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991.
绢毛蔷薇果实的化学成分   总被引:16,自引:0,他引:16  
目的:研究绢毛蔷薇果实的化学成分。方法:将醇提取物用H2O溶解,EtOAc萃取,经柱色谱分离纯化,通过波谱分析并结合化学转化鉴定化合物。结果:从该植物果实中分离、鉴定了6个化合物:euscaphic acid 3,4-monoacetonide (1), euscaphic acid (2), 4-O-β-D-吡喃葡糖基没食子酸甲酯(3),槲皮素(4),齐墩果酸(5),豆甾醇(6)。结论:1是新化合物,3为首次从植物中分离得到。  相似文献   
992.
目的探讨平调饮对原发性肝癌患者AFP mRNA、GPC-3 mRNA表达的影响。方法抽取60例肝癌患者的抗凝血液,配对法随机分为试验组和对照组各30例。采用Tr-Izol一步法提取总RNA,用逆转录巢式聚合酶链反应(RT-nested PCR)技术检测治疗前后试验组及对照组患者AFP mRNA、GPC-3 mRNA的表达情况。结果治疗后试验组及对照组AFP mRNA、GPC-3 mRNA表达均显著下降,在降低AFP mRNA表达方面试验组与对照组无显著性差异,降低GPC-3 mRNA表达方面试验组明显优于对照组(P0.05)。结论平调饮能有效抑制人血液中AFP mRNA、GPC-3 mRNA的高表达,在降低GPC-3 mRNA表达方面效果优于华蟾素。其治疗原发性肝癌机制与临床应用价值值得进一步研究。  相似文献   
993.
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995.
Amide is a fundamental group that is present in molecular structures of all domains of organic chemistry and the construction of this motif with high atom economy is the focus of the current research. Specifically, N-methyl amides are valuable building blocks in natural products and pharmaceutical science. Due to the volatile nature of methyl amine, the generation of N-methyl amides using simple acids with high atom economy is rare. Herein, we disclose an atom economic protocol to prepare this valuable motif under DABCO/Fe3O4 cooperative catalysis. This protocol is operationally simple and compatible with a range of aliphatic and (hetero)aromatic acids with very good yields (60–99%). Moreover, the Fe3O4 can be easily recovered and high efficiency is maintained for up to ten cycles.

The generation of N-methyl amides using simple acids with high atom economy is rare owning to the volatile nature of methyl amine. Herein, an atom economic protocol was disclosed to prepare this valuable motif under DABCO/Fe3O4 cooperative catalysis.

Amide is a fundamental group that is present in molecular structures of all domains of organic chemistry.1 It is widely distributed in natural products, synthetic drugs and functional polymers, and is also the key chemical connection in proteins.2 It has been shown that amide bond formation alone accounts for 65% of all preliminary screening reactions in the pharmaceutical industry.3 This means the generation of amide bonds with high atom efficiency is of high practical importance. And not surprisingly, ‘amide formation avoiding poor atom economy reagents’ was voted as the top challenge for organic chemistry by the ACS Green Chemistry Institute in 2007.3From synthetic point of view, the ideal way to produce amide bonds would be the direct coupling of readily available carboxylic acids and amines, but this process is thermodynamically unfavourable due to the formation of the corresponding carboxylate-ammonium salt,4 therefore, stoichiometric amount of coupling reagents, such as DCC, DIC, EDCI, HATU, HBTU, HCTU, SOCl2, BOP, acid chloride etc, are generally required to sidestep thermal conditions for amide bond formation.5 These reagents are highly successful, but the process generally suffers from poor atom economy and side products removal issue especially in the large-scale applications.5 To overcome these drawbacks, “nonclassical” amide bonds formation routes were investigated.6 In these processes, the catalyst takes the role of a coupling reagent in generating an active ester suitable for amidation in a waste-free manner. However, these processes have not been applied in the preparation of N-methyl amides, probably because the methyl amine was delivered in its hydrochloride salt, alcoholic or aqueous form due to its volatile nature.On a different note, N-methyl amides are extensively presented in numerous natural products and pharmaceutical molecules, as shown in Fig. 1,7 and the methylation of amides is a promising way to improve the pharmacological property of molecules.8 However, the synthesis of N-methyl amides compounds relies heavily on non-catalytic approaches.5,9 Catalytic approaches were also investigated by Hisaeda,10 Kundu,11 Li,12 Guo,13 Yu,14 Maruoka,15 Wang,16 Chen,17 Lamaty18 and their co-workers starting from nitriles, primiary amides, aldoximes, aldehydes, lignin, carbamoylsilane and alcohols. Until recently, Thakur,19 Marce,20 Sadeghzadeh21 and their co-workers developed elegant N-methyl amidation approach starting from carboxylic acids under nano-MgO, diatomite Earth@IL/ZrCl4 and Mg(NO3)2·6H2O catalysis respectively, while limitations like poor substrate scope or sophisticated tailored catalyst still persist. Mindful of all the above issues, developing an N-methyl amidation process of simple carboxylic acids, which is still of great challenge in synthesis, and establishing a broad (hetero)aryl scope with high atom economy from commercial available reagents and catalysts were critical considerations in this study. Moreover, the significance of N-methyl amides combined with our interests in the development of green synthetic approaches motivated us to explore the direct coupling of the carboxylic acids and isothiocyanates. To the best of our knowledge, this is the first successful work using isothiocyanatomethane to prepare N-methyl amides.Open in a separate windowFig. 1Marketed drugs bearing N-methyl amide group.Our initial investigation begins with phenylacetic acid and isothiocyanatomethane as model substrate for condition optimization. Using acetonitrile as solvent, only trace amount of product was detected under catalyst free or p-toluenesulfonic acid (PTSA) catalysis conditions (
EntryAdditiveTime (h)CatalystYield (%)
1245
224PTSA
348TEA17
448DBU45
548DMAP43
648DBN51
748DABCO65
8LiBr48DABCO71
9Mn(OAc)248DABCO75
10MnO48DABCO79
11MgO48DABCO88
12Al2O348DABCO85
13Fe3O448DABCO98
14Fe3O424DABCO75
15bFe3O448DABCO80
Open in a separate windowaReactions were run on 1 mmol 1a and 1.1 mmol 2a with 10 mol% catalyst and 10 mol% additive in 1 mL of MeCN at 85 °C for 48 hours unless otherwise noted.bReaction was conducted at 60 °C.Firstly, different acids were employed to react with isothiocyanatomethane and the results were summarized in Open in a separate windowaReactions were run on 1 mmol 1 and 1.1 mmol 2 with 10 mol% DABCO and 10 mol% Fe3O4 in 1 mL of MeCN for 48 hours at 85 °C unless otherwise noted.Subsequently, aromatic and heteroaromatic acids were tested for their compatibility with current reaction conditions and the results were summarized in Fig. 1) respectively, and all could be convenient prepared using current procedure with excellent yields.Substrate scope for the amidation reactiona
Open in a separate windowaReactions were run on 1 mmol 1 and 1.1 mmol 2 with 10 mol% DABCO and 10 mol% Fe3O4 in 1 mL of MeCN for 48 hours at 85 °C unless otherwise noted.Furthermore, to demonstrate the synthetic utilization of our methodology, the preparation of bioactive compounds was demonstrated Scheme 1. Compounds 3as is a patent HDAC4 inhibitor.22 Under the standard reaction conditions, 3as could be obtained from commercial available 1as in 92% yield. Our procedure is much more atom economy as it excluded the usage of activating reagent and excess amount of base. In a recent report, Yang group reported their pilot-scale synthesis of substituted phenylacetamides to tetrahydroisoquinoline-2-ones.23 In their practice, corrosive thionyl chloride was applied as activating reagent and large excess amount of methyl amine was required, however, moderate yield of 3a was obtained, while our method can achieve better yield along with the exclusion of corrosive thionyl chloride. Following this report, tetrahydroisoquinoline-2-one 4a could be obtained in 82% yield, which could be used in the preparation of various bioactive 4-aryl-tetrahydroisoquinolines 5a with known procedure.24Open in a separate windowScheme 1Application of N-methyl amide.Finally, owing to the magnetic nature of Fe3O4, we try to recover the Fe3O4 from the reaction system and test its efficiency. As the Fe3O4 is always stick to the magnetic stir bar, after the termination of the reaction, the reaction solution was pour out and the tub along with the magnetic stir bar was rinsed with MeCN three times, oven dried and used for the next cycle. The results shown that the Fe3O4 could be used 10 times and still maintained very good efficiency (Fig. 2).Open in a separate windowFig. 2The efficiency of recovered Fe3O4.Combined with the literature reports and experimantal observation,25 a plausable mechanism was proposed in Scheme 2. Firstly, the carboxylic acid reacts with the Fe3O4 to get iron (II and III) carboxylate A, which will coordinate to the intermediate B generated from DABCO and isothiocyanate to get intermediate C. Then, one of the carboxylate attack intermediate B to release DABCO and generates intermediate D. Intermediate D go through an intramolecular addition to generate intermediate E, which go through a rearrangement reaction to get intermediate F with the release of carbonyl sulfide. Finally, the protonation of F with carboxylic acid to get the final product and regenerate the iron (II and III) carboxylate A.Open in a separate windowScheme 2Proposed reaction mechanism.  相似文献   
996.
Qiangli Wuhu mixture alleviates LPS-induced pneumonia by inhibiting the TLR4/NF-κB/NLRP3 pathway: a study based on network pharmacology     
Jie Tian  Xiao-Long Wang  Long-Cheng Wang  Fei Chen  Yun Tian  Li Ma  Chao-Yun Pan  Yan-Ping Wang 《Pharmaceutical biology》2022,60(1):1331
ContextQiangli Wuhu (QLWH) mixture is a concoction approved and registered by Ningxia Medical Products Administration. It has therapeutic effects on various types of pneumonia.ObjectiveTo clarify the mechanisms of QLWH in treating pneumonia.Materials and methodsThe potential targets of QLWH in the treatment of pneumonia were predicted by network pharmacology. Male, Institute of Cancer Research (ICR) mice were randomly divided into five groups of 12 mice, control, vehicle, QLWH (10 and 20 mg/kg) and dexamethasone (DXM), and orally treated twice daily with normal saline, QLWH or DXM. The pneumonia model was established by tracheal instillation of lipopolysaccharide (LPS). After treatment five days, ELISA, H&E staining and Western blot were used to investigate protective effects of QLWH.ResultsNine hundred and ninety-four active ingredients were found through network pharmacology, corresponding to 135 targets for the treatment of pneumonia; compared to the vehicle group, QLWH (10 and 20 mg/kg) significantly decreased the levels of TNF-α (14.3% and 28.8%), IL-1β (23.9% and 42.8%) and IL-6 (13.2% and 16.1%), increased the levels of IL-10 (134.3% and 172.9%); in terms of mechanism, QLWH down-regulated TLR4/NF-κB/NLRP3 axis related proteins in lung tissue of pneumonia model mice (p < 0.05).Discussion and conclusionsThis study combined network pharmacology and animal experiments, providing effective evidence for the clinical promotion of QLWH. Meanwhile, it is of significance for further development.  相似文献   
997.
The changing epidemiology of opioid overdose in Baltimore,Maryland, 2012–2017: insights from emergency medical services     
Chen Dun  Sean T. Allen  Carl Latkin  Amy Knowlton  Brian W. Weir 《Annals of medicine》2022,54(1):1738
IntroductionAn estimated 100,306 people died from an overdose from May 2020 to April 2021. Emergency Medical Services (EMS) are often the first responder to opioid overdose, and EMS encounter records can provide granular epidemiologic data on opioid overdose. This study describes the demographic, temporal, and geographic epidemiology of suspected opioid overdose in Baltimore City using data from Baltimore City Fire Department EMS encounters with the administration of the opioid antagonist naloxone.MethodThe present analyses used patient encounter data from 2012 to 2017 from the Baltimore City Fire Department, the city’s primary provider of EMS services. The analytic sample included patient encounters within the city that involved naloxone administration to patients 15 years of age or older (n = 20,592). Negative binomial regression was used to calculate the incidence rates based on demographic characteristics, year, and census tract. Choropleth maps were used to show the geographic distribution of overdose incidence across census tracts in 2013, 2015, and 2017.ResultsFrom 2012 to 2017, the annual number of EMS encounters with naloxone administrations approximately doubled every 2 years, and the temporal pattern of naloxone administration was similar to the pattern of fatal opioid-related overdoses. For most census tracts, incidence rates significantly increased over time. Population-based incidence of naloxone administration varied significantly by socio-demographic characteristics. Males, non-whites, and those 25–69 years of age had the highest incidence rates.ConclusionThe incidence of naloxone administration increased dramatically over the study period. Despite significant cross-sectional variation in incidence across demographically and geographically defined groups, there were significant proportional increases in incidence rates, consistent with fatal overdose rates over the period. This study demonstrated the value of EMS data for understanding the local epidemiology of opioid-related overdose.

Key Messages

  • Patterns of EMS encounters with naloxone administration appear to be an excellent proxy for patterns of opioid-related overdoses based on the consistency of fatal overdose rates over time.
  • EMS plays a central role in preventing fatal opioid-related overdoses through the administration of naloxone, provision of other emergency services, and transportation to medical facilities.
  • EMS encounters with naloxone administration could also be used to evaluate the impact of overdose prevention interventions and public health services.
  相似文献   
998.
Qishen Yiqi dropping pills improve isoproterenol-induced cardiomyocyte hypertrophy by regulating X-inactive specific transcript (XIST) expression in rats     
Ying Luo  Jiaxian Chen  Yuewu Chen  Yangshen Su  Xiaoyan Wu  Wanling Zheng  Xianxia Liu  Lei Chen 《Journal of thoracic disease》2022,14(6):2213
  相似文献   
999.
Prevalence and risk factors for postinfectious cough in discharged patients with coronavirus disease 2019 (COVID-19)     
Yuehan Chen  Xu Zhang  Xiansheng Zeng  Tingting Xu  Wei Xiao  Xuejiao Yang  Wenzhi Zhan  Chen Zhan  Kefang Lai 《Journal of thoracic disease》2022,14(6):2079
BackgroundCough is one of the most common symptoms of coronavirus disease 2019 (COVID-19). However, the prevalence of persistent cough in recovered patients with COVID-19 during a longer follow-up remained unknown. This study aims to investigate the prevalence, and risk factors for postinfectious cough in COVID-19 patients after discharge.MethodsWe conducted a follow-up study for 129 discharged patients with laboratory-confirmed COVID-19 in two large hospitals located in Hubei Province, China from January 2020 to December 2020. Baseline demographics, comorbidities and smoking history were extracted from the medical record. Current symptoms and severity were recorded by a uniform questionnaire. Spirometry, diffuse function and chest computed tomography (CT) were performed on part of patients who were able to return to the outpatient department at follow-up.ResultsThe median (interquartile range) follow-up time was 8.1 (7.9–8.5) months after discharge. The mean (standard deviation) age was 51.5 (14.9) years and 57 (44.2%) were male. A total of 27 (20.9%) patients had postinfectious cough (>3 weeks), 6 patients (4.7%) had persistent cough by the end of follow-up, including 3 patients with previous chronic respiratory diseases or current smoking. Other symptoms included dyspnea (6, 4.7%), sputum (4, 3.1%), fatigue (4, 3.1%), and anorexia (4, 3.1%) by the end of follow-up. Thirty-six of 41 (87.8%) patients showed impaired lung function or diffuse function, and 39 of 50 (78.0%) patients showed abnormal CT imaging. Patients with postinfectious cough demonstrated more severe and more frequent cough during hospitalization (P<0.001), and more chronic respiratory diseases (P=0.01). In multivariate logistic regression analysis, digestive symptoms during hospitalization [odds ratio (OR) 2.95, 95% confidence interval (CI): 1.10–7.92] and current smoking (OR 6.95, 95% CI: 1.46–33.14) were significantly associated with postinfectious cough of COVID-19.ConclusionsA small part of patients developed postinfectious cough after recovery from COVID-19, few patients developed chronic cough in spite of a higher proportion of impaired lung function and abnormal lung CT image. Current smoking and digestive symptoms during hospitalization were risk factors for postinfectious cough in COVID-19.  相似文献   
1000.
EGFR mutation types and abundance were associated with the overall survival of advanced lung adenocarcinoma patients receiving first-line tyrosine kinase inhibitors     
Yang Liu  Hongyan Wang  Sen Yang  Yuanyuan Yang  Yufeng Wu  Zhen He  Shuxiang Ma  Yuqing Mo  Haiyang Chen  Qiming Wang  Hong Ge 《Journal of thoracic disease》2022,14(6):2254
BackgroundEpidermal growth factor receptor tyrosine kinases inhibitors (EGFR-TKIs) are currently recognized as the standard treatment for advanced non-small cell lung cancer (NSCLC) patients with EGFR mutations. Clinically found patients with different EGFR mutational status have different prognosis.MethodsA retrospective cohort study was performed to explore the relationship between EGFR mutations and abundance with patient survival by using patient data from the Affiliated Cancer Hospital of Zhengzhou University between January 2013 and November 2016. All patients involved in the present study had sensitive EGFR mutations [either exon 19 deletion (DEL) or exon 21 L858R] and treated by EGFR-TKIs. They were followed up every three months until lost or dead. Mutation abundance was calculated as the copies of EGFR mutation divided by copies of EGFR locus, and the cut-off values for 19DEL and L858R were 4.9% and 9.5%, respectively.ResultsTotal of 236 patients were included, comprising 116 (49.2%) patients with 19DEL mutation and 120 (50.8%) patients with L858R mutation. The median follow-up duration was 23.2 months (95% CI: 14.9–26.7 months). Overall survival (OS) was significantly longer in patients with 19DEL mutation (20.9 months, 95% CI: 17.7–24.1 months versus 17.0 months, 95% CI: 14.4–19.6 months in patients with L858R; P=0.008) and in patients with high mutation abundance (20.9 months, 95% CI: 18.3–23.5 months versus 13.0 months, 95% CI: 10.3–15.7 months in patients with low mutation abundance; P<0.001). Multivariate Cox regression including age, performance status and tumor stage revealed that longer OS was independently associated with 19DEL mutation (HR: 0.48, 95% CI: 0.39–0.67, P=0.033) and high mutation abundance (HR: 0.62, 95% CI: 0.50–0.79, P=0.027).ConclusionsEGFR mutation types and abundance was associated with the patients’ survival which might be used to predict the efficacy of targeted therapy by EGFR-TKIs.  相似文献   
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