全文获取类型
收费全文 | 4717篇 |
免费 | 462篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 148篇 |
妇产科学 | 87篇 |
基础医学 | 680篇 |
口腔科学 | 110篇 |
临床医学 | 406篇 |
内科学 | 757篇 |
皮肤病学 | 44篇 |
神经病学 | 365篇 |
特种医学 | 293篇 |
外科学 | 814篇 |
综合类 | 152篇 |
一般理论 | 31篇 |
预防医学 | 365篇 |
眼科学 | 62篇 |
药学 | 527篇 |
中国医学 | 11篇 |
肿瘤学 | 324篇 |
出版年
2021年 | 76篇 |
2020年 | 42篇 |
2019年 | 67篇 |
2018年 | 74篇 |
2017年 | 47篇 |
2016年 | 60篇 |
2015年 | 77篇 |
2014年 | 105篇 |
2013年 | 161篇 |
2012年 | 217篇 |
2011年 | 209篇 |
2010年 | 134篇 |
2009年 | 120篇 |
2008年 | 176篇 |
2007年 | 188篇 |
2006年 | 229篇 |
2005年 | 206篇 |
2004年 | 209篇 |
2003年 | 179篇 |
2002年 | 181篇 |
2001年 | 183篇 |
2000年 | 193篇 |
1999年 | 167篇 |
1998年 | 70篇 |
1997年 | 71篇 |
1996年 | 60篇 |
1995年 | 53篇 |
1994年 | 66篇 |
1993年 | 55篇 |
1992年 | 124篇 |
1991年 | 114篇 |
1990年 | 98篇 |
1989年 | 85篇 |
1988年 | 108篇 |
1987年 | 81篇 |
1986年 | 86篇 |
1985年 | 71篇 |
1984年 | 48篇 |
1983年 | 45篇 |
1982年 | 36篇 |
1981年 | 26篇 |
1980年 | 37篇 |
1979年 | 55篇 |
1978年 | 44篇 |
1977年 | 47篇 |
1976年 | 39篇 |
1975年 | 34篇 |
1974年 | 32篇 |
1973年 | 43篇 |
1972年 | 27篇 |
排序方式: 共有5187条查询结果,搜索用时 78 毫秒
991.
Ciara Conlon Emma Nicholson Aoife De Brún Therese McDonnell Eilish McAuliffe 《Health expectations》2021,24(5):1649
BackgroundUnscheduled health care constitutes a significant proportion of health‐care utilization. Parental decision making when accessing unscheduled care for their children is multifaceted and must be better understood to inform policy and practice.DesignNineteen semi‐structured interviews and one focus group (n = 4) with parents of children younger than twelve in Ireland were conducted. Participants had accessed unscheduled care for their children in the past. Data were thematically analysed.ResultsParents accessed unscheduled care for their children after reaching capacity to manage the child''s health themselves. This was informed by factors such as parental experience, perceived urgency and need for reassurance. Parents considered the necessity to access care and situated their health‐seeking behaviour within a framework of ‘appropriateness’. Where parents sought unscheduled care was largely determined by timely access, and inability to secure a general practitioner (GP) appointment often led parents to access other services. Parents expressed a need for more support in navigating unscheduled care options.ConclusionsBetter resources to educate and support parents are required, and structural issues, such as accessibility to GPs, need to be addressed to enable parents to better navigate the unscheduled health system and manage their children''s health. The discourse around ‘appropriate’ and ‘inappropriate’ access to health care has permeated parental decision making when accessing unscheduled health care for their children. What constitutes appropriate access should be examined, and a shift away from this framing of health‐seeking behaviour may be warranted.Patient or Public ContributionThere was no explicit patient or public involvement. All authors hold experience as users of the health system. 相似文献
992.
Catherine Okello Tom Treasure Andrew G Nicholson Julian Peto Henrik Møller 《BMC cancer》2009,9(1):28-3
Background
Mesothelioma is a highly fatal cancer that is caused by exposure to asbestos fibres. In many populations, the occurrence of mesothelioma is monitored with the use of mortality data from death certification. We examine certified causes of death of patients who have been diagnosed with mesothelioma, and assess the validity of death certification data as a proxy for mesothelioma incidence. 相似文献993.
Hiscox S Jordan NJ Smith C James M Morgan L Taylor KM Green TP Nicholson RI 《Breast cancer research and treatment》2009,115(1):57-67
Acquired resistance to endocrine therapies presents a major obstacle to the successful treatment of breast cancer patients.
Previously, we have shown that acquisition of resistance to tamoxifen in breast cancer cells is accompanied by an elevation
in Src kinase activity which promotes an aggressive, invasive phenotype in vitro. Here, we have explored the potential therapeutic
effects of combining Src inhibition with anti-oestrogen treatment on the development of endocrine insensitivity in breast
cancer cells. Treatment of MCF7 and T47D cells with tamoxifen alone resulted in an initial growth inhibitory phase followed
by the eventual development of tamoxifen resistance together with an elevation of Src kinase activity, which was central to
their increased invasive capacity. Chronic exposure of both cell types to the Src inhibitor, AZD0530, as a monotherapy resulted
in outgrowth of AZD0530-resistant cells, in which Src kinase activity remained suppressed as did their in vitro invasive nature.
Treatment of both MCF7 and T47D cells with AZD0530 in combination with tamoxifen resulted in a reduction of Src activity together
with inhibition of focal adhesion kinase phosphorylation and a complete abrogation of their in vitro invasive behaviour. Furthermore,
combination therapy significantly suppressed expression of cyclinD1 and c-myc and prevented cell proliferation and the subsequent
emergence of a resistant phenotype, with total cell loss occurring by 12 weeks. These data demonstrate that pharmacological
targeting of Src kinase, in conjunction with antihormone therapies, effectively prevents antihormone resistance in breast
cancer cells in vitro and suggests a potential novel therapeutic benefit of Src kinase inhibitors clinically. 相似文献
994.
Kelly JG Singh MN Stringfellow HF Walsh MJ Nicholson JM Bahrami F Ashton KM Pitt MA Martin-Hirsch PL Martin FL 《Cancer letters》2009,274(2):208-217
Endometrial carcinoma consists of endometrioid (type I) and serous papillary (SP; type II) subtypes; a rarer form is malignant mixed müllerian tumours (MMMT; type II/mixed). We set out to determine whether one might be able to biochemically signature these subtypes using Fourier-transform infrared (FTIR) microspectroscopy and distinguish non-tamoxifen associated from tamoxifen-associated cases. Paraffin-embedded blocks were obtained from non-tamoxifen associated cases reported as endometrioid (n=7), SP (n=4) or MMMT (n=4). From tamoxifen-associated cases, endometrioid (n=1), SP (n=3) and MMMT (n=4) blocks were retrieved; benign tissues (n=3) were also analysed. Exploiting synchrotron-based radiation, sections (10-microm thick) on BaF(2) windows were interrogated through a 10 microm x 10 microm aperture. Point spectra were derived from >or=10 locations in each of six glandular elements per tissue; a further 20 stromal spectra were obtained. Following normalisation to Amide I, average spectra (1800-900 cm(-1)) per gland or stroma were analysed for variance using principal component analysis (PCA) and linear discriminant analysis (LDA). In scores plots, segregation of spectra from different subtypes or benign tissues was noted and it proved possible to distinguish tamoxifen-associated cases. In the PCA-LDA loadings plots, the wavenumbers that highlighted variance for benign or endometrioid carcinoma tissues were in the protein region (1800-1480 cm(-1)) whereas those contributing most to SP or MMMT segregation were primarily in the DNA/RNA region (1425-900 cm(-1)) of the vibrational spectrum. Our results suggest that the application of FTIR microspectroscopy is a powerful new approach in disease diagnosis and characterisation. 相似文献
995.
Anderson E Berg J Black R Bradshaw N Campbell J Cetnarskyj R Drummond S Davidson R Dunlop J Fordyce A Gibbons B Goudie D Gregory H Hanning K Holloway S Longmuir M McLeish L Murday V Miedzybrodska Z Nicholson D Pearson P Porteous M Reis M Slater S Smith K Smyth E Snadden L Steel M Stirling D Watt C Whyte C Young D 《Familial cancer》2008,7(4):361-366
Published guidelines adopted in many countries recommend that women whose family history of breast cancer places them at a
risk ≥1.7 times that of the age-matched general population, should be considered for inclusion in special surveillance programmes.
However validation of risk assessment models has been called for as a matter of urgency. The databases of the four Scottish
Familial Breast Cancer clinics and the Scottish Cancer Registry have been searched to identify breast cancers occurring among
1,125 women aged 40–56, with family histories placing them below the “moderate” level of genetic risk. The observed incidence
over 6 years was compared with age-specific data for the Scottish population. Our findings confirm that when there are two
affected relatives (one first degree) the relative risk (RR) exceeds 1.7 regardless of their ages at diagnosis. When only
one (first degree) relative was affected at any age from 40 to 55, the RR does not reach 1.7 if that relative was a mother
but exceeds it if the relative was a sister. The probable explanation is that sisters are more likely than mother/daughter
pairs to share homozygosity for a risk allele. Surveillance programmes might therefore accommodate sisters of women affected
before age 55. Evidence that “low penetrance” alleles contributing to breast cancer risk may be recessive should be taken
into account in strategies for identifying them.
All the authors are from the Scottish Cancer Family Clinical Centres. 相似文献
996.
Smith-Olinde L Nicholson N Chivers C Highley P Williams DK 《American journal of audiology》2006,15(1):75-80
PURPOSE: The purpose of this study was to examine test-retest reliability of in situ unaided thresholds measured using a handheld hearing aid programmer coupled to a hearing aid transducer in adults with normal hearing. METHOD: Randomized in situ thresholds at 4 octave frequencies were established in 1 ear of 43 adults twice using the Widex Diva SP3 device with the stimulus generated by and transduced through a Widex Diva SD-9 behind-the-ear hearing aid. Insert earphone tips were used in each of the measures to couple the hearing aid/transducer to the ear canal. RESULTS: Mean decibel differences between the test and retest thresholds were less than 1 dB at each frequency. Using an 80% statistical test criterion, results revealed test-retest reliability within 5 dB for all frequencies: 98% at 500 Hz, 100% at 1000 and 2000 Hz, and 93% at 4000 Hz. CONCLUSIONS: Test-retest reliability of in situ unaided thresholds using the SP3/SD-9 device is equivalent to that of currently accepted audiometric procedures. 相似文献
997.
Nicholson O Mellins C Dolezal C Santamaria EK Brackis-Cott E Abrams EJ 《Archives of pediatrics & adolescent medicine》2006,160(12):1307-1308
998.
Pranzatelli MR Tate ED Travelstead AL Barbosa J Bergamini RA Civitello L Franz DN Greffe BS Hanson RD Hurwitz CA Kalinyak KA Kelfer H Khakoo Y Mantovani JF Nicholson SH Sanders JM Wegner S 《Journal of pediatric hematology/oncology》2006,28(9):585-593
PURPOSE: To determine if rituximab, an anti-CD20 monoclonal antibody, reduces cerebrospinal fluid (CSF) B-cell expansion in opsoclonus-myoclonus syndrome (OMS) and results in clinical improvement. METHODS: Sixteen children with OMS and increased % CD20 B-cells in CSF received 4 rituximab infusions (375 mg/m IV) as add-on therapy to corticotropin (ACTH), intravenous immunoglobulins, or both, and were reevaluated 6 months later. Outcome measures were clinical (motor function, behavior, sleep) and immunologic (CSF and blood immunophenotype and Ig levels). Controls were 16 age-matched and sex-matched children, who did not have OMS. RESULTS: After rituximab, 81% of OMS had a lower motor severity score, and 44% improved one severity category. Mean total score decreased by 44% (P = 0.0005). Rituximab reduced rage score, nighttime awakenings, and the number of children with opsoclonus, action myoclonus, drooling, gait ataxia, and rage. Despite a 51% reduction in ACTH dose, 9 of 11 children on ACTH did not relapse. The percentage of CSF CD19 (and CD20) B-cells was lowered in all children (undetectable in 6), with a 90% reduction in the group mean (P = 0.00003). CSF B-cells were no longer expanded compared with controls. In blood, CD19 B-cells decreased (-90%, P = 0.0003), as did the CSF:blood CD19 B-cell ratio (P = 0.00003). Serum IgM fell by 69% (below reference range), with no statistically significant change in IgG or IgA. CONCLUSIONS: Rituximab seems efficacious and safe as adjunctive therapy for OMS. Selective targeting of CSF B lymphocytes represents a novel and valuable paradigm shift in the therapy for centrally mediated paraneoplastic disorders. 相似文献
999.
Curtner-Smith ME Middlemiss W Green K Murray AD Barone M Stolzer J Parker L Nicholson B 《Child maltreatment》2006,11(4):373-4; author reply 381-6
1000.
Purulent fluid collections, including brain abscess and subdural empyema, are exceedingly rare in association with meningococcal meningitis. We present a 5-month-old infant with meningococcal meningitis and sepsis complicated by an intracerebral abscess. 相似文献