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71.
通过运用仿真人体模型对松果体区靶病灶直线加速器多聚弧照射的监测,论证直线加速器作为放射外科工具治疗颅内病变的科学性,探讨有关辐射参数对剂量分布的影响。作者认为,直线器放射外科可实现与伽玛马相似的剂量分布,同是神经外科安全有效的治疗技术,准直器孔径越小,照射范围越大,则剂量梯度即越大,剂量分布越理想;靶区最大剂量对上器孔径有相当高的依赖性,本文还就合理的照射弧范围及边缘处方剂量作了讨论。  相似文献   
72.
心房纤颤(atrial fibrillation, AF)是临床上最常见的心律失常之一,也是心血管疾病发病率和死亡率增加的重要原因。心外膜脂肪(epicardial adipose tissue, EAT)是位于脏层心包和心肌之间的一种特殊脂肪组织,研究表明EAT参与AF的发生与维持,但是具体机制尚未得到完全阐释。EAT来源的脂肪干细胞(adipose-derived stromal cells, ADSCs)分泌的细胞外囊泡(extracellular vesicles, EVs) 近年来受到重视。该文主要从EAT特点、定量检测及其与心肌结构与电重构的关系,特别是EVs对AF发生的影响等方面进行综述,以期进一步认识AF的发病机制,为今后的治疗提供新的思路。  相似文献   
73.
To determine the optimum dose of epidural morphine for postoperative pain control, 0.5–4.0mg of morphine was administered to 198 patients who had undergone operations on lower abdomen or lower extremities under continuous epidural anesthesia. Analgesic effect of morphine and incidence of nausea or vomiting were studied using linear discriminant analysis. As explanatory variables, age and dose of morphine were statistically significant in discriminating analgesic effect of morphine. Among indices for physique of patients, height was the most useful for predicting the analgesic effect. The dose which made the discriminant function zero corresponded to the minimum effective dose (MED) of morphine and it was expressed as follows; MED (mg·meter–1) = –0.0107 × age + 1.85. Predicting the incidence of nausea or vomiting in relation to the dose of morphine did not reach a level of statistical significance.(Ochi G, Yamane C, Arai T: Optimum dose of epidural morphine for postsurgical analgesia. J Anesth 4: 35–39, 1990)  相似文献   
74.
根据薄膜理论基础,分析了受抑全内反射(FTIR)的理论机制,并导出相应的光线透过率及反射率公式,绘制出透射率、反射率随棱镜相对间隙d/λ、入射角θ。的变化曲线。并建立了一套FTIR组合测试原理实验装置,得到了透过及发射光脉冲曲线,通过实验地其特性进行了具体分析。  相似文献   
75.
Compared with the nucleic acid amplification test (NATT), the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapid antigen self-testing (RAST) has advantages in speed and convenience. However, little is known about people's acceptance and influencing factors for SARS-CoV-2 RAST. A cross-sectional study was conducted from April 21 to 30, 2022 in China. The χ2 test and multivariate logistic regressions were used to identify the influencing factors. The structural equation model was used to test the extended protective motivation theory (PMT) model hypotheses. Among the total of 5107 participants, 62.5% were willing to accept the SARS-CoV-2 RAST. There were significant differences in acceptance among different residences (p < 0.001), educational level (p < 0.001), occupation (p < 0.001), monthly income (p < 0.001), travel frequency (p < 0.05), and feelings about NATT (p < 0.001). Response efficacy (β = 0.05; p = 0.025) and self-efficacy (β = 0.84; p < 0.001) had a positive effect, while response cost showed a negative effect (β = −0.07; p < 0.001). The public's major concerns about SARS-CoV-2 RAST are its reliability, testing method, price, and authority. Overall, a moderate intention to use SARS-CoV-2 RAST was found among the Chinese population. The extended PMT can be used for the prediction of intention to accept the RAST. We need to take measures to increase people's acceptance of SARS-CoV-2 RAST.  相似文献   
76.
77.
人体双侧对称经络电阻抗失衡与疾病的相关研究   总被引:2,自引:0,他引:2  
通过实验装置.分别测量人体双侧对称经络对称两穴位之间的电流波形,计算其电阻抗值,探讨经络的导电特性。证明了正常人双侧经络电阻抗的对称性、经络循行线的低阻性及双侧经络电阻抗失衡与其络属脏器病变的相关性等问题。  相似文献   
78.
目的:为掌握壮族骨盆的结构特点并向临床应用提供骨盆的形态学资料,作者对来源于壮族居民世代聚居地区,生前资料比较完整可靠的壮族成人骨盆标本100例,进行体质人类学调查。方法:采用国际标准进行了28项线性测量。结果:得到了壮族成年男女骨盆各50例较系统的形态学资料及12项指数。对壮族骨盆与其他不同种族、民族的骨盆作了比较,并对壮族骨盆的特点及有关临床问题进行了讨论。  相似文献   
79.
Purpose. The described structure pharmacokinetic pharmacodynamic relationships (SPPR) study explored the utilization of tetramethylcyclopropane analogues of valpromide (VPD), or tetra-methylcyclopropane carboxamide derivatives of valproic acid (VPA) as new antiepileptics. Methods. The study was carried out by investigating the pharmacokinetics in dogs and pharmacodynamics (anticonvulsant activity and neurotoxicity) of the following three cyclopropane analogues of VPD: 2,2,3,3-tetramethylcyclopropane carboxamide (TMCD), N-methyl TMCD (M-TMCD) and N-[(2,2,3,3-tetramethylcyclopropyl)carbonyl]-glycinamide (TMC-GLD). Results. The three investigated compounds showed a good anticonvulsant profile in mice and rats due to the fact that they were metabolically stable VPD analogues which were not biotransformed to their non-active acid, 2,2,3,3-tetramethylcyclopropane carboxylic acid (TMCA). M-TMCD was metabolized to TMCD and TMC-GLD underwent partial biotransformation to its glycine analogue N-[(2,2,3,3-tetramethylcyclopropyl)carbonyl]-glycine (TMC-GLN). Unlike TMC-GLN, the above mentioned amides had low clearance and a relatively long half life. Conclusions. In contrast to VPD which is biotransformed to VPA, the aforementioned cyclopropane derivatives were found to be stable to amide-acid biotransformation. TMCD and M-TMCD show that cyclic analogues of VPD, like its aliphatic isomers, must have either two substitutions at the position to the carbonyl, such as in the case of TMCD, or a substitution in the and in the positions like in the VPD isomer, valnoctamide (VCD). This paper discusses the antiepileptic potential of tetramethylcyclopropane analogues of VPD which are in animal models more potent than VPA and may be non-teratogenic and non-hepatotoxic.  相似文献   
80.
To investigate the effects of growth hormone (GH) on the reversal of growth failure in uremia, recombinant human GH (rhGH) was administered to rats with chronic renal failure (CRF). The dosage of rhGH was 3 IU/day (i.p.) for 13 days after the induction of CRF by 5/6 nephrectomy. Animals were classified into four groups: untreated nephrectomized rats (NX,n=40), GH-treated nephrectomized rats (NX+GH,n=18), sham-operated rats fed ad libitum (SHAMAL,n=27), and sham-operated rats pair-fed with 10 NX rats (SHAMPF,n=10). NX and NX+GH rats developed a similar and moderate degree of CRF, serum urea nitrogen being (mean±SEM) 49±3 and 54±4 mg/dl, respectively, compared with 16±4 and 19±0 mg/dl in SHAMAL and SHAMPF groups. Weight (56.0±3.3 g) and length (3.5±0.1 cm) gains of NX rats were lower than those of SHAMAL rats (94.2±4.0 g,P<-0.0001 and 4.1±0.2 cm,P<-0.01). Growth of the SHAMPF group and the matched NX rats was not significantly different. Weight (56.2±5.0 g) and length (3.4±0.2 cm) gains of NX+GH and NX rats were similar, the beneficial effect of GH therapy on growth being observed in only those animals with more severe degrees of uremia. This growth-promoting action resulted from greater food efficiency and not from stimulated food intake. The hypercholesterolemia seen in NX rats, 81±2 mg/dl versus 55±3 mg/dl in SHAMAL (P0.0001), was not increased in the NX+GH group, 87±3 mg/dl. There was a positive and significant correlation between serum cholesterol and serum urea nitrogen values in NX and NX+GH animals. This study suggests that growth impairment of mild CRF is mainly due to malnutrition and is refractory to GH administration. GH therapy improves the growth rate of animals with advanced CRF without aggravating their lipid abnormalities.  相似文献   
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