A sustainable process to 100%bio-based nylons integrated chemical and biological conversion of lignocellulose

Considerable progress has been made in recent years to the development of sustainable polymers from bio-based feedstocks.In this study,100%bio-based nylons were prepared via an integrated chemical and biological process from lignocellulose.These novel nylons were obtained by the melt polymerization of 3-propyladipic acid derived from lignin and 1,5-pentenediamine/1,4-butanediamine derived from carbohydrate sugar.Central to the concept is a three-step noble metal free catalytic chemical funnelling sequence(Raney Ni mediated reductive catalytic fractionation-reductive funnelling-oxidative funnelling),which allowed for obtaining a single component 3-propyladipic acid from lignin with high efficiency.The structural and thermodynamic properties of the obtained nylons have been systematically investigated,and thus obtained transparent bio-based nylons exhibited higher Mw(>32,000)and excellent thermal stability(Td5%>265℃).Considering their moderate Tg and good melt strength,these transparent bio-based nylons could serve as promising functional additives or temperature-responsive materials.

Modified DIX model for ion-exchange equilibrium of L-phenylalanine on a strong cation-exchange resin

L-phenylalanine,one of the nine essential amino acids for the human body,is extensively used as an ingredient in food,pharmaceutical and nutrition industries.A suitable equilibrium model is required for purification of L-phenylalanine based on ion-exchange chromatography.In this work,the equilibrium uptake of L-phenylalanine on a strong acid-cation exchanger SH11 was investigated experimentally and theoretically.A modified Donnan ion-exchange(DIX) model,which takes the activity into account,was established to predict the uptake of L-phenylalanine at various solution pH values.The model parameters including selectivity and mean activity coefficient in the resin phase are presented.The modified DIX model is in good agreement with the experimental data.The optimum operating pH value of 2.0,with the highest L-phenylalanine uptake on the resin,is predicted by the model.This basic information combined with the general mass transfer model will lay the foundation for the prediction of dynamic behavior of fixed bed separation process.

Transformation of microstructure and phase of disodium guanosine 5′-monophosphate: Thermodynamic perspectives

Microstructure and phase transformation of disodium guanosine 5′-monophosphate(5′-GMPNa_2) are extremely important for controlling the process and understanding the mechanism of crystallization. In this work, the thermodynamic properties of polymorphous 5′-GMPNa_2 especially the solubility were studied, the solubility results show that 5′-GMPNa_2 is more soluble in ethanol–water(E–W) than in isopropanol–water(I–W). The amorphous form of 5′-GMPNa_2 is more soluble than the crystalline form at the same mole fraction and temperature. Meanwhile, the crystalline forms and morphologies of the residual solids were characterized by PXRD and SEM. The results indicate that solid forms of 5′-GMPNa_2 transformed spontaneously from amorphous to crystalline when the ethanol proportion is ≥20%. In addition, increasing the pH facilitates the dissolution of 5′-GMPNa_2 and helps to maintain the crystalline form. The associated Gibbs free energy values were calculated to verify the trend of transformation from amorphous to crystalline 5′-GMPNa_2. These results should help to guide the industrial crystallization process and to obtain the crystalline form of 5′-GMPNa_2.

Reversible regulation of enzyme-like activity of molybdenum disulfide quantum dots for colorimetric pharmaceutical analysis

Regulating the catalytic activity of nanozymes is significant for their applications in various fields.Here,we demonstrate a new strategy to achieve reversible regulation of the nanozyme’s activity for sensing purpose.This strategy involves the use of zero-dimensional MoS;quantum dots(MQDs)as the building blocks of nanozymes which display very weak peroxidase(POD)-like activity.Interestingly,such POD-like activity of the MQDs largely enhances in the presence of Fe;while diminishes with the addition of captopril thereafter.Further investigations identify the mechanism of Fe;-mediated aggregation-induced enhancement of the POD-like activity and the inhibitory effect of captopril on the enhancement,which is highly dependent on their concentrations.Based on this finding,a colorimetric method for the detection of captopril is developed.This sensing approach exhibits the merits of simplicity,rapidness,reliability,and low cost,which has been successfully applied in quality control of captopril in pharmaceutical products.Moreover,the present sensing platform allows smartphone read-out,which has promising applications in point-of-care testing devices for clinical diagnosis and drug analysis.

Enhanced production of cytidine 5'-monophosphate using biocatalysis of di-enzymes immobilized on amino-functionalized sepharose

Cytidine 5'-monophosphate(5'-CMP)is an essential nucleotide for additives.In this study,enhanced production of 5'-CMP was realized by the transformation of cytidine using co-immobilized di-enzymes,uridine-cytidine kinase(UCK)and acetate kinase(AcK).The immobilization yield of the enzyme had a clear correlation with the surface charges as zeta potential(ξ).Among them,ε-polylysinefunctionalized sepharose(SA-EPL,ξ=9.31 m V)showed high immobilization yield(78.8%),which was4.9-fold than that of nitrilotriacetic acid functionalized sepharose(SA-NTA,ξ=-12.6 m V).The residual activity of affinity co-immobilized enzyme(EPL-Ni/EPL@Ac K-UCK)was higher than 70.6%after recycled 10 times.Thus,this study provides an effective approach for the production of 5'-CMP with the advantages of low adenosine 5'-triphosphate(ATP)consumption,reduced side reactions,and improved reusability by co-immobilized UCK and Ac K on the functionalized Sepharose.

A Robust N-Terminal Pro-Brain Natriuretic Peptide Assay for Clinical Diagnosis of Heart Failure in Elderly Patients

Heart failure(HF)is a clinical hallmark of cardiovascular syndrome leading to substantial morbidity,repeated hospitalization,and enormous healthcare expenditure.As elderly populations continue to increase,biomarker-guided diagnosis and treatment for age-related cardiac decline have become essential.Accumulating evidence demonstrates that N-terminal proBNP(NT-proBNP)can provide a unique window into the diagnosis and risk stratification with HF.Herein,a simple yet robust aptasensor is developed for on-site recognizing the NT-proBNP by its targeting aptamer,thus achieving the accurate diagnosis of HF.This aptasensing system is prepared by absorbing the fluorophore-labeled aptamer strand onto the graphene oxide(GO),leading to efficient quenching without possible off-site signal leakage.The aptamer strand can specifically identify target NT-proBNP molecules via a versatile conformational transformation,resulting in the desorption of the aptamer-NTproBNP complexes from GO and re-generation fluorescence signal,thus allowing sensitive detection of NT-proBNP in 37 clinical blood samples.Taking advantage of the high specificity of aptamer-guaranteed recognitions of NT-proBNP,this aptasensor system readily achieves better diagnostic performance for HF than commercially adopted chemiluminescence immunoassay(Siemens,CLIA)in hospitals in terms of accuracy(89.2%vs 83.8%),specificity(89.5%vs 84.2%),and positive predictive value(88.9%vs 83.3%).This work provides a stable option for the diagnosis and treatment of elderly HF-related diseases inclinics.

The Role of Lactic Acid Bacteria in Milk Fermentation

Species of lactic acid bacteria (LAB) represent as potential microorganisms and have been widely applied in food fermentation worldwide. Milk fermentation process has been relied on the activity of LAB, where transformation of milk to good quality of fermented milk products made possible. The presence of LAB in milk fermentation can be either as spontaneous or inoculated starter cultures. Both of them are promising cultures to be explored in fermented milk manufacture. LAB have a role in milk fermentation to produce acid which is important as preservative agents and generating flavour of the products. They also produce exopolysaccharides which are essential as texture formation. Considering the existing reports on several health-promoting properties as well as their generally recognized as safe (GRAS) status of LAB, they can be widely used in the developing of new fermented milk products.

OsSCE1 Encoding SUMO E2-Conjugating Enzyme Involves in Drought Stress Response of Oryza sativa

Small ubiquitin-like modifier(SUMO)-conjugating enzymes are involved in post-translational regulatory processes in eukaryotes, including the conjugation of SUMO peptides to protein substrate(SUMOylation). SUMOylation plays an important role in improving plant tolerance to abiotic stress such as salt, drought, heat and cold. Herein, we reported the isolation of OsSCE1(LOC_Os10 g39120) gene encoding a SUMO-conjugating enzyme from rice(Oryza sativa cv. Nipponbare) and its functional validation in response to drought stress. The E2 enzyme, Os SCE1, is one of three key enzymes involved in the conjugation of SUMO to its target proteins. Activated SUMO is transferred to the cysteine of an E2 enzyme and then to the target lysine residue of the substrate, with or without the help of an E3 SUMO ligase. Expression of OsSCE1 was strongly induced by polyethylene glycol 6000(PEG6000) treatment, which suggested OsSCE1 may be involved in the drought stress response. Overexpression of OsSCE1(OsSCE1-OX) in Nipponbare reduced the tolerance to drought stress. Conversely, the drought tolerance was slightly improved by the knockdown of OsSCE1(OsSCE1-KD). These results were further supported by measurement of proline content in OsSCE1-OX and OsSCE1-KD transgenic lines under induced drought stress, which showed OsSCE1-KD transgenic lines accumulated higher proline content than the wild type, whereas OsSCE1-OX line had lower proline content than the wild type. These findings suggested OsSCE1 may play a role as a negative regulator in response to drought stress in rice.

原位合成的介孔TiO_2-B/锐钛微粒:改善的锂离子电池阳极材料（英文）

Mesoporous TiO_2-B/anatase microparticles have been in-situ synthesized from K_2Ti_2O_5 without template.The TiO_2-B phase around the particle surface accelerates the diffusion of charges through the interface,while the anatase phase in the core maintains the capacity stability.The heterojunction interface between the main polymorph of anatase and the trace of TiO_2-B exhibits promising lithium ion battery performance.This trace of 5%(by mass) TiO_2-B determined by Raman spectra brings the first discharge capacity of this material to 247 mA · h ·g^(-1),giving 20%improvement compared to the anatase counterpart Stability testing at 1 C reveals that the capacity maintains at 171 mA·h·^(-1),which is better than 162 mA·h·g^(-1) for single phase anatase or 159 mA·h·g^(-1) for TiO_2-B.The mesoporous TiO_2-B/anatase rnicroparticles also show superior rate performance with 100 mA·h·g^(-1) at 40 C,increased by nearly 25%as compared to pure anatase.This opens a possibility of a general design route,which can be applied to other metal oxide electrode materials for rechargeable batteries and supercapacitors.

Cembranoids of Soft Corals:Recent Updates and Their Biological Activities

Soft corals are well-known as excellent sources of marine-derived natural products.Among them,members of the genera Sar-cophyton,Sinularia,and Lobophytum are especially attractive targets for marine natural product research.In this review,we reported the marine-derived natural products called cembranoids isolated from soft corals,including the genera Sarcophyton,Sinularia,and Lobophytum.Here,we reviewed 72 reports published between 2016 and 2020,comprising 360 compounds,of which 260 are new compounds and 100 are previously known compounds with newly recognized activities.The novelty of the organic molecules and their relevant biological activities,delivered by the year of publication,are presented.Among the genera presented in this report,Sarcophyton spp.produce the most cembranoid diterpenes;thus,they are considered as the most important soft corals for marine natural product research.Cembranoids display diverse biological activities,includ-ing anti-cancer,anti-bacterial,and anti-inflammatory.As cembranoids have been credited with a broad range of biological activities,they present a huge potential for the development of various drugs with potential health and ecological benefits.

First report of furuncular myiasis caused by the larva of botfly,Dermatobia hominis,in a Taiwan Residents traveler

A case of furuncular myiasis was reported for the first time in a 29-year-old young Taiwan Residents traveler returning from an ecotourism in Peru.Furuncle-like lesions were observed on the top of his head and he complained of crawling sensations within his scalp.The invasive larva of botfly,Dermatobia hominis,was extruded from the furuncular lesion of the patient.Awareness of cutaneous myiasis for clinicians should be considered for a patient who has a furuncular lesion and has recently returned from a botfly-endemic area.

Development of <i>in vitro</i>culture of rat Leydig cells after purification with Nycodenz gradient

The study examined the effect of human Chorionic Gonadotrophin (hCG) and/or Insulin Transferring Sodium Selenite (ITS) on the proliferation and development of rat Leydig cells purified by Nycodenz gradient. Leydig cells purity, viability and proliferation after purification and 3 days of cultured were evaluated. Leydig cells 1 × 106 cells/ml were cultured in DMEM containing 10% Newborn Calf Serum (NBCS) and divided into four kinds of treatments 1) as a control, 2) control + 2.5 IU/ml hCG, 3) control + ITS (5 μg/ml insulin, 10 μg/ml transferrin, 5 μg/ml Se), and 4) control + hCG + ITS. Leydig cells purification results showed 91.40% of purity, viability was 98.17% and concentration 7.03 × 106 cells/ml. The addition of ITS and hCG + ITS in DMEM produced Leydig cell proliferation by 88.35% and 90.64% higher than in controls (86.82%) (p p

Gene Expression Profiling of Human Epidermal Keratinocytes in Simulated Microgravity and Recovery Cultures

Simulated microgravity （SMG） bioreactors and DNA microarray technology are powerful tools to identify ＂space genes＂ that play key roles in cellular response to microgravity. We applied these biotechnology tools to investigate SMG and post-SMG recovery effects on human epidermal keratinocytes by exposing cells to SMG for 3, 4, 9, and 10 d using the high aspect ratio vessel bioreactor followed by recovery culturing for 15, 50, and 60 d in normal gravity. As a result, we identified 162 differentially expressed genes, 32 of which were ＂center genes＂ that were most consistently affected in the time course experiments. Eleven of the center genes were from the integrated stress response pathways and were coordinately downregulated. Another seven of the center genes, which are all metallothionein MT-Ⅰ and MT-Ⅱ isoforms, were coordinately up-regulated. In addition, HLA-G, a key gene in cellular immune response suppression, was found to be significantly upregulated during the recovery phase. Overall, more than 80% of the differentially expressed genes from the shorter exposures （≤4 d） recovered in 15 d; for longer （≥9 d） exposures, more than 50 d were needed to recover to the impact level of shorter exposures. The data indicated that shorter SMG exposure duration would lead to quicker and more complete recovery from the microgravity effect.

Genomics in Space Life Sciences

Since the early days of manned spaceflight, hazardous effects of the space environment on living organisms have been disputed. With the continuous manning of the International Space Station, the planned Chinese space station, and renewed interest in returning to the Moon and sending manned flights to Mars, identifying and addressing the potential outcomes of long-term space exposures is critically important.

Macroalgae-derived rare sugars: Applications and catalytic synthesis

Rare sugars have attracted much attention since they are highly beneficial for health as alternative sweeteners and full of potential economic value in industry.The limited availability of rare sugars in nature has promoted efforts on the conversion of sugars obtained from terrestrial plants into rare sugars,either via biological or chemo-catalytic approaches.However,the processes are generally complicated and consist of multiple steps.Macroalgae or seaweeds have been industrially used as a natural source of phycocolloids.These water-soluble polysaccharides contain monomeric sugars with unique chemical structures and are categorized as rare.In this review,the potency of macroalgae as a sustainable source of rare sugars and the recent progress on their catalytic conversion,either via biological or chemo-catalytical process,are summarized and discussed.Especially,the depolymerization of macroalgae for the production of rare sugars is presented.It is expected to enrich our knowledge in the development of sustainable production of rare sugars from macroalgae.

High cell density and high expression of recombinant human ApoA-I_(Milano) in Escherichia coli by twice temperature-shifted induction

The effect of temperature on the formation of recombinant protein,apolipoprotein A-IMilano was investigated in the present study.The temperature of the initial growth phase was set at 30ºC,while temperature variation in induction phase was arranged in three modes.High cell-density culture of Escherichia coli and high expression of recombinant human by twice temperature-shifted induction were carried out.Experimental results showed that ApoA-IMilano reached 4.8 g/L with the final cell density of OD600,150.It was found that twice temperature-shifted induction could successfully avoid the effect of acetic acid on cell density and the expression of the product.The present study provides a basic procedure for the production of recombinant ApoA-IMilano.

Isolation,purification and characterization of extracellular protease produced by marine-derived endophytic fungus Xylaria psidii KT30

Objective:To isolate,purify and characterize extracellular protease produced by Xylaria psidii(X.psidii)KT30.Methods:In the present study,the extracellular protease secreted by X.psidii KT30 was isolated and purified by using three steps of protein purification,then the purified protease was characterized by applying qualitative and quantitative enzymatic assays.Results:Extracellular protease with molecular mass 71 kDa has been purified successfully by applying diethylaminoethanol-Sepharose followed by sephadex SG75 with its final specific protease activity of 0.091 IU/mg.Protease was the most active at temperature 60℃ and pH 7.The activity of enzyme was abolished mostly by phenylmethanesulfonyl fluoride,showing it is family of serine protease.Conclusions:Extracellular serine protease produced by X.psidii KT30 with good biochemical properties displayed some promising results for its further application in field of biotechnology or medicine.

MHC class Ⅱ in renal tubules plays an essential role in renal fibrosis

Immunomodulation has been considered a potential therapeutic approach for chronic kidney disease(CKD).Although it has been previously reported that CD4+T cells contribute to the development of renal fibrosis after UUO,the role of MHC class Ⅱ(MHCII)in UUO-induced renal fibrosis remains largely uncharacterized.The present study reports that the expressions of MHCII molecules in renal cortical tubules are upregulated in a mouse unilateral ureter obstruction(UUO)model.Global or renal tubule-specific ablation of MHCII significantly alleviates renal fibrosis following UUO.Additionally,renal expression of profibrotic genes showcased consistent reduction in both MHCII gene deficient mouse lines.These results demonstrate that renal tubular MHCII plays an important role in pathogenesis of renal fibrosis.