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Strain rate sensitivity will change the cyclic mechanical response of materials under multiaxial thermomechanical fatigue loading; thus, it will lead to errors in fatigue life prediction if strain rate sensitivity is not considered in constitutive simulation. In order to more accurately express the time/rate dependence of viscoplastic behavior, a strain rate sensitivity factor is proposed to modify the viscoplastic function of Chaboche model first. On this basis, a viscoplastic constitutive model considering strain rate sensitivity under multiaxial thermomechanical fatigue loading is proposed, which can describe the varying influence of strain rate sensitivity on cyclic mechanical behavior. Meanwhile, the exponential isotropic hardening rule with the linear term is adopted to characterize the initial rapid softening and subsequent stable softening of the material under fatigue loading at elevated temperature. Moreover, the material‐dependent nonproportional hardening coefficient and the loading path‐dependent rotation factor are used in the kinematic hardening rule to consider the effect of nonproportional additional hardening on the cyclic mechanical behavior of materials. Finally, the proposed method is verified by the stress–strain data of titanium alloy TC4 and Ni‐based superalloy GH4169 under uniaxial and multiaxial thermomechanical fatigue loadings, and a good agreement is obtained. HighlightsThe time/rate dependence of viscoplastic behavior is expressed more accurately.Initial rapid cyclic softening and subsequent stable cyclic softening are described.The effect of nonproportional hardening on cyclic mechanical behavior is considered.The proposed model is verified by two materials with different damage types. [ABSTRACT FROM AUTHOR]

A growing number of bacterial species are known to move electrons across their cell envelopes. Naturally this occurs in support of energy conservation and carbon-fixation. For biotechnology it allows electron exchange between bacteria and electrodes in microbial fuel cells and during microbial electrosynthesis. In this context Rhodopseudomonas palustris TIE-1 is of much interest. These bacteria respond to light by taking electrons from their external environment, including electrodes, to drive CO2-fixation. The PioA cytochrome, that spans the bacterial outer membrane, is essential for this electron transfer and yet little is known about its structure and electron transfer properties. Here we reveal the ten c-type hemes of PioA are redox active across the window +250 to −400 mV versus Standard Hydrogen Electrode and that the hemes with most positive reduction potentials have His/Met and His/H2O ligation. These chemical and redox properties distinguish PioA from the more widely studied family of MtrA outer membrane decaheme cytochromes with ten His/His ligated hemes. We predict a structure for PioA in which the hemes form a chain spanning the longest dimension of the protein, from Heme 1 to Heme 10. Hemes 2, 3 and 7 are identified as those most likely to have His/Met and/or His/H2O ligation. Sequence analysis suggests His/Met ligation of Heme 2 and/or 7 is a defining feature of decaheme PioA homologs from over 30 different bacterial genera. His/Met ligation of Heme 3 appears to be less common and primarily associated with PioA homologs from purple non-sulphur bacteria belonging to the alphaproteobacteria class. [ABSTRACT FROM AUTHOR]

In this paper, a notch stress correction method based on the structural yield surface is proposed, in which the actual stress increment at the notch root can be obtained by multiplying two quantities, that is, the pseudo stress increment and the ratio of the slopes of the material and structural stress-strain curves. In the proposed method, the influence of temperature on the notch stress correction can be taken into account, and no iteration is required during the calculation process. Moreover, based on the proposed notch correction method and a unified viscoplastic constitutive model at high temperature condition, a notch stress-strain estimation method is developed under multiaxial thermo-mechanical cyclic loading. In order to assess the prediction accuracy of the proposed method, the calculated results are correlated to those from thermal-structural non-linear finite element analysis under various proportional and non-proportional mechanical loadings at non-isothermal high temperature condition. The comparison between the calculated and analyzed results shows that the proposed method can precisely estimate the notch stress and strain under multiaxial thermo-mechanical cyclic loading. [ABSTRACT FROM AUTHOR]

A fatigue–oxidation–creep damage model that can take into account the effect of multiaxial cyclic feature on the damage mechanism is proposed under axial-torsional thermo-mechanical fatigue loading. In the proposed model, the effects of non-proportional additional hardening on fatigue, oxidation, and creep damages are considered, and the variation of oxidation damage under different high temperature loading conditions is also described. Moreover, the intergranular creep damage needs to be equivalent to the transgranular damage before accumulating with the fatigue and oxidation damages. The fatigue, oxidation, and creep damages can be expressed as the fractions of fatigue life, critical crack length, and creep rupture time, respectively, which allows the linear accumulation of different types of damages on the basis of life fraction rule. In addition, the proposed model is validated by various fatigue experimental results, including uniaxial thermo-mechanical fatigue, axial-torsional thermo-mechanical fatigue, and isothermal axial-torsional fatigue under proportional and non-proportional loadings. The results showed that the errors are within a factor of 2. [ABSTRACT FROM AUTHOR]

BACKGROUND: The new type Palindrome H-heparin-coated dialysis catheter is supposed to reduce the incidence of catheter-related infection and catheter dysfunction. However, the effect of this new type catheter on the systemic coagulation function is little reported. OBJECTIVE: To evaluate the effects of the new type heparin-coated dialysis catheter of Palindrome H on the systemic coagulation function in hemodialysis patients. METHODS: Patients who underwent maintenance hemodialysis and could not establish internal fistula at Blood Purification Center of the First People's Hospital of Foshan from January 2014 to June 2016 were enrolled. All participants were divided into Palindrome H heparin-coated and Permcath noncoated groups depending on the catheter type. The blood platelet count, prothrombin time, international normalized ratio, activated partial thromboplastin time, thrombin time and fibrinogen degradation products were detected and compared between two groups. The study was approved by the Ethics Committee of the First People's Hospital of Foshan, approval No. L[2014]5. RESULTS AND CONCLUSION: Sixty patients were involved in the study (28 patients used the Palindrome H-heparin-coated catheter and 32 patients used Permcath noncoated catheter). All patients were followed up for 30 months. The final measurement outcome was the average value at 0, 3, 6, 9, 12, 15, 18, 21, 24, 27 and 30 months after surgery. No significant difference was found in the blood platelet count, prothrombin time, international normalized ratio, activated partial thromboplastin time, thrombin time or fibrinogen degradation products between two groups (P > 0.05). No heparin induced thrombocytopenia was observed in all participants. Therefore, in clinical practice, the new type Palindrome H-heparin-coated dialysis catheters makes no effect on the systemic coagulation function compared with noncoated catheter. [ABSTRACT FROM AUTHOR]

Abstract Arsenic (As) and cadmium (Cd) are known to be toxic to humans, and elevated concentrations have been documented in food crops worldwide. However, little is known regarding their uptake, translocation, and distribution in wheat plants during plant development. A series of experiments were conducted to investigate the spatial distribution and dynamics of As and Cd in two wheat cultivars (cv. JN12 and JM85; the latter is a low grain Cd accumulator) at different developmental stages. Root concentrations of As decreased by 84%, and those of Cd by 67%, from tillering to maturity. In contrast, As concentrations in the stems increased 3.1-fold. A significant decrease in root As accumulation was observed at the mature stage, whereas root Cd accumulation decreased largely at the elongation stage. The concentrations of Cd in all leaves and As in new leaves increased as plant growth advanced. However, As concentrations in old leaves decreased significantly from grain filling to maturity. In both cultivars, the upward transfer toward younger parts of shoots was greater in the case of Cd than of As. The remobilization of As and Cd from stems and roots differed between the two cultivars. Arsenic concentrations in rachis, glumes, and grain in JM85 were significantly higher than those in JN12, whereas As concentrations in roots and stems did not differ between the cultivars. Grain Cd was significantly higher in JN12 than in JM85, but Cd concentrations in rachis and glumes were similar between the cultivars. The difference in grain Cd concentration between the two cultivars depended on root and stem Cd remobilization and redistribution from rachis to glumes and grain; in contrast, accumulation of As in grain was influenced by As remobilization from the leaves and stem to the spike. Graphical abstract Unlabelled Image Highlights • Concentration of Cd in all leaves and As in new leaves increased with growth stage. • The upward transport toward younger internodes was greater in case of Cd than As. • Low grain As cultivar showed low As translocation from leaves and stem to the spike. • Low grain Cd cultivar showed low root-to-shoot and rachis-to-grain remobilization. [ABSTRACT FROM AUTHOR]

Highlights • A constitutive model was proposed under multiaxial thermo-mechanical cyclic loading. • The proposed model can consider the effect of non-proportional hardening. • The dynamic strain aging can induce a cyclic hardening. • The effect of dynamic strain aging is considered in the proposed model. Abstract A unified viscoplastic constitutive model, which can consider the influences of non-proportional hardening and dynamic strain aging on the responded stress, was proposed under axial-torsional thermo-mechanical cyclic loading. In the proposed model, the rotation factor and the non-proportional hardening coefficient were considered in the kinematic hardening rule. And the dynamic strain aging influence factor was also proposed to further modify the kinematic hardening rule, which can consider the induced dynamic strain aging under special strain rate and temperature conditions. Moreover, the simulation using the proposed model can achieve a better fit with the measured data under isothermal and non-isothermal axial-torsional cyclic loadings. Graphical abstracts Image, graphical abstract [ABSTRACT FROM AUTHOR]

The axial-torsional thermo-mechanical fatigue behavior for Ni-based superalloy GH4169 was investigated experimentally in the temperature interval from 360 °C to 650 °C. The experimental results showed that, in the same von Mises equivalent mechanical strain amplitude condition, the fatigue life can be seriously decreased when the axial mechanical strain and the temperature are in-phase, and the non-proportional loading of mechanical strains can result in the fatigue life to further decrease. The analysis results showed that the fatigue lives depend on the summation of fatigue, creep and oxidation damages. The interaction between dislocations and precipitations can induce the additional hardening under mechanical non-proportional loading, which can obviously increase the fatigue damage. The tensile mean stress and the non-proportional additional hardening can further increase the oxidation damage existed in all loading conditions, which result in the increase of inelastic strain at high temperature. Creep damage behavior on grain boundaries can be shown in the case of the high tensile stress and the high temperature acting simultaneously, and increased with shear stress at the same time. In addition, the tensile stress has an obvious effect on the nucleation of creep cavities contrasted to the shear stress at high temperature, and more creep damage can be caused by the non-proportional additional hardening. [ABSTRACT FROM AUTHOR]

• A mechanism based multiaxial thermo-mechanical fatigue damage model is proposed. • The value of the scatter band of life prediction result is less than ± 2. • The mean relative error between predicted and experimental strain amplitudes is 6.54%. In this paper, a life prediction method based on damage mechanism for titanium alloy TC4 under multiaxial thermo-mechanical fatigue loading is proposed. Temperature and time dependent influence factors are proposed and introduced into the strain amplitude-life curve method to consider the temperature and time dependence of damage, respectively. The increase in fatigue and oxidation damages caused by tensile mean stress and non-proportional additional hardening is expressed by the mean stress in Macaulay brackets and by using a multiaxial damage parameter, respectively. A fast cracking influence factor is proposed to consider the influence of fast cracking of materials caused by the combined action of high temperature, tensile stress and shear stress on damage behavior. The material constants are identified by test data under uniaxial and proportional loadings, and are further used for prediction under non-proportional loading. The failure life results of uniaxial isothermal fatigue tests with and without dwell time, uniaxial and multiaxial thermo-mechanical fatigue tests are used to verify the proposed method. The value of the scatter band of life prediction result is less than ± 2, as well as the maximum and mean relative errors between predicted and experimental strain amplitudes are 18.49% and 6.54%, respectively. [ABSTRACT FROM AUTHOR]

Exoelectrogenic bacteria (EEB) play a central role in bioenergy recovery, biogeochemistry of elements, and polluting remediation. The electrochemical activity of EEB biofilm on electrode was proven to be dependent on the electrode potential, but the mechanism behind such a phenomenon is unclear. In this work, Geobacter sulfurreducens biofilms were developed at potentials ranging from −0.1 V to +0.6 V vs. standard hydrogen electrode to explore the profiles of potential regulation on G. sulfurreducens biofilm development and the electrochemical activity. We found that elevating the developing potential could improve the current generation by G. sulfurreducens biofilm until +0.1 V. At higher potentials less current was generated, although more biomass was formed on the electrode. The same cytochrome c species were synthesized for electron transfer in all biofilms, independent of the developing potential. Electrochemical experimental results and redox-sensitive staining imagings proved that the biofilms developed at +0.2 V–+0.4 V had greater cytochrome c contents and reducing capacities than the others. Current generation at high potentials was likely to be limited by both the metabolic rate and the electron transfer kinetics. These findings are useful for tuning the electrochemical activity of biofilm in catalyzing redox processes or generating electricity, which is crucial for the environmental and electrochemical application of EEB. [ABSTRACT FROM AUTHOR]

Three-point bending of a beam is studied based on the Timoshenko beam theory. Large deflection and large rotation of a beam resting on simple supports with friction are calculated for a concentrated force acting at the midspan. Using the Lagrangian kinematic relations, a system of non-linear differential equations are obtained for a prismatic shear-deformable Timoshenko beam. Exact solutions for the deflection, horizontal displacement, and rotation of cross-section are derived analytically. Two deflections of small and large scale exist under three-point bending. The solutions corresponding to linearized model coincide with the well-known solutions to the classical Timoshenko beams. Numerical calculations are carried out to show the effect of the important parameters such as shear rigidity of the beam and the coefficient of friction at the contact position between the beam and supports on the deflection. The load–deflection curves are graphically presented. A comparison of large deflections and large rotations with their classical counterparts and with experimental data is made. The obtained results are useful in safety design of linear and non-linear beams subject to three-point bending. [ABSTRACT FROM AUTHOR]

• Multiaxial thermo-mechanical fatigue behavior of titanium alloy is understood. • Effects of tensile and compressive dwell time on fatigue behavior are found out. • Fast cracking mode may be activated by multiaxial thermo-mechanical loading. • Failure life of material is reduced by non-proportional additional hardening. • Fatigue and oxidation damages are increased by tensile mean stress. In this paper, the experimental investigation was carried out on the TC4 titanium alloy to understand the cyclic deformation behavior and fatigue damage mechanism of materials under multiaxial thermo-mechanical loading. The results showed that the fast cracking mode of the material may be activated by the combined action of high temperature, tensile stress and shear stress, inducing a fast degradation in the axial mechanical properties of the material, which results in a drastic decrease in the failure life of the material. Moreover, it is also found that the non-proportional additional hardening and the tensile mean stress can increase the fatigue and oxidation damages of the material, and the material damage behavior is temperature dependent and time dependent. It should be pointed out that the damage mechanisms identified in this paper can reasonably explain the life law under uniaxial isothermal fatigue loading with and without dwell time, uniaxial and multiaxial thermo-mechanical fatigue loadings. [ABSTRACT FROM AUTHOR]

In the real world crashes, brain injury is one of the leading causes of deaths. Using isolated human head finite element (FE) model to study the brain injury patterns and metrics has been a simplified methodology widely adopted, since it costs significantly lower computation resources than a whole human body model does. However, the degree of precision of this simplification remains questionable. This study compared these two kinds of methods: (1) using a whole human body model carried on the sled model and (2) using an isolated head model with prescribed head motions, to study the brain injury. The distribution of the von Mises stress (VMS), maximum principal strain (MPS), and cumulative strain damage measure (CSDM) was used to compare the two methods. The results showed that the VMS of brain mainly concentrated at the lower cerebrum and occipitotemporal region close to the cerebellum. The isolated head modelling strategy predicted higher levels of MPS and CSDM 5%, while the difference is small in CSDM 10% comparison. It suggests that isolated head model may not equivalently reflect the strain levels below the 10% compared to the whole human body model. [ABSTRACT FROM AUTHOR]

Abstract: This paper studies free vibration of horn-shaped single-walled carbon nanotube (SWCNT) carrying a nanoparticle, which is used to model a mass sensor. A non-uniform cantilever with a concentrated mass at the free end is analyzed according to the nonlocal Euler–Bernoulli beam theory. A governing equation of a horn-shaped SWCNT-based mass sensor is established. The transfer function method incorporating with the perturbation method is utilized to obtain the natural frequencies of a nonlocal Euler–Bernoulli beam with an attached nanoparticle. The effects of the geometry parameter, the nonlocal parameter and the attached mass on the natural frequencies or frequency shift are discussed. Obtained results show that the SWCNT-based mass sensor becomes more sensitive to the frequency shift due to the attached mass when the free end becomes sharper. In addition, there exists a horn-shaped SWCNT with special geometry, for which the fundamental frequencies are independent of size effect. [Copyright &y& Elsevier]

• Multiaxial fatigue behavior at high temperature is experimentally characterized. • Fatigue-oxidation-creep damage behaviors are comprehensively captured. • The effect of non-proportional hardening on fatigue behavior is considered. • The notch stress–strain history is determined by the elastic-viscous-plastic analysis. • A new method is proposed to evaluate the fatigue life and applied to a notched bar. In this paper, a new life assessment framework is proposed based on the elastic-viscoplastic modeling and the damage behavior for the structural component under multiaxial non-proportional loading at high temperature. The viscoplastic constitutive model with the ability to capture the non-proportional hardening effect is used to obtain the stress–strain fields, in which a new method based on the rotation of strain axis is proposed to evaluate the notch rotation factor. The damage model, which can comprehensively capture the multiaxial fatigue-oxidation-creep behaviors, is used to assess the failure life. In addition, the proposed framework is evaluated by the life results under proportional and non-proportional fatigue loadings at 650 °C, and the errors are found to be within a factor of 2. [ABSTRACT FROM AUTHOR]

The frequency shift of a nanomechanical sensor carrying a nanoparticle is studied. A bridged single-walled carbon nanotube (SWCNT) carrying a nanoparticle is modeled as a clamped micro-beam with a concentrated micro-mass at any position. Based on the nonlocal Timoshenko theory of beams, which incorporates size effects into the classical theory, the natural frequencies of the nanomechanical sensor are derived using the transfer function method. The effects of the mass and position of the nanoparticle on the frequency shift are discussed. In the absence of the nonlocal effect, the frequencies are reduced to the results of the classical model, in agreement with those using the finite element method. The obtained results show that when the mass of the attached nanoparticle increases or its location is close to the beam center, the natural frequency decreases, but the shift in frequency increases. The effect of the nonlocal parameter on the frequency shift is significant. Decreasing the length-to-diameter ratio also increases the frequency shift. The natural frequencies and shifts are strongly affected by rotary inertia, and the nonlocal Timoshenko beam model is more adequate than the nonlocal Euler-Bernoulli beam model for short nanomechanical sensors. The obtained results are helpful in the design of SWCNT-based resonator as nanomechanical mass sensor. [ABSTRACT FROM AUTHOR]

Abstract: CuO/γ-Al2O3 was employed as catalyst in the coupling reaction of iodobenzene with m-cresol to give 3-methyldiphenyl ether under ligand-free conditions. It performed more efficiently than other supported CuO catalysts (CuO/SBA-15, CuO/ZrO2, CuO/CeO2, CuO/La2O3). Reaction conditions were investigated and the yield reached 76% under the optimized terms. As a heterogeneous catalyst, CuO/γ-Al2O3 could be reused for three cycles with moderate to good yields. According to the results of XRD, TPR and XPS, the catalytic activities of supported CuO catalysts were due to the highly dispersed Cu(II) species and independent of the electronic state of these copper species. [Copyright &y& Elsevier]

The aroma active compounds of three Tuber fruiting bodies (i.e., Tuber himalayense, Tuber indicum, and Tuber sinense) were firstly systematically evaluated by instrumental gas chromatography-olfactometry combining with quantitative analysis, aroma reconstitution, and omission tests. Twelve aroma active compounds were characterized by aroma extract dilution analysis, and 3-(methylthio) propanal, 3-methylbutanal, and 1-octen-3-ol with the highest flavor dilution (FD) factor (i.e., 1,024-2,048) were suggested as key contributors to the aroma. Odor activity value (OAV) was employed to determine the relative contribution of each compound to the aroma, and the compound with the highest FD factor also had the highest OAV (i.e., 10,234-242,951). Then, the synthetic blends of odorants (aroma reconstitution) were prepared with OAV larger than 15, and their aromas were very similar to the originals. Omission tests were carried out to verify the significance of 3-(methylthio) propanal, 1-octen-3-ol, and 3-methylbutanal as key compounds in the aroma of tested Tuber fruiting bodies. [ABSTRACT FROM AUTHOR]

Abstract: A series of Ce–La–O mixed oxide catalysts with different compositions have been prepared by sol–gel method and characterized by XRD, BET, Raman, TPR and CO2-TPD techniques. The activity of Ce–La–O catalysts for methane oxidation has been investigated. When the ratio of Ce/Ce+La is changed from 1.0 to 0.2, only cubic phase CeO2 with fluorite structure is observed, whose crystal size decreases significantly with the increase in La amount, due to the formation of LaCeO x solid solution. The peak at 533°C on TPR profiles of Ce–La–O with fluorite structure is ascribed to the reduction of non-stoichiometric CeO2−x . Raman bands around 570 and 1167cm−1 for samples with the Ce/Ce+La ratios of 1–0.2 might be assigned to oxygen vacancies and surface superoxide ions, respectively. The addition of La promotes the formation of non-stoichiometric CeO2−x , which is responsible for the oxygen vacancies and surface superoxide ions. However, when the ratio of Ce/Ce+La decreases to 0.2, ceria-in-lanthanum solid solutions are formed, where non-stoichiometric CeO2−x cannot be observed. The high activity of Ce–La–O mixed oxide catalyst for methane combustion is related to superoxide ions and surface reducibility. [ABSTRACT FROM AUTHOR]

A novel intumnescent flame melamine salt of dipentaerythriol phosphate (MDP), was prepared from dipentaerythritol (DPE) polyphosphoric acid, and melamine. The flammability, combustion behavior, and thermal degradation and stability of PP-MDP were characterized. When MDP loading was 20 wt%, LOI values of the composites reached up to 27%, and UL94 rating, V-2. PP-MDP containing 1 wt%; Cu-ZSM-5 presented the highest LOI value of 30.5%; and UL94 rating, V-0, and released lest heat during cone test. TG data showed that the thermal degradation of PP was improved by the addition of MDP. While the loading of ZSM-5 was 1 wt%; or higher, the main weight loss delayed with 50°C, and 80°C, compared with PP and PP-MDP respectively. The appropriate loading Cu-ZSM-5 made PP-MDP possess higher thermal oxidative stability. By SEM, the formation of a dense and thick char layer was observed on the char layer of PP-MDP-containing Cu-ZSM-5, responsible for high flame retardancy. So, the synergistic flame retardancy effects of MDP and Cu-ZSM-5 on PP existed. The mechanism of synergistic effect of Cu-ZSM-5 zeolite on flame retarded PP by MDP was discussed. [ABSTRACT FROM AUTHOR]

Abstract: During both the spring- and the neap-tide periods of November 2005, quasi-simultaneous observations were carried out by six boats over 26 h at 12 stations in the Changjiang (Yangtze River) plume. The simultaneous observations provided the actual distribution isopleths of salinity and nutrients that displayed considerable intra-tidal variations at surface, especially in the southeastern section of the study area. The lack of synopticity in sampling might lead to large discrepancies of the interpolated contours of salinity from the actual distribution isopleths. No clear flood-ebb asymmetry of salinity stratification was observed; whereas at inner stations, surface-to-bottom bulk velocity difference (current layering) always tended to be greater during the ebb fraction of a semidiurnal cycle. At a given station, the weaker neap tides commonly induced stronger salinity stratification, less intra-tidal variability of salinity and nutrients, and less intrusion of bottom saltwater. Nutrients (SiO3 2−, NO3 −, and PO4 3−) showed more nonconservative behaviors during the neap tides, presumably as a result of the prolonged residence time of seawater and decreased suspended particulate matter levels than during the spring tides. [Copyright &y& Elsevier]

Abstract: During four surveys at spring and neap tides in July and November 2005, continuous observations were conducted at four stations adjacent to the Changjiang (Yangtze River) mouth. The observation times lasted for 26h that covered two consecutive semidiurnal cycles. Resuspension events and subsequently enhancements of suspended particulate matter (SPM) were commonly observed within a tidal cycle. Although nutrients (SiO3 2−, NO3 −, and PO4 3−) were primarily governed by salinity, their statistically significant correlations with SPM could always be extracted after partial correlation analysis. Three parameter (salinity, SPM, nutrients) regressions generally produced better results of simulating nutrient concentrations than two parameter (salinity and nutrients) regressions, although compared to the latter, the former R 2 values were elevated by no more than 13%. The partial correlation between SPM and a specific nutrient could be either positive or negative in different surveys, suggesting SPM influenced the nutrients in different ways under various conditions. The minor (albeit statistically significant) impacts of highly dynamic SPM on nutrients might be ascribed to the short duration time of resuspension events and estuarine mixing process, together with the complex nature of circulation in the Changjiang plume seawater. [Copyright &y& Elsevier]

Abstract: Pt-loaded MCM-41 catalysts modified with phosphorus acids at various Si/P ratios were prepared. Phosphoric acid molecules may react with surface Si–OH groups, which prevented the direct attack of H2PtCl4 on mesostructure and improved the structural stability of Pt-loaded catalysts. Ammonia temperature-programmed desorption (NH3-TPD) indicated that P-MCM-41 samples possessed weak Brønsted acidities, and the Brønsted acidities on P-MCM-41 decreased with the incorporation of Pt, depending on the phosphoric acid loading. The interaction of Pt with phosphoric species resulted in the change of Pt oxidation state and the Brønsted acidity strength. The results of catalytic combustion of trichloroethylene over these catalysts showed that the modification with phosphoric acid endowed the catalysts with good catalytic performance of high trichloroethylene conversion and absence of tetrachloroethylene. The combination of Brønsted acidities and oxidation state Pt would propose a novel catalytic material suitable for the combustion of chlorinated volatile organic compounds. Carbon deposit over acid sites resulted in the deactivation of Pt/P-MCM-41 catalysts, and the deactivated catalysts were recovered at 500°C in air. [Copyright &y& Elsevier]

Abstract: During the spring tide period in November 2005, continuous observations were conducted over 25h (approximately two M 2 tidal cycles) at 12 stations within the Changjiang (Yangtze River) Estuary; and among them nine stations formed a closed rectangle. The observation items included current, salinity, suspended particulate matter (SPM), and nutrients. By establishing a simplified model, physical and chemical hydrography data were used to calculate the net and tidal-averaged budgets of seawater, salt, SPM, and nutrients in this rectangle. The results showed that the inflows and outflows of conservative seawater and salt, as well as SPM, matched well with deficits less than 10%; whereas the outputs of the five nutrient species were only 52%–86% of the respective inputs, suggesting the study area acted as a nutrient sink. Processes that might contribute to the nutrient budgets in the study area were discussed, including phytoplankton uptakes, exchanges at sediment-water interface, atmospheric depositions, nitrogen fixation, and denitrification. [Copyright &y& Elsevier]

Abstract: Pt-loaded P-MCM-41 catalysts with different Si/P ratio were prepared and used as novel bifunctional catalysts for catalytic combustion of trichloroethylene (TCE). Acidic materials, ZSM-5, P-SiO2 and Al2O3 as supports in Pt-loaded catalysts were also studied for comparison. The high activity for TCE conversion and low selectivity to tetrachloroethylene were observed on Pt/P-MCM-41 catalysts, indicating that phosphorus modified MCM-41 with an amount of weak Brønsted acid sites, in combination with Pt, was effective to form a bifunctional catalyst. [Copyright &y& Elsevier]

Caged bicyclic phosphate (CBP) and its dimelamine salt (PDS) were synthesized and added to epoxy resins to obtain the flame retarded epoxy resin composites. The flammability of the composites was characterized by the limiting oxygen index (LOI) and cone calorimeter tests. The LOI values of flame retarded composites increase consistently with the increase of flame retardant amounts, and they are almost the same when the loading of CBP is the same as that of PDS, although the phosphorus content of PDS is much lower than that of CBP. The total heat release increases in the order of CBP30/ER < PDS30/ER < PDS15/ER < CBP15/ER, whereas that of specific extinction area is CBP15/ER > CBP30/ER > PDS30/ER ≅ PDS15/ER. PDS exhibits more effective inhibition of oxidation of combustible gases. In the tests of thermogravimetric analyses (TG) and Fourier transform infrared spectroscopy (FT-IR), it is found that the degradation of the composites is influenced greatly by the addition of flame retardants. By scanning electron microscopy (SEM), a thick and tight char-layer is observed for PDS30/ER, resulting from the interaction of nitrogen species with phosphorus species. Therefore, the combination of CBP with melamine in the flame retarded system can improve the flame retardancy greatly. [ABSTRACT FROM AUTHOR]

Objective: AML1-ETO fusion protein is a product of chromosome translocation t(8;21) frequently occurred in acute myeloid leukemia (AML), but its sole expression appears to fail to cause overt leukemia in vivo. In this study, we investigated whether AML1-ETO expression impinged on action of chemical carcinogens-DNA adduct formation. Materials and Methods: AML1-ETO fusion protein was conditionally induced in engineered U937-A/E 9/14/18 cells. The formation of polycyclic aromatic hydrocarbon (PAH)-DNA adducts and the expression of PAH-metabolizing enzymes cytochrome P450 (CYP) 1A1 and arylhydrocarbon receptor (AhR) were detected by Western blot and/or quantitative RT-PCR. Luciferase reporter system was used to detect the regulation of AML1-ETO on CYP1A1 transcription. Results: Our results showed that AML1-ETO induction significantly increased the formation of carcinogen benzopyrene-DNA adducts in leukemic cells. In line with the effect, we also found that AML1-ETO induction upregulated CYP1A1 expression, which was dependent on AML1-binding motif in the promotor of CYP1A1 gene. Additionally, AML1-ETO protein also increased AhR expression, a ligand-activated transcription factor that mediates PAHs-induced CYP1A1 gene expression. Conclusion: These data, combined with its inhibitory effect on DNA repair as reported previously, propose that the presence of AML1-ETO increases the susceptibility of cells to chemical carcinogens, which favors the development of additional genetic alterations. [Copyright &y& Elsevier]

Abstract: Palladium-based catalysts were prepared by the impregnation (I) and ion-exchange method (E) with ZSM-5 and γ-Al2O3 as support respectively. The high activity of Pd/ZSM-5(I) and Pd-ZSM-5(E) catalysts for methane combustion was observed. The order of activity is consistent with Brønsted acidity of catalysts: Pd/ZSM-5(I)>Pd-ZSM-5(E)>Pd/Al2O3. It is shown by FT-IR that methane adsorbs on acidic bridging hydroxyl groups of ZSM-5-supported Pd catalysts. Symmetric v 1 C–H stretching vibrations of methane shift to low frequency due to the interaction between methane molecules and Brønsted acid sites or Pd2+, indicating that methane molecules can be activated. [Copyright &y& Elsevier]

The community composition of total bacteria and ammonia-oxidizing bacteria in a full-scale aerated submerged biofilm reactor for drinking water pretreatment was characterized by analysis of 16S rRNA gene and the functional gene amoA, respectively. Sampling was performed in February and in July. 16S rRNA gene clone libraries revealed 13 bacterial divisions. At both sampling dates, the majority of clone sequences were related to the Alpha- and Betaproteobacteria. A minor proportion belonged to the following groups: Gammaproteobacteria, Deltaproteobacteria, Nitrospira, Firmicutes, Acidobacteria, Verrucomicrobia, Actinobacteria, Planctomycetes, Chloroflexi, Gemmatimonadetes and the Cytophaga–Flavobacterium–Bacteroides group. Some sequences related to bacteria owning high potential metabolic capacities were detected in both samples, such as Rhodobacter-like rRNA gene sequences. Surveys of cloned amoA genes from the two biofilm samples revealed ammonia-oxidizing bacterial sequences affiliated with the Nitrosomonas oligotropha lineage, Nitrosomonas communis lineage. An unknown Nitrosomonas group of amoA gene sequences was also detected. [ABSTRACT FROM AUTHOR]

The rhodium(I)-species-catalyzed cycloisomerization reaction of a wide spectrum of 1 ,6-enynes with an unusual intramolecular halogen shift was investigated. This Rh-catalyzed enyne cyclization reaction represents a new process for the synthesis of stereodefined α-halomethylene-γ-butyrolactones, lactams, tetrahydrofurans, pyrrolidines, and cyclopentanes. Coordinatively unsaturated rhodium species ([Rh(COD)- Cl]2 + dppb + AgSbF6) only catalyzes the reaction with enyne substrates bearing a Z-form double bond, while neutral rhodium species (RhCl(PPh3)3) could catalyze enyne substrates bearing a Z- or E-form double bond to form the desired products and has a wider substrate scopes. The mechanism of the reaction was studied by the employment of control experiments with different enyne isomers, and a π-allyl rhodium intermediate was suggested to explain the formation of the cyclic products with an intramolecular halogen shift. [ABSTRACT FROM AUTHOR]

Rare earth elements (La, Nd, Sm, Gd and Dy) were characterized by NH3-TPD, Py-FTIR and CO-DRIFTS and tested for n-octane hydroconversion. The Bronsted acidity of modified catalysts increased as the rare earth ionic radius became longer. A similar relationship between metallic function and ionic radius was also observed. Among rare earth elements, lanthanum improved the nickel dispersion and then the ratio of metallic to acid functions. This led to the high catalytic activity and isomerization selectivity of Ni/HY catalyst. However, the catalysts modified by the other rare earth elements showed poor catalytic performance due to the reduction of Bronsted acidity and nickel dispersion, especially a lower ratio of metallic to acid functions. [Copyright &y& Elsevier]

• Physically-based modeling of cyclic softening damage is implemented. • Microstructural degradation of the material under cyclic loading can be captured. • The decrease of dislocation density can be quantitatively described. • The coarsening of martensitic lath width can be reasonably calculated. A unified viscoplastic constitutive model coupled with a physically-based damage variable, is proposed to capture the cyclic mechanical behavior and microstructural evolution of the material at elevated temperature. The mechanical strength can be reduced by the decrease in the dislocation density, the coarsening of the martensitic lath and the loss of the martensitic structure under cyclic loading. The proposed physically-based damage variable is driven by the evolutions of dislocation density and martensitic lath width. The good comparisons with test results mean that the proposed model can reasonably model the cyclic elastic-viscoplastic constitutive behavior of the material at high temperature. [ABSTRACT FROM AUTHOR]

We clarify the transient process and its mechanism of scanning electron microscope (SEM) images of a trench microstructure buried in insulators. First, interface charges of primary electrons trapped on the trench are derived from the charging model of a capacitor considering the electron beam induced current, and the surface potential is therefore assumed. The SEM signal current is then determined from its simplified relation with the surface potential. Calculated profiles of the secondary electron (SE) signal current and their time-evolution behaviors can well fit the transient of the experimental SEM images. Results show that the variation of the surface potential due to the transient interface charges and the effect of SE redistribution result in transients of the SEM imaging signal and the image width of the buried trench. [ABSTRACT FROM AUTHOR]

• Online fatigue-oxidation-creep damage evaluation is implemented. • Influence of temperature on the damage accumulation is considered. • Effect of non-proportional additional hardening on all damages is considered. • Changed oxidation damage is quantitatively calculated. A real-time multiaxial thermo-mechanical damage evaluation method was proposed under variable amplitude loading. In order to achieve real-time damage evaluation, a real-time multiaxial cycle counting method that can take into account temperature loading history was proposed. The proposed multiaxial cycle counting method can obtain the reversals one by one in order with the reading of the load-time history data, which can realize the damage calculation immediately as a single reversal is counted out. At the same time, to consider the effect of temperature loading on the damage accumulation, an equivalent temperature was determined for the time period of the counted reversal. A fatigue-oxidation-creep damage model that can consider the influence of the non-proportional additional hardening on the fatigue, oxidation and creep damages was used to predict the lives in cases of isothermal axial-torsional fatigue, uniaxial thermo-mechanical fatigue and axial-torsional thermo-mechanical fatigue under constant and variable amplitude loadings. The results showed that the prediction errors were within a factor of 2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Path-dependent line integral multiaxial cycle counting method was proposed. • The proposed method can be reduced to a uniaxial rain-flow counting form. • A recursive algorithm is provided to implement the proposed method. • The proposed method achieved excellent results in fatigue life prediction. A multiaxial cycle counting method was proposed by path-dependent line integral (PDLI). In the proposed PDLI multiaxial cycle counting method, the length increment of loading path is assigned a positive or negative sign in the strain space, and the interval from zero to the maximum value of PDLI is defined as a half-cycle. A very concise recursive algorithm is provided to implement the proposed multiaxial cycle counting method. The experimental verification showed that the proposed multiaxal cycle counting method was used to count multiaxial cycle, which can obtain satisfactory life prediction results under multiaxial variable amplitude loading. In addition, the PDLI multiaxial cycle counting method can be reduced to a uniaxial rainflow counting form. [ABSTRACT FROM AUTHOR]

A new creep–fatigue damage cumulative model is proposed under multiaxial thermomechanical random loading, in which the damage at high temperature can be divided into the pure fatigue damage and the equivalent fatigue damage from creep. During the damage accumulation process, the elementary percentage of the equivalent fatigue damage increment is proportional to that of the creep damage increment, and the creep damage is converted to the equivalent fatigue damage. Moreover, combined with a multiaxial cyclic counting method, a life prediction method is developed based on the proposed creep–fatigue damage cumulative model. In the developed life prediction method, the effects of nonproportional hardening on the fatigue and creep damages are considered, and the influence of mean stress on damage is also taken into account. The thermomechanical fatigue experimental data for thin‐walled tubular specimen of superalloy GH4169 under multiaxial constant amplitude and variable amplitude loadings were used to verify the proposed model. The results showed that the proposed method can obtain satisfactory life prediction results. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • One-pot sol–gel synthesis of La(III)-doped nanofibrous TiO 2 xerogel for Claus catalysts. • Decrease reaction temperature for Claus catalytic converter by 50 K and reduce the amount of catalyst by ca. 76%. • More macropores result in less fouling: less catalyst deactivation by condensation of sulfur in the mesopores. • Higher catalytic activity and higher thermal stability by doping La(III). • La(III) doping introduces more oxygen defects and Lewis-base sites. Abstract Not only do the natural gas and petroleum industries face the challenge of stringent sulfur compound emission limits, but it is also important to use new technologies to reduce the carbon footprint and improve energy efficiency. Herein this research is aimed at developing a new generation of catalysts that can potentially decrease the reaction temperature of Claus catalytic converters (used to convert sulfur compounds to elemental sulfur), and also reduce the amount of catalyst. There are two factors that affect the performance of the conventional Claus catalysts. First, the conventional metal oxide catalysts suffer from ageing, trapped liquid sulfur fouling in the mesopores and high steady-state concentration of surface sulfate, which reduce the number of active sites for CS 2 conversion. Therefore, the industry has to pay the price for a high reaction temperature to maintain a satisfactory CS 2 conversion, while sacrificing Claus conversion (2H 2 S + SO 2). Second, Al 2 O 3 and TiO 2 are widely used for Claus reactions; nevertheless, they are not active for conversion of CS 2 at lower temperatures. In this context, our approach in this research is using nanofibrous La(III)-doped TiO 2 as a new Claus catalyst. La(III) is incorporated into titanium-oxo-acetate complexes via a one-pot sol-gel process, followed by calcination to form a nanofibrous xerogel. Because the nanofibers join together to form a connected network, the xerogel monolith has large macroporosity and exhibits a low density. The exterior surface of the nanofibers, which makes a large contribution to the surface area, remains intact under harsh conditions and thereby is accessible by the reactants. In addition, the La(III) doped TiO 2 exhibits more Lewis-base activity that is effective for CS 2 conversion. For comparison, TiO 2 xerogels were deposited with La(III) by means of an impregnation method and also tested for Claus reaction activity; however, the catalytic performance of this material was reduced compared to the pure TiO 2 counterpart. On the basis of characterization studies on these catalysts, it is concluded that (i) a good distribution of La(III) in TiO 2 matrix and (ii) the method of La(III) incorporation are important for CS 2 conversion. [ABSTRACT FROM AUTHOR]

Background: Saponins from Rhizoma Panacis Majoris (SRPM) are confirmed to have cardioprotective effect against myocardial ischemia injury by reducing oxidative stress, while its underlying mechanism has not been elucidated until recently. Objective: The objective of this study was to investigate the SRPM's cardioprotection and elucidate its underlying mechanisms. Materials and Methods: Adult male rats were received SRPM treatment in the presence or the absence of the silent information regulator 1 (Sirt1) inhibitor Ex-527 or nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor ATRA for 14 days and subjected to myocardial ischemia for 0.5 h and then 2 h reperfusion. Cardiac function, infarct size, antioxidant enzyme activities, ROS level and the related mRNA and protein expressions of antiapoptosis protein Bcl-2, proapoptosis protein Bax, caspase-3, caspase-9, Sirt1 and Nrf2-relatived signaling pathways were assessed. Results: SRPM was confirmed to have cardioprotective effects by ameliorating cardiac function, decreasing infarct size, reducing serum creatine kinase (CK), creatine kinase isoenzyme, lactate dehydrogenase and ROS releases and malondialdehyde level, raising total antioxidant capacity, superoxide dismutase, glutathione peroxidase, catalase activities, upregulating myocardial Sirt1, Nrf2, Bcl-2 protein and manganese superoxide dismutase, heme oxygenase-1, NAD(P)H-quinone oxidoreductase 1 and γ-glutamylcysteine synthetase mRNA expressions and downregulating acetylated forkhead box O 1, acetylated peroxisome proliferator-activated receptor γ coactivator 1α, Bax, cleaved caspase-3 and cleaved caspase-9 protein expressions; histopathological observations provided supportive evidence for the aforementioned results. Interestedly, its protective effects were significantly blocked for its combination with Ex-527 or ATRA. Conclusion: The studies demonstrated that SRPM exerted beneficially protective effects on myocardial ischemia/reperfusion injury. It was possibly related to reducing oxidative stress damage by activations of Sirt1 and Nrf2-related antioxidant signaling pathways. Abbreviations used: Ac-FoxO1: Acetylated FoxO1, Ac-Pgc-1α: Acetylated Pgc-1α, ARE: Antioxidant-response element, CK: Creatine kinase, CK-MB: Creatine kinase isoenzyme, DEPPD: N, N-diethyl-paraphenylendiamine, ELSD: Evaporative light scattering detection, FoxO: Forkhead box O, GCLC: Glutamate-cysteine ligase catalytic subunit, GSH-Px: Glutathione peroxidase, HO-1: Heme oxygenase-1, H2O2: Hydrogen peroxide, Keap-1: Kelch-like ECH-associated protein 1, HPLC: High-performance liquid chromatography, LDH: Lactate dehydrogenase, MDA: Malondialdehyde, NAD+: Nicotinamide adenine dinucleotide, MnSOD: Manganese superoxide dismutase, NF-κB: Nuclear factor-kappa B, NQO1: Nicotinamide quinone oxidoreductase 1, NAD(P) H: NAD(P)H-quinone oxidoreductase 1, Nrf2: Nuclear factor erythroid 2-related factor 2, Pgc-1α: Peroxisome proliferator-activated receptor γ coactivator 1α, Sirt1: Silent information regulator 1, SOD: Superoxide dismutase, SRPM: Saponins from Rhizoma Panacis Majoris, I/R: Ischemia/reperfusion, T-AOC: Total antioxidant capacity, TTC: 2,3,5-triphenyltetrazolium chloride. [ABSTRACT FROM AUTHOR]

Fluorescence spectroscopy is frequently used to analyze the concentration of fluorescent materials in solution. However, in conventional fluorescence spectroscopy, the response between the fluorescence intensity and fluorophore concentration is nonlinear at high concentrations due to uncompensated inner-filter effects (IFE). Many methods to resolve this problem have been developed in recent decades. This review introduces the methods used to correct the IFE, including direct correction and parameter correction. Relevant detection parameters, including the materials, matrices, detection limits, detection instruments and relative standard deviations, are tabulated. The advantages and limitations of these correction techniques are also discussed. Finally, the methods used to correct for the IFE are summarized, and future research directions are discussed. [ABSTRACT FROM AUTHOR]

Pressure sensitive capacitance of laser-induced chemical vapor deposition processed nanosized silicon nitride has been studied. It is found that the capacitance varies linearly with the pressure and its sensitivity is as high as 2.64 pf/Torr. The capacitance pressure sensitivity results from the huge interfaces and microvoids existing in the nanomaterials. [ABSTRACT FROM AUTHOR]

In the previous studies, we have found that arsenic (As) accumulation in roots of bread wheat ( Triticum aestivum L.) seedlings were significantly different among different wheat cultivars, and As(V) tolerant wheat cultivars have much higher capacities of root As accumulation. However, the reason for the difference remains unclear. Four wheat cultivars with high (MM45 and FM8) or low (QF1 and HM29) levels of arsenic (As) accumulation were selected to investigate the relationship between root As(V) uptake kinetics and root As accumulation. MM45 and HM29 were also used to examine As(V) reduction ability and non-protein thiol (cysteine [Cys], glutathione [GSH], and phytochelatins [PCs]) concentrations in wheat seedlings. MM45 had the lowest Michaelis–Menten constant ( K m ) and maximum influx rate ( V max ). No difference in the K m values was found among the three other cultivars. No difference in As(V) reduction capacity was observed between MM45 and HM29. GSH and PC 2 were significantly induced by 10 μM As(V) in roots of wheat seedlings, particularly in MM45. Synthesis of GSH and PCs was completely suppressed in the presence of l -buthionine sulfoximine (BSO), a specific inhibitor of γ-glutamylcysteine synthetase. BSO markedly decreased the As tolerance of wheat seedlings and decreased the accumulation of As in roots, but increased As accumulation in shoots. No significant difference in As concentrations was found between MM45 and HM29 under the BSO treatment. GSH and PCs are the reason why As accumulation and As(V) tolerance differ in roots of different wheat cultivars. [ABSTRACT FROM AUTHOR]

Antagonistic storage potential of Tagetes minuta Linnaeus, Eupatorium fortunei Turcz. and Ocimum basilicum L. volatile oils hydrodistillated with main secondary metabolites against two storage pests, Tribolium castaneum and Lasioderma serricorne adults were evaluated. More than 95% volatile secondary metabolites obtained at different hydrodistillation time were identified by gas chromatography-mass spectrometry (GC-MS), and analyzed with principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Further insecticidal assay exhibited interesting results that T. minuta oil showed the strongest fumigant toxicity against both T. castaneum (LC 50 = 6.68 mg/L air) and L. serricorne (LC 50 = 3.13 mg/L air) among the three essential oils. As one of the main volatile secondary metabolites, methylthymol was found to possess more powerful fumigant (LC 50 = 2.42 mg/L air) and contact toxicity (LD 50 = 5.43 µg/adult) against T. castaneum. While, precocene I exhibited the strongest insecticidal toxicity on L. serricorne with the LC 50 value of 0.88 mg/L air and LD 50 of 3.46 µg/adult, respectively. During the repellent assay, T. minuta oil showed the same repellent rate against both T. castaneum and L. serricorne at the highest concentration of 78.63 nL/cm2. The results proved that the essential oils as well as the main volatile secondary metabolites have potential to be developed into novel natural botanical resources on antagonistic storage with traditional Chinese medicine (TCM). [Display omitted] • Essential oils and the major components showed effective anti-insect properties. • Volatile secondary metabolites were extracted at different hydrodistillation time. • GC-MS analysis of oils was followed by scientific PCA and OPLS-DA performance. • Volatile secondary metabolites have potential to be used on storage pests control. [ABSTRACT FROM AUTHOR]

Background: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Current therapies are insufficient, making HCC an intractable disease. Our previous studies confirmed that inhibition of protein phosphatase 2A (PP2A) may provide a promising therapeutic strategy for cancer. Unfortunately, constitutive expression of PP2A in normal tissues limits the application of PP2A inhibition. Thus, a HCC-specific gene delivery system should be developed. The α-fetoprotein (AFP) promoter is commonly used in HCC-specific gene therapy strategies; however, the utility of this approach is limited due to the weak activity of the AFP promoter. It has been shown that linking the AFP enhancer with the promoter of the non-tissue-specific, human housekeeping phosphoglycerate kinase (pgk) gene can generate a strong and HCC-selective promoter.Methods: We constructed a HCC-specific gene therapy system to target PP2A using the AFP enhancer/pgk promoter, and evaluated the efficiency and specificity of this system both in vitro and in vivo.Results: AFP enhancer/pgk promoter-driven expression of the dominant negative form of the PP2A catalytic subunit α (DN-PP2Acα) exerted cytotoxic effects against an AFP-positive human hepatoma cell lines (HepG2 and Hep3B), but did not affect AFP-negative human hepatoma cells (SK-HEP-1) or normal human liver cells (L-02). Moreover, AFP enhancer/pgk promoter driven expression of DN-PP2Acα inhibited the growth of AFP-positive HepG2 tumors in nude mice bearing solid tumor xenografts, but did not affect AFP-negative SK-HEP-1 tumors.Conclusions: The novel approach of AFP enhancer/pgk promoter-driven expression of DN-PP2Acα may provide a useful cancer gene therapy strategy to selectively target HCC. [ABSTRACT FROM AUTHOR]

• A multiaxial total life prediction method based on short crack growth is proposed. • The additional damage from non-proportional loading path is characterized. • Effect of shear stress on crack growth under tensile/compressive stress is considered. • The proposed method is verified by two materials under multiaxial loading. A total life prediction method based on short crack propagation considering additional damage from non-proportional loading is proposed under multiaxial fatigue loading. Firstly, a new calculation method of equivalent stress range is proposed to consider the effect of shear stress on crack propagation under tensile or compressive stress, then it is further modified to consider the additional damage. Combined with Paris formula and crack closure correction, a total life prediction method is proposed. The life results were used to verify the proposed method for two materials, which showed that most errors are within a factor of 3. [ABSTRACT FROM AUTHOR]

A new polygon positron emission mammography imaging system (PEMi) was developed in 2009 by the Institute of High Energy Physics, Chinese Academy of Sciences. PEMi is constructed in a polygon structure with lutetium yttrium orthosilicate crystal arrays mounted on a position-sensitive photomultiplier. The system consists of 64 blocks and each block is arranged in 16 \times 16 crystal arrays with a pixel size of 1.9~\times 1.9~ \times 15 mm. The diameter of the detector ring is 166 mm, and the axial length is 128 mm. The transaxial field of view of PEMi is 110 mm. The goal of the initial study was to test PEMi’s performance and the clinical imaging ability with a small group of selected subjects. The detectors have a measured intrinsic spatial resolution averaging 1.67 mm. The axial and tangential resolution remained under 2.5-mm full width at half maximum within the central 5-cm diameter of the field of view. The hot rods with a diameter of 1.7 mm can be clearly identified, and the structure of the region containing 1.35-mm diameter rods can also be observed. Using a 6-ns coincidence timing window and a \ 360 \sim \ 660-keV energy window, the peak sensitivity of the tomograph is 6.88%. The noise-equivalent count rate peak is 110\thinspace766 cps for a breast-like cylindrical phantom of 100 mm in diameter at an activity concentration of 0.03~\MBq/cc. The recovery coefficients ranged from 0.21 to 0.85 for rods between 1 mm and 5 mm in the image-quality phantom. The reconstructed image resolution achieved an improvement compared with whole-body positron emission tomography (PET), which might reduce the lower threshold on detectable lesion size. Example patient images demonstrate that PEMi is clinically feasible. And more detailed structure information was obtained with PEMi than with the whole-body PET imaging. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of composite adsorbents for rapid adsorption of gaseous iodine. • The adsorption capacity at 95 °C is 1.29 g g−1. • Adsorption rate increased by 2.3–10.1 times. • The dynamic maximum iodine adsorption capacity reached 1077 mg g−1. • Prediction of adsorption properties using the Levenberg-Marquardt neural network. In addressing the urgent challenge of mitigating gaseous iodine, a highly volatile and hazardous element in nuclear incidents, this study synthesized composite adsorbents with diverse C/Zn molar ratios using MOF and carbon powder. The saturated iodine adsorption at 75 °C exhibited the sequence: CZ-3 (1.15 g g−1) > CZ-2 (1.08 g g−1) > CZ-1 (0.93 g g−1) > C (0.79 g g−1), displaying 2.3–10.1 times increase in adsorption rate compared to carbon powder and Zn-MOF-2. At an elevated temperature of 95 °C, it achieved saturated adsorption of 1.29 g g−1(CZ-3). The adsorbed iodine primarily manifested in the forms of I 2 , I 3 -, and I 5 -. The dynamic maximum iodine adsorption capacity under specific conditions (75 °C, 300 ppm, 100 mL min−1, 0.5 MPa, 4 cm column length, and 6 mm diameter) reached 1077 mg g−1. Leveraging the Levenberg-Marquardt backpropagation neural network (LM-BPNN) algorithm, a superior fit was achieved. This research provides a theoretical foundation for the rapid and efficient treatment of gaseous iodine in nuclear scenarios. [ABSTRACT FROM AUTHOR]

Background: Cervical cancer is the fourth most common malignancy in women, which is threatening female reproductive tract health. Chemotherapy can be used for neoadjuvant therapy of locally advanced cervical cancer and postoperative adjuvant therapy for patients with high-risk factors, so as to reduce the focus, sensitize radiotherapy, and reduce recurrence. The current first-line treatment is paclitaxel combined with platinum. Many literature studies have found that As2O3 alone or in combination with platinum drugs have good efficacy in a variety of tumors both in vivo and in vitro. Moreover, our research group has verified that the efficacy of As2O3 combined with platinum drugs in the treatment of cervical cancer is not inferior to the traditional first-line regimen at the cellular and animal levels, and paclitaxel is more expensive than As2O3. Hence, we aim to evaluate the clinical efficacy and safety of neoadjuvant chemotherapy with As2O3 and carboplatin in locally advanced cervical cancer.Methods: Sixty participants in the IB2, IIA2, and IIB stages of cervical cancer will be recruited in this study. After excluding patients who did not meet the criteria, they were randomly assigned to two groups in a 1:1 ratio. All patients underwent colposcopic biopsies to confirm the diagnosis and detailed clinical examinations. Eligible patients will receive either 2 cycles of paclitaxel and carboplatin or As2O3 and carboplatin every 3 weeks. Patients were assessed for clinical efficacy after the second cycle of chemotherapy. Patients who had disease stable or disease progression at these time points will receive concurrent chemotherapy and radiation directly, while responders will receive PiverRutledge grade III radical hysterectomy and bilateral pelvic lymphadenectomy. Both groups of patients undergoing radical hysterectomy were given adjuvant therapy as per protocol-defined criteria. The efficacy and toxicity of the two groups were evaluated according to WHO acute and subacute toxicity classification standards.Discussion: This is the first single-center, prospective, two-arm design, open-label randomized control trial that will evaluate the clinical efficacy and safety of neoadjuvant chemotherapy with As2O3 and carboplatin in locally advanced cervical cancer.Trial Registration: ChineseClinicalTrialRegistry ChiCTR1900023822 . Registered on 13 June 2019. [ABSTRACT FROM AUTHOR]

This paper studies the vibrational behavior of nonuniform single-walled carbon nanotube (SWCNT) carrying a nanoparticle. A nonuniform cantilever beam with a concentrated mass at the free end is analyzed according to the nonlocal Timoshenko beam theory. A governing equation of a nonuniform SWCNT with attached mass is established. The transfer function method incorporating with the perturbation method is utilized to obtain the resonant frequencies of a vibrating nonlocal cantilever-mass system. The effects of the nonlocal parameter, taper ratio and attached mass on the natural frequencies and frequency shifts are discussed. Obtained results indicate that the sensitivity of the frequency shifts on the attached mass increases when the length-to-diameter ratio decreases. Tapered SWCNT possesses higher fundamental frequencies if the taper ratio becomes larger. [ABSTRACT FROM AUTHOR]