Citric acid incorporated in a chitosan film as an active packaging material to improve the quality and duration of matured cheese shelf life.

Chitosan-based film incorporated with citric acid was prepared by the casting method for application in a Brazilian matured cheese. Three formulations of cheese were processed, with the intention of evaluating the application of a starter culture and the effect of the film in terms of its physiochemical, microbiological, and sensorial characteristics. It was observed by scanning electron microscopy (sem) analysis that the film has a homogeneous appearance, and the crosslinking between citric acid and chitosan was confirmed by the Fourier transform infrared spectroscopy (FTIR) analysis. The cheese with chitosan-based film presented lower weight loss (5.2%) and showed antimicrobial activity against aerobic mesophilic bacteria. All samples showed high rates of sensorial acceptability (>79%), with no significant differences between them. It is apparent that the chitosan film maintained the typical cheese characteristics. Therefore, chitosan and citric acid film can be used to improve the characteristics of matured cheese and extend its shelf life.

Effect of green tea extract on gelatin-based films incorporated with lemon essential oil.

The use of natural polymers, such as gelatin and other proteins, has increased in an attempt to replace part of the consumption of petroleum-based packaging. This study evaluated the influence of green tea extract and lemon nanoemulsion on mechanical, thermal and permeability properties of gelatin matrix. The results showed that green tea increased the gelatin tensile strength (TS) from 86 ± 7 MPa to 101 ± 5 MPa, on the other hand, the nanoemulsion decreases to 78 ± 8 MPa. The incorporation of green tea and nanoemulsion enhanced the water vapor permeability of gelatin film; this could be due to the interacting with the hydrophobic domains of gelatin. This was indicated by melting point (Tm) in differential scanning calorimetry (DSC) and degradation temperatures in the thermogravimetric analysis (TG), respectively. Changes in FTIR spectra of gelatin film were observed when the green tea and nanoemulsion were incorporated. Therefore, this study showed a new characterization and formulation of gelatin films incorporated by green tea extract and lemon nanoemulsion and their potential for edible film.

Estimated prevalence of moderate to severely elevated total homocysteine levels in the United States: A missed opportunity for diagnosis of homocystinuria?

Classical homocystinuria (HCU) is a genetic disorder caused by mutations in the cystathionine beta synthase gene, which results in impaired metabolism of the sulfur-bearing amino acid homocysteine and its accumulation in blood and tissues. Classical HCU can be detected via newborn screening in the United States, but the test is widely acknowledged to miss many patients. While severely elevated homocysteine levels (>100 µmol /L) frequently lead to a classical HCU diagnosis, intermediate levels (>30 to 100 µmol /L), though linked to many of the known complications of HCU, are not always recognized as associated with HCU. We aimed to identify and describe potentially undiagnosed classical HCU patients using a nationally-representative database of administrative claims and laboratory results. We estimated the national prevalence of patients with homocysteine >30 µmol /L, and compared their demographic and clinical characteristics to those of patients with homocysteine levels ≤30 µmol/L. Among 57,580 patients with a homocysteine test result, 1.8% had a value >30 µmol /L. Patients with homocysteine >30 µmol /L were more frequently diagnosed with hypothyroidism (39.2% vs. 20.7%, p < .001) and renal disease (9.7% vs. 5.5%, p < .001), and were more likely to have a prescription for an anxiolytic/antidepressant (44.5% vs. 38.9%), opioid (58.4% vs. 53.1%), steroid (46.4% vs. 42.5%), or thyroid hormone (38.8% vs. 18.8%), compared to patients with homocysteine ≤30 µmol /L (all p < .05). Both groups were equally likely to have a diagnosis of homocystinuria or another disorder of sulfur-bearing amino acid metabolism (3.8% vs. 4.0%, p = .752). The age-adjusted national prevalence of homocysteine >30 µmol /L was estimated at 33,068 (95% CI: 1033 - 35,104). These findings suggest that thousands of people in the US may be living with intermediate to severely elevated homocysteine levels and may require further evaluation for the presence of classical HCU.

Spatio-temporal dynamics of Aedes aegypti and Aedes albopictus oviposition in an urban area of northeastern Brazil.

OBJECTIVE: The objective of this study was to analyse abundance and spatial distribution of Aedes aegypti and Aedes albopictus oviposition in the city of Natal-RN, 2016 to 2018. METHODS: Three hundred and seven oviposition traps were installed covered the whole city and were monitored weekly from January 2016 to December 2018. To verify the abundance of the vector based on its location, the formation of oviposition clusters was studied using the Kernel statistics. Egg Density Index (EDI) and Oviposition Positivity Index (OPI) values were calculated. RESULTS: Temperature and humidity presented weak and very weak correlation, respectively, with the oviposition indicators. The median of oviposition positivity index (OPI) was 60.5%, and the egg density index (EDI) was 45.4 eggs/trap. The OPI (71.1%) was higher in the second quarter of the year. The areas with the most persistent oviposition are located in a continuous strip that extends from the extreme of the northern district and extends along the western district of the city. Also noteworthy is the proximity to the strategic points. CONCLUSION: The spatio-temporal distribution of oviposition revealed that there is spatial segregation and marked seasonality. Therefore, this study highlights the importance of maintaining surveillance targeting and control strategies focused on these areas, especially during the most important period of the year.

OBJECTIF: L'objectif de cette étude était d'analyser l'abondance et la distribution spatiale de la ponte d'Aedes aegypti et d'Aedes albopictus dans la ville de Natal-RN, de 2016 à 2018. MÉTHODES: 307 pièges de ponte ont été installés dans toute la ville et surveillés chaque semaine de janvier 2016 à décembre 2018. Pour vérifier l'abondance du vecteur en fonction de sa localisation, la formation de grappes de ponte a été étudiée à l'aide des statistiques de Kernel. Les valeurs de l'indice de densité des œufs (IDO) et de l'indice de positivité de la ponte(IPP) ont été calculées. RÉSULTATS: La température et l'humidité ont présenté une corrélation faible et très faible, respectivement, avec les indicateurs de ponte. L'indice médian de positivité de ponte (IPP) était de 60,5% et l'indice de densité des œufs (IDO) était de 45,4 œufs/piège. L'IPP (71,1%) était plus élevé au deuxième trimestre de l'année. Les zones avec la ponte la plus persistante sont situées dans une bande continue qui s'étend de l'extrémité du district nord et s'étend le long du district ouest de la ville. A noter également la proximité des points stratégiques. CONCLUSIONS: La distribution spatiotemporelle de la ponte a révélé une ségrégation spatiale et une saisonnalité marquée. Par conséquent, cette étude met en évidence l'importance de maintenir des stratégies de surveillance ciblée et de contrôle axés sur ces zones, en particulier pendant la période la plus importante de l'année.

Prevalence, characteristics, and costs of diagnosed homocystinuria, elevated homocysteine, and phenylketonuria in the United States: a retrospective claims-based comparison.

BACKGROUND: Classical homocystinuria (HCU), an inborn error of homocysteine metabolism, has previously been estimated to affect approximately 1 in 100,000-200,000 people in the United States (US). HCU is poorly detected by newborn screening, resulting in underestimates of its prevalence. This study compared characteristics, healthcare use and costs, and projected prevalence between patients with diagnosed HCU, elevated total homocysteine (tHcy), and diagnosed phenylketonuria (PKU). METHODS: Patients in the MarketScan® Research Databases were identified with strictly-defined HCU (> 2 diagnoses, including 1 ICD-10), broadly-defined HCU (> 1 ICD-10), elevated tHcy (> 20 µmol/L) without an HCU diagnosis, or > 1 ICD-9/ICD-10 PKU diagnosis during 1/1/2010-12/31/2016 (first qualifying claim = index). Demographics and healthcare utilization and costs per patient per month (PPPM) were compared between all cohorts, frequencies of comorbidities and medications were compared between HCU and elevated tHcy patients, and healthcare provider types were assessed among HCU patients. The prevalence of patients meeting each cohort definition was projected to the United States (US) population. RESULTS: Patients with strictly-defined (N = 2450) and broadly-defined (N = 6613) HCU, and with elevated tHcy (N = 2017), were significantly older than PKU patients (N = 5120) (57 vs. 56 vs. 53 vs. 18 years; p < 0.05). Vitamin D deficiency, hyperlipidemia, folic acid/B vitamins, and lipid-lowering medications, among others, were more common among diagnosed HCU patients vs. those with elevated tHcy (all p < 0.05). Rates of healthcare utilization were generally higher among HCU and elevated tHcy patients, compared to PKU, though total healthcare costs were similar between groups. Most HCU patients (~ 38%) received their index diagnosis from a primary care physician; very few (~ 1%) had any claim from a geneticist during their enrollment. The age-adjusted national prevalence of HCU was projected at 31,162 (95% CI: 30,411 - 31,913; ~ 1 in 10,000 of the US population) using the broad definition. CONCLUSIONS: The actual prevalence of HCU may be > 10 times prior estimates, at 1 in 10,000 in the US, and this study suggests that HCU is not being diagnosed until later in life. Improvements to newborn screening, detection in young children, and physician education regarding HCU among patients may be necessary to alleviate the burden of this genetic disease.

Water Absorption and Physicochemical Characterization of Novel Zeolite-PMAA-co-PAAm Nanocomposites.

The growth in global population has caused an increase in the demand for food production, leading to an increase in the use of agrochemicals. Their overuse causes serious damage to the environment. In this way, nanocomposite hydrogels are promising materials for use as carrier vehicles for the controlled release of agrochemicals, which helps reduce the damage caused by their indiscriminate use. In this work, a novel hydrogel nanostructure based on carboxymethylcellulose (CMC) and zeolite with a poly(methacrylic acid)-co-polyacrylamide (PMAA-co-PAAm) support network was synthesized. The CMC polysaccharide increased the zeolite stability in the solution. Increasing the concentration of acrylamide (AAm) monomer improved the mechanical stability of the nanocomposites. FTIR, XRD and TG results confirmed the presence of zeolite in the PMAA-co-PAAm matrices. In addition, the zeolite decreased the water absorption of the nanocomposites from 33 ± 2 g/g to approximately 22 ± 1 g/g, but increased the thermal stability of the nanocomposites. However, the reduction in water absorption in saline solutions was more significant in hydrogels without zeolite. Fertilizer desorption studies confirmed the controlled release behavior and this trend may be improved by zeolite structure. Thus, the presence of zeolite increased the amount of monobasic potassium phosphate (KH2PO4) release from 250 to 275 mg of fertilizer per gram of hydrogel. Controlling the water absorption and kinetic properties by adjusting the nanocomposite constituents may increase the applicability of the composites in agriculture, specifically as carrier vehicles in the controlled release of agrochemicals.

Hybrid Biodegradable Hydrogels Obtained from Nanoclay and Carboxymethylcellulose Polysaccharide: Hydrophilic, Kinetic, Spectroscopic and Morphological Properties.

In this paper, series of novel nanocomposite hydrogels based on polyacrylamide (PAAm), carboxymethylcellulose (CMC) and nanoclay were synthesized. Hydrophilic, kinetic, spectroscopic and morphological properties were investigated as function of their constituents. Spectroscopic properties confirmed the obtaining of the nanocomposites. It was also observed that the nanocomposites have walls of pores with a more rugged morphology compared with the morphology of the hydrogel without clay, contributing to repel the water molecules. Besides, the results showed that the velocity and quantity of water uptake may be controlled by adjusting of matrix rigidity, i.e., nanoclay content into polymeric matrix. This behavior is required to future application in agriculture fields, specifically as carrier vehicle in controlled release of agrochemicals. Thus, these nanocomposites have technological application.

Recent Advances on Edible Films Based on Fruits and Vegetables-A Review.

Food packaging materials are traditionally expected to contain foodstuffs and protect them from deteriorating agents. Although petroleum-derived polymers have been widely used for this purpose, the rising concern with their nonrenewable and/or nonbiodegradable nature paves the route for the development of greener alternatives, including polysaccharides and polypeptides. The use of these food-grade biomacromolecules, in addition to fruits and vegetables, provides edible packaging with suitable physical-mechanical properties as well as unique sensory and nutritional characteristics. This text reviews the chronological development pathway of films based on fruit and vegetable purees, pomaces, and extracts. Recent advances are extensively reviewed with an emphasis on the role that each film component plays in the resulting materials, whose production methods are examined from a technical standpoint and essential properties are compiled and contrasted to their conventional, synthetic counterparts. Finally, this comprehensive review discusses advantages and limitations of edible films based on fruits and vegetables.

Cytotoxic and genotoxic effects of silver nanoparticle/carboxymethyl cellulose on Allium cepa.

Several mutagenic agents may be present in substances released in the environment, which may cause serious environmental impacts. Among these substances, there is a special concern regarding the widespread use of silver nanoparticles (AgNP) in several products due to their widely known bactericidal properties, including in the medical field and the food industry (e.g., active packaging). The assessment of the effects of AgNP released in the environment, having different concentrations, sizes, and being associated or not to other types of materials, including polymers, is therefore essential. In this research, the objective was to evaluate the genotoxic and cytotoxic effects of AgNP (size range between 2 and 8 nm) on root meristematic cells of Allium cepa (A. cepa). Tests were carried out in the presence of colloidal solution of AgNP and AgNP mixed with carboxymethylcellulose (CMC), using distinct concentrations of AgNP. As a result, when compared to control samples, AgNP induced a mitotic index decrease and an increase of chromosomal aberration number for two studied concentrations. When AgNP was in the presence of CMC, no cytotoxic potential was verified, but only the genotoxic potential for AgNP dispersion having concentration of 12.4 ppm.

New Edible Bionanocomposite Prepared by Pectin and Clove Essential Oil Nanoemulsions.

Nanocomposites are being extremely investigated to provide packaging with interesting characteristics for packages. Because of essential oils' natural occurrence and antibacterial activity, they are considered as an alternative for synthetic additives in the food industry. In this paper, we studied an edible bionanocomposite film made up of pectin and clove essential oil nanoemulsion for application as edible package. Mechanical properties, water vapor permeability (WVP), and antibacterial activity were analyzed. From mechanical and WVP analyses, we noticed an interesting improvement in film properties. In the antibacterial activity test, disk diffusion was used to assess the inhibition zones of Escherichia coli and Staphylococcus aureus. With these results, we concluded that the most interesting results were promoted by smaller nanodroplets (diameter of approximately 142 nm).

Evaluation of antimicrobial activity of silver nanoparticles for carboxymethylcellulose film applications in food packaging.

In this study, silver nanoparticles were prepared and incorporated into carboxymethylcellulose films to evaluate the antimicrobial activity for food packaging applications. The techniques carried out for material characterization were: infrared spectroscopy and thermal analysis for the silver nanoparticles and films, as well as particle size distribution for the nanoparticles and water vapor permeability for the films. The antimicrobial activity of silver nanoparticles prepared by casting method was investigated. The minimum inhibitory concentration (MIC) value of the silver nanoparticles to test Gram-positive (Enterococcus faecalis) and Gram-negative (Escherichia coli) microorganisms was carried out by the serial dilution technique, tested in triplicate to confirm the concentration used. The results were developed using the Mcfarland scale which indicates that the presence or absence of turbidity tube demonstrates the inhibition of bacteria in relation to the substance inoculated. It was found that the silver nanoparticles inhibited the growth of the tested microorganisms. The carboxymethylcellulose film embedded with silver nanoparticles showed the best antimicrobial effect against Gram-positive (E. faecalis) and Gram-negative (E. coli) bacteria (0.1 microg cm(-3)).

Development of New Edible Biodegradable Films Containing Camu-Camu and Agro-Industry Residue.

The use of edible films has garnered significant interest in the food and environmental sectors due to their potential to prevent food deterioration and their biodegradability. This study aimed to develop and characterize edible films based on camu-camu residue, gelatin, and glycerol, evaluating their solubility, thermal, degradability, antioxidant, and water vapor permeability properties of the gelatin matrix. This is the first study incorporating camu-camu into a gelatin and glycerol matrix. The films produced with camu-camu residue were manageable and soluble, with some non-soluble residues, providing a shiny and well-presented appearance. In the biodegradation results, samples 3 and 4 appeared to degrade the most, being two of the three most affected samples in the triplicate. The films showed degradation modifications from the third day of the experiment. In the germination and plant growth analysis, sample 4 exhibited satisfactory development compared to the other samples, emerging as the sample with the best overall result in the analyses, attributed to a 13.84 cm increase in the growth of the upper part of the seedling. These results indicate that the produced materials have potential for food packaging applications.

Clinical outcomes with biodegradable versus durable polymer drug-eluting stents in patients with ST-elevation myocardial infarction.

BACKGROUND: Coronary drug-eluting stents (DES) built with either durable (DP) or biodegradable (BP) polymeric coatings have been largely tested and are extensively available for routine use. However, their comparative performance remains an open question, particularly in more complex subsets of patients. AIMS: We evaluated the outcomes of patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI) using DP-DES versus BP-DES in a large multicenter real-world registry. METHODS: The population comprised patients with STEMI treated with pPCI within 12 h of symptoms onset. Those treated with more than one DES who received different polymer types were excluded. The final cohort for analysis was selected after propensity score matching (PSM), computed to generate similar groups of DP DES versus BP DES. Primary endpoint was the incidence of major adverse cardiac events (MACE), defined as the composite of total death, myocardial infarction and target lesion revascularization at 2 years. RESULTS: From January 2017 to April 2022, a total of 1527 STEMI patients underwent pPCI with a single DES type (587 DP-DES; 940 BP-DES). After PSM, 836 patients (418 patients in the DP-DES and 418 patients in the BP-DES groups), comprised the final study population. Both study groups had a similar baseline profile. Patients treated with BP-DES group had similar rates of MACE (15.3 % vs. 19.4 %, HR 0.69, 95 % CI 0.50-0.94, p = 0.022). Rates of target lesion revascularization was lower in BP DES group (0.7 % vs. 3.8 %, HR 0.17, 95 % CI 0.05-0.51, p = 0.006). CONCLUSION: In a cohort of STEMI patients submitted to pPCI, BP and DP DES had similar rates of the primary outcome. Patients treated with BP DES, however, had a decreased incidence of TLR at after 2-year follow-up.

Hybrid nanocomposites containing carboxymethylcellulose and silver nanoparticles.

Silver nanoparticles have high temperature stability and low volatility, and at the nanoscale are known to be an effective antifungal and antimicrobial agent. The present investigation involves the synthesis of silver nanoparticle/carboxymethylcellulose nanocomposites. The nanoparticles synthesised in this study had sizes in the range of 100 and 40 nm. The nanocomposites formed by a combination of metallic nanoparticles and carboxymethylcellulose were characterised by contact angle measurements, solubility tests, thermal and mechanical analyses, and morphological images. Improvements in the hydrophobic properties were observed with inclusion of the nanoparticles in the nanocomposites, with the best results occurring after the addition of 40 nm nanoparticles in a carboxymethylcellulose matrix. The silver nanoparticles tend to occupy the empty spaces in the pores of the carboxymethylcellulose matrix, inducing the collapse of these pores and thereby improving the tensile and barrier properties of the film.

Combining Chitosan Nanoparticles and Garlic Essential Oil as Additive Fillers to Produce Pectin-Based Nanocomposite Edible Films.

Edible films were produced by combining a pectin (PEC) matrix with chitosan nanopar-ticle (CSNP), polysorbate 80 (T80), and garlic essential oil (GEO) as an antimicrobial agent. CSNPs were analyzed for their size and stability, and the films, throughout their contact angle, scanning electron microscopy (SEM), mechanical and thermal properties, water vapor transmission rate, and antimicrobial activity. Four filming-forming suspensions were investigated: PGEO (control); PGEO@T80; PGEO@CSNP; PGEO@T80@CSNP. The compositions are included in the methodology. The average particle size was 317 nm, with the zeta potential reaching +21.4 mV, which indicated colloidal stability. The contact angle of the films exhibited values of 65°, 43°, 78°, and 64°, respec-tively. These values showed films with variations in hydrophilicity. In antimicrobial tests, the films containing GEO showed inhibition only by contact for S. aureus. For E. coli, the inhibition occurred in films containing CSNP and by direct contact in the culture. The results indicate a promising al-ternative for designing stable antimicrobial nanoparticles for application in novel food packaging. Although, it still shows some deficiencies in the mechanical properties, as demonstrated in the elongation data.

Real-World Assessment of an Ultrathin Strut, Sirolimus-Eluting Stent in Patients with ST-Elevation Myocardial Infarction Submitted to Primary Percutaneous Coronary Intervention (INSTEMI Registry). / Avaliação no Mundo Real de um Stent Eluidor de Sirolimus de Hastes Ultrafinas em Pacientes com Infarto do Miocárdio com Supradesnivelamento do Segmento ST Submetidos à Intervenção Coronária Percutânea Primária (Registro INSTEMI).

BACKGROUND: The current gold standard of coronary drug-eluting stents (DES) consists of metal alloys with thinner struts and bioresorbable polymers. OBJECTIVES: Our aim was to compare an ultrathin strut, sirolimus-eluting stent (Inspiron®) with other third-generation DES platforms in patients with ST-elevation myocardial infarction (STEMI) submitted to primary percutaneous coronary intervention (PCI). METHODS: We analyzed data from a STEMI multicenter registry from reference centers in the South Region of Brazil. All patients were submitted to primary PCI, either with Inspiron® or other second- or third-generation DES. Propensity score matching (PSM) was computed to generate similar groups (Inspiron® versus other stents) in relation to clinical and procedural characteristics. All hypothesis tests had a two-sided significance level of 0.05. RESULTS: From January 2017 to January 2021, 1711 patients underwent primary PCI, and 1417 patients met our entry criteria (709 patients in the Inspiron® group and 708 patients in the other second- or third-generation DES group). After PSM, the study sample was comprised of 706 patients (353 patients in the Inspiron® group and 353 patients in the other the other second- or third-generation DES group). The rates of target vessel revascularization (OR 0.52, CI 0.21 - 1.34, p = 0.173), stent thrombosis (OR 1.00, CI 0.29 - 3.48, p = 1.000), mortality (HR 0.724, CI 0.41 - 1.27, p = 0.257), and major cardiovascular outcomes (OR 1.170, CI 0.77 - 1.77, p = 0.526) were similar between groups after a median follow-up of 17 months. CONCLUSION: Our findings show that Inspiron® was effective and safe when compared to other second- or third-generation DES in a contemporary cohort of real-world STEMI patients submitted to primary PCI.

FUNDAMENTO: O padrão-ouro atual dos stents farmacológicos (SF) coronários consiste em ligas metálicas com hastes mais finas e polímeros bioabsorvíveis. OBJETIVOS: Nosso objetivo foi comparar um stent eluidor de sirolimus de hastes ultrafinas (Inspiron®) com outras plataformas de SF de terceira geração em pacientes com infarto do miocárdio com supradesnivelamento do segmento ST (IAMCSST) submetidos à intervenção coronária percutânea (ICP) primária. MÉTODOS: Analisamos dados de um registro multicêntrico de IAMCSST de centros de referência da Região Sul do Brasil. Todos os pacientes foram submetidos à ICP primária, seja com Inspiron® ou outro SF de segunda ou terceira geração. Foi calculado pareamento por escore de propensão (PEP) para gerar grupos semelhantes (Inspiron® versus outros stents) em relação às características clínicas e do procedimento. Todos os testes de hipótese tiveram um nível de significância bilateral de 0,05. RESULTADOS: De janeiro de 2017 a janeiro de 2021, 1.711 pacientes foram submetidos à ICP primária, e 1.417 pacientes preencheram nossos critérios de inclusão (709 pacientes no grupo Inspiron® e 708 pacientes no grupo dos outros SF de segunda ou terceira geração). Após PEP, a amostra do estudo foi composta por 706 pacientes (353 pacientes no grupo Inspiron® e 353 pacientes no grupo dos demais SF de segunda ou terceira geração). As taxas de revascularização do vaso alvo (odds ratio [OR] 0,52; intervalo de confiança [IC] 0,21 a 1,34; p = 0,173), trombose de stent (OR 1,00; IC 0,29 a 3,48;p = 1,000), mortalidade (hazard ratio 0,724; IC 0,41 a 1,27; p = 0,257) e os desfechos cardiovasculares maiores (OR 1,170; IC 0,77 a 1,77; p = 0,526) foram semelhantes entre os grupos após um acompanhamento mediano de 17 meses. CONCLUSÃO: Nossos achados mostram que o stent Inspiron® foi eficaz e seguro quando comparado a outros SF de segunda ou terceira geração em uma coorte contemporânea do mundo real de pacientes com IAMCSST submetidos à ICP primária.

Development of novel guava puree films containing chitosan nanoparticles.

One of the overall goals of industries is to use packages that do not cause environmental problems at disposal time, but that have the same properties as the conventional ones. The goal of this study is to synthesize edible films based on hydroxypropyl methylcellulose (HPMC) with guava puree and chitosan (CS) nanoparticles. This was divided into two stages, the first is the synthesis of chitosan nanoparticles and the second is the production of the films. For the nanoparticles, average size and zeta potential measurements were performed. The characterizations of mechanical and thermal properties, solubility and water vapor permeability tests were conducted in the films. It was observed that when the nanoparticles were added to HPMC and guava puree films, they improved their mechanical and thermal properties, as well as decreased the films solubility and permeability. The potential application of the films prepared would be in edible films with flavor and odor to extend the shelf life of products.

Synthesis, Application and Effect of Hybrid Nanocomposites Based on Hydrogel and Nanoclay in Cement-Mortars.

Hybrid nanocomposite hydrogels, as admixtures for internal curing of cementitious materials, have been widely studied. This study analyzes the effect of applying 0.5% (wt/wt cement) of pre-soaked hydrogels based on polyacrylamide, carboxymethylcellulose, and three different concentrations of Cloisite-Na+ (0, 10, and 20% wt/wt) on the fresh and hardened properties of cementitious mortars. In general, all mortars with hydrogel decreased the consistency index, mainly M20, due to the high concentration of Cloisite-Na+ that modifies the release kinect of the hydrogel. The results showed a slight variation, with an overall average value of 99% water retention in all mortars. This behavior is due to the portion of hydrogel-mortars dosage water retained to reduce the availability of free water in the mixture because this amount of water is stored, a priori, within the polymer particles. At 28 d, the mortars produced with hydrogels containing 20% of nanoclay (M20) exhibit mechanical behavior similar to the reference mortar (M), which corroborates the percentage of voids found. Scanning electron microscope images confirm that the M and M20 mortars are uniform and possess few pores or microcracks. Thus, these hybrid hydrogels have the potential to be innovative materials for water control improvements in cementitious materials technology.

Effect of corn stigma extract on physical and antioxidant properties of biodegradable and edible gelatin and corn starch films.

The development of bio-based food packaging with antioxidant properties is an important research topic and has gained prominence these days. In this study, bioactive films were developed based gelatin-corn starch (GCS) incorporated with corn stigma extract (CSE) at different concentrations (15% and 25%; w/v). In preliminary tests, the extract maintained cell viability above 90% indicating that it is safe for application as an active ingredient. Insertion of the extract did not influence the thickness of the films but caused a slight change in optical properties. Scanning electron microscopy (SEM) analysis revealed interactions between the extract's bioactive compounds with gelatin and corn starch compounds, which may have improved the mechanical properties (elongation at break, Young's modulus). The addition of 25% corn stigma extract increased the contact angle, giving the film a hydrophobic character. Furthermore, at this concentration, a 15% reduction in water vapor permeability was observed. The elaborated films showed complete biodegradability before the tenth day of the study. It can be inferred that the films with corn stigma extract have good antioxidant properties, indicating that they can be used as an ingredient for food packaging.

Novel pulp capping material based on sodium trimetaphosphate: synthesis, characterization, and antimicrobial properties.

OBJECTIVES: To evaluate the mechanical, physicochemical, and antimicrobial properties of four different formulations containing micro- or nanoparticles of sodium trimetaphosphate (mTMP and nTMP, respectively). METHODOLOGY: Four experimental groups were used in this investigation: two mTMP groups and two nTMP groups, each containing zirconium oxide (ZrO2), and solution containing either chitosan or titanium oxide (TiO2) nanoparticles (NPs). Setting time, compression resistance, and radiopacity were estimated. The agar diffusion test was used to assess the antimicrobial activity of the formulations against five different microbial strains: Streptococcus mutans, Lactobacillus casei, Actinomyces israelii, Candida albicans, and Enterococcus faecalis. Parametric and nonparametric tests were performed after evaluating homoscedasticity data (p<0.05). RESULTS: From the properties evaluated, nTMP cements required less setting time and showed greater resistance to compression. Cements containing TiO2 showed greater radiopacity for both nTMP and mTMP. All four cement formulations showed antimicrobial activity against S. mutans and L. casei. CONCLUSION: Formulations containing nTMP have shorter setting times and higher compressive strength, and those with TiO2 nanoparticles showed antimicrobial activities. Clinical relevance: The cement containing nTMP, ZrO2, and TiO2 could be an alternative material for protecting the pulp complex.