Miracle-dz/UniFAR-FTUs huggingface dataset:
In vitro fertilization with single blastocyst-stage versus single cleavage-stage embryos

Single-embryo transfer has been proposed as a way of limiting multiple births after in vitro fertilization (IVF) in women less than 36 years of age. Extending embryo culture from the 3-day cleavage stage to the 5-day blastocyst stage might make pregnancy likelier and, in addition, the morphologic criteria that guide embryo selection are less subjective at the later date. This study analyzed the outcome of IVF in 351 infertile women age 35 and younger; 176 were assigned to have transfer of a single cleavage-stage embryo, whereas 175 received a single blastocyst-stage embryo. Multifol-licular ovarian stimulation was carried out using recombinant follicle-stimulating hormone and a gonadotropin-releasing hormone antagonist. Oocyte maturation was promoted by administering human chorionic gonadotropin, and the luteal phase was supported by vaginally administered progesterone. More than 90% of women in both treatment groups were having their first or second trial of IVF or intracytoplasmic sperm injection. The groups were similar demographically and in embryologic characteristics, but significantly more embryos in the cleavage-stage group were cryopreserved. Approximately two thirds of each group had a top-quality embryo for transfer. Compared with cleavage-stage cases, the blastocyst-stage group had a significantly higher rate of ongoing pregnancy (33% vs 22%). The relative risk (RR) was 1.54 with a 95% confidence interval (CI) of 1.08 to 2.18. Deliveries also were significantly more frequent in the blastocyst-stage group (32% vs 22%); the RR was 1.48 with a 95% CI of 1.04 to 2.11. A higher rate of first-trimester pregnancy loss in the cleavage-stage group (34% vs 19%) may be partly responsible, although the difference was not statistically significant. Two of 94 deliveries (2%), both in the cleavage-stage group, resulted in monozygotic twin births. These results affirm the effectiveness of single-embryo transfer in reducing the risk of multiple births. In younger women having their first or second trial of IVF, transfer of a single blastocyst-stage embryo is significantly likelier than use of a cleavage-stage embryo to result in pregnancy and delivery.
The interaction of pulsed electric fields and texturizing ‐ antifreezing agents in quality retention of defrosted potato strips

Summary The combination of pulsed electric fields (PEF) and texturizing and antifreeze agents on quality retention of defrosted potato strips were studied. Potato strips (10 mm thickness, 100 g) were placed in different solutions (1% w/v) of CaCl2, glycerol, trehalose as well as NaCl and sucrose, treated with PEF (0.5 kV cm−1, 100 pulses, 4 Hz). Then, all the samples were soaked in the same solutions for 10 min. After draining, samples were packed into polypropylene pouches and stored at −18 °C for 12 h. Samples were thawed out at room temperature (20 °C) in 3 h. Untreated controls and PEF treated control samples were also frozen and thawed in similar conditions. To assess the potato strip quality, the thawed samples were analysed for moisture content, weight loss, firmness and colour attributes. The results indicate that PEF treatment by itself is not a suitable pre-treatment method for frozen potato strips and should be assisted by CaCl2 and trehalose treatment to prevent softening after defrosting. Firmness analyses determined that application of PEF alone results in 2.38 N. However, PEF in combination with CaCl2 and trehalose result in 2.97 N and 2.99 N, respectively, which are both significantly firmer than the samples solely treated with PEF. CaCl2 and trehalose were effective in not only maintaining the structural integrity of the cells, but also retaining colour attributes. The L* value was found to be higher (P < 0.05) in CaCl2 and trehalose treated samples (58.95 and 57.21, respectively), as compared to PEF treated samples (53.97) denoting a darker colour. Application of CaCl2 and trehalsoe in combination with PEF also resulted in significantly less weight loss after thawing.
Viscosity, Self‐Diffusion, and Allied Effects in Solid Polymers

An attempt has been made to explain the observed viscous behavior of bulk polymers. It is found that the viscosity and diffusion may be represented by a theory which takes into account the coupling together of the molecules. Two equivalent treatments are given. One makes use of a segmental friction factor in the same manner as the common formulation of dilute solution viscosity of polymers. The second method uses the concept of segmental jumping. Since both are equivalent, an expression for the friction factor is found in terms of the segmental jumping frequency. Using this fact it is possible to calculate the segmental jumping frequency from bulk viscosity data. A simple application leads to the result that the jumping frequency is about 0.3 sec−1 at the transition temperature in polystyrene.In addition a simple relation is found to hold between bulk viscosity and diffusion constant. The proportionality constant is easily evaluated and so one is now able to obtain self‐diffusion constants directly from v.
Fe3O4 Nanoparticles Confined in Mesocellular Carbon Foam for High Performance Anode Materials for Lithium‐Ion Batteries

Fe3O4 nanocrystals confined in mesocellular carbon foam (MSU‐F‐C) are synthesized by a “host–guest” approach and tested as an anode material for lithium‐ion batteries (LIBs). Briefly, an iron oxide precursor, Fe(NO3)3·9H2O, is impregnated in MSU‐F‐C having uniform cellular pores ∼30 nm in diameter, followed by heat‐treatment at 400 °C for 4 h under Ar. Magnetite Fe3O4 nanocrystals with sizes between 13–27 nm are then successfully fabricated inside the pores of the MSU‐F‐C, as confirmed by transmission electron microscopy (TEM), dark‐field scanning transmission electron microscopy (STEM), energy dispersive X‐ray spectroscopy (EDS), X‐ray diffraction (XRD), and nitrogen sorption isotherms. The presence of the carbon most likely allows for reduction of some of the Fe3+ ions to Fe2+ ions via a carbothermoreduction process. A Fe3O4/MSU‐F‐C nanocomposite with 45 wt% Fe3O4 exhibited a first charge capacity of 1007 mA h g−1 (Li+ extraction) at 0.1 A g−1 (∼0.1 C rate) with 111% capacity retention at the 150th cycle, and retained 37% capacity at 7 A g−1 (∼7 C rate). Because the three dimensionally interconnected open pores are larger than the average nanosized Fe3O4 particles, the large volume expansion of Fe3O4 upon Li‐insertion is easily accommodated inside the pores, resulting in excellent electrochemical performance as a LIB anode. Furthermore, when an ultrathin Al2O3 layer (<4 Å) was deposited on the composite anode using atomic layer deposition (ALD), the durability, rate capability and undesirable side reactions are significantly improved.
High-pressure phase transitions in MgSiO3 orthoenstatite studied by atomistic computer simulation

Abstract Molecular dynamics simulations and first-principles electronic structure calculations are used to study the structural behavior of orthoenstatite, MgSiO3, at high pressures. The calculations suggest two possible high-pressure polymorphs of orthoenstatite, one with P21ca and the other with Pbca symmetry. Both polymorphs are structurally related to orthoenstatite. Molecular dynamics simulations reveal the displacive nature of the phase transitions between the three phases. Electronic structure calculations predict a phase transition from orthoenstatite to the metastable P21ca structure at 9 GPa, which may explain the anomalies in elastic and vibrational properties observed experimentally. A second metastable transition from the P21ca to the high-pressure Pbca structure may be observable above 20 GPa.
Antireflective Nanoparticle Arrays Enhance the Efficiency of Silicon Solar Cells

In this study, the phenomenon of light trapping in Si solar cells coated with metal (Au) and dielectric (TiO2, SiO2) nanoparticles (NPs) is systematically investigated. In contrast to previous reports, herein it is proposed that the photocurrent enhancement of solar cells should be attributed to the limited antireflection ability of the Au NP arrays. In other words, the Au NP arrays might not enhance the absorption of the active layer in cells when no light is reflected from the air–substrate interface. Therefore, the Au NPs are replaced with dielectric NPs, which possess lower extinction coefficients, and then the antireflection property of the TiO2 NP arrays is optimized. A simple, rapid, and cheap solution‐based method is used to prepare close‐packed TiO2 NP films on Si solar cells; these devices exhibit a uniform and remarkable increase (ca. 30%) in their photocurrents. To the best of the authors’ knowledge, this uniform photocurrent enhancement is greater than those obtained from previously reported metal and dielectric NP–enhanced Si wafer‐based solar cells.
Excited-State Photophysics and Dynamics of a Hemicyanine Dye in AOT Reverse Micelles

The internal rotation of a photoexcited hemicyanine dye, trans-4-[4-(dimethylamino)-styryl]-1-methylpyridinium iodide (DASPI), was investigated in water-containing reverse micelles. The rate constants for the twisting motion were obtained from the measured fluorescence lifetimes in various sizes of water nanoclusters (ca. 0.6−5.6 nm in radius) prepared from sodium bis(2-ethylhexyl) sulfosuccinate (AOT)−alkane−water solutions by changing the molar ratio of water/AOT. It was observed that the fluorescence lifetime of DASPI in the water pool formed by the reverse micelle markedly increases as the nanocluster size decreases, implying that the excited-state twisting motion is significantly influenced by the microstructure of the reverse micelle. An endeavor was made to relate the rate process for internal rotation to water pool characteristics such as polarity and viscosity.
The Passivation of Zinc in Alkaline Solutions

Comportement d'electrodes de zinc dans des solutions basiques agitees saturees de composes solubles de zinc. Mecanisme de croissance des couches passives sur les electrodes de zinc dans les batteries. Durant la croissance de la couche de passivation, la diffusion de l'electrolyte dans la couche poreuse joue le role principal, et, apres passivation, le film devient plus compact, les grains prenant une forme spherique
Combined Application of Ionic Liquid and Hybrid Poly (Ionic Liquid)-Bonded Silica: An Alternative Method for Extraction, Separation and Determination of Flavonoids from Plants

Hybrid poly (ionic liquid)-bonded silica was combined with an ionic liquid solution for the extraction, separation, and determination of flavonoids from natural plants by using a multi-phase dispersive extraction (MPDE) method. The hybrid material was synthesized using a facile method. A suitable sorbent was identified based on the adsorption behaviors of flavonoids on different poly (ionic liquid)-bonded silicas. In contrast to traditional matrix solid-phase dispersion (MSPD) method, the target analytes were first extracted by three-phase (sample-solvent-sorbent) dispersive extraction with ionic liquid (1-oxyl-3-methylimidazolium bromide) solutions as the solvent, and then cleaned up after removal from the sample matrix, called MPDE. This process combines the advantages of ionic liquids, ionic liquid-based sorbent, and MPDE. The recovery rates were achieved by MPDE of the flavonoids from Chamaecyparis obtusa: 76.4% for myricetin and 90.3% for amentoflavone. The proposed method may be used to extract and separate other flavonoids or even polyphenolic compounds from complex samples.
Fast photodynamics of aqueous formic acid

Femtosecond transient absorption spectroscopy is used to investigate the primary reaction dynamics of aqueous formic acid, HCOOH(aq), following the photoexcitation of the n → π* transition at 200 nm. Using probe pulses covering the spectral range from 200 to 620 nm, we find that the only detectable photoproduct is the OH radical, which suggests that HCOOH(aq) dissociates predominantly into the HCO + OH channel. The absence of signals assignable to the formyl radical is discussed, and the properties of hydrated formyl radicals are investigated using high-level electronic structure calculations.
Improved design of mantle tanks for small low flow SDHW systems

Side‐by‐side tests of two small low flow solar domestic hot water (SDHW) systems based on mantle tanks have been carried out under the same test conditions in a laboratory test facility. The systems are identical with exception of the mantle tanks. One of the mantle tanks has the mantle inlet port located at the top of the mantle and the other mantle tank has the mantle inlet port moved 0.175 m down from the top of the mantle. The thermal performance is almost the same for the two systems in the measuring period of 252 days. The solar fractions were 0.66 and 0.68 for the two systems. The tests showed also that the system with the low mantle inlet perform better than the system with the high mantle inlet in periods with low solar fractions, that is in less sunny periods. Further, calculations with a simulation model for low flow SDHW systems based on mantle tanks showed that mantle tanks currently marketed can be greatly improved by relatively simple design changes: increasing the height/diameter ratio, reducing the mantle height and increasing the insulation thickness on the sides of the tank. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis of hierarchical porous spinel nickel cobaltite nanoflakes for high performance electrochemical energy storage supercapacitors

Hierarchical porous spinel nickel cobaltite (NiCo2O4) nanoflakes synthesized through a cost-effective and scalable chemical precipitation method exhibited high specific capacitance (1270 F g−1), excellent rate capability (81% capacity retention at 10 A g−1) and cycling stability (only 4.8% loss after 5000 cycles).
Catalytic degradation of methylene blue in aqueous solutions over Ni- and Co- oxide systems

AbstractThe oxidative catalytic degradation of the cationic dye methylene blue (MB) with NaOCl in aqueous solutions was studied using individual and iron modified Ni- and Co-oxide systems as catalysts. The adsorption extent and the contribution of the uncatalyzed oxidation on the overall degree of MB were determined. The results indicate that methylene blue—a representative of a class of dyestuffs resistant to biodegradation—could be successfully decolorized and degraded using nickel and cobalt oxide catalysts at room temperature. The highest catalytic activity manifests in the Co-oxide system which is consistent with the adsorption data. The oxidative degradation reaction proceeds via first-order kinetics. Temperature has a relatively small effect on the methylene blue degradation kinetics. The results obtained reveal that the catalysts investigated are suitable for oxidative destruction of methytlene blue dye in wastewaters.
A comparative study of the preparation and physical properties of polystyrene–silica mesocomposite and nanocomposite materials

In this paper, a comparative study with regard to the preparation and physical properties of as-prepared polystyrene – silica mesocomposite (PSM) and polystyrene-silica nanocomposite (PSN) materials is presented. Vinyl-modified mesoporous silica particles with a wormhole structure were first prepared by doping a sol-gel metal oxide with an optically active nonsurfactant (dibenzoyl-L-tartaric acid) as a template, followed by template removal through Soxhlet extraction. The as-prepared silica particles with/without mesopores were subsequently characterized using the Brunauer – Emmett – Teller method and transmission electron microscopy (TEM) and Fourier transform infrared, 13 CN MR and 29 Si NMR solid-state spectroscopy. A specific feed amount of silica particles was subsequently reacted with styrene monomer by free radical polymerization to yield a series of PSM and corresponding PSN materials. Both as-prepared composite systems were further characterized using TEM and scanning electron microscopy/energy-dispersive X-ray mapping studies. A systematic comparative study of the physical properties of both as-prepared composite materials clearly illustrated that PSM had effectively enhanced thermal stability, optical clarity and dielectric properties compared to the corresponding PSN counterpart. Evaluation was carried out using thermogravimetric analysis, differential scanning calorimetry, UV-visible transmission spectroscopy and dielectric constant measurements. c � 2011 Society of Chemical Industry
Modeling of biogas formation and utilization using Aspen Plus

A flexible model for biogas generation and utilization was developed using simulation tool Aspen Plus. It is based on two interacting submodels, describing the process of biogas generation via anaerobic digestion and biogas utilization. Three possible approaches to model biogas production have been employed calculation via chemical oxygen demand (COD), calculation according to Buswell’s equation, and implementing stoichiometric reactions. For purpose of biogas utilization three paths are included combined heat and power generation (CHP) by means of a gas engine, a second path which could further be used for biogas upgrading, and adiabatic combustion of generated biogas. The model can be used for a rough estimate whether integration of a biogas process with systems processing organic waste material streams is beneficial or not. An economic approach is no target of this work. This model simply calculates how much biogas can maximal be obtaind out of a specific organic feedstock and how much heat and power can be generated by the use of a gas engine or a simple combustion process. Because of its flexible and simple configuration, the model can be adapted to various types of substrate with respect to model setup. The difference between the calculation methods used have been discussed. The model was evaluated in terms of comparing with results from literature, comparing the results of the model with results of a model from literature, and sensing potential limits by appling several kinds of input data.
Optical absorption measurements of band-gap shrinkage in moderately and heavily doped silicon

Optical absorption studies in the infra-red region around the fundamental energy gap have been carried out on both n- and p-Si samples in the range of concentrations from 3*1014 cm-3 to 7.3*1018 cm-3 for p-Si and from 6.5*1016 cm-3 to 9.2*1018 cm-3 for n-Si at room temperature (294 K). The transmission ratios were first measured for each sample in the range of wavelengths from about 0.9 mu m to 2.5 mu m. These ratios were then applied to calculate the reflectivity and the absorption coefficients for the samples. After correcting for free-carrier absorption, the band-gap shrinkage was then determined from the absorption coefficients for each sample. These results were then compared with those determined from other optical absorption studies, with those found by electrical device measurements and with those predicted from theories. It was found that even well below 3*1018 cm-3, a reduction in band-gap energy Delta Eg could be determined for both n- and p-Si, in contrast to the earlier optical absorption studies which reported that none could be detected. Between 1018 cm-3 and 1019 cm-3 the authors experimental values are consistent with those determined by other optical absorption studies. Their results also show that even in the moderately doped regime, their values of mod Delta Eg mod are less than those found by electrical device measurements and those predicted by various recent theories. This is consistent with the findings of the other optical studies in the heavily doped regime. The authors also found that the gap shrinkage mod Delta Eg mod depends on the dopant concentration as N13/. This is in agreement with the experimental results of Wagner and Vol'fson and Subashiev as well as with the theoretical results of Mahan and Berggren and Sernelius.
Helical screw sense of peptide molecules. Crystal structures of three Aib-based pentapeptides1

The molecular and crystal structures of three terminally blocked (Aib) n /(L-Xxx) m (n = 3, 4; m = 1,2; n + m = 5) pentapeptides [pBrBz-L-Ala-(Aib) 4 -OtBu (1), pBrBz-L-Val-(Aib)4-OtBu (2), pBrBz-L-Ala-(Aib) 3 -L-Ala-OMe (3)] were determined by X-ray diffraction. The three compounds are characterized by the following parameters: (1) orthorhombic, P2 1 2 1 2 1 , a = 33.833(3) A, b = 11.776(2) A, c = 9.317(1) A, and Z = 4; (2) triclinic, P1, a = 10.316(6) A, b = 10.580(5) A, c = 18.735(6) A, α = 95.46(4)°, β = 90.08(6)°, γ = 111.92(4)°, and Z = 2; (3) monoclinic, P2 1 , a = 9.002(1) A, b = 19.242(3) A, c = 9.668(1) A, β = 113.69(1)°, and Z = 2. The structures were solved by direct methods. The least-squares refinements led to R values of 0.042, 0.060, and 0.046 for (1), (2), and (3), respectively. The three pentapeptides are folded in a 3 10 -helical structure. However, the structure of (1) is left-handed helical from residue 1, whereas that of (3) begins with a non-helical type-II β-bend that is followed by a left-handed helix. The two independent molecules, A and B, in the asymmetric unit of (2) are diastereomeric, the former being right-handed helical from residue 1, while the latter is left-handed.
Charge-Transfer-Driven Diffusion Processes in Cu@Cu-Oxide Core−Shell Nanoparticles: Oxidation of 3.0 ± 0.3 nm Diameter Copper Nanoparticles

Copper nanoparticles with a diameter of 3.0 ± 0.3 nm were generated under vacuum, using a sputtering−aggregation source, and deposited onto glass or highly ordered pyrolytic graphite substrates. Upon exposure to room-temperature air, core−shell particles formed, as determined by surface plasmon resonance spectroscopy, high resolution X-ray photoelectron spectroscopy, and quartz crystal microgravimetry. At 160 °C in air, the core−shell particles converted predominantly to Cu2O. At 220 °C, they converted to CuO almost exclusively. The maximum oxide shell thickness attainable at room temperature was 0.56 nm, as determined by quartz crystal microgravimetry and scanning tunnelling microscope imaging. The shell thicknesses formed are compatible with a simple charge-transfer-based model akin to Mott and Fromhold−Cook theories of metal oxidation processes. The model, which yields the change in the height of the energy barrier to diffusion as a function of shell thickness, is found to be consistent with many adsor.
Effects of the dipole moments behavior on a vibronic coupling model for the four-wave mixing signal

In the present work, we have studied modifications in the transition and permanent dipole moments of states in a coupled basis (including vibronic coupling) due to variations in the transition dipole moment between the uncoupled states, m12, as a function of the parameter δ = 0/ω0 (relative aperture) of the potential-energy curves of the states involved. Modifications in the slopes of the transition and permanent dipole moments of the coupled states and changes in the magnitude of maximal intensity of the four-wave mixing (FWM) signal are observed due to variations in these parameters. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004