Miracle-dz/UniFAR-FTUs huggingface dataset:
A two-step spin transition and order-disorder phenomena in the mononuclear compound [Fe(Hpy-DAPP)](BF4)2

This paper reports the synthesis and detailed characterization of the mononuclear complex [FeII(Hpy-DAPP)](BF4)2 (Hpy-DAPP = {bis[N-(2-pyridylmethyl)-3-aminopropyl](2-pyridylmethyl)amine}), which manifests a two-step spin crossover accompanied by an ordering and a conformational transition in the ligand. The magnetic susceptibility measurements and Mossbauer spectra reveal that the two steps of the spin transition are separated by an inflexion point at about 130 K at which 50 % of the complex undergoes a spin conversion. The high-temperature step centered at 181 K is gradual, whereas the low-temperature one displays a thermal hysteresis with two transition temperatures (Tc↓ = 119 and Tc↑ = 123 K). The single-crystal X-ray structure has been determined for the HS (298 K) and LS (90 K) forms, as well as for the mixed form with an HS:LS ratio of 1:1 (130 K). The structural studies show that the crystal lattice contains a single FeII crystallographic site over the whole temperature range. At room temperature, the most important peculiarity of the HS complex structure is the disorder of the N3 amino aliphatic atom, which is in the first coordination sphere of FeII, over two positions. The strong involvement of the N3 atoms in H-bonding with two neighboring counterions is considered as a possible origin of this disorder. At 130 K, the disorder is increased by the distribution of the N1 and C9 atoms over two positions, leading to the conformational disorder (chair and twist-boat conformations with a 1:1 ratio) in the six-membered N2C7C8C9N1Fe chelate cycle. At 90 K, the disorder in the positions of the N1, N3, and C9 atoms disappears and the N2C7C8C9N1Fe metallacycle adopts a unique twist-boat conformation. The results of structural studies suggest that the two-step spin-transition behavior of the complex [Fe(Hpy-DAPP)](BF4)2 is induced by two different geometries of the [FeN6] coordination core generated by the disorder in the ligand. The HS → LS transition is also associated with the conformational change in the chelate cycle. Both crystallographic data analysis and electronic structure calculations allow us to relate the disordered geometries of the [FeN6] coordination core to their HS and LS character. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Defect Engineering of Photocatalysts by Doping of Aliovalent Metal Cations for Efficient Water Splitting

Doping of aliovalent metal cations to SrTiO3, a photocatalyst for overall water splitting, was variously examined for the control of defect structure as well as the photocatalysis. Doping of a cation with valence lower than that of the parent cation effectively enhanced photocatalytic activity, while the doping of a higher valence cation led to the suppressed photocatalysis. It was demonstrated that the doping of a lower valence cation to intentionally introduce oxygen vacancies and decrease Ti3+ is effective to enhance photocatalytic activity.
Free volume‐size dependence on temperature and average molecular‐weight in poly(ethylene oxide) determined by positron annihilation lifetime spectroscopy

Positron lifetime measurements were carried out in a series of poly(ethyl- ene oxide)—PEO— of different average molecular weights (M # w): 1000, 1500, 6000, 10,000, 300,000, and 4 M. The mean radius (R # ) and the mean free volume size (Vf) values were determined using a semiempirical equation that correlates the ortho- positronium (o-Ps) lifetime (t3) and size of holes existing in the amorphous phases. The hole mean radius values determined at room temperature from lifetime spectra were found to be between 2.68 and 2.97 A, and the hole volumes between 80 and 110 A 3 . Free volume size evolution was studied with temperature variation until the melting tem- perature of the PEO samples. The degree of crystallinity and the melting temperatures were determined by Differential Scanning Calorimetry. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 219 -226, 1999
FREEZE-DRIED BIOMOLECULES : FT-ICR STUDIES OF THE SPECIFIC SOLVATION OF FUNCTIONAL GROUPS AND CLATHRATE FORMATION OBSERVED BY THE SLOW EVAPORATION OF WATER FROM HYDRATED PEPTIDES AND MODEL COMPOUNDS IN THE GAS PHASE

Solvent evaporation from extensively hydrated peptides and selected model compounds formed by electrospray ionization has been examined using an external ion source Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. Water evaporation from the clusters, formed at room temperature by appropriate operation of an electrospray ion source, is initially rapid and results in evaporative cooling of the clusters to a temperature around 130−150 K, determined by the balance between evaporative cooling and heating by background blackbody radiation. In this “freeze-drying” process, it is observed that the kinetics of solvent evaporation and the cluster size distributions are highly dependent on the nature of the core ion in the cluster. In agreement with earlier studies of the hydrated proton, pure water clusters exhibit special stability characteristic of clathrate formation where, for example, a hydronium ion is encapsulated by a pentagonal dodecahedron of twenty water molecules. Similar clustering.
The use of organo alkoxysilane coupling agents for wood preservation

Abstract Corsican pine (Pinus nigra) sapwood was treated with methanolic solutions of two organo alkoxysilanes ([γ-(methacryloxy)propylx] trimethoxy silane (TMPS), or vinyl trimethoxy silane (VTMS)). Various treatment parameters were studied in order to determine the optimum method for obtaining a stable weight percentage gain. For TMPS, it was found that best results were obtained when a free-radical initiator was used in conjunction with the silane. This indicates that polymerisation of this species occurs via the pendant methacryloxy moeity, a result confirmed by solid-state nuclear magnetic resonance studies of the treated wood. For VTMS, wood moisture content had a profound influence upon the weight percentage gain due to treatment, with higher weight percentage gains obtained as wood moisture content was increased. This indicates that polymerisation in this case occurred via the formation of silanol groups to form siloxane linkages. Solid-state NMR confirmed that the double bond of the organo-functional group was intact after polymerisation had occurred. Modified wood samples were then prepared using optimised treatments for each silane. The wood was prepared to a variety of weight percentage gains and the effect of treatment on the dimensional stability and decay properties of the treated material studied. Treatment of Corsican pine sapwood with the two organo-alkoxy silanes, resulted in only moderate increases in dimensional stabilisation, with anti shrink efficiency values (after 5 water-soak/oven-dry cycles) no greater than 40%. Treatments were found to be relatively stable to hydrolysis. Some differences were observed in the effectiveness of the two silanes in providing protection. Full decay protection required high treatment levels with the silanes.
Muscle but not cutaneous C‐afferent input produces prolonged increases in the excitability of the flexion reflex in the rat.

Stimulation of cutaneous afferent fibres in the sural nerve and muscle afferent fibres in the gastrocnemius‐soleus nerve at a strength that excites C axons produces a delayed and long‐lasting burst of activity in posterior biceps femoris/semitendinosus flexor motoneurones. Following a 20 s stimulation at 1 Hz to the sural nerve the flexor motoneurones continue to fire for 20 s while a similar stimulus to gastrocnemius‐soleus nerve results in an after‐discharge lasting three times longer. Using stimuli to the sural and gastrocnemius‐soleus nerves as conditioning stimuli (20 s, 1 Hz) changes in the excitability of the flexor reflex were measured by recording the discharge evoked by a test sural nerve stimulus or by a standard pinch to the ipsilateral and contralateral toes. Prior to any conditioning stimulus the flexor reflex remained stable for prolonged periods. Conditioning stimuli at strengths that activated large myelinated afferent fibres only, or large and small myelinated afferent fibres, failed to produce more than a very transient alteration in the reflex excitability. Conditioning stimuli at C‐fibre strength to the sural nerve produced a marked increase in the excitability of the reflex for 10 min. C‐fibre strength gastrocnemius‐soleus nerve conditioning stimuli resulted in a similar increase in excitability followed by a second phase of facilitation peaking at 20‐30 min and lasting for up to 90 min. The afferent barrage initiated by cutting the sural and gastrocnemius‐soleus nerves resulted in similar patterns of reflex excitability increases with the muscle nerve resulting in a more prolonged effect than the cutaneous nerve. The results show that a brief C‐afferent fibre input into the spinal cord can produce a prolonged increase in the excitability of the flexion reflex and that muscle C‐afferent fibres evoke longer‐lasting changes than cutaneous C fibres. The differences in the time course of the post‐conditioning effects may be related to the well‐described differences in the sensory consequences of injury to skin versus deep tissue.
Analgesic effect of μ‐and κ‐opioid agonists in beige and CXBK mice

Abstract— The analgesic effects of μ‐and κ‐opioid agonists, including morphine, FK33,824, U50,488H, tifluadom and bremazocine, have been determined in C57BL/6J‐bgJ (beige) and CXBK mice which are hyporesponsive to μ‐opioid receptor‐mediated analgesia compared with those of control mice (C57BL/6J (C6J), C57BL/6By (C6By), BALB/cBy (BALB)) using an abdominal constriction assay. The analgesic effect of subcutaneously administered morphine and FK33,824 in both beige and CXBK mice was significantly reduced compared with the controls and the analgesic effect of U50,488H and tifluadom in beige mice was significantly reduced compared with the wild strain (C6J). No reduction of analgesic effect of U50,488H and tifluadom was seen in CXBK compared with its progenitor strains, C6By and BALB, except for a reduction of the effect of tifluadom in CXBK compared with C6By. There was no strain difference in the bremazocine‐induced analgesia. These results suggest that the beige mouse has a deficit in analgesia mediated by both μ‐and κ‐opioid receptors, whereas the CXBK is deficient only in the μ‐opioid receptor‐mediated analgesia.
Recent developments in the fungal transformation of steroids

Abstract Steroids constitute a vital part of the active ingredients in pharmaceuticals and intermediates used to produce medicines, and their application in chemical and agrochemical fields is also valued. The complex stereochemistry of steroids requires attention to regio- and stereoselectivity of the reaction during preparation, and therefore, biocatalytic methods are appropriate for their production. This work reviews the recent application of fungi for the transformation of different steroid substrates, new biotransformation techniques, recently characterized reactions, and practical aspects, covering the period from 1990 to 2014. The future prospects of fungal biotechnology and biotransformation in the biopharmaceutical industry are also considered.
A review of environmental effects and management of nanomaterials

Nanomaterials are widely used in the field of engineering and in modern society. Although the unique characteristics of nanoparticles also enable them to provide environmental solutions to reduce the formation and emissions of pollutants, adverse effects on human health may occur from the exposure to nanomaterials during the manufacturing processes and when nanomaterials are released and they contaminate the environment. It is essential to understand the factors affecting the accumulation, aggregation, deposition, translocation, and distribution of nanomaterials (natural or engineered) in the ecosystem. This study presents an extensive review of the environmental effects of nanomaterials, including classification, adverse impacts on human health and the environment, transport pathways, monitoring methods, and the current regulations regarding nanomaterials. The review indicates that the diversity of nanoparticles and their properties make the identification and characterization of nanomaterials a difficult task, and an improvement in sensitivity and selectivity of analytical methods for detecting nanoparticles in the environment is required. Besides, few regulations have been established for the management of nanoparticles released into the environment. In order to expedite the environmental management of nanomaterials, this study proposes a risk assessment framework based on the findings in the review as a practice alternative for the environmental assessment and effective management of nanomaterials. Development of practical innovative risk-based management measures may help us to find answers to the concerns such as safety of engineering and applying nanomaterials and effective control of nanoparticle contamination in the environment.
Sequential Amino-Claisen Rearrangement/Intramolecular 1,3-Dipolar ­Cycloaddition/Reductive Cleavage Approach to the Stereoselective Synthesis of cis-4-Hydroxy-2-aryl-2,3,4,5-tetrahydro-1(1H)-benzazepines

A novel stereoselective synthesis of cis-2-aryl-4-hydroxy-2,3,4,5-tetrahydro-1-benzazepines from N-allylanilines utilizing aromatic amino-Claisen rearrangement and intramolecular 1,3-dipolar cycloaddition methodologies is described. This sequence involves N-allylation of corresponding N-benzylanilines followed by amino-Claisen rearrangement, subsequent oxidation with in situ 1,3-dipolar cycloaddition affording isoxazolidines, and finally reductive cleavage of the isoxazolidinic N-O bond.
Exact Solution of a Directed-Site Animals-Enumeration Problem in three Dimensions.

An exact equivalence is established between the directed-site animals-enumeration (DSAE) problem in $d$ dimensions and a crystal-growth model defined on the same lattice. In special cases, the latter reduces to the calculation of the free energy of a ($d\ensuremath{-}1$)-dimensional lattice gas with extended hard cores. The author solves a DSAE problem with $d=3$ exactly by using its equivalence to the hard-hexagon problem, and shows that the exponent $\ensuremath{\theta}=\frac{5}{6}$. A new and simpler solution to the DSAE problem on the square and triangular lattices is given.
Effect of Surfactant Concentration on Particle Nucleation in Emulsion Polymerization of n-Butyl Methacrylate

The effect of surfactant concentration on particle nucleation in emulsion polymerization of n-butyl methacrylate has been studied using sodium dodecyl sulfate as the surfactant and potassium persulfate as the initiator. The rates of reaction as a function of time were determined for surfactant concentrations above and below critical micelle concentration of the surfactant. The order of dependence of the particle number on the surfactant concentration was found to be different in different ranges of surfactant concentration. This has been explained on the basis of the predominant phenomenon that affects particle nucleation in each range of surfactant concentration. In the range where the end of particle nucleation is determined by a critical surfactant coverage necessary for colloidal stability, the particle number is expected to increase in proportion to the third power of the surfactant concentration. It has been shown how a size-dependent volumetric growth-rate of particles can result in different expon.
The Effects of Establishment Methods and Fertilization Practices on Nitrate Leaching from Turfgrass

A lysimeter study was conducted the Ohio State University Turfgrass Research Center, Columbus, to investigate NO 3 -N leaching losses from fertilized turfgrass. Nitrogen fertilizer treatments were applied to 'Baron' Kentucky bluegrass (Poa pratensis L.) seeded and sodded turf established on a Miamian silt loam (fine, mixed, mesic Typic Hapludalf. Treatments included two N sources, urea and resin-coated urea (RCU); and Two fertilization programs, one that emphasize spring and summer applicatlons (SSF) and the and second program that included a late season application (LSF) []
Intestinal Microbiota and Its Link with Mind and Heart

Summary A mini review about how the Intestinal Microbiota (IM) is linked to the mind and heart is carried out. It is pointed out how once IM inflammation (Dysbiosis) generated, a series of mechanisms, immunological, neuronal and endocrine, that affect host phenotypes are triggered. The interpretation of what the gut-microbiota-brain axis is deepened. (GBA), and it is exemplified how, through bidirectional communications with the Intestinal Microbiota, a series of changes, which impact human health, are translated. Likewise, 10 conclusions are proposed on diverse topics, because the IM not only relates to the mind-heart binomial, but it has to do with many organs and consequently with many sufferings.
Efficient photocatalytic Suzuki cross-coupling reactions on Au–Pd alloy nanoparticles under visible light irradiation

We report herein highly efficient photocatalysts comprising supported nanoparticles (NPs) of gold (Au) and palladium (Pd) alloys, which utilize visible light to catalyse the Suzuki cross-coupling reactions at ambient temperature. The alloy NPs strongly absorb visible light, energizing the conduction electrons of NPs which produce highly energetic electrons at the surface sites. The surface of the energized NPs activates the substrates and these particles exhibit good activity on a range of typical Suzuki reaction combinations. The photocatalytic efficiencies strongly depend on the Au : Pd ratio of the alloy NPs, irradiation light intensity and wavelength. The results show that the alloy nanoparticles efficiently couple thermal and photonic energy sources to drive Suzuki reactions. Results of the density functional theory (DFT) calculations indicate that transfer of the light-excited electrons from the nanoparticle surface to the reactant molecules adsorbed on the nanoparticle surface activates the reactants. The knowledge acquired in this study may inspire further studies of new efficient photocatalysts and a wide range of organic syntheses driven by sunlight.
Acid soil tolerances of wheat lines selected for high grain protein content

Abstract Literature suggests that nitrogen (N) metabolism is involved in differential acid soil (Al) tolerances among wheat (Triticwn aestivum L. en Thell) genotypes. Atlas 66 wheat is characterized by acid soil and aluminum (Al) tolerance, nitrate (NO3 ‐) preference, pH increase of the rhizosphere, high nitrate reductase activity, and high protein in the grain. Atlas 66 has been used as a high protein gene donor in the development of new high protein wheat lines at Lincoln, NE. The objective of our study was to determine the acid soil tolerances of such lines and to relate such tolerances to their abilities to accumulate grain protein when grown on near‐neutral, non‐toxic soils. Twenty‐five experimental lines, nine cultivars not previously classified as Al‐tolerant or ‐sensitive and three cultivars previously classified according to acid soil tolerance, were grown for 28 days in greenhouse pots of acid, Al‐toxic Tatum subsoil. Relative shoot dry weight (pH 4.35/pH 5.41%) varied from 83.2% for Atlas 66 to.
Wasser: von Clustern in die Flüssigkeit

Wasser ist fr jede Form des Lebens von fundamentaler Bedeutung und spielt in vielen biologischen und che- mischen Prozessen eine wichtige Rolle. Obwohl Wasser zu den am h‰ufigsten vorkommenden Substanzen z‰hlt, ist es bei Weitem keine einfache Flssig- keit. Wasser weist stark polare Wasser- stoffbrcken auf, die fr eine Reihe anomaler physikalischer und chemi- scher Eigenschaften verantwortlich sind. Seit mehr als einem Jahrhundert inspirieren die Bedeutung und die Besonderheiten des Wassers Wissen- schaftler zur Entwicklung von Model- len, die das beobachtete Verhalten von Wasser reproduzieren knnen. Die Kenntnisseber Struktur und Bindung in kleinen Wasserclustern sind ein Schlssel fr das Verst‰ndnis von Was- ser in der flssigen Phase und im Eis sowie seiner Lsungsmitteleigenschaf- ten. Moderne quantenmechanische und hochauflsende spektroskopische Methoden konnten in jngster Zeit grose Erfolge bei der Charakterisie- rung solcher Cluster erringen. Mit Clustermodellen versucht man, den ‹bergang von solchen Strukturen in die Flssigkeit nachzuvollziehen. Die wichtige Frage lautet nun: Wie mssen solche Cluster beschaffen sein, damit sie Wasser im flssigen Zustand be- schreiben knnen?
Why is LDL-cholesterol bad cholesterol?

The high circulating LDL-cholesterol levels seen in the inherited disease familial hypercholesterolaemia cause high rates of cardiovascular disease whereas the low circulating LDL-cholesterol levels following statin treatment cause low rates of cardiovascular disease. This is why LDL-cholesterol is referred to as bad cholesterol by the media. Atherosclerosis is caused not by native circulating LDL particles but rather by oxidized LDL particles in the arterial wall. Oxidized LDL particles unlike native particles are taken up by macrophages via scavenger receptors to form foam cells and are treated as autoantigens by the immune system provoking inflammation. Hence many of the characteristics of the atherosclerotic plaque including its tendency to rupture and cause thrombosis and heart attacks can be explained in molecular detail by the effects of oxidized LDL particles.
Geochemical Distribution of Lead and Chromium in River Getsi-Kano

Geochemical forms of lead (Pb) and Chromium (Cr) from the sediment of River Getsi Kano-Nigeria were determined using Atomic Absorption spectrometer for eighteen months. Apart from determination of the metals in water, geochemical forms of the metals were also evaluated into five fractions. Exchangeable, bound to carbonates, bound to concentrations of the metals in water alone will not be enough to tell on the toxicity of particular heavy metal, as such the need for the geochemical forms of the metal become necessary in order to quantify the form in which the toxic metals exist. The distribution of the metals at the sediment shows that the metals were distributed in all the fractions. This suggests different pollution sources. Hence the sediment may be said to be a reservoir for the heavy metals. Keywords: Heavy metals, River Getsi, Environment, Pollution, Sediment, Geochemical forms
The Raman spectrum of brookite, TiO2 (Pbca, Z = 8)

The Raman microprobe spectra of natural brookite crystals from Switzerland and Brazil and a synthetic brookite powder exhibit a characteristic intense band at 153 cm−1. In contrast, anatase has a band of similar intensity at 144 cm−1 and rutile lacks a strong band in this region. Polarization experiments with the Brazilian crystal permit 17 out of a predicted 36 vibrational bands to be readily assigned as A1g (127, 154, 194, 247, 412, 640 cm−1), B1g (133, 159, 215, 320, 415, 502 cm−1), B2g (366, 395, 463, 584 cm−1) and B3g (452 cm−1). Eight weaker bands and component sub-bands resolved at 172, 287, 545, 618 cm−1, 254, 329, 476 cm−1 and 497 cm−1 are tentatively assigned to B3g, B2g and A1g modes respectively. Traces of Si and Fe in the Brazilian crystal and Si, Fe, Al and S in the Swiss sample are indicated by spot electron microprobe analysis. Electron spin resonance spectra suggest small amounts of Fe3+ are substituting for Ti4+ in the structure. Concomitant protonation of oxygens to maintain charge balance yields OH groups which give rise to three sharp, low-intensity absorption bands near 3360, 3380 and 3404 cm−1 in the infrared spectra. X-ray photoelectron spectroscopy shows that surface-bound OH/H2O species exist in both crystals but no detectable Ti3+.