全文获取类型
收费全文 | 16674篇 |
免费 | 774篇 |
国内免费 | 91篇 |
专业分类
耳鼻咽喉 | 254篇 |
儿科学 | 441篇 |
妇产科学 | 131篇 |
基础医学 | 1947篇 |
口腔科学 | 523篇 |
临床医学 | 1060篇 |
内科学 | 4375篇 |
皮肤病学 | 248篇 |
神经病学 | 1229篇 |
特种医学 | 573篇 |
外科学 | 2936篇 |
综合类 | 87篇 |
预防医学 | 553篇 |
眼科学 | 366篇 |
药学 | 1098篇 |
中国医学 | 34篇 |
肿瘤学 | 1684篇 |
出版年
2023年 | 82篇 |
2022年 | 126篇 |
2021年 | 377篇 |
2020年 | 190篇 |
2019年 | 242篇 |
2018年 | 294篇 |
2017年 | 259篇 |
2016年 | 338篇 |
2015年 | 313篇 |
2014年 | 405篇 |
2013年 | 563篇 |
2012年 | 818篇 |
2011年 | 918篇 |
2010年 | 559篇 |
2009年 | 477篇 |
2008年 | 829篇 |
2007年 | 915篇 |
2006年 | 960篇 |
2005年 | 953篇 |
2004年 | 913篇 |
2003年 | 822篇 |
2002年 | 807篇 |
2001年 | 433篇 |
2000年 | 437篇 |
1999年 | 454篇 |
1998年 | 247篇 |
1997年 | 194篇 |
1996年 | 156篇 |
1995年 | 142篇 |
1994年 | 119篇 |
1993年 | 105篇 |
1992年 | 290篇 |
1991年 | 267篇 |
1990年 | 252篇 |
1989年 | 292篇 |
1988年 | 221篇 |
1987年 | 214篇 |
1986年 | 200篇 |
1985年 | 191篇 |
1984年 | 137篇 |
1983年 | 108篇 |
1982年 | 74篇 |
1981年 | 62篇 |
1980年 | 50篇 |
1979年 | 84篇 |
1978年 | 60篇 |
1977年 | 59篇 |
1975年 | 55篇 |
1974年 | 51篇 |
1973年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Toshiro Hara Rony Chanoch-Myers Nathan D. Mathewson Chad Myskiw Lyla Atta Lillian Bussema Stephen W. Eichhorn Alissa C. Greenwald Gabriela S. Kinker Christopher Rodman L. Nicolas Gonzalez Castro Hiroaki Wakimoto Orit Rozenblatt-Rosen Xiaowei Zhuang Jean Fan Tony Hunter Inder M. Verma Kai W. Wucherpfennig Itay Tirosh 《Cancer cell》2021,39(6):779-792.e11
- Download : Download high-res image (228KB)
- Download : Download full-size image
2.
Hiroto Kinoshita Hitomi Nishioka Aya Ikeda Kyoko Ikoma Yoichi Sameshima Hidehisa Ohi Mizuki Tatsuno Junka Kouyama Chiaki Kawamoto Tomohiro Mitsui Yuko Tamura Yu Hashimoto Masashi Nishio Tsuyoshi Ogashiwa Yusuke Saigusa Shin Maeda Hideaki Kimura Reiko Kunisaki Kazuhiko Koike 《Journal of gastroenterology and hepatology》2019,34(11):1929-1939
3.
Regional fractional ventilation mapping in spontaneously breathing mice using hyperpolarized 129Xe MRI
下载免费PDF全文
![点击此处可从《NMR in biomedicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hirohiko Imai Hironobu Matsumoto Erika Miyakoshi Shintaro Okumura Hideaki Fujiwara Atsuomi Kimura 《NMR in biomedicine》2015,28(1):24-29
The feasibility of ventilation imaging with hyperpolarized (HP) 129Xe MRI has been investigated for quantitative and regional assessment of ventilation in spontaneously breathing mice. The multiple breath ventilation imaging technique was modified to the protocol of spontaneous inhalation of HP 129Xe delivered continuously from a 129Xe polarizer. A series of 129Xe ventilation images was obtained by varying the number of breaths before the 129Xe lung imaging. The fractional ventilation, r, was successfully evaluated for spontaneously breathing mice. An attempt was made to detect ventilation dysfunction in the emphysematous mouse lung induced by intratracheal administration of porcine pancreatic elastase (PPE). As a result, the distribution of fractional ventilation could be visualized by the r map. Significant dysfunction of ventilation was quantitatively identified in the PPE‐treated group. The whole‐lung r value of 0.34 ± 0.01 for control mice (N = 4) was significantly reduced, to 0.25 ± 0.07, in PPE‐treated mice (N = 4) (p = 0.038). This study is the first application of multiple breath ventilation imaging to spontaneously breathing mice, and shows that this methodology is sensitive to differences in the pulmonary ventilation. This methodology is expected to improve simplicity as well as noninvasiveness when assessing regional ventilation in small rodents. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
4.
5.
Jun Agata Nobuyuki Ura Hideaki Yoshida Yasuyuki Shinshi Haruki Sasaki Masaya Hyakkoku Shinya Taniguchi Kazuaki Shimamoto 《Hypertension research》2006,29(11):865-874
Angiotensin II receptor blockers (ARBs) are widely used for the treatment of hypertension. It is believed that treatment with an ARB increases the level of plasma angiotensin II (Ang II) because of a lack of negative feedback on renin activity. However, Ichikawa (Hypertens Res 2001; 24: 641-646) reported that long-term treatment of hypertensive patients with olmesartan resulted in a reduction in plasma Ang II level, though the mechanism was not determined. It has been reported that angiotensin 1-7 (Ang-(1-7)) potentiates the effect of bradykinin and acts as an angiotensin-converting enzyme (ACE) inhibitor. It is known that ACE2, which was discovered as a novel ACE-related carboxypeptidase in 2000, hydrolyzes Ang I to Ang-(1-9) and also Ang II to Ang-(1-7). It has recently been reported that olmesartan increases plasma Ang-(1-7) through an increase in ACE2 expression in rats with myocardial infarction. We hypothesized that over-expression of ACE2 may be related to a reduction in Ang II level and the cardioprotective effect of olmesartan. Administration of 0.5 mg/kg/day of olmesartan for 4 weeks to 12-week-old stroke-prone spontaneously hypertensive rats (SHRSP) significantly reduced blood pressure and left ventricular weight compared to those in SHRSP given a vehicle. Co-administration of olmesartan and (D-Ala7)-Ang-(1-7), a selective Ang-(1-7) antagonist, partially inhibited the effect of olmesartan on blood pressure and left ventricular weight. Interestingly, co-administration of (D-Ala7)-Ang-(1-7) with olmesartan significantly increased the plasma Ang II level (453.2+/-113.8 pg/ml) compared to olmesartan alone (144.9+/-27.0 pg/ml, p<0.05). Moreover, olmesartan significantly increased the cardiac ACE2 expression level compared to that in Wistar Kyoto rats and SHRSP treated with a vehicle. Olmesartan significantly improved cardiovascular remodeling and cardiac nitrite/ nitrate content, but co-administration of olmesartan and (D-Ala7)-Ang-(1-7) partially reversed this anti-remodeling effect and the increase in nitrite/nitrate. These findings suggest that olmesartan may exhibit an ACE inhibitory action in addition to an Ang II receptor blocking action, prevent an increase in Ang II level, and protect cardiovascular remodeling through an increase in cardiac nitric oxide production and endogenous Ang-(1-7) via over-expression of ACE2. 相似文献
6.
Nobuhiko Joki Hiroki Hase Yuri Tanaka Yasunori Takahashi Tomokatsu Saijyo Hiroyaou Ishikawa Yoji Inishi Yoshihiko Imamura Hisao Hara Taro Tsunoda Masato Nakamura 《Nephrology, dialysis, transplantation》2006,21(6):1633-1639
BACKGROUND: In patients with chronic kidney disease (CKD), although strong associations have been observed between malnutrition and atherosclerosis, the relationship between serum albumin concentration and angiographic changes of coronary artery disease (CAD) remains poorly explored. The goal of the present study was, in patients with CKD, to clarify the relationship between the angiographic severity of CAD and serum albumin concentration reflecting either inflammation or nutrition or both. METHODS: In this study, 100 end-stage renal disease (ESRD) patients were enrolled, who commenced long-term dialysis therapy at our hospital and underwent coronary angiography within 3 months of the first haemodialysis (HD) session. Mean age was 63+/-11 years, 20% of the subjects were female and 62% had diabetes. Severity of CAD was evaluated in terms of (i) number of vessels exhibiting CAD (>or=75% stenosis) and (ii) Gensini score (GS). Clinical characteristics and laboratory findings were recorded at initiation of long-term HD therapy. We then evaluated a possible association with the presence and degree of CAD. RESULTS: Sixty-four patients exhibited signs of CAD. Forty-one among them (64%) had multivessel disease. On univariate logistic regression analysis, age, diabetes and hypoalbuminaemia were significantly associated with multivessel CAD. Univariate linear regression analysis demonstrated a positive correlation of age and diabetes with GS, and an inverse correlation of BMI and serum albumin level with GS. Stepwise regression analysis showed age and serum albumin level to be independently associated with multivessel CAD and GS. The ROC curves demonstrated best cut-off levels of age and albumin for predicting multivessel CAD to be 70 years and 3.15 g/dl, respectively. CONCLUSION: Hypoalbuminaemia at the initiation of dialysis is an important predictor of advanced CAD, particularly in male and in diabetic patients. It may reflect mainly a state of inflammation. However, malnutrition as a confounding factor cannot be entirely excluded. 相似文献
7.
8.
M Sasa M Hara S Takaori 《Progress in neuro-psychopharmacology & biological psychiatry》1991,15(1):119-128
1. Spike generation by stimulation of the parafascicular nucleus of thalamus was extracellularly recorded in the nucleus accumbens of chloral hydrate-anesthetized adult Wistar rats using a silver-wire microelectrode attached along a seven-barreled micropipette, each of which was filled with dopamine, SKF 38393 (D-1 agonist), bromocriptine (D-2 agonist), haloperidol, SCH 23390 (D-1 antagonist) and domperidone (D-2 antagonist). The drugs were microiontophoretically applied to the target neurons recorded. 2. Effects of dopamine receptor antagonists on the inhibition of the spike generation by conditioning stimuli applied to the ventral tegmental area preceding the test stimulus to the parafascicular nucleus and those of dopamine agonists on the test stimulus-induced spikes were examined. 3. The parafascicular nucleus stimulation-induced spikes were inhibited by dopamine as well as D-1 and D-2 agonists and by the conditioning stimulation of the ventral tegmental area. The conditioning stimulation-induced inhibition was antagonized by haloperidol and SCH 23390, but not by domperidone. 4. Activation of D-1 receptors, which make probably synaptic contact with dopaminergic nerve terminals from the ventral tegmental area, is considered to result in inhibition of the neuronal activity of the nucleus accumbens neurons receiving input from the parafascicular nucleus of the thalamus. In addition, D-2 receptors located extrajunctionally may be involved in the inhibition of the same neurons in the nucleus accumbens. 相似文献
9.
Takayuki Takeichi Hideaki Okajima Hiroko Suda Shintarou Hayashida Hironori Iwasaki Manuel Zeledon Ramirez Mikako Ueno Katsuhiro Asonuma Yukihiro Inomata 《Liver transplantation》2005,11(10):1285-1288
Congenital absence of the portal vein (CAPV) is a rare malformation of the splanchnic venous system. Although CAPV is usually detected in the pediatric age group, our patient was a 35-year-old woman. She had been diagnosed with CAPV in 1996 when she was 27 years old. In 1998, she was placed on hemodialysis due to chronic renal failure. After several episodes of encephalopathy in 2002, liver transplantation (LT) was recommended to her and her family. Since there was no suitable living donor candidate, she was put on the waiting list for a deceased donor liver transplant in Japan. In 2004, her ammonia level increased to around 300 microg/dl, and she went into a coma lasting for three days. After recovering from this event, she underwent a living domino transplantation using a whole liver donated by a familial amyloid polyneuropathy (FAP) patient. Her portal vein, which had drained directly into the inferior vena cava (IVC), was transected together with a cuff of the IVC wall and anastomosed to the graft liver portal vein in an end-to-end fashion. In conclusion, liver transplantation proved to be a safe and effective way to save this patient and improve her quality of life. 相似文献
10.