首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2185篇
  免费   92篇
  国内免费   8篇
耳鼻咽喉   25篇
儿科学   20篇
妇产科学   67篇
基础医学   284篇
口腔科学   18篇
临床医学   172篇
内科学   655篇
皮肤病学   20篇
神经病学   288篇
特种医学   36篇
外科学   221篇
综合类   16篇
一般理论   3篇
预防医学   106篇
眼科学   59篇
药学   169篇
中国医学   5篇
肿瘤学   121篇
  2023年   6篇
  2022年   74篇
  2021年   100篇
  2020年   18篇
  2019年   17篇
  2018年   49篇
  2017年   33篇
  2016年   28篇
  2015年   49篇
  2014年   68篇
  2013年   80篇
  2012年   148篇
  2011年   183篇
  2010年   96篇
  2009年   68篇
  2008年   120篇
  2007年   185篇
  2006年   159篇
  2005年   155篇
  2004年   134篇
  2003年   143篇
  2002年   131篇
  2001年   5篇
  2000年   13篇
  1999年   7篇
  1998年   8篇
  1997年   10篇
  1996年   10篇
  1995年   16篇
  1994年   9篇
  1993年   6篇
  1991年   9篇
  1990年   4篇
  1989年   10篇
  1988年   9篇
  1987年   8篇
  1986年   12篇
  1985年   10篇
  1984年   10篇
  1983年   8篇
  1982年   10篇
  1981年   6篇
  1980年   4篇
  1979年   5篇
  1978年   7篇
  1977年   6篇
  1976年   5篇
  1973年   4篇
  1971年   4篇
  1967年   6篇
排序方式: 共有2285条查询结果,搜索用时 15 毫秒
81.
The analysis included 46 women after radical breast amputation because of cancer with which lymphoedema occurred in the upper limb, as well as 51 women in whom no lymphoedema occurred during the period of the observation. Both groups were subjected to a comparative analysis as for height, body mass, and weight–height indexes: BMI, Quetelet, Rohrer, and Pignet–Verwaeck. The results show that women with high body mass, obesity (BMI > 30.0), and high values of the Quetelet (>370), Rohrer (>1.59), and Pignet–Verwaeck (>93.1) indexes are threatened to a significant degree with lymphoedema of the upper limbs after cancer‐related mastectomy. On the other hand, slim body build and low index values appear to be a factor protecting from the occurrence of lymphoedema of the upper limb. Am. J. Hum. Biol. 15:433–439, 2003. © 2003 Wiley‐Liss, Inc.  相似文献   
82.
Intravenous immunoglobulin (IVIG) is a potential therapy for chronic inflammatory demyelinating polyneuropathy (CIDP). To investigate the efficacy and safety of the IVIG IgPro10 (Privigen) for treatment of CIDP, results from Privigen Impact on Mobility and Autonomy (PRIMA), a prospective, open‐label, single‐arm study of IVIG in immunoglobulin (Ig)‐naïve or IVIG pre‐treated subjects (NCT01184846, n = 28) and Polyneuropathy And Treatment with Hizentra (PATH), a double‐blind, randomized study including an open‐label, single‐arm IVIG phase in IVIG pre‐treated subjects (NCT01545076, IVIG restabilization phase n = 207) were analyzed separately and together (n = 235). Efficacy assessments included change in adjusted inflammatory neuropathy cause and treatment (INCAT) score, grip strength and Medical Research Council (MRC) sum score. Adverse drug reactions (ADRs) and ADRs/infusion were recorded. Adjusted INCAT response rate was 60.7% in all PRIMA subjects at Week 25 (76.9% in IVIG pre‐treated subjects) and 72.9% in PATH. In the pooled cohort (n = 235), INCAT response rate was 71.5%; median time to INCAT improvement was 4.3 weeks. No clear demographic differences were noticed between early (responding before Week 7, n = 148) and late responders (n = 21). In the pooled cohort, median change from baseline to last observation was ?1.0 (interquartile range ?2.0; 0.0) point for INCAT score; +8.0 (0.0; 20.0) kPa for maximum grip strength; +3.0 (1.0; 7.0) points for MRC sum score . In the pooled cohort, 271 ADRs were reported in 105 subjects (44.7%), a rate of 0.144 ADRs per infusion. This analysis confirms the efficacy and safety of IgPro10, a recently FDA‐approved IVIG for CIDP, in a population of mainly pre‐treated subjects with CIDP [Correction added on 14 March 2019 after first online publication: the INCAT response rate has been corrected.].  相似文献   
83.
Adenosine deaminase (ADA) activity was estimated in human gastric mucosal specimens taken endoscopically. Three groups of patients were studied: 6 subjects with achlorhydria, 11 patients with normal gastric acid secretion and 6 patients with hypersecretion. The activity of ADA in mucosal homogenates was measured by determination of the ammonia liberated from the substrate. It was found that in the subjects with normal or increased gastric acid secretion, ADA activities were higher in specimens taken from the gastric fundus than in slices coming from the antral region. In the fundic mucosa the highest ADA activity was noted in patients with hypersecretion. Moreover, in this gastric region a positive correlation between ADA activity and basal or maximal acid output values was found. It is concluded that ADA might be involved in the regulatory system of gastric acid secretion.  相似文献   
84.
Sulfur dioxide undergoes copolymerization with ethylene oxide in the presence of Lewis bases capable of forming onium ions (such as amines, phosphines, diethyl sulfide, dimethyl sulfoxide, N,N-dimethylformamide) yielding poly(ethylene sulfite) bearing also a small amount of ethylene oxide monomeric units homosequencies. After 4–6 h of reaction at 50°C in bulk, the monomer conversion reaches 70–90%. The copolymer obtained is a mixture of linear and cyclic products which tend to degrade to yield ethylene sulfite. At 50°C this decomposition is very slow when unreacted SO2 is completely removed. However, it proceeds very rapidly, within a few hours, in the presence of compounds with strong electrophilic properties like BF3, H3PO4, or chlorotrimethylsilane. Studies of model reactions indicate that in the systems studied the macrocyclization results mainly from the attack of sulfite or alcoholate active species at the carbon atoms in polysulfites. Chain transfer reactions with the solvent occur also in reactions carried out in ethanol.  相似文献   
85.
The global impact of LRRK2 mutations is yet to be realized with a lack of studies in specific ethnic groups, including those of Asian and African descent. Herein, we investigated the frequency of common LRRK2 variants by complete exon sequencing in a series of publicly available African American Parkinson's disease patients. Our study identified three novel synonymous exonic variants and 13 known coding variations; however, there did not appear to be any frequent (>5%) pathogenic mutations. Given the ethnic‐specific LRRK2 variation previously identified in PD further studies in under‐represented populations are warranted. © 2010 Movement Disorder Society.  相似文献   
86.
A role for the immune system in the pathogenesis of Parkinson's Disease (PD) has previously been suggested. A recent genome-wide association (GWA) study identified an association between one single nucleotide polymorphism (SNP) in the human leucocyte antigen (HLA) region (HLA-DRA rs3129882) and PD in a population of American patients with European ancestry. In that study, the minor rs3129882 allele (G) was associated with an increased risk of PD under an additive model. Due to the increased likelihood of obtaining false positive results in GWA studies compared to studies conducted based on a hypothesis-driven approach, repeated validation of findings from GWA studies are necessary. Herein, we evaluated the association between rs3129882 and PD in three different Caucasian patient-control series (combined 1313 patients and 1305 controls) from the US, Ireland, and Poland. We observed no association (OR: 0.96, P = 0.50) between rs3129882 and PD when analyzing our data under an additive or dominant model. In contrast, when examined under a recessive model, the GG genotype was observed to be protective in the Irish (OR: 0.55, P = 0.008), Polish (OR: 0.67, P = 0.040) and combined (OR: 0.75, P = 0.006) patient-control series. In view of these diverging results, the exact role of genetic variation at the HLA region and susceptibility to PD remains to be resolved.  相似文献   
87.
88.
Pyoderma Vegetans   总被引:1,自引:0,他引:1  
BACKGROUND: Pyoderma vegetans is a rare condition that is clinically characterized by large verrucous plaques with elevated borders and multiple pustules. The etiology of this disorder remains unknown. OBJECTIVES: We describe a 24-year-old woman with rapidly evolving pyoderma vegetans. Our patient had the unique additional findings of a highly elevated serum IgE level and a history of hidradenitis suppurativa. CONCLUSIONS: Pyoderma vegetans is diagnosed on clinical and histological criteria. Differentiation must be made from disorders such as pyoderma gangrenosum, Sweet's syndrome, and deep fungal infections. We illustrate a case of pyoderma vegetans and review the literature on this rare disorder. Clinical and histological criteria for diagnosis are presented, as well as differentiation from some mimicking disorders.  相似文献   
89.
Lucilia sericata bottle fly worms can be used to heal infected, chronic, or necrotic wounds, including those associated with ulceration and diabetic foot. The study aimed to evaluate changes in the microflora in patients treated with L sericata larvae due to leg ulcers and diabetic foot. One hundred twenty-nine patients diagnosed with lower limb ulceration and diabetic foot were enrolled in the study, of which 80 of them met the eligibility criteria for maggot debridement therapy (MDT). On the contrary, 49 unqualified patients were offered ozone therapy (22 with leg ulcers; 27 with diabetic foot). In each of these patients, a microbiological swab was performed before and after the start of therapy. The group of 80 patients was further divided into four equal groups in terms of the treated area (lower leg vs foot) and the number of larvae/cm2 (5 vs 10). Twenty-three particular species of bacteria in the infected wound were studied microbiologically in terms of presence/absence within the wound environment before and after treatment of patients with diabetic foot and lower limb ulceration. It was noted that there was a more intensive bacterial accumulation in the feet of patients compared to legs; furthermore, this applies to almost all analysed species. Diabetes status is also a clinical factor that generates a lower chance of bacterial appearance in the wound environment. Densification of MDT larvae per wound area unit also reduced the chance of the presence of Corynebacterium species, Enterobacteriaceae, Pseudomonas aeruginosa, Staphylococcus aureus MSSA, and Streptococcus coagulase negativa; however, it increased the likelihood of occurrence for Proteus mirabilis and the Proteus species. A microbiological analysis in this non-reference study shows the efficacy of larval therapy for leg and foot ulcers. Rearrangement of the microflora within the wound has been reported as a result of the therapy.  相似文献   
90.
Parent‐of‐origin–dependent (epi)genetic factors are important determinants of prenatal development that program adult phenotype. However, data on magnitude and specificity of maternal and paternal genome effects on fetal bone are lacking. We used an outbred bovine model to dissect and quantify effects of parental genomes, fetal sex, and nongenetic maternal effects on the fetal skeleton and analyzed phenotypic and molecular relationships between fetal muscle and bone. Analysis of 51 bone morphometric and weight parameters from 72 fetuses recovered at day 153 gestation (54% term) identified six principal components (PC1–6) that explained 80% of the variation in skeletal parameters. Parental genomes accounted for most of the variation in bone wet weight (PC1, 72.1%), limb ossification (PC2, 99.8%), flat bone size (PC4, 99.7%), and axial skeletal growth (PC5, 96.9%). Limb length showed lesser effects of parental genomes (PC3, 40.8%) and a significant nongenetic maternal effect (gestational weight gain, 29%). Fetal sex affected bone wet weight (PC1, p < 0.0001) and limb length (PC3, p < 0.05). Partitioning of variation explained by parental genomes revealed strong maternal genome effects on bone wet weight (74.1%, p < 0.0001) and axial skeletal growth (93.5%, p < 0.001), whereas paternal genome controlled limb ossification (95.1%, p < 0.0001). Histomorphometric data revealed strong maternal genome effects on growth plate height (98.6%, p < 0.0001) and trabecular thickness (85.5%, p < 0.0001) in distal femur. Parental genome effects on fetal bone were mirrored by maternal genome effects on fetal serum 25‐hydroxyvitamin D (96.9%, p < 0.001) and paternal genome effects on alkaline phosphatase (90.0%, p < 0.001) and their correlations with maternally controlled bone wet weight and paternally controlled limb ossification, respectively. Bone wet weight and flat bone size correlated positively with muscle weight (r = 0.84 and 0.77, p < 0.0001) and negatively with muscle H19 expression (r = –0.34 and –0.31, p < 0.01). Because imprinted maternally expressed H19 regulates growth factors by miRNA interference, this suggests muscle‐bone interaction via epigenetic factors. © 2014 American Society for Bone and Mineral Research.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号