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排序方式: 共有508条查询结果,搜索用时 15 毫秒
31.
The objective of the study was to investigate the influence of mutational breeding on the contents of nutritionally relevant minerals in low phytic acid (lpa) mutants compared to their wild-types. Three lpa rice (Os-lpa-XQZ-1, Os-lpa-XS110-1, Os-lpa-XS110-2) and two lpa soybean mutants (Gm-lpa-TW75-1, Gm-lpa-ZC-2) were analyzed regarding their contents of phytic acid, lower inositol phosphates and the minerals calcium, iron and zinc. Additionally, cadmium was included into the spectrum of divalent cations analyzed. The phytic acid reduction in lpa rice was consistently more pronounced in Os-lpa-XS110-1 than in Os-lpa-XQZ-1 and Os-lpa-XS110-2. However, only for Os-lpa-XQZ-1, levels of calcium, iron and zinc were found to be consistently increased, whereas the cadmium level was shown to be predominantly decreased compared to the wild-type. Investigation of the two lpa soybean mutants, characterized by absence (Gm-lpa-TW75-1) and accumulation (Gm-lpa-ZC-2) of lower inositol phosphates, respectively, revealed no consistently decreased or increased contents of calcium, iron, zinc and cadmium. The data do not change the view that lpa mutations do not result in systematic increases or decreases of mineral contents in these crops. However, on the basis of the molar ratios of phytate/minerals in lpa rice and soybean mutants which are considered as predictive parameters, an improved bioavailability of minerals in the lpa materials can be expected.  相似文献   
32.
李世卿 《职业与健康》2009,25(23):2513-2514
目的建立操作简便、重现性好、空白值低的测定水中总铁的方法。方法采用非离子表面活性剂吐温20(Tween2/3)作助溶剂对硫氰酸钾比色法做进一步改进。结果改进后的方法测定水中总铁,与当前广泛使用的二氮杂菲法比较,其结果差异无统计学意义(P〉0.05),且铁含量在0~25μg范围内线性关系良好。最低检出浓度为0.02mg/L。回收率在94%~100%之间。变异系数为CV=1.9%。结论该方法操作简便,试剂空白值低,显色稳定,便于推广应用。  相似文献   
33.
Verma RP  Hansch C 《Virology》2007,359(1):152-161
The human rhinoviruses (HRVs) are the single most important cause of common colds. The widespread nature of this affliction, the economic consequences, and the well-known impracticality of vaccine development due to the large number of HRV serotypes (>100) have justified the search for chemotherapeutic agents. The interest in the application of quantitative structure-activity relationships has steadily increased in recent decades and we hope it may be useful in the search for anti-HRV agents. In the present paper, we have discussed the inhibition of various six compound series against HRV-1A, -1B, -2, -9, -14, -21, -22, -25, -64, and -89 by the formulation of a total number of 14 QSAR. Hydrophobicity is found to be one of the most important determinants of activity. Parabolic correlation with the hydrophobic parameter (Eq. ) is an encouraging example, where the optimal hydrophobicity is well defined. We believe that this may be the predictive model to narrow the synthetic challenges in order to yield very specific HRV-2 inhibitors. On the basis of this model, we have predicted eleven compounds (I-1 to I-11) that may be the next synthetic target. The proposed molecules (I-1 to I-11) also fulfill the conditions of Lipinski's "rule of five".  相似文献   
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35.
Objectives:To evaluate quantitatively the relationship between molar intrusion (change [Δ] maxillary first molar [U6]–palatal plane [PP]) and changes in vertical and sagittal cephalometric parameters and to determine the center of mandibular autorotation.Materials and Methods:Twenty-one patients diagnosed with anterior open bite and successfully treated with molar intrusion (overbite [OB] > 0 mm) were retrospectively enrolled. Lateral cephalograms taken before and after molar intrusion were used to measure changes in vertical and sagittal cephalometric parameters. The center of mandibular autorotation was calculated by measuring displacement of gonion (Go) and pogonion (Pog). Paired t-tests were used to compare variables, and linear regression analysis was used to examine the relationship between ΔU6-PP and other variables.Results:The mandible exhibited counterclockwise rotation after maxillary molar intrusion, which led to closure of anterior open bite. Strong linear relationships, in descending order, between ΔU6-PP and ΔOB, Δanterior facial height (AFH), Δvertical reference plane (Pog), and Δsella-nasion to Go-menton (SN-GoMe), were observed. When the maxillary molar was intruded 1 mm, OB increased by 2.6 mm, AFH decreased by 1.7 mm, Pog moved forward by 2.3 mm, and SN-GoMe decreased by 2°. The center of mandibular autorotation was located 7.4 mm behind and 16.9 mm below condylion after molar intrusion.Conclusions:The mandible exhibited counterclockwise rotation after maxillary molar intrusion; the center of mandibular autorotation was located behind and below condylion with individual variations.  相似文献   
36.
目的:通过锥形束CT(cone-beam computed tomography,CBCT)图像分析上颌恒磨牙牙根和根管的解剖形态.方法:对2012年5~9月因牙体牙周疾病行CBCT检查的患者资料进行回顾性分析.健康、未经过治疗、发育良好的630颗上颌第一磨牙、519颗上颌第二磨牙被纳入本研究,分析每颗磨牙的牙根数目、根管数目及根管形态,采用Venucci分类法对根管构型进行分类描述.将Vertucci Ⅰ型计为常规形态,其他类型计为变异形态,计算变异率.结果:上颌第一磨牙中,2.38%有2个独立牙根,97.14%有3个牙根,0.48%有4个牙根.上颌第二磨牙中,10.41%为单根牙,15.22%有2个牙根,73.60%有3个牙根,0.77%有4个牙根.存在3个牙根的612颗上颌第一磨牙中,近中颊根变异率为30.88%;存在3个牙根的382颗上颌第二磨牙中,近中颊根变异率为13.87%.结论:CBCT精确地显示了关于牙根及根管数目与形态的三维图像,这为疑难根管治疗提供了直观而准确的信息.  相似文献   
37.
Buccal bifurcation cyst (BBC) is a rare inflammatory odontogenic cyst that typically occurs at the buccal region of the first or second mandibular molars of children. In the current case, a 9-year-old boy complained of an extraoral soft tissue painful swelling. Intraoral examination revealed a partial eruption of the right permanent mandibular first molar with drainage of purulent material and clinical absence of the left mandibular first molar. Panoramic radiographic and computed tomography showed two well-defined areas surrounding the mandibular first molars consistent with cystic lesions. Surgical enucleations were performed and histopathologic analysis revealed inflammatory cysts. Based on the clinical, microscopic, radiographic, and CT images, the diagnosis of bilateral BBC was established. Patient has been under follow-up for about 1 year showing normal bone repair and eruption of the involved teeth. Although BBC is uncommon, it is important to recognize this entity.  相似文献   
38.
This randomized, controlled, double-blinded study related the effect of osteopathic manipulative treatment (OMT) of the temporomandibular joint (TMJ) and the orthostatic posture using the molar shim (MS) as a postural adjustment factor. Twenty individuals classified with temporomandibular disorder (TMD) were randomly assigned to a treated group (TG, n = 10) and placebo (PG, n = 10). The independent variables were: MS and OMT of the TMJ. The dependent variables were: DC-TMD data; local pressure pain using algometry; and orthostatic posture assessed by the distribution of plantar pressures (baropodometry), in the evaluation periods before and immediately after the interventions. Results: pain did not show a statistically significant difference after the interventions. However, when comparing the Effect Size (ES) between the groups in the post-intervention moment, a moderate relationship was observed for the left trapezius muscle (0.51) and right and left TMJ (0.41 and 0.54 respectively). When correlating the pain and percentage of anteroposterior postural dislocation variables, a significant moderate inverse correlation was observed in the post-intervention moment. The results of the MS pointed to a significant decrease (p ≤ 0.05) of the average peak pressure (Medium P) during the use of the MS (503.4 ± 44.1 kgf/cm2) and after performing the OMT (516.5 ± 49.6 kgf/cm2), both for the TG compared to the pre intervention moment (519.3 ± 42.9 kgf/cm2). There is a correlation between TMJ and orthostatic posture. OMT of the TMJ influences orthostatic posture. The MS can be added to the evaluative context of TMD.  相似文献   
39.
目的介绍微钛板支抗在远中移动磨牙中的临床效果及特点。方法选择7名应用微钛板矫治患者,分析其治疗前后头颅侧位片、模型等临床资料,测量磨牙远中移动量。结果 1)利用微钛板远中移动磨牙效果明显,最多可达3.5mm。2)中轻度牙列拥挤患者利用微钛板远中移动磨牙获得间隙排齐整平牙列,不需拔除双尖牙便可达到较理想的治疗效果。结论微钛板作为一种绝对支抗,远中移动磨牙有效而稳定,同时可避免常规拔牙矫治,维持上下颌第二磨牙间的全部牙齿和牙弓的连续性。  相似文献   
40.
新鲜老黄牛颚牙根制配成0.2g/ml 混悬剂,家兔以伤寒三联菌苗致热,体温升高1℃时分别以混悬剂、柴胡液及助悬剂灌胃,150min 牛齿根组兔温39.2±0.5,柴胡组38.5±0.4,对照组39.9±0.4。牛齿根灌胃,抖笼实验及滚棒实验,小鼠活动减少,反应迟钝,协调运动差;能延长戊巴比妥钠致小鼠的睡眠(牛齿根组108±5.1sec,对照组96.2±3.6sec),对抗戊四氮的致惊厥作用。认为动物实验符合临床牛齿根治疗小儿热病惊厥作用,机制值得进一步探讨。  相似文献   
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