Research Progress in Techniques for Postharvest Preservation of Green Sweet Peppers

Green sweat peppers are rich in nutrients and diverse in shape and color. Apart from being eaten as a vegetable, it is widely used as seasoning and side dishes. Due to respiration and infection by harmful microorganisms, postharvest green peppers are prone to water loss, wilting and even rot. Appropriate preservation technology can maximize the preservation of nutrients and extend the storage period of green peppers. This paper introduces the techniques used for postharvest preservation of green sweet peppers: physical preservation methods such as refrigeration and packaging, biological preservatives such as microbial, plant and animal extracts, and chemical preservatives such as calcium agents and 1-methylcyclopropene (1-MCP), and compares the advantages and disadvantages of these preservation techniques. It elaborates the effect of chitosan or konjac glucomannan-based composite coatings on preserving the quality of green sweet peppers. Our intention is to provide a reference and guidance for the storage and preservation of postharvest green peppers

Targeted inhibition of Wnt signaling with a Clostridioides difficile toxin B fragment suppresses breast cancer tumor growth

Wnt signaling pathways are transmitted via 10 homologous frizzled receptors (FZD1-10) in humans. Reagents broadly inhibiting Wnt signaling pathways reduce growth and metastasis of many tumors, but their therapeutic development has been hampered by the side effect. Inhibitors targeting specific Wnt-FZD pair(s) enriched in cancer cells may reduce side effect, but the therapeutic effect of narrow-spectrum Wnt-FZD inhibitors remains to be established in vivo. Here, we developed a fragment of C. difficile toxin B (TcdBFBD), which recognizes and inhibits a subclass of FZDs, FZD1/2/7, and examined whether targeting this FZD subgroup may offer therapeutic benefits for treating breast cancer models in mice. Utilizing 2 basal-like and 1 luminal-like breast cancer models, we found that TcdBFBD reduces tumor-initiating cells and attenuates growth of basal-like mammary tumor organoids and xenografted tumors, without damaging Wnt-sensitive tissues such as bones in vivo. Furthermore, FZD1/2/7–positive cells are enriched in chemotherapy-resistant cells in both basal-like and luminal mammary tumors treated with cisplatin, and TcdBFBD synergizes strongly with cisplatin in inhibiting both tumor types. These data demonstrate the therapeutic value of narrow-spectrum Wnt signaling inhibitor in treating breast cancers

Gaining New Insights into Fundamental Biological Pathways by Bacterial Toxin-Based Genetic Screens

Genetic screen technology has been applied to study the mechanism of action of bacterial toxins—a special class of virulence factors that contribute to the pathogenesis caused by bacterial infections. These screens aim to identify host factors that directly or indirectly facilitate toxin intoxication. Additionally, specific properties of certain toxins, such as membrane interaction, retrograde trafficking, and carbohydrate binding, provide robust probes to comprehensively investigate the lipid biosynthesis, membrane vesicle transport, and glycosylation pathways, respectively. This review specifically focuses on recent representative toxin-based genetic screens that have identified new players involved in and provided new insights into fundamental biological pathways, such as glycosphingolipid biosynthesis, protein glycosylation, and membrane vesicle trafficking pathways. Functionally characterizing these newly identified factors not only expands our current understanding of toxin biology but also enables a deeper comprehension of fundamental biological questions. Consequently, it stimulates the development of new therapeutic approaches targeting both bacterial infectious diseases and genetic disorders with defects in these factors and pathways

Crystalline WO₃ nanowires synthesized by templating method

A new method is developed to obtain crystalline nanowires of WO3 using mesoporous silica SBA-15 as template. The method includes aminosilylation of the surface silanols within SBA-15 channels, anchoring of the heteropoly acid (HPA) to the grafted amine groups, thermal decomposition of the HPA, and removal of the silica framework with HF. The formation of the crystalline nanowires is monitored by the in situ XRD technique. TEM images intuitively confirm that the nanowires are uniform in diameter and HRTEM images further indicate that each nanowire belongs to single crystal although the growth orientations of these nanowires are different. (C) 2003 Elsevier B.V. All rights reserved.</p

Crystalline WO₃ nanowires synthesized by templating method

A new method is developed to obtain crystalline nanowires of WO3 using mesoporous silica SBA-15 as template. The method includes aminosilylation of the surface silanols within SBA-15 channels, anchoring of the heteropoly acid (HPA) to the grafted amine groups, thermal decomposition of the HPA, and removal of the silica framework with HF. The formation of the crystalline nanowires is monitored by the in situ XRD technique. TEM images intuitively confirm that the nanowires are uniform in diameter and HRTEM images further indicate that each nanowire belongs to single crystal although the growth orientations of these nanowires are different. (C) 2003 Elsevier B.V. All rights reserved.</p

Highly efficient catalysts for the hydrogenation of nitro-substituted aromatics

Nanoparticles of Co and NiPd, derived from colloidal precursors and supported on commercially available nonordered mesoporous silica, are highly effective, cheap, recyclable and industrially viable catalysts for the hydrogenation of a range of nitro-substituted aromatics under mild conditions.</p

Autoantibodies Targeting AT1 Receptor from Patients with Acute Coronary Syndrome Upregulate Proinflammatory Cytokines Expression in Endothelial Cells Involving NF-κB Pathway

Our study intended to prove whether agonistic autoantibodies to angiotensin II type 1 receptor (AT1-AAs) exist in patients with coronary heart disease (CHD) and affect the human endothelial cell (HEC) by upregulating proinflammatory cytokines expression involved in NF-κB pathway. Antibodies were determined by chronotropic responses of cultured neonatal rat cardiomyocytes coupled with receptor-specific antagonists (valsartan and AT1-EC2) as described previously. Interleukin-6 (IL-6), vascular cell adhesion molecule-1 (VCAM-1), and monocyte chemotactic protein-1 (MCP-1) expression were improved at both mRNA and protein levels in HEC, while NF-κB in the DNA level was improved detected by electrophoretic mobility shift assays (EMSA). These improvements could be inhibited by specific AT1 receptor blocker valsartan, NF-κB blocker pyrrolidine dithiocarbamate (PDTC), and specific short peptides from the second extracellular loop of AT1 receptor. These results suggested that AT1-AAs, via the AT1 receptor, induce expression of proinflammatory cytokines involved in the activation of NF-κB. AT1-AAs may play a great role in the pathogenesis of the acute coronary syndrome by mediating vascular inflammatory effects involved in the NF-κB pathway

Ordered, highly zeolitized mesoporous aluminosilicates produced by a gradient acidic assembly growth strategy in a mixed template system

Tremendous efforts have been made in recent years to synthesize ordered mesoporous zeolite materials, because of the accelerating demands of industrial bulky molecule conversion. Here, we develop a novel gradient acidic assembly growth strategy to prepare ordered highly zeolitized mesoporous aluminosilicate (SBA-16) materials in a mixed template system. This gradient acidic assembly growth strategy can achieve the high zeolitization of mesoporous aluminosilicate walls without any ordering loss of the mesostructure. The resultant highly zeolitized mesoporous materials, composed of the intergrown zeolite subcrystal particles (2-3 nm), exhibit high surface area (?834 m2 g-1) and pore volume (?0.64 cm3 g-1), typical channel of MFI framework (0.52 nm), and uniform mesopore (?5.75 nm), respectively. Moreover, these highly ordered crystallized mesostructures endow them with high exposed active sites and excellent hydrothermal stability, which consequently make their catalytic activities in bulky molecule transformations at least 10 times higher than conventional zeolites or amorphous mesoporous materials. Without the use of any special surfactants, this general synthetic process provides a brand new view for the synthesis and application of highly crystalline ordered mesoporous materials. 2016 American Chemical Society.This work was supported by the 973 Program (No. 2013CB934101), NSFC (Nos. U1463206, 21473037, 21433002, and 21573046), and National Plan for Science, Technology and Innovation (MAARIFAH), King Abdulaziz City for Science and Technology, Kingdom of Saudi Arabia (No. 14-PET827-02), and Sinopec (No. X514005).Scopu