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1.
Talanta ; 236: 122866, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635248

RESUMO

Small molecular contaminants (such as mycotoxins, antibiotics, pesticide residues, etc.) in food and environment have given rise to many biological and ecological toxicities, which has attracted worldwide attention in recent years. Meanwhile, due to the advantages of aptamers such as high specificity and stability, easy synthesis and modification, as well as low cost and immunogenicity, various aptasensors for the detection of small molecular contaminants have been flourishing. An aptasensor as a whole is composed of an aptamer-based target recognizer and a signal transducer, which are fields of concentrated research. In the practical detection applications, in order to achieve the quantitative detection of small molecular contaminants at low abundance in real samples, a large number of signal enhancing strategies have been utilized in the development of aptasensors. Recent years is a vintage period for efficient signal enhancing strategies of aptasensors by the aid of nanomaterials and nucleic acid amplification that are applied in the elements for target recognition and signal conversion. Therefore, this paper meticulously reviews the signal enhancing strategies based on nanomaterials (including the (quasi-)zero-dimensional, one-dimensional, two-dimensional and three-dimensional nanomaterials) and nucleic acid amplification (including enzyme-assisted nucleic acid amplification and enzyme-free nucleic acid amplification). Furthermore, the challenges and future trends of the abovementioned signal enhancing strategies for application are also discussed in order to inspire the practitioners in the research and development of aptasensors for small molecular contaminants.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanoestruturas , Ácidos Nucleicos , Técnicas de Amplificação de Ácido Nucleico
2.
J Colloid Interface Sci ; 605: 101-109, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34311304

RESUMO

The development of nonprecious metal-based electrocatalysts for oxygen reduction reaction (ORR) is a central task in renewable electrochemical energy conversion and storage technologies. Iron-nitrogen doped carbon-based (Fe-N/C) materials are promising alternatives to Pt-based ORR electrocatalysts. Owing to large specific surface area and outstanding electrical conductivity, carbon black is an inborn support for electrocatalysts. Unfortunately, the direct incorporation of Fe-Nx moieties onto the surface of carbon black has not been realized to date. Herein, Fe-Nx moieties are directly incorporated onto the surface of carbon black through surface modification and the following Fe and N co-doping. The obtained Fe and N co-doped carbon back (Fe-N/CB) catalyst has very large specific surface area and abundant accessible Fe-Nx moieties. As a result, Fe-N/CB electrocatalyst exhibits a more positive half-wave potential (0.86 V) than Pt/C. The Fe-N/CB catalyst also displays better stability and methanol resistance than Pt/C. The Zn-air battery with Fe-N/CB as cathodic catalyst shows a maximum power density of 68 mW cm-2 and a specific capacity of 676 mAh gZn-1. Our finding provides a convenient and low-cost approach to fabricating efficient M-N/C-based catalysts and will be helpful to the development of renewable electrochemical energy conversion and storage technologies.

3.
Spectrochim Acta A Mol Biomol Spectrosc ; 265: 120394, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34555696

RESUMO

Viscosity of cell microenvironment plays a significant role in maintaining the normal life activities of cells. Particularly, the abnormal viscosity in mitochondria is closely associated with lots of diseases and cellular dysfunctions. Herein, we developed a group of p-aminostyryl thiazole orange derivatives with different amino side chains. These probes showed good fluorescence response to viscosity with twisted intramolecular charge transfer mechanism, among them, the probes with diethylamino (TOB), dibutylamino (TOC) and pyrrolidin (TOE) side chains showed better response to the viscosity with 78-fold, 55-fold, and 88-fold fluorescence enhancement in 95% glycerol solution respectively. TOB, TOC, and TOE could enter live cells and mainly located in mitochondria. Treatment HeLa cells with nystatin, lipopolysaccharide or oleic acid caused significant fluorescence enhancement of these probes, suggesting the good potential for monitoring the variation of mitochondrial viscosity, as well as for investigating the related physiological process of inflammation and lipid metabolism.


Assuntos
Corantes Fluorescentes , Mitocôndrias , Benzotiazóis , Células HeLa , Humanos , Quinolinas , Viscosidade
4.
Chemosphere ; 286(Pt 1): 131600, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34346334

RESUMO

Mixed industrial wastewaters are often highly contaminated with heavy metals and organic pollutants. Treating these mixed wastewaters requires many stagewise unit operations. Our work investigates using an electrochemical oxidation-in-situ coagulation (ECO-IC) process as a pre-treatment step toward the efficient treatment of real mixed industrial wastewater rich with heavy metals and organic contaminants. The process degraded organic contaminants in the wastewater via anodic electrochemical oxidation. Simultaneously, heavy metals were precipitated in the solution by coagulants (iron hydroxides) formed in-situ by cathode-generated hydroxyl ions reacting with the significant amounts of dissolved iron in the wastewater. IrO2-RuO2 mixed metal oxide anodes were identified as the best electrodes for organic compound degradation demonstrating 97% degradation of methyl orange (MO) as a model compound within 15 min. These anodes were used to treat real industrial wastewater produced from the industrial cleaning of train tanker cars transporting industrial solvents. The electrochemical treatment experiments resulted in a treated solution with a lower heavy metal content, achieving 96% reduction in Fe and 30% reduction in As content. Only moderate decreases in organic content were observed up to a maximum of 13% reduction in total organic carbon after 1 h of treatment. Electrochemical treatment of the mixed industrial wastewater produced greater effective diameter of the suspended particles and distinct sediment, liquid, and suspended foam phases that could be easily separated for further treatment. ECO-IC shows promise as an efficient and chemical-free method to coagulate heavy metals in real industrial wastewaters and could be an effective pre-treatment in their separation.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Eletrodos , Compostos Orgânicos , Oxirredução , Óxidos , Águas Residuárias
5.
J Hazard Mater ; 422: 126837, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34399209

RESUMO

Debate and scientific inquiries regarding airborne transmission of respiratory infections such as COVID-19 and influenza continue. Health authorities including the WHO and the US CDC have recognized the airborne transmission of COVID-19 in specific settings, although the ventilation requirements remain to be determined. In this work we consider the long-range airborne transmission as an extended short-range airborne route, which reconciles the link between short- and long-range airborne routes. The effective short-range distance is defined as the distance in short range at which long-range route has the same volumetric exposure value as that due to short-range route. Our data show that a decrease in ventilation rate or room volume per person, or an increase in the ratio of the number of infected to susceptible people reduces the effective short-range distance. In a normal breathing scenario with one out of five people infected and a room volume of 12 m3 per person to ensure an effective short-range distance of 1.5 m, a ventilation rate of 10 L/s per person is needed for a duration of 2 h. Our results suggest that effective environmental prevention strategies for respiratory infections require appropriate increases in the ventilation rate while maintaining a sufficiently low occupancy. PRACTICAL IMPLICATIONS: Demonstration of the long-range airborne route as an extended short-range airborne route suggests the significant role played by building ventilation in respiratory infection exposure. The reconciliation of short- and long-range airborne transmission suggests that the commonly observed dominance of close-contact transmission is a probable evidence of short-range airborne transmission, following a separate earlier study that revealed the relative insignificance of large droplet transmission in comparison with the short-range airborne-route. Existing ventilation standards do not account for respiratory infection control, and this study presents a possible approach to account for infection under new ventilation standards.


Assuntos
COVID-19 , Infecções Respiratórias , Humanos , SARS-CoV-2 , Ventilação
6.
Acta Trop ; 225: 106196, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34687640

RESUMO

Trichomoniasis is the most common nonviral sexually transmitted disease; it is caused by Trichomonas vaginalis and seriously threatens human reproductive health. Telomeres are specialised DNA-protein complexes at the ends of chromosomes that have a protective function. The aim of the present study was to identify and characterise the telomeric DNA of T. vaginalis-which has not been previously reported-by multiple molecular methods including sequencing, the Bal nuclease (BAL) 31 nuclease assay, fluorescence in situ hybridisation (FISH), and Southern blotting. We found numerous repeated units of TTTTAGGG in T. vaginalis genomic DNA digested with S1 nuclease in combination with XbaI restriction enzyme. The (TTTTAGGG)n tandem repeats were also highly sensitive to BAL 31 exonuclease digestion. We confirmed that the (TTTTAGGG)n repeats were located at the end of T. vaginalis chromosomes by FISH. Restriction enzyme digestion combined with Southern blotting using a digoxigenin-labelled (TTTTAGGG)5 probe showed that the T. vaginalis telomeric DNA length varied from 1.0 to 1.5 kb. This is the first report on the telomeric DNA sequence of T. vaginalis which includes the length and distribution on chromosomes; our findings lay a foundation for further study on telomere maintenance mechanisms in T. vaginalis.


Assuntos
Tricomoníase , Trichomonas vaginalis , Sequência de Bases , DNA , Humanos , Telômero/genética , Trichomonas vaginalis/genética
7.
Chemosphere ; 286(Pt 2): 131469, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34340118

RESUMO

The strong ability of ferrihydrite and its aged minerals for fixing arsenate is a key factor in remediating arsenate-polluted environments. It is therefore crucial to clarify the stability of Fe-As complexes and the release conditions for As(V). The As(V) release amount was evaluated and compared in the presence of six representative anions, namely, phosphate, silicate, sulfate, inositol hexaphosphate, citrate, and oxalate. It was found that the As(V) release amount changed with the aging time of ferrihydrite and that this tendency generally followed two rules. These are, longer aging time leads to lower As(V) release (Rule 1), and longer aging time leads to higher As(V) release (Rule 2). Whether Rule 1 or Rule 2 dominated As release depended on the number of surface groups, size of competing anions, and contribution of As(V) re-adsorption. Characterization results using X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) provided evidence for the predicted mechanisms of As(V) release under various circumstances. In this work, it was demonstrated that when inorganic anions such as sulfate and silicate are present, ferrihydrite with longer aging time led to decreased As(V) release. When organic anions are present, ferrihydrite with less aging time results in reduced As(V) leaching. For anions such as phosphate, the As(V) release amount in relation to the ferrihydrite aging time depends on the concentration of phosphate ions. Nevertheless, the ligand concentration and As(V) loading rate on ferrihydrite should be simultaneously considered for the rule governing As(V) releasing.


Assuntos
Compostos Férricos , Fosfatos , Adsorção , Minerais , Silicatos , Difração de Raios X
8.
Sci Total Environ ; 805: 150395, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34818768

RESUMO

Serious concerns regarding stone biodeterioration have been raised due to the loss of aesthetic value and hidden dangers in stone cultural heritages and buildings. Stone biodeterioration involves a complex ecological interplay among organisms, however, the ecological mechanisms (deterministic or stochastic processes) that determine the microbial community on stone remain poorly understood. Here, using both amplicon and shotgun metagenomic sequencing approaches, we comprehensively investigated the biodiversity, assembly, and function of communities (including prokaryotes, fungi, microfauna, and plants) on various types of deteriorating limestone across different habitats in Feilaifeng. By generalizing classic ecological models to stone habitats, we further uncovered and quantified the mechanisms underlying microbial community assembly processes and microbial interactions within the biodeteriorated limestone. Community profiling revealed stable ecosystem functional potential despite high taxonomic variation across different biodeterioration types, suggesting non-random community assembly. Increased niche differentiation occurred in prokaryotes and fungi but not in microfauna and plant during biodeterioration. Certain microbial groups such as nitrifying archaea and bacteria showed wider niche breadth and likely contributing to the initiation, succession and expansion of stone biodeterioration. Consistently, prokaryotes were more strongly structured by selection-based deterministic processes, while micro-eukaryotes were more influenced by dispersal and drift-based stochastic processes. Importantly, microbial coexistence maintains network robustness within stone microbiotas, highlighting mutual cooperation among functional microorganisms. These results provide new insights into microbial community assembly mechanisms in stone ecosystems and may aid in the sustainable conservation of stone materials of interest.


Assuntos
Lagos , Microbiota , Archaea , Biodiversidade , China , UNESCO
9.
Clin Imaging ; 81: 15-23, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34597999

RESUMO

OBJECTIVE: To explore the value of amide proton transfer-weighted (APTw) magnetic resonance imaging (MRI) for differential diagnosis of fibroadenomas and malignant breast tumors. MATERIALS AND METHODS: This prospective study enrolled 56 patients with suspected breast tumors and performed APTw imaging. Based on the histopathology results, patients were divided into group 1 with malignant breast tumors (n = 41) and group 2 with fibroadenomas (n = 15). The measured image parameters (APTw value, ADC value, type of Time of Intensity Curve, maximum tumor diameter in image) and the maximal diameter of the tumors measured from surgical resection were compared between the two groups, and the diagnostic performance based on these parameters was quantified with ROC curve. Spearman's correlation coefficient was used to analyze the association between APTw or ADC values and ER, PR, HER2, and Ki-67 expressions. RESULTS: The intraclass correlation coefficients (ICC = 0.87 and 0.91) indicated a good inter-observer agreement of the measured APTw values. APTw values of malignant lesions were significantly higher than those of fibroadenomas (3.21 ± 1.04% vs 1.50 ± 0.54%, p < 0.001). Area under the curve (AUC) obtained from APTw imaging, DWI, DCE, APTw imaging+DWI, APTw imaging+DWI, and APTw imaging+DWI + DCE was 0.959, 0.897, 0.976, 0.997, and 1 respectively. The APTw value showed a negative correlation with ER expression (r = -0.357). CONCLUSION: APTw imaging yielded similar diagnosis performance in discriminating fibroadenomas and malignant breast tumors when compared to the DCE and better than DWI imaging, and provided supplement information on tumor cell activity to DWI images. The APTw value showed correlations with some prognostic factors for breast cancer.


Assuntos
Neoplasias da Mama , Fibroadenoma , Amidas , Neoplasias da Mama/diagnóstico por imagem , Diferenciação Celular , Imagem de Difusão por Ressonância Magnética , Feminino , Fibroadenoma/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Estudos Prospectivos , Prótons
10.
Chemosphere ; 287(Pt 1): 132054, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34474377

RESUMO

Melamine foam (MF) is a widely used commercial product and exhibits wide applications in many fields ranging from building, transportation to daily chemical product. Recent researches confirm that the special three-dimensional (3D) framework structure of MF can be an ideal substrate to prepare functional materials. In this work, the water-soluble polyethylenimine (PEI) was grafted onto the framework of MF to develop the water purification material toward heavy metal ions removal. The grafting of PEI on MF was achieved with the aids of polydopamine (PDA) coating and epoxy chloropropane (ECH) cross-linking successively. The 3D framework of MF could be well reserved and PEI was homogeneously grafted onto the framework surface. The adsorption capacity of the adsorbent was dependent upon the molecular wight of PEI. Lower PEI molecular weight endowed the adsorbent with better adsorption ability. The maximum adsorption capacity reached 328.95 mg/g, and the adsorbent exhibited extremely high adsorption stability with increasing cycling measurement numbers. Further results showed that the adsorbent also exhibited high reduction ability and induced about 62.5% toxic Cr(VI) to be reduced. This work confirms that the PEI-modified MF sample is a promising adsorbent in the removal of heavy metal ions and it can be used in wastewater treatment.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Concentração de Íons de Hidrogênio , Indóis , Cinética , Polietilenoimina , Polímeros , Triazinas , Poluentes Químicos da Água/análise
11.
Biomed Mater Eng ; 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34744060

RESUMO

BACKGROUND: Magnesium (Mg) alloy have biodegradation and mechanical properties that are similar to those of human bone, making it a promising candidate material for inclusion in implantable medical devices. OBJECTIVE: The osteointegration effect of Mg alloy scaffolds with different corrosion rates were studied and evaluated in large bone defect models. METHOD: Mg-Sr and Mg-Ca alloy scaffolds with a 20-µm Micro-arc oxidation (MAO) coating were used to repair critical bone defects for subsequent assessment of each alloy's degradation and osteointegration by X-ray, Micro-CT, fluorescence and histological examination. RESULTS: At 12 weeks post-implantation, each defect was found to be effectively reconstructed by either of the Mg alloys based on X-ray and Micro-CT images. The corrosion rate (CR) of each Mg alloy - as calculated based on micro-computed tomography information - demonstrated that the MAO coating could provide effective protection for only 4 weeks post-surgery. From weeks 8 to 12, the CR of the Mg-Ca alloy scaffold increased from 1.34 ± 0.23 mm/y to 1.57 ± 0.16 mm/y. In contrast, the CR of the Mg-Sr alloy scaffold decreased from 0.58 ± 0.14 mm/y to 0.54 ± 0.16 mm/y. However, fluorescence and histological examination revealed more mature, closely and regularly arranged newborn osteocytes at the Mg-Ca scaffold-fracture interface e from weeks 8 to 12 after surgery. RESULTS: The Mg-Sr scaffold was more corrosion resistant and the Mg-Ca scaffold yielded a better overall repair, which indicates that the CR of magnesium alloys matches the rate of new bone formation and is the key to repair bone defects as a bone substitute.

12.
Bioengineered ; 2021 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-34747301

RESUMO

The discarding and burning of corn stalks in the fields after harvesting lead to environmental pollution and waste of resources. Composting is an effective way to disposal of the crop straws. Composting is a complex biochemical process and need a detail studied in cold region. Hence, the succession process of bacteria and Actinomycetes in the process of corn stalk composting in cold region was studied by 16SrRNA. Alpha diversity analysis showed that the detection results could represent the real situation. The bacterial community diversity from high to low was F50 > F90 > F0 > F10 > F20. The results of beta analysis showed that F20 and F50 had the most similar microbial structure at the phylum level, and the difference between F0 and F20 was the largest. The dominant microbes changed from Proteobacteria and Bacteroidetes in F0 in heating stage to Firmicutes and Proteobacteria, Actinobacteria and Firmicutes in F10 during early high temperature stage, and Actinobacteria, Proteobacteria and Bacteroidetes in cooling and post composting phases. Actinobacteria and Firmicutes were the dominant bacteria in the whole composting process. In the composting process, the microbial community was mainly involved in amino acid metabolism related to nitrogen transformation and carbohydrate metabolism related to lignocellulose degradation. Lignin and hemicellulose were mainly degraded in thermophilic stage. The conversion of nitrogen and degradation of cellulose occurred mainly in the early stages of composting. The research will be helpful to understand the biochemical process of composting in cold region.

13.
Environ Pollut ; 291: 118221, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34740294

RESUMO

Sulfur, an essential macronutrient, plays important roles in plant development and stress mitigation. Sulfur deficiency, a common problem in agricultural soils, may disturb plant stress resistance and xenobiotic detoxification. In the present study, the function and mechanism of limited sulfur nutrition on the residues and phtotoxicity of imidacloprid were investigated in lettuce plants. Sulfur deficiency significantly increased imidacloprid accumulation in lettuce tissues, exacerbated imidacloprid biological toxicity by enhancing the accumulation of toxic metabolites, like imidacloprid-olefin. Simultaneously, imidacloprid-induced detoxification enzymes including cytochromes P450, glutathione S-transferases (GSTs) and glycosyltransferases were inhibited under limited sulfur supply. On the other hand, sulfur deficiency further enhanced the generation of reactive oxygen species and exacerbated lipid peroxidation in lettuce tissues. Sulfur deficiency mainly reduced the abundance of thiol groups, which are essential redox modulators as well as xenobiotic conjugators, and significantly inhibited GSTs expression. These results clearly suggested that sulfur deficiency inhibited the synthesis of sulfur-containing compounds, leading to increased accumulation of pesticide residues and toxic metabolites as well as reduced detoxification capacity, consequently leading to oxidative damage to plants. Therefore, moderate sulfur supply in regions where neonicotinoid insecticides are intensively and indiscriminately used may be an efficient strategy to reduce pesticide residues and the potential risk to ecosystem.


Assuntos
Inseticidas , Plântula , Ecossistema , Inseticidas/toxicidade , Alface , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Compostos de Sulfidrila , Enxofre
14.
Cornea ; 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34759198

RESUMO

PURPOSE: Endothelial plaque is an important sign of fungal keratitis and is related to diagnosis, surgical indications, and prognosis. However, bacterial keratitis sometimes involves fibrin formation on the back corneal surface, similar to endothelial plaques. Because corneal infiltration interferes with precise observation of the posterior corneal plaque, distinguishing pathogens with a slitlamp is difficult. We hope to assist clinicians in early diagnosis and timely treatment by observing the connection state of endothelial plaques and the corneal endothelium through anterior segment optical coherence tomography (AS-OCT) and the different forms of endothelial plaques in infectious keratopathy through in vivo confocal microscopy (IVCM). METHODS: We analyzed 52 patients in the Eye Hospital of the First Affiliated Hospital of Harbin Medical University who were clearly diagnosed with fungal or bacterial keratitis with endothelial plaques. All patients underwent AS-OCT and IVCM on admission. RESULTS: According to the smear, IVCM, or fungal and bacterial culture results, the patients were diagnosed with fungal (28 patients) or bacterial keratitis (24 patients). AS-OCT in 25 patients diagnosed with fungal keratitis revealed that the corneal endothelium-endothelial plaque boundary was unclear and wavy, and 24 patients had unclear cell boundaries and a large number of compactly distributed inflammatory cells in the endothelial layer according to IVCM. AS-OCT in 23 patients diagnosed with bacterial keratitis revealed clear corneal endothelium-endothelial plaque boundaries, and insufficient endothelial cell boundaries with a large number of visible and scattered inflammatory cell structures were observed through IVCM in 22 patients. CONCLUSIONS: Corneal endothelial plaque detection by AS-OCT and IVCM can be used for early diagnosis of infectious keratitis.

15.
Cornea ; 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34759200

RESUMO

PURPOSE: The purpose of this study was to assess the distribution and morphological variation of conjunctiva-associated lymphoid tissue (CALT) in healthy human subjects and patients with meibomian gland dysfunction (MGD) using laserscanningin vivo confocal microscopy. METHODS: A total of 34 healthy subjects and 32 patients with MGD were enrolled. All subjects underwent a conventional examination consisting of slitlamp biomicroscopy, tear film break-up time, and the Schirmer test. In vivo microscopy was applied to analyze the morphological changes in the diffuse lymphoid layer and lymphoid follicles in CALT. Conjunctival impression cytology (CIC) of samples of patients' palpebral conjunctiva and immunofluorescence staining of CD4 and CD8 antibodies were also performed to indicate the immune response status of CALT. RESULTS: In the MGD group, the density of diffuse lymphocytes (P < 0.001), follicles (P < 0.001), and perifollicular lymphocytes was higher (P < 0.001) and the central reflection of the follicles was stronger (P < 0.001) than in the control group, while there was no difference in the follicle area (P = 0.758). Besides, diffuse lymphocyte density was correlated with telangiectasia, and follicular center reflection intensity was correlated with plugging. CIC immunofluorescence staining showed a higher percentage of CD4+ (P < 0.001) and CD8+ (P < 0.001) cells in the MGD group than in the control group. CONCLUSIONS: Using laser scanning in vivo confocal microscopy and CIC immunofluorescence staining, we observed the activation of CALT in patients with MGD, and some CALT-related parameters correlated with the lid margin findings of patients with MGD.

16.
Artigo em Inglês | MEDLINE | ID: mdl-34750754

RESUMO

Empathy can be measured based on behavioral tasks and self-report scales, which have been used to characterize the state and trait empathy, respectively, in previous studies. The neural correlates of state empathy have been deeply investigated, whereas the association between trait empathy and brain activity remains unclear. Thus, this study employed multiple variate pattern analysis (MVPA) to explore whether intrinsic brain activity (IBA) within state-empathy-related regions was associated with trait empathy. Meta-analysis of empathy-related fMRI experiments identified a general network underlying state empathy, which is located in the bilateral supplementary motor area (SMA) extending to the middle cingulate cortex (MCC) and left anterior insula (AI) and extending to the inferior frontal gyrus (IFG). The subsequent MVPA found that empathic concern can be predicted through the IBA of the general network at the female individual level (i.e., the fractional amplitude of low-frequency fluctuations and regional homogeneity). Based on the resting state fMRI (rs-fMRI), these results further support the involvement of SMA/MCC and AI/IFG in empathy. Meanwhile, the significant predictive association between IBA and trait empathy offers new insights into the general component of empathy, which may indicate the potential of using rs-fMRI to achieve the objective measurement of empathic ability.

17.
Materials (Basel) ; 14(21)2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34771842

RESUMO

Dense SiC ceramics were fabricated by high-temperature physical vapor transport (HTPVT) growth process using SiC nanoarrays as the crystal seeds, which was obtained by vacuum heat treatment of amorphous SiC films prepared by plasma-enhanced chemical vapor deposition (PECVD) with a porous anodic aluminum oxide (AAO) template. In the HTPVT process, two-step holding was adopted, and the temperature at the first step was controlled at 2100 and 2150 °C to avoid SiC nanoarrays evaporation, and the grain size of SiC crystal increased with the increase in temperature and decrease in the pressure of Ar. The temperature of the second step was 2300 °C, and rapid SiC grain growth and gradual densification were achieved. The prepared SiC ceramics exhibited a relative density of more than 99%, an average grain size of about 100 µm, a preferred orientation along the (0 0 0 6) plane, a Vickers hardness of about 29 GPa, a flexural strength of about 360 MPa, and thermal conductivity at room temperature of more than 200 W·m-1·K-1.

18.
Appl Environ Microbiol ; : AEM0180621, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34788071

RESUMO

Dimethylsulfoniopropionate (DMSP) is one of the most abundant organic sulfur compounds in the oceans, which is mainly degraded by bacteria through two pathways, a cleavage pathway and a demethylation pathway. Its volatile catabolites dimethyl sulfide (DMS) and methanethiol (MT) in these pathways play important roles in the global sulfur cycle and have potential influences on the global climate. Intense DMS/DMSP cycling occurs in the Arctic. However, little is known about the diversity of cultivable DMSP-catabolizing bacteria in the Arctic and how they catabolize DMSP. Here, we screened DMSP-catabolizing bacteria from Arctic samples and found that bacteria of four genera (Psychrobacter, Pseudoalteromonas, Alteromonas and Vibrio) could grow with DMSP as the sole carbon source, among which Psychrobacter and Pseudoalteromonas are predominant. Four representative strains (Psychrobacter sp. K31L, Pseudoalteromonas sp. K222D, Alteromonas sp. K632G and Vibrio sp. G41H) from different genera were selected to probe their DMSP catabolic pathways. All these strains produce DMS and MT simultaneously during their growth on DMSP, indicating that all strains likely possess the two DMSP catabolic pathways. On the basis of genomic and biochemical analyses, the DMSP catabolic pathways in these strains were proposed. Bioinformatic analysis indicated that most bacteria of Psychrobacter and Vibrio have the potential to catabolize DMSP via the demethylation pathway, and that only a small portion of Psychrobacter strains may catabolize DMSP via the cleavage pathway. This study provides novel insights into DMSP catabolism in marine bacteria. IMPORTANCE Dimethylsulfoniopropionate (DMSP) is abundant in the oceans. The catabolism of DMSP is an important step of the global sulfur cycle. Although Gammaproteobacteria are widespread in the oceans, the contribution of Gammaproteobacteria in global DMSP catabolism is not fully understood. Here, we found that bacteria of four genera belonging to Gammaproteobacteria (Psychrobacter, Pseudoalteromonas, Alteromonas and Vibrio), which were isolated from Arctic samples, were able to grow on DMSP. The DMSP catabolic pathways of representative strains were proposed. Bioinformatic analysis indicates that most bacteria of Psychrobacter and Vibrio have the potential to catabolize DMSP via the demethylation pathway, and that only a small portion of Psychrobacter strains may catabolize DMSP via the cleavage pathway. Our results suggest that novel DMSP dethiomethylases/demethylases may exist in Pseudoalteromonas, Alteromonas and Vibrio, and that Gammaproteobacteria may be important participants in marine, especially in polar DMSP cycling.

19.
Eur J Prev Cardiol ; 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34792124

RESUMO

AIMS: To examine the effects of sodium-glucose cotransporter-2 inhibitors (SGLT2i) on cardiac remodelling in patients with type 2 diabetes mellitus (T2DM) and/or heart failure (HF), and to explore the subsets of patients who may have greater benefit from SGLT2i therapy. METHODS AND RESULTS: Four electronic databases were searched for randomized controlled trials (RCTs) that evaluated the effects of SGLT2i on parameters reflecting cardiac remodelling in patients with T2DM and/or HF. Standardized mean differences (SMDs) or mean differences (MDs) were pooled. Subgroup analyses were performed according to the baseline HF and T2DM, HF type, SGLT2i agent, follow-up duration, and imaging modality. A total of 13 RCTs involving 1251 patients were analysed. Sodium-glucose cotransporter-2 inhibitors treatment significantly improved left ventricular (LV) ejection fraction [SMD, 0.35; 95% confidence interval (CI) (0.04, 0.65); P = 0.03], LV mass [SMD, -0.48; 95% CI (-0.79, -0.18); P = 0.002], LV mass index [SMD, -0.27; 95% CI (-0.49, -0.05); P = 0.02], LV end-systolic volume [SMD, -0.37; 95% CI (-0.71; -0.04); P = 0.03], LV end-systolic volume index [MD, -0.35 mL/m2; 95% CI (-0.64, -0.05); P = 0.02], and E-wave deceleration time [SMD, -0.37; 95% CI (-0.70, -0.05); P = 0.02] in the overall population. Subgroup analyses showed that the favourable effects of SGLT2i on LV remodelling were only significant in HF patients, especially HF with reduced ejection fraction (HFrEF), regardless of glycaemic status. Among the four included SGLT2i, empagliflozin was associated with a greater improvement of LV mass, LV mass index, LV end-systolic volume, LV end-systolic volume index, LV end-diastolic volume, and LV end-diastolic volume index (all P < 0.05). CONCLUSIONS: Sodium-glucose cotransporter-2 inhibitors treatment significantly reversed cardiac remodelling, improving LV systolic and diastolic function, LV mass and volume, especially in patients with HFrEF and amongst those taking empagliflozin compared with other SGLT2i. Reversed remodelling may be a mechanism responsible for the favourable clinical effects of SGLT2i on HF.

20.
J Control Release ; 340: 292-307, 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34748871

RESUMO

Ligands, mostly binding to proteins to form complexes and catalyze chemical reactions, can serve as drug and probe molecules, as well as sensing elements. DNA nanotechnology can integrate the high editability of DNA nanostructures and the biological activity of ligands into functionalized DNA nanostructures in a manner of controlled ligand stoichiometry, type, and arrangement, which provides significant advantages for targeted therapeutics and diagnostics. As therapeutic agents, multiple- and multivalent-ligands functionalized DNA nanostructures increase ligand-receptor affinity and activate multivalent ligand-receptor interactions, enabling improved regulation of cell signaling and enhanced control of cell behavior. As diagnostic agents, multiple ligands interaction via DNA nanostructures endows DNA nanosensors with high sensitivity and excellent signal transduction capability. Herein, we review the principles and advantages of using DNA nanostructures to manipulate ligands for targeted therapeutics and diagnostics and provide future perspectives.

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