High Strength, Conductivity, and Bacteriostasis of the P(AM-co-AA)/Chitosan Quaternary Ammonium Salt Composite Hydrogel through Ionic Crosslinking and Hydrogen Bonding.

Traditional hydrogels with a single-crosslinked network structure suffer from poor stretchability, low sensitivity, and easy contamination, which seriously affect their practical application in the strain sensor field. To overcome these shortcomings, herein, a multiphysical crosslinking strategy (ionic crosslinking and hydrogen bonding) was designed to prepare a hydrogel strain sensor based on chitosan quaternary ammonium salt (HACC)-modified P(AM-co-AA) (acrylamide-co-acrylic acid copolymer) hydrogels. The ionic crosslinking for the double-network P(AM-co-AA)/HACC hydrogels was achieved by an immersion method with Fe3+ as crosslinking sites, which crosslinked with the amino group (-NH2) on HACC and the carboxyl group (-COOH) on P(AM-co-AA) and enabled the hydrogels to recover and reorganize rapidly, resulting in a hydrogel-based strain sensor with excellent tensile stress (3 MPa), elongation (1390%), elastic modulus (0.42 MPa), and toughness (25 MJ/m3). In addition, the prepared hydrogel exhibited high electrical conductivity (21.6 mS/cm) and sensitivity (GF = 5.02 at 0-20% strain, GF = 6.84 at 20-100% strain, and GF = 10.27 at 100-480% strain). Furthermore, the introduction of HACC endowed the hydrogel with excellent antibacterial properties (up to 99.5%) and excellent antibacterial activity against bacteria of three forms, bacilli, cocci, and spores. The flexible, conductive, and antibacterial hydrogel can be applied as a strain sensor for real-time detection of human motions such as joint movement, speech, and respiration, which exhibits a promising application prospect in wearable devices, soft robotic systems, and other fields.

Carbon Nanotubes and Silica@polyaniline Core-Shell Particles Synergistically Enhance the Toughness and Electrical Conductivity in Hydrophobic Associated Hydrogels.

Soft, conductive, and stretchable sensors are highly desirable in many applications, including artificial skin, biomonitoring patches, and so on. Recently, a combination of good electrical and mechanical properties was regarded as the most important evaluation criterion for judging whether hydrogel sensors are suitable for practical applications. Herein, we demonstrate a novel carboxylated carbon nanotube (MWCNT-COOH)-embedded P(AM/LMA)/SiO2@PANI hydrogel. The hydrogel benefits from a double-network structure (hydrogen bond cross-linking and hydrophobic connectivity network) due to the role of MWCNT-COOH and SiO2@PANI as cross-linkers, thus resulting in tough composite hydrogels. The obtained P(AM/LMA)/SiO2@PANI/MWCNT-COOH hydrogels exhibited high tensile strength (1939 kPa), super stretchability (3948.37%), and excellent strain sensitivity (gauge factor = 11.566 at 100-1100% strain). Obviously, MWCNT-COOH not only improved the electrical conductivity but also enhanced the mechanical properties of the hydrogel. Therefore, the integration of MWCNT-COOH and SiO2@PANI-based hydrogel strain sensors will display broad application in sophisticated intelligence, soft robotics, bionic prosthetics, personal health care, and other fields using inexpensive, green, and easily available biomass.

Streptomyces chengmaiensis sp. nov., isolated from the stem of a mangrove plant in Hainan.

A novel Streptomyces strain, designated as HNM0663T, was isolated from the stem of a mangrove plant (Avicennia marina) collected from the coast of Chengmai city, Hainan Island, PR China. On the basis of the alignment of 16S rRNA gene sequences, strain HNM0663T was closely related to Streptomyces lichenis LCR6-01T (98.67 %), Streptomyces nanningensis YIM 33098T (98.12 %) and Streptomyces palmae CMU-AB204T (97.93 %). Genome-based comparisons showed that strain HNM0663T was distinguished from its closest related species with 80.3 % average nucleotide identity and 20.2 % digital DNA-DNA hybridization values. The main cellular fatty acids were iso-C16 : 0, iso-C15 : 0 and anteiso-C15 : 0. The main menaquinones were MK-9 (H6), MK-9 (H4) and MK-8 (H4). The predominant phospholipids contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylcholine. Based on these polyphasic taxonomy results, strain HNM0663T should represent a novel Streptomyces species, for which the name Streptomyces chengmaiensis sp. nov. is proposed. The type strain is HNM 0663T (=CCTCC AA 2019075T=LMG 31909T).

New Diterpene and Indole Alkaloid Analogs from the Streptomyces malaysiensis SCSIO 41397.

One new cyclooctatin-type diterpenoid, 15-hydroxycyclooctatin (1), and one new indole alkaloid, streptoprenylindole D (3), along with 9 known compounds, were isolated from the Streptomyces malaysiensis SCSIO 41397. Their structures were established on the basis of spectroscopic analysis, optical rotation, and by a comparison with data from the literature. All isolated compounds were evaluated for their antibacterial (MRSA), antitumor (22Rv1 and PC-3) and antiviral (HSV-1/2) activities. According to the analysis of biological gene clusters in the whole genome, we preliminarily locate the gene clusters related to the synthesis of 15-hydroxycyclooctatin (1).

Cyclopentenone-Containing Tetrahydroquinoline and Geldanamycin Alkaloids from Streptomyces malaysiensis as Potential Anti-Androgens against Prostate Cancer Cells.

Malaymycin (1), a new cyclopentenone-containing tetrahydroquinoline alkaloid, and mccrearamycin E (2), a geldanamycin analogue bearing a rare ring-contracted cyclopentenone moiety, and a C2-symmetric macrodiolide (7) were isolated from Streptomyces malaysiensis SCSIO41397. Their structures including absolute configurations were determined by detailed analyses of NMR and HRMS data and ECD calculations. The occurrence of mccrearamycin E (2) bearing a ring-contracted cyclopentenone is rare in the geldanamycin class. All isolated compounds were evaluated for their cytotoxicities against five cancer cell lines. As a result, compounds 1, 4, 5, and 7 showed cytotoxicity against some or all of the five cancer cell lines with IC50 values ranging from 0.067 to 7.2 µM. In particular, compound 1 inhibited the growth of C42B and H446 cell lines with IC50 values of 67 and 70 nM, respectively. Malaymycin (1) significantly induced cell cycle arrest at the G0/G1 phase in C42B cell lines and caused cell shrinkage and inhibited the expression of the androgen receptor (AR) at both the mRNA and protein levels in a dose-dependent manner. Further examination by qRT-PCR analysis showed that 1 strongly suppressed the expression of AR target genes KLK2 and KLK3 in the C42B and 22RV1 cell lines, which suggested that 1 might be a promising potential lead compound for the development of a treatment for the castration-resistant prostate cancer (CRPC).

Gordonia mangrovi sp. nov., a novel actinobacterium isolated from mangrove soil in Hainan.

A novel actinobacterium, designated strain HNM0687T, was isolated from mangrove soil samples collected from Hainan Province, PR China and its polyphasic taxonomy was studied. Based on the results of 16S rRNA gene sequence analysis, strain HNM0687T was closely related to Gordonia bronchialis NBRC 16047T (98.7 %), Gordonia rhizosphera NBRC 16068T (98.2 %), Gordonia oryzae RS15-1ST (97.9 %), Gordonia polyisoprenivorans NBRC 16320T (97.7 %) and Gordonia sediminis AMA 120T (97.7 %). Genome-based comparisons revealed a clear distinction in average nucleotide identity values between strain HNM0687T and its closely related strains (74.4-78.3 %). Strain HNM0687T contained meso-diaminopimelic acid, arabinose and galactose in whole-cell hydrolysates. Mycolic acid was present. The menaquinones of strain HNM0687T were MK-9(H2) and MK-7(H2). The phospholipids of the isolate were composed of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were C16 : 0, C16 : 1 ω7c/C16 : 1 ω6c, C18 : 010-methyl (TBSA), C18 : 0 and C18 : 1 ω9c. Based on its genotypic, chemotaxonomic and phenotypic characteristics, it is concluded that strain HNM0687T represents a novel species of the genus Gordonia for which the name Gordonia mangrovi sp. nov. is proposed. The type strain is HNM0687T (=CCTCC AA 2019074 T=KCTC 49383 T).

Determination of newly synthesized lipoic acid-niacin dimer in rat plasma by UPLC/electrospray ionization tandem mass spectrometry: assay development, validation and application to a pharmacokinetic study.

A simple, sensitive and specific ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method was developed to determine the newly synthesized compound lipoic acid-niacin dimer (N2L) in plasma. Plasma samples were precipitated by methanol using tetrahydropalmatine as internal standard. Chromatographic separation was achieved on an Acquity BEH C18 (2.1 × 50 mm i.d., 1.7 µm) column; the mobile phase contains methanol and buffer solution (water with 0.5% formic acid and 10 mmol/L ammonium acetate). Multiple reaction monitoring (m/z 353.9 → 148.6 for N2L and m/z 356.0 → 192.0 for internal standard) was performed for detection and quantification. The method was validated to be rapid, specific, accurate and precise over the concentration range of 1-750 ng/mL; N2L was not stable on the bench-top or during freeze-freeze-thaw cycles in plasma, but was stable in the stock solution and after preparation in the autosampler for 24 h. The utility of the assay was confirmed by pharmacokinetic study of N2L in rats.

Unraveling fluorescent mechanism of biomass-sourced carbon dots based on three major components: Cellulose, lignin, and protein.

The complexity of biomass components leads to significant variations in the performance of biomass-based carbon dots (CDs). To shed light on this matter, this study presents a comparative analysis of the fluorescence properties of CDs using pure cellulose, lignin, and protein as models. Three CDs showed different fluorescent properties, resulting from the structure difference and carbonization behavior in the hydrothermal. The relatively gentle thermal degradation of proteins allows the macromolecular structure of amino acids to be preserved. This preservation results in a more regular lattice structure, a larger sp2 domain size, and N-doping, which contribute to the highest quantum yield (QY) of 8.7% of the CDs. In contrast, cellulose undergoes more severe thermal degradation with large amounts of small molecules generated, resulting in the CDs with fewer surface defects, more irregular lattice structures, and lower QY. These results provide a guideline for the design of carbon dots from different biomass.

Leakage Proof, Flame-Retardant, and Electromagnetic Shield Wood Morphology Genetic Composite Phase Change Materials for Solar Thermal Energy Harvesting.

Phase change materials (PCMs) offer a promising solution to address the challenges posed by intermittency and fluctuations in solar thermal utilization. However, for organic solid-liquid PCMs, issues such as leakage, low thermal conductivity, lack of efficient solar-thermal media, and flammability have constrained their broad applications. Herein, we present an innovative class of versatile composite phase change materials (CPCMs) developed through a facile and environmentally friendly synthesis approach, leveraging the inherent anisotropy and unidirectional porosity of wood aerogel (nanowood) to support polyethylene glycol (PEG). The wood modification process involves the incorporation of phytic acid (PA) and MXene hybrid structure through an evaporation-induced assembly method, which could impart non-leaking PEG filling while concurrently facilitating thermal conduction, light absorption, and flame-retardant. Consequently, the as-prepared wood-based CPCMs showcase enhanced thermal conductivity (0.82 W m-1 K-1, about 4.6 times than PEG) as well as high latent heat of 135.5 kJ kg-1 (91.5% encapsulation) with thermal durability and stability throughout at least 200 heating and cooling cycles, featuring dramatic solar-thermal conversion efficiency up to 98.58%. In addition, with the synergistic effect of phytic acid and MXene, the flame-retardant performance of the CPCMs has been significantly enhanced, showing a self-extinguishing behavior. Moreover, the excellent electromagnetic shielding of 44.45 dB was endowed to the CPCMs, relieving contemporary health hazards associated with electromagnetic waves. Overall, we capitalize on the exquisite wood cell structure with unidirectional transport inherent in the development of multifunctional CPCMs, showcasing the operational principle through a proof-of-concept prototype system.

Metabolite-based biosensors for natural product discovery and overproduction.

Natural products derived from bacterial secondary metabolites contribute greatly to the pharmaceutical industry. Heterologous expression of natural product biosynthetic pathways can remarkably improve the yield of target products and lead to the discovery of numerous derivatives. Therefore, high-throughput analytical methods are urgently needed for the detection of natural products. Biosensors allow fast, real-time detection and efficient screening. With the growth of in-depth knowledge of biosensors, biosensors with high efficiency and specificity are exploited for broader applications. Here, we summarized how biosensors targeting different metabolites were constructed and optimized and the applications of metabolite-based biosensors in heterologous bacterial hosts. Finally, we prospected the future development of biosensors, including combinations with other advanced technologies, to solve the challenges hampering wider applications.

Fabrication of thermoplastic polyurethane with functionalized MXene towards high mechanical strength, flame-retardant, and smoke suppression properties.

Recently, two-dimensional MXene demonstrated promising advantages to improve the flame-retardant performance of composites; however, its compatibility with polymer matrix is a great concern. In this study, MXene was first functionalized with phosphorylated chitosan (PCS) to obtain the PCS-MXene nanohybrid. The resulting nanohybrid was introduced into the thermoplastic polyurethane (TPU) matrix via solution mixing followed by the hot-pressing method, affording TPU/PCS-MXene nanocomposite. The resulting nanohybrid exhibited superior compatibility with the TPU matrix, enhancing mechanical performance of the TPU/PCS-MXene nanocomposite compared to the pristine TPU and TPU/MXene nanocomposite. Besides, the flame-retardant performance of TPU/PCS-MXene nanocomposite was greatly enhanced, while the smoke emission was effectively suppressed. As only 3 wt% PCS-MXene was introduced, peak heat release rate, total heat release, and total smoke production of the composite decreased by 66.7%, 21.0%, and 27.7%, respectively, compared to the pristine TPU. Systematical characterization was then carried out to investigate the enhancement mechanism of PCS-MXene, highlighting the crucial role of PCS combined with the catalytic effect of MXene. In brief, the compatibility issues of MXene were effectively addressed, and its flame-retardancy enhanced greatly via the PCS modification, the bio-based characteristic of which, in turn greatly benefits the further development of MXene-polymer composite.

Complete genome sequence of Streptomyces malaysiensis HNM0561, a marine sponge-associated actinomycete producing malaymycin and mccrearamycin E.

Streptomyces malaysiensis HNM0561 is a marine sponge-associated actinomycete with the potential to produce potential anti-androgens against prostate cancer cells, including malaymycin and mccrearamycin E. Here, we present the complete genome sequence of S. malaysiensis HNM0561, which consists of a linear chromosome of 11,656,895 bp and a circular plasmid of 32,797 bp, 9849 protein coding genes, 18 rRNA genes, 66 tRNA genes, and 191 sRNA genes. Genomic annotations revealed that 72.03% of the protein-coding genes were assigned to the COG database, among which the abundant genes were predicted to be involved in transcription, replication, carbohydrate transport and metabolism, and amino acid transport and metabolism. Forty-nine putative secondary metabolite biosynthetic gene clusters were found in the genome. Among them, the potential biosynthetic gene clusters of malaymycin and mccrearamycin E have been described respectively. The complete genome information presented here will enable us to investigate the biosynthetic mechanism of two novel structures of malaymycin and mccrearamycin E and to discover novel secondary metabolites with potential against prostate cancer cell activities.

Diketopiperazine and enterotoxin analogues from the mangrove derived-soil Streptomyces sp. SCSIO 41400 and their biological evaluation.

A new diketopiperazine, cyclo-(d-8-acetoxyl-Pro-l-Leu) (1), together with eight known compounds (2-9) including three enterotoxins (2-4), four diketopiperazines (5-8) and maltol (9), were isolated from the mangrove derived-soil Streptomyces sp. SCSIO 41400. The planar structures of all compounds were determined from analysis of NMR spectra, MS, optical rotation and comparing with literature data. The absolute configuration of compound 1 was assigned by electronic circular dichroism (ECD). The isolated compounds (1-9) were tested for their acetyl cholinesterase (AChE) and pancreatic lipase (PL) enzyme inhibitory activities. Among them, the new diketopiperazine (1) displayed preferable PL enzyme inhibitory activity with IC50 value of 27.3 µg/mL, while compounds 2, 5 and 6 showed weak PL enzyme inhibitory activity. Further molecular docking simulation exhibited that compound 1 could be well bind with the catalytic pocket of the PL. Besides, compound 9 showed moderate antibacterial activity against Methicillin-resistant Staphylococcus aureus with MIC value of 12.5 µg/mL, which was comparable to that of the positive control ampicillin with MIC value of 3.125 µg/mL.

LAMC2 promotes the proliferation of cancer cells and induce infiltration of macrophages in non-small cell lung cancer.

BACKGROUND: Non-small-cell lung cancer (NSCLC) is the most prevalent cancer worldwide. Tumor microenvironment (TME) plays a very important role in the cancer development. Thus, it is urgent to find the change of TME that contributes to NSCLC carcinogenesis and progression. METHODS: The bioinformatics analysis approach was applied to evaluate the change of TME and screen the differentially immune cells in NSCLC tissue based on The Cancer Genome Atlas (TCGA) data. Meanwhile, the association of differentially immune cells with tumor stage and prognosis of NSCLC was evaluated. Then, we screen the different expression genes between macrophages infiltration high group and low group. After that, the expression of LAMC2 was detected in 48 cases of NSCLC tissues and paired normal tissues. The function of LAMC2 was detected through cell experiments in vitro. Immunohistochemistry assay was used to detect the correlation between LAMC2 expression and macrophages infiltration in NSCLC tissue. LAMC2-related pathways were identified by gene set enrichment analysis. RESULTS: Compared with early stage, middle-advanced stage of NSCLC exhibited lower immune score. Macrophages were the main component of different immune cells and correlated with poor outcome. The results of immunohistochemistry indicated that the expression of LAMC2 in NSCLC tissues was higher than paired normal tissues. Down-regulation of LAMC2 inhibited the proliferation, migration and invasion of NSCLC cells in vitro. Overexpression of LAMC2 was positively associated with macrophages infiltration in NSCLC tissues. Inhibition of LAMC2 expression in NSCLC cells could reduce THP-1 infiltration, and LAMC2 protein could promote the infiltration of THP-1. The Gene Set Enrichment Analysis results showed that high expression of LAMC2 was correlated with focal adhesion and extracellular matrix receptor interaction. CONCLUSIONS: Immune suppression and macrophages infiltration were correlated with poor outcomes in NSCLC. LAMC2 promoted macrophages infiltration and extracellular matrix remolding in NSCLC. Our studies suggested an oncogenic role of LAMC2 in NSCLC progression and it perhaps serve as a potential immune therapy target for NSCLC.

Synthesis and Electrochemical Stability of Ultrahigh Aspect Ratio Nanoporous Gold after Calixarene-Phosphine Ligand Removal.

Leveraging our previous report on the synthesis of calixarene-capped ultrahigh aspect-ratio nanoporous gold, we now report a new class of nanoporous gold comprising removed calixarene-phosphine ligands using UV/ozone treatment. The removal of the calixarene ligands by this treatment is supported by XPS measurements. TEM further shows the extraordinary stability of the ∼1 nm building blocks comprising the nanoporous gold wall after UV/ozone treatment and subsequent strongly reducing electrochemical environments. Sensing of nitrobenzene is used as a method of characterization to show that the surface chemistry of the nanoporous gold assemblies has radically changed after the UV/ozone treatment.

[Effects of beta-asarone on expression of FOS and GAD65 in cortex of epileptic rat induced by penicillin].

OBJECTIVE: To study effects of beta-asarone on expression of FOS and GAD65 in cortex of epileptic rat induced by penicillin. METHODS: The epileptic animal models were induced by penicillin. The rats were randomly divided into beta-asarone of high (100 mg/kg), medium (50 mg/kg), low (25 mg/kg) dose group, positive control group (Phenytoin sodium), negative control group (matrix). The medicine was administered orally. The effects of beta-asarone on expression of FOS and GAD65 in cortex of epileptic rat were detected by immuohistochemistry method. RESULTS: beta-asarone could raise expression of FOS and reduce expression of GAD65 obviously. There were significant differences between negative control group and beta-asarone group. And it showed significant dose-effect relationship. CONCLUSION: Up-regulation of FOS may be a effective link of anti-epileptic effect of beta-asarone; reduced expression of GAD65 may be a follow-up impact of beta-asarone treatment.

[Effects of beta-asarone on morphology and cell viability in PC12 cells and cultured rat cortical neurons].

OBJECTIVE: To observe the effects of beta-asarone on the morphology and cell viability in PC12 cells and cultured neonate rat cortical neurons. METHODS: The cultured neonate rat cortical neurocytes were stained immunocytochemically with NSE, GFAP antibodies, respectively; Morphological changes were observed under phase contrast microscope after PC12 cells and cultured rat cortical neurons with beta-asarone of different concentrationfor 24h in vitro, and the cell viability of PC12 and cortical neurons were examined by MTT assay. RESULTS: Most of the cultured neonate rat cortical neurocytes were positively stained with NSE antibody, and positively with GFAP in a less degree; Treatment of PC12 cells with concentrations of 7.5, 15, 30, 60 microg/ml beta-asarone for 24 h could facilitate the proliferation in PC12 cells, 120, 240, 480 microg/ml beta-asarone could inhibit the proliferation inversely, and with the concentration of beta-asarone increasing, the inhibition was enhanced; Treatment of cultured neonate rat cortical neurons with concentrations of 7.5, 15, 30, 60,120 nicrog/ml beta-asarone for 24 h, there were no visible effects on morphology and cell viability, 240 microg/ml beta-asarone could facilitate the proliferation obviously, but 480 microg/ml beta-asarone induced injury on neurons. CONCLUSION: beta-asarone maybe has anti-tumor and protective effects on cultured neurons.

Sequencing and analysis of the complete mitochondrial genome of Hyla ussuriensis (Anura: Hylidae).

In this study, the complete mitogenome sequence of Hyla ussuriensis (Anura: Hylidae) is first determined using long PCR. It is a circular molecule of 18 023 bp in length (GenBank accession no. KT964710). Similar to the typical mtDNA of amphibians, the complete mtDNA sequence of Hyla ussuriensis contained two rRNA genes (12S rRNA and 16S rRNA), 22 tRNA genes, 13 protein-coding genes (PCGs), and a control region (D-loop). The nucleotide composition was 29.9% A, 25.4% C, 14.5% G, and 30.2% T. Mitochondrial genomes analyses based on NJ method yield phylogenetic trees, indicating 13 reported Anura frogs belonging to five families (Hylidae, Bufonidae, Microhylidae, Ranidae, and Rhacophoridae). These molecular data presented here provide a useful tool for systematic analyses of genus Hyla and family Hylidae.

Large-Scale Synthesis of Monodisperse Red Blood Cell (RBC)-Like Polymer Particles.

Red blood cell (RBC)-like particles have shown great interest as a model for the understanding of the cell behavior and as promising biomaterials in targeted drug delivery. In this study, a simple and versatile route was proposed for the large-scale synthesis of monodisperse and well-defined RBC-like PS particles using divinylbenzene (DVB) as the cross-linker and ethanol as reaction medium. RBC-like particles were obtained due to the asymmetric shrinkage of a cross-linked network during the phase separation process. An ordered self-assembly monolayer with the concave facing up at the air-water interface was also demonstrated.