Miracle-dz/UniFAR-FTUs huggingface dataset:
Coarse‐grained methods for polymeric materials: enthalpy‐ and entropy‐driven models

Polymers are multiscale systems by construction. They are formed by several monomeric units connected by covalent bonds whose chemical nature defines the rigidity of the chain. The interconnection between the monomeric units determines the interdependence of the motion of the different chain segments and the intrinsic multiscale nature of polymeric materials. This characteristic is reflected on the different modeling techniques that can be used to simulate polymeric materials. Because of the large conformational space that needs to be sampled when simulating polymers, coarse‐grained (CG) models are commonly used and depending on which part of the system free energy (enthalpy, entropy, or both) is relevant for the properties of interest, the appropriate modeling techniques should be used. Each model is characterized by advantages and limitations that can have a great impact on the quality of the results obtained. In this overview, we address some of the more common CG techniques presented in the literature for the modeling of polymeric materials at different length scales. WIREs Comput Mol Sci 2014, 4:62–70. doi: 10.1002/wcms.1149
Coolant-side heat-transfer rates for a hydrogen--oxygen rocket and a new technique for data correlation

An experimental investigation was conducted to determine the coolant-side, heat transfer coefficients for a liquid cooled, hydrogen-oxygen rocket thrust chamber. Heat transfer rates were determined from measurements of local hot gas wall temperature, local coolant temperature, and local coolant pressure. A correlation incorporating an integration technique for the transport properties needed near the pseudocritical temperature of liquid hydrogen gives a satisfactory prediction of hot gas wall temperatures.
Total Synthesis and Structure Confirmation of Cryptocaryol A

The first enantioselective total synthesis of Pdcd4-stabilizing cryptocaryol A, a secondary metabolite obtained from a tropical tree, has been achieved through an iterative approach to the 1,3-polyol motif. The key steps are a Maruoka allylation, a Reetz chelation-controlled allylation with 1,3-induction, iterative diastereoselective iodocyclization, and ring-closing metathesis reactions.
Tracking of Transplanted Human Mesenchymal Stem Cells in Living Mice using Near‐Infrared Ag2S Quantum Dots

Stem cell therapeutics has emerged as a novel regenerative therapy for tissue repair in the last decade. However, dynamically tracking the transplanted stem cells in vivo remains a grand challenge for stem cell‐based regeneration medicine in full understanding the function and the fate of the stem cells. Herein, Ag2S quantum dots (QDs) in the second near‐infrared window (NIR‐II, 1.0–1.4 μm) are employed for dynamically tracking of human mesenchymal stem cells (hMSCs) in vivo with high sensitivity and high spatial and temporal resolution. As few as 1000 Ag2S QDs‐labeled hMSCs are detectable in vivo and their fluorescence intensity can maintain up to 30 days. The in situ translocation and dynamic distribution of transplanted hMSCs in the lung and liver can be monitored up to 14 days with a temporal resolution of 100 ms. The in vivo high‐resolution imaging indicates the heparin‐facilitated translocation of hMSCs from lung to liver as well as the long‐term retention of hMSCs in the liver contribute to the treatment of liver failure. The novel NIR‐II imaging offers a possibility of tracking stem cells in living animals with both high spatial and temporal resolution, and encourages the future clinical applications in imaging‐guided cell therapies.
La internacionalización de las franquicias mexicanas: el efecto de las variables organizacionales sobre el grado de internacionalización.

El presente estudio evalua la importancia de la experiencia, el tamano, la estructura de la cadena y la dispersion geografica sobre el grado de internacionalizacion de las franquicias mexicanas. Los resultados indican que la experiencia tiene un efecto positivo sobre el grado de internacionalizacion, mientras que la estructura y la dispersion geografica tienen un efecto negativo. El tamano resulto tener una correlacion positiva, pero no significativa. El crecimiento resulto tener un efecto significativo en el tamano de la franquicia. Los datos fueron evaluados mediante la tecnica de minimos cuadrados parciales, usando el software SMART PLS. Ecuaciones estructurales, Franquicias, internacionalizacion, SmartPLS. Introduccion La franquicia puede entenderse como un modelo de comercializacion que consiste en un acuerdo por un periodo de tiempo, en el cual el propietario de una marca registrada llamado franquiciador garantiza a otra persona o firma llamado franquiciado, el derecho de operar bajo una marca registrada con el proposito de producir o distribuir un producto o servicio (Caves & Murphy, 1976)
Double Dispersion effects on free convection along a vertical Wavy Surface in Porous Media with Variable Properties

In the present paper, we analyzed double diffusive free convection past a vertical wavy surface embedded in a fluid saturated porous medium with variable properties. The Darcy law is assumed to describe the homogenous fluid saturated porous medium. The temperature dependent variable properties (variable viscosity and variable thermal conductivity) are considered. The fluid flow, momentum, energy and solutal governing equations are transformed into boundary layer non-dimensional nonlinear ordinary differential equations with specified transformation and then solved with numerical technique. The results are reported for various physical parameters; variable viscosity, variable thermal conductivity, thermal dispersion and solutal dispersion and amplitude of the wavy surface on hydrodynamic velocity, temperature and concentration distributions as well as rate of heat (Nusselt number) and mass (Sherwood number) transfers. The numerical results obtained in the present method compared with previously published results and found to be in good agreement.
Electron scattering correction of x‐ray‐excited Ni and Cu KLL Auger spectra emitted from thin and thick metallic samples

High-energy Cu and Ni KLL Auger lines, excited by Mo and Cu bremsstrahlung, were measured for polycrystalline metallic samples as well as for thin (10 nm) films deposited onto Si substrates, to determine the respective Auger transition energies and probabilities. 1 The spectra of homogeneous samples show a broad tail of inelastically scattered electrons. This tail is strongly suppressed in the thin-film spectra. These spectra have been subjected to a recently proposed background subtraction procedure, 2 accurately accounting for the details of the signal electron emission process (depth distribution of the emitting species, elastic scattering, experimental geometry, etc.). As a result, the inelastic tail is removed in the background-corrected spectra. Comparison of the spectra from the thin films and the homogeneous samples after background correction provides an experimental test of the background subtraction procedure. In our case these corrected spectra are essentially identical, proving the consistency of the method applied.
Gas Exchange in Exercise

The sections in this article are: 1 Steady State 1.1 External Gas Exchange 1.2 Alveolar Gas Exchange 1.3 Blood O2-Carrying Capacity 1.4 Energy Cost of Blood Pumping 1.5 Cardiovascular Adjustments 1.6 Oxygen Utilization and its Limiting Factors 1.7 Comparative Aspects of Gas Exchange 2 Unsteady State 2.1 Pulmonary Gas-Exchange Transients 2.2 Cardiovascular Transients 2.3 Control and Kinetics of Gas Exchange in Muscle 3 Conclusions
Seasonal physicochemical variation in the Nabugabo wetland

The study determined physicochemical characteristics of Lake Nabugabo wetland during a wet and a dry season to evaluate season variation in water quality. Standard (APHA 1992) and HACH methods were used to determine the physicochemical parameters for a period of one seasonal cycle. Results were pH 3.8 (3.0-4.2); temperature 23.0 (19.4 – 26.4) 0C; conductivity 20.5(15.6-30.45) iScm-1; total dissolved solids 11.4 (4.1-14.2) mgl-1;dissolved oxygen 3.9(0.0 -5.3) mgl-1; Ca++ 3.0 (0.2-4.3) mgl-1; Mg++ 2.1(0.06-2.5) mgl-1; K+ 0.9 (0.8-1.1) mgl-1; Na+ 2.9 (2.1-3.2) mgl-1; total phosphorus 0.3 (0.07-1.3) mgl-1; soluble reactive phosphate 0.002 (0.004-0.06) mgl-1; total nitrogen 0.8 (0.5-1.8) mgl-1; nitrate-nitrogen 0.01(0.001-0.12) mgl-1; ammonianitrogen 0.46 (0.1-2.2) mgl-1. Nitrate-nitrogen and dissolved oxygen varied significantly (P conductivity and the cations exhibited non-significant (P>0.05) variation with season. The wetland hydroperiods were 0.83 north of Lake Nabugabo and 0.58 south of the Lake. Seasonal variations of nitrogen and phosphorus concentrations were strongly linked to rainfall and hydroperiods. The study showed that the wetland water quality varies with season which is important for designing temporal sampling strategy and the understanding of wetland influence on adjacent open water bodies.
The breakdown process of a liquid trigatron

A description of the mechanism of a breakdown of the liquid trigatron is proposed on the basis of the experimental data obtained in the past and additional measurements presented in the paper. Liquid trigatrons are considered both with the trigger at the cathode and at the anode. The mechanism proposed is as follows: in a liquid trigatron, some of the liquid in the gap will be vaporized and a local region of low density will develop there due to heat produced in the plasma of the triggering spark. There will also be increased probability for electron ionization in the plasma region. If the time lag is long enough, this vaporization of part of the liquid in the gap will transform the nature of a process of breakdown and gas phase will be involved. The breakdown condition is formed basically by electric-field distortion and intensification due to the positive space charge in the gap. In consequence, for the cathode triggered trigatron, if the field in the gap is high enough, negative streamers will develop. When the main gap voltage V is higher, the distance for which plasma region together with growing space charge must move in the gap before the main discharge will start, will be shorter, as is shown by the measurements. For the anode triggered trigatron, the growing space charge reinforces the electric field ahead of the plasma to allow development of a positive streamer. In the range of high values of V the avalanche produced by the photoelectrons is large and the positive streamer can be initiated immediately. In effect the corresponding time lag will be very short, as the measurements show. >
Trace Elements in Terrestrial Environments: Biogeochemistry, Bioavailability, and Risks of Metals

1 Introduction. - 2 Biogeochemical Processes Regulating Metal Behavior. - 3 Bioavailability of Trace Metals. - 4 Environmental Contamination and Regulation. - 5 Ecological and Health Risks of Metals. - 6 Risk Assessment and Management in Metal-Contaminated Sites. - 7 Arsenic. - 8 Cadmium. - 9 Chromium. - 10 Lead. - 11 Mercury. - 12 Boron. - 13 Copper. - 14 Manganese. - 15 Molybdenum. - 16 Zinc. - 17 Nickel. - 18 Selenium. - 19 Other Trace Elements. - Appendix A Tables. - Appendix B Abbreviations, Acronyms, Symbols, and Terms. - Appendix C Scientific Names for Plants and Animals. - About the Author.
Advances and Prospects for Whispering Gallery Mode Microcavities

Microlasers have experienced tremendous development in the past decade and become an essential part in laser evolution, as miniature lasers provide strong optical confinement and feature greatly enhanced light–matter interactions. Among all the configurations, whispering gallery mode (WGM) microcavities and microlasers exhibit outstanding optical performances with high quality factors and small mode volumes, thus ensuring low lasing thresholds. In addition, some unique properties inherent to WGM cavities, like bi‐directional propagation and an evanescent field that spans several hundred nanometers across the boundary, can be exploited for novel applications. Therefore, designing and engineering innovative WGM microcavities and microlasers has attracted increasing research interest. The fundamentals and characteristics of WGM are introduced here, and then the developments and current status of WGM microcavities and microlasers are reviewed in terms of the evolution of fabrication techniques and built‐up materials. In particular, the melting of glassy materials in early studies, top‐down and bottom‐up approaches with semiconductors, coating structures, as well as flexible, soft microresonators in recent years are presented. Finally, the application prospects of microlasers including the wavelength manipulation, sensing and microresonator coupling, are discussed.
Innovative chiral resolution using enantiospecific cocrystallization in solution

A large number of active pharmaceutical ingredients (API) are chiral. Most of them are synthesized as racemic mixtures, and a chiral resolution step is introduced somewhere along the production process. In this study, we have used the specific hydrogen bonding interactions present in co-crystals to develop a new resolution technique. As these interactions are strongly direction dependent, we highlighted that an enantiopure API only forms a co-crystal with one of two enantiomers of a chiral co-crystal former (or co-former). Unlike salts, a diastereomeric pair cannot be obtained. This enantiospecific behavior of co-crystal candidates suggests that a racemic mixture of this candidate can be resolved through a co-crystallization in solution, which hitherto has not been observed yet. As a study system, we chose (RS)-2-(2-oxopyrrolidin-1-yl)butanamide, as the S-enantiomer is an API and no viable salts of this compound have been identified. The only known resolution technique for this compound is, therefore, based on chiral chromatography. Because of enantiospecific interactions with an S-mandelic acid coformer, we were able to selectively co-crystallize the S-enantiomer in acetonitrile. This enantiospecific co-crystallization in solution has been thermodynamically verified, by construction of ternary phase diagrams at different temperatures. Initial results not only validate our innovative resolution technique through co-crystallization but also furthermore already showed high efficiency, as 70% of the S-enantiomer could be separated from the racemic mixture in a single co-crystallization step.
The efficient adsorption removal of Cr(VI) by using Fe3O4 nanoparticles hybridized with carbonaceous materials

Fe3O4 nanoparticles hybridized with carbonaceous materials, such as pinecone and graphene, were successfully synthesized by a facile hydrothermal method, which could be applied for Cr(VI) removal in aqueous solution. The nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2 adsorption–desorption isotherms. Due to the combination of pinecone and graphene, both the surface properties and morphologies of Fe3O4 were modified. Fe3O4 spherical particles were distributed and firmly anchored on the loose surface of pinecone or wrinkled graphene layers. The specific surface area increased from 23.85 to 27.86 and 121.17 m2 g−1 for Fe3O4/P and Fe3O4/G, respectively. It enhanced the adsorption capacity for Cr(VI) of Fe3O4/P (62.5 mg g−1) and Fe3O4/G (78.5 mg g−1). Study of the kinetics and isotherms showed that the pseudo-second-order kinetic and Langmuir isotherm models fitted the adsorption data well. There were three steps in the adsorption process, namely an instantaneous adsorption step, intraparticle diffusion and a final equilibrium stage. The reaction rate decreased along with temperature increasing, which indicated that Cr(VI) adsorption was an exothermic process. The Ea values were 34.39, 25.77 and 34.92 kJ mol−1 for Fe3O4, Fe3O4/P and Fe3O4/G, respectively, which illustrated that the adsorption of Cr(VI) onto the surface of the nanocomposites was a physical process. In no more than 5 h, about 92.6% and 94% Cr(VI) were desorbed from the surface of Fe3O4/P and Fe3O4/G, respectively, which indicated that the adsorption–desorption process for Cr(VI) was reversible. The results demonstrated that Fe3O4/P and Fe3O4/G exhibited excellent adsorption performance in the removal of Cr(VI). It was proved that carbonaceous materials, such as pinecone or graphene, could enhance the adsorption performance of Fe3O4, and could be used as adsorbents to remove heavy metals in industrial effluents.
Large Strain and Fracture Properties of Poly(dimethylacrylamide)/Silica Hybrid Hydrogels

The synthesis and mechanical characterization of novel, tough poly(N,N-dimethylacrylamide) (PDMA)−silica hydrogel hybrids are presented to understand the role played by strong physical interactions between silica nanoparticles and the PDMA polymer on the properties of chemically cross-linked highly swollen PDMA networks. A detailed comparison of the hybrids with unmodified PDMA gels indicates that the incorporation of silica nanoparticles in the hydrogel increases the compression strength and the fracture toughness of notched samples up to an order of magnitude while increasing its modulus by a factor of 6 with a volume fraction of particles of the order of only 7%. The hybrid gels present a strain-dependent hysteresis but no permanent damage or residual strain upon unloading even after repeated cycling, a very unique property for such tough hydrogels. The reason for this exceptional increase in toughness is attributed mainly to the combined effect of breakable silica/polymer bonds and of a wide distribut.
Fluorescence Quenching Investigation for Janus Green B and used as Probe in Determination of Nucleic Acids

Fluorescence quenching of janus green B (JGB) in sodium dodecyl sulfate (SDS) micelle by nucleic acids (DNA) was studied using UV-vis absorption, steady state fluorescence emission methods and lifetime measurements. In the SDS micelle, weak fluorescence of JGB was enhanced, and the maximum emission shifted from 425 to 410 nm. In the presence of DNA, the fluorescence of JGB was quenched. Linear relationships between the fluorescence quenching (F0/F) and concentrations of DNA were observed in the range of 2.4×10^-8 to 1.08×10^-7mol·L^-1 for calf thymus nucleic acids (ct DNA) and 1.9×10^-8 to 3.8×10^-8 mol·L-1 for fish sperm nucleic acids (fs DNA) when 2.5×10^-5 mol·L^-1 JGB was employed. The limit detection were 1.3×10^-8 mol·L^-1 for ct DNA and 6.4×10^-9 mol·L^-1 for fs DNA. At high DNA concentration, there was a systematic deviation from the Stem-Volmer equation due to the static and dynamic quenching occurring simultaneously. The proposed method was applied to the determination of the nucleic acids in chicken blood extraction and the analytical results were in good agreement with the UV-method.
Resonance Parameters of Tantalum-181 in Neutron Energy Range from 100 to 4,300eV

Neutron transmission measurements were performed on natural tantalum (abundance ratio 99.988% for 181Ta) in the energy range of 100–4,300 eV using the Japan Atomic Energy Research Institute linac. The transmissions were measured using 55 and 190 m time-of-flight spectrometers for two and three samples of different thicknesses, respectively. These transmission data were simultaneously analyzed with a least squares fitting program based on a multl-level Breit-Wigner formula, and resonance energies and neutron width were obtained for 696 resonances of 181Ta. The statistical analysis of these parameters gave the s-wave average level spacing of D=4.10±0.14 eV and s-wave neutron strength functions of (1.67±0.13) × 10−4, (1.09 ± 0.09) × 10−4 and (1.42 ± 0.20) × 10−4 for the energy intervals from 100 − 1,700 eV, 1,700–3,400 eV and 3,400–4,300 eV, respectively. This significant difference among the neutron strength function for each energy interval is a prominent result of the present experiments and is of great i.
Novel Lanthanide(III) Ternary Complexes with Naphthoyltrifluoroacetone: A Synthetic and Spectroscopic Study

A series of lanthanide complexes with general formula [Ln(NTA)3X] were prapared [Ln = Y (a), Er (b), Eu (c), NTA = naphthoyltrifluoroacetone, X = H2O (1), phen = phenanthroline (2), bpyO1 = 2, 2′-bipyridine N-oxide (3), and bpyO2 = 2, 2′-bipyridine-N,N′-dioxide (4)]. The crystal structures of [Eu(NTA)3bpyO2] (4b), [Er(NTA)3bpyO1] (3c), and [Er(NTA)3phen] (2c) were determined. X-ray crystallographic analysis reveals that the complexes are of mononuclear structure with three NTA and one ancillary ligand. The photoluminescence spectra of 3c and 4b exhibit strong characteristic emissions arising from Eu3+ central ion due to the efficient sensitization of bpyO1 and bpyO2, respectively.
Transient Absorption Investigation of the Photophysical Properties of Thiophene Linked [2H]-Chromenes

ABSTRACT The photophysical and photochemical properties of a bi-thiophene linked 2H-chromene are investigated by femtosecond and nanosecond transient absorption spectroscopy. The spectral characteristics and dynamics of the lowest excited singlet and triplet states are determined. The ring-opening reaction responsible for the photochromism is observed to occur in the S1 state with a time constant of about 150 ps in acetonitrile.
People, primates and predators in the Pontal: from endangered species conservation to forest and landscape restoration in Brazil's Atlantic Forest

This study describes the 35-year progression of activities in the Pontal do Paranapanema region of São Paulo State, Brazil. These activities began as a research project on the conservation ecology of the highly endangered Black Lion Tamarin and broadened into a landscape-scale restoration and conservation project involving the active participation of hundreds of landless families that colonized the region. Rather than viewing these colonists as a threat, a non-governmental organization arose to address their needs, providing training and support livelihoods. Local communities were engaged in conservation and restoration activities focused on studying the movement patterns of endangered species, environmental education programmes, planting native trees along riparian corridors, establishing coffee agroforestry plantings and initiating community-managed nurseries for the production of local native seedlings and non-native fruit trees. Farmers gained knowledge, income and food security, and developed a sense of ownership and shared responsibility for protecting wildlife, conserving forest fragments and restoring forests. Land sharing and restoring forest functions within an agricultural landscape matrix created new opportunities for people and endangered wildlife. We explore how key factors and partnerships critically influenced the landscape trajectory and conclude with lessons learned that may be relevant to sustainable landscape initiatives in other contexts.
Computer Methods and Programs in Biomedicine

Background and Objectives: SARS-CoV-2 emerged in December 2019 and rapidly spread into a global pandemic. Designing optimal community responses (social distancing, vaccination) is dependent on the stage of the disease progression, discovery of asymptomatic individuals, changes in virulence of the pathogen, and current levels of herd immunity. Community strategies may have severe and undesirable social and economic side effects. Modeling is the only available scientiﬁc approach to develop effective strategies that can minimize these unwanted side effects while retaining the effectiveness of the interventions. Methods: We extended the agent-based model, SpatioTemporal Human Activity Model (STHAM), for simulating SARS-CoV-2 transmission dynamics. Results: Here we present preliminary STHAM simulation results that reproduce the overall trends observed in the Wasatch Front (Utah, United States of America) for the general population. The results presented here clearly indicate that human activity patterns are important in predicting the rate of infection for different demographic groups in the population. Conclusions: Future work in pandemic simulations should use empirical human activity data for agent-based techniques.