Key role of K+ and Ca2+ in high-yield ethanol production by S. Cerevisiae from concentrated sugarcane molasses.

BACKGROUND: Saccharomyces cerevisiae is an important microorganism in ethanol synthesis, and with sugarcane molasses as the feedstock, ethanol is being synthesized sustainably to meet growing demands. However, high-concentration ethanol fermentation based on high-concentration sugarcane molasses-which is needed for reduced energy consumption of ethanol distillation at industrial scale-is yet to be achieved. RESULTS: In the present study, to identify the main limiting factors of this process, adaptive laboratory evolution and high-throughput screening (Py-Fe3+) based on ARTP (atmospheric and room-temperature plasma) mutagenesis were applied. We identified high osmotic pressure, high temperature, high alcohol levels, and high concentrations of K+, Ca2+, K+ and Ca2+ (K+&Ca2+), and sugarcane molasses as the main limiting factors. The robust S. cerevisiae strains of NGT-F1, NGW-F1, NGC-F1, NGK+, NGCa2+ NGK+&Ca2+-F1, and NGTM-F1 exhibited high tolerance to the respective limiting factor and exhibited increased yield. Subsequently, ethanol synthesis, cell morphology, comparative genomics, and gene ontology (GO) enrichment analysis were performed in a molasses broth containing 250 g/L total fermentable sugars (TFS). Additionally, S. cerevisiae NGTM-F1 was used with 250 g/L (TFS) sugarcane molasses to synthesize ethanol in a 5-L fermenter, giving a yield of 111.65 g/L, the conversion of sugar to alcohol reached 95.53%. It is the highest level of physical mutagenesis yield at present. CONCLUSION: Our results showed that K+ and Ca2+ ions primarily limited the efficient production of ethanol. Then, subsequent comparative transcriptomic GO and pathway analyses showed that the co-presence of K+ and Ca2+ exerted the most prominent limitation on efficient ethanol production. The results of this study might prove useful by promoting the development and utilization of green fuel bio-manufactured from molasses.

A pregnant woman with pre-XDR PTB giving birth to a healthy newborn: A case report.

We reported a late-pregnancy woman with pre-XDR PTB who had not received regular anti-tuberculosis treatment prior to delivery. Despite this, she successfully delivered a premature baby who exhibited normal growth and development, and subsequently completed her anti-tuberculosis treatment. This report suggests that delayed treatment for pre-XDR TB during late pregnancy does not necessarily increase the risk of treatment failure for the mother or the risk of neonatal tuberculosis.

A trapped covalent intermediate as a key catalytic element in the hydrolysis of a GH3 ß-glucosidase: An X-ray crystallographic and biochemical study.

Glycoside hydrolases (GHs) are industrially important enzymes that hydrolyze glycosidic bonds in glycoconjugates. In this study, we found a GH3 ß-glucosidase (CcBgl3B) from Cellulosimicrobium cellulans sp. 21 was able to selectively hydrolyze the ß-1,6-glucosidic bond linked glucose of ginsenosides. X-ray crystallographic studies of the ligand complex ginsenoside-specific ß-glucosidase provided a novel finding that support the catalytic mechanism of GH3. The substrate was clearly identified within the catalytic center of wild-type CcBgl3B, revealing that the C1 atom of the glucose was covalently bound to the Oδ1 group of the conserved catalytic nucleophile Asp264 as an enzyme-glycosyl intermediate. The glycosylated Asp264 could be identified by mass spectrometry. Through site-directed mutagenesis studies with Asp264, it was found that the covalent intermediate state formed by Asp264 and the substrate was critical for catalysis. In addition, Glu525 variants (E525A, E525Q and E525D) showed no or marginal activity against pNPßGlc; thus, this residue could supply a proton for the reaction. Overall, our study provides an insight into the catalytic mechanism of the GH3 enzyme CcBgl3B.

Effect of Corticosteroids on Long-term Humoral and Memory T-Cell Responses in Follow-up Visit of Hospitalized Patients With COVID-19.

BACKGROUND: Corticosteroids have beneficial effects in improving outcomes in hospitalized patients with severe COVID-19 by suppressing excessive immune responses. However, the effect of corticosteroids on the humoral and T-cell responses of survivors of COVID-19 1 year after infection remains uncertain because it relates to the extent of immediate, antigen-specific defense provided by protective memory. RESEARCH QUESTION: What is the effect of corticosteroids on long-term humoral and T-cell immune responses? STUDY DESIGN AND METHODS: In this retrospective cohort study conducted at a single center, we analyzed data from a cohort who had survived COVID-19 to compare the 1-year seropositivity and titer changes in neutralizing antibodies (NAbs) and SARS-CoV-2-specific antibodies. Additionally, we evaluated the magnitude and rate of SARS-CoV-2-specific T-cell response in individuals who received corticosteroids during hospitalization and those who did not. RESULTS: Our findings indicated that corticosteroids do not statistically influence the kinetics or seropositive rate of NAbs against the Wuhan strain of SARS-CoV-2 from 6 months to 1 year. However, subgroup analysis revealed a numerical increase of absolute NAbs titers, from 20.0 to 28.2, in categories where long-term (> 15 days) and high-dose (> 560 mg) corticosteroids are administered. Similarly, corticosteroids showed no significant effect on nucleoprotein and receptor-binding domain IgG at 1 year, except for spike protein IgG (ß, 0.08; 95% CI, 0.04-0.12), which demonstrated a delayed decline of titers. Regarding T-cell immunity, corticosteroids did not affect the rate or magnitude of T-cell responses significantly. However, functional assessment of memory T cells revealed higher interferon-γ responses in CD4 (ß, 0.61; 95% CI, 0.10-1.12) and CD8 (ß, 0.63; 95% CI, 0.11-1.15) memory T cells in the corticosteroids group at 1 year. INTERPRETATION: Based on our findings, short-term and low-dose corticosteroid therapy during hospitalization does not have a significant effect on long-term humoral kinetics or the magnitude and rate of memory T-cell responses to SARS-CoV-2 antigens. However, the potential harmful effects of long-term and high-dose corticosteroid use on memory immune responses require further investigation.

High tunneling electroresistance in ferroelectric tunnel junctions based on two-dimensional α-In2Se3/MoTe2 van der Waals heterostructures.

Ferroelectric polarization-controlled band alignment can be realized in van der Waals heterostructures (vdWHs), which can be used to create new types of ferroelectric tunnel junctions (FTJs). In this work, we design six probable configurations of two-dimensional vdWHs based on a two-dimensional α-In2Se3 ferroelectric material which has two opposite polarization states P↑ and P↓, and the semiconductor MoTe2. First-principles calculations show robust ferroelectric polarization-controlled switching behavior between the high conductance state in configuration AA-P↓ and the low conductance state in configuration AA-P↑ in the most stable AA stacked vdWHs. Based on this vdWH, a two-dimensional transverse FTJ with AA-P↓ or AA-P↑ as the tunneling barrier and (In0.5Sn0.5)2Se3 monolayers (n-type doped) as electrodes is designed. The tunneling electroresistance ratio of the FTJs at the Fermi level reaches 1.22 × 104% when the tunneling barrier contains two repeating units N = 2 and can be greatly increased by increasing the thickness of the ferroelectric layer. Analysis of the work function, charge redistribution, and local density of states is performed to interpret the above phenomena. The findings suggest the great potential of the AA stacked α-In2Se3/MoTe2 vdWH in the design of high-performance FTJs and application in high-density non-volatile memory devices.

Electrically function-switchable magnetic domain-wall memory.

Versatile memory is strongly desired for end users, to protect their information in the information era. In particular, bit-level switchable memory that can be switched from rewritable to read-only function would allow end users to prevent important data being tampered with. However, no such switchable memory has been reported. We demonstrate that the rewritable function can be converted into read-only function by applying a sufficiently large current pulse in a U-shaped domain-wall memory, which comprises an asymmetric Pt/Co/Ru/AlOx heterostructure with strong Dzyaloshinskii-Moriya interaction. Wafer-scale switchable magnetic domain-wall memory arrays on 4-inch Si/SiO2 substrate are demonstrated. Furthermore, we confirm that the information can be stored in rewritable or read-only states at bit level according to the security needs of end users. Our work not only provides a solution for personal confidential data, but also paves the way for developing multifunctional spintronic devices.

A radio pulsar phase from SGR J1935+2154 provides clues to the magnetar FRB mechanism.

The megajansky radio burst, FRB 20200428, and other bright radio bursts detected from the Galactic source SGR J1935+2154 suggest that magnetars can make fast radio bursts (FRBs), but the emission site and mechanism of FRB-like bursts are still unidentified. Here, we report the emergence of a radio pulsar phase of the magnetar 5 months after FRB 20200428. Pulses were detected in 16.5 hours over 13 days using the Five-hundred-meter Aperture Spherical radio Telescope, with luminosities of about eight decades fainter than FRB 20200428. The pulses were emitted in a narrow phase window anti-aligned with the x-ray pulsation profile observed using the x-ray telescopes. The bursts, conversely, appear in random phases. This dichotomy suggests that radio pulses originate from a fixed region within the magnetosphere, but bursts occur in random locations and are possibly associated with explosive events in a dynamically evolving magnetosphere. This picture reconciles the lack of periodicity in cosmological repeating FRBs within the magnetar engine model.

Endoplasmic Reticulum Stress in Osteoarthritis: A Novel Perspective on the Pathogenesis and Treatment.

Osteoarthritis (OA), the most common degenerative joint disease, causes an enormous socioeconomic burden due to its disabling properties and high prevalence. Increasing evidence suggests that OA is a whole-joint disease involving cartilage degradation, synovitis, meniscal lesions, and subchondral bone remodeling. Endoplasmic reticulum (ER) stress is the accumulation of misfolded/unfolded proteins in the ER. Recent studies have found that ER stress is involved in the OA pathological changes by influencing the physiological function and survival of chondrocytes, fibroblast-like synoviocytes, synovial macrophages, meniscus cells, osteoblasts, osteoclasts, osteocytes, and bone marrow mesenchymal stem cells. Therefore, ER stress is an attractive and promising target for OA. However, although targeting ER stress has been proven to alleviate OA progression in vitro and in vivo, the treatments for OA remain in preclinical stage and require further investigation.

Phosphorylation of a wheat aquaporin at two sites enhances both plant growth and defense.

Eukaryotic aquaporins share the characteristic of functional multiplicity in transporting distinct substrates and regulating various processes, but the underlying molecular basis for this is largely unknown. Here, we report that the wheat (Triticum aestivum) aquaporin TaPIP2;10 undergoes phosphorylation to promote photosynthesis and productivity and to confer innate immunity against pathogens and a generalist aphid pest. In response to elevated atmospheric CO2 concentrations, TaPIP2;10 is phosphorylated at the serine residue S280 and thereafter transports CO2 into wheat cells, resulting in enhanced photosynthesis and increased grain yield. In response to apoplastic H2O2 induced by pathogen or insect attacks, TaPIP2;10 is phosphorylated at S121 and this phosphorylated form transports H2O2 into the cytoplasm, where H2O2 intensifies host defenses, restricting further attacks. Wheat resistance and grain yield could be simultaneously increased by TaPIP2;10 overexpression or by expressing a TaPIP2;10 phosphomimic with aspartic acid substitutions at S121 and S280, thereby improving both crop productivity and immunity.

Arthroscopic therapy of rotator cuff diseases: A bibliometric study of the past 2 decades (2002-2021).

Purpose: Rotator cuff diseases, as a common cause of shoulder pain and disability, have seriously affected the patients' daily life. Rotator cuff repair techniques have been a hot topic in the arthroscopic therapy field. Our study was to use bibliometrics analysis to clarify the current status and research trends in the field of arthroscopic therapy of rotator cuff diseases. Methods: The publications relating to arthroscopic therapy of rotator cuff diseases published from 2001 to 2021 were obtained from the Web of Science Core Collection (WoSCC) database. The R software and VOSviewer software were used for the cross-sectional bibliometric and scientometric analysis. Results: A total of 4,567 publications about arthroscopic therapy of rotator cuff diseases published between 2002 and 2021 retrieved from the WoSCC database were analyzed in our study. The results showed that the United States made the largest contribution to this field. The most relevant institutions were Seoul National University, Rush University, and Hospital for Special Surgery. Stephen S Burkhart was the most relevant researcher in this field with the largest number of publications, as well as the highest H-index and G-index. The journal ARTHROSCOPY contributed the largest number of publications in the past 2 decades. Considering the H-index and G-index, ARTHROSCOPY was also the journal with the largest impact in this field. Conclusions: Arthroscopic Therapy of Rotator Cuff Diseases Related research presented a rising trend in the past 2 decades. The United States can be regarded as the leader because of its huge contributions to this field. The journal ARTHROSCOPY published the largest number of publications in this field. It can be predicted that research about advanced arthroscopic techniques and postoperative pain management of patients with rotator cuff diseases will be the next research hotspots in the following years.

Enhancing the Production of Pinene in Escherichia coli by Using a Combination of Shotgun, Product-Tolerance and I-SceI Cleavage Systems.

Tolerance breeding through genetic engineering, sequence and omics analyses, and gene identification processes are widely used to synthesize biofuels. The majority of related mechanisms have been shown to yield endogenous genes with high expression. However, the process was time-consuming and labor-intensive, meaning there is a need to address the problems associated with the low-throughput screening method and significant time and money consumption. In this study, a combination of the limit screening method (LMS method) and product-tolerance engineering was proposed and applied. The Escherichia coli MG1655 genomic DNA library was constructed using the shotgun method. Then, the cultures were incubated at concentrations of 0.25%, 0.5%, 0.75% and 1.0% of pinene with different inhibitory effects. Finally, the genes acrB, flgFG, motB and ndk were found to be associated with the enhanced tolerance of E. coli to pinene. Using the I-SceI cleavage system, the promoters of acrB, flgFG and ndk genes were replaced with P37. The final strain increased the production of pinene from glucose by 2.1 times.

Roles of the calcified cartilage layer and its tissue engineering reconstruction in osteoarthritis treatment.

Sandwiched between articular cartilage and subchondral bone, the calcified cartilage layer (CCL) takes on both biomechanical and biochemical functions in joint development and ordinary activities. The formation of CCL is not only unique in articular cartilage but can also be found in the chondro-osseous junction adjacent to the growth plate during adolescence. The formation of CCL is an active process under both cellular regulation and intercellular communication. Abnormal alterations of CCL can be indications of degenerative diseases including osteoarthritis. Owing to the limited self-repair capability of articular cartilage and core status of CCL in microenvironment maintenance, tissue engineering reconstruction of CCL in damaged cartilage can be of great significance. This review focuses on possible tissue engineering reconstruction methods targeting CCL for further OA treatment.

Exosomes in osteoarthritis: Updated insights on pathogenesis, diagnosis, and treatment.

Osteoarthritis (OA) has remained a prevalent public health problem worldwide over the past decades. OA is a global challenge because its specific pathogenesis is unclear, and no effective disease-modifying drugs are currently available. Exosomes are small and single-membrane vesicles secreted via the formation of endocytic vesicles and multivesicular bodies (MVBs), which are eventually released when MVBs fuse with the plasma membrane. Exosomes contain various integral surface proteins derived from cells, intercellular proteins, DNAs, RNAs, amino acids, and metabolites. By transferring complex constituents and promoting macrophages to generate chemokines and proinflammatory cytokines, exosomes function in pathophysiological processes in OA, including local inflammation, cartilage calcification and degradation of osteoarthritic joints. Exosomes are also detected in synovial fluid and plasma, and their levels continuously change with OA progression. Thus, exosomes, specifically exosomal miRNAs and lncRNAs, potentially represent multicomponent diagnostic biomarkers for OA. Exosomes derived from various types of mesenchymal stem cells and other cell or tissue types affect angiogenesis, inflammation, and bone remodeling. These exosomes exhibit promising capabilities to restore OA cartilage, attenuate inflammation, and balance cartilage matrix formation and degradation, thus demonstrating therapeutic potential in OA. In combination with biocompatible and highly adhesive materials, such as hydrogels and cryogels, exosomes may facilitate cartilage tissue engineering therapies for OA. Based on numerous recent studies, we summarized the latent mechanisms and clinical value of exosomes in OA in this review.

A Worldwide Bibliometric Analysis of Tetrandrine Research in Recent Two Decades.

Background: Tetrandrine has been the focus of many studies in recent years. Currently, no bibliometric study in this field has been published. This study presents a bibliometric analysis of the articles on tetrandrine research from the WOS core database during the recent two decades. Methods: Documents were retrieved for further bibliometric analysis based on the search terms: [TI = (Tetrandrine OR Sinomeninea OR Hanfangchin A) AND PY = (2000-2021)]. We used Microsoft Excel to conduct the frequency analysis, VOSviewer for data visualization, and RStudio for citation metrics and analysis. The standard bibliometric indicators such as the temporal trends and geographical distribution of publications and citations, prolific authors and co-authorship, keywords citation burst, preferred journals, top-cited articles, and important institutions were applied in this study. Results: 490 documents were retrieved from WOS core database, the retrieved document type consists of 8 categories: 425 articles, 42 meeting abstracts, 8 reviews, 7 corrections, 3 editorial material, 2 proceedings paper, 1 letter, 1 retraction. Corrections and Retractions was excluded from this investigation, the left 482 document were included for furter bibliometric analysis. Conclusion: Based on our findings, there was a continuous growth of publications on tetrandrine research for 22 years since 2000. China was the largest contributor to tetrandrine research, followed by the United States. The most influential author was Cheng Y (Natl Taiwan Univ Hosp). Acta Pharmacol Sin remained the main publication related to tetrandrine research. Chinese Academy of Sciences, is expected to be a good collaborating center in tetrandrine research. The use of tetrandrine in cancer treatment, could be the promising research subject areas to follow.

Cloning, Expression, and Characterization of Endo-ß-1,6-galactanase PoGal30 from Penicillium oxalicum.

Because ß-1,6-galactans are significant components in arabinogalactans from plant cell walls, identifying selective endo-ß-1,6-galactanases is crucial to degrading these polysaccharides and to analyzing and modifying their structures. Here, we cloned and expressed in E. coli a novel endo-ß-1,6-galactanase in the glycosidic hydrolase family 30 (GH30) from Penicillium oxalicum. Our recombinant PoGal30 hydrolase (1464 bp gene) that contains an N-terminal His-tag for purification by nickel affinity chromatography has a specific activity of 3.8 U/mg on the substrate de-arabinosylated gum Arabic (dGA) polysaccharide. The enzyme has 487 residues with a molecular mass of 60 kDa, an isoelectric point of 6, and functional pH and temperature optima of pH 2.5 to pH 5.0 and 40 °C, respectively. While the activity of PoGal30 is activated by Mg2+ (5 or 50 mmol/L), it is completely inhibited by Cu2+ and Fe3+ (50 mmol/L) and partially inhibited by Hg2+, EDTA, and SDS (50 mmol/L). The enzyme demonstrates high specificity towards ß-1,6-galactosidic linkages in dGA, but is inactive against aryl-glycosides and galactobioses with different linkages. Using PoGal30 is, therefore, an effective approach to analyzing the fine structure of polysaccharides and preparing bioactive oligosaccharides.

Study on a Nonionic Surfactant/Nanoparticle Composite Flooding System for Enhanced Oil Recovery.

The composite flooding system composed of a surfactant and nanoparticles has shown great application potential in enhancing oil recovery. However, at present, these research studies are mainly focused on anionic surfactants. Relatively speaking, alkanolamide (CDEA), a nonionic surfactant, has the characteristics of a small adsorption amount on the rock surface, no cloud point, good temperature resistance, and good salt resistance. However, to the best of our best knowledge, there is no research report on the composite flooding system composed of CDEA and nanoparticles. Therefore, the surfactant/nanoparticle (S/NP) flooding system based on CDEA and nano-SiO2 was studied in this paper. The S/NP flooding system (0.1% CDEA + 0.05% SiO2) was constructed based on the performance in reducing the oil-water interfacial tension (IFT) and the stability of the composite system. The IFT between the S/NP flooding system and the crude oil can reach ultra-low values (3 × 10-3 mN/m), and there is no obvious sedimentation within 72 h. The sandpack flood tests show that the oil recovery rate is increased by 16.8% compared with water flooding and finally reaches 58.2%. Based on micromodel flooding tests, the mechanisms of the S/NP flooding system are studied as follows: the synergistic effect of nanoparticles and surfactants can re-enforce its oil-water interface performance and improve the oil displacement efficiency and the Jamin effect of emulsified oil droplets, combined with the thickening property and retention plugging of nanoparticles, improves the sweep efficiency. As the surfactant and nanoparticle used in this study are commercially available industrial products, the research results have important guiding significance for promoting the industrial application of surfactant/nanoparticle composite flooding technology.

Biochemical Characterization of Two Rhamnogalacturonan Lyases From Bacteroides ovatus ATCC 8483 With Preference for RG-I Substrates.

Rhamnogalacturonan lyase (RGL) cleaves backbone α-1,4 glycosidic bonds between L-rhamnose and D-galacturonic acid residues in type I rhamnogalacturonan (RG-I) by ß-elimination to generate RG oligosaccharides with various degrees of polymerization. Here, we cloned, expressed, purified and biochemically characterized two RGLs (Bo3128 and Bo4416) in the PL11 family from Bacteroides ovatus ATCC 8483. Bo3128 and Bo4416 displayed maximal activity at pH 9.5 and pH 6.5, respectively. Whereas the activity of Bo3128 could be increased 1.5 fold in the presence of 5 mM Ca2+, Bo4416 required divalent metal ions to show any enzymatic activity. Both of RGLs showed a substrate preference for RG-I compared to other pectin domains. Bo4416 and Bo3128 primarily yielded unsaturated RG oligosaccharides, with Bo3128 also producing them with short side chains, with yields of 32.4 and 62.4%, respectively. Characterization of both RGLs contribute to the preparation of rhamnogalacturonan oligosaccharides, as well as for the analysis of the fine structure of RG-I pectins.

Diosmetin alleviates acute kidney injury by promoting the TUG1/Nrf2/HO-1 pathway in sepsis rats.

BACKGROUND: We aimed to study the effects and the underlying mechanisms of Diosmetin (DIOS) in rats with sepsis-induced acute kidney injury (AKI). METHODS: The AKI model in RMCs was induced using LPS, and the cells were then treated with DIOS. Cell viability, apoptosis, inflammatory response, and antioxidant were measured using MTT, Flow cytometry, ELISA, and Lucigenin assay, respectively. The correlation between TUG1 and Nrf2 was confirmed by RNA pull-down and RNA immunoprecipitation. Real-time quantitative PCR and Western blot were performed to detect the expressions of gene and proteins during the development of AKI. The effects of lncRNA-TUG1 silencing and Nrf2 silencing on cell physiological functions were detected. Moreover, a rat sepsis-induced AKI model followed by Hematoxylin & Eosin (H&E) and immunofluorescence staining were performed. RESULTS: The experimental concentration of DIOS was determined to be 20 µM. After LPS treatment, the activity of RMCs was decreased, the apoptosis rate, inflammation and oxidative stress damage were increased, moreover, the expression of Nrf2/HO-1 signal axis was inhibited and caspase-3 was activated. However, DIOS significantly reversed these effects caused by LPS treatment, and increased the expression of lncRNA-TUG1, but lncRNA-TUG1 silencing effectively reversed the effects of DIOS. In addition, lncRNA-TUG1 was found to interact with Nrf2. Overexpression of TUG1 could reduce the damage of LPS caused to cell physiological functions, which were reversed by siNrf2. Thus, DIOS treatment could improve the physiological and pathological damages of renal tissues in AKI rats. CONCLUSION: DIOS may reduce sepsis-induced AKI through enhancing the TUG1/Nrf2/HO-1 pathway.