Separation of chitin from shrimp shells enabled by transition metal salt aqueous solution and ionic liquid

Chitin is a widely used important industrial polymer mainly from shrimp shells, but its commercial preparation is under the great challenge of serious pollution due to the requirement of HCl and Na OH.Herein, we demonstrated that high purity chitin can be obtained from waste shrimp shells(WSSs) by cascade separation with transition metal salt aqueous solution and ionic liquid(IL). Firstly, calcium carbonate of WSSs was effectively removed in the metal salt aqueous solution driven by the ion exchange interaction. Subsequently, 1-butyl-3-methylimidazolium chloride([Bmim]Cl) had bifunctional abilities to remove residual protein and introduced metal salts simultaneously by hydrogen bonding and coordination interactions. The key experimental factors affecting the separation process were systematically studied, including the type of metal salts, temperature, and [Bmim]Cl loading. After sequential treatment with a 20%(mass) Ni SO4aqueous solution at 130 ℃ and [Bmim]Cl at 150 ℃, the purity of a-chitin can be up to 96.5%(mass) that meets commercial requirements. The use of metal salts with higher coordination ability makes the preparation of chitin no longer depend on the commonly acid-base reaction, which is conducive to the preservation of chitin structure.

Multidimensional(0D-3D)functional nanocarbon:Promising material to strengthen the photocatalytic activity of graphitic carbon nitride

As a prospective visible-light-responsive photochemical material,graphitic carbon nitride(g-C_(3)N_(4))has become a burgeoning research hot topics and aroused a wide interest as a metal-free semiconductor in the area of energy utilization and conversion,environmental protection due to its unique properties,such as facile synthesis,high physicochemical stability,excellent electronic band structure,and sustainability.However,the shortcomings of high recombination rate of charge carriers,relatively low electrical conductivity and visible light absorption impede its practical application.Various strategies,such as surface photosensitization,heteroatom deposition,semiconductor hybridization,etc.,have been applied to overcome the barriers.Among all the strategies,functional nanocarbon materials with various dimensions(0D~3D)attract much attention as modifiers of g-C_(3)N_(4)due to their unique electronic properties,optical properties,and easy functionalization.More importantly,the properties of these functional nanocarbon materials can be tuned by various dimensions and thus there will be a way to overcome the defects of g-C_(3)N_(4)by choosing different dimensional carbon materials.Distinguishing from some present reviews,this review starts with the fundamental physicochemical characteristics of g-C_(3)N_(4)materials,followed by analyzing the advantages of functional nanocarbon materials modifying gC_(3)N_(4).Then,we present a systematic introduction to various dimensional carbon materials.The design philosophy of carbon/g-C_(3)N_(4)composites and the advanced studies are exemplified in detail.Finally,a nichetargeting summary and outlook on the major challenges,opportunities for future research in high-powered carbon/g-C_(3)N_(4)composites was proposed.

Erratum to“Immobilized laccase on magnetic nanoparticles for enhanced lignin model compounds degradation”[Chin.J.Chem.Eng.28(8)(2020)2152-2159]

The authors regret that Fig.7b in our original article was incorrectly published,which is the same as Fig.6b due to an unintentional and random error.The correct Fig.7b is shown as follows(Reusability of the immobilized laccase).The change does not affect the results and conclusions.

Immobilized laccase on magnetic nanoparticles for enhanced lignin model compounds degradation

As a natural aromatic polymer,lignin has great potential but limited industrial application due to its complex chemical structure.Among strategies for lignin conversion,biodegradation has attracted promising interest recently in term of efficiency,selectivity and mild condition.In order to overcome the issues of poor stability and non-reusability of enzyme in the biodegradation of lignin,this work explored a protocol of immobilized laccase on magnetic nanoparticles(MNPs)with rough surfaces for enhanced lignin model compounds degradation.Scanning electron microscope with energy dispersive spectrometer(SEM-EDS),flourier transformation infrared spectroscopy(FTIR)and thermal gravimetric analysis(TGA)were utilized to characterize the immobilization of laccase.The results showed a maximum activity recovery of 64.7%towards laccase when it was incubated with MNPs and glutaraldehyde(GA)with concentrations of 6 mg·ml^-1and 7.5 mg·ml^-1for 5 h,respectively.The immobilized laccase showed improved thermal stability and pH tolerance compared with free laccase,and remained more than 80%of its initial activity after 20 days of storage at 4℃.In addition,about 40%residual activity of the laccase remained after 8 times cycles.Gas chromatography–mass spectrometry(GC–MS)was utilized to characterize the products of lignin model compound degradation and activation,and the efficiency of immobilized laccase was calculated to be 1–5 times that of free laccase.It was proposed that the synergistic effect between MNPs and laccase displays an important role in the enhancement of stability and activity in lignin model compound biodegradation.

Three-month effects of corneal cross-linking on corneal fibroblasts

Corneal collagen crosslinking(CXL)has revolutionized the treatment of keratoconus in the past decade.In order to evaluate the 3-month effects of CXL on corneal fibroblasts,a longitudinal study at the tissue and cellular level was carried out with a total of 16 rabbits that underwent CXL,deepithelialization(DEP),or non-treatment(control)and kept for 1 to 3 months.The duration of corneal stromal remodeling after CXL was determined by examining the differentiation,apoptosis,and number changes of keratocytes in tissue sections from animals 1,2,or 3 months post-treatment.Upon the finish of tissue remodeling,separate rabbits were used to extract keratocytes and set up cell culture for vimentin immunofluorescence staining.The same cell culture was used for(1)migration measurement through the wound-healing assay;(2)elastic modulus measurement by atomic force microscope(AFM);(3)the proliferation,apoptosis,cytoskeleton andα-SMA expression tests through EdU(5-ethynyl-2’-deoxyuridine)assay,TUNEL(TdT-mediated dUTP Nick-End Labeling)assay,phalloidin andα-SMA(alpha-smooth muscle actin)immunofluorescence analysis,respectively.Results showed that the migratory activity,elastic modulus,andα-SMA expression of the corneal fibroblasts increased after CXL treatment,while apoptosis,proliferation,and morphology of F-actin cytoskeleton of the fibroblasts had no significant change after 3 months.In contrast,measured cellular parameters(migratory,elastic moduli,α-SMA expression,apoptosis,proliferation,and morphology of F-actin cytoskeleton of fibroblasts)did not change significantly after DEP.In conclusion,the dynamic changes of keratocytes were nearly stable 3 months after CXL treatment.CXL has an impact on corneal fibroblasts,including migration,elastic modulus andα-SMA expression,while epithelialization may not alter the biological behavior of cells significantly.

秀丽隐杆线虫RNA结合蛋白复合物AMG-1/SLRP-1通过线粒体稳态维持实现调控生殖腺发育和精子发生

RNA结合蛋白(mtRBP)介导的mRNA转录后调节对精子发生必不可少但却鲜有报道.在本文中,我们鉴定到一个在生殖腺中特异性表达的线粒体RNA结合蛋白AMG-1,它是秀丽隐杆线虫精子发生过程中必需的蛋白,同时与哺乳动物LRPPRC蛋白同源.amg-1突变会阻碍生殖腺的发育,最终导致生殖细胞的线粒体形态和结构异常以及线粒体功能障碍.通过测序鉴定RNA结合蛋白的靶点发现,AMG-1更倾向于与mtDNA编码的参与线粒体核糖体组装的12S和16S核糖体RNA(rRNA)结合,12S rRNA对于维持生殖细胞线粒体蛋白稳态至关重要,而12S rRNA的表达却受AMG-1蛋白调节.此外,哺乳动物SLIRP在秀丽线虫中的同源蛋白SLRP-1蛋白与AMG-1在遗传上存在互作关系,它们可共同调节秀丽线虫的精子发生和育性.综上所述,这些发现揭示了mtRBP蛋白AMG-1在线粒体调控中的新机制,这可能为由线粒体功能障碍引发的男性不育治疗提供新的理论基础.

Essential factors of Sui Zheng Shi Liang strategy in Type 2 diabetes treatment assessed by questionnaire

OBJECTIVE: Sui Zheng Shi Liang strategy (regulating prescription dosage with different syndromes) is an important part of syndrome differentiation and treatment in Traditional Chinese Medicine (TCM). Questionnaires were given to doctors and patients to study the essential factors (indicators and timing) of Sui Zheng Shi Liang strategy in the treatment process of type 2 diabetes (T2DM). METHODS: Two questionnaires were designed for diabetes patients and their doctors. The questionnaires included the most important indicators for determining the patient's condition, the ability of TCM in treating T2DM, the length of time it takes for TCM to be effective, and when to adjust the prescription dosage.The frequency of answers was calculated, summarized, and analyzed after the survey. RESULTS: Twenty questionnaires from doctors and 90 questionnaires from patients were included in the analysis. Doctors and patients recognized thatTCM could decrease blood glucose, improve syndromes, and delay complications. Doctors were mainly concerned about glycosylated hemoglobin, while the patients were concerned about fasting plasma glucose for determining whether treatment was effective. Doctors also paid attention to changes in blood sugar and syndromes 2 weeks after medication was given as the indication to adjust the prescription dosage, while patients were concerned about these factors in 4 weeks.The prescription should be regulated when there are side effects or the medication is ineffective. CONCLUSION: The essential factor in the treatment process of T2DM in Sui Zheng Shi Liang strategy is that if fasting blood glucose level did not decrease after 4 weeks of treatment, the Chinese medicine prescription should be adjusted.

RING finger 138 deregulation distorts NF-κB signaling and facilities colitis switch to aggressive malignancy

Prolonged activation of nuclear factor(NF)-кB signaling significantly contributes to the development of colorectal cancer(CRC).New therapeutic opportunities are emerging from targeting this distorted cell signaling transduction.Here,we discovered the critical role of RING finger 138(RNF138)in CRC tumorigenesis through regulating the NF-кB signaling,which is independent of its Ubiquitin-E3 ligase activity involved in DNA damage response.RNF138^(−/−) mice were hyper-susceptible to the switch from colitis to aggressive malignancy,which coincided with sustained aberrant NF-кB signaling in the colonic cells.Furthermore,RNF138 suppresses the activation of NF-кB signaling pathway through preventing the translocation of NIK and IKK-Beta Binding Protein(NIBP)to the cytoplasm,which requires the ubiquitin interaction motif(UIM)domain.More importantly,we uncovered a significant correlation between poor prognosis and the downregulation of RNF138 associated with reinforced NF-кB signaling in clinical settings,raising the possibility of RNF138 dysregulation as an indicator for the therapeutic intervention targeting NF-кB signaling.Using the xenograft models built upon either RNF138-dificient CRC cells or the cells derived from the RNF138-dysregulated CRC patients,we demonstrated that the inhibition of NF-кB signaling effectively hampered tumor growth.Overall,our work defined the pathogenic role of aberrant NF-кB signaling due to RNF138 downregulation in the cascade events from the colitis switch to colonic neoplastic transformation and progression,and also highlights the possibility of targeting the NF-кB signaling in treating specific subtypes of CRC indicated by RNF138-ablation.