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.

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.

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.

Occupational burnout analysis of border guards in the background of COVID-19 / 中国职业医学

@#Objective To analyze the occupational burnout status and its influencing factors of border guards in the prevention （ - ）Methods and control of coronavirus disease COVID 19 . A total of 1 313 border guards who participate in the prevention and control of epidemic diseases were selected as research subjects using the random cluster sampling method. Military Occupational Burnout Scale and Military Occupational Stress Scale were used to investigate the occupational burnout status and Results occupational stress in the research subjects. The median and 25th and 75th percentiles of military occupational （ ， ） （ ， ）， burnout and occupational stress total scores were 9.0 3.0 15.0 and 76.0 70.0 86.0 respectively. About 73.1% of the subjects were suffered from high occupational stress. The results of multiple linear regression analysis indicated that the higher the scores of interpersonal relationship, military special life, work pressure, unclear role and leadership ability factor in P occupational stress, and the lower the score of personal development, the more serious the occupational burnout (all <0.05 ) ， after excluding the influence of confounding factors; subjects with panic psychology inconvenience caused by closed ， management fear on accountability for poor prevention and no personal hobbies had more serious occupational burnout than （ P ） Conclusion - ， subjects without those factors all <0.05 . In the period of COVID 19 prevention the level of occupational burnout and occupational stress of border guards were generally low. The occupational burnout was mainly affected by occupational stress and fear of the epidemic.

Polarization design for ground-to-satellite quantum entanglement distribution.

High-fidelity transmission of polarization encoded qubits plays a key role in long distance quantum communication. By establishing the channel between ground and satellite, the communication distance can even exceed thousands of kilometers. Aimed to achieve the efficient uplink quantum communication, here we describe a high-fidelity polarization design of a transmitting antenna with an average polarization extinction ratio of 887:1 by a local test. We also implement a feasible polarization-compensation scheme for satellite motions with a fidelity exceeding 0.995 ± 0.001. Based on these works, we demonstrate the ground-to-satellite entanglment distribution with a violation of Bell inequality by 2.312±0.096, which is well above the classic limit 2.

RBM4 modulates the proliferation and expression of inflammatory factors via the alternative splicing of regulatory factors in HeLa cells.

Regulatory factors function by modulating a variety of cascade mechanisms in cells. RBM4 is a multifunctional RNA-binding protein in post-transcriptional gene regulation. Cytoplasmic RBM4 interacts with Ago2 to regulate inflammatory responses by affecting mRNA decay and cap-dependent translation. However, it is unclear whether RBM4 functions in inflammation regulation by its splicing factor role. Here, the cell biology, gene expression profile and alternative splicing pattern of HeLa cells with RBM4 overexpression (RBM-OE) were compared with the control. The results showed that RBM4-OE inhibited proliferation. RBM4-OE extensively affects the transcriptional level of genes involved in cell surface receptor signalling pathway, inflammatory responses and the response to lipopolysaccharide. RBM4 broadly regulated the alternative splicing of hundreds of genes with functions of protein binding, helicase activity, DNA binding and transcription co-activator. RBM4-regulated splicing of these genes plays an important role in apoptotic process and gene transcription regulation. As an example, exon inclusion of TNIP1 mediated by RBM4 affects the expression of its targets in inflammatory pathways. These results indicated that RBM4 can mediate the inflammatory response via splicing regulation, which adds to the understanding of the critical role of RBM4 in cancer complicated by inflammation. In conclusion, this study indicated a mechanism in which the dysregulation of alternative splicing can influence cellular biology and lead to various immune-related diseases.

Satellite testing of a gravitationally induced quantum decoherence model.

Quantum mechanics and the general theory of relativity are two pillars of modern physics. However, a coherent unified framework of the two theories remains an open problem. Attempts to quantize general relativity have led to many rival models of quantum gravity, which, however, generally lack experimental foundations. We report a quantum optical experimental test of event formalism of quantum fields, a theory that attempts to present a coherent description of quantum fields in exotic spacetimes containing closed timelike curves and ordinary spacetime. We experimentally test a prediction of the theory with the quantum satellite Micius that a pair of time-energy-entangled particles probabilistically decorrelate passing through different regions of the gravitational potential of Earth. Our measurement results are consistent with the standard quantum theory and hence do not support the prediction of event formalism.

Point-ahead demonstration of a transmitting antenna for satellite quantum communication.

A low-divergence beam is an essential prerequisite for a high-efficiency long-distance optical link, particularly for satellite-based quantum communication. A point-ahead angle, caused by satellite motion, is always several times larger than the divergence angle of the signal beam. We design a novel transmitting antenna with a point-ahead function, and provide an easy-to-perform calibration method with an accuracy better than 0.2 µrad. Subsequently, our antenna establishes an uplink to the quantum satellite, Micius, with a link loss of 41-52 dB over a distance of 500-1,400 km. The results clearly confirm the validity of our model, and provide the ability to conduct quantum communications. Our approach can be adopted in various free space optical communication systems between moving platforms.

[Theoretical Investigation of the Electron Paramagnetic Resonance Parameters and Local Structures for Zinc Phosphate Glass Doped with VO2+].

As an important model system, 3d(1) ions (VO2+, V4+ et al) have been extensively investigated by means of electron paramagnetic resonance (EPR), and many experimental results of EPR parameters were also measured. The optical absorption and EPR parameters (g factors g||, g⊥ and hyperfine structure constants A||, A⊥) of a tetragonal V4+ center in zinc phosphate glass are theoretically investigated, using the perturbation formulas for a 3d(1) ion in tetragonally compressed octahedra. Since the spin-orbit coupling parameter r (150 cm(-1)) of ligand O2- is close to that ξp(0) (≈248 cm(-1)) of the central 3d(1) ion in zinc phosphate glass doped VO2+, the effect of the spin-orbit coupling parameter ξp(0) on the EPR spectra and optical absorption spectra should be taken into account. In this work, the relationship between the EPR parameters as well as the optical absorption spectra and the local structure of the impurity center are established based on the superposition model. By fitting the calculated EPR parameters and optical absorption spectra for V4+ center in zinc phosphate glass to the experimental data, the local structure parameters of [VO6](8-) cluster are obtained. According to the investigation, the magnitudes of the metal-ligand distances parallel and perpendicular to the C4-axis of [VO6](8-) cluster are, respectively, R|| ≈ 0.175 nm and R⊥ ≈ 0.197 nm, the local structure around the V4+ ions possesses a compressed tetragonal distortion along C4 axis. Theoretical results of EPR parameters and optical absorption spectra are in good agreement with experimental data, the validity of the calculated results has also been discussed. Thus, perturbation method is effective to the studies the EPR parameters and optical spectra of transition-metal 3d ions in crystals. In addition, based on the studies of the hyperfine structure constants (All and A1), one can found that the large value of kappa indicates a large contribution to the hyperfine constant by the unpaired selectron.

Analysis of blood flow and local expression of angiogenesis­associated growth factors in infected wounds treated with negative pressure wound therapy.

Angiogenesis is involved in the wound healing process. Increased angiogenesis and blood flow constitute a major mechanism of negative pressure wound therapy (NPWT), which has been shown to facilitate the healing of infected wounds. However, the effect on the expression of angiogensis­related growth factor remains unknown. The goal of the current study was to investigate the angiogenic factor levels prior to and following NPWT in infected wounds. A total of 20 patients with infected wounds treated with NPWT were included in the study. Patients acted as their own control; the postoperative measurements of patients were considered as the experimental group, while preoperative measurements were considered as the controlled group. Blood flow was recorded prior to and during NPWT. A total of 10 angiogensis­related growth factors were detected using a protein biochip array to analyze the change in protein levels prior to NPWT, and on the third day during NPWT. All wounds were successfully reconstructed by skin grafting or using local flaps following NPWT. NPWT resulted in significantly increased blood flow in the wound. There was a significant increase in vascular endothelial growth factor (VEGF), EGF, platelet­derived growth factor and angiotesin­2 following NPWT, while basic fibroblast growth factor decreased significantly. NPWT affects the local expression of angiogenesis­associated growth factors, which represents another mechanism to explain how NPWT accelerates wound healing.

Changed accumulation of active ingredient in different localities and growth period of Hemsleya zhejiangensis (Cucurbitaceae) / 中国中药杂志

In this paper, the content of moisture, ethanol-soluble extractives, total saponins and polysaccharide of different tuber samples of Hemsleya zhejiangensis, from different localities, years and seasons, were detected based upon Chinese Pharmacopoeia 2010 version. The samples of roots, stems and leaves in summer were detected as well. The results are mainly as follows. (1)With tuber quality increasing, the content of total saponins increased and then decreased. The individual quality of tubers getting 594.06 g, the content of total saponins reached the peak. (2) The content of active ingredients in different localities was significantly different, and the population of Wuyanling had the maximum content of total saponins and polysaccharide. (3) The content of active ingredients revealed stability between the years 2012 and 2013, but the content of polysaccharide was significantly different. The content in 2012 was higher than that of 2013. (4) The content of active ingredients reached the peak in autumn, which was the best harvest season. (5) Among different component content detection of nutritional organs, tubers had the maximum content of ethanol-soluble extractives, total saponins and polysaccharide. Leaves also contained higher content of ethanol-soluble extractives and total saponins than roots and stems. All of these provide theoretical basis for plant, harvest and production of H. zhejiangensis, which is an endemic, rare, and endangered medicinal plants.

Absorbable implants versus metal implants for the treatment of ankle fractures: A meta-analysis.

This meta-analysis was performed to evaluate the efficiency and the safety of absorbable implants. Five major electronic databases (PubMed, Embase, Cochrane Library, SinoMed and Wanfang Data) were systematically searched for randomized controlled trials (RCTs) from their establishment to November 2012. Studies on absorbable implants and metal implants for ankle fractures were selected. The meta-analysis was performed using RevMan 5.1. Ten studies with 762 patients were included and analyzed. Compared with metal implants, absorbable implants used for the internal fixation of ankle fractures produce similar radiographic and functional outcomes (P= 0.52). Normally, removal of the internal fixation is unnecessary (P<0.0001) and the incidence of palpable implants is lower (P=0.02) for absorbable implants. No statistically significant difference was observed between the two groups with regard to foreign body reactions (P=0.07), infection (P= 0.69), osteoarthritis (P= 0.39), pain (P= 0.06), refracture (P=0.67), skin necrosis (P=0.99), deep vein thrombosis (P=0.21) and nerve injury (P=0.94). Absorbable implants used in ankle fractures rarely require reoperation and result in similar functional outcomes and complications compared with metal implants. These characteristics make them efficient and reasonably safe for the treatment of ankle fractures.

Combination of negative pressure wound therapy with open bone grafting for bone and soft tissue defects.

The aim of this study was to investigate the efficiency of negative pressure wound therapy (NPWT) combined with open bone graft (OBG; NPWT-OBG) for the treatment of bone and soft tissue defects with polluted wounds in an animal model. All rabbits with bone and soft tissue defects and polluted wounds were randomly divided into two groups, the experimental group (NPWT with bone graft) and the control group (OBG). The efficacy of the treatment was assessed by the wound conditions and healing time. Bacterial bioburdens and bony calluses were evaluated by bacteria counting and X-rays, respectively. Furthermore, granulation tissue samples from the wounds on days 0, 3, 7 and 14 of healing were evaluated for blood vessels and vascular endothelial growth factor (VEGF) levels. Wounds in the experimental group tended to have a shorter healing time, healthier wound conditions, lower bacterial bioburden, improvement of the bony calluses and an increased blood supply compared with those in the control group. With NPWT, wound infection was effectively controlled. For wounds with osseous and soft tissue defects, NPWT combined with bone grafting was demonstrated to be more effective than an OBG.