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   3849篇
  免费   192篇
  国内免费   32篇
耳鼻咽喉   15篇
儿科学   106篇
妇产科学   30篇
基础医学   443篇
口腔科学   77篇
临床医学   314篇
内科学   1060篇
皮肤病学   56篇
神经病学   257篇
特种医学   113篇
外科学   810篇
综合类   24篇
预防医学   78篇
眼科学   14篇
药学   272篇
中国医学   30篇
肿瘤学   374篇
  2023年   27篇
  2022年   48篇
  2021年   94篇
  2020年   67篇
  2019年   72篇
  2018年   88篇
  2017年   67篇
  2016年   62篇
  2015年   72篇
  2014年   107篇
  2013年   122篇
  2012年   223篇
  2011年   227篇
  2010年   108篇
  2009年   96篇
  2008年   208篇
  2007年   184篇
  2006年   191篇
  2005年   230篇
  2004年   208篇
  2003年   179篇
  2002年   185篇
  2001年   72篇
  2000年   88篇
  1999年   85篇
  1998年   67篇
  1997年   51篇
  1996年   41篇
  1995年   43篇
  1994年   35篇
  1993年   35篇
  1992年   62篇
  1991年   59篇
  1990年   61篇
  1989年   54篇
  1988年   45篇
  1987年   48篇
  1986年   37篇
  1985年   42篇
  1984年   32篇
  1983年   32篇
  1982年   17篇
  1981年   12篇
  1979年   19篇
  1978年   20篇
  1977年   19篇
  1974年   14篇
  1973年   13篇
  1971年   16篇
  1970年   19篇
排序方式: 共有4073条查询结果,搜索用时 15 毫秒
21.
The media has recently been featuring organ transplantation from various viewpoints. Furthermore, Novel Prizes 1990 for Medical & Physiological fields were awarded to Drs. JE Murray and ED Thomas, both pioneers of clinical transplantation. Our topic has been timely indeed. This symposium mainly dealt with laboratory tests vs. various types of organ transplantation. In reality though, only kidney and bone marrow transplantations have been practiced in Japan; thus, Dr. I Yokoyama, University of Pittsburgh, discussed liver transplantation. First, Dr. K Uchida lectured on the recent advancement of immunosuppressive drugs and improvement in the clinical outcome of kidney transplantation. Serum creatinine determination is the only parameter for rejection besides renal biopsy. Drs. K Miyamura & Y Morishima discussed about PCR method to detect MRD (minimal residual diseases). There are positive relationships between the remaining leukemic cells and the relapse of leukemia even though the patients are in clinical remission. Dr. H Funada dealt with the importance of "sterile room treatment" for bone marrow transplantation. It protects patients from infection, minimizes GVHD and prolongs survival time after transplantation. Dr. Yokoyama stressed the importance of back-up system, i.e. drug-monitoring, coagulation tests, pathological examination, biochemical tests, blood transfusion services for successful liver transplantations. Dr. T Fukunishi discussed the importance of developing the organ donor and coordinator system to promote kidney transplantation from cadaver. He also dealt with virus antibody tests for selecting donors. All discusssions stressed on the importance of the 24-hour laboratory back-up system performing emergency tests but no specific laboratory test for organ transplantation was necessary.  相似文献   
22.
"Essential laboratory tests" advocated by Japan Society of Clinical Pathology were simultaneously performed with the history taking of the present illness and the physical examination in 1,026 new patients visited the outpatient unit of Comprehensive Medicine, National Defense Medical College. We have analyzed the usefulness of the "essential laboratory tests" for the establishment of the initial diagnosis in evaluable 750 patients by comparing the diagnosis made only by the history taking and the physical examination (tentative initial diagnosis) with that included the results of these laboratory tests. The "essential laboratory tests" had contributed to remarkably increased incidences of metabolic and endocrine diseases, liver or biliary tract diseases, renal and urinary tract diseases and anemia after the application of these tests. The initial diagnoses of 61 patients were successfully established by the addition of the "essential laboratory tests" among 157 cases of which tentative initial diagnoses remained undetermined. These tests confirmed the tentative diagnoses in 78 patients, while 78 tentative diagnoses were negated and corrected after evaluation of the results of these tests. Furthermore, the diagnostic tests such as CRP and leukocyte count were useful for the estimation of the nature or degree of seriousness of the disease in 57 patients. In addition, other diseases not related to the patient's chief complaint could be detected in 238 patients (303 total number of diseases) by these tests. These results indicate the usefulness of the "essential laboratory tests" not only for the establishment of more accurate initial diagnosis but also for the screening of the "hidden" diseases such as hyperlipidemia and liver dysfunction.  相似文献   
23.
Effects of mechanical trauma of platelets and red blood cells on dynamic viscoelasticity of blood during clotting were examined. Two different methods were attempted to give the mechanical damage to blood cells. In one method, a flow apparatus consisting of a thin teflon tube and two sample reservoirs connecting to both ends of the tube was employed. After a blood sample repeated the shuttle flow many times through the tube, the dynamic rigidity modulus (G') and loss modulus (G") of the blood sample during clotting were measured. The mechanical trauma of platelets brought about the increase of G' and G" for clots of PRP and whole blood, in addition to shorter clotting time. Slight hemolysis of red blood cells (less than 0.5% of total hemolysis) only yielded shorter clotting time for whole blood. In other method, packed red blood cells were hemolyzed by exposing the ultrasonic wave (the amount of hemolysis was about 5% of total hemolysis). Addition of supernatant of hemolyzed red blood cells to PRP caused the platelet aggregation. Furthermore, a marked hemolysis brought about higher values of G' and G" for blood clot, in addition to shorter clotting time. These results suggest that the release of constituents from damaged red blood cells and alteration of cell surface due to mechanical damage would accelerate the coagulation sequence.  相似文献   
24.
ObjectivesWe aimed to evaluate the effect of frailty on health-related quality-of-life (HRQOL) and lower urinary symptoms (LUTS) following robot-assisted radical prostatectomy (RARP) in patients with prostate cancer (CaP).Materials and MethodsWe longitudinally evaluated geriatric 8 (G8), HRQOL, and LUTS for 12 months in 118 patients with RARP from January 2017 to April 2020. Patients were divided into frail (G8 ≤14) and nonfrail (G8 >14) groups. We compared the effect of frailty on HRQOL and LUTS between the frail and nonfrail groups before and 12 months after RARP.ResultsThe median age of patients was 68 years. The number of patients in the frail and nonfrail groups were 41 and 77, respectively. No significant difference in patients’ background was observed between the groups, except for the presence of cardiovascular disease (22% vs. 7.8%, P = 0.041). There was no significant difference in HRQOLs and LUTS between the groups at baseline. Similarly, HRQOLs, LUTS, and pad-free continence rates were not significantly different between the groups at 12 months after RARP. In the nonfrail group, LUTS at 12 months following RARP significantly improved compared to those at the baseline, but it did not significantly improve in the frail group. Multivariable logistic regression analysis demonstrated that frailty was not significantly associated with LUTS worsening.ConclusionsFrailty was not significantly associated with the worsening of HRQOL, LUTS, and pad-free continence rates in patients treated with RARP.  相似文献   
25.
The present study was performed to evaluate postoperative hoarseness quantitatively by means of acoustic wave form analysis. Pitch and amplitude perturbation (PPQ, and APQ), and normalized noise energy (NNE) were measured along with the frequency characteristics in 51 adult patients undergoing elective surgery. The normal values for these acoustic parameters were less than 0.5%, less than 2.0%, and less than -10 dB, respectively. Vowel sound "E" was recorded and evaluated before the induction of anesthesia and on the morning of the day after the surgery. PPQ increased from 0.39% to 1.00% (P less than 0.05), APQ increased from 3.34% to 6.62% (P less than 0.05), and NNE increased from -9.19 dB to -4.74 dB (P less than 0.05). Eighteen percent of the patients showed abnormal values in all parameters preoperatively, but 45% of the patients postoperatively (P less than 0.05). These findings suggest that even the short term intubation resulted in the postoperative hoarseness, and this method is a useful and non-invasive bed-side test to evaluate postoperative hoarseness quantitatively.  相似文献   
26.
The dreher mutation (gene symbol: dr) is an autosomal recessive mutation located on chromosome 1 of the mouse. Homozygous dreher mice (dr/dr) are ataxic, have a white belly spot, a short-tail, inner ear and skeletal malformations, and a variety of CNS abnormalities. Recently in our dreher colony (the drsst-J allele on a B6C3Fe background), we noticed mice with one or more white belly spots typical of drsst-J/drsst-J mice but which were non-ataxic and had a normal tail length; wild-type mice (+/+) of the same genetic background do not have simialr belly spots. Results of three breeding experiments indicate that a new mutation had not occurred, but rather that the spotted, non-ataxic mice are heterozygous dreher mice (drsst-J/+). Histological examination showed that drsst-J/+ mice have abnormalities in the hippocampal formation that are qualitatively similar to those found in drsst-J/drsst-J mice. Most frequently there is an increase in the number of pyramidal cells in CA3 and a marked thickening of the pyramidal cell layer. In contrast to dreher homozygotes the cerebellum appears to have a normal foliation pattern and no discernible laminar abnormalities. Thus, both breeding experiments and histological examination indicate that drsst-J is semidominant. We speculate that drsst-J is a "loss of function" mutation, but, in any event, the presence of phenotypic abnormalities in drsst-J/+ mice may be useful in identifying the primary developmental defect in dreher mice.  相似文献   
27.
Raising medical expenditure is a universal problem. The Japanese government started taking measures not to increase medical expenses in the recent years. Laboratory tests are no exception. Therefore we as clinical pathologists have reevaluated laboratory tests from the primary care situations to more advanced stages of clinical medicine. As the first step, we formed a subcommittee to effective by utilize laboratory tests and agreed to establish the "essential lab tests". Essential lab tests are made of qualitative bed side tests (type I) and slightly advanced tests (type II) and these tests are to be done on every patient at their first clinic visit. These tests are also to be performed parallel to physical examination and history-taking. The results revealed 50% and 90% positivities on the type I and type II tests, which indicate rather effective means for making an initial impression.  相似文献   
28.
The stoichiometry of the reaction catalyzed by skin sulfhydryl oxidase was investigated. Dithiothreitol (DTT) was used as the substrate for skin sulfhydryl oxidase. The consumption of DTT, consumption of oxygen, and production of hydrogen peroxide were measured during the enzyme reaction. The molar ratio of DTT:O2:H2O2 in the enzyme reaction was 1:1.02:0.89. Correspondingly, the stoichiometry of the enzyme reaction was calculated to be R(SH)2 + O2 → + H2O2.  相似文献   
29.
30.
sigma Receptor antagonists may be effective antipsychotic drugs that do not induce motor side effects caused by ingestion of classical drugs such as haloperidol. We obtained evidence that 1-(2-dipropylaminoethyl)-4-methoxy-6H-dibenzo[b,d]pyran hydrochloride 2a had selective affinity for sigma receptor over dopamine D2 receptor. This compound was designed to eliminate two bonds of apomorphine 1 to produce structural flexibility for the nitrogen atom and to bridge two benzene rings with a -CH2O- bond to maintain the planar structure. In light of the evidence, N, N-dipropyl-2-(4-methoxy-3-benzyloxylphenyl)ethylamine hydrochloride 10b was designed. Since compound 10b had eliminated a biphenyl bond of 6H-dibenzo[b,d]pyran derivative 2a, it might be more released from the rigid structure of apomorphine 1 than compound 2a. The chemical modification of compound 10b led to the discovery that N, N-dipropyl-2- [4-methoxy-3-(2-phenylethoxyl)phenyl]ethylamine hydrochloride 10g (NE- 100), the best compound among arylalkoxyphenylalkylamine derivatives 3, had a high and selective affinity for sigma receptor and had a potent activity in an animal model when the drug was given orally. We report here the design, synthesis, structure-activity relationships, and biological characterization of novel arylalkoxyphenylalkylamine derivatives 3.  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