Crystal structure of a thermophilic GrpE protein: insight into thermosensing function for the DnaK chaperone system.

A homodimeric GrpE protein functions as a nucleotide exchange factor of the eubacterium DnaK molecular chaperone system. The co-chaperone GrpE accelerates ADP dissociation from, and promotes ATP binding to, DnaK, which cooperatively facilitates the DnaK chaperone cycle with another co-chaperone, DnaJ. GrpE characteristically undergoes two-step conformational changes in response to elevation of the environmental temperature. In the first transition at heat-shock temperatures, a fully reversible and functionally deficient structural alteration takes place in GrpE, and then the higher temperatures lead to the irreversible dissociation of the GrpE dimer into monomers as the second transition. GrpE is also thought to be a thermosensor of the DnaK system, since it is the only member of the DnaK system that changes its structure reversibly and loses its function at heat-shock temperatures of various organisms. We here report the crystal structure of GrpE from Thermus thermophilus HB8 (GrpE(Tth)) at 3.23 A resolution. The resolved structure is compared with that of GrpE from mesophilic Escherichia coli (GrpE(Eco)), revealing structural similarities, particularly in the DnaK interaction regions, and structural characteristics for the thermal stability of GrpE(Tth). In addition, the structure analysis raised the possibility that the polypeptide chain in the reported GrpE(Eco) structure was misinterpreted. Comparison of these two GrpE structures combined with the results of limited proteolysis experiments provides insight into the protein dynamics of GrpE(Tth) correlated with the shift of temperature, and also suggests that the localized and partial unfolding at the plausible DnaK interaction sites of GrpE(Tth) causes functional deficiency of nucleotide exchange factor in response to the heat shock

On Retrieval Order of Statistics Information from OpenFlow Switches to Locate Lossy Links by Network Tomographic Refinement

To maintain service quality and availability in managed networks, detecting and locating high loss-rate links (i.e., lossy links that are likely congested or physically unstable) in a fast and light-weight manner is required. In our previous study, we proposed a framework of network-assisted location of lossy links on OpenFlow networks. In the framework, a measurement host launches a series of multicast probe packets traversing all full-duplex links; and then the controller retrieves statistics on the arrival of those probe packets at different input ports on different switches and compares them to locate high loss-rate links. The number of accesses to switches required to locate all lossy links strongly depends on the retrieval order in collecting the statistics and should be small as much as possible. Therefore, in this paper, to minimize the necessary number of accesses, we develop a new location scheme with an appropriate retrieval order using a Bayesian-based network tomography to refine candidates for lossy links. The results of numerical simulation on a real-world topology demonstrate the effectiveness of the new location scheme.11th International Conference on Intelligent Networking and Collaborative Systems(INCoS 2019), September 5-7, 2019, Oita, Japa

KEY FACTORS FOR THE SEPARATION OF SILICON AND IRON DURING PHOSPHORUS RECOVERY FROM SLAG DISCHARGED FROM THE DOUBLE-SLAG REFINING PROCESS

In the present study, we developed a technology for concentrating and recovering phosphorus from slag-like phosphorus-containing unused resources and applied it to slag discharged during the latest steelmaking process, that is, double-slag refining process (DRP). The technology we developed consists of the following four processes: Process (1) is the initial acid elution; Process (2) involves alkali precipitation; Process (3) is the second acid elution; and, Process (4) utilizes ion-exchange. In Process (1), the addition of DPR slag to 0.5 M of a nitric acid solution for 24 min resulted in sufficient phosphorus dissolution. In Process (2), ammonia was added to the dissolved solution, and phosphorus was precipitated with high efficiency. The timing of the addition of ammonia significantly influenced the removal of silicon and iron, which would have been inconvenient to accomplish in subsequent processes. In Process (3), the precipitation obtained in Process (2) was re-dissolved in a nitric acid solution. The dissolution of phosphorus together with other elements progressed sufficiently, and we confirmed that silicon could be completely separated as silica by using high-concentration nitric acid at this stage. The fact that silicon could be removed during Process (3) was an important finding, since silicon could not have been separated in the Process (4). In Process (4), by passing the phosphorus-containing solution obtained in Process (3) through an ion exchange resin, elements other than phosphorus and silicon could be removed, which confirms that the range of applications for this technology could be expanded

Investigation of quality of life in athletes from an anti-aging perspective

U radu je proučavan utjecaj tankih filmova cinkovog oksida narastanih na poroznim strukturama na fotokatalitičku razgradnju metilenskog modrila kao modelnog zagađivača u otpadnim vodama. S obzirom na to da se kemijske reakcije između fotokatalizatora i vodenih otopina odvijaju upravo na njihovoj međupovršini, fotokatalizatori velikih aktivnih površina pripremani su postupcima elektrokemijske oksidacije aluminija u trajanju od 2 h, 4 h, i 6 h u 0,1 M fosfornoj kiselini (H3PO4) i jetkanja u trajanju od 1 h i 2 h u 85 %-tnoj H3PO4. Na dobivene porozne strukture različitih dubina sintetiziran je tanki film (25 nm) cinkovog oksida tehnikom depozicije atomskih slojeva (ALD). Elementna analiza i detaljna karakterizacija morfologije i poprečnog presjeka uzoraka na mikro i nano-skalama provedene su pretražnim elektronskim mikroskopom (SEM), dok su njihova fotokataliticka svojstva, u cilju određivanja optimalnog fotokatalizatora, promatrana mjerenjem optičke apsorpcije UV-Vis spektrofotometrom u periodu od 200 minuta. Rezultati fotokataliticke razgradnje ukazali su na učinkovito uklanjanje bojila metilenskog modrila pod utjecajem sintetiziranih fotokatalizatora. Pojačana fotokatalitička aktivnost primijećena je kod tankog filma cinkovog oksida sintetiziranog na uzorcima aluminija elektrokemijski oksidiranih 4 sata koji su u 200 minuta razgradili nešto više od 50 % modelnog organskog zagađivača. To možemo pripisati njihovoj pogodnoj morfologiji koja se odlikuje povećanom hidrofilnošću u odnosu na ostala 4 uzorka. Također, analizama je pokazano da uzorci jetkani jedan sat pokazuju bolja fotokatalitička svojstva nego oni jetkani dva sata, što se može objasniti degradacijom poroznosti struktura pri dužem nagrizanju uzorka kiselinom.Photocatalytic degradation of methylene blue, as a model pollutant in wastewaters, was studied using zinc oxide thin films synthesized on porous structures. Given that chemical reactions between photocatalyst and aqueous solutions take place by contact between their surface and fluid, photocatalysts of large specific surfaces were prepared by the processes of electrochemical oxidation of aluminium for 2, 4 and 6 hours in 0,1 M H3PO4 and etching during the period of 1 and 2 hours in 85 % H3PO4. On the obtained porous structures of different depths, a thin film (25 nm) of zinc oxide was synthesized using the atomic layer deposition technique (ALD). Elemental analysis and detailed characterization of morphology and cross-section on the microand nanoscale were performed by scanning electron microscope (SEM), while the photocatalytic properties of the sample were studied by measuring optical absorption by UV-Vis spectrophotometer over a 200 minute time period to determine the optimum photocatalyst. The results of photocatalytic degradation indicated the efficient removal of methylene blue dye under the influence of synthesized photocatalysts. However, remarkable results were achieved with samples of zinc oxide thin films synthesized on aluminium samples electrochemically oxidized of 4 hours. These samples dissipated slightly more than 50 % of the model organic pollutant in 200 minutes, which can be ascribed to their specific morphology with increased hydrophilicity compared to the other 4 samples. Also, analyzes showed that samples of 1 hour of etching showed better photocatalytic properties than those of two hours, which can be explained by the degradation of the porosity of the structures during prolonged etching

Food Pyramid for Low Carbohydrate Diet (LCD) with its Efficacy and Actual Intake

U radu je prikazan glavni projekt poslovno-stambene zgrade u Put Brodarice u Splitu. Građevina se sastoji od dva dijela, a to su niži i viši toranj s ukupno 4, odnosno 6 katova iznad prizemlja i garažom ispod zemlje kojom su tornjevi povezani. Građevina je izvedena u armiranom betonu monolitnom izvedbom s armirano-betonskim temeljima, stupovima, zidovima te armirano betonskim pločama kao međukatnim konstrukcijama. Projekt sadrži: tehnički opis konstrukcije, proračun nosivih konstrukcijskih elemenata te karakteristične građevinske nacrte.Main design of the business and residential building, which is positioned in Put Brodarice street in Split, is presented in this work. The building has two parts. There are lower and higher tower with 4 and 6 floors above the ground floor and the garage underground to which the towers are connected with. The building is made of reinforced concrete in monolithic construction with reinforced concrete foundations, walls, columns, beams and reinforced concrete plates as ceiling slabs. The project includes: technical description of the construction, calculation of bearing structural elements and characteristic construction design