全文获取类型
收费全文 | 215312篇 |
免费 | 17712篇 |
国内免费 | 6880篇 |
专业分类
耳鼻咽喉 | 1251篇 |
儿科学 | 7594篇 |
妇产科学 | 1541篇 |
基础医学 | 18954篇 |
口腔科学 | 3636篇 |
临床医学 | 22813篇 |
内科学 | 54483篇 |
皮肤病学 | 2709篇 |
神经病学 | 25725篇 |
特种医学 | 6231篇 |
外国民族医学 | 4篇 |
外科学 | 16577篇 |
综合类 | 30032篇 |
现状与发展 | 31篇 |
一般理论 | 9篇 |
预防医学 | 17069篇 |
眼科学 | 2334篇 |
药学 | 14976篇 |
185篇 | |
中国医学 | 10105篇 |
肿瘤学 | 3645篇 |
出版年
2024年 | 225篇 |
2023年 | 4337篇 |
2022年 | 5841篇 |
2021年 | 10916篇 |
2020年 | 10963篇 |
2019年 | 8326篇 |
2018年 | 8244篇 |
2017年 | 8196篇 |
2016年 | 8520篇 |
2015年 | 8227篇 |
2014年 | 15610篇 |
2013年 | 17066篇 |
2012年 | 12768篇 |
2011年 | 13815篇 |
2010年 | 10871篇 |
2009年 | 10443篇 |
2008年 | 10463篇 |
2007年 | 10123篇 |
2006年 | 9009篇 |
2005年 | 7436篇 |
2004年 | 6321篇 |
2003年 | 5434篇 |
2002年 | 4569篇 |
2001年 | 3958篇 |
2000年 | 3277篇 |
1999年 | 2722篇 |
1998年 | 2445篇 |
1997年 | 2102篇 |
1996年 | 1865篇 |
1995年 | 1937篇 |
1994年 | 1779篇 |
1993年 | 1512篇 |
1992年 | 1458篇 |
1991年 | 1282篇 |
1990年 | 1014篇 |
1989年 | 860篇 |
1988年 | 805篇 |
1987年 | 734篇 |
1986年 | 636篇 |
1985年 | 736篇 |
1984年 | 617篇 |
1983年 | 380篇 |
1982年 | 447篇 |
1981年 | 376篇 |
1980年 | 282篇 |
1979年 | 247篇 |
1978年 | 185篇 |
1977年 | 165篇 |
1976年 | 135篇 |
1975年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Functionally, platelets are primarily recognized as key regulators of thrombosis and hemostasis. Upon vessel injury, the typically quiescent platelet interacts with subendothelial matrix to regulate platelet adhesion, activation and aggregation, with subsequent induction of the coagulation cascade forming a thrombus. Recently, however, newly described roles for platelets in the regulation of angiogenesis have emerged. Platelets possess an armory of pro- and anti-angiogenic proteins, which are actively sequestered and highly organized in α-granule populations. Platelet activation facilitates their release, eliciting potent angiogenic responses through mechanisms that appear to be tightly regulated. In conjunction, the release of platelet-derived phospholipids and microparticles has also earned merit as synergistic regulators of angiogenesis. Consequently, platelets have been functionally implicated in a range of angiogenesis-dependent processes, including physiological roles in wound healing, vascular development and blood/lymphatic vessel separation, whilst facilitating aberrant angiogenesis in a range of diseases including cancer, atherosclerosis and diabetic retinopathy. Whilst the underlying mechanisms are only starting to be elucidated, significant insights have been established, suggesting that platelets represent a promising therapeutic strategy in diseases requiring angiogenic modulation. Moreover, anti-platelet therapies targeting thrombotic complications also exert protective effects in disorders characterized by persistent angiogenesis. 相似文献
992.
993.
BackgroundPatients with Parkinson's disease (PD) may develop several gait disturbances during the course of illness and Freezing of gait (FOG) is one of them. Several neuroimaging studies have been conducted to identify the neural correlates of FOG but results have not been uniform. Resting state functional MRI (rs-fMRI) is relatively less explored in PD patients with FOG. This study aims to compare the whole brain resting state connectivity of PD patients with and without FOG using rs-fMRI.Methodsrs-fMRI was obtained for 28 PD patients (15 with and 13 patients without FOG) who were matched for various demographic and clinical characteristics. Seed to voxel analysis was performed at whole brain level and compared between the two groups.ResultsWhen compared to patients without FOG, the patients with FOG had reduced functional connectivity across multiple seeds. Major finding was reduced inter-hemispheric connectivity of left parietal opercular cortex with multiple regions of the brain primarily involving the primary somatosensory and auditory areas, which also negatively correlated with the FOGQ scores.ConclusionOur findings suggest that alterations in the resting state functional connectivity of the opercular parietal cortex may be one of the substrates of FOG. Reduced interhemispheric connectivity probably is the reason for impairment of control and coordination in bilateral leg movements while walking. 相似文献
994.
Jennifer C Burgis Kaylie Nguyen KT Park Kenneth Cox 《World journal of gastroenterology : WJG》2016,22(6):2111-2117
AIM: To investigate the specific carbohydrate diet(SCD) as nutritional therapy for maintenance of remission in pediatric Crohn's disease(CD). METHODS: Retrospective chart review was conducted in 11 pediatric patients with CD who initiated the SCD as therapy at time of diagnosis or flare. Two groups defined as SCD simple(diet alone, antibiotics or 5-ASA) or SCD with immunomodulators(corticosteroids and/or stable thiopurine dosing) were followed for one year and compared on disease characteristics, laboratory values and anthropometrics.RESULTS: The mean age at start of the SCD was 11.8 ± 3.0 years(range 6.6-17.6 years) with five patients starting the SCD within 5 wk of diagnosis. Three patients maintained a strict SCD diet for the study period and the mean time for liberalization was 7.7 ± 4.0 mo(range 1-12) for the remaining patients. In both groups, hematocrit, albumin and ESR values improved while on strict SCD and appeared stable after liberalization(P-value 0.006, 0.002, 0.002 respectively). The majority of children gained in weight and height percentile while on strict SCD, with small loss in weight percentile documented with liberalization. CONCLUSION: Disease control may be attainable with the SCD in pediatric CD. Further studies are needed to assess adherence, impact on mucosal healing and growth. 相似文献
995.
《Pancreatology》2016,16(2):244-248
BackgroudMicroRNAs play important roles in the development and progression of many human diseases. mir-146a could significantly suppress the induction of proinflammatory cytokines IL-1β, IL-6, TNF-α, NF-κB and chemokine MCP-1, which might play important roles in chronic pancreatitis. This study was conducted to evaluate the association between mir-146a rs2910164, a functional polymorphism in the pre-mir-146a, and chronic pancreatitis risk.MethodsThe rs2910164 genotypes were determined in 165 patients with chronic pancreatitis and 200 healthy controls who were frequency matched for age and gender. One single nucleotide polymorphism (rs2910164) was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RLFP).ResultsThe frequency of individuals who carried [G] allele was significantly higher in cases (62.7%) than in controls (53.7%, p = 0.015), which resulted in a statistically significant pathogenic effect associated with this variant allele (OR: 1.448, CI: 1.076–1.950; p = 0.015). The GC and GG genotypes showed strong and significant increased risk for complication of chronic pancreatitis (OR = 3.668, 95%CI = 1.233–10.916, p = 0.019; OR = 5.667, 95%CI = 1.852–17.336, p = 0.002). The individuals carrying G allele confer a lower expression level of mature mir-146a.ConclusionThese findings suggest that the mir-146a rs2910164 may contribute to genetic susceptibility to chronic pancreatitis, and that mir-146a might be involved in chronic pancreatitis development. 相似文献
996.
Jennifer Wang Jonathan G. Stine Scott L. Cornella Curtis K. Argo Steven M. Cohn 《临床与转化肝病杂志(英文版)》2015,3(4):254-259
Background and Aims: Gastric antral vascular ectasia (GAVE) is commonly found in patients with cirrhosis, but it is also associated with other diseases in the absence of cirrhosis. Whether GAVE confers a different severity of gastrointestinal (GI) bleeding between patients with and without cirrhosis remains unknown. We aim to examine whether there is a difference in clinically significant GI bleeding due to GAVE in patients with or without cirrhosis. Methods: This is a retrospective case-control study of patients who were diagnosed with GAVE between January 2000 and June 2014. Patients were categorized into cirrhosis and noncirrhosis groups, and those with an additional GI bleeding source were excluded. Univariate comparisons and multivariable models were constructed using logistic regression. Results: In total, 110 patients diagnosed with GAVE on esophagogastroduodenoscopy (EGD) were included in our analysis; 84 patients had cirrhosis (76.4%) and 26 (23.6%) did not. Active GI bleeding was more prevalent in patients without cirrhosis (63.4% vs. 32.1%, p=0.003) despite similar indications for EGD, and endoscopic treatment with argon plasma coagulation (APC) was required more often in this group, approaching statistical significance (27% vs. 10.7%, p=0.056). There was no difference in bleeding severity, as evidenced by similar re-bleeding rates, surgery, or death attributed to uncontrolled bleeding. The strongest independent risk factor for GI bleeding was the absence of cirrhosis (odds ratio (OR): 5.151 (95% confidence interval (CI): 1.08-24.48, p=0.039). Conclusions: Patients with GAVE in the absence of cirrhosis are at higher risk for active GI bleeding and require more frequent endoscopic treatment than similar patients with cirrhosis. It may be worthwhile to treat GAVE in this population even in the absence of active bleeding. 相似文献
997.
998.
目的:讨论普通变异型免疫缺陷病(common variable immunodeficiency disease,CVID)的发病机制、临床表现及治疗方法。方法:报道1例普通变异型免疫缺陷病合并肝硬化患者并复习相关文献。结果:普通变异型免疫缺陷病是临床少见病,易误诊,病因不清,临床表现复杂,部分患者病程中可出现肝功能异常,甚至并发肝硬化。结论:临床反复感染的患者应考虑CVID的可能,须进一步作血浆免疫球蛋白的检测确诊。对已经确诊患者定期补充静脉丙种球蛋白,同时还应定期检查肝功能。 相似文献
999.
Gokul Vidyasankar Carolina Souza Chi Lai Sunita Mulpuru 《Canadian respiratory journal》2015,22(2):77-79
The present report describes a 48-year-old woman with a history of recurrent ‘crack’ cocaine use, who developed progressive shortness of breath over a period of years. Serial imaging revealed progressive interstitial fibrosis secondary to recurrent alveolar hemorrhage and inflammation from crack cocaine. The present case serves as a reminder of the numerous sequelae of crack cocaine use, highlighting one particularly severe outcome. 相似文献
1000.
Sentinel lymph node biopsy for 102 patients with primary cutaneous melanoma at a single Japanese institute 下载免费PDF全文
Masaki Otsuka Osamu Yamasaki Tatsuya Kaji Keiji Iwatsuki Kenji Asagoe 《The Journal of dermatology》2015,42(10):954-961
Sentinel lymph node biopsy (SLNB) is a widely accepted standard procedure for patients with clinically localized melanoma. Melanoma prevalence and Clark's subtype differ between Asians and Caucasians. Here, we evaluated our experience on SLNB for cutaneous melanoma in a Japanese population. SLNB was performed for patients with melanoma between July 2000 and June 2014. We retrospectively analyzed 102 patients regarding association of clinicopathological features with sentinel lymph node (SLN) status, melanoma‐specific survival (MSS) and disease‐free survival (DFS). A positive SLN was significantly associated with primary Breslow thickness. Compared with 43 patients with negative SLN, 59 patients with positive SLN had significantly shorter MSS (5‐year survival rate, 94.3% vs 63.2%; P = 0.0002) and DFS (5‐year survival rate, 92.7% vs 63.4%; P = 0.0004). According to our subgroup analyses, nine patients with positive non‐SLN had significantly shorter MSS compared with 32 patients with negative non‐SLN (5‐year survival rate, 32.4% vs 68.5%; P = 0.0273). The survival of 51 Japanese patients with acral lentiginous melanoma (ALM) was not inferior to the survival of patients with other Clark's subtype. Breslow thickness is an important factor for both MSS and DFS, and the status of SLN is the most predictive prognostic factor in Japanese patients with clinically localized melanomas, as in case of Caucasians. Features of ALM may be different between Asians and Caucasians. 相似文献