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941.
942.
Stigma is a recognised problem for effective prevention, treatment, and care of HIV/AIDS. However, few studies have measured changes in the magnitude and character of stigma over time. This paper provides the first quantitative evaluation in Africa of the changing nature of stigma and the potential determinants of these changes. More specifically, it evaluates the dynamic relationship between stigma and (1) increased personal contact with people living with HIV/AIDS and (2) knowing people who died of AIDS. Panel survey data collected in Cape town 2003 and 2006 for 1074 young adults aged 14–22 years were used to evaluate changes in three distinct dimensions of stigma: behavioural intentions towards people living with HIV/AIDS; instrumental stigma; and symbolic stigma. Individual fixed effects regression models are used to evaluate factors that influence stigma over time. Each dimension of stigma increased in the population as a whole, and for all racial and gender sub-groups. Symbolic stigma increased the most, followed by instrumental stigma, while negative behavioural intentions showed a modest increase. Knowing someone who died of AIDS was significantly associated with an increase in instrumental stigma and symbolic stigma, while increased personal contact with people living with HIV/AIDS was not significantly associated with any changes in stigma. Despite interventions, such as public-sector provision of antiretroviral treatment (which some hoped would have reduced stigma), stigma increased among a sample highly targeted with HIV-prevention messages. These findings emphasise that changes in stigma are difficult to predict and thus important to monitor. They also indicate the imperative for renewed efforts to reduce stigma, perhaps through interventions to weaken the association between HIV/AIDS and death, to reduce fear of HIV/AIDS, and to recast HIV as a chronic manageable disease.  相似文献   
943.
建立了水产品中多组分生物胺的反相高效液相色谱-柱后衍生-荧光检测方法。采用荧光试剂邻苯二甲醛(OPA)为柱后衍生化试剂,在Capcell Pak MG-C18色谱柱上,通过梯度洗脱使酪胺、腐胺、尸胺、组胺、胍丁胺、精胺和亚精胺等7种生物胺得到良好分离,在给定的浓度范围内,各组分生物胺呈现良好线性相关(R^2〉0.999)。在水产品中添加生物胺混合标准溶液,平均回收率为88.3%~110.1%,相对标准偏差RSD小于10%。结合水产品的感官鉴定、pH值和TVBN值测定等方法检测水产食品的新鲜程度,分析了鱿鱼在不同保藏温度、保藏时间下的生物胺种类及含量的变化。其中胍丁胺和尸胺在鱿鱼的保藏过程中发生最显著变化,可以作为其质量变化的参考指标。  相似文献   
944.
目的:探讨单侧输尿管梗阻后大鼠肾间质纤维化发生过程中肝细胞生长因子(HGF)的表达及中药参附注射液对其的影响。方法:采用单侧输尿管结扎(UUO)制造梗阻性肾病模型,将56只大鼠随机分为对照组(假手术组)、手术组(UUO组)和治疗组(UUO+参附),术后7d、14d观察肾组织病理改变,应用免疫组织化学方法检测肾组织中HGF的表达。结果:与对照组相比,手术组肾间质出现了明显的纤维化,HGF的表达在术后第7天明显增加,第14天较第7天减弱,与手术组相比,治疗组肾间质纤维化明显减轻,而且HGF的表达在术后第7天明显上调,第14天较第7天上调更明显,有统计学差异(P〈0.05)。结论:参附注射液可以上调肾组织HGF的表达,减轻肾小管一间质纤维化,发挥肾保护作用。  相似文献   
945.
The present study was aimed to investigate the chemopreventive effects of Solanum trilobatum (ST) extract against diethylnitrosamine (DEN)-induced hepatocarcinogenesis promoted by Phenobarbital (PB) in Wistar rats. Hepatocarcinogenesis was initiated by a single intraperitoneal injection of DEN (200 mg/kg b.w.) and promoted with PB (0.05%) in basal diet. The experimental study extended for periods of 13 and 26 weeks. Alcoholic extract of ST was orally administered for the entire experimental period after initiation along with commencement of promotion. The chemopreventive effect of ST was assessed from the incidence of nodules, drug metabolizing phase I components such as contents of cytochrome P450, cytochrome b(5), activities of NADPH cytochrome c reductase, NADH - cytochrome b(5) reductase and phase II components such as levels of glutathione, activities of UDP-glucuronyl transferase, glutathione S-transferase and gamma-glutamyl transpeptidase in the liver. Lipid peroxidation at basal and prooxidants-induced (NADPH + ADP + Fe and Ascorbate + Fe) states was assessed in the microsomes. Animals administered with ST extract evidenced significant inhibition of tumor nodular incidence in DEN + PB + ST animals compared to DEN + PB animals, with favorable alterations in the hepatic drug-metabolizing phase I and phase II components. Administration of ST inhibited basal and pro-oxidant-induced lipid peroxidation. The present result suggests the probable mediation of chemoprevention by ST against DEN-induced carcinogenesis by the modulation of drug metabolizing components in the liver of treated animals.  相似文献   
946.
A new radioactivity solution standard of 210Pb has been developed and will be disseminated by the National Institute of Standards and Technology (NIST) as standard reference material (SRM) 4337. This new 210Pb solution standard is contained in a 5 mL flame-sealed borosilicate glass ampoule, consists of (5.133±0.002) g of a nominal 1 mol L−1 nitric acid solution, has a density of (1.028±0.002) g mL−1 at 20 °C, has carrier ion concentrations of about 11 μg Pb2+ and 21 μg Bi3+ per gram of solution, and is certified to contain a massic activity (9.037±0.22) kBq g−1 as of the reference time 1200 EST, 15 June 2006. All of the uncertainties cited above correspond to standard uncertainties multiplied by a coverage factor k=2. The standardization for the 210Pb content of the solution was based on 4πβ liquid scintillation (LS) measurements using CIEMAT/NIST 3H-standard efficiency tracing (CNET). Confirmatory determinations were also performed by high-resolution HPGe γ-ray spectrometry, by 2π spectrometry with a Si surface barrier detector of separated 210Po, and by 4πβ(LS)–γ(NaI) anticoincidence counting.  相似文献   
947.
Ultrashort echo time (UTE) imaging is a technique that can visualize tissues with sub-millisecond T(2) values that have little or no signal in conventional MRI techniques. The short-T(2) tissues, which include tendons, menisci, calcifications, and cortical bone, are often obscured by long-T(2) tissues. This paper introduces a new method of long-T(2) component suppression based on adiabatic inversion pulses that significantly improves the contrast of short-T(2) tissues. Narrow bandwidth inversion pulses are used to selectively invert only long-T(2) components. These components are then suppressed by combining images prepared with and without inversion pulses. Fat suppression can be incorporated by combining images with the pulses applied on the fat and water resonances. Scaling factors must be used in the combination to compensate for relaxation during the preparation pulses. The suppression is insensitive to RF inhomogeneities because it uses adiabatic inversion pulses. Simulations and phantom experiments demonstrate the adiabatic pulse contrast and how the scaling factors are chosen. In vivo 2D UTE images in the ankle and lower leg show excellent, robust long-T(2) suppression for visualization of cortical bone and tendons.  相似文献   
948.
We assessed the relations of visual hallucinations (VH) to cardiovascular autonomic dysfunction in patients with Parkinson's disease (PD). The subjects were 37 patients without VH (VH(-)) and 31 with VH (VH(+)). Autonomic function was evaluated on the basis of cardiac 123-radioiodinated metaiodobenzylguanidine (123I-MIBG) uptake and hemodynamic testing with Valsalva maneuver. Systolic blood pressure (SBP) and plasma norepinephrine concentrations (NE) were measured by tilt-table testing. 123I-MIBG uptake was lower in VH(+) than VH(-). Hemodynamic studies showed that VH(-) had only cardiac sympathetic and parasympathetic dysfunction, while VH(+) additionally had reduced vasomotor sympathetic functions. The fall in SBP during tilt-table testing was greater in VH(+) than VH(-). NE and its difference in the supine and upright positions were decreased in VH(+). We conclude that cardiac and vasomotor sympathetic dysfunction is more severe in VH(+) than in VH(-). Severe dysfunction in PD with VH is probably attributed to Lewy-body lesions or neuronal loss in sympathetic ganglia, the central autonomic system, or both.  相似文献   
949.
The purpose of this study was to evaluate the dose to normal tissues as a function of increasing margins around the lumpectomy cavity in accelerated partial breast irradiation (APBI) using 3D-conformal radiotherapy (3DCRT). Eight patients with Stage 0-I breast cancer underwent treatment planning for 3DCRT APBI. The clinical target volume (CTV) was defined as a 15-mm expansion around the cavity limited by the chest wall and skin. Three planning target volumes (PTV1, PTV2, PTV3) were generated for each patient using a 0, 5-, and 10-mm expansion around the CTV, for a total margin of 15, 20, and 25 mm. Three treatment plans were generated for every patient using the 3 PTVs, and dose-volume analysis was performed for each plan. For each 5-mm increase in margin, the mean PTV:total breast volume ratio increased 10% and the relative increase in the mean ipsilateral breast dose was 15%. The mean volume of ipsilateral breast tissue receiving 75%, 50%, and 25% of the prescribed dose increased 6% to 7% for every 5 mm increase in PTV margin. Compared to lesions located in the upper outer quadrant, plans for medially located tumors revealed higher mean ipsilateral breast doses and 20% to 22% more ipsilateral breast tissue encompassed by the 25% IDL. The use of 3DCRT for APBI delivers higher doses to normal breast tissue as the PTV increases around the lumpectomy cavity. Efforts should be made to minimize the overall PTV when this technique is used. Ongoing studies will be necessary to determine the clinical relevance of these findings.  相似文献   
950.
目的:探讨胃肠间质瘤(GIST)的CT表现及分子靶向药物甲磺酸伊马替尼(STI571)对胃肠间质瘤疗效的CT评价。方法:选择经手术及病理证实的胃肠间质瘤病例32例进行回顾性分析。对19例接受STI571治疗者进行定期CT检查随访,观察病灶大小、形态及密度变化,评价药物疗效。结果:32例GIST中,发生于胃部的18例,小肠11例,肠系膜1例,直肠2例。①CT特征:恶性度较高的胃肠间质瘤CT表现为:肿块相对较大,密度不均,肿瘤中央坏死及囊变多见;肿瘤边缘多不光整,可呈分叶状。增强扫描肿瘤呈不均匀强化;少数巨大肿瘤密度较低,极少数可见高密度出血及钙化灶。良性GIST体积较小,密度均匀,肿瘤坏死及囊变少见,病灶边缘光整,增强扫描多呈均匀强化;②19例接受STI571治疗者定期CT检查疗效评价为(肿瘤缩小):疗效达PR(部分缓解)者9例,占47.4%,疗效为SD(疾病稳定)者8例,占42.1%,病灶进展(PD)者2例,占10.5%。术后2年内复发及转移者19例。结论:①螺旋CT扫描是诊断胃肠间质瘤最常用和最有价值的影像检查手段,其定位诊断率达81%以上;②应用CT扫描观察测量病灶变化是评价药物(STI571)治疗胃肠间质瘤疗效最重要和最直接的方法之一;对指导临床治疗具有重要意义。  相似文献   
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