全文获取类型
收费全文 | 5411篇 |
免费 | 233篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 54篇 |
儿科学 | 112篇 |
妇产科学 | 118篇 |
基础医学 | 688篇 |
口腔科学 | 178篇 |
临床医学 | 336篇 |
内科学 | 1311篇 |
皮肤病学 | 141篇 |
神经病学 | 532篇 |
特种医学 | 372篇 |
外科学 | 716篇 |
综合类 | 18篇 |
预防医学 | 125篇 |
眼科学 | 72篇 |
药学 | 263篇 |
中国医学 | 5篇 |
肿瘤学 | 630篇 |
出版年
2023年 | 40篇 |
2022年 | 82篇 |
2021年 | 130篇 |
2020年 | 62篇 |
2019年 | 84篇 |
2018年 | 117篇 |
2017年 | 78篇 |
2016年 | 111篇 |
2015年 | 110篇 |
2014年 | 145篇 |
2013年 | 161篇 |
2012年 | 305篇 |
2011年 | 342篇 |
2010年 | 210篇 |
2009年 | 180篇 |
2008年 | 320篇 |
2007年 | 369篇 |
2006年 | 373篇 |
2005年 | 381篇 |
2004年 | 314篇 |
2003年 | 264篇 |
2002年 | 324篇 |
2001年 | 82篇 |
2000年 | 74篇 |
1999年 | 80篇 |
1998年 | 71篇 |
1997年 | 55篇 |
1996年 | 58篇 |
1995年 | 37篇 |
1994年 | 35篇 |
1993年 | 44篇 |
1992年 | 41篇 |
1991年 | 43篇 |
1990年 | 49篇 |
1989年 | 48篇 |
1988年 | 42篇 |
1987年 | 41篇 |
1986年 | 28篇 |
1985年 | 22篇 |
1984年 | 27篇 |
1983年 | 23篇 |
1981年 | 24篇 |
1980年 | 15篇 |
1979年 | 27篇 |
1978年 | 18篇 |
1976年 | 15篇 |
1975年 | 15篇 |
1974年 | 23篇 |
1973年 | 31篇 |
1972年 | 23篇 |
排序方式: 共有5671条查询结果,搜索用时 15 毫秒
111.
112.
113.
Koizumi Noriyuki Hanamura Yukio Nishida Kazuya Mori Atsushi Watabe Keiji Takemura Takeshi Man Alias Kassim Faizul M. Morioka Shinsuke 《Conservation Genetics Resources》2015,7(1):133-135
Conservation Genetics Resources - We have developed microsatellite DNA markers for Mesopodopsis orientalis (Tattersall 1908), a widely distributed mysid crustacean in shallow waters of the coastal... 相似文献
114.
Clustered features of the metabolic syndrome and the risk for increased aortic pulse wave velocity in middle-aged Japanese men 总被引:11,自引:0,他引:11
The association between different features of the metabolic syndrome (MS) (obesity, hypertension, hypercholesterolemia, low high-density lipoprotein cholesterol level, hypertriglyceridemia, high fasting plasma glucose level, and hyperuricemia) and the risk for increased aortic pulse wave velocity (PWV) of > or = 8.0 m/sec was examined in 2431 Japanese men aged 35 to 54 years who were not taking antihypertensive medication. After controlling for age, cigarette smoking, and alcohol intake, the odds ratios for increased aortic PWV in subjects with 1, 2, 3, and > or = 4 features of the MS, compared with those without features of the MS, were 1.35 (95% CI, 0.86 to 2.11), 1.90 (95% CI, 1.18 to 3.06), 1.57 (95% CI, 0.89 to 2.76), and 2.38 (95% CI, 1.26 to 4.49), respectively (p for trend = 0.003). A 9-year longitudinal study was also performed to prospectively examine the association between clustered features of the MS and the development of increased aortic PWV in 2073 men without aortic stiffness with a PWV < 8.0 m/sec and without antihypertensive medication during the follow-up period. The multivariate-adjusted hazard ratios for the incidence of increased aortic PWV in subjects with 1, 2, 3, and > or = 4 features of the MS, compared with those without features of the MS, were 1.39 (95% CI, 1.10 to 1.77), 1.46 (95% CI, 1.1 1 to 1.92), 1.75 (95% CI, 1.27 to 2.40), and 2.22 (95% CI, 1.52 to 3.25), respectively (p for trend < 0.001). These results suggest that clustered features of the MS are closely associated with the risk for increased aortic PWV in middle-aged Japanese men. 相似文献
115.
Microsatellite instability in gallbladder carcinoma: two independent genetic pathways of gallbladder carcinogenesis 总被引:10,自引:0,他引:10
Yoshida T Sugai T Habano W Nakamura S Uesugi N Funato O Saito K 《Journal of gastroenterology》2000,35(10):768-774
Although the genetic basis for gallbladder carcinogenesis has not been clarified, considerable evidence has shown that genetic
alterations play an important role in the development and progression of human cancers. In this study, we analyzed 30 gallbladder
carcinomas to investigate the role of genetic alterations in their tumorigenesis, and to study correlations with their clinicopathological
features. Tissue samples were obtained from 30 patients with gallbladder carcinoma (11 men and 19 women; mean age, 62 years;
age range, 38–80 years). Genomic DNAs were extracted from fresh tumor tissue. We examined loss of heterozygosity (LOH) in
the p53, APC, DCC, RB, and NM23-H1 gene regions by polymerase chain reaction (PCR)-LOH assay using an automated fluorescent DNA sequencer employing four microsatellite
markers (p53, APC, DCC, NM23-H1). Five additional microsatellite markers were used for the determination of microsatellite
instability (MSI). LOH was found at p53 in 9 of 15 informative cases (60%), at DCC in 10 of 22 (45%), at APC in 5 of 15 (33%), at RB in 1 of 8 (13%), and at NM23-H1 in 1 of 15 (7%). MSI was observed in 5 of 30 cases (17%) in at least one chromosomal loci of these nine microsatellite markers.
None of the patients with MSI-positive tumors showed lymph node metastasis, and there was an inverse correlation between MSI
and the presence of LOH in gallbladder carcinoma. These results suggest that there are two independent genetic pathways in
gallbladder carcinogenesis; that is, an MSI pathway and an LOH pathway.
Received: December 24, 1999 / Accepted: May 26, 2000 相似文献
116.
Ryushi Shudo Takeshi Obara Satoshi Tanno Tsuneshi Fujii Noriyuki Nishino Miho Sagawa Hitoshi Ura Yutaka Kohgo 《Journal of gastroenterology》1998,33(2):289-294
"Groove pancreatitis", a form of segmental pancreatitis affecting the head of the pancreas, is local-ized within the "groove"
between pancreas head, duo-denum, and common bile duct. Differentiation between groove pancreatitis and pancreatic head carcinoma
is often difficult. We report a case of groove pancreatitis in which a hypoechoic mass between the duodenal wall and pancreas
was clearly imaged, and narrowing of the second portion of the duodenum and bile duct stenosis were also found. The diagnosis
was confirmed by surgery (pylorus-preserving pancreato duodenectomy). The patient was relieved from abdominal pain post operation.
Up to the present, the patient has been good condition. We review the clinicopathologic and radiologic features of groove
pancreatitis in the Japanese literature and discuss the possible role of Santorini's duct in its pathogenesis. We consider
that impacted protein plugs in Santorini's duct are a pathogenic factor in the development of groove pancreatitis. Therefore,
the findings of Santorini's duct on endoscopic retrograde pancreatography are very important in the diagnosis of groove pancreatitis.
Groove pancreatitis presents various clinical features, such as biliary stenosis, duodenal stenosis, and pancreatic mass,
and often masquerades as pancreatic head carcinoma. This condition should be kept in mind in the differential diagnosis of
pancreatic head carcinoma.
(Received Apr. 17, 1997; accepted Sept. 26, 1997) 相似文献
117.
Osteoclast (OC) differentiation requires that precursors, such as macrophage colony-stimulating factor (M-CSF)-dependent bone marrow macrophages, receive signals transduced by receptor activator of nuclear factor kappaB (RANK) and c-Fms, receptors for RANK ligand (RANKL) and M-CSF, respectively. Activated c-Fms autophosphorylates cytoplasmic tail tyrosine residues, which, by recruiting adaptor molecules, initiate specific signaling pathways. To identify which tyrosine residues are involved in c-Fms signaling in primary cells, we retrovirally transduced M-CSF-dependent bone marrow macrophages with a chimera comprising the external domain of the erythropoietin (Epo) receptor linked to the transmembrane and cytoplasmic domains of c-Fms. Transduced cells differentiate into bone-resorbing osteoclasts when treated with RANKL and either M-CSF or Epo, confirming that both endogenous and chimeric receptors transmit osteoclastogenic signals. Cells expressing chimeric receptors with Y(697)F, Y(706)F, Y(721)F, and Y(921)F single point mutations generate normal numbers of bone-resorbing OCs, with normal bone-resorbing activity when treated with RANKL and Epo. In contrast, those expressing Y(559)F generate fewer OCs, whereas theY807F mutant is incapable of osteoclastogenesis. Finally, although mature OCs expressing Y(559)F exhibit impaired bone resorption, those bearing Y807F do not. Thus, we have identified specific tyrosine residues in the cytoplasmic tail of c-Fms that are critical for transmitting M-CSF-initiated signals individually required for OC formation or function, respectively. 相似文献
118.
Nobuaki Chinzei Takafumi Hiranaka Takahiro Niikura Takaaki Fujishiro Shinya Hayashi Noriyuki Kanzaki Shingo Hashimoto Yoshitada Sakai Ryosuke Kuroda Masahiro Kurosaka 《Clinics in Orthopedic Surgery》2015,7(2):152-157
Background
In daily clinical practice, it is essential to properly evaluate the postoperative sliding distance of various femoral head fixation devices (HFD) for trochanteric fractures. Although it is necessary to develop an accurate and reproducible method that is unaffected by inconsistent postoperative limb position on radiography, few studies have examined which method is optimal. Therefore, the purpose of this study is to prospectively compare the accuracy and reproducibility of our four original methods in the measurement of sliding distance of the HFD.Methods
Radiographs of plastic simulated bone implanted with Japanese proximal femoral nail antirotation were taken in five limb postures: neutral, flexion, minute internal rotation, greater external rotation, and flexion with external rotation. Orthopedic surgeons performed five measurements of the sliding distance of the HFD in each of the flowing four methods: nail axis reference (NAR), modified NAR, inner edge reference, and nail tip reference. We also assessed two clinical cases by using these methods and evaluated the intraclass correlation coefficients.Results
The measured values were consistent in the NAR method regardless of limb posture, with an even smaller error when using the modified NAR method. The standard deviation (SD) was high in the nail tip reference method and extremely low in the modified NAR method. In the two clinical cases, the SD was the lowest in the modified NAR method, similar to the results using plastic simulated bone. The intraclass correlation coefficients showed the highest value in the modified NAR method.Conclusions
We conclude that the modified NAR method should be the most recommended based on its accuracy, reproducibility, and usefulness. 相似文献119.
120.
A method was developed to measure the mucosal blood flow (BF), mucosal pH (pH), and transmucosal potential difference (PD) in various sites from the oral cavity to the duodenum without surgical operation or damage to the subject rats. These measurements were carried out by using three indicator electrodes, which were attached to the various sites through the suction channel of an endoscope. The hydrogen gas clearance method was used for the measurement of BF. BF values obtained at the fundic, pyloric, and duodenal regions were 119±17, 69.9±8.8, and 114±18 ml/min/100 g (mean±se), respectively. The pH values were lowest at the cardiac portion and the forestomach and highest at the duodenum. PD showed higher values at the stomach and lower values at the pharynx and duodenum. Using this technique, it was possible to measure the BF, pH, and PD repeatedly and safely at various sites in the same rat. Therefore, it was suggested that this method is useful in studying the physiological functions of the stomach and duodenum and the pathogenesis of gastroduodenal ulceration and that this method is applicable to measure the change of the above parameters in the healing process of gastric ulcer in rats. 相似文献