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   4166篇
  免费   329篇
  国内免费   31篇
耳鼻咽喉   18篇
儿科学   213篇
妇产科学   76篇
基础医学   542篇
口腔科学   105篇
临床医学   447篇
内科学   1007篇
皮肤病学   53篇
神经病学   260篇
特种医学   405篇
外科学   363篇
综合类   65篇
一般理论   1篇
预防医学   468篇
眼科学   60篇
药学   279篇
  1篇
中国医学   2篇
肿瘤学   161篇
  2022年   18篇
  2021年   48篇
  2020年   31篇
  2019年   45篇
  2018年   55篇
  2017年   58篇
  2016年   55篇
  2015年   74篇
  2014年   96篇
  2013年   128篇
  2012年   123篇
  2011年   127篇
  2010年   109篇
  2009年   147篇
  2008年   146篇
  2007年   169篇
  2006年   158篇
  2005年   132篇
  2004年   120篇
  2003年   141篇
  2002年   121篇
  2001年   143篇
  2000年   131篇
  1999年   128篇
  1998年   129篇
  1997年   144篇
  1996年   140篇
  1995年   103篇
  1994年   112篇
  1993年   123篇
  1992年   94篇
  1991年   87篇
  1990年   91篇
  1989年   107篇
  1988年   105篇
  1987年   68篇
  1986年   77篇
  1985年   79篇
  1984年   57篇
  1983年   52篇
  1982年   37篇
  1981年   54篇
  1980年   41篇
  1979年   34篇
  1978年   29篇
  1977年   40篇
  1976年   42篇
  1975年   18篇
  1974年   24篇
  1973年   16篇
排序方式: 共有4526条查询结果,搜索用时 15 毫秒
91.
92.
Cutaneous manifestations of malignancy are not uncommon, especially in advanced disease. They may also occur early in malignant disease or they may even signify recurrence particularly if they are paraneoplastic in nature. Clinical diagnosis can be difficult because of the wide spectrum of appearance of these lesions, and, in many cases, because of the lack of an identifiable underlying primary. Presented here is the case of a 65-year-old woman with multiple inflammatory cutaneous metastases, which were sclerodermoid in nature. These appeared 14 months after initial diagnosis of adenocarcinoma of unknown primary (ACUP) and signified the beginning of a rapid deterioration in her condition. The coexistence of limited systemic sclerosis (scleroderma) and ACUP initially raised several interesting diagnostic possibilities. Adenocarcinoma of unknown primary and the sclerodermoid reaction in malignancy are discussed.  相似文献   
93.
94.
Objective. To determine how the addition of generalist care managers and collaborative information technology to an ambulatory team affects the care of patients with diabetes.
Study Setting. Multiple ambulatory clinics within Intermountain Health Care (IHC), a large integrated delivery network.
Study Design. A retrospective cohort study comparing diabetic patients treated by generalist care managers with matched controls was completed. Exposure patients had one or more contacts with a care manager; controls were matched on utilization, demographics, testing, and baseline glucose control. Using role-specific information technology to support their efforts, care managers assessed patients' readiness for change, followed guidelines, and educated and motivated patients.
Data Collection. Patient data collected as part of an electronic patient record were combined with care manager-created databases to assess timely testing of glycosylated hemoglobin (HbA1c) and low-density lipoprotein (LDL) levels and changes in LDL and HbA1c levels.
Principal Findings. In a multivariable model, the odds of being overdue for testing for HbA1c decreased by 21 percent in the exposure group ( n =1,185) versus the control group ( n =4,740). The odds of being tested when overdue for HbA1c or LDL increased by 49 and 26 percent, respectively, and the odds of HbA1c <7.0 percent also increased by 19 percent in the exposure group. The average HbA1c levels decreased more in the exposure group than in the controls. The effect on LDL was not significant.
Conclusions. Generalist care managers using computer-supported diabetes management helped increase adherence to guidelines for testing and control of HbA1c levels, leading to improved health status of patients with diabetes.  相似文献   
95.
Pathologic accumulation of neurofilament protein (NF), both within spheroids of the proximal axon and within inclusions of motor neuron somata, is a hallmark of neurodegeneration in amyotrophic lateral sclerosis (ALS). Transgenic mice that express mutations in superoxide dismutase (SOD-1), which were genetically linked to familial ALS, develop symptomatology and pathology that strongly resemble ALS and therefore provide a useful model for studying the disease. Examining NF in the G86R mutant SOD-1 transgenic mice, we previously demonstrated that phosphorylated NF accumulates in motor neuron somata of symptomatic transgenic mice. In the present study, we expand these results by examining the immunocytochemical distribution of the three subunits of NF (i.e., light, medium, and heavy chains) as well as tubulin in presymptomatic and symptomatic SOD-1 transgenic mice. Although all NF subunits, but not tubulin, accumulate along with phosphorylated NF in the spinal cord inclusions of symptomatic mice, numerous inclusions containing only light chain NF are found in the spinal cord of presymptomatic SOD-1 transgenic mice. In addition to these results in the spinal cord, intensely immunoreactive aggregates of NF-L, but not the other NF subunits or tubulin, were observed in the sciatic nerve of both symptomatic and presymptomatic mutant SOD-1 transgenic mice. These results suggest that the mechanism of NF alteration in SOD-1 transgenic mice, and also perhaps in ALS patients, originates with the disruption of NF-L, only later involving the other subunits.  相似文献   
96.
BACKGROUND: Moxonidine, a novel imidazoline-alpha2-adrenergic receptor-selective analgesic, was recently identified as antinociceptive but has yet to be evaluated in neuropathic pain models. alpha2-adrenergic receptor-selective analgesics, and high-efficacy opioids, effectively inhibit neuropathic pain behaviors in rodents. In contrast, morphine potency and efficacy decreases in states of neuropathic pain, both in rodents and in humans, but may be restored or enhanced by coadministration of morphine with alpha2-adrenergic receptor-selective analgesics. The current experiments extend the evaluation of opioid-coadjuvant interactions in neuropathic subjects by testing the respective antihyperalgesic interactions of moxonidine and clonidine with morphine in a test of mechanical hyperalgesia. METHODS: Nerve-injured mice (Chung model) were spinally administered moxonidine, clonidine, morphine, and the combinations moxonidine-morphine and clonidine-morphine. Hyperalgesia was detected by von Frey monofilament stimulation (3.3 mN) to the hind paws (plantar surface). The ED50 values were calculated and the interactions tested by isobolographic analysis. RESULTS: In nerve-injured mice, moxonidine, clonidine, and morphine all dose-dependently inhibited mechanical hyperalgesia. Furthermore, the combinations of moxonidine-morphine and clonidine-morphine resulted in substantial leftward shifts in the dose-response curves compared with those of each agonist administered separately. The calculated ED50 values of the dose-response curves of these combinations were significantly lower than their corresponding theoretical additive ED50 values. These results confirmed that both interactions were synergistic. CONCLUSIONS: Moxonidine and clonidine both synergize with morphine to inhibit paw withdrawal from nociceptive mechanical stimuli in nerve-injured mice.  相似文献   
97.
98.
The psychostimulants considered the gold standard in the treatment of attention deficit hyperactivity disorder, one of the most common childhood disorders, are also finding their way into the hands of healthy young adults as brain augmentation to improve cognitive performance. The possible long-term effects of psychostimulant exposure in adolescence are considered controversial, and thus, the objective of this study was to investigate whether the chronic exposure to the psychostimulant amphetamine affects the behavioral diurnal rhythm activity patterns of female adolescent Wistar-Kyoto (WKY) rat. The hypothesis of this study is that change in diurnal rhythm activity pattern is an indicator for the long-term effect of the treatment. Twenty-four rats were divided into two groups, control (N = 12) and experimental (N = 12), and kept in a 12:12-h light/dark cycle in an open-field cage. After 5–7 days of acclimation, 11 days of consecutive non-stop behavioral recordings began. On experimental day 1 (ED1), all groups were given an injection of saline. On ED2 to ED7, the experimental group was injected with 0.6 mg/kg amphetamine followed by 3 days of washout from ED8 to ED10, and amphetamine re-challenge on ED11 similar to ED2. The locomotor movements were counted by the computerized animal activity monitoring system, and the cosinor statistical test analysis was used to fit a 24-h curve of the control recording to the activity pattern after treatment. The horizontal activity, total distance, number of stereotypy, vertical activity, and stereotypical movements were analyzed to find out whether the diurnal rhythm activity patterns were altered. Data obtained using these locomotor indices of diurnal rhythm activity pattern suggest that amphetamine treatment significantly modulates the locomotor diurnal rhythm activity pattern of female WKY adolescent rats.  相似文献   
99.
100.
Iclaprim is a diaminopyrimidine, which inhibits bacterial dihydrofolate reductase, and it is highly active against Gram-positive pathogens including emerging drug-resistant pathogens. In vitro activity of iclaprim and comparators against 2814 Gram-positive clinical isolates from the United States, Asia Pacific, Latin American and Europe collected between 2012 and 2014 were tested. Susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Minimum inhibitory concentration (MIC) interpretations were based on CLSI and European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. MIC50/MIC90 for all S. aureus, methicillin susceptible S. aureus, methicillin resistant S. aureus, beta-hemolytic streptococci, and Streptococcus pneumoniae were 0.06/0.12, 0.06/0.12, 0.06/0.5, 0.06/0.25, and 0.06/2 μg/mL, respectively. Iclaprim was 8 to 32-fold more potent than trimethoprim, the only FDA approved dihydrofolate reductase inhibitor, against all Gram-positive isolates including resistant phenotypes. The MIC90 of iclaprim was also lower than most of the comparators including linezolid and vancomycin against Gram-positive pathogens. Iclaprim demonstrated potent activity against a contemporary collection (2012–2014) of Gram-positive clinical isolates from the United States, Asia Pacific, Latin America and Europe.  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