Synthesis of calix (4) resorcinarene based amphiphilic macrocycle as an efficient nanocarrier for Amphotericin-B to enhance its oral bioavailability.

The supramolecular-based macrocyclic amphiphiles have fascinating attention and find extensive utilization in the pharmaceutical industry for efficient drug delivery. In this study, we designed and synthesized a new supramolecular amphiphilic macrocycle to serve as an efficient nanocarrier, achieved by treating 4-hydroxybenzaldehyde with 1-bromotetradecane. The derivatized product was subsequently treated with resorcinol to cyclize, resulting in the formation of a calix(4)-resorcinarene-based supramolecular amphiphilic macrocycle. The synthesized macrocycle and intermediate products were characterized using mass spectrometry, IR, and 1H NMR spectroscopic techniques. The amphotericin-B (Amph-B)-loaded and unloaded amphiphiles were screened for biocompatibility studies, vesicle formation, particle shape, size, surface charge, drug entrapment, in-vitro release profile, and stability through atomic force microscopy (AFM), Zetasizer, HPLC, and FT-IR. Amph-B -loaded macrocycle-based niosomal vesicles were investigated for in-vivo bioavailability in rabbits. The synthesized macrocycle exhibited no cytotoxicity against normal mouse fibroblast cells and was found to be hemocompatible and safe in mice following an acute toxicity study. The drug-loaded macrocycle-based vesicles appeared spherical, nano-sized, and homogeneous in size, with a notable negative surface charge. The vesicles remained stable after 30 days of storage. The results of Amph-B oral bioavailability and pharmacokinetics revealed that the newly tailored niosomal formulation enhanced drug solubility, protected drug degradation at gastric pH, facilitated sustained drug release at the specific target site, and delayed plasma drug clearance. Incorporating such advanced niosomal formulations in the field of drug delivery systems has the potential to revolutionize therapeutic outcomes and improve the quality of patient well-being.

A comprehensive study of product distributions and coke deposition during catalytic cracking of vacuum gas oil over hierarchical zeolites.

In this study, zeolites (Z) were used as catalysts in the cracking of a Colombian vacuum gas oil (VGO), with a focus on product distribution and coke deposition. The catalytic tests were carried out in a MAT-type reactor under typical conditions. The zeolites were subjected to alkaline treatment with NaOH at concentrations ranging from 0.05 to 0.4 mol/L, resulting in the creation of several samples (Z-0.05, Z-0.10, Z-0.20, Z-0.30 and Z-0.40) that were then hydrothermally stabilized (Z-0.05-M, Z-0.10-M, Z-0.20-M, Z-0.30-M and Z-0.40-M) to increase mesoporosity and reduced crystallinity. The increase in mesoporosity was accompanied by an improvement in acidity. Despite Z-0.30-M having higher acidity, Z-0.00-M and Z-0.10-M exhibited the highest activity due to their high crystallinity and microporosity, yielding the highest gas yields. Gasoline was the main product, with maximum yields exceeding 30%. Z-0.20-M produced more aromatic and olefin compounds than the others, resulting in higher quality gasoline. Coke formation followed the trend: Z-0.00-M < Z-0.10-M < Z-0.20-M < Z-0.30-M. The higher intracrystalline mesoporosity in the zeolites favored the formation of a more condensed coke.

Associated factors for mortality in a COVID-19 colombian cohort: is the third wave relevant when Mu variant was predominant epidemiologically?

OBJECTIVES: To evaluate the association between Colombia's third wave when the Mu variant was predominant epidemiologically (until 75%) in Colombia and COVID-19 all-cause in-hospital mortality. METHODS: In this retrospective cohort, we included hospitalized patients ≥18 years with SARS-CoV-2 infection between March 2020 to September 2021 in ten hospitals from three cities in Colombia. Description analysis, survival, and multivariate Cox regression analyses were performed to evaluate the association between the third epidemic wave and in-hospital mortality. RESULTS: A total of 25,371 patients were included. The age-stratified time-to-mortality curves showed differences according to epidemic waves in patients ≥75 years (log-rank test p = 0.012). In the multivariate Cox analysis, the third wave was not associated with increased mortality relative to the first wave (aHR 0.95; 95%CI 0.84-1.08), but there was an interaction between age ≥75 years and the third wave finding a lower HR for mortality (aHR 0.56, 95%CI 0.36-0.86). CONCLUSIONS: We did not find an increase in in-hospital mortality during the third epidemic wave in which the Mu variant was predominant in Colombia. The reduced hazard in mortality in patients ≥75 years hospitalized in the third wave could be explained by the high coverage of SARS-CoV-2 vaccination in this population and patients with underlying conditions.

Iron Oxide Powder as Responsible for the Generation of Industrial Polypropylene Waste and as a Co-Catalyst for the Pyrolysis of Non-Additive Resins.

For the synthesis of polymeric resins, it is of great importance to review the raw materials and the equipment to be used to avoid the presence of compounds that may affect the effectiveness of the polymerization and the characteristics of the plastic to be obtained. Iron oxide is a compound that can be present in reactors after maintenance due to the techniques used and the cleaning of this equipment, and it can affect the characteristics of the resins, reducing their quality. In this study, the presence of FeO in different concentrations was evaluated to determine its effects on the properties and pyrolysis of polypropylene resins by using X-ray refraction to determine the elements of the samples, evaluating thermal degradation by TGA, the variation in molecular weight by measuring the MFI, and the compounds obtained from pyrolysis by chromatography. The results showed that the thermal degradation decreased as the FeO concentration increased, while for the MFI, the relationship was directly proportional. The evaluation of the compounds obtained from pyrolysis showed an increase in the production of alcohols, alkynes, ketones, and acids, and a decrease in alkanes and alkenes, showing that FeO affects the properties of polypropylene and the compounds that are produced during pyrolysis.

Experimental Study of the Impact of Trace Amounts of Acetylene and Methylacetylene on the Synthesis, Mechanical and Thermal Properties of Polypropylene.

During the production of polymer-grade propylene, different processes are used to purify this compound and ensure that it is of the highest quality. However, some impurities such as acetylene and methyl acetylene are difficult to remove, and some of these impurities may be present in the propylene used to obtain polypropylene, which may have repercussions on the process. This study evaluates the impact of these acetylene and methyl acetylene impurities on the productivity of the polypropylene synthesis process and on the mechanical and thermal properties of the material obtained through the synthesis of eight samples with different concentrations of acetylene and eight samples with different concentrations of acetylene. We discovered that for the first concentrations of both acetylene (2 and 3 ppm) and methyl acetylene (0.03 and 0.1), the MFI, thermal recording, and mechanical properties of the resin were unaffected by the variation of the fluidity index, thermal degradation by TGA, and mechanical properties such as resistance to tension, bending, and impact. However, when the concentration exceeded 14 ppm for methyl acetylene and 12 ppm for acetylene, the resistance of this resin began to decrease linearly. Regarding production, this was affected by the first traces of acetylene and methyl acetylene progressively decreasing.

Pre-concentration of rosuvastatin using solid-phase extraction in a molecularly imprinted polymer and analytical application in water supply.

In this work, it is shown the development and validation of innovative analytical methodology based on solid-phase extraction (SPE) with molecularly imprinted polymers (MIP) as a sorbent associated to UV-Vis spectroscopy to isolate and quantify, respectively, rosuvastatin (RSV) in water samples. For this purpose, porogenic solvent in MIP synthesis and SPE extraction parameters for MIP and non-imprinted polymers (NIP) were evaluated univariately for comparison purposes. The sorptive capacity and characterization studies by infrared spectroscopy and atomic force microscopy showed difference between MIP and NIP. The selectivity study of the MIP-RSV against other statins (simvastatin and atorvastatin) showed that the synthesized MIP can also be applied as a solid phase for isolation and quantitative pre-concentration of RSV and atorvastatin. The conjugation of SPE and UV-Vis spectroscopy in the determination of RSV in aqueous matrices led to large factor of pre-concentration (125 times), limit of detection (LOD) of 3 µg L-1, limit of quantification (LOQ) of 10 µg L-1, precision of 2.87% (n = 10), and accuracy of 83.1% (n = 4).

Quantification of neomycin in rubella vaccine by off/on metal ion mediated photoluminescence from functionalized graphene quantum dots.

The determination of neomycin sulfate was made using photoluminescent amino-functionalized graphene quantum dots (obtained from hydro-exfoliation of a mixture of citric acid and glutathione). From the several ions tested, Fe3+ was the best mediator to enable an off/on photoluminescence effect used for quantification. The mediation of Fe3+ was found to be crucial as it is responsible for the photoluminescence quenching effect, due to the interaction with quantum dots surface, also having large affinity towards neomycin that removes Fe3+ from the surface of GQDs, consequently, promoting restoration of the original nanomaterial photoluminescence. Such signal restoration was proportional to the neomycin sulfate concentration added. The linearized analytical response covered three orders of magnitude (10-7 to 10-5 mol L-1). The proposed method is an alternative to those requiring labor-intensive procedures for chemical the derivatization of neomycin (due to the lack of chromophore groups in aminoglycosides). The method was successfully tested in the analysis of rubella vaccine containing trace residues of neomycin and in pharmaceutical compositions containing neomycin sulfate after solid phase extraction using an aminoglycoside imprinted polymer to improve selectivity in determinations.

Gold nanoparticles coupled with graphene quantum dots in organized medium to quantify aminoglycoside anti-biotics in yellow fever vaccine after solid phase extraction using a selective imprinted polymer.

The determination of kanamycin sulfate was made indirectly by measuring its effect on photoluminescent amino functionalized graphene quantum dots (GQDs-amino) associated with gold nanoparticles (AuNPs) that were produced by the reduction of AuCl4 with NaBH4 in an aqueous dispersion of GQDs-amino (obtained by the pyrolysis of citric acid and glutathione) also containing the cationic surfactant CTAB. The AuNPs-GQDs-amino-CTAB system presents a suppressed photoluminescence that is amplified in the presence of kanamycin. Under optimized experimental conditions, the photoluminescence amplification of the nanomaterial system showed a linear response as a function of kanamycin concentration, covering three orders of magnitude (10-7 to 10-5 mol L-1). The use of solid phase extraction with a cartridge packed with aminoglycoside selective molecularly imprinted polymer ensured selectivity in determinations made on yellow-fever vaccine and veterinary pharmaceutical formulations. The analytical results were statistically similar to those obtained with an HPLC-based fluorescence method (after chemical derivatization). The proposed method is a simple, sensitive and selective approach that does not involve the use of toxic reagents employed for chemical derivatization of aminoglycoside antibiotics.

Kanamycin detection at graphene quantum dot-decorated gold nanoparticles in organized medium after solid-phase extraction using an aminoglycoside imprinted polymer.

This is a description of the indirect determination of kanamycin sulfate though the photoluminescence enhancement of an aqueous dispersion of amino-functionalized graphene quantum dots (amino-GQDs) coupled with gold nanoparticles (AuNPs) in a cationic surfactant-rich medium. Specifically, cetyltrimethylammonium bromide (CTAB) was used as the cationic surfactant in our work. Previously, solid phase extraction with a cartridge packed with aminoglycoside-selective imprinted polymer ensured selectivity in kanamycin determination in yellow-fever vaccine and veterinary pharmaceutical samples. The proposed method has trace analysis capability and it is simple to perform as it does not involve the use of toxic reagents employed for chemical derivatization of aminoglycoside antibiotics.

Alopecia en pénfigo vulgar / Alopecia in pemphigus vulgaris

El pénfigo vulgar (PV) es la forma más frecuente, representando el 70% de los casos de pénfigo. Es una enfermedad autoinmune adquirida en la cual los anticuerpos IgG están dirigidos a las proteínas desmosomales para producir la formación de ampollas intraepiteliales mucocutáneas. Las erosiones delcuero cabelludo son una manifestación clínica relativamente común del PV. Sin embargo, la pérdida de cabello progresiva o discretas placas alopécicas se describen raramente en pacientes con PV. Presentamos un caso de PV con pérdida progresiva del cabello y zonas alopécicas.

Pemphigus vulgaris (PV) is the most frequent form, accounting for 70% of the cases. It is an acquired autoimmune disease in which IgG antibodies target desmosomal proteins to produce intraepithelial, mucocutaneous blistering. Erosions of the scalp are a relatively ordinary clinical presentation. However, progressive loss of hairor discreet alopecic plaques are rarely described in patients with PV. The study presents a case of PV with progressive hair loss and alopecic zones.

O pênfigo vulgar (PV) é a forma mais frequente de pênfigo representando 70% dos casos desta patologia. É uma doença autoimune adquirida na qual os anticorpos IgG estão orientados às proteínas desmosomais causando a formação de bolhas intraepiteliais mucocutâneas. As erosões do couro cabeludo são uma manifestação clínica relativamente comum do PV. No entanto, a perda de cabelo progressiva ou a presença de placas alopécicas discretas raramente são descritas em pacientes com PV. Apresentamos um caso de PV com perda progressiva do cabelo e zonas alopécicas.

Caracteristicas clinico-epidemiologicas de la diarrea aguda del adulto en un hospital de la ciudad de Cordoba / Clinical and epidemiologic characteristics of acute diarrhea of the adult in a hospital from Cordoba city

El objetivo de este estudio fue observar las principales características clínicas y epidemiológicas de la presentación de la diarrea aguda del adulto en un hospital público de la ciudad de Córdoba. Para su realización se incluyeron todos los pacientes mayores de 14 años que concurrieron a la Guardia Central del Hospital Nacional de Clínicas con diarrea aguda durante los períodos A(15-12-89 al 15-3-90), B(15-12-93 al 15-3-94), y C(15-12-94 al 15-3-95). El total de pacientes incluídos en los 3 períodos fue de 594: 337 mujeres (65,7 por ciento) y 257 varones; 143 consultaron en el período A, 250 en el B y 201 en el C. El promedio + DE de edad fue 34,6 + 13,3 años y de deposiciones diarias al momento de la consulta 7,3 + 4,7. El 86,1 por ciento presentó materia fecal de consistencia líquida durante el pisodio, 89,6 por ciento dolor abdominal, 44,7 por ciento vómitos y 18,8 por ciento sangre. El porcentaje de pacientes que concurrieron al hospital por diarrea aguda en relación al total de consultas aumentó del período A (2,47 por ciento) al B (3,61 por ciento), p=0,002 y disminuyó del período B al C(2,85 por ciento), p=0,01. Los promedios + DE de días transcurridos desde el inicio del cuadro hasta la consulta fueron 3,5 + 2,7 + 2,3 y 2,9 + 3,5 en los períodos A, B y C, diferencia estadísticamente significativa entre A y B, p<0,01. Presentó moco en la material fecal el 36,2 por ciento, 21.1 por ciento y 23,1 por ciento de los pacientes en los períodos A, B y C (p=0,01) y fiebre constatada el 61,1 por ciento, 48,1 por ciento y 48,5 por ciento respectivamente (p=0,04). El 27.1 por ciento de los coprocultivos resultó positivo en el período A, 17,6 por ciento en el B y 11,5 por ciento en el C; diferencia entre a y C: p=0,008. Se concluye que en un hospital público de la ciudad de Córdoba la diarrea aguda del adulto es causa frecuente de consulta, constatándose modificaciones de las características clínico-epidemiológicas en los ultimos años.