全文获取类型
收费全文 | 5764篇 |
免费 | 337篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 121篇 |
儿科学 | 73篇 |
妇产科学 | 114篇 |
基础医学 | 1079篇 |
口腔科学 | 100篇 |
临床医学 | 420篇 |
内科学 | 960篇 |
皮肤病学 | 218篇 |
神经病学 | 441篇 |
特种医学 | 417篇 |
外科学 | 765篇 |
综合类 | 17篇 |
一般理论 | 3篇 |
预防医学 | 221篇 |
眼科学 | 111篇 |
药学 | 440篇 |
中国医学 | 46篇 |
肿瘤学 | 590篇 |
出版年
2023年 | 26篇 |
2022年 | 95篇 |
2021年 | 167篇 |
2020年 | 82篇 |
2019年 | 121篇 |
2018年 | 150篇 |
2017年 | 127篇 |
2016年 | 153篇 |
2015年 | 222篇 |
2014年 | 255篇 |
2013年 | 343篇 |
2012年 | 500篇 |
2011年 | 488篇 |
2010年 | 267篇 |
2009年 | 248篇 |
2008年 | 349篇 |
2007年 | 335篇 |
2006年 | 293篇 |
2005年 | 275篇 |
2004年 | 233篇 |
2003年 | 261篇 |
2002年 | 201篇 |
2001年 | 197篇 |
2000年 | 187篇 |
1999年 | 126篇 |
1998年 | 50篇 |
1997年 | 37篇 |
1996年 | 23篇 |
1995年 | 16篇 |
1994年 | 15篇 |
1993年 | 12篇 |
1992年 | 42篇 |
1991年 | 39篇 |
1990年 | 34篇 |
1989年 | 22篇 |
1988年 | 27篇 |
1987年 | 24篇 |
1986年 | 12篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 10篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1974年 | 9篇 |
1973年 | 4篇 |
1970年 | 5篇 |
1969年 | 3篇 |
排序方式: 共有6136条查询结果,搜索用时 62 毫秒
11.
H D Lee C O Suh W H Jung K K Oh H B Park H S Chi B R Kim J S Min 《Yonsei medical journal》1992,33(3):272-276
This is the first preliminary report among two consecutive papers. Partial mastectomy(PM), axillary lymph node dissection(AD) and radiotherapy (RT) were performed on seventeen operable breast cancer patients who had been admitted from April 1991 to March 1992 to the department of surgery, Yongdong Severance Hospital for improved cosmetic appearance and better survival rate. Of seventeen patients, 47% were T1 lesion and 76% were stage I and II. Extensive intraductal component(EIC) within or around the tumor was also analyzed. Twenty nine per cent of the patients were EIC positive. The mean number of axillary lymph nodes was 21.5 after PM with AD and 20.5 after mastectomy. For radiotherapy, 4,500 rad was delivered to the breast parenchyma and 1,600 rad of boost to the primary tumor site using the electron beam method after surgery. All patients have since been living well without any local recurrence and were satisfied with breast preservation for the one-year follow-up period. We concluded that the PM, AD and RT can be another surgical treatment modality of breast cancer. A longer follow-up data will be followed on the second paper. 相似文献
12.
A comparison of 17 narrowly defined borderline patients with 20 nonpatient control subjects indicated that certain individual and combinations of criteria may be more highly correlated with the disorder than others. Requiring any four or certain specific combinations of two or three of the five most discriminating criteria provided the optimal balance of sensitivity, specificity, predictive power, and diagnostic efficiency considerations. Fewer than five DSM-III-R criteria adequately identified the patients. 相似文献
13.
14.
15.
Guk-Hee Suh Hyun Gyun Son Young-Su Ju Kyeong Hyeong Jcho Byeong Kil Yeon Young Min Shin Baik Seok Kee Sung-Ku Choi 《The American journal of geriatric psychiatry》2004,12(5):509-516
OBJECTIVE: Behavioral disturbances in dementia are extremely prominent and distressful, and often result in serious physical, social, and economic consequences. The authors compared the efficacy and tolerability of risperidone and haloperidol in the treatment of behavioral and psychological symptoms of dementia (BPSD) in institutionalized elderly Korean patients with Alzheimer disease, vascular dementia, or mixed dementia. METHODS: This was an 18-week double-blind, crossover study involving 120 patients who were randomly assigned to receive flexible doses (0.5-1.5 mg/day) of risperidone or haloperidol. BPSD were assessed using the Korean version of the Behavioral Pathology in Alzheimer's Disease Rating Scale (BEHAVE-AD-K), the Korean version of the Cohen-Mansfield Agitation Inventory (CMAI-K), and the Clinical Global Impression of Change scale (CGI-C). Safety and tolerability assessments included the Extrapyramidal Symptom Rating Scale and the incidence of adverse events. RESULTS: Both risperidone and haloperidol were efficacious in alleviating BPSD. However, when receiving risperidone, patients showed significantly greater improvement than when receiving haloperidol in the total and subscale scores of the BEHAVE-AD-K, the total and subscale scores of the CMAI-K, and the scores on the CGI-C scale. Also, risperidone had an additional benefit on aggressiveness and anxieties/phobias. The risk of antipsychotic-induced parkinsonism throughout this study was significantly lower with risperidone than with haloperidol. CONCLUSION: Risperidone had a favorable efficacy and tolerability profile compared with haloperidol in the treatment of BPSD in this patient population. 相似文献
16.
17.
Aaron A. Vogan S. Lorena Ament-Velsquez Eric Bastiaans Ola Wallerman Sven J. Saupe Alexander Suh Hanna Johannesson 《Genome research》2021,31(5):789
The genomes of eukaryotes are full of parasitic sequences known as transposable elements (TEs). Here, we report the discovery of a putative giant tyrosine-recombinase-mobilized DNA transposon, Enterprise, from the model fungus Podospora anserina. Previously, we described a large genomic feature called the Spok block which is notable due to the presence of meiotic drive genes of the Spok gene family. The Spok block ranges from 110 kb to 247 kb and can be present in at least four different genomic locations within P. anserina, despite what is an otherwise highly conserved genome structure. We propose that the reason for its varying positions is that the Spok block is not only capable of meiotic drive but is also capable of transposition. More precisely, the Spok block represents a unique case where the Enterprise has captured the Spoks, thereby parasitizing a resident genomic parasite to become a genomic hyperparasite. Furthermore, we demonstrate that Enterprise (without the Spoks) is found in other fungal lineages, where it can be as large as 70 kb. Lastly, we provide experimental evidence that the Spok block is deleterious, with detrimental effects on spore production in strains which carry it. This union of meiotic drivers and a transposon has created a selfish element of impressive size in Podospora, challenging our perception of how TEs influence genome evolution and broadening the horizons in terms of what the upper limit of transposition may be.Transposable elements (TEs) are major agents of change in eukaryotic genomes. Their ability to selfishly parasitize their host replication machinery has large impacts on both genome size and on gene regulation (Chénais et al. 2012). In extreme cases, TEs can contribute up to 85% of genomic content (Schnable et al. 2009), and expansion and reduction of TEs can result in rapid changes in both genome size and architecture (Haas et al. 2009; Möller and Stukenbrock 2017; Talla et al. 2017). Generally, TEs have small sizes (∼50–12,000 bp) and accomplish these large-scale changes through their sheer number. For example, there are ∼1.1 million Alu elements in the human genome, which have had a large impact on genome evolution (Jurka 2004; Bennett et al. 2008). The largest known cases among Class I retrotransposons are long terminal repeat (LTR) elements that can be as large as 30 kb, but among Class II DNA transposons, Mavericks/Polintons are known to grow as large as 40 kb through the capture of additional open reading frames (ORFs) (Arkhipova and Yushenova 2019). Recently, a behemoth TE named Teratorn was described in teleost fish; it can be up to 182 kb in length, dwarfing all other known TEs. Teratorn has achieved this impressive size by fusing a piggyBac DNA transposon with a herpesvirus, thereby blurring the line between TEs and viruses (Inoue et al. 2017, 2018). Truly massive transposons may be lurking in the depths of many eukaryotic genomes, but the limitations of short-read genome sequencing technologies and the lack of population-level high-quality assemblies may make them difficult to identify.The Spok block is a large genomic feature that was first identified thanks to the presence of the spore killing (Spok) genes in species from the genus Podospora (Grognet et al. 2014; Vogan et al. 2019). The Spoks are selfish genetic elements that bias their transmission to the next generation in a process known as meiotic drive. Here, drive occurs by inducing the death of spores that do not inherit them, through a single protein that operates as both a toxin and an antidote (Grognet et al. 2014; Vogan et al. 2019). The first Spok gene described, Spok1, was discovered in Podospora comata (Grognet et al. 2014). In P. anserina, the homologous gene Spok2 is found at high population frequencies, whereas two other genes of the Spok family, Spok3 and Spok4, are at low to intermediate frequencies (Vogan et al. 2019). Unlike Spok1 and Spok2, however, Spok3 and Spok4 are always associated with a large genomic region (the Spok block). The Spok block can be located at different chromosomal locations in different individuals but is never found more than once in natural strains. The number of Spok genes and the location of the Spok block (which carries Spok3, Spok4, or both) define the overall meiotic driver behavior of a given genome, which can be classified into the so-called Podospora spore killers or Psks (van der Gaag et al. 2000; Vogan et al. 2019). The Spok block stands out not only because of its size, typically around 150 kb, but also because there is otherwise high genome collinearity among strains of P. anserina and with the related species P. comata and P. pauciseta (Vogan et al. 2019).The fact that the Spok block is found at unique genomic positions between otherwise highly similar strains is of prime interest as each novel Spok block position creates a unique meiotic drive type (Psk) due to the intricacies of meiosis in Podospora (Vogan et al. 2019). We therefore set out to determine the mechanism through which the Spok block relocates throughout the genome. Additionally, we annotated the gene content of the various Spok blocks to describe their composition and understand what represents the minimal component of the Spok block. Lastly, we conducted fitness assays to investigate whether the presence of the Spok block imparts any detrimental effects upon the host. 相似文献
18.
The purpose of this study was to investigate the epidemiologic characteristics of the death by poisoning in Korea. We recoded the Death Certificates Database by injury based on the short version of the International Classification of External Causes of Injuries (ICECI). We evaluated the mortality rate by total injury and poisoning, and analyzed the mortality rate by age, gender, year and month, toxic agent, and intent. Adjusted odds ratios were calculated to evaluate the effects of socioeconomic factors on suicidal poisoning death. The total number of death cases by injury was 346,656. The proportion of death cases by injury decreased from 13.53% of all death cases in 1991 to 11.89% in 2001. However, the mortality rate by poisoning increased rapidly from 1998, and then remained stable. The number of suicidal poisoning deaths has gradually increased, and its mortality rate was 6.41 (per 100,000) in 2001. Major toxic agents were pesticides and herbicides (50.90%) in 2001. Adjusted odds ratios of suicidal poisoning versus other poisonings showed significant differences in education attainment, region, and marital status. In conclusion, the mortality rate by poisoning has increased, and the proportion of suicidal poisoning also has increased compared to that of accidental poisoning. 相似文献
19.
This study evaluated the change in the ultimate tensile strength (UTS) of five polymerised resin blends of increasing hydrophilicity, after ageing in distilled water or silicon oil. Resin blocks were prepared from each resin blend by dispensing the uncured resin into a flexible, embedding mould, containing multiple cavities. The resins were polymerised in the moulds under nitrogen at 551.6 kPa and light-activated at 125 degrees C for 10 min. After dry ageing for 24 h at 37 degrees C, the middle third of each resin specimen was trimmed into an 'I' shape. Fifteen control specimens were randomly selected from each resin blend for baseline UTS evaluation. The UTS of the experimental specimens were determined after 1, 3, 6 and 12 months of ageing in water or oil. The UTS of each group of resins at different storage periods in water or oil were analysed using the Friedman multiple ANOVA on ranks and Dunn's multiple comparison tests at 95% confidence level. Significant reduction (p < 0.01) in UTS was observed in Groups II-V resins after 12-month storage in water, while the most hydrophobic Group I resin showed no significant change (p > 0.05) in the same period. The percentage reduction in UTS increased with the hydrophilicity of the resin blends. Long-term water storage of hydrophilic resin blends such as those employed in dentine adhesives, resulted in a marked reduction in their mechanical strength that may compromise the durability of resin-dentine bonds. 相似文献
20.
Baek WK Cho JW Suh SI Suh MH Shin DH Cho CH Lee TS Cha SD 《Journal of Korean medical science》2000,15(1):65-67
A common polymorphism of the wild type p53 is known at codon 72 of exon 4, with 2 alleles encoding either arginine (CGC, p53Arg) or proline (CCC, p53Pro). A recent study suggested that this polymorphism affects the susceptibility of p53 protein to human papillomavirus E6 oncoprotein mediated degradation and that individuals homozygous for p53Arg are seven times more susceptible to HPV-associated carcinogenesis of the cervix than heterozygotes. To examine whether the p53Arg genotype could be a risk factor for HPV-associated cervical carcinomas in the Korean population, we analyzed the p53 codon 72 polymorphism status of HPV-positive invasive cervical carcinomas from 52 Korean women and 103 healthy control samples. The proportion of individuals homozygous for p53Arg, homozygous for p53Pro, and heterozygous for the two alleles were 40%, 19%, and 41% in normal healthy controls; 42%, 17%, and 40% in women with HPV-positive invasive cervical carcinoma. There were no significant differences in the distribution of p53 genotypes between controls and cervical carcinomas. This finding indicates that the p53Arg genotype is not associated with an increased susceptibility to cervical carcinoma in Korean women. 相似文献