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The rapid emergence of large language model (LLM) technology presents promising opportunities to facilitate the development of synthetic reactions. In this work, we leveraged the power of GPT-4 to build an LLM-based reaction development framework (LLM-RDF) to handle fundamental tasks involved throughout the chemical synthesis development. LLM-RDF comprises six specialized LLM-based agents, including Literature Scouter, Experiment Designer, Hardware Executor, Spectrum Analyzer, Separation Instructor, and Result Interpreter, which are pre-prompted to accomplish the designated tasks. A web application with LLM-RDF as the backend was built to allow chemist users to interact with automated experimental platforms and analyze results via natural language, thus, eliminating the need for coding skills and ensuring accessibility for all chemists. We demonstrated the capabilities of LLM-RDF in guiding the end-to-end synthesis development process for the copper/TEMPO catalyzed aerobic alcohol oxidation to aldehyde reaction, including literature search and information extraction, substrate scope and condition screening, reaction kinetics study, reaction condition optimization, reaction scale-up and product purification. Furthermore, LLM-RDF's broader applicability and versability was validated on various synthesis tasks of three distinct reactions (SNAr reaction, photoredox C-C cross-coupling reaction, and heterogeneous photoelectrochemical reaction). The rise of large language model (LLM) technology offers new opportunities for advancing chemical synthesis. Here, the authors developed an LLM-based reaction development framework (LLM-RDF) to copilot the design and experimental tasks throughout the end-to-end chemical synthesis development. [ABSTRACT FROM AUTHOR]

The envelope structure with high light transmittance accounts for an increasing proportion of building energy consumption, which is one of the shortcomings of energy conservation and emission reduction. Cellulose-based aerogel has become a research topic of interest because of its low thermal conductivity and good mechanical properties. However, most cellulose-based aerogels are opaque and flammable limiting their applications. Herein, cellulose/silica composite aerogels (CAS) with "organic–inorganic" structures were fabricated by two-step sol–gel method, spin-coating technique and supercritical CO2 drying, using the ionic liquid 1-allyl 3-methylimidazolium chloride salt to dissolve the Cotton pulp, followed by the addition of tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) co-precursors into the cellulose gels. The synthesis mechanism, microstructure, mechanical and thermal properties of as-prepared aerogels samples were investigated. The obtained CAS have low density (0.093–0.170 g/cm3), high specific surface area (660.87–1089.70 m2/g), and high mechanical property (compressive strength of 18.74 MPa, tensile strength as high as 1.54 MPa, and bending tests above 500 times). In particular, the CAS4 shows the lowest thermal conductivity (0.0188 W·m−1·K−1), good thermal stability (> 331 °C), high transparency (91.7%) and excellent flame retardancy. In addition, the self-designed aerogels glasses model was placed in a real outdoor environment for 5 h. The results showed that the temperature difference between the inside and outside of the aerogels glasses model was as high as 12 ℃ under the thermal equilibrium state. Thus, the as-prepared high-performance cellulose/silica composite aerogels may increase the role of aerogels glasses in the building envelope and have promising applications in transparent energy-efficient construction and thermal insulation. [ABSTRACT FROM AUTHOR]

Water-quenched copper-nickel metallurgical slag enriched with olivine minerals exhibits promising potential for the production of CO2-mineralized cementitious materials. In this work, copper-nickel slag-based cementitious material (CNCM) was synthesized by using different chemical activation methods to enhance its hydration reactivity and CO2 mineralization capacity. Different water curing ages and carbonation conditions were explored related to their carbonation and mechanical properties development. Meanwhile, thermogravimetry differential scanning calorimetry and X-ray diffraction methods were applied to evaluate the CO2 adsorption amount and carbonation products of CNCM. Microstructure development of carbonated CNCM blocks was examined by backscattered electron imaging (BSE) with energy-dispersive X-ray spectrometry. Results showed that among the studied samples, the CNCM sample that was subjected to water curing for 3 d exhibited the highest CO2 sequestration amount of 8.51wt% at 80°C and 72 h while presenting the compressive strength of 39.07 MPa. This result indicated that 1 t of this CNCM can sequester 85.1 kg of CO2 and exhibit high compressive strength. Although the addition of citric acid did not improve strength development, it was beneficial to increase the CO2 diffusion and adsorption amount under the same carbonation conditions from BSE results. This work provides guidance for synthesizing CO2-mineralized cementitious materials using large amounts of metallurgical slags containing olivine minerals. [ABSTRACT FROM AUTHOR]

Flavour precursors are finding increased utility within the tobacco industry to offset the diminishing aroma of cigarettes with the development of low tar cigarettes. Ethyl vanillin (EV) glucoside serves as an important flavour precursor, and the synthesis of its intermediate (EV-O-acetyl-β-d-glucopyranoside, 2) in a batch reaction, prolonged reaction times have been observed, thereby limiting its industrial applications. The application of continuous flow chemistry offered a faster and more scalable approach for the preparation of glycoside precursors. Initial exploration in batch reactions established general conditions for the synthesis of 2, and further optimization in continuous flow reactions facilitated the synthesis of a range of glycoside precursors. These were achieved using tetra-O-acetyl-α-d-glycosyl bromide (1) in conjunction with various food flavours containing phenolic hydroxyl groups. The preparation of glycoside precursors was studied by advanced flow reactor (AFR) system and conventional coil flow chemistry system. [ABSTRACT FROM AUTHOR]

Hydrophobic SiO2 aerogels show great promise for diverse smart applications due to their superhydrophobic surfaces combined with low thermal conductivity property. Hydrophobic tetraethoxysilane (TEOS)/methyltrimethoxysilane (MTMS) (TM) and TEOS/methyltriethoxysilane (MTES) (TE) gels were prepared by in-situ technique, and dried by ambient pressure drying (APD). The evolution of microstructure and chemical-physical properties of the TM and TE aerogels treated by different temperatures were investigated. Under the ultra-low and high temperature treatment, the TM and TE aerogels showed the low thermal conductivity (0.020 ~ 0.031 W m− 1 K− 1), high specific surface area (410.85 ~ 830.10 m2 g− 1) and good hydrophobicity with the water contact value from 124.2 ~ 155.7°. This work provided an effective method to prepare hydrophobic SiO2 aerogels with excellent ultra-low, high temperature resistant using double silicon sources as co-precursors, which could be an appropriate candidate for thermal insulation, catalysis and environmental protection. [ABSTRACT FROM AUTHOR]

Red mud (RM) is a kind of solid waste by the production of alumina. Long-term storage of RM can occupy a large amount of land and cause serious pollution to soil, air and water. Alkali activated cementitious material (AACM) is a new type of green environmental protection material, which provides a new idea for the efficient use of RM. In this research, RM is thermally activated and mixed with ground granulated blast-furnace slag (GGBFS) and alkali activator to prepare AACM. In order to improve the performance of this AACM, the influence of activator content and type on the chemical shrinkage and mechanical property of the AACM were studied and discussed comprehensively. The obtained results show that the used RM shows best activity after calcined at 700 °C; the suitable ratio of RM to GGBFS is 5:5. Water glass has better activation effect on the AACM made with RM and GGBFS than calcium hydroxide (Ca(OH)2). But, the use of water glass and Ca(OH)2 together is more appropriate for this AACM. The strength of the AACM activated by 20 wt% Ca(OH)2 and 20 wt% water glass can reach 88 MPa at 120 days. [ABSTRACT FROM AUTHOR]

To further explore the effects of limestone powder (LP) on the hydration of Portland cement as well as the formation and transformation mechanism of calcium carboaluminate phases, the hydration reaction between LP and tricalcium aluminate (C3A) is thoroughly studied in this paper. Due to the crucial influence of gypsum on the hydration of C3A, two systems are well studied, viz. the C3A–LP–H2O and the C3A–LP–CaSO4·2H2O–H2O system. The replacement levels of LP are 0, 5 mass%, 15 mass% and 25 mass% by mass of total binder. The hydration behavior of these two systems are studied using isothermal calorimetry, XRD and quantitative XRD, and chemical shrinkage. The obtained results show that more LP delays the formation of hemicarboaluminate. In the C3A–LP–CaSO4·2H2O–H2O system, the formation of calcium carboaluminate phases only begins after gypsum is consumed. Moreover, LP can reduce the chemical shrinkage resulting from the volume increase of the formation of calcium carboaluminate phases. [ABSTRACT FROM AUTHOR]

Coral wastes are produced during the construction of island. The use of coral wastes in concrete is beneficial to economy and environment. Coral waste as aggregate in concrete has been studied well. Now, coral powder (CP) as mineral admixture to replace cement partially in concrete is a different approach to reuse coral waste. However, the use of more CP in concrete will definitely affect the property of cement-based material. In order to improve the mechanical property and use more CP in construction, ground-granulated blast-furnace slag (GGBFS), a kind of latent hydraulic material, is considered in this study. Furthermore, the synergetic effect of CP and GGBFS on the hydration of Portland cement (PC) is seldom researched systematically. In this study, CP and GGBFS are mixed into cement in five proportions to research the hydration process of cement paste comprehensively by isothermal calorimetry test, X-ray diffraction, and thermogravimetric analysis. The properties of the GGBFS-CP-PC ternary system, such as the chemical shrinkage and compressive strength, are also determined. The results show that the existence of GGBFS will influence the secondary hydration of C3A when the mass ratio of GGBFS to cement is above 0.25 in binder. The reaction of CP is accelerated by the active alumina phase in GGBFS. The presence of GGBFS can promote the formation of carboaluminate. During the infrastructure construction in island, it is reasonable to use CP in concrete, and the use of CP together with GGBFS can ensure the mechanical properties of concrete structures. [ABSTRACT FROM AUTHOR]

Heavy metal ions have become a major problem that seriously affects the environment, ecology, and human health with the development of industrialization. Herein, the amino-grafted attapulgite/graphene oxide (A-ATP/GO) nanocomposites were synthesized for Pb(II) removal. The influencing factors including the ratio of the components, pH value, adsorption time, initial concentration of Pb(II) solution, and adsorbent amount were investigated to achieve the optimal adsorption performance. The as-prepared A-ATP/GO were used in Pb(II) solution (150 mg/L, 30 mL, pH = 5) for Pb(II) adsorption, which exhibited a great adsorption ability of 146.97 mg/g for Pb(II). The adsorption kinetic model and isotherms model were applied to investigate the adsorption mechanism of Pb(II) on A-ATP/GO. The A-ATP/GO composite could still maintain an original adsorption of 79.85% after 5 consecutive times, exhibiting the good reproducibility. It was believed that our results could shed light on the design and fabrication of low-cost graphene-based composite adsorbents for high-efficient Pb(II) removal. [ABSTRACT FROM AUTHOR]

The design of three-dimensional (3D) core-shell heterostructures is an efficient method to achieve high mass specific capacity of electroactive materials under high mass loading. In this work, porous Ni4Co1-OH nanosheets with a mass loading of 7.7 mg·cm−2 are obtained by using Ni4Co1-(NO3)2(OH)4 supported on the CuO nanowires as precursors via an unavoidable electrochemically induced phase reconstruction. During the electrochemical reconstruction process, the NO3− anions in Ni4Co1-(NO3)2(OH)4 are easily replaced by OH− anions in the electrolyte. The phase reconstruction is accompanied by the decrease of ionic diffusion resistance and the increase of pore volume, and the shift of binding energy. The obtained Ni4Co1-OH nanosheets show a high mass specific capacity of 363.6 mAh·g−1 at 5 mA·cm−2. The as-fabricated alkaline hybrid supercapacitor and Ni-Zn battery deliver high energy density of 293.1 and 604.9 Wh·kg−1, respectively, indicating excellent alkaline energy storage performance. [ABSTRACT FROM AUTHOR]

Streptococcus suis serotype 2 (S. suis 2) is an important zoonotic pathogen that presents a significant threat both to pigs and to workers in the pork industry. The initial steps of S. suis 2 pathogenesis are unclear. In this study, we found that the type II histidine triad protein HtpsC from the highly virulent Chinese isolate 05ZYH33 is structurally similar to internalin A (InlA) from Listeria monocytogenes, which plays an important role in mediating listerial invasion of epithelial cells. To determine if HtpsC and InlA function similarly, an isogenic htpsC mutant (ΔhtpsC) was generated in S. suis by homologous recombination. The htpsC deletion strain exhibited a diminished ability to adhere to and invade epithelial cells from different sources. Double immunofluorescence microscopy also revealed reduced survival of the ΔhtpsC mutant after co-cultivation with epithelium. Adhesion to epithelium and invasion by the wild type strain was inhibited by a monoclonal antibody against E-cadherin. In contrast, the htpsC-deficient mutant was unaffected by the same treatment, suggesting that E-cadherin is the host-cell receptor that interacts with HtpsC and facilitates bacterial internalization. Based on these results, we propose that HtpsC is involved in the process by which S. suis 2 penetrates host epithelial cells, and that this protein is an important virulence factor associated with cell adhesion and invasion. [ABSTRACT FROM AUTHOR]

The use of Li-excess approach can achieve efficient lithium ion storage of cation-disordered rock-salt cathode materials. However, their application is limited by poor intrinsic electronic conductivity and insufficient Li-ion diffusion. Herein, a carbon nanotube is incorporated in the Li-excess Li1.24Fe0.38Ti0.38O2 cathode material, resulting in the formation of refined Li1.24Fe0.38Ti0.38O2 nanoparticles that are well loaded in a continuous conductive network. This facilitates the charge transfer and ion diffusion in the cathode. The as-prepared Li1.24Fe0.38Ti0.38O2/carbon nanotube (LFT/CNT) cathode, therefore, delivers significantly enhanced rate capability with a reversible capacity of 108 mAh g−1 after 200 cycles at 1 C compared to 36 mAh g−1 of the as-prepared LFT cathode. The result of ex situ x-ray diffraction demonstrates the reversible and small lattice volume change of the LFT/CNT cathode during cycling. [ABSTRACT FROM AUTHOR]

A cellulose aerogel (CA) was fabricated by a phase inversion induced sol-gel process along with supercritical drying. An amine grafted cellulose aerogel (AGCA) was prepared by grafting 3-aminopropyltriethoxysilane (APTES) onto the framework of the cellulose gel. The morphology, microstructure, pore structure and elemental composition of the CA and AGCA were characterized. Both CA and AGCA exhibited highly porous network consisting of fibrous network and nanopores. APTES grafting leaded to the blockage of the pore space of the CA and generated more nanopores. The specific surface area and pore volume of the AGCA is higher than those of the CA owing to the APTES grafting. The AGCA achieved a CO2 adsorption capacity of 1.20 mmol/g with dry 1% CO2, and exhibited excellent stability within 20 adsorption-desorption cycles [ABSTRACT FROM AUTHOR]

This study concerns the long-term hydration behavior and pore structure of cement paste incorporated with limestone powder. The cement paste specimens are investigated by isothermal calorimetry, X-ray diffraction, thermogravimetric analysis and mercury intrusion porosimetry. The dosages of limestone powder are 5, 15 and 25%, respectively. The experimental results are collected within 180 days. From the obtained results, 25% limestone powder accelerates the transformation of hemicarboaluminate to monocarboaluminate. The ettringite stably exists in cement paste incorporated with limestone powder at all curing ages. The presence of limestone powder does not significantly influence the value of the critical pore width (Dcr) of cement pastes at later curing ages. [ABSTRACT FROM AUTHOR]

Hydrophobic silica aerogel (HSA) was synthesized by a facile sol–gel method and ambient pressure drying with methyltrimethoxysilane as precursor. The effect of precursor concentration on the sol–gel behavior, structure, and thermal conductivity of HSA was investigated. HSA with apparent density of 0.088 g/cm3 showed a thermal conductivity of 0.018 W/(m·K), a specific surface area of 502 m2/g and a pore volume of 1.66 cm3/g. The hydrophobic groups in HSA had a good thermal stability up to 450 °C. Polypropylene felt was used to synthesize hydrophobic silica aerogel composite (HSAC). The effect of sol loading on the structure and thermal conductivity of HSAC was investigated. HSAC with equivalent sol loading exhibited a low shrinkage of 2.5% and a low thermal conductivity of 0.020 W/(m·K). Finally, the preparation method of the HSA is facile and environmentally friendly, and the resulting composite is a promising candidate for thermal insulation under humid environments. [ABSTRACT FROM AUTHOR]

Alumina (Al2O3)-based diphasic aerogels have better physical properties than those of pure Al2O3 aerogel according to previous studies. In the present research, we focused on an alumina–titania (Al2O3-TiO2) diphasic aerogel. A series of Al2O3 aerogels were synthesized and studied with and without minor TiO2 dopants (up to 10 mol%). We found that the pure Al2O3 aerogel, which had the fiber-like particles, was stronger than those with TiO2 dopants that possessed the sphere-like particles. However, the sphere-like particles make the TiO2-doped Al2O3 aerogel (with 3 mol% TiO2) possessing the largest specific surface area (SSA) of 650 m2/g, much larger than that of the pure Al2O3 aerogel (326 m2/g). This work proved that fiber-like particles enhance strength but reduce SSA of Al2O3 aerogel. At last, ceramic fibers reinforced Al2O3 aerogel composites with the sizes of 20 cm width × 20 cm length × 1 cm thickness were fabricated. The aerogel composites possessed a thermal conductivity of 0.136 W/m K at 1000 °C, better than those of the ceramic fiber blankets itself (0.30 W/m K), indicating potential application as high-temperature thermal insulator. Highlights: Particle morphology within Al2O3 aerogel changed due to the inhibited crystallization. Fiber-like particles enhance strength but reduce specific surface area. The optimized Al2O3 aerogel composites possessed a thermal conductivity of 0.136 W/m K at 1000 °C. [ABSTRACT FROM AUTHOR]

BaTiO3 aerogels with a photocatalytic property were synthesized from metal barium via nanoparticle assembly method combined with ethanol supercritical drying technology. The specific surface area of the BaTiO3 aerogel could reach up to 233.24 m2/g, and the average pore size and total pore volume were 26.1 nm and 3.50 cm3/g, respectively. The sample showed excellent adsorption capacity and photocatalytic performance for 10 mg/L methyl orange solution (pH = 3), and the degradation rate reached up to 92.59% in 2 h, which was superior to BaTiO3 nanopowder. Moreover, the photodegradation rate was still about 80% after five-cycle experiments. (a) Photograph of sample, (b) SEM image, (c) nitrogen adsorption/desorption isotherms with pore size distribution curve and (d) photocatalysis performance test of BaTiO3 aerogels Highlights: The bulk BaTiO3 aerogel is synthesized via nanoparticle assembly method without heat treatment. The specific surface area of the BaTiO3 aerogel can reach up to 233.24 m2/g. When the volume ratio of ethanol/water is 2:1, the BaTiO3 aerogel exhibits an outstanding photodegradation performance that 92.59% methyl orange (MO) can be removed in 2 h. [ABSTRACT FROM AUTHOR]

This paper investigated the feasibility of replacing cement with fly ash (FA) mass ratios ranging from 40 to 70% to produce high-volume FA (HVFA) concrete. A suite of mechanical tests were conducted over a 180-day time frame. The hydration properties were systematically evaluated using isothermal calorimetry test, X-ray diffraction analysis, thermogravimetric analysis and selective dissolution method. Specially, a thermodynamic modeling was also used to predict phase assemblage and compare the experimental results in terms of the HVFA blended cement system. Experimental results showed that HVFA concrete exhibited lower early-age compressive strengths. However, beyond 28 days, the compressive strength of HVFA concrete developed faster than that of control concrete and the HVFA concrete with FA replacement of 40% showed comparable 180-day compressive strength to the control concrete. Hydration tests showed that the dilution and the pozzolanic effects of FA on cement hydration can be the critical reasons for the compressive strength development of HVFA concrete at early and later ages, respectively. Additionally, a good agreement between the experimental and modeling results can also be observed. These findings help to provide a sustainable and environmentally friendly solution to local FA disposal. [ABSTRACT FROM AUTHOR]

Objective: To investigate the impact factors of the outcome of the first 131I treatment in patients with papillary thyroid carcinoma (PTC) after total thyroidectomy.Methods: Three hundred and fifty-three patients [256 females, 97 males, average age (43.58 ± 12.33 years)] with PTC after total thyroidectomy who underwent 131I treatment from July 2014 to August 2017 were retrospectively analyzed. Curative efficacy of 131I treatment was assessed 6 months afterward. Therapeutic outcome was determined according to thyrotropin (TSH)-stimulated thyroglobulin (sTg) level, 131I diagnostic whole-body scan (Dx-WBS) after 131I treatment and other imaging modalities. Twelve possible factors affecting the therapeutic outcome of 131I treatment including patients' gender, age, interval between surgery and 131I treatment, primary tumor size and extrathyroidal extension (ETE), number and range of primary tumor lesions, result of 99mTcO4- thyroid scan, number of metastatic lymph nodes (LN), pre-treatment laboratory measurements [TSH, sTg and Tg antibody (TgAb)], therapeutic dose of 131I and result of 131I post-treatment whole-body scan (Rx-WBS) were analyzed using univariate and multivariate logistic regression. The receiver operator characteristic (ROC) curve and diagnostic cutoff value were analyzed to evaluate the predictive value of the significant quantitative impact factors for the outcome of 131I treatment.Results: The curative rate of the first 131I treatment in patients with PTC after total thyroidectomy was 62.32% (220/353). Univariate analysis indicated that gender, age, number and range of primary tumor lesions, number of metastatic LN, pre-treatment sTg and TgAb, therapeutic dose of 131I and result of 131I Rx-WBS (all P < 0.05) were significant factors affecting the outcome of 131I treatment. Multivariate analysis revealed that the numbers of metastatic LN (regression coefficient = 1.170) and sTg (regression coefficient = 0.280) were significant impact factors (all P < 0.001). The regression equation was: Logit P = - 3.997 + 1.170 × number of metastatic LN + 0.280 × sTg (χ2 = 210.68, P < 0.001). Taking sTg as a predictive factor for the outcome of the first 131I treatment, the area under the curve (AUC) of ROC for sTg was 0.917 (95% CI 0.890-0.944). The cutoff value of sTg was 2.69 ng/mL with a sensitivity of 92.48% (123/133) and specificity of 74.09% (163/220).Conclusion: Patients with PTC after total thyroidectomy with low pre-treatment sTg level and few lymph node metastases are more likely to be cured by the first 131I treatment. [ABSTRACT FROM AUTHOR]

Influences of alkali oxides doping on the crystal structure, defects and hydration behavior of tricalcium silicate C3S were investigated by X-ray powder diffraction with the Rietveld method, inductively coupled plasma optical emission spectroscopy, thermoluminescence and isothermal calorimetry. All the samples were stabilized as T1 form C3S. Changes in the crystal structure of C3S could mainly be monitored by changes in lattice parameters, which were closely correlated with the incorporation concentration and substitution types of alkalis. Although alkalis were incorporated at trace level in C3S, the thermoluminescence and hydration behavior of C3S were significantly influenced. Initial hydration activity was dramatically increased and highly related to the intensity of the irradiation-induced thermoluminescence peaks at low temperatures due to their direct correlation with defects. The oxygen vacancy sites resulting from the substitution of alkalis for Ca could readily account for the acceleration of the initial hydration of C3S. [ABSTRACT FROM AUTHOR]

Abstract: A novel co-polyimide aerogel using aromatic monomers (4,4′-diaminodiphenyl ether, ODA) and aliphatic monomers (1,3-Diaminopropa) as mixing diamines has been prepared via the sol-gel technique. The effects on the properties (density, shrinkage, surface area, and average pore size) of co-polyimide aerogel have been investigated by changing the molar ratios of mixing diamines. The density of co-polyimide aerogel reaches as low as 0.0448 g cm−3, because of replacing part of ODA (M = 269.5) in the backbone with 1,3-diaminopropa (molecular M = 76.1).The thermal conductivities reach as low as ~0.031 W m−1 K−1 (25 °C), BET surface areas are 331 m2 g−1 and the compressive modulus range from 1.253 to 3.273 MPa. The facile preparation route and low thermal conductivity indicate that co-polyimide aerogels may be ideal candidates for aerospace and thermal insulations.The co-polyimide aerogel produced in this study is golden yellow. The morphology of co-polyimide aerogel shows a three-dimensional network structure of fibrous strands winding. When the molar ratios of ODA to 1,3-propanediamine is 3: 1, the resulting aerogel has the lowest thermal conductivity (0.031 W m−1 K−1) We have developed a sol-gel route to synthesize co-polyimide aerogel using aromatic monomers (ODA) and aliphatic monomers (1,3-diaminopropa) as mixing diamines.The density of co-polyimide aerogel reaches as low as ~0.0448 g cm−3.The thermal conductivities of co-polyimide aerogel reach as low as ~0.031 W m−1 K−1 (25 °C). [ABSTRACT FROM AUTHOR]

In this study, the effective TiO2/Ag composite antibacterial aerogel powder is prepared by facile sol-gel method and ethanol supercritical technology. The surface morphology, structural properties, and chemical components are monitored by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and energy disperse spectroscopy (EDS). Meanwhile, absorbance spectra and specific surface area of TiO2/Ag composite aerogel are characterized by UV-Vis spectra and Brunauer-Emmett-Teller. The TiO2/Ag composite aerogel with Ti/Ag molar ratios of 10:1, 30:1, 50:1 are measured for its antibacterial property by using Escherichia coliform (E.coli) and Staphylococcus aureus (S. aureus). The results show that the size of TiO2 and Ag nanoparticles are 40 nm and 25 nm, respectively. Simultaneously, the obtained composite aerogel with a porous structure possessed a surface area of 148 m2/g, an average pore size 11.5 nm, and a pore volume 0.39 cm3/g. With the increase of Ag content, the antibacterial properties of composite aerogel are greatly improved compared with pure TiO2 aerogel. When Ag/Ti molar ratios was 1:10, the highest antibacterial rate can up to 99%, and the inhibition bands of E. coli and S. aureus are 23 mm and 19 mm, respectively.Schematic representation of growth mechanism of TiO2/Ag composite aerogel (a) and antibacterial performance test (b, c) [ABSTRACT FROM AUTHOR]

A novel ZrCO composite aerogel is synthesized using zirconium oxychloride and resorcinol-formaldehyde (RF) as precursors through the sol-gel route and carbothermal reduction process. The effects of different Zr/R molar ratios and calcination temperatures on the physical chemistry properties of ZrCO aerogels are investigated. The ZrCO composite aerogel consists of the C/ZrO2/ZrC ternary aerogel. The results show that with the increase of R/Zr molar ratios, the specific surface area and bulk density increase with calcination temperature up to 1300 °C, but decrease at even temperature (1500 °C). The specific surface area is as high as 637.4 m2/g for ZrCO composite aerogel (R:Zr = 2:1), which was higher than ever reported. As the heat-treatment temperature increases to 1500 °C, the ZrC crystalline phase occurs and the t-ZrO2 phase still appears within the composite. The thermal conductivity of the carbon fiber mat-reinforced composite aerogel is as low as 0.057 W/m/K at room temperature (25 °C). [ABSTRACT FROM AUTHOR]

This paper reports the effects of welan gum on the hydration and hardening behaviors of Portland cement (PC) by using X-ray diffractometry, mercury instruction porosimetry, thermogravimetry, differential scanning calorimetry and scanning electron microscopy. Results show that welan gum has notable influence on the setting time of PC paste and the formation of calcium hydroxide (Ca(OH)2); welan gum has little impact on the total hydration heat, AFt content and/or the morphologies of hydration products even though it delays the induction period of hydration and the second reaction of the aluminate phase. Welan gum retards the early hydration of C3S and accelerates the early hydration of C4AF. The compressive strength is improved, and pore size of hardened cement paste is reduced with at the studied period when welan gum is no more than 0.05%. In this research, the cement paste with 0.05% welan gum exhibits the highest long-term (90 d) compressive strength and lowest porosity. [ABSTRACT FROM AUTHOR]

Recent studies on biochars confirmed their potential benefits in improving soil fertility and sequestrating contaminants. However, little information on the changes in structural characteristics and metal speciation of biochars after exposure to soils is currently available. The aim of this study was to use double experimental bags to study the transformation of ozonized biochars derived from poultry manure and drying sludge (denoted PB and SB, respectively) in typic udic ferrisols. The carbon and sulfur functional groups and chemical characteristics of the biochars were determined using spectroscopic techniques, such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and near-edge X-ray absorption fine structure spectroscopy spectroscopy, combined with chemical extractions. Metal species were characterized using Cu K-edge X-ray absorption near-edge structure and chemical sequential fractionation schemes. The results showed that the potential changes in structural characteristics and metal species of biochars in soil were highly dependent on the composition of the biochars. PB comprised highly aromatic and chemically stable C, whereas SB contained a substantial amount of easily degradable C. Oxygen-containing groups slightly increased after incubation in the soil with either 60% water holding capacity (WHC) or flooding for 3 months. Sulfur in the biochars was predominantly inorganic S. Minerals such as K, Na, Mg, and S were mobilized from the biochars, accounting for 5-55% depending on the properties and sources of the element. Both PB and SB contained high concentrations of Cu and Zn. CuO in PB dissolved within 3 months, whereas CuS in both PB and SB was partly oxidized in the soil with 60% WHC for 9 months and adsorbed to the organic phase. Zn had relatively high mobility in both biochars, resulting in its vertical migration into soils. [ABSTRACT FROM AUTHOR]

Four types of alkanolamines (i.e., traditional alkanolamines represented by TEA and TIPA and new alkanolamines represented by DEIPA and EDIPA) were added to Portland cement as chemical additives, and their effects on the cement properties and hydration process were investigated. An isothermal calorimeter was used to track the hydration heat flow of the cement pastes with or without alkanolamines. Thermogravimetric analyses were performed to measure the degree of hydration over the course of 28 days. In addition, X-ray diffraction, MIP analysis and SEM were used as auxiliary tests. The results indicated that alkanolamines improved the compressive strength of the cement mortars. It was found that TEA increased the rate of the second hydration of CA, and TIPA accelerated the hydration of CAF. DEIPA and EDIPA promoted the hydration of both the aluminum and ferrite phases as well as catalyzed the conversion of AFt to the AFm phase. By contrast, the new alkanolamines represented by DEIPA and EDIPA expressed more superior properties. [ABSTRACT FROM AUTHOR]

In this paper, a MnFeO-Cellulose magnetic composite aerogel (MnCA) with high adsorption capacity was fabricated by in situ incorporating MnFeO to regenerated cellulose hydrogel matrix, followed by CO supercritical drying. A green synthetic strategy was performed by using renewable cellulose materials, environmentally benign cellulose solvents and facile synthetic conditions. The results showed that the obtained magnetic cellulose aerogel had a continuous and tiered three dimensional network with interconnected fibrils of about 30 nm in width, which was similar to those of cellulose aerogel prepared from NaOH/urea solution via CO supercritical drying. Meanwhile, they had high specific surface areas of 236-288 m/g and total pore volume of 0.55-0.88 cm/g. In addition, the hybrid aerogel showed superparamagnetism with maximum saturation magnetization reaching up to 18.53 emu/g. The magnetic nanocomposite aerogel could be used for biological and environmental applications. The adsorption test showed that MnCA had rapid adsorption rate and excellent adsorption ability of removing heavy metal ions in aqueous solution which could attain to 63.3 mg/g within 100 min. Moreover, all the composite aerogels exhibited good reusability and could be easily reused from the water after adsorption. [ABSTRACT FROM AUTHOR]

Amine hybrid titania/silsesquioxane composite aerogel (AHTSA) was prepared by an one-pot sol-gel process without any catalyst. The sol-gel reaction mechanism of AHTSA was proposed. The use of 3-aminopropyltriethoxysilane (APTES) plays as an 'internal catalyst' and promotes the formation of gel during sol-gel process. The morphology, microstructure, pore structure and CO capture performances of AHTSA were investigated. AHTSA exhibits microstructure of the typical silica aerogels with colloidal structure. Moreover, AHTSA has a large number of macropores which favor the CO adsorption. Thermogravimetric analysis reveals that AHTSA has a high CO/N selectivity in CO/N mixture gas. CO adsorption capacity with dry and humid 1 vol% CO is as high as 4.19 and 5.04 mmol/g, respectively. Correspondingly, amine efficiency under dry and humid conditions is 0.37 and 0.44, respectively. AHTSA has very short adsorption halftime below 4 min, and its CO adsorption capacity do not show obvious attenuation after 30 adsorption-regeneration cycles, indicating AHTSA is a dynamic and regenerable sorbent. Graphical abstract: [ABSTRACT FROM AUTHOR]

This paper illustrates the retarding effects of welan gum on the hydration of CA$ both in the absence and presence of gypsum. By using the methods of isothermal calorimetry, X-ray diffractometry, mercury instruction porosimetry, thermogravimetry and scanning electron microscopy, it reveals that the hydration of CA$ is significantly retarded and reduced in the presence of welan gum, while the total hydration heat of CA$ is reduced with the rise of dose of welan gum. The retarding effect of welan gum on the hydration of CA$ in the absence of gypsum is much stronger than that in the presence of gypsum. The hydration product of AFm is AFm-12 at curing time longer than 1 d at the w/c ratio of 1. As a whole, welan gum will not affect the composition of hydration products of CA$, even though the AFm phase grains grown well and are better shaped with addition of 0.50% welan gum. [ABSTRACT FROM AUTHOR]

The hydration of calcium sulfoaluminate cement in the presence of borax and citric acid has been studied using isothermal calorimetry, X-ray diffraction, thermogravimetric analysis, Fourier transfer infrared spectrometry and mercury intrusion porosimetry. The results suggest that the formation of complex between calcium and citrate in the solution adsorbed on the solid surface delayed the CA $$ \bar{S} $$ and anhydrite dissolution and AFt nucleation. At the same time, the presence of borate replaced sulfate anion in ettringite (AFt) to form B-AFt. These reactions have an effect on the setting times and the mechanical strength values. The setting times of the calcium sulfoaluminate cement increased when the mineral admixtures increased in the cement. The effect of borax and citric acid on the strength development at different hydration stages presented different results, namely a decreased strength in an early stage and an increased strength at 3 and 28 days. [ABSTRACT FROM AUTHOR]

The objective of this research was to develop a high-strength carbon-fiber felt reinforced carbon/alumina aerogel (CF-C/AlO) with low thermal conductivity. The carbon-fiber felt reinforced resorcinol formaldehyde/alumina aerogel (CF-RF/AlO) was initially prepared using sol­gel technique followed by ambient pressure drying technique. The CF-C/AlO was obtained after the thermal treatment at 1600 °C under flowing argon atmosphere. Both CF-RF/AlO and CF-C/AlO displayed extremely little linear shrinkages due to the high structural strength of carbon fiber felt. The compression strength of CF-C/AlO were 0.50, 0.78, 1.30 and 2.35 MPa, the corresponding compressive stress at the strains of Ɛ , Ɛ , Ɛ and Ɛ , respectively. The thermal conductivity of CF-C/AlO is as low as 0.284 W/(m·K) at a ultrahigh temperature 1600 °C under argon, which is only about one half of the value of carbon fiber felt (0.538 W/(m·K)). The as-synthesized CF-C/AlO possessed greatly controllable and stable structure, which would be fabricated and machined to a large-scale composites and be used as high temperature thermal insulators. Graphical abstract: [ABSTRACT FROM AUTHOR]

Amine-modified SiO aerogel was prepared using 3-(aminopropyl)triethoxysilane (APTES) as the modification agent and rice husk ash as silicon source, its CO adsorption performance was investigated. The amine-modified SiO aerogel remains porous, the specific surface area is 654.24 m/g, the pore volume is 2.72 cm/g and the pore diameter is 12.38 nm. The amine-modified aerogel, whose N content is up to 3.02 mmol/g, can stay stable below the temperature of 300 °C. In the static adsorption experiment, amine-modified SiO aerogel (AMSA) showed the highest CO adsorption capacity of 52.40 cm/g. A simulation was promoted to distinguish the adsorption between the physical process and chemical process. It is observed that the chemical adsorption mainly occurs at the beginning, while the physical adsorption affects the entire adsorption process. Meanwhile, AMSA also exhibits excellent CO adsorption-desorption performance. The CO adsorption capacity dropped less than 10 % after ten times of adsorption-desorption cycles. As a result, AMSA with rice husk ash as raw material is a promising CO sorbent with high adsorption capacity and stable recycle performance and will have a broad application prospect for exhaust emission in higher temperature. [ABSTRACT FROM AUTHOR]

The SO concentration distributions in surface region of cement mortar immersed in sulfate solution at early stage were measured by layered sampling method combined with chemical analysis, and the diffusion coefficients of SO anions in surface region of mortar into internal area were calculated by means of instantaneous plane diffusion theory. The experimental results showed that the SO concentration gradually reduced when the diffusion depth increased in the surface region of mortar. Diffusion coefficient (D) was relevant with the concentration and kind of environmental sulfate solution, which reduced with immersion time at the beginning, and then rose slowly after a period of time. The calculation of initial diffusion coefficient ( D ) and starting time of deterioration (t) caused by sulfate attack was further attempted based on the data of diffusion coefficient, and it was found that D and t∞ were all relevant with concentrations of sulfate and different kind of sulfate as well. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii is an important opportunistic pathogen that causes severe nosocomial infections, especially in intensive care units (ICUs). Over the past decades, an everincreasing number of hospital outbreaks caused by A. baumannii have been reported worldwide. However, little attention has been directed toward the relationship between A. baumannii isolates from the ward environment and patients in the burn ICU. In this study, 88 A. baumannii isolates (26 from the ward environment and 62 from patients) were collected from the burn ICU of the Southwest Hospital in Chongqing, China, from July through December 2013. Antimicrobial susceptibility testing results showed that drug resistance was more severe in isolates from patients than from the ward environment, with all of the patient isolates being fully resistant to 10 out of 19 antimicrobials tested. Isolations from both the ward environment and patients possessed the β-lactamase genes bla, bla, bla, bla, and bla. Using pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST), these isolates could be clustered into 4 major PFGE types and 4 main sequence types (ST368, ST369, ST195, and ST191) among which, ST368 was the dominant genotype. Epidemiologic and molecular typing data also revealed that a small-scale outbreak of A. baumannii infection was underway in the burn ICU of our hospital during the sampling period. These results suggest that dissemination of β-lactamase genes in the burn ICU might be closely associated with the high-level resistance of A. baumannii, and the ICU environment places these patients at a high risk for nosocomial infection. Cross-contamination should be an important concern in clinical activities to reduce hospitalacquired infections caused by A. baumannii. [ABSTRACT FROM AUTHOR]

SnO nanoparticles have been successfully synthesized by a facile hydrothermal method from SnCl·2HO, hexamethylenetetramine, and trisodium citrate in water at 120 °C for 12 h. The effects of surfactant and precipitant on SnO synthesis were investigated. SnO nanoparticles can be synthesized in the temperature range of 120-180 °C with long reaction time in the presence of trisodium citrate. When NaOH was used as precipitant instead of hexamethylenetetramine, it is difficult to obtain SnO nanoparticles at 120 °C in the presence of trisodium citrate. SnO nanoparticles with an average size of about 5 nm show good crystallinity and excellent sensitivity to ethanol and acetaldehyde in about 55% relative humidity. [ABSTRACT FROM AUTHOR]

Purpose: Colloid-facilitated transport of metals is widely observed while manure is used for the improvement of contaminated soil. Details on the mechanism of colloid-associated metal transport are still lacking. This work investigated the nature of water-dispersible colloids (WDC) from different organic manures, differentiated the significance of clay and organic colloids in the metal transport, and finally provided direct and quantitative evidence for the importance of WDC in the colloid-facilitated transport of metals. Materials and methods: Column experiments were conducted to assess the overall significance of WDC from effective microbial inoculated manure (EM) and leaf mulch (LM) for metal transport in alkali-contaminated soil. The properties of organic colloids such as hydrophilicity, aromaticity, and functional characteristics were analyzed by DAX-8 resin column, specific UV absorbance, and Fourier-transform infrared spectroscopy, respectively. Colloid identification and metal species determination were conducted using a combination of X-ray absorption near-edge structure, X-ray fluorescence spectroscopy, and transmission electron microscopy coupled with energy-dispersive X-ray analysis. Results and discussion: Approximately 100 % of Pb, 69 % of Zn, and 38 % of Cu in the colloidal particles came from soil clay in the presence of EM colloids, while more than 80 % of Pb, Zn, and Cu in the LM colloids. Combined with the quantities of colloidal metals, it revealed that clay release was inhibited in the former and enhanced in the latter. The quantities of Cu and Zn associated with the EM colloids were much higher than that with the LM colloids. The contrary result was observed for Pb. LM colloids increased the quantities of organically associated Pb significantly. Conclusions: Clay-associated metal transfer was influenced by the nature of WDC. Microbial manure colloids inhibited the clay-associated transfer of metals in the soils probably due to the presence of polysaccharide and microbially derived extracellular proteins. Leaf mulch colloids, with more hydrophobicity and aromaticity, enhanced the clay-facilitated transfer of metals in the soils. [ABSTRACT FROM AUTHOR]

Carbon/alumina (C/AlO) composite aerogel with high compressive strength and low thermal conductivity has been successfully synthesized by sol-gel method, followed by CO supercritical drying and carbonization. SEM images and compressive Young's modulus measurements show that the C/AlO aerogel with a molar ratio of Resorcinol/Alumina (R/Al) of 1.0 presents homogeneous pore structures and obtains excellent compressive Young's modulus up to 90 MPa. Three weight losses regions are observed during heat treatment process, confirmed by TG/DSC measurements. XRD patterns and TEM images indicate that α-AlO phase transition occurs only when heat treatment temperature reaches up to 1500 °C with the adding of carbon source, 200 °C higher than pure AlO aerogel. The as-dried RF/AlO aerogel possesses thermal conductivity as low as 0.025 W m K. The thermal conductivities of C/AlO aerogels increase gradually with the increase of heat treatment temperatures, caused by increasing solid thermal conductivity. The thermal conductivities range from 0.033 to 0.049 W m K, suitable for efficient thermal insulations uses. [ABSTRACT FROM AUTHOR]

The Co-S/ x wt.% AB ( x=0, 10, 20, 30) composite materials were prepared by simply mixing Co-S material fabricated by hydrothermal method and AB alloy. The structure and morphology of the composite materials were characterized by XRD and SEM, respectively. The electrochemical properties of the composite electrodes were studied by the galvanostatic charge, discharge test and electrochemical impedance spectroscopy. The results showed that the Co-S/20 wt.% AB composite electrode showed the highest discharge capacity and the best cycling stability. The existence of the AB alloy improved the electrochemical activity of composite electrodes, reduced the electrochemical polarization resistances and promoted the electrochemical conversion reaction between Co and Co(OH). In order to improve the utilization rate of active materials, 0.01 mol/L NaSO was added into the electrolyte. The electrochemical properties of the composite electrode were significantly enhanced. After fifty cycles, the discharge capacity of the composite electrode increased from 407 to 481.7 mAh/g and the capacity retention increased from 79.7% to 91.2%. [ABSTRACT FROM AUTHOR]

There have been no major advances for the treatment of metastatic urothelial bladder cancer (UBC) in the last 30 years. Chemotherapy is still the standard of care. Patient outcomes, especially for those in whom chemotherapy is not effective or is poorly tolerated, remain poor. One hallmark of UBC is the presence of high rates of somatic mutations. These alterations may enhance the ability of the host immune system to recognize tumour cells as foreign owing to an increased number of antigens. However, these cancers may also elude immune surveillance and eradication through the expression of programmed death-ligand 1 (PD-L1; also called CD274 or B7-H1) in the tumour microenvironment. Therefore, we examined the anti-PD-L1 antibody MPDL3280A, a systemic cancer immunotherapy, for the treatment of metastatic UBC. MPDL3280A is a high-affinity engineered human anti-PD-L1 monoclonal immunoglobulin-G1 antibody that inhibits the interaction of PD-L1 with PD-1 (PDCD1) and B7.1 (CD80). Because PD-L1 is expressed on activated T cells, MPDL3280A was engineered with a modification in the Fc domain that eliminates antibody-dependent cellular cytotoxicity at clinically relevant doses to prevent the depletion of T cells expressing PD-L1. Here we show that MPDL3280A has noteworthy activity in metastatic UBC. Responses were often rapid, with many occurring at the time of the first response assessment (6 weeks) and nearly all were ongoing at the data cutoff. This phase I expansion study, with an adaptive design that allowed for biomarker-positive enriched cohorts, demonstrated that tumours expressing PD-L1-positive tumour-infiltrating immune cells had particularly high response rates. Moreover, owing to the favourable toxicity profile, including a lack of renal toxicity, patients with UBC, who are often older and have a higher incidence of renal impairment, may be better able to tolerate MPDL3280A versus chemotherapy. These results suggest that MPDL3280A may have an important role in treating UBC-the drug received breakthrough designation status by the US Food and Drug Administration (FDA) in June 2014. [ABSTRACT FROM AUTHOR]

Asymmetric catalysis is seen as one of the most economical strategies to satisfy the growing demand for enantiomerically pure small molecules in the fine chemical and pharmaceutical industries. And visible light has been recognized as an environmentally friendly and sustainable form of energy for triggering chemical transformations and catalytic chemical processes. For these reasons, visible-light-driven catalytic asymmetric chemistry is a subject of enormous current interest. Photoredox catalysis provides the opportunity to generate highly reactive radical ion intermediates with often unusual or unconventional reactivities under surprisingly mild reaction conditions. In such systems, photoactivated sensitizers initiate a single electron transfer from (or to) a closed-shell organic molecule to produce radical cations or radical anions whose reactivities are then exploited for interesting or unusual chemical transformations. However, the high reactivity of photoexcited substrates, intermediate radical ions or radicals, and the low activation barriers for follow-up reactions provide significant hurdles for the development of efficient catalytic photochemical processes that work under stereochemical control and provide chiral molecules in an asymmetric fashion. Here we report a highly efficient asymmetric catalyst that uses visible light for the necessary molecular activation, thereby combining asymmetric catalysis and photocatalysis. We show that a chiral iridium complex can serve as a sensitizer for photoredox catalysis and at the same time provide very effective asymmetric induction for the enantioselective alkylation of 2-acyl imidazoles. This new asymmetric photoredox catalyst, in which the metal centre simultaneously serves as the exclusive source of chirality, the catalytically active Lewis acid centre, and the photoredox centre, offers new opportunities for the 'green' synthesis of non-racemic chiral molecules. [ABSTRACT FROM AUTHOR]

Resorcinol-formaldehyde/alumina composite (RF/AlO) gels were initially prepared using sol-gel techniques, and then dried to aerogels with supercritical fluid CO. RF/AlO aerogels were successfully converted to monolithic carbon/alumina composite (C/AlO) aerogels after carbonization under flowing Ar at 800 °C. The samples were characterized by Brunauer-Emmett-Teller, scanning electron microscopy, transmission electron microscope and X-ray diffraction, and the compressive strengths were also measured. The results indicated that the resulting C/AlO aerogels prepared from hydrated AlCl possessed microstructures containing highly reticulated networks of fibers, 2-5 nm in diameter and of varying lengths, whereas the samples prepared from hydrated Al(NO) were amorphous with microstructures comprised of interconnected spherical particles with diameters in the 5-15 nm range and the alumina were surrounded by amorphous carbon. The difference in microstructure resulted in each type of aerogels displaying distinct physical and mechanical properties. In particular, the as-prepared C/AlO aerogels with the weblike microstructure were far more mechanically robust than those with the colloidal network. Correspondingly, the compressive strengths are 5.6 and 2.8 MPa, respectively. [ABSTRACT FROM AUTHOR]

Fiber-shaped cupric oxide (CuO) nanoparticles and flower-shaped ZnO nanoparticles were facilely synthesized by plasma-induced technique directly from copper and zinc electrode pair in water, respectively. The phase composition, morphologies and optical property of nanoparticles have been investigated by energy dispersive X-ray analysis, X-ray powder diffraction, transmission electron microscopy and UV-vis. The in situ analysis by an optical emission spectroscopy clarified the formation mechanism. Plasma was generated from the discharge between a metal electrode pair in water by a pulse direct current power. CuO and ZnO nanoparticles were synthesized via almost the same formation mechanism, which were prepared via the rapid energetic radicals' bombardment to electrodes' surface, atom vapour diffusion, plasma expansion, solution medium condensation, and in situ oxygen reaction and further growth. This novel plasma-induced technique will become a potential application in nanomaterials synthesis. [ABSTRACT FROM AUTHOR]

The hydrophobic silica aerogel (SiO aerogel) was prepared by in situ polymerization sol-gel method and ethanol supercritical drying, with tetraethoxysilane (TEOS) as silica source, phenyltriethoxysilane (PTES) as modifier, ethanol as solvent and ammonia as catalyst. The effects of n(PTES)/ n(TOES) were investigated on gel time, structure, and hydrophobicity. The SiO aerogel was measured by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The effects of n(PTES)/ n(TOES) were also studied on adsorption property of pentane, hexane, heptane, octane, benzene, toluene, o-xylene, nitromethane, nitroethane, and nitrobenzene. The adsorption intensity of SiO aerogel was compared with that of activated carbon. The results show, with the increasing of n(PTES)/ n(TOES), the surface area, pore volume, and pore size of SiO aerogel decreased, gel time and hydrophobicity increased, and the contact angle could be 154° with n(PTES)/ n(TOES)=0.7. The adsorption intensity of SiO2 aerogel with n(PTES)/ n(TOES)=0.5 was bigger than that of activated carbon with an average 5.84 times of 10 organic liquid. The adsorption intensity of aerogel with n(PTES)/ n(TOES) =0.1 was the best one in all samples with the average 8.33 times compared with that of activated carbon. [ABSTRACT FROM AUTHOR]

The effects of CaO-BO-SiO (CBS) glass addition on the sintering temperature and dielectric properties of MgNbO ceramics have been investigated using X-ray diffraction, Scanning electron microscopy and Differential thermal analysis. The CBS glass can change to liquid phase at about 750 °C and a small amount of CBS glass addition to MgNbO ceramics can greatly decrease the sintering temperature to about 1,125 °C. It is revealed that the reduced sintering temperature is attributed to the formation of liquid phase. The major phases of the sample are MgNbO and MgNbO. The relationship between τ values and the content of glass additions have the reverse change trends. The MgNbO ceramics with 2wt% glass addition sintered 1,125 °C exhibit good microwave dielectric properties: dielectric constant ( ε) of 13 and Q·f value of 69,000 GHz. [ABSTRACT FROM AUTHOR]

Streptococcus suis serotype 2 (SS2) is a major swine pathogen of significant commercial importance worldwide and an emerging zoonotic agent of human streptococcal toxic shock-like syndrome. We previously reported that the Chinese highly pathogenic SS2 strains specifically harbor an 89K pathogenicity island, and the SalK/SalR two-component system encoded within this island mediates a piglet-lethal phenotype. However, its regulatory mechanism remains obscure. In the present study, we performed a proteome analysis to identify the target proteins regulated by the SalK/SalR system. This expression profiling analysis reveals 14 down-regulated proteins and 1 up-regulated protein. In partial accord with our previous microarray analysis, 9 out of the 14 down-regulated genes are also repressed at the transcriptional level. From the 9 matched genes, 5 were selected and further subjected to gene knockout and experimental infection of mice. The results show that the selected 5 genes are potential virulence factors and participate to various extents in the pathogenesis of SS2 infection, and may contribute to the attenuation of virulence mediated by the SalK/SalR system. [ABSTRACT FROM AUTHOR]

The adsorption properties of TNT from wastewater by hydrophobic silica aerogel/activated carbon composite materials were investigated. The effects of adsorption time, pH value, adsorption temperature, and the amount of the composite materials on the adsorption intensity were studied. The adsorption principle and mechanism of the composite materials was discussed along with the Freundlich equation. The results showed that the best adsorption intensity of the hydrophobic silica aerogel/activated carbon composite materials could reach 96.5% with adsorption conditions of adsorption temperature 25°C, pH value 7, the amount of SiO aerogel dosage 3.33 g/L, and adsorption time of 120 min. The adsorption of hydrophobic SiO aerogel/activated carbon composite materials for TNT solution is mainly surface adsorption, and also has some chemical adsorption when the aerogel hydrophobic modified. [ABSTRACT FROM AUTHOR]

Terminase proteins are responsible for DNA recognition and initiation of DNA packaging in phages. We previously reported the genomic sequence of a temperate Pseudomonas aeruginosa phage, PaP3, and determined its precise integration site in the host bacterial chromosome. In this study, we present a detailed functional identification of the DNA packaging terminase for phage PaP3. The purified large subunit p03 was demonstrated to possess ATPase and nuclease activities, as well as the ability to bind to specific DNA when it is unassembled. In addition, a small terminase subunit (p01) of a new type was found and shown to bind specifically to cos-containing DNA and stimulate the cos-cleavage and ATPase activities of p03. The results presented here suggest that PaP3 utilizes a typical cos site mechanism for DNA packaging and provide a first step towards understanding the molecular mechanism of the PaP3 DNA packaging reaction. [ABSTRACT FROM AUTHOR]

The investigated low temperature Co fired ceramics(LTCC) composite of 60wt% CaO-AlO-B2O-SiO glass and 40wt% α-AlO as a filler is a non-reactive system, which is a critical part of the low temperature Co fired ceramics process. Through a study on densification process, the phase transformation and microstructure can be revealed. Its composites typically consist of CaO-AlO-BO-SiO glass and α-AlO powders of average particle size ( D=3.49 μm). The sintering behavior, phase evaluation, sintered morphology, and microwave dielectric properties were investigated. In the fire range of 800 to 900 °C, the composites were crystallized after completion of densification. It is found that the composites start to densify at 825 °C, simultaneously, the dielectric constant ( ɛ) reaches its maximum. With increasing heat-treatment temperatures, due to the loose microstructure of the material, tan δ increases slightly. The last of the sintered samples were identified as partly Anorthite at 850 °C. At that temperature it has ɛ of 7.9 and tan δ less than 1×10, and can be used as a promising LTCC material. [ABSTRACT FROM AUTHOR]

The hydrophobic SiO aerogels were prepared by in-situ polymerization sol-gel method and supercritical drying of ethanol method with tetraethylorthosilicate(TEOS) as silica source, methyl triethoxysilane (MTMS) as modifier, ethanol as solvent. Moreover, the structure and adsorption property of SiO aerogels were also studied. As results, the surface area of SiO aerogels was 863.59 m/g, the pore volume was 3.57 cm/g, and the contact angle was 150°. Adsorption intensity of silica aerogels for organic liquid (alkanes, benzene compounds, and nitro-compounds) is bigger than that of activated carbon. The mass of the liquid absorbed increased linearly with the surface tension of the liquid. The lower surface tension and boiling point are, the shorter desorption time is. After regenerating 10 times, nitromethane regeneration rate remain the same, and almost more than 94%. So SiO aerogels have good absorption and regeneration property. [ABSTRACT FROM AUTHOR]