5,012 research outputs found

    Common fixed-point theorems and c-distance in ordered cone metric spaces

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    We present a generalization of several fixed and common fixed point theorems on c -distance in ordered cone metric spaces. In this way, we improve and generalize various results existing in the literature.Наведено узагальнення деяких теорем про нерухому точку та спільну нерухому точку для с-відстані в упорядкованих конічних метричних просторах. Таким чином, покращено та узагальнено різноманітні результати, що наведені в літературі

    Genome expression analysis by suppression subtractive hybridization identified overexpression of Humanin, a target gene in gastric cancer chemoresistance

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    Background: In cancer cells, apoptosis is an important mechanism that influences the outcome of chemotherapy and the development of chemoresistance. To find the genes involved in chemoresistance and the development of gastric cancer, we used the suppression subtractive hybridization method to identify the genes that are overexpressed in gastric cancer tissues compared to normal gastric tissues. Results: In the suppression subtractive hybridization library we constructed, the most highly overexpressed genes were humanin isoforms. Humanin is a recently identified endogenous peptide that has anti-apoptotic activity and has been selected for further study due to its potential role in the chemoresistance of gastric cancer. Upregulation of humanin isoforms was also observed in clinical samples by using quantitative real-time PCR. Among the studied isoforms, humanin isoform 3, with an expression level of 4.166 ± 1.44 fold, was the most overexpressed isoform in GC. Conclusions: The overexpression of humanin in gastric cancer suggests a role for chemoresistance and provides new insight into the biology of gastric cancer. We propose that humanin isoforms are novel targets for combating chemoresistance in gastric cancer. © 2014 Mottaghi-Dastjerdi et al.; licensee BioMed Central Ltd

    Identification of novel genes involved in gastric carcinogenesis by suppression subtractive hybridization

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    Gastric cancer (GC) is one of the most common and life-threatening types of malignancies. Identification of the differentially expressed genes in GC is one of the best approaches for establishing new diagnostic and therapeutic targets. Furthermore, these investigations could advance our knowledge about molecular biology and the carcinogenesis of this cancer. To screen for the overexpressed genes in gastric adenocarcinoma, we performed suppression subtractive hybridization (SSH) on gastric adenocarcinoma tissue and the corresponding normal gastric tissue, and eight genes were found to be overexpressed in the tumor compared with those of the normal tissue. The genes were ribosomal protein L18A, RNase H2 subunit B, SEC13, eukaryotic translation initiation factor 4A1, tetraspanin 8, cytochrome c oxidase subunit 2, NADH dehydrogenase subunit 4, and mitochondrially encoded ATP synthase 6. The common functions among the identified genes include involvement in protein synthesis, involvement in genomic stability maintenance, metastasis, metabolic improvement, cell signaling pathways, and chemoresistance. Our results provide new insights into the molecular biology of GC and drug discovery: each of the identified genes could be further investigated as targets for prognosis evaluation, diagnosis, treatment, evaluation of the response to new anticancer drugs, and determination of the molecular pathogenesis of GC. © The Author(s) 2014

    Yield and yield components of six canola (Brassica napus L.) cultivars affected by planting date and water deficit stress

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    In order to study the effect of planting dates and different irrigation regimes on yield and yield components of six canola cultivars, an experiment was conducted in two growing seasons; 2008 to 2009 and 2009 to 2010. Six canola cultivars (Zarfam, GKH1103, GKH1605, GKH2005, GKH305 and GKH3705) were cultivated in two different dates (October 7th and November 6th) with two levels of irrigation regimes (irrigation after 60 mm evaporation from Class A evaporation pan and irrigation interrupting at flowering stage). The experiments were conducted in randomized complete block design arrangement in split factorial with four replications The results demonstrated that late planting date and interrupting of irrigation at flowering stage significantly decreased growth, yield and yield components the of canola cultivars. In addition, oil yield was affected by late planting and water stress and it was dramatically decreased. Also, there was no significant difference among the cultivars with respect to oil percentage. The highest seed yield (5930.4 kg. ha-1) was obtained from GKH1103 cultivars planted on October 7th under the conditions of full irrigation. Seed yield and oil yield in the second year was more than that of the first year; this increase was related to the increase in seed weight and pod number per plant but not to number of seed per pod. In general, canola cultivation on November 6th considerably decreased seed and oil yield and it is an important point to achieve desirable yield to seed sowing not done later than October 7th. Additionally, complementary irrigation was very important to gain high yield in canola under the conditions of this study.Key words: Canola, planting date, water stress, yield and yield components

    Heavy metal concentrations in the selected tissues of the Persian sturgeon, Acipenser persicus, from the southern coast of the Caspian Sea

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    Bioaccumulation of heavy metals including Cd, Pb, Cu and Zn in muscle, gill, liver, kidney and stomach in Acipenser persicus was studied. Fish were collected from the ‘Iranian fishery zone 1’ located between Astara and Kiyahshahr. Samples (n=25) were collected from five stations in the study area during the autumn catch season in 2001. Samples were analyzed by wet digestion with hydrogen peroxide and nitric acid. Analyses were testified using spike method. A sample of bovine liver (CRM 185R) was tested to ascertain reliability of analyses. Digested samples were analyzed using Flame Atomic Absorption Spectrophotometer. The bioaccumulation pattern for Zn in different tissues studied was stomach>liver> kidney> gills>muscle tissue. The mean concentration of Zn in the stomach was 136.6±10.70μg g-1 dry weight. Cu with the maximum concentration of 39.71±8.85μg g-1 dry weight in liver showed a bioaccumulation pattern of liver>kidney>stomach>gills>muscle tissue. The bioaccumulation pattern for Pb was determined as gills>liver> kidney>stomach>muscle tissue. Maximum mean concentrations of Pb 6.87±2.25μg g-1 dry weight belonged to gills. Bioaccumulation pattern for Cd in the different organs studied in A. persicus was kidney>liver>gills>stomach> muscle tissue. Maximum mean concentration of 5.1±0.97μg g-1 dry weight belonged to kidneys and the minimum mean concentration of 0.05±0.007μg g-1 dry weight belonged to muscle tissue. Concentration of the metals in the muscles samples were below the most guidelines for human consumption. Concentrations for heavy metals were lower than the guidelines in some organs and were higher than that in the other organs studied. The observed concentrations do not pose health problems as these organs are not used for human consumption

    Decadal-centennial scale monsoon variations in the Arabian Sea during the Early Holocene

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    An essential prerequisite for the prediction of future climate change due to anthropogenic input is an understanding of the natural processes that control Earth's climate on timescales comparable to human-lifespan. The Early Holocene period was chosen to study the natural climate variability in a warm interval when solar insolation was at its maximum. The monsoonal system of the Tropics is highly sensitive to seasonal variations in solar insolation, and consequently marine sediments from the region are a potential monitor of past climate change. Here we show that during the Early Holocene period rapid

    Impact of Demand-Response on the Efficiency and Prices in Real-Time Electricity Markets

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    International audienceWe study the effect of Demand-Response (DR) in dynamic real-time electricity markets. We use a two-stage market model that takes into account the dynamical aspects of gen-eration, demand, and DR. We study the real-time market prices in two scenarios: in the former, consumers anticipate or delay their flexible loads in reaction to market prices; in the latter, the flexible loads are controlled by an independent aggregator. For both scenarios, we show that, when users are price-takers, any competitive equilibrium is efficient: the players' selfish responses to prices coincide with a socially optimal policy. Moreover, the price process is the same in all scenarios. For the numerical evaluation of the properties of the equilibrium, we develop a solution technique based on the Alternating Direction Method of Multipliers (ADMM) and trajectorial forecasts. The forecasts are computed us-ing wind generation data from the UK. We challenge the assumption that all players have full information. If the as-sumption is verified, then, as expected, the social welfare increases with the amount of DR available, since DR relaxes the ramping constraints of generation. However, if the day-ahead market cannot observe how elastic loads are affected by DR, a large quantity of DR can be detrimental and leads to a decrease in the welfare. Furthermore, the DR operator has an incentive to under-dimension the quantity of avail-able DR. Finally, we compare DR with an actual energy storage system. We find that storage has a faster response-time and thus performs better when only a limited amount is installed. However, storage suffers from charge-discharge in-efficiency: with DR, prices do concentrate on marginal cost (for storage, they do not) and provide a better welfare

    Management of Streptococcus mutans-Candida spp. Oral biofilms’ infections: Paving the way for effective clinical interventions

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    Oral diseases are considered the most common noncommunicable diseases and are related to serious local and systemic disorders. Oral pathogens can grow and spread in the oral mucosae and frequently in biomaterials (e.g., dentures or prostheses) under polymicrobial biofilms, leading to several disorders such as dental caries and periodontal disease. Biofilms harbor a complex array of interacting microbes, increasingly unapproachable to antimicrobials and with dynamic processes key to disease pathogenicity, which partially explain the gradual loss of response towards conventional therapeutic regimens. New drugs (synthesized and natural) and other therapies that have revealed promising results for the treatment or control of these mixed biofilms are presented and discussed here. A structured search of bibliographic databases was applied to include recent research. There are several promising new approaches in the treatment of Candida spp.–Streptococcus mutans oral mixed biofilms that could be clinically applied in the near future. These findings confirm the importance of developing effective therapies for oral Candida–bacterial infections.C.F.R. would like to acknowledge the UID/EQU/00511/2019 Project—Laboratory of Process Engineering, Environment, Biotechnology and Energy (LEPABE), financed by national funds through FCT/MCTES (PIDDAC). N.M. would like to thank the Portuguese Foundation for Science and Technology (FCT-Portugal) for the Strategic project ref. UID/BIM/04293/2013 and “NORTE2020—Northern Regional Operational Program” (NORTE-01-0145-FEDER-000012)
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