Weak Catalytic Activity Research Articles

Arabidopsis lysin motif/F-box-containing protein InLYP1 fine-tunes glycine metabolism by degrading glycine decarboxylase GLDP2.

Lysin motif (LysM) is a carbohydrate-binding module often found in secreted or transmembrane proteins in living organisms from prokaryotes to eukaryotes. Thus far, all characterized LysM-containing proteins in plants are plasma membrane-resident receptors or co-receptors playing roles in plant-microbe interactions. Here, we interrogate the Arabidopsis LysM/F-box-containing protein InLYP1 and reveal its function in glycine metabolism. InLYP1 was mainly expressed by vigorously growing tissues, encoding a nuclear-cytoplasmic protein. We validated InLYP1 as part of the SKP1-CULLIN1-F-box E3 complex for mediating protein degradation. The glycine decarboxylase P-protein 1 (GLDP1) was identified as an InLYP1-interacting protein by both immunoprecipitation/mass spectrometry and yeast two-hybrid library screening. InLYP1 could also interact with GLDP2, a paralog of GLDP1 with weaker catalytic activity, and could mediate the degradation of GLDP2 but not GLDP1. Interestingly, both GLDPs could be O-glycosylated and form homodimers or heterodimers. Overexpression of InLYP1L9A encoding a dominant-negative variant could cause seedling germination retardation on the medium containing glycine. Collectively, these results shed light on the function of plant intracellular LysM-containing proteins, and suggest that InLYP1 may deplete GLDP2 to facilitate glycine decarboxylation in Arabidopsis.

Multisystem Inflammatory Syndrome in Children and SARS-CoV-2 Serology.

* Abbreviations: COVID-19 — : coronavirus disease 2019 MIS-C — : multisystem inflammatory syndrome in children RBD — : receptor-binding domain S — : severe acute respiratory syndrome coronavirus 2 spike protein SARS-Co-V-2 — : severe acute respiratory syndrome coronavirus 2 Coronavirus disease 2019 (COVID-19) is arguably the most socially and economically disruptive pandemic since the 1918 influenza pandemic. Although pediatric COVID-19 shares features with the adult disease, there are several differences. Children produce virus in amounts at least equal to adults, if not higher,1 and can transmit the virus, just as adults can.2 School-aged children are generally less-severely affected than infants or adults, but some children without significant underlying disease become ill or die in a disease process analogous to the one most commonly seen in adults: severe pulmonary disease and respiratory failure.3–6 Children and adults appear to have different humoral immune responses to COVID-19.7 A small fraction of children with COVID-19 experience a hyperinflammatory process,8–13 termed multisystem inflammatory syndrome in children (MIS-C) in the United States, with features distinct from Kawasaki disease.14 This case definition includes ≥2 of these symptoms: rash, conjunctivitis, or mucocutaneous inflammation; hypotension; cardiac disease; coagulopathy; or acute gastrointestinal problems.15 MIS-C, which is not correlated with viral load levels, typically appears some time after initial infection.13 MIS-C’s incidence is difficult to determine, given the high rate of asymptomatic infection.12 Adults with COVID-19 also can experience inflammatory disorders: coagulopathies, vasculitis, cardiomyositis, and neuroinflammatory processes.16–18 That the most effective therapy to reduce mortality in adults with severe COVID-19 yet established is an immune suppressant, dexamethasone,19 reveals the importance of inflammatory and immune-mediated pathologies. In this issue of … Address correspondence to Steven Zeichner, MD, PhD, Department of Pediatrics, University of Virginia, Box 801349, Charlottesville, VA 22908. E-mail: zeichner{at}virginia.edu

A low temperature catalytic-type combustible gas sensor based on Pt supported zeolite catalyst films

In this study, a catalytic-type combustible gas sensor was fabricated by the screen-printing method. Pt supported catalysts (Pt-HZSM5) were prepared by a wet impregnation method using HZSM5 zeolite as support. It was found that Pt-HZSM5 catalysts have a highly catalytic activity to H2 and CO at low temperatures and a selectively and fully combustible was observed at only 150 °C. A good dispersion state of Pt nanoparticles on HZSM5 zeolite particles was beneficial for the catalytic oxidization of CO and H2. However, a high loading amounts lead to a poor dispersion state and a weak catalytic activity. The thick film sensor based on Pt-HZSM5 catalyst was found to be highly sensitive to combustible gas with a good linearity up to 2% and a limitation of detection (LOD) around 50 ppm. Due to the low operation temperature, a highly selectivity was obtained for CO and H2 and no cross-sensitivity to interfering gases such as CH4 and VOCs. It was indicated that the present developed catalytic-type gas sensors could be used for the leakage detection and monitor for H2 and CO with a low power consumption and a good selectivity.

High Voltage Electrodes for Li-Ion Batteries and Efficient Water Electrolysis: An Oxymoron?

We demonstrate that key parameters for efficient electrocatalytic oxidation of water are the energetics of the redox complexes associated with their ionization and electrochemical potentials coupled to the change of metal-oxygen band hybridization. We investigate the catalytic activity of the LiCoPO4-LiCo2P3O10 tailored compound, which is a 5 V cathode material for Li-ion batteries. The reason for the weak catalytic activity of the lithiated compound toward the oxygen evolution reaction is a large energy difference between the electronic states involved in the electrochemical reaction. A highly active catalyst is obtained by tuning the relative energetic position of the electronic levels involved in the charge transfer reaction, which in turn are governed by the lithium content. A significant lowering of the overpotential from >550 mV to ∼370 mV at 10 mA cm-2 is achieved via a decrease of the ionization potential and shifting the electrochemical potential near the electronic states of the molecule, thereby facilitating water oxidation.

Ultrasound-treated metal-organic framework with efficient electrocatalytic oxygen evolution activity.

Metal-organic frameworks (MOFs) and their derivatives are excellent candidates for electrocatalysts profiting from their unique structures and accessible active sites. Generally, due to the weak poor conductivity and catalytic activity when used as OER electrocatalysts, MOFs are more likely to be used as precursors to obtain composite catalysts through further pyrolysis treatment, rather than directly applied as OER electrocatalysts. But heat treatment usually results in structural collapse and loss of active sites. Specially, as a kind of two-dimensional (2D) materials with rapid electron transfer, metal-organic framework nanosheets (MONs) have great application potential in various fields, especially in the field of catalysis, due to the advantages of both MOFs and 2D materials. Here, we have reported a simple top-down approach to synthesize Co-MONs which can be directly adopted as efficient OER catalysts. Ultrasonic bath (40 KHz, 100 W) was employed to control the exposing of the preponderant lattice plane, which can offer plentiful active catalytic sites and accelerate ions transport. The optimized Co-MONs attain 10 mA cm-2 at an overpotential of 309 mV with a small Tafel slope of 75.71 mV dec-1.

Three-dimensional Cu/C porous composite: Facile fabrication and efficient catalytic reduction of 4-nitrophenol

Developing a facile method to fabricate new heterogeneous Metal-Organic Framework (MOFs) based catalysts with high catalytic activity and stability has drawn significant attention. Herein, we demonstrate a simple in-situ pyrolysis reduction strategy to fabricate a novel three-dimensional (3D) Cu-based catalyst, which displays an outstanding performance for the decomposition of 4-nitrophenol (4-NP). Detailed characterization including SEM, FTIR, XPS, ICP-OES, HRTEM, SAED, XRD and BET confirmed the formation of the Cu/C porous composites (Cu/C-PC). Taking advantage of enormous Cu particles in the composite as well as ultrahigh surface area (196.7 m2/g) of carbon support, Cu/C-PC presents prominent catalytic activity for the hydrogenation reduction 4-NP to 4-aminophenol (4-AP) with apparent rate constant (Kapp) of 0.0267 s−1 (the ratio of Kapp to the catalyst amount is 119 s−1 g−1), which is dramatically higher than that previous reports. On the contrary, after being washed successively (Cu/C-PC-AW) by FeCl3, HCl aqueous solution and deionized water, the Cu/C porous composite materials exhibit fairly weak catalytic activity. The catalytic performance of Cu/C-PC is better than Cu, Cu2O and CuO nanoparticles as well as other catalysts in previous reports. Furthermore, Cu/C-PC shows excellent reusability, indicating its potential applications in treatment of water pollution.

Treatment of aqueous solutions of 1,4-dioxane by ozonation and catalytic ozonation with copper oxide (CuO)

ABSTRACT In this study, treatment for the removal of 1,4-dioxane by ozone and by catalytic ozonation using CuO as the catalyst was investigated. While the removal of 1,4-dioxane was small (20%) and mineralization negligible after 6 h of ozonation treatment, the removals of 1,4-dioxane and total organic carbon increased by factors of 10.35 and 81.25, respectively, after catalytic ozonation in the presence of CuO. The mineralization during catalytic ozonation was favoured at pH 10 (94.91 min−1), although it proceeded even at pH 3 (54.41 min−1). The CuO catalyst decreased the equilibrium concentration of soluble ozone and favoured its decomposition to reactive oxidative species. Radical scavenging experiments demonstrated that superoxide radicals were the main species responsible for the degradation of 1,4-dioxane. Further scavenging experiments with phosphate confirmed the presence of Lewis active sites on the surface of CuO, which were responsible for the adsorption and decomposition of ozone. The reaction mechanism proceeded through the formation of ethylene glycol diformate, which quickly hydrolyzed to ethylene glycol and formic acid as intermediate products. The stability of CuO indicated weak copper leaching and high catalytic activity for five recycling cycles. The toxicity of the water, assessed by Vibrio fischeri bioluminescence assays, remained the same (low toxicity) after catalytic ozonation while it increased after treatment with ozonation alone.

AA Homozygous Genotype of GSTP1 I105V Polymorphism in Oral Cancer: In Silico Screening, Molecular Dynamics Simulation and Activity Studies of Wild and Mutant GSTP1

Background: Highest incidence of oral squamous cell carcinoma (OSCC) has been reported in north-eastern India and causal association between cancer and raw areca-nut (RAN) consumption are well evident. Earlier studies revealed that monitoring the occurrence of precocious anaphase and expression of securin in blood lymphocytes can be a good biomarkers for cancer risk in RAN+lime chewers. Glutathione S-transferases (GSTs) are considered an important cellular detoxification system that provide protection against the effects of toxins and determine individual's cancer susceptibility. Aim: Although GST gene family has been extensively studied, its role as susceptibility factor in oral cancer risk in the RAN chewing population in Meghalaya state, India has not been explored. The association of polymorphisms in GSTP1 (Ile105Val) gene with OSCC risk in Meghalaya, India, was evaluated. Earlier both AA reference and the GG/AG mutant genotype of GSTP1 gene showed an association with different types of cancers. Methods: Genetic polymorphism was evaluated by genotyping 129 cases and 156 controls using PCR-RFLP method and validated by Sanger sequencing in a hospital-based case-control study. GSTP1's interaction status with c-Jun Kinase (JNK) was evaluated through protein-protein docking analysis and this was also validated experimentally by immunohistochemistry and qRT-PCR. Results: Individuals with AA allele of GSTP1 showed significant association with the risk of OSCC compared with individuals with AG/GG mutant genotypes in habit-matched “RAN-only” and “RAN+Tobacco” group. The binding geometry between JNK and GSTP1 was disrupted in mutant combinations. It was demonstrated that AA homozygous genotype of oral epithelial cells showed reduced c-Jun-phosphorylation and proapoptotic genes expression than AG/GG genotypes. In silico docking revealed that homodimeric GSTP1 with AA genotype showed weak catalytic activity in detoxification of RAN and tobacco toxins compared with the AG/GG mutant proteins. Interestingly, the quantitation of 8-Oxo-2´-deoxyguanosine in DNA digests by ELISA-kit showed no differences in these genotypes, however the frequency of sister-chromatid exchanges was significantly higher in individuals with GSTP1 AA genotype than GG genotype. Conclusion: Thus in this population, specific traditional habit along with GSTP1 AA genotype play a significant role in predisposition to oral cancer risk by showing higher DNA-lesions, might be caused by some specific RAN/tobacco metabolites, and lower c-Jun phosphorylation which may inhibit apoptosis.

GTP as a peroxidase-mimic to mediate enzymatic cascade reaction for alkaline phosphatase detection and alkaline phosphatase-linked immunoassay

Guanosine triphosphate (GTP), a substrate for RNA synthesis, plays a pivotal role in life-form metabolism at the cellular level. Herein, we first showed that GTP exhibited an intrinsic peroxidase-mimic activity, accelerating H2O2-mediated oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to produce a color reaction. Compared to GTP, weaker catalytic activity was observed from guanosine diphosphate (GDP) and virtually no catalytic activity was observed from guanosine monophosphate (GMP) and guanosine. Alkaline phosphatase (ALP) can catalyze the dephosphorylation of GTP with in situ generation of GDP, GMP and guanosine, which followed by receding the oxidation of TMB. Inspired by this, a novel colorimetric sensor for ALP detection was designed based on the enzymatic cascade reaction by coupling ALP-catalyzed dephosphorylation of GTP with GTP-catalyzed oxidation of TMB. This method allowed ALP sensing in a range from 0.01 to 100 U/L with a detection limit of 0.009 U/L, which was sensitive enough for ALP activity assay in biological samples (the normal ALP level range of adult serum is 20–140 U/L). Moreover, ALP is widely used in enzyme-linked immunosorbent assays (ELISA) as a signal reporter, the proof-of-concept ELISA for alpha-fetoprotein (AFP) detection was established. This unexpected discovery not only extends the new biological function of GTP, but also holds great promise for development of versatile biosensors that initiate the concentration changes of GTP.

Catalytic ozonation of high saline petrochemical wastewater using PAC@Fe II Fe 2 III O 4 : Optimization, mechanisms and biodegradability studies

Abstract This work specially focused on preparation of a magnetic catalyst, carbon impregnated by iron oxide (PAC@Fe3O4), and consider its catalytic ability for the first time in ozonation of high saline petrochemical wastewater (PCW) from PVC and VCM manufacturing industries. The structural and surface properties of the catalyst, the effect of operational factors, biodegradability and mechanisms were also studied in details. Results revealed that the influence of pH on COD removal rate was negligible, whereas process performance was significantly affected by various concentrations of catalyst and ozone. Under the optimum operational conditions, COD and TOC removal reached to 75.3 and 50.3% after 120 min catalytic ozonation, respectively. Organic compounds were also degraded through transformation of ozone into OH both over catalyst surface and in the solution as identified by tert-butanol. A probable comprehensive mechanism include adsorption, homogeneous and heterogeneous catalytic ozonation was also proposed. The biodegradability of PCW was noticeably improved based on the BOD5/COD ratio, AOS and COS indices after 120 min reaction by PAC@Fe3O4/O3 system. The catalyst indicated a weak iron leaching and high catalytic activity upon five recycling cycles, which confirms that it can be reused many times. Therefore, the PAC@Fe3O4/O3 process was an effective and promising technique for successful PCW treatment, due to the efficient reduction of COD, achieve discharge standards and enhance biodegradability.

Gallium Catalysed Direct Growth of Graphene Epitaxial Layer on SiC Substrates By Chemical Vapor Deposition

Graphene, fascinates with its relativistic linear dispersion relation at low energies and the chiral nature of charge carriers, has garnered tremendous interest due to its unusual properties including high electron mobility with low electronic scattering which makes it as a potential candidate in nanoelectronics and photonic devices. Several outstanding advancements in graphene fabrication technology have been explored including research grade mechanical exfoliation of graphite, chemical vapor deposition (CVD), and thermal decomposition of SiC and chemical methods. In particular, the thermal decomposition of SiC surfaces is presently being a very promising approach since it offers wafer scale growth of graphene layers and a promise for high speed nanoelectronics devices. This method utilizes thermal energy to sublimate the topmost Si atoms from the SiC and carbon atoms bond together to form epitaxial graphene. At present, ever growing effort is centered on the direct growth of graphene on SiC substrates by external carbon feedstock using CVD as it would offer several benefits toward the development of wafer scale industrial production of graphene technology on SiC. Moreover, this method facilitates the controlled monolayer growth on the flat SiC surface with high mobility and desirable band gap by varying the mass transport of the carbon precursor. However, a catalytic material must entail to soluble the decomposed carbon atoms on SiC surface to form carbon layers since the underlying SiC shown to have very weak catalytic activity. In this work, we employ a novel approach by utilizing metal gallium vapors as a catalyst and exposing it onto the SiC substrates along the carbon precursor to promote the catalytic activity for the direct fabrication of graphene. At elevated temperatures on the SiC surface, the gallium vapors assist to decompose the acetylene gases and nucleate the carbon atoms to form graphene layers over the substrate scale. The growth mechanism of epitaxial graphene on SiC substrate and the results will be presented in detail.

Sensitivity of human cells expressing low-fidelity or weak-catalytic-activity variants of DNA polymerase ζ to genotoxic stresses

Translesion DNA polymerases (TLS pols) play critical roles in defense mechanisms against genotoxic agents. The defects or mutations of TLS pols are predicted to result in hypersensitivity of cells to environmental mutagens. In this study, human cells expressing DNA polymerase ζ (Pol ζ) variants with low fidelity or weak catalytic activity have been established with Nalm-6-MSH+ cells and their sensitivity to mutagenicity and cytotoxicity of benzo[a]pyrene diol epoxide (BPDE) and ultraviolet-C light (UV-C) was examined. The low-fidelity mutants were engineered by knocking-in DNA sequences that direct changes of leucine 2618 to either phenylalanine (L2618F) or methionine (L2618M) of Pol ζ. The weak-catalytic-activity mutants were generated by knocking-in DNA sequences that direct changes of either tyrosine 2779 to phenylalanine (Y2779F) or aspartate 2781 to asparagine (D2781N). In addition, a +1 frameshift mutation, i.e., CCC to CCCC, was introduced in the coding region of the TK1 gene to measure the mutant frequencies. Doubling time and spontaneous TK mutant frequencies of the established cell lines were similar to those of the wild-type cells. The low-fidelity mutants displayed, however, higher sensitivity to the mutagenicity of BPDE and UV-C than the wild-type cells although their cytotoxic sensitivity was not changed. In contrast, the weak-catalytic-activity mutants were more sensitive to the cytotoxicity of BPDE and UV-C than the wild-type cells, and displayed much higher sensitivity to the clastogenicity of BPDE than the wild-type cells in an in vitro micronucleus assay. These results indicate that human Pol ζ is involved in TLS across DNA lesions induced by BPDE and UV-C and also that the TLS plays important roles in induction of mutations, clastogenicity and in cellular survival of the damaged human cells. Similarities and differences in in vivo roles of yeast and human Pol ζ in genome integrity are discussed.

Identification of Human UDP-Glucuronosyltransferase 1A4 as the Major Isozyme Responsible for the Glucuronidation of 20(S)-Protopanaxadiol in Human Liver Microsomes.

20(S)-protopanaxadiol (PPD), one of the representative aglycones of ginsenosides, has a broad spectrum of pharmacological activities. Although phase I metabolism has been investigated extensively, information regarding phase II metabolism of this compound remains to be elucidated. Here, a glucuronidated metabolite of PPD in human liver microsomes (HLMs) and rat liver microsomes (RLMs) was unambiguously identified as PPD-3-O-β-d-glucuronide by nuclear magnetic resonance spectroscopy and high resolution mass spectrometry. The chemical inhibition and recombinant human UDP-Glucuronosyltransferase (UGT) isoforms assay showed that the PPD glucuronidation was mainly catalyzed by UGT1A4 in HLM, whereas UGT1A3 showed weak catalytic activity. In conclusion, PPD-3-O-β-d-glucuronide was first identified as the principal glucuronidation metabolite of PPD in HLMs, which was catalyzed by UGT1A4.

Flavone synthases from Lonicera japonica and L. macranthoides reveal differential flavone accumulation.

Flavones are important secondary metabolites found in many plants. In Lonicera species, flavones contribute both physiological and pharmaceutical properties. However, flavone synthase (FNS), the key enzyme responsible for flavone biosynthesis, has not yet been characterized in Lonicera species. In this study, FNSII genes were identified from Lonicera japonica Thunb. and L. macranthoides Hand.-Mazz. In the presence of NADPH, the recombinant cytochrome P450 proteins encoded by LjFNSII-1.1, LjFNSII-2.1, and LmFNSII-1.1 converted eriodictyol, naringenin, and liquiritigenin to the corresponding flavones directly. The different catalytic properties between LjFNSII-2.1 and LjFNSII-1.1 were caused by a single amino acid substitution at position 242 (glutamic acid to lysine). A methionine at position 206 and a leucine at position 381 contributed considerably to the high catalytic activity of LjFNSII-1.1. In addition, LjFNSII-1.1&2.1 and LmFNSII-1.1 also biosynthesize flavones that were further modified by O-glycosylation in transgenic tobacco. The expression levels of the FNSII genes were consistent with flavone accumulation patterns in flower buds. Our findings suggested that the weak catalytic activity of LmFNSII-1.1 and the relatively low expression of LmFNSII-1.1 in flowers might be responsible for the low levels of flavone accumulation in flower buds of L. macranthoides.

Catalytic ozonation of benzotriazole over alumina supported transition metal oxide catalysts in water

Mineralization of benzotriazole (BTZ) by heterogeneous catalytic ozonation was studied in aqueous phase. Performance of three catalysts (Mn/Al2O3, Cu/Al2O3 and Mn–Cu/Al2O3) were compared at various pH levels and operating conditions. Compared to noncatalytic ozonation, a higher level of mineralization of BTZ was achieved over a wide range of pH values. Adsorption of BTZ on alumina support and catalysts was negligible. At neutral pH, Cu/Al2O3 was the most effective catalyst with close to 90% mineralization in 15min reaction time. At pH 2, Mn/Al2O3 had the fastest ozone decomposition and the fastest reaction with 75% mineralization of BTZ in 10min. Under an alkaline pH environment, the mineralization of BTZ by using Cu/Al2O3 showed a weak catalytic activity (22%) whereas mineralization with Mn–Cu/Al2O3 was 77% complete in 30min of reaction. It was observed that the presence of molecular ozone is essential for catalytic oxidation of organic compounds and ozone decomposition has a direct relationship with catalyst activity. The results indicate that not only the pH of solution but also the type of buffer used can influence the catalytic activity. The chloride and sulfate ions in aqueous solutions act as hydroxyl radical scavengers. All the catalysts showed high stability and reusability.

The Retinaldehyde Reductase Activity of DHRS3 Is Reciprocally Activated by Retinol Dehydrogenase 10 to Control Retinoid Homeostasis

The retinoic acid-inducible dehydrogenase reductase 3 (DHRS3) is thought to function as a retinaldehyde reductase that controls the levels of all-trans-retinaldehyde, the immediate precursor for bioactive all-trans-retinoic acid. However, the weak catalytic activity of DHRS3 and the lack of changes in retinaldehyde conversion to retinol and retinoic acid in the cells overexpressing DHRS3 undermine its role as a physiologically important all-trans-retinaldehyde reductase. This study demonstrates that DHRS3 requires the presence of retinol dehydrogenase 10 (RDH10) to display its full catalytic activity. The RDH10-activated DHRS3 acts as a robust high affinity all-trans-retinaldehyde-specific reductase that effectively converts retinaldehyde back to retinol, decreasing the rate of retinoic acid biosynthesis. In turn, the retinol dehydrogenase activity of RDH10 is reciprocally activated by DHRS3. At E13.5, DHRS3-null embryos have ∼4-fold lower levels of retinol and retinyl esters, but only slightly elevated levels of retinoic acid. The membrane-associated retinaldehyde reductase and retinol dehydrogenase activities are decreased by ∼4- and ∼2-fold, respectively, in Dhrs3(-/-) embryos, and Dhrs3(-/-) mouse embryonic fibroblasts exhibit reduced metabolism of both retinaldehyde and retinol. Neither RDH10 nor DHRS3 has to be itself catalytically active to activate each other. The transcripts encoding DHRS3 and RDH10 are co-localized at least in some tissues during development. The mutually activating interaction between the two related proteins may represent a highly sensitive and conserved mechanism for precise control over the rate of retinoic acid biosynthesis.

Relationship of angiogenin to pathophysiology of diseases

Angiogenin is a powerful stimulator of new blood vessel formation. It is a member of pancreatic ribonuclease (RNase) superfamily. It was originally isolated from conditioned medium of cultured tumor cells. Along with other associated molecules, it has been recognized in a variety of somatic tissues in embryonic stages and adult of vertebrate development. It binds to high-affinity endothelial cell surface receptors and, with lower affinity, to extracellular matrix. This suggests that angiogenin and related molecules are likely to play a vital role in normal physiology, even though the biological significance of angiogenin is uncertain due to weak catalytic activity of the protein. It has a significant critical role in angiogenesis. Angiogenin transported to the nucleus after being endocytosed by endothelial cell, where it was built up in the nucleolus and is a normal constituent of the circulation, rarely undergoes proliferation and promotes neovascularization. In blood angiogenin, levels increase in some physiological and pathological conditions, which may be of a prognostic significance. It also plays an important role in a number of nonmalignant vasculo-proliferative pathological conditions such as inflammatory bowel disease, proliferative diabetic retinopathy, cardiovascular diseases, and rheumatoid arthritis and in malignant diseases such as colorectal, gastric, pancreatic, melanoma, and urothelial cancer lesions. This review article aims to give an overview of the biochemical structure, receptor translocation, physiology, and types of angiogenin, in addition to its main role in pathological states and ultimately it's effect as a beneficial therapeutic approach.

PVC 함유 폐기물의 열분해를 위한 탈염흡수제 연구

PVC 함유 가연성폐기물의 열분해시 Ca 계열 및 Fe 계열 산화물을 탈염 흡수제로 사용하여 생성물의 분포, 액상 생성물의 비점분포, 생성물의 염소 농도에 미치는 영향을 조사하였다. Fe 계열 산화물 분말을 액상에서 흡수제로 사용시 오일의 수율이 뚜렷하게 감소하였다. 이러한 현상은 산화철이 열분해시 일부 열분해 촉매의 역할을 하였을 가능성을 나타낸다. 반면에 오일의 비점분포가 낮아지는 현상은 발견되지 않았으며 이러한 현상은 산화철의 촉매 반응성이 크지 않기 때문으로 보인다. Ca 계열 산화물 분말을 흡수제로 사용한 경우 오일 수율이 감소하는 현상은 발견되지 않았으며 비점분포도 큰 변화가 없었으나 탈염성능이 산화철 분말 흡수제 보다 더 우수하였다. The influences of Ca and Fe based oxides as dechlorination sorbents on the product distribution, boiling point distribution of liquid product, concentration of Cl of the products from the pyrolysis of PVC containing combustible wastes were investigated. With Fe based oxides as the sorbents, the yield of liquid product remarkably decreased whereas the decrease of the boiling point distribution of the liquid product was not noticeable. This phenomenon indicated that Fe based oxides worked as catalysts with weak catalytic activity. With Ca based oxides as the sorbents, the yield of liquid product did not decrease and the boiling point distribution of liquid product did not change significantly, but the dechlorination performance of these was much better than that with Fe based oxides.

One-pot hydrothermal synthesis of Co(OH)2 nanoflakes on graphene sheets and their fast catalytic oxidation of phenol in liquid phase

A cobalt hydroxide (Co(OH)2) nanoflake-reduced graphene oxide (rGO) hybrid was synthesized by a one-pot hydrothermal method using glucose as a reducing agent for graphene oxide (GO) reduction. The structural and surface properties of the material were investigated by scanning and transmission electron microscopies, energy-dispersive X-ray spectrometry, powder X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Catalytic activities of GO, rGO, Co(OH)2 and Co(OH)2–rGO in aqueous phenol degradation using peroxymonosulfate as an oxidant were compared. A synergetic effect on the catalytic activity was found on the Co(OH)2–rGO hybrid. Although rGO has weak catalytic activity, Co(OH)2–rGO hybrid showed a higher catalytic activity than Co(OH)2. The phenol degradation on Co(OH)2–rGO was extremely fast and took around 10min for 100% phenol removal. The degradation was found to follow the first order kinetics and a mechanism for phenol degradation was presented.

Porous Metal-Organic Framework Materials: Microwave Assisted Synthesis and Oxidative Catalytic Tests

Metal-Organic Framework Materials MIL‑101(Cr) ([Cr3X(H2O)2O(bdc)3]∙n(H2O), where X− = F− or OH−, n ≈ 25 and H2bdc stands for 1,4-benzene-dicarboxylic acid] and MOF‑5(Zn) [Zn4O(bdc)3] were prepared by hydrothermal or solvothermal methods as well as Microwave‑Assisted Synthesis (MWAS), for which the detailed synthetic parameters were optimized. The crystal structures were confirmed by powder X-ray diffraction and the materials were further characterized by FT‑IR absorption spectroscopy. MIL‑101(Cr) and MOF‑5(Zn) showed weak catalytic activity in the oxidation of terpene, thiophene and cis-cyclooctene. Reasonable catalytic activity was observed for MOF-5(Zn) in the epoxidation of cis-cyclooctene and a 100 % of selectivity was observed for the epoxide. The structural stability of the materials was tested under the employed catalytic medium for oxidation reactions. MOF-5(Zn) revealed a remarkable structural stability at high temperature and also in the presence of high oxidant amounts.