全文获取类型
收费全文 | 3156篇 |
免费 | 148篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 152篇 |
妇产科学 | 24篇 |
基础医学 | 365篇 |
口腔科学 | 54篇 |
临床医学 | 250篇 |
内科学 | 872篇 |
皮肤病学 | 37篇 |
神经病学 | 149篇 |
特种医学 | 101篇 |
外科学 | 464篇 |
综合类 | 110篇 |
预防医学 | 189篇 |
眼科学 | 63篇 |
药学 | 232篇 |
中国医学 | 16篇 |
肿瘤学 | 206篇 |
出版年
2023年 | 19篇 |
2022年 | 61篇 |
2021年 | 121篇 |
2020年 | 45篇 |
2019年 | 66篇 |
2018年 | 87篇 |
2017年 | 60篇 |
2016年 | 74篇 |
2015年 | 78篇 |
2014年 | 109篇 |
2013年 | 130篇 |
2012年 | 257篇 |
2011年 | 227篇 |
2010年 | 150篇 |
2009年 | 109篇 |
2008年 | 201篇 |
2007年 | 218篇 |
2006年 | 157篇 |
2005年 | 132篇 |
2004年 | 157篇 |
2003年 | 121篇 |
2002年 | 93篇 |
2001年 | 59篇 |
2000年 | 47篇 |
1999年 | 61篇 |
1998年 | 25篇 |
1997年 | 18篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 20篇 |
1991年 | 26篇 |
1990年 | 26篇 |
1989年 | 22篇 |
1988年 | 18篇 |
1987年 | 22篇 |
1986年 | 33篇 |
1985年 | 18篇 |
1984年 | 15篇 |
1983年 | 16篇 |
1982年 | 9篇 |
1976年 | 10篇 |
1975年 | 9篇 |
1974年 | 11篇 |
1973年 | 17篇 |
1972年 | 14篇 |
1971年 | 19篇 |
1968年 | 12篇 |
1966年 | 9篇 |
排序方式: 共有3314条查询结果,搜索用时 15 毫秒
81.
Ramachandran R Wedatilake Y Coats C Walker F Elliott P Lee PJ Lachmann RH Murphy E 《Journal of inherited metabolic disease》2012,35(2):245-251
We present a review of our experience and pregnancy outcome in patients with GSD III managed by our centre. Between 1997 and
2010 there were 15 pregnancies in seven women with GSD III. Four women had GSD IIIb (nine pregnancies) and three GSD IIIa
(six pregnancies). There was a successful outcome in all 15 pregnancies with delivery of 15 liveborn infants. Four infants
were of low birthweight (<2nd centile) but all have developed normally apart from one with behavioural/psychiatric problems.
Three women had pre-existing cardiomyopathy prior to pregnancy. One of these women had deterioration of her cardiomyopathy
during pregnancy and again in the post-partum period. Women with GSD III do not seem to have any issues with fertility. Overall
the outcome of pregnancy for both mother and child is good. Care needs to be taken to avoid maternal hypoglycemia which may
be associated with intrauterine growth restriction and low birth weight. Cardiac function should be monitored carefully particularly
in those with pre-existing cardiomyopathy. 相似文献
82.
Patel A Chang CC Terner JS Tuggle CT Persing JA 《The Journal of craniofacial surgery》2012,23(2):370-373
Orbital rim deficits are a feature of metopic, unilateral coronal, and bilateral coronal craniosynostosis. Several procedures have been developed to address this issue, but relapse to the preoperative hypoplastic deformity and stunted growth of the fronto-orbital region are common. The authors describe a technique modification of the conventional lateral canthal advancement referred to as the orbital rim "tilt" procedure, which aims to preserve inferior bony support for the orbital rim and create projection with optimal proclination of the fronto-orbital complex. 相似文献
83.
84.
85.
86.
Sadofsky LR Ramachandran R Crow C Cowen M Compton SJ Morice AH 《Experimental lung research》2012,38(2):75-81
Lung fibroblasts are involved in interstitial lung disease, chronic asthma, and chronic obstructive pulmonary disease (COPD). The expanded fibroblast population in airway disease leads to airway remodeling and contributes to the inflammatory process seen in these diseases. The cation channel transient receptor potential vanilloid-1 (TRPV1) is activated by noxious stimuli, including capsaicin, protons, and high temperatures and is thought to have a role in inflammation. Although TRPV1 expression is primarily reported to be neuronal, some extraneuronal expression has been reported. The authors therefore sought to determine whether human primary bronchial fibroblasts (HPBFs) express TRPV1 and whether inflammatory mediators can induce TRPV1 expression. The authors show that fibroblasts are predominantly TRPV1 negative; however, following stimulation with 3 common inflammatory mediators, tumor necrosis factor α (TNF-α), lipopolysaccharide (LPS), and interleukin-1α (IL-1α), TRPV1 mRNA was observed at 24 and 48 hours post treatment with all 3 mediators. Using Western blotting an increase in TRPV1 expression with all 3 inflammatory mediators was detected with significant increases seen at 72 hours post LPS and IL-1α treatment. In stark contrast to the untreated fibroblasts, significant calcium signaling in response to capsaicin and resiniferatoxin in HPBFs treated for 24 and 48 hours with TNF-α, LPS, or IL-1α was also observed. These results indicate that TRPV1 can be expressed on bronchial fibroblasts in situations where an underlying inflammatory stimulus exists, as is the case in airway diseases such as asthma and COPD. 相似文献
87.
Pellicoro A Aucott RL Ramachandran P Robson AJ Fallowfield JA Snowdon VK Hartland SN Vernon M Duffield JS Benyon RC Forbes SJ Iredale JP 《Hepatology (Baltimore, Md.)》2012,55(6):1965-1975
Elastin has been linked to maturity of liver fibrosis. To date, the regulation of elastin secretion and its degradation in liver fibrosis has not been characterized. The aim of this work was to define elastin accumulation and the role of the paradigm elastase macrophage metalloelastase (MMP-12) in its turnover during fibrosis. Liver fibrosis was induced by either intraperitoneal injections of carbon tetrachloride (CCl(4) ) for up to 12 weeks (rat and mouse) or oral administration of thioacetamide (TAA) for 1 year (mouse). Elastin synthesis, deposition, and degradation were investigated by immunohistochemistry, quantitative polymerase chain reaction (qPCR), western blotting, and casein zymography. The regulation of MMP-12 elastin degradation was defined mechanistically using CD11b-DTR and MMP-12 knockout mice. In a CCl(4) model of fibrosis in rat, elastin deposition was significantly increased only in advanced fibrosis. Tropoelastin expression increased with duration of injury. MMP-12 protein levels were only modestly changed and in coimmunoprecipitation experiments MMP-12 was bound in greater quantities to its inhibitor TIMP-1 in advanced versus early fibrosis. Immunohistochemistry and macrophage depletion experiments indicated that macrophages were the sole source of MMP-12. Exposure of CCl(4) in MMP-12(-/-) mice led to a similar degree of overall fibrosis compared to wildtype (WT) but increased perisinusoidal elastin. Conversely, oral administration of TAA caused both higher elastin accumulation and higher fibrosis in MMP-12(-/-) mice compared with WT. Conclusion: Elastin is regulated at the level of degradation during liver fibrosis. Macrophage-derived MMP-12 regulates elastin degradation even in progressive experimental liver fibrosis. These observations have important implications for the design of antifibrotic therapies. 相似文献
88.
Molecular characterization of β-thalassemia (β-thal) is essential in prevention and in understanding the biology of the disease. Deletion mutations are relatively uncommon in β-thal. In this report, we describe a novel 26 bp deletion from codon 6 to codon 14 in the β-globin in a consanguineous family from Tamil Nadu, India. This novel mutation causes a shift in the normal reading frame of the β-globin coding sequence, and consequently, a premature chain termination of translation due to the creation of a stop codon at the position of codon 21. The identification of this novel deletional mutation adds to the repertoire of β-thal mutations in India. 相似文献
89.
Jennifer E. Ho Martin G. Larson Ramachandran S. Vasan Anahita Ghorbani Susan Cheng Eugene P. Rhee Jose C. Florez Clary B. Clish Robert E. Gerszten Thomas J. Wang 《Diabetes》2013,62(8):2689-2698
To identify distinct biological pathways of glucose metabolism, we conducted a systematic evaluation of biochemical changes after an oral glucose tolerance test (OGTT) in a community-based population. Metabolic profiling was performed on 377 nondiabetic Framingham Offspring cohort participants (mean age 57 years, 42% women, BMI 30 kg/m2) before and after OGTT. Changes in metabolite levels were evaluated with paired Student t tests, cluster-based analyses, and multivariable linear regression to examine differences associated with insulin resistance. Of 110 metabolites tested, 91 significantly changed with OGTT (P ≤ 0.0005 for all). Amino acids, β-hydroxybutyrate, and tricarboxylic acid cycle intermediates decreased after OGTT, and glycolysis products increased, consistent with physiological insulin actions. Other pathways affected by OGTT included decreases in serotonin derivatives, urea cycle metabolites, and B vitamins. We also observed an increase in conjugated, and a decrease in unconjugated, bile acids. Changes in β-hydroxybutyrate, isoleucine, lactate, and pyridoxate were blunted in those with insulin resistance. Our findings demonstrate changes in 91 metabolites representing distinct biological pathways that are perturbed in response to an OGTT. We also identify metabolite responses that distinguish individuals with and without insulin resistance. These findings suggest that unique metabolic phenotypes can be unmasked by OGTT in the prediabetic state.Diabetes affects >1 in 10 adults 20 years of age or older in the U.S., and more than one-third of all adults have prediabetes (1). Changes in traditional measures of glucose and insulin metabolism are known to occur years before the diagnosis of diabetes is made (2). Using high-throughput profiling of metabolic status, we have shown that elevations in plasma branched-chain and aromatic amino acids are also able to predict future diabetes in otherwise normoglycemic, healthy adults (3). Similarly, lipid profiling has demonstrated novel perturbations in triacylglycerol distribution that signal future diabetes risk (4). These findings highlight how emerging technologies are able to broaden our perspective on early disease states, potentially lending insights into biological mechanisms that underlie diabetes and metabolic disease. Characterizing early metabolic changes may also lead to the early identification of at-risk individuals and may prompt the initiation of proven preventive strategies (5).The oral glucose tolerance test (OGTT) provides a dynamic view of glucose and insulin physiology and has been widely used for decades to diagnose diabetes (6,7). Therefore, we conducted a systematic evaluation of biochemical changes after OGTT in a community-based population, with the goal of providing a broad view of the metabolic response to a glucose challenge. An important advantage of profiling plasma samples before and after glucose ingestion is that each individual is able to serve as their own biological control. In addition to attenuating noise attributable to interindividual variation, this approach limits confounding effects of diet, medications, and other inputs that impact the human metabolome. We used a liquid chromatography/mass spectrometry (LC/MS)–based platform that allowed highly specific identification of small molecules in a targeted manner. In prior pilot studies, our group has shown that metabolite excursions with OGTT revealed a switch from catabolism to anabolism, largely attributable to insulin actions (8). In the current study, we sought to evaluate perturbations with OGTT in an expanded panel of metabolites and in a more comprehensive population-based sample with a high propensity for the development of diabetes, and to investigate these changes in individuals with and without insulin resistance. 相似文献
90.