全文获取类型
收费全文 | 12952篇 |
免费 | 641篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 171篇 |
儿科学 | 377篇 |
妇产科学 | 352篇 |
基础医学 | 1616篇 |
口腔科学 | 304篇 |
临床医学 | 758篇 |
内科学 | 3510篇 |
皮肤病学 | 407篇 |
神经病学 | 859篇 |
特种医学 | 198篇 |
外科学 | 1709篇 |
综合类 | 133篇 |
一般理论 | 2篇 |
预防医学 | 1394篇 |
眼科学 | 232篇 |
药学 | 887篇 |
中国医学 | 79篇 |
肿瘤学 | 637篇 |
出版年
2023年 | 87篇 |
2022年 | 91篇 |
2021年 | 282篇 |
2020年 | 150篇 |
2019年 | 342篇 |
2018年 | 509篇 |
2017年 | 289篇 |
2016年 | 304篇 |
2015年 | 283篇 |
2014年 | 368篇 |
2013年 | 534篇 |
2012年 | 880篇 |
2011年 | 942篇 |
2010年 | 508篇 |
2009年 | 360篇 |
2008年 | 788篇 |
2007年 | 818篇 |
2006年 | 852篇 |
2005年 | 806篇 |
2004年 | 737篇 |
2003年 | 712篇 |
2002年 | 655篇 |
2001年 | 379篇 |
2000年 | 457篇 |
1999年 | 328篇 |
1998年 | 72篇 |
1997年 | 55篇 |
1996年 | 41篇 |
1995年 | 29篇 |
1994年 | 33篇 |
1993年 | 34篇 |
1992年 | 104篇 |
1991年 | 88篇 |
1990年 | 102篇 |
1989年 | 70篇 |
1988年 | 59篇 |
1987年 | 63篇 |
1986年 | 62篇 |
1985年 | 46篇 |
1984年 | 24篇 |
1983年 | 28篇 |
1982年 | 17篇 |
1980年 | 14篇 |
1979年 | 14篇 |
1978年 | 18篇 |
1976年 | 14篇 |
1974年 | 14篇 |
1973年 | 16篇 |
1971年 | 20篇 |
1969年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
152.
FGFR3 and Tp53 mutations in T1G3 transitional bladder carcinomas: independent distribution and lack of association with prognosis. 总被引:3,自引:0,他引:3
Silvia Hernández Elena López-Knowles Josep Lloreta Manolis Kogevinas Roberto Jaramillo Alex Amorós Adonina Tardón Reina García-Closas Consol Serra Alfredo Carrato Núria Malats Francisco X Real 《Clinical cancer research》2005,11(15):5444-5450
FGFR3 and Tp53 mutations have been proposed as defining two alternative pathways in the pathogenesis of transitional bladder cancer. FGFR3 mutations are associated with low-grade tumors and a favorable prognosis. Tp53 alterations are associated with advanced tumors and, possibly, with a poor prognosis. We focus here on the subgroup of T1G3 superficial tumors because they are a major clinical challenge. Patients (n = 119) were identified from a prospective study of 1,356 cases. Mutations in FGFR3 (exons 7, 10, and 15) and Tp53 (exons 4-9) were analyzed using PCR and direct sequencing. All cases were followed for recurrence and death. Survival was analyzed using Kaplan-Meier curves and multivariable Cox regression. FGFR3 mutations were detected in 20 (16.8%) tumors; 100 mutations in Tp53 were found in tumors from 78 (65.5%) cases. Multiple alterations in Tp53 were present in 19 tumors (16%). Inactivating mutations were present in 58% of tumors. The combined mutation distribution (FGFR3/Tp53) was: wt/wt (34.5%), mut/wt (7.6%), wt/mut (48.7%), and mut/mut (9.2%), indicating that the presence of either mutation did not depend on the other (P value = 0.767). FGFR3 and Tp53 mutations were not associated with clinicopathologic characteristics of patients and did not predict, alone or in combination, recurrence or survival. Taking the risk of the wt/wt group as reference, the mutation-associated risks of cancer-specific mortality were: mut/wt 1.42 (0.15-13.75), wt/mut 0.67 (0.19-2.31), mut/mut 1.62 (0.27-9.59). These molecular features support the notion that T1G3 tumors are at the crossroads of the two main molecular pathways proposed for bladder cancer development and progression. 相似文献
153.
154.
155.
Significance of High Density Lipoprotein-Cholesterol in Cardiovascular Risk Prevention 总被引:2,自引:0,他引:2
Juan F. Ascaso Arturo Fernández-Cruz Pedro González Santos Antonio Hernández Mijares Alipio Mangas Rojas Prof. Jesus Millán Luis Felipe Pallardo Juan Pedro-Botet Francisco Pérez-Jiménez Gonzalo Pía Xavier Pintó Ignacio Plaza Juan Rubiés-Prat 《Am J Cardiovasc Drugs》2004,4(5):299-314
In the approach to lipid-related risk factors for cardiovascular diseases, serum high density lipoprotein-cholesterol (HDL-C) levels bear a particular significance as this lipoprotein is considered to be an antiatherogenic factor mainly, but not only, because of its influence and impact on reverse cholesterol transport. Hence the need and requirement to consider serum HDL-C levels for both primary and secondary prevention of cardiovascular disease. A particularly important aspect is the association of the 'low HDL syndrome' with the metabolic syndrome. These factors force us to consider serum HDL-C level as a therapeutic target by itself, or even in association with low density lipoprotein-cholesterol (LDL-C) levels when the latter are increased. This review stresses the aspects connecting serum HDL-C levels and cardiovascular risk, and looks at the populations that should be considered amenable to therapeutic management because of low serum HDL-C levels. We review therapeutic strategies, both pharmacological and nonpharmacological. The aim of this review is to present therapeutic management recommendations for correcting the proportion of cardiovascular risk that is attributable to changes in HDL-C. Serum HDL-C levels of >40 mg/dL must be a therapeutic target in primary and secondary prevention. This goal is particularly important in patients with low serum HDL-C levels and ischemic heart disease (IHD) or its equivalents, even if the therapeutic target for serum LDL-C levels (<100 mg/dL) has been achieved. The first choice for this clinical condition is fibric acid derivates. The same therapeutic option should be considered in patients without IHD with low serum HDL-C levels and high cardiovascular risk (>20%), hypertriglyceridemia, type 2 diabetes mellitus, or metabolic syndrome. 相似文献
156.
Luz A. López-Ramírez Nahúm V. Hernández Nancy E. Lozoya-Pérez Leila M. Lopes-Bezerra Héctor M. Mora-Montes 《Research in microbiology》2018,169(3):188-197
Sporothrix schenckii is one of the causative agents of the deep-seated mycosis sporotrichosis, a fungal infection with worldwide distribution. Fungus-specific molecules and biosynthetic pathways are potential targets for the development of new antifungal drugs. The MNT1/KRE2 gene family is a group of genes that encode fungus-specific Golgi-resident mannosyltransferases that participate in the synthesis of O-linked and N-linked glycans. While this family is composed of five and nine members in Candida albicans and Saccharomyces cerevisiae, respectively, the S. schenckii genome contains only three putative members. MNT1 has been previously characterized as an enzyme that participates in the synthesis of both N-linked and O-linked glycans. Here, we aimed to establish the functional role of the two remaining family members, KTR4 and KTR5, in the protein glycosylation pathways by using heterologous complementation in C. albicans mutants lacking genes of the MNT1/KRE2 family. The two S. schenckii genes restored defects in the elaboration of N-linked glycans, but no complementation of mutants that synthesize truncated O-linked glycans was observed. Therefore, our results suggest that MNT1 is the sole member with a role in O-linked glycan elaboration, whereas the three family members have redundant activity in the S. schenckii N-linked glycan synthesis. 相似文献
157.
158.
Armando Pérez-Rangel José Manuel Hernández Araceli Castillo-Romero Lilián Yépez-Mulia Rafael Castillo Francisco Hernández-Luis Benjamín Nogueda-Torres Juan Pedro Luna-Arias Gerardo Radilla Gloria León-Avila 《Parasitology research》2013,112(9):3251-3257
In the present study, we evaluated the effect of an albendazole (ABZ) derivative JVG9 on cultured Giardia intestinalis. To assess the JVG9 effects, we evaluated the tubulin cytoskeleton by confocal microscopy, and we found that the characteristic staining was modified. The scanning electron microscopy images revealed extremely damaged trophozoites and cyst-like cells. The confocal images revealed that this drug triggered the expression of cyst wall protein 1 and encystation. We also found that at low doses, AL triggered the encystation process too. 相似文献
159.
Leticia Fiss Maria de Lourdes Adrien Clairton Marcolongo-Pereira Nathalia D. Assis-Brasil Eliza S. V. Sallis Franklin Riet-Correa Jerônimo L. Ruas Ana Lucia Schild 《Parasitology research》2013,112(2):883-887
Eight outbreaks of acute and subacute fasciolosis are reported in sheep in the municipality of Santa Vitória do Palmar, southern Brazil, in areas used for irrigated rice cultivation, which are subject to frequent flooding. Two outbreaks occurred mid-winter during July and August, and six occurred during spring and early summer. Morbidity ranged from 3 to 66.7 %, and mortality ranged from 3 to 50 %. Clinical signs included weight loss, mucosal pallor, apathy, depression, muscle tremors, and drooling; these were followed by death within approximately 24 h. Some sheep were found dead. Gross lesions were characterized by an irregular liver capsule with fibrin deposition and hemorrhages. The liver parenchyma contained hemorrhagic tracts or irregular clear areas alternated with dark hemorrhagic areas. Histologically, hemorrhagic dark red tracts of necrotic liver parenchyma and an inflammatory infiltrate were noted; these lesions coincided with the presence of immature flukes. Langhans-type giant cells, fibrous tissue, and bile duct cell proliferation were observed in subacute cases. Chronic fasciolosis is a well-known disease to farmers in southern Brazil; nevertheless, acute and subacute fasciolosis, which are more difficult to diagnose and treat, may cause important economic losses. Efficient control of fasciolosis requires integration of measures to treat infections in the definitive host, to reduce the population of snails of the genus Lymnaea, and to avoid contact between the parasite and host by appropriate pasture management. 相似文献