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   1211篇
  免费   97篇
  国内免费   26篇
耳鼻咽喉   4篇
儿科学   45篇
妇产科学   20篇
基础医学   209篇
口腔科学   13篇
临床医学   123篇
内科学   321篇
皮肤病学   18篇
神经病学   87篇
特种医学   90篇
外科学   114篇
综合类   28篇
一般理论   2篇
预防医学   66篇
眼科学   15篇
药学   85篇
中国医学   8篇
肿瘤学   86篇
  2024年   2篇
  2023年   7篇
  2022年   25篇
  2021年   45篇
  2020年   19篇
  2019年   30篇
  2018年   32篇
  2017年   21篇
  2016年   27篇
  2015年   54篇
  2014年   44篇
  2013年   60篇
  2012年   75篇
  2011年   88篇
  2010年   59篇
  2009年   67篇
  2008年   76篇
  2007年   89篇
  2006年   53篇
  2005年   58篇
  2004年   50篇
  2003年   47篇
  2002年   35篇
  2001年   17篇
  2000年   11篇
  1999年   12篇
  1998年   15篇
  1997年   16篇
  1996年   23篇
  1995年   13篇
  1994年   20篇
  1993年   13篇
  1992年   6篇
  1991年   3篇
  1990年   4篇
  1989年   14篇
  1988年   7篇
  1987年   10篇
  1986年   15篇
  1985年   12篇
  1984年   8篇
  1983年   7篇
  1982年   9篇
  1981年   9篇
  1980年   8篇
  1977年   6篇
  1975年   3篇
  1974年   2篇
  1957年   1篇
  1948年   1篇
排序方式: 共有1334条查询结果,搜索用时 62 毫秒
21.
Patients (n = 231) diagnosed with solid tumors and undergoing chemotherapy were randomly assigned to the experimental arm (n = 114) or to conventional care (n = 117). A symptom severity index based on summed severity scores across 15 symptoms was the primary outcome. Building on previously published work, an analysis was undertaken to determine the effects of patient characteristics and treatment complications on reductions in symptom severity achieved by a trial of a cognitive-behavioral intervention (CBI). The impact of the intervention on symptom severity differed by the occurrence of neutropenic events, chemotherapy dose delays or dose reductions, and number of comorbid conditions. Patients with more comorbid conditions, as well as those who did not experience neutropenia or dose delay/reduction, who received the intervention reported lower severity at 20 weeks compared to those who received conventional care. This research begins to specify the clinical conditions under which CBIs are effective in lowering symptom severity.  相似文献   
22.
23.
We analyzed the patients files suffered from acute viral encephalitis in 39 months period: January 2000-march 2003. According to our data there was a total of 33 patients; one of them died. The most involved patients were male and of the 8-14 year group of age; for the first three month in 2003 were admitted 11 patients. Coma and seizures were the most frequent clinical signs. LCR had the usual abnormalities for the above mentioned disease; the treatment was mainly performed with corticosteroids; 28 cases were admitted more than 8 days period. The evolution of the clinical status was satisfactory for all 32 patients.  相似文献   
24.
To study the clinical and epidemiological aspects of acute B hepatitis during the last 11 years. We retrospectively studied 1712 patient files, admitted in the Department of Infectious Diseases Ia?i, with acute B hepatitis between 1992-2002. The majority of the patients (69%) had an urban origin. Teenagers and young adults were predominantly affected (59% had between 15 and 34 years). A point of entry of the pathogen was identified only in 20% of the patients. The mean incubation period was 4 month. 24% of the patients had a prolonged form of the disease (over 30 days of jaundice). A fulminant evolution was noted in 1.2% of cases. Extrahepatic involvement was described in 25% of the patients. The global mortality was 1.15%. The number of patients with acute B hepatitis decreased by half during the last 11 years.  相似文献   
25.
BACKGROUND: Anaphylactic and anaphylactoid reactions occurring during anesthesia remain a major cause of concern for anesthesiologists. The authors report the results of a 2-yr survey of such reactions observed during anesthesia in France. METHODS: Between January 1, 1999, and December 31, 2000, 789 patients who experienced immune-mediated (anaphylaxis) or nonimmune-mediated (anaphylactoid) reactions were referred to one of the 40 participating centers. Anaphylaxis was diagnosed on the basis of clinical history, skin tests, and/or specific immunoglobulin E assay. RESULTS: Anaphylactic and anaphylactoid reactions were diagnosed in 518 cases (66%) and 271 cases (34%), respectively. The most common causes of anaphylaxis were neuromuscular blocking agents (NMBAs) (n = 306, 58.2%), latex (n = 88, 16.7%), and antibiotics (n = 79, 15.1%). Rocuronium (n = 132, 43.1%) and succinylcholine (n = 69, 22.6%) were the most frequently incriminated NMBAs. Cross-reactivity between NMBAs was observed in 75.1% of cases of anaphylaxis to an NMBA. No difference was observed between anaphylactoid and anaphylactic reactions when the incidences of atopy, asthma, or drug intolerance were compared. However, atopy, asthma, and food allergy were significantly more frequent in the case of latex allergy when compared with NMBA allergy. Clinical manifestations were more severe in anaphylaxis. The positive predictive value of tryptase for the diagnosis of anaphylaxis was 92.6%; the negative predictive value was 54.3%. The diagnostic value of specific NMBA immunoglobulin E assays was confirmed. CONCLUSIONS: These results further corroborate the need for systematic screening in the case of anaphylactoid reaction during anesthesia and for the constitution of allergoanesthesia centers to provide expert advice to anesthesiologists and allergists.  相似文献   
26.
27.
As pretreatment with intraperitoneal capsaicin (8-methyl-N-vanillyl-6-nonenamide, CAP), an agonist of the vanilloid receptor known as VR1 or transient receptor potential channel-vanilloid receptor subtype 1 (TRPV-1), has been shown to block the first phase of lipopolysaccharide (LPS) fever in rats, this phase is thought to depend on the TRPV-1-bearing sensory nerve fibers originating in the abdominal cavity. However, our recent studies suggest that CAP blocks the first phase via a non-neural mechanism. In the present work, we studied whether this mechanism involves the TRPV-1. Adult Long-Evans rats implanted with chronic jugular catheters were used. Pretreatment with CAP (5 mg kg(-1), i.p.) 10 days before administration of LPS (10 microg kg(-1), i.v.) resulted in the loss of the entire first phase and a part of the second phase of LPS fever. Pretreatment with the ultrapotent TRPV-1 agonist resiniferatoxin (RTX; 2, 20, or 200 microg kg(-1), i.p.) 10 days before administration of LPS had no effect on the first and second phases of LPS fever, but it exaggerated the third phase at the highest dose. The latter effect was presumably due to the known ability of high doses of TRPV-1 agonists to cause a loss of warm sensitivity, thus leading to uncontrolled, hyperpyretic responses. Pretreatment with the selective competitive TRPV-1 antagonist capsazepine (N-[2-(4-chlorophenyl)ethyl]-1,3,4,5-tetrahydro-7,8-dihydroxy-2H-2-benzazepine-2-carbothioamidem, CPZ; 40 mg kg(-1), i.p.) 90 min before administration of LPS (10 microg kg(-1), i.v.) or CAP (1 mg kg(-1), i.p.) did not affect LPS fever, but blocked the immediate hypothermic response to acute administration of CAP. It is concluded that LPS fever is initiated via a non-neural mechanism, which is CAP-sensitive but RTX- and CPZ-insensitive. The action of CAP on this mechanism is likely TRPV-1-independent. It is speculated that this mechanism may be the production of prostaglandin E(2) by macrophages in LPS-processing organs.  相似文献   
28.
Rapidly progressive glomerulonephritis (RPGN) is a rare occurrence in IgA nephropathy (IgAN) in renal transplant patients on immunosuppressive therapy. RPGN post ischemia-reperfusion has not been previously reported. We report a 62 year old male patient on azathioprine therapy, 9 years after left cadaveric renal transplantation due to end stage renal disease of unknown etiology, who presented with progressive deterioration in renal function and hematuria. Renal biopsy was consistent with IgAN. Duplex and CT scan demonstrated a decreased renal graft perfusion, due to severe atherosclerosis and stenosis of iliac arteries. The patient underwent left axilo-femoral bypass graft surgery with improvement in kidney graft perfusion and function. However, few weeks later, patient presented with pulmonary edema and advanced renal failure and he was initiated on hemodialysis. Repeated renal biopsy demonstrated crescentic GN. To the best of our knowledge, this is the first report of RPGN following reversal of ischemia and reperfusion. There was no evidence for atherembolic disease which is not uncommon after vascular surgery and it has been reported to be rarely associated to crescentic GN. Theoretical explanations for exacerbation of IgAN to crescentic GN, following successful reperfusion, could be enhancement of capillary damage, inflammation and oxidative stress. Putative mechanisms for these phenomena may be interaction of reperfusion-induced hyperfiltration, high intraglomerular capillary pressure, oxidative stress, increased polymorphonucler cells infiltration and inflammation; the presence of IgA immune deposits and azathioprine metabolites, both can also be associated to enhancement of oxidative stress.  相似文献   
29.
PURPOSE: Antitumor lymphocytes can be generated ex vivo unencumbered by immunoregulation found in vivo. Adoptive transfer of these cells is a promising therapeutic modality that could establish long-term antitumor immunity. However, the widespread use of adoptive therapy has been hampered by the difficulty of consistently generating potent antitumor lymphocytes in a timely manner for every patient. To overcome this, we sought to establish a clinical grade culture system that can reproducibly generate antigen-specific cytotoxic T lymphocytes (CTL). EXPERIMENTAL DESIGN: We created an off-the-shelf, standardized, and renewable artificial antigen-presenting cell (aAPC) line that coexpresses HLA class I, CD54, CD58, CD80, and the dendritic cell maturation marker CD83. We tested the ability of aAPC to generate tumor antigen-specific CTL under optimal culture conditions. The number, phenotype, effector function, and in vitro longevity of generated CTL were determined. RESULTS: Stimulation of CD8(+) T cells with peptide-pulsed aAPC generated large numbers of functional CTL that recognized a variety of tumor antigens. These CTLs, which possess a phenotype consistent with in vivo persistence, survived ex vivo for prolonged periods of time. Clinical grade aAPC(33), produced under current Good Manufacturing Practices guidelines, generated sufficient numbers of CTL within a short period of time. These CTL specifically lysed a variety of melanoma tumor lines naturally expressing a target melanoma antigen. Furthermore, antitumor CTL were easily generated in all melanoma patients examined. CONCLUSIONS: With clinical grade aAPC(33) in hand, we are now poised for clinical translation of ex vivo generated antitumor CTL for adoptive cell transfer.  相似文献   
30.
PURPOSE: The effect of systemic administration of the gamma-aminobutyric acid (GABA)-transaminase inhibitor vigabatrin (VGB) on different components of convulsions was tested in the model of audiogenically kindled seizures, which consist of brainstem (running, tonus) and forebrain (clonus) elements. METHODS: Audiogenically susceptible rats of Krushinsky-Molodkina (KM), Wistar, and WAG/Rij strains received repeated sound stimulation (60 dB, 10-80 kHz) until kindled audiogenic seizures were reliably elicited. Kindled audiogenic seizures consisted of running, tonic, and generalized clonic phases in KM rats (severe audiogenic seizures) and of running and Racine stage 5 facial/forelimb clonus in Wistar and WAG/Rij rats (moderate seizures). Vehicle, 100, or 200 mg/kg of VGB was intraperitoneally injected 2, 4 and 24 h before the induction of kindled audiogenic seizures. RESULTS: At both doses, VGB did not change the seizure latency and the duration of running and tonic convulsions, but suppressed clonic ones in all rat strains. In KM rats, the mean duration of posttonic clonus was significantly reduced at 24 h after 100 mg/kg and from 4 h after 200 mg/kg. In Wistar and WAG/Rij rats, the mean duration of facial/forelimb clonus was reduced from 4 and 2 h after 100- and 200-mg/kg administration, respectively; 24 h after the high-dose injection, clonus was completely blocked in all rats of both strains. No difference in efficacy of VGB between Wistar and WAG/Rij rats was observed. CONCLUSIONS: VGB more effectively suppresses clonic convulsions than running and tonic ones in audiogenically kindled rats. It is supposed that this selective anticonvulsive effect of VGB results from different sensitivities of forebrain and brainstem epileptic networks to the presumed GABA enhancement.  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