全文获取类型
收费全文 | 7630篇 |
免费 | 302篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 164篇 |
妇产科学 | 37篇 |
基础医学 | 986篇 |
口腔科学 | 151篇 |
临床医学 | 428篇 |
内科学 | 2425篇 |
皮肤病学 | 51篇 |
神经病学 | 432篇 |
特种医学 | 287篇 |
外科学 | 1108篇 |
综合类 | 40篇 |
预防医学 | 205篇 |
眼科学 | 41篇 |
药学 | 512篇 |
中国医学 | 62篇 |
肿瘤学 | 1016篇 |
出版年
2023年 | 31篇 |
2022年 | 59篇 |
2021年 | 118篇 |
2020年 | 57篇 |
2019年 | 80篇 |
2018年 | 104篇 |
2017年 | 75篇 |
2016年 | 110篇 |
2015年 | 119篇 |
2014年 | 167篇 |
2013年 | 221篇 |
2012年 | 382篇 |
2011年 | 439篇 |
2010年 | 241篇 |
2009年 | 247篇 |
2008年 | 442篇 |
2007年 | 475篇 |
2006年 | 494篇 |
2005年 | 540篇 |
2004年 | 532篇 |
2003年 | 521篇 |
2002年 | 572篇 |
2001年 | 107篇 |
2000年 | 110篇 |
1999年 | 114篇 |
1998年 | 195篇 |
1997年 | 144篇 |
1996年 | 116篇 |
1995年 | 107篇 |
1994年 | 104篇 |
1993年 | 113篇 |
1992年 | 96篇 |
1991年 | 79篇 |
1990年 | 93篇 |
1989年 | 71篇 |
1988年 | 45篇 |
1987年 | 48篇 |
1986年 | 51篇 |
1985年 | 39篇 |
1984年 | 27篇 |
1983年 | 23篇 |
1982年 | 37篇 |
1981年 | 41篇 |
1980年 | 35篇 |
1979年 | 14篇 |
1978年 | 20篇 |
1977年 | 14篇 |
1976年 | 16篇 |
1974年 | 10篇 |
1973年 | 10篇 |
排序方式: 共有7988条查询结果,搜索用时 0 毫秒
71.
The effect of calcium-balanced heparin (471896, CIBA CORNING) on blood gas and electrolyte analysis was evaluated, by comparing with that of sodium heparin (Na heparin). One ml of whole blood was collected into a syringe, which contained calcium-balance heparin (Ca balanced heparin) or Na heparin. 122 pairs of blood samples obtained from 15 patients were analyzed for Na, K, ionized calcium (Ca(++)), total hemoglobin, pH, P(CO)(2), and P(O)(2) by an automatic blood gas and electrolyte analyzer, CIBA CORNING model 288. There was a significant difference ( P < 0.05) in pH, P(CO)(2), Na, and Ca(++) between the two different groups. Ca(++) concentration was significantly less in Na heparin group than in Ca balanced heparin group, probably due to more chelation of Ca(++) by Na heparin than Ca balanced heparin. The present study suggests that the Ca balanced heparin has minimal effect on the blood gas and electrolyte analysis, and is a suitable anticoagulant for the Ca(++) measurement. 相似文献
72.
Shigemi K Takahashi H Hashimoto S Nomi S Chihara E Kinoshita T Tanaka Y Miyazaki M 《Journal of anesthesia》1990,4(1):91-93
Finger arterial blood pressures determined by a newly developed sphygmomanometer, HEM-802F, were compared with arterial pressure obtained from direct measurement of the radial artery. An excellent correlation was found between the two methods (systolic: r = 0.93, diastolic: r = 0.91), although there was a large variability among individual subjects. The range of differences between them are from +32 to –13mmHg for systolic and +15 to –25mmHg for diastolic blood pressure measurement. HEM-802F underestimated systolic pressure (–4.0mmHg) and overestimated diastolic pressure (+6.7mmHg), compared with intra-arterial readings.The HEM-802F was useful for the non-invasive arterial pressure monitoring during general anesthesia.(Shigemi K, Takahashi H, Hashimoto S et al.: A comparative study of measurement of arterial blood pressure using HEM-802F and arterial cannulation. J Anesth 4: 91–93, 1990) 相似文献
73.
Tomita M Ayabe H Tagawa Y Hara S Tsuji H Oka T Akamine S Takahashi T Shingu H 《Breast cancer (Tokyo, Japan)》1995,2(2):113-117
The procedure of aspiration biopsy cytology by fine needle aspiration (ABC) is as option in establishing definitive diagnoses for breast cancers. In this series, a needle size of 21G was considered most suitable for ABC as well as flow cytometric DNA analysis. Histograms from fresh samples aspirated by fine needle clearly delineated a sharp peak in G&sup0;G(1) phases and also a better CV was obtained than with paraffin-embedded preparations. In addition, fresh samples gave more reliable DI and suggested the value of measuring nuclear DNA contents. It is believed that the prognoses of breast cancers are closely associated with DNA ploidy patterns. In this sense, flow cytometric DNA analysis of fresh samples of ABC is regarded as important in clinical use. 相似文献
74.
Kuba H Sato N Uchiyama A Nakafusa Y Mibu R Yoshida K Kuroiwa K Tanaka M 《Surgery today》1999,29(4):375-377
We herein describe a patient with mediastinal lymph node metastases which occurred after both a primary sigmoid colon cancer
and metachronous ovarian metastasis had been resected. The most likely route of metastases to the mediastinum in this case
is the paravertebral venous plexus probably connected to the ovarian metastasis, or so-called remetastasis. This case illustrates
that the mediastinum is thus a possible metastatic site in patients with colon cancer. Surgeons should therefore pay attention
to the mediastinum as well as the lung fields when checking chest X-ray films during a follow-up of patients after a resection
of colon cancer. 相似文献
75.
Fifteen infants and children (M = 7, F = 8), aged from 0 to 13 years, who underwent cardiac catheterization and cardioangiography under ketamine-diazepam anesthesia were the subjects of this study. The effect of a contrast medium, isolamate sodium (66.8%) on the plasma somolality and vasopressin concentration was studied. The plasma osmolality was significantly elevated after contrast medium administration (289 ± 3 vs. 303 ± 8mosmol·kg–1) as well as plasma vasopressin (from 2.1 ± 0.9 vs. 4.7 ± 2.0 micro-unit·ml–1).It is concluded that the administration of contrast medium for cardioangiography causes elevation of plasma osmolality, which leads to the elevation of plasma vasopressin concentration.(Yamashita M, Horigome H, Kudo T, et al.: Plasma vasopressin response to contrast medium during cardiac catheterization in infants and children. J Anesth 5: 203–204, 1991) 相似文献
76.
Hirose M Yoda K Sakai K Saitoh A Nakagawa H Tanaka M Miyazaki M 《Journal of anesthesia》1991,5(1):30-35
Prostaglandin E1-induced hypotension (25% reduction from the preadministration level in mean arterial pressure) was applied to thirteen patients. Eight patients among them were operated in the supine position (group I) and other five in the prone position (group II). The maintenance dose of PGE1 was considerably lower in group II than in group I (0.067µg·kg–1·min–1 vs. 0.119µg·kg–1·min–1). In group I, there was a significant increase in CI, with a significant decrease in SVRI and PVRI during PGE1-induced hypotension. Such a high dose of PGE1 (0.119µg·kg–1·min–1) was considered to have a direct dilating action on the systemic resistance bed as well as on the pulmonary vasculature. It was considered that the suppression of hypoxic pulmonary vasoconstriction could be a mechanism to increase venous admixture during PGE1-induced hypotension. In group II, there was no significant increase in CI, and no significant decrease in SVRI and PVRI. PGE1-induced hypotension can be safely applied to the anesthetized patients, but we should be careful to apply it to the patients in the prone position, because lower dose of PGE1 can induce severe hypotension, which is not accompanied by the increase in CI as occures in the patients in the supine position.(Hirose M, Yoda K, Sakai K, et al.: Comparative Study on the cardio-respiratory change during prostaglandin E1-induced hypotention in the patients in the supine and prone position. J Anesth 5: 30–35, 1991) 相似文献
77.
Manometric Evidence of Improved Early Gastric Stasis by Erythromycin after Pylorus-preserving Pancreatoduodenectomy 总被引:3,自引:0,他引:3
Matsunaga H Tanaka M Takahata S Ogawa Y Naritomi G Yokohata K Yamaguchi K Chijiiwa K 《World journal of surgery》2000,24(10):1236-1242
Gastric stasis is a frequent complication of pylorus-preserving pancreatoduodenectomy (PPPD). We demonstrated that it might be attributable to delayed recovery of phase III activity of the gastric migrating motor complex due to low concentrations of plasma motilin caused by resection of the duodenum. Leucine 13-motilin is effective for treating gastric stasis, but it is not yet available for clinical use. Whether erythromycin would improve early gastric stasis after PPPD was tested clinically and by manometry. A manometric tube assembly and a gastrostomy tube were inserted in the stomach of 10 patients at PPPD for pressure recording from the gastric antrum and jejunum and for gastric juice drainage, respectively. After baseline recording, erythromycin 5 mg/kg was given intravenously on day 14 and saline as a placebo on day 17 every 4 hours four times a day. The daily volume of gastric juice output and the gastric motility index were measured. The mean period until the return of gastric phase III was 31 +/- 1 days. Erythromycin significantly increased the gastric motility index from 7.9 +/- 1.3 mmHg to 15.7 +/- 1.8 mmHg (p = 0.0005), whereas saline did not (7.2 +/- 1.6 mmHg to 6.5 +/- 1.2 mmHg; p = 0.21). Erythromycin significantly decreased the gastric juice output from 1,080 +/- 190 ml to 738 +/- 199 ml (p < 0.0001), but the saline injections did not (1,064 +/- 174 ml to 1,115 +/- 189 ml; p = 0.35). Erythromycin, a universally available motilin agonist, is a safe, effective, potent drug for the treatment of early gastric stasis after PPPD. 相似文献
78.
The human T-cell factor-4 gene splicing isoforms, Wnt signal pathway, and apoptosis in renal cell carcinoma. 总被引:4,自引:0,他引:4
79.
80.
The 1.5 GHz Electromagnetic Near-field Used for Cellular Phones Does Not Promote Rat Liver Carcinogenesis in a Medium-term Liver Bioassay 总被引:3,自引:1,他引:3
Katsumi Imaida Masao Taki So-ichi Watanabe Yoshitsugu Kamimura Takayasu Ito Tsuyoshi Yamaguchi Nobuyuki Ito Tomoyuki Shirai 《Cancer science》1998,89(10):995-1002
We have recently established that local exposure to a 929.2 MHz electromagnetic near-field, used for cellular phones, does not promote rat liver carcinogenesis in a medium-term bioassay system. In the present study, a 1.439 GHz electromagnetic near-field (EMF), another microwave band employed for cellular phones in Japan, was similarly investigated. Time division multiple access (TDMA) signals for the Personal Digital Cellular (PDC) Japanese cellular telephone standard system were directed to rats through a quarter-wavelength monopole antenna. Numerical dosimetry showed that the peak SARs within the liver were 1.91–0.937 W/kg, while the whole-body average specific absorption rates (SARs) were 0.680–0.453 W/kg, when the time-averaged antenna radiation power was 0.33 W. Exposure was for 90 min a day, 5 days a week, over 6 weeks, to male F344 rats given a single dose of diethylnitrosamine (200 mg/kg, i.p.) 2 weeks previously. At week 3, all rats were subjected to a two-thirds partial hepatectomy. At week 8, the experiment was terminated and the animals were killed. Carcinogenic potential was scored by comparing the numbers and areas of the induced glutathione S-transferase placental form (GST-P)-positive foci in the livers of exposed (48) and sham-exposed rats (48). Despite increased serum levels of corticosterone, adrenocorticotropic hormone (ACTH) and melatonin, the numbers and the areas of GST-P-positive foci were not significantly altered by the exposure. These findings clearly indicated that local body exposure to a 1.439 GHz EMF, as in the case of a 929.2 MHz field, has no promoting effect on rat liver carcinogenesis in the present model. 相似文献