全文获取类型
收费全文 | 2104篇 |
免费 | 434篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 48篇 |
妇产科学 | 164篇 |
基础医学 | 172篇 |
口腔科学 | 28篇 |
临床医学 | 1109篇 |
内科学 | 309篇 |
皮肤病学 | 15篇 |
神经病学 | 161篇 |
特种医学 | 53篇 |
外科学 | 102篇 |
综合类 | 35篇 |
预防医学 | 175篇 |
眼科学 | 4篇 |
药学 | 58篇 |
中国医学 | 1篇 |
肿瘤学 | 110篇 |
出版年
2024年 | 7篇 |
2023年 | 58篇 |
2022年 | 13篇 |
2021年 | 34篇 |
2020年 | 32篇 |
2019年 | 20篇 |
2018年 | 106篇 |
2017年 | 114篇 |
2016年 | 113篇 |
2015年 | 103篇 |
2014年 | 103篇 |
2013年 | 127篇 |
2012年 | 87篇 |
2011年 | 82篇 |
2010年 | 79篇 |
2009年 | 109篇 |
2008年 | 79篇 |
2007年 | 79篇 |
2006年 | 72篇 |
2005年 | 69篇 |
2004年 | 53篇 |
2003年 | 56篇 |
2002年 | 31篇 |
2001年 | 61篇 |
2000年 | 43篇 |
1999年 | 60篇 |
1998年 | 49篇 |
1997年 | 73篇 |
1996年 | 66篇 |
1995年 | 60篇 |
1994年 | 53篇 |
1993年 | 36篇 |
1992年 | 48篇 |
1991年 | 42篇 |
1990年 | 47篇 |
1989年 | 31篇 |
1988年 | 29篇 |
1987年 | 23篇 |
1986年 | 25篇 |
1985年 | 16篇 |
1984年 | 15篇 |
1983年 | 14篇 |
1982年 | 15篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 12篇 |
1977年 | 10篇 |
1976年 | 13篇 |
1975年 | 11篇 |
1974年 | 7篇 |
排序方式: 共有2545条查询结果,搜索用时 31 毫秒
1.
2.
Fluid role boundaries: exploring the contribution of the advanced nurse practitioner to multi‐professional palliative care
下载免费PDF全文
![点击此处可从《Journal of clinical nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
3.
4.
MR compatibility of Guglielmi detachable coils 总被引:6,自引:0,他引:6
5.
BEVERLY HAVENS RN MN MPH INGRID SWENSON RN DPH 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》1986,15(5):406-411
Seventy-four 8th- and 10th-grade students attending a private girls' school in Hawaii were queried about their perceptions of and preparation for menstruation using a questionnaire administered in a health education class. Eighty percent had already started menstruating. The most frequently cited perceptions by the respondents referred to both the inconveniences and the normalcy of menstruation. Many were first informed about menstruation by their mothers and stated that they also first informed their mothers when they started menstruating. Surprise, fear, and embarrassment were common initial reactions, while strong negative or positive emotions were more rare. Only 35% wanted boys and girls together during class discussion, but 89% stated that boys needed to be informed about menstruation. The most frequent reasons cited for noncoed settings were the girls' concern about their comfort in openly discussing menstruation. Thirty-eight percent thought parents should inform other siblings when they started menstruation, although almost half gave specific conditions the parents should consider. The majority thought the fifth to sixth grades were the best times to introduce menstruation content. 相似文献
6.
In the present study we have examined the in vivo effects of thyroid hormone and TRH on secretory tissue concentrations of TRH and TRH-Gly (pGlu-His-Pro-Gly), a TRH precursor. Within secretory granules, TRH-Gly is converted to TRH through alpha-amidation of the C-terminal proline residue, using Gly as the NH2 donor. Using specific RIA, we measured the TRH-Gly immunoreactivity (TRH-Gly-IR) and TRH-IR concentrations in tissues from the reproductive and gastrointestinal systems, adrenals, and other internal organs in euthyroid, hypothyroid, and T4-treated 250-g Sprague-Dawley male rats. TRH-Gly-IR concentrations were more than 2-fold higher than TRH-IR concentrations within the adrenal, pancreas, bowel, and stomach at the time of death. Untreated hypothyroidism and exogenous TRH significantly increased adrenal TRH-Gly-IR levels. Pancreatic TRH-Gly levels increased about 2-fold in hypothyroid rats. Incubation at 60 C significantly increased TRH-Gly-IR levels in the pancreas, adrenal, bowel, stomach, and epididymis by 14-, 3-, 6-, 6-, and 6-fold, respectively. Also after 60 C incubation increases in the TRH-Gly-IR/TRH-IR ratio of 2.7-, 4-, and 1.7-fold were observed in the pancreas, epididymis, and bowel, respectively. Pooled tissue extracts were fractionated by cation exchange and reverse phase HPLC for characterization of TRH-Gly-IR. Both chromatographic methods revealed a major peak of TRH-Gly-IR coeluting with synthetic TRH-Gly. Incubation at 60 C caused 13.5-, 4.1-, 1.5-, and 5-fold increments in the TRH-Gly-IR for adrenal, pancreas, prostate, and thyroid, respectively, compared to the immediately extracted control aliquots. Cation exchange and reverse phase HPLC also revealed production of higher mol wt TRH precursor peptides after incubation at 60 C for 4 or 20 h. Only the TRH-Gly-IR peak coeluting with pGlu-His-Pro-Gly was converted into TRH by rat brain alpha-amidating enzyme. The data suggest that biosynthesis of TRH occurs in rat extrahypothalamic tissues and may be modulated by thyroid status, iv TRH, and selective thermal inactivation of enzymes that convert prepro-TRH to TRH. 相似文献
7.
8.
9.
10.