全文获取类型
收费全文 | 16265篇 |
免费 | 620篇 |
国内免费 | 86篇 |
专业分类
耳鼻咽喉 | 175篇 |
儿科学 | 348篇 |
妇产科学 | 111篇 |
基础医学 | 2072篇 |
口腔科学 | 443篇 |
临床医学 | 850篇 |
内科学 | 3986篇 |
皮肤病学 | 156篇 |
神经病学 | 1444篇 |
特种医学 | 560篇 |
外科学 | 2620篇 |
综合类 | 116篇 |
预防医学 | 443篇 |
眼科学 | 658篇 |
药学 | 1288篇 |
中国医学 | 85篇 |
肿瘤学 | 1616篇 |
出版年
2023年 | 61篇 |
2022年 | 121篇 |
2021年 | 210篇 |
2020年 | 133篇 |
2019年 | 154篇 |
2018年 | 205篇 |
2017年 | 174篇 |
2016年 | 242篇 |
2015年 | 268篇 |
2014年 | 318篇 |
2013年 | 482篇 |
2012年 | 830篇 |
2011年 | 911篇 |
2010年 | 489篇 |
2009年 | 440篇 |
2008年 | 897篇 |
2007年 | 1052篇 |
2006年 | 1052篇 |
2005年 | 1063篇 |
2004年 | 1083篇 |
2003年 | 1073篇 |
2002年 | 1105篇 |
2001年 | 383篇 |
2000年 | 330篇 |
1999年 | 333篇 |
1998年 | 301篇 |
1997年 | 246篇 |
1996年 | 236篇 |
1995年 | 192篇 |
1994年 | 194篇 |
1993年 | 162篇 |
1992年 | 204篇 |
1991年 | 196篇 |
1990年 | 174篇 |
1989年 | 156篇 |
1988年 | 152篇 |
1987年 | 141篇 |
1986年 | 140篇 |
1985年 | 124篇 |
1984年 | 118篇 |
1983年 | 86篇 |
1982年 | 77篇 |
1981年 | 68篇 |
1980年 | 85篇 |
1979年 | 64篇 |
1978年 | 48篇 |
1977年 | 45篇 |
1975年 | 49篇 |
1974年 | 42篇 |
1967年 | 33篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Tsunao Imamura Rie Takeshita Rikako Koyama Chikao Okuda Kazuo Takeuchi Masamichi Matsuda Masashi Hashimoto Goro Watanabe Hitoshi Yoshida Michio Imawari 《Digestive endoscopy》2006,18(4):303-307
Background: Pancreatic carcinoma is one of the most lethal cancers. Because pancreatic carcinoma is still very difficult to diagnose in its early stage, many of these patients will be considered unsuitable for surgery. If a cytological diagnosis is obtained at initial endoscopic retrograde cholangiopancreatography (ERCP), suitable treatment will be initiated without delay. Methods: To increase the number of exfoliated cells from the pancreatic duct, we devised a new technique, pancreatic duct lavage fluid (PDLF), following bronchoalveolar lavage fluid. The present paper reports the effectiveness of cytological examination using PDLF in the diagnosis of pancreatic carcinoma. We examined 18 pancreatic carcinoma cases. After the endoscopic retrograde pancreatography (ERP), PDLF was collected from a double‐lumen catheter inserted into the main pancreatic duct. Saline injected from the lumen for the injection, and PDLF was aspirated from the other lumen for the guidewire at the same time. The cytological examination was performed using PDLF. Results: Exfoliated cells were more frequently found in PDLF from all patients. In 15 cases (83%), cytological examination of PDLF revealed positive cytological results as the diagnosis of pancreatic carcinoma. Conclusion: Cytological examination using PDLF has a high sensitivity for detection of pancreatic carcinoma. The new examination, PDLF, is simple, safe and effective, so we expect PDLF to become widely popular. 相似文献
22.
Kiyoshi Hashizume Kazuo Ichikawa Satoru Suzuki Teiji Takeda Keishi Yamauchi Mutsuhiro Kobayashi Xiao-Yun MA 《Journal of bone and mineral metabolism》1992,10(2):39-49
Calorie restriction is important in managing patients with maturity onset diabetes mellitus (NIDDM). The effect of such restriction
on calcium metabolism is not known. The objective of this study was to determine whether patients on calorie restricted diets
would show any modification of parathyroid hormone (PTH) and calcitonin (CTN).
The serum levels of PTH and CTN were measured by radioimmunoassays in 269 patients with NIDDM. The patients were divided into
two groups depending on the intake of calorie, and PTH and CTN were monitored for 2 years. Plasma levels of vitamin D were
measured by competitive protein binding assays before and after each program.
The level of PTH (520.8±266.0 pg/ml) (mean±S.D.) was significantly (P<0.01) higher in 109 diabetic patients whose calorie intake was restricted for 2 years (diet (D) group) as compared with that
(256.6±103.8 pg/ml) of 160 diabetic patients whose calorie intake was not restricted (non-diet (ND) group). The daily oral
calcium intake of the two groups did not differ significantly. We found no significant difference in the serum PTH level in
the ND groupVS. normal control subjects (248.8±98.4, N=78). The serum calcium concentration and the amount of calcium excreted in urine
were slightly but significantly (P<0.01) lower in the D than in the ND group. The rate of tubular reabsorption of phosphate (% TRP) was significantly lower
in the D group than that in the ND group (P<0.01). The serum CTN level was significantly (P<0.01) lower in the D group (33.9±11.3 pg/ml) than in the ND group (64.9±21.2 pg/ml) 2 years after each treatment. The plasma
1,25-(OH)2-vitamin D level was significantly (P<0.01) lower in the D group (22.2±6.6 pg/ml) than in the ND group (50.6±4.2 pg/ml). When
the restriction of calorie intake in the D group was canceled, their PTH levels decreased, which was accompanied by increase
in the 1,25-(OH)2-vitamin D levels, whereas their CTN levels were unchanged.
These observations suggested that a restricted calorie intake is a risk factor for secondary hyperparathyroidism as well as
for a low serum level of CTN in patients with NIDDM. 相似文献
23.
BACKGROUND AND METHODS. It is not certain whether patients with Kawasaki disease have a higher death rate than the age-matched healthy population. We therefore undertook a study to investigate this question. Between July 1982 and December 1988, 53 collaborating treatment centers collected data on all patients who had an unequivocal new diagnosis of Kawasaki disease; patients who had recurrent disease or whose first visit to the treatment center occurred more than 14 days after the onset of symptoms were excluded. Patients were followed from the time of the first visit to the treatment center until December 31, 1989, or until death, whichever occurred first. The expected number of deaths was calculated from Japanese vital-statistics data and compared with the number observed. RESULTS. Of 4676 patients who met the eligibility criteria, 4608 (98.5 percent) were followed through either the end of the study or the date of death. Thirteen patients (10 boys and 3 girls) died during the study period. The number of deaths expected was 7.61 (ratio of observed to expected deaths, 1.71; 95 percent confidence interval, 0.91 to 2.92). The ratio was 2.04 (95 percent confidence interval, 0.98 to 3.76) for boys and 1.11 (95 percent confidence interval, 0.23 to 3.23) for girls. During the acute phase of the disease (the first two months after onset), the ratios of observed to expected deaths were higher: 9.86 overall (95 percent confidence interval, 3.95 to 20.31), 13.33 for boys (95 percent confidence interval, 4.89 to 29.07), and 3.85 for girls (95 percent confidence interval, 0.10 to 21.42). After the acute phase, however, both sexes had ratios of observed to expected deaths that were lower than 1, and the difference from the control population was not statistically significant. CONCLUSIONS. The mortality rate among boys with Kawasaki disease in Japan is twice that among healthy boys of the same age, and most deaths occur within two months of diagnosis. The mortality rate among girls with the disease appears similar to that among healthy girls, although the numbers are very small. 相似文献
24.
Kazuo Kitagawa Masayasu Matsumoto Keisuke Kuwabara Masafumi Tagaya Toshiho Ohtsuki Ryuji Hata Hirokazu Ueda Nobou Handa Kazufumi Kimura Takenobu Kamada 《Brain research》1991,561(2)
We investigated the effects of mild and non-lethal ischemic insult on neuronal death following subsequent lethal ischemic stress in various brain regions, using a gerbil model of bilateral cerebral ischemia. Single 10-min ischemia consistently caused neuronal damage in the hippocampal CA1, CA2, CA3 and CA4, layer III/IV of the cerebral cortex, dorsolateral part of the caudoputamen and ventrolateral part of the thalamus. On the other hand, in double ischemia groups, 2-min ischemic insult 2 days before 10-min ischemia exhibited significant protection in the CA1 and CA3 of the hippocampus, the cerebral cortex, the caudoputamen and the thalamus. Five-min ischemic insult 2 days before 10-min ischemia also showed protective effect in the same areas as those of 2-min ischemia except for the CA1 region of the hippocampus, while 1-min ischemic insult exhibited no protective effect in any brain regions. In the immunoblot analysis, both 2- and 5-min ischemia caused increased synthesis of heat shock protein 72 (HSP 72) in the hippocampus, but 1-min ischemia did not. The present study demonstrated that the ‘ischemic tolerance’ phenomenon was widely found in the brain and also suggested that ischemic treatment severe enough to cause HSP 72 synthesis might be needed for induction of ‘ischemic tolerance’. 相似文献
25.
K Mochizuki Y Yamashita M Torisaki M Komatsu T Tanahashi K Kawasaki 《Ophthalmic research》1992,24(3):150-154
The concentration of ceftazidime was determined in the aqueous humor and the vitreous body of normal, vitrectomized and aphakic/vitrectomized eyes and in the serum of albino rabbits 1 h after intravenous injection of 100 mg/kg ceftazidime. The intravitreal ceftazidime concentration was low (0.1-0.2 microgram/ml) in normal eyes 1 h after intravenous injection, and high (8.7 +/- 8.5 micrograms/ml) in vitrectomized and aphakic/vitrectomized eyes when injected immediately after surgery. The ceftazidime concentration was also determined in the aqueous humor and the vitreous body of normal eyes and in the serum of albino rabbits 3, 6, 12, 24 and 48 h after intravitreal injection of 200 micrograms. The intravitreal ceftazidime concentration after intravitreal injection decreased exponentially for 12 h (half-life about 7.4 h). It decreased more slowly thereafter and remained at 13.0 micrograms/ml (mean) even 48 h after injection. This concentration exceeded the minimum inhibitory concentrations against common gram-positive and gram-negative organisms causing endophthalmitis. 相似文献
26.
Miya Yoshino Hidetoshi Yamazaki Hisahiro Yoshida Shumpei Niida Shin-Ichi Nishikawa Kazuo Ryoke Takahiro Kunisada Shin-Ichi Hayashi 《Journal of bone and mineral research》2003,18(1):108-116
Alveolar bone resorption by osteoclasts is essential for tooth eruption. Osteoclast-deficient Csfm(op) homozygous (op/op) mice, which lack functional macrophage colony-stimulating factor (M-CSF), suffer from osteopetrosis and completely lack tooth eruption. Although osteoclasts appear, and osteopetrosis is cured with age in op/op mice, tooth eruption is never seen. This fact suggests that there is a critical period when osteoclasts are required for tooth eruption. In this study, to detect the critical period, we administered an antagonistic antibody directed against c-Fms, a receptor for M-CSF, to inbred C57BL/6 mice for various periods. Administration of this antibody decreased tartrate-resistant acid phosphatase-positive (TRAP) osteoclasts, and incisor eruption was completely inhibited by continual administration of this antibody from embryonic day 15.5 (E15.5) until postnatal day 12.5 (D12.5). A 1-day delay of this administration abolished the inhibition of incisor eruption. The number of TRAP-positive osteoclasts was significantly reduced between E16.5 and E18.5 in the mice treated with antibody from E15.5 compared with those treated from E16.5. These results indicate that this period, during which the number of osteoclasts decreases significantly, is critical for inhibiting incisor eruption in C57BL/6 mice. 相似文献
27.
Eduardo Kazuo Sannomiya Jun-ichi Asaumi Kanji Kishi Gisele da Silva Dalben 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(2):e41-e44
Dens invaginatus is a developmental variation resulting from an alteration in the normal growth pattern of the dental papilla. Synonyms of this disturbance include dens in dente, invaginated odontome, tooth inclusion, and dentoid in dente. Radiographically, it is observed as infolding of a radiopaque ribbon-like structure, with equal density as enamel, extending from the cingulum into the root canal and sometimes reaching the root apex, assigning the appearance of a small tooth within the coronal pulp cavity. This article presents 2 case reports. The first describes an 8-year-old girl with dens invaginatus in a mesiodens; the second report describes a 16-year-old boy presenting with 2 mesiodens, both associated with dens invaginatus. 相似文献
28.
Silent cerebral lesions are increasingly found in mass screenings using MRI and magnetic resonance angiography (MRA). The purpose of this paper is to assess the usefulness of two non-invasive clinical tests-carotid ultrasound examination and brachial-ankle pulse wave velocity (baPWV) measurement-for predicting silent cerebral infarction (SCI) and silent intracranial arterial stenosis. Data were collected on 480 asymptomatic adult subjects who participated in a brain screening program at a single hospital between April 2003 and March 2006. All participants underwent baPWV measurement, B-mode ultrasonography of carotid arteries, MRI, and MRA. Data on 476 (99.1%) subjects were included in the analysis. Among these, 273 (57.4%) were male and the mean age was 51.5 years; 161 (33.8%) had carotid plaque; 33 (6.9%) had increased intima-media thickness (IMT); 99 (20.8%) had SCI; and 7 (1.5%) had intracranial arterial stenosis. The multivariate analysis showed that age (odds ratio [OR]: 1.12; 95% confidence interval [CI]: 1.08-1.17), carotid plaque (OR: 2.69; 1.59-4.56), increased IMT (OR: 2.40; 1.02-5.65), and a history of hypertension treatment (OR 2.22; 1.11-4.43) were significantly associated with SCI. Also, increased IMT (OR 9.70: 1.48-63.71) was related to intracranial arterial stenosis. Brachial-ankle PWV was related to SCI (p<0.01) and intracranial stenosis (p=0.01) in univariate analysis but not in multivariate analysis. The presence of carotid plaque and that of increased IMT on ultrasound examination are useful for assessing the risk of SIC. Increased IMT is also predictive of intracranial arterial stenosis. 相似文献
29.
Mitsuru Masaki Tadashi Kuroda Naoki Hosen Hisao Hirota Kazuo Terai Yuichi Oshima Yoshikazu Nakaoka Shoko Sugiyama Ryusuke Kimura Satoshi Yoshihara Manabu Kawakami Norishige Iizuka Yasuhiko Tomita Hiroyasu Ogawa Ichiro Kawase Keiko Yamauchi-Takihara 《Journal of the American Society of Echocardiography》2004,17(4):397-398
A 57-year-old man with a history of renal cell carcinoma presented with presyncope. He underwent nephrectomy years earlier followed by HLA-matched allogeneic peripheral-blood stem-cell transplantation. Echocardiographic investigation revealed a solitary right ventricle mass without contiguous vena caval or right atrial involvement. The mass was pathologically confirmed to be metastatic carcinoma in the right ventricular cavity. This case highlights the need to consider an underlying neoplastic syndrome in patients presenting isolated right ventricle mass by echocardiography. 相似文献
30.
Tomomi Iwashita Kazuo Kitazawa Jun-Ichi Koyama Hisashi Nagashima Toru Koyama Yuichiro Tanaka Kazuhiro Hongo Hiroshi Okudera Kazufumi Okamoto 《Journal of clinical neuroscience》2007,14(1):68-71
A patient with cerebral deep sinus thrombosis, which was not diagnosed on the first examination, is reported. A 46-year-old woman presented with headache and vomiting. Neurological examination and a brain computed tomography (CT) scan showed no obvious abnormal findings. The patient suffered disturbed consciousness on the day after the examination, and was admitted to our emergency centre. A CT scan and magnetic resonance imaging revealed an ischaemic lesion in the left basal ganglia, suggesting deep sinus occlusion. Anticoagulant therapy was administered. One day after admission, a CT scan showed a haematoma and severe brain swelling in the same region. Cerebral angiography demonstrated a straight sinus occlusion. Intracranial pressure was not controlled with hypothermia, and the patient died 25 days after admission. Review of the initial CT scan revealed subtle, early findings of deep venous thrombosis that were missed on first examination. 相似文献