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101.
Production of aflatoxins on both natural (rice and corn) and semisynthetic (YES) media was conducted using an identified toxin-producing strain ofAspergillus flavus. TheA flavus strain was able to produce 4 types of aflatoxins, namely B1, B2, G1, and G2 on rice, corn, and YES media. Quantitative data showed that the concentrations of aflatoxins B1 and G1 produced were 52, 40.3, and 39.6; and 64.7, 45.0, and 58.0jug for 50g of rice, corn, and YES media, respectively. In comparison, the yielded amounts of aflatoxins B2 and G2 were much lower: 11.5, 17.9, and 17.5; and 28.S, 40.3, and 39.5 μg for 50 g of rice, corn, and YES media, respectively. A bioassay was conducted using the following 5 standard bacterial strains:Bacillus megaterium. Bacillus subtilis, Streptococcus faecal is, Staphylococcus epidermidis, andParacoccus denitrificans as well as a field strain of Candida albicans. All strains exceptP denitrificans showed varied degrees of inhibition when applied with crude aflatoxins at 5 to 40μg/mL. The minimum concentration of crude aflatoxins needed to inhibitP denitrificans was 10μg/mL. Moreover,Candida albicans was not inhibited at any concentration of aflatoxins applied in this work. Both undiluted and diluted (1/10, 1/100, and 1/1000) bacterial broth cultures showed a direct relationship between the diameter of inhibition zones and the concentrations of crude aflatoxins. Mean diameters of (7.0–20.5), (5–14), (4.5–13.0), (3.0–12.0), and (1.5–11.0) mm were observed when various concentrations of aflatoxins were applied usingB megaterium, S epidermidis, S faecal is, B subtilis, andP denitrificans, respectively. Field trials were applied to testify the validity of our data. A 1/100 dilution was prepared from each strain of 4 different species to estimate aflatoxins in samples of contaminated corn. Both chemical and biological assays were carried out at the same time. Data revealed that the most sensitive organism inhibited by as low as 7.5μg aflatoxins/mL wasB megaterium giving an inhibition zone of 10.5 mm, followed byS epidermidis with an inhibition zone of 7.5mm. In relation, the other 2 organisms were less sensitive to crude aflatoxins. Similarly, the biological assay was applied to detect aflatoxins in some samples of wheat, corn, peanut, rice, and poultry rations. Of the 14 wheat and 10 corn samples, only 4 wheat and 2 corn samples were found to be positive. The same results were obtained using TLC analysis. 相似文献
102.
Background
Patients with multiple sclerosis (MS) have a decreased frequency of CD8+ T cells reactive to their own Epstein-Barr virus (EBV) infected B cells. We have proposed that this might predispose to the development of MS by allowing EBV-infected autoreactive B cells to accumulate in the central nervous system. The decreased CD8+ T cell response to EBV results from a general CD8+ T cell deficiency and also a decreased proportion of EBV-specific T cells within the total CD8+ T cell population. Because decreased HLA class I expression on monocytes and B cells has been reported in MS and could influence the generation and effector function of EBV-specific CD8+ T cells, the present study was undertaken to measure the expression of HLA molecules on B cells and monocytes in patients with MS. 相似文献103.
104.
Nicolli Bellotti de Souza Isabel M de Andrade Paula F Carneiro Guilherme AM Jardim Isadora MM de Melo Eufranio N da Silva Júnior Antoniana Ursine Krettli 《Memórias do Instituto Oswaldo Cruz》2014,109(5):546-552
Due to the recent advances of atovaquone, a naphthoquinone, through clinical trials
as treatment for malarial infection, 19 quinone derivatives with previously reported
structures were also evaluated for blood schizonticide activity against the malaria
parasite Plasmodium falciparum. These compounds include 2-hydroxy-3-methylamino
naphthoquinones (2-9), lapachol (10), nor-lapachol (11), iso-lapachol (12), phthiocol
(13) and phenazines (12-20). Their cytotoxicities were also evaluated against human
hepatoma and normal monkey kidney cell lines. Compounds 2 and 5 showed the highest
activity against P. falciparum chloroquine-resistant blood-stage parasites (clone
W2), indicated by their low inhibitory concentration for 50% (IC50) of
parasite growth. The therapeutic potential of the active compounds was evaluated
according to the selectivity index, which is a ratio of the cytotoxicity minimum
lethal dose which eliminates 50% of cells and the in vitro IC50.
Naphthoquinones 2 and 5, with activities similar to the reference antimalarial
chloroquine, were also active against malaria in mice and suppressed parasitaemia by
more than 60% in contrast to compound 11 which was inactive. Based on their in vitro
and in vivo activities, compounds 2 and 5 are considered promising molecules for
antimalarial treatment and warrant further study. 相似文献
105.
Jennifer H Humphreys Jessica AB van Nies Jackie Chipping Tarnya Marshall Annette HM van der Helm-van Mil Deborah PM Symmons Suzanne MM Verstappen 《Arthritis research & therapy》2014,16(6)
Introduction
This study aimed to investigate rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) status and levels as predictors of mortality in two large cohorts of patients with early inflammatory arthritis (EIA).Methods
Data from the Norfolk Arthritis Register (NOAR) and Leiden Early Arthritis Clinic (EAC) cohorts were used. At baseline, patients had demographic data and smoking status recorded; RF, ACPA and inflammatory markers were measured in the local laboratories. Patients were flagged with national death registers until death or censor date. Antibody status was stratified as negative, low or high positive by RF and ACPA levels individually. In addition, patients were grouped as seronegative, RF positive, ACPA positive or double antibody (RF and ACPA) positive. Cox regression models explored associations between antibody status and mortality adjusting for age, sex, smoking status, inflammatory markers and year of enrolment.Results
A total of 4962 patients were included, 64% were female. Median age at onset was 56 (NOAR) and 54 (EAC) years. In NOAR and EAC respectively, 35% and 42% of patients were ACPA/RF positive. When antibody status was stratified as negative, low or high positive, there were no consistent findings between the two cohorts. Double antibody positivity was associated with excess mortality in both cohorts compared to seronegative patients: NOAR and EAC respective adjusted HR (95% confidence interval) 1.35 (1.09 to 1.68) and 1.58 (1.16 to 2.15).Conclusions
Patients with EIA who are seropositive for both RF and ACPA have increased mortality compared to those who are single positive or seronegative. Antibody level in seropositive patients was not consistently associated with excess mortality.Electronic supplementary material
The online version of this article (doi:10.1186/s13075-014-0483-3) contains supplementary material, which is available to authorized users. 相似文献106.
This paper unfolds the events, the people and the times that led up to the
founding of AChemS and fashioned its character during its early formative
years. It describes the path over which AChemS came, going from the
original assertions and denials for the need of such an organization to its
later inception and nascent development. This narration highlights such
topics as the debate over the need for AChemS, the role of National Science
Foundation in the founding of AChemS, the derivation of the Association's
name, the choice of Sarasota and the Hyatt House as the meeting site, the
generation of the programs for the early annual meetings, the adoption of
the bylaws, the process of incorporation and tax deferment, and the birth
of the Givaudan Lectureship. Most emphatically highlighted, however, is the
enthusiasm, commitment and hard work that the members of the chemosensory
research community displayed in bringing AChemS to fruition.
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