全文获取类型
收费全文 | 452篇 |
免费 | 37篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 25篇 |
妇产科学 | 1篇 |
基础医学 | 59篇 |
口腔科学 | 9篇 |
临床医学 | 66篇 |
内科学 | 80篇 |
皮肤病学 | 8篇 |
神经病学 | 30篇 |
特种医学 | 82篇 |
外科学 | 33篇 |
综合类 | 10篇 |
预防医学 | 35篇 |
眼科学 | 5篇 |
药学 | 23篇 |
2篇 | |
肿瘤学 | 17篇 |
出版年
2023年 | 5篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 19篇 |
2012年 | 15篇 |
2011年 | 7篇 |
2010年 | 18篇 |
2009年 | 21篇 |
2008年 | 15篇 |
2007年 | 7篇 |
2006年 | 10篇 |
2005年 | 6篇 |
2004年 | 11篇 |
2003年 | 6篇 |
2002年 | 8篇 |
2001年 | 8篇 |
2000年 | 10篇 |
1999年 | 12篇 |
1998年 | 21篇 |
1997年 | 20篇 |
1996年 | 16篇 |
1995年 | 16篇 |
1994年 | 15篇 |
1993年 | 12篇 |
1992年 | 8篇 |
1991年 | 13篇 |
1990年 | 15篇 |
1989年 | 18篇 |
1988年 | 5篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 11篇 |
1984年 | 7篇 |
1983年 | 12篇 |
1982年 | 6篇 |
1981年 | 2篇 |
1980年 | 7篇 |
1979年 | 12篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 7篇 |
1975年 | 4篇 |
1958年 | 2篇 |
1933年 | 1篇 |
排序方式: 共有493条查询结果,搜索用时 0 毫秒
91.
Mediastinal tumors: evaluation with suprasternal sonography 总被引:1,自引:0,他引:1
Twelve patients with mediastinal masses evaluated by computed tomography (CT) and histologically verified were evaluated sonographically by means of the suprasternal approach. Eleven of 12 mediastinal tumors could be visualized sonographically, mainly as hypoechoic and perivascularly situated masses, and could be located topographically with a fair degree of certainty. Suprasternal sonography is particularly useful in the detection of small, perivascular lymphomas of the supraaortic branches. In patients with problematic CT findings, particularly children and patients with allergies to contrast media, suprasternal sonography can provide important additional information. Moreover, suprasternal sonography can be used to determine the consistency and to monitor the treatment of mediastinal tumors. Finally, the suprasternal approach is suitable for sonographically guided biopsies of mediastinal tumors. 相似文献
92.
R F Peppard W R Martin C M Clark G D Carr P L McGeer D B Calne 《Journal of neuroscience research》1990,27(4):561-568
Characteristic regional patterns of decreased cerebral glucose metabolism (rCMRG) have been described in a variety of neurodegenerative conditions associated with dementia. The present study was undertaken to determine whether the metabolic pattern in Parkinson's disease is altered by the presence of impaired cognitive function. Glucose metabolism was measured with positron emission tomography in 6 patients with Parkinson's disease and dementia (PDD), 8 patients with Parkinson's disease and normal cognition (PD), and 6 patients with Alzheimer's disease (AD). All AD patients subsequently had the diagnosis proven neuropathologically at autopsy. Correlation coefficients of the metabolic rates across 32 regions of interest were calculated between each pair of patients. Q-component analysis of the correlation matrix showed that the AD and PD groups formed two distinct clusters and that the PDD group had a metabolic pattern which was similar to that of the AD group. Comparison of standardized rCMRG values showed that the PDD group differed from the PD group in having significantly lower relative rCMRG in the left perirolandic and bilateral angular gyrus regions. There were no significant differences between the PDD and AD groups. These results suggest a similar pattern of cortical dysfunction in both Alzheimer's disease and in Parkinson's disease/dementia. 相似文献
93.
JE Osborne PE Hutchinson 《Journal of the European Academy of Dermatology and Venereology》2002,16(4):367-373
Little attention is given to accurate dosage of topical medication which is a potential source of side-effects and treatment failure. There are studies on the dosage for 'sparing' application relevant to topical steroids but not for 'liberal' application. Though calcipotriol is a first line topical treatment for psoriasis, approximately one-third of patients do not respond adequately. The aims of the present study were to define liberal dosage, to develop a method of calculation of area of involved skin and to evaluate the efficacy of calcipotriol in optimized liberal dosages, based on preliminary studies, in calcipotriol treatment failures. Weight/unit area of ointment and cream base, constituting liberal application, was determined in six normal volunteers. The area of psoriatic involvement in 24 calcipotriol non-responders was estimated by a 'fill-up' method and a modified 'hand' method. The results of the two methods were similar (Pearson correlation coefficient 0.68, P < 0.0001) but the 'hand' method proved easier in use and was the preferred method for the rest of the study. The patients applied calcipotriol at their accustomed rates for at least 2 weeks and then at the calculated liberal rates, using cream in the morning and ointment at night, for 4 weeks. The efficacy measures were Psoriasis Area and Severity Index (PASI) (primary measure), a four-point efficacy score and a visual analogue scale. As a result of the preliminary study and the actual amounts used by the patients in the psoriasis treatment study reported below, liberal application has been defined as 50 g/m2 per application for ointment base and 40 g/m2 per application for cream. At this dosage, an average individual would use approximately 100 g of medication/week to treat 10% of the body surface. During the 4-week treatment study, the psoriasis patients used an average of 39 g (SD 17 g)/m2 per application of cream and 52 g (SD 13 g)/m2 per application of ointment. All efficacy measures showed marked improvement (P < 0.0001). The frequency distribution of the PASI reduction defined responsive (70% of patients) and poorly responsive groups (30%), with mean PASI reduction of 60% and 17%, respectively. 相似文献
94.
JOSHUA E. LANE MD EDWARD M. O''BRIEN PHD PE DAVID E. KENT MD 《Dermatologic surgery》2006,32(5):669-675
PURPOSE: Electrosurgery is routinely used in cutaneous surgery for hemostasis. Thermocautery can be used in patients with implantable cardiac devices. This technique relies on heat without electrical current passing through the patient to produce hemostasis. The temperatures and utility of a commercially available, adjustable thermocautery unit are examined. METHODOLOGY: Tip temperature of the commercially available thermocautery unit was measured in air and tissue via a type E thermocouple (0.002 in. diameter) around the unit's tip. Time intervals of 20 to 30 seconds were recorded at device settings 1 to 9 in air and 3 to 8 on surgical patients (Institutional Review Board approval obtained). RESULTS: In vitro analysis demonstrated predictable temperatures at increasing settings in air: 350 to 900 degrees C. Analysis in vivo during surgery demonstrated similar findings. Tissue contact decreased tip temperature by approximately 50% from in vitro values, and use in a bloody field caused a further decrease in the tip temperature. CONCLUSION: The thermocautery unit examined is an effective and safe unit to achieve hemostasis. In addition, the temperature may be adjusted as opposed to hand-held units that operate at in vitro temperatures exceeding 1,400 degrees F. Hemostasis at approximately 100 to 400 degrees C provided optimal hemostasis. 相似文献
95.
96.
Parsons DW; McAndrew PE; Monani UR; Mendell JR; Burghes AH; Prior TW 《Human molecular genetics》1996,5(11):1727-1732
The gene for autosomal recessive spinal muscular atrophy (SMA) has been
mapped to 5q12 in a region that contains repeated markers and genes. Three
cDNAs that detect deletions in SMA patients have been reported. One of
these, the survival motor neuron (SMN) cDNA, is encoded by two genes (SMNT
and SMNC) which are distinguished by base changes in exons 7 and 8. Exon 7
of the SMNT gene is not detectable in approximately 95% of SMA cases, due
either to deletion or sequence conversion. There is limited information on
the mutations in SMA patients that have detectable SMNT, these are critical
for confirmation of SMNT as the SMA gene. Using SSCP analysis of the SMN
exons we screened our SMA patients that possess at least one intact SMNT
allele for mutations in SMNT. We identified one type I SMA patient with an
11 bp duplication in exon 6 which causes a frameshift and premature
termination of the deduced SMNT protein. Dosage and SSCP analysis of SMNT
in this family indicated that the father contributed a SMNT-deleted allele
to the affected child whereas the mother passed on the 11 bp exon 6
duplication SMNT allele. Analysis of RNA by RT-PCR conclusively
demonstrated that the 11 bp duplication is associated with the SMNT locus
and not SMNC. This mutation provides strong support for SMN as the
SMA-determining gene and indicates that disruption of SMNT on its own is
sufficient to produce a severe type I SMA phenotype.
相似文献
97.
Heterogeneity of autosomal dominant osteopetrosis 总被引:4,自引:0,他引:4
A review of the radiographs of 26 patients with autosomal dominant osteopetrosis disclosed two distinct and strictly family-related radiographic types. Both types had universal osteosclerosis. In type 1 the most striking finding was pronounced sclerosis of the cranial vault while the spine was almost unaffected. In type 2 the sclerosis of the skull was most pronounced at the base, the vertebrae always had end-plate thickening, and in the pelvis the iliac wings contained convex arcs of sclerotic bone. Age and sex distribution did not differ between the types. Autosomal dominant osteopetrosis may be a heterogeneous group of inherited bone disorders. 相似文献
98.
Krzyzanski Wojciech Milad Mark A. Jobe Alan H. Peppard Thomas Bies Robert R. Jusko William J. 《Journal of pharmacokinetics and pharmacodynamics》2021,48(3):411-438
Journal of Pharmacokinetics and Pharmacodynamics - Population pharmacokinetic/pharmacodynamic (PK/PD) analysis was performed for extensive data for differing dosage forms and routes for... 相似文献
99.
Culture and direct immunofluorescent microscopy (DFA) results for Legionella pneumophila were reviewed over a two-year period. In the first year, a positive result was defined as having at least one morphologically typical fluorescing organism. In the second year, a positive was defined as at least five typical fluorescing organisms. Despite these stricter criteria and other measures to reduce the possibility of reagent contamination, there was no statistically significant difference in the sensitivity or specificity of the DFA in the two years for sputa, deep specimens or overall. Of 37 sputum specimens from infected patients, 16 were positive on DFA. Thirty-two of 38 positive patients were detected by sputum culture. DFA can provide rapid diagnostic information but cannot be used to rule out the diagnosis. Sputum is a useful specimen for the initial laboratory investigation of patients with legionellosis. 相似文献
100.
Transforming growth factor β1 regulates the expression of CCN2 in human keratinocytes via Smad‐ERK signalling
下载免费PDF全文
![点击此处可从《International wound journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Connective tissue growth factor (CCN2/CTGF) and transforming growth factor β1 (TGF‐β1) are important regulators of skin wound healing, but controversy remains regarding their expression in epithelial cell lineages. Here, we investigate the expression of CCN2 in keratinocytes during reepithelialisation and its regulation by TGF‐β1. CCN2 was detected in the epidermis of healing full‐thickness porcine wounds. Human keratinocytes were incubated with or without 10 ng/ml TGF‐β1, and signalling pathways were blocked with 10‐μM SIS3 or 20‐μM PD98059. Semi‐quantitative real‐time PCR was used to study CCN2 mRNA expression, and western blot was used to measure CCN2, phosphorylated‐ERK1/2, ERK1/2, phosphorylated‐Smad3 and Smad2/3 proteins. CCN2 was transiently expressed in neoepidermis at the leading edge of the wound in vivo. In vitro, CCN2 expression was induced by TGF‐β1 at 2 hours (7·5 ± 1·9‐fold mRNA increase and 3·0 ± 0·6‐fold protein increase) and 12 hours (5·4 ± 1·9‐fold mRNA increase and 3·3 ± 0·6‐fold protein increase). Compared with inhibiting the SMAD pathway, inhibiting the mitogen‐activated protein kinase (MAPK) pathway was more effective in reducing TGF‐β1‐induced CCN2 mRNA and protein expression. Inhibition of the MAPK pathway had minimal impact on the activity of the SMAD pathway. CCN2 is expressed in keratinocytes in response to tissue injury or TGF‐β1. In addition, TGF‐β1 induces CCN2 expression in keratinocytes through the ras/MEK/ERK pathway. A complete understanding of CCN2 expression in keratinocytes is critical to developing novel therapies for wound healing and cutaneous malignancy. 相似文献