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排序方式: 共有914条查询结果,搜索用时 11 毫秒
1.
P Coni G Pichiri-Coni G M Ledda-Columbano E Semple S Rajalakshmi P M Rao D S Sarma A Columbano 《Cancer letters》1992,61(3):233-238
The present study was undertaken to determine the effect of two different types of liver cell proliferative stimuli, namely compensatory regeneration and direct hyperplasia on DNA synthesis of normal and preneoplastic isolated hepatocytes. Platelet-poor plasma (PPP) isolated from male Wistar rats treated with three different hepato-mitogens, lead nitrate (LN), cyproterone acetate (CPA) and ethylene dibromide (EDB), or subjected to surgical partial hepatectomy (PH), was tested for its ability to stimulate DNA synthesis in normal and preneoplastic hepatocytes in primary cultures. Induction of DNA synthesis was detected as early as 30 min after CPA, EDB and PH administration and persisted up to 5 days after the LN administration. In addition, hepatocytes isolated from preneoplastic liver nodules were also able to respond in culture to the DNA synthesis stimulus induced by these factors. 相似文献
2.
G. M. Ledda-Columbano P. Coni G. Faa G. Manenti A. Columbano 《The American journal of pathology》1992,140(3):545-549
A single administration of the inhibitor of protein synthesis cycloheximide results in the occurrence of apoptosis in rat liver. The presence of intracellular apoptotic bodies was detected as early as 2 hours after treatment. No evidence of cell necrosis could be observed by histologic and biochemical analysis. Apoptosis was followed by an increased expression of testosterone-repressed prostate message-2 RNA, a gene whose activity has been associated to apoptotic cell death in involuting rat prostate. The finding of in vivo induction of apoptosis in nonproliferating cells by an inhibitor of protein synthesis, together with the rapidity and synchrony in the occurrence of cell death make this model potentially useful for the analysis of the kinetics of the apoptotic cycle and in exploring some of the mechanisms of regulation of genes possibly involved in this type of cell death. 相似文献
3.
Enrico Bertino Carolina Bisson Claudio Martano Alessandra Coscia Claudio Fabris Giovanna Monti Tiziana Testa Amedeo Conti 《Pediatric allergy and immunology》2006,17(7):484-488
AIM: A positive correlation between maternal and cord-blood IgE levels is well documented for total IgEs, but not for specific IgEs. The difficulty in detecting specific cord-blood IgEs is due to their low concentrations, which hinder their dosage by low-sensitivity methods. The study aimed to correlate maternal and foetal specific IgEs against individual cow's milk proteins, detected by highly sensitive and specific techniques. METHODS: Cow's milk specific IgE detection was performed by chemiluminescence on 52 specimens of maternal and cord blood after cow's milk protein separation by 1D and 2D gel electrophoresis. Cow's milk protein (CMP) antigens were identified by mass spectrometry techniques. RESULTS: Specific IgEs for CMPs were found in 25/52 (48.1%) of maternal sera and in 19/52 (37%) of cord-blood sera. In order of decreasing frequency, the proteins found were BSA, IgG heavy chain, caseins and, in a single case, b-lactoglobulin. Positive cord-blood sera in all cases corresponded to a positive maternal result, and maternal and foetal immunoreactivity patterns were closely correlated. Moreover, in no case was there a positive cord-blood response with a negative maternal response. CONCLUSION: The study demonstrates a close relationship between maternal and cord-blood specific IgE patterns. The phenomenon observed could provide a model to elucidate the general production method of foetal IgEs, which might only be produced in the presence of both the corresponding maternal IgE and the related allergen. 相似文献
4.
5.
Dexamethasone inhibits induction of liver tumor necrosis factor-alpha mRNA and liver growth induced by lead nitrate and ethylene dibromide. 下载免费PDF全文
G. M. Ledda-Columbano A. Columbano A. Cannas G. Simbula K. Okita K. Kayano Y. Kubo S. L. Katyal H. Shinozuka 《The American journal of pathology》1994,145(4):951-958
We have recently demonstrated that a single injection of the mitogen lead nitrate to rats induced a rapid increase of tumor necrosis factor-alpha (TNF-alpha) mRNA in the liver and suggested that this cytokine may be involved in triggering hepatocyte proliferation in this model of direct hyperplasia. In this study, we examined whether a similar induction of liver TNF-alpha mRNA could be observed preceding the onset of hepatocyte proliferation induced by ethylene dibromide, another hepatocyte mitogen. In addition, we used dexamethasone, a well known inhibitor of TNF-alpha production, to determine whether its administration could suppress hepatocyte proliferation induced by lead nitrate and ethylene dibromide. A single intragastric administration of ethylene dibromide (100 mg/kg) to male Wistar rats enhanced liver TNF-alpha mRNA after 4 and 7 hours, which then returned to control levels by 24 hours. TNF-alpha mRNA was detectable only in a nonparenchymal cell fraction of the liver. Pretreatment of rats with a single dose of dexamethasone (2 mg/kg) 60 minutes before lead nitrate (100 mumol/kg) or ethylene dibromide completely abolished the increased levels of liver TNF-alpha mRNA induced by these agents. Inhibition by dexamethasone of TNF-alpha mRNA was associated with an inhibition of liver cell proliferation induced by these mitogens, as measured by [3H]thymidine incorporation into hepatic DNA, mitotic index, and DNA content. These results further support the hypothesis that TNF-alpha may be involved in triggering hepatocyte proliferation induced by primary mitogens. 相似文献
6.
Different effects of the liver mitogens triiodo-thyronine and ciprofibrate on the development of rat hepatocellular carcinoma 总被引:1,自引:0,他引:1
Ledda-Columbano GM Perra A Concas D Cossu C Molotzu F Sartori C Shinozuka H Columbano A 《Toxicologic pathology》2003,31(1):113-120
Previous work has shown that treatment with thyroid hormone (T3) decreased the incidence of rat hepatocellular carcinoma (HCC). The present study was designed to determine whether the inhibitory effect of T3 on HCC development was limited to early steps of the carcinogenetic process or, whether a similar effect could also be exerted by starting T3 treatment at later stages. Hepatic nodules were induced in Fischer rats by a single dose of DENA, followed by a 2-week exposure of the animals to 2-AAF and partial hepatectomy. Rats were then divided into 3 groups: group 1 was maintained on basal diet: group 2 was fed a diet containing 4 mg/kg T3 for a week, every month/7 months, starting 9 weeks after DENA administration: group 3 was exposed to cycles of T3 starting 8 months after initiation. Results demonstrate that inhibition of HCC development was essentially similar in rats exposed to T3 starting either 9 weeks or 8 months after initiation (50% inhibition compared to control rats). We have previously shown that T3-induced nodule regression and HCC inhibition occurred in spite of its mitogenic effect. Therefore, we next wished to determine whether a similar antitumoral effect could be exerted by other liver mitogens, such as peroxisome proliferators. Rats exposed to the initiation-promotion protocol described previously, were subjected to 11 cycles of a T3 or a ciprofibrate-supplemented diet, each cycle consisting of 7 days/month: the incidence of HCC and lung metastases was determined 13.5 months after initiation. Results showed that although treatment with T3 strongly inhibited HCC development (only 31% of T3+ rats showed HCC vs 91% of controls), rats given ciprofibrate developed the same number of HCC as T3-untreated rats. In conclusion, the results of this study showed that the anticarcinogenic effect of T3 is maintained also when treatment begins late in the process, and its antitumoral property appears to be specific and may not be shared by other liver mitogens. 相似文献
7.
Cloning and characterization of two catechol 1,2-dioxygenase genes from Acinetobacter radioresistens S13 总被引:2,自引:0,他引:2
Caposio P Pessione E Giuffrida G Conti A Landolfo S Giunta C Gribaudo G 《Research in microbiology》2002,153(2):69-74
Two novel catechol 1,2-dioxygenase (C 1,2-O) genes have been isolated from an Acinetobacter radioresistens strain that grows on phenol or benzoate as sole carbon and energy source. Designated as catA(A) and catA(B), they encode proteins composed of 314 and 306 amino acids, whose deduced sequences indicate that they have approximately 53% identity, whereas their NH2-terminal and COOH-terminal regions have no sequences in common. This may explain their different thermal and pH stability. Polyclonal antibodies raised against an amino-terminal CatA(A) peptide or the whole CatA(B) protein were used to establish their inducible and differential expression patterns upon bacterial growth in phenol or benzoate. The CatA(A) protein (IsoA) was induced by both phenol and benzoate though with different kinetics, whereas the catA(B) product (IsoB) was constitutively produced at low levels that increased only during growth in the presence of benzoate. 相似文献
8.
Simone Baldi Marta Menicatti Giulia Nannini Elena Niccolai Edda Russo Federica Ricci Marco Pallecchi Francesca Romano Matteo Pedone Giovanni Poli Daniela Renzi Antonio Taddei Antonino S. Calabr Francesco C. Stingo Gianluca Bartolucci Amedeo Amedei 《Nutrients》2021,13(3)
Altered circulating levels of free fatty acids (FFAs), namely short chain fatty acids (SCFAs), medium chain fatty acids (MCFAs), and long chain fatty acids (LCFAs), are associated with metabolic, gastrointestinal, and malignant diseases. Hence, we compared the serum FFA profile of patients with celiac disease (CD), adenomatous polyposis (AP), and colorectal cancer (CRC) to healthy controls (HC). We enrolled 44 patients (19 CRC, 9 AP, 16 CD) and 16 HC. We performed a quantitative FFA evaluation with the gas chromatography–mass spectrometry method (GC–MS), and we performed Dirichlet-multinomial regression in order to highlight disease-specific FFA signature. HC showed a different composition of FFAs than CRC, AP, and CD patients. Furthermore, the partial least squares discriminant analysis (PLS-DA) confirmed perfect overlap between the CRC and AP patients and separation of HC from the diseased groups. The Dirichlet-multinomial regression identified only strong positive association between CD and butyric acid. Moreover, CD patients showed significant interactions with age, BMI, and gender. In addition, among patients with the same age and BMI, being male compared to being female implies a decrease of the CD effect on the (log) prevalence of butyric acid in FFA composition. Our data support GC–MS as a suitable method for the concurrent analysis of circulating SCFAs, MCFAs, and LCFAs in different gastrointestinal diseases. Furthermore, and notably, we suggest for the first time that butyric acid could represent a potential biomarker for CD screening. 相似文献
9.
Vittorio Scaravilli Silvia Scansani Alice Grasso Amedeo Guzzardella Marco Vicenzi Irene Rota Mario Nosotti Alberto Zanella Francesco Blasi Antonio Pesenti Giacomo Grasselli 《Transplantation proceedings》2021,53(1):260-264
Knowledge of preoperative right heart function of adult patients with cystic fibrosis (CF) awaiting lung transplant (LUTX) is limited. The echocardiography of adult patients with CF enlisted for LUTX was retrospectively analyzed and compared with standards and invasive analyses (right heart catheterization, multigated radionuclide ventriculography). We included 49 patients (reported as mean ± standard deviation; 29 ± 9 years of age; forced expiratory volume in first second of expiration, 31% ± 11% predicted; lung allocation score, 36 ± 5; invasive mean pulmonary artery pressure, 17 ± 5 mm Hg; multigated radionuclide ventriculography right ventricle [RV] ejection fraction, 50% ± 9%). Patients had increased RV end-diastolic area, RV wall thickness, and increased pulmonary artery acceleration time with subnormal tricuspid annular plane systolic excursion, tissue Doppler positive peak systolic velocity, and fraction area change. Subnormal tricuspid annular plane systolic excursion (< 23 mm), tissue Doppler positive peak systolic velocity (< 14 cm/s), and fraction area change (< 49%) had high sensitivity and negative predictive value in predicting impaired RV.ejection fractionA good correlation between echocardiographic estimated and invasively measured systolic pulmonary artery pressure was observed (R2 = 0.554, P < .001). Adults with CF awaiting LUTX have morphologic alterations of the right heart, with subclinical impairment of RV systolic function. Echocardiography may be used as a bedside, repeatable, and reliable noninvasive test to screen further deterioration in RV function while on the waiting list for LUTX. More prospective follow-up echocardiographic studies are necessary to confirm such a hypothesis. 相似文献
10.
The European Food Safety Authority is currently evaluating the risks related to the presence of emerging mycotoxins in food and feeds. The aim of this study was to investigate the role of soil fertility, resulting from different nitrogen fertilization rates, on the contamination of regulated mycotoxins and emerging fungal metabolites in maize grains. The trial was carried out in the 2012–2013 growing seasons as part of a long-term (20-year) experimental platform area in North-West Italy, where five different N rates, ranging from 0 to 400 kg N ha−1, were applied to maize each year. Maize samples were analyzed by means of a dilute-and-shoot multi-mycotoxin LC-MS/MS method, and more than 25 of the most abundant mycotoxins and fungal metabolites were detected. Contamination by fumonisins and other fungal metabolites produced by Fusarium spp. of the section Liseola was observed to have increased in soils that showed a poor fertility status. On the other hand, an overload of nitrogen fertilization was generally associated with higher deoxynivalenol and zearalenone contamination in maize kernels, as well as a higher risk of other fungal metabolites produced by Fusarium spp. sections Discolor and Roseum. A balanced application of N fertilizer, in accordance with maize uptake, generally appears to be the best solution to guarantee an overall lower contamination by regulated mycotoxins and emerging fungal metabolites. 相似文献