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Polymers Jun 2024The freeze-drying of biopolymers presents a fresh option with greater potential for application in soil subgrade stabilization. A freeze-dried combination of β-glucan...
The freeze-drying of biopolymers presents a fresh option with greater potential for application in soil subgrade stabilization. A freeze-dried combination of β-glucan (BG) and γ-poly-glutamic acid (GPA) biopolymers was used to treat low compressible clay (CL) and low compressible silt (ML) soils in dosages of 0.5%, 1%, 1.5%, and 2%. The California bearing ratio (CBR) test for the treated specimens was performed under three curing conditions: (i) thermal curing at 60 °C, (ii) air-curing for seven days followed by submergence for 4 days, and (iii) no curing, i.e., tested immediately after mixing. To investigate the influence of shear strength on the freeze-dried biopolymer-stabilized soil specimens and their variations with aging, unconfined compressive strength (UCS) tests were conducted after thermal curing at 60 °C for 3 days, 7 days, and 7 days of thermal curing followed by 21 days of air curing. The maximum CBR of 125.3% was observed for thermally cured CL and a minimum CBR of 6.1% was observed under soaked curing conditions for ML soils. Scanning electron microscopy (SEM), infrared spectroscopy, average particle size, permeability, and adsorption tests revealed the pore filling, biopolymer adsorption and coating on the soil surface, and agglomeration of the soil along with the presence of hydrogen bonds, covalent amide bonds, and Van der Waals forces that contributed to the stiffening of the stabilized soil. Using three-dimensional (3D) finite element analysis (FEA) and layered elastic analysis (LEA), a mechanistic-empirical pavement design was carried out for the stabilized soil and a design thickness catalog was prepared for the maximum CBR. The cost reductions for a 1 km section of the pavement were expected to be 12.5%.
PubMed: 38891532
DOI: 10.3390/polym16111586 -
Marine Drugs Jul 2023The macroalga could be a sustainable and nutritional food resource. However, its composition may vary according to its environment and to processing methods used. To...
The macroalga could be a sustainable and nutritional food resource. However, its composition may vary according to its environment and to processing methods used. To investigate these variations, wild from Quebec were harvested in October 2019 and June 2020, and dried (40 °C, ≃5 h) or stored as frozen controls (-80 °C). The chemical (lipids, proteins, ash, carbohydrates, fibers), mineral (I, K, Na, Ca, Mg, Fe), potential bioactive compound (carotenoids, polyphenols, β-carotene, α-tocopherol) compositions, and the in vitro antioxidant activity and angiotensin-converting enzyme (ACE) inhibition potential of water-soluble extracts were determined. The results suggested a more favorable macroalgae composition in June with a higher content of most nutrients, minerals, and bioactive compounds. October specimens were richer only in carbohydrates and carotenoids. No significant differences in antioxidant or anti-ACE inhibitory activities were found between the two harvest months. The drying process did not significantly impact the chemical and mineral compositions, resulting in only small variations. However, drying had negative impacts on polyphenols and anti-ACE activities in June, and on carotenoids in October. In addition, a concentration effect was observed for carotenoids, β-carotene and α-tocopherol in June. To provide macroalgae of the highest nutritional quality, the drying process for June specimens should be selected.
Topics: alpha-Tocopherol; beta Carotene; Rhodophyta; Antioxidants; Seaweed; Carotenoids; Carbohydrates; Polyphenols
PubMed: 37504923
DOI: 10.3390/md21070392 -
Polymers Sep 2023The degradability of the biocomposite produced from a binary mixture of thermoplastic banana starch (TPS) and polycaprolactone (PCL) reinforced with fique fibers (Fs)...
The degradability of the biocomposite produced from a binary mixture of thermoplastic banana starch (TPS) and polycaprolactone (PCL) reinforced with fique fibers (Fs) was evaluated in three different environments (soil, compost, water). An experimental design with two factors (soil and compost) and three levels (5, 10, and 20 cm) was used, with additional tests for a third aqueous environment (water from the lake of the Universidad del Valle) at a depth of 20 cm. The biocomposite was prepared from the implementation of a twin-screw extrusion process of the binary mixture TPS/PCL and fique fibers (54, 36, and 10% composition, respectively), followed by hot compression molding, and after that, generating ASTM D638 type V specimens using a stainless-steel die. The specimens were dried and buried according to the experimental design, for a total experimental time of 90 days, and removing samples every 30 days. After 90 days, all samples showed signs of degradation, where the best results were obtained in the compost at a depth of 20 cm (34 ± 4% mass loss and a decrease in tensile strength of 77.3%, which indicates that the material lost mechanical properties). TPS was the fastest disappearing component and promoted the degradation of the composite material as it disappeared. Finally, the aqueous media presented the lowest degradation results, losing only 20% of its initial mass after 90 days of the experiment, being the least effective environment in which the biocomposite can end up.
PubMed: 37836001
DOI: 10.3390/polym15193952 -
Malaria Journal Dec 2023In many studies to evaluate the quality of malaria diagnosis, microscopy or rapid diagnostic tests (RDT) are compared to PCR. Depending on the method for sample...
In many studies to evaluate the quality of malaria diagnosis, microscopy or rapid diagnostic tests (RDT) are compared to PCR. Depending on the method for sample collection and storage (whole blood or dried blood spot), volume of blood used for extraction, volume of DNA used as PCR template, and choice of PCR target (single vs. multi-copy gene), the limit of detection (LOD) of PCR might not exceed the LOD of expert microscopy or RDT. One should not assume that PCR always detects the highest number of infections.
Topics: Humans; Malaria; Polymerase Chain Reaction; Limit of Detection; Specimen Handling; Microscopy; Diagnostic Tests, Routine; Malaria, Falciparum; Plasmodium falciparum; Sensitivity and Specificity
PubMed: 38102649
DOI: 10.1186/s12936-023-04822-w -
Polymers Sep 2023A composite of polymer blends-thermoplastic polyurethane (TPU) and poly(lactic acid) (PLA)-and BaTiO-SiC was fabricated. BaTiO particles were used to improve the...
Enhancing Dielectric Properties, Thermal Conductivity, and Mechanical Properties of Poly(lactic acid)-Thermoplastic Polyurethane Blend Composites by Using a SiC-BaTiO Hybrid Filler.
A composite of polymer blends-thermoplastic polyurethane (TPU) and poly(lactic acid) (PLA)-and BaTiO-SiC was fabricated. BaTiO particles were used to improve the dielectric properties of the composite materials, whereas SiC was used to enhance thermal conductivity without altering the dielectric properties; notably, SiC has a good dielectric constant. The surfaces of the filler particles, BaTiO and SiC particles, were activated; BaTiO was treated with methylene diphenyl diisocyanate (MDI) and SiC's surface was subjected to calcination and acid treatment, and hybrid fillers were prepared via solution mixing. The surface modifications were verified using Fourier transform infrared spectroscopy (the appearance of OH showed acid treatment of SiC, and the presence of NH, CH, and OH groups indicated the functionalization of BaTiO particles). After the extruded products were cooled and dried, the specimens were fabricated using minimolding. The thermal stability of the final composites showed improvement. The dielectric constant improved relative to the main matrix at constant and variable frequencies, being about fivefold for 40% BaTiO-SiC-TPU-PLA composites. Upon inclusion of 40 wt.% MDI functionalized BaTiO-SiC particles, an improvement of 232% in thermal conductivity was attained, in comparison to neat TPU-PLA blends.
PubMed: 37765588
DOI: 10.3390/polym15183735 -
Italian Journal of Food Safety May 2024The aim of this work is the description and characterization of a severe microsporidian infection in a batch of salted and dried cod. Particularly, the case involves a...
The aim of this work is the description and characterization of a severe microsporidian infection in a batch of salted and dried cod. Particularly, the case involves a batch of approximately 800 kg obtained from (Food and Agriculture Organization Zone 61 - Northwest Pacific Ocean), which, after rehydration and sectioning operations, underwent routine company checks before packaging. In about 20% of the samples, the presence of whitish nodules with a diameter ranging from 1 to 2 mm was observed on the surface of the fillets and in cross-section. The lesions ranged from a few units to 10 per cm. Some samples were subjected to fresh microscopic observation with the stereomicroscope, confirming the nodular nature of the lesions, which were often confluent, alternating with empty spaces, giving the tissue a honeycombing aspect. The histological examination at low magnification allowed us to observe the heavy vacuolization of nodular lesions irregularly surrounded by a spongy-like wall. The observation at higher magnification of other sections allowed us to identify intra-myofibrillar cists containing presumptive microsporidian elements. The tissue damage derived from the technological processes and gravity of lesions did not allow a morphological characterization of presumptive protozoans. The molecular examination of the nodular lesions and the analysis of the sequence of an 897 bp fragment of the small subunit 16S rRNA revealed 100% identity with (GenBank accession number MT928885-89) first isolated from the skeletal muscles of specimens from the Sea of Okhotsk. This finding confirms the importance of selecting suppliers and raw materials in the seafood industry, as well as the usefulness of an effective traceability system.
PubMed: 38887589
DOI: 10.4081/ijfs.2024.12333 -
International Journal of Clinical... Aug 2023To compare the effect of salivary contamination on the shear bond strength (SBS) of seventh- and eighth-generation adhesives.
AIM
To compare the effect of salivary contamination on the shear bond strength (SBS) of seventh- and eighth-generation adhesives.
MATERIALS AND METHODS
Specimens were randomly divided into group I and group II, subdivided into three subgroups of 11 samples. Subgroup IA-seventh-generation uncontaminated (control); adhesive; air-dried; light cured. Subgroup IB-seventh-generation adhesive; saliva application, air-dried; light cured. Subgroup IC-seventh-generation adhesive; saliva application, air-dried, reapplication of adhesive, air-dried, light cured. Subgroup IIA- eighth-generation uncontaminated (control); adhesive, air-dried; light cured. Subgroup IIB- eighth-generation adhesive; saliva application, air-dried; light cured. Subgroup IIC-eighth-generation adhesive, saliva application, air-dried, reapplication of adhesive, air-dried; light cured. Following bonding procedure, composite resin restoration was done and subjected to SBS analysis.
RESULTS
Mean SBS of eighth-generation adhesive was higher compared to seventh with and without saliva contamination. Reduction of SBS in seventh- and eighth-generation after saliva contamination was regained by reapplication of adhesive, which was less compared to the control [statistically significant ( < 0.05) for seventh and statistically not significant for eighth-generations].
CONCLUSION
The eighth-generation adhesives show better SBS with and without saliva contamination and reapplication of eighth-generation adhesives significantly improved the SBS close to the control.
CLINICAL SIGNIFICANCE
Single-step self-etch adhesives are the adhesives which are currently used for bonding composite restorations to dentin. The adhesive bond strength can be adversely affected by moisture contamination, especially by saliva, which can lead to failure of restoration. So, it is imperative to study a material which gives better bond strength and is less affected by salivary contamination and effect of decontamination to regain the bond strength. The study concluded that eighth-generation adhesives showed higher mean SBS with and without saliva contamination and reapplication of eighth-generation adhesives significantly improved the bond strength close to the control group.
HOW TO CITE THIS ARTICLE
Mohan MC, Geetha P, Soman D, The Effect of Salivary Contamination on the Shear Bond Strength of Seventh- and Eighth-generation Adhesive Systems. Int J Clin Pediatr Dent 2023;16(S-1):S63-S66.
PubMed: 37663220
DOI: 10.5005/jp-journals-10005-2587 -
Cureus Nov 2023Silver nanoparticles (AgNPs) are considered to be a very significant and intriguing type within the category of metallic nanoparticles, particularly in the context of...
AIM
Silver nanoparticles (AgNPs) are considered to be a very significant and intriguing type within the category of metallic nanoparticles, particularly in the context of their involvement in biological applications. The objective of this research is to use the green synthesis method in order to synthesize AgNPs by using the leaf extract of . Furthermore, the study aims to evaluate the antioxidant and anti-inflammatory properties of these nanoparticles.
MATERIALS AND METHODS
Fresh and healthy specimens of were gathered from Palk Bay, Tamil Nadu, India, and afterward subjected to a thorough washing process using tap water. The cleaned materials were air-dried and then fragmented into small bits and finely ground. The ethanolic extract of seagrass was then combined with a solution containing 1 millimolar (mM) silver nitrate (AgNo). The decrease of silver ions in the solution was frequently measured using a UV-visible spectrophotometer. Synthesized AgNPs were investigated for antioxidants by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay and anti-inflammatory activity was measured by protein-denaturation assay.
RESULTS
The use of leaf extract in the green synthesis of AgNPs, in the presence of 1 mM AgNO, led to a noticeable alteration in the colour of the mixture, transitioning from a pale hue to a brown shade. This change in colour serves as evidence of the reduction of AgNo ions to silver ions, thereby facilitating the creation of AgNPs. The duration of the bio-reduction process of silver ions in the reaction mixture was observed to be two hours. The antioxidant and anti-inflammatory activity showed promising activity for AgNPs.
CONCLUSION
This study concluded that had antioxidant capabilities, and AgNPs derived from have potential use in pharmaceuticals and medication administration.
PubMed: 38143665
DOI: 10.7759/cureus.49316 -
American Journal of Human Biology : the... Feb 2024The Health and Retirement Study (HRS) has collected biomarker data over multiple waves. Such data can help improve our understanding of health changes in individuals and...
INTRODUCTION
The Health and Retirement Study (HRS) has collected biomarker data over multiple waves. Such data can help improve our understanding of health changes in individuals and the causal pathways related to health. There are, however, technical challenges to using the HRS dried blood spots (DBS) biomarker data due to changes over time in assay protocols, platforms, and laboratories. We provide technical and summary information on biological indicators collected as part of the HRS from 2006 to 2016 that should be helpful to users of the data.
METHODS
We describe the opportunities and challenges provided by the HRS DBS data as well as insights provided by the data. The HRS collected DBS from its nationally representative sample of respondents 51 years of age or older from 2006 to 2016. DBS-based biomarkers were collected from half the sample in 2006, 2010, and 2014, and from the other half of the sample in 2008, 2012, and 2016. These DBS specimens were used to assay total and HDL cholesterol, glycosylated hemoglobin, C-reactive protein, and cystatin C from 2006 to 2016, and Interleukin 6 was added in 2014/2016. Samples included approximately 6000 individuals at each wave, and completion rates ranged from 81% to 90%. HRS transformed DBS values into venous blood equivalents to make them more comparable to those of the whole blood-based assays collected in most other studies and to facilitate longitudinal analysis.
RESULTS
Distribution of changes over time by age shows that total cholesterol levels decreased for each age, while HbA1c levels increased. Cystatin C shows a clear age gradient, but a number of other markers do not. Non-Hispanic Black persons and Hispanic respondents have a higher incidence of risk levels of each biomarker except for CRP among non-Hispanic Black older persons.
CONCLUSION
These public-use DBS data provide analysis opportunities that can be used to improve our understanding of health change with age in both populations and among individuals.
Topics: Humans; Aged; Aged, 80 and over; Cystatin C; Retirement; Dried Blood Spot Testing; Biomarkers; C-Reactive Protein
PubMed: 37803815
DOI: 10.1002/ajhb.23997 -
Saudi Journal of Biological Sciences Feb 2024Seahorses, part of the small marine teleost fish family , are increasingly under threat due to habitat degradation and overfishing. Notably used in traditional Chinese...
Seahorses, part of the small marine teleost fish family , are increasingly under threat due to habitat degradation and overfishing. Notably used in traditional Chinese medicine, these fish have demonstrated significant pharmacological and cosmetic properties. In Morocco, however, seahorses are minimally exploited. This study aims to explore the biodiversity of Moroccan seahorses, focusing on identifying species from the Atlantic and Mediterranean coasts both morphologically and molecularly, and evaluating their antioxidant activity. The research involved collecting 62 dried seahorses from local fishermen. These specimens were subjected to detailed morphological and molecular identification through the DNA barcoding method, concentrating on the mitochondrial marker Cytochrome Oxidase I (COI) gene. Following DNA extraction and amplification, the sequences were analyzed for species identification and phylogenetic relationships. Additionally, the antioxidant activities of the seahorses were quantified using assays such as ABTS, reducing power, phosphomolybdenum, and β-carotene-linoleic acid. The combined morphological and molecular analyses consistently identified all specimens as , and phylogenetic trees suggested a close relation with European and Turkish counterparts. Furthermore, the antioxidant assays revealed significant activity, with the ABTS assay showing an IC50 of 14.571 mg/mL ± 0.334, and the β-carotene-linoleic acid assay showing an IC50 of 1.273 mg/mL ± 0.166. The reducing power and phosphomolybdenum assays recorded EC50 values of 1.868 mg/mL ± 0.033 and 1.156 mg/mL ± 0.112, respectively. These results confirm the high antioxidant potential of Moroccan seahorses, suggesting their therapeutic value and necessitating measures for their biodiversity preservation at a national level.
PubMed: 38188538
DOI: 10.1016/j.sjbs.2023.103898