COVID-19 and energy: Influence mechanisms and research methodologies.

Considering the important role of energy in modern society, it is imperative to study the current situation and future development of energy under the influence of COVID-19. This paper identifies the current research hotspots, proposes future research directions accordingly, and summarizes the methodologies via a bibliometric analysis. Five research hotspots include COVID-19 and the changes of energy consumption, COVID-19 and the fluctuation of the energy market, COVID-19 and the development of renewable energy, COVID-19 and climate impacts caused by energy consumption, and COVID-19 and the energy policy. According to the influence mechanism of COVID-19 on each hotspot, the pandemic has exerted short-term influencs on energy consumption, energy price, and air pollution. Meanwhile, the pandemic could have a far-reaching impact on the renewable energy sector, climate, and energy policy. In addition, the main methodologies are reviewed, revealing that regression analysis and scenario analysis are commonly used as the quantitative and qualitative methods, respectively. Moreover, given the nonlinear relations between the pandemic and energy, an artificial neural networks model is used to enhance the prediction efficiency of energy demand and price. Finally, policy implications for obtaining clean, low-carbon, safe, and efficient energy in the context of COVID-19 are proposed.

Improving the High-Frequency Response of PEI-Based Earphone with Sodium Copper Chlorophyllin.

The polyetherimide diaphragm, sodium copper chlorophyllin (SCC), and copper ion coating composite used on earphones were observed to improve the high-frequency (10k-14k Hz) performance. This reinforcement phenomenon was expected to make the sound experience brighter and more diverse. By SEM observation, the mixed coating of SCC/Cu2+ on the polyethylenimine (PEI) diaphragm exhibited a planar blocky structure and was tightly bonded to the surface of the PEI polymer without the aid of colloids. The endothermic process of SCC and metal ion complexation was analyzed by isothermal titration calorimetry. The association ratios of SCC/Cu2+ and SCC/Ni2+ were 4/1 and 6/1, respectively, and the SCC/Cu2+ association yielded a stronger binding constant and more free energy. It was expected that the SCC/Cu2+(4/1) mixed liquid would be immobilized on the PEI polymer by multivalent interaction, including hydrogen-bonding networks between carboxyl groups of SCC and amine groups of PEI, and cross-linking of bridging copper ions. We used dimethylethylenediamine (DME) monomer instead of PEI polymer to analyze this multivalent interaction and observed a two-stage exothermic association of SCC/Cu2+(4/1) and DME with a total Gibbs free energy of 15.15 kcal/mol. We observed that the binding energy could be used to explain that the SCC/Cu2+ mixed formulation could be fixed on the surface of the PEI polymer and could enhance the strength of the PEI film. Compared with graphene films, which can continuously improve the performance of high and ultrasonic frequencies, this study was devoted to and was initiated for the purpose of applying porphyrin compounds to improve music performance.

Light-driven oxygen production from superoxide by Mn-binding bacterial reaction centers.

One of the outstanding questions concerning the early Earth is how ancient phototrophs made the evolutionary transition from anoxygenic to oxygenic photosynthesis, which resulted in a substantial increase in the amount of oxygen in the atmosphere. We have previously demonstrated that reaction centers from anoxygenic photosynthetic bacteria can be modified to bind a redox-active Mn cofactor, thus gaining a key functional feature of photosystem II, which contains the site for water oxidation in cyanobacteria, algae, and plants [Thielges M, et al. (2005) Biochemistry 44:7389-7394]. In this paper, the Mn-binding reaction centers are shown to have a light-driven enzymatic function; namely, the ability to convert superoxide into molecular oxygen. This activity has a relatively high efficiency with a k(cat) of approximately 1 s(-1) that is significantly larger than typically observed for designed enzymes, and a K(m) of 35-40 µM that is comparable to the value of 50 µM for Mn-superoxide dismutase, which catalyzes a similar reaction. Unlike wild-type reaction centers, the highly oxidizing reaction centers are not stable in the light unless they have a bound Mn. The stability and enzymatic ability of this type of Mn-binding reaction centers would have provided primitive phototrophs with an environmental advantage before the evolution of organisms with a more complex Mn(4)Ca cluster needed to perform the multielectron reactions required to oxidize water.

Paraneoplastic polymyositis associated with crescentic glomerulonephritis.

A female concurrently developed polymyositis (PM), lung cancer, and nephrotic range proteinuria. Renal biopsy revealed crescentic glomerulonephritis. Pathology of lung cancer was proved to be adenocarcinoma. After surgical treatment of lung cancer, the symptoms of PM-associated crescentic glomerulonephritis disappeared. PM is associated with a higher risk of malignancy, though renal involvement in patients with PM is thought to be uncommon. In patients with PM, there have been few reports concerning the coexistence of glomerular disease, including crescent glomerulonephritis. Herein we report a case of crescentic glomerulonephritis-associated PM that was successfully treated after the surgical removal of lung cancer. We consider that such association of PM and crescent glomerulonephritis is rare in adults. Careful evaluation of underlying malignancy is important. The definite treatment is adequate management of underlying malignancy.

Proteomic analysis of peritoneal dialysate fluid in patients with dialysis-related peritonitis.

The prognosis of uremia patients on continuous ambulatory peritoneal dialysis (CAPD) is related to frequent peritonitis rate. Frequent peritonitis will lead to peritoneum failure, making CAPD unfeasible. We have performed proteomic profiling of peritoneal dialysis effluent samples from a cross-section of CAPD patients with and without peritonitis in order to identify biomarkers of peritonitis. We performed 2D gel electrophoresis and surface-enhanced laser esorption/ionization time of flight mass spectrometry (SELDI-TOF MS) on peritoneal dialysis effluent from 16 subjects with peritonitis. A genetic algorithm search of principal component space revealed a group of a peak distinguishing peritonitis-positive subjects, with mass/charge (m/z) values of 11,117.4. Our analyses identified the peak at m/z 11,117.4 with an accuracy of 95% for classifying peritonitis. Mass spectrometric analysis of peritonitis PDE samples identified the 11,117.4 protein as beta2-microglobulin (B2M). Using an unbiased protein profiling approach, we have validated previously reported findings of B2M as a biomarker associated with CAPD peritonitis. Prospective studies are warranted to establish additional biomarkers that would be predictive of peritoneal dialysis peritonitis. Besides, extending the study to a larger number of patients with subgroup analyses may yield additional information of the peritoneal dialysate proteins in association with dialysis adequacy, residual renal function, nutritional status, and risk of peritoneal infection.

Sjogren's syndrome complicated with IgA nephropathy and leukocytoclastic vasculitis.

We report a case of primary Sjogren's syndrome (SS) with cutaneous leukocytoclastic vasculitis and IgA nephropathy. The accurate diagnosis of SS was established based on objective signs and symptoms of ocular and oral dryness, a characteristic appearance of a biopsy sample from a minor salivary gland, and the presence of anti-SS-A autoantibody. A second autoimmune disorder was not present, so the diagnosis of primary SS was established. A histologic finding of skin biopsy of purpuric lesion was typical for leukocytoclastic vasculitis. Renal biopsy was performed for nephrotic range proteinuria. The pathologic finding of renal biopsy was IgA glomerulonephritis with crescent formation. The patient was treated with small doses of glucocorticoids and maintenance hemodialysis. Leukocytoclastic vasculitis is one of the most characteristic extraglandular manifestations of SS. However, IgA nephropathy associated with SS and leukocytoclastic vasculitis is a rare finding. SS patients with glomerulonephritis present a more diverse outcome, even requiring hemodialysis. Therefore, renal biopsy is warranted in SS with glomerulonephritis and systemic vasculitis.

Fas expression on peritoneal macrophages during continuous ambulatory peritoneal dialysis peritonitis.

BACKGROUND: Peritonitis is a common complication of end stage renal failure (ESRF) patients receiving continuous ambulatory peritoneal dialysis (CAPD). Peritoneal macrophage may participate in the activation of specific T cells and in the generation of local cell-mediated immunity to various pathogens. The purpose of this study is to investigate the possible role of macrophage in CAPD patients with peritonitis. METHODS: We evaluated the expression of Fas receptor (CD95), ICAM-1 (CD54), CD25, and CD69 by two-color flow cytometry on extravasted macrophages from 16 ESRF patients on CAPD with peritonitis (peritonitis-positive) and compared them to 11 ESRF patients on CAPD without peritonitis (peritonitis-negative) and normal controls. RESULTS: We found an increased expression of CD95, CD54, and CD25 on macrophage in peritonitis-positive group compared to controls (all p < 0.001). In the peritonitis-positive group, the CD95 expression was significantly higher than that of the peritonitis-negative group (p < 0.001). The expression of CD54, CD25, and CD69, however, was not significantly different between the peritonitis-positive and peritonitis-negative CAPD subgroups. CONCLUSION: We found an abnormally increased percentage of macrophage-expressing Fas receptor and ICAM-1, and the percentage of CD95+ macrophage, but not those of other markers, were increased among the subset of CAPD patients with peritonitis. The later finding suggests that this macrophage phenotype is associated with peritonitis occurring in CAPD.

Aminograms during continuous hemodiafiltration in the treatment of hyperammonemia due to ornithine transcarbamylase deficiency.

BACKGROUND: Hyperammonemia caused by ornithine transcarbamylase (OTC) deficiency can be properly managed by continuous arteriovenous hemodiafiltration (CAVHDF). Removal of amino acids (AA) during CAVHDF has not been thoroughly investigated. AA losses in patients with urea cycle defects due to ornithine transcarbamylase deficiency treated by CAVHDF were analyzed. METHODS: Twelve neonates with elevated serum ammonia levels, confirmed through urine organic acid analysis and serum amino acid studies, were documented to have OTC deficiency. CAVHDF was administered in an attempt to lower serum ammonia concentration. Amino acid analysis of ultrafiltration and serum were performed by liquid chromatography. RESULTS: Serum levels of leucine, isoleucine, methionine, phenylalanine, and tyrosine were significantly lower than acceptable in these patients. Glutamine was the only amino acid that increased significantly, which is clinically relevant to OTC enzyme deficiency. Although the mean serum concentrations of tyrosine and glutamine concentrations were lower in the dialysate, the serum and dialysate concentrations of other amino acids did not differ. CONCLUSION: CAVHDF may induce changes in amino acid metabolism and distribution as well. The requirement of aminogram monitor for amino acid supplementation in urea cycle defect patients is important.

Continuous hemodiafiltration in the treatment of hyperammonemia due to methylmalonic acidemia.

Methylmalonic academia (MMA) is a rare inborn error of branched-chain amino acid metabolism. Therapy consists of a special formulated protein diet, carnitine supplementation, and emergent detoxification during acute decompensation. Continuous hemodiafiltration is a modality choice to treat acute metabolic decompensation in inborn error of metabolism. We report the successful use of continuous hemodiafiltration in the management of acute decompensation in patients with methylmalonic academia. Three male patients were diagnosed with methylmalonic academia with the initial presentation of hyperammonemia. Continuous hemodiafiltration was utilized to treat acute decompensation of metabolic crisis. This approach results in a rapid reduction of systemic toxin levels. Continuous hemodiafiltration should be considered as a treatment modality for symptomatic neonates with MMA where hemodialysis is not feasible.