Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 111
Filter
1.
Sci Rep ; 14(1): 11002, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38745014

ABSTRACT

The recommended bearing capacity of medium weathering mudstone foundation is less than the capacity of the rock structure to withstand loads in Southwest China. A comprehensive failure characterization of medium weathering mudstone in Chengdu has been performed including bearing plate test (BPT), binocular vision measurement (BVM) test, uniaxial compressive strength test, trial trench test of shallow rock surface and 3D imaging in this paper. Failure behavior of rock has been modeled with 3D imaging algorithm that utilizes Zhang's calibration method in BVM system combination with trial trench test of shallow rock surface. The bearing capacity of medium weathering mudstone foundation were extracted from uniaxial experiments and BPT-BVM test by fitting relevant material properties to the data. The results revealed that: Bearing capacity of medium weathering mudstone of layered isotropic in Chengdu is undervalued. Specifically, the characteristic load carrying value is in the range 1500-2500 kP, that is 50% higher than in the local standard system. Failure process is different from Hoek-Brown Failure Criterion, presenting a wave peak transfer phenomenon of the increment displacement into the distance. Thus, it can be reduced to that of punching failures for thin bedded structures of Moudstone foundations. Compressive strength of soft rock proves to be main factor limiting the bearing capacity, a clear correlation between the uniaxial compressive strength reduction coefficient and the bearing capacity has been used to establish, leading to the proposal of a load bearing capacity prediction model.

2.
Chem Soc Rev ; 2024 May 01.
Article in English | MEDLINE | ID: mdl-38690681

ABSTRACT

Ferroelectricity, which has diverse important applications such as memory elements, capacitors, and sensors, was first discovered in a molecular compound, Rochelle salt, in 1920 by Valasek. Owing to their superiorities of lightweight, biocompatibility, structural tunability, mechanical flexibility, etc., the past decade has witnessed the renaissance of molecular ferroelectrics as promising complementary materials to commercial inorganic ferroelectrics. Thus, on the 100th anniversary of ferroelectricity, it is an opportune time to look into the future, specifically into how to push the boundaries of material design in molecular ferroelectric systems and finally overcome the hurdles to their commercialization. Herein, we present a comprehensive and accessible review of the appealing development of molecular ferroelectrics over the past 10 years, with an emphasis on their structural diversity, chemical design, exceptional properties, and potential applications. We believe that it will inspire intense, combined research efforts to enrich the family of high-performance molecular ferroelectrics and attract widespread interest from physicists and chemists to better understand the structure-function relationships governing improved applied functional device engineering.

3.
Cell Mol Biol (Noisy-le-grand) ; 70(1): 40-45, 2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38372116

ABSTRACT

The purpose of this study was to explore the differential expression of Pax3, Rad51 and VEGF-C in esophageal gastric junction adenocarcinoma and distal gastric adenocarcinoma and their relationship with cancer occurrence and development. 57 patients with gastric cancer were included and divided into esophageal gastric junction adenocarcinoma group (n=28) and distal gastric adenocarcinoma group (n=29). The positive expressions of Pax3, Rad51 and VEGF-C in the control group were lower than those in the esophageal gastric junction adenocarcinoma group and distal gastric adenocarcinoma group respectively (P<0.05). In esophageal gastric junction adenocarcinoma with low differentiation, positive expressions of Pax3, Rad51, and VEGF-C surpassed those in high/medium differentiation (P<0.05). Serosa-infiltrated cases exhibited higher Pax3 and Rad51 expressions compared to non-infiltrated cases (P<0.05). Rad51 and VEGF-C positivity were notably elevated in cases with lymph node metastasis compared to those without (P<0.05). Distal gastric adenocarcinoma displayed higher VEGF expression than middle/low differentiated adenocarcinomas. Rad51 expression was significantly higher in women than in men (P<0.05). The positive rates of Pax3, Rad51, and VEGF-C were markedly increased in esophageal gastric junction adenocarcinoma and distal gastric adenocarcinoma compared to normal gastric tissue, and these were associated with the degree of differentiation, depth of invasion, and lymph node metastasis in patients. Particularly, Rad51 exhibited a positive correlation with cancer cell differentiation, invasion depth, and lymph node metastasis in cancer tissue.


Subject(s)
Adenocarcinoma , Esophageal Neoplasms , PAX3 Transcription Factor , Rad51 Recombinase , Stomach Neoplasms , Vascular Endothelial Growth Factor C , Female , Humans , Male , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Esophageal Neoplasms/genetics , Esophageal Neoplasms/pathology , Lymphatic Metastasis , Stomach Neoplasms/genetics , Stomach Neoplasms/pathology , Transcription Factors , Vascular Endothelial Growth Factor C/genetics , PAX3 Transcription Factor/genetics , Rad51 Recombinase/genetics
4.
Adv Mater ; 36(11): e2307518, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38041802

ABSTRACT

On the path of persisting Moore's Law, one of the biggest obstacles is the "Boltzmann tyranny," which defines the lower limit of power consumption of individual transistors. Negative capacitance (NC) in ferroelectrics could provide a solution and has garnered significant attention in the fields of nanoelectronics, materials science, and solid-state physics. Molecular ferroelectrics, as an integral part of ferroelectrics, have developed rapidly in terms of both performance and functionality, with their inherent advantages such as easy fabrication, mechanical flexibility, low processing temperature, and structural tunability. However, studies on the NC in molecular ferroelectrics are limited. In this study, the focus is centered on the fabricated high-quality thin films of trimethylchloromethyl ammonium trichlorocadmium(II), and a pioneering investigation on their NC responses is conducted. The findings demonstrate that the NC exhibited by molecular ferroelectrics is comparable to that of conventional HfO2 -based ferroelectrics. This underscores the potential of molecular material systems for next-generation electronic devices.

5.
Adv Sci (Weinh) ; 11(4): e2305016, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38037482

ABSTRACT

With outstanding advantages of chemical synthesis, structural diversity, and mechanical flexibility, molecular ferroelectrics have attracted increasing attention, demonstrating themselves as promising candidates for next-generation wearable electronics and flexible devices in the film form. However, it remains a challenge to grow high-quality thin films of molecular ferroelectrics. To address the above issue, a volume-confined method is utilized to achieve ultrasmooth single-crystal molecular ferroelectric thin films at the sub-centimeter scale, with the thickness controlled in the range of 100-1000 nm. More importantly, the preparation method is applicable to most molecular ferroelectrics and has no dependency on substrates, showing excellent reproducibility and universality. To demonstrate the application potential, two-dimensional (2D) transitional metal dichalcogenide semiconductor/molecular ferroelectric heterostructures are prepared and investigated by optical spectroscopic method, proving the possibility of integrating molecular ferroelectrics with 2D layered materials. These results may unlock the potential for preparing and developing high-performance devices based on molecular ferroelectric thin films.

6.
Materials (Basel) ; 16(23)2023 Nov 21.
Article in English | MEDLINE | ID: mdl-38067992

ABSTRACT

In this work, the long-term skid resistance attenuation law of asphalt mixtures in the presence of aeolian sand was studied. Four types of asphalt mixtures underwent skid resistance abrasion tests using an accelerated loading tester. The pendulum value (BPN) and structure depth (MTD) of these four mixtures were determined under various conditions of sand density and abrasion times. The correlation between the BPN and density and the number of times of abrasion were investigated, respectively, to analyze the skid resistance attenuation law at the microscopic and macroscopic levels. Our results indicate that the skid resistance of the four types of asphalt mixtures initially decreased and subsequently reached a stable state. Sand density primarily influences skid resistance during the initial stage, while the number of abrasions becomes the dominant factor affecting skid resistance in the later stages.

7.
Nano Lett ; 23(16): 7419-7426, 2023 Aug 23.
Article in English | MEDLINE | ID: mdl-37539988

ABSTRACT

Multifarious molecular ferroelectrics with multipolar axial characteristics have emerged in recent years, enriching the scenarios for energy harvesting, sensing, and information processing. The increased polar axes have enhanced the urgency of distinguishing different polarization states in material design, mechanism exploration, etc. However, conventional methods hardly meet the requirements of in situ, fast, microscale, contactless, and nondestructive features due to their inherent limitations. Herein, SHG polarimetry is introduced to probe the multioriented polarizations on a nanosized multiaxial molecular ferroelectric, i.e., TMCM-CdCl3 nanoplates, as an example. Combined with the analysis of the second-order susceptibility tensor, SHG polarimetry could serve as an effective method to detect the polarization orders and domain distributions of molecular ferroelectrics. Profiting from the full-optical feature, SHG polarimetry can even be performed on samples covered by transparent mediums, 2D materials, or thin metal electrodes. Our research might spark further fundamental studies and expand the application boundaries of next-generation ferroelectric materials.

8.
Cancer Cell ; 41(7): 1345-1362.e9, 2023 07 10.
Article in English | MEDLINE | ID: mdl-37352863

ABSTRACT

Lineage plasticity causes therapeutic resistance; however, it remains unclear how the fate conversion and phenotype switching of cancer-associated fibroblasts (CAFs) are implicated in disease relapse. Here, we show that androgen deprivation therapy (ADT)-induced SPP1+ myofibroblastic CAFs (myCAFs) are critical stromal constituents that drive the development of castration-resistant prostate cancer (CRPC). Our results reveal that SPP1+ myCAFs arise from the inflammatory CAFs in hormone-sensitive PCa; therefore, they represent two functional states of an otherwise ontogenically identical cell type. Antiandrogen treatment unleashes TGF-ß signaling, resulting in SOX4-SWI/SNF-dependent CAF phenotype switching. SPP1+ myCAFs in turn render PCa refractory to ADT via an SPP1-ERK paracrine mechanism. Importantly, these sub-myCAFs are associated with inferior therapeutic outcomes, providing the rationale for inhibiting polarization or paracrine mechanisms to circumvent castration resistance. Collectively, our results highlight that therapy-induced phenotypic switching of CAFs is coupled with disease progression and that targeting this stromal component may restrain CRPC.


Subject(s)
Prostatic Neoplasms, Castration-Resistant , Male , Humans , Prostatic Neoplasms, Castration-Resistant/drug therapy , Prostatic Neoplasms, Castration-Resistant/genetics , Prostatic Neoplasms, Castration-Resistant/metabolism , Androgen Antagonists/pharmacology , Androgen Antagonists/therapeutic use , Cellular Reprogramming , Neoplasm Recurrence, Local/drug therapy , Castration , Receptors, Androgen/genetics , Receptors, Androgen/metabolism , Cell Line, Tumor , SOXC Transcription Factors/genetics
9.
Cancer Lett ; 559: 216104, 2023 04 10.
Article in English | MEDLINE | ID: mdl-36863507

ABSTRACT

Hepatoid adenocarcinoma (HAC) is a rare, malignant, extrahepatic tumor with histologic features similar to those of hepatocellular carcinoma. HAC is most often associated with elevated alpha-fetoprotein (AFP). HAC can occur in multiple organs, including the stomach, esophagus, colon, pancreas, lungs, and ovaries. HAC differs greatly from typical adenocarcinoma in terms of its biological aggression, poor prognosis, and clinicopathological characteristics. However, the mechanisms underlying its development and invasive metastasis remain unclear. The purpose of this review was to summarize the clinicopathological features, molecular traits, and molecular mechanisms driving the malignant phenotype of HAC, in order to support the clinical diagnosis and treatment of HAC.


Subject(s)
Adenocarcinoma , Carcinoma, Hepatocellular , Liver Neoplasms , Stomach Neoplasms , Humans , Liver Neoplasms/pathology , Stomach Neoplasms/pathology , Adenocarcinoma/drug therapy , Carcinoma, Hepatocellular/pathology , alpha-Fetoproteins
10.
Front Microbiol ; 14: 1093668, 2023.
Article in English | MEDLINE | ID: mdl-36998407

ABSTRACT

In this study, we isolated a lytic Pseudomonas aeruginosa phage (vB_PaeP_ASP23) from the sewage of a mink farm, characterized its complete genome and analyzed the function of its putative lysin and holin. Morphological characterization and genome annotation showed that phage ASP23 belonged to the Krylovirinae family genus Phikmvvirus, and it had a latent period of 10 min and a burst size of 140 pfu/infected cell. In minks challenged with P. aeruginosa, phage ASP23 significantly reduced bacterial counts in the liver, lung, and blood. The whole-genome sequencing showed that its genome was a 42,735-bp linear and double-stranded DNA (dsDNA), with a G + C content of 62.15%. Its genome contained 54 predicted open reading frames (ORFs), 25 of which had known functions. The lysin of phage ASP23 (LysASP), in combination with EDTA, showed high lytic activity against P. aeruginosa L64. The holin of phage ASP23 was synthesized by M13 phage display technology, to produce recombinant phages (HolASP). Though HolASP exhibited a narrow lytic spectrum, it was effective against Staphylococcus aureus and Bacillus subtilis. However, these two bacteria were insensitive to LysASP. The findings highlight the potential of phage ASP23 to be used in the development of new antibacterial agents.

11.
Mater Horiz ; 10(3): 869-874, 2023 Mar 06.
Article in English | MEDLINE | ID: mdl-36628648

ABSTRACT

The electrocaloric effect (ECE) is an efficient and environmentally friendly method for solid-state refrigeration driven by an electric field. However, disregarding the ECE performance, the mass of materials also limits the amount of energy transferred in the cooling process. While molecular ECE materials have been attracting intensive attention with their excellent ECE properties, most reported molecular compounds can only be utilized in the form of thin films or single crystals. Unlike inorganic ceramics, molecular thin films and single crystals are very difficult to prepare in a large amount, which greatly restrains the future application of those materials. In this work, we report an excellent molecular ECE material in the form of polycrystalline molecular ceramics. Such molecular ceramics are composed of plastic molecular ferroelectrics, and can fulfil the requirement of large mass, easy processing, excellent performance and low energy consumption. Our molecular ceramic of HQReO4 (HQ: protonated quinuclidine) demonstrates an isothermal entropy change of 5.8 J K-1 kg-1 and an adiabatic temperature change of 3.1 K. Notably, by a simple low-temperature pressing process without added adhesives (about 373 K), an HQReO4 molecular ceramic block can be obtained, and its ECE performance is observed to be comparable to that of single crystals, for the first time. This work proposes a new application form for molecular electrocaloric materials, which opens up new ideas for solid-state refrigeration.

12.
Virus Res ; 324: 199026, 2023 01 15.
Article in English | MEDLINE | ID: mdl-36529302

ABSTRACT

As an aquatic animal of great commercial relevance, Penaeus vannamei is currently the dominant species of cultured shrimp in China and many other countries worldwide. In recent years, the outbreak of glass post-larvae disease (GPD), which accounts for more than 90% of the mortality of shrimp seedlings in serious cases, in many regions of China has caused significant losses and threatened the sustainability of the aquaculture industry and the economy. It is extremely urgent to determine the infectious agent of GPD in P. vannamei. In this work, we performed metagenomic sequencing of glass post-larvae collected from diseased prawns in Tangshan Hebei, where GPD broke out recently. An evolutionary tree was constructed by MEGA 7 to understand the evolutionary history and relationship of the pathogen genome. A novel virus in the family Marnaviridae was first identified in P. vannamei suffering from GPD, and we tentatively named this virus Baishivirus (GenBank: ON550424). The identified pathogen was validated according to Koch's rule with a pathogenic challenge assay and reverse transcription-polymerase chain reaction. There was only 8% query coverage with 64.96% identity in the Baishivirus genome when compared with its most closely related genome sequence of Wenzhou picorna-like virus 21 reported in 2016. Baishivirus genomic RNA is 9.895 kb in length and encodes three potential open reading frames (ORFs). The identification of Baishivirus in P. vannamei enriches the family Marnaviridae and potentially provides a new candidate to study and prevent GPD in the aquaculture industry.


Subject(s)
Penaeidae , RNA Viruses , Animals , Genome , Genomics , China
13.
Food Chem ; 407: 135126, 2023 May 01.
Article in English | MEDLINE | ID: mdl-36493471

ABSTRACT

Effects of sweep frequency ultrasound (SFU) pretreatment of a new multifunctional ultrasonic equipment on hydrolysis characteristics of zeins and angiotensin-converting enzyme (ACE) inhibitory activity of zein hydrolysates were investigated. Degree of hydrolysis of zeins reached the highest of 25.93 % and 25.72 % at 40 kHz and 25/40 kHz, respectively. While 25/40 kHz increased solubility, surface hydrophobicity, particle size uniform of zeins and ACE inhibitory activities of the hydrolysates significantly. Endogenous fluorescence indicated that 25/40 kHz promoted unfolding of protein molecules and exposure of hydrophobic residues, thereby facilitating enzymatic hydrolysis. Circular dichroism spectrum and Fourier transform infrared spectrometer illustrated that 25/40 kHz unfolded protein molecules and decreased α-helical contents remarkably. Gel permeation chromatography showed that more small-molecule active peptides were obtained from hydrolysates at 25/40 kHz. In conclusion, SFU pretreatment at 25/40 kHz with the new equipment before proteolysis is an efficient method to improve ACE inhibitory activity of the hydrolysates.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors , Zein , Angiotensin-Converting Enzyme Inhibitors/chemistry , Zein/metabolism , Peptides/chemistry , Hydrolysis , Proteolysis , Protein Hydrolysates/chemistry
14.
J Cell Commun Signal ; 17(1): 89-102, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36042157

ABSTRACT

Aberrant composition of glycans in the tumor microenvironment (TME) contributes to tumor progression and metastasis. Chondroitin polymerizing factor (CHPF) is a glycosyltransferase that catalyzes the biosynthesis of chondroitin sulfate (CS). It is also correlated to transforming growth factor-ß1 (TGF-ß1) expression, a crucial mediator in the interaction of cancer cells with TME. In this study, we investigated the association of CHPF expression with the clinicopathological features of breast cancer (BRCA), as well the oncogenic effect and the underling mechanisms of CHPF upon BRCA cells. We found that CHPF expression is significantly increased in human BRCA tissues, and it is positively associated with TGF-ß expression (r = 0.7125). The high-expression of CHPF predicts a poor prognosis and is positively correlated with tumor mass, lymph node metastasis, clinical staging and HER-2 negative-expression. The mechanistic study revealed that it promotes BRCA cell proliferation, migration and invasion through TGF-ß1-induced SMAD3 and JNK activation in vitro, JNK (SP600125) or SMAD3 (SIS3) inhibitor can remove the promotion of CHPF upon cell proliferation, migration and invasion in MDA-MB-231 cells, which is derived from triple-negative breast cancer (TNBC). Collectively, our finding suggested CHPF may function as an oncogene and is highly expressed in human BRCA tissues. Pharmacological blockade of the upstream of JNK or SMAD3 signaling may provide a novel therapeutic target for refractory TNBC patients with CHPF abnormal high-expression.

15.
Molecules ; 27(24)2022 Dec 14.
Article in English | MEDLINE | ID: mdl-36558030

ABSTRACT

As one of the vital shrubs growing in crusted areas in China, Artemisia ordosica (belonging to the Asteraceae family) is abundant in essential oil, and its aerial part's essential oil has been reported to have some biological activities during the flowering and fruit set stage, and has been used in folk medicine. However, little is known about the biological activities of its aerial part's essential oil during the vegetative period. Thus, the purpose of this work was to determine the chemical composition and evaluate the antioxidant and antibacterial potencies of the essential oil extracted from A. ordosica aerial parts during the vegetative stage. Gas chromatography coupled with mass spectrometry (GC-MS) revealed that spathulenol (9.93%) and α-curcumene (9.24%), both sesquiterpenes, were the most abundant of the 74 chemical constituents detected in the essential oil of A. ordosica. The antioxidant activity of the essential oil was found to be relatively moderate against 2,2-diphenylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and hydroxyl radical (OH●) radicals. The essential oil exhibited strong antibacterial activity against Staphylococcus aureus, Salmonella abony and Escherichia coli, with minimum inhibitory concentrations (MICs) of 2.5, 5, and 10 µL/mL, respectively. The results indicate that the essential oil of A. ordosica possesses notable antibacterial properties as well as antioxidant capability and can thus be employed as a natural ingredient which can be used as a substitute for antibiotics in the animal feed industry. However, in vivo toxicological studies are still required to determine the safety level and beneficial outcomes of the A. ordosica essential oil for future utilization.


Subject(s)
Artemisia , Oils, Volatile , Animals , Oils, Volatile/chemistry , Antioxidants/chemistry , Artemisia/chemistry , Anti-Bacterial Agents/chemistry , Plant Components, Aerial/chemistry , Microbial Sensitivity Tests
16.
Nat Commun ; 13(1): 7281, 2022 11 26.
Article in English | MEDLINE | ID: mdl-36435834

ABSTRACT

Chronic inflammation and an immunosuppressive microenvironment promote prostate cancer (PCa) progression and diminish the response to immune checkpoint blockade (ICB) therapies. However, it remains unclear how and to what extent these two events are coordinated. Here, we show that ARID1A, a subunit of the SWI/SNF chromatin remodeling complex, functions downstream of inflammation-induced IKKß activation to shape the immunosuppressive tumor microenvironment (TME). Prostate-specific deletion of Arid1a cooperates with Pten loss to accelerate prostate tumorigenesis. We identify polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) as the major infiltrating immune cell type that causes immune evasion and reveal that neutralization of PMN-MDSCs restricts the progression of Arid1a-deficient tumors. Mechanistically, inflammatory cues activate IKKß to phosphorylate ARID1A, leading to its degradation via ß-TRCP. ARID1A downregulation in turn silences the enhancer of A20 deubiquitinase, a critical negative regulator of NF-κB signaling, and thereby unleashes CXCR2 ligand-mediated MDSC chemotaxis. Importantly, our results support the therapeutic strategy of anti-NF-κB antibody or targeting CXCR2 combined with ICB for advanced PCa. Together, our findings highlight that the IKKß/ARID1A/NF-κB feedback axis integrates inflammation and immunosuppression to promote PCa progression.


Subject(s)
Myeloid-Derived Suppressor Cells , Prostatic Neoplasms , Male , Humans , Prostate/metabolism , Chemotaxis , I-kappa B Kinase/genetics , I-kappa B Kinase/metabolism , Prostatic Neoplasms/metabolism , NF-kappa B/metabolism , Receptors, Interleukin-8B/metabolism , Protein Serine-Threonine Kinases , Inflammation/genetics , Inflammation/metabolism , Tumor Microenvironment/genetics , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism
17.
Front Microbiol ; 13: 938616, 2022.
Article in English | MEDLINE | ID: mdl-36051756

ABSTRACT

Salmonella enterica subspecies enterica serovar abortus equi (S. Abortus equi) is the most common cause of abortion in mares. It has recently been found to cause abortion in donkeys more frequently in China. A novel virulent bacteriophage vB_SabS_Sds2 (hereafter designated as Sds2) was isolated from the feces of donkeys using a S. Abortus equi strain as a host. Phage Sds2 had an isometric polyhedral head and an uncontracted long tail, belonging to the Tequintavirus, Markadamsvirinae, Demerecviridae, Caudovirales. The genome of phage Sds2 was 114,770 bp, with a GC content of 40.26%. The genome contained 160 open reading frames (ORFs), and no ORFs were associated with pathogenicity, drug resistance, or lysogenization by sequence analysis. Both genome annotation and phylogenetic analysis indicated that phage Sds2 was highly similar to T5-like bacteriophages. Phage Sds2 could lyse 100% (30/30) of S. Abortus equi strains, 25.3% (24/95) of other serotypes of Salmonella strains, and 27.6% (8/29) of Escherichia coli strains using the double-layer agar plate method. The in vitro test showed that phage Sds2 had high bactericidal activity against S. Abortus equi at a wide range of MOIs. The in vivo test indicated that phage Sds2 had an inhibitory effect on abortion in mice challenged with S. Abortus equi. In general, phage Sds2 is a novel lytic phage with a wide host range and has the potential to prevent abortion caused by S. Abortus equi.

18.
Virus Res ; 321: 198913, 2022 11.
Article in English | MEDLINE | ID: mdl-36064043

ABSTRACT

A lytic bacteriophage vB_EcoM_DE7 (hereafter designated DE7) that could infect donkey-derived Escherichia coli was isolated. The bacteriophage was examined by transmission electron microscopy, and the result showed that DE7 belonged to the family Myoviridae. The microbiological characterization revealed that DE7 was stable over a broad range of pHs (3 ∼10) at 40-50 °C. The latent period was 10 min, and the burst size was 43 PFUs/infected cell. The whole-genome sequencing showed that DE7 was a dsDNA virus and had a genome of 86,130 bp. The genome contained 124 predicted open reading frames (ORFs), 35 of which had known functions, including DNA replication and modification, transcriptional regulation, structural and packaging proteins, and host cell lysis. Twenty tRNA genes were identified, but no genes associated with bacterial pathogenicity, lysogeny and drug resistance were identified. BLASTN analysis revealed that phage DE7 had a high sequence identity (96%) with Salmonella phage vB_SPuM_SP116, but it could not lyse any Salmonella strain tested in this study. DE7 was classified as a Felix O1-like virus based on its general characterization and genomic information. Since phage DE7 exhibited high efficacy in lysing E. coli and lacked genes associated with bacterial virulence, antimicrobial resistance and lysogeny, it could be potentially used to control foal diarrhoea caused by E. coli.


Subject(s)
Anti-Infective Agents , Bacteriophages , Animals , Bacteriophages/genetics , Equidae , Escherichia coli/genetics , Genome, Viral , Horses , RNA, Transfer/genetics
19.
J Am Chem Soc ; 144(30): 13806-13814, 2022 Aug 03.
Article in English | MEDLINE | ID: mdl-35816081

ABSTRACT

Ferroelectric domains and domain walls are unique characteristics of ferroelectric materials. Among them, charged domain walls (CDWs) are a special kind of peculiar microstructure that highly improve conductivity, piezoelectricity, and photovoltaic efficiency. Thus, CDWs are believed to be the key to ferroelectrics' future application in fields of energy, sensing, information storage, and so forth. Studies on CDWs are one of the most attractive directions in conventional inorganic ferroelectric ceramics. However, in newly emerged molecular ferroelectrics, which have advantages such as lightweight, easy preparation, simple film fabrication, mechanical flexibility, and biocompatibility, CDWs are rarely observed due to the lack of free charges. In inorganic ferroelectrics, doping is a traditional method to induce free charges, but for molecular ferroelectrics fabricated by solution processes, doping usually causes phase separation or phase transition, which destabilizes or removes ferroelectricity. To realize stable CDWs in molecular systems, we designed and synthesized an n-type molecular ferroelectric, 1-adamantanammonium hydroiodate. In this compound, negative charges are induced by defects in the I- vacancy, and CDWs can be achieved. Nanometer-scale CDWs that are stable at temperatures as high as 373 K can be "written" precisely by an electrically biased metal tip. More importantly, this is the first time that the charge diffusion of CDWs at variable temperatures has been investigated in molecular ferroelectrics. This work provides a new design strategy for n-type molecular ferroelectrics and may shed light on their future applications in flexible electronics, microsensors, and so forth.

20.
Org Biomol Chem ; 20(27): 5452-5462, 2022 07 13.
Article in English | MEDLINE | ID: mdl-35770913

ABSTRACT

We have developed an improved cyanide-free strategy for the synthesis of glycosyl carboxylic acids, employing stereoselective C-vinyl glycosylation and oxidative cleavage of C-vinyl glycosides as key steps. Compared to our previous work, the amount of NaIO4 required for the oxidative cleavage step is reduced significantly from 18 equivalents to 4.5 equivalents. This modification not only is advantageous in terms of operation and costs but also avoids the over-oxidation problem, thus greatly expanding the substrate scope, which is evidenced by the fact that 10 out of 21 glycosyl carboxylic acids synthesized are undocumented. With differently O5-protected furanosyl acids in hand, we demonstrate that an electron-rich protecting group is beneficial for the decarboxylative arylation of furanosyl carboxylic acids. This represents a rare example of protecting groups affecting the reaction efficiency in radical C-glycosylation. As C-vinyl glycosides can be prepared stereoselectively and the oxidative step is stereoretentive, the approach provides an effective means to access 1,2-trans or 1,2-cis glycosyl acids, which would be a valuable alternative to the cyanide-based synthesis of glycosyl carboxylic acids.


Subject(s)
Carboxylic Acids , Glycosides , Glycosylation , Oxidative Stress , Stereoisomerism
SELECTION OF CITATIONS
SEARCH DETAIL
...