全文获取类型
收费全文 | 16508篇 |
免费 | 1092篇 |
国内免费 | 92篇 |
专业分类
耳鼻咽喉 | 162篇 |
儿科学 | 355篇 |
妇产科学 | 277篇 |
基础医学 | 2249篇 |
口腔科学 | 160篇 |
临床医学 | 1502篇 |
内科学 | 4006篇 |
皮肤病学 | 284篇 |
神经病学 | 1732篇 |
特种医学 | 764篇 |
外国民族医学 | 3篇 |
外科学 | 2841篇 |
综合类 | 38篇 |
一般理论 | 2篇 |
预防医学 | 763篇 |
眼科学 | 148篇 |
药学 | 1086篇 |
中国医学 | 19篇 |
肿瘤学 | 1301篇 |
出版年
2024年 | 12篇 |
2023年 | 121篇 |
2022年 | 194篇 |
2021年 | 519篇 |
2020年 | 241篇 |
2019年 | 498篇 |
2018年 | 586篇 |
2017年 | 388篇 |
2016年 | 391篇 |
2015年 | 478篇 |
2014年 | 738篇 |
2013年 | 882篇 |
2012年 | 1357篇 |
2011年 | 1390篇 |
2010年 | 778篇 |
2009年 | 743篇 |
2008年 | 1118篇 |
2007年 | 1066篇 |
2006年 | 1093篇 |
2005年 | 948篇 |
2004年 | 920篇 |
2003年 | 757篇 |
2002年 | 722篇 |
2001年 | 165篇 |
2000年 | 136篇 |
1999年 | 154篇 |
1998年 | 138篇 |
1997年 | 124篇 |
1996年 | 94篇 |
1995年 | 81篇 |
1994年 | 77篇 |
1993年 | 53篇 |
1992年 | 89篇 |
1991年 | 62篇 |
1990年 | 54篇 |
1989年 | 66篇 |
1988年 | 62篇 |
1987年 | 58篇 |
1986年 | 47篇 |
1985年 | 37篇 |
1984年 | 26篇 |
1983年 | 22篇 |
1982年 | 17篇 |
1975年 | 16篇 |
1974年 | 16篇 |
1972年 | 19篇 |
1971年 | 14篇 |
1970年 | 21篇 |
1969年 | 15篇 |
1968年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Danel Thierry; Cottencin Olivier; Tisserand Laurence; Touitou Yvan 《Alcohol and alcoholism (Oxford, Oxfordshire)》2009,44(1):42-45
Aims: The inversion of melatonin circadian rhythm secretionin some alcoholics during both intake and acute withdrawal hasbeen widely reported. In the same way, what happens to thisinversion when these patients are in long-term withdrawal isnot known. To document this abnormality in alcoholics afterwithdrawal we investigated melatonin secretion observed duringchronic alcoholization and after withdrawal. Methods: We measuredthe urinary 6-sulfatoxymelatonin (6SM) (6SM/creatinine ratio),main metabolite of the hormone, in two fractions, one diurnaland the other nocturnal, in seven alcohol-dependent patientspresenting with this abnormality during alcoholization at twotimes: in acute withdrawal phase (under benzodiazepines) and15 days after beginning of withdrawal (free of any psychotropictreatment). Results: Our results show that this reversed rhythmof melatonin secretion as seen by the diurnal excretion of 6SM(6SM/creatinine ratio) persists during acute withdrawal in morethan half of the patients and is still present 15 days afterwithdrawal in three patients. Conclusion: It is remarkable thatthe inversion of the melatonin rhythms gets corrected in fourout of seven patients after withdrawal. But, the circadian disorganizationof melatonin secretion in three patients could underline a desynchronizationin some alcoholic patients and may indicate more widespreadcircadian temporal structure disturbances in these patients. 相似文献
52.
Ethylene oxide does not extinguish the osteoinductive capacity of demineralized bone: A reappraisal in rats 总被引:7,自引:0,他引:7
We examined the influence of ethylene oxide (EO) and gamma irradiation on the osteoinductive capacity of demineralized bone. Demineralized bone powder prepared from Wistar rats was exposed to EO (55 °C or 40 °C) or gamma irradiation (25 KGy) or was preserved in ethanol. Sterilely-prepared bones served as controls. The powder was packed in a gelatin capsule and implanted for 6 weeks in muscles of 6-week-old female rats. Exposure of demineralized bone particles to EO 55 °C resulted in an almost complete loss of osteoinductivity. Irradiated bones lost about 40% of their osteoinductive capacity, while sterilization with EO at 40 °C resulted in only a slight alteration of the osteoinductivity, as assessed by the recovered weight ratio, calcium content, alkaline phosphatase activity measurements and histo-morphometry. Ethanol treatment had no influence on the new bone yield when compared to controls.
As EO exposure at 40 °C is a true sterilization procedure, it can be recommended in a clinical setting for its small effect on osteoinductive capacity as assessed experimentally in rats. 相似文献
As EO exposure at 40 °C is a true sterilization procedure, it can be recommended in a clinical setting for its small effect on osteoinductive capacity as assessed experimentally in rats. 相似文献
53.
Das traumatisch bedingte Kompartmentsyndrom des Unterschenkels 总被引:2,自引:0,他引:2
K. Küllmer L. Olivier P. Eysel J. D. Rompe und K. P. Schmit-Neuerburg 《European Journal of Trauma》1997,23(3):87-91
Zusammenfassung Um den Stellenwert der Sonographie als Methode der Diagnostik von Sp?tsch?den der Muskulatur nach operativ behandeltem Kompartmentsyndrom
zu prüfen, wurden 27 Patienten (sechs Frauen, 21 M?nner) der Abteilung für Unfallchirurgie des Universit?tsklinikums Essen
am ventralen Unterschenkel nach durchschnittlich 98 Monaten (43 bis 154 Monate) nach dem Trauma standardisiert untersucht
und ein Vergleich mit der gesunden Gegenseite durchgeführt. Bei 15 Patienten war die Dermatofasziotomie wegen eines drohenden
und bei zw?lf Patienten wegen eines manifesten Kompartmentsyndroms erfolgt. Im Vergleich zur gesunden Gegenseite konnte eine
qualitative Gradeinteilung (0 bis 3) der Ver?nderungen erstellt werden, die das Ausma? der Echogenit?tsvermehrung sowie des
Verlustes der muskeltypischen Textur wiedergibt. Grauwerthistogramme konnten die qualitative Einteilung best?tigen. Die Gruppe
mit manifestem Kompartmentsyndrom zeigte ausschlie?lich deutliche und massive Ver?nderungen (Grad 2 und 3). Bei drohendem
Kompartmentsyndrome fand sich zweimal Grad 2 und 13mal Grad 0 oder 1. Die sonographischen Ver?nderungen sind erkl?rbar durch
die bekannten pathomorphologischen Zust?nde nach Kompartmentsyndrom der Muskulatur (Denervierung, Vernarbung). Die Sonographie
eignet sich zur Beurteilung der Weichteile nach Kompartmentsyndrom. Die Ergebnisse unterstützen die Forderung nach einer frühzeitigen
Fasziotomie bei drohendem Kompartmentsyndrom zur Pr?vention vor Muskel- und Nervensch?digungen.
Traumatic compartment syndrome of the lower limb: Significance of ultrasonography in evaluating long-term damage of muscle after dermatofasciotomy
To determine the significance of sonography in evaluating long-term damage of muscle surgically treated for compartment syndrome 27 patients of the Department for Trauma Surgery, University Clinic Essen, Germany, were examined on their anterior lower limb after an average of 98 (43 to 154) months after trauma. They had had a fasciotomy for imminent (n=15) or manifest (n=12) compartment syndrome. Comparing the healthy side a qualitative grading (0 to 3) of the changes could be introduced reflecting the extent of the increase in echogenicity and the loss of the typical muscle texture. Gray scale histograms confirmed the qualitative grading. Patients with manifest compartment syndrome showed severe changes (grade 2 and 3). In imminent compartment syndrome 2 patients with grade 2 and 13 patients with grade 0 or 1 were found. The sonographical changes can be explained by the known pathomorphological changes after compartment syndrome (denervation, scarification). Sonography is useful in the evaluation of soft tissue after compartment syndrome. The results underline the demands of early fasciotomy in imminent compartment syndrome for prevention of damage of muscle and nerve.相似文献
54.
55.
Comparative trial of sclerotherapy for hydroceles 总被引:1,自引:0,他引:1
We present a prospective single-blind trial of sclerotherapy for hydroceles with tetradecyl sulphate and rolitetracycline as sclerosants. Twenty-seven hydroceles were treated with tetradecyl sulphate and 28 with rolitetracycline. The median follow-up was 13 months. There were no statistically significant differences between the 2 drugs in respect of cure rate and complications. The overall cure rate for both drugs was 96%. Complications were rare and common to both drugs. Tetradecyl sulphate and rolitetracycline were found to be equally effective as sclerosants. 相似文献
56.
Purification of Encephalitozoon Cultures Contaminated by Mycoplasmas by Murine Intraperitoneal Inoculation
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Olivier Ridoux Cdric Foucault Michel Drancourt 《Journal of clinical microbiology》1998,36(8):2380-2382
Encephalitozoon species are strict intracellular microsporidia. Cocultures with eukaryotic cell lines can become accidently contaminated by mycoplasmas. We propose a decontamination protocol based on differential cell targeting after intraperitoneal inoculation in mice. Mycoplasma-free microsporidia were isolated from the brains and spleens of inoculated mice 24 h postinoculation by using the centrifugation shell vial system. Identification was confirmed by direct sequencing of PCR-amplified 16S rRNA. 相似文献
57.
Metabotropic Glutamate Receptors Inhibiting Excitatory Synapses in the CA1 Area of Rat Hippocampus 总被引:2,自引:0,他引:2
In the CA1 region of hippocampal slices prepared from young adult rats, we studied the ability of several specific agonists of metabotropic glutamate receptors (mGluRs) to depress excitatory synaptic transmission at the CA3–CA1 pyramidal cell synapses. Three groups of mGluRs have been described: group 1 (mGluR1 and 5) receptors are positively coupled to phospholipase C whereas group 2 (mGluR2 and 3) and group 3 (mGluR4, 6, 7 and 8) receptors are negatively coupled to adenylate cyclase. We found that the broad-spectrum agonist (1 S ,3R)-1-aminocyclopentyl-1,3-dicarboxylate and the group 1-specific agonist ( R,S )-dihydroxyphenylglycine both reversibly inhibited evoked field excitatory postsynaptic potentials, indicating the involvement of group 1 mGluRs. ( R,S )-3,5-dihydroxyphenylglycine presumably inhibited transmission via a presynaptic mechanism, as whole-cell voltage-clamp recordings revealed that inhibition of the synaptic transmission was always accompanied with an increase in paired-pulse facilitation. Treatment with a specific blocker of mGluR1 receptors, the phenylglycine derivative ( S )-4-carboxyphenylglycine, was without effect on the (1 S ,3 R )-1-amino-cyclopentyl-1,3-dicarboxylate-induced depression of the field excitatory postsynaptic potentials, strongly suggesting that mGluR5 receptors are responsible for the (1 S ,3 R )-1-aminocyclopentyl-1,3-dicarboxylate effect. Two selective agonists of group 2 mGluRs, (2 S ,1' s ,2' s )-2-(2'-carboxycyclopropyl)glycine and 4-carboxy-3-hydroxyphenylglycine, were totally ineffective in blocking CA3-CA1-evoked synaptic transmission, excluding the involvement of mGluR2/3 subtypes at this developmental stage. 相似文献
58.
Aneurysm of the abdominal aorta in an eighteen-month-old child 总被引:1,自引:0,他引:1
Jean Olivier Defraigne MD Jean Pierre Paquot MD Etienne Creemers MD Raymond MD Limet 《Annals of vascular surgery》1988,2(2):193-195
We report the case of an infected aneurysm of the abdominal aorta in a 18 month-old child, discovered by routine palpation of the abdomen during hospitalization for pneumonia. Ultrasonography and arteriography showed a 6 cm aneurysm of the abdominal aorta beginning distal to the renal arteries which occluded the right common Iliac artery. The aneurysm was treated by interposing a 6 mm Gore-Tex graft between the infrarenal aorta and the aortic bifurcation. Pathologic examination of the aneurysmal wall demonstrated a leukocytic Infiltrate and the presence of encapsulated Gram positive organisms. Arterial aneurysms are exceedingly rare in children. Their etiology is varied: infection, connective tissue disease, trauma, inflammatory arterial disease or other rare diseases such as tuberous sclerosis, neurofibromatosis, or Beçhet’s disease. 相似文献
59.
Renate A. Morawetz G. Paolo Rizzardi Didier Glauser Olivier Rutschmann Bernard Hirschel Luc Perrin Milos Opravil Markus Flepp Jan von Overbeck Michel P. Glauser Silvia Ghezzi Elisa Vicenzi Guido Poli Adriano Lazzarin 《European journal of immunology》1997,27(12):3223-3227
Homozygous (Δccr5/Δccr5) and heterozygous (CCR5/Δccr5) deletions in the β-chemokine receptor 5 (CCR5) gene, which encodes for the major co-receptor for macrophage-tropic HIV-1 entry, have been implicated in resistance to HIV infection and in protection against disease progression, respectively. The CCR5/Δccr5 genotype was found more frequently in long-term nonprogressors (LTNP) (31.0%) than in progressors (10.6%, p < 0.0001), in agreement with previous studies. Kaplan-Meier survival analyses showed that a slower progression of disease, i.e. higher proportion of subjects with CD4+ T cell counts >500/μl (p = 0.0006) and a trend toward a slower progression to AIDS (p = 0.077), was associated with the CCR5/Δccr5 genotype. However, when LTNP were analyzed separetely, no significant differences in CD4+ T cell counts (p = 0.12) and viremia levels (p = 0.65) were observed between the wild-type (69 % of LTNP) and the heterozygous (31.0 %) genotypes. Therefore, there are other factors which play a major role in determining the status of nonprogression in the majority of LTNP. Furthermore, there was no evidence that the CCR5/Δccr5 genotype was associated with different rates of disease progression in the group of progressors. Taken together, these results indicate that the CCR5/Δccr5 genotype is neither essential nor sufficient for protection against the progression of HIV disease. 相似文献
60.
Picone O Costa JM Chaix ML Ville Y Rouzioux C Leruez-Ville M 《Journal of clinical microbiology》2005,43(1):25-29
The human cytomegalovirus (HCMV) UL144 gene is a tumor necrosis factor-like receptor with the potential to affect HCMV virulence. HCMV strains display genetic variability in the UL144 region, and the analysis of a potential link between UL144 gene polymorphisms and disease severity has scarcely been studied. However, a correlation between the UL144 genotype and congenital-disease outcome has been reported in one previous study, with the observation that all asymptomatic infants had a single UL144 genotype. In order to confirm or refute this finding, we determined the UL144 polymorphisms of HCMV strains recovered from the amniotic fluids of 38 infected fetuses and compared them to HCMV strains obtained from 30 viremic adult controls. The UL144 sequences were distributed among five genotypes (A, B, C, AC, and AB), as previously described. We observed similar percentages of the three major genotypes A (37%), B (33%), and C (27%) in our population. The UL144 genotype distributions were similar among the group of infected adults and the group of infected fetuses and among symptomatic and asymptomatic fetuses (P < 0.05). In our series, all five UL144 genotypes could be vertically transmitted from mothers to fetuses, and all could cause symptomatic congenital infection. We concluded that determination of UL144 polymorphisms in cases of congenital infection is not relevant, since it is unlikely to help predict the outcome of the infection. 相似文献