全文获取类型
收费全文 | 1413篇 |
免费 | 79篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 42篇 |
妇产科学 | 21篇 |
基础医学 | 162篇 |
口腔科学 | 99篇 |
临床医学 | 108篇 |
内科学 | 396篇 |
皮肤病学 | 43篇 |
神经病学 | 103篇 |
特种医学 | 81篇 |
外科学 | 142篇 |
综合类 | 66篇 |
预防医学 | 105篇 |
眼科学 | 23篇 |
药学 | 69篇 |
中国医学 | 3篇 |
肿瘤学 | 60篇 |
出版年
2023年 | 15篇 |
2022年 | 18篇 |
2021年 | 46篇 |
2020年 | 30篇 |
2019年 | 36篇 |
2018年 | 37篇 |
2017年 | 22篇 |
2016年 | 37篇 |
2015年 | 31篇 |
2014年 | 57篇 |
2013年 | 74篇 |
2012年 | 99篇 |
2011年 | 105篇 |
2010年 | 69篇 |
2009年 | 54篇 |
2008年 | 72篇 |
2007年 | 84篇 |
2006年 | 83篇 |
2005年 | 54篇 |
2004年 | 60篇 |
2003年 | 32篇 |
2002年 | 33篇 |
2001年 | 34篇 |
2000年 | 22篇 |
1999年 | 23篇 |
1998年 | 32篇 |
1997年 | 39篇 |
1996年 | 33篇 |
1995年 | 22篇 |
1994年 | 14篇 |
1993年 | 19篇 |
1992年 | 8篇 |
1991年 | 12篇 |
1990年 | 12篇 |
1989年 | 16篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 5篇 |
1985年 | 18篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1975年 | 5篇 |
1973年 | 4篇 |
1969年 | 2篇 |
1967年 | 5篇 |
1966年 | 3篇 |
排序方式: 共有1536条查询结果,搜索用时 93 毫秒
1.
2.
Hugo Maia Julio Casoy Tania Correia Luís Freitas Kleber Pimentel Célia Athayde Elsimar Coutinho 《Gynecological endocrinology》2006,22(10):547-551
OBJECTIVES: To determine whether aromatase expression in the eutopic endometrium and adenomyotic foci is affected by previous use of oral contraceptives containing gestodene, and to determine whether changes in cyclooxygenase-2 (COX-2) expression occur in adenomyosis during the menstrual cycle. PATIENT AND METHODS: This was a retrospective cohort study carried out in paraffin-embedded endometrial tissue obtained from patients with a histological diagnosis of adenomyosis obtained during the proliferative (n = 25) and luteal (n = 10) phases of the menstrual cycle and following the use of continuous oral contraception with gestodene/ethinyl estradiol (n = 7). COX-2 and aromatase expression were measured in both eutopic endometrium and adenomyotic foci using immunohistochemical methods. RESULTS: Aromatase expression was detected in 80% of the endometrial slices by immunohistochemistry. In positive cases, aromatase was mainly detected in the stromal cells of the eutopic endometrium, whereas in the adenomyotic foci this expression was negative in the majority of the cases. Oral contraceptives containing gestodene, on the other hand, were effective in suppressing aromatase expression in both eutopic and ectopic endometrium. COX-2 expression was detected by immunohistochemistry in the glandular epithelium of both eutopic endometrium and adenomyotic foci and there were no significant changes in its intensity throughout the menstrual cycle. CONCLUSION: Aromatase expression in the eutopic endometrium and adenomyotic foci is suppressed by oral contraceptives containing gestodene. Increased aromatase activity may be responsible for the persistent COX-2 expression during the luteal phase. 相似文献
3.
4.
Anya Pimentel Gomes Fernandes Vieira Jose Maria Sampaio Meneses Jr Renato Luiz Maia 《Journal of oral pathology & medicine》2007,36(2):117-119
Cementoblastomas are benign lesions of the odontogenic ectomesenchyme that rarely occur related to the primary dentition, especially on the left side of the mandible. This study describes a case of a true cementoblastoma related to the left second primary mandibular molar in a 7-year-old child (the largest one seen in the left side of the mandible). Additionally, the radiographic and histologic findings of the lesion are described in details. 相似文献
5.
Therapy of post-renal transplantation hyperlipidaemia: comparative study with simvastatin and fish oil 总被引:1,自引:0,他引:1
Castro R; Queiros J; Fonseca I; Pimentel J; Henriques A; Sarmento A; Guimaraes S; Pereira M 《Nephrology, dialysis, transplantation》1997,12(10):2140-2143
Background: Recipients of renal transplantation (RT)
exhibit disturbances of serum lipids and apoproteins that may contribute to
their cardiovascular morbidity and mortality. In our renal transplant
department the hypercholesterolaemia prevalence at the first and fifth year
of RT is 70.0% and 81.2%, respectively. Lipid-lowering therapy has been
utilized in many Transplant Units. The aim of our study was to evaluate
post-RT hyperlipidaemia control with simvastatin or fish oil.
Method: Forty-three RT patients (26 men and 17 women)
with persistent hypercholesterolaemia and stable graft function which were
resistant to a lipid-lowering diet (American Heart Association Step Two)
were randomized into two groups and treated for 3 months with simvastatin
(S) (10 mg/day; n=25) and fish oil (F) (6 g/day; n=18). Total cholesterol
(TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), lipoprotein a
(Lp(a)), apolipoprotein A1 (Apo A1), and apolipoprotein B (Apo B) were
monitored and at the study baseline they were similar between the two
groups. Results: No side effects were detected after 3
months of therapy. In group S, the concentrations of TC (271±46
mg% vs 228±49mg%; P <0.001), TG (180±78 vs
134±45; P<0.01), LDL-C (177& plusmn;40 vs
144±43; P <0.01) and Apo B (96±18 vs
82±16; P <0.001) were significantly reduced, and Apo A1
concentration had increased (135±24 vs 149±30; P
<0.01). In group F, the concentrations of TC (266±25 vs
240±31; P <0.001), TG (203±105 vs
156±72; P=0.02) and HDL-C (63±15 vs 53±12;
P <0.01) were significantly reduced.
Conclusion: We concluded that low-dose simvastatin and
fish oil are both effective and safe in correcting post-RT hyperlipidaemia.
Further prospective studies with larger follow-up are needed to clarify
whether this therapy has an impact on cardiovascular morbidity and
mortality in RT patients. 相似文献
6.
Paulo Gustavo Sampaio Lacativa Laura Maria Carvalho de Mendon?a Pedro José de Mattos Patrício Filho José Raimundo Pimentel Manoel Domingos da Cruz Gon?alves Maria Lucia Fleiuss de Farias 《Journal of clinical densitometry》2005,8(3):352-361
Hyperparathyroidism contributes significantly to decreased bone mineral density (BMD) in end-stage renal disease patients, but this negative influence is not homogeneous throughout the skeleton. We studied the BMD by dual-energy X-ray absorptiometry on total body and on different regions of the skeleton in 42 patients with severe hyperparathyroidism on hemodialysis. We also evaluated the relationship between different risk factors and BMD found on the regions examined in these patients. The legs and other sites where cortical bone predominate were mostly affected, whereas trabecular bone was relatively preserved. This is probably the result of the different effects of hyperparathyroidism on cortical and trabecular bone, but we cannot rule out the interference of ectopic calcifications and sclerotic lesions of vertebral end-plates falsely increasing lumbar spine BMD. The main determinants of low total-body BMD were, in order of importance, immobility, high intact parathyroid hormone levels, low body mass index, and low albumin. Eleven patients presented with pathologic fractures, mainly in the legs, and BMD was lower in this group than in patients without fractures. In conclusion, our study makes clear that hyperparathyroidism is a great threat to bone density in hemodialysis patients, mainly in the legs, the site mostly affected by fragility fractures in our patients. Physicians must worry not only with high parathyroid hormone levels, but also with the nutritional state of these patients. 相似文献
7.
8.
Relative carriage rates of nuclear dehydrogenating clostridia in two populations of different colorectal cancer risk
下载免费PDF全文
![点击此处可从《Journal of clinical pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Carriage of nuclear dehydrogenating clostridia has been associated with colon cancer and implicated in its aetiology. This study has compared the carriage of these organisms in a British population at high risk for the development of colon cancer with a low risk Nigerian population. Clostridia were found in all of the stools from both populations. Nuclear dehydrogenating clostridia were only found in the stools of the British subjects (32%). These results support the suggestion that the carriage rate of nuclear dehydrogenating clostridia in a population is related to the risk of colon cancer. 相似文献
9.
Development of hatching blastocysts from immature human oocytes following in-vitro maturation and fertilization using a co-culture system 总被引:8,自引:0,他引:8
Hwu YM; Lee RK; Chen CP; Su JT; Chen YW; Lin SP 《Human reproduction (Oxford, England)》1998,13(7):1916-1921
Recently, in-vitro maturation (IVM) of immature human oocytes recovered
from non-stimulated follicles has been applied in the treatment of
infertility. However, in previous reports, very few embryos cultured in
conventional medium have reached the expanded blastocyst stage following
in-vitro maturation and fertilization (IVM/IVF). The objective of this
study was to investigate whether the developmental competence of human
embryos following IVM/IVF could be enhanced by the use of a human ampullary
cell co-culture system. Immature human oocytes were aspirated from small
follicles at Caesarean section and then cultured in medium containing human
menopausal gonadotrophin for 36 to 48 h, followed by insemination. Zygotes
were randomly cultured either in conventional culture medium alone or in
the co-culture system. Of 48 embryos cultured in conventional medium alone,
all arrested at the 2-16- cell stage on day 3 after insemination. Of 46
embryos cultured in the co-culture system, 26 embryos (56.5%) arrested at
the 2-16-cell stage. Six embryos (13%) developed to the morula stage.
Fourteen embryos (30.4%) developed to expanded blastocysts and two
blastocysts were hatching on day 7 after insemination. We conclude that
co-culture significantly enhances the development of blastocysts in embryos
resulting from IVM/IVF.
相似文献
10.
Detection of chromosomes and estimation of aneuploidy in human spermatozoa using fluorescence in-situ hybridization 总被引:11,自引:0,他引:11
The development and application of fluorescence in-situ hybridization
(FISH) has opened the way for comprehensive studies on numerical chromosome
abnormalities in human spermatozoa. FISH can be rapidly applied to large
numbers of spermatozoa and thus overcomes the major limitation of
karyotyping spermatozoa after penetration of zona-free hamster oocytes. The
simultaneous hybridization of two or more chromosome-specific probes to
spermatozoa and subsequent detection of the bound probes using different
fluorescent detection systems enables two or more chromosomes to be
localized simultaneously in the same spermatozoon and provides a technique
for undertaking reasonable estimates of aneuploidy. The most commonly used
probes are those which bind to the centromeric region of specific
chromosomes. Most studies to date have concentrated on estimating
aneuploidy in spermatozoa from normospermic men, although reports are
beginning to appear on aneuploidy in spermatozoa from subfertile and
infertile men. Multi- probe FISH studies have generally reported disomy
(hyperhaploidy) estimates of 0.05-0.2% per chromosome. There is preliminary
evidence that some chromosomes such as X, Y and 21 are predisposed towards
higher rates of non-disjunction during spermatogenesis. There are also
suggestions of inter-donor variability in aneuploidy frequencies for
specific chromosomes, although this requires confirmation in larger
studies. While FISH is clearly a powerful technique that has many
applications in reproductive medicine, it must also be realized that it
does have limitations and the technology itself is still evolving and has
yet to be fully validated on spermatozoa.
相似文献