Miracle-dz/UniFAR-FTUs huggingface dataset:
Chitosan Nanoparticles Self-Assembled from Electrospun Composite Nanofibers

Molecular self-assembly has been intensively investigated for “bottom-up” nanofabrication in recent years. A strategy that offers simple routes to functional nano-scale objects directly from templates through molecular self- assembly may lead to the development of new advanced materials for nanotechnology. Electrospun nanofibers can be good templates for manipulating molecular self-assembly by virtue of their nanometer confinement effect and the formulation of their components into a composite material. One-dimensional nanofiber composites of hydrophilic polyvinylpyrrolidone (PVP) and chitosan (CS) were successfully prepared through an elevated temperature electrospinning process. Scanning electron and transmission electron microscopy observations indicated that the fibers have an average diameter of 77 ± 11 nm with a homogeneous inner structure. Differential scanning calorimetry and X-ray diffraction results demonstrated that PVP and CS were in an amorphous state in the nanofibers, indicating they were mixed on the molecular scale. IR spectra revealed that second-order hydrogen bonding and electrostatic interactions played a fundamental role in promoting the structural homogeneity of the amorphous nanofiber composites. CS nanoparticles of about 10 nm in diameter are spontaneously self-assembled in situ when the nanofibers are added to water. Through a combination of “top-down” electrospinning and a “bottom-up” molecular self-assembly, a brand-new process has been developed for preparing polymer nanoparticles in situ .
An Efficient and One Pot Synthesis of Polysubstituted Imidazoles Catalyzed by BiCl3.

Multicomponent reactions (MCRs) have drawn great interest enjoying an outstanding status in modern organic synthesis and medicinal chemistry because they are one-pot processes bringing together three or more components and show high atom economy and high selectivity 1 . MCRs have great contribution in convergent synthesis of complex and important organic molecules from simple and readily available starting materials, and have emerged as powerful tools for drug discovery 2 . The synthesis, reactions and biological properties of substituted imidazole constitutes a significant part of modern heterocyclic chemistry 3 . Compounds with the imidazole ring system have many pharmacological properties and play important roles in biochemical processes 4 . Many of substituted diaryl imidazoles are known as inhibitors of P38 MAP kinase. There are several methods reported in the literature for the synthesis of imidazoles such as the hetero-Cope rearrangement 5 , four-component condensation of arylglyoxals, primary amines, carboxylic acids and isocyanides on Wang resin 6 , of N-(2-oxo)-amides with ammonium trifluoroacetate, 1,2-aminoalcohols in the presence of PCl5, diketones, aldehyde, amine and ammonium acetate in phosphoric acid and in acetic acid, organo catalyst in acetic acid as well as H2SO4 and DMSO. Several microwave (MW) assisted syntheses of imidazoles from 1,2-diketones and aldehydes in the presence of a variety of catalysts such as silica-gel, silica-gel/HY, Al2O3, DMF, acetic acid 7 , ZrCl4 (Ref 8), NiCl2.6H2O (Ref 9) and ionic liquid 10 have been reported. Most of these synthetic methods suffer from one or more serious drawbacks, such as laborious and complex work-up and purification, significant amounts of waste materials, strongly acidic conditions, and occurrence of side reactions, low yields and the use of expensive reagents. Additionally, most require elevated temperatures created either by microwave irradiation 11 at 180200°C or by refluxing 12 and heating 13 the reaction mixture at high temperatures. Therefore, the development of a new catalytic system to overcome these shortcomings and fulfil the criteria of a mild, efficient and environmentally benign protocol for the synthesis of highly substituted imidazoles is an important task for organic chemists. In recent years, bismuth compounds have been used as catalysts in organic synthesis because these compounds are relatively nontoxic, easy to handle, inexpensive, and possess good stability 14,15 . Among these, bismuth (III) trichloride has gained special attention because not only is this compound commercially available and cheap, but also has high stability 16,17 and is an environmentally friendly catalyst 18 . In this paper is reported a simple, mild and expeditious synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted derivatives of imidazoles in high yields using catalytic amounts of BiCl3 at ambient temperature.
Pyridinium Oxime Compounds as Antimicrobial Agents

Abstract : Pyridinium oxime compounds have been utilised by a number of military organisations as one of the antidotes for nerve-agent poisoning. In Canada, the preferred compound from this class is HI-6, which has been demonstrated to be tolerated at high doses without significant ill effects. In this study, HI-6 and 15 structural analogues have been examined for their antimicrobial properties against a series of model organisms: Bacillus cereus and B. anthracis Sterue (as models for virulent B. anthracis), Ochrobactrum intermedium (as a model for Brucella spp.), Mycobacterium marinum (as a model for M. tuberculosis), and Crithidia luciliae (as a model for Leishmania spp.). In general, the compounds were found to have little to no antimicrobial effect, with KJD-2-11, a thiourea derivative, being the most active in all the test systems.
Static and dynamic properties of two-dimensional polymer melts

Dense linear two-dimensional polymer chains are simulated by the recently developed bond fluctuation method. The chain length and densities considered cover the crossover from the expanded single chain limit to a dense polymer melt. The chains completely segregate and follow a power law of the chain extension ∼N 2 ν, N being the number of bonds of the chains. Relaxation functions and mean square displacements display typical Rouse-like bahavior, with the distinction, that the prefactors for the various relaxation processes differ
Quantitative analysis of hepatitis B virion stability upon single-site amino acid mutation based on computational nanotechnology

Computational biology is an interdisciplinary field that applies the techniques of computer science, functional mathematics and statistics to address problems inspired by biology. Numerous studies have shown that structure of proteins contribute towards their functionality in a direct or indirect way. The structure of viral capsid proteins are critical for hosting and shielding the genetic material and are also crucial for viral entry. In this work, molecular energetics of mutated hepatitis B capsid protein dimer was studied for determining the stability of the virus upon single-site amino acid mutation. Results provide structural information regarding the key residues contributing to hepatitis B virion stability and synthesis. This work illustrates the salience of computational nanotechnology and paves the way for future pharmaceutical applications aimed at the destabilisation of the capsid–surface protein interactions.
Chemical and thermo‐responsive characterisation of surfaces formed by plasma polymerisation of N‐isopropyl acrylamide

Plasma polymerisation of N ‐isopropyl acrylamide (NIPAAm) presents an exciting route for the production of thermally responsive coatings on a wide variety of substrates for applications in tissue culture and microfluidics. One issue associated with the polymerisation of NIPAAm via plasma polymerisation is the limited volatility of the monomer and the subsequent requirement for monomer and reactor heating to create and maintain the vapour. It is already well established that power is critical in the balance between polymer functionality and coating stability in plasma polymers. However, little is known of how reactor and substrate temperatures may be used to influence the physico‐chemical characteristics of polymers produced from such low‐volatility monomers. In this paper, we examine the effects of a range of plasma deposition parameters on the functionality and stability of plasma‐polymerised NIPAAm surfaces. X‐ray photoelectron spectroscopy (XPS), near‐edge X‐ray absorption fine structure spectroscopy (NEXAFS), ellipsometry and contact angle goniometry have been used to examine coating chemistry, stability in aqueous environments, deposition rates and thermo‐responsive behaviour. Our results indicate that plasma polymerisation at low powers and low temperatures enhances the ability of plasma‐polymerised NIPAAm to display a wettability phase transition, but also contributes to instability of the coating to dissolution or delamination in water. Our spectroscopic measurements confirm that retention of the monomer structure is facilitated by low power and temperature deposition and reveal that conversion of the amide groups to amine and nitrile groups occurs during the polymerisation process, particularly at high discharge powers. Copyright © 2006 John Wiley & Sons, Ltd.
Analysis of Bioaerosols from Chicken Houses by Culture and Non-Culture Method

In livestock breeding, high bioaerosol concentrations in environments such as chicken houses are an occupational health concern. Two sampling methods (impinger and filter) and three non-culture methods [epifluoresence microscopy with fluorochrome (EFM/FL), flow cytometry with the fluorochrome (FCM/FL), and fluorescent in situ hybridization (FISH)] were used to monitor the total concentration, viability, and culturability of bioaerosols in chicken houses. These results were compared to the commonly used culture method. Total microbial cell concentrations measured by the non-culture methods averaged about 5 × 10 7 cells/m 3 . However, culture method underestimated bioaerosol concentrations by a factor of 10. For sampler comparison, viability determined following impinger collection was higher than that following filter method. In conclusion, impinger was considered an appropriate sampler, and EFM/FL, FCM/FL, and FISH approaches could adequately assess total microbial cell concentration and viability of bioaerosols in environmental samples.
Structural modelling of silicon carbide-derived nanoporous carbon by hybrid reverse Monte Carlo simulation

An atomistic model of the nanoparticle size Silicon Carbide Derived Carbon (SiC-CDC) is constructed using the Hybrid Reverse Monte Carlo (HRMC) simulation technique through a two-step modeling procedure. Pore volume and three-membered ring constraints are utilized in addition to the commonly used structure factor and energy constraints in the HRMC modeling to overcome the challenges arising from uncertainties involved in determining the structure. The final model is characterized for its important structural features including pore volume, surface area, pore size distribution, physical pore accessibility, and structural defects. It is shown that the microporous structure of SiC-CDC 800 possesses a high pore volume and surface area, making it potentially a good candidate for gas adsorption applications. The HRMC model reveals the SiC-CDC 800 structure to be highly amorphous, largely comprising twisted graphene sheets. It is found that these distorted graphene-like carbon sheets comprising the carbon struct.
Atomic‐Scale Observation of the Ni Activation Process for Partial Oxidation of Methane Using In Situ Environmental TEM

In situ environmental transmission electron microscopy (ETEM) studies on nanostructures, in parallel with conversion and selectivity measurements, have been carried out on Ni/SiO2 catalysts for partial oxidation of methane, in order to elucidate structure–property relationships. In situ ETEM experiments under different gas conditions are carried out to simulate the various gas atmospheres that exist in the reactor. During ramp‐up in CH4 and O2, Ni metal particles transform to void‐like NiO particles at temperatures above 300 °C due to preferential migration of Ni cations along grain boundaries and extended defects. As the temperature increases, the gas environment becomes more reducing, transforming NiO back to Ni and favoring syngas formation. The NiO reduction mechanism also involves diffusion of Ni cations along grain boundaries and extended defects. This transformation pathway suppresses the formation Ni metal crystallites on the catalyst surface during the early stage in NiO reduction. Syngas formation only takes place during the later stages of NiO reduction, when Ni metal nanoparticles have broken through the NiO shell.
System performance modeling of extreme ultraviolet lithographic thermal issues

Numerical simulation is used in the development of an extreme ultraviolet lithography Engineering Test Stand. Extensive modeling was applied to predict the impact of thermal loads on key lithographic parameters such as image placement error, focal shift, and loss of CD control. We show that thermal issues can be effectively managed to ensure that their impact on lithographic performance is maintained within design error budgets.
Advanced techniques for glancing angle deposition

When a thin film is deposited by physical vapor deposition, with the vapor flux arriving at an oblique angle from the substrate normal, and under conditions of sufficiently limited adatom mobility to create a columnar microstructure, the resulting structure is somewhat porous and grows at an angle inclined toward the vapor source. For a given material and set of deposition conditions, there is a fixed relationship between the angle of vapor flux incident on the substrate and the inclination angle at which the columnar thin film grows. As the porosity of the film is also dependent on the incident flux angle, column growth angle and porosity cannot be chosen independently. If a large columnar angle (more parallel to the substrate) is desired, the flux must be deposited at a large oblique angle resulting in a very porous film. Conversely, if a near vertical columnar film is desired, the flux must arrive more perpendicular to the substrate and the resulting film has a tightly packed, dense microstructure. We .
The right Treatment Step Ozone and Ozone/H2O2 for the Degradation of None-biodegradable COD

Many waste water treatment plants utilise an activated sludge biology as a final step of their treatment process. The biological step is able to reduce the biodegradable part of the COD. The COD in this secondary effluent – usually the remaining, not biodegradable COD – might be still too high in order to meet specific limits for direct discharge or re-use purposes. The article describes data from a municipal treatment plant with a high input of industrial waste water. Therefore, the COD level in this secondary effluent is still in the range of 120 – 180 mg/l. An ozone treatment step was installed to reduce the COD to the given limit values. Additional pilot trials showed the advantage of ozone/ H2O2 combination for advanced COD degradation. Furthermore the principle aspects for combining ozone and biological treatment as well as using
Synthesis and Characterisation of First Generation Luminescent Lanthanide Complexes Suitable for Being Adapted for Uptake via the Mannose Receptor

With the aim of directing lanthanide complex uptake via the mannose receptor, a first generation of luminescent lanthanide complexes has been developed with an α-D-mannose targeting motif. Four complexes were produced to investigate photophysical properties and determine the effect of the coordinated mannose residue on emission intensity. The free hydroxyls of the α-D-mannose residue quenched lanthanide phosphorescence due to their close proximity, though they did not bind the lanthanide centre as observed by q-values ≈1.0 for all complexes between pH 3 and 10. Fluorescent emission was found to vary significantly with pH, though phosphorescent emission was relatively insensitive to pH. This lack of pH sensitivity has the potential to provide stable emission for the visualisation of the endosome-lysosome system where acidic pH is often encountered.
Ab initio Study of the Potential Energy Surface and Product Branching Ratios for Reaction of O(1D) with C2H5Cl

The potential energy surface of O(1D)+C2H5Cl reaction was studied using QCISD(T)/6311++G(d,p)//MP2/631G(d,p) method. The calculations reveal an insertion-elimination mechanism. The insertion reaction of O(1D) and C2H5Cl produces two energy-rich intermediates, IM1 and IM2, which subsequently decompose into various products. The calculations of the branching ratios of various products formed through the two intermediates were carried out using RRKM (Rice-Ramsperger-Kassel-Marcus) theory at the collision energies of 0, 20.9, 41.8, 62.7, 83.6, 104.5, and 125.4 kJ/mol. HCl is the main decomposition product for IM1; CH2OH is the main decomposition product for IM2. Since IM1 is more stable than IM2, HCl is probably the main product of the O(1D)+C2H5Cl reaction.
Na + ,K + -ATPase, THE STAR OF EPITHELIAL NET TRANSPORTS: WHAT DO WE KNOW ABOUT ITS OWN POLARIZED DISTRIBUTION

( ( The cells of metazoan organisms exchange nutrients and wastes with an extremely thin layer of interstitial milieu, that would be quickly spoiled, were it not for a circulatory apparatus that constantly restores nutrients and takes away waste products by carrying them to and from large areas of epithelia (intestinal, renal, lung, gills, etc.), where they are finally exchanged with the external environment. Therefore metazoans ultimately depend on the ability of their epithelia to transport substances in a net amount towards the outside of the organism or in the opposite direction. In the second half of the Nineteen Century Emile Du Bois Raymond found that the frog skin maintains a spontaneous electrical potential across, and in 1904 G. Galeotti proposed that it was due to a higher Na + permeability in the inward than in the outward direction, but his suggestion was rejected lest that it would be in violation of the first and second laws of thermodynamics ( for reviews see Cereijido and Rotunno 1971, Cereijido et al. 2004). To circumvent this difficulty it was proposed that energy would be afforded by cellular metabolism. Yet this was also refuted because, according to Curie’s Principle, phenomena of different tensorial order cannot be coupled, i.e. since the transport of Na + is a vectorial phenomenon (it occurs in the outside -> inside direction) it cannot be driven by a scalar phenomenon (in those days chemical reactions were assumed to be scalar, and therefore was not expected to proceed in a given direction of space). Half a century later electric and tracer methods unambiguously demonstrated that the frog skin can actually transport a net amount of Na + in the inward direction, in the absence of an external electrochemical potential gradient. This demanded, of course, a closer look at the arguments that had stood in the way of accepting that metabolism can drive Na + transport.
Terminologia para as técnicas analíticas de eletromigração em capilares

This is a contribution that presents a translation of the work "Terminology for Analytical Capillary Electromigration Techniques" by Riekkola and collaborators (Pure Appl. Chem., Vol. 76, No. 2, 443-451, 2004) from IUPAC© for the Portuguese Language. Additional terms that had not been defined in native Portuguese were included for the benefit of the local community. Additional notes were also included to clarify some important concepts and to highlight the differences between techniques.
Adsorption of fluids in model zeolite cavities

The adsorption of molecules into a zeolite has been studied in two simple model systems with spherical cavities and with Lennard-Jones molecules as adsorbents. The thermodynamic and structural properties have been calculated by a virial expansion and by direct calculation of the partition functions. The results are compared with those obtained by a grand canonical Monte Carlo simulation and good agreement is found at low occupancies with the virial expansion, and up to medium occupancies with the partition functions. It is shown that the direct calculation of the partition functions can be made for systems containing up to about six molecules.
Broadband Vibrational Cooling of Cold Cesium Molecules: Theory and Experiments

The use of a broadband, frequency shaped femtosecond laser on translationally cold cesium molecules has recently demonstrated to be a very efficient method of cooling also the vibrational degree of freedom. A sample of cold molecules, initially distributed over several vibrational levels, has thus been transfered into a single selected vibrational level of the singlet X1Σg ground electronic state. Our method is based on repeated optical pumping by laser light with a spectrum broad enough to excite all populated vibrational levels but limited in its frequency bandwidth with a spatial light modulator. In such a way we are able to eliminate transitions from the selected level, in which molecules accumulate. In this paper we briefly report the main experimental results and then address, in a detailed way by computer simulations, the perspectives for a "complete" cooling of the molecules, including also the rotational degree of freedom. Since the pumping process strongly depends on the relative shape of the ground and excited potential curves, ro-vibrational cooling through different excited states is theoretically compared.
One‐Pot Homogeneous and Heterogeneous Oxidation of Glycerol to Ketomalonic Acid Mediated by TEMPO

Glycerol, an increasingly abundant by- product of biodiesel production, is selectively con- verted to ketomalonic acid in one pot at pH 10 using NaOCl as regenerating oxidant in water at 2 C in the presence of catalytic Br along with the radical TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl). The reaction can also be conducted at completion over a sol-gel silica glass doped with the nitroxyl radical. Considering the stability and versatility of such doped glasses, these materials show real promise as reusable metal-free catalysts for the conversion of a readily available and renewable biofeedstock into a highly valued compound.
Electrocatalytic Methanol Oxidation of Pt0.5Ru0.5-xSnx/C (x = 0−0.5)

In this paper, we reported on the electrocatalytic activities for methanol oxidation of Pt0.495Ru0. 505/C, Pt0.526Sn0. 474/C, Pt0.467Ru0. 495Sn0.038/C, Pt0.472Ru0. 413Sn0.115/C, Pt0.504Ru0. 354Sn0.142/C.
Orientational properties of perylene tetracarboxylic diimide molecules in liquid–crystalline matrices

Molecular orientational order of perylene tetracarboxylic diimide, N,N’-di(n-hexyl)-1,6,7,12-tetrachloroperylene-3,4,9,10-carboxylic acid imide (Cl4-PTCDI-6C), dissolved in homologous series of liquid crystals, i.e. 4-(trans-4′-n-alkylcyclohexyl)-isothiocyanato-benzene (nCHBT) and 4-n-alkyl-4′-cyanobiphenyl (nCB), is investigated by using UV–V is absorption and fluorescence spectroscopies. The orientational order parameter , determined experimentally for Cl4-PTCDI-6C molecules in nCHBT and nCB, is much lower than that for some other derivatives of perylene dissolved in the same liquid crystal hosts. The order parameter , obtained for Cl4-PTCDI-6C in nCHBT and nCB, is also smaller than obtained previously from Raman scattering in the liquid crystal hosts. The orientational order parameter for the Cl4-PTCDI-6C probe takes extremely low negative values, which indicates the importance of higher rank order parameters in the description of the dye distribution in the liquid–crystalline matrices. The bulky chlorine atoms, substituted in the perylene tetracarboxylic diimide molecular core, seem to be primarily responsible for the small orientational order parameters of the dye molecules. Finally, the odd–even effect, manifesting itself in an alternating increase and decrease of and for Cl4-PTCDI-6C along with increasing number of carbon atoms in the alkyl chains in nCHBT homologous series, is discussed.