全文获取类型
收费全文 | 671篇 |
免费 | 37篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 39篇 |
妇产科学 | 34篇 |
基础医学 | 100篇 |
口腔科学 | 17篇 |
临床医学 | 85篇 |
内科学 | 149篇 |
皮肤病学 | 3篇 |
神经病学 | 105篇 |
特种医学 | 28篇 |
外科学 | 45篇 |
综合类 | 4篇 |
预防医学 | 41篇 |
眼科学 | 2篇 |
药学 | 19篇 |
肿瘤学 | 36篇 |
出版年
2023年 | 5篇 |
2022年 | 12篇 |
2021年 | 24篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2018年 | 17篇 |
2017年 | 14篇 |
2016年 | 9篇 |
2015年 | 13篇 |
2014年 | 33篇 |
2013年 | 33篇 |
2012年 | 38篇 |
2011年 | 33篇 |
2010年 | 34篇 |
2009年 | 27篇 |
2008年 | 40篇 |
2007年 | 60篇 |
2006年 | 46篇 |
2005年 | 42篇 |
2004年 | 52篇 |
2003年 | 41篇 |
2002年 | 34篇 |
2001年 | 13篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有709条查询结果,搜索用时 15 毫秒
1.
2.
Galit Mimouni Paul Merlob Francis B. Mimouni Alona Bin‐Nun 《American journal of medical genetics. Part A》2021,185(1):46-49
Retrognathia (recessed chin) and prognathism (prominent chin) often present as signs of an underlying condition. Accurate clinical definitions are important. Yet their definitions were according to “clinical impression”, or to seldom used X‐ray criteria. We propose a statistical and anthropometric definition of retrognathia and prognathism based upon the ratio between the goniomaxillar length (distance between the gonion at the mandible angle and the subnasale and the goniomandibular length (distance between the mandible angle and the most anterior point of the bony chin). We assumed that an increase in the ratio indicates retrognathia and a decrease reflects prognathism. We conducted a prospective, observational, anthropometric study in 204 consecutive healthy term infants. Measurements took place on the second day of life, using sliding calipers. Mean ± SD of goniomandibular length (5.1 ± 0.3 cm), goniomaxillar length (5.4 ± 0.3 cm), were calculated. All measurements correlated significantly with gestational age, and with infant birthweight. The mean ± SD goniomaxillar length/goniomandibular length ratio was 1.06 ± 0.05. We defined a normal ratio as being within 2 SD of the mean, that is, between 0.96 and and 1.16. This ratio correlated with neither gestational age nor with birthweight. We conclude that the goniomaxillar length/goniomandibular length ratio can be calculated whenever retro ‐ or prognathism is suspected. A ratio outside of the 95% confidence interval should help in making this diagnosis. An increase in this ratio beyond 2 SD above the mean (1.16) could be interpreted as retrognathia and a decrease beyond 2 SD below the mean (0.96) as prognathism. 相似文献
3.
Multiple mechanisms govern the dynamics of depression at neocortical synapses of young rats 总被引:2,自引:0,他引:2
Galit Fuhrmann Anna Cowan Idan Segev Misha Tsodyks Christian Stricker 《The Journal of physiology》2004,557(2):415-438
Synaptic transmission between pairs of excitatory neurones in layers V ( N = 38) or IV ( N = 6) of somatosensory cortex was examined in a parasagittal slice preparation obtained from young Wistar rats (14–18 days old). A combined experimental and theoretical approach reveals two characteristics of short-term synaptic depression. Firstly, as well as a release-dependent depression, there is a release-independent component that is evident in smaller postsynaptic responses even following failure to release transmitter. Secondly, recovery from depression is activity dependent and is faster at higher input frequencies. Frequency-dependent recovery is a Ca2+ -dependent process and does not reflect an underlying augmentation. Frequency-dependent recovery and release-independent depression are correlated, such that at those connections with a large amount of release-independent depression, recovery from depression is faster. In addition, both are more pronounced in experiments performed at physiological temperatures. Simulations demonstrate that these homeostatic properties allow the transfer of rate information at all frequencies, essentially linearizing synaptic responses at high input frequencies. 相似文献
4.
V Bogomolski-Yahalom E Granot N Linder R Adler S Korman N Manny R Tur-Kaspa D Shouval 《Journal of medical virology》1991,34(4):217-222
Israel has no official prevention policy at present against perinatal and horizontal transmission of hepatitis B virus (HBV) infection in newborns and children at risk. The present study was designed to assess the prevalence of HBV carrier state in a population of 11,123 pregnant women at term. Among this population (mean age 29.7 +/- 5.9), 98 women (0.88%) were found to be asymptomatic HBsAg+ carriers, and 97% of these carriers were anti-HBe+. Evidence for HBV replication, as determined by serum HBV-DNA, was established in 6.6% of the HBsAg+/anti-HBe+ population. The HBsAg carrier rate was strongly influenced by religion, continent, and country of birth of the carrier mothers. The highest relative carrier rate was found among women of Moslem origin (4.3%), as compared to Jewish women (0.67%). Most carrier women were born in Israel (56.1%) to mothers who had emigrated from regions with intermediate or high endemicity of HBV, such as North Africa or the Middle East. In these groups, the HBsAg carrier rate ranged between 1.2 and 3.0%. Ninety-three percent of newborns receiving passive/active vaccination against HBV developed protective levels of anti-HBs. Finally, evidence for horizontal transmission of HBV was found in 19.3% of 83 non-vaccinated children in families of HBsAg carriers. The present study therefore establishes HBsAg prevalence rates in specific risk groups of women at term and confirms the need for an official policy on immunization against HBV in Israel. Since over 50% of women at term belong to the defined risk groups, universal active vaccination of the entire newborn population each year is suggested as the most rational and needed policy in Israel. 相似文献
5.
6.
7.
8.
9.
Tumors are theoretically capable of eliciting an antitumor immune response, but are often poorly immunogenic. Oncolytic viruses (OVs) have recently emerged as a promising strategy for the immunogenic delivery of tumor-associated antigens (TAAs) to cancer patients. However, safe and effective OV/TAA therapies have not yet been established. We have previously demonstrated that vectors based on Sindbis virus (SV) can inhibit tumor growth and activate the innate immune system in mice. Here, we demonstrate that SV vectors carrying a TAA generate a dramatically enhanced therapeutic effect in mice bearing subcutaneous, intraperitoneal, and lung cancers. Notably, SV/TAA efficacy was not dependent on tumor cell targeting, but was characterized by the transient expression of TAAs in lymph nodes draining the injection site. Early T-cell activation at this site was followed by a robust influx of NKG2D expressing antigen-specific cytotoxic CD8+ T cells into the tumor site, subsequently leading to the generation of long-lasting memory T cells which conferred protection against rechallenge with TAA-positive as well as TAA-negative tumor cells. By combining in vivo imaging, flow cytometry, cytotoxicity/cytokine assays, and tetramer analysis, we investigated the relationship between these events and propose a model for CD8+ T-cell activation during SV/TAA therapy. 相似文献