Miracle-dz/UniFAR-FTUs huggingface dataset:
Single Chromatin Fibre Assembly Using Optical Tweezers

Here we observe the formation of a single chromatin fibre using optical tweezers. A single -DNA molecule was suspended between two micron-sized beads, one held by a micropipette and the other in an optical trap. The constrained DNA molecule was incubated with Xenopus laevis egg extract in order to reconstitute a single chromatin fibre. An eight-fold compaction of the DNA molecule was observed in real-time. The compaction kinetics were found to be strongly dependent upon the tension applied to the DNA molecule. We incorporated the analysis of Brownian motion to accurately determine the tension throughout the compaction process. At forces exceeding 10 pN complete inhibition of compaction was observed for the time scale of the experiment. We have previously shown that stretching of a reconstituted chromatin fibre results in discrete and quantized structural opening events that we can attribute to the unravelling of single nucleosomes. Assembly kinetics therefore provide insight into rates of nucleosome formation and we demonstrate the possibility of probing these kinetics under different experimental conditions.
Measurement of vibrational populations in low‐pressure hydrogen plasma by coherent anti‐Stokes Raman scattering

Coherent anti‐Stokes Raman scattering (CARS) has been applied to the measurement of vibrational populations in a low‐pressure H2 plasma. We describe the plasma generator and give some particulars of the optical arrangement. For an electron density of 2×1011 cm−3 and a total pressure of 0.13 mbar, the rotational temperature is found to be 475 K. The populations of vibrational states v = 0, 1, and 2 have also been measured. Their distribution is non‐Boltzmann. The influence of pressure and discharge parameters is briefly discussed. The instrument detection sensitivity for a given rovibrational state is about 1012 cm−3.
Li‐ion anodes in air‐stable and hydrophobic ionic liquid‐based electrolyte for safer and greener batteries

In this paper we report on the use of the ionic liquid N‐butyl‐N‐methylpyrrolidinium bis(trifluoromethansulfonyl)imide, PYR14TFSI, in combination with a graphite and silicon electrodes at room temperature. The performance of the investigated electrodes has been considered in terms of specific capacity, cycling efficiency and cycling stability. The influence of two different binders on the performance of graphite electrode has also been considered. The results show that in electrolytic solutions based on PYR14TFSI the addition of an electrolyte additive is necessary for the formation of the solid electrolyte interphase (SEI). The reported results show also that the selection of the binder is important for the increase of the performance in graphite electrodes. Finally, the comparison of the performance of the investigated electrodes showed that silicon electrodes display higher compatibility with PYR14TFSI with respect to graphite electrodes. Copyright © 2009 John Wiley & Sons, Ltd.
Atmospheric corrosion of zinc Part 2: Marine atmospheres

Abstract This paper summarises the results obtained in the MICAT (Mapa Ibero-Americano de Corrosão Atmosférica (Latin American Map of Atmospheric Corrosion)) atmospheric corrosion project (an Iberoamerican project on atmospheric corrosion, involving 14 countries and 75 atmospheric test sites) for zinc specimens exposed in the Latin American region for 1–4 years at 23 pure marine and 19 mixed marine (i.e. SO2 polluted) sites. The atmospheres at these sites were characterised climatologically and in terms of their pollution levels so that their corrosivity could be expressed in accordance with ISO standards. Morphological and chemical characterisation of the zinc corrosion product layers (ZCPLs) was performed using scanning electron microscopy coupled with energy dispersive spectrometry (SEM–EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and soluble salt evaluation techniques. The results obtained show that the corrosion rate of zinc is a function of both the chloride pollution level and the time of wetness. Some synergetic effects of Cl- and SO2 were demonstrated, although some special types of behaviour were also observed.
Computational and experimental study of oxygen-enhanced axisymmetric laminar methane flames

Three axisymmetric laminar coflow diffusion flames, one of which is a nitrogen-diluted methane/air flame (the ‘base case’) and the other two of which consist of nitrogen-diluted methane vs. pure oxygen, are examined both computationally and experimentally. Computationally, the local rectangular refinement method is used to solve the fully coupled nonlinear conservation equations on solution-adaptive grids. The model includes C2 chemistry (GRI 2.11 and GRI 3.0 chemical mechanisms), detailed transport, and optically thin radiation. Because two of the flames are attached to the burner, thermal boundary conditions at the burner surface are constructed from smoothed functional fits to temperature measurements. Experimentally, Raman scattering is used to measure temperature and major species concentrations as functions of the radial coordinate at various axial positions. As compared to the base case flame, which is lifted, the two oxygen-enhanced flames are shorter, hotter, and attached to the burner. Computational and experimental flame lengths show excellent agreement, as do the maximum centreline temperatures. For each flame, radial profiles of temperature and major species also show excellent agreement between computations and experiments, when plotted at fixed values of a dimensionless axial coordinate. Computational results indicate peak NO levels in the oxygen-enhanced flames to be very high. The majority of the NO in these flames is shown to be produced via the thermal route, whereas prompt NO dominates for the base case flame.
Ionic dispersion of Pt and Pd on CeO2 by combustion method : Effect of metal-ceria interaction on catalytic activities for NO reduction and CO and hydrocarbon oxidation

Ceria-supported Pt and Pd catalysts have been synthesized by the combustion method. The catalysts are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Pt and Pd metals are ionically dispersed on the CeO2 surface of crystallite sizes in the range of 15-20 nm. In 1% Pt/CeO2 Pt is found to be in the +2 and +4 oxidation states whereas Pd is in the +2 state in 1% Pd/CeO2. Catalytic activities for NO reduction by CO, NH3, CH4, and C3H8 and CO, CH4, and C3H8 oxidation by O-2 have been investigated over all these catalysts using the temperature-programmed reaction technique. The results are compared with Pt and Pd metals dispersed on alpha -Al2O3 support prepared by the combustion technique. Both oxidation and reduction reactions occur at much lower temperatures over M/CeO2 compared to those over M/Al2O3 (M = Pt, Pd). The rate and turnover frequency of NO + CO and CO + O-2 reactions over M/CeO2 are higher than those over M/Al2O3. The observed enhanced catalytic activity of M/CeO2 has been attributed to the ionic dispersion of Pt and Pd on CeO2 leading to a strong metal-ceria interaction in the form of solid solution, Ce1-xMxO2-(4-n)x/2, having linkages of the type -O2--Ce4+-O2--Mn+-O2--(n=2, 4) on the CeO2 surface
Optical Absorption Spectra and Dynamic Jahn-Teller Effect of V2+ Ions in ZnSe

The Hamiltonian matrices for 3d3 ions in a cubic crystal field are introduced, based on a molecular orbital model, including the electronic Coulomb and tetrahedral crystal-field interactions and the spin-orbit coupling. The optical absorption spectra of V2+ ions in ZnSe are studied. Moreover, the various additional levels found close to 5680 cm−1 are considered. These levels are assumed to result from the dynamic Jahn-Teller splitting within the excitation levels 2T2 and 2T1 in ZnSe:V2+. The good agreement between the present results and the experimental observations indicates that the contribution of the covalence reduction factors NE and NT2 and of the Racah parameter A to the optical absorption spectra of V2+ ions in ZnSe is important. However, most of the previous theoretical studies of these spectra in ZnSe:V2+ have neglected the Racah parameter A, based on the classical crystalfield model. A significant charge-transfer effect found in recent works is confirmed in ZnSe:V2+.
Removal of model proteins by means of low-pressure inductively coupled plasma discharge

Surgical instruments are intended to come into direct contact with the patients' tissues and thus interact with their first immune defence system. Therefore they have to be cleaned, sterilized and decontaminated, in order to prevent any kind of infections and inflammations or to exclude the possibility of transmission of diseases. From this perspective, the removal of protein residues from their surfaces constitutes new challenges, since certain proteins exhibit high resistance to commonly used sterilization and decontamination techniques and hence are difficult to remove without inducing major damages to the object treated. Therefore new approaches must be developed for that purpose and the application of non-equilibrium plasma discharges represents an interesting option. The possibility to effectively remove model proteins (bovine serum albumin, lysozyme and ubiquitin) from surfaces of different materials (Si wafer, glass, polystyrene and gold) by means of inductively coupled plasma discharges sustained in different argon containing mixtures is demonstrated and discussed in this paper.
Complexation of C60 on a Cyclothiophene Monolayer Template

The design and synthesis of molecules that form self-assembled monolayers on substrates is fairly well understood and developed. [1–3] Nevertheless, the controlled hierarchical construction of hybrid multilayers [4,5] comprising molecular-scale (electronic) functionalities is a major challenge, and the first systems have been demonstrated only recently. [6,7] Here, we present the direct observation of self-assembled two-dimensional (2D) crystals of a novel class of organic semiconductors [8,9] on graphite by means of scanning tunneling microscopy (STM). Highly organized monolayers of hexagonally packed ring-shaped cyclo[12]thiophene (C[12]T) uniformly cover large areas of the surface. [3,8] On top of the modified template surface, C 60 -fullerenes uniquely adsorb and self-assemble in a second layer whose crystallinity is governed by the formation of 1:1 p -donor– p -acceptor (D–A) complexes through a true host–guest interaction. We have been able to analyze the complexation sites and dynamics of the fullerenes with submolecular resolution. The electronic properties have been determined by scanning tunneling spectroscopy (STS) measurements on individual D–A complexes. We have studied the long-range and short-range ordering of the conjugated macrocycle C[12
Rheology of polystyrene solutions around the coil overlapping concentration: A phenomenological description of stresses in simple shear flow

Linear viscoelasticity behavior is described with the sum of two terms for polystyrene solutions in tricresyl phosphate around the coil overlapping concentration (K. Osaki, T. Inoue, & T. Uematsu, J Polym Sci Part B: Polym Phys 2001, 39, 211). One is a Rouse–Zimm (RZ) term represented by the Zimm theory with arbitrarily chosen values of the hydrodynamic interaction parameter and the longest relaxation time (τRZ). The other (the L term) consists of a relaxation mode with a single relaxation time (τL > τRZ) and a high-frequency limiting modulus proportional to the square of the concentration. In this study, we describe the viscosity (η) and first normal stress coefficient (Ψ1) in steady shear with simple formulas. The stress due to the L term is assumed to be given by a Kaye, Bernstein, Kearsley, and Zapas (K-BKZ) equation with the damping function h(γ) = (1 + 0.2γ2)−1/2, where γ is the magnitude of shear. Contributions to η and Ψ1 from the RZ term are derived from the RZ model, in which the relaxation time in steady flow is given by τst = τ + (τRZ − τ)/(1 + 0.35τRZ γ˙) instead of τRZ. Here, γ˙ is the rate of shear, and τ is the τRZ value at the infinite dilution limit. η and Ψ1 at various concentrations for two polystyrene samples (with molecular weights of 2890 and 8420 kg mol−1) are well described with parameters derived from dynamic viscoelasticity. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1038–1045, 2002
Ethers from Esters; from Exceptional Transformation to Synthetic Method

Most ether-bond forming reactions based on traditional methods or modifications thereof require strongly acidic or basic conditions and often harsh reaction conditions. Reduction of esters to ethers has been regarded as an impracticable method, generally affording alcohols as the principal products. Only recently, original, mostly catalytic methods for reduction of esters to ethers have been reported, which proceed under mild conditions and are compatible with many functional groups present in the substrate ester molecule. These reactions are considered as a valuable alternative to traditional methods, and specific protocols have been reported. An account of the progress in this synthetic methodology is given .
The Effect of Storm Interval on the Transport of Soluble Phosphorus in Runoff

The effect of varying the interval between events on the transport of soluble phosphorus (P) in runoff was evaluated under simulated rainfall conditions. A decrease in soluble P concentration was observed during each runoff event although initial concentrations increased as the interval between events was decreased from 1 day to 5 min (0.027–0.033 mg/liter and 0.020–0.028 mg/liter for Bernow fine sandy loam and Woodward loam soils). This was attributed in part to a movement of soil water down the profile following cessation of runoff, resulting in a decrease in the surface soil of the “pool” of soluble P susceptible to transport in runoff. In contrast, a marked increase in the mean concentration of soluble P in runoff was observed as event interval increased from 1 to 6 days (0.018–0.026 mg/liter and 0.011–0.041 mg/liter for Bernow and Woodward soils). This increase was found to be related to the phosphatase enzyme activity of the five soils studied and could thus, be partially attributed to mineralization of organic P.
Monodisperse copper- and silver-nanocolloids suitable for heat-conductive fluids

Copper colloid was prepared via reductive stabilization. The suspension of the trioctylaluminum-stabilized copper colloid was peptized using Korantin SH and cashew nut shell liquid (CNSL). Fluids with particle sizes <10 nm were obtained with Korantin and 7–15 nm in the case of CNSL. However, the copper colloid is air sensitive. A very straightforward one-step method leads to air-stable silver nanofluids. Thermal decomposition of silver lactate in the presence of Korantin SH and mineral oil as the medium gave a silver nanofluid. Silver particle formation and air stability were monitored using UV–VIS spectroscopy. The presence of monodispersed spherical silver nanoparticles was confirmed. Transmission electron microscopy showed a two-dimensional assembly of the silver particles with a size distribution of 9.5 ± 0.7 nm. FTIR has revealed information about the interaction between the surfactant and the silver surface. Copyright © 2005 John Wiley & Sons, Ltd.
Industrially Feasible Approach to Transparent, Flexible, and Conductive Carbon Nanotube Films: Cellulose-Assisted Film Deposition Followed by Solution and Photonic Processing

We report that single-walled nanotube (SWNT) films with precisely controlled thicknesses and transmittances can be produced through the doctor-blade method using SWNT–polymer inks. The matrix polymer around SWNTs were successfully removed by either solution curing or photonic curing at room temperature, which are advantageous processes enabling direct film formation on plastic substrates. Sheet resistances as low as 68–240 Ω/sq at T=89–98% were obtained. Furthermore, the SWNT film on poly(ethylene naphthalate) exhibited superior flexibility and stability in a flexure endurance test. The method may open a wide range of opportunities for flexible electrical devices.
Polylactide/Polyethylene/Organoclay Blend Nanocomposites: Structure, Mechanical and Thermal Properties

Structure and physical properties of PLA/PE/organoclay with and without compatibilizer (PE-g-MA) with PLA as a matrix phase were investigated by X-ray diffraction, transmission electron microscopy, rheometric mechanical spectrometer, thermal gravimetric analysis, dynamic mechanical thermal analysis and Mechanical experiments. Two types of compatibilized-blend nanocomposites were prepared by two feeding orders: (1) simultaneous feeding, (2) PLA/organoclay-based master batch. The XRD results showed an intercalated structure for nanocomposites. The mechanical results demonstrated that presence of PE and compatibilizer improved the elongation at break, while organoclay enhanced Young's modulus. Thermogravimetric analysis showed that organoclays could retard the thermal decomposition process in the nanocomposites.
The Zwitterion Effect in Ionic Liquids: Towards Practical Rechargeable Lithium‐Metal Batteries

Practical lithium-metal batteries are the ultimate goal of battery researchers. The addition of a zwitterionic compound (see Figure) to an ionic liquid electrolyte doped with a lithium salt results in a 100% enhancement of the current densities achieved in the cycling of a lithium-metal cell. This phenomenon arises due to increased lithium-ion mobility or a reduced solid electrolyte interphase layer resistance.
Evaluation of the Frequency of Clinical Manifestations of Premenstrual Syndrome in Young Married Women in Yazd

Â Introduction : Premenstrual Syndrome (PMS) includes physical, psychological and emotional symptoms that occur during the last days of premenstrual cycle and subside with the start of menstruation or during the first days of bleeding. The aim of this study was to evaluate the frequency of clinical manifestations of premenstrual syndrome in young married women in Yazd. Â Material and Methods: This descriptive -cross-sectional study was carried out on 240 young married women reterring to Yazd Health Care Centers. Data collection tools to measure the PMS, was Premenstrual Symptoms Screening Tool and demographic information. The Criteria for entraning the study was non-pregnant married women less than 45 years who had been married for at least 6 months and maximum 5 years. T -tests and ANOVA were used to analyze the data. Â Results : Results showed that the frequency of moderate or severe PMS was 91.3% and the frequency of premenstrual dysphoric disorder was 8.7% . Considering the severity of the symptoms , the most common indications included . "Physical symptoms" with 22.9%, "nervous irritability" with 21.7%, , tiredness and lack of energy (19.2%), crying and increased sensitivity to negative reaction (13.8%) , oversleeping (10.8%) and, anxiety and tension (10.4%). The Other common symptoms were below 10%. The im pact of symptoms in the family members with the frequency of 12.1% was the most intensive symptom of all. Â Conclusion : According to the results, the large outbreak of premenstrual symptoms and the impact of signs on life and social relationships is undeniable. Thus, there is a need for more studies to be done on understanding the symptoms and implementing training stssions.
Synthesis of Diblock Codendrimer by Double Click Chemistry

E-mail: jihyeon@gachon.ac. krReceived September 9, 2012, Accepted September 24, 2012Efficient double click methods for the synthesis of diblock codendrimers were developed. The syntheticstrategy involved the sequential click reactions between an alkyne and an azide. The short core building block,1,4-diazidobutane, was chosen to serve as the azide functionalities for dendrimer growth via click reactionswith the alkyne-functionalized PAMAM dendrons as hydrophilic dendron and alkyne-functionalized Frechet-type dendrons as hydrophobic dendron. The structure of diblock codendrimers was confirmed by
Characterization and permeation properties of ZSM‐5 tubular membranes

ZSM-5 zeolite membranes with reproducible properties were prepared by in-situ synthesis on porous {alpha}- and {gamma}-alumina tubular supports and characterized by XRD, SEM and electron microprobe analysis. Single-gas permeances for H{sub 2}, CH{sub 4}, N{sub 2}, CO{sup 2}, n-butane, and i-butane increase over some temperature range, but some gases exhibit maxima or minima. The highest ideal selectivities at room temperature are 299 for N{sub 2}/SF{sub 6}, 392 for H{sup 2}/n-butane, and 2,820 for H{sub 2}/i-butane. These membranes can separate n-butane/i-butane, H{sub 2}/n-butane and H{sub 2}/i-butane mixtures. All n-butane/i-butane separation selectivities have maxima as a function of temperature and are higher than ideal selectivities because n-butane inhibits i-butane permeation. Thus, separation is not by size selectivity, but is due to pore blocking. Temperature dependencies of single-gas permeances and separation selectivities depend strongly on the location of zeolite crystals and the location is determined by preparation procedure. Ideal selectivities also depend strongly on the preparation procedure. When the zeolite forms a continuous layer on the inside surface of the support tubes, pure i-butane permeates faster than pure n-butane so that the single-gas permeances are not determined just by molecular size. The i-butane permeance also increases much more with temperature than the n-butanemore » permeance. The permeation behavior may be the result of permeation through nonzeolitic pores in parallel with zeolite pores. When zeolite crystals are dispersed throughout the pores of {alpha}-alumina supports, permeances are lower and gas permeation and separation properties are quite different. Ideal selectivities are lower, pure n-butane permeates faster than i-butane, and the permeances increase much less with temperature. Separation selectivities are lower but can be maintained to higher temperatures. « less
Green illusions: the dirty secrets of clean energy and the future of environmentalism

ables. We need sacrifice on the scale that brought victory in World War II and we need something akin to the Marshall Plan in support of research and development. The clock is ticking. The fix will neither be easy nor cheap. It will be painful. We need to decarbonise the world economy and fast. Current and past strategies have failed and need to be jettisoned. How we live needs to change. How we eat and how we get around needs to change. How comfortable we are needs to change. Above all, we need to tell the truth. The carbon crunch is upon us. How we respond now will determine how severe that crunch will be.
Efecto de los minerales sobre la cinética de degradación térmica de aserrín de álamo

The kinetics of thermal degradation in inert atmosphere for poplar sawdust using both untreated samples and demineralized ones by a mild acid treatment, is comparatively studied in order to examine the influence of the minerals naturally present in this resource on the process kinetics. Proximate analysis of the untreated and demineralized samples is performed to evaluate the effectiveness and changes in their chemical characteristics promoted by the applied treatment. Kinetic measurements are carried out by non-isothermal thermogravimetric (TG) analysis in the range of temperatures comprised between 20 and 900°C. For each case, kinetics parameters are evaluated from TG curves by applying a conventional model. Partial removal of the minerals leads to shift the process beginning and the maximum degradation rate towards higher temperatures. Besides it induces to enhance the activation energy. The behavior may be attributed to catalytic effects exerted by the inorganic material on sawdust degradation.