全文获取类型
收费全文 | 9467篇 |
免费 | 744篇 |
国内免费 | 276篇 |
专业分类
耳鼻咽喉 | 139篇 |
儿科学 | 165篇 |
妇产科学 | 168篇 |
基础医学 | 1131篇 |
口腔科学 | 660篇 |
临床医学 | 903篇 |
内科学 | 1200篇 |
皮肤病学 | 321篇 |
神经病学 | 1022篇 |
特种医学 | 587篇 |
外国民族医学 | 3篇 |
外科学 | 809篇 |
综合类 | 1334篇 |
现状与发展 | 1篇 |
预防医学 | 339篇 |
眼科学 | 136篇 |
药学 | 602篇 |
8篇 | |
中国医学 | 280篇 |
肿瘤学 | 679篇 |
出版年
2024年 | 33篇 |
2023年 | 161篇 |
2022年 | 302篇 |
2021年 | 427篇 |
2020年 | 377篇 |
2019年 | 316篇 |
2018年 | 288篇 |
2017年 | 339篇 |
2016年 | 374篇 |
2015年 | 353篇 |
2014年 | 690篇 |
2013年 | 651篇 |
2012年 | 569篇 |
2011年 | 616篇 |
2010年 | 445篇 |
2009年 | 383篇 |
2008年 | 391篇 |
2007年 | 351篇 |
2006年 | 313篇 |
2005年 | 249篇 |
2004年 | 228篇 |
2003年 | 215篇 |
2002年 | 147篇 |
2001年 | 160篇 |
2000年 | 117篇 |
1999年 | 120篇 |
1998年 | 113篇 |
1997年 | 106篇 |
1996年 | 109篇 |
1995年 | 111篇 |
1994年 | 93篇 |
1993年 | 78篇 |
1992年 | 73篇 |
1991年 | 81篇 |
1990年 | 61篇 |
1989年 | 66篇 |
1988年 | 52篇 |
1987年 | 47篇 |
1986年 | 42篇 |
1985年 | 88篇 |
1984年 | 103篇 |
1983年 | 67篇 |
1982年 | 80篇 |
1981年 | 71篇 |
1980年 | 87篇 |
1979年 | 57篇 |
1978年 | 52篇 |
1977年 | 51篇 |
1976年 | 60篇 |
1973年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Bengi Balci Alp Yildiz Sezai Leventoğlu Bulent Mentes 《World journal of gastrointestinal surgery》2021,13(11):1327-1337
Retrorectal or presacral tumors are rare lesions located in the presacral area and considered as being derived from multiple embryological remnants. These tumors are classified as congenital, neurogenic, osseous, inflammatory, or miscellaneous. The most common among these are congenital benign lesions that present with non-specific symptoms, such as lower back pain and change in bowel habit. Although congenital and developmental tumors occur in younger patients, the median age of presentation is reported to be 45 years. Magnetic resonance imaging plays a crucial role in treatment management through accurate diagnosis of the lesion, the evaluation of invasion to adjacent structures, and the decision of appropriate surgical approach. The usefulness of preoperative biopsy is still debated; currently, it is only indicated for solid or heterogeneous tumors if it will alter the treatment management. Surgical resection with clear margins is considered the optimal treatment; described approaches are transabdominal, perineal, combined abdominoperineal, and minimally invasive. Benign retrorectal tumors have favorable long-term outcomes with a low incidence of recurrence, whereas malignant tumors have a potential for distant organ metastasis in addition to local recurrence. 相似文献
62.
63.
应用粘液组化方法AB—PAS、HID—AB、OR—AB、PAT—KOH—PAS、PATB—KOH—PAS显示大肠上皮分泌粘液的类型。结果发现:大肠慢性炎、大肠克隆病及炎性息肉、增生性息肉、幼年性息肉分泌粘液类型与正常粘膜相似(P>0.05),而伴有异型增生的溃疡性结肠炎、管状腺瘤、绒毛状腺瘤、家族性息肉、腺瘤癌变、大肠癌及癌旁粘膜粘液分泌性质与量均有变化。在这些病变中氮乙酰化及含有邻位羟基的氧乙酰化粘液阳性率明显高于正常粘膜(P<0.05)。其检出阳性率与异型增生的程度有关。笔者认为应用粘液组化方法分析大肠癌前病变粘液性质对于判断粘膜上皮恶性倾向提供了有价值的手段。 相似文献
64.
65.
黄参方剂诱导胃癌癌前病变细胞凋亡和影响BCL—2蛋白表达的研究 总被引:2,自引:0,他引:2
目的:探讨黄参方剂对胃癌癌前病变细胞凋亡及相关基因表达的影响。方法:将72例胃癌癌前变患者随机分为2组,治疗组37例,口服黄参方剂60ml/d;对照组35例,口服维酶素片12片/天,疗程2月。治疗后胃镜同一部位取材,检测治疗前后细胞凋亡指数和BCL-2蛋白的表达。采用原位末端标记法(TUNEL)检测细胞凋亡,采用免疫组化检测BCL-2蛋白的表达。结果:黄参方剂组服药前后细胞凋亡指数分别为(19.8 相似文献
66.
Molecular genetic studies of early breast cancer evolution 总被引:9,自引:0,他引:9
Peter O'Connell PhD Vladimir Pekkel PhD Suzanne Fuqua PhD C. Kent Osborne MD D. Craig Allred MD 《Breast cancer research and treatment》1994,32(1):5-12
Summary In the past few years there has been an explosion in the number of patients diagnosed with hyperplastic breast disease andin situ breast cancer. Based on epidemiological data, these morphologically defined lesions may be categorized as those with little malignant potential (e.g. typical hyperplasia or proliferative disease without atypia [PDWA]), those with significant malignant potential which may already be initiated (e.g. atypical ductal hyperplasia [ADH]), and early transformed lesions which are malignant but not yet invasive (e.g. ductal carcinomain situ [DCIS]). They may represent sequential evolutionary stages in the ontogeny of invasive breast cancer, with each morphologically defined stage resulting from accumulating genetic changes culminating in a transformed clonal lineage capable of invasion and metastasis. Using loss-of-heterozygosity (LOH) analysis, we are studying the genetic changes associated with these lesions in archival tissue samples. 50% (6/12) of the proliferative lesions (PDWA and ADH) and 80% of the DCIS shared their LOH patterns with more advanced lesions from the same breast, strongly supporting a precursor/product relationship between these lesions and the cancers they accompany. 相似文献
67.
Post-stroke depression: Relationships with morphological damage and cognition over time 总被引:9,自引:0,他引:9
M. Iacoboni A. Padovani V. Di Piero G. L. Lenzi 《The Italian Journal of Neurological Sciences》1995,16(3):209-216
The aim of the present study was to investigate the relationships between poststroke depression (PSD), lesion location and cognitive deficits after stroke. We studied 20 patients within the first month after clinical onset (T1), and one year later (T2). PSD was observed in 55% of patients at T1 and 35% of patients at T2. At T1, depression was reliably correlated with dorsal lesions in the right-hemisphere and anterior lesions in the left hemisphere. Lesion location was no longer a significant factor determining PSD at T2. Changes in PSD, from T1 to T2, were inversely correlated with the performances in cognitive tests exploring the domains of attention, visuospatial learning, executive/motor functions, and with the global composite cognitive score. Our data suggest that: 1) in the mix of influences that may produce PSD, lesion location is the main factor determining mood changes after stroke in the first month; 2) PSD produces deficits in attention, learning, and executive/motor functions, without affecting language and other cognitive domains.
Sommario Scopo di questo studio sono i rapporti tra la depressione post-stroke (PSD), la localizzazione della lesione cerebrovascolare e i disturbi cognitivi conseguenti alla lesione. Abbiamo studiato 20 pazienti entro il primo mese dall'episodio ictale (T1) ed un anno dopo (T2). La PSD era osservabile nel 55% dei pazienti a T1 e nel 35% dei pazienti a T2. A T1, la PSD era significativamente correlata con lesioni dorsali nell'emisfero di destra e con lesioni anteriori nell'emisfero di sinistra. Queste correlazioni non erano più significative a T2. Le variazioni della PSD da T1 a T2 erano inversamente correlate con le prestazioni dei pazienti a compiti cognitivi di attenzione, apprendimento visuospaziale, funzioni esecutivo/motorie, e con un punteggio cognitivo composito.Questi dati suggeriscono che: 1) tra le numerose cause che possono produrre la PSD, la localizzazione della lesione sembra essere il fattore principale nel primo mese dopo l'episodio cerebrovascolare; 2) la PSD produce disturbi attentivi, di apprendimento visuospaziale ed esecutivi/motori senza determinare disturbi nella sfera del linguaggio e di altre funzioni cognitive.相似文献
68.
Susumu Furukawa Tomoyo Matsubara Toshihir Ino Keijiro Yabuta Yoshimi Umezawa Toshikazu Motohashi 《European journal of pediatrics》1994,153(9):663-667
We compared the efficacy of oral administration of pentoxifylline (PTX) and intravenous infusions of gamma globulin (IVGG) combination therapy with that of IVGG in reducing the frequency of coronary-artery lesions (CAL) in children with Kawasaki disease (KD), in a randomized trial. All patients with KD received acetylsalicylic acid (30 mg/kg per day), until the 30th day, after the onset of fever, followed by daily acetylsalicylic acid at a dose of 3-5 mg/kg per day there-after, and intravenous IVGG, 200 mg/kg per day, for 5 consecutive days. In addition, patients randomly assigned to PTX and IVGG combination therapy groups received oral PTX at a dosage of 10 mg/kg per day (low-dose) or 20 mg/kg per day (high-dose), in three divided doses until the 30th day. Patients with KD were all free from CAL prior to treatment. We assessed the presence of CAL by two-dimensional echocardiography which was also done prior to treatment and then twice a week after hospital admission. We detected CAL in 3 of 18 patients (16.7%) in the IVGG therapy group, as compared with 2 of 18 patients (11.1%) in the low-dose PTX and IVGG combination therapy group. There were no significant differences between the two groups. In the next study, we detected CAL in 3 of 21 patients (14.3%) in the IVGG therapy group, as compared with none of 22 patients (0%) in the high-dose PTX and IVGG combination therapy group (2 = 6.4, P < 0.02). No adverse side-effects were observed in 79 patients with KD. 相似文献
69.
Both the hippocampus and the entorhinal cortex are known to be crucial for spatial learning, but the contribution of the pathway linking the two structures, the perforant path (PP), has never been tested in a spatial learning paradigm. The present study examined the role of the PP in spatial learning using the Morris water maze. Seven days after bilateral transection of the PP with a fine-bladed knife, rats were habituated to the pool, then trained to swim from varying start locations to a platform submerged in a fixed location. After 28 training trials over 5 days, probe trials (without any platform present) were given to assess spatial memory for the location. Compared to sham-operated controls, lesioned rats showed slower learning and poorer asymptotic performance in terms of both swim path distance and escape latency, and less preference for the correct quadrant during probe trials. When the platform location was "reversed" to the opposite quadrant, the lesioned rats again showed poorer learning, poorer asymptotic performance, and reduced preference for the correct quadrant on the probe trial. When tested with a visible platform whose position varied from trial to trial, lesioned rats performed as well as controls. These results are congruent with previous analyses of the contributions of the entorhinal cortex and hippocampus to spatial learning and suggest that for spatial learning, the PP is a critical functional link between these two structures. 相似文献
70.
R. Formisano B. Schmidhuber-Eiler L. Saltuari E. Cigany G. Birbamer F. Gerstenbrand 《Acta neurochirurgica》1991,109(1-2):1-4
Summary The most frequent sequelae after severe brain injury include changes in personality traits, disturbances of emotional behaviour and impairment of cognitive functions. In particular, emotional changes and/or verbal and non verbal dysfunctions were found in patients with bilateral or unilateral temporal lobe lesions. The aim of our study is to correlate the localization of the brain damage after severe brain injury, in particular of the temporal lobe, with the cognitive impairment and the emotional and behavioural changes resulting from these lesions.The patients with right temporal lobe lesions showed significantly better scores in verbal intelligence and verbal memory in comparison with patients with left temporal lobe lesions and those with other focal brain lesions or diffuse brain damage. In contradistinction, study of the personality and the emotional changes (MMPI and FAF) failed to demonstrate pathological scores in the 3 groups with different CT lesions, without any significant difference being found between the groups with temporal lesions and those with other focal brain lesions or diffuse brain damage.The severity of the brain injury and the prolongation of the disturbance of consciousness could, in our patients, account for prevalence of congnitive impairment on personality and emotional changes. 相似文献