Remarked Suppression of Aβ 42 Protomer-Protomer Dissociation Reaction Elucidated by Molecular Dynamics Simulation

Multimeric protein complexes are molecular apparatuses to regulate biological systems and often determine their fate. Among proteins forming such molecular assemblies, amyloid proteins have drawn attention over a half-century since amyloid fibril formation of these proteins is supposed to be a common pathogenic cause for neurodegenerative diseases. This process is triggered by the accumulation of fibril-like aggregates, while the microscopic mechanisms are mostly elusive due to technical limitation of experimental methodologies in individually observing each of diverse aggregate species in the aqueous solution. We then addressed this problem by employing atomistic molecular dynamics simulations for the paradigmatic amyloid protein, amyloid-β (1-42) (Aβ ). Seven different dimeric forms of oligomeric Aβ fibril-like aggregate in aqueous solution, ranging from tetramer to decamer, were considered. We found additive effects of the size of these fibril-like aggregates on their thermodynamic stability and have clarified kinetic suppression of protomer-protomer dissociation reactions at and beyond the point of pentamer dimer formation. This observation was obtained from the specific combination of the Aβ protomer structure and the physicochemical condition that we here examined, while it is worthwhile to recall that several amyloid fibrils take dimeric forms of their protomers. We could thus conclude that the stable formation of fibril-like protomer dimer should be involved in a turning point where rapid growth of amyloid fibrils is triggered.

Gem-Grade Garnet With Metamorphic Origin in the Tiemurt Orogenic-Type Deposit, Chinese Altay Orogen: Texture, Chemistry, and Physicochemical Condition

The Chinese Altay Orogen represents an accretionary collage with episodic subduction-related accretion from the Neoproterozoic to Permian, followed by Triassic continent–continent collision. Reddish gem-grade garnet grains are widespread in Au–Cu–Pb–Zn sulfide deposits of the Chinese Altay Orogen, and how their formation links to regional geological processes such as seafloor sedimentation, magmatic hydrothermal metasomatic, or orogenic metamorphism remains unclear. In this context, we present an integrated set of geological occurrences, mineral texture, and major trace elemental geochemistry of six garnet grains from the representative Tiemurt Cu–Pb–Zn(-Au) deposit. Two categories of garnets, Grt1 and Grt2, are identified in terms of distinct mineral assemblages, textures, and geochemistry. The sub- to euhedral biotite inclusion–rich Grt1 with fine grains of less than 0.3 cm in diameter is intergrown with amphibole, chlorite, and biotite. Comparatively, the euhedral mineral inclusion–poor Grt2 with coarse grains of 0.5–5 cm in diameter is paragenetic with quartz, calcite, chlorite, and biotite. Forty-one EMPA analyses show that Grt1 and Grt2 have similar major elemental compositions of SiO2 (36.2–37.5 wt%), Al2O3 (19.9–20.7 wt%), and CaO (5.3–7.8 wt%) but host variable contents of FeO (31.7–35.9 wt% for Grt1 and 23.0–30.0 wt% for Grt2) and MnO (0.8–3.7 wt% for Grt1 and 4.3–12.7 wt% for Grt2). Both Grt1 (with a chemical formula of Alm49.3–54.6Spe19.7–24.6Gro14.6–18.4Pyr3.7–4.8And3.5–4.9) and Grt2 (Alm57.4–64.4Gro15.5–18.3Spe9.62–19.8Pyr3.8–5.7And1.1–4.4) are plotted into the field close to the end-member of almandine (Fe-Al–garnet). Compared to Grt1, Grt2 displays a Fe-enriched and Mn-depleted trend. Additionally, Mn is enriched in the core but Fe is enriched in the rim on the major elemental profile of Grt1. Regarding the trends of trace elements and REEs, Grt2 is believed to be produced during the detriment and replacement of Grt1 by an intense external metal-rich fluid. In combination with previous fluid inclusion research, the garnet-related fluids are characterized by CO2-rich, mesothermal, mildly acidic, and reduced redox, analogous to metamorphic fluids generated during orogenesis. Collectively, we conclude that the reddish gem-grade garnet crystals in the Chinese Altay Orogen are of metamorphic origin.

A New Constraint on the Physicochemical Condition of Mars Surface during the Amazonian Epoch Based on Chemical Speciation for Secondary Minerals in Martian Nakhlites

Iddingsite in Martian nakhlites contains various secondary minerals that reflect water–rock interaction on Mars. However, the formation processes of secondary Fe minerals in iddingsite are unclear because they include carbonates precipitated under reductive and alkaline conditions and sulfates that are generally precipitated under oxidative and acidic conditions. Mineral types cannot coexist under equilibrium. Herein, we characterize the carbonate phase of meteorite Yamato 000593 as siderite and Mn-bearing siderite via field-emission electron probe microanalyzer (FE-EPMA). Then, we examined the distribution and speciation of trace Cr and S within the carbonates through synchrotron micro-focused X-ray fluorescence-X-ray absorption fine structure and scanning transmission X-ray microscopy (μ-XRF-XAFS/STXM) analysis to estimate the transition history of Eh-pH conditions during siderite formation to explain the coexistence of carbonate and sulfate phases in the nakhlite vein. Specifically, the distribution and speciation of S in the mesostasis and carbonate phases and the heterogeneous distribution of Mn-FeCO3 incorporating Cr(III) in the carbonate constrain the Eh-pH condition. The conditions and transition of the fluid chemistry determined herein based on speciation of various elements provide a new constraint on the physicochemical condition of the water that altered the nakhlite body during the Amazonian epoch.

Analysis of the Physicochemical Quality of Water Within the Hydropower Plant on the Ślęza River in Wrocław, Poland

The aim of the article was the analysis of the physicochemical quality of water within the hydropower plant on the Ślęza River in Wrocław (south-west Poland) in the context of the European Union's classification of water quality, as well as an assessment of the potential impact of hydropower plants on this quality. The study uses the results of monthly tests from three measurement points within the hydropower plant on the Ślęza River in the city of Wrocław (points upstream and downstream the hydropower plant and the reference point), from the period June 2018 to May 2020. The analyses covered 10 physicochemical parameters, i.e.: pH, electrical conductivity (EC), water temperature, turbidity, NH4-N, NO3-N, NO2-N, total phosphorus, dissolved oxygen and BOD5. The conducted analysis showed that the hydropower plant has no clear influence on the physicochemical quality of the water in the Ślęza River, other interactions present in the catchment area are more important. From the effects visible in the results, a decrease in the amplitudes of water temperature downstream the hydropower plant compared to the other points was noted, as well as a lower median of its value (statistically significant changes). An additional noticeable effect was the increase in water oxygenation below the damming, but it was not statistically significant. It has been shown that the physicochemical condition of water at the tested points does not meet the assumed standards for 8 out of 9 parameters (except for water temperature). The largest exceedances of the limit values concerned NO2-N (up to 923% of the norm), and the most consistent, almost constantly occurring – EC (23 out of 24 months). The reason for the high NO2-N content was most probably surface runoff from the fields and the re-suspension of sediments rich in nutrients, while in the case of EC, its high values result from the specificity of the catchment area.

Bioremediation of arable soil using Nitrogen, Phosphorus, Potassium fertilizer treatment

This study seeks to examine “in situ” remediation effectiveness of NPK fertilizer treatment as a viable biostimulation-based bioremediation technology for soil remediation by evaluating data obtained from soil physicochemical properties before and after initiation of bioremediation. Bioremediation was initiated by stimulating indigenous microorganisms in soil by NPK application while remediation was determined by soil physicochemical condition after nutrient amendment and changes observed in plant height after 60, 90, 120, 150, 180 and 210 days of planting. Rhizomes of turmeric were planted in soil treated with NPK fertilizer and control in a randomized complete block design (RCBD) with three replications. Data generated from soil physicochemical parameters in laboratory and field was analyzed before and after treatment. Study showed increase in available potassium, available phosphorus, total nitrogen, pH, cation exchange capacity (CEC) and organic carbon. However, there was decrease in aluminium, soil organic matter and acidity. Sand, silt and clay also decreased slightly. Study revealed significant increase in plant height from plants that benefitted from nutrient amendment.

USING THE METHODOLOGY OF "GREEN" CONSTRUCTION FOR RATING EVALUATION OF ROADS

The use of new technologies and raw materials, including man-made materials, in the production of con-struction and road materials increases the risks of forming a negative technogenic load on environmental objects when used in road construction. This is of particular relevance due to the fact that the road network has a long extension in the settlements and as a result has a negative impact on the person. A new methodolo-gy for "green" construction, which is currently being effectively used in a number of developed European countries, can give a comprehensive assessment of the emergence of risks. On the basis of analytical and la-boratory studies it is shown that the methodology of "green" construction used for the evaluation of residen-tial and industrial buildings can not be applied to the evaluation of road construction objects. When as-sessing the building materials used in road construction, the change in their physicochemical condition dur-ing long-term operation in the elements of road structures is not taken into account. It is shown that the emis-sion of environmentally hazardous chemical compounds that make up construction materials increases with the cyclicity of the pH of the medium of their placement, the discontinuity of the surface. It was proposed to include such provisions as "protection from the aquatic environment", "stable pH values of the external envi-ronment" for the formation of a rating system for assessing the "green" construction of motor roads in order to ensure environmental safety.

Evaluation of Environmental Hazard During Shale Gas Exploration Process in Poland in the Years 2012-2014

This paper is a summary of results of environmental analysis conducted by PGI-NRI, AGH-UST within the monitoring of natural gas prospecting in unconventional deposits. All elements of natural environment were analyzed and on this basis the qualitative and quantitative impact of drilling and hydraulic fracturing of shales could be assessed. Special attention was drawn to the analysis of the physicochemical condition of post-reaction fluids, soil gas in the well pad area and drilling fluids. The results of analysis reveal that prospecting works do not create a significant environmental hazard. Some indices connected, e.g. with the noise climate lightly exceeded permissible values. Nonetheless, if extensive prospecting and production of shale gas are involved, the environmental studies need to be broadened to supplement this report.

Pigments from fungi, an opportunity of production for diverse applications

Fungi provide a readily available alternative source of naturally derived pigmented molecules that may be utilized in different areas as foods, textile, medicine and cosmetics. These have been considered as potent biocompounds under two perspectives: for coloring to products, or as powerful chemical structures with biological functions. Both properties are also often found in their study and application in these areas. The present review presents an overview of diverse aspects that have been studied on the obtaining of fungal pigments, including pigment class, and metabolic pathway of biosynthesis, producer’s species of pigment, physicochemical condition of biosynthesis, extracting, isolation, purifying and storage. Commercial production and application of fungal pigments status is also described in this research as main findings.

Ore-Forming Fluid System of the Anqing Cu-Fe Deposit, Anhui Province, China

Fluid inclusions, carbon and oxygen isotopic compositions were discussed to understanding the ore-forming fluid system of Anqing Cu-Fe deposit. Homogeneous temperatures of fluid inclusions ranged from 124°C to 570°C, δ13CPDBvalues of the gangue minerals ranged from-3.3 to-0.9, and δ18O values ranged from 9.4 to 10.7, respectively. The results reveal that the primary ore-forming fluid was magmatic hydrothermal fluid characterized by high temperature, the boiling and mixing of fluids occurred in the main mineralization stage, the magmatic water was dominant in the ore-forming process, the physicochemical condition changes of the fluid system led to the formation of skarn and the deposition of the ore minerals. The ore-forming materials were mainly derived from magma, partly provided by sedimentary strata.