全文获取类型
收费全文 | 35172篇 |
免费 | 2871篇 |
国内免费 | 962篇 |
专业分类
耳鼻咽喉 | 240篇 |
儿科学 | 1466篇 |
妇产科学 | 1075篇 |
基础医学 | 2237篇 |
口腔科学 | 944篇 |
临床医学 | 4266篇 |
内科学 | 6870篇 |
皮肤病学 | 432篇 |
神经病学 | 1516篇 |
特种医学 | 867篇 |
外国民族医学 | 2篇 |
外科学 | 3191篇 |
综合类 | 5095篇 |
现状与发展 | 1篇 |
预防医学 | 5033篇 |
眼科学 | 404篇 |
药学 | 2644篇 |
36篇 | |
中国医学 | 1352篇 |
肿瘤学 | 1334篇 |
出版年
2024年 | 166篇 |
2023年 | 937篇 |
2022年 | 1804篇 |
2021年 | 2336篇 |
2020年 | 1996篇 |
2019年 | 1804篇 |
2018年 | 1820篇 |
2017年 | 1423篇 |
2016年 | 1336篇 |
2015年 | 1263篇 |
2014年 | 2648篇 |
2013年 | 2536篇 |
2012年 | 2098篇 |
2011年 | 2296篇 |
2010年 | 1862篇 |
2009年 | 1740篇 |
2008年 | 1602篇 |
2007年 | 1627篇 |
2006年 | 1204篇 |
2005年 | 1078篇 |
2004年 | 850篇 |
2003年 | 712篇 |
2002年 | 487篇 |
2001年 | 468篇 |
2000年 | 346篇 |
1999年 | 301篇 |
1998年 | 247篇 |
1997年 | 240篇 |
1996年 | 196篇 |
1995年 | 194篇 |
1994年 | 191篇 |
1993年 | 135篇 |
1992年 | 150篇 |
1991年 | 133篇 |
1990年 | 102篇 |
1989年 | 90篇 |
1988年 | 62篇 |
1987年 | 64篇 |
1986年 | 51篇 |
1985年 | 69篇 |
1984年 | 65篇 |
1983年 | 51篇 |
1982年 | 40篇 |
1981年 | 35篇 |
1980年 | 32篇 |
1979年 | 26篇 |
1978年 | 26篇 |
1977年 | 21篇 |
1976年 | 17篇 |
1974年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
氯胺酮和依托咪酯的BIS50及其对脑电双频指数的影响 总被引:4,自引:0,他引:4
目的 分别测定氯胺酮和依托咪酯诱导时半数患者入睡时的脑电双频指数(BIS)即BIS50和半数有效量(ED50),比较他们对BIS的影响。方法 选择40例无服用精神药物和镇静催眠药、无术前用药的择期手术患者(ASAⅠ~Ⅱ级),随机分为氯胺酮组(K组,n=20)和依托咪酯组(E组,n=20),以半数效量序贯法分别进行氯胺酮和依托咪酯诱导的睡眠观察,以对语言指令不应和睫毛反射消失为入睡指标,同时记录BIS的变化。对取得的数据以直线回归的方法和加权均数法分别求得氯胺酮、依托咪酯的BIS50和ED50。结果 氯胺酮和依托咪酯诱导后,BIS明显下降(P=0.000983),但两者各自BIS下降幅度在入睡与未睡患者之间没有明显差异(P=0.920501和0.956263)。氯胺酮的BIS50和ED50分别是78.81(95%可信区间67.27~97.10)和0.757mg/kg(95%可信区间0.535~1.071mg/kg),依托咪酯的BIS50和ED50分别是60.00(95%可信区间49.74~76.95)和0.089mg,/kg(95%可信区间0.073~0.107mg/kg)。结论 氯胺酮和依托咪酯皆显著降低BIS,但仅凭BIS难以准确预计是否进入睡眠状态。 相似文献
62.
Hy De Lee Euy Young Soh Hoon Sang Chi Byong Ro Kim Kyong Sik Lee Kyung Soon Song Hyun Joo Jung 《Surgery today》1990,20(2):180-185
The relationship between primary tumor proliferative activity and clinical and pathologic characteristics was analyzed in
relation to menopausal status in 32 patients with malignant or benign breast disease. The thymidine labeling index (TLI) showed
significantly higher median values in the cancer patients (3.48 per cent) than in the patients with benign diseases (1.02
per cent). TLI was not significantly affected by delayed incubation at room temperature for about 1 hour. In the breast cancer
patients, TLI did not significantly correlate to tumor size, the presence of axillary lymph node metastasis or pathologic
nuclear grading. The only significant difference was limited to the breast cancer patients without axillary lymph node metastasis
in relation to menopausal status; the TLI in the premenopausal patients (5.10 per cent) was significantly higher (p<0.05)
than that in the postmenopausal patients (2.28 per cent). These data thus suggest that among premenopausal patients without
axillary lymph node metastasis, those with a high TLI could be potential candidates for adjuvant chemotherapy. 相似文献
63.
浙江医科大学附二院门诊处方中精神药物使用调查 总被引:1,自引:0,他引:1
本文对浙江医科大学附属二院1993年7月间31378张合格处方进行统计分析,并用限定日剂量(DDD)和药物使用指数(DUI)为指标,分析镇静催眠药物使用情况。结果表明苯二氮 类药方2067张,占总处方量的6.59%,巴比妥类药方49张,占0.16%,麻醉药方111张;占0.35%。苯二氮 类药方中.女性处方量1202张,男性处方量865张,男、女组间比较有显著性差异。苯二氮 类药方多分布在神经内科,常用的药有舒乐安定和阿普唑仑。九种常用的苯二氮 类药和麻醉性镇痛药的DUI均小于1。提示药物滥用现象少见,该院对这类药物的管理比较严格。麻醉性镇痛药中二氢埃托啡处方占67.57%。 相似文献
64.
L. LEIBOVICI W. R. GRANSDEN S. J. EYKYN H. KONSIBERGER M. DRUCKER S. D. PITLIK I. PHILLIPS 《Journal of internal medicine》1993,234(1):83-89
Abstract. Objectives. To define risk factors associated with bacteraemia caused by Staphylococcus aureus or coagulase-negative staphylococci; and to use them to define patients in need of empiric anti-staphylococcal antibiotic treatment. Design, Derivation set: observational, prospective study; validation set: retrospective analysis of a prospectively collected database. Setting. Derivation set: Beilinson Medical Centre, Petah Tiqva, Israel—a 900-bed university hospital. Validation set: St Thomas's Hospital, London, UK—an 800-bed teaching hospital. Subjects. All episodes of bacteraemia detected at Beilinson Medical Centre between March 1988 and September 1990 (derivation set, n = 1410), and at St Thomas's Hospital during 1987–1990 (validation set, n = 1040). Interventions. None. Main outcome measures. Percentage of staphylococcal bacteraemia in groups of patients defined by the models. Results. The following factors were associated with Staphylococcus aureus bacteraemia: focus of infection (whether high or low risk), haemodialysis, intravenous drug abuse and infection acquired in the orthopaedic ward. A logistic model was used to divide the derivation set into three groups with percentages of Staphylococcus aureus bacteraemia of 1.8%, 13.2% and 33.7% (P < 0.0001); and the validation group 2.5%, 18.2% and 53.2% (P < 0.0001). Factors associated with coagulase-negative staphylococcal bacteraemia were: central or peripheral intravenous catheter as the focus of infection, a preterm neonate, the presence of a central intravenous catheter, low temperature, and a low white blood cell count. A second model including those factors was used to divide the derivation set into three groups with percentages of coagulase-negative staphylococcal bacteraemia of 1.9%, 22.8%, and 43% (P < 0.0001). In the validation set, the percentages were 2.9%, 22.4% and 31.0% (P < 0.001). Conclusions. The present study defines groups at high risk for staphylococcal bloodstream infection, in which empiric treatment should include an anti-staphylococcal drug. 相似文献
65.
高校科研业绩量化评价指标体系及评价方法初探 总被引:2,自引:0,他引:2
目的:建立高校科研业绩量化计算公式及评价方法。方法:通过对高校科研业绩的表现形式和特点进行分析,根据高校科研和教学工作实际,提出高校科研业绩量化评价指标选取原则。结果:初步拟定了指标体系和评价指标的计算方式。结论:为高校科研管理部门对科研人员评价提供量化方法。 相似文献
66.
目的:利用检测下肢动脉硬化性闭塞症患的踝/肱指数对其下肢缺血程度进行评估。方法:采用以色列Flo-link 500T血管多普勒诊断仪对我院50例确诊为下肢动脉硬化性闭塞症患进行了分组踝/肱指数的检测。结果:踝/肱指数在0.5—0.9之间,常提示下肢动脉或近端有单水平阻塞;踝/肱指数在0.45以下常提示患下肢缺血程度严重,为坏疽前期静息痛表现;踝/肱指数在0.30以下多伴有缺血性溃癌或坏死。结论:踝/肱指数的检测可以反映下肢缺血程度,指导临床选择治疗方法,判断愈后及疗效,其无创性、可重复性、价格低康,更易被患接受。 相似文献
67.
应用流式细胞计对30例宫颈腺癌和混合癌细胞的DNA指数和细胞增殖周期各时相细胞分布比例进行分析,结果显示非整倍体肿瘤29例,占96.7%.流式细胞计在诊断恶性肿瘤方面是有价值的。细胞增殖周期比DNA指数对预后的估价更有意义.乳头型腺癌、分化I级的肿瘤,S+G2M比率最低,5年生存率最高. 相似文献
68.
M. NISKANEN A. KARI P. NIKKI E. IISALO L. KAUKINEN V. RAUHALA E. SAARELA 《Acta anaesthesiologica Scandinavica》1994,38(6):587-593
Prognostic factors determining the outcome from intensive care were studied in 952 patients admitted to 25 Finnish ICUs after gastroenterologic emergency. Logistic regression analysis was used to create predictive models based on the APACHE II–system. The models were constructed by using data from a random two–thirds of the study population and validated in the remaining independent one–third together with the original APACHE II–index. The Acute Physiology Score, age, and a pre–existing liver disease were the three most important determinants of outcome. The inclusion of the TISS score describing the intensity of treatment into a model did not enhance the accuracy of the prediction. Our models were better calibrated than the original APACHE II–equation when tested by the goodness–of–fit –statistics. These statistical models may help the clinicians to predict the outcome for an individual patient by providing them information about the relative impacts of predictive factors or about the probability of death. These probabilities should be interpreted cautiously, taking into acount the limitations of statistical methods. This is especially important when assessing the highrisk patients. Their number in our study was too low for accurate outcome prediction. 相似文献
69.
采用Barthel指数对120例脑卒中住院患者在发病后5 ̄6周进行日常生活活动(ADL)能力的证实。因脑卒中遗留的功能不全,ADL的受损率达66.7%,肢体的Brunnstrom功能分级与ADL积分高度相关,相关性下肢高于上肢;多元逐步回归分析显示,躯体(偏瘫)和心理(认知障碍和抑郁因素)影响ADL的能力。认为ADL能力的提高,不仅依赖于肢体功能障碍的改善,提高认知功能,改善情感状况,对于脑卒中患 相似文献
70.
双频谱指数在心脏瓣膜置换术中的观察 总被引:2,自引:0,他引:2
目的应用脑电双频谱指数(BIS)监测常规经验麻醉下瓣膜置换术病人的麻醉深度(意识水平),观察BIS在伤害性刺激时的变化.方法选择30例瓣膜置换术病人,采用芬太尼、咪唑安定、哌库溴铵及心血管活性药物对病人实施麻醉;术中监测并有专人分别记录入室(基础值)、诱导后、插管后、切皮后、锯胸骨时、缝胸骨时及术毕BIS和MAP,HR各参数值,观察不同阶段各参数的变化.结果诱导后各参数均明显降低,虽然切皮后、锯胸骨及缝胸骨等强刺激后MAP和HR未见统计学意义的显著改变,但BIS却显著增高(P<0.01);全部病人锯胸骨时BIS均在60(67.28±8.97)以上,缝胸骨时63(68.46±8.70)以上,而无1例低于50者.结论该组瓣膜置换术病人麻醉偏浅,尤以锯胸骨、缝胸骨及术毕等时段为甚,表现为BIS值偏高,有知晓发生;知晓可发生在临床认为满意的麻醉中;应用BIS监测,可更加合理地评价麻醉深度. 相似文献