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• Traditional diffusion mechanism dominates at V F > 2 V. A lower effective band gap is derived, which attributed to a band fluctuation caused by dislocations. • At 1.35 V < V F < 2 V, a trap-assisted tunneling process becomes important, whose ideality factor is still larger than 4.1 at T = 400 K. • Two distinct power-law relationships were observed at lower biases, separated at V F = 0.8 V, whose exponents are extracted to be ∼8 and ∼4, respectively. Excessive forward leakage currents in GaN p-i-n diodes were investigated. Traditional diffusion mechanism dominates at V F > 2 V. The effective band gap is derived to be ∼2.21 eV, which is much lower than 3.4 eV and attributed to a band fluctuation caused by dislocations; At 1.35 V < V F < 2 V, a trap-assisted tunneling process becomes important, whose ideality factor is still larger than 4.1 at T = 400 K; Two distinct power-law relationships were observed at lower biases, separated at V F = 0.8 V, whose exponents are extracted to be ∼8 and ∼4, respectively. The behavior is in a good agreement with the space-charge-limited model, featuring an exponentially decaying distribution of trap states below the conduction band. [ABSTRACT FROM AUTHOR]

The purpose of this study was to synthesize DHPD polymers through the conjugation of doxorubicin (DOX) molecules onto poly(ethylene glycol) (PEG) chains via acylhydrazone bonds, and to fabricate pH-responsive DHPD nanoparticles (NPs) for investigation of their biosecurity and in vivo anti-tumor activity. The morphology, size distribution, stability, pH-responsiveness, biosecurity, and in vivo anti-tumor effects of the DHPD NPs were evaluated. Characterization of the DHPD polymers using 1H NMR, FTIR, and Raman spectra confirmed their successful synthesis. The DHPD NPs exhibited a round morphology with an average diameter of 144.4 ± 1.7 nm and a polydispersity index (PDI) of 0.23 ± 0.02. Biosecurity studies indicated that the DHPD NPs were non-toxic to treated mice, and in vitro cell tests demonstrated their ability to be taken up by 4T1 cells. Under the acidic microenvironment of 4T1 cells, the acylhydrazone bonds were cleaved, resulting in increased DOX delivery to tumor cells and improved in vivo anti-tumor effects. Animal experiments confirmed that the DHPD NPs reduced DOX toxicity while enhancing its anti-tumor activity. Furthermore, results from the analysis of γ-interferon (INF-γ), tumor necrosis factor-α (TNF-α), epidermal growth factor (EGF), and vascular endothelial growth factor (VEGF) indicated that the DHPD NPs improved the anti-4T1 tumor effect of DOX, suggesting their potential application in the treatment of breast cancer. [Display omitted] • The novel DHPD NPs with good pH-responsibility were first fabricated with a simple method. • The DHPD NPs decreased the toxicity of free DOX. • The DHPD NPs improved the anti-tumor effect of DOX in vitro and in vivo. [ABSTRACT FROM AUTHOR]

Lightweight crosslinked polyvinyl chloride (PVC) foam composites containing 20 wt% anhydrous calcium sulfate whiskers (CSW) were further modified with different weight ratios (5, 10, and 15 wt%) of recycled thermoplastic propenoic acid paint slag (PAPS). The effects of PAPS content were investigated regarding chemical structure, heat resistance, cellular structure, and selected properties, such as apparent density and specific compressive strength, of the resulting CSW/PVC foams. Results indicated that PAPS modified the interpenetrating polymer network (semi-IPN) by adjusting the relative ratios of cyano groups, urea, biuret, and amide linkages. The trend in the foams’ thermal properties showed an inflection point at 10 wt% PAPS content. In this case, compared with a CSW/PVC sample without PAPS, the PAPS foams exhibited increasing degradation temperature from 389.3 to 416.2 °C, with a 50% weight loss and glass transition temperature (T g ) increasing from 70.9 to 79.6 °C. Moreover, the use of PAPS produced small and homogeneous cellular structures, providing greater foam stiffness. Although PAPS addition resulted in foams of higher density, a 0.6–3.5-fold improvement in specific compressive strength, compared to foam without PAPS, was observed. [ABSTRACT FROM AUTHOR]

Abstract: It is known that the plasticity models affect characterization of the crack tip fields. To predict failure one has to understand the crack tip stress field and control the crack. In the present work the element-free Galerkin methods for gradient plasticity theories have been developed and implemented into the commercial finite element code ABAQUS and used to analyze crack tip fields. Based on the modified boundary layer formulation it is confirmed that the stress singularity in the gradient plasticity theories is significantly higher than the known HRR solution and seems numerically to equal to 0.78, independently of the strain-hardening exponent. The strain singularity is much lower than the known HRR one. The crack field in gradient plasticity under small-scale yielding condition consists of three zones: The elastic K-field, the plastic HRR-field dominated by the J-integral and the hyper-singular stress field. Even under gradient plasticity there exists an HRR-zone described by the known J-integral, whereas the hyper-singular zone cannot be characterized by J. The hyper-singular zone is very small (r ≪ J/σ 0) and contained by the HRR zone in the infinitesimal deformation framework. The finite strains under the gradient plasticity will not eliminate the stress singularity as r →0, in contrast to the known finite strain results under the Mises plasticity. Numerically no significant changes in characterization of the stress field were found in comparison with the infinitesimal deformation theory. Since the hyper-singular stress field is much smaller than the HRR zone and in the same size as the fracture process zone, one may still use the known J concept to control the crack in the gradient plasticities. In this sense the gradient plasticity will not change characterization of the crack. [Copyright &y& Elsevier]

Abstract: In using complex material models, especially the strain-gradient-dependent damage models, the convergence of the finite element computation increasingly becomes a problem. Due to large strains in damaging elements the computation may often result in non-convergence. For the higher-order gradient plasticity the special element formulation would often be necessary, which causes additional difficulties in implementation and computations. In recent years, meshless methods have been developed as an alternative to the finite element method (FEM) and can overcome some known shortcomings of FEM. In the present paper an algorithm of element-free Galerkin (EFG) methods for strain-gradient based nonlocal damage models has been developed and used to simulate ductile material damage. The method provides a reliable and robust results for material failure with large damage zones. The strain gradient-dependent terms can be evaluated from the direct differentiation. The investigation confirms that the nonlocal damage model with element-free Galerkin method is suitable for computing the damage problems and predicting the size effects. With the help of the meshless method, material failure in specimens as well as the size effects are predicted accurately. [ABSTRACT FROM AUTHOR]

In order to improve the waste heat recovery efficiency of high-temperature metallized pellets and save spraying cooling water, a waste heat recovery drum cooler with cooling water channel was creatively proposed for waste heat recovery. Due to the flow properties of two-component metallized pellets impact its heat transfer properties, the DEM (Discrete Element Method) and soft ball model were used to investigate the flow properties of two-component metallized pellets in the waste heat recovery drum cooler. By comparison with experimental data, the calculated values for the flow properties of two-component metallized pellets were in good agreement with the experimental values. The results show that the two-component metallized pellets are predominantly mixed and separated as they flow from top to bottom, with the large metallized pellets surrounding the small metallized pellets. The axial velocity and total velocity are significantly influenced by the dip angle and rotating velocity, and the filling rate has a substantial impact on the contact number. As the dip angle increases from 1° to 5°, the axial velocity and total velocity increase by 382.86 % and 333.33 %, respectively. With the rotating velocity from 1.2 r/min to 3.2 r/min, the axial velocity and total velocity increased by 175.00 % and 161.82 %, respectively. As the filling rate went from 1.5 % to 15 %, the contact number increased by 68.27 %. The axial velocity/total velocity of the two-component particles varies from 0.893 to 0.996 during the change of the dip angle, rotating velocity and filling rate. This shows that the axial velocity always makes up a large part of the total velocity. By efficiently organizing the movement of two-component metallized pellets, it is possible to increase the heat transfer efficiency, and it can also eliminate the pollution of cooling wastewater caused by the conventional spray rotary drum cooling method. [ABSTRACT FROM AUTHOR]

Abstract: Most porphyry Cu deposits in the world occur in magmatic arc settings and are formed in association with calc-alkaline arc magmas related to subduction of oceanic lithosphere. This contribution reviews a number of significant porphyry Cu deposits in the eastern Tethyan metallogenic domain. They widely occur in a variety of non-arc settings, varying from post (late)-collisional transpressional and extensional environments to intracontinental extensional environments related to orogenic and anorogenic processes. Their spatial–temporal localization is controlled by strike–slip faults, orogen-transverse normal faults, lineaments and their intersections in these non-arc settings. These deposits are dominated by porphyry Cu–Mo deposits with minor porphyry Cu–Au and epithermal Au deposits, and exhibit a broad similarity with those in magmatic arcs. The associated magmas are generally hydrous, relatively high fO2, high-K calc-alkaline and shoshonitic, and show geochemical affinity with adakites. They are distinguished from arc magmas and/or oceanic-slab derived adakites, by their occurrence as isolated complexes, high K2O contents (1.2–8.5%), and much wider range of εNd(t) values(−10 to +3) and positive εHf(t) values (+4.6 to +6.9). These potassic magmas are most likely formed by partial melting of thickened juvenile mafic lower-crust or delaminated lower crust, but also involving various amounts of asthenospheric mantle components. Key factors that generate hydrous fertile magmas are most likely crust/mantle interaction processes at the base of thickened lower-crust in non-arc settings, rather than oceanic-slab dehydration (as in arc settings). Breakdown of amphibole in thickened lower crust (e.g., amphibole eclogite and garnet amphibolite) during melting is considered to release fluids into the fertile magmas, leading to an elevated oxidation state and higher H2O content necessary for development of porphyry Cu–Mo–Au systems. Copper and Au in hydrous magmas are likely derived from mantle-derived components and/or melts, which either previously underplated and infiltrated at the base of the thickened lower crust, or were input into the primitive magmas by melt/mantle interaction. In contrast, Mo and (part of the) S in the fertile magmas are probably supplied by old crust during melting and subsequent ascent. [Copyright &y& Elsevier]

Representing the first line of host defense against virus infections and an essential link between innate and adaptive immune response, the role of dendritic cells (DCs) in peripheral blood of juvenile-onset recurrent respiratory papillomatosis (JORRP) patients and association with disease activity were still not established. In our present study, 28 JORRP patients and 28 age and sex matched healthy controls were enrolled. The percentage, phenotype and cytokine secretion of DC and was measured by flow cytometry. Plasma cytokine were detected by the enzyme-linked immunosorbent assay (ELISA). We found that the percentage of myeloid DC (mDC) was significantly lower in JORRP patients compared to healthy controls and was negatively correlated with interval times, but not surgical times or disease onset. Moreover, the activation marker, CD40 and CD86 was significantly up-regulated on the surfaces of mDC in JORRP patients compared with healthy controls. Neither the percentage nor activation of plasmacytoid DC (pDC) showed statistical difference between JORRP patients and healthy controls. HLA-DR expression on both mDC and pDC was down-regulated in JORRP group and negatively correlated with surgical times. Antigen presenting ability of DC was greatly impaired in JORRP patients of higher number of operations and shorter interval time. Plasma IL-10 as well as IL-10 secreted by mDC was higher in JORRP patients compared with healthy control. Finally, we detected an up-regulated TLR2 and TLR4 expression on mDCs and TLR4 expression was positively correlated with HLA-DR expression on mDC of JORRP patients. Our results demonstrate an abnormal TLR2 and TLR4 expression in mDCs may contribute to suppressive immune response to HPV6 or HPV11 infection and associated with disease activity in JORRP patients. [ABSTRACT FROM AUTHOR]

• The two magma chambers experienced chemically closed magmatic evolution. • The calcium needed for the scheelite mineralization may have been provided by the BG. • The highly evolved felsic magma chamber is critical to the formation of the giant Shimensi deposit. The Shimensi W–Cu–Mo deposit is one of the largest tungsten deposits in the world. Despite numerous geochemical studies conducted on ore-related granites in the district, few studies have concerned magma chambers processes. In this study, systematic in-situ major- and trace-element studies across plagioclase crystals from the ore-related Mesozoic granites as well as whole-rock Sr–Nd isotopic compositions of such granites in the Shimensi deposit were used to constrain the sources of calcium, the dynamics of the magmatic system and the metallogenic geodynamic setting. In-situ analyses of plagioclase showed no obvious positive correlations between An and FeO, while Sr was positively correlated with Ba, indicating that the magma chambers in the Shimensi deposit may have experienced chemically-closed evolution affected only by thermal mixing and/or decompression, without chemical mixing with mafic magma from the mantle. This conclusion was also supported by whole-rock Sr–Nd isotopic characteristics of high (87Sr/86Sr) i (0.71664–0.73689) and negative ε Nd (t) values (−9.81 to −5.07). It was found that the calcium needed for scheelite mineralization may have been predominantly provided by biotite granodiorite (BG) because of its high calcium content and large size, while ore-forming metals should mainly have been derived from the magma sources of pelites and basic volcanic rocks in the Shuangqiaoshan Group instead of the recharging of mafic magma. Moreover, change of the stress environment likely facilitated the formation of long-term stable, large-volume, highly evolved felsic magma chambers in the shallow crust, which would have been critical to the formation of the giant Shimensi W–Cu–Mo deposit. [ABSTRACT FROM AUTHOR]