全文获取类型
收费全文 | 1361篇 |
免费 | 92篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 70篇 |
妇产科学 | 52篇 |
基础医学 | 173篇 |
口腔科学 | 42篇 |
临床医学 | 103篇 |
内科学 | 208篇 |
皮肤病学 | 86篇 |
神经病学 | 86篇 |
特种医学 | 35篇 |
外科学 | 150篇 |
综合类 | 18篇 |
一般理论 | 1篇 |
预防医学 | 86篇 |
眼科学 | 84篇 |
药学 | 89篇 |
中国医学 | 14篇 |
肿瘤学 | 151篇 |
出版年
2023年 | 10篇 |
2022年 | 32篇 |
2021年 | 53篇 |
2020年 | 28篇 |
2019年 | 53篇 |
2018年 | 59篇 |
2017年 | 46篇 |
2016年 | 45篇 |
2015年 | 43篇 |
2014年 | 61篇 |
2013年 | 95篇 |
2012年 | 133篇 |
2011年 | 127篇 |
2010年 | 73篇 |
2009年 | 51篇 |
2008年 | 88篇 |
2007年 | 84篇 |
2006年 | 77篇 |
2005年 | 68篇 |
2004年 | 48篇 |
2003年 | 57篇 |
2002年 | 38篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1969年 | 3篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1942年 | 1篇 |
1935年 | 1篇 |
1927年 | 1篇 |
1926年 | 1篇 |
排序方式: 共有1457条查询结果,搜索用时 15 毫秒
1.
Edward J. Holland Walter O. Whitley Kenneth Sall Stephen S. Lane Aparna Raychaudhuri Steven Y. Zhang 《Current medical research and opinion》2016,32(10):1759-1765
Objective: Report efficacy findings from three clinical trials (one phase 2 and two phase 3 [OPUS-1, OPUS-2]) of lifitegrast ophthalmic solution 5.0% for treatment of dry eye disease (DED).Research design and methods: Three 84-day, randomized, double-masked, placebo-controlled trials. Adults (≥18 years) with DED were randomized (1:1) to lifitegrast 5.0% or matching placebo. Changes from baseline to day 84 in signs and symptoms of DED were analyzed.Main outcome measures: Phase 2, pre-specified endpoint: inferior corneal staining score (ICSS; 0–4); OPUS-1, coprimary endpoints: ICSS and visual-related function subscale (0–4 scale); OPUS-2, coprimary endpoints: ICSS and eye dryness score (EDS, VAS; 0–100).Results: Fifty-eight participants were randomized to lifitegrast 5.0% and 58 to placebo in the phase 2 trial; 293 to lifitegrast and 295 to placebo in OPUS-1; 358 to lifitegrast and 360 to placebo in OPUS-2. In participants with mild-to-moderate baseline DED symptomatology, lifitegrast improved ICSS versus placebo in the phase 2 study (treatment effect, 0.35; 95% CI, 0.05–0.65; p?=?0.0209) and OPUS-1 (effect, 0.24; 95% CI, 0.10–0.38; p?=?0.0007). Among more symptomatic participants (baseline EDS ≥40, recent artificial tear use), lifitegrast improved EDS versus placebo in a post hoc analysis of OPUS-1 (effect, 13.34; 95% CI, 2.35–24.33; nominal p?=?0.0178) and in OPUS-2 (effect, 12.61; 95% CI, 8.51–16.70; p?<?0.0001).Limitations: Trials were conducted over 12 weeks; efficacy beyond this period was not assessed.Conclusions: Across three trials, lifitegrast improved ICSS in participants with mild-to-moderate baseline symptomatology in two studies, and EDS in participants with moderate-to-severe baseline symptomatology in two studies. Based on the overall findings from these trials, lifitegrast shows promise as a new treatment option for signs and symptoms of DED. 相似文献
2.
3.
ABSTRACTA qualitative grounded theory approach was used to analyze 34 narratives from young men about their experience of retaining, losing, or giving away their virginity, where 7 said they were virgins, 26 said they were non-virgins, and one did not mention his virginity status. We found that virginity is a multidimensional concept, with two distinct dimensions: the experiential and the developmental. The experiential dimension refers to young men's perception and understanding of their virginity in four overlapping areas: physical, spiritual, relational, and emotional. The developmental dimension refers to young men's perception of their underlying sexual identity growth processes and the gendered and sexual double standards that influence this understanding. Clinical implications of this study are useful in education and counseling. They seek to empower young men with information relating to the multidimensional nature of virginity experience, and minimize the negative effects on romantic relationships, sexual adjustment, and self-identity development. The findings are helpful in designing interventions for young men and women who are at high risk for sexually transmitted infections and can help them negotiate mutually safe and pleasurable experiences regarding their virginity. 相似文献
4.
Aparna Gangopadhyay 《Nutrition and cancer》2020,72(8):1438-1442
AbstractBackground: The prognostic nutritional index (PNI), a marker of immune-nutrition balance, has predictive value in the survival and prognosis of various cancers. However, the impact of PNI on response to chemoradiation is poorly understood.Materials and Methods: A total of 583 women with locally advanced cervical cancer from two centers were clinically assessed for complete response after chemoradiation. The baseline PNI was individually recorded, and the significance of association between PNI and complete response was analyzed using logistic regression. ROC (receiver operating characteristics) curves were analyzed to determine the cutoff value of PNI that significantly predicted complete response.Results: Logistic regression analysis demonstrated that the PNI was significantly associated with complete response following chemo radiation (p?<?0.0001). Analysis of the ROC curve for PNI demonstrated an optimal cut off value of 44.8 (p?<?0.0001, sensitivity 66.7, and specificity 88.5); the area under the ROC curve was 0.813 (Youden’s index J, 0.7519).Conclusions: The PNI is significantly associated with clinical complete response to chemoradiation in locally advanced cervical cancer. Low baseline PNI may lower the likelihood of complete response after chemoradiation. In particular, those with PNI values below 44 should be carefully monitored during treatment; nutritional interventions may offer benefit in these women. 相似文献
5.
目的探讨肝、肺细胞因子基因表达与腹腔吞噬细胞上清液、循环血中细胞因子含量的关系,为临床诊治多细菌感染引发的炎症提供实验依据.方法将30只小鼠分为假手术对照组(sham组)和盲肠结扎组(CLP组).采用RT-PCR法检测肝脏和肺脏肿瘤坏死因子α(TNF-α)和白细胞介素10(IL-10)的基因表达情况,采用ELISA法检测腹腔巨噬细胞上清液和循环血液中相应细胞因子含量.结果CLP组的TNF-α、IL-10基因表达和腹腔巨噬细胞上清液、循环血液中的相应细胞因子含量均高于sham组.CLP后18h组与4h组比较,TNF-α在腹腔巨噬细胞上清液、循环血液中的活性均有显著性差异(P<0.05),在肝、肺中基因表达有非常显著性差异(P<0.01);IL-10在腹腔巨噬细胞上清液和循环血液中的含量无显著性差异,而在肝、肺中基因表达有显著性差异.结论发生多细菌感染性炎症时,肝、肺参与细胞因子的表达;血液中细胞因子含量不能完全代表组织器官内的基因表达情况;多细菌感染性炎症治疗应考虑靶器官细胞因子的表达状态. 相似文献
6.
V K Srivastava G Palit A K Agarwal K Shanker 《Pharmacological research communications》1987,19(9):617-628
Sixteen new compounds 2-methylamino substituted phenyl-3-substituted anilino 4 (3H) quinazolinones (3-18) were prepared. All the compounds were evaluated for their antiparkinsonian activity and compared with bromocriptine. Compounds 10,15 and 18 showed better activity. These compounds also bind with the dopamine receptors in striatal membrane preparations of rat brain. 相似文献
7.
Dai Z Weichenhan D Wu YZ Hall JL Rush LJ Smith LT Raval A Yu L Kroll D Muehlisch J Frühwald MC de Jong P Catanese J Davuluri RV Smiraglia DJ Plass C 《Genome research》2002,12(10):1591-1598
Knudson's two-hit hypothesis postulates that genetic alterations in both alleles are required for the inactivation of tumor-suppressor genes. Genetic alterations include small or large deletions and mutations. Over the past years, it has become clear that epigenetic alterations such as DNA methylation are additional mechanisms for gene silencing. Restriction Landmark Genomic Scanning (RLGS) is a two-dimensional gel electrophoresis that assesses the methylation status of thousands of CpG islands. RLGS has been applied successfully to scan cancer genomes for aberrant DNA methylation patterns. So far, the majority of this work was done using NotI as the restriction landmark site. Here, we describe the development of RLGS using AscI as the restriction landmark site for genome-wide scans of cancer genomes. The availability of AscI as a restriction landmark for RLGS allows for scanning almost twice as many CpG islands in the human genome compared with using NotI only. We describe the development of an AscI-EcoRV boundary library that supports the cloning of novel methylated genes. Feasibility of this system is shown in three tumor types, medulloblastomas, lung cancers, and head and neck cancers. We report the cloning of 178 AscI RLGS fragments via two methods by use of this library. 相似文献
8.
Tushar K. Chatterjee Rajat K. Das Santi R. Palit 《Macromolecular chemistry and physics.》1971,141(1):43-53
The aqueous polymerisation of methyl methacrylate initiated by the chromate/arsenite system has been studied. It is observed that the polymerisation by the above redox system is catalysed by OH? though the parent reaction between chromate and arsenite is catalysed by H⊕. It is also observed that traces of Cu2⊕ inhibit both the polymerization reaction as also the parent reaction. From these observations it is concluded (1) intermediate valency states of chromium has no initiating power in alkali solution and (2) the redox reaction between chromate and arsenite is a chain reaction involving single electron transfer and the intermediate As4⊕ thus produced is the initiating species. 相似文献
9.
Effect of low-frequency repetitive transcranial magnetic stimulation on interhemispheric inhibition 总被引:5,自引:0,他引:5
Pal PK Hanajima R Gunraj CA Li JY Wagle-Shukla A Morgante F Chen R 《Journal of neurophysiology》2005,94(3):1668-1675
We studied the effects of 1-Hz repetitive transcranial magnetic stimulation (rTMS) on the excitability of interhemispheric connections in 13 right-handed healthy volunteers. TMS was performed using figure-eight coils, and surface electromyography (EMG) was recorded from both first dorsal interosseous (FDI) muscles. A paired-pulse method with a conditioning stimulus (CS) to the motor cortex (M1) followed by a test stimulus to the opposite M1 was used to study the interhemispheric inhibition (ppIHI). Both CS and TS were adjusted to produce motor-evoked potentials of approximately 1 mV in the contralateral FDI muscles. After baseline measurement of right-to-left IHI (pre-RIHI) and left-to-right IHI (pre-LIHI), rTMS was applied over left M1 at 1 Hz with 900 stimuli at 115% of resting motor threshold. After rTMS, ppIHI was studied using both the pre-rTMS CS (post-RIHI and post-LIHI) and an adjusted post-rTMS CS set to produce 1-mV motor evoked potentials (MEPs; post-RIHI(adj) and post-LIHI(adj)). The TS was set to produce 1-mV MEPs. There was a significant reduction in post-LIHI (P = 0.0049) and post-LIHI(adj) (P = 0.0169) compared with pre-LIHI at both interstimulus intervals of 10 and 40 ms. Post-RIHI was significantly reduced compared with pre-RIHI (P = 0.0015) but pre-RIHI and post-RIHI(adj) were not significantly different. We conclude that 1-Hz rTMS reduces IHI in both directions but is predominantly from the stimulated to the unstimulated hemisphere. Low-frequency rTMS may be used to modulate the excitability of IHI circuits. Treatment protocols using low-frequency rTMS to reduce cortical excitability in neurological and psychiatric conditions need to take into account their effects on IHI. 相似文献
10.
Genus-specific leptospiral antigen and its possible use in laboratory diagnosis 总被引:4,自引:1,他引:4 下载免费PDF全文
Sheep red cells, sensitized with a genus-specific leptospiral substance extracted from a water leptospira, were preserved by freeze drying. The serological reactivity of the preparation was tested against a total of 41 sera from proven cases of human leptospirosis and 27 from proven cases of animal leptospirosis. The sensitized, freeze-dried red cells appeared to be a sensitive reagent for the detection of leptospiral antibodies by haemagglutination. The use of this reagent as a screening test for leptospiral diagnosis is discussed. In the reported haemagglutination test on human and rabbit antisera the findings suggested that only IgM (19S) antibodies took part in the reaction. 相似文献