全文获取类型
收费全文 | 1842篇 |
免费 | 155篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 38篇 |
妇产科学 | 64篇 |
基础医学 | 218篇 |
口腔科学 | 60篇 |
临床医学 | 185篇 |
内科学 | 348篇 |
皮肤病学 | 63篇 |
神经病学 | 193篇 |
特种医学 | 56篇 |
外科学 | 210篇 |
综合类 | 19篇 |
预防医学 | 114篇 |
眼科学 | 62篇 |
药学 | 176篇 |
中国医学 | 17篇 |
肿瘤学 | 176篇 |
出版年
2023年 | 41篇 |
2022年 | 78篇 |
2021年 | 98篇 |
2020年 | 53篇 |
2019年 | 103篇 |
2018年 | 93篇 |
2017年 | 56篇 |
2016年 | 95篇 |
2015年 | 74篇 |
2014年 | 101篇 |
2013年 | 132篇 |
2012年 | 190篇 |
2011年 | 161篇 |
2010年 | 102篇 |
2009年 | 54篇 |
2008年 | 101篇 |
2007年 | 106篇 |
2006年 | 74篇 |
2005年 | 54篇 |
2004年 | 40篇 |
2003年 | 42篇 |
2002年 | 32篇 |
2001年 | 11篇 |
2000年 | 11篇 |
1999年 | 16篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1988年 | 13篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1971年 | 2篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1962年 | 1篇 |
排序方式: 共有2010条查询结果,搜索用时 15 毫秒
1.
N Watanabe Y Niitsu H Umeno H Kuriyama H Neda N Yamauchi M Maeda I Urushizaki 《Gan to kagaku ryoho. Cancer & chemotherapy》1987,14(12):3337-3343
Effects of human recombinant TNF on the tumor blood vessels and on the thrombus formation were investigated in relation to its mode of antitumor action against Meth-A sarcoma transplanted in BALB/c mice. The extent of the blood vessel lesion was evaluated by using transparent chamber placed in the mouse skin. Bleeding, hyperemia and congestion were observed at 1-2h, 4-6h and 24h after TNF (1 X 10(4)U/mouse) administration, respectively. In contrast, no histological changes in the normal blood vessels were observed microscopically following TNF injection. Thrombus formation was evoked in the tumor vessels 4h after TNF injection. However, when thrombus formation was prevented by heparin, no difference was observed among antitumor action of TNF against Meth-A fibrosarcoma necrotic response and the rate of complete cure. These results suggest that the direct effects of TNF causing lesions in the tumor blood vessels plays an important role in its antitumor action. 相似文献
2.
3.
4.
Endogenous tumor necrosis factor exerts its protective function intracellularly against the cytotoxicity of exogenous tumor necrosis factor. 总被引:5,自引:0,他引:5
T Okamoto N Watanabe N Yamauchi Y Tsuji N Tsuji Y Itoh H Neda Y Niitsu 《Cancer research》1992,52(19):5278-5281
Based on the findings that expression of endogenous tumor necrosis factor (enTNF), which is not present in TNF-susceptible cells, was generally observed in TNF-resistant cells and that TNF gene transfection gives rise to TNF resistance, the assumption was made that enTNF may be a protective protein against the cytotoxicity of exogenous TNF. However, it remains unknown whether the protection by enTNF is exerted in an intracellular or extracellular (autocrine) manner. We therefore transfected a nonsecretory human TNF gene (pTNF delta pro) into highly TNF-sensitive mouse tumorigenic fibroblasts (L-M cells) and investigated their TNF susceptibility. The transfectants expressed enTNF which was not secreted into the medium and acquired an appreciable degree of resistance to exogenous TNF. A significant increase in the manganous superoxide dismutase level was also noted in the transfectants. These findings suggest that enTNF exerts its protective function intracellularly by inducing manganous superoxide dismutase production. 相似文献
5.
Moderate acute rejection detected during annual catheterization in pediatric heart transplant recipients. 总被引:2,自引:0,他引:2
Micheal A Kuhn Douglas D Deming Constance E Cephus Neda F Mulla Richard E Chinnock Anees J Razzouk Ranae L Larsen 《The Journal of heart and lung transplantation》2003,22(3):276-280
BACKGROUND: Acute rejection commonly occurs within the first year after heart transplantation, and then decreases in frequency with time. Recently, the long-term utility of endomyocardial biopsy during routine annual catheterization has been questioned. The purpose of this study was to retrospectively review the prevalence of biopsy-proven rejection during routine annual catheterization in our patient population, determine whether biopsies late after transplant are useful, and identify factors that correlate with late unsuspected rejection. METHODS: Biopsy results from the annual catheterization were evaluated from 1986 to August 2000. The prevalence of moderate rejection was evaluated and compared with the patient's immunosuppressive regimen; the prevalence of late rejection; and how late rejection correlated with recipient age, number of first-year rejections and presence of sub-therapeutic cyclosporine. RESULTS: A total of 1108 biopsies were performed in 269 children with a mean follow-up of 5 +/- 3 years (median 5 years, range 1 to 11 years). Three-drug immunosuppressive therapy, including steroids, was used in 93 patients. There was a persistent 8% to 10% prevalence of moderate rejection at up to 10 years post-transplantation. Moderate rejection was more likely in patients: (1). on 3-drug immunosuppressive therapy; (2). with a recipient age >1 year; and (3). with a relatively lower cyclosporine level. CONCLUSIONS: These data suggest that continued surveillance of pediatric transplant patients for acute rejection is indicated for long-term follow-up. 相似文献
6.
Neuroprotective effects of IGF-I against TNFalpha-induced neuronal damage in HIV-associated dementia
Ying Wang J Peruzzi F Lassak A Del Valle L Radhakrishnan S Rappaport J Khalili K Amini S Reiss K 《Virology》2003,305(1):66-76
Human immunodeficiency virus type 1 (HIV-1) infection often results in disorders of the central nervous system, including HIV-associated dementia (HAD). It is suspected that tumor necrosis factor-alpha (TNFalpha) released by activated and/or infected macrophages/microglia plays a role in the process of neuronal damage seen in AIDS patients. In light of earlier studies showing that the activation of the insulin-like growth factor I receptor (IGF-IR) exerts a strong neuroprotective effect, we investigated the ability of IGF-I to protect neuronal cells from HIV-infected macrophages. Our results demonstrate that the conditioned medium from HIV-1-infected macrophages, HIV/CM, causes loss of neuronal processes in differentiated PC12 and P19 neurons and that these neurodegenerative effects are associated with the presence of TNFalpha. Furthermore, we demonstrate that IGF-I rescues differentiated neurons from both HIV/CM and TNFalpha-induced damage and that IGF-I-mediated neuroprotection is strongly enhanced by overexpression of the wt IGF-IR cDNA and attenuated by the antisense IGF-IR cDNA. Finally, IGF-I-mediated antiapoptotic pathways are continuously functional in differentiated neurons exposed to HIV/CM and are likely supported by TNFalpha-mediated phosphorylation of I(kappa)B. All together these results suggest that the balance between TNFalpha and IGF-IR signaling pathways may control the extent of neuronal injury in this HIV-related experimental setting. 相似文献
7.
Katharina Voigt Emily Giddens Romana Stark Emma Frisch Neda Moskovsky Naomi Kakoschke Julie C. Stout Mark A. Bellgrove Zane B. Andrews Antonio Verdejo-Garcia 《Nutrients》2021,13(6)
Food homeostatic states (hunger and satiety) influence the cognitive systems regulating impulsive responses, but the direction and specific mechanisms involved in this effect remain elusive. We examined how fasting, and satiety, affect cognitive mechanisms underpinning disinhibition using a novel framework and a gamified test-battery. Thirty-four participants completed the test-battery measuring three cognitive facets of disinhibition: attentional control, information gathering and monitoring of feedback, across two experimental sessions: one after overnight fasting and another after a standardised meal. Homeostatic state was assessed using subjective self-reports and biological markers (i.e., blood-derived liver-expressed antimicrobial protein 2 (LEAP-2), insulin and leptin). We found that participants who experienced greater subjective hunger during the satiety session were more impulsive in the information gathering task; results were not confounded by changes in mood or anxiety. Homeostatic state did not significantly influence disinhibition mechanisms linked to attentional control or feedback monitoring. However, we found a significant interaction between homeostatic state and LEAP-2 on attentional control, with higher LEAP-2 associated with faster reaction times in the fasted condition only. Our findings indicate lingering hunger after eating increases impulsive behaviour via reduced information gathering. These findings identify a novel mechanism that may underpin the tendency to overeat and/or engage in broader impulsive behaviours. 相似文献
8.
Fatemeh Jahanian Iraj Goli Khatir Hamed Amini Ahidashti Sepideh Amirifard 《Ethiopian journal of health sciences》2021,31(2):267
BackgroundAcute exacerbations of chronic obstructive pulmonary disease (AECOPD) are serious complications that often require immediate intervention in an emergency department (ED). The aim of this study was to investigate the effect of intravenous magnesium sulphate as an adjuvant in the treatment of AECOPD in the ED.MethodsIn a double-blind, randomized clinical trial, a total of 60 patients with AECOPD presenting to the ED of Imam Khomeini Hospital in Sari, Iran, were included. The study was conducted between September 2016 and February 2018. Eligible patients were randomly allocated into two groups of intervention and control. Patients in the intervention and control groups received intravenous infusion of magnesium sulfate (2 gr) or normal saline over 30 minutes, respectively. For all patients, Borgdyspnea score, forced expiratory volume in one second (FEV1) result and clinical variables of interest were evaluated before the beginning of the intervention, and also 45 minutes and 6 hours after the commencement of intervention.ResultsRegardless of time of evaluation, pulse rate (PR), respiratory rate (RR) and Borg score in intervention group was lower than control group. Also, FEV1 and SPO2 were greater in intervention group compared to control group. However, these differences were not statistically significant (between-subject differences or group effect) (p<0.001). The trends of FEV1, SPO2, PR, RR and Borg score were similar between two groups of study (no interaction effect; P>0.05).ConclusionAccording to the results of this study, it seems that using intravenous magnesium sulfate has no significant effect on SPO2, FEV1, RR, and PR of patients with AECOPD who presented to ED. 相似文献
9.
Ghoreifi Alireza Basin Michael F. Ghodoussipour Saum Bazargani Soroush T. Amini Erfan Aslzare Mohammad Cai Jie Miranda Gus Sugeir Shihab Bhanvadia Sumeet Schuckman Anne K. Daneshmand Siamak Lumb Philip Djaladat Hooman 《International urology and nephrology》2021,53(9):1827-1833
International Urology and Nephrology - The aim of this study is to evaluate the intra/perioperative fluid management and early postoperative outcomes of patients who underwent radical cystectomy... 相似文献
10.
Zohreh Talebi-Yazdabadi Neda Jahanbakhsh Kianoush Dormiani Mahboobeh Forouzanfar Liana Lachinani Dina Zohrabi Marziyeh Tavalaee Mohammad Hossein Nasr-Esfahani 《Andrologia》2021,53(10):e14187
MUSASHI (MSI) family plays the main role in the spermatogenesis process. The purpose of this study was the assessment of sperm MSI1 and MSI2, and sperm functional tests in infertile men (n = 30) with varicocele and fertile men (n = 30). Furthermore, MSI1 and MSI2 proteins were assessed in testicular tissue of azoospermic men (n = 9) as well as epididymal spermatozoa and testis of mice. Expression of MSI1 and MSI2 was assessed at RNA and protein levels in human spermatozoa. Sperm concentration and motility were significantly lower, while abnormal sperm morphology, lipid peroxidation, DNA fragmentation and protamine deficiency were significantly higher in men with varicocele compared to fertile individuals. Any significant difference was not observed in the expression of MSI1 and MSI2 mRNA between the two groups. Unlike MSI1 protein that was not detectable in humans, the relative expression of MSI2 protein was similar in varicocele and fertile individuals. The expression level of both Msi1 and Msi2 proteins was also observable in mouse spermatozoa. No significant relationship was observed between sperm functional parameters with expression of these genes. The data of this study demonstrated that although MSI1 and MSI2 play important roles during spermatogenesis, their relative expression in spermatozoa was not affected by varicocele. 相似文献