全文获取类型
收费全文 | 13107篇 |
免费 | 968篇 |
国内免费 | 119篇 |
专业分类
耳鼻咽喉 | 94篇 |
儿科学 | 443篇 |
妇产科学 | 404篇 |
基础医学 | 1778篇 |
口腔科学 | 271篇 |
临床医学 | 1133篇 |
内科学 | 2531篇 |
皮肤病学 | 211篇 |
神经病学 | 919篇 |
特种医学 | 460篇 |
外科学 | 2274篇 |
综合类 | 607篇 |
一般理论 | 4篇 |
预防医学 | 720篇 |
眼科学 | 342篇 |
药学 | 740篇 |
1篇 | |
中国医学 | 78篇 |
肿瘤学 | 1184篇 |
出版年
2023年 | 125篇 |
2022年 | 156篇 |
2021年 | 340篇 |
2020年 | 235篇 |
2019年 | 306篇 |
2018年 | 334篇 |
2017年 | 263篇 |
2016年 | 289篇 |
2015年 | 348篇 |
2014年 | 443篇 |
2013年 | 541篇 |
2012年 | 858篇 |
2011年 | 915篇 |
2010年 | 547篇 |
2009年 | 472篇 |
2008年 | 721篇 |
2007年 | 683篇 |
2006年 | 710篇 |
2005年 | 701篇 |
2004年 | 670篇 |
2003年 | 593篇 |
2002年 | 553篇 |
2001年 | 518篇 |
2000年 | 411篇 |
1999年 | 351篇 |
1998年 | 114篇 |
1997年 | 111篇 |
1996年 | 91篇 |
1995年 | 85篇 |
1994年 | 65篇 |
1993年 | 53篇 |
1992年 | 162篇 |
1991年 | 149篇 |
1990年 | 161篇 |
1989年 | 158篇 |
1988年 | 132篇 |
1987年 | 139篇 |
1986年 | 108篇 |
1985年 | 86篇 |
1984年 | 53篇 |
1983年 | 44篇 |
1981年 | 34篇 |
1980年 | 29篇 |
1979年 | 52篇 |
1978年 | 37篇 |
1977年 | 32篇 |
1976年 | 26篇 |
1975年 | 25篇 |
1974年 | 21篇 |
1973年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
151.
H W Ng 《Bulletin on narcotics》1985,37(2-3):91-97
A wide range of drug demand reduction programmes are being carried out in Hong Kong. These include community involvement projects; preventive drug education and publicity through the use of mass media in the form of television and radio announcements and posters; and the production of educational and publicity materials. Most of these programmes are intended to reach young people. The local district campaigns are held every year to arouse awareness of the dangers of drug abuse and to encourage public support in combating such abuse. A selected volunteer group encourages young people to participate in the planning, organization and implementation of drug-abuse prevention projects. A programme called "Youth against drugs scheme", which was launched in 1981, is open to all youth groups, providing an opportunity for young people to plan and implement anti-narcotics publicity projects in their own way with limited supervision. These programmes have proved successful in involving the young in the fight against drug abuse and associated problems. 相似文献
152.
Identification and order of sequential mutations in beta-actin genes isolated from increasingly tumorigenic human fibroblast strains. 总被引:11,自引:1,他引:10 下载免费PDF全文
C S Lin S Y Ng P Gunning L Kedes J Leavitt 《Proceedings of the National Academy of Sciences of the United States of America》1985,82(20):6995-6999
We have sequenced the mutant beta-actin gene of a tumorigenic human fibroblast cell line (HuT-14T) and found that it carries three mutations that alter the amino acids at positions 36, 83, and 244 as well as a 22-base-pair "insertion" sequence, in the 5' intron, not present in a wild-type gene. The less tumorigenic cell line HuT-14, a progenitor of HuT-14T, has the same codon-244 mutation and the insertion sequence but not the other two mutations. A nontumorigenic cell line that is related to HuT-14 but that has no beta-actin mutations does carry the intron-length polymorphism. We conclude that the mutation at codon 244 occurred first in a beta-actin allele already bearing the 22-base-pair intron insert and that mutations at codons 36 and 83 arose subsequently during the selection for the HuT-14T phenotype. Rat-2 cells synthesize the appropriate charge-variant species of mutant actin protein when transfected with either the singly or the triply mutated beta-actin gene. 相似文献
153.
K T Goh S K Ng S Kumarapathy 《The Southeast Asian journal of tropical medicine and public health》1985,16(1):49-53
Fifty-seven (17.3%) of 330 incoming aircraft landing at Changi International Airport were found to harbour mosquitoes and other insects on board. The frequency of insects detected in aircraft from the Southeast Asian countries varied from 7.1% to 32.2%. Live insects were found in 5 (6.1%) of 82 aircraft disinsectized by the "block away" method. The species of mosquitoes brought in were: Culex quinquefasciatus (96), Culex tritaeniorhynchus (1), Aedes albopictus (2) and Aedes aegypti (1). None of the 51 female Culex quinquefasciatus dissected was found to be infected with microfilariae. They key to the prevention of introduction of exotic vectors and transmission of vector- borne diseases is to continue with the existing system of vector surveillance and control at the international airport, rather than routine disinsecting of aircraft landing in Singapore. 相似文献
154.
Ng Stella L. Crukley Jeff Brydges Ryan Boyd Victoria Gavarkovs Adam Kangasjarvi Emilia Wright Sarah Kulasegaram Kulamakan Friesen Farah Woods Nicole N. 《Advances in health sciences education : theory and practice》2022,27(2):323-354
Advances in Health Sciences Education - Critical reflection supports enactment of the social roles of care, like collaboration and advocacy. We require evidence that links critical teaching... 相似文献
155.
Grad Roland Leger Daniel Kaczorowski Janusz Schuster Tibor Adler Samara Aman Marya Archibald Douglas Beaulieu Marie-Claude Chmelicek John Cornelissen Evelyn Delleman Bethany Hadj-Mimoune Sonia Horvey Samantha Macaluso Steven Mintsioulis Stephen Murdoch Stuart Ng Brian Papineau Alain Rangwala Sohil Rousseau Mathieu Rudkin Teresa Schabort Inge Schultz Karen Snow Pamela Wong Eric Wu Pearson Brailovsky Carlos 《Advances in health sciences education : theory and practice》2021,26(3):771-783
Advances in Health Sciences Education - Spaced education is a learning strategy to improve knowledge acquisition and retention. To date, no robust evidence exists to support the utility of spaced... 相似文献
156.
Benedict Wei Jun Pang Shiou-Liang Wee Lay Khoon Lau Khalid Abdul Jabbar Wei Ting Seah Daniella Hui Min Ng Queenie Lin Ling Tan Kenneth Kexun Chen Mallya Ullal Jagadish Tze Pin Ng 《Journal of the American Medical Directors Association》2021,22(4):885.e1-885.e10
ObjectivesTo describe the normative values of sarcopenia among community-dwelling adults (≥21 years of age); compare the prevalence of sarcopenia using Asian Working Group for Sarcopenia criteria, 2014 (AWGS2014), Asian Working Group for Sarcopenia criteria, 2019 (AWGS2019), and European Working Group on Sarcopenia in Older People criteria, 2018 (EWGSOP2) guidelines; and identify factors associated with sarcopenia.DesignParticipants were recruited through random sampling. Sarcopenia assessments were performed using a dual-energy x-ray absorptiometry scan (muscle mass), handgrip test (muscle strength), and usual walking test (physical performance). Questionnaires were administered to evaluate lifestyle and cognition.Setting and ParticipantsIn total, 542 community-dwelling Singaporeans were recruited (21?90 years old, 57.9% women).MethodsWe assessed anthropometry, body composition, and questionnaire-based physical and cognitive factors, and estimated sarcopenia prevalence according to the AWGS2014, AWGS2019, and EWGSOP2 recommendations, and examined associations using logistic regression.ResultsAccording to AWGS2019, the Singapore population-adjusted sarcopenia prevalence was 13.6% (men 13.0%; women 14.2%) overall, and 32.2% (men 33.7%, women 30.9%) in those aged 60 years and above. The cut-offs derived from young adult reference group for low appendicular lean mass index were 5.28 kg/m2 for men and 3.69 kg/m2 for women (lower than AWGS recommended cut-off); for gait speed it was 0.82 m/s, (AWGS2019 recommended cut-off 1.0 m/s, AWGS2014 cut-off was 0.8 m/s); and for handgrip strength it was 27.9 kg/m2 for men and 16.7 kg/m2 for women (close to AWGS2019 recommendation). Age, sex, marital status, alcoholism, physical activity, body mass index, waist circumference, and global cognition were associated with sarcopenia (P < .05).Conclusions and ImplicationsThis is the first study to provide reference values of muscle mass, strength, and gait speed across the adult lifespan of Singaporeans. Using AWGS2019 criteria, sarcopenia is prominent in older age (32.2% in ≥60 years old), but it is already nontrivial (6.9%) among young and middle-age persons. Multidomain lifestyle modifications addressing muscle strength, cognition, and nutrition over the adult lifespan are important to delay the development of sarcopenia. 相似文献
157.
Kenneth Siu-Sing Leung Timothy Ting-Leung Ng Alan Ka-Lun Wu Miranda Chong-Yee Yau Hiu-Yin Lao Ming-Pan Choi Kingsley King-Gee Tam Lam-Kwong Lee Barry Kin-Chung Wong Alex Yat Man Ho Kam-Tong Yip Kwok-Cheung Lung Raymond Wai-To Liu Eugene Yuk-Keung Tso Wai-Shing Leung Man-Chun Chan Yuk-Yung Ng Kit-Man Sin Kitty Sau-Chun Fung Sandy Ka-Yee Chau Wing-Kin To Tak-Lun Que David Ho-Keung Shum Shea Ping Yip Wing Cheong Yam Gilman Kit-Hang Siu 《Emerging infectious diseases》2021,27(1):196
Initial cases of coronavirus disease in Hong Kong were imported from mainland China. A dramatic increase in case numbers was seen in February 2020. Most case-patients had no recent travel history, suggesting the presence of transmission chains in the local community. We collected demographic, clinical, and epidemiologic data from 50 patients, who accounted for 53.8% of total reported case-patients as of February 28, 2020. We performed whole-genome sequencing to determine phylogenetic relationship and transmission dynamics of severe acute respiratory syndrome coronavirus 2 infections. By using phylogenetic analysis, we attributed the community outbreak to 2 lineages; 1 harbored a common mutation, Orf3a-G251V, and accounted for 88.0% of the cases in our study. The estimated time to the most recent common ancestor of local coronavirus disease outbreak was December 24, 2019, with an evolutionary rate of 3.04 × 10−3 substitutions/site/year. The reproduction number was 1.84, indicating ongoing community spread. 相似文献
158.
159.
160.
Marcus Wei Ping Tan Stacy Wei Ling Ng Jerry Yongqiang Chen Ming Han Lincoln Liow Ngai Nung Lo Seng Jin Yeo 《The Journal of arthroplasty》2021,36(4):1269-1276
BackgroundThe aim of this study is to compare the long-term functional outcome and quality of life between total knee arthroplasty (TKA) and fixed-bearing unicompartmental knee arthroplasty (UKA) for the treatment of isolated medial compartment osteoarthritis.MethodsBetween 2000 and 2008, a total of 218 patients underwent primary UKA at our tertiary hospital. A TKA group was matched through 1:1 propensity score matching and adjusted for age, gender, body mass index, preoperative knee flexion, and function scores. All patients had medial compartment osteoarthritis. The patients were assessed with the range of motion, Knee Society Knee Score and Knee Society Function Score, Oxford Knee Score, Short Form-36 physical component score (PCS) and mental component score preoperatively, at 6 months, 2 years, and 10 years. Patients’ satisfaction, expectation fulfillment, and minimal clinically important difference were analyzed.ResultsThere were no differences in baseline characteristics between groups after propensity score matching (P > .05). UKA had greater knee flexion at all time points. Although the Knee Society Function Score was superior in UKA by 5.5, 3, and 4.3 points at 6 months, 2 years, and 10 years, respectively (P < .001), these differences did not exceed the minimal clinically important difference (Knee Society Knee Score 6.1). There were no significant differences in the Oxford Knee Score and Short Form-36 physical component score/mental component score. At 10 years, similar proportions of UKA and TKA were satisfied (90.8% vs 89.9%, P = .44) and had expectation fulfillment (89.4% vs 88.5%, P = .46). Between 2 and 10 years, all function scores deteriorated significantly for both groups (P < .01).ConclusionUKA and TKA are excellent treatment modalities for isolated medial compartment osteoarthritis, with similar functional outcomes, quality of life, and satisfaction at 10 years. 相似文献