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Preassembled materials are ubiquitous in our everyday life due to their readiness and functionality; an end-user simply follows instructions to assemble them and harness function. Here, metastable rotaxanes are utilized to approach preassembled materials: a multicomponent, preprogrammed system can be conveniently (via heating) transformed into colorful polymer networks at the end-user’s will.

Background: Few data exist for referral processes in resource-limited settings. We utilized mixed-methods to evaluate the impact of a standardized algorithm and training module developed for locally identified needs in referral/counter-referral procedures between primary health centers (PHCs) and a Guatemalan referral hospital. Methods : PHC personnel and hospital physicians participated in surveys and focus groups pre-implementation and 3, 6, and 12 months post-implementation to evaluate providers’ experience with the system. Referred patient records were reviewed to evaluate system effectiveness. Results : A total of 111 initial focus group participants included 96 (86.5%) from PHCs and 15 from the hospital. Of these participants, 53 PHC physicians and nurses and 15 hospital physicians initially completed written surveys. Convenience samples participated in follow-up. Eighteen focus groups achieved thematic saturation. Four themes emerged: effective communication; provision of timely, quality patient care with adequate resources; educational opportunities; and development of empowerment and relationships. Pre- and post-implementation surveys demonstrated significant improvement at the PHCs ( P < .001) and the hospital ( P = .02). Chart review included 435 referrals, 98 (22.5%) pre-implementation and 337 (77.5%) post-implementation. There was a trend toward an increased percentage of appropriately referred patients requiring medical intervention (30% vs 40%, P = .08) and of patients requiring intervention who received it prior to transport (55% vs 73%, P = .06). Conclusions : Standardizing a referral/counter-referral system improved communication, education, and trust across different levels of pediatric health care delivery. This model may be used for extension throughout Guatemala or be modified for use in other countries. Mixed-methods research design can evaluate complex systems in resource-limited settings.

Cavia tschudii Fitzinger, 1867 is a wild guinea pig species living in South America that according to the analysis of mitochondrial genes is the closest wild form of the domestic guinea pig. To investigate the genetic divergence between the wild and domestic species of guinea pigs from a cytogenetic perspective, we characterized and compared the C, G and AgNOR banded karyotypes of molecularly identified Cavia tschudii and Cavia porcellus Linnaeus, 1758 specimens for the first time. Both species showed 64 chromosomes of similar morphology, although C. tschudii had four medium size submetacentric pairs that were not observed in the C. porcellus karyotype. Differences in the C bands size and the mean number of AgNOR bands between the karyotypes of the two species were detected. Most of the two species chromosomes showed total G band correspondence, suggesting that they probably represent large syntenic blocks conserved over time. Partial G band correspondence detected among the four submetacentric chromosomes present only in the C. tschudii karyotype and their subtelocentric homologues in C. porcellus may be explained by the occurrence of four pericentric inversions that probably emerged and were fixed in the C. tschudii populations under domestication. The role of the chromosomal and genomic differences in the divergence of these two Cavia species is discussed.

La intervención realizada a principios del siglo XX en el puente “San Ignacio”, modificó significativamente su funcionamiento, debido a la construcción de un embaldosado fabricado a partir del moldeo en baldosas prismáticas, del material incandescente de desecho de los procesos de la Gran Fundición Central. Mexicana de Salomón Guggenheim, las cuales fueron utilizadas para recuperar la calzada. Sin embargo, este sistema constructivo ha fallado debido al tráfico, por lo que el objetivo principal de este estudio se centró en la caracterización del sistema constructivo con base en la normatividad aplicable, evaluando su geometría, propiedades mecánicas y realizando una prospección eléctrica de los estratos. del sistema con la finalidad de evaluar la viabilidad de la conservación del embaldosado. Los resultados obtenidos llevaron a proponer su retiro debido al comportamiento frágil del material, su gran contribución al peso muerto y los problemas de drenaje de la calzada ocasionados por el sistema.

The non-destructive technique known as Electrical Resistivity Tomography (ERT) has been used in the analysis of historical buildings in recent years. It provides insights into the internal structure of the structural elements, such as layer thicknesses, and potential irregularities. In this investigation the ERT technique was applied to the ancient San Ignacio Bridge, located in the state of Aguascalientes, Mexico. The resulting resistivity profiles unveil the primary construction stages of the bridge, which corroborate and enhance the historical information regarding its construction phases. Additionally, the profiles indicate the presence of moisture concentrations in the pavement fillings, which could be attributed to rainwater infiltration. The usefulness of the ERT technique applied to edified patrimony is demonstrated in this study.

Lightweight materials that combine high mechanical strength, insulation, and fire resistance are of great interest to many industries. This work explores the properties of environmentally friendly alginate aerogel composites as potential sustainable alternatives to petroleum-based materials. This study analyzes the effects of two additives (tannic acid and montmorillonite clay), the orientation that results during casting, and the crosslinking of the biopolymer with glutaraldehyde on the properties of the aerogel composites. The prepared aerogels exhibited high porosities between 90% and 97% and densities in the range of 0.059–0.191 g/cm3. Crosslinking increased the density and resulted in excellent performance under loading conditions. In combination with axial orientation, Young’s modulus and yield strength reached values as high as 305 MPa·cm3/g and 7 MPa·cm3/g, respectively. Moreover, the alginate-based aerogels exhibited very low thermal conductivities, ranging from 0.038 W/m·K to 0.053 W/m·K. Compared to pristine alginate, the aerogel composites’ thermal degradation rate decreased substantially, enhancing thermal stability. Although glutaraldehyde promoted combustion, the non-crosslinked aerogel composites demonstrated high fire resistance. No flame was observed in these samples under cone calorimeter radiation, and a minuscule peak of heat release of 21 kW/m2 was emitted as a result of their highly efficient graphitization and fire suppression. The combination of properties of these bio-based aerogels demonstrates their potential as substituents for their fossil-based counterparts.

Soft tissue defects, such as incisional hernia or pelvic organ prolapse, are prevalent pathologies characterized by a tissue microenvironment rich in fragile and dysfunctional fibroblasts. Precision medicine could improve their surgical repair, currently based on polymeric materials. Nonetheless, biomaterial-triggered interventions need first a better understanding of the cell-material interfaces that truly consider the patients’ biology. Few tools are available to study the interactions between polymers and dysfunctional soft tissue cells in vitro. Here, we propose polypropylene (PP) as a matrix to create microscale surfaces w/wo functionalization with an HBII-RGD molecule, a fibronectin fragment modified to include an RGD sequence for promoting cell attachment and differentiation. Metal mold surfaces were roughened by shot blasting with aluminum oxide, and polypropylene plates were obtained by injection molding. HBII-RGD was covalently attached by silanization. As a proof of concept, primary abdominal and vaginal wall fasciae fibroblasts from control patients were grown on the new surfaces. Tissue-specific significant differences in cell morphology, early adhesion and cytoskeletal structure were observed. Roughness and biofunctionalization parameters exerted unique and combinatorial effects that need further investigation. We conclude that the proposed model is effective and provides a new framework to inform the design of smart materials for the treatment of clinically compromised tissues.

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Abstract Background An Amerindian genetic background could play an important role in susceptibility to metabolic diseases, which have alarmingly increased in recent decades. Mexico has one of the highest prevalences of metabolic disease worldwide. The purpose of this study was to determine the prevalence of metabolic syndrome and its components in a population with high Amerindian ancestry. Methods We performed a descriptive, quantitative, and analytical cross-sectional study of 2596 adult indigenous volunteers from 60 different ethnic groups. Metabolic syndrome and its components were evaluated using the American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement criteria. Results The overall prevalence of metabolic syndrome in the indigenous Mexican population was 50.3%. Although females had a higher prevalence than males (55.6% vs. 38.2%), the males presented with combinations of metabolic syndrome components that confer a higher risk of cardiovascular disease. The most frequent metabolic syndrome component in both genders was low HDL-cholesterol levels (75.8%). Central obesity was the second most frequent component in females (61%), though it had a low prevalence in males (16.5%). The overall prevalence of elevated blood pressure was 42.7% and was higher in males than females (48.8 vs. 40%). We found no gender differences in the overall prevalence of elevated triglycerides (56.7%) or fasting glucose (27.9%). Conclusions We documented that individuals with Amerindian ancestry have a high prevalence of metabolic syndrome. Health policies are needed to control the development of metabolic disorders in a population with high genetic risk.