Search

Infection following inguinal hernia repair (IHR) is uncommon. Rational use of antibiotics can significantly improve the prognosis of patients. However, accurately identifying the pathogen involved is usually challenging. This case report describes a patient who developed intermittent fever after undergoing open preperitoneal tensionfree repair of a bilateral inguinal hernia. The scrotal fluid specimen was cultured and subjected to metagenomic next-generation sequencing (mNGS). Culture revealed the presence of Enterococcus faecalis (a facultative anaerobe). However, mNGS detected E. faecalis along with multiple anaerobic bacteria including Bacteroides thetaiotaomicron, Parabacteroides distasonis, and Levyella massiliensis. The patient was finally diagnosed with a mixed infection of E. faecalis and multiple anaerobes, and his condition was effectively controlled after timely adjustment of the antibiotic regimen. Treating postoperative infections with multiple concurrent conditions can be challenging. mNGS is valuable for the accurate diagnosis and treatment of infections, as it not only can further verify the culture results, but also assist clinicians in ruling out pulmonary infection caused by hematogenous dissemination after IHR in patients. [ABSTRACT FROM AUTHOR]

In the practical application of microwave absorbing materials, traditional powder materials need to be mixed with the matrix to fabricate composite coatings. However, the complex preparation process of composite coatings and the uneven dispersion of powders in the matrix limit their application. To solve these problems, two-dimensional (2D) F-WS2/CP composite films were prepared by using carbon paper (CP) as a dispersion matrix and loading flower-like WS2 on its surface through a simple hydrothermal method. The morphology and microwave absorption (MA) performance of the composite films are easily regulated by adjusting the amount of reaction precursors. The combination of WS2 and CP facilitates impedance matching and improves the electromagnetic wave attenuation performance based on the synergistic effect of different loss mechanisms including multiple reflections and scattering, interfacial polarization, dipolar polarization, and conduction loss. At a low filler content (5 wt%), the maximum reflection loss (RL) of the composite film is up to -50 dB (99.999% energy absorption) at 12.5 GHz with 2.8 mm thickness. Moreover, at a relatively thin 1.8 mm thickness, its maximum RL remains -35 dB (>99.9% energy absorption). The as-prepared composite film shows excellent MA properties at a thinner thickness and lower filling content, providing inspiration for the preparation of light weight and efficient 2D thin-film microwave absorbers in the future. [ABSTRACT FROM AUTHOR]

Polyaspartic acid modified by sulfonic acid group (PASP/ASA) was synthesized and characterized, and then its comprehensive scale inhibition performance was tested in the laboratory simulated environment as an oilfield scale inhibitor. By statically experiment the performance of polyaspartic acid/aminomethanesulfonic acid in inhibiting CaSO4 and CaCO3 scale under different synthesis condition, results present that the maximum scale inhibition efficiency of the prepared PASP/ASA for CaSO4 and CaCO3 scale is 100% and 83.36% at the dosage of 2.5 mgL-1 and 10 mgL-1, respectively. However, the average scale inhibition efficiency of PASP/ASA can reach 61.63% which is higher than 51.21% of PASP at both dosage of 30 mgL-1. PASP/ASA and unmodified PASP exhibit unequal calcium scale inhibition performance because of the introduction of -- SO3H. The scale crystal morphology analyzed by SEM and X-ray diffraction revealed that the calcium scale crystals were eliminated in the presence of PASP/ASA by chelation, electrostatic dispersion and lattice distortion mechanism. [ABSTRACT FROM AUTHOR]

Incomplete magnetization switching may take place between two recorded transitions in perpendicular magnetic recording. These write process issues were studied with a micromagnetic model. The relatively poor effective field from the central part of the perpendicular writer is unable to reverse the media grains properly. Consequently, media dc noise will increase as the incomplete switching becomes more severe. An expression for the effective field heff was proposed to easily discover those cases. The incompletely switched magnetization observed in the static footprint could also be partially transferred into the dynamic write process. The calculated media signal-to-noise ratio on a pseudorandom sequence could be reduced by as much as 3 dB (compared to the fully switched case). On the other hand, transition quality does not become worse with a smaller heff. This insensitivity to the transition quality was caused by the magnetostatic field from the opposite magnetization polarity on the other side of the recorded bit. [ABSTRACT FROM AUTHOR]

A novel double-hydrophilic copolymer (acrylic acid-isoprenyl polyethoxy carboxylate, AA-TPEL) is synthesized and the structural properties are identified by FT-IR, ¹HNMR and GPC analyses. The inhibitory behavior of the copolymer is determined by using a static scale inhibition method. It is shown that AA-TPEL exhibits an excellent ability to control the formation of CaCO3 scale with an inhibition efficiency of 88.67 % at the 8 mg L-1, and it still maintains a superior efficiency even at increasing solution temperature, pH, and Ca2+ concentration. Weight loss test, potentiodynamic polarization and electrochemical impedance spectroscopy are applied to investigate the inhibition efficiency on mild steel corrosion. All measurements show that, AA-TPEL acts as an efficient corrosion inhibitor and also displays a superior ability to prevent the corrosion of mild steel with approximately 83.21 % inhibition efficiency at the low level of 10 mg L-1. Scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) are used to characterize the surface morphology of CaCO3 and steel. [ABSTRACT FROM AUTHOR]

Scale could be inhibited by adding polymer inhibitors. In this article, water-soluble polymer, AA-TPEO, was synthesized successfully, which was characterized by FT-IR and 1H NMR. Its stability was studied and its molecular weight was measured using gel permeation chromatography. Through the static scale-inhibition method, the effect of several parameters on the inhibition efficiency of CaCO3, such as composition and dose, molecular weight, pH, temperature, and ion concentration of solution, was investigated. It was found that when the molar ratio was 1:2 (TPEO/AA), the inhibition efficiency could reach 89%, better than common inhibitors. The appropriate molecular weight (Mw) was 17158 g/mol. The supersaturation had been studied, which had a great influence on scale-inhibition efficiency. Meanwhile, the effect of the polymer's composition and dose on the inhibition efficiency toward Ca3(PO4)2 was investigated. The best molar ratio was 3:1 (TPEO/AA). At last, the polymer's effectiveness on scale crystal was assessed using XRD. [ABSTRACT FROM AUTHOR]

The aim of this paper is to inhibit the formation of calcium carbonate and barium sulfate scales which are common but unwanted crystalline products in the production of oil from off-shore rigs. A multifunctional antiscalant APES/AA/AMPS was prepared by reaction of acrylic acid, ammonium allylpolyethoxy sulphate and 2-acrylamido-2-methyl-propanesulfonic acid with different molar ratios. The experimental results showed that the polymer has high performance towards scales, nearly 90% for CaCO3 and 87% for BaSO4 respectively by static scale inhibition tests. The crystals of scales were characterized by using scanning electron microscopy and X-ray powder diffraction. According to the changes of the crystal shape, size and morphology, the inhibition mechanisms of complexation and adsorption between the inhibitor and the crystal surface were proposed. [ABSTRACT FROM AUTHOR]

In this study, a novel environmentally friendly copolymer acrylic acid-itaconic acid-allylpolyethoxy maleic carboxylate was synthesized and used for inhibiting the calcium sulfate dehydrate (gypsum) scale. The properties of the synthesized copolymer were characterized by Fourier-transform infrared, nuclear magnetic resonance spectroscopy and thermal gravity analysis. Also, the structure and morphology changes of scale crystals were studied by scanning electronic microscopy, transmission electron microscopy and X-ray powder diffraction analysis. The copolymer inhibition ability was evaluated by means of static scale inhibition experiments. Results show that the copolymer was effective in inhibiting the scales by changing the size and morphology of the crystals. The maximum inhibition efficiency was 99.8% at a concentration of 2 mg · L-1, far more efficient than most commercial inhibitors. [ABSTRACT FROM AUTHOR]

The precipitation of CaCO3 (calcite, vaterite, aragonite and calcium carbonate hydrates) and CaSO4 (calcium sulfate anhydride, calcium sulfate dihydrate and calcium sulfate hemihydrates) scale on pipe surfaces widely occurs in numerous industrial processes. For the control of CaCO3 and CaSO4 scales, a novel environmentally friendly scale inhibitor, maleic anhydride (MA)-allypolyethoxy carboxylate (APEM9), was synthesized. MA-APEM9 was characterized by Fourier transform infrared spectroscopy (FT-IR) and ¹H-NMR. The inhibitor property of the MA-APEM9 copolymer towards CaCO3 and CaSO4 in the artificial cooling water was studied by static scale inhibition tests. The effect on formation of CaCO3 and CaSO4 was investigated with a combination of scanning electronic microscopy (SEM) and transmission electron microscopy (TEM) analysis. The observation showed that MA-APEM9 was a much better inhibitor both for CaCO3 and CaSO4 compared to the commercial inhibitors. An inhibition mechanism is proposed. It shows that the interactions between calcium and allyl-terminated PMA are the fundamental impetus to restrain the formation of the scale in cooling water systems. The MA-APEM9 Inhibitor can be used safely in cooling water systems. [ABSTRACT FROM AUTHOR]

Multilayered optically active polyurethane/titania/manganese dioxide (OPU/TiO2/MnO2) nanohybrids were prepared and characterized. The MnO2 nanorods were coated by TiO2 with the thickness around 15 nm, and the amount of OPU grafted onto TiO2/MnO2 was about 0.21 g/g inorganics. OPU/TiO2/MnO2 nanorods possess well defined multicoated core-shell architectures. Compared with the bare MnO2, the infrared emissivity values decreased after the wrapping, indicating a potential for practical application. Interfacial interactions, crystallinity and helical secondary structure of OPU significantly affected the infrared radiation property of the nanocomposites. [ABSTRACT FROM AUTHOR]

This work presents an effective method for fabricating hierarchical Al2O3 ceramic fibers with high surface-to-volume ratios. To do this, the microscaled Al2O3 fibers are fabricated via a simple biotemplate method employing cotton fibers as bio-templates. The hierarchical architectures are designed by in situ growth of AlOOH nanocrystal on surface of Al2O3 microtube walls in a closed hydrothermal system. The developed facile route is highly valuable and feasible for hierarchical porous Al2O3 ceramic materials for applications in research and industrial fields. [ABSTRACT FROM AUTHOR]

Chiral amino acid-based monosubstituted acetylene monomers [N-tert-butoxy-carbonyl-l-phenylalanine-N'-propargylamide (LP), and N-tert-butoxycarbonyl-l-serine-N'-propargylamide (LS)] were (co)polymerized with rhodium zwitterion catalyst in THF to afford helical polyacetylenes (PAs) with moderate molecular weights (4400-14,800) in good yields. The optically active PA copolymers were soluble in common organic solvents and proven to adopt predominately single-handed helical conformations according to their intense Cotton effect and large specific rotations. Various contents of amino acid units in side chains facilitated controllable helical secondary structure while the helix was primarily stabilized by hydrogen bonding and steric repulsion between the substituents. Intramolecular hydrogen bonds constructed between hydroxyl and amide groups, in particular, played a significant role in adjusting the helicity and orderliness of the helix. The infrared emissivity values of the PAs at wavelength of 8-14 μm were measured and the correlation between helical conformations and their effect on infrared emission were systematically investigated. The results showed that more well-ordered and compact screw-sense could enhance the performance of organic polymers in lowering their infrared emissivity. Among all the as-prepared PAs, poly(LP50-co-LS50) exhibited the lowest infrared emissivity value (ε25 = 0.632) and possessed excellent resistance against heat. [ABSTRACT FROM AUTHOR]

A novel hollow tubular SiO2-Au catalyst with a mesoporous structure (HTMS) was successfully fabricated by a combination of the sol-gel and calcination processes. This method involves the preparation of modified MWCNTs, the sequential deposition of Au and then silica layers through the sol-gel processes, and finally the calcination at the desired temperature to remove the MWCNTs. The obtained samples were characterized by several techniques, such as N2 adsorption-desorption isotherms, transmission electron microscopy, energy-dispersive X-ray spectroscopy analysis, UV-Vis spectra, X-ray diffraction and Thermogravimetric Analysis (TGA). The results established that a different calcination temperature has an obvious influence on the morphology and structure of the final hollow tubular. When the temperature is 550 °C, the obtained materials exhibit the distinctly tubular structure because of the decomposition of MWCNTs and the preservation of hollow tubes. Furthermore, in the catalyst system, the mesoporous silica layer can act as the physical barrier to resist the agglomeration and sintering of Au nanoparticles even after being subjected to harsh treatments up to 650 °C. In our experiments, the catalytic activities of HTMS SiO2-Au were investigated by photometrically monitoring the reduction of p-nitrophenol (p-NPh) by an excess of NaBH4. It was found that the prepared HTMS SiO2-Au catalysts exhibited a high catalytic activity and this sample could be easily recycled without a decrease of the catalytic activities in the reaction. [ABSTRACT FROM AUTHOR]

ln an attempt to control Ca3(PO4)2 and iron(lll) scaling in cooling water systems, a water-soluble copolymer, acrylic acid-oxalic acid-allylpolyethoxy carboxylate-8-hydroxy-1,3,6-pyrene trisulfo- nic acid trisodium salt (pyranine) (AA-APEM-APTA) was examined as an environmentally friendly inhibitor. Structures of APTA, APEM, and AA-APEM-APTA were determined by FT-IR and 1H- NMR. The observation shows that the dosage of AA-APEM-APTA plays an important role on Ca3(PO4)2 inhibition. The performance of copolymer on inhibition of Ca3(PO4)2 precipitation was compared with that of current commercial inhibitors. It was shown that the copolymer exhibited an excellent ability to control inorganic minerals, with approximately 94.7% Ca3(PO4)2 inhibition. Correlation coefficient R2 of AA-APEM-APTA's is 0.9975. The effect on formation of Ca3(PO4)2 was investigated with combination of scanning electronic microscopy (SEM) and X-ray powder diffraction (XRD) analysis. The polymer had good dispersing ability with respect to iron(lll). AA-APEM-APTA can be used to measure accurately polymer consumption on line besides providing excellent Ca3(PO4)2 inhibition and dispersing to iron(lll). [ABSTRACT FROM AUTHOR]

The corrosion and scale inhibition properties of acrylic acid-oxalic acid-allylpolyethoxy carboxylate (AA-APEM9) were investigated by determining the corrosion and scale inhibition efficiency, the Tafel polarization curve and significant control of CaCO3 scales. The AA-APEM9 exhibits the highest inhibition efficiency of 81.4% when the carbon steel immersion in 3% NaCI solution. AA-APEM9 possess excellent CaCO3 inhibition, approximately 70.2% at threshold dosage of 6 mg/L. Compared to T-225, HPMA, PAA, PESA, AA-APEM9, possessing PEG, shows a superior inhibitory efficiency. AA-APEM9 has the best inhibition because of possessing the greatest degree of polymerization of PEG among it. SEM and TEM images indicate that AA-APEM9 changes highly the morphology and size of CaCO3 crystals during the inhibition process. XRD analysis shows that the AA-APEM9 copolymer influence CaCO3 crystal crystallinity. AA-APEM9 may be a potentially useful corrosion and scale inhibitor in a cooling water system. [ABSTRACT FROM AUTHOR]

We report the synthesis of a new Au nanocatalyst with increased thermal stability. This catalyst system consisted of gold nanoparticles attached to functionalized TiO2/SiO2 core-shell nanocomposites, together with the encapsulation of mesoporous silica. The synthesis process mainly involved four steps, which included the synthesis of the TiO2/SiO2 core-shell composites, synthesis of the Au/TiO2/SiO2 particles, coating of Au/TiO2/SiO2 with silica, and etching the outer silica layer. TEM images were used to confirm the success of each of the synthesis steps, and both UV-vis adsorption spectra and the catalytic activity evaluation were employed to investigate the degree of re-exposure of Au nanoparticles after the etching treatment. In our experiments, the obtained mesoSiO2/Au/TiO2/SiO2 catalyst showed a superior thermal stability and higher activity for CO conversion compared to the mesoSiO2/Au/SiO2 one. It resisted sintering during the calcination at 500 °C, whereas the unprotected one was found to sinter. Moreover, it was found that on the mesoSiO2/Au/TiO2/SiO2 sample, the outside silica material could hinder the phase transformation of titania to some extent. Thus, small crystalline particles of TiO2 anchored on the silica beads of the core-shell composites, leading to a better dispersion of small Au nanoparticles and improved catalytic capacity to resist sintering. [ABSTRACT FROM AUTHOR]

With the aim of deep desulfurization of the gasoline, an amphiphilic catalyst, which is composed of lacunary anion [PW11O39]7-and quaternary ammonium cation [C18H37(CH3)3]N, assembled in hydrophobic ionic liquid emulsions, can oxidize the sulfur compounds present in oil into their corresponding sulfones under ambient reaction conditions. In this process, catalytic oxidation of sulfur-containing molecules in model oil was investigated in detail under different reaction conditions (including different desulfurization systems, H2O2/DBT molar ratio, temperature, and various sulfur compounds). Moreover; this ionic liquid emulsion system could be recycled five times with an unnoticeable decrease in catalytic activity, and, from the kinetics study, it can be shown that the catalytic oxidative reaction is a pseudofirst-order reaction and the half-life is 30.4 min. Furthermore, the mechanism of catalytic oxidation desulfurization was elaborated, and the total sulfur level of real gasoline can be decreased from 1236 to 65 ppm after catalytic oxidation using an ionic liquid emulsion system. [ABSTRACT FROM AUTHOR]

The effect of lanthanum addition on catalytic properties of PtSnK/Al2O3catalyst for isobutane dehydrogenation was investigated. The catalysts were characterized by nitrogen adsorption, H2chemisorption, XRF, XRD, XPS, TG, TPO, and NH3-TPD. Results showed that with the appropriate addition of lanthanum, the platinum dispersion increased, and carbon depositions decreased. The presence of La in the PtSnK/Al2O3catalysts could not only strengthen the Sn−Al2O3interaction, but also stabilize the oxidation states of Sn species, thus increasing the reaction activity and stability. Among the catalysts investigated, PtSnKLa(0.9 wt %)/Al2O3had the best catalytic performance. After reaction for 8 h, the isobutane conversion of 49% was achieved with the corresponding isobutene selectivity of higher than 95%. [ABSTRACT FROM AUTHOR]

This paper is aimed at studying the influence of the competitive adsorbates (HCl, lactic acid, and citric acid) on the structural and catalytic properties of PtSnNaMg/ZSM-5 catalysts for propane dehydrogenation. N2adsorption, X-ray diffraction, inductively coupled plasma, NH3temperature-programmed desorption, H2temperature-programmed reduction and transmission electron microscopy were applied for characterization of the prepared catalysts. The catalytic performance was tested in a microreactor. The obtained results indicate that the catalyst prepared in HCl medium exhibited the best catalytic activity and stability due to relatively better metal distribution on the support and/or the strong interactions between Pt and Sn as well as between them and the support. [ABSTRACT FROM AUTHOR]

PtSnK/ZSM-5 catalysts with different amounts of K were prepared by the sequential impregnation method on HZSM-5 zeolites, and their catalytic activities and stabilities in propane dehydrogenation were investigated. The effect of the addition of K on the physicochemical properties was studied by means of BET, XRD, SEM, NH3-TPD, TPR, and TPO. The results indicated that the addition of K had an obvious impact on the catalytic performance of the PtSn/ZSM-5 catalyst. A suitable amount of K could not only change the acid of the catalysts but also improve the relation between metals and the support, thus reduce the deactivation rate and increase the selectivity to propylene. It was found that the propylene selectivity and yield could reach the maximum when the content of K was 0.8%. [Figure not available: see fulltext.] The effect of different amount of potassium added on the acid sites on the surface of the catalyst, pore structure and catalytic performance for PtSn/ZSM-5 catalyst was studied in the paper. After the addition of K, the propylene yield increased obviously and the stability of catalysts also improved. The optimum amount of K was 0.8%. [ABSTRACT FROM AUTHOR]

The effect of Mg addition to PtSnNa/ZSM-5 on the catalytic properties in propane dehydrogenation was investigated. The catalysts were characterized by using different techniques: XRD, BET, TEM, NH3-TPD, XPS, TPO, and TG-DTA. Results indicate that the presence of magnesium not only modifies the acid function and the structure of metallic phase but also diminishes carbon deposition on the catalyst. Among the catalysts studied, the PtSnNaMg(0.5%)/ZSM-5 exhibits the best performance in terms of propane conversion and stability. The high catalytic performance may be due to the strong interaction between Pt and Sn. [ABSTRACT FROM AUTHOR]

Previous research shows that class size can influence the associations between object-oriented (OO) metrics and fault-proneness and therefore proposes that it should be controlled as a confounding variable when validating OO metrics on fault-proneness. Otherwise, their true associations may be distorted. However, it has not been determined whether this practice is equally applicable to other external quality attributes. In this paper, we use three size metrics, two of which are available during the high-level design phase, to examine the potentially confounding effect of class size on the associations between OO metrics and change-proneness. The OO metrics that are investigated include cohesion, coupling, and inheritance metrics. Our results, based on Eclipse, indicate that: 1) The confounding effect of class size on the associations between OO metrics and change-proneness, in general, exists, regardless of whichever size metric is used; 2) the confounding effect of class size generally leads to an overestimate of the associations between OO metrics and change-proneness; and 3) for many OO metrics, the confounding effect of class size completely accounts for their associations with change-proneness or results in a change of the direction of the associations. These results strongly suggest that studies validating OO metrics on change-proneness should also consider class size as a confounding variable. [ABSTRACT FROM AUTHOR]

The effect of different preparation processes (impregnation and agglomeration) on the performance and properties of PtSnNa/ZSM-5 catalyst for propane dehydrogenation was studied. Some methods such as BET surface area measurement, catalyst particle mechanical strength, temperature-programmed desoption of ammonia (TPDA), Solid-state 27Al MAS NMR spectroscopy and temperature-programmed reduction of hydrogen (H2-TPR) were used to characterize the catalysts. The channel of ZSM-5 was hardly blocked after adding the binder despite the sequence of agglomeration and impregnation. Meanwhile the Pt metal dispersion on the preimpregnating catalyst with 5 wt % binder was the highest and the acidity was the weakest. The experimental results of propane dehydrogenation reaction showed that the preimpregnating catalyst with 5 wt % binder indicated the optimum reactivity in three catalysts. Therefore, the preimpregnating method in the case of adding a small amount binder was the optimal preparation method of the catalyst, which could replace the conventional preagglomerating method. Finally, a model for the effect of preparation processes on catalytic performance of PtSnNa/ZSM-5 catalyst was proposed. [ABSTRACT FROM AUTHOR]

Web site success is significantly associated with navigability, an important attribute of usability that denotes the ease with which users find desired information as they move through a Web site. Navigable Web sites allow users to form a mental model of the type and location of information in the Web site and an expectation of where and to what a particular hyperlink will lead. Existing navigability measures are based mainly on the static hyperlink structure of a Web site. Such measures, however, have two main drawbacks: 1) the effect on navigability of a hyperlink structure cannot be well characterized and 2) the effect on navigability of the navigation aids (such as the "Back" button provided by a browser) is ignored. In this paper, we abstract a dynamic Web surfing behavior as a Markov model which synthesizes typical surfing actions. Based on this model, we propose a novel navigability measure MNav. The experimental results show that MNav can be efficiently computed and it provides an effective and useful measurement of Web site navigability. [ABSTRACT FROM AUTHOR]

Focuses on a study which developed a system level model to stimulate the overall write process and pattern dependent nonlinearities. Details on the system model; Information on the tradeoff between peak current and slew rate; Conclusions.

The inhibition effect of three inhibitors with different chain lengths of their ether groups on Q235 steel in 0.5 M HCl solution at 318 K was determined by means of weight loss measureme nt, electrochemical methods (Tafel and EIS) and surface analysis (SEM). Moreover, the further study of corrosion inhibition mechanism was also conducted by computational methods (Quantum chemical calculations and Molecular dynamics simulations). Results reveal that the three inhibitors exhibit an excellent inhibition performance for carbon steel, and the corrosion inhibition efficiency of the three inhibitors increases with the increase of the chain length, which favors the formation of a protection film adsorbed on the surface. Analysis of polarization data informs that the adsorption type of three inhibitors basically obeys the Langmuir monolaye r adsorption, which is mainly of chemisorptive nature. Computational methods also tell that the three inhibitors possess a high reactivity and strong interaction with the iron surface, furthermore, the interaction is increased with the increase of the chain length of three inhibitors. The conclusion is in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

A novel fluorescent-tagged scale inhibitor, the linear-dendritic double hydrophilic block copolymer [acrylic acid (AA)/allyloxy poly(ethylene glycol) polyglycerol (APEG-PG-(OH)n)/8-allyloxy-1,3,6-pyrene trisulfonic acid trisodium salt (PA) (AA/APEG-PG-(OH)n/PA)] was synthesized by polymerisation of AA, APEG-PG-(OH)n and PA. Structures of APEG, APEG-PG-(OH)n and AA/APEG-PG-(OH)n/PA were determined by 1HNMR. The experiments show that the dosage and the n value of AA/APEG-PG-(OH)n/PA play an important role on CaCO3 inhibition. The polymer AA/APEG-PG-(OH)5/PA displays a 90% inhibition of CaCO3 precipitate formation at a dosage of 8 mg/L. The relationship between the fluorescent intensity of AA/APEG-PG-(OH)5/PA and the dosage of this polymer was studied. The correlation coefficient R of AA/APEG-PG-(OH)5/PA's is 0.9995. The effect on formation of CaCO3 was investigated with combination of XRD and SEM analysis. Finally, the significant cause and mechanism for calcium carbonate inhibition were analysed in depth. [ABSTRACT FROM AUTHOR]

The clinical efficacy of ulinastatin (UTI) combined with continuous renal replacement therapy (CRRT) in the treatment after early cardiopulmonary resuscitation (CPR) was evaluated. A total of 70 patients who were successfully treated with CPR in Ganzhou People's Hospital from October 2016 to March 2017 were selected as the subjects. The patients were randomly divided into control group (35 cases, conventional treatment) and UTI combined with CRRT group (35 cases, UTI + CRRT). The whole blood of patients was collected at 0, 3, 6 and 12 h after CPR. Reverse transcription-polymerase chain reaction assay was used to detect the changes of tolllike receptor 4 (TLR4) gene in mRNA levels between the two groups, i-STAT system 300 was used to analyze pH level, SO2, HCO3 - and lactic acid (LAC) concentration; Abbott AXSYM system was used to detect the expression of cardiac troponin I (cTnI) in serum; the concentration of plasma malondialdehyde (MDA) was examined by a special kit; interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in patients was determined by enzyme-linked immunosorbent assay. The effect of UTI combined with CRRT in the early stage of CPR was analyzed. The levels of TLR4, cTnI, TNF-α, IL-6 and MDA in the plasma of patients in both groups were significantly increased (P<0.05), but the expression level in UTI + CRRT group was lower than that in control group (P<0.05). Compared with the control group, the HCO3 - decreased significantly (P<0.05) in the UTI + CRRT group at 3 h, while the pH and SO2 did not change significantly. UTI + CRRT could significantly shorten the average recovery time of consciousness and the average recovery time of consciousness and spontaneous respiration in patients treated with CPR (P<0.05). Moreover, the score of APACHE II was significantly lower than that of control group (P<0.05). UTI combined with CRRT treatment can significantly improve the patient's condition after early CPR. [ABSTRACT FROM AUTHOR]

A novel strategy was reported for the fabrication of yolk–shell magnetic MFSVmS-Au nanocomposites (NCs) consisting of double-layered ellipsoidal mesoporous silica shells, numerous sub-4 nm Au nanoparticles (NPs), and magnetic Fe central cores. The hierarchical FSVmS NCs with ellipsoidal α-Fe2O3@mSiO2/mSiO2 as yolks/shells were first prepared through the facile sol–gel template-assisted method, and plenty of extremely stable ultrafine Au NPs were postencapsulated within interlayer cavities through the unique deposition–precipitation method mediated with Au(en)2Cl3 compounds. Notably, ethylenediamine ligands were used to synthesize the stable cationic complexes, [Au(en)2]3+, that readily underwent the deprotonation reaction to chemically modify negatively charged mesoporous silica under alkaline conditions. The subsequent two-stage programmed hydrogen annealing initiated the in situ formation of Au NPs and the reduction of α-Fe2O3 to magnetic Fe, where the synthesized Au NPs were highly resistant to harsh thermal sintering even at 700 °C. Given its structural superiority and magnetic nature, the MFSVmS-Au was demonstrated to be a highly efficient and recoverable nanocatalyst with superior activity and reusability toward the reduction of 4-nitrophenol to 4-aminophenol, and the pristine morphology was retained after six recycling tests. [ABSTRACT FROM AUTHOR]

In this study, we fabricated broadband anti-reflection coatings using a method based on layer-by-layer self assembly of positively charged layer double hydroxide (LDH) nanosheets and negatively charged silica nanoparticles via electrostatic interaction. Scanning electron microscopy and atomic force microscopy were used to observe the morphology, structure, and surface topography of LDH/SiO2 multilayer coatings. The anti-reflection properties of the coatings were investigated by UV visible spectrophotometry. Glass substrates covered with the LDH/SiO2 multilayer coatings exhibited broadband anti-reflection properties. The obtained [LDH(0.4 g/L)/SiO2(25 nm)]8, [LDH(0.4 g/L)/SiO2(50 nm)]10, and [LDH(0.8 g/L)/SiO2(25 nm)]6 coatings exhibited the best broadband anti-reflection properties among the as-prepared LDH/SiO2 multilayer coatings with different deposition cycles. Transmission levels of 97% were achieved in these optimal systems. Moreover, a maximum transmittance of 98% was achieved at a wavelength of 550 nm in the [LDH(0.4 g/L)/SiO2(25nm)]8 system and at 700 nm in the [LDH(0.8 g/L)/SiO2(25nm)]6 system. Different packing patterns of the two oppositely charged nanomaterials (dense packing of LDH nanosheets and loose stacking of silica nanoparticles) and the moderate textured surface of the coatings contributed to the enhanced light transmission and reduced wavelength dependence in the UV visible spectral range. [ABSTRACT FROM AUTHOR]

This manuscript describes the deposition of carbon on the surface of ZnO nanoparticles via a simple adsorption and calcination process. The prepared ZnO/C sample was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) and thermogravimetric analysis (TGA); the results indicated that carbon was successfully doped on the surface of the ZnO nanoparticles. The photocatalytic activity and adsorption capacity were evaluated by photocatalytic decomposition and adsorption of the dye methylene blue (MB) in aqueous solution. The results showed that the obtained ZnO/C sample exhibited much higher photocatalytic properties and adsorption capacity for MB than pure ZnO and carbon because of the formation of heteroarchitectures, which might have improved the separation of photogenerated electrons and holes. In particular, the pseudo-first-order rate constant of the ZnO/C sample was 0.326 min-1, which was 10 times greater than that of pure ZnO. Moreover, the ZnO/C composites could remove dyes from different water sources like the Changjiang River water with high efficiency as well as from deionized water, greatly promoting their application in the area of environmental remediation. [ABSTRACT FROM AUTHOR]

The properties of materials are largely determined by the microstructures and components of materials. The design of layered double hydroxide (LDH) based composites has garnered much interest as a way of fabricating novel multiscale architectures with tunable micro/nanostructures and chemical compositions. The present study aims at exploiting the Zn-Al composites for controlled synthesis of multi-scale structures and multi-component materials. Firstly, microscaled Al2O3 fibers are successfully fabricated via a simple, convenient, and cost-effective biotemplate method employing paper fibers as bio-templates. Then, the multi-scale architectures are designed by an in situ growth method, which involves direct growth of nanoscaled LDH platelets on the surfaces of Al2O3 fibers. Finally, the multi-component LDH based materials are prepared based on the controlled crystal growth of LDHs and ZnO. The microstructure, morphology, and textural properties of the as-prepared samples are characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption/ desorption. The experimental results show that the longer reaction times are favorable for the crystal growth of LDHs, and the higher hydrothermal temperatures are favorable for the formation of ZnO. This study shows that the design of multi-scale structures and multi-components Zn-Al composites can be extended for the preparation of other hierarchical LDH based materials with controlled morphological and tunable chemical compositions for separation, catalysis, adsorption, sensor, and optical applications. [ABSTRACT FROM AUTHOR]

Allyloxy polyethoxy ether (APEG) and succinic anhydride were used to prepare allyloxy polyethoxy carboxylate (APEL). 8-Hy-droxy-l,3,6-pyrene trisulfonic acid trisodium salt (PY) reacted with allyl chloride to produce fluorescent monomer 8-allyloxy-1,3,6-pyrene trisulfonic acid trisodium salt (PA). APEL and PA were copolymerized with maleic anhydride (MA) to synthesize the PA tagged, phosphate and nitrogen free CaC03 inhibitor MA-APEL-PA. Structures of PA, APEG, APEL, and MA-APEL-PA were obtained by FT-IR and 'H-NMR measurements. The obser-vation shows that the dosage of MA-APEL-PA plays an important role on CaC03 inhibition. The effect on the formation of CaC03 was investigated by a combination of scanning electron micro-scopy (SEM) and X-ray powder diffraction (XRD) analysis. The relationship between MA-APEL-PA's fluorescent intensity and its dosage was also studied. Correlation coefficient Y of MA-APEL-PA's fluorescent intensity and its dosage is 0.9997. MA-APEL-PA can be used to measure accurately the polymer consumption on line besides providing excellent CaC03 inhibition. [ABSTRACT FROM AUTHOR]

A novel environmentally friendly type of calcium carbonate and iron(III) scale inhibitor (ALn) was synthesized. The anti-scale property of the Acrylic acid-allylpolyethoxy carboxylate copolymer (AA-APELn or ALn) towards CaCO3 and iron(III) in the artificial cooling water was studied through static scale inhibition tests. The observation shows that both calcium carbonate and iron (III) inhibition increase with increasing the degree of polymerization of ALn from 5 to 15, and the dosage of ALn plays an important role on calcium carbonate and iron(III)-inhibition. The effect on formation of CaCO3 was investigated with a combination of scanning electronic microscopy (SEM), Transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis and Fourier transform infrared spectrometer, respectively. The results showed that the ALn copolymer not only influences calcium carbonate crystal morphology and crystal size but also the crystallinity. The crystallization of CaCO3 in the absence of inhibitor was rhombohedral calcite crystal, whereas a mixture of calcite with vaterite crystals was found in the presence of the ALn copolymer. Inhibition mechanism is proposed that the interactions between calcium or iron ions and polyethylene glycol (PEG) are the fundamental impetus to restrain the formation of the scale in cooling water systems. [ABSTRACT FROM AUTHOR]

Novel SSZ-39 zeolite-based Ru catalysts were synthesized by impregnation on as-synthesized metallic and protonated SSZ-39 and a one-pot synthesis strategy. The study focused on the influence of the SSZ-39 zeolite characteristics and catalyst preparation method type toward levulinic acid (LA) selective conversion to γ-valerolactone (GVL) under relatively mild reaction conditions (150 °C, 4 h and 2 MPa of H 2 with H 2 O and THF as solvents). Catalysts exhibited excellent catalytic efficiency (100 % LA conversion and 98.3 % GVL selectivity) and remarkable hydrothermal stability. The results revealed a correlation between excellent catalytic activity and the structural features of the synthesized catalysts, predominantly dependent on their appropriate surface acidity (strong Lewis acid sites) and enhanced electronic interaction between Ru species and SSZ-39. The one-pot method promoted the formation of mesopores besides the zeolitic micropores present in SSZ-39; therefore, the catalyst prepared by the one-pot method (Ru/SSZ-39) showed purer SSZ-39 crystallites and a slightly larger catalytic surface area of 439 m2/g than the original zeolite surface area of 424 m2/g. In addition, the original zeolite crystals retained their morphology as spherical aggregates and remained unaffected by Ru impregnation on the metallic or protonated support during the synthesis of Ru/Na-SSZ-39 and Ru/H-SSZ-39 catalysts, respectively. Notably, it has been demonstrated that SSZ-39 zeolite effectively acts as a support for the preparation of Ru catalyst in biomass conversion reactions. Moreover, the reused catalyst exhibited consistent activity over six cycles, maintaining its structural framework without significant loss in activity. [Display omitted] • Ru/SSZ-39 zeolite catalysts were achieved using impregnation and one-pot method synthesis methods. • The one-pot synthesis yielded purer SSZ-39 crystallites and a larger catalytic surface area. • The addition of Ru generates intermediate acidic sites, enhancing catalytic performance toward hydrogenating LA to GVL. • SSZ-39 zeolite effectively acts as a Ru catalyst support in biomass conversion reactions. [ABSTRACT FROM AUTHOR]

Bifunctional Pt-Ru/zeolite Y catalysts were prepared by ethylene glycol reduction (EGR) method, with 3 wt% of Pt and various ratios of Ru. The performance of catalysts was investigated for hydrogenation of levulinic acid (LA) to produce gamma-valerolactone (GVL). Catalysts were thermally treated in presence of NaOH and re-evaluated. The results showed that the thermal treatment contributed to adjustment of bifunctional Pt-Rux/Y acidity and further improved hydrogenation activity conversion of LA up to 100% and yield of GVL up to 97.99%. It also preserved the crystal structure of zeolite and showed better thermal stability as compared to Pt/Y and Ru/Y catalysts. • Pt-Rux/zeolite Y catalyst was achieved using the ethylene glycol reduction method. • Subsequent alkaline treatment allowed activation of Pt sites and adjusted zeolite acidity. • Treated Pt-Ru/zeolite catalysts showed the highest product and selectivity to GVL. • The treated catalysts showed better thermal stability and preserved the structure of the zeolite. [ABSTRACT FROM AUTHOR]

Background: Ambient particulate matter exposure has been shown to increase the risks of respiratory diseases. However, the role of the lung microbiome and the immune response to inhaled particulate matter are largely unexplored. We studied the influence of biomass fuel and motor vehicle exhaust particles on the lung microbiome and pulmonary immunologic homeostasis in rats.Methods: Fifty-seven Sprague-Dawley rats were randomly divided into clean air (CON), biomass fuel (BMF), and motor vehicle exhaust (MVE) groups. After a 4-week exposure, the microbial composition of the lung was assessed by 16S rRNA pyrosequencing, the structure of the lung tissue was assessed with histological analysis, the phagocytic response of alveolar macrophages to bacteria was determined by flow cytometry, and immunoglobulin concentrations were measured with commercial ELISA kits.Results: There was no significant difference in lung morphology between the groups. However, the BMF and MVE groups displayed greater bacterial abundance and diversity. Proteobacteria were present in higher proportions in the MVE group, and 12 bacterial families differed in their relative abundances between the three groups. In addition, particulate matter exposure significantly increased the capacity of alveolar macrophages to phagocytose bacteria and induced changes in immunoglobulin levels.Conclusion: We demonstrated that particulate matter exposure can alter the microbial composition and change the pulmonary immunologic homeostasis in the rat lung. [ABSTRACT FROM AUTHOR]

For the control of carbonate and sulphate scales, a new type of green scale inhibitors AQn was synthesized. The thermal stability and the molecular weight of the copolymers were investigated by thermal gravimetric analysis and gel permeation chromatography, respectively. The anti-scale property of the AQn copolymers towards CaCO3 and CaSO4 in the artificial cooling water was studied through static scale inhibition tests. The results show that both CaCO3 and CaSO4 inhibition increase with increasing the degree of polymerization of AQn from 5 to 15. The dosage of AQn plays also an important role on CaCO3 and CaSO4 inhibition. Surface morphology characterization of CaCO3 and CaSO4 was investigated with combination of scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and X-ray powder diffraction (XRD) analysis. An inhibition mechanism is proposed that the interactions between calcium and polyethylene glycol (PEG) are the fundamental impetus to restrain the formation of the scale in cooling water systems. [ABSTRACT FROM AUTHOR]

An optimization procedure based on the dynamic characteristics of a submersible electromagnetic actuator constrained in a specific volume has been developed. In order to achieve the minimum response time and low vibration when the actuator is opened, five radial dimensions are optimized when the main limiting quantity is the maximum allowed temperature. Three models, including a thermal model, an electromagnetic model, and a mechanical model are constructed, and optimization calculation is performed by using Matlab/Simulink software. According to the optimization results, an actuator is manufactured and dynamic experiments are performed. The results show substantial agreement between experimental response times and simulated response times. In order to investigate the vibration when the actuator is opened and closed, vibration experiments of the actuator are also performed. The results show that the measured vertical and horizontal accelerations are near the calculated acceleration of the plunger. Both of the experiments show that the optimization procedure is sufficiently accurate, and the optimal submersible electromagnetic actuator is sufficiently secure to be used in subsea BOP stacks. [ABSTRACT FROM AUTHOR]

In this paper, a series of linear-dendritic block copolymers allyloxy poly(ethylene glycol) polyglycerol (APEG-PG-(OH)n) copolymer, was synthesized by anionic polymerization of glycerol using allyloxy poly(ethylene glycol) (APEG). The polymers were characterized by FT-IR and ¹H NMR. The polymers were tested as novel environment-friendly inhibitors for industrial cooling water circulation. The performance of AA/APEG-PG-(OH)n on inhibition of calcium phosphate and calcium carbonate precipitation was studied by static scale inhibition tests. It was shown that AA/APEG-PG-(OH)n exhibited excellent ability to control inor-ganic minerals, with approximately 99% calcium phosphate inhibition and 85% calcium carbonate inhibition at levels of 4 and 10 mg/L AA/APEG-PG-(OH)n, respectively. The effect on formation of calcium phosphate and calcium carbonate was investi-gated with combination of scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis, respectively. [ABSTRACT FROM AUTHOR]

The influence of different binders (alumina, silica sol, and montmorillonite) on the structure and performance of PtSnNa/ZSM-5 catalysts for propane dehydrogenation to propene was studied. Temperature-programmed desoption of ammonia (NH 3-TPD), hydrogen chemisorption, BET surface area measurement, solid-state 27Al MAS NMR spectroscopy, catalyst particle mechanical strength, and X-ray diffraction (XRD) were used to characterize the catalysts. After agglomeration with different binders, the mechanical strength of all catalyst particles increased obviously in comparison with the nonagglomerated sample and the Al species amounts of the catalysts were affected greatly by the binder. A slightly acidic change was observed for the catalysts with different binders, but the metal dispersion on the carrier of different samples was clearly different. The result of propane dehydrogenation indicated that the catalyst based on PtSnNa/ZSM-5 agglomerated with alumina showed the highest conversion and high selectivity. [ABSTRACT FROM AUTHOR]

The reactions of iron(II) complexes [Fe(Tpt-Bu,i-Pr)(OH)] (1a, Tpt-Bu,i-Pr = hydrotris(3-tert-butyl-5-isopropyl-1-pyrazolyl)-borate), [Fe(6-Me2BPMCN)(OTf)2] (1b, 6-Me2BPMCN = N,N′-bis((2-methylpyridin-6-yl)methyl)-N,N′-dimethyl-trans-1 ,2-diaminocyclohexane), and [Fe(L8Py2)(OTf)](OTf) (1c, L8Py2 = 1 ,5-bis(pyridin-2-ylmethyl)-1,5-diazacyclooctane) with tert-BuOOH give rise to high-spin FeIII-OOR complexes. X-ray absorption spectra (XAS) of these high-spin species show characteristic features, distinct from those of low-spin Fe-OOR complexes (Rohde, J.-U.; et al. J. Am. Chem. Soc. 2004, 126, 16750-16761). These include (1) an intense 1s → 3d preedge feature, with an area around 20 units, (2) an edge energy, ranging from 7122 to 7126 eV, that is affected by the coordination environment, and (3) a 1.86-1.96 Å Fe-OOR bond, compared to the 1.78 Å Fe-OOR bond in low-spin complexes. These unique features likely arise from a flexible first coordination sphere in those complexes. The difference in Fe-OOR bond length may rationalize differences in reactivity between low-spin and high-spin FeIII-OOR species. [ABSTRACT FROM AUTHOR]

Perpendicular recording applications use a soft magnetic underlayer (SUL) in the media to enhance the writer field and control its angle. In this paper, a micromagnetic/FEM model (MagPar) was used to investigate the physics of the write process while a nonlinear magnetoelectrical model (Klaassen) helped identify the value of the damping constant under a particular MagPar mesh. The field strength and direction produces a domain under the writer pole in areas where the field opposes the SUL magnetization direction. These areas are located over the next tracks (right or left). This temporary domain changes the response of the SUL by affecting the flux path and increasing the return pole field near the domain. Since the return poles are very large and behave quite linearly, fields in some areas near the return pole edge are bigger due to large writer currents with overshoot and little or no damping from saturated regions. The return pole fields could be large enough to degrade transitions in adjacent tracks particularly when they are applied multiple times to those tracks. The erasure location changes with current polarity and SUL magnetization direction. [ABSTRACT FROM AUTHOR]

Head keeper spacing (HKS) is an important parameter in the keepered perpendicular magnetic recording. In this paper, a nondestructive method to measure HKS from the playback waveform of a specific recording pattern was proposed. Time and frequency domain techniques can be utilized for the measurements. The measured HKS was shown to be consistent by using different playback harmonic peaks. The effect of head surface potential distribution due to the HKS change was also discussed. [ABSTRACT FROM AUTHOR]

Adjacent track erasure in longitudinal recording was studied using a micromagnetic model. The gap and fringe fields of two heads designed to work for 100 kTPI were used to write and erase a 31-bit pseudorandom sequence (PRS) in the main track. Comparisons on recording performance were made based on the calculated magnetization profile and the equalized PRS read back signal. It was shown that, for the case of a 3800-Oe fringe field, the quality of the transitions degraded drastically when the transitions were exposed to the fringe field more than 1000 times. On the other hand, a 2000-Oe fringe field left unaffected transitions even when the transitions were exposed to the field more than 100 000 times. [ABSTRACT FROM AUTHOR]