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We first describe a photoinduced decatungstate-catalyzed direct coupling of cycloalkanes and cyclic aldimines. The desired products were generated in moderate to good yields with wide substrate scope under mild reaction conditions. The mechanistic study revealed a radical process. In addition, the usefulness of the reaction in organic synthesis was proved by the scale-up synthesis as well as the late-stage modification of drug-like molecules. [ABSTRACT FROM AUTHOR]

We consider the computations of the action ground state for a rotating nonlinear Schr\"odinger equation. It reads as a minimization of the action functional under the Nehari constraint. In the focusing case, we identify an equivalent formulation of the problem which simplifies the constraint. Based on it, we propose a normalized gradient flow method with asymptotic Lagrange multiplier and establish the energy-decaying property. Popular optimization methods are also applied to gain more efficiency. In the defocusing case, we prove that the ground state can be obtained by the unconstrained minimization. Then the direct gradient flow method and unconstrained optimization methods are applied. Numerical experiments show the convergence and accuracy of the proposed methods in both cases, and comparisons on the efficiency are discussed. Finally, the relation between the action and the energy ground states is numerically investigated. [ABSTRACT FROM AUTHOR]

Cold chain logistics is a common way of fresh-keeping transportation at present, but in the actual transportation and storage process, temperature control is often not accurate, which leads to shortened shelf life. We evaluated the changes in the quality of yellow croaker (Pseudosciaena crocea) at different temperatures during transportation. Specimens of P. crocea were immersed in slurry ice for 20 min and stored at 22, 4, or −1°C for 4 days. During this period, the development of rancidity of P. crocea was measured by sensory (odor, skin, color, and flesh appearance) and biochemical (total number of colonies, total volatile basic nitrogen, and K value) analyses. A combination of sensory and biochemical parameters and the Arrhenius equation were used to predict the shelf life of P. crocea during storage. After verification under different storage temperatures, the relative error between the predicted and the measured values was found to be within 15%. The present work provides theoretical guidance for the quality control of P. crocea during transportation and storage. [ABSTRACT FROM AUTHOR]

The blood clam, Tegillarca granosa, is a benthic filter feeder with a strong capacity to accumulate and tolerate cadmium (Cd). In our previous study, DPEP1 was shown to be significantly up-regulated under Cd stress based on proteomic analysis. To investigate whether DPEP1 is involved in Cd-induced response, the function of DPEP1 in T. granosa was investigated by integrated molecular and protein approaches. Rapid amplification cDNA end (RACE) assay was established to achieve the complete cDNA sequence of DPEP1 from T. granosa. The full-length cDNA of DPEP1 was 1811 bp, and it contained a 1359-bp open reading frame (ORF), including a 22-amino acid signal peptide. qRT-PCR analysis revealed that DPEP1 was expressed in all examined tissues with the highest expression in gills. At the same time, we investigated DPEP1 gene expression changes after Cd stress at different time points over 96 h. We found that the expression of DPEP1 increased upon initial Cd stress, then it was inhibited, and finally, it was maintained at a low level. Moreover, recombinant DPEP1 showed that higher glutathione (GSH) hydrolysis activity in the temperature range of 30-40°C, and its maximum activity was at pH = 6. Additionally, the results of immunohistochemistry also confirmed that DPEP1 protein was expressed in all test tissues with the highest expression in gills. In addition, there was a positive correlation between QRT-PCR and immunohistochemistry. These results suggested that DPEP1 is probably involved in Cd-induced response by balancing GSH. [ABSTRACT FROM AUTHOR]

We rigorously analyze the error estimates of the conservative finite difference method (CNFD) for the Zakharov system (ZS) with a dimensionless parameter ε ∈ (0, 1], which is inversely proportional to the ion acoustic speed. When ε → 0+, ZS collapses to the standard nonlinear Schr¨odinger equation (NLS). In the subsonic limit regime, i.e., ε → 0+, there exist highly oscillatory initial layers in the solution. The initial layers propagate with O(ε) wavelength in time, O(1) and O(ε2) amplitudes, for the ill-prepared initial data and well-prepared initial data, respectively. This oscillatory behavior brings significant difficulties in analyzing the errors of numerical methods for solving the Zakharov system. In this work, we show the CNFD possesses the error bounds h2/ε+τ2/ε3 in the energy norm for the ill-prepared initial data, where h is mesh size and τ is time step. For the well-prepared initial data, CNFD is uniformly convergent for ε ∈ (0, 1], with second-order accuracy in space and O(τ4/3) accuracy in time. The main tools involved in the analysis include cut-off technique, energy methods, ε-dependent error estimates of the ZS, and ε-dependent error bounds between the numerical approximate solution of the ZS and the solution of the limit NLS. Our approach works in one, two and three dimensions, and can be easily extended to the generalized Zakharov system and nonconservative schemes. Numerical results suggest that the error bounds are sharp for the plasma densities and the error bounds of the CNFD for the electric fields are the same as those of the splitting methods. [ABSTRACT FROM AUTHOR]

Recent studies have shown that activation of liver X receptors (LXRs) attenuates the development of atherosclerosis, not only by regulating lipid metabolism but also by suppressing inflammatory signaling. Sphingosine 1-phosphate receptor 2 (S1PR2), an important inflammatory gene product, plays a role in the development of various inflammatory diseases. It was proposed that S1PR2 might be regulated by LXR-α. In the present study, the effect of LXR-α on tumor necrosis factor-α (TNF-α)-induced S1PR2 expression in human umbilical vein endothelial cells (HUVECs) was investigated and the underlying mechanism was explored. The results demonstrated that TNF-α led to an increase in S1PR2 expression and triggered a downregulation of LXR-α expression in HUVECs as well. Downregulation of LXR-α with specific small interfering RNA (siRNA) remarkably enhanced the primary as well as TNF-α-induced expression of S1PR2 in HUVECs. Activation of LXR-α by agonist GW3965 inhibited both primary and TNF-α-induced S1PR2 expression. GW3965 also attenuated S1PR2-induced endothelial barrier dysfunction. The data further showed that TNF-α induced a significant decrease in miR-130a-3p expression. Overexpression of miR-130a-3p with mimic product reduced S1PR2 protein expression, and inhibition of miR-130a-3p by specific inhibitor resulted in an increase in S1PR2 protein expression. Furthermore, activation of LXRs with agonist enhanced the expression of miR-130a-3p, and knockdown of LXR-α by siRNA suppressed miR-130a-3p expression. These results suggest that LXR-α might downregulate S1PR2 expression via miR-130a-3p in quiescent HUVECs. Stimulation of TNF-α attenuates the activity of LXR-α and results in enhanced S1PR2 expression. [ABSTRACT FROM AUTHOR]

Background Traumatic brain injury (TBI) and hemorrhagic shock (HS) are the leading causes of death in trauma. Recent studies suggest that TBI may influence physiological responses to acute blood loss. This study was designed to assess to what extent superimposed TBI may modulate physiologic vasomotor responses in third-order blood vessels in the context of HS. Methods We have combined two established experimental models of pressure-controlled hemorrhagic shock (HS; MAP 50 mmHg/60 min) and TBI (lateral fluid percussion (LFP)) to assess vasomotor responses and microcirculatory changes in third-order vessels by intravital microscopy in a spinotrapezius muscle preparation. 23 male Sprague-Dawley rats (260-320 g) were randomly assigned to experimental groups: i) Sham, ii) HS, iii) TBI + HS, subjected to impact or sham operation, and assessed. Results HS led to a significant decrease in arteriolar diameters by 20% to baseline (p < 0.01). In TBI + HS this vasoconstriction was less pronounced (5%, non-significant). At completed and at 60 minutes of resuscitation arteriolar diameters had recovered to pre-injury baseline values. Assessment of venular diameters revealed similar results. Arteriolar and venular RBC velocity and blood flow decreased sharply to < 20% of baseline in HS and TBI + HS (p < 0.01). Immediately after and at 60 minutes of resuscitation, an overshoot in arterial RBC velocity (140% of baseline) and blood flow (134.2%) was observed in TBI + HS. Conclusion Superimposed TBI modulated arteriolar and venular responses to HS in third-order vessels in a spinotrapezius muscle preparation. Further research is necessary to precisely define the role of TBI on the microcirculation in tissues vulnerable to HS. [ABSTRACT FROM AUTHOR]

Monascus pigments, which are produced by various species of Monascus, often have been used as a natural colourant and as traditional natural food additives, especially in Southern China, Japan and Southeastern Asia. The limitation of wide using Monascus pigment is attributed to one of its secondary metabolites named citrinin. The aim of this study was to investigate the influence of pigment and citrinin production via submerged fermentation (SmF) and solid-state fermentation (SF) from rice (Oryza sativa L.) by Monascus purpureus AS3.531. The optimal fermentation temperature and pH were significantly different for pigment production through different fermentation mode (35 °C, pH 5.0 for SF and 32 °C, pH 5.5 for SmF, respectively). Adding 2% (w/v) of glycerol in the medium could enhance the pigment production. On the optimized condition, although the concentration of citrinin produced by SmF (19.02 ug/g) increased more than 100 times than that by SF (0.018 ug/g), the pigment yield by SmF (7.93 U/g/g) could be comparable to that by SF (6.63 U/gig). Those indicate us that fermentation mode seems to be the primary factor which influence the citrinin yield and secondary factor for pigment production. [ABSTRACT FROM AUTHOR]

In this paper, in order to numerically solve for multiple positive solutions to a singularly perturbed Neumann boundary value problem in mathematical biology and other applications, a local minimax method is modified with new local mesh refinement and other strategies. Algorithm convergence and other related properties are verified. Motivated by the numerical algorithm and convinced by the numerical results, a Morse index approach is used to identify the Morse index of the root solution u¹ε = 1 at any perturbation value, its bifurcation points, and then the critical perturbation value. Many interesting numerical solutions are computed for the first time and displayed with their contours and mesh profiles to illustrate the theory and method. [ABSTRACT FROM AUTHOR]

Response surface methodology (RSM) was used to optimize a protective medium for enhancing the cell viability of Lactobacillus delbrueckii subsp. bulgaricus LB14 during freeze-drying. Using a previous Plackett–Burman design, it was found that sucrose, glycerol, sorbitol and skim milk were the most effective freeze-drying protective agents for L. bulgaricus LB14. A full factorial central composite design was applied to determine the optimum levels of these four protective agents. The experimental data allowed the development of an empirical model ( P<0.0001) describing the inter-relationships between the independent and dependent variables. By solving the regression equation, and analyzing the response surface contour and surface plots, the optimal concentrations of the agents were determined as: sucrose 66.40 g/L, glycerol 101.20 g/L, sorbitol 113.00 g/L, and skim milk 130.00 g/L. L. bulgaricus LB14 freeze-dried in this medium obtained a cell viability of up to 86.53%. [ABSTRACT FROM AUTHOR]

Recently, semiconducting chalcogenide nanostructures have attracted intense attention due to their excellent properties and broad applications, especially metal chalcogenides in the form of A2(V)B3(VI). Here we synthesized one-dimensional (1D) bismuth sulfide (Bi2S3) nanostructures with a length of more than 100 μm via a one-step hydrothermal method, and found that the reaction temperature and the alkali concentration play vital roles in the morphology of the 1D nanostructures. Since the as-synthesized Bi2S3 nanostructures were disordered in powder form, it is necessary to align them with ordered orientation and uniform distribution before further application. A blown bubble method was specifically applied to align these ultralong 1D nanostructures, and the assembly mechanism was also deeply analyzed, including the drift of nanostructures in the bubble film thickness direction, the relationship between (nanowire) NW spacing and array density, and the angle deviation of aligned arrays assembled from different bubble solutions. Interestingly, the initial straight Bi2S3 NWs could also be converted into buckled nanosprings (NSs) with regular pitches during the assembly process, and different NS formation stages were observed. A possible deformation mechanism or load bearing model of the wavy NS was proposed and verified, and the Young’s modulus of an individual NW was figured out for the first time. After annealing under a N2 atmosphere, the aligned Bi2S3 NWs embedded in the bubble film were exposed, and the clean arrays were fabricated into functional optoelectronic devices such as photodetectors with a high performance. [ABSTRACT FROM AUTHOR]