bluuebunny/crossref_metadata_2025_split huggingface dataset:
Psychological impact of the COVID-19 pandemic among health care workers in Tunisia
Authors: Jaballah Fares , Boudrigua Mohamed Moussa , Romdhane Islèm , Ferhi Mohamed , Mannaii Jihène 
Published: October 2022

Abstract
Background
The coronavirus 2019 (COVID-19) pandemic has caused a worldwide health crisis. In Tunisia, this large-scale health crisis urgently triggered the restructuring and reorganization of health services to support Emergency Departments, intensive care units, and continuing medical care units. Concerns about the mental health, psychological adjustment, and recovery of health care workers treating and caring for are now emerging. The objective was to assess the psychological impact of the Covid-19 pandemic on health care workers' work, psychological outcomes, and return to work.
Methods
Our study is a retrospective monocentric clinical trial. It is performed between June and July 2022 using a self-administered questionnaire to assess: (i) the impact on their work; (ii) the psychological consequences of the Covid-19 epidemic for health care workers.
Results
We collected 140 responses from 73 nurses (34.76%), 23 public health physicians (10.95%), 15 health technicians (7.14%), 13 residents (6.19%), 7 interns (3.33%), 5 workers (2.38%), and 4 medical specialists (1.90%). The HAD score for depression favoured certain symptomatology in most cases (n = 72, 51.43%) and certain symptomatology in most cases (n = 73, 52.14%) for anxiety.
Conclusions
The Covid-19 pandemic has brought about changes in the work organization and an overall increase in the workload for health care personnel.
Computational Modeling of Virally-encoded Ion Channel Structure
Authors: Weissman Alexander , Bennett Jeremy , Smith Nicole , Burdorf Carly , Johnston Emma , Malachowsky Beth , Banks Lori 
Published: October 2022

AbstractViroporins are ion channels encoded within a virus’s genome, that facilitate a range of devastating infectious diseases such as COVID-19, HIV, and rotavirus. The non-structural protein 4 (NSP4) from rotavirus includes a viroporin domain that disrupts cellular Ca2+ homeostasis, initiating viral replication, and leading to life-threatening vomiting and diarrhea. Though the structure of soluble segments of NSP4 has been determined, membrane-associated regions, including the viroporin domain, remain elusive when utilizing well-established available experimental methods such as x-ray crystallography. However, two recently published protein folding algorithms, AlphaFold2 and trRosetta, demonstrated a high degree of accuracy, when determining the structure of membrane proteins from their primary amino acid sequences, though their training datasets are known to exclude proteins from viral systems. We tested the ability of these non-viral algorithms to predict functional molecular structures of the full-length NSP4 from SA11 rotavirus. We also compared the accuracy of these structures to predictions of other experimental structures of eukaryotic proteins from the Protein Data Banks (PDB), and show that the algorithms predict models more similar to corresponding experimental data than what we saw for the viroporin structure. Our data suggest that while AlphaFold2 and trRosetta each produced distinct NSP4 models, constructs based on either model showed viroporin activity when expressed in E. coli, consistent with that seen from other historical NSP4 sequences.
A new family of Polyak and Ribiere conjugate gradient method for impulse noise removal
Authors: Mousavi Ali , Esmaeilpour Mansour , Sheikhahmadi Amir 
Published: October 2022

Abstract
In this paper, impulse noise removal problem is formulated as an unconstrained optimization problem with smooth objective function. It can be solved by conjugate gradient methods with desired properties (low memory and strong global convergence) in high dimensions. Accordingly, a family of the Polyak-Ribi`ere conjugate gradient directions is constructed for which the descent condition holds. Using several images, it is shown that the new methods are very robust and efficient in comparison with other competitive methods for impulse noise removal, especially in terms of the peak signal to noise ratio (PSNR).
Mathematics Subject Classification (2000) 90C30a · 90C25 · 90C90 · 68U10 · 03D15
Analysis of frequency dependence of complex impedance and electrical characterization of Fe2O3/kaolin ceramics for civil engineering applications
Authors: Bouchehma Abdeltif , Essaleh Mohamed , Bouferra Rachid , Belhouideg Soufiane , Benjelloun Mohamed , Sfa Imad 
Published: October 2022

The complex impedance spectroscopy (CIS) method is usually used in order to analyze the electrical response of different semiconducting disordered materials as a function of frequency at different temperatures. The real and imaginary parts of the complex impedance can show different semicircles in the complex plane that give evidence for the presence of both bulk and grain boundary contributions. Many parameters can be deduced from the analysis of CIS data, such as relaxation times and activation energies. There are some literature data concerning electrical properties of clays and (semiconductor, sand, cement,…)/clay mixtures. Most of the published works are related to the AC conductivity of rocks with the effect of water or oil content but there are no similar studies on the characterization of the microstructure of individual clays as ceramic materials by analyzing their temperature and frequency dependence of their electrical conductivities. Hence, this paper presents an analysis of electric complex impedance of the Fe2O3/Kaolin composite in the high temperature range up to 740 °C. Sinusoidal voltage with frequency in the range [100 Hz, 1 MHz] is applied to the material in order to measure the electrical conductivity for various concentrations of Fe2O3 from zero to 100 %. The activation energies for the conduction and for the relaxation processes are determined and their dependence on the density of Fe2O3 analyzed. Furthermore, let’s found that Fe2O3 have the effect to increase the electrical conductivity in our samples. From the Nyquist diagrams, only one semi-circle related to the contribution of the grains to the total electrical conduction is identified for all investigated samples.
Research and analysis of characteristics of fuel from organic and industrial waste
Authors: Nurkina Sholpan , Kinzhibekova Akmaral , Prikhodko Evgeniy 
Published: October 2022

The article is devoted to the actual problem of utilisation of agricultural and industrial waste as a solution to the problem of replacing traditional energy sources.
As an alternative fuel, researchers suggest using briquettes from biomass (leafy debris, waste paper, sunflower and buckwheat husks), as well as their combination with industrial waste (coal dust). The choice of these sources of raw materials is determined by their presence in the north-eastern part of Kazakhstan.
Studies of the physical and mechanical and thermophysical characteristics of fuel briquettes from organic mass and bio-charcoal briquettes were carried out. The studies showed the following results: the moisture content of the samples we studied lies in the range from 3.86 to 8 %; ash content of briquettes from vegetable raw materials varies from 2.05 % to 3.6 %, combined briquettes from foliage and coal dust varies from 10 % to 14 %; average density values varies from 979.91 to 1172.63 kg/m3; mechanical strength is in the range from 90 to 100 %; the yield of volatile studied samples ranges from 9 to 21.4 %. Analysis of the obtained characteristics of fuel briquettes demonstrated that they meet the requirements of existing standards. Herewith, the lower calorific value of briquettes (15290‑19048 kJ/kg) is comparable to the calorific value of coal from the Ekibastuz deposit.
The authors studied the influence of the parameters of the briquetting process on the briquette’s strength characteristics from leaves and waste paper, and obtained a regression dependence of these briquette’s calorific value on their characteristics. The analysis of regression dependencies showed that the pressure and pressing time have the greatest influence on the briquette strength, and its composition, i.e., the ratio of leaves and waste paper in the feedstock, has the greatest influence on the lower calorific value
The development a fully-balanced current-tunable first-order low-pass filter with Caprio technique
Authors: Lertkonsarn Samran , Sa-ngiamvibool Worawat 
Published: October 2022

This paper presents the development and design of a fully-balanced current-tunable first-order low-pass filter with Caprio technique, which could include the design and implementation of a first-order low-pass filter circuits. The filter consists of six bipolar junction transistor (BJT) and a single capacitor. The filter construction uses a bipolar junction transistor (BJT) as the main device and a single capacitor. A fully-balanced current-tunable first-order low-pass filter with Caprio technique developed. The architecture of the circuit is quite simple and proportional, symmetrical with signs of difference. Circuits developed into integrated circuits act like basic circuits for frequency filter circuits, current modes with Caprio techniques, obtained by improving the first-order low-pass filter for signal differences with incoming impedances. Adjusting the parameters of the circuit with the caprio technique achieves the optimal parameter value for correcting the total harmonic distortion value.
The results of testing the operation of the circuit, a fully-balanced current-tunable first-order low-pass filter with Caprio technique developed and designed using the PSpice program. The simulation results showed good results in line with predicted theoretical analysis. The sensitivity of the device to the center frequency (ω0) response is low and independent of variables, the angular frequency is linear with wide current adjustment throughout the sweeping range of a wide frequency range, with a wide range of over tree orders of magnitude. Therefore, fully-balanced current-tunable first-order low-pass filter developed is very suitable to apply various applications regarding low frequency signal filtration, for example in biomedical systems, for example.
Principal component analysis as tool for data reduction with an application
Authors: Latif Shereen Hamdy Abdel , Alwan Asraa Sadoon , Mohamed Amany Mousa 
Published: October 2022

The recent trends in collecting huge datasets have posed a great challenge that is brought by the high dimensionality and aggravated by the presence of irrelevant dimensions. Machine learning models for regression is recognized as a convenient way of improving the estimation for empirical models. Popular machine learning models is support vector regression (SVR). However, the usage of principal component analysis (PCA) as a variable reduction method along with SVR is suggested. The principal component analysis helps in building a predictive model that is simple as it contains the smallest number of variables and efficient. In this paper, we investigate the competence of SVR with PCA to explore its performance for a more accurate estimation. Simulation study and Renal Failure (RF) data of SVR optimized by four different kernel functions; linear, polynomial, radial basis, and sigmoid functions using R software, version (R x64 3.2.5) to compare the behavior of ε SVR and v-SVR models for different sample sizes ranges from small, moderate to large such as; 50, 100, and 150. The performance criteria are root mean squared error (RMSE) and coefficient of determination R2 showed the superiority of ε-SVR over v- SVR. Furthermore, the implementation of SVR after employing PCA improves the results. Also, the simulation results showed that the best performing kernel function is the linear kernel. For real data the results showed that the best kernels are linear and radial basis function. It is also clear that, with ε-SVR and v-SVR, the RMSE values for almost kernel functions decreased with increasing sample size. Therefore, the performance of ε-SVR improved after applying PCA. In addition sample size n=50 gave good results for linear and radial kernel
Evaluating The hydrological response due to the changes in climate and land use on streamflow in the Karkheh basin, Iran
Authors: Chegnizadeh Alireza , Rabieifar Hamidreza , Ebrahimi Hossein , Nayeri Mahmoud Zakeri 
Published: October 2022

Abstract
The Karkheh basin is one of Iran's largest and most waterlogged rivers. In this study, we aim to analyze the impact of Climate change and landuse change on the Karkheh basin using the Soil and Water Assessment Tool (SWAT). In this research, the considered land-use change is based on Iran's future policies, and climate change is studied by employing the RCP series and GCM in Mid-term (2040–2060) and Long-term (2080–2100). Firstly, changes in climate and land use are separately examined, and then the simultaneous impact of these two parameters is investigated. The results of the climate change study illustrate that the highest rate of change, which is a decrease of 14.3–22.8%, is achieved from the RCP 8.5 series in the long term. The results obtained from investigating the land-use change based on future policies in Iran show a maximum reduction of 7% in the average monthly runoff. The flow rate also decreases further when considering the simultaneous effects of both changes in the basin. In this case, the RCP 8.5 series shows a reduction of up to 39% in the long term. This study suggests that the effects of climate change are more significant than changes in landuse.
An O-phosphotyrosine-containing analogue of human angiotensin ii exhibits increased serum stability
Authors: Wadel John D , Perich John W , Tregear Geoffrey W , Szendrei Gyorgyi I , Jr. Laszlo Otvos 
Published: October 2022

Abstract:
Synthetic human [Tyr (P)]4-angiotensin II was analyzed by CD spectroscopy and compared with
native human angiotensin II. The data showed there to be no apparent conformational difference between the
two peptides in both aqueous and graded TFE solutions. An assessment of the in vitro stability of the two
peptides to serum proteases showed clearly that the O-phosphorylated angiotensin II was more resistant to
enzymic degradation suggesting that the tyrosyl O-phosphate plays a significant role in inhibiting this process.
Calculation of the proton chemical shifts as a tool to explain the peculiarities of 1H NMR spectra of protein in a compact denatured state
Authors: Kivaeva Lilly S. , lbragimova Gulshat T. , Kutyshenko Victor P. 
Published: October 2022

Abstract:
Using the protein crystal structure the chemical shift dispersi<ms of binase a-CH protons were calculated for
protein in native state and in a compact denatured one. The same models of internal fields with different
adjusting parameters were used to describe data for protons disposed in regions of both regular and irregular
secondary structures. It was shown that peculiarities of 1H NMR spectra, bserved for compact denatured
proteins, could be explained through fluctuations of hydrogen bonds network in conserved secondary structures.
Crystallization and preliminary x-ray analysis of triosephospha te isomerase from trypanosoma cruzi
Authors: Gomez-Puyout Armando , Maldonado Ernesto , Moreno Abel , Panneerselvam Kaliyamoorthy , Ostoa-Saloma Pedro , Garza-Ramos Georgina , Soriano-Garcia Manuel , Perez-Montforti Ruy , de Gomez-Puyou Marietta Tuena 
Published: October 2022

Abstract:
Recombinant triosephosphate isomerase from Trypanosoma cruzi was crystallized at room
temperature from 0.1 M Na Hepes pH 7.5, 2 % (v/v) PEG 400 and 2.0 M ammonium sulfate. Crystals belong to
the orthorhombic space group P212121with cell dimensions a= 43.71A, b = 77.65A, c = 149.54A, and a= p = y
= 90°. Another crystal with cell dimensions a= b = 56.16A, c = 161.85A, and a= P = y = 90° with two possible
tetragonal space groups P41212 or P43212 was obtained. Both crystals diffract up to I.86 A.
Crystallization and preliminary x-ray crystallographic studies of dutpase from equine infectious anemia virus
Authors: Persson Rebecca , Rosengren Anna Maria , Nyman Per Olof , Dauter Zbigniew , Cedergren-Zeppezauer Eila 
Published: October 2022

Abstract:
Deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase), an enzyrrie in the nucleotide metabolism, from the retrovirus Equine Infectious Anemia Virus (EIAV) has been crystilllized from PEG mixtures at
neutral pH using a vapour diffusion method. Crystals of native enzyme belong to the space group R32, while
crystals formed in the presence of Sr2+ and dUDP, a substrate analogue, belong to the space group P4132 or
P4332. Both forms are suitable for high resolution X-ray structure analyses.
The effect of truncation on shk toxin:• elimination of the amino-carboxyl
terminal (3-35) disulfide linkage stabilizing the amino and carboxyl terminal segments
Authors: Pennington M.W. , Mahnir V.M. , Baur P. , McVaugh C.T. , Behm D. , Kem W.R. 
Published: October 2022

Abstract:
We have synthesized two truncated analogs of ShK toxin which contain the main residues comprising the binding surface of the toxin. In both of these analogs, the disulfide bond which links the N and C terminal Cys residues has been eliminated. The remaining two disulfide bonds (Cys12-Cys28, Cysl 7-Cys32) have been retained in one analog and the other analog contains only the Cys17-Cys32 linkage. The CD spectrum of the bicyclic peptide appears to have a small amount of the helical structure whereas the monocyclic peptide spectrum appears to be disordered. The activity of the bicyclic and monocyclic peptides were respectively reduced by 1360- and >3000-fold relative to wild type ShK toxin.
Human a-fetoprotein is in the molten globule state under conditions modelling protein environment near the membrane surface
Authors: Uversky Vladimir N. , Narizhneva Natalya V. 
Published: October 2022

Abstract:
Conformational transitions induced in a-fetoprotein by such organic solvents as methanol and trifluoroethanol were studied using circular dichroism, tryptophan fluorescence spectroscopy and digital scanning calorimetry. The existence of well-populated intermediate state without rigid tertiary structure but with native-like secondary structure content and compactness (i.e., the molten globule-like intermediate state) was established. A possible implication of such structural rearrangement to function of this protein is discussed.
Sequence-specific 1h nmr assignments and secondary structure of neuropeptide y analogs in aqueous solution
Authors: Samarasinghe S. D. , Kar L. , Balasubramaniam A. , Johnson M. E. 
Published: October 2022

Abstract:
Solution structures of neuropeptide Y analogs NP158 and NP181 were studied by 1H NMR spectroscopy. Sequential assignments were made at pH 3.5 at 25°C and 45°C using COSY, HOHAHA and ROESY spectra. Modeling shows turn-type loop structures in aqueous solution that could be important for receptor binding and/or antagonistic potency.. No significant conformational differences were observed between the two polypeptides despite vastly different antagonistic potency towards NPY YI receptors.
Crystal structure of myotoxin-11: a myotoxic phospholipase A2 - homologue from bothrops moojenivenom
Authors: de Azevedo W.F. , Ward R.J. , Lombardi F.R. , Giglio J.R. , Soares A.M. , Fontes M.R.M. , Arni R.K. 
Published: October 2022

Abstract:
The crystal structure ofMyotoxin-II (MjTX-II), a Lys49 PLAi-homologue from Bothrops moojeni venom has been determined and refined at 2.0 A to a crystallographic residual of 19.7% (Ru.0=28.1%). MjTX-II is a dimer in the crystal, with the monomers in the asymmetric unit related by a two-fold symmetry axis running through the dimer interface. The dimers of MjTX-II and the Lys49 PLA2 from B. asper venom are similar, however the relative orientations of the monomers suggests a flexible dimer interface, which serves as a hinge between the two molecules.
Crystallization and preliminary crystallographic analysis of scilla campanulata lectin complexed with A-D-mannose
Authors: Wright Lisa M. , Wood Stephen D. , Reynolds Colin D. , Rizkallaht Pierre J. , Allen Anthony K. 
Published: October 2022

Abstract:
Recently many new lectins have been isolated from monocotyledonous plants which have interesting glycan­ binding behaviour. In this paper we present the crystallization and preliminary X-ray analysis of a lectin, isolated from bluebell (Scilla campanulata) bulbs, complexed with a-D-mannose. The complex crystallizes in space group P21212 with a= 70.73, b = 92.97 and c = 47.07A. Synchrotron X-ray data have been measured at 1.86A resolution and the crystal structure of the complex will be solved by the molecular replacement method.
Simulation of the unfolding of a leucine zipper
Authors: Flanagan Karen , Goodfellow Julia M. 
Published: October 2022

Abstract:
Molecular dynamics simulations of the 33 residue coiled-coil domain of the GCN4 leucine zipper GCN4-p1 have been carried out at 298 and 328K. The room temperature simulation correlated well with the findings of Rozelle et al. [l] and is consistent with NMR data [2]. The higher temperature simulation indicates the presence of a conformational substate on the folding pathway. Analysis of breaking of hydrogen bonds and hydrophobic interactions gives information on the order of protein unfolding events.