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1.
JCI Insight ; 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38980725

ABSTRACT

We evaluated the safety and viral rebound, after analytical treatment interruption (ATI), of vedolizumab and ART in recent HIV-1 infection. We used this model to analyze the impact of α4ß7 on the HIV-1 reservoir size. Participants started ART with monthly Vedolizumab infusions and ATI was performed at week 24. Biopsies were obtained from ileum and caecum at baseline and week 24. Vedolizumab levels, HIV-1 reservoir, flow cytometry and cell-sorting and antibody competition experiments were assayed. Vedolizumab was safe and well-tolerated. No participant achieved undetectable viremia off ART 24 weeks after ATI. Only a modest effect on the time to achieve >1000 HIV-RNA copies/mL and the proportion of participants off ART was observed, being higher compared to historical controls. Just before ATI, α4ß7 expression was associated with HIV-1 DNA and RNA in peripheral blood and with PD1 and TIGIT levels. Importantly, a complete blocking of α4ß7 was observed on peripheral CD4+ T-cells but not in gut (ileum and caecum), where α4ß7 blockade and vedolizumab levels were inversely associated with HIV-1 DNA. Our findings support α4ß7 as an important determinant in HIV-1 reservoir size, suggesting the complete α4ß7 blockade in tissue as a promising tool for HIV-cure combination strategies.

2.
Plant Dis ; 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38982676

ABSTRACT

Wheat (Triticum aestivum) loses 21.5% yield to pests and diseases annually (Savary et al. 2019). Among the wheat diseases, bacterial leaf streak (BLS) is a growing problem, costing $78.5 million in losses (https://cropprotectionnetwork.org/). In July 2022, we sampled winter wheat leaf samples at Volga (44.30, -96.92), South Dakota, USA with an estimated disease incidence of 40% (n=100). The typical symptoms were water-soaking with large necrotic and chlorotic streaks extending the length of the leaves and were strikingly similar to BLS. To isolate the pathogen, leaves were cut lengthwise into 1 cm pieces and surface-sterilized using a 10% NaOCl solution for 3 min, followed by 70% ethanol for 3 min, and then rinsed with sterile distilled water and placed in 500 ul of sterile distilled water for 5 min and using a sterile loop the water was streaked over a plate of Nutrient Agar (NA). Following Duveiller et al. (1997), the streaked plate was incubated in the dark at 28℃ for 48 h. Observed single colonies were sub-cultured thrice onto fresh NA plates to obtain a pure culture. We named the culture SD101. Bacteria were found to be gram-negative with a colony morphology initially raised, smooth, and white that later turned yellow. DNA was extracted using the Wizard HMW DNA Extraction Kit (Promega, Madison, WI) following the manufacturer's protocol, and sequenced using Nanopore MinION R9.4 (Oxford Nanopore Technology). We used the Rapid Annotation Using Subsystems Technology approach (Aziz eal. 2008) to extract the 16S rDNA, DNA gyrase subunit B (gyrB), and translation initiation factor IF-2 (infB) gene sequences that were deposited in GenBank under accession numbers PP329908.1 for 16S rDNA, PP496481 for infB, and PP328920.1 for gyrB. Homology analysis using CLC Genomics Workbench 22.0.2 (QIAGEN) and BLASTn against the GenBank nucleotide database resulted in a 99.74% match (1543/ 1547 bp) of the 16S sequence, 99.59% match (2674/ 2685 bp) of the infB sequence, and 99.42% match (2396/ 2410 bp) of the gyrB sequence with Pantoea ananatis strain AJ13355 (AP012032). To test pathogenicity, seeds of spring wheat breeding line SD4892 were planted in 30 cm × 30 cm pots in a greenhouse under a 16 h light photoperiod. The inoculum was prepared from 48-h-old NA plates of SD101 rinsed with 1X Phosphate Buffer Saline (PBS buffer), adjusted to an OD600 = 1.0, and amended with two drops of Tween 20 (polyoxyethylene sorbitol ester, Millipore Sigma). PBS with Tween 20 was used as a negative control. The inoculum was sprayed on 15 replicates of 15-day-old seedlings, kept at 95% relative humidity for 48 h, then moved to the greenhouse at 23 to 25°C. The symptoms appeared as water soaking that later turned to necrotic streaks with surrounding chlorosis on all 15 inoculated plants while control plants remained healthy. The pathogen was re-isolated from the leaves as described above. The 16S rDNA, infB, and gyrB sequences amplified and sequenced were identical to the gene sequences from the whole genome sequencing. The experiment was repeated with the same results, completing Koch's postulates. Although P. ananatis is pathogenic on corn, rice, and other plant species in the United States (Coutinho et al. 2009), and was reported pathogenic on wheat in Poland (Krawczyk et al. 2020), this is the first report of its pathogenicity on wheat in the United States. The prevalence, and incidence of BLS disease caused by P. ananatis in wheat is needed to estimate its threat to wheat production and to develop management strategies.

3.
Int J Cardiol ; : 132340, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38992809

ABSTRACT

BACKGROUND: The current incidence and outcomes of structural transcatheter procedures in heart transplant (HTx) recipients and left-ventricular assist devices (LVAD) carriers is unknown. AIMS: To provide insights on structural transcatheter procedures performed across HTx and LVAD patients in Spain. METHODS: Multicenter, ambispective, observational nationwide registry. RESULTS: Until May/2023, 36 percutaneous structural interventions were performed (78% for HTx and 22% for LVAD) widely varying among centers (0%-1.4% and 0%-25%, respectively). Percutaneous mitral transcatheter edge-to-edge (TEER) was the most common (n = 12, 33.3%), followed by trancatheter aortic valve replacement (n = 11, 30.5%), and tricuspid procedures (n = 9, 25%). Mitral TEER resulted in mild residual mitral regurgitation in all but one case, mean gradient was <5 mmHg in 75% of them at 1-year, with no mortality and 8.3% re-admission rate. Tricuspid TEER resulted in 100% none/mild residual regurgitation with a 1-year mortality and readmission rates of 22% and 28.5%, respectively. Finally, trancatheter aortic valve replacement procedures (n = 8 in LVADs due to aortic regurgitation and n = 3 in HTx), were successful in all cases with one prosthesis degeneration leading to severe aortic regurgitation at 1-year, 18.2% mortality rate and no re-admissions. Globally, major bleeding rates were 7.9% and 12.5%, thromboembolic events 3.7% and 12.5%, readmissions 37% and 25%, and mortality 22% and 25%, in HTx and LVADs respectively. No death was related to the implanted transcatheter device. CONCLUSIONS: Most centers with HTx/LVAD programs perform structural percutaneous procedures but with very inconsistent incidence. They were associated with good safety and efficacy, but larger studies are required to provide formal recommendations.

4.
Biomed Mater Eng ; 35(4): 387-399, 2024.
Article in English | MEDLINE | ID: mdl-38968040

ABSTRACT

BACKGROUND: Polymeric electrospun mats have been used as scaffolds in tissue engineering for the development of novel materials due to its characteristics. The usage of synthetic materials has gone in decline due to environmental problems associated with their synthesis and waste disposal. Biomaterials such as biopolymers have been used recently due to good compatibility on biological applications and sustainability. OBJECTIVE: The purpose of this work is to obtain novel materials based on synthetic and natural polymers for applications on tissue engineering. METHODS: Aloe vera mucilage was obtained, chemically characterized, and used as an active compound contained in electrospun mats. Polymeric scaffolds were obtained in single, coaxial and tri-layer structures, characterized and evaluated in cell culture. RESULTS: Mucilage loaded electrospun fibers showed good compatibility due to formation of hydrogen bonds between polymers and biomolecules from its structure, evidenced by FTIR spectra and thermal properties. Cell viability test showed that most of the obtained mats result on viability higher than 75%, resulting in nontoxic materials, ready to be used on scaffolding applications. CONCLUSION: Mucilage containing fibers resulted on materials with potential use on scaffolding applications due to their mechanical performance and cell viability results.


Subject(s)
Aloe , Cell Survival , Gelatin , Plant Mucilage , Polyesters , Tissue Engineering , Tissue Scaffolds , Polyesters/chemistry , Tissue Engineering/methods , Gelatin/chemistry , Tissue Scaffolds/chemistry , Cell Survival/drug effects , Aloe/chemistry , Plant Mucilage/chemistry , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Materials Testing , Humans , Membranes, Artificial , Animals
5.
J Clin Med ; 13(13)2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38999202

ABSTRACT

Transcatheter aortic valve implantation (TAVI) now represents the mainstay of treatment for severe aortic stenosis. Owing to its exceptional procedural efficacy and safety, TAVI has been extended to include patients at lower surgical risk, thus now encompassing a diverse patient population receiving this treatment. Yet, long-term outcomes also depend on optimal medical therapy for secondary vascular prevention, with antithrombotic therapy serving as the cornerstone. Leveraging data from multiple randomized controlled trials, the current guidelines generally recommend single antithrombotic therapy, with either single antiplatelet therapy (SAPT) or oral anticoagulation (OAC) alone in those patients without or with atrial fibrillation, respectively. Yet, individualization of this pattern, as well as specific case uses, may be needed based on individual patient characteristics and concurrent procedures. This review aims to discuss the evidence supporting antithrombotic treatments in patients treated with TAVI, indications for a standardized treatment, as well as specific considerations for an individualized approach to treatment.

6.
Sensors (Basel) ; 24(13)2024 Jul 01.
Article in English | MEDLINE | ID: mdl-39001059

ABSTRACT

This paper presents an innovative technique, Advanced Predictor of Electrical Parameters, based on machine learning methods to predict the degradation of electronic components under the effects of radiation. The term degradation refers to the way in which electrical parameters of the electronic components vary with the irradiation dose. This method consists of two sequential steps defined as 'recognition of degradation patterns in the database' and 'degradation prediction of new samples without any kind of irradiation'. The technique can be used under two different approaches called 'pure data driven' and 'model based'. In this paper, the use of Advanced Predictor of Electrical Parameters is shown for bipolar transistors, but the methodology is sufficiently general to be applied to any other component.

7.
Patient ; 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38980645

ABSTRACT

BACKGROUND: The stage of the pandemic significantly affects people's preferences for (the societal impacts of) COVID-19 policies. No discrete choice experiments were conducted when the COVID-19 pandemic was in a transition phase. OBJECTIVES: This is the first study to empirically investigate how citizens weigh the key societal impacts of pandemic policies when the COVID-19 pandemic transitions into an endemic. METHODS: We performed two discrete choice experiments among 2181 Dutch adults that included six attributes: COVID-19 deaths, physical health problems, mental health problems, financial problems, surgery delays and the degree to which individual liberties are restricted. We used latent class choice models to identify heterogeneous preferences for the impacts of COVID-19 measures across different groups of respondents. RESULTS: A large majority of the participants in this study was willing to accept deaths to avoid that citizens experience physical complaints, mental health issues, financial problems and the postponement of surgeries. The willingness to tolerate COVID-19 deaths to avoid these societal impacts differed substantially between participants. When participants were provided with information about the stringency of COVID-19 measures, they assigned relatively less value to preventing the postponement of non-urgent surgeries for 1-3 months across all classes. CONCLUSIONS: Having gone through a pandemic, most Dutch citizens clearly prefer pandemic policies that consider citizens' financial situations, physical problems, mental health problems and individual liberties, alongside the effects on excess mortality and pressure on healthcare.

8.
Curr Microbiol ; 81(9): 264, 2024 Jul 13.
Article in English | MEDLINE | ID: mdl-39001894

ABSTRACT

One of the main interests in the food industry is the preservation of food from spoilage by microorganisms or lipid oxidation. A novel alternative is the development of additives of natural origin with dual activity. In the present study, a chemically modified lysozyme (Lys) with epigallocatechin gallate (EGCG) was developed to obtain a conjugate (Lys-EGCG) with antibacterial/antioxidant activity to improve its properties and increase its application potential. The modification reaction was carried out using a free radical grafting method for the Lys modification reaction, using ascorbic acid and hydrogen peroxide as radical initiators in an aqueous medium. The synthesis of Lys-EGCG conjugate was confirmed by spectroscopic (FT-IR, 1H-RMN, and XPS) and calorimetry differential scanning (DSC) analyses. The EGCG binding to the Lys biomolecule was quantified by the Folin-Ciocalteu method; the antibacterial activity was evaluated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MCB) against Staphylococcus aureus and Pseudomonas fluorescens; the antioxidant activity was evaluated by ABTS, DPPH, and FRAP. The spectroscopic results showed that the Lys-EGCG conjugate was successfully obtained, and the DSC analysis revealed a 20 °C increase (P < 0.05) in the denaturation temperature of Lys due to EGCG modification. The EGCG concentration in Lys-EGCG was 97.97 ± 4.7 µmol of EGCG/g of sample. The antibacterial and antioxidant activity of the Lys-EGCG conjugate was higher (P < 0.05) than pure EGCG and Lys. The chemical modification of Lys with EGCG allows for the bioconjugate with a dual function (antibacterial/antioxidant), broadening the range of Lys and EGCG applications to different areas such as food, cosmetic, and pharmaceutical industries.


Subject(s)
Anti-Bacterial Agents , Antioxidants , Catechin , Microbial Sensitivity Tests , Muramidase , Pseudomonas fluorescens , Staphylococcus aureus , Catechin/analogs & derivatives , Catechin/chemistry , Catechin/pharmacology , Muramidase/pharmacology , Muramidase/chemistry , Muramidase/metabolism , Antioxidants/pharmacology , Antioxidants/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Staphylococcus aureus/drug effects , Pseudomonas fluorescens/drug effects
9.
G3 (Bethesda) ; 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38938172

ABSTRACT

Meiotic drivers are selfish genetic loci that can be transmitted to more than half of the viable gametes produced by a heterozygote. This biased transmission gives meiotic drivers an evolutionary advantage that can allow them to spread over generations until all members of a population carry the driver. This evolutionary power can also be exploited to modify natural populations using synthetic drivers known as 'gene drives.' Recently, it has become clear that natural drivers can spread within genomes to birth multicopy gene families. To understand intragenomic spread of drivers, we model the evolution of two or more distinct meiotic drivers in a population. We employ the wtf killer meiotic drivers from Schizosaccharomyces pombe, which are multicopy in all sequenced isolates, as models. We find that a duplicate wtf driver identical to the parent gene can spread in a population unless, or until, the original driver is fixed. When the duplicate driver diverges to be distinct from the parent gene, we find that both drivers spread to fixation under most conditions, but both drivers can be lost under some conditions. Finally, we show that stronger drivers make weaker drivers go extinct in most, but not all, polymorphic populations with absolutely linked drivers. These results reveal the strong potential for natural meiotic drive loci to duplicate and diverge within genomes. Our findings also highlight duplication potential as a factor to consider in the design of synthetic gene drives.

10.
Toxics ; 12(6)2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38922119

ABSTRACT

This study investigates the occurrence and characteristics of macroplastic and polymer microparticles in the Urias coastal lagoon's beach sediments, in northwest Mexico. Coastal lagoons, productive and vulnerable ecosystems, are impacted significantly by anthropogenic activities, leadings to their pollution by various contaminants, including plastics. Our research involved sampling sediments from four sites within the lagoon that were influenced by different human activities such as fishing, aquaculture, thermoelectric power plant operations, industrial operations, and domestic wastewater discharge. Our methodology included collecting macroplastics and beach sediment samples, followed by laboratory analyses to identify the plastic debris' size, shape, color, and chemical composition. The results indicated a notable presence of macroplastic items (144), predominantly bags, styrofoam, and caps made of polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). The polymer microparticles were mainly fibers, with cotton and polyester as the most common polymers, suggesting a significant contribution from clothing-related waste. The dominant colors of the microparticles were blue and transparent. High densities were observed in areas with slower water exchange. Our findings highlight the urgent need for better waste management practices to mitigate plastic pollution in coastal lagoons, preserving their ecological and economic functions.

11.
Biomedicines ; 12(6)2024 May 25.
Article in English | MEDLINE | ID: mdl-38927381

ABSTRACT

Inherited thrombophilia (IT) has been implicated as a potential causal factor of adverse pregnancy outcomes (APOs), including recurrent miscarriage with and without the presence of antiphospholipid syndrome (APS). The aim of this study was to assess the prevalence and impact of IT on fetal-maternal outcomes and thrombotic risk in women within the spectrum of obstetric APS. Three hundred and twenty-eight women with APS-related obstetric morbidity ever pregnant were included. Of these, 74 met the APS classification criteria, 169 were non-criteria (NC)-APS, and 85 were seronegative (SN)-APS. Patients with other autoimmune diseases were excluded. APOs included early pregnancy loss, fetal death, preeclampsia, abruptio placentae, and preterm birth. Successful pregnancy was defined as the achievement of a live newborn. A literature search was also performed. The mean age of the overall group was 33.9 ± 5.3 years, and the patients were followed up for 35 (11-79) months. During the study period, there were 1332 pregnancies. Nearly 14% of the patients had an associated IT. IT patients more frequently received the standard-of-care (SoC) therapy. The presence of IT was not associated with worse maternal-fetal outcomes in patients treated with SoC treatment. Overall, IT patients had a lower frequency of newborns without treatment, especially those without definite APS. In addition, IT did not increase the risk of thrombosis during pregnancy or the postpartum period. A detailed analysis of the literature review identified only four publications related to our study and did not show conclusive evidence of the impact of IT on patients with obstetric APS. The group of women with APS-related obstetric morbidity and IT who did not receive treatment, especially those without definite APS, had a worse prognosis in terms of a live birth. However, with SoC therapy, the prognosis is similar in those patients without IT. The association of IT with APS does not seem to predispose to the development of thrombosis during pregnancy and/or the postpartum period.

12.
Cancers (Basel) ; 16(12)2024 Jun 19.
Article in English | MEDLINE | ID: mdl-38927969

ABSTRACT

Cancer is characterized by increased metabolic activity and vascularity, leading to temperature changes in cancerous tissues compared to normal cells. This study focused on patients with abnormal mammogram findings or a clinical suspicion of breast cancer, exclusively those confirmed by biopsy. Utilizing an ultra-high sensitivity thermal camera and prone patient positioning, we measured surface temperatures integrated with an inverse modeling technique based on heat transfer principles to predict malignant breast lesions. Involving 25 breast tumors, our technique accurately predicted all tumors, with maximum errors below 5 mm in size and less than 1 cm in tumor location. Predictive efficacy was unaffected by tumor size, location, or breast density, with no aberrant predictions in the contralateral normal breast. Infrared temperature profiles and inverse modeling using both techniques successfully predicted breast cancer, highlighting its potential in breast cancer screening.

14.
ACS Omega ; 9(23): 24721-24727, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38882092

ABSTRACT

Motivated by the experimental findings of Wolff et al., we investigated the TiN|FeCo multilayers at the atomic scale. Four different models were employed to investigate the interface, considering both Fe and Co surface terminations of the FeCo compounds. The interface formation energy formalism was employed to study the thermodynamic stability of these models. The results show that an interface mediated by Co atoms is most likely to appear in the experiment. Also, the Fe surface termination is more viable than a Co surface termination. The magnetic moments of Co at the interface are 1.48 µB/atom, which denotes a decay compared to bulk (1.76 µB/atom). Besides, Ti acquires a very small induced magnetization of -0.05 µB/atom. Our proposed atomistic model of the TiN|FeCo multilayer system fits perfectly with the structure obtained in experiments, and it is a step forward in the theoretical-experimental design of wear-resistant coatings with outstanding magnetic and mechanical properties.

15.
Phys Eng Sci Med ; 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38884672

ABSTRACT

Positron Emission Tomography (PET) imaging after 90 Y liver radioembolization is used for both lesion identification and dosimetry. Bayesian penalized likelihood (BPL) reconstruction algorithms are an alternative to ordered subset expectation maximization (OSEM) with improved image quality and lesion detectability. The investigation of optimal parameters for 90 Y image reconstruction of Q.Clear, a commercial BPL algorithm developed by General Electric (GE), in PET/MR is a field of interest and the subject of this study. The NEMA phantom was filled at an 8:1 sphere-to-background ratio. Acquisitions were performed on a PET/MR scanner for clinically relevant activities between 0.7 and 3.3 MBq/ml. Reconstructions with Q.Clear were performed varying the ß penalty parameter between 20 and 6000, the acquisition time between 5 and 20 min and pixel size between 1.56 and 4.69 mm. OSEM reconstructions of 28 subsets with 2 and 4 iterations with and without Time-of-Flight (TOF) were compared to Q.Clear with ß = 4000. Recovery coefficients (RC), their coefficient of variation (COV), background variability (BV), contrast-to-noise ratio (CNR) and residual activity in the cold insert were evaluated. Increasing ß parameter lowered RC, COV and BV, while CNR was maximized at ß = 4000; further increase resulted in oversmoothing. For quantification purposes, ß = 1000-2000 could be more appropriate. Longer acquisition times resulted in larger CNR due to reduced image noise. Q.Clear reconstructions led to higher CNR than OSEM. A ß of 4000 was obtained for optimal image quality, although lower values could be considered for quantification purposes. An optimal acquisition time of 15 min was proposed considering its clinical use.

16.
Am J Cardiol ; 225: 25-34, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38871156

ABSTRACT

Shortening the duration of dual-antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) was shown to be effective and safe in patients at high bleeding risk (HBR). We aimed to investigate the effect of 1 versus 3-month DAPT on outcomes after drug-eluting stent in HBR patients with or without chronic kidney disease (CKD). Data from 3 prospective single-arm studies (XIENCE Short DAPT Program) enrolling HBR patients after successful coronary implantation of cobalt-chromium everolimus-eluting stent (XIENCE, Abbott) were analyzed. Subjects were eligible for DAPT discontinuation at 1 or 3 months if free from ischemic events. The primary end point was all-cause death or any myocardial infarction. The key secondary end point was Bleeding Academic Research Consortium Type 2 to 5 bleeding. Outcomes were assessed from 1 to 12 months after PCI. CKD was defined as baseline creatinine clearance <60 ml/min. Of 3,286 patients, 1,432 (43.6%) had CKD. One-month versus 3-month DAPT was associated with a similar 12-month risk of the primary outcome irrespective of CKD status (CKD: 9.5% vs 10.9%, adjusted hazard ratio 0.86, 95% confidence interval 0.60 to 1.22; no-CKD: 6.6% vs 5.6%, adjusted hazard ratio 1.15, 95% confidence interval 0.77 to 1.73; p interaction 0.299). Bleeding Academic Research Consortium 2 to 5 bleeding rates were numerically but not significantly lower with 1-month versus 3-month DAPT in both CKD (9.9% vs 12%) and no-CKD (6.4% vs 9.0%) patients. In conclusion, in HBR patients, 1-month versus 3-month DAPT was associated with a similar risk of ischemic complications and a trend toward fewer bleeding events at 12 months after PCI, irrespective of CKD status.

17.
Polymers (Basel) ; 16(11)2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38891558

ABSTRACT

When the cocoa pod husk (CPH) is used and processed, two types of flour were obtained and can be differentiated by particle size, fine flour (FFCH), and coarse flour (CFCH) and can be used as a possible reinforcement for the development of bio-based composite materials. Each flour was obtained from chopping, drying by forced convection, milling by blades, and sieving using the 100 mesh/bottom according to the Tyler series. Their physicochemical, thermal, and structural characterization made it possible to identify the lower presence of lignin and higher proportions of cellulose and pectin in FFCH. Based on the properties identified in FFCH, it was included in the processing of thermoplastic starch (TPS) from the plantain pulp (Musa paradisiaca) and its respective bio-based composite material using plantain peel short fiber (PPSF) as a reinforcing agent using the following sequence of processing techniques: extrusion, internal mixing, and compression molding. The influence of FFCH contributed to the increase in ultimate tensile strength (7.59 MPa) and higher matrix-reinforcement interaction when obtaining the freshly processed composite material (day 0) when compared to the bio-based composite material with higher FCP content (30%) in the absence of FFCH. As for the disadvantages of FFCH, reduced thermal stability (323.57 to 300.47 °C) and losses in ultimate tensile strength (0.73 MPa) and modulus of elasticity (142.53 to 26.17 MPa) during storage progress were identified. In the case of TPS, the strengthening action of FFCH was not evident. Finally, the use of CFCH was not considered for the elaboration of the bio-based composite material because it reached a higher lignin content than FFCH, which was expected to decrease its affinity with the TPS matrix, resulting in lower mechanical properties in the material.

18.
Materials (Basel) ; 17(12)2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38930413

ABSTRACT

Sulfuric acid anodizing assisted by a hydrothermal sealing with inhibitors [Ce3+-Mo6+] was used to prevent pitting corrosion on spray-deposited hypereutectic Al-Si alloy (A390). An investigation concerning the evaluation of pitting corrosion resistance on the anodic oxide thin film with ions incorporated was carried out in NaCl solution using electrochemical measurements (i.e., potentiodynamic polarization and electrochemical impedance spectroscopy, EIS). The influence of Si phase morphology and size on the growth mechanism of an anodic oxide film was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results were then compared with those for its equivalent IM390 alloy (Al-17Si-4.5Cu-0.6Mg) produced through a conventional process ingot metallurgy, IM. The electrochemical findings indicate that sulfuric acid anodizing followed by a simple hot water sealing treatment was ineffective. In this manner, an intense attack was localized by pitting corrosion that occurred on the anodic oxide film in less than three days, as denoted by characteristic changes in the EIS spectra at the lowest frequencies. Improved results were achieved for Ce-Mo surface modification, which can provide better corrosion resistance on the aluminum alloys because no signs of pits were observed during the corrosion testing.

19.
Plants (Basel) ; 13(9)2024 May 02.
Article in English | MEDLINE | ID: mdl-38732483

ABSTRACT

The current investigation aims to underline the impact of salicylic acid or calcium chloride seed pre-treatments on mineral status and oxidative stress markers, namely levels of electrolyte leakage (EL) and lipid peroxidation levels, measured as thiobarbituric reactive substances (TBARS), and the activity of some antioxidant enzymes in roots and leaves of plants in two barley species grown under various salt treatments. Overall, our results revealed that salinity inhibits essential nutrient absorption such as iron, calcium, magnesium and potassium and stimulates the absorption of sodium. Also, this environmental constraint induced oxidative stress in plants in comparison with the control conditions. This state of oxidative stress is reflected by an increase in TBARS content as well as the stimulation of EL values. In addition, salinity induced disturbances in the activity of antioxidant enzymes, which were mainly dependent on the applied salt concentration and the species. In addition, Hordeum marinum maintained high antioxidant enzyme activity and low levels of oxidative stress parameters, which reinforces its salt-tolerant character. Importantly, salicylic acid or calcium chloride seed priming alleviated the mineral imbalance and the oxidative damage induced by salinity. Moreover, seed priming improves iron, calcium magnesium and potassium content and limitsthe accumulation of sodium. Also, both treatments not only decrease TBARS levels and limit EL, but they also stimulate the antioxidant enzyme activities in the leaves and roots of the stressed plants as compared with stressed plants grown from non-primed seeds. Interestingly, the beneficial effects of the mentioned treatments were more notable on Hordeum vulgare species.

20.
ACS Catal ; 14(9): 6897-6914, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38737398

ABSTRACT

A family of 4,4'-tBu2-2,2'-bipyridine (tBubpy) ligands with substituents in either the 6-position, 4,4'-tBu2-6-Me-bpy (tBubpyMe), or 6 and 6'-positions, 4,4'-tBu2-6,6'-R2-bpy (tBubpyR2; R = Me, iPr, sBu, Ph, or Mes), was synthesized. These ligands were used to prepare Ni complexes in the 0, I, and II oxidation states. We observed that the substituents in the 6 and 6'-positions of the tBubpy ligand impact the properties of the Ni complexes. For example, bulkier substituents in the 6,6'-positions of tBubpy better stabilized (tBubpyR2)NiICl species and resulted in cleaner reduction from (tBubpyR2)NiIICl2. However, bulkier substituents hindered or prevented coordination of tBubpyR2 ligands to Ni0(cod)2. In addition, by using complexes of the type (tBubpyMe)NiCl2 and (tBubpyR2)NiCl2 as precatalysts for different XEC reactions, we demonstrated that the 6 or 6,6' substituents lead to major differences in catalytic performance. Specifically, while (tBubpyMe)NiIICl2 is one of the most active catalysts reported to date for XEC and can facilitate XEC reactions at room temperature, lower turnover frequencies were observed for catalysts containing tBubpyR2 ligands. A detailed study on the catalytic intermediates (tBubpy)Ni(Ar)I and (tBubpyMe2)Ni(Ar)I revealed several factors that likely contributed to the differences in catalytic activity. For example, whereas complexes of the type (tBubpy)Ni(Ar)I are low spin and relatively stable, complexes of the type (tBubpyMe2)Ni(Ar)I are high-spin and less stable. Further, (tBubpyMe2)Ni(Ar)I captures primary and benzylic alkyl radicals more slowly than (tBubpy)Ni(Ar)I, consistent with the lower activity of the former in catalysis. Our findings will assist in the design of tailor-made ligands for Ni-catalyzed transformations.

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