全文获取类型
收费全文 | 22255篇 |
免费 | 1675篇 |
国内免费 | 643篇 |
专业分类
耳鼻咽喉 | 105篇 |
儿科学 | 289篇 |
妇产科学 | 190篇 |
基础医学 | 1492篇 |
口腔科学 | 175篇 |
临床医学 | 1923篇 |
内科学 | 5163篇 |
皮肤病学 | 308篇 |
神经病学 | 1127篇 |
特种医学 | 306篇 |
外国民族医学 | 1篇 |
外科学 | 2459篇 |
综合类 | 1643篇 |
现状与发展 | 2篇 |
预防医学 | 672篇 |
眼科学 | 228篇 |
药学 | 5395篇 |
11篇 | |
中国医学 | 313篇 |
肿瘤学 | 2771篇 |
出版年
2024年 | 57篇 |
2023年 | 511篇 |
2022年 | 804篇 |
2021年 | 1070篇 |
2020年 | 1006篇 |
2019年 | 895篇 |
2018年 | 832篇 |
2017年 | 896篇 |
2016年 | 817篇 |
2015年 | 920篇 |
2014年 | 1243篇 |
2013年 | 2473篇 |
2012年 | 1155篇 |
2011年 | 1350篇 |
2010年 | 1012篇 |
2009年 | 1024篇 |
2008年 | 984篇 |
2007年 | 934篇 |
2006年 | 874篇 |
2005年 | 681篇 |
2004年 | 558篇 |
2003年 | 545篇 |
2002年 | 495篇 |
2001年 | 388篇 |
2000年 | 326篇 |
1999年 | 273篇 |
1998年 | 267篇 |
1997年 | 257篇 |
1996年 | 199篇 |
1995年 | 187篇 |
1994年 | 150篇 |
1993年 | 152篇 |
1992年 | 118篇 |
1991年 | 105篇 |
1990年 | 96篇 |
1989年 | 92篇 |
1988年 | 76篇 |
1987年 | 93篇 |
1986年 | 59篇 |
1985年 | 86篇 |
1984年 | 77篇 |
1983年 | 52篇 |
1982年 | 78篇 |
1981年 | 54篇 |
1980年 | 55篇 |
1979年 | 46篇 |
1978年 | 45篇 |
1977年 | 28篇 |
1976年 | 27篇 |
1973年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Leslie J. Crofford Lindsay E. Nyhoff Jonathan H. Sheehan Peggy L. Kendall 《Expert Review of Clinical Immunology》2016,12(7):763-773
Bruton’s tyrosine kinase (BTK) mediates B cell signaling and is also present in innate immune cells but not T cells. BTK propagates B cell receptor (BCR) responses to antigen-engagement as well as to stimulation via CD40, toll-like receptors (TLRs), Fc receptors (FCRs) and chemokine receptors. Importantly, BTK can modulate signaling, acting as a “rheostat” rather than an “on-off” switch; thus, overexpression leads to autoimmunity while decreased levels improve autoimmune disease outcomes. Autoreactive B cells depend upon BTK for survival to a greater degree than normal B cells, reflected as loss of autoantibodies with maintenance of total antibody levels when BTK is absent. This review describes contributions of BTK to immune tolerance, including studies testing BTK-inhibitors for treatment of autoimmune diseases. 相似文献
952.
Ting Huyan Qi Li Dan-Dan Dong Hui Yang Jian Zhang Qing-Sheng Huang 《Immunopharmacology and immunotoxicology》2016,38(2):77-86
Heat shock protein 90 (Hsp90) is a ubiquitously expressed ATP-dependent molecular chaperone across all species that helps to the correct the folding of many proteins related to important signaling pathways. Tumor cells expressing Hsp90 have more ATP-binding affinity than normal cells. Many correlative inhibitors have been developed to promising anti-tumor strategies and have been evaluated in clinical trials. However, the effect of Hsp90 inhibitors on immunocytes cannot be ignored. Natural killer (NK) cells are key components of the innate immune system that play a pivotal role in tumor surveillance. The present study has investigated the potential effect of four Hsp90 inhibitors (NVP-AUY922, BIIB021, 17-DMAG, and SNX-2112) on human primary NK cells. The viability, cytotoxicity, apoptosis, phenotype, and cytokine secretion of NK cells after inhibitor treatment were assessed. The results of this study demonstrated that the inhibitors had negative effects on NK cell activity in a dose-dependent manner. The four inhibitors significantly reduced the cytotoxicity of the NK cells by decreasing viability, inducing apoptosis and down-regulating the expression of cytokines and functional receptors. These findings suggest that more attention should be given to the effect of Hsp90 inhibitors on NK cell function during clinical trials and also represent a potential immunosuppressant strategy. 相似文献
953.
Lass-Flörl C Wiedauer B Mayr A Kirchmair M Jenewein I Ledochowski M Dierich MP 《International journal of medical microbiology : IJMM》2002,291(8):655-657
This study shows that 5-hydroxytrypatmine (5-HT, serotonin) is fungicidal towards conidia and hyphae of clinical isolates of Aspergillus (A.) fumigatus, A. flavus and A. terreus. The minimal fungicidal concentrations for Aspergillus conidia and hyphae ranged between 14.68 to 117.5 mM and 29.37 to 235 mM during 24 and 48 h of incubation. Several serotonin receptor antagonists (5-HT2, 5-HT3) studied in vitro did not influence antifungal activity. 相似文献
954.
Mitogen activated protein kinase pathway is involved in RhoC GTPase induced motility,invasion and angiogenesis in inflammatory breast cancer 总被引:9,自引:0,他引:9
van Golen KL Bao LW Pan Q Miller FR Wu ZF Merajver SD 《Clinical & experimental metastasis》2002,19(4):301-311
Inflammatory breast cancer (IBC) is the most lethal form of locally advanced breast cancer known. IBC carries a guarded prognosis
primarily due to rapid onset of disease, typically within six months, and the propensity of tumor emboli to invade the dermal
lymphatics and spread systemically. Although the clinical manifestations of IBC have been well documented, until recently
little was known about the genetic mechanisms underlying the disease. In a comprehensive study aimed at identifying the molecular
mechanisms responsible for the unique IBC phenotype, our laboratory identified overexpression of RhoC GTPase in over 90% of
IBC tumors in contrast to 36% of stage-matched non-IBC tumors. We also demonstrated that overexpression of RhoC GTPase in
human mammary epithelial (HME) cells nearly recapitulated the IBC phenotype with regards to invasion, motility and angiogenesis.
In the current study we sought to delineate which signaling pathways were responsible for each aspect of the IBC phenotype.
Using well-established inhibitors to the mitogen activated protein kinase (MAPK) and phosphatidylinositol-3 kinase (PI3K)
pathways. We found that activation of the MAPK pathway was responsible for motility, invasion and production of angiogenic
factors. In contrast, growth under anchorage independent conditions was dependent on the PI3K pathway.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
955.
The fourth-generation centrifugal blood pump 总被引:1,自引:0,他引:1
The NEDO Gyro permanently implantable (PI) centrifugal blood pump has been developed as a simple, durable, centrifugal blood
pump without a complex magnetic suspension system. In vitro studies were performed using a Gyro PI pump with the transparent
pump housing in a mock circuit. These studies revealed that the impeller transfers to a floating or a top contact condition,
which was dependent on the revolutions per minute (RPM). This pump can be easily converted from a left ventricular assist
device (LVAD) to a right ventricular assist device (RVAD) by simply adding a spacer between the pump and the actuator. In
order to optimize the impeller suspension for the LVAD and RVAD, spacers of the proper thickness are inserted between both
of the pumps and the actuators to regulate the magnetic force. Two Gyro PI pumps were implanted in a bovine model in a 3-month
biventricular assist device (BVAD) animal study. This experiment was electively terminated 90 days after implantation. All
of the parameters, including pump flow rate, power consumption, and plasma free hemoglobin, were in acceptable ranges. No
thrombus formation was observed in either pump. Antithrombogenesis and effectiveness were demonstrated in this animal study.
The NEDO Gyro PI pump is ready to move on to the 3-month preclinical system evaluation.
Received: February 28, 2002 / Accepted: May 30, 2002
Acknowledgment The New Energy and Industrial Technology Development Organization (NEDO) under the Ministry of Economy, Trade and Industry
of Japan financially supported this project.
Correspondence to:S. Ichikawa 相似文献
956.
为了探讨血小板计数在血泵离体实验中的意义。我们用两种滚压泵分成两组,作5对16小时离体长时间转流实验,血样本为转前作对照组、转流4h后每隔2h抽1次。测定项目:血小板计数、游离血红蛋白。结果:两组血小板计数值均随转流时间延长而呈线性逐渐增加,各时点值与前时点比(P<0.05),有显著差异,两组游离血红蛋白量也随转流时间延长而呈线性增加。血小板计数与游离血红蛋白呈直线回归相关关系。结论;在血泵离体转流实验中,血小板计数可反映血细胞碎片的数量,因此可作为一项评价血泵离体溶血性能的客观指标。 相似文献
957.
目的:探讨乳腺癌转移的机制,为深入研究乳腺癌发生、发展机制提供理论基础。方法:不同浓度的弗林蛋白酶(furin)抑制剂处理人乳腺癌细胞MCF-7 48 h。细胞划痕实验(wound healing assay)和细胞趋化实验(Transwell assay)检测MCF-7细胞迁移和侵袭能力。Western blotting 检测细胞迁移相关蛋白膜型基质金属蛋白酶1(MT1-MMP)、血管内皮生长因子(VEGF)-C和VEGF-D水平。酶联免疫吸附法(ELISA)检测细胞培养液中基质金属蛋白酶(MMP)2和9水平。结果:与对照组相比,200 nmol/L的furin抑制剂α1-PDX即对细胞迁移及侵袭起显著抑制作用(均P<0.05);细胞迁移相关的MT1-MMP、VEGF-C和VEGF-D表达水平均显著降低(P<0.05);MCF-7细胞上清液中MMP2 和 MMP9的表达均显著降低(P<0.05)。结论:Furin抑制剂通过下调乳腺癌细胞MCF-7的MMPs及VEGFs表达抑制其迁移。 相似文献
958.
磁液悬浮离心血泵体外溶血的实验及耐久性实验 总被引:1,自引:0,他引:1
通过建立模拟循环管路系统来研究磁液悬浮离心血泵的溶血性能及机械稳定性。建立体外模拟循环管路系统,体外溶血实验中以新鲜羊血为循环介质,调节前负荷和后负荷分别为15、100 mmHg,血泵转速设定为2 900 rpm,测定血浆游离血红蛋白含量(FHb)和红细胞压积(Hct),计算血泵标准溶血指数(NIH);耐久性试验其他各项设定同体外溶血实验,循环介质改为甘油水溶液。在体外溶血实验中,测得磁液悬浮离心血泵NIH值为(0.0038±0.0008)g/100L;耐久性实验中血泵连续正常运转90 d,期间无卡壳、停泵等现象,电压、电流、转速稳定。该血泵溶血性能处于较高水平,机械性能稳定可靠,满足进一步进行动物实验的要求。 相似文献
959.
J. Narváez P. Juarez-López J. LLuch J.A. Narváez R. Palmero X. García del Muro J.M. Nolla E. Domingo-Domenech 《Autoimmunity reviews》2018,17(10):1040-1045
Objective
To evaluate the prevalence and type of rheumatic immune-related adverse events (IRAEs) in patients receiving programmed cell death protein-1 (PD-1) inhibitors.Methods
This is a single-center prospective observational study, including all cancer patients receiving PD-1 inhibitors between January 2016 and January 2018.Results
During the period analyzed, we evaluated a total of 11 patients. No patient had pre-existing rheumatic or autoimmune disease. In this period, a total of 220 patients were treated with PD1 inhibitors in our center; therefore, the estimated minimum prevalence of rheumatic IRAEs related to these therapies in our population was 5%.The rheumatic IRAEs evaluated included 5 cases of oligo- or polyarthritis, 1 with a polymialgia rheumatica-type syndrome, 2 cases of immunotherapy-induced sicca syndrome, 2 patients who presented symptomatic inflammatory myositis with fasciitis in lower extremities, and 1 patient with a paraneoplastic acral vascular syndrome. The median time to IRAE after anti-PD1 exposure was 8?weeks (range: 2–24). In 5 patients, immunotherapy was discontinued (due to the adverse effect in three and cancer progression in two).In general terms the symptoms resolved completely with symptomatic treatment. Disease-modifying antirheumatic drugs were needed for 2 patients.Conclusion
Rheumatic IRAEs should be kept in mind during the follow-up and evaluation of patients treated with PD-1 inhibitors. The concomitant development of symptomatic inflammatory myositis with fasciitis in lower extremities appears to be a new adverse effect of anti-PD-1 immunotherapy. Additional studies are needed to determine how to adequately control and manage these complications. 相似文献960.
PCSK9 and neurocognitive function: Should it be still an issue after FOURIER and EBBINGHAUS results?
Massimo R. Mannarino Amirhossein Sahebkar Vanessa Bianconi Maria-Corina Serban Maciej Banach Matteo Pirro 《Journal of clinical lipidology》2018,12(5):1123-1132
The serine protease proprotein convertase subtilisin/kexin type 9 (PCSK9) modulates the levels of low-density lipoprotein cholesterol and cardiovascular risk. Potential risks of adverse neurological effects of intensive lipid-lowering treatment have been hypothesized, as cholesterol is a component of the central nervous system. Moreover, several observations suggest that PCSK9 might play a role in neurogenesis, neuronal migration and apoptosis. In rodents, increased expression of PCSK9 has been detected in specific areas of the central nervous system during embryonic development; also, PCSK9 modulates low-density lipoprotein receptor levels in the ischemic brain areas. Despite a putative participation of PCSK9 in nervous system physiology, the absence of PCSK9 in knockout mice or in humans with loss-of-function mutations of PCSK9 gene has not been linked to neurological alterations. In recent years, some concerns have been raised about the potential neurological side effects of cholesterol-lowering treatments and, more specifically of PCSK9 inhibitors. In this review, the evidence regarding the function of PCSK9 in neuron differentiation, apoptosis, and migration and in nervous system development and latest clinical trials evaluating the effects of PCSK9 inhibitors on neurocognitive function will be described. 相似文献