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排序方式: 共有362条查询结果,搜索用时 15 毫秒
1.
To determine whether the increase in baroreflex sensitivity previously reported in lifetime captopril-treated spontaneously hypertensive rats (SHR) was due to an inhibition of brain angiotensin II mechanisms, we tested the effect of intracerebroventricular administration of an angiotensin II receptor antagonist on baroreflex control of heart rate in lifetime captopril-treated and untreated male and female SHR. Baroreceptor reflex control of heart rate was assessed by the slope of the relationship between changes in mean arterial pressure (delta MAP, mmHg) and changes in pulse interval (delta PI, ms). MAP was raised and lowered with infusions of phenylephrine and nitroprusside, respectively. Following basal assessment of baroreflex control of heart rate, rats received an intracerebroventricular injection (100 pmol) of Sar1Thr8 angiotensin II (sarthran) and reflex control of heart rate was reassessed. Adequacy of blockade was tested with central and peripheral administration of angiotensin II. Captopril-treated male (130 +/- 7 mmHg) and female (123 +/- 4 mmHg) rats had significantly lower MAP than untreated rats (174 +/- 4 and 173 +/- 8 mmHg, respectively) and enhanced bradycardia in response to increases in MAP. Intracerebroventricular administration of sarthran had no effect on basal blood pressure or heart rate but enhanced the bradycardia in response to increases in MAP in both untreated and captopril-treated rats. The increase in the slope of the line relating delta MAP to delta PT was greater for untreated than captopril-treated SHR (male untreated 2.7-fold versus captopril-treated 1.5-fold; female untreated 1.6-fold versus captopril-treated 1.5-fold).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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Winkler  ML; Olsen  WL; Mills  TC; Kaufman  L 《Radiology》1987,165(1):203-207
Two fast magnetic resonance (MR) imaging techniques, advanced Fourier and partial-flip imaging, were used at 0.35 T to examine 21 patients with suspected intracranial lesions; the results were quantitatively compared with a conventional spin-echo study. Both of the fast MR techniques yielded a fourfold reduction in imaging time per section. The advanced Fourier sequence showed contrast that was identical to the conventional spin-echo study with signal-to-noise ratios of 58% and 57% for the first and second echoes, respectively. The partial-flip sequence showed a contrast of 109% and 57% for lesions versus substantia alba, and 107% and 78% for substantia grisea versus substantia alba relative to the first and second echoes of the conventional spin-echo study. The partial-flip sequence was particularly sensitive to magnetic susceptibility; this produced artifacts that may undermine the usefulness of partial flip for routine screening in certain parts of the brain. However, this susceptibility significantly improved the detection of intracranial hemorrhage when compared with the spin-echo sequence, particularly when combined with phase mapping of the partial-flip study.  相似文献   
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Kuligowska  E; Olsen  WL 《Radiology》1985,154(1):79-82
We describe a new method for the percutaneous drainage of pancreatic pseudocysts using a transgastric approach. We used this technique in three dogs and six patients for whom no other "safe" access route was available. The procedures were performed under US guidance alone or with US combined with fluoroscopy. No complications were observed.  相似文献   
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为了寻找毒性低、增敏作用强的乏氧细胞放射增敏剂,设计并合成了一系列5-溴-,5-甲基-,和5-未取代的3-硝基-1,2,4-三唑-1-乙酰胺类化合物,用HeLaS3细胞进行了体外试验。结果表明5-溴取代衍生物的增敏作用强于相应的5-甲基-或5-未取代的硝基三唑衍生物,但是它们的毒性亦增大。修饰1位乙酰胺侧链也可以改变化合物的增敏作用和亲脂性。在所测定的化合物中TA-101[2-(3-硝基-1-三唑基)乙酰胺]由于有高的增敏作用和低亲脂性,可能是一个有希望的放射增敏剂。  相似文献   
6.
BACKGROUNDPatients with p16+ oropharyngeal squamous cell carcinoma (OPSCC) are potentially cured with definitive treatment. However, there are currently no reliable biomarkers of treatment failure for p16+ OPSCC. Pathologist-based visual assessment of tumor cell multinucleation (MN) has been shown to be independently prognostic of disease-free survival (DFS) in p16+ OPSCC. However, its quantification is time intensive, subjective, and at risk of interobserver variability.METHODSWe present a deep-learning–based metric, the multinucleation index (MuNI), for prognostication in p16+ OPSCC. This approach quantifies tumor MN from digitally scanned H&E-stained slides. Representative H&E-stained whole-slide images from 1094 patients with previously untreated p16+ OPSCC were acquired from 6 institutions for optimization and validation of the MuNI.RESULTSThe MuNI was prognostic for DFS, overall survival (OS), or distant metastasis–free survival (DMFS) in p16+ OPSCC, with HRs of 1.78 (95% CI: 1.37–2.30), 1.94 (1.44–2.60), and 1.88 (1.43–2.47), respectively, independent of age, smoking status, treatment type, or tumor and lymph node (T/N) categories in multivariable analyses. The MuNI was also prognostic for DFS, OS, and DMFS in patients with stage I and stage III OPSCC, separately.CONCLUSIONMuNI holds promise as a low-cost, tissue-nondestructive, H&E stain–based digital biomarker test for counseling, treatment, and surveillance of patients with p16+ OPSCC. These data support further confirmation of the MuNI in prospective trials.FUNDINGNational Cancer Institute (NCI), NIH; National Institute for Biomedical Imaging and Bioengineering, NIH; National Center for Research Resources, NIH; VA Merit Review Award from the US Department of VA Biomedical Laboratory Research and Development Service; US Department of Defense (DOD) Breast Cancer Research Program Breakthrough Level 1 Award; DOD Prostate Cancer Idea Development Award; DOD Lung Cancer Investigator-Initiated Translational Research Award; DOD Peer-Reviewed Cancer Research Program; Ohio Third Frontier Technology Validation Fund; Wallace H. Coulter Foundation Program in the Department of Biomedical Engineering; Clinical and Translational Science Award (CTSA) program, Case Western Reserve University; NCI Cancer Center Support Grant, NIH; Career Development Award from the US Department of VA Clinical Sciences Research and Development Program; Dan L. Duncan Comprehensive Cancer Center Support Grant, NIH; and Computational Genomic Epidemiology of Cancer Program, Case Comprehensive Cancer Center. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH, the US Department of VA, the DOD, or the US Government.  相似文献   
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Breast cancer is the most common cause of cancer death in women in this country. Until recently, the traditional treatment has been radical surgery with or without radiation therapy for patients with primary breast cancer, and palliative endocrine therapy followed by chemotherapy for patients with advanced disease. These treatments have met with limited effectiveness in terms of eradicating the disease. Studies in the past decade have given cause for optimism for breast cancer patients. Adjuvant systemic therapy after local treatment appears promising for certain subsets of patients with primary breast cancer. The development of estrogen receptor assays has markedly changed our approach to the disease and improved patient care. Estrogen receptor is an important prognostic factor and is useful in planning appropriate therapy for patients with primary breast cancer as well as those with advanced disease. Further research is urgently needed to improve the dismal survival of certain women with this common malignancy.  相似文献   
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缺血性脑损伤诱导内源性神经干细胞的增殖和迁移   总被引:1,自引:0,他引:1  
目的:观察缺血性脑损伤对内源性神经干细胞增殖、迁移的影响。方法:实验于2004-09/2005-03在新乡医学院人体解剖与组织胚胎重点实验室进行。10~12周体质量300~350g的健康雄性SD大鼠62只,由新乡医学院实验动物中心提供。按随机数字表方法将其分为正常组6只、假手术对照组14只、脑缺血再灌注组42只(分为再灌注1,3,5,7,10,15,20d7个时间点,每时间点6只)。参照Pulsinelli-Brierley法,夹闭大鼠双侧颈总动脉制作短暂性全脑缺血动物模型,全脑缺血10min后再灌注,假手术对照组不夹闭颈总动脉。于脑缺血再灌注不同时间点应用SABC免疫组化法染色显示5-溴-2-脱氧尿嘧啶阳性细胞和巢蛋白阳性细胞,光镜下观察并分析脑缺血损伤后内源性神经干细胞增殖、迁移的变化过程。结果:正常组、假手术对照组大鼠均存活,脑缺血再灌注组大鼠1d、5d、15d、20d各死亡1只,共58只大鼠进入结果分析。①正常组与假手术对照组室管膜下区、海马CA1区、齿状回区域均偶见5-溴-2-脱氧尿嘧啶阳性细胞和巢蛋白阳性细胞。②脑缺血再灌注后1d于海马、齿状回和室管膜下区均有5-溴-2-脱氧尿嘧啶阳性细胞和巢蛋白阳性细胞,随后逐渐增加,7~10d达高峰,术后20d仍有表达;在室管膜下区的5-溴-2-脱氧尿嘧啶阳性细胞和巢蛋白阳性细胞有向皮质、海马迁移的现象。结论:成年大鼠全脑缺血后7~10d内源性神经干细胞增殖达到高峰;增殖的内源性神经干细胞存在由增殖区向靶区迁移的现象。  相似文献   
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