkaline phosphatase. 相似文献
95.
Y. Giudicelli A. Pierre-Kahn A. M. Bourdeaux P. de Mazancourt D. Lacasa J. F. Hirsch 《Child's nervous system》1986,2(6):290-296
Congenital intraspinal lipomas are frequently responsible for progressive neurological deficits caused by distortion or compression of the nervous system. Since fat metabolism in these lesions has not been previously studied, the aim of this study was to determine whether intraspinal lipoma cells behave like lipomas or like normal adipocytes. In 11 patients, intraspinal lipoma cells were compared with normal adipocytes isolated from adjacent subcutaneous adipose tissue for the following parameters: lipoprotein lipase (LPL), lipogenesis from U14C glucose, ß-receptor number, adenylate cyclase activity, cyclic AMP production, and lipolysis in response to ß- and 2-adrenergic agonists. No significant difference between these two cell populations was found, suggesting that intraspinal lipomas are not lipomatous tumors, but hamartomatous lesions capable of growth and regression along with the changes in the rest of the fatty pool. This emphasizes the danger of an abnormal weight gain, as well as the possible usefulness of an hypocaloric diet in patients who worsen in spite of previous surgery.Research supported by INSERM (CRL 824005 and CRE 854010) and the D.G.R. 相似文献
96.
G. Meiser K. Meissner 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1986,368(3):197-207
Zusammenfassung Anhand einer prospektiven, auslesefreien Serie von 22 Patienten mit perforierten Ulcera im Gastroduodenalbereich verweisen wir auf die begrenzte diagnostische Aussagekraft einfacher anamnestischer, klinischer und radiologischer Daten. Lediglich bei acht Patienten (36%) ergaben sich wesentliche Indizien aus Krankengeschichte und Aufnahmebefund. Bei 16 Patienten (73%) verriet die Thoraxübersichtsaufnahme durch Nachweis einer subphrenischen Luftsichel eine Perforation im Magen-Darm-Trakt. Die Ultraschalluntersuchung wird als bedeutungsvolle Ergänzungsmethode vor allem in der diagnostischen Abklärung radiologisch negativer Ulcusperforationen vorgestellt und diskutiert. Dabei werden die sonographisch faßbare flüssigkeitsbedingte Magendistension sowie das Magenwandödem als unspezifische Kriterien gewertet. Der Objektivierung einer pathologischen Magenkokarde kommt bei gleichzeitigem Nachweis freier Luft und/oder extraluminärer Ingesta sowie freier echoloser Transsudatflüssigkeit pathognomonische Beweiskraft zu. Selbige Ultraschallkriterien erlaubten im einschlägigen Krankengut bei 16 Patienten (73%) eine definitive Diagnose und erfaßte 4 Patienten mit negativem Röntgen. Die kombinierte Analyse radiologischer und sonographischer Befunde führte somit bei 20 Patienten (91 %) unverzüglich zur korrekten Diagnose.
Perforated peptic ulcer: Diagnosis and assessment by sonography
Summary In a prospective unselected series of 22 patients with perforated gastroduodenal ulcers the diagnostic efficacy of clinical and radiologic data was modest. In eight patients only (36%), clinical data yielded sufficient evidence; in 16 patients (73%), plain X-ray demonstrated subphrenic gas. Sonography was proven to be a major advance, especially rewarding in the diagnosis of perforations with negative plain X-ray. Gastric distention and stomach wall edema are unspecifc sonographic criteria, whereas objectivation of a pathologic stomach cockade in the presence of free gas, extraluminary ingesta or echofree fluid in the peritoneal cavity are pathognomonic data. These criteria yielded a definite diagnosis in 16 patients (73%) including four patients with negative X-ray. The combined analysis of radiologic and sonographic findings yielded an immediate correct diagnosis in 20 patients (91%).相似文献
97.
98.
99.
CT诊断输尿管梗阻病因分析 总被引:3,自引:0,他引:3
目的 探讨CT诊断输尿管梗阻病因的价值。方法 本文收集 17例经多种泌尿系统的检查而未能确诊病因的资料。其中 ,12例经手术病理证实 ,2例经体外震波碎石治疗 ,3例经临床随访证实。结果 单纯性结石 5例 ,炎性狭窄 4例 ,乳头状移行细胞癌 2例 ,输尿管慢性炎症伴结石 1例 ,黄色肉芽肿性慢性肾盂肾炎伴结石 1例 ,右侧异位输尿管开口伴囊肿结石 1例 ,多囊肾伴左肾盂输尿管交界处狭窄 1例 ,左输尿管结核1例 ,乳房癌、直肠癌转移 /或侵犯输尿管各 1例。定位诊断率 10 0 % ,定性诊断率 88 2 4 %。结论 CT做为输尿管梗阻常规检查后的补充检查手段能有效提高病因诊断的正确率。 相似文献
100.
目的验证JOA X-线骨质疏松诊断标准的可靠性.方法47名女性病人(年龄65.3±7.2岁)行腰椎常规X-线检查和第三腰椎正、侧位DEXA骨密度测量.用t检验验证X-线骨质疏松等级间骨密度的差异性,用Spearman相关性分析法检验X-线骨质疏松等级与骨密度值的相关性.结果X-线骨质疏松等级间骨密度具有显著性差异(P<0.01),X-线骨质疏松等级与第三腰椎侧位骨密度值之间相关性最高(r=0.714).结论通过腰椎X-线片按照JOA标准划分骨质疏松等级,可以作为粗略检查腰椎骨质疏松的方法. 相似文献