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排序方式: 共有612条查询结果,搜索用时 31 毫秒
601.
Effect of chromium(VI) on bacterial kinetics of heterotrophic biomass of activated sludge 总被引:3,自引:0,他引:3
The effect of hexavalent chromium, Cr(VI), on the maximum specific growth rate, mu(m) and biomass yield, Y(H), of heterotrophic biomass was studied in batch tests conducted under high (= 10) and low (= 1.5) substrate-to-biomass ratios (S0/X0). The effects of sludge age and biomass acclimatization to Cr(VI) on the bacterial kinetics were also studied. The mu(m) values were determined by measuring oxygen uptake rate (OUR) and volatile suspended solids (VSS) increase. Cr(VI) concentrations equal or greater than 10 mg l(-1) inhibited the growth of unacclimatized activated sludge and caused a significant decrease in mu(m) and Y(H) values. The acclimatization of biomass and the selection of a high operating sludge age reduced the inhibitory effect of Cr(VI). At a sludge age of 20 days, Cr(VI) concentrations of <10 mg l(-1) stimulated bacterial growth as evidenced by an increase in both the mu(m) and Y(H) values. Determining mu(m) values by OUR and VSS methods, revealed that the presence of Cr(VI) in unacclimatized biomass caused an inhibitory effect mostly on substrate oxidation, while in acclimatized biomass, anabolic pathways were inhibited more. 相似文献
602.
Pappas AC Zoidis E Georgiou CA Demiris N Surai PF Fegeros K 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2011,28(4):446-454
The aim of the study was to investigate the interactions between selenium (Se) and various trace elements, both toxic and essential, involved in the antioxidant system. A total of 128 day-old chicks (Gallus gallus, broilers) were used to investigate the effect of Se yeast supplementation on the accumulation of cadmium (Cd), copper (Cu) iron (Fe) and zinc (Zn). There were four replicates of four dietary treatments: T1 (basal diet with no added Se, analyzed to contain 0.21 mg kg(-1)), T2 (T1 with 0.15 mg kg(-1) Se added), T3 (T1 with 0.3 mg kg(-1) Se) and T4 (T1 with 3.0 mg kg(-1) Se). At week 4 and 6, two chickens per replicate pen were sacrificed for whole blood, breast muscle and liver sampling. Samples were analyzed by ICP-MS. Supplementation with Se-yeast, not only increased Se concentration but also reduced Cd concentration in the tissues. Selenium was negatively correlated with Cd and positively correlated with Zn, Cu and Fe. Cadmium was negatively correlated with Zn and Cu. Zinc was positively correlated with Cu. Iron was negatively correlated with Cu and uncorrelated with Zn and Cd. The balance between Se, Cu, Fe and Zn is important for proper antioxidant defense since they are an integral part of various antioxidant enzymes. 相似文献
603.
Internet of Things (IoT) and its relevant technologies have been attracting the attention of researchers from academia, industry, and government in recent years. However, since the requirements of the IoT are quite different from what the Internet today can offer, several innovative techniques have been gradually developed and incorporated into IoT, which is referred to as the Future Internet of Things (FIoT). Among them, how to extract “data” and transfer them into “knowledge” from sensing layer to application layer has become a vital issue. This paper begins with an overview of IoT and FIoT, followed by discussions on how to apply data mining and computational intelligence to FIoT. An intelligent data management framework inspired by swarm optimization will then given. Finally, open issues and future trends of this field will be addressed. 相似文献
604.
Loukatos P Kanellaki M Komaitis M Athanasiadis I Koutinas AA 《Journal of Bioscience and Bioengineering》2003,95(1):35-39
A new technological approach to distillate production using immobilized cells was investigated. The effect of temperature on the main volatile by-products in distillates was determined. Wines produced by delignified cellulose-, gluten- and kissiris-supported biocatalysis were used as starting materials. The produced distillates were analyzed for ethanol, methanol, acetaldehyde, ethyl acetate, propanol-1, isobutanol and amyl alcohol content. The results showed that distillates from delignified cellulosic material (DCM) at 16 degrees C contained smaller amounts of amyl alcohols, 57% of that produced by gluten and 32% of that produced by kissiris. The ethyl acetate content of distillates from DCM improved the aroma of distillates. These results agree with those of sensory evaluation. Subsequently, the scale-up for low-temperature distillate production at 16 degrees C using DCM was further investigated. A new version of an industrial multi-stage fixed bed tower (MFBT) bioreactor with a capacity of 11,000 l proved to be suitable for continuous fermentation by DCM-supported biocatalysis. Economic analysis showed a reduction in the cost of almost 30% for distillate production and 78% for wine production. 相似文献
605.
Catherine Gabriel Olga Tsave Maria P. Yavropoulou Theodore Architektonidis Catherine P. Raptopoulou Vassilis Psycharis Athanasios Salifoglou 《International journal of molecular sciences》2021,22(13)
Diabetes mellitus is a debilitating disease, plaguing a significant number of people around the globe. Attempts to develop new drugs on well-defined atoxic metalloforms, which are capable of influencing fundamental cellular processes overcoming insulin resistance, has triggered an upsurge in molecular research linked to zinc metallodrugs. To that end, meticulous efforts were launched toward the design and synthesis of materials with insulin mimetic potential. Henceforth, trigonelline and N-(2-hydroxyethyl)-iminodiacetic acid (HeidaH2) were selected as organic substrates seeking binding to zinc (Zn(II)), with new crystalline compounds characterized by elemental analysis, FT-IR, X-rays, thermogravimetry (TGA), luminescence, NMR, and ESI-MS spectrometry. Physicochemical characterization was followed by in vitro biochemical experiments, in which three out of the five zinc compounds emerged as atoxic, exhibiting bio-activity profiles reflecting enhanced adipogenic potential. Concurrently, well-defined qualitative–quantitative experiments provided links to genetic loci responsible for the observed effects, thereby unraveling their key involvement in signaling pathways in adipocyte tissue and insulin mimetic behavior. The collective results (a) signify the quintessential role of molecular studies in unearthing unknown facets of pathophysiological events in diabetes mellitus II, (b) reflect the close associations of properly configured molecular zincoforms to well-defined biological profiles, and (c) set the stage for further physicochemical-based development of efficient zinc antidiabetic metallodrugs. 相似文献
606.
Dimitra Dimitrellou Panagiotis Kandylis Athanasios Mallouchos Michalis Komaitis Athanasios A. Koutinas Yiannis Kourkoutas 《Food chemistry》2010
The effect of freeze–dried kefir culture on the proteolysis of feta-type and whey-cheese was investigated. All nitrogen fractions increased during ripening. Although no significant differences were observed in total nitrogen (TN), the levels of water-soluble nitrogen (WSN), pH 4.4-soluble nitrogen (SN), 12% trichloroacetic acid-soluble nitrogen (TCA-SN) and phosphotungstic acid-soluble nitrogen (PTA-SN) were significantly higher in cheeses produced by freeze–dried kefir culture during the later stages of ripening. Content of total free amino acids (FAA) was significantly affected by freeze–dried kefir starter culture and it was continuously increased in kefir-cheese while, in rennet-cheese it was increased up to 30 days of ripening and then slightly decreased. On the other hand, FAA content continuously decreased in kefir-whey-cheese whereas it increased in whey-cheese. The cheese samples produced by freeze–dried kefir as starter culture were characterised as high-quality products during the preliminary sensory evaluation and they were accepted by the panel. Overall, the use of freeze–dried kefir suggested acceleration of cheese ripening and resulted in improved sensory characteristics. 相似文献
607.
Armelle Vardelle Christian Moreau Jun Akedo Hossein Ashrafizadeh Christopher C. Berndt Jörg Oberste Berghaus Maher Boulos Jeffrey Brogan Athanasios C. Bourtsalas Ali Dolatabadi Mitchell Dorfman Timothy J. Eden Pierre Fauchais Gary Fisher Frank Gaertner Malko Gindrat Rudolf Henne Margaret Hyland Eric Irissou Bertrand Jodoin Eric H. Jordan Khiam Aik Khor Andreas Killinger Yuk-Chiu Lau Chang-Jiu Li Li Li Jon Longtin Nicolaie Markocsan Patrick J. Masset Jiri Matejicek Georg Mauer André McDonald Javad Mostaghimi Sanjay Sampath Günter Schiller Kentaro Shinoda Mark F. Smith Asif Ansar Syed Nickolas J. Themelis Filofteia-Laura Toma Juan Pablo Trelles Robert Vassen Petri Vuoristo 《Journal of Thermal Spray Technology》2017,26(5):985-986
608.
Deng Li Zhi-Gang Chen Hui Liu Athanasios V. Vasilakos Yi Pan 《The Journal of supercomputing》2009,49(2):159-189
The current representatives of Grid systems are Globus and Web services, however, they have poor scalability and single point
failure. It is these two factors which make the building of an improved P2P and grid hybrid framework for resource management
and task schedule such a popular research topic. This paper differs from current research because it puts forward an Information
Pool Based Grid Architecture (IPBGA), which is a real sense hybrid of P2P and grid instead of only introducing P2P methods
into grid systems for resource management. Based on virtualizations, abstract physical resources and tasks to be, the information
requests from resources for tasks and appeals from tasks for resources are upgraded as information services by using an information
pool protocol (IPP). Thus, grid resource management and task scheduling are regarded as information matching by IPP which
is adaptive to the heterogeneous, dynamic, and distributed characteristics of a grid system. Tri-Information Center (Tri-IC)
and source ranking mechanisms are presented in IPP to improve robustness, prevent sybil attack, and to discourage free riding.
Experiments and theory analysis show that the IPP of the IPBGA is more efficient and robust in dealing with information while
both the bandwidth and process costs are less.
相似文献
Yi PanEmail: |
609.
Sevasti Matsia Olga Tsave Antonios Hatzidimitriou Athanasios Salifoglou 《International journal of molecular sciences》2022,23(13)
The plethora of flavonoid antioxidants in plant organisms, widespread in nature, and the appropriate metal ions known for their influence on biological processes constitute the crux of investigations toward the development of preventive metallodrugs and therapeutics in several human pathophysiologies. To that end, driven by the need to enhance the structural and (bio)chemical attributes of the flavonoid chrysin, as a metal ion complexation agent, thereby rendering it bioavailable toward oxidative stress, synthetic efforts in our lab targeted ternary Cr(III)-chrysin species in the presence of auxiliary aromatic N,N′-chelators. The crystalline metal-organic Cr(III)-chrysin-L (L = bipyridine (1) and phenanthroline (2)) compounds that arose were physicochemically characterized by elemental analysis, FT-IR, UV-Visible, ESI-MS, luminescence, and X-ray crystallography. The properties of these compounds in a solid state and in solution formulate a well-defined profile for the two species, thereby justifying their further use in biological experiments, intimately related to cellular processes on oxidative stress. Experiments in C2C12 myoblasts at the cellular level (a) focus on the antioxidant capacity of the Cr(III)-complexed flavonoids, emphasizing their distinct antiradical activity under oxidative stress conditions, and (b) exemplify the importance of structural speciation in Cr(III)-flavonoid interactions, thereby formulating correlations with the antioxidant activity of a bioavailable flavonoid toward cellular pathophysiologies, collectively supporting flavonoid introduction in new metallo-therapeutics. 相似文献
610.
Athanasios S. Alexandris Yiqing Wang Constantine E. Frangakis Youngrim Lee Jiwon Ryu Zahra Alam Vassilis E. Koliatsos 《International journal of molecular sciences》2022,23(13)
White matter pathology is common across a wide spectrum of neurological diseases. Characterizing this pathology is important for both a mechanistic understanding of neurological diseases as well as for the development of neuroimaging biomarkers. Although axonal calibers can vary by orders of magnitude, they are tightly regulated and related to neuronal function, and changes in axon calibers have been reported in several diseases and their models. In this study, we utilize the impact acceleration model of traumatic brain injury (IA-TBI) to assess early and late changes in the axon diameter distribution (ADD) of the mouse corticospinal tract using Airyscan and electron microscopy. We find that axon calibers follow a lognormal distribution whose parameters significantly change after injury. While IA-TBI leads to 30% loss of corticospinal axons by day 7 with a bias for larger axons, at 21 days after injury we find a significant redistribution of axon frequencies that is driven by a reduction in large-caliber axons in the absence of detectable degeneration. We postulate that changes in ADD features may reflect a functional adaptation of injured neural systems. Moreover, we find that ADD features offer an accurate way to discriminate between injured and non-injured mice. Exploring injury-related ADD signatures by histology or new emerging neuroimaging modalities may offer a more nuanced and comprehensive way to characterize white matter pathology and may also have the potential to generate novel biomarkers of injury. 相似文献