全文获取类型
收费全文 | 4962篇 |
免费 | 249篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 93篇 |
妇产科学 | 66篇 |
基础医学 | 683篇 |
口腔科学 | 215篇 |
临床医学 | 290篇 |
内科学 | 1380篇 |
皮肤病学 | 51篇 |
神经病学 | 216篇 |
特种医学 | 114篇 |
外科学 | 941篇 |
综合类 | 20篇 |
预防医学 | 73篇 |
眼科学 | 138篇 |
药学 | 312篇 |
中国医学 | 8篇 |
肿瘤学 | 618篇 |
出版年
2023年 | 19篇 |
2022年 | 48篇 |
2021年 | 105篇 |
2020年 | 52篇 |
2019年 | 88篇 |
2018年 | 115篇 |
2017年 | 81篇 |
2016年 | 104篇 |
2015年 | 109篇 |
2014年 | 148篇 |
2013年 | 174篇 |
2012年 | 276篇 |
2011年 | 310篇 |
2010年 | 198篇 |
2009年 | 156篇 |
2008年 | 272篇 |
2007年 | 306篇 |
2006年 | 295篇 |
2005年 | 291篇 |
2004年 | 302篇 |
2003年 | 301篇 |
2002年 | 260篇 |
2001年 | 105篇 |
2000年 | 103篇 |
1999年 | 99篇 |
1998年 | 66篇 |
1997年 | 46篇 |
1996年 | 69篇 |
1995年 | 47篇 |
1994年 | 48篇 |
1993年 | 30篇 |
1992年 | 61篇 |
1991年 | 65篇 |
1990年 | 37篇 |
1989年 | 42篇 |
1988年 | 44篇 |
1987年 | 36篇 |
1986年 | 44篇 |
1985年 | 45篇 |
1984年 | 21篇 |
1983年 | 30篇 |
1982年 | 19篇 |
1981年 | 18篇 |
1980年 | 14篇 |
1979年 | 17篇 |
1977年 | 10篇 |
1976年 | 11篇 |
1974年 | 10篇 |
1971年 | 14篇 |
1969年 | 10篇 |
排序方式: 共有5238条查询结果,搜索用时 31 毫秒
1.
Keiko Goto Yutaka Fujiwara Takeshi Isobe Naoko Chayahara Naomi Kiyota Toru Mukohara Yukari Tsubata Takamasa Hotta Kenji Tamura Noboru Yamamoto Hironobu Minami 《Cancer science》2019,110(6):1987-1994
Although dose reduction of S‐1 is recommended for patients with impaired renal function, dose modification for such patients has not been prospectively evaluated. The aim of the present study was to investigate the pharmacokinetic parameters of 5‐fluorouracil, 5‐chloro‐2,4 dihydroxypyridine and oteracil potassium, and to review the recommended dose modification of S‐1 in patients with renal impairment. We classified patients receiving S‐1 into 4 groups according to their renal function, as measured using the Japanese estimated glomerular filtration rate (eGFR) equation. The daily S‐1 dose was adjusted based on the patient's eGFR and body surface area. Blood samples were collected for pharmacokinetic analysis. A total of 33 patients were enrolled and classified into 4 groups as follows: 10 patients in cohort 1 (eGFR ≥ 80 mL/min/1.73 m2), 10 patients in cohort 2 (eGFR = 50‐79 mL/min/1.73 m2), 10 patients in cohort 3 (eGFR = 30‐49 mL/min/1.73 m2), and 3 patients in cohort 4 (eGFR < 30 mL/min/1.73 m2). Those in cohorts 3 and 4 treated with an adjusted dose of S‐1 showed a similar area under the curve for 5‐fluorouracil (941.9 ± 275.6 and 1043.5 ± 224.8 ng/mL, respectively) compared with cohort 2 (1034.9 ± 414.3 ng/mL). Notably, while there was a statistically significant difference between cohort 1 (689.6 ± 208.8 ng/mL) and 2 (P = 0.0474) treated with an equal dose of S‐1, there was no significant difference observed in the toxicity profiles of the cohorts. In conclusion, dose adjustment of S‐1 in patients with impaired renal function using eGFR is appropriate and safe. 相似文献
2.
3.
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
4.
5.
Kazuki Hotta 《Ophthalmic surgery, lasers & imaging》2007,38(4):336-338
To determine postoperative refractive errors of secondary intraocular lens (IOL) implantation, this study was performed in 42 eyes of 42 patients following secondary IOL implantation fixed in the sulcus after simultaneous vitrectomy and phacoemulsification and aspiration. Controls were 138 eyes of 124 patients with cataract who underwent phacoemulsification and aspiration and IOL implantation. The spread between expected and actual refraction (actual - expected) was -0.81 +/- 0.86 diopters (average +/- standard deviation) in the study group and 0.01 +/- 0.91 diopters in the control group (statistically significant, P < .001, Student's t test). The actual refractive errors in the study subjects were shifted toward myopia compared with the controls. 相似文献
6.
Long-term lithium treatment causes serotonin receptor down-regulation via serotonergic presynapses in rat brain 总被引:2,自引:0,他引:2
The effects of lithium treatment on serotonin (5-HT) receptors in rat frontal cortex and hippocampus were investigated. Long-term lithium treatment strongly blocked 5-hydroxytryptophan-induced head twitches, while acute lithium administration by itself induced head twitches in rats, and ketanserin blocked this acute lithium action. Long-term administration of lithium decreased the number of not only 5-HT2 receptors in the frontal cortex but also 5-HT1 and 5-HT2 receptors in the hippocampus in rats. Decreases in 3H-5-HT binding to hippocampal 5-HT1 receptors and 3H-spiperone binding to frontal cortical 5-HT2 receptors, caused by chronic lithium treatment, were abolished by co-administration of p-chlorophenylalanine, and were enhanced by co-administration with methiothepin. The turnover of 5-HT in either frontal cortex or hippocampus was facilitated by lithium, and co-administered methiothepin enhanced this facilitation. These results suggest that long-term lithium treatment causes the down-regulation of postsynaptic 5-HT1 and 5-HT2 receptors, in part probably through its action on presynaptic nerve terminals. 相似文献
7.
Senichiro Kikuchi Kazuhiko Iwata Yasunori Onishi Fumio Kubota Koichi Nisijima Hideaki Tamai Yuiko Koizumi Eiju Watanabe Satoshi Kato 《Psychiatry Research: Neuroimaging》2007,156(3):199-208
We conducted a noninvasive near-infrared spectroscopy (NIRS) study using the game of rock, paper, scissors (RPS) as a simple neurocognitive task for the prefrontal cortex (PFC) in 15 healthy volunteers. We employed an opposite “to lose” RPS task coupled with a normal “to win” RPS task, since the former requires inhibition of behavior, one of the most important functions of the prefrontal cortex. During the NIRS examination, subjects had to present one of the three RPS hands in response to hands displayed randomly on a computer screen every 1.5 s, and were required to show hands that lose to the computer, or that beat the computer. We measured the relative concentrations of oxyhemoglobin (oxy-Hb) using the prefrontal probes of the NIRS system during the tasks. The increases in oxy-Hb during the “to win” RPS task were small, but were quite large and laterally dominant during the “to lose” RPS task. The difference between the two tasks might have been due to the participants’ cognitive conflict with losing on the RPS. We conclude that losing is better than winning on the RPS as a sensitive indicator in the NIRS examination of PFC. 相似文献
8.
Kentaro Yamashita Hiroyuki Tsukuda Yasuyo Mizukami Jun Ito Shigeo Ikuta Yoshihiro Kondo Hiroshi Kinoshita Yasunori Fujisawa Kohzoh Imai 《Journal of gastroenterology》1997,32(5):684-688
A case of hepatic infarction with portal thrombosis is reported. A 63-year-old woman with liver cirrhosis and esophageal varices
was admitted for treatment of the esophagel varices. Endoscopic variceal ligation (EVL) and endoscopic injection sclerotherapy
(EIS) were performed. Two months later, she experienced right hypochondralgia and right flank pain. Serum transaminase levels
were suddenly elevated, and computed tomography scans of the liver showed multiple small nodular lesions. Her condition worsened,
and she died of hepatic failure. Autopsy revealed splenic and portal vein thrombosis, multiple hepatic infarction, and evidence
of chronic pancreatitis. We believe that liver cirrhosis and chronic pancreatitis were the main risk factors for the portal
thrombosis, and the treatment for esophageal varices appeared to have triggered the thrombosis. The hepatic infarction was
caused by the portal thrombosis. 相似文献
9.
Soichi Hotta Hiromasa Kashimura Shinji Hirai Akira Nakahara Hisayuki Fukutomi Toshiaki Osuga Yasuo Uchiyama 《Lasers in surgery and medicine》1995,16(3):262-271
Background and Objective: To further understand the precise process of the tumor cell degeneration after photodynamic therapy (PDT), laser hyperthermic therapy (LH), and combined treatments using an Nd:YAG laser. It is important to examine initial morphological alteration of tumor cells after these treatments. Study Design/Materials and Methods: In this study, nude mice bearing HeLa cell tumors were treated with PDT, LH, and combined treatments of the two. Tumor tissues obtained immediately after these treatments were analyzed using electron microscopy and morphometry. Results: In the combined treatments, which produced more severe effects on tumor cells, morphological features of apoptosis such as cytoplasmic condensation, blebs, and apoptotic bodies appeared in the cells, although the typical alteration in the nuclear chromatin was not seen. Conclusion: Cytoplasmic alterations may proceed more rapidly than nuclear alterations in the cellular degeneration induced by the single or combined treatments of PDT and LH. 相似文献
10.
Hiroyuki Ishizu Masatoshi Takahashi Yukifumi Kondo Akihiko Kataoka Takashi Nakamura Kuniaki Okada Hiroyuki Masuko Yasunori Nishida Hideaki Ogawa Ryoji Yokoyama Yutaka Kimura 《Surgery today》1997,27(3):285-287
Magnetic resonance cholangiopancreatography (MRCP) was performed in 35 patients to evaluate the feasibility of its use as a postsurgical imaging technique after resection of the pancreas. The surgical procedures performed were: pancreatoduodenectomy in 22 patients, segmental pancreatectomy in 1, distal pancreatectomy in 7, and pyroluspreserving pancreatoduodenectomy in 5. The pancreatic duct was shown in its entirety in 24 of the 35 patients (68.6%) and was partially visualized in 8 patients (22.9%), but the intrahepatic and extrahepatic bile ducts were visualized completely in all patients. Furthermore, MRCP was able to demonstrate lesions in 3 of 6 patients who had shown clinical evidence of recurrence. The visualization of the pancreatic and bile duct system was satisfactory despite anatomical changes brought about by resection of the pancreas. Thus, we conclude that MRCP is an appropriate follow-up screening test for patients with suspected abnormalities of the biliary and pancreatic duct system. 相似文献