64 research outputs found
Research on recycling channel selection of closed-loop supply chain considering consumer preference and fairness concern
This paper studied the influence of consumer preference and fairness concern on recycling and pricing decisions of closed-loop supply chain (CLSC) under different recycling channels. The results show that consumers' fairness concern cannot affect the manufacturer's decisions and profit; consumers' fairness concern is benefit to consumers, and it can improve the recycle rate. The channel selection strategy is depend on consumers' fairness attitude
Versatile gold-silver-PB nanojujubes for multi-modal detection and photo-responsive elimination against bacteria
Bacterial infections have become a serious threat to global public health. Nanomaterials have shown promise in the development of bacterial biosensing and antibiotic-free antibacterial modalities, but single-component materials are often less functional and difficult to achieve dual bacterial detection and killing. Herein, we report a novel strategy based on the effective integration of multi-modal bacterial detection and elimination, by constructing the versatile gold-silver-Prussian blue nanojujubes (GSP NJs) via a facile template etching method. Such incorporation of multi-components involves the utilization of cores of gold nanobipyramids with strong surface-enhanced Raman scattering (SERS) activity, the shells of Prussian blue as both an efficient bio-silent SERS label and an active peroxidase-mimic, and functionalization of polyvinyl pyrrolidone and vancomycin, respectively endowing them with good colloidal dispersibility and specificity against S. aureus. The GSP NJs show operational convenience in the SERS detection and excellent peroxidase-like activity for the sensitive colorimetric detection. Meanwhile, they exhibit robust near-infrared photothermal/photodynamic effects, and the photo-promoted Ag+ ions release, ultimately achieving a high antibacterial efficiency over 99.9% in 5Â min. The NJs can also effectively eliminate complex biofilms. The work provides new insights into the design of multifunctional core-shell nanostructures for the integrated bacterial detection and therapy
Metabolic Engineering to Improve Docosahexaenoic Acid Production in Marine Protist Aurantiochytrium sp. by Disrupting 2,4-Dienoyl-CoA Reductase
Docosahexaenoic acid (DHA) has attracted attention from researchers because of its pharmacological and nutritional importance. Currently, DHA production costs are high due to fermentation inefficiency; however, improving DHA yield by metabolic engineering in thraustochytrids is one approach to reduce these costs. In this study, a high-yielding (53.97% of total fatty acids) DHA production strain was constructed by disrupting polyunsaturated fatty acid beta-oxidation via knockout of the 2,4-dienyl-CoA reductase (DECR) gene (KO strain) in Aurantiochytrium sp. Slight differences in cell growth was observed in the wild-type and transformants (OE and KO), with cell concentrations in stationary of 2.65×106, 2.36×106 and 2.56×106 cells mL-1 respectively. Impressively, the KO strain yielded 21.62% more neutral lipids and 57.34% greater DHA production; moreover, the opposite was observed when overexpressing DECR (OE strain), with significant decreases of 30.49% and 64.61%, respectively. Furthermore, the KO strain showed a prolonged DHA production period with a sustainable increase from 63 to 90 h (170.03 to 203.27 mg g−1 DCW), while that of the wildtype strain decreased significantly from 150.58 to 140.10 mg g−1 DCW. This new approach provides an advanced proxy for the construction of sustainable DHA production strains for industrial purposes and deepens our understanding of the metabolic pathways of Aurantiochytrium sp
Defining Global Gene Expression Changes of the Hypothalamic-Pituitary-Gonadal Axis in Female sGnRH-Antisense Transgenic Common Carp (Cyprinus carpio)
BACKGROUND: The hypothalamic-pituitary-gonadal (HPG) axis is critical in the development and regulation of reproduction in fish. The inhibition of neuropeptide gonadotropin-releasing hormone (GnRH) expression may diminish or severely hamper gonadal development due to it being the key regulator of the axis, and then provide a model for the comprehensive study of the expression patterns of genes with respect to the fish reproductive system. METHODOLOGY/PRINCIPAL FINDINGS: In a previous study we injected 342 fertilized eggs from the common carp (Cyprinus carpio) with a gene construct that expressed antisense sGnRH. Four years later, we found a total of 38 transgenic fish with abnormal or missing gonads. From this group we selected the 12 sterile females with abnormal ovaries in which we combined suppression subtractive hybridization (SSH) and cDNA microarray analysis to define changes in gene expression of the HPG axis in the present study. As a result, nine, 28, and 212 genes were separately identified as being differentially expressed in hypothalamus, pituitary, and ovary, of which 87 genes were novel. The number of down- and up-regulated genes was five and four (hypothalamus), 16 and 12 (pituitary), 119 and 93 (ovary), respectively. Functional analyses showed that these genes involved in several biological processes, such as biosynthesis, organogenesis, metabolism pathways, immune systems, transport links, and apoptosis. Within these categories, significant genes for neuropeptides, gonadotropins, metabolic, oogenesis and inflammatory factors were identified. CONCLUSIONS/SIGNIFICANCE: This study indicated the progressive scaling-up effect of hypothalamic sGnRH antisense on the pituitary and ovary receptors of female carp and provided comprehensive data with respect to global changes in gene expression throughout the HPG signaling pathway, contributing towards improving our understanding of the molecular mechanisms and regulative pathways in the reproductive system of teleost fish
EZH2 Mediates miR-146a-5p/HIF-1α to Alleviate Inflammation and Glycolysis after Acute Spinal Cord Injury
Acute spinal cord injury (ASCI) is a severe traumatic disease of the central nervous system, the underlying mechanism of which is unclear. This study was intended to study the role of EZH2 and miR-146a-5p/HIF-1α in inflammation and glycolysis after ASCI, providing reference and basis for the clinical treatment and prognosis of ASCI injury. We used lipopolysaccharide (LPS) to induce inflammation of microglia, and we constructed the ASCI animal model. qRT-PCR detected the relative expression levels of EZH2, HIF-1α, miR-146a-5p, IL-6, TNF-α, IL-17, PKM2, GLUT1, and HK2 in cells and tissues. Western blot was performed to detect the expression levels of EZH2, HIF-1α, H3K27me3, IL-6, TNF-α, IL-17, PKM2, GLUT1, and HK2. ChIP verified the enrichment of H3K27me3 in the miR-146a-5p promoter region. Bioinformatics predicted the binding sites of HIF-1α and miR-146a-5p, and dual-luciferase reporter assay verified the binding of HIF-1α and miR-146a-5p. ELISA detects the levels of inflammatory factors IL-6, TNF-α, and IL-17 in the cerebrospinal fluid of rats. The GC-TOFMS was used to detect the changes of glycolytic metabolites in the cerebrospinal fluid of rats. EZH2 could mediate inflammation and glycolysis of microglia. EZH2 regulates inflammation and glycolysis through HIF-1α. EZH2 indirectly regulated the HIF-1α expression by mediating miR-146a-5p. EZH2 mediates miR-146a-5p/HIF-1α to alleviate inflammation and glycolysis in ASCI rats. In the present study, our results demonstrated that EZH2 could mediate miR-146a-5p/HIF-1α to alleviate the inflammation and glycolysis after ASCI. Therefore, EZH2/miR-146a-5p/HIF-1α might be a novel potential target for treating ASCI
Research on recycling channel selection of closed-loop supply chain considering consumer preference and fairness concern
This paper studied the influence of consumer preference and fairness concern on recycling and pricing decisions of closed-loop supply chain (CLSC) under different recycling channels. The results show that consumers' fairness concern cannot affect the manufacturer's decisions and profit; consumers' fairness concern is benefit to consumers, and it can improve the recycle rate. The channel selection strategy is depend on consumers' fairness attitude
BIO-MODIFICATION OF EUCALYPTUS CHEMITHERMO- MECHANICAL PULP WITH DIFFERENT WHITE-ROT FUNGI
Modification of chemithermomechanical pulp (CTMP) by fungal treatment was investigated. Eucalyptus CTMP was treated with three different types of white-rot fungi, namely, Phanerochaete chrysosporium (P.c-1767), Trametes hirsute 19-6 (T.h-19-6), and Trametes hirsute19-6w (T.h-19-6w), under a stationary culture condition. Pulp total weight loss, lignin loss, and cellulose loss were determined to compare the different enzymes secreted by the three fungal strains. Pulp physical strengths, optical properties, and bleachability after the fungal treatment were investigated to compare the effect of fungal treatment on the pulp quality improvement. The results show that lignin reduction by both T.h-19-6 and T.h-19-6 (w) was about twice as much as that by P.c-1767. However, the selectivity of T.h-19-6 (w) towards lignin over cellulose was only 0.82, while that of T.h-19-6 was as high as 4.43. After T.h-19-6 treatment, pulp tensile, tear, and internal bonding strength increased by about 27%, 38%, and 40%, respectively
Anti-Disturbance Finite-Time Adaptive Sliding Mode Backstepping Control for PV Inverter in Master–Slave-Organized Islanded Microgrid
With the aim to solve the problem related to the power chattering and anti-disturbance performance of a photovoltaic (PV) inverter in master–slave-organized islanded microgrid, an anti-disturbance finite-time adaptive sliding mode backstepping (DFA-SMB) controller is designed in this paper. First, the topology and the second-order dynamic model of PV inverter are established based on constant DC voltage and constant reactive power control method. Subsequently, the backstepping method is adopted to perform the control of a high-order system. Moreover, a second-order sliding mode differentiator is used to realize the function of command-filter, solving the differential expansion problem caused by the derivation of virtual controller. Besides, the terminal sliding mode control (TSMC) is introduced into the q-axis controller and d-axis inner loop controller, increasing the robustness and reducing the convergence time of the system. Adaptive control and disturbance-observer (DO) are used to perform the adaptive estimation of model parameters and the observation of lumped disturbances, respectively, enhancing the dynamic characteristics of the controller. Finally, a master–slave-organized islanded microgrid with 100 kW PV array is established in MATLAB/Simulink. The results demonstrate that the proposed control method can effectively reduce power chattering and improve the anti-disturbance ability of the PV system
Enhanced Electrochemical Characteristics of the Glucose Oxidase Bioelectrode Constructed by Carboxyl-Functionalized Mesoporous Carbon
This research revealed the effect of carboxyl-functionalization on the mesoporous carbon (MC)-fixed glucose oxidase (GOx) for promoting the properties of bioelectrodes. It showed that the oxidation time, temperature and concentration, can significantly affect MC carboxylation. The condition of 2 M ammonium persulfate, 50 °C and 24 h was applied in the study for the successful addition of carboxyl groups to MC, analyzed by FTIR. The nitrogen adsorption isotherms, and X-ray diffraction analysis showed that the carboxylation process slightly changed the physical properties of MC and that the specific surface area and pore size were all well-maintained in MC-COOH. Electrochemical characteristics analysis showed that Nafion/GOx/MC-COOH presented better electrocatalytic activity with greater peak current intensity (1.13-fold of oxidation peak current and 4.98-fold of reduction peak current) compared to Nafion/GOx/MC. Anodic charge-transfer coefficients (α) of GOx/MC-COOH increased to 0.77, implying the favored anodic reaction. Furthermore, the GOx immobilization and enzyme activity in MC-COOH increased 140.72% and 252.74%, leading to the enhanced electroactive GOx surface coverage of Nafion/GOx/MC-COOH electrode (22.92% higher, 1.29 × 10−8 mol cm−2) than the control electrode. Results showed that carboxyl functionalization could increase the amount and activity of immobilized GOx, thereby improving the electrode properties
- …