Real-Time Direct Monitoring of Chirality Fixation and Recognition at the Single-Molecule Level.

Chirality, a fundamental attribute of nature, significantly influences a wide range of phenomena related to physical properties, chemical reactions, biological pharmacology, and so on. As a pivotal aspect of chirality research, chirality recognition contributes to the synthesis of complex chiral products from simple chiral compounds and exhibits intricate interplay between chiral materials. However, macroscopic detection technologies cannot unveil the dynamic process and intrinsic mechanisms of single-molecule chirality recognition. Herein, we present a single-molecule detection platform based on graphene-molecule-graphene single-molecule junctions to measure the chirality recognition involving interactions between amines and chiral alcohols. This approach leads to the realization of in situ and real-time direct observation of chirality recognition at the single-molecule level, demonstrating that chiral alcohols exhibit compelling potential to induce the formation of the corresponding chiral configuration of molecules. The amalgamation of theoretical analyses with experimental findings reveals a synergistic action between electrostatic interactions and steric hindrance effects in the chirality recognition process, thus substantiating the microscopic mechanism governing the chiral structure-activity relationship. These studies open up a pathway for exploring novel chiral phenomena from the fundamental limits of chemistry, such as chiral origin and chiral amplification, and offer important insights into the precise synthesis of chiral materials.

Steering CO2 Electroreduction Selectivity U-Turn to Ethylene by Cu-Si Bonded Interface.

Copper (Cu), with the advantage of producing a deep reduction product, is a unique catalyst for the electrochemical reduction of CO2 (CO2RR). Designing a Cu-based catalyst to trigger CO2RR to a multicarbon product and understanding the accurate structure-activity relationship for elucidating reaction mechanisms still remain a challenge. Herein, we demonstrate a rational design of a core-shell structured silica-copper catalyst (p-Cu@m-SiO2) through Cu-Si direct bonding for efficient and selective CO2RR. The Cu-Si interface fulfills the inversion in CO2RR product selectivity. The product ratio of C2H4/CH4 changes from 0.6 to 14.4 after silica modification, and the current density reaches a high of up to 450 mA cm-2. The kinetic isotopic effect, in situ attenuated total reflection Fourier-transform infrared spectra, and density functional theory were applied to elucidate the reaction mechanism. The SiO2 shell stabilizes the *H intermediate by forming Si-O-H and inhibits the hydrogen evolution reaction effectively. Moreover, the direct-bonded Cu-Si interface makes bare Cu sites with larger charge density. Such bare Cu sites and Si-O-H sites stabilized the *CHO and activated the *CO, promoting the coupling of *CHO and *CO intermediates to form C2H4. This work provides a promising strategy for designing Cu-based catalysts with high C2H4 catalytic activity.

Ferritinophagy: A new idea for liver diseases regulated by ferroptosis.

BACKGROUND: The discovery of regulatory cell death has led to a breakthrough in the therapeutic field. Various forms of cell death, such as necrosis, apoptosis, pyroptosis, autophagy, and ferroptosis, play an important role in the development of liver diseases. In general, more than one form of cell death pathways is responsible for the disease state. Therefore, it is particularly important to study the regulation and interaction of various cell death forms in liver diseases. DATA SOURCES: We performed a PubMed search up to November 2022 with the following keywords: ferritinophagy, ferroptosis, and liver disease. We also used terms such as signal path, inducer, and inhibitor to supplement the query results. RESULTS: This review summarized the basic characteristics of ferritinophagy and ferroptosis and the regulation of ferroptosis by ferritinophagy and reviewed the key targets and treatment strategies of ferroptosis in different liver diseases. CONCLUSIONS: Ferritinophagy is a potential therapeutic target in ferroptosis-related liver diseases.

Chiral derivatives of covalent organic framework TpBD (NH2 )2 used as stationary phases in gas chromatography.

Chiral covalent organic framework materials have many excellent properties, which have received much attention in the field of separation. Synthesized the covalent organic framework COF-TpBD (NH2 )2 modified, respectively, by L-valine trifluoroacetyl derivative, L-hydroxyproline, and (1S)-(+)-10-camphorsulfonyl chloride, three capillary columns of chiral covalent organic framework materials were obtained for gas chromatography. Those columns are able to separate some chiral compounds, positional isomers, n-alkanes, n-alcohols, aromatic hydrocarbon mixture, and Grob's reagents. They are complementary to other chiral capillary columns and are possible for potential applications.

Research progress on lncRNAs in Alzheimer's disease.

Alzheimer's disease (AD) is the common neurodegenerative disease in the center never system and the typical dementia in old people. The major pathological changes of AD are the accumulation of amyloid-ß (Aß) plaques, neurofibrillary tangles, loss of cholinergic neurons, inflammation and metabolism dysfunction. However, the molecular mechanism leading to AD pathogenesis is not clear. More and more studies reported that long non-coding RNAs (lncRNAs) play important roles in AD. In this review, we briefly introduce the recent research progress on lncRNAs in AD, including their regulation of clearance of the Aß plaques, synaptic function, inflammation reaction and mitochondrial function, and thus providing the references for that lncRNAs can serve as a potential diagnostic biomarker and therapeutic target in AD.

Vibration-Assisted Charge Transport through Positively Charged Dimer Junctions.

Intermolecular charge transport plays a vital role in the fields of electronics, as well as biochemical systems. Here, we design supramolecular dimer junctions and investigate the effects of charge state and energy level alignment on charge transport under nanoconfinement. Incoherent tunneling caused by thermally-induced vibrations is enhanced in positively charged systems. The transition between coherent and incoherent tunneling is associated with specific molecular vibration modes. Positively charged systems with smaller torsional barriers and vibrational frequencies result in lower transition temperatures. Multiple thermal effects have a great impact on the conductance in the off-resonant tunneling, while thermally-induced vibron-assisted tunneling contributes more to the transport in the resonant tunneling. These investigations offer a deep mechanism understanding of intermolecular charge transport and facilitate the development of practical functional molecular devices.

The thermodynamics and electronic structure analysis of P-doped spinel Co3O4.

The thermodynamics of phosphorus (P) doping to spinel Co3O4, for both bulk cases and (100) and (110) surface cases, is studied using first principles calculations. The doping energies of the P atom at different doping sites are carefully calculated and compared. It is shown that P doping at Co sites, at either tetrahedral or octahedral sites, is energetically favorable, while P doping and replacing O atoms are energetically unfavorable. The doping energy difference is large enough to conclude that P doping has a very strong preference to take the Co sites, rather than the O sites in spinel Co3O4. Even when O-vacancy is available, P doping and taking the O-vacancy site is thermodynamically unfavorable. The physical/chemical mechanism behind this phenomenon is carefully analyzed. Electronic structure analysis shows that P doping and replacing the Co atom brings excess electrons to the Co3O4 system, which is beneficial to enhance the electrochemical and catalytic performance of the spinel Co3O4. Our results clarified the misleading results of P doping and replacing O atoms in spinel Co3O4 reported in the literature.

[Anti-inflammatory effect, plasma effective components and therapeutic targets of Huanglian Jiedu Decoction on ulcerative colitis mice].

This paper was to investigate the effect of Huanglian Jiedu Decoction(HLJD) on ulcerative colitis(UC) in mice, and determine the effective components in plasma, and virtually screen its therapeutic target, and predict its mechanism. Sixty Balb/c mice were randomly divided into blank group, model group, mesalazine treatment group(0.3 g·kg~(-1)), and HLJD treatment groups(24.66, 12.33, 6.17 g·kg~(-1)). Excepted for the blank group, all the mice in HLJD and mesalazine treatment groups were gavage administration. All mice freely drank 2.5% DSS solution for seven days to induce UC. The disease activity index(DAI) was detected each day. At the end of the experiment, HE staining was used to observe the pathological changes in colon. The content of IL-1ß, IL-6 and TNF-α in colon were determined by ELISA. The effective components in plasma were determined by UPLC-Q-TOF-MS. The reverse docking in PharmMapper was used to screen the component targets. The disease targets of UC were collected by searching TTD, OMIM and GeneCards databases. The intersection of the component targets and disease targets was selected as the therapeutic targets. Then the therapeutic targets were imported into the STRING for GO and KEGG enrichment analysis. Discovery Studio was used to simulate the docking between the components and the targets. RESULTS:: showed that the DAI in the model group increased significantly(P<0.05), and the number of inflammatory cells and infiltration degree increased significantly compared with the blank group. The DAI in HLJD treatment group was significantly reduced(P<0.05), and the number and infiltration degree of inflammatory cells were reduced compared with the model group. The ELISA results showed that the levels of IL-1ß, IL-6 and TNF-α were increased significantly in the model group(P<0.01) compared with the blank group, and significantly down regulated in the HLJD treatment group(P<0.05) compared with the model group. After UPLC-Q-TOF-MS analyse, ten components were identified. The network pharmacology analysis showed that the action targets were significantly enriched in 129 of biological processes, such as response to organic substance, chemical and oxygen-containing compound, etc., as well as 16 of signal pathways, such as IL-17, TNF and hepatitis B signal pathways, were enriched too. The results of molecular docking showed that limonin, palmatine and berberine could bind to CASP3 and MMP9 by hydrogen bond. In conclusion, HLJD could alleviate the colonic mucosal inflammatory infiltration and mucosal damage in UC mice. The mechanism may be related to the anti-inflammatory effect on UC mice by reducing the levels of IL-1ß, IL-6 and TNF-α in colon through limonin, palmatine and berberine regulating IL-17 signal pathway and TNF signal pathway via CASP3 and MMP9 meditated.

[Effect of nuciferine on gut microbiota and inflammatory response in obese model mice].

The aim of this study was to elucidate the mechanism of nuciferine on alleviating obesity based on modulating gut microbiota, ameliorating chronic inflammation, and improving gut permeability. In this study, the obese model mice were induced by high-fat diet and then randomly divided into model group, and nuciferine group; some other mice of the same week age were fed with normal diet as normal group. In the modeling process, the mice were administered intragastrically(ig) for 12 weeks. In the course of both modeling and treatment, the body weight and food intake of mice in each group were measured weekly. After modeling and treatment, the Lee's index, weight percentage of inguinal subcutaneous fat, and the level of blood lipid in each group were measured. The pathological changes of adipocytes were observed by HE staining to evaluate the efficacy of nuciferine treatment in obese model mice. 16 S rRNA sequencing analysis was conducted to study the changes in diversity and abundance of gut microbiota after nuciferine treatment. Enzyme-linked immunosorbent assay(ELISA) and quantitative Real-time polymerase chain reaction(qPCR) were used to detect the levels of inflammatory factors interleukin-6(IL-6), interleukin-1ß(IL-1ß), tumor necrosis factor-α(TNF-α) and the expression of related genes in adipose tissue of mice in each group, so as to evaluate the effect of nuciferine on chronic inflammation of mice in obese model group. qPCR was used to detect the expression of occludin and tight junction protein 1(ZO-1)gene in colon tissure, so as to evaluate the effect of nuciferine on intestinal permeability of mice in obese group. Nuciferine decreased the body weight of obese mice, Lee's index, weight percentage of inguinal subcutaneous fat(P<0.05), and reduced the volume of adipocytes, decreased the level of total cholesterol(TC), triglyceride(TG), and low density lipoprotein cholesterol(LDL-C)(P<0.05) in serum, improved dysbacteriosis, increased the relative abundance of Alloprevotella, Turicibacter, and Lactobacillus, lowered the relative abundance of Helicobac-ter, decreased the expression of inflammatory cytokines IL-6, IL-1ß, and TNF-α genes in adipose tissue(P<0.01), decreased the levels of inflammatory cytokines IL-6, IL-1ß, and TNF-α in serum(P<0.05), and increased the expression of occludin and ZO-1 genes related to tight junction in colon tissue(P<0.01). Nuciferine could treat obesity through modulating gut microbiota, decreasing gut permeability and ameliorating inflammation.

Interpenetrating graphene network bct-C40: a promising anode material for Li ion batteries.

The stable sp2-C atoms in graphite enable its excellent structural and electrochemical stability as an anode material for Li-ion battery applications, while the limited Li-storage capacity of graphite also originates from the sp2 hybridization. Herein, from first-principles calculations, we show that a synergistic effect of sp2 and sp3 hybridized C atoms can substantially enhance the Li-storage performance in carbon-based anodes, using bct-C40 as an example, which is constructed with interconnected graphene layers (sp2 hybridized C atoms) and the connecting points are composed of sp3-C atoms. Charge transfer from sp2-C atoms to sp3-C atoms has been found, leading to unoccupied electronic states forming around the Fermi level. Furthermore, we found that the unoccupied electronic states are contributed by the pz orbital of the sp2-C atoms, resulting in stronger interactions between C atoms and intercalated Li atoms. As a result, the Li intercalation concentration in bct-C40 can reach as high as LiC2.5 (corresponding to a capacity of 893 mA h g-1), much higher than that of LiC6 in graphite (372 mA h g-1). Furthermore, bct-C40 inherits good structural and electrochemical stability, a metallic electronic structure, and low Li-ion migration energy barriers (0.067-0.112 eV) from the sp2 hybridized graphene structures, therefore very good Li-storage performance is expected, indicating that bct-C40 can be used as a high-performance anode material for lithium ion batteries. Our study provides new insights into the functionality of sp2- and sp3-C atoms in carbon-based anode materials and is helpful for the designing of new carbon-based anodes.

The effect of protons on the Mg2+ migration in an α-V2O5 cathode for magnesium batteries: a first-principles investigation.

The scarce inventory of cathode materials with reasonable diffusion of Mg ions is the main obstacle in the development of rechargeable magnesium batteries. In this regard, vanadium pentoxide (V2O5) has been reported to be a candidate cathode material for Mg batteries. In this study, via first-principles calculations, we showed that the Mg-ion diffusion energy barrier in α-V2O5 could be substantially decreased through hydrogenation. It is found that the Mg-ion migration energy barrier in HxV2O5 is gradually decreased with an increase in H concentration. When the H concentration x reaches 2, the migration barrier is decreased to 0.56 eV from that in α-V2O5 without hydrogenation (1.28 eV). This indicates that the Mg diffusion kinetics can be substantially improved through hydrogenation, and the resultant energy barrier makes Mg diffusion acceptable even at room temperature. The mechanism of the H-enhanced Mg-diffusion has also been studied, and it has been found that H atoms not only can expand the Mg-diffusion pathway, but also have a screening effect on the interactions between Mg ions and the α-V2O5 lattice.

Exosomal miRNAs as Biomarkers of Cancer: a Meta-Analysis.

BACKGROUND: Tumor-derived exosomal miRNAs secreted by cancer cells play significant roles in the pathological processes of cancer, but no systematic meta-analysis has focused on the diagnostic efficiency of exosomal miRNAs. This meta-analysis assessed the diagnostic value of circulating exosomal miRNA in cancer. METHODS: Studies evaluating the diagnostic value of exosomal miRNA were identified in EMBASE, PubMed, Cochrane Library, and Web of Science up to August 1, 2018. The quality of each study was assessed according to the Quality Assessment of Diagnostic Accuracy Studies 2, and STATA 14.0 was used for the analyses. The true positive (TP), false positive (FP), true negative (TN), and false negative (FN) rates were extracted from each study to obtain the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and their 95% confidence intervals (CIs). RESULTS: The meta-analysis included 16 studies with 1,591 patients. Five studies reported sensitivity values, and the pooled sensitivity was 0.86 (95% CI = 0.80 - 0.90, while 29 studies reported specificity values, and the pooled specificity was 0.89 (95% CI = 0.83 - 0.93). The pooled PLR was 7.8 (95% CI = 4.9 - 12.4), the pooled NLR was 0.16 (95% CI = 0.11 - 0.24), the pooled DOR was 48 (95% CI = 23 - 101), and the AUC was 0.94 (0.91 - 0.96). CONCLUSIONS: Our meta-analysis indicated that body fluid exosomal miRNAs are highly accurate for distinguishing patients from healthy individuals, and exosomal miRNAs have superior diagnostic value in plasma, prostate cancer patients, and non-Asian individuals.

Soil properties and species composition under different grazing intensity in an alpine meadow on the eastern Tibetan Plateau, China.

As the main form of land use and human disturbance of grassland, livestock grazing has great influences on the soil resources and plant communities. This study observed the variation of soil properties and community characteristics of four treatments of different grazing intensity (no grazing, UG; light grazing, LG; moderate grazing, MG; and heavy grazing, HG) in an alpine meadow of Sichuan Province on the northeastern margin of the Tibetan Plateau. The results showed that grazing increased the pH, soil bulk density (BD), and contents of total carbon (TC) and total nitrogen (TN), and the BD increased while the others decreased with the grazing intensity. At the community level, with the increase of the grazing intensity, the vegetation coverage (R 2 = 0.61, P < 0.001), mean height of community (R 2 = 0.37, P < 0.001), aboveground biomass (R 2 = 0.54, P < 0.001), litter biomass (R 2 = 0.84, P < 0.001), and percentage of aboveground biomass of palatable grasses to total biomass (R 2 = 0.74, P < 0.001) significantly decreased, while the belowground biomass (R 2 = 0.72, P < 0.001) and the root/shoot (R/S) ratio (R 2 = 0.65, P < 0.001) increased. The species richness was the greatest at LG and the total biomass at UG. With grazing, the dominant species of the plant community shifted from palatable grasses (Gramineae and Cyperaceae) to unpalatable grasses (Compositae and Ranunculaceae). Based on the results, LG may be the optimal grassland management mode to be used in the long time in the alpine meadow of the Tibetan Plateau.

Br, O-Modified Cu(111) Interface Promotes CO2 Reduction to Multicarbon Products.

Electrochemical reduction of CO2 to multicarbon (C2+) products with added value represents a promising strategy for achieving a carbon-neutral economy. Precise manipulation of the catalytic interface is imperative to control the catalytic selectivity, particularly toward C2+ products. In this study, a unique Cu/UIO-Br interface is designed, wherein the Cu(111) plane is co-modified simultaneously by Br and O from UIO-66-Br support. Such Cu/UIO-Br catalytic interface demonstrates a superior Faradaic efficiency of ≈53% for C2+ products (ethanol/ethylene) and the C2+ partial current density reached 24.3 mA cm-2 in an H-cell electrolyzer. The kinetic isotopic effect test, in situ attenuated total reflection Fourier transform infrared spectroscopy and density functional theory calculations have been conducted to elucidate the catalytic mechanism. The Br, O co-modification on the Cu(111) interface enhanced the adsorption of CO2 species. The hydrogen-bond effect from the doped Br atom regulated the kinetic processes of *H species in CO2RR and promoted the formation of *COH intermediate. The formed *COH facilitates the *CO-*COH coupling and promotes the C2+ selectivity finally. This comprehensive investigation not only provides an in-depth study and understanding of the catalytic process but also offers a promising strategy for designing efficient Cu-based catalysts with exceptional C2+ products.

Extracellular vesicles derived from mesenchymal stem cells mediate extracellular matrix remodeling in osteoarthritis through the transport of microRNA-29a.

BACKGROUND: Knee osteoarthritis (KOA) is a common orthopedic condition with an uncertain etiology, possibly involving genetics and biomechanics. Factors like changes in chondrocyte microenvironment, oxidative stress, inflammation, and immune responses affect KOA development. Early-stage treatment options primarily target symptom relief. Mesenchymal stem cells (MSCs) show promise for treatment, despite challenges. Recent research highlights microRNAs (miRNAs) within MSC-released extracellular vesicles that can potentially promote cartilage regeneration and hinder KOA progression. This suggests exosomes (Exos) as a promising avenue for future treatment. While these findings emphasize the need for effective KOA progression management, further safety and efficacy validation for Exos is essential. AIM: To explore miR-29a's role in KOA, we'll create miR-29a-loaded vesicles, testing for early treatment in rat models. METHODS: Extraction of bone marrow MSC-derived extracellular vesicles, preparation of engineered vesicles loaded with miR-29a using ultrasonication, and identification using quantitative reverse transcription polymerase chain reaction; after establishing a rat model of KOA, rats were randomly divided into three groups: Blank control group injected with saline, normal extracellular vesicle group injected with normal extracellular vesicle suspension, and engineered extracellular vesicle group injected with engineered extracellular vesicle suspension. The three groups were subjected to general behavioral observation analysis, imaging evaluation, gross histological observation evaluation, histological detection, and immunohistochemical detection to compare and evaluate the progress of various forms of arthritis. RESULTS: General behavioral observation results showed that the extracellular vesicle group and engineered extracellular vesicle group had better performance in all four indicators of pain, gait, joint mobility, and swelling compared to the blank control group. Additionally, the engineered extracellular vesicle group had better pain relief at 4 wk and better knee joint mobility at 8 wk compared to the normal extracellular vesicle group. Imaging examination results showed that the blank control group had the fastest progression of arthritis, the normal extracellular vesicle group had a relatively slower progression, and the engineered extracellular vesicle group had the slowest progression. Gross histological observation results showed that the blank control group had the most obvious signs of arthritis, the normal extracellular vesicle group showed signs of arthritis, and the engineered extracellular vesicle group showed no significant signs of arthritis. Using the Pelletier gross score evaluation, the engineered extracellular vesicle group had the slowest progression of arthritis. Results from two types of staining showed that the articular cartilage of rats in the normal extracellular vesicle and engineered extracellular vesicle groups was significantly better than that of the blank control group, and the engineered extracellular vesicle group had the best cartilage cell and joint surface condition. Immunohistochemical detection of type II collagen and proteoglycan showed that the extracellular matrix of cartilage cells in the normal extracellular vesicle and engineered extracellular vesicle groups was better than that of the blank control group. Compared to the normal extracellular vesicle group, the engineered extracellular vesicle group had a better regulatory effect on the extracellular matrix of cartilage cells. CONCLUSION: Engineered Exos loaded with miR-29a can exert anti-inflammatory effects and maintain extracellular matrix stability, thereby protecting articular cartilage, and slowing the progression of KOA.

Exploring Electronic Characteristics of Acceptor-Donor-Acceptor-Type Molecules by Single-Molecule Charge Transport.

The electronic characteristics of organic optoelectronic materials determine the performance of corresponding devices. Clarifying the relationship between molecular structure and electronic characteristics at the single-molecule level can help to achieve high performance for organic optoelectronic materials and devices, especially for organic photovoltaics. In this work, a typical acceptor-donor-acceptor (A-D-A)-type molecule is explored by combining theoretical and experimental studies to reveal the intrinsic electronic characteristics at the single-molecule level. Specifically, the A-D-A-type molecule with 1,1-dicyano methylene-3-indanone (INCN) acceptor units exhibits an enhanced conductance in single-molecule junctions when compared with the control donor molecule, because the acceptor units of the A-D-A-type molecule contribute additional transport channels. In addition, through opening the S∙∙∙O noncovalent conformational lock by protonation to expose the -S anchoring sites, the charge transport of the D central part is detected, proving that the conductive orbitals contributed by the INCN acceptor groups can penetrate the whole A-D-A molecule. These results provide important insights into the development of high-performance organic optoelectronic materials and devices toward practical applications.

Associations between Mobile Internet Use and Self-Rated and Mental Health of the Chinese Population: Evidence from China Family Panel Studies 2020.

With societal and technological developments, mobile Internet has become the most popular and widespread means to use the Internet in China. Thus, exploring the relationship between mobile Internet use and the self-rated health and mental health of the Chinese population is of great importance. This study empirically examined the impact of mobile Internet use on residents' health using data from the China Family Panel Studies 2020 and conducted a heterogeneity analysis. The results revealed a significant negative association between mobile Internet use and the self-rated health of the population, but a significant positive association was found relative to their mental health. The results of this analysis passed a robustness test. The results of the heterogeneity analysis showed that mobile Internet use had a more significant association with the health of residents with secondary school education and university education compared to those with primary school education or below and graduate education. Furthermore, this study addresses the endogeneity problem using the propensity-score matching model, which is shown to be better at eliminating sample selectivity bias. If endogeneity is not addressed, the negative association with mobile Internet use on residents' self-rated health will be underestimated and its positive association with their mental health will be overestimated. The Chinese government should issue guidelines on the duration of Internet use, strictly regulate exaggerated and harmful content on mobile network platforms, and strengthen people's online skills through training to improve their digital literacy, especially for rural populations.

Simultaneous toughening and strengthening of chitin-based composites via tensile-induced orientation and hydrogen bond reconstruction.

Chitin, an abundant, biodegradable, and biocompatible polysaccharide, is one of the most ideal eco-friendly alternatives to petroleum-based plastics. However, the applications of chitin-based materials are hindered by their low processability and brittleness induced by strong hydrogen bonds. Herein, a tensile-induced orientation and hydrogen bond reconstruction strategy was developed to fabricate a chitin nanowhiskers/poly(vinyl alcohol) composite film with high strength and toughness. After stretching and hydrogen bond reconstruction, the tensile strength and elongation at break of the composite film increased from 38.6 to 115.2 MPa and 9.37% to 40.7%, respectively. Furthermore, strengthening and toughening mechanisms were also studied, which were attributed to the effects of the intra-layer orientation and interlayer sliding, respectively.

[Improvement of natural product production in Streptomyces by manipulating pathway-specific regulators].

Streptomyces are major sources of bioactive natural products. Genome sequencing reveals that Streptomyces have great biosynthetic potential, with an average of 20-40 biosynthetic gene clusters each strain. However, most natural products from Streptomyces are produced in low yields under regular laboratory cultivation conditions, which hamper their further study and drug development. The production of natural products in Streptomyces is controlled by the intricate regulation mechanisms. Manipulation of the regulatory systems that govern secondary metabolite production will strongly facilitate the discovery and development of natural products of Streptomyces origin. In this review, we summarize progresses in pathway-specific regulators from Streptomyces in the last five years and highlight their role in improving the yields of corresponding natural products.