全文获取类型
收费全文 | 2546篇 |
免费 | 148篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 84篇 |
妇产科学 | 54篇 |
基础医学 | 246篇 |
口腔科学 | 71篇 |
临床医学 | 246篇 |
内科学 | 554篇 |
皮肤病学 | 32篇 |
神经病学 | 157篇 |
特种医学 | 106篇 |
外科学 | 540篇 |
综合类 | 40篇 |
预防医学 | 120篇 |
眼科学 | 70篇 |
药学 | 202篇 |
中国医学 | 25篇 |
肿瘤学 | 130篇 |
出版年
2023年 | 38篇 |
2022年 | 114篇 |
2021年 | 119篇 |
2020年 | 91篇 |
2019年 | 102篇 |
2018年 | 92篇 |
2017年 | 73篇 |
2016年 | 85篇 |
2015年 | 95篇 |
2014年 | 101篇 |
2013年 | 122篇 |
2012年 | 178篇 |
2011年 | 166篇 |
2010年 | 82篇 |
2009年 | 92篇 |
2008年 | 163篇 |
2007年 | 143篇 |
2006年 | 116篇 |
2005年 | 138篇 |
2004年 | 109篇 |
2003年 | 88篇 |
2002年 | 89篇 |
2001年 | 39篇 |
2000年 | 53篇 |
1999年 | 35篇 |
1998年 | 20篇 |
1997年 | 15篇 |
1996年 | 12篇 |
1995年 | 12篇 |
1994年 | 11篇 |
1993年 | 3篇 |
1992年 | 10篇 |
1991年 | 12篇 |
1990年 | 10篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1979年 | 7篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1971年 | 5篇 |
1969年 | 3篇 |
1967年 | 3篇 |
排序方式: 共有2700条查询结果,搜索用时 0 毫秒
91.
Asad Ur Rehman Khan Muhammad Ramzan Muhammad Faisal Iqbal Muhammad Hafeez Mohammed M. Fadhali Hamoud H. Somaily Muhammad Javid Muhammad Waqas Mukhtar Muhammad Farooq Saleem 《Materials》2022,15(22)
Zinc sulfide (ZnS) thin films with variable structural, optical, electrical, and thermoelectric properties were obtained by changing the source-to-substrate (SSD) distance in the physical-vapor-thermal-coating (PVTC) system. The films crystallized into a zinc-blende cubic structure with (111) preferred orientation. The films had a wide 3.54 eV optical band gap. High-quality homogenous thin films were obtained at 60 mm SSD. The sheet resistance and resistivity of the films decreased from 1011 to 1010 Ω/Sq. and from 106 to 105 Ω-cm, when SSD was increased from 20 mm to 60 mm, respectively. The phase and band gap were also verified by first principles that were in agreement with the experimental results. Thermoelectric characteristics were studied by using the semi-classical Boltzmann transport theory. The high quality, wide band gap, and reduced electrical resistance make ZnS a suitable candidate for the window layer in solar cells. 相似文献
92.
93.
94.
95.
Sehrish Bilal Muhammad Nasir M. Mudassir Hassan Muhammad Fayyaz ur Rehman Amtul Jamil Sami Akhtar Hayat 《RSC advances》2022,12(26):16860
Herein, an electrochemical biosensor has been prepared to assess the sensitivity of an organophosphate insecticide, malathion, to acetylcholinesterase (AChE) enzyme of three insects including Apis mellifera (honeybee), Tribolium castaneum (red flour beetle), and Zootermopsis nevadensis (dampwood termite). A composite of nickel chromite (NiCr2O4) and graphitic carbon nitride (g-C3N4) was prepared and characterized for its morphological, chemical and electrical properties. The NiCr2O4/g-C3N4 composite integrated pencil graphite electrodes were used to covalently immobilize insect AChE enzymes and amperometric response of bioelectrodes was determined through cyclic voltammetry. The prepared bioelectrodes exhibited high enzyme immobilization efficiency and electro-catalytic performance. The integrated bioelectrodes could efficiently detect malathion induced inhibition of insects'' AChEs. The linear ranges for malathion were found to be 0.1–1.6 μM, 1–40 nM and 2–100 nM, and LODs were 2 nM, 0.86 nM and 2.3 nM for A. mellifera, T. castaneum, and Z. nevadensis, respectively. Additionally, the biosensing platform developed using A. mellifera AChE was found highly sensitive and effective for malathion recoveries from spiked wheat flour samples with high recovery rates. Moreover, the proposed method was adequately reproducible and selective. The results revealed that A. mellifera AChE is less sensitive to inhibition by malathion as compared to T. castaneum, and Z. nevadensis AChE. The experimental results were validated through computational docking of malathion with insect AChEs and the results were in correspondence to experimental outcomes. The proposed method can be a plausible alternate to conventional analytical methods to assess the pesticide sensitivity and toxicity of various compounds against insect enzymes.An innovative electrochemical assay has been established to determine pesticide sensitivity against acetylcholinesterase and possible toxicity against insects. The analytical efficiency of three common insect AChEs was determined through this method. 相似文献
96.
Saeed Khan Nadeem N Jaffer Mohammad Nasherwan Khan Mohammad A Rai Majid Shafiq Adnan Ali Shahid Pervez Nusrat Khan Aliya Aziz Syed H Ali 《International journal of infectious diseases》2007,11(4):313-317
INTRODUCTION: Human papillomavirus (HPV) is recognized as a major causative agent for cervical carcinomas. Based on their oncogenic potential, HPV subtypes have been divided into high- and low-risk. In Pakistan, screening for HPV in female patients is not commonly practiced, and as a consequence, the degree of HPV prevalence and its correlation with cervical cancer is unknown. OBJECTIVE: In this study, we have attempted to estimate the prevalence of HPV infection, and also the HPV subtype profile, among Pakistani women with cervical cancer from varied geographical, racial, and social backgrounds within Pakistan. METHODOLOGY: Women visiting two tertiary care hospitals in Karachi, diagnosed with carcinoma of the cervix within the past 15 years, were analyzed for HPV subtypes in their cancer specimens. Retrospectively, 60 paraffin-embedded cervical cancer biopsies were examined for the presence of HPV DNA. After DNA extraction from these samples, polymerase chain reaction (PCR) was used to amplify the HPV L1 gene using the consensus (general) primers, and primers specific for subtypes 16 and 18. RESULTS: Of the 60 samples analyzed, only one sample was HPV negative; the rest of the samples were positive for the presence of HPV. Of the 59 HPV positive samples, 56 showed the presence of HPV16 and one sample was positive for HPV18; HPV subtype could not be determined in two samples. CONCLUSION: Our results show a strong relationship between HPV infection and cervical cancer among Pakistani women. These results underscore the need to implement regular HPV screening for Pakistani women. An early diagnosis of HPV infection will allow better health management to reduce the risk of developing cervical cancer. 相似文献
97.
Muafia Shafique Iqbal Ahmad Alvi Zaigham Abbas Shafiq ur Rehman 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2017,125(6):579-584
Pseudomonas aeruginosa is an efficient biofilm‐dwelling microbial pathogen, associated with nosocomial infections. These biofilm‐associated infections are resistant to antibiotics and immune defenses, therefore pose major problem against their treatment. This scenario demands alternative therapeutic regimens, and bacteriophage therapy is one among potential strategies for clinical management of multiple drug resistance. In this investigation, the efficacy of a bacteriophage, JHP, is evaluated to eradicate P. aeruginosa biofilms. Growth kinetics of P. aeruginosa biofilm revealed that the highest cell density biofilm (1.5 × 1016 CFU/mL) was established within the polystyrene microtiter plate at 72 h post inoculation. Pseudomonas aeruginosa biofilms of different ages, treated with JHP (0.6 MOI) for different post‐infection durations, reduced biomass from 2 to 4.5 logs (60–90%). JHP treatment before biofilm development reduced the bacterial load up to 9 logs (>95% bacterial load reduction) as compared with untreated control, which highlights its potential to prevent biofilm formation in indwelling medical devices. Combinations of JHP with other phages or antibiotics could be an efficient alternative for P. aeruginosa biofilm removal in clinical and industrial settings. 相似文献
98.
Shahid Yar Khan Saima Riazuddin Mohsin Shahzad Nazir Ahmed Ahmad Usman Zafar Atteeq Ur Rehman Robert J Morell Andrew J Griffith Zubair M Ahmed Sheikh Riazuddin Thomas B Friedman 《European journal of human genetics : EJHG》2010,18(1):125-129
Genetic analysis of an inbred Pakistani family PKDF280, segregating prelingual severe to profound sensorineural hearing loss, provided evidence for a DFNB locus on human chromosome 9q34.3. Co-segregation of the deafness trait with marker D9SH159 was determined by a two-point linkage analysis (LOD score 9.43 at θ=0). Two additional large families, PKDF517 and PKDF741, co-segregate recessive deafness with markers linked to the same interval. Haplotype analyses of these three families refined the interval to 3.84 Mb defined by D9S1818 (centromeric) and D9SH6 (telomeric). This interval overlaps with the previously reported DFNB33 locus whose chromosomal map position has been recently revised and assigned to a new position on chromosome 10p11.23–q21.1. The nonsyndromic deafness locus on chromosome 9q segregating in family PKDF280 was designated DFNB79. We are currently screening the 113 candidate DFNB79 genes for mutations and have excluded CACNA1B, EDF1, PTGDS, EHMT1, QSOX2, NOTCH1, MIR126 and MIR602. 相似文献
99.
Rehman HU 《Yonsei medical journal》2003,44(6):947-954
Sjogren's syndrome (SS) describes xeropthalmia and xerostomia due to lymphocytic infiltrates of lacrimal and salivary glands. SS may occur alone (primary SS) or in association with several other autoimmune diseases (secondary SS). The clinical features involve a wide variety of organs, including skin, eyes, oral cavity and salivary glands, and systems, including nervous, musculoskeletal, genitourinary and vascular. Sicca symptoms can be found in a number of other disorders including rheumatoid arthritis, systemic lupus erythematosus, scleroderma, primary biliary cirrhosis, and other rheumatic disorders. 相似文献
100.
Abid Qureshi Vaqar Gani Tantray Altaf Rehman Kirmani Abdul Ghani Ahangar 《Reviews in medical virology》2018,28(4)
Viral diseases like influenza, AIDS, hepatitis, and Ebola cause severe epidemics worldwide. Along with their resistant strains, new pathogenic viruses continue to be discovered so creating an ongoing need for new antiviral treatments. RNA interference is a cellular gene‐silencing phenomenon in which sequence‐specific degradation of target mRNA is achieved by means of complementary short interfering RNA (siRNA) molecules. Short interfering RNA technology affords a potential tractable strategy to combat viral pathogenesis because siRNAs are specific, easy to design, and can be directed against multiple strains of a virus by targeting their conserved gene regions. In this review, we briefly summarize the current status of siRNA therapy for representative examples from different virus families. In addition, other aspects like their design, delivery, medical significance, bioinformatics resources, and limitations are also discussed. 相似文献