Miracle-dz/UniFAR-FTUs huggingface dataset:
General Two-Phase Routes to Synthesize Colloidal Metal Oxide Nanocrystals: Simple Synthesis and Ordered Self-Assembly Structures

Different two-phase approaches have been developed for the synthesis of two classes of monodisperse colloidal metal oxide nanocrystals (NCs): rare earth oxide NCs and transition metal oxide NCs. These routes were simple and inexpensive, using metal salts instead of organometallic compounds, with mild reaction conditions, easily controlled size and shape, and multigram-scale products. The obtained products were characterized by transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), Fourier transform infrared absorption spectroscopy (FTIR), and nitrogen adsorption−desorption isotherms (BET). The possible mechanisms for the formation and growth of nanocrystals were discussed. Accordingly, tert-butylamine (nucleophile agent) and ethanol (reduced agent) are the key factors for the formation of rare earth oxide NCs and transition metal oxide NCs, respectively. Different sizes and shapes of monodisperse nanoparticles such as .
HIV-1 latency is established preferentially in minimally activated and non-dividing cells during productive infection of primary CD4 T cells

Latently infected CD4 T cells form a stable reservoir of HIV that leads to life-long viral persistence; the mechanisms involved in establishment of this latency are not well understood. Three scenarios have been proposed: 1) an activated, proliferating cell becomes infected and reverts back to a resting state; 2) an activated cell becomes infected during its return to resting; or 3) infection is established directly in a resting cell. The aim of this study was, therefore, to investigate the relationship between T cell activation and proliferation and the establishment of HIV latency. Isolated primary CD4 cells were infected at different time points before or after TCR-induced stimulation. Cell proliferation within acutely infected cultures was tracked using CFSE viable dye over 14 days; and cell subsets that underwent varying degrees of proliferation were isolated at end of culture by flow cytometric sorting. Recovered cell subpopulations were analyzed for the amount of integrated HIV DNA, and the ability to produce virus, upon a second round of cell stimulation. We show that cell cultures exposed to virus, prior to stimulus addition, contained the highest levels of integrated and replication-competent provirus after returning to quiescence; whereas, cells infected during the height of cell proliferation retained the least. Cells that did not divide or exhibited limited division, following virus exposure and stimulation contained greater amounts of integrated and inducible HIV than did cells that had divided many times. Based on these results, co-culture experiments were conducted to demonstrate that latent infection could be established directly in non-dividing cells via cell-to-cell transmission from autologous productively infected cells. Together, the findings from our studies implicate the likely importance of direct infection of sub-optimally activated T cells in establishment of latently infected reservoirs in vivo, especially in CD4 lymphocytes that surround productive viral foci within immune tissue microenvironments.
Fabrication and Surface Functionalization of Nanoporous Gold by Electrochemical Alloying/Dealloying of Au–Zn in an Ionic Liquid, and the Self‐Assembly of L‐Cysteine  Monolayers

This paper describes a totally electrochemical process for the fabrication and functionalization of high‐surface‐area, nanoporous gold films. The fabrication process involves the electrodeposition of a binary gold–zinc alloy at gold wires, followed by subsequent electrochemical dealloying of the less noble component zinc from the surface. Both the deposition and dealloying steps are conducted in a single low‐temperature bath of 40.0–60.0 mol‐% zinc chloride–1‐ethyl‐3‐methylimidazolium chloride ionic liquid at 120 °C without using any other corrosive acids or bases. The porous structure and morphology of the nanostructured gold film could be controlled by electrochemical variation of the composition of the Au–Zn surface alloy. It is demonstrated that the nanoporous gold surface can be successfully functionalized with self‐assembled monolayers of L‐cysteine. Such functionalization greatly improves the utility of the nanoporous gold, as is demonstrated in the sensitive and selective determination of Cu(II).
Orientational ordering of three SiO4 tetrahedra in α´L-Ca1.5Sr0.5SiO4 that satisfies bond-valence requirements and avoids O-O repulsion

The crystal structure of α´L-Ca1.55(4)Sr0.45(4)SiO4 was analyzed by single-crystal X-ray diffraction. Refinement with isotropic temperature factors yielded R = 5.4%. The occupancies of the M(11), M(12), M(13), M(21), M(22), and M(23) sites by Sr are 0.40(3), 0.37(3), 0.42(3), 0.11(3), 0.04(2), and 0, respectively. The structure contains SiO4 tetrahedra in three different orientations. The orientational ordering of the Si(n)O4 (n = 1-3) tetrahedra accommodates the M(1n)-O (n = 1-3) bond-valence unbalances caused by the ionic radii mismatch and also avoids increasing the O-O electric repulsions between adjacent Si(n)O4 tetrahedra.
The Impairment of River Systems by Metal Mine Contamination: A Review Including Remediation Options

Contamination of aquatic environments as a consequence of deep metal mining for Pb, Zn, Cu, Cd, and Fe is of widespread international concern. Pollution resulting from metal mining activities can result in significant environmental and ecological degradation and can pose serious risks to human health through contamination of food and drinking water. This paper provides a review of the impacts of deep metal mine water discharges on riverine sedimentology, hydrology, and ecology and explores strategies for the restoration of rivers draining historically abandoned metal mines. The review is concluded by identifying key recommendations for future research. An interdisciplinary approach, incorporating collaborative expertise and knowledge regarding sedimentological, hydrological, chemical, and ecological consequences of active and historic deep metal mining, is advocated and should be utilized for effective river basin management and the remediation and restoration of mining-impacted river systems.
Novel Attempts to Change the Colour of Dye Molecules Utilizing the Aggregation Mode of Saccharides

Ten saccharide-dye (azophenol and azonaphthol) conjugate molecules and four methylated reference compounds were synthesized. The purpose of the present study using these molecules is to change the colour of the common dye moiety, both in solution and in solid by the structural difference in the saccharide moieties and eventually to mimic the colour creation mechanism in a nature's flower family. In azophenol derivatives, the solution (THF) colour was more or less the same but the solid colour was significantly different (yellow-orange-pink). The XRD study established that the colour change is correlated to the crystallinity of the solid samples: the u max shifts to shorter wavelength with the increase in the crystallinity. In azonaphthol derivatives, the solution colour was more different than the solid colour. The spectroscopic studies established that this change is due to an azo-hydrazone tautomerism. The colour changes were quantitatively expressed by the CIE L * a * b * colourimetric system. The foregoing results indicate that the colour of the dye molecules can be changed utilizing the intra- and intermolecular hydrogen-bonding interactions among the appended saccharide moieties.
Formation and stabilization of ibuprofen nanoparticles by pulsed rapid expansion of supercritical solutions

Pulsed rapid expansion of supercritical solutions (RESS) was used to micronize racemic ibuprofen and S-ibuprofen. The characterization of the particles was carried out with rapid-scan infrared spectroscopy in situ, 3-wavelengths-extinction measurements, a scanning mobility particle sizer, scanning electron microscopy, and X-ray diffraction. We observed the formation of nanosized primary particles that coagulate and agglomerate strongly to form large chains of many microns in size. It is investigated where the coagulation/agglomeration processes take place and we demonstrate that it is possible to avoid these processes by forming mixed ibuprofen/polymer particles. The stabilization of separate particles depends strongly on the amount of polymer in the particles. Our specially designed RESS apparatus with two different extractor units allows us to vary the fraction of polymer systematically.
Unique Crystallization Behavior of Poly(L-lactic acid) Nucleated by Stereocomplex with Different Fine Structure

Effect of the addition of poly(D-lactic acid) (PDLA) as stereocomplex (SC) on crystallization behavior of poly(L-lactic acid) (PLLA) had been systemically investigated. The result indicated that the inclusion of PDLA with higher MW into PLLA exhibited lower t 1/2 and showed accelerated crystallization behavior. Meanwhile, SC formed in blends with higher MW of PDLA exhibited enhanced nucleation activity. In combination with both DSC and WAXD analysis, it was believed that nucleation process was more related to the crystalline size of SC. The result in this study would provide guidance for the application of SC as nucleating agent for the PLA-based products.
Cyclic powder formation during pulsed injection of hexamethyldisiloxane in an axially asymmetric radiofrequency argon discharge

A new approach of periodic production of dusty plasma consisting of pulsed injection of hexamethyldisiloxane (HMDSO) in argon axially asymmetric radiofrequency (RF) discharge was investigated in this work. The range of plasma operating conditions in which this dusty plasma can exist was closely examined. The obtained results clearly show that a net periodicity in the formation/disappearance of dust particles in the plasma can be maintained on a very large scale of discharge duration. The significance of discharge axial asymmetry to the dust particles behaviour in the plasma is revealed by the development of an asymmetric in shape void shifted towards the powered RF electrode. The key role of the reactive gas and its pulsed injection on each stage of the oscillating process of formation/disappearance of dust particles is disclosed by optical and electrical measurements. It is shown that the period of dusty plasma formation/disappearance is inversely related to the HMDSO injection time. Moreover, the impact.
Aluminum Speciation Using Morin: I. Morin and Its Complexes with Aluminum

Etude de la chimie en solution aqueuse du morin (pentahydroxy-2,3,4,5,7 flavone) comprenant (i) ses equilibres d'ionisation acide, (ii) la stœchiometrie et la stabilite de ses complexes avec l'aluminium et (iii), ses liaisons avec des ions perturbateurs
Evaluation of Rice Straw-Based Hydrogels for Purification of Wastewater

The use of rice straw waste (RS) as a substrate for the preparation of metal adsorbents hydrogels has been demonstrated. Four types of RS-based hydrogels were prepared, and evaluated for their effectiveness on purification of wastewater loaded with Cu(II), Fe(II), Zn(II) and Mn(II). Freundlich and Langmuir adsorption equations were used for estimating the adsorption capacities. The results indicated that the hydrogels have significant effect on removing the metal ions from wastewater. The removal efficiency exceeded 95% for Cu(II) and Mn (II) ions and 85 for Fe (II) and Zn (II) ions.
Simultaneous Determination of 13 Phenoxy Acid Herbicide Residues in Soybean by GC‐ECD

Abstract In this study, a gas chromatography method for the multiresidue determination of 13 phenoxy acid herbicide residues (4‐CPA, 4‐CPP, phenoxy butyric acid, dicamba, MCPA, MCPP, MCPB, 2,4‐D, 3,4‐D, 2,4,5‐T, 2,4,5‐TP, 2,4‐DP, and 2,4‐DB) in soybean was developed. After the removal of fat using n‐hexane, the sample was extracted with acetonitrile‐50 mM HCl (v/v 7:3), and then followed by liquid‐liquid partition with n‐hexane (saturated by acetonitrile). The soybean extract was further cleaned up by anion exchange column. Then the residues were derived with pentafluorobenzyl bromide and the resulting pentafluorobenzyl (PFB) esters were analyzed by a gas chromatograph equipped with an electron capture detector (ECD), quantified by the external standard method. Recoveries of spiked samples at two fortified levels (0.01 and 0.1 mg/kg) are all above 70%. And the relative standard deviation was less than 20%. It shows that the limits of determination (LOD) of this method (S/N≥3) can meet the requirement of maximum residue analysis in import/export inspection for soybean.
Development of high-field STM and its application to the study on magnetically-tuned criticality in Sr3Ru2O7

Scanning tunneling microscopy/spectroscopy (STM/STS) is a powerful method to investigate the spatial variation of electronic states with an atomic resolution. The energy resolution of STM/STS is also very high, better than ~meV, which enable us to study the details of low-lying quasi-particle excitation spectrum. In addition, STM/STS works even in extreme environments e.g. at low temperatures and under high magnetic fields. Taking these advantages into account, we have built a versatile STM/STS system working under combined extreme conditions of ultra-high vacuum, very-low temperature and high magnetic field. We apply this system to the study of strongly correlated electron systems in which subtle interplay among charge, spin and orbital degrees of freedom brings about various electronic phenomena. As one of the examples, we describe the evolution of the tunneling spectrum across the metamagnetic transition in Sr3Ru2O7.
Investigation of Cobalt Deposition Behavior with Zinc Injection on Stainless Steel under BWR Conditions

Radioactive58Co and 65Zn were used together to investigate the deposition behavior of cobalt and zinc in the oxide film formed on the stainless steel piping of an apparatus simulating the high temperature and pressure conditions of a boiling water reactor. Using these radioactive tracers allowed the experimental setup to closely approximate the conditions found in actual plants. The accumulation of 58Co and 65Zn on the stainless steel piping was monitored using an online gamma-ray detector. The results were as follows. At higher zinc concentrations, the early period of fast deposition was shortened and the later deposition phase was slowed. Two mechanisms appeared to be responsible for the suppression of cobalt deposition by zinc injection. The first worked by decreasing the growth rate of the oxide film. This effect appeared most conspicuously in the outer oxide layer under normal water chemistry conditions. The second mechanism worked by reducing the cobalt concentration in the oxide film. This second effect was prominent in the inner oxide layer under hydrogen water chemistry conditions.
Role of the structural domains of linker histones and histone H3 in the chromatin fiber structure at low-ionic strength: scanning force microscopy (SFM) studies on partially trypsinized chromatin

Chromatin fibers have been hydrolyzed by trypsin and examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) and scanning force microscopy (SFM). At early points of hydrolysis, when mostly only the tails of the linker histones have been cleaved, nucleosomes appear to pile upon each other within a fiber. Later, once significant hydrolysis of the N-terminal tail of histone H3 has occurred, fibers exhibit an open, three-dimensional arrangement of nucleosomes. Linker DNA between adjacent nucleosomes is observed for the first time. Adjacent nucleosomes appear to have a 'zig-zag' arrangement. Finally, when all the tails of the linker histones and the N-terminal tails of H3 have been cleaved, then the fibers exhibit (i) a flat two- dimensional arrangement of nucleosomes, (ii) linker DNA between nearly all nucleosomes, and (iii) a zig-zag arrangement among some nucleosomes. We suggest that (i) the linker histone globular domains help fix the angle of the DNA entering and exiting the nucleosome, (ii) the angle, however, is not sufficient to maintain the three-dimensionality of the fiber, and (iii) the N-terminal tails of histone H3 ares necessary for the three-dimensional conformation of the fiber at low ionic strength.
Comets and Carbon Dioxide

We present a 25-year database of comet photometry and discuss how this can be combined with the Spitzer large comet survey and the WISE Survey data to investigate the role of carbon dioxide activity in comets and the relation to proto-planetary disk chemistry. The Earth’s atmosphere is opaque at the wavelengths at which CO2can be observed, and this will give us a new means of exploring the distribution of CO2in the solar system.
APLICAÇÃO SEQUENCIAL DE HERBICIDAS DESSECANTES NO MANEJO DO CAPIM-AMARGOSO (Digitaria insularis (L.) Fedde)

O capim-amargoso (Digitaria insularis) se destaca devido a seu elevado potencial competitivo, sua distribuicao em praticamente todas as regioes produtoras do Brasil e ao aumento da populacao de biotipos resistentes ao glyphosate e, mais recente resistencia a alguns herbicidas inibidores da ACCase (fenoxaprop e haloxyfop). Este trabalho tem como objetivo avaliar o controle do capim-amargoso (D. insularis) atraves do posicionamento de herbicidas de contato associados a aplicacao sequencial de Glyphosate em combinacao com Clethodin em diferentes intervalos em pre-semeadura. O experimento foi conduzido em blocos completos casualizados, com quatro repeticoes em esquema fatorial 4x4, onde foram avaliadas quatro estrategias com herbicidas de contato (Glufosinato de amonio 600 g i.a. ha-1, Paraquat 600 g i.a. ha-1 e Saflufenacil, 49 g i.a. ha-1) e uma testemunha que nao recebeu a primeira aplicacao. O segundo fator foi o tempo de aplicacao do tratamento com herbicida Glyphosate combinado com Clethodin visando dessecacao do amargoso em pre-semeadura. Aos 7, 14, 21 e 28 dias, foi avaliada a altura – AL (m) e a Eficiencia dos Herbicidas de Contato – EHC (%), previamente a segunda aplicacao. Apos a segunda aplicacao, aos 7, 14, 21 e 28 dias avaliou-se o controle do capim-amargoso atraves de notas de fitointoxicacao (utilizando-se escala de notas de 0 a 100%), e o Percentual da Rebrota – PR (%) aos 14, 21 e 28 dias apos aplicacao. Os manejos isolados com herbicidas de contato, bem como a aplicacao isolada de Glyphosate + Clethodin na dessecacao em pre-semeadura nao foram eficientes no controle das plantas de D. insularis perenizadas. As maiores medias de controle envolvem a primeira aplicacao com Paraquat, 95,5% de controle, e com Glufosinato de amonio, 91,7% de controle. O intervalo entre as aplicacoes sequenciais que melhor favorece o controle das plantas de capim-amargoso na fase reprodutiva e de 14 dias. Aos 28 dias apos aplicacao de Glyphosate + Clethodin, o efeito dos tratamentos reduz e ha rebrota em todas as propostas de manejo avaliadas, exceto no tratamento com Glufosinato de amonio na primeira aplicacao e intervalo de 21 dias para a segunda aplicacao.
Fundamentals of Mesostructuring Through Evaporation‐Induced Self‐Assembly

This article gives an overall view of the mechanisms involved in the mesostructuring that takes place during the formation of surfactant‐templated inorganic materials by evaporation. Since such a method of preparation is well suited to fabricating thin films by dip coating, spin coating, casting, or spraying, it is of paramount interest to draw a general description of the processes occurring during the formation of self‐assembled hybrid organic/inorganic materials, taking into account all critical parameters. The following study is based on very recent works on the meso‐organization of thin silica films using tetraethylorthosilicate (TEOS) as the inorganic source and cetyltrimethylammonium bromide (CTAB) as the structuring agent, but we will show that the method can also be extended to other systems based on non‐silica oxides and block copolymer surfactants. We demonstrate that the organization depends mainly on the chemical composition of the film when it reaches the modulable steady state (MSS), where the inorganic framework is still flexible and the composition is stable after reaching an equilibrium in the diffusion of volatile species. This MSS state is generally attained seconds after the drying line, and the film's composition depends on various parameters: the relative vapor pressures in the environment, the evaporation conditions, and the chemical conditions in the initial solution. Diagrams of textures, in which the stabilized structures are controlled by local minima, are proposed to explain the complex phenomena associated with mesostructuring induced by evaporation.
Crystal structure of diaqua bis(di(pyrazin-2-yl)sulfane-κ1N)bis(acetato-κ1O)cobalt(II), C20H22CoN8O6S2

C20H22CoN8O6S2, monoclinic, P21/c (no. 14), a = 12.09(1) Å, b = 11.256(9) Å, c = 9.310(7) Å, " = 93.68(2)°, V = 1263.9 Å, Z = 2, Rgt(F) = 0.0390, wRref(F ) = 0.1074, T = 293 K.
Recombination coefficients of GaN-based laser diodes

We measure the charge carrier recombination coefficients of InGaN quantum wells by analyzing the dynamical properties of (Al,In)GaN laser diodes emitting in the violet spectral range. Relaxation oscillations and turn-on delays are fitted to a rate equation model including a charge carrier density dependent recombination rate. Using optical gain spectroscopy we can directly determine the injection efficiency of the devices and thereby separate the effect of charge carrier leakage from that of carrier recombination. We find a third-order recombination coefficient of (4.5±0.9)×10-31cm6s-1 which is in agreement with theoretical predictions for phonon- and alloy-disorder-assisted Auger scattering.
Microwave-Assisted Green Synthesis of Small Gold Nanoparticles Using Aqueous Garlic (Allium sativum) Extract: Their Application as Antibiotic Carriers

ABSTRACT This article establishes a rapid, microwave-assisted green synthetic method for the production of gold nanoparticles (AuNPs) using garlic extract as a reducing and stabilizing agent and seeks their application as antibiotic carriers. The appearance, crystalline nature, size, and shape of nanoparticles are understood by different physical techniques like UV-vis spectroscopy, transmission electron microscopy, and X-ray diffraction. The AuNPs of size varying from 1.8 ± 0.85 nm to 23.2 ± 4.1 nm were synthesized successfully by varying the power of microwave irradiation. Further, AuNPs (of size 23.2 ± 4.1 nm) were functionalized with ciprofloxacin (cfH), a broad-spectrum antibiotic. A red shift in absorption and emission maxima with decreased intensity suggested successful binding of cfH to AuNPs. AuNPs-conjugated cfH (cfH@AuNPs) were found to have better antibacterial activities in terms of zone of inhibition compared to free cfH against the tested bacterial strains.
Formation of carbon monoxide from the photodegradation of terrestrial dissolved organic carbon in natural waters

The photochemical formation of carbon monoxide (CO) in water samples obtained from wetlands, lakes, and near-coastal/shelf areas and in aqueous solutions of soil organic matter was investigated. All of these samples contained dissolved organic matter that was largely derived from terrestrial sources. The studies show that, although the water samples had widely varying optical properties and CO photoproduction rates, the efficiencies for photochemical CO formation were remarkably similar in all waters examined. Model calculations further indicated that photodegradation of terrestrial dissolved organic matter (e.g., in wetland and near-coastal environments) may be an important global source of carbon monoxide and a key process in cycling of dissolved organic matter in these environments.