Relationship between Adult Handgrip Strength and Metabolic Syndrome

Background: Metabolic syndrome is becoming more prevalent around the world, with insulin resistance and obesity as particularly critical factors determining the condition. It is known that insulin resistance has a very strong correlation between muscle mass and muscular strength. However, there are few studies on the relationship between handgrip strength and metabolic syndrome, and those studies that have been carried out have mainly focused on the elderly. The purpose of the current study is to use the Korea National Health and Nutrition Examination Survey to identify the relationship between handgrip strength and metabolic syndrome among Korean adults aged 19 years old and above. Participants and methods: The Korea National Health and Nutrition Examination Survey is a nationwide cross-sectional survey that assesses the health and nutritional status of the Korean population. The current study analyzed the relationship between grip strength and metabolic syndrome of 10,094 Korean adults aged ≥19 years (4,402 men and 5,692 women) in the Korea National Health and Nutrition Examination Survey (2014-2017). Those with cancer or those who had experienced a stroke, angina, or myocardial infarction were excluded, as were pregnant or breast-feeding women. The diagnostic criteria for metabolic syndrome were based on those of the American Heart Association/National Heart Long and Blood Institute, which are altered versions of the National Cholesterol Education Program – Adult Treatment Panel III criteria. Grip strength was measured data using a digital grip strength dynamometer. Results: Logistic regression analysis was performed by dividing grip strength into quintiles. A significant decrease in figures compared to Q1 in the odds ratio for both men and women was observed due to age adjustment (Q2: 0.84, Q3: 0.43, Q4: 0.24, Q5: 0.15 for men; Q2: 0.63, Q3: 0.41, Q4: 0.23, Q5: 0.08 for women). Also, due to the correction of demographic factors (age, educational status, marital status, income status, smoking status, drinking status, and menopausal status for women), the odds ratio significantly decreased figures compared to Q1 for both men and women (Q2: 0.80, Q3: 0.37, Q4: 0.21, Q5: 0.13 for men; Q2: 0.63, Q3: 0.45, Q4: 0.24, Q5: 0.09 for women). Conclusions: Higher grip strength brought down the risk of metabolic syndrome for both men and women. Therefore, to prevent and treat metabolic syndrome, it is recommended that patients exercise steadily to enhance muscular strength and muscle mass for better health outcomes. [Ethiop. J. Health Dev. 2020;34(Special issue-3):18-27] Keywords: Muscle strength, metabolic syndrome, grip strength, grip strength/body weigh

Recent advances in computational modeling as a conduit to understand the plant circadian clock

The circadian clock is necessary for plants to anticipate environmental changes. This leads to a coordination of plant development and growth and thus to increased fitness. Many clock components were identified by genetic and biochemical approaches, and studies on these components revealed a core oscillator with multiple feedback loops. A suite of computation analyses is uncovering the outputs of this oscillating network. Mathematical analysis is contributing to our understanding of the network under clock control, moving toward an explanation of how the clock integrates and coordinates various developmental programs with daily environmental cues. From there, these systems approaches will look to establish further nodes within the clock network

Investigating the Catalytic Mechanisms of Bio-degrading Copper Proteins: Multi-copper Oxidases (MCOs) and Lytic Polysaccharide Monooxygenases (LPMOs)

Lignin and cellulose comprise a large portion of the renewable biomass on Earth. However, substantially due to laborious course of processing, the conversion efficiency of these biomaterials to accessible biofuel is very low. Therefore, effective depolymerization and utilization of these biopolymers are requirements for environmentally friendly and sustainable energy development. In the hope of finding solutions to these biomass utilization challenges, there have been growing interests in using biodegrading metalloenzymes as active biocatalysts. However, there still remain many questions regarding mechanistic details of enzyme catalysis and effective application of these enzymes. This thesis focuses on investigating the redox chemistry involved in the catalytic mechanisms of two main lignin- and cellulose- degrading copper enzymes: multicopper oxidases (MCOs) and lytic polysaccharide monooxygenases (LPMOs). MCOs are capable of aerobic oxidation of lignin as their primary function, but the nature of their substrate variability also allows the oxidation of not only diverse high potential organic and inorganic complexes, but also earth abundant divalent metal ions such as manganese. LPMOs, on the other hand, enable the cleavage of glycosidic bonds in recalcitrant insoluble cellulosic substances, which are not degradable by other hydrolytic enzymes such as endoglucanases and cellulobiohydrolases. It is remarkable that nature has created such versatile enzymes with specific active site metals and redox-active amino acids involved in electron transfer, which contribute to substrate oxidation as well as enzyme survival against oxidative damage during catalysis. By gaining a deeper understanding of how these enzymes work, we could greatly enhance current usage efficiencies and develop more energy-efficient biocatalysts. Chapter I gives an introduction to biological coppers, two groups of bio-degrading copper enzymes: multicopper oxidases (MCOs) and lytic polysaccharide monooxygenases (LPMOs), and the role of redox-active amino acids in electron transfer and enzyme catalysis. For the MCO work, a thermophilic laccase (Tth-lac) from Thermus thermophilus HB27 and a CotA laccase (CotA-lac) from Bacillus Subtilis were studied. For the LPMO work, two cellulose active LPMOs (ScLPMO10B and ScLPMO10C) and a chitin active LPMO (BlLPMO10A) were studied. Chapter II describes thermodynamic aspects of Tth-lac catalysis. The temperature dependence of the formal potential of type I copper (CuT1) in Tth-lac is reported, and the interplay between many competing dynamic and thermodynamic factors which results in thermostability and activity of Tth-lac is discussed. Chapter III reports the electron transfer (ET) kinetics data obtained with Tth-lac using the transient absorption spectroscopy. The results of photochemical electron/hole transfer studies indicate that the chains of Trp and Tyr can participate in electron transfer through Tth-lac, which could potentially have a role in enzyme catalysis as well. Chapter IV discusses the protective role of a Trp/Tyr pair positioned close to the trinuclear copper cluster (TNC) in Tth-lac. It is indeed remarkable that laccases are capable of utilizing the power of oxygen to catalyze the oxidation of diverse high-potential substrates. But, as a tradeoff, the utilization of dioxygen can make the enzyme highly susceptible to oxidative damage. Chapter IV provides supporting evidence that led us to conclude that the TNC-proximal Trp/Tyr pair functions as an internal antioxidant for prolonging the enzyme lifetime. Chapter V describes investigations on the factors that affect MCO catalysis, which include the potentials of the active site coppers, possible reactive intermediates, and common structural motifs. Based on the structural homology between Tth-lac and CotA-lac, some preliminary work done on CotA-lac is also reported. Chapter VI outlines the work on LPMOs. After the successful expression and purification of ScLPMO10B, ScLPMO10B and BlLPMO10A, standard activity assays were done with insoluble cellulose and chitin substrates to confirm the enzyme activity. The results are compared with that from the photo-degradation experiments to investigate if the photochemically generated Cu(III) species are active intermediates in LPMO catalysis. Chapter VII reports the results on bioinformatics analysis on the distribution of vicinal amino acids in different enzyme classes. This study was to examine the biological significance of amino acid pairs and clusters existing in many different enzyme classes, with vicinal surface tyrosines in CotA-lac as an underlying motivation behind the work. This thesis demonstrates that MCOs and LPMOs are truly versatile enzymes which can oxidize such diverse refractory substrates, and there could be multiple pathways that the enzymes achieve this task. As shown so far, not only the active site metals but also the chain of redox-active amino acids as well as metal coordinating residues can contribute to enzyme catalysis.</p

Effects of Expert- and User-Generated Evaluations on Food Product Choices via a Food Literacy App

With the proliferation of mobile apps to promote healthy diets, it is important to understand the influence of evaluation information presented through these apps on users\u27 decisions. Deriving from information processing concepts, we examine the influence of information cues (authority and social proof cues) obtained via food literacy apps on users’ food product choices. We employ clickstream data from such an app that provides labeling information, expert grades, and user ratings/reviews of food products. We use a regression discontinuity design to uncover the effects of authority cue (expert grade) and Poisson regression to analyze the effects of social proof (user rating, review) on food product choices. The initial results add to our knowledge of the influence of these two key cues (authority and social proof) on food product choice. There are also salient implications for the app providers, for experts evaluating food products, for users, and for public health

Stability/activity tradeoffs in Thermus thermophilus HB27 laccase

We report the temperature dependence of the formal potential of type 1 copper (Cu_(T1)) in Thermusthermophilus HB27 laccase. Employing [Ru(NH₃)₄ (bpy)](PF₆)₂ (0.505 vs. NHE) as the redox titrant, we found that the Cu_(T1)^(2+/+) potential decreased from approximately 480 to 420 mV (vs. NHE) as the temperature was raised from 20 to 65 °C. Of importance is that the ΔS_(rc)° of − 120 J mol⁻¹ K⁻¹ is substantially more negative than those for other blue copper proteins. We suggest that the highly unfavorable reduction entropy is attributable to Cu_(T1) inaccessibility to the aqueous medium. Although the active site residues are buried, which is critical for maintaining thermostability, the flexibility around Cu_(T1) is maintained, allowing enzyme activity at ambient temperature

Stability/activity tradeoffs in Thermusthermophilus HB27 laccase

We report the temperature dependence of the formal potential of type 1 copper (Cu_(T1)) in Thermusthermophilus HB27 laccase. Employing [Ru(NH₃)₄ (bpy)](PF₆)₂ (0.505 vs. NHE) as the redox titrant, we found that the Cu_(T1)^(2+/+) potential decreased from approximately 480 to 420 mV (vs. NHE) as the temperature was raised from 20 to 65 °C. Of importance is that the ΔS_(rc)° of − 120 J mol⁻¹ K⁻¹ is substantially more negative than those for other blue copper proteins. We suggest that the highly unfavorable reduction entropy is attributable to CuT1 inaccessibility to the aqueous medium. Although the active site residues are buried, which is critical for maintaining thermostability, the flexibility around Cu_(T1) is maintained, allowing enzyme activity at ambient temperature

Selective synthesis of pure cobalt disulfide on reduced graphene oxide sheets and its high electrocatalytic activity for hydrogen evolution reaction

We synthesized single-phase CoS2 on a large scale by adding graphene oxide of sufficient quantity via the hydrothermal method using cobalt acetate and thioacetamide as precursors; this produced the hybrid of CoS2 with reduced graphene oxide which exhibited high electrocatalytic activity in the hydrogen evolution reaction.ope

Multilayer Heterojunction Anodes for Saline Wastewater Treatment: Design Strategies and Reactive Species Generation Mechanisms

Multilayer heterojunction SbSn/CoTi/Ir anodes, which consist of Ir_(0.7)Ta_(0.3)O_2 bottom layers coated onto a titanium base, Co-TiO_2 interlayers, and overcoated discrete Sb-SnO_2 islands, were prepared by spray pyrolysis. The Ir_(0.7)Ta_(0.3)O_2 bottom layer serves as an Ohmic contact to facilitate electron transfer from semiconductor layers to the Ti base. The Co-TiO_2 interlayer and overcoated Sb-SnO_2 islands enhance the evolution of reactive chlorine. The surficial Sb-SnO_2 islands also serve as the reactive sites for free radical generation. Experiments coupled with computational kinetic simulations show that while ·OH and Cl· are initially produced on the SbSn/CoTi/Ir anode surface, the dominant radical formed in solution is the dichlorine radical anion, Cl_2·–. The steady-state concentration of reactive radicals is 10 orders of magnitude lower than that of reactive chlorine. The SbSn/CoTi/Ir anode was applied to electrochemically treat human wastewater. These test results show that COD and NH_4^+ can be removed after 2 h of electrolysis with minimal energy consumption (370 kWh/kg COD and 383 kWh/kg NH_4^+). Although free radical species contribute to COD removal, anodes designed to enhance reactive chlorine production are more effective than those designed to enhance free radical production