Miracle-dz/UniFAR-FTUs huggingface dataset:
Coordination of N-Donor Ligands by the Monomeric Ferric Porphyrin N-Acetylmicroperoxidase-8

The monomeric ferric hemepeptide from cytochrome c, N-acetylmicroperoxidase-8 (NAcMP8), retains the proximal His ligand and has a coordinated water molecule in the second axial site. It provides an opportunity for quantitatively studying in aqueous solution the coordination chemistry of an iron porphyrin with a single accessible coordination site. An examination of the dependence of the spectrophotometrically determined equilibrium constants for coordination of imidazole and cyanide as a function of pH provides a procedure for correcting conditional equilibrium constants for the ionization of coordinated H2O in NAcMP8 and protonation of the entering ligand, L. An examination of the coordination by NAcMP8 of L = primary amines and imidazoles (25 °C, μ = 0.1 M) and pyridines (as a function of temperature, μ = 0.1 M) has shown that the process of binding L to NAcMP8 may be complex. With some ligands such as pyridines and some primary amines there is evidence for formation of an outer-sphere complex before di.
Molecular‐dynamics computer simulation of an aqueous NaCl solution: Structure

A classical molecular‐dynamics simulation of a 1.791 molal aqueous NaCl solution is performed using a flexible/polarizable five‐site water model. Through an investigation of the ion‐water pair‐correlation functions and the relative orientation of the waters of hydration, we are able to study the solvation structure in this moderately concentrated salt solution. Under perturbations from the solvated ions, there appears a considerable reorganization of the water molecules. Some of the original intermolecular hydrogen bonding structure is broken down, as bonding with the neighboring cations and anions takes place. Also considered in this paper are the energetics of hydration, and the effect of ionic perturbations on properties such as the water intramolecular structure and vibrations, and the solution phase dielectric constant. An important conclusion from this work is that, in the NaCl solution studied here, perturbations on the water structure by the ions affect mainly intermolecular orientational properti.
A semi-automated system for quantifying the oxidative potential of ambient particles in aqueous extracts using the dithiothreitol (DTT) assay: Results from the Southeastern Center for Air Pollution and Epidemiology (SCAPE)

Abstract. A variety of methods are used to measure the capability of particulate matter (PM) to catalytically generate reactive oxygen species (ROS) in vivo, also defined as the aerosol oxidative potential. A widely used measure of aerosol oxidative potential is the dithiothreitol (DTT) assay, which monitors the depletion of DTT (a surrogate for cellular antioxidants) as catalyzed by the redox-active species in PM. However, a major constraint in the routine use of the DTT assay for integrating it with large-scale health studies is its labor-intensive and time-consuming protocol. To specifically address this concern, we have developed a semi-automated system for quantifying the oxidative potential of aerosol liquid extracts using the DTT assay. The system, capable of unattended analysis at one sample per hour, has a high analytical precision (coefficient of variation of 15% for positive control, 4% for ambient samples) and reasonably low limit of detection (0.31 nmol min−1). Comparison of the automated approach with the manual method conducted on ambient samples yielded good agreement (slope = 1.08 ± 0.12, r2 = 0.92, N = 9). The system was utilized for the Southeastern Center for Air Pollution & Epidemiology (SCAPE) to generate an extensive data set on DTT activity of ambient particles collected from contrasting environments (urban, roadside, and rural) in the southeastern US. We find that water-soluble PM2.5 DTT activity on a per-air-volume basis was spatially uniform and often well correlated with PM2.5 mass (r = 0.49 to 0.88), suggesting regional sources contributing to the PM oxidative potential in the southeastern US. The correlation may also suggest a mechanistic explanation (oxidative stress) for observed PM2.5 mass-health associations. The heterogeneity in the intrinsic DTT activity (per-PM-mass basis) across seasons indicates variability in the DTT activity associated with aerosols from sources that vary with season. Although developed for the DTT assay, the instrument can also be used to determine oxidative potential with other acellular assays.
Swelling of larch wood in organic liquids

Abstract The swelling of larch wood in 1-butanol, dimethyl sulfoxide, N,N-dimethyl formamide, ethylene glycol, ethanol, methyl cellosolve, 1-propanol and toluene was investigated at room temperature. The volumetric, tangential and radial swelling completion was lagging behind the liquid absorption process. The kinetic indices of swelling of larch wood were determined based on the equation of Kolmogorov-Erofeev. The volumetric swelling was related to molecular mass, molar volume, dielectric permittivity and integral heat of wood wetting. The anisotropy of wood swelling was characterized by the ratio of equilibrium tangential swelling to radial swelling (α t,/α r). It was demonstrated that α t,/α r is related to the dipole component of Hansen's parameter and cannot exceed the value 3.
Mechanism of Controlled/“Living” Radical Polymerization of Styrene in the Presence of Nitroxyl Radicals. Kinetics and Simulations

The polymerization of styrene in the presence of a stable radical, TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy), has been simulated using a Predici simulations package. On the basis of the experimental data, a kinetic model for the TEMPO-mediated polymerization of styrene is proposed. In order to simulate the experimental data properly, it was necessary to include thermal self-initiation, transfer, and irreversible decomposition of intermediate alkoxyamines in addition to the reversible cleavage of the TEMPO-polymeric radical adduct. This model, combined with the values of the rate constants of propagation (kp), termination (kt), transfer (ktrm), and alkoxyamines decomposition (kdecomp), was then employed to estimate the kinetic and thermodynamic parameters for the exchange between dormant and active species. The equilibrium constant, K, was estimated to be approximately 10-11 mol·L-1, the deactivation rate constant, kd = 8 × 107 mol-1·L·s-1, and the activation rate constant, ka = 8 × 10-4 s-1, for bulk s.
Challenges and coping mechanisms of persons deprived of liberty of sablayan prison and penal farm in the Philippines

The primary purpose of the study was to determine the challenges and coping mechanisms of the selected Persons Deprived of Liberty (PDLs) of Sablayan Prison and Penal Farm (SPPF), Occidental Mindoro, Philippines. The study made use of qualitative descriptive design. An interview guide was used to collect the data. Owing to the Prison Superintendent's permission and prerogative only three (3) PDLs were allowed to participate in the study. The participants were selected based on criteria such as being not form Mindoro, being head of the family, on minimum security, and first time offender. The participants during the data gathering disclosed that they had trouble inside the prison. It includes difficulties in adjusting to prison life, the feeling of powerlessness, adherence to unwritten laws, bearing the pain for the sake of the family, staying out of trouble, exploitation of the weak, and they feel that they are the forgotten the victims. The effects of these difficulties vary among individuals because they have their ways of adapting to the prison environment. One of the participants thought of self- destruction, while others develop adaptive behavior towards incarceration. Other repercussions of challenges are self- reflection and self- renewal, faith in God, prison as a haven and positive outlooks in life. The challenges were either helpful or harmful in the participants’ life. Moreover, the study revealed that to cope with the prison environment the participant chose to become submissive, bear the consequences of their act, keeps themselves busy, and, remained active in religious activities.
A Gated Service MAC Protocol for Sub-Ms Latency 5G Fiber-Wireless mmWave C-RANs

In order to meet the ever-increasing traffic demands, the combination of fiber and Millimeter Wave (mmWave) is expected to play a key role for 5G Centralized-Radio Access Networks (C-RANs). Due to the inefficiency of the Common Public Radio Interface for the Baseband Unit (BBU)-Remote Radio Head (RRH) communication, analog-Radio-over-Fiber (a-RoF) technology is considered a promising solution, mainly due to the RRH simplification and lower fronthaul requirements it imposes. In such mmWave a-RoF C-RANs, efficient Medium Transparent-Medium Access Control (MT-MAC) protocols are needed able to meet the challenging 5G requirements. To this end, in this paper, we propose a gated service MT-MAC protocol which authorizes each user to transmit the amount of data it requested. A detailed delay model is proposed, which is validated through simulations for different fiber lengths, network load conditions and number of available optical wavelengths. Moreover, the proposed protocol is compared with the state-of-the-art (SoA) and is shown to achieve up to 20 times higher throughput, 2 times lower delay with 100% lower blocking probability and 5 times higher data wavelength utilization, while being able to adapt to varying network traffic conditions. Our proposal also attains sub-ms latency in most cases, constituting it a promising candidate for 5G mmWave a-RoF C-RANs.
The storage of herring (Clupea harengus) in ice, refrigerated sea water and at ambient temperature. Chemical and sensory assessment

Herring caught during the winter and summer were stored in ice, refrigerated sea water (RSW) and at ambient temperature. Chemical tests and a sensory assessment of the fish were made on samples stored for up to 13 days. Results indicate that herring can be chilled simply and rapidly using an RSW plant and that spoilage changes in the fish stored in ice and RSW are similar during the first 4 or 5 days of storage. The chemical tests investigated serve more as indicators of spoilage rather than quantitative guides.
Structure and guest distribution of the mixed carbon dioxide and nitrogen hydrates as revealed by X-ray diffraction and 13C NMR spectroscopy

In this contribution, X-ray diffraction and 13C NMR spectroscopy were used to identify structure and guest distribution of the mixed N2 + CO2 hydrates. X-ray diffraction results of the mixed N2 + CO2 hydrates confirmed that the unit cell parameter was ∼11.8 A over the gas mixture composition range of 3−20 mol % CO2 and the formed hydrates were identified as structure I. When the composition of the gas mixture was reduced to 1 mol % CO2, the structure of the mixed hydrate was transformed to structure II showing the unit cell parameter of 17.26(2) A. 13C cross-polarization (CP) NMR spectroscopy was used to examine the distribution of carbon dioxide molecules in small 512 and large 51262 cages of structure I. From NMR spectra of the mixed N2 + CO2 hydrate formed from gas mixture of 20 and 10 mol % CO2, powder patterns having chemical shift anisotropy of −54.5 and −53.8 ppm were observed, respectively. There was no clear isotropic line indicating carbon dioxide molecules in the small 512 cages of structure I.
Some aspects of the periurban dairy system in Cameroon

A survey to establish baseline data for future intervention in milk and dairy production in the peri-urban areas of Garoua, Maroua and Bamenda was carried out. Dairy products are still produced in a traditional way in areas around Maroua and Garoua with milk from native zebu cattle (Red and White Fulani breeds). The important dairy products are pendidam and kindirmu, both of which are fermented milks. Naturally sour milk was found occasionally. Around Bamenda, milk is produced by herds comprising pure Holsteins, Jerseys and their crosses with local zebu cows; cross-breeding is being intensified to increase rapidly the size of the dairy herds. Appreciable volumes of milk are produced daily, so allowing the industrial processing of fresh milk into pasteurized milk, yogurt and cheese. The potential for expansion of the dairy industry, and the possible constraints, were identified and solutions proposed.
The Mechanism, Thermodynamic and Kinetic Characteristics of the Microbial Reduction of Goethite Mediated by Anthraquinone-2-Sulfonate

The microbial reduction process of goethite by Shewanella decolorationis S12 was evaluated. The results showed the electron shuttle, anthraquinone-2-sulfonate (AQS), could enhance the microbial reduction. The thermodynamic and kinetic characteristics of goethite reduction by microorganisms were influenced by AQS, concentrations of iron oxide, and electron donor. Transformation between oxidized and reduced species of the electron shuttle during the microbial reduction could be newly noticed. Two interactive steps, biotic and abiotic, were involved in the microbial reduction of Fe (III) oxide mediated by electron shuttle.
Ab-initio study of the interfacial properties in ultrathin MgO films on O-rich FeO/Fe(001) surfaces

Using ab-initio simulations based on density functional theory, we systematically studied the interfacial properties of MgO films on O-rich FeO/Fe(001) surfaces with increasing number of MgO layers from one to three monolayers (MLs). The structural and the adhesion properties of the MgO/FeO/Fe(001) system were assessed and compared with those of simple MgO/Fe(001) interfaces. Our calculated results showed that the adhesion energy for MgO/FeO/Fe(001) was smaller than that for simple MgO/Fe(001). An analysis of the electronic structures and the charge rearrangements of the MgO/FeO/Fe(001) interfaces was also performed. The work functions of the MgO/FeO/Fe(001) systems upon the deposition of MgO films exhibited smaller decreases (0.45–0.67 eV) than those (1.43–1.74 eV) of the MgO/Fe(001) systems. In addition, the obtained work functions (3.77–3.99 eV) for MgO/FeO/Fe(001) were much larger than those (2.12–2.43 eV) for MgO/Fe(001).
Variation of Surface Ozone Recorded at the Eastern Coastal Region of the Malaysian Peninsula

Problem statement: Variations of ozone (O3) concentrations in the Eastern Coastal Region of the Malaysia peninsula were investigated using data obtained from the Malaysian Department of the Environment. The aim of this study was to determine the monthly and seasonal variations of ozone concentrations at all monitoring sites. This study deals with the air quality data recorded at four air quality monitoring stations in the East Coast of the Malaysian peninsula over a ten year period (1997- 2006). Approach: We focused on the usage of S-Plus and SPSS to analyze this data. The S-Plus programming was used to impute missing data and SPSS was used to obtain the variations of ozone and also to clarify the relationship between stations. Results: Over the entire 10 year period (1997- 2006), the trend in annual baseline ozone generally increased each year for all the four monitoring sites. There was also a seasonal variability in the measured ozone levels with high concentrations during the southwest monsoon and the northeast monsoon season, producing a significant increase in the amplitude of the seasonal cycle. The results also shown that the highest ozone concentrations were recorded at the Bukit Kuang air monitoring station (S1), with a daily mean value of 19 ppb followed by the Indera Mahkota air monitoring station (S2). The concentration of ozone recorded at Kota Bharu (S3) and Kuala Terengganu (S4), two stations located in the city centre, was found to be lower than the values recorded at Bukit Kuang and Indera Mahkota. The correlation between O3 and NO is high at Kuala Terengganu (S4) (ρ = -0.579), whilst the relationship between O3 and NO2 are high (ρ = -0.397) at Indera Mahkota (S2). Conclusion: The concentration of ozone in the East Coast of Malaysian peninsula depends on the concentration of NOx and seasonal meteorological factors.
Solid State Electrical Conductivity of Radical Polymers as a Function of Pendant Group Oxidation State

We establish the relationship between pendant group chemical identity and the ability of a specific radical polymer, poly(2,2,6,6-tetramethylpiperidinyloxy methacrylate) (PTMA), to transport charge in the solid state. Radical polymers (i.e., macromolecules with aliphatic carbon backbones and pendant groups containing stable radical moieties) have attracted much attention in organic electronic applications due to straightforward synthetic methods, easily tunable electronic properties, and relatively high-performance with respect to charge transport. Because charge transport can occur only through the pendant group of these completely amorphous radical polymers, controlling the precise chemical nature of these functional groups is of key import. Specifically, we have determined that the deprotection step, which converts the pendant group functionality through a simple oxidation reaction, can lead to four distinct chemical functionalities along the radical polymer, as monitored by a range of complementary sp.
Surface physicochemistry of corona‐discharge‐treated polypropylene film

Corona discharge treatment (CDT) is a surface modification technique commonly used to treat plastic films prior to adhesive bonding, printing with inks, lamination to other films and other coating applications. In this study, the treatment conditions are, in energy terms, representative of those used in industrial and laboratory coating applications.
Quantal analysis of synaptic plasticity in the rat hippocampus

Long-term potentiation (LTP) is a long-lasting increase in efficacy shown by some synapses in the brain and elsewhere that might be involved in certain types of learning and memory. It has been most intensively studied in the hippocampus, a brain area known to be important in memory. LTP induction is triggered by a rise in calcium concentration inside the postsynaptic cell. Whether LTP is expressed presynaptically or postsynaptically is less clear, with results from different laboratories appearing to contradict one another. Quantal analysis is one approach to this question. Neurotransmitter is released from the presynaptic cell in discrete packets of roughly equal size, known as quanta. If the increased response recorded during LTP is composed of a greater number of quanta, it would suggest a presynaptic change. On the other hand, an increase in the postsynaptic effect produced by each quantum would suggest that there had been a change in the postsynaptic cell. I made intracellular voltage recordings of small excitatory postsynaptic potentials (EPSPs) from pyramidal neurones in area CA1 of rat hippocampal slices. I induced LTP and determined the site of the change using three quantal analysis procedures: 1/CV² graphs, amplitude frequency histograms and 'constant N analysis'. The results indicate that EPSPs can show both presynaptic and postsynaptic changes. However, the proportions varied considerably between individual EPSPs and seemed to depend on the initial 'setting' of the synapse. This, in turn, can depend on the experimental conditions, which might explain at least some of the contradictions in earlier results. I also carried out a similar study of a briefer form of enhancement known as shortterm potentiation (STP). I found that this too is caused by both presynaptic and postsynaptic changes and that their proportions seem to obey a similar rule to LTP. This suggests that LTP and STP are not separate phenomena, as some have suggested, but are closely related. I attempted a similar study of mossy fibre inputs to pyramidal cells in area CA3 of hippocampal slices. However, it was difficult to obtain uncontaminated mossy fibre responses, so the results of this study are preliminary.
Turbulent gravitational convection from maintained and instantaneous sources

Theories of convection from maintained and instantaneous sources of buoyancy are developed, using methods which are applicable to stratified body fluids with any variation of density with height; detailed solutions have been presented for the case of a stably stratified fluid with a linear density gradient. The three main assumptions involved are (i) that the profiles of vertical velocity and buoyancy are similar at all heights, (ii) that the rate of entrainment of fluid at any height is proportional to a characteristic velocity at that height, and (iii) that the fluids are incompressible and do not change volume on mixing, and that local variations in density throughout the motion are small compared to some reference density. The governing equations are derived in non-dimensional form from the conditions of conservation of volume, momentum and buoyancy, and a numerical solution is obtained for the case of the maintained source, This leads to a prediction of the final height to which a plume of light fluid will rise in a stably stratified fluid. Estimates of the constant governing the rate of entrainment are made by comparing the theory with some previous results in uniform fluids, and with the results of new experiments carried out in a stratified salt solution. For the case of an instantaneous source of buoyancy there is an exact solution; the entrainment constant is again estimated from laboratory results for a stratified fluid Finally, the analysis is applied to the (compressible) atmosphere, by making the customary substitution of potential temperature for temperature. Predictions are made of the height to which smoke plumes from typical sources of heat should rise in a still, stably stratified atmosphere under various conditions.
Effect of soil microorganisms on arsenite oxidation in paddy soils under oxic conditions

Abstract The contribution of abiotic and biotic processes to the oxidation of arsenite [As(III)] when anaerobic paddy soils were shifted to oxic conditions was investigated. Soil slurries were first incubated under reducing conditions to allow indigenous arsenic (As) to be dissolved into the liquid phase as As(III), and were then switched to oxic incubation conditions with shaking. One day after switching to oxic incubation, As(III) almost disappeared from the liquid phase without any increase of arsenate [As(V)], suggesting that dissolved As(III) was co-precipitated or adsorbed on the soil solid phase. X-ray adsorption near-edge structure (XANES) analysis revealed that the predominant species of As in the solid phase before the oxic incubation was As(III), ranging from 74 to 85% of total As. After 1 d of the oxic incubation, the proportion of As(III) decreased to 46–47%. This oxidation step was an abiotic process and 28–38% of As(III) was oxidized per day on average. However, the abiotic oxidation ceased within 24 h probably due to passivation of reactive sites on the mineral surface. Afterward, a second slow oxidation step (2.5–2.8% per day on average) became predominant. Interestingly, this step was microbiologically mediated, since it did not occur in sterilized soil slurries. Determination of putative arsenite oxidase gene (aioA) sequences suggested that arsenite-oxidizing bacteria are actually present in our soil slurries. Our results suggest that microbial As(III) oxidation accounts for more than 30% of total As(III) oxidation, and thus it is an important process especially after abiotic oxidation ceases.