全文获取类型
收费全文 | 736篇 |
免费 | 123篇 |
国内免费 | 7篇 |
专业分类
儿科学 | 8篇 |
妇产科学 | 9篇 |
基础医学 | 124篇 |
口腔科学 | 4篇 |
临床医学 | 75篇 |
内科学 | 232篇 |
皮肤病学 | 13篇 |
神经病学 | 13篇 |
特种医学 | 40篇 |
外科学 | 53篇 |
综合类 | 22篇 |
一般理论 | 3篇 |
预防医学 | 115篇 |
眼科学 | 17篇 |
药学 | 46篇 |
1篇 | |
肿瘤学 | 91篇 |
出版年
2021年 | 8篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2016年 | 10篇 |
2015年 | 13篇 |
2014年 | 11篇 |
2013年 | 18篇 |
2012年 | 30篇 |
2011年 | 33篇 |
2010年 | 21篇 |
2009年 | 22篇 |
2008年 | 46篇 |
2007年 | 51篇 |
2006年 | 51篇 |
2005年 | 56篇 |
2004年 | 42篇 |
2003年 | 37篇 |
2002年 | 48篇 |
2001年 | 27篇 |
2000年 | 31篇 |
1999年 | 23篇 |
1998年 | 19篇 |
1997年 | 13篇 |
1996年 | 22篇 |
1995年 | 10篇 |
1994年 | 10篇 |
1993年 | 7篇 |
1992年 | 11篇 |
1991年 | 11篇 |
1990年 | 16篇 |
1989年 | 16篇 |
1988年 | 12篇 |
1987年 | 17篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1971年 | 4篇 |
1970年 | 7篇 |
1969年 | 5篇 |
1968年 | 5篇 |
1967年 | 4篇 |
排序方式: 共有866条查询结果,搜索用时 15 毫秒
1.
2.
Oisin R. O'Neill M.D. F.R.C.S.I. Grant Gilliland M.D. Johnny B. Delashaw M.D. Thomas J. Purtzer M.D. 《Surgical neurology》1994,42(6)
The development of more complex and diverse hunting weapons may result in an increase of uncommon forms of penetrating injury to the brain. We present a case of non-fatal transorbital arrow injury to the brain. High velocity projectile injuries merit certain management adaptations from gunshot or low velocity stab wounds. This case highlights the necessity for anterograde removal of the arrow in the direction of its line of trajectory. Early assessment of the patient with cerebral angiography to identify surgically correctable vascular injury is recommended. 相似文献
3.
Objective Some conditions, previously managed by general surgeons, may be treated more successfully by colorectal specialists. This argument is well established for rectal cancer but does it also apply to benign conditions? This study compares the treatment strategies and outcomes for fistulae‐in‐ano by general and colorectal surgeons in a district general hospital. Method Patients who had surgery for fistula‐in‐ano from January 1992–October 2003 were identified from theatre records. Case notes were reviewed for data on type of fistula, aetiology, surgery performed and recurrence. All patients were sent a questionnaire requesting details of recurrence and incontinence. The severity of incontinence was assessed using the Faecal Incontinence Quality of Life Scale (FIQOLS) and the Faecal Incontinence Severity Index (FISI). Results Eighty four patients (male = 53) were identified. Colorectal surgeons performed surgery in 34 and general surgeons in 50 patients. These groups were comparable with terms of age, gender, aetiology (colorectal: IBD = 5, cryptoglandular = 21: general IBD = 14, cryptoglandular = 24; P = 0.28; Chi‐squared test), and type of fistulae (colorectal: inter‐sphincteric = 20, trans‐sphincteric = 13: general inter‐sphincteric = 30, trans‐sphincteric = 18: P = 1.0; Fisher's exact test). Colorectal surgeons carried out fewer fistulotomies (47.1%vs 84.0%; P < 0.001; Fisher's exact test), more staged fistulotomies with Setons (44.1%vs 10.0%: P < 0.001; Fisher's exact test), and had fewer recurrences (9.7%vs 30.0%: P < 0.05; Fisher's exact test) when compared with general surgeons. Five patients with recurrence from the general surgery group were subsequently referred to the colorectal surgeons; four patients had further surgery (fistulotomy = 2; staged fistulotomy = 2) with no recurrence to date; one patient required proctectomy. Forty seven (64.4%) patients answered the questionnaire. There was no difference between patients operated on by colorectal or general surgeons with regards the frequency (43.5%vs 62.5%: P = 0.25; Fisher's exact test) or severity [FISI 26 (21–38); median (inter‐quartile range) vs 26 (17–38); median (inter‐quartile range: P = 0.85; Mann–Whitney test) of faecal incontinence. There was no difference between the groups with regards any of the four scales that comprised the FIQOLS. Conclusions The number of included patients is far too low to draw any conclusions but there were some interesting trends. For similar patient samples, colorectal surgeons seem to adopt a more conservative approach and have fewer recurrences than general surgeons. These differences are not reflected in the frequency or severity of postoperative incontinence. 相似文献
4.
Liu JQ; Bai XF; Shi FD; Xiao BG; Li HL; Levi M; Mustafa M; Wahren B; Link H 《International immunology》1998,10(8):1139-1148
Induction of mucosal tolerance by inhalation of soluble peptides with
defined T cell epitopes is receiving much attention as a means of
specifically down-regulating pathogenic T cell reactivities in autoimmune
and allergic disorders. Experimental autoimmune encephalomyelitis (EAE)
induced in the Lewis rat by immunization with myelin basic protein (MBP)
and Freund's adjuvant (CFA) is mediated by CD4+ T cells specific for the
MBP amino acid sequences 68-86 and 87-99. To further define the principles
of nasal tolerance induction, we generated three different MBP peptides
(MBP 68-86, 87-99 and the non- encephalitogenic peptide 110-128), and
evaluated whether their nasal administration on day -11, -10, -9, -8 and -7
prior to immunization with guinea pig MBP (gp-MBP) + CFA confers protection
to Lewis rat EAE. Protection was achieved with the encephalitogenic
peptides MBP 68-86 and 87-99, MBP 68-86 being more potent, but not with MBP
110-128. Neither MBP 68-86 nor 87-99 at doses used conferred complete
protection to gp-MBP-induced EAE. In contrast, nasal administration of a
mixture of MBP 68-86 and 87-99 completely blocked gp-MBP-induced EAE even
at lower dosage compared to that being used for individual peptides. Rats
tolerized with MBP 68-86 + 87-99 nasally showed decreased T cell responses
to MBP reflected by lymphocyte proliferation and IFN-gamma ELISPOT assays.
Rats tolerized with MBP 68-86 + 87-99 also had abrogated MBP-reactive
IFN-gamma and tumor necrosis factor-alpha mRNA expression in lymph node
cells compared to rats receiving MBP 110-128 nasally, while similar low
levels of MBP-reactive transforming growth factor-beta and IL-4 mRNA
expressing cells were observed in the two groups. Nasal administration of
MBP 68-86 + 87-99 only slightly inhibited guinea pig spinal cord
homogenate-induced EAE, and passive transfer of spleen mononuclear cells
from MBP 68-86 + 87-99-tolerized rats did not protect naive rats from EAE.
Finally, we show that nasal administration of MBP 68-86 + 87-99 can reverse
ongoing EAE induced with gp-MBP, although higher doses are required
compared to the dosage needed for prevention. In conclusion, nasal
administration of encephalitogenic MBP peptides can induce antigen-specific
T cell tolerance and confer incomplete protection to gp-MBP-induced EAE,
and MBP 68-86 and 87-99 have synergistic effects. Non-regulatory mechanisms
are proposed to be responsible for tolerance development after nasal
peptide administration.
相似文献
5.
6.
Mutational analysis of the SOX9 gene in campomelic dysplasia and autosomal sex reversal: lack of genotype/phenotype correlations 总被引:9,自引:1,他引:9
Meyer J; Sudbeck P; Held M; Wagner T; Schmitz ML; Bricarelli FD; Eggermont E; Friedrich U; Haas OA; Kobelt A; Leroy JG; Van Maldergem L; Michel E; Mitulla B; Pfeiffer RA; Schinzel A; Schmidt H; Scherer G 《Human molecular genetics》1997,6(1):91-98
It has previously been shown that, in the heterozygous state, mutations in
the SOX9 gene cause campomelic dysplasia (CD) and the often associated
autosomal XY sex reversal. In 12 CD patients, 10 novel mutations and one
recurrent mutation were characterized in one SOX9 allele each, and in one
case, no mutation was found. Four missense mutations are all located within
the high mobility group (HMG) domain. They either reduce or abolish the
DNA-binding ability of the mutant SOX9 proteins. Among the five nonsense
and three frameshift mutations identified, two leave the C-terminal
transactivation (TA) domain encompassing residues 402-509 of SOX9 partly or
almost completely intact. When tested in cell transfection experiments, the
recurrent nonsense mutation Y440X, found in two patients who survived for
four and more than 9 years, respectively, exhibits some residual
transactivation ability. In contrast, a frameshift mutation extending the
protein by 70 residues at codon 507, found in a patient who died shortly
after birth, showed no transactivation. This is apparently due to
instability of the mutant SOX9 protein as demonstrated by Western blotting.
Amino acid substitutions and nonsense mutations are found in patients with
and without XY sex reversal, indicating that sex reversal in CD is subject
to variable penetrance. Finally, none of 18 female patients with XY gonadal
dysgenesis (Swyer syndrome) showed an altered SOX9 banding pattern in SSCP
assays, providing evidence that SOX9 mutations do not usually result in XY
sex reversal without skeletal malformations.
相似文献
7.
Alloys based on Ni–Ti intermetallics generally exhibit special shape memory and pseudoelastic properties, which make them desirable for use in the dental field as orthodontic wires. The possibility of nickel release from these materials is of high concern, because the allergenicity of this element. The aim of this study was to test pseudoelastic Ni–Ti wires in simulated physiological conditions, investigating the combined effect of strain and fluoridated media: the wires were examined both under strained (5% tensile strain) and unstrained conditions, in fluoridated artificial saliva at 37 °C. Real time electrochemical nickel release testing was performed using a novel application of a radiotracer based method, thin layer activation (TLA). TLA was validated, in unstrained conditions, against adsorptive stripping voltammetry methodology. Control tests were also performed in non-fluoridated artificial saliva. From our research it transpired that the corrosion behaviour of Ni–Ti alloy is highly affected by the fluoride content, showing a release of 4.79 ± 0.10 μg/cm2/day, but, differently from other biomaterials, it does not seem to be affected by elastic tensile strain. The application of the TLA method in the biomedical field appears a suitable technique to monitor in real time the corrosion behaviour of biomedical devices. 相似文献
8.
The interaction of CD4 with CD3/Ti regulates tyrosine phosphorylation of substrates during T cell activation 总被引:4,自引:0,他引:4
Phosphorylation of proteins on tyrosine residues during activation was studied in CD3+ CEM T cells. Crosslinking of either CD4 alone or CD3/Ti alone induced weak and transient responses, but the patterns of induced tyrosine-phosphorylated proteins were different. A synergistic but still transient response occurred by the specific interaction of CD4 with CD3/Ti, whereas simultaneous but separate ligation of CD3/Ti and CD4 decreased rather than increased tyrosine phosphorylation of proteins in comparison to CD3/Ti stimulation alone. Stimulation of T cells with immobilized anti-CD3 induced strong and prolonged tyrosine phosphorylation of distinct substrates. CD4 therefore regulates protein tyrosine kinase activation by specific interaction with CD3/Ti, whereas immobilized anti-CD3 may differ from anti-CD3 in solution in the activation of protein tyrosine phosphatase(s) such as CD45. 相似文献
9.
Gina Martin Drew D. Bowman Megan Graat Andrew F. Clark Alexander J. Wray Zoe Askwith Jamie A. Seabrook Jason A. Gilliland 《Canadian journal of public health. Revue canadienne de santé publique》2021,112(3):440
ObjectivesOn January 1, 2020, the Government of Ontario passed a regulation banning vaping advertisements by retailers, apart from specialty shops. A motivation for this ban was to limit youth exposure to vaping advertisements. The primary goal of this research was to evaluate the impact of this ban on the number and density of vaping advertisements surrounding secondary schools. Additionally, we examined whether the number of vaping advertisements varied by school socio-demographic characteristics.MethodsThis study used a pre-post design. Audits were conducted December 2019 (pre-ban) and again January to February 2020 (post-ban), to identify vaping advertisements within 800 m surrounding secondary schools (n = 18) in London, Ontario.ResultsPrior to the ban, there were 266 vaping advertisements within 800 m of secondary schools. After the ban, this was reduced to 58, a 78.2% reduction. The mean number of vaping advertisements surrounding schools significantly decreased from 18.1 before the ban to 3.6 after the ban (p < 0.001). A significant positive correlation was found, prior to the ban, between the number of vaping advertisements surrounding schools and school-level residential instability (r = 0.42, p = 0.02). After the ban, no significant correlations were found between the number of vaping advertisements and school socio-demographic characteristics.ConclusionThe provincial ban of vaping advertisements in select retail settings significantly reduced the number of vaping advertisements in the areas surrounding secondary schools in London, Ontario. The ban also reduced socio-demographic inequities in youths’ potential exposure to marketing of vaping products. Continued monitoring of the geographic accessibility and promotion of vaping products is warranted. 相似文献
10.
Assessing the laryngeal cough reflex and the risk of developing pneumonia after stroke 总被引:7,自引:0,他引:7
Addington WR Stephens RE Gilliland K Rodriguez M 《Archives of physical medicine and rehabilitation》1999,80(2):150-154
OBJECTIVE: To determine the effectiveness of a new reflex cough test, using nebulized tartaric acid, in the evaluation of the laryngeal cough reflex and the development of aspiration pneumonia. STUDY DESIGN: In this two-phase study, the cough test assessed the cough reflex in 161 stroke subjects. Phase 1 was a double-blinded prospective study of 40 subjects scheduled to have both modified barium swallow and the reflex cough test. Phase 1 subjects with an abnormal cough test showed an increased pneumonia incidence, and therefore, phase 2 was not blinded. In phase 2, 121 subjects were evaluated using the cough test; 38 received a modified barium swallow. Test results were compared using the Fisher exact test. RESULTS: A total of 131 subjects from both phases had a normal reflex cough test; none developed pneumonia (p < .01). Thirty subjects from both phases had abnormal reflex cough test results; 5 developed pneumonia. Modified barium swallow findings did not reliably indicate the risk for developing pneumonia. Specificity of a normal reflex cough test was 100%. CONCLUSION: The reflex cough test reliably evaluated the laryngeal cough reflex and the associated risk of developing aspiration pneumonia in stroke patients. Testing the laryngeal cough reflex may significantly reduce morbidity, mortality, and costs in stroke patients. 相似文献