Aloe vera mucilage loaded gelatin electrospun fibers contained in polylactic acid coaxial system and polylactic acid and poly(e-caprolactone) tri-layer membranes for tissue engineering.

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.

Evaluation of Strain Sensors Based on Poly(acrylonitrile-co-butadiene) and Polypyrrole Synthesized by the Diffusion Method.

In this study, the functionality of an elastomer composite material containing polypyrrole (PPy) as a stress sensor was evaluated. The material was prepared using the swelling method by diffusing the pyrrole monomer into the elastomer before polymerization. To achieve adequate diffusion, organic solvents with affinity for the elastomer were used. The resulting materials were characterized by scanning electron microscopy (SEM), surface electrical resistance, and thermal and mechanical properties for application as a stress sensor. The simultaneous change in electrical resistance and tension stress was measured using a digital multimeter with electrodes connected to the jaws of a universal mechanical testing machine. The influence of stress cycles on the piezoresistivity of the composite materials was investigated. The obtained PPy/NBR composite presented a good combination of electrical conductivity and mechanical properties. The strain at break remained with mild variation after coating with PPy.

Synthesis and toxicological study of chitosan-pirul (Schinus molle L.) essential oil nanoparticles on Aspergillus flavus.

In recent years, the study of essential oils as antifungal alternatives and their encapsulation to increase their properties for greater effects has been tested. In this work, nanoparticles of chitosan-Schinus molle L. essential oil (CS-PEO-Np) with a size of 260 ± 31.1 nm were obtained by ionic gelation and evaluated in some growth phases of Aspergillus flavus, a toxigenic fungus. At a concentration of 250 µg/mL of CS-PEO-Np, the A. flavus mycelial growth was inhibited at 97.1% with respect to control, at 96 h of incubation; the germination and viability of spores were inhibited at 74.8 and 40%, respectively, after exposure to 500 µg/mL of these nanomaterials, at 12 h of incubation. The fluorescence images of stained spores with DAPI showed the affectations caused by nanoparticles in the cell membrane, vacuoles and vacuolar content, cell wall, and nucleic acids. For both nanoparticles, CS-Np and CS-PEO-Np, no mutagenic effect was observed in Salmonella Typhimurium; also, the phytotoxic assay showed low-to-moderate toxicity toward seeds, which was dependent on the nanoparticle's concentration. The acute toxicity of CS-PEO-Np to A. salina nauplii was considered low in comparison to CS-Np (control), which indicates that the incorporation of Schinus molle essential oil into nanoparticles of chitosan is a strategy to reduce the toxicity commonly associated with nanostructured materials. The nanoparticulated systems of CS-PEO-Np represent an effective and non-toxic alternative for the control of toxigenic fungi such as A. flavus by delaying the initial growth stage.

Nanocomposite Hydrogels Based on Poly(vinyl alcohol) and Carbon Nanotubes for NIR-Light Triggered Drug Delivery.

Photothermal nanocomposite hydrogels are promising materials for remotely triggering drug delivery by near-infrared (NIR) radiation stimuli. In this work, a novel hydrogel based on poly(vinyl alcohol), poly(vinyl methyl ether-alt-maleic acid), poly(vinyl methyl ether), and functionalized multiwalled carbon nanotubes (MWCNT-f) was prepared by the freeze/thaw method. A comparative characterization of materials (with and without MWCNT-f) was carried out by infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, mechanical assays, swelling kinetics measurements, and photothermal analysis under NIR irradiation. Hydrophilic chemotherapeutic 5-fluorouracil (5-FU) and hydrophobic ibuprofen drugs were independently loaded into hydrogels, and the drug release profiles were obtained under passive and NIR-irradiation conditions. The concentration-dependent cytotoxicity of materials was studied in vitro using noncancerous cells and cancer cells. Notable changes in the microstructure and physicochemical properties of hydrogels were observed by adding a low content (0.2 wt %) of MWCNT-f. The cumulative release amounts of 5-FU and ibuprofen from the hydrogel containing MWCNT-f were significantly increased by 21 and 39%, respectively, through the application of short-term NIR irradiation pulses. Appropriate concentrations of the nanocomposite hydrogel loaded with 5-FU produced cytotoxicity in cancer cells without affecting noncancerous cells. The overall properties of the MWCNT-f-containing hydrogel and its photothermal behavior make it an attractive material to promote the release of hydrophilic and hydrophobic drugs, depending on the treatment requirements.

Effect of Degradation on the Physicochemical and Mechanical Properties of Extruded Films of Poly(lactic acid) and Chitosan.

This study addresses the fabrication of extruded films using poly(lactic acid) (PLA) and chitosan, with and without maleic anhydride as a compatibilizing agent, for potential applications in disposable food packaging. These films underwent controlled conditions of UV irradiation, water condensation, and temperature variations in an accelerated weathering chamber. The investigation analyzed the effect of different exposure periods on the structural, morphological, mechanical, and thermal properties of the films. It was observed that PLA films exhibited a lower susceptibility to degradation compared to those containing chitosan. Specifically, the pure PLA film showed an increase in elastic modulus and strength during the initial 144 h of exposure, associated with cross-linking induced by UV radiation. On the other hand, film Q2 composed of PLA, chitosan, and maleic anhydride and Q1 without maleic anhydride experienced a tensile strength loss of over 50% after 244 h of exposure. The Q2 film exhibited greater homogeneity, leading to increased resistance to degradation compared to that of Q1. As the degradation time increased, both the Q1 and Q2 films demonstrated a decline in thermal stability. These films also exhibited alterations in crystallinity attributed to the chemo-crystallization process, along with fluctuations in the glass transition temperature and crystallization, particularly at 288 h.

Preparation and Characterization of Poly(lactic acid) Membranes and Films Coated with Polyaniline for Potential Use in Environmental Remediation.

This research outlines the fabrication of polymeric membranes and films of poly(lactic acid) (PLA), prepared via electrospinning and extrusion, respectively. These materials were subsequently coated with polyaniline (PANi) by using the in situ chemical polymerization technique. Scanning electron microscopy micrographs revealed that the best coatings were achieved when 3 and 30 min of contact time with the monomeric solution were used for the membrane and film, respectively. Additionally, Fourier transform infrared spectra, thermogravimetric studies, and contact angle measurements demonstrated proper interaction between PLA and PANi. The findings of these studies suggest that PLA membranes and films can serve as suitable substrates for the deposition of PANi, and the composite materials hold potential for use in environmental remediation applications.

Within-host bayesian joint modeling of longitudinal and time-to-event data of Leishmania infection.

The host immune system plays a significant role in managing and clearing pathogen material during an infection, but this complex process presents numerous challenges from a modeling perspective. There are many mathematical and statistical models for these kinds of processes that take into account a wide range of events that happen within the host. In this work, we present a Bayesian joint model of longitudinal and time-to-event data of Leishmania infection that considers the interplay between key drivers of the disease process: pathogen load, antibody level, and disease. The longitudinal model also considers approximate inflammatory and regulatory immune factors. In addition to measuring antibody levels produced by the immune system, we adapt data from CD4+ and CD8+ T cell proliferation, and expression of interleukin 10, interferon-gamma, and programmed cell death 1 as inflammatory or regulatory factors mediating the disease process. The model is developed using data collected from a cohort of dogs naturally exposed to Leishmania infantum. The cohort was chosen to start with healthy infected animals, and this is the majority of the data. The model also characterizes the relationship features of the longitudinal outcomes and time-to-death due to progressive Leishmania infection. In addition to describing the mechanisms causing disease progression and impacting the risk of death, we also present the model's ability to predict individual trajectories of Canine Leishmaniosis (CanL) progression. The within-host model structure we present here provides a way forward to address vital research questions regarding the understanding of the progression of complex chronic diseases such as Visceral Leishmaniasis, a parasitic disease causing significant morbidity worldwide.

Survival, Short And Long-Term Outcomes Of Open And Endovascular Surgical Repair Of Unruptured Infrarenal Abdominal Aortic Aneurysms.

INTRODUCTION: Endovascular Aortic Repair (EVAR) has become the standard management of Unruptured Infrarenal Abdominal Aortic Aneurysm (UIAAA); however, current evidence is limited and uncertain in our environment compared to Open repair. Our study aimed to determine the survival, short and long-term outcomes of EVAR vs. Open in a Peruvian cohort of UIAAA. METHODS: A single-center observational, analytical, longitudinal study using a retrospective registry of 251 patients treated (EVAR=205 vs Open=46) for UIAAA from 2000 to 2017. Variables considered were baseline, comorbidities, type of treatment, short-term (<30 days) and long-term (<5 years) outcomes, postoperative mortality according to the Vascular Quality Initiative (VQI) Risk Score, survival curves including reoperation-free rate and according to size (<65 mm vs. >65 mm) of long-term UIAAA. All variables were grouped according to the treatment performed (EVAR vs. Open) and we used the descriptive, multivariate, Cox regression, and Kaplan-Meier survival statistical analyses. RESULTS: 251 UIAAA were evaluated and the mean age was 74.5 years [±13.32], smoking, family members with UIAAA, and previous abdominal surgery were the main antecedents. Diabetes mellitus 2 was the main comorbidity; more than 50% of patients with UIAAA had diameters greater than 65 mm (p=0.021). The calculated mortality (VQI) was Open=2.21% vs. EVAR=1.65%. The outcomes in short-term were mortality (Open=2.92% vs. EVAR=0%; p=0.039), blood transfusion >4 Units (Open=72.68% vs. EVAR=17.39%; p=0.021) and overall hospital stay (Open=14 vs. EVAR=5 days; p=0.049. A reduction in mortality (HR 0.76, 95% CI, 0.62-0.96, p=0.045) and readmission for aneurysmal rupture was identified for EVAR (HR 0.81, 95% CI, 0.79-0.85, p=0.031). In long-term outcomes, mortality (Open=3.41% vs. EVAR=19.56%; p=0.047), aneurysmal rupture (Open=0% vs. EVAR 13.04%; p=0.032) and reinterventions (Open=2.43% vs. EVAR=10.86%; p=0.002). An 86% risk of mortality (HR 1.86, 95% CI, 1.32-2.38, p=0.039) and elevated risk of readmission for aneurysmal rupture was identified for EVAR (HR 2.21, 95% CI, 1.98-2.45, p=0.028). At 5 years, survival for Open=93.67% vs. EVAR=80.44% (p=0.043), reintervention-free survival for Open=89.26% vs. EVAR=47.82% (p=0.021), survival for treated IUAAA <65 mm for Open=95.77% vs. EVAR=63.63% (p=0.019) and >65 mm for Open=92.53% vs. EVAR=85.71% (p=0.059). CONCLUSION: EVAR has shown better short-term benefits and survival than Open management; however, the latter still prevails in the long term in our Peruvian UIAAA cohort. Further follow-up studies are required to demonstrate the long-term benefit of EVAR in our population.

Physically and Chemically Cross-Linked Poly(vinyl alcohol)/Humic Acid Hydrogels for Agricultural Applications.

The preparation method of hydrogels has a significant effect on their structural and physicochemical properties. In this report, physically and chemically cross-linked poly(vinyl alcohol) (PVA) networks containing humic acid (HA) were alternatively prepared by autoclaving (AC) and through glutaraldehyde (GA) addition, respectively, for agricultural purposes. PVA/HA hydrogels were comparatively characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, mechanical assays, scanning electron microscopy, swelling kinetics measurements, and water retention tests in soil. AC hydrogels showed a more homogeneous porous microstructure, higher swelling levels, and a better capacity to preserve the humidity of soil than those obtained by adding GA. Both PVA/HA hydrogels exhibited no phytotoxicity on cultivation trials of Sorghum sp., but the plant growth was promoted with the GA-cross-linked network as compared to the effect of the AC sample. The release behavior of urea was modified according to the preparation method of the PVA/HA hydrogels. After 3 days of sustained urea release, 91% of the fertilizer was delivered from the AC hydrogel, whereas a lower amount of 56% was released for the GA-cross-linked hydrogel. Beyond the advantages of applying PVA/HA hydrogels in the agricultural field, an appropriate method of preparing these materials endows them with specific properties according to the requirements of the target crop.

Nanoparticles of Betalain-Gelatin with Antioxidant Properties by Coaxial Electrospraying: Preparation and Characterization.

Betalains are bioactive compounds with attractive antioxidant properties for the food industry, endowing them with potential application in food coatings to maintain quality and extend shelf life. However, they have low stability to factors such as light, temperature, and humidity. An alternative to protect bioactive compounds is nanoencapsulation; one of the most used techniques to produce an encapsulation is coaxial electrospraying. In this research, the preparation and characterization of gelatin-betalain nanoparticles were carried out using the coaxial electrospray technique. Betalains were extracted from pitaya (Stenocereus thurberi) and encapsulated in gelatin. The obtained material was evaluated by SEM, FTIR, TGA, and DSC techniques and for its antioxidant capacity. By SEM, nanoparticles with spherical and monodisperse morphologies were observed, with betalain concentrations of 1 and 3% w/v and average diameters of 864 and 832 µm, respectively. By FTIR, the interaction between betalain and gelatin was observed through amino groups and hydrogen bonds. Likewise, the antioxidant activity of the betalains was maintained at the time of encapsulation, increasing the antioxidant activity as the concentration increased. The results of the DPPH, ABTS, and total phenols methods were 645.4592 µM T/g, 832.8863 ± 0.0110 µM T/g, and 59.8642 ± 0.0279 mg GAE/g for coaxial nanoparticles with 3% betalains, respectively. Therefore, the coaxial electrospray technique was useful for obtaining nanoparticles with good antioxidant properties, and due to the origin of its components and since the use of toxic solvents is not necessary in the technique, the material obtained can be considered food grade with potential application as a coating on functional foods.

Active and Intelligent Packaging: A Review of the Possible Application of Cyclodextrins in Food Storage and Safety Indicators.

Natural cyclodextrins (CDs) can be formed by 6, 7, or 8 glucose molecules (α-, ß-, and γ-, respectively) linked in a ring, creating a cone shape. Its interior has an affinity for hydrophobic molecules, while the exterior is hydrophilic and can interact with water molecules. This feature has been used to develop active packaging applied to food, interacting with the product or its environment to improve one or more aspects of its quality or safety. It also provides monitoring information when food is optimal for consumption, as intelligent packaging is essential for the consumer and the merchant. Therefore, this review will focus on discerning which packaging is most appropriate for each situation, solubility and toxicological considerations, characterization techniques, effect on the guest properties, and other aspects related to forming the inclusion complex with bioactive molecules applied to packaging.

Effect of a Prolonged-Release System of Urea on Nitrogen Losses and Microbial Population Changes in Two Types of Agricultural Soil.

Urea is the nitrogen-containing fertilizer most used in agricultural fields; however, the nutrient given by the urea is lost into the environment. The aim of this research was to determine the effect of two soil textures by applying a prolonged-release system of urea (PRSU) on the N losses. This research shows an important decrease of the nitrate and ammonium losses from 24.91 to 87.94%. Also, the microbiological population increases after the application of the PRSU. It was concluded that both soil textures presented the same loss-reduction pattern, where the N from the nitrates and ammonium was reduced in the leachates, increasing the quality of the soil and the microbial population in both soil textures after the PRSU application.

Preparation and Characterization of Extruded PLA Films Coated with Polyaniline or Polypyrrole by In Situ Chemical Polymerization.

Conductive polymers, such as polypyrrole and polyaniline, have been extensively studied for their notable intrinsic electronic and ionic conductivities, rendering them suitable for a range of diverse applications. In this study, in situ chemical polymerization was employed to coat extruded PLA films with PPy and PANi. Morphological analysis reveals a uniform and compact deposition of both polyaniline and polypyrrole after polymerization periods of 3 and 1 h, respectively. Furthermore, the PLA-PANi-3h and PLA-PPy-1h composites exhibited the highest electrical conductivity, with values of 0.042 and 0.022 S cm-1, respectively. These findings were in agreement with the XPS results, as the polyaniline-coated film showed a higher proportion of charge carriers compared to the polypyrrole composite. The elastic modulus of the coated films showed an increase compared with that of pure PLA films. Additionally, the inflection temperatures for the PLA-PANi-3h and PLA-PPy-1h composites were 368.7 and 367.2 °C, respectively, while for pure PLA, it reached 341.47 °C. This improvement in mechanical and thermal properties revealed the effective interfacial adhesion between the PLA matrix and the conducting polymer. Therefore, this work demonstrates that coating biopolymeric matrices with PANi or PPy enables the production of functional and environmentally friendly conductive materials suitable for potential use in the removal of heavy metals in water treatment.

Within-Host Bayesian Joint Modeling of Longitudinal and Time-to-Event Data of Leishmania Infection.

The host immune system plays a significant role in managing and clearing pathogen material during an infection, but this complex process presents numerous challenges from a modeling perspective. There are many mathematical and statistical models for these kinds of processes that take into account a wide range of events that happen within the host. In this work, we present a Bayesian joint model of longitudinal and time-to-event data of Leishmania infection that considers the interplay between key drivers of the disease process: pathogen load, antibody level, and disease. The longitudinal model also considers approximate inflammatory and regulatory immune factors. In addition to measuring antibody levels produced by the immune system, we adapt data from CD4+ and CD8+ T cell proliferation, and expression of interleukin 10, interferon-gamma, and programmed cell death 1 as inflammatory or regulatory factors mediating the disease process. The model is developed using data collected from a cohort of dogs naturally exposed to Leishmania infantum. The cohort was chosen to start with healthy infected animals, and this is the majority of the data. The model also characterizes the relationship features of the longitudinal outcomes and time of death due to progressive Leishmania infection. In addition to describing the mechanisms causing disease progression and impacting the risk of death, we also present the model's ability to predict individual trajectories of Canine Leishmaniosis (CanL) progression. The within-host model structure we present here provides a way forward to address vital research questions regarding the understanding progression of complex chronic diseases such as Visceral Leishmaniasis, a parasitic disease causing significant morbidity worldwide.

HT-B and S-RNase CRISPR-Cas9 double knockouts show enhanced self-fertility in diploid Solanum tuberosum.

The Gametophytic Self-Incompatibility (GSI) system in diploid potato (Solanum tuberosum L.) poses a substantial barrier in diploid potato breeding by hindering the generation of inbred lines. One solution is gene editing to generate self-compatible diploid potatoes which will allow for the generation of elite inbred lines with fixed favorable alleles and heterotic potential. The S-RNase and HT genes have been shown previously to contribute to GSI in the Solanaceae family and self-compatible S. tuberosum lines have been generated by knocking out S-RNase gene with CRISPR-Cas9 gene editing. This study employed CRISPR-Cas9 to knockout HT-B either individually or in concert with S-RNase in the diploid self-incompatible S. tuberosum clone DRH-195. Using mature seed formation from self-pollinated fruit as the defining characteristic of self-compatibility, HT-B-only knockouts produced little or no seed. In contrast, double knockout lines of HT-B and S-RNase displayed levels of seed production that were up to three times higher than observed in the S-RNase-only knockout, indicating a synergistic effect between HT-B and S-RNase in self-compatibility in diploid potato. This contrasts with compatible cross-pollinations, where S-RNase and HT-B did not have a significant effect on seed set. Contradictory to the traditional GSI model, self-incompatible lines displayed pollen tube growth reaching the ovary, yet ovules failed to develop into seeds indicating a potential late-acting self-incompatibility in DRH-195. Germplasm generated from this study will serve as a valuable resource for diploid potato breeding.

Bayesian multivariate longitudinal model for immune responses to Leishmania: A tick-borne co-infection study.

While many Bayesian state-space models for infectious disease processes focus on population infection dynamics (eg, compartmental models), in this work we examine the evolution of infection processes and the complexities of the immune responses within the host using these techniques. We present a joint Bayesian state-space model to better understand how the immune system contributes to the control of Leishmania infantum infections over the disease course. We use longitudinal molecular diagnostic and clinical data of a cohort of dogs to describe population progression rates and present evidence for important drivers of clinical disease. Among these results, we find evidence for the importance of co-infection in disease progression. We also show that as dogs progress through the infection, parasite load is influenced by their age, ectoparasiticide treatment status, and serology. Furthermore, we present evidence that pathogen load information from an earlier point in time influences its future value and that the size of this effect varies depending on the clinical stage of the dog. In addition to characterizing the processes driving disease progression, we predict individual and aggregate patterns of Canine Leishmaniasis progression. Both our findings and the application to individual-level predictions are of direct clinical relevance, presenting possible opportunities for application in veterinary practice and motivating lines of additional investigation to better understand and predict disease progression. Finally, as an important zoonotic human pathogen, these results may support future efforts to prevent and treat human Leishmaniosis.

Antioxidant and Antimicrobial Effect of Biodegradable Films Containing Pitaya (Stenocereus thurberi) Extracts during the Refrigerated Storage of Fish.

This study focused on the quality loss inhibition of fish muscle during refrigerated storage. Two parallel experiments were carried out that were focused on the employment of pitaya (Stenocereus thurberi) extracts in biodegradable packing films. On the one hand, a pitaya-gelatin film was employed for hake (Merluccius merluccius) muscle storage. On the other hand, a pitaya-polylactic acid (PLA) film was used for Atlantic mackerel (Scomber scombrus) muscle storage. In both experiments, fish-packing systems were stored at 4 °C for 8 days. Quality loss was determined by lipid damage and microbial activity development. The presence of the pitaya extract led to an inhibitory effect (p < 0.05) on peroxide, fluorescent compound, and free fatty acid (FFA) values in the gelatin-hake system and to a lower (p < 0.05) formation of thiobarbituric acid reactive substances, fluorescent compounds, and FFAs in the PLA-mackerel system. Additionally, the inclusion of pitaya extracts in the packing films slowed down (p < 0.05) the growth of aerobes, anaerobes, psychrotrophs, and proteolytic bacteria in the case of the pitaya-gelatin films and of aerobes, anaerobes, and proteolytic bacteria in the case of pitaya-PLA films. The current preservative effects are explained on the basis of the preservative compound presence (betalains and phenolic compounds) in the pitaya extracts.

Capacidad de un ensayo rápido para diagnosticar la COVID-19 y relación con síntomas clínicos

Introducción: La detección del virus SARS-CoV-2, agente causal de la COVID-19, es determinante para disminuir la propagación de la actual pandemia. Si bien el procedimiento de elección es la determinación del ácido nucleico del virus mediante la reacción en cadena de la polimerasa, también es necesario disponer de pruebas rápidas, con alta sensibilidad y precisión. Objetivo: Analizar la validez diagnóstica de un ensayo rápido de antígeno SARS-CoV-2, utilizado para la detección de la COVID-19 en el policlínico "5 de Septiembre" del municipio Playa. Material y Métodos: Se realizó un estudio analítico de corte transversal con 590 pacientes atendidos en la consulta de infecciones respiratorias agudas, en el período de enero a agosto de 2021. La determinación de antígeno SARS-CoV-2 se realizó con un ensayo rápido y la confirmación se hizo mediante la reacción en cadena de la polimerasa. Resultados: La prueba rápida de antígeno tuvo una elevada sensibilidad (98,19 %) y especificidad (92,39 %). La concordancia de los resultados obtenidos entre ambas pruebas fue elevada (0,868). Las sintomatologías más frecuentes reportadas, fueron, cefalea (51,69 %), fiebre (39,15 %), tos (37,16 %), pérdida del gusto/olfato (34,06 %) y rinorrea (30,16 %). Conclusiones: El ensayo rápido de antígeno del SARS-CoV-2 usado para la detección de la COVID-19 demostró validez y puede ser utilizado para el diagnóstico de la enfermedad. Las sintomatologías cefalea, fiebre, tos, pérdida del gusto/olfato y rinorrea fueron las más frecuentes, reportadas en más de 30 de los casos.

Introduction: The detection of the SARS-CoV-2 virus, the causal agent of COVID-19, is decisive to reduce the spread of the current pandemic. Although the procedure of choice is the determination of the nucleic acid of the virus using the polymerase chain reaction, the availability of rapid, highly sensitive, and accurate tests is also necessary. Objective: To analyze the diagnostic validity of a SARS-CoV-2 antigen rapid diagnostic test for the detection of COVID-19 in the "5 de Septiembre" Polyclinic in Playa municipality. Material and Methods: A cross-sectional analytical study was carried out on 590 patients seen in the acute respiratory infections consulting room in the period from January to August 2021. The detection of the SARS-CoV-2 antigen was performed using a rapid test and it was confirmed by polymerase chain reaction. Results: The rapid antigen test had a high sensitivity (98.19%) and specificity (92.39%). The concordance of the results obtained from both tests was high (0.868). The most frequent reported symptoms were headache (51.69%), fever (39.15%), cough (37.16%), loss of taste/smell (34.06%), and runny nose (30.16%). Conclusions: The SARS-CoV-2 antigen rapid diagnostic test used for the detection of COVID-19 is valid and can be used in the diagnosis of the disease. Symptoms such as headache, fever, cough, loss of taste/smell, and runny nose were the most frequently reported in more than 30% of cases.

Arteriographic patterns of peripheral arterial disease in lower limbs in a Peruvian cohort of patients.

INTRODUCTION: There is currently no universal and uniform pattern of peripheral arterial disease (PAD) in the lower limbs; however, it is influenced by various cardiovascular factors of the individual. The objective of this study was to identify the arteriographic patterns of PAD in the lower limbs according to cardiovascular factors in a Peruvian cohort of patients. METHODS: This is an analytical, observational, and retrospective study. The arteriographic patterns of PAD in the aortoiliac segment were analyzed with the TransAtlantic InterSociety Consensus (TASC-II) score and the Global Anatomic Staging System (GLASS) for the femoropopliteal (FP), infraopopliteal (IP), and pedial (P) segments in a Peruvian cohort from January 2018 to May 2021. RESULTS: 595 patients (833 extremities) were analyzed with a mean age of 67.54 ± 16.39 years, and the main cardiovascular factor was diabetes (65.04%). The patients older than 65 years with GLASS FP 4 (p = 0.042), IP 0 (p = 0.004), and P2 (p = 0.047) presented significant findings: in men and women with GLASS IP 4 (p = 0.031) and P 2 (p = 0.045); diabetes with TASC-II A (p = 0.031), GLASS FP 4 (p = 0.038), IP 4 (p = 0.009), and P2 (p = 0.003); dyslipidemia with TASC-II D (p = 0.027), GLASS FP 4 (p = 0.038), IP 0 (p = 0.009), and P0 (p = 0.003); smoking with TASC-II D (p = 0.001), GLASS FP 4 (p = 0.049) and IP 0 (p = 0.008); chronic coronary disease with GLASS IP 4 (p = 0.049) and P2 (p = 0.037); chronic kidney disease with GLASS FP 4 (p=0.047), IP 4 (p = 0.004), and P2 (p = 0.016); and previous amputation history with GLASS IP 4 (p = 0.015) and P2 (p = 0.039). The most frequent arteriographic pattern of PAD in the lower limbs of our cohort was TASC-II A, GLASS FP 0 and 4, IP 0, and P2 (p = 0.047). CONCLUSION: Our work will allow the limb salvage teams to understand the behavior of PAD affectation in the population of our environment, allowing a timely control of cardiovascular risk factors, adequate revascularization planning, and a significant reduction in the risk of loss of limb.

Gold(I) Catalysis Applied to the Stereoselective Synthesis of Indeno[2,1-b]thiochromene Derivatives and Seleno Analogues.

A gold(I)-catalyzed cascade reaction for the stereoselective synthesis of sulfur- or selenium-containing indeno[1,2-b]chromene derivatives from o-(alkynyl)styrenes substituted at the triple bond with a thio- or seleno-aryl group is described. The reaction involves a double cyclization process through a proposed key gold-cyclopropyl carbene intermediate that evolves by the intramolecular addition of an aromatic to the cyclopropane ring, affording polycyclic structures. The enantioselective version was studied using gold(I) complexes bearing chiral ligands.