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排序方式: 共有4921条查询结果,搜索用时 15 毫秒
1.
目的 建立蒙药绿松石的质量标准。方法 收集不同产地绿松石,共10批。观察绿松石样品和粉末的性状并进行理化鉴别;按2020年版《中国药典》(四部)通则方法测定绿松石样品中水分、浸出物含量;采用原子吸收光谱法测定绿松石样品铜元素含量。结果 绿松石为不规则、周围带有黑石的块状物,表面蓝绿色,体重,质硬脆,难砸碎,断面呈贝壳状,蜡样光泽,粉末呈灰绿色,无臭,味淡;理化鉴别结果显示,呈铜盐反应;10批次样品中水分含量为0.41%-3.94%(SD=1.37%),浸出物含量为0.21%-0.81%(SD=0.21%),铜元素含量为3.03%-4.63%(SD=0.63%)。结论 初步拟定绿松石中水分含量不得超多5.0%、浸出物含量不得低于0.10%,铜元素含量应为2.60%-4.84%,制定的标准可用于蒙药材绿松石的质量控制。  相似文献   
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Background

The purpose of this analysis is to describe the differences in cardiac magnetic resonance characteristics between benign and malignant tumors, which would be helpful for surgical planning.

Methods

This was a prospective cohort study of 130 patients who underwent cardiac magnetic resonance imaging for evaluation of a suspected cardiac mass. After excluding thrombi and tumors without definitive diagnosis, 66 tumors were evaluated for morphologic features and tissue composition.

Results

Of the 66 patients, 39 (59.0%) had malignant tumors and 27 (41.0%) had benign tumors. Patients with malignant tumors were younger when compared with those with benign tumors (age 51 years [42.8-60.0] vs 65 years [60.0-71.0] median). Malignant tumors more often demonstrated tumor invasion (69% vs 0% P < .001) and were more often associated with pericardial effusion (41% vs 7.4% P = .004). Presence of first-pass perfusion (100% vs 33% P < .001) and late gadolinium enhancement (100% vs 59.2%, P < .001) were significantly higher in malignant tumors. In logistic regression modeling, tumor invasion (P < .001) and first-pass perfusion (P < .001) were independently associated with malignancy. Furthermore, using classification and regression tree analysis, we developed a decision tree algorithm to help differentiate benign from malignant tumors (diagnostic accuracy ~90%). The algorithm-weighted cost of misclassifying a malignant tumor as benign was twice that of classifying a benign tumor as malignant.

Conclusions

Our study demonstrates that cardiac magnetic resonance imaging is a useful noninvasive method for differentiating malignant from benign cardiac tumors. Tumor size, invasion, and first-pass perfusion were useful imaging characteristics in differentiating benign from malignant tumors.  相似文献   
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Objective: To investigate the ability of contrast enhancement patterns of contrast-enhanced ultrasound in differentiating benign and malignant soft tissue tumours.  相似文献   
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BACKGROUND: To evaluate potential differences in light absorbing properties and stability of indocyanine green (ICG) adsorbed to the retinal surface and of ICG dissolved in water and balanced salt solution. METHODS: The retina of four human donor eyes was prepared by removing the vitreous from the retinal surface. The inner surface of the specimen was covered with two to three drops of a 0.05% or 0.15% ICG solution respectively. After 1 min, the dye was removed by careful irrigation using BSS plus. The retinal specimens were then investigated by diffuse reflection spectroscopy (UV/VIS/NIR Spectrometer Lambda 900/Perkin Elmer equipped with a PELA-1020 integrating sphere accessory) and their absorption evaluated by the Kubelka-Munk function. To control the sensitivity of the setting, diffuse reflectance spectra of ICG adsorbed to a cellulose membrane and Al(2)O(3) were measured. For comparison, absorption spectra of ICG dissolved in water and BSS plus solution were measured in relation to ICG concentration and time using an UV/VIS/NIR Spectrometer Lambda 900/Perkin Elmer. RESULTS: On the retinal surface, absorption spectra exhibited a steep increase of absorption beginning at 620 nm, with a maximum at 736 nm (0.05%) and a shoulder at 745 (0.15%) and a second maximum at approximately 800 nm for both concentrations. Repeated measurement of the retinal surface 13 days after the ICG exposure revealed no changes in the position of the maxima as compared to the initial measurements. Light absorbing properties of ICG on cellulose or Al(2)O(3) are similar to those seen on the retinal surface with respect to the pattern and location of absorption maxima. In contrast, ICG dissolved in water or BSS plus disclosed variations in absorption characteristics depending on dye concentration, solute and time of measurement. CONCLUSIONS: Absorption characteristics and stability of ICG bound to the retinal surface could be of relevance when investigating potential pathomechanisms of ICG related toxicity, which might be related not only to intraoperative but also to postoperative light exposure of patients after intravitreal use of ICG.  相似文献   
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目的 探讨各种脑膜病变脑膜MRI强化类型与病因的关系。方法 回顾性分析78例资料完整,MRI增强扫描脑膜异常强化的非脑膜瘤。结果 78例中,脑膜癌病16例(硬脑膜-蛛网膜型2例,软脑膜-蛛网膜下腔型11例,混合型3例);感染性脑膜炎18例(硬脑膜-蛛网膜型3例,软脑膜-蛛网膜下腔型13例,混合型2例);脑梗死22例(软脑膜-蛛网膜下腔型18例,混合型4例);开颅术后15例(硬脑膜-蛛网膜型10例,混合型5例);硬膜下积液(血肿)7例,均为硬脑膜-蛛网膜型。结论 MRI双倍剂量Gd-DTPA增强扫描对脑膜病变敏感性高,脑膜强化类型与各种病因侵犯脑膜三层结构的方式和程度有关。  相似文献   
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Enhanced and non-enhanced computed tomography (CT) brain scans were performed within 72 h of surgery on 21 children in whom brain tumors had been resected totally or subtotally, and scans were repeated at varying intervals thereafter. Biopsies of the resection margins were performed in 12 patients at the end of the surgical procedure. The immediate CT scan showed enhancement in the resection margin in 13 of the 21 patients and in 9 of the 13, the enhancement disappeared on follow-up scans. There was discordance between the results of immediate CT scan examination and the biopsies of the resection margins in 7 of the 12 cases. The advantages and disadvantages of an immediate postoperative scan versus a more delayed CT scan are discussed.  相似文献   
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目的探讨臂丛加强化麻醉后颈部抽动的原因及防治。方法对近年来在麻醉方法、用药相同,术后颈部抽动患者的观察治疗过程进行分析。结果臂丛麻醉并发颈部抽动给予充分镇静后可完全治愈。结论麻醉后并发颈部抽动为药物副作用及颈局部刺激的综合作用。  相似文献   
10.
食品添加剂KAl(SO4)2中Al的吸收,排泄,蓄积实验研究   总被引:1,自引:0,他引:1  
目的:探讨我国主要含铝食品添加剂——硫酸铝钾中铝的吸收、排泄和贮留的基本情况。方法:1.采用6月龄日本雄性大耳兔8只进行3天的代谢平衡实验。2.选用2~3月龄21只雄性兔进行32周的蓄积实验。结果:代谢实验表明铝的表观吸收率平均在10%左右,约90%的口服铝在粪中排出。尿铝随摄入铝的增加而增加,但肾排铝能力不足吸收的10%。兔的蓄积实验证明在32周实验后实验兔随铝摄入的增加其主要脏器均有不同程度的铝蓄积。其蓄积量的顺序为:骨>肝>肾>脑>心(3.89~105.46mg/kg干重);蓄积增长倍数为:肝>脑>肾>骨>心(1.51~4.58倍)。结论:1.食品添加剂硫酸铝钾中铝的表观吸收率平均在10%左右。尿铝随摄入铝的增加而增加,但肾排铝量不足吸收的10%。2.长期大量摄入含铝食品添加剂可导致机体铝蓄积,其中脑、骨、肝、肾蓄积较明显。  相似文献   
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