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  • Author: Heng Yang x
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Abstract

On March 11, 2020, the WHO declared that coronavirus disease 2019 (COVID-19) can be characterized as a pandemic based on the alarming levels of spread and severity and on the alarming levels of inaction. COVID-19 has received worldwide attention as emergency, endangering international public health and economic development. There is a growing body of literatures regarding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as COVID-19. This review will focus on the latest advance of epidemiology, pathogenesis, and clinical characteristics about COVID-19. Meanwhile, tuberculosis (TB) remains the leading representative respiratory tract communicable disease threatening public health. There are limited data on the risk of severe disease or outcomes in patients with concurrence of TB and COVID-19. Nevertheless, co-infection of some virus would aggravate TB, such as measles. And tuberculosis and influenza co-infection compared with tuberculosis single infection was associated with increased risk of death in individuals. This review will also introduce the characteristics about the concurrence of TB and emerging infectious diseases to provide a hint to manage current epidemic.

Abstract

The fructose-2,6-bisphosphatase domain of the bifunctional chicken liver enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase shares approximately 95% amino acid sequence homology with that of the rat enzyme. However, these two enzymes are significantly different in their phosphatase activities. In this report, we show that the COOH-terminal 25 amino acids of the two enzymes are responsible for the different enzymatic activities. Although these 25 amino acids are not required for the phosphatase activity, their removal diminishes the differences in the activities between the two enzymes. In addition, two chimeric molecules (one consisting of the catalytic core of the chicken bisphosphatase domain and the rat COOH-terminal 25 amino acids, and the other consisting of most of the intact chicken enzyme and the rat COOH-terminal 25 amino acids) showed the same kinetic properties as the rat enzyme. Furthermore, substitution of the residues Pro456pro457Ala458 of the chicken enzyme with GluAlaGlu, the corresponding sequence in the rat liver enzyme, yields a chicken enzyme that behaves like the rat enzyme. These results demonstrate that the different bisphosphatase activities of the chicken and rat liver bifunctional enzymes can be attributed to the differences in their COOH-terminal amino acid sequences, particularly the three residues.

Abstract

The kinetics of cellulose decomposition in an ionic liquid/organic solvent were investigated using microcrystalline cellulose as the raw material. Curve fitting of the cellulose degradation kinetic data was conducted using MATLAB. Results indicated that the catalytic decomposition reactions of cellulose, glucose and 5-hydroxymethylfurfural (5-HMF), along with the diffusion process of 5-HMF, were all first-order reactions in the biphasic system. The decomposition rate constants of cellulose, glucose and 5-HMF, along with the diffusion coefficient of 5-HMF (k5), in the biphasic system were obtained using the first-order reaction model. The organic solvent could suppress the formation of by-products to a certain extent and reduced the activation energy of cellulose, glucose and 5-HMF degradation by 4.24 %, 5.17 % and 3.73 %, respectively, compared with cellulose degradation in ionic liquid. The amount of organic solvent had little effect on glucose yield within the optimum reaction time and did not ascertain the presence of glucose in the organic solvent. k5 was relatively small and increased with an increase in temperature, reaction time and amounts of [BMIM]Cl, catalyst and organic solvent, with temperature exerting the greatest effect.

Abstract

Shell model calculations have been carried out for 90Nb nucleus with the model space in which the valence protons occupy the f5/2, p3/2, p1/2, and g9/2 orbitals and the valence neutrons occupy the p1/2, g9/2, d5/2, and g7/2 orbitals. According to the calculated results, the negative parity is from the contribution of the proton of the f5/2, p3/2, and p1/2 orbits. The moderate spin states of 90Nb are mainly due to the excitation of protons from the f5/2 and p3/2 orbits to the p1/2 and g9/2 orbits across the Z = 38 subshell closure, and the high spin states arise from the excitation of a single neutron from the g9/2 orbit into the d5/2 orbit across the N = 50 shell closure.

Abstract

Si3N4/nano-carbon black (CB) composite ceramics with boron nitride (BN) as interphase were fabricated by gelcasting. The results of scanning electron microscopy (SEM) and X-ray diffraction (XRD) showed that the structures of BN interphase and BN coated CB were formed and were uniform distributed in the Si3N4 ceramic. The permittivity (εε″) of BN-coated CB was obviously lower than that of the pure CB, and the impedance of the BN-coated CB particles was close to the Z 0 (Z 0 = 1, Z 0 is impedance under vacuum) compared with that of the CB particles; therefore, electromagnetic wave can enter into the BN-coated CB particles and be dissipated due to the high conductivity of CB particles. When incorporating the BN(CB) into Si3N4 substrate, the electromagnetic wave can pass through Si3N4/nano-CB composite ceramics easily and be absorbed by CB, so the tgδ of the composite ceramic increased as the mass content of BN(CB) increased. The tgδ of the composite ceramic was about 0.43 when the content of BN(CB) increased to 15 wt%.

Abstract

C4H7N4O5V, monoclinic, P21/c (no. 14), a = 9.6179(8) Å, b = 8.3133(7)(11) Å, c = 10.8235(9) Å, β = 102.253(2)°, V = 845.69(12) Å3, Z = 8, R gt(F) = 0.0242, wR ref(F 2) = 0.0718, T = 296(2) K.

Abstract

Background and aims

The aim of the study was to examine the effect of mirror and tactile therapy on phantom and stump pain in patients with traumatic amputations, with particular reference to amputees in low-income communities.

Methods

The study was conducted with an open, randomized, semi-crossover case-control design in rural Cambodia. A study sample of 45 landmine victims with trans-tibial amputations was allocated to three treatment arms; mirror therapy, tactile therapy, and combined mirror-and-tactile therapy. Non-responders from the mono-therapy interventions were crossed over to the alternative intervention. The intervention consisted of 5 min of treatment every morning and evening for 4 weeks. Endpoint estimates of phantom limb pain (PLP), stump pain, and physical function were registered 3 months after the treatment.

Results

All three interventions were associated with more that 50% reduction in visual analogue scale (VAS)-rated PLP and stump pain. Combined mirror-tactile treatment had a significantly better effect on PLP and stump pain than mirror or tactile therapy alone. The difference between the three treatment arms were however slight, and hardly of clinical relevance. After treatment, the reduction of pain remained unchanged for an observation period of 3 months.

Conclusions

The study documents that a 4-week treatment period with mirror and/or tactile therapy significantly reduces PLP and stump pain after trans-tibial amputations.

Implications

The article reports for the first time a randomized controlled trial of mirror therapy in a homogenous sample of persons with traumatic amputations. The findings are of special relevance to amputees in low-resource communities.