全文获取类型
收费全文 | 3491篇 |
免费 | 191篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 42篇 |
妇产科学 | 41篇 |
基础医学 | 489篇 |
口腔科学 | 93篇 |
临床医学 | 254篇 |
内科学 | 811篇 |
皮肤病学 | 36篇 |
神经病学 | 294篇 |
特种医学 | 153篇 |
外科学 | 538篇 |
综合类 | 13篇 |
一般理论 | 2篇 |
预防医学 | 136篇 |
眼科学 | 23篇 |
药学 | 285篇 |
中国医学 | 17篇 |
肿瘤学 | 444篇 |
出版年
2023年 | 34篇 |
2022年 | 48篇 |
2021年 | 74篇 |
2020年 | 44篇 |
2019年 | 62篇 |
2018年 | 68篇 |
2017年 | 60篇 |
2016年 | 68篇 |
2015年 | 55篇 |
2014年 | 73篇 |
2013年 | 98篇 |
2012年 | 187篇 |
2011年 | 180篇 |
2010年 | 115篇 |
2009年 | 95篇 |
2008年 | 157篇 |
2007年 | 184篇 |
2006年 | 154篇 |
2005年 | 148篇 |
2004年 | 146篇 |
2003年 | 119篇 |
2002年 | 115篇 |
2001年 | 121篇 |
2000年 | 137篇 |
1999年 | 125篇 |
1998年 | 36篇 |
1997年 | 32篇 |
1996年 | 29篇 |
1995年 | 23篇 |
1994年 | 14篇 |
1993年 | 18篇 |
1992年 | 70篇 |
1991年 | 77篇 |
1990年 | 88篇 |
1989年 | 90篇 |
1988年 | 55篇 |
1987年 | 61篇 |
1986年 | 51篇 |
1985年 | 56篇 |
1984年 | 38篇 |
1983年 | 29篇 |
1982年 | 17篇 |
1979年 | 35篇 |
1978年 | 24篇 |
1977年 | 16篇 |
1975年 | 15篇 |
1974年 | 16篇 |
1970年 | 17篇 |
1969年 | 23篇 |
1965年 | 13篇 |
排序方式: 共有3700条查询结果,搜索用时 15 毫秒
21.
Kunii Y Kamada M Ohtsuki S Araki T Kataoka K Kageyama M Nakagawa N Seino Y 《Acta medica Okayama》2003,57(4):191-197
This study was designed to explore whether it was possible to evaluate the severity of VSD, PDA, and ASD by measuring brain natriuretic peptide (BNP) levels. We also investigated normal BNP levels in children to provide a baseline for our study. We measured BNP levels in 253 normal children, including 11 normal neonates, and in 91 VSD patients, 29 PDA patients, and 34 ASD patients. BNP levels showed no age-related differences in normal children (the mean value: 5.3 +/- 3.8 pg/ml). In the healthy neonates, BNP levels rose from 10.4 +/- 11.9 pg/ml in cord blood to 118.8 +/- 83.2 pg/ml on day 0, then fell to 15.3 +/- 7.8 pg/ml by day 7. In VSD and PDA patients, BNP levels correlated significantly with Qp/Qs, LVEDV, and peak RVP/LVP. In ASD patients, BNP levels correlated with Qp/Qs and RVEDV. Especially, in VSD patients, as an index corresponding to 1.5-2.0 of the Qp/Qs ratio, BNP levels of 20-35 pg/ml were found to be best with regard to both sensitivity and specificity. In the healthy neonates, BNP levels changed rapidly after birth. In VSD, PDA, and ASD patients, BNP levels were well-correlated with the severity of the disease. Especially, in VSD patients, it that appears BNP levels may be useful in evaluating surgical indications, with 20-35 pg/ml levels being the appropriate cut-off value. 相似文献
22.
Masuyama K Taniguchi I Kataoka N Ohno M 《Genes to cells : devoted to molecular & cellular mechanisms》2004,9(10):959-965
Different classes of RNA are exported to the cytoplasm by distinct mechanisms. Each class of RNA forms distinct complexes with nuclear proteins prior to its export to the cytoplasm. In our attempt to obtain comprehensive information of protein factors that specifically associate with mRNAs in the nucleus, we performed in vivo UV-crosslinking analysis after microinjection of various RNAs into Xenopus oocyte nucleus. We found a group of proteins preferentially crosslinked to mRNAs. Immunoprecipitation experiments revealed that some of the crosslinked signals corresponded to SR (serine/arginine-rich) proteins, a family of essential RNA-binding proteins involved in pre-mRNA splicing. It was previously suggested that some members of SR protein family are involved in export of a specific intronless mRNA, histone H2A mRNA and some spliced mRNAs. However, it is still to be clarified if SR proteins are involved in export of general mRNAs, especially general intronless mRNAs that do not contain specific RNA export elements. When we microinjected an antibody against SR proteins into the nucleus, export of mRNAs was severely inhibited, regardless of whether the mRNAs were produced via pre-mRNA splicing or not, whereas export of other RNAs was not affected. These results unequivocally showed that SR proteins are involved in export of both general intronless and spliced mRNAs. 相似文献
23.
Akihisa Kataoka Naoki Nishimura Noboru Uchiyama Hiroshi Ono Jun Kishi Naohiko Chonabayashi 《Arerugī》2007,56(7):685-690
BACKGROUND: Many drugs and the combinations of drugs are recommended for each treatment step in bronchial asthma. However, there are few issues examined about the optimal drug and combination of drugs in a long term prognosis. In this study, we investigated the optimal drugs and combinations of drugs from a point of view of prognosis. METHODS: One hundred and ninety four patients who visited our hospital for treatment from November, 2003 to October, 2004 and were managed according to GINA guideline were surveyed retrospectively. We compared the rate of step up and the frequency of urgent visit and urgent hospitalization in one year between drug groups in each treatment step. RESULTS: The rate of step up was significantly higher in leukotriene receptor antagonist (LTRA) group than in inhalation corticosteroid (ICS) group and theophylline group in Step 2. The frequency of urgent visit and urgent hospitalization was significantly higher in ICS+LTRA group than in ICS+theophylline group and ICS+long-acting beta 2-agonist (LABA) group in Step 3. CONCLUSION: There is a possibility that the prognosis becomes bad when we use LTRA in the practical treatment according to GINA guideline. 相似文献
24.
Shigeru Amano Hideo Kataoka Fumitada Hazama Minora Nakatake Atsuhiko Maki 《Pathology international》1985,35(4):969-974
Hepatocellular carcinoma (HCC) showing marked elevation of serum alpha fetoprotein (AFP) (maximum; 70942.0 ng/ml at the end stage) and serum carcinoembryonic antigen (CEA)(maximum; 7368.4 ng/ml at the end stage) was surgically resected. In the resected liver, there were two different tumor nodules which were adjacent to each other but clearly separated by a thin connective tissue. One of the nodules was a well differentiated and the other was poorly differentiated HCC. Immunoperoxidase study revealed that both CEA and AFP were localized in the tumor cells of the poorly differentiated HCC. This is the first report which clearly proved CEA synthesis in the cells of HCC. Serial staining showed that there was simultaneous synthesis of CEA and AFP in some of the tumor cells. ACTA PATHOL. JPN. 35: 969–974, 1985. 相似文献
25.
A mesenchymal chondrosarcoma found in a 7-year-old Holstein cow was studied by light and electron microscopy. There was a primary site in the subcutaneous tissue at the base of the neck and metastases in the lungs, pleura, broncho-mediastinal lymph nodes, kidneys and heart. The neoplasm was composed of undifferentiated mesenchymal tissue, myxoid tissue and chondroid tissue. The neoplastic cells of the former two tissues were characterized by desmosome-like junctions and moderate to small amounts of rough endoplasmic reticulum (RER). 相似文献
26.
We investigated the interactions in the KOC-2s human ovarian cancer cells on the effect of glucocorticoids, and sex steroid hormones in ovarian carcinomas. At 10(-8) M to 10(-5) M, dexamethasone (Dex) decreased the number of cells by 75-80% (p<0.001). At 10(-8) M and 10(-7) M, hydrocortisone (HC) decreased the number by 50% (p<0.01); at 10(-6) M and 10(-5) M, the decrease in number of cells was 65%. The E-2 decrease in number was not statistically significant. Progesterone (PG) showed at 10(-8) to 10(-6) M an increase in number of cells, however, at 10(-5) M it was decreased by 70% with a significant difference (p<0.001). Dex (10(-8)-10(-5) M), HC (10(-8)-10(-5) M) and PG (10(-5) M) produced internucleosomal cleavage of DNA into fragments with multiples of 180 to 200 bp. The TNF-alpha with addition of Dex (10(-8)-10(-5) M) and HC (10(-8)-10(-5) M) was increased after 24 h, 48 h (p<0.001); however, gradually decrease after 72 h. When PG (10(-8)-10(-5) M) was added, PG (10(-5) M) increased the secretion of TNF-alpha after 72 h. Our findings demonstrate that glucocorticoids, and PG directly induce apoptotic DNA fragmentation of KOC-2s cells. However, the secretion of TNF-alpha and expression of Fas antigen were totally different in these substances. These data provide a basis for future studies on the mechanisms of apoptotic effect of glucocorticoids, and PG and the therapeutic effects of these substances. 相似文献
27.
Nishida T Sugiyama T Kataoka A Ushijima K Ueyama T Yakushiji M 《Oncology reports》1995,2(6):1045-1048
The incidence and transplantability of ovarian teratoma in LT/Sv mice were examined following cisplatin treatment at the age of 16 days, and compared to those in the control group. Cisplatin had not affected the emergence of egg cleavage, which simultaneously appeared in the mouse ovaries in both groups. Although 7 teratomas, occasionally transplantable, developed in the control mice aged over 30 days, only 2 tumors occurred in cisplatin-treated mice at the age of 120 days and they were not transplantable. The results suggest that cisplatin might influence the tumorigenic process after egg cleavage, or transplantability of teratoma. 相似文献
28.
29.
Kataoka K Hayakawa T Mushiroi T Wakayama A Yamada K Kuroda R Ioku M 《Restorative neurology and neuroscience》1992,4(5):323-330
We compared the functional and anatomical alterations of somatosensory circuits in the acute (1-3 days after infarct) and chronic (3 months after infarct) stage after subcortical striatal infarct in Wistar rats. Occlusion of the left middle cerebral artery produced subcortical striatal infarct in approximately 69% of the rats. The others developed cortical infarct. The function of the somatosensory circuits was evaluated by [14C]2-deoxyglucose autoradiography during physiological stimulation of the right vibrissae and face. In rats with subcortical infarct, the areas activated by sensory stimulation of the right vibrissae and face, applied 1 and 3 days after occlusion, were reduced compared to sham-operated controls (P < 0.05). In the chronic stage of subcortical infarct, the areas of metabolic activation of the left anterior vibrissal and facial sensory area were increased compared to rats with acute subcortical infarct (P < 0.05). To evaluate the anatomical changes in the somatosensory pathway, at 1 day and 3 months after occlusion, we injected wheat germ agglutinin-horseradish peroxidase solution as an axonal transport substance bilaterally into the anterior vibrissal and facial sensory area. Tract tracing studies in both the acute and chronic stage of subcortical infarct showed a reduction in the peroxidase-positive area in the left thalamus compared to the control hemispheres (P < 0.01). The functional disturbance and recovery of the somatosensory circuits after subcortical infarct are discussed. 相似文献
30.
RATIONALE AND OBJECTIVES: Nitric oxide (NO) regulation of endothelial function is involved in the development of acute lung injury. The role of NO in contrast media-induced increases in pulmonary vascular permeability was investigated in a rat model. METHODS: Nonionic (iohexol) and ionic (ioxaglate) contrast media were intravenously injected at 1.5 mL/min in rats. Pulmonary vascular permeability was evaluated by measuring the amount of Evans blue dye uptake as a quantitative marker of albumin extravasation in lung tissue. RESULTS: Intravenous injections of contrast media at doses of 4 and 6 g I/kg induced a dose-dependent increase in pulmonary vascular permeability. L-Arginine (an NO synthase substrate) and N(G)-nitro-L-arginine (L-NNA) (an NO synthase inhibitor) prevented and aggravated, respectively, the increase in pulmonary vascular permeability induced by the contrast medium. An aggravating action of L-NNA was confirmed by morphological and histological observations, this action being blocked by L-arginine (300 mg/kg) but not by D-arginine. Isosorbide dinitrate (1-20 mg/kg), an NO donor, had a dose-dependent protective effect on ioxaglate-increased vascular permeability. CONCLUSIONS: Our experimental findings suggest that contrast media at high doses produce pulmonary edema by inhibiting endothelial NO production, and nitrovasodilators protect against this adverse effect in rats. 相似文献