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61.
Elevated levels of plasma uric acid have been linked to increased risk of cardiovascular diseases and their complications. As dairy proteins have been found to decrease plasma uric acid without increasing glomerular filtration rate, a sample of postmenopausal women living in Montreal was studied to investigate the nature of this relationship. Participants (158 Roman Catholic nuns) were randomly assigned to one of two test diets for a period of four weeks: the dairy foods group (n=81) consumed approximately 30 grams of dairy protein daily and the dairy-free diet group (n=77) ate no dairy foods at all. Subjects completed two one-day food records, a core questionnaire and a dairy foods diet history; blood specimens were obtained, and blood pressure, height and weight were measured. Average nutrient intakes differed as a consequence of the test diets, with significantly greater intakes of protein, fat, saturated fat, monounsaturated fat, potassium and calcium (p<0.01) in the dairy group after the study period, and lower dietary levels of protein, cholesterol, calcium and retinol (p<0.01) in the dairy-free group. Plasma uric acid was unchanged after the dietary intervention in the dairy group, but increased by 7.8 µmol/1 (p=0.03) in subjects on the dairy-free diet; however, diastolic blood pressure decreased in response to calcium (=–22.9, SE=10.0,p=0.02) among those whose diet included dairy foods. The study results suggest that proteins of dairy origin may play a role in stabilising or lowering plasma uric acid, and that calcium or other components found in milk products may also reduce diastolic blood pressure. While these findings have implications for dietary prevention to decrease cardiovascular risk in postmenopausal women, further investigations should examine these mechanisms in men over the age of 50 to ascertain whether a similar response would occur.  相似文献   
62.
ObjectiveTo determine the circadian influence on sound sensitivity produced by temporal hearing deprivation in healthy normal human subjects.DesignParticipants underwent bilateral earplugging before completion of anthropometry, the author's developed questionnaire, the Hamilton Anxiety and Depression Inventory, pure tone audiometry (PTA), stapedial reflex thresholds (SRT), distortion products otoacoustic emissions input/output (DPOAE-I/O), and uncomfortable loudness levels (ULLs). Afterward, the participants were randomly divided into group A, starting at 8:00 a.m. and finishing at 8:00 p.m., and group B, starting at 4:00 p.m. and ending at 4:00 a.m. Serum cortisol levels and audiological test results were obtained at the beginning and end of the session and 24-h free urinary cortisol levels were measured.Study sampleThirty healthy volunteers.ResultsPTA was 2.68 and 3.33 dB HL in groups A and B, respectively, with no statistical difference between them. ULLs were significantly lower in group A compared to group B, with an average of 8.1 dB SPL in group A and 3.3 dB SPL in group B (p < 0.0001). A SRT shift was observed in group A, with no difference in group B, and a night shift in DPOAE-I/O in group B.ConclusionsReduced loudness tolerance is demonstrated during daytime hearing deprivation in contrast to nighttime; this may be due to increased central gain in the awake cortex.  相似文献   
63.
The object of this study was to investigate whether exposure of pipe-layers to thermal degradation products of diphenylmethane diisocyanate (MDI) could be assessed by analysing 4,4-methylenedianiline (MDA) in hydrolysed plasma and urine, and whether the genotype for N-acetylation affected these biomarker levels. Blood and urine samples were drawn from 30-pipe-layers who had been welding polyurethane (PUR) insulated pipes during the preceding 3 months. MDA in hydrolysed plasma and urine was determined with a gas chromatography-mass spectrometry technique, and genotype for N-acetylation was analysed with a polymerase chain reaction technique. MDA in plasma was detected in 18 of the 30 pipe-layers. Their plasma concentrations of MDA varied from 0.05 to 8.48 g/1. There was a significant negative correlation between time since last welding of PUR-insulated pipes and P-MDA (r s = 0.50, P = 0.005). There was also a significant positive correlation between the estimated number of welded PUR-insulated pipes during the preceding 3 months and P-MDA (r s = 0.68, P = < 0.001). No significant association between genotype of N-acetylation and P-MDA was observed in a multiple regression analysis when adjustment was made for the estimated cumulative exposure to thermal degradation products of MDI. MDA in urine was detected in only four of the 30 pipe-layers. These four subjects had been welding PUR pipes on the same day as the sampling, or on the day before. The present results indicate the spot plasma samples analysed for MDA may give a rather good estimate of exposure to MDI during the preceding months. P-MDA, but not U-MDA, therefore seems to be a useful biomarker of long-term exposure to MDI. The individual N-acetylation capacity did not affect the plasma levels of MDA.  相似文献   
64.
Summary Six patients with recently ruptured intracranial aneurysms were treated preoperatively with tranexamic acid (AMCA). Two patients received 6 g daily in i.v. infusion, two had 6 g daily by i.v. injection, and two patients were given AMCA 9 g daily by mouth during the first week after bleeding. Serial assays of AMCA and fibrin/fibrinogen degradation products (FDP) in cerebrospinal fluid (CSF) were performed during 6–13 days after the initial subarachnoid haemorrhage (SAH). Judged from the decline in CSF-FDP, an assumed therapeutic level of 1 mg/l of AMCA in CSF was reached within 24–36 hours after the first dose when the drug was administered intravenously and within 48 hours when the drug was given orally.  相似文献   
65.
海绵动物的生物活性产物及其药理作用   总被引:8,自引:0,他引:8  
巫志峰  许东晖  梅雪婷  许实波 《中草药》2003,34(11):1064-1069
概括来源于海洋海绵动物中新发现的36种生物活性次生代谢产物,阐述其化学成分及药理作用的研究进展。其化学成分具有生物碱、甾醇、萜类、大环内酯、肽类等。经药效评价且有抗菌、抗病毒、抗肿瘤以及心血管活性等药理作用。这些具明显药理作用的生理活性化合物,作为新药先导化合物进行研究开发,具有良好的应用前景。  相似文献   
66.
吸附树脂及其在天然产物和抗生素中的应用   总被引:7,自引:0,他引:7  
简要介绍了吸附树脂的概念、发展和最新的研究进展;药用吸附树脂的研究现状,以及在天然产物和抗生素分离纯化中的应用进展。  相似文献   
67.
Chemical respiratory allergy is an important occupational health problem, but there are currently available no validated methods for hazard identification. This is due in part to the fact that the relevant cellular and molecular mechanisms of sensitization of the respiratory tract have been unclear, with particular controversy regarding the role of IgE. There is now increasing evidence that respiratory sensitization is associated with the preferential activation of type 2 T lymphocytes and the expression of type 2 cytokines interleukin (IL)-4, IL-5, IL-10, and IL-13. Type 2 cell products favor immediate type hypersensitivity reactions, serving as growth and differentiation factors for mast cells and eosinophils, the cellular effectors of the clinical manifestations of the allergic responses, and promoting IgE antibody production. There has been considerable interest in the application of cytokine profiling for the characterization of chemical allergens, with cytokine phenotypes analyzed in freshly isolated tissue, or following culture in the presence or absence of mitogen at the level of protein secretion or mRNA expression. Experience to date suggests that the measurement of induced cytokine secretion profiles shows promise for the hazard identification and characterization of chemical respiratory allergens. The purpose of this brief review article is to consider the approaches available and to highlight key procedural issues.  相似文献   
68.
This study determines the relative ocular lens irritancy of 16 common partially transparent or non-transparent consumer hygiene products. The irritancy was found by measuring the changes in the sharpness of focus [referred to as the back vertex distance (BVD) variability] of the cultured bovine lens using a scanning laser In Vitro Assay System. This method consists of a laser beam that scans across the lens, and a computer, which then analyses the average focal length (mm), the BVD variability (mm), and the intensity of the beam transmitted. Lenses were exposed to the 16 hygiene products and the lens’ focusing ability was monitored over 192 h. The products are semi-solids or solids (e.g. gels, lotions, shampoos). They are categorized into six groups: shampoos, body washes, lotions, toothpastes, deodorant, and anti-perspirant. Damage (measured by > 1 mm BVD variability) occurred slower for the shampoos, especially in the case of baby shampoo. The results indicate that shampoos exhibit the lowest level of ocular lens toxicity (irritability) while the deodorant is the most damaging.  相似文献   
69.
陈爱平  刘晖  周素花  戴淑真  徐冰 《肿瘤》2003,23(5):406-408
目的:探讨凋亡抑制基因bcl-2、bcl-xl在上皮性卵巢肿瘤中的表达及其相互关系。方法:应用免疫组织化学S-P方法检测10例正常卵巢、2l例良性上皮性卵巢肿瘤、12例交界性肿瘤、72例恶性肿瘤组织中bcl-2、bcl-xl基因表达情况.并分析其表达与不同临床病理特征之间的关系。结果:bcl-2在正常卵巢、良性上皮性卵巢肿瘤、交界性肿瘤、恶性肿瘤中阳性表达率分别为10%(1/10)、19.1%(4/21)、50%(6/12)、和55.6%(41/72),bcl-xl在正常卵巢、良性上皮性卵巢肿瘤中均为阴性表达,在交界性肿瘤和恶性肿瘤中阳性表达率分别为16.67%和48.61%。bcl-2与肿瘤的分化程度有关,分化差者bcl-2表达低。bcl-xl与肿瘤的临床分期有关,在Ⅲ、Ⅳ期恶性肿瘤中的阳性率分别为54.05%、71.43%,Ⅰ、Ⅱ期为12.50%、45.00%;两者均与肿瘤的病理学类型无关。未发现两者有相关关系。结论:本实验结果表明bcl-2和bcl-xl基因参与了卵巢肿瘤的发生发展过程,可作为卵巢恶性肿瘤的分子生物学指标之一。  相似文献   
70.
畸变产物耳声发射对侧抑制效应的研究   总被引:4,自引:3,他引:4  
利用ILO92耳动态分析仪,测试23例(46耳)正常青年人的畸变产物耳声发射(DPOAE)和对侧窄带噪声(NBN)的影响。结果:(1)对侧NBN对DPOAE的抑制非常明显,随NBN强度增加DPOAE幅值下降增加,二者呈显著负相关(F2为1~6kHz,γ为-0.49~-0.24,均P〈0.05,斜率0.26~0.08dB/10dB)。(2)在F2为中频(1.2kHz)且为中等强度(45~65dBSP  相似文献   
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