首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   218篇
  免费   4篇
  国内免费   3篇
儿科学   35篇
基础医学   11篇
口腔科学   4篇
临床医学   13篇
内科学   47篇
皮肤病学   7篇
神经病学   21篇
外科学   37篇
综合类   4篇
药学   16篇
中国医学   6篇
肿瘤学   24篇
  2021年   1篇
  2020年   2篇
  2016年   1篇
  2015年   1篇
  2012年   3篇
  2011年   2篇
  2010年   1篇
  2009年   4篇
  2008年   1篇
  2007年   3篇
  2006年   13篇
  2005年   5篇
  2004年   5篇
  2003年   7篇
  2002年   4篇
  2001年   3篇
  2000年   2篇
  1999年   5篇
  1998年   16篇
  1997年   15篇
  1996年   20篇
  1995年   18篇
  1994年   16篇
  1993年   11篇
  1992年   6篇
  1991年   3篇
  1989年   4篇
  1988年   2篇
  1987年   5篇
  1986年   8篇
  1985年   10篇
  1984年   3篇
  1983年   3篇
  1982年   2篇
  1981年   2篇
  1980年   5篇
  1979年   5篇
  1978年   2篇
  1972年   2篇
  1971年   2篇
  1968年   1篇
  1966年   1篇
排序方式: 共有225条查询结果,搜索用时 937 毫秒
41.
Summary Phosphorylcholine-bearing component levels in extracts of various parasites were determined by a capillary precipitin test using anti-phosphorylcho-line Ig A myeloma protein, TEPC-15. Phosphorylcholine was demonstrated as a structural component not only in nematodes but also in trematodes and cestodes. The phosphorylcholine-bearing component was isolated from an extract of Toxocara canis larvae using a TEPC-15-Sepharose 4B column. The component reacted with C-reactive protein in sera to form one precipitin line in Immunoelectrophoresis. The component provided two Brilliant Coomassie Blue positive bands in SDS-polyacrylamide gel electrophoresis. It reacted with C-reactive protein to activate complement in serum.  相似文献   
42.
43.
目的了解医科大学生口腔状况及卫生保健行为,分析相关影响因素。方法采用唾液隐血试验及问卷调查方式对192名医科大学生进行调查。结果卡方分析显示唾液隐血阳性率在性别间差异无显著性,但在不同学科专业间有显著性差异。且与牙龈病、牙列不齐显著相关。结论医科大学生的口腔卫生令人堪忧,口腔卫生实施效率较低,尤其特殊清洁工具应用较少,口腔卫生习惯、牙列状态、饮食、就医行为等是主要相关影响因素。  相似文献   
44.
In patients with an implanted DDD pacemaker (PM), the atrial contribution may be interrupted by too short an atrioventricular (AV) delay, and filling time may be shortened by too long an AV delay. The AV delay at which the end of the A wave on transmitral flow coincides with complete closure of the mitral valve may be optimal. The subjects were 15 patients [70.3+/-12.3 (SD) years old] with an implanted DDD PM. Cardiac output (CO) and pulmonary capillary wedge pressure (PCWP) were measured by Swan-Ganz catheter. Transmitral flow was recorded by pulsed Doppler echocardiography. AV delay was prolonged stepwise by 25 msc. When the AV delay was set at 155+/-26 ms, the end of the A wave coincided with complete closure of the mitral valve. When the AV delay was prolonged 25, 50, 75, and 100 ms from this AV delay, the interval between the end of the A wave and complete closure of mitral the valve was prolonged 16+/-5, 39+/-6, 65+/-4 and 88+/-5 ms, respectively (r = 0.97, P<0.0001) and diastolic mitral regurgitation was observed during this period. Thus, the optimal AV delay may be predicted as follows: the slightly prolonged AV delay minus the interval between the end of the A wave and complete closure of the mitral valve. When the AV delay was set at 215 ms, there was a significant positive correlation between the predicted optimal AV delay (166+/-23 ms) and the optimal AV delay (CO: 161+/-26 msec, r = 0.93, P<0.0001, PCWP: 161+/-28 msec, r = 0.95, P<0.0001). In conclusion, optimal AV delay can be predicted by this simple formula: slightly prolonged AV delay minus the interval between end of A wave and complete closure of mitral valve at the AV delay setting.  相似文献   
45.
A 72-year-old Japanese man presented with a painless swollen left scrotal mass with elevated levels of serum alpha-fetoprotein and prostate specific antigen. The patient underwent high orchiectomy under diagnosis and a final pathological examination revealed embryonal carcinoma of the left testis. A systematic needle prostate biopsy under guidance of transrectal ultrasound revealed prostate cancer (Gleason score, 8) on the left lobe (T2aN0M0). Systemic chemotherapy was given for retroperitoneal lymph node metastasis of testicular cancer and hormonal therapy (LH-RH analog) was given for prostate cancer. The patient was well with no evidence of metastasis from the testicular cancer or prostate cancer and with no elevation of serum alpha-fetoprotein or prostate specific antigen 26 months after the orchiectomy.  相似文献   
46.
OBJECTIVES: In a variety of cancers, several polymorphisms of the tumor necrosis factor (TNF) genes have been reported to result in different clinical outcomes. We investigated whether a polymorphism of the TNF gene is associated with a susceptibility to bladder cancer and its disease status. METHODS: Polymorphisms in the TNF-alpha gene promoter (-308 bp) and the NcoI site in the first intron of the TNF-beta gene were analyzed in 141 Japanese patients with bladder cancer and 173 Japanese controls by polymerase chain reaction-restriction fragment length polymorphism. The correlations between the polymorphisms of the TNF genes and the clinicopathological features were analyzed. RESULTS: The number of cases and controls with TNF-alpha2 was too small to be assessable. In contrast, the TNF-beta1/2 genotype at the NcoI site in the first intron conferred a 1.71-fold increased risk of bladder cancer compared to the TNF-beta2/2 genotype. In the bladder cancer group, patients with the TNF-beta1 allele had a significantly higher risk for a high-grade tumor (grade 3) or carcinoma in situ (CIS) than those without the TNF-beta1 allele. Moreover, in the superficial bladder cancers, patients with the TNF-beta1 allele showed a significantly higher intravesical recurrence rate than those without the TNF-beta1 allele. CONCLUSION: This polymorphism in the TNF-beta gene appears to be associated with tumor occurrence and disease status, such as the tumor grade and the presence of CIS. Further study with an increased sample size is warranted.  相似文献   
47.
Abstract Tonsillectomy was performed on 10 adult sleep apnea patients (five males, five females; average age, 39 years old; average body mass index, 24.8 kg/m2). Tonsillectomy alone was indicated if tonsillar hypertrophy was moderate to severe and the length of the soft palate was less than 35 mm according to cephalometry. Remarkable improvements were observed in all cases following surgery. The average weight of the resected tonsils was 11 g. The patients demonstrated a preoperative apnea + hypopnea index (AHI) of 14.4/h. This decreased to 2.9/h postoperatively. The intraesophageal pressure change improved from -36.6 to -15.7 cmH2O following surgery. A significant correlation between preoperative AHI and the degree of obesity ( r = 0.684, P < 0.05) was found. Although uvulopalatopharyngoplasty has been used extensively to treat sleep apnea, the present results suggests that certain subjects can be effectively treated through only tonsillectomy.  相似文献   
48.
Between January 1981 and December 1983, 4 patients, aged 6 to 50 years, with It-PAPVC were operated upon at the Kokura Memorial Hospital, by a new technique of anastomosis between the left anomalous PV and the left auricular appendage. One patient, a 9-year-old male, had unilateral anomalous pulmonary venous connection of the entire left lung to the innominate vein. The other three patients had partial anomalous pulmonary venous connection from the left upper lobe to the innominate vein. Two patients has pulmonary valvular stenosis, and the other two had ASD. All patients were operated upon through a midsternal incision. After cardiopulmonary bypass was established, the anomalous vein was divided as high as was reachable. The present operative method involved the use of an oval pericardial gusset extending from the left auricular appendage into the split anomalous vein so as to obtain a wide anastomotic orifice. Other associated congenital anomalies were simultaneously corrected. All patients had uneventful recovery and at postoperative cardiac catheterization and angiography, the anastomosis between the pulmonary vein and the left auricular appendage was widely patent.  相似文献   
49.
Although not all newborns with Ebstein's anomaly present with severe cardiomegaly in utero, some of them cannot live after birth because of the lung hypoplasia. To clarify the relationship between the intrauterine cardiomegaly and the outcome of the patients with Ebstein's anomaly or tricuspid valve dysplasia, we calculated the ratio of the area of the heart against the thorax (CTAR) in the transverse view of the thorax at the level of the cardiac four-chamber view in the fetal echocardiogram and compared it to the outcome. The study population consisted of four patients with Ebstein's anomaly and one patient with tricuspid valve dysplasia who were diagnosed in utero. The ranges obtained from 53 normal fetal cases were 20%± 8% (mean ± 2 SD) at below 20 week's gestation, 25%± 10% at the gestational age of 21 to 30 weeks, and 29%± 6.4% at the gestational age of 31 to 40 weeks. The CTARs of these five cases measured 81.6%, 51%, 55.2%, 47.5%, and 75.6%, respectively, and were abnormally higher than the normal value. Two fetuses died in utero with severe hydrops fetalis. Two fetuses whose cardiothoracic ratios by chest X ray were 100% died at twelve hours of life. One patient died at 110 days. The cross-sectional area of the thorax was smaller than the normal range in 3 (cases 1, 4, and 5) out of these 5 cases. Thus, we conclude that fetal Ebstein's anomaly and tricuspid valve dysplasia associated with massive tricuspid regurgitation with a large CTAR ratio (higher than 50%) and small thoracic cross-sectional area has a very poor prognosis bothprena-tally and neonatally. (ECHOCARDIOGRAPHY, Volume 11, May 1994)  相似文献   
50.
Cyclic peptides     
In order to explore the route for the preparation of cyclodepsipeptide by cyclization through an ester bond formation, two analogs of AM-toxin II, cyclotetradepsipeptide, were synthesized. As a preliminary experiment, synthesis of [L-Phe3, L-Ser(Bzl)4]-AM-toxin II, containing L-Phe and L-Ser(Bzl) in place of L-App (2-amino-5-phenyl-pentanoic acid) and ΔAla (α,β-dehydroalanine), respectively, was attempted. Cyclization of H-L-Hmb-L-Phe-L-Ser(Bzl)-L-Ala-OH in CH2CI2 at 10mM concentration using water-soluble carbodiimide (EDC) and 4-dimethylaminopyridine (DMAP) successfully gave a cyclic monomer in 16% yield. Cyclization of H-L-Hmb-L-App-L-Ser(Bzl)-L-Ala-OH under the same conditions also afforded a cyclic monomer, [L-Ser(Bzl)4]AM-toxin II, in 19% yield. Analytical parameters of these cyclic monomers obtained were identical to those of the authentic samples obtained by cyclization through a peptide bond formation.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号