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1.
Int J Biol Macromol ; 269(Pt 1): 132097, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38710249

ABSTRACT

Biodegradable polymer blends filled with rod-like polysaccharide nanocrystals have attracted much attention because each component in this type of ternary composites is biodegradable, and the final properties are more easily tailored comparing to those of binary composites. In this work, chitin nanocrystals (ChNCs) were used as nanofiller for the biodegradable poly(ε-caprolactone) (PCL)/polylactide (PLA) immiscible blend to prepare ternary composites for a crystallization study. The results revealed that the crystallization behavior of PCL/PLA blend matrices strongly depended on the surface properties of ChNCs. Non-modified ChNCs and modified ChNCs played completely different roles during crystallization of the ternary systems: the former was inert filler, while the latter acted as anti-nucleator to the PCL phase. This alteration was resulted from the improved ChNC-PCL affinity after modification of ChNCs, which was due to the 'interfacial dilution effect' and the preferential dispersion of ChNCs. This work presents a unique perspective on the nucleation role of ChNCs in the crystallization of immiscible PCL/PLA blends, and opens up a new application scenario for ChNCs as anti-nucleator.


Subject(s)
Chitin , Crystallization , Hydrophobic and Hydrophilic Interactions , Nanoparticles , Polyesters , Polyesters/chemistry , Chitin/chemistry , Nanoparticles/chemistry
2.
JOR Spine ; 7(2): e1331, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38606423

ABSTRACT

Objectives: The objective of this study is to evaluate the value of S100-A8 protein as a diagnostic marker for spinal tuberculosis and to explore its role in the potential pathogenesis of spinal tuberculosis (STB). Methods: The peripheral blood of 100 spinal tuberculosis patients admitted to the General Hospital of Ningxia Medical University from September 2018 to June 2021 were collected as the observation group, and the peripheral blood of 30 healthy medical examiners were collected as the control group. Three samples from the observation group and three samples from the control group were selected for proteomics detection and screening of differential proteins. Kyoto Encyclopedia of Genes (KEGG) was used to enrich and analyze related signaling pathways to confirm the target protein. The serum expression levels of the target proteins were determined and compared between the two groups using enzyme-linked immunosorbent assay (ELISA). Statistical methods were used to evaluate the value of target protein as a diagnostic marker for STB. A macrophage model of Mycobacterium tuberculosis infection was constructed and S100-A8 small interfering RNA was used to investigate the molecular mechanism of the target protein. Results: S100-A8 protein has the value of diagnosing spinal tuberculosis (AUC = 0.931, p < 0.001), and the expression level in the peripheral blood of the observation group (59.04 ± 19.37 ng/mL) was significantly higher than that of the control group (43.16 ± 10.07 ng/mL) (p < 0.05). S100-A8 protein expression showed a significant positive correlation with both CRP and ESR values (p < 0.01). Its AUCs for combined bacteriological detection, T-SPOT results, diagnostic imaging, antacid staining results, and pathological results were 0.705 (p < 0.05), 0.754 (p < 0.01), 0.716 (p < 0.01), 0.656 (p < 0.05), and 0.681 (p < 0.01), respectively. Lack of S100-A8 leads to a significant decrease in the expression levels of TLR4 and IL-17A in infected macrophages. Conclusion: S100-A8 protein is differentially expressed in the peripheral blood of patients with spinal tuberculosis and healthy individuals and may be a novel candidate biomarker for the diagnosis of spinal tuberculosis. The feedback loop on the S100-A8-TLR4-IL-17A axis may play an important role in the inflammatory mechanism of spinal tuberculosis.

3.
Angew Chem Int Ed Engl ; : e202405895, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38660927

ABSTRACT

Light-driven micro/nanorobots (LMNRs) are tiny, untethered machines with great potential in fields like precision medicine, nano manufacturing, and various other domains. However, their practicality hinges on developing light-manipulation strategies that combine versatile functionalities, flexible design options, and precise controllability. Our study introduces an innovative approach to construct micro/nanorobots (MNRs) by utilizing micro/nanomotors as fundamental building blocks. Inspired by silicon Metal-Insulator-Semiconductor (MIS) solar cell principles, we design a new type of optomagnetic hybrid micromotors (OHMs). These OHMs have been skillfully optimized with integrated magnetic constituent, resulting in efficient light propulsion, precise magnetic navigation, and the potential for controlled assembly. One of the key features of the OHMs is their ability to exhibit diverse motion modes influenced by fracture surfaces and interactions with the environment, streamlining cargo conveyance along "micro expressway"-the predesigned microchannels. Further enhancing their versatility, a template-guided assembly strategy facilitates the assembly of these micromotors into functional microrobots, encompassing various configurations such as "V-shaped", "N-shaped", and 3D structured microrobots. The heightened capabilities of these microrobots, underscore the innovative potential inherent in hybrid micromotor design and assembly, which provides a foundational platform for the realization of multi-component microrobots. Our work moves a step toward forthcoming microrobotic entities boasting advanced functionalities.

4.
Poult Sci ; 103(5): 103587, 2024 May.
Article in English | MEDLINE | ID: mdl-38479099

ABSTRACT

Trichomonas gallinae (T. gallinae) is a globally distributed protozoan parasite and could cause serious damage to the pigeon industry. MiRNAs have important roles in regulating parasite infection, but its impacts on T. gallinae resistance have rarely been reported. In the present study, we identified a new miRNA (novel-miR-741) and its predicted target OTU deubiquitinase 1 (OTUD1) that might be associated with immunity to T. gallinae in pigeon. Novel-miR-741 and OTUD1 over-expression vectors and interference vectors were constructed. Results from dual luciferase activity assay demonstrated that OTUD1 was a downstream target of novel-miR-741. The Cell Counting Kit-8 and apoptosis assays showed that novel-miR-741 inhibited the proliferation and promoted apoptosis of pigeon crop fibroblasts. Meanwhile, mRNA levels of OTUD1 were significantly reduced in novel-miR-741 mimic-transfected fibroblasts, while mRNA levels of OTUD1 were significantly increased in the novel-miR-741 inhibitor-transfected fibroblasts. The regulatory roles of si-OTUD1 on fibroblasts proliferation, apoptosis, and migration were similar to novel-miR-741 mimic. Our findings demonstrated that novel-miR-741 inhibited the proliferation, and migration of crop fibroblasts, while OTUD1 promoted the proliferation and migration of crop fibroblasts. Therefore, the regulation of OTUD1 by novel-miR-741 was proposed as a potential therapeutic strategy for T. gallinae.


Subject(s)
Apoptosis , Cell Proliferation , Columbidae , Fibroblasts , MicroRNAs , MicroRNAs/genetics , MicroRNAs/metabolism , Animals , Fibroblasts/physiology , Columbidae/physiology , Avian Proteins/genetics , Avian Proteins/metabolism
5.
Arch Insect Biochem Physiol ; 115(1): e22086, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38288496

ABSTRACT

The mitochondrial gene order in Thysanoptera is notably distinct and highly rearranged, with each species exhibiting its own unique arrangement. To elucidate the relationship between gene rearrangements and phylogeny, the complete mitochondrial genome (mitogenome) of the wheat pest, Aptinothrips stylifer, was sequenced and assembled, spanning a total length of 16,033 bp. Compared with the ancestral arthropod mitogenome, significant rearrangement differences were evident in A. stylifer, whereas the gene order between A. stylifer and Anaphothrips obscurus was similar. Phylogenetic trees were reconstructed based on all 13 protein-coding gene sequences using Bayesian inference and maximum-likelihood methods, both yielding similar topological structures. Notably, A. stylifer was robustly clustered with A. obscurus, affirming its classification within Anaphothrips genus group. This exemplifies the potential correlation between gene rearrangements and phylogeny in the Thripidae family. Additionally, the mitogenome of A. stylifer exhibited several atypical features, including: (1) Three putative control regions (CRs) in close proximity, with CR2 and CR3 displaying partial similarity, and CR1 differing in base composition; (2) Two transfer RNAs (tRNAs), trnS1 and trnV, lacking the DHU arm; (3) Two ribosomal RNA (rRNA) genes inverted and positioned distant from each other; (4) Negative AT and GC skew (AT skew = -0.001, GC skew = -0.077); (5) One transposition (nad6), one inverse transposition (trnQ), four inversions (trnF, trnH, trnC, and gene block nad1-trnL1-rrnL-trnV-rrnS), and four tandem duplication random loss events; and (6) Two protein-coding genes, nad2 and atp8, terminated with an incomplete stop codon "T".


Subject(s)
Genome, Mitochondrial , Thysanoptera , Animals , Phylogeny , Thysanoptera/genetics , Triticum/genetics , Bayes Theorem
6.
Adv Mater ; 36(8): e2305632, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37805826

ABSTRACT

Optically controlled neuromodulation is a promising approach for basic research of neural circuits and the clinical treatment of neurological diseases. However, developing a non-invasive and well-controllable system to deliver accurate and effective neural stimulation is challenging. Micro/nanorobots have shown great potential in various biomedical applications because of their precise controllability. Here, a magnetically-manipulated optoelectronic hybrid microrobot (MOHR) is presented for optically targeted non-genetic neuromodulation. By integrating the magnetic component into the metal-insulator-semiconductor junction design, the MOHR has excellent magnetic controllability and optoelectronic properties. The MOHR displays a variety of magnetic manipulation modes that enables precise and efficient navigation in different biofluids. Furthermore, the MOHR could achieve precision neuromodulation at the single-cell level because of its accurate targeting ability. This neuromodulation is achieved by the MOHR's photoelectric response to visible light irradiation, which enhances the excitability of the targeted cells. Finally, it is shown that the well-controllable MOHRs effectively restore neuronal activity in neurons damaged by ß-amyloid, a pathogenic agent of Alzheimer's disease. By coupling precise controllability with efficient optoelectronic properties, the hybrid microrobot system is a promising strategy for targeted on-demand optical neuromodulation.


Subject(s)
Light , Magnetics
7.
Int J Syst Evol Microbiol ; 73(11)2023 Nov.
Article in English | MEDLINE | ID: mdl-37934673

ABSTRACT

Deinococcus saudiensis YIM F302T was compared with Deinococcus soli N5T to examine the taxonomic relationship between the two type strains. The 16S rRNA gene sequence of D. saudiensis YIM F302T showed high similarity (99.9 %) to that of D. soli N5T. The results of phylogenetic analyses based on 16S rRNA gene sequences indicated that the two strains formed a tight cluster within the genus Deinococcus. A draft genomic comparison between the two strains revealed average nucleotide identity values of 96.8-97.9 % and a digital DNA-DNA hybridization estimate of 80.7±1.9 %, strongly indicating that the two strains represented a single species. Based on the combined phylogenetic, genomic and phenotypic characterization presented here, we propose D. saudiensis as a later heterotypic synonym of D. soli N5T.


Subject(s)
Deinococcus , Phylogeny , Deinococcus/genetics , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , DNA, Bacterial/genetics , Bacterial Typing Techniques , Fatty Acids/chemistry , Base Composition , Nucleic Acid Hybridization
8.
Appl Opt ; 62(15): 3967-3975, 2023 May 20.
Article in English | MEDLINE | ID: mdl-37706707

ABSTRACT

In this paper, we implement integrated magnetic flux concentrators (MFCs) combined with a multi-frequency modulation method to achieve high-magnetic-detection sensitivity using a nuclear spin on the solid nuclear spin in diamonds. First, we excited the nuclear spin in diamonds using a continuous-wave technique, and a linewidth of 1.37 MHz and frequency resolution of 79 Hz were successfully obtained, which is reduced by one order of the linewidth, and increased by 56 times in frequency resolution compared to that excited by an electron spin. The integrated high-permeability MFC was designed to magnify the magnetic field near the diamond, with a magnification of 9.63 times. Then, the multi-frequency modulation technique was used to fully excite the hyperfine energy level of Nitrogen Vacancy (NV) centers along the four axes on the diamond with MFC, and magnetic detection sensitivity of 250p T/H z 1/2 was realized. These techniques should allow designing an integrated NV magnetometer with high sensitivity in a small volume.

9.
Nanomicro Lett ; 15(1): 174, 2023 Jul 07.
Article in English | MEDLINE | ID: mdl-37420043

ABSTRACT

Composite organohydrogels have been widely used in wearable electronics. However, it remains a great challenge to develop mechanically robust and multifunctional composite organohydrogels with good dispersion of nanofillers and strong interfacial interactions. Here, multifunctional nanofiber composite reinforced organohydrogels (NCROs) are prepared. The NCRO with a sandwich-like structure possesses excellent multi-level interfacial bonding. Simultaneously, the synergistic strengthening and toughening mechanism at three different length scales endow the NCRO with outstanding mechanical properties with a tensile strength (up to 7.38 ± 0.24 MPa), fracture strain (up to 941 ± 17%), toughness (up to 31.59 ± 1.53 MJ m-3) and fracture energy (up to 5.41 ± 0.63 kJ m-2). Moreover, the NCRO can be used for high performance electromagnetic interference shielding and strain sensing due to its high conductivity and excellent environmental tolerance such as anti-freezing performance. Remarkably, owing to the organohydrogel stabilized conductive network, the NCRO exhibits superior long-term sensing stability and durability compared to the nanofiber composite itself. This work provides new ideas for the design of high-strength, tough, stretchable, anti-freezing and conductive organohydrogels with potential applications in multifunctional and wearable electronics.

10.
Nat Commun ; 14(1): 3537, 2023 06 15.
Article in English | MEDLINE | ID: mdl-37322000

ABSTRACT

The SARS-CoV-2 Omicron variant evades most currently approved neutralizing antibodies (nAbs) and caused drastic decrease of plasma neutralizing activity elicited by vaccination or prior infection, urging the need for the development of pan-variant antivirals. Breakthrough infection induces a hybrid immunological response with potentially broad, potent and durable protection against variants, therefore, convalescent plasma from breakthrough infection may provide a broadened repertoire for identifying elite nAbs. We performed single-cell RNA sequencing (scRNA-seq) and BCR sequencing (scBCR-seq) of B cells from BA.1 breakthrough-infected patients who received 2 or 3 previous doses of inactivated vaccine. Elite nAbs, mainly derived from the IGHV2-5 and IGHV3-66/53 germlines, showed potent neutralizing activity across Wuhan-Hu-1, Delta, Omicron sublineages BA.1 and BA.2 at picomolar NT50 values. Cryo-EM analysis revealed diverse modes of spike recognition and guides the design of cocktail therapy. A single injection of paired antibodies cocktail provided potent protection in the K18-hACE2 transgenic female mouse model of SARS-CoV-2 infection.


Subject(s)
COVID-19 , SARS-CoV-2 , Female , Animals , Mice , SARS-CoV-2/genetics , Breakthrough Infections , COVID-19 Serotherapy , Antibodies, Neutralizing , Mice, Transgenic , Antibodies, Viral
11.
Materials (Basel) ; 16(5)2023 Feb 21.
Article in English | MEDLINE | ID: mdl-36902875

ABSTRACT

Creep deformation is an important aspect of magnesium phosphate cement (MPC) used as a structural material. In this study, the shrinkage and creep deformation behaviors of three different MPC concretes were observed for 550 days. The mechanical properties, phase composition, pore structure, and microstructure of MPC concretes after shrinkage and creep tests were investigated. The results showed that the shrinkage and creep strains of MPC concretes stabilized in the ranges of -140 to -170 µÎµ and -200 to -240 µÎµ, respectively. The low water-to-binder ratio and the formation of crystalline struvite were responsible for such low deformation. The creep strain had almost no effect on the phase composition; however, it increased the crystal size of struvite and reduced the porosity, especially the volume of pores with diameters <20 nm and >200 nm. The modification of struvite and densification of microstructure led to an improvement in both compressive strength and splitting tensile strength.

12.
Molecules ; 27(24)2022 Dec 12.
Article in English | MEDLINE | ID: mdl-36557960

ABSTRACT

The PROteolysis TArgeting Chimeras (PROTACs) is an innovative technique for the selective degradation of target proteins via the ubiquitin-proteasome system. Compared with traditional protein inhibitor drugs, PROTACs exhibit advantages in the efficacy and selectivity of and in overcoming drug resistance in cancer therapy, providing new insights into the discovery of anti-cancer drugs. In the last two decades, many PROTAC molecules have been developed to induce the degradation of cancer-related targets, and they have been subjected to clinical trials. Here, we comprehensively review the historical milestones and latest updates in PROTAC technology. We focus on the structures and mechanisms of PROTACs and their application in targeting tumor-related targets. We have listed several representative PROTACs based on CRBN, VHL, MDM2, or cIAP1 E3 ligases, and PROTACs that are undergoing anti-cancer clinical trials. In addition, the limitations of the current research, as well as the future research directions are described to improve the PROTAC design and development for cancer therapy.


Subject(s)
Antineoplastic Agents , Neoplasms , Humans , Proteolysis , Proteasome Endopeptidase Complex/metabolism , Ubiquitin/metabolism , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Neoplasms/drug therapy
13.
Arch Microbiol ; 204(10): 638, 2022 Sep 21.
Article in English | MEDLINE | ID: mdl-36131209

ABSTRACT

A novel marine Gram-stain-negative, aerobic, rod-shaped bacterium, designated as strain PS1T, was isolated from the deep-sea sediments of the Mariana Trench and characterized phylogenetically and phenotypically. Bacterial optimal growth occurred at 35 °C (ranging 10-45 °C), pH 6 (ranging pH 5-10) and with 11% (w/v) NaCl (ranging 0-17%). The 16S rRNA gene sequence similarity results revealed that strain PS1T was most closely related to Pseudomonas stutzeri ATCC 17588T, Pseudomonas nitrititolerans GL14T, Pseudomonas zhaodongensis NEAU-ST5-21T, Pseudomonas xanthomarina DSM 18231T and Pseudomonas kunmingensis HL22-2T with 98.3-98.7%. The digital DNA-DNA hybridization values and the average nucleotide identity between strain PS1T and the reference strains were 20.4-40.1% and 78.7-79.4%, respectively. The major respiratory quinone is ubiquinone Q-9. The major polar lipids were phosphatidylethanolamine, diphosphatidyglycerol, phosphatidylglycerol, phosphatidylcholine, aminoglycolipid, two unidentified glycolipids and one unidentified lipid. The predominant cellular fatty acids of strain PS1T were summed feature 8 (C18:1ω7c and/or C18:1ω6c), summed feature 3 (C16:1ω7c and/or C16:1ω6c), C16:0 and cyclo-C19:0 ω8c. The G + C content of the genomic DNA was 63.0%. The combined genotypic and phenotypic data indicated that strain PS1T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas marianensis sp. nov. is proposed, with the type strain PS1T (= DSM 112238T = MCCC 1K05112T).


Subject(s)
Phosphatidylethanolamines , Sodium Chloride , Ancitabine , Bacterial Typing Techniques , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Fatty Acids/analysis , Glycolipids/chemistry , Nucleotides , Phosphatidylcholines , Phosphatidylglycerols , Phospholipids/analysis , Phylogeny , Pseudomonas , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Ubiquinone/chemistry
14.
Article in English | MEDLINE | ID: mdl-35550236

ABSTRACT

A Gram-stain-negative bacterial strain, designated as E165T, was isolated from a tidal flat sediment of the East China Sea. Strain E165T grew optimally at pH 6, at 32 °C and with 1-2 % (w/v) NaCl. The 16S rRNA gene sequence similarity results revealed that strain E165T was most closely related to Marinomonas rhizomae IVIA-Po-145T, Marinomonas polaris CK13T, Marinomonas foliarum IVIA-Po-155T, Marinomonas hwangdonensis HDW-15T, Marinomonas pontica 46-16T, Marinomonas mangrovi B20-1T and Marinomonas shanghaiensis DSL-35T with values of 97.0-98.5 %. The digital DNA-DNA hybridization and average nucleotide identity values between strain E165T and the reference strains were 21.9-34.3 % and 77.6-87.3 %, respectively. The DNA G+C content of the isolate was 42.9 mol%. Strain E165T contained Q-8 as the sole ubiquinone and C16 : 0, summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) as the major fatty acids. The major polar lipids of strain E165T were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, aminolipid and aminophospholipid. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness, a novel species, Marinomonas lutimaris sp. nov., is proposed with E165T (=MCCC 1K06241T=KCTC 82809T) as the type strain.


Subject(s)
Marinomonas , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/chemistry , Phospholipids/chemistry , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
15.
Bioresour Technol ; 354: 127192, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35452828

ABSTRACT

High concentrations of heavy metals and other pollutants affect microbial activity in the wastewater treatment system and impede biological denitrification process. In this study, a novel Zn(II)-resistant aerobic denitrifier (Pseudomonas stutzeri KY-37) was isolated with potential in Bisphenol A (BPA) biodegradation and removal. The capability of this denitrifier in removing nitrogen, zinc, and BPA was tested. Using 56 mg/L nitrate as the sole nitrogen source, its removal efficiency achieved 98.5% in 12 h. This novel denitrifier had a strong auto-aggregation (maximum 65.8%), a high hydrophobicity rate (maximum 88.2%), and a massive amount (maximum 41.1 mg/g cell dry weight) of extracellular polymeric substances (EPS) production. Moreover, Zn(II) removal efficiency reached more than 95% with the initial high concentrations of 200 mg/L. The maximum BPA removal efficiency reached 88.8% with initial 10 mg/L. The removal mechanism of BPA was further explored in terms of microbial degradation, EPS adsorption, and intermediate degradation products.


Subject(s)
Nitrogen , Wastewater , Aerobiosis , Benzhydryl Compounds , Denitrification , Nitrogen/metabolism , Phenols , Zinc
16.
ACS Omega ; 7(11): 9142-9151, 2022 Mar 22.
Article in English | MEDLINE | ID: mdl-35350347

ABSTRACT

High-performance fiber-reinforced cement composites (HPFRCCs) have been widely used in structural engineering due to their excellent performance. With the trend of lightweight construction, these materials, which can be used in prefabricated components, are becoming more and more important. This study investigated the influence of the water-cement (w/c) ratio, within the 0.19-0.28 range, on the rheological and mechanical properties of HPFRCCs; the pore structure and microstructure were observed to evaluate its effect. An elastic modulus test showed that a smaller w/c ratio would result in a higher rigidity of the material. Both the yield shear stress and plastic viscosity decreased to significantly different degrees with an increasing w/c ratio; a decrease in the yield shear stress and plastic viscosity was conducive to air discharge from the composite and, hence, reduced the air content. Most of the internal pores had a diameter of 20-100 nm or larger than 200 nm, while the proportion of those with a diameter of 100-200 nm was relatively low. When the w/c ratio was below 0.22, the flexural and compressive strengths barely increased due to an increment in the number of larger pores (i.e., diameter >200 nm). The results showed that the yield shear stress, plastic viscosity, pore uniformity, and the number of pores with a diameter above 200 nm are the dominant factors affecting the HPFRCC performance at a low w/c ratio.

17.
Materials (Basel) ; 15(3)2022 Jan 22.
Article in English | MEDLINE | ID: mdl-35160791

ABSTRACT

The objective of this paper is to investigate the coupling effect of cement and organosilicon hydrophobic agents on the water resistance of phosphogypsum. Different weight ratios of Portland cement were added to adjust the alkalinity of this system and further improve the work efficiency of the organosilicon hydrophobic agents. Some macroscopic performances, such as the water absorption, the compressive strength, the flexural strength, and the softening coefficient, were measured to characterize the water-resistance of phosphogypsum. The microscopic characteristics were analyzed via contact angle tests, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) to understand the mechanism of organosilicon hydrophobicity. The results indicated that both the compressive and flexural strengths of phosphogypsum first increased and then decreased with the increase of organosilicon hydrophobic agents. Meanwhile, the surface contact angle continued to increase and the softening coefficient exhibited an obvious increase. When the hydrophobic agent was combined with Portland cement, the softening coefficient of phosphogypsum further increased from 0.80 to 0.99, while the water absorption rate was significantly reduced from 16.0% to 0.8%. Microscopic tests proved that the hydrophobic organic molecules can be polymerized under the high alkalinity, and promote the formation of a hydrophobic film, thus significantly improving the water-resistance of phosphogypsum.

18.
Toxicology ; 465: 153058, 2022 01 15.
Article in English | MEDLINE | ID: mdl-34863901

ABSTRACT

Few studies exist on the toxic effects of chronic exposure to microcystins (MCs) on amphibian intestines, and the toxicity mechanisms are unclear. Here, we evaluated the impact of subchronic exposure (30 days) to environmentally realistic microcystin-leucine arginine (MC-LR) concentrations (0 µg/L, 0.5 µg/L and 2 µg/L) on tadpole (Lithobates catesbeianus) intestines by analyzing the histopathological and subcellular microstructural damage, the antioxidative and oxidative enzyme activities, and the transcriptome levels. Histopathological results showed severe damage accompanied by inflammation to the intestinal tissues as the MC-LR exposure concentration increased from 0.5 µg/L to 2 µg/L. RNA-sequencing analysis identified 634 and 1,147 differentially expressed genes (DEGs) after exposure to 0.5 µg/L and 2 µg/L MC-LR, respectively, compared with those of the control group (0 µg/L). Biosynthesis of unsaturated fatty acids and the peroxisome proliferator-activated receptor (PPAR) signaling pathway were upregulated in the intestinal tissues of the exposed groups, with many lipid droplets being observed on transmission electron microscopy, implying that MC-LR may induce lipid accumulation in frog intestines. Moreover, 2 µg/L of MC-LR exposure inhibited the xenobiotic and toxicant biodegradation related to detoxification, implying that the tadpoles' intestinal detoxification ability was weakened after exposure to 2 µg/L MC-LR, which may aggravate intestinal toxicity. Lipid accumulation and toxin efflux disorder may be caused by MC-LR-induced endoplasmic reticular stress. This study presents new evidence that MC-LR harms amphibians by impairing intestinal lipid metabolism and toxin efflux, providing a theoretical basis for evaluating the health risks of MC-LR to amphibians.


Subject(s)
Intestinal Absorption/drug effects , Intestines/drug effects , Lipid Metabolism/drug effects , Marine Toxins/toxicity , Microcystins/toxicity , Rana catesbeiana/metabolism , Animals , Endoplasmic Reticulum/drug effects , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum Stress/drug effects , Intestines/enzymology , Intestines/metabolism , Larva/drug effects , Larva/genetics , Larva/metabolism , Mitochondria/drug effects , Mitochondria/metabolism , Organic Anion Transporters/genetics , Organic Anion Transporters/metabolism , Oxidative Stress/drug effects , Rana catesbeiana/embryology , Rana catesbeiana/genetics , Reactive Oxygen Species/metabolism , Transcriptome/drug effects
19.
Int J Syst Evol Microbiol ; 72(12)2022 Dec.
Article in English | MEDLINE | ID: mdl-36748599

ABSTRACT

A Gram-stain-negative, non-motile and rod-shaped bacterium, designated as strain W52T, was isolated from deep seawater of the Mariana Trench and characterized phylogenetically and phenotypically. The strain could grow at 10-47 °C (optimum 32 °C), at pH 5.0-8.0 (optimum 6.0) and with 0-9% NaCl (optimum 3 %, w/v). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that W52T was related to members of the genus Muricauda and shared the highest identity with Muricauda oceani 501str8T (99.0 %), followed by Muricauda aquimarina JCM 11811T, Muricauda ruestringensis DSM 13258T, Muricauda oceanensis 40DY170T, Muricauda beolgyonensis KCTC 23501T and Muricauda zhangzhouensis 12C25T with 97.0-98.8 % sequence similarity. 16S rRNA gene sequence identities between W52T and other members of the genus Muricauda were below 97.0 %. The major respiratory quinone was MK-6. The polar lipids were phosphatidylethanolamine (PE), one unidentified aminolipid and three unidentified lipids. The strain had iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1G as the major fatty acids. The G+C content of the genomic DNA was 41.7 %. The combined genotypic and phenotypic data indicated that strain W52T represents a novel species of the genus Muricauda, for which the name Muricauda abyssi sp. nov. is proposed, with the type strain W52T (=MCCC 1K05111T= KCTC 82315T).


Subject(s)
Fatty Acids , Seawater , Fatty Acids/chemistry , Phylogeny , RNA, Ribosomal, 16S/genetics , DNA, Bacterial/genetics , Nucleic Acid Hybridization , Base Composition , Bacterial Typing Techniques , Sequence Analysis, DNA , Vitamin K 2/chemistry , Seawater/microbiology
20.
Materials (Basel) ; 14(21)2021 Oct 27.
Article in English | MEDLINE | ID: mdl-34771979

ABSTRACT

Iron ore tailings (IOTs) are gradually used as building materials to solve the severe ecological and environmental problems caused by their massive accumulation. However, the bulk density of IOT as aggregate is too large, which seriously affects the concrete properties. Therefore, in this paper, the effect of hydroxypropyl methylcellulose (HPMC) on the workability, mechanical properties, and durability of concrete prepared from IOT recycled aggregate was studied. The action mechanism of HPMC on the workability and the mechanical properties of the IOT concrete was analyzed by mercury intrusion porosimetry (MIP) and scanning electron microscope (SEM). The results show that HPMC can effectively improve the segregation problem caused by the sinking and air entrainment of IOT aggregate and improve the crack resistance of concrete with little effect on its compressive strength and electric flux. These results are due to the air-entraining thickening effect of HPMC, which improves the slurry viscosity, hinders the sinking of aggregate, and improves the workability. At the same time, HPMC film, after concrete hardening, will bridge the slurry and aggregate through physical and chemical effects, hinder the propagation of microcracks, and improve the crack resistance.

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