Novel Electrolytic Regeneration Method for Cyclic Regeneration of Ozone Decomposition MnOx Catalysts.

The deactivation of ozone decomposition catalysts has been a bottleneck in their industrial application. As an efficient catalyst regeneration method, the liquid-phase method has attracted wide attention due to its operability and universality. However, the amount of waste liquid generated by the used regeneration liquid is a major drawback of its application. Therefore, we propose an electrolytic regeneration method for cyclic regeneration of MnOx ozone decomposition catalysts by combining the advantages of the electrolytic process. In this method, NaNO2 solution is used to react with O22- to efficiently regenerate the inactivated MnOx catalysts, while NO2- is oxidized to NO3-, and then the oxidized NO3- can be efficiently reduced to NO2- through the electrolysis process at the cathode with an 88% Faraday efficiency, ultimately realizing the recycling of the NO2-/NO3- regeneration solution. By this method, the regeneration of inactivated MnOx ozone catalysts can be realized only using electricity.

Regulating Strain and Electronic Structure of Indium Tin Oxide Supported IrOx Electrocatalysts for Highly Efficient Oxygen Evolution Reaction in Acid.

The development of proton exchange membrane water electrolysis is a promising technology for hydrogen production, which has always been restricted by the slow kinetics of the oxygen evolution reaction (OER). Although IrOx is one of the benchmark acidic OER electrocatalysts, there are still challenges in designing highly active and stable Ir-based electrocatalysts for commercial application. Herein, a Ru-doped IrOx electrocatalyst with abundant twin boundaries (TB-Ru0.3Ir0.7Ox@ITO) is reported, employing indium tin oxide with high conductivity as the support material. Combing the TB-Ru0.3Ir0.7Ox nanoparticles with ITO support could expose more active sites and accelerate the electron transfer. The TB-Ru0.3Ir0.7Ox@ITO exhibits a low overpotential of 203 mV to achieve 10 mA cm-2 and a high mass activity of 854.45 A g-1noble metal at 1.53 V vs RHE toward acidic OER, which exceeds most reported Ir-based OER catalysts. Moreover, improved long-term stability could be obtained, maintaining the reaction for over 110 h at 10 mA cm-2 with negligible deactivation. DFT calculations further reveal the activity enhancement mechanism, demonstrating the synergistic effects of Ru doping and strains on the optimization of the d-band center (εd) position and the adsorption free energy of oxygen intermediates. This work provides ideas to realize the trade-off between high catalytic activity and good stability for acidic OER electrocatalysts.

Chromosome-level genome assembly of a high-altitude-adapted frog (Rana kukunoris) from the Tibetan plateau provides insight into amphibian genome evolution and adaptation.

BACKGROUND: The high-altitude-adapted frog Rana kukunoris, occurring on the Tibetan plateau, is an excellent model to study life history evolution and adaptation to harsh high-altitude environments. However, genomic resources for this species are still underdeveloped constraining attempts to investigate the underpinnings of adaptation. RESULTS: The R. kukunoris genome was assembled to a size of 4.83 Gb and the contig N50 was 1.80 Mb. The 6555 contigs were clustered and ordered into 12 pseudo-chromosomes covering ~ 93.07% of the assembled genome. In total, 32,304 genes were functionally annotated. Synteny analysis between the genomes of R. kukunoris and a low latitude species Rana temporaria showed a high degree of chromosome level synteny with one fusion event between chr11 and chr13 forming pseudo-chromosome 11 in R. kukunoris. Characterization of features of the R. kukunoris genome identified that 61.5% consisted of transposable elements and expansions of gene families related to cell nucleus structure and taste sense were identified. Ninety-five single-copy orthologous genes were identified as being under positive selection and had functions associated with the positive regulation of proteins in the catabolic process and negative regulation of developmental growth. These gene family expansions and positively selected genes indicate regions for further interrogation to understand adaptation to high altitude. CONCLUSIONS: Here, we reported a high-quality chromosome-level genome assembly of a high-altitude amphibian species using a combination of Illumina, PacBio and Hi-C sequencing technologies. This genome assembly provides a valuable resource for subsequent research on R. kukunoris genomics and amphibian genome evolution in general.

Therapeutic experience of a pancreatic mixed serous neuroendocrine neoplasm invading peripancreatic vessels: A case report.

RATIONALE: Pancreatic mixed serous neuroendocrine neoplasm (PMSNN) is an extremely rare disease. Only a few cases on the surgical treatment of PMSNN have been reported in the literature, and it is unclear whether there is invasion of important peripancreatic vessels. PATIENT CONCERNS: We report the case of a 39-year-old female patient with PMSNN accompanied by invasion of important peripancreatic vessels. She underwent surgery and achieved satisfactory recovery. DIAGNOSIS: Abdominal enhanced CT images showed an enhanced mass with a nonenhanced cyst involving the head and body of the pancreas, which invaded important peripancreatic vessels. The lesion had been misdiagnosed and mistreated as a metastatic carcinoma before admission. INTERVENTIONS: CT 3-dimensional (3D) visualization reconstruction images showed intact peripancreatic vessels. Radical pancreatoduodenectomy was successfully performed and confirmed that the main blood vessels around the pancreas were only compressed or even wrapped by the mass, but not penetrated. OUTCOMES: The patient recovered well and was discharged on the 19th day after surgery. Pathological examination reported the diagnosis of PMSNN with the collision type combination and the well-differentiated grade 2 pancreatic neuroendocrine tumor. She was followed up for 18 months without any abnormalities. LESSONS: This case demonstrates that surgical treatment of PMSNN with invasion of peripancreatic vessels can be successful. Preoperative abdominal CT 3D visualization reconstruction is helpful in determining the degree of invasion of important peripancreatic vessels, and plays a key role in formulating an accurate surgical plan and improving patient outcome.

The mitochondrial genome and phylogenetic analysis of Rhacophorus rhodopus.

Classification of the genus Rhacophorus has been problematic. In particular there has been considerable controversy surrounding the phylogenetic relationships among Rhacophorus rhodopus, R. bipunctatus, and R. reinwardtii. To examine the relationship among these Rhacophorus species, we assembled the complete mitochondrial genome sequence of R. rhodopus. The R. rhodopus genome is 15,789 bp in length with 12 protein-coding genes (PCGs) (losing ND5), two ribosomal genes, 22 transfer RNA genes, and a control region (D-loop). Base composition of the overall sequence was 60.86% for A + T content and 39.14% for C + G content. Most of the PCGs used ATG as a start codon, except for the COX I gene, which used the ATA start codon. COX I and ND6 used AGG and ATP8 stop codons respectively, while ND3 and ND4L used the TAA stop codon. For the remaining seven genes, the stop codons was incomplete. In addition, both 5' and 3' of the control areas had distinct repeating regions. Based on three datasets and two methods (Bayesian inference (BI) and maximum likelihood (ML)), we reconstructed three phylogenetic trees to explore the taxonomic status of the species and the phylogenetic relationship among R. rhodopus, R. bipunctatus and R. reinwardtii. Our results indicated that these three species are non-monophyletic; thus, the phylogenetic relationship among them is complex and difficult to determine. Further, R. rhodopus is divided into three lineages from different parts of China. The two Rhacophorus samples showed very close phylogenetic relationship with R. rhodopus. Our results add to the mitochondrial genome database of amphibians and will help to disentangle the phylogenetic relationships within the Rhacophoridae.

The complete mitochondrial genome sequence of big-eyed Mountain keelback Pseudoxenodon macrops.

In this study, the complete mitochondrial genome of big-eyed mountain keelback Pseudoxenodon macrops was sequenced adopting Illumina high-throughput sequencing technology. The complete mitogenome of the species was 19,444 bp in length, including 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA genes, and two non-coding control regions (CR). The overall base composition of mitogenome was 32.0% A, 25.5% T, 28.2% C, and 14.3% G. Most mitochondrial genes are encoded on the heavy strand, only ND6 and eight tRNA genes are on the light strand. We expect that the presented mitogenome can provide important data for future studies on phylogenetic relationship and population genetics of this species.

The complete mitochondrial genome sequence of Himalayan toad Duttaphrynus himalayanus (Anura: Bufonidae).

In this study, the complete mitochondrial genome of Duttaphrynus himalayanus was sequenced adopting Illumina high-throughput sequencing method. The complete mitogenome of the species was 17,172 bp in length, including 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA genes, and a non-coding control region (CR). The overall base composition of mitogenome was 29.7% A, 29.6% T, 26.0% C, and 14.7% G. Most mitochondrial genes are encoded on the heavy strand, only ND6 and eight tRNA genes on the light strand. The complete mitogenome of D. himalayanus can provide an important data for future studies on phylogenetic relationship and population genetics of this species.

The complete mitochondrial genome sequences of Nanorana chayuensis.

In this study, we obtained the complete mitochondrial genome sequence of Nanorana chayuensis. The mitogenome length is 17,882 bp, including 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNA), 2 ribosomal RNA genes (rRNA), and 1 non-coding control region (CR). Present data will contribute to further analysis of phylogenetic relationship and population genetics of this species.

Therapeutic experience of an 89-year-old high-risk patient with incarcerated cholecystolithiasis: A case report and literature review.

BACKGROUND: The global pandemic of coronavirus disease 2019 pneumonia poses a particular challenge to the emergency surgical treatment of elderly patients with high-risk acute abdominal diseases. Elderly patients are a high-risk group for surgical treatment. If the incarceration of gallstones cannot be relieved, emergency surgery is unavoidable. CASE SUMMARY: We report an 89-year-old male patient with acute gangrenous cholecystitis and septic shock induced by incarcerated cholecystolithiasis. He had several coexisting, high-risk underlying diseases, had a history of radical gastrectomy for gastric cancer, and was taking aspirin before the operation. Nevertheless, he underwent emergency laparoscopic cholecystectomy, with maintenance of postoperative heart and lung function, successfully recovered, and was discharged on day 8 after the operation. CONCLUSION: Emergency surgery for elderly patients with acute abdominal disease is safe and feasible during the coronavirus disease 2019 pandemic, the key is to abide strictly by the hospital's epidemic prevention regulations, fully implement the epidemic prevention procedure for emergency surgery, fully prepare before the operation, accurately perform the operation, and carefully manage the patient postoperatively.

Ischemic or toxic injury: A challenging diagnosis and treatment of drug-induced stenosis of the sigmoid colon.

A 48-year-old woman was admitted with 15-mo history of abdominal pain, diarrhea and hematochezia, and 5-mo history of defecation difficulty. She had been successively admitted to nine hospitals, with an initial diagnosis of inflammatory bowel disease with stenotic sigmoid colon. Findings from computed tomography virtual colonoscopy, radiography with meglumine diatrizoate, endoscopic balloon dilatation, metallic stent implantation and later overall colonoscopy, coupled with the newfound knowledge of compound Qingdai pill-taking, led to a subsequent diagnosis of ischemic or toxic bowel disease with sigmoid colon stenosis. The patient was successfully treated by laparoscopic sigmoid colectomy, and postoperative pathological examination revealed ischemic or toxic injury of the sigmoid colon, providing a final diagnosis of drug-induced sigmoid colon stenosis. This case highlights that adequate awareness of drug-induced colon stenosis has a decisive role in avoiding misdiagnosis and mistreatment. The diagnostic and therapeutic experiences learnt from this case suggest that endoscopic balloon expansion and colonic metallic stent implantation as bridge treatments were demonstrated as crucial for the differential diagnosis of benign colonic stenosis. Skillful surgical technique and appropriate perioperative management helped to ensure the safety of our patient in subsequent surgery after long-term use of glucocorticoids.

Fluorinated graphene as high performance dielectric materials and the applications for graphene nanoelectronics.

There is broad interest in surface functionalization of 2D materials and its related applications. In this work, we present a novel graphene layer transistor fabricated by introducing fluorinated graphene (fluorographene), one of the thinnest 2D insulator, as the gate dielectric material. For the first time, the dielectric properties of fluorographene, including its dielectric constant, frequency dispersion, breakdown electric field and thermal stability, were comprehensively investigated. We found that fluorographene with extremely thin thickness (5 nm) can sustain high resistance at temperature up to 400 °C. The measured breakdown electric field is higher than 10 MV cm(-1), which is the heightest value for dielectric materials in this thickness. Moreover, a proof-of-concept methodology, one-step fluorination of 10-layered graphene, is readily to obtain the fluorographene/graphene heterostructures, where the top-gated transistor based on this structure exhibits an average carrier mobility above 760 cm(2)/Vs, higher than that obtained when SiO2 and GO were used as gate dielectric materials. The demonstrated fluorographene shows excellent dielectric properties with fast and scalable processing, providing a universal applications for the integration of versatile nano-electronic devices.

One-step formation of a single atomic-layer transistor by the selective fluorination of a graphene film.

In this study, the scalable and one-step fabrication of single atomic-layer transistors is demonstrated by the selective fluorination of graphene using a low-damage CF4 plasma treatment, where the generated F-radicals preferentially fluorinated the graphene at low temperature (<200 °C) while defect formation was suppressed by screening out the effect of ion damage. The chemical structure of the C-F bonds is well correlated with their optical and electrical properties in fluorinated graphene, as determined by X-ray photoelectron spectroscopy, Raman spectroscopy, and optical and electrical characterizations. The electrical conductivity of the resultant fluorinated graphene (F-graphene) was demonstrated to be in the range between 1.6 kΩ/sq and 1 MΩ/sq by adjusting the stoichiometric ratio of C/F in the range between 27.4 and 5.6, respectively. Moreover, a unique heterojunction structure of semi-metal/semiconductor/insulator can be directly formed in a single layer of graphene using a one-step fluorination process by introducing a Au thin-film as a buffer layer. With this heterojunction structure, it would be possible to fabricate transistors in a single graphene film via a one-step fluorination process, in which pristine graphene, partial F-graphene, and highly F-graphene serve as the source/drain contacts, the channel, and the channel isolation in a transistor, respectively. The demonstrated graphene transistor exhibits an on-off ratio above 10, which is 3-fold higher than that of devices made from pristine graphene. This efficient transistor fabrication method produces electrical heterojunctions of graphene over a large area and with selective patterning, providing the potential for the integration of electronics down to the single atomic-layer scale.

Calneuron I inhibits Ca(2+) channel activity in bovine chromaffin cells.

Calneuron I (CalnI) is a calmodulin-like protein that contains two functional EF-hand motifs at the N-terminal and a hydrophobic segment at the C-terminal. CalnI was cloned from the adult rat cortex and fused with GFP at its N-terminal. When expressed in bovine chromaffin cells, wild-type CalnI was localized at the plasma membrane. However, a mutant that lacked the hydrophobic segment was localized in the cytosol and nucleus, while a Ca(2+)-binding-deficient mutant was found in the cytosol and at the plasma membrane. Evaluation using the whole-cell patch-clamp technique revealed that Ca(2+) currents were inhibited by both wild-type CalnI and the Ca(2+)-binding-deficient mutant. When the bovine N-type Ca(2+) channel was expressed in 293T cells, Ca(2+) currents were mostly inhibited by co-expression of CalnI, but not by the mutant without the hydrophobic tail. These results suggest that CalnI attenuates Ca(2+) channel activity and that its subcellular localization is important for this effect.

Dynasore inhibits rapid endocytosis in bovine chromaffin cells.

Vesicle recycling is vital for maintaining membrane homeostasis and neurotransmitter release. Multiple pathways for retrieving vesicles fused to the plasma membrane have been reported in neuroendocrine cells. Dynasore, a dynamin GTPase inhibitor, has been shown to specifically inhibit endocytosis and vesicle recycling in nerve terminals. To characterize its effects in modulating vesicle recycling and repetitive exocytosis, changes in the whole cell membrane capacitance of bovine chromaffin cells were recorded in the perforated-patch configuration. Constitutive endocytosis was blocked by dynasore treatment, as shown by an increase in membrane capacitance. The membrane capacitance was increased during strong depolarizations and declined within 30 s to a value lower than the prestimulus level. The amplitude, but not the time constant, of the rapid exponential decay was significantly decreased by dynasore treatment. Although the maximal increase in capacitance induced by stimulation was significantly increased by dynasore treatment, the intercepts at time 0 of the curve fitted to the decay phase were all approximately 110% of the membrane capacitance before stimulation, regardless of the dynasore concentration used. Membrane depolarization caused clathrin aggregation and F-actin continuity disruption at the cell boundary, whereas dynasore treatment induced clathrin aggregation without affecting F-actin continuity. The number of invagination pits on the surface of the plasma membrane determined using atomic force microscopy was increased and the pore was wider in dynasore-treated cells. Our data indicate that dynamin-mediated endocytosis is the main pathway responsible for rapid compensatory endocytosis.