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Application of high pressure can substantially enhance the chemical reactivity of xenon and has recently extended the Xe-compounds to unexpected elements such as Fe and H. Using unbiased structure searching techniques combined with first-principles calculations, we predict novel compounds of stable XeH2 and XeH4, and metastable XeH, XeH3, XeH5, XeH6, XeH7, and XeH8 under high pressure. Rather than van der Waals complexes, these are weakly covalent or ionic compounds stabilized by a pressure-induced increase in charge transfer from Xe to H atoms. The calculated electronic structures with hybrid exchange-correlation functionals reveal that only XeH and XeH2 are metalized under 300 GPa. For the metallic XeH and XeH2 at certain pressures, the superconducting critical temperatures are finally studied, by using Allen-Dynes modified McMillan equation combined with the calculated electron-phonon coupling parameter. [ABSTRACT FROM AUTHOR]

The fiber morphology, the content of hydrogen bonds (HBs) of different models, cellulose crystalline structure, water retention value (WRV), and strength properties of eucalyptus pulp bleached by different bleaching methods (hydrogen peroxide bleaching and sodium dithionite bleaching) were investigated. The results of fourier transform infrared spectrometer (FTIR) showed that the content of intramolecular hydrogen bonds (HBintra) increased by 11.6% and 4.8% after hydrogen peroxide bleaching and sodium dithionite bleaching, respectively. The energy of the hydrogen bonds was changed after bleaching treatment. The hydrogen bonding distances showed a small change after different bleaching treatment. The results of X-ray diffraction (XRD) demonstrated a decrease in the average width of crystallite size in the (002) lattice plane after different bleaching treatment, which was the same trend with the variability of cellulose crystallinity. Compared with the unbleached pulp, the WRV and strength properties of the bleached pulp increased after each bleaching process. Tear index of handsheets made from the hydrogen peroxide and sodium dithionite bleaching pulps were 46.0% and 54.8%, respectively. The sodium dithionite bleaching treatment had more significant effects on fiber swelling capability.

For improving the physical properties of old corrugated container (OCC) fiber, the laccase/histidine system was used in this paper. Firstly, the paper studied the optimum conditions that the laccase/histidine system modified the OCC fiber, including enzyme dosage, histidine dosage, reaction time, reaction temperature, and pH. Experimental results showed that the optimum reaction conditions of laccase/histidine system for OCC pulp were: dose of enzyme 1 U·g-1, 4 h reaction time, pH 4.5, dose of histidine 1%. Under the optimum reaction conditions, the tensile and burst indexes of the sheet made from laccase/histidine treatment were increased by 25.2% and 34.0%, compared with that of the control sample. The SEM results showed that compared with the control sample, the fibrillation of the fiber modified with laccase/histidine was more obvious. Finally, the content of acid-insoluble lignin of the fiber was determined. The content of acidinsoluble lignin of the control sample was 29.2%, and the content of acid-insoluble lignin of the fiber treated by laccase/histidine system in optimum reaction conditions was 16.0%, which decreased by 13.2%. Laccase/histidine system could improve the physical properties of recycled fiber, alleviate fiber decay, which are of great significance to solve the resource shortage and environment pollution of the paper-making industry.

The supramolecular structure of eucalyptus pulp cellulose was studied by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and water retention value (WRV) after subjecting the pulp to pressures of 0.1, 0.2, 0.3, 0.4 and 0.5 MPa. It was interpreted from the FTIR spectra of the sheets after pressing that the amount of intermolecular hydrogen bonds (HBinter) first increased and then decreased as a function of increasing pressure, while the number of the intramolecular hydrogen bonding (HBintra) exhibited an opposite trend. In the pressed fibers, the number of HB intra O(6)H…O(3') increased by 16% compared to the un-pressed fibers, while the number of HBinter O(2)H…O(6) and O(3)H…O(5) decreased by 23% at 0.3 MPa. XRD analysis showed that the crystallite size corresponding to the diffraction peaks for (002) lattice planes and the crystallinity of eucalyptus fibers were the lowest at a pressure of 0.3 MPa. Pressing produced an irreversible reduction of fiber pore volume, which was manifested by reduced WRV data. [ABSTRACT FROM AUTHOR]

Laccase activity and stability were improved and modified through the interaction between laccase amino acid residues (e.g., amino groups (- NH2) and carboxyl groups (-COOH)) and the chemical reagents thiourea dioxide (TDO) and L-phenylalanine methyl ester hydrochloride (L-PME). Compared with the control sample, the activity of the laccase modified with these chemical reagents was increased by 209% and 50%, respectively. The stability of the laccase modified with L-PME increased by 56.9%. However, the laccase modified with TDO only improved slightly. It was clear that reagent L-PME was more efficacious than TDO. The paper formed with addition of L-PME-modified laccase exhibited better performance in terms of tensile strength, bursting strength, and tear strength, which increased by 13%, 10%, 9%, respectively, compared with the paper formed with unmodified laccase. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide was applied to bleach recycled de-inked pulp from old newspaper (ONP) in this study. Following single-stage bleaching, the fiber properties of the pulp (viz. brightness, yield, fiber length, fiber charge, and strength properties) were determined. Finally, the crystal structure of cellulose, fiber surface morphology, and functional groups of the control pulp and the bleached pulp using hydrogen peroxide were analyzed by XRD, SEM, and FT-IR, respectively. The single-stage peroxide bleaching applied to the de-inked ONP pulp could produce a high brightness pulp of 58% ISO at a yield of 92%. Fiber length decreased after bleaching treatment. The crystallinity index of cellulose of de-inked ONP pulp during bleaching or rinsing treatment increased due to the dissolution of cellulose in amorphous regions and/or the dissolution or loss of non-cellulosic constituents (hemicelluloses and lignin). Hydrogen peroxide bleaching resulted in fibrillation and longitudinal tearing of the fiber surface due to delignification, which led to an increase in the paper strength. FT-IR data showed that the content of carboxylic acid groups decreased during peroxide bleaching. The main chromophore (conjugated carbonyl groups) and the guaiacyl units of the pulp were damaged after bleaching resulting in delignification. [ABSTRACT FROM AUTHOR]

We explore the reactivity of xenon with sulfur under high pressure, using unbiased structure searching techniques combined with first-principles calculations, which identify a stable XeS2 compound crystallized in a Laves phase with hypercoordinated (16-fold) Xe at 191 GPa and 0 K. Taking the thermal effects into account, we find that increasing the temperature could further stabilize it. The formation of XeS2 is a consequence of pressure-induced charge transfer from Xe to S atoms and the delocalization of Xe 5p and S 3p electrons. Meanwhile, the stabilization into a Laves phase of XeS2 is the result of delocalized chemical bonding and the need for optimum structure packing. The present discussion of the formation mechanism in XeS2 is general, and conclusions can be used to understand the formation of other Laves-phase compounds and the Xe chemistry that allows closed-shell Xe to participate in chemical reactions. [ABSTRACT FROM AUTHOR]

The dissolution of sugarcane bagasse cellulose (SBC) in zinc chloride solution was studied at elevated temperatures. Based on single factor experiments, the effects of zinc chloride mass fraction, dissolution time, temperature, and bagasse cellulose mass fraction were investigated by an orthogonal experiment, and the optimal dissolution conditions were obtained. The dissolution process of bagasse cellulose was observed under a microscope. Additionally, the original SBC and regenerated SBC were both characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Temperature was found to be the most important factor affecting dissolution time. The best dissolving process took place at 85 °C to dissolve 2% SBC in 85% zinc chloride for 210 min. It was shown that the zinc chloride was a direct solvent for SBC. After regeneration of cellulose in zinc chloride, the crystallinity of cellulose was decreased greatly, from 77% to 54%, its crystalline form was transformed from cellulose I to cellulose II, its thermal decomposition temperature was reduced, its thermal stability was slightly decreased, and its internal structure was disrupted. [ABSTRACT FROM AUTHOR]

The mechanisms that underlie the pathogenesis of intractable epilepsy (IE) remain to be elucidated. The present study aimed to investigate the expression of D site of albumin promoter binding protein (DBP) and mitogen-activated protein kinases (MAPKs) in the temporal lobes of patients with IE, in order to examine the possible roles of DBP in the pathogenesis of IE. The expression of DBP and MAPK was detected by immunohistochemistry and double-label immunofluorescence staining against DBP/MAPK in 35 patients with IE, and the data were compared with those of the 15 controls. The results demonstrated that DBP expression in IE group (0.31±0.03) was significantly higher compared with that in the controls (0.18±0.02; P<0.05) and MAPK expression in the IE group (0.19±0.03) was also higher compared with that in the controls (0.12±0.02; P<0.05). DBP and MAPK were mainly expressed in the cytoplasm of neurons and the double-label immunofluorescence staining demonstrated that DBP and MAPK expression occurred in the same neurons. Therefore, the expression of DBP and MAPK in epilepsy patients was upregulated, suggesting a possible pathogenetic role in IE. [ABSTRACT FROM AUTHOR]

Objective. To investigate the efficacy and safety of traditional Chinese medicine Duliang soft capsule (DSC) in prophylactic treatment for patients with chronic daily headache (CDH). Methods. A multicenter, double-blind, randomized, placebo-controlled clinical study was conducted at 18 Chinese clinical centers. The participants received either DSC or placebo for 4 weeks. The primary efficacy measure was headache-free rate (HFR) in a 4-week period between the pretreatment and posttreatment stages. The secondary efficacy measures were the decrease of headache days, the duration of headache attacks, the frequency of analgesic usage, quality of life, disability, and the headache severity (VAS scores). The accompanying symptoms and adverse events were also assessed. Results. Of 584 CDH patients assessed, 468 eligible patients were randomized. 338 patients received DSC, while 111 patients were assigned in the placebo group. Following treatment, there was a 16.56% difference in HFR favoring DSC over placebo (P < 0.01). Significant differences were also observed between DSC and placebo groups in the secondary measures. However, no statistical difference was found between the two groups in the associated symptoms. No severe adverse effects were observed in the study. Conclusions. DSC might be an effective and well-tolerated option for the prophylactic treatment of patients with CDH. [ABSTRACT FROM AUTHOR]

Oxidative decolorization of Orange G (OG) in Fe(II)/(S,S)-ethylenediamine-N,N'-disuccinic acid (EDDS)/persulfate (PS) process was investigated. Hydroxylamine was combined to accelerate the Fe(II) recovery for improvement of PS activation. Effects of the reagents dosage, pH, and hydroxylamine adding mode were evaluated in batch experiments. All the decolorization experiments were performed at 25 °C within 180 min and with initial OG concentration ranging from 0.25 to 2.5 mM. The results indicated that EDDS decreased the Fe(II) accessibility to 11.9% at the molar ratio of EDDS/Fe(II) = 1/1 and could improve the OG decolorization by slowing down the Fe(II) depletion rate. The addition of hydroxylamine was effective in further enhancement of the oxidative ability and 98% OG decolorization was obtained rapidly with only 50.6% PS decomposition when hydroxylamine/Fe(II) = 8/5. The combination of EDDS and hydroxylamine could expand the effective pH range up to 7. The hydroxylamine adding mode also played a significant role and OG decolorization efficiency was 49.4%, 67.7% and 70.7% when adding times was 1, 3 and 5, respectively. In addition, under the condition of PS/Fe(II)/hydroxylamine = 5/10/16, OG suffered incomplete decolorization up to 71.8% due to the insufficient PS dosage, while a decline of OG decolorization was observed as well when PS/Fe(II)/hydroxylamine = 80/10/16 because of the intensive consumption of hydroxylamine and hydroxyl radicals (*OH) by excessive PS. The radicals characterization via electron spin resonance (ESR) technique was also conducted and the results indicated hydroxyl radicals were the predominant oxidative species in studied processes. [ABSTRACT FROM AUTHOR]

Different hydrogen bond and crystalline cellulose structure models of eucalyptus fibers were studied by Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), and Cross-Polarization Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance (CP/MAS 13C NMR). It was shown that when the beating time was increased from 5 to 15 min., the content of inter-molecular hydrogen bonds, O(6)H…O3', increased by 11.2% as measured by FTIR. However, the content of the inter-molecular hydrogen bonds decreased quickly as the beating time was increased from 15 to 25 min. Meanwhile, the contents of the intra-molecular hydrogen bond, O(2)H…O(6) and O(3)H…O(5), changed from 8.25% to 8.18% and from 39.33% to 31.27%, respectively, when the beating time increased from 5 to 15 min. The content of the intra-molecular hydrogen bonds increased quickly with the further increase in the beating time. It was shown by XRD that there was a little difference in the average width of crystallite size in the (002) lattice plane when the beaten time was between 5 to 25 min. Non-linear fitting of the cellulose C4 region of the 13C CP/MAS NMR showed that the average lateral fibril aggregate dimensions and the content of different cellulose polymorphs changed during beating. [ABSTRACT FROM AUTHOR]

TβRs (transforming growth factor β receptors) have recently been identified in animal experiments as being involved in the pathogenesis of epilepsy. The aim of the present study was to understand further the potential effects of TβRs in human epilepsy. Tissue samples of temporal neocortices from 30 patients with temporal lobe epilepsy were prepared for detecting TβR-I (type 1 TβR) protein expression using immunohistochemistry, immunofluorescence and Western blotting. We compared these tissues with histologically normal temporal lobes from controls. TβR-I immunoreactivity was increased in the patient group compared with controls using immunohistochemistry, and this finding was consistently observed with Western blot analysis. Immunofluorescence showed that TβR-I fluorescence stain mainly accumulated in the cytoplasm of astrocytes. In conclusion, our findings demonstrate that an up-regulation of TβR-I is present in patients with temporal lobe epilepsy. [ABSTRACT FROM AUTHOR]

The synthesis of hydrogen sulfides, with the potential of high-temperature superconductivity, was recently proposed at high Tc = 203 K. It motivated us to employ an ab initio approach for the predictions of crystal structures to find the stable scandium hydrides. In addition to the earlier predicted three stoichiometries of ScH, ScH2, and ScH3, we identify three other metallic stoichiometries of ScH4, ScH6, and ScH8, which show superconductivity at significantly higher temperatures. The phases of ScH4 and ScH6, whose stability does not require extremely high pressures (< 150 GPa with ZPE), are primarily ionic compounds containing exotic quasimolecular H2 arrangements. The present electron-phonon calculations revealed the superconductive potential of ScH4 and ScH6 with estimated Tc of 98 K and 129 K at 200 GPa and 130 GPa, respectively. The superconductivity of ScHn stems from the large electron-phonon coupling associated with the wagging, bending, and intermediate-frequency modes attributed mainly to the hydrogen atoms. [ABSTRACT FROM AUTHOR]