The Effect of Sanitizing Treatments on Respirator Filtration Performance

The potential for alcoholic vapors emitted by common sanitizing treatments to deteriorate the (electrostatic) filtration performance of disposable respirator masks has been investigated. Reports in the literature and some standard test methods provide a confusing and ambiguous picture concerning the relevance of this effect. Four different types of exposure were investigated in this study to clarify the effect of alcoholic vapor emissions on respirator masks. These included exposure to saturated vapors, use of hand sanitizers, cleaning of table surfaces and sanitization of masks by spraying them with alcohol-containing solutions. Methods employed were designed to be as real-world oriented as possible while remaining reproducible. Filtration performance and deterioration effects on exposure to the different treatments were determined on three different types of certified commercial respirator masks—a P2 and two KN95 masks. This study provides substantial evidence that disposable respirator masks with an accepted performance rating are seriously compromised from an exposure to saturated alcoholic vapors, can tolerate a one-off spray treatment with an alcoholic solution and retain their attested protection under the influence of alcoholic vapors from the use of hand sanitizer or spray sanitizer. Considering the range of vastly different outcomes obtained from the four treatments investigated, it seems prudent to assess in each case the specific effects of alcoholic solution treatments and vapors on respirator masks before use.

Modeling the Properties of Curcumin Derivatives in Relation to the Architecture of the Siloxane Host Matrices

Research in the field of natural dyes has constantly focused on methods of conditioning curcumin and diversifying their fields of use. In this study, hybrid materials were obtained from modified silica structures, as host matrices, in which curcumin dyes were embedded. The influence of the silica network structure on the optical properties and the antimicrobial activity of the hybrid materials was monitored. By modifying the ratio between phenyltriethoxysilane:diphenyldimethoxysilane (PTES:DPDMES), it was possible to evaluate the influence the organosilane network modifiers had on the morphostructural characteristics of nanocomposites. The nanosols were obtained by the sol–gel method, in acid catalysis. The nanocomposites obtained were deposited as films on a glass support and showed a transmittance value (T measured at 550 nm) of around 90% and reflectance of about 11%, comparable to the properties of the uncovered support. For the coatings deposited on PET (polyethylene terephthalate) films, these properties remained at average values of T550 = 85% and R550 = 11% without significantly modifying the optical properties of the support. The sequestration of the dye in silica networks reduced the antimicrobial activity of the nanocomposites obtained, by comparison to native dyes. Tests performed on Candida albicans fungi showed good results for the two curcumin derivatives embedded in silica networks (11–18 mm) by using the spot inoculation method; in comparison, the alcoholic dye solution has a spot diameter of 20–23 mm. In addition, hybrids with the CA derivative were the most effective (halo diameter of 17–18 mm) in inhibiting the growth of Gram-positive bacteria, compared to the curcumin derivative in alcoholic solution (halo diameter of 21 mm). The results of the study showed that the presence of 20–40% by weight DPDMES in the composition of nanosols is the optimal range for obtaining hybrid films that host curcumin derivatives, with potential uses in the field of optical films or bioactive coatings.

Osmium Recovery as Membrane Nanomaterials through 10–Undecenoic Acid Reduction Method

The recovery of osmium from residual osmium tetroxide (OsO4) is a necessity imposed by its high toxicity, but also by the technical-economic value of metallic osmium. An elegant and extremely useful method is the recovery of osmium as a membrane catalytic material, in the form of nanoparticles obtained on a polymeric support. The subject of the present study is the realization of a composite membrane in which the polymeric matrix is the polypropylene hollow fiber, and the active component consists of the osmium nanoparticles obtained by reducing an alcoholic solution of osmium tetroxides directly on the polymeric support. The method of reducing osmium tetroxide on the polymeric support is based on the use of 10-undecenoic acid (10–undecylenic acid) (UDA) as a reducing agent. The osmium tetroxide was solubilized in t–butanol and the reducing agent, 10–undecenoic acid (UDA), in i–propanol, t–butanol or n–decanol solution. The membranes containing osmium nanoparticles (Os–NP) were characterized morphologically by the following: scanning electron microscopy (SEM), high-resolution SEM (HR–SEM), structurally: energy-dispersive spectroscopy analysis (EDAX), Fourier transform infrared (FTIR) spectroscopy. In terms of process performance, thermal gravimetric analysis was performed by differential scanning calorimetry (TGA, DSC) and in a redox reaction of an organic marker, p–nitrophenol (PNP) to p–aminophenol (PAP). The catalytic reduction reaction with sodium tetraborate solution of PNP to PAP yielded a constant catalytic rate between 2.04 × 10−4 mmol s–1 and 8.05 × 10−4 mmol s−1.

Nanomaterial by Sol-Gel Method: Synthesis and Application

The sol-gel process is a more chemical method (wet chemical method) for the synthesis of various nanostructures, especially metal oxide nanoparticles. In this method, the molecular precursor (usually metal alkoxide) is dissolved in water or alcohol and converted to gel by heating and stirring by hydrolysis/alcoholysis. Since the gel obtained from the hydrolysis/alcoholysis process is wet or damp, it should be dried using appropriate methods depending on the desired properties and application of the gel. For example, if it is an alcoholic solution, the drying process is done by burning alcohol. After the drying stage, the produced gels are powdered and then calcined. The sol-gel method is a cost-effective method and due to the low reaction temperature there is good control over the chemical composition of the products. The sol-gel method can be used in the process of making ceramics as a molding material and can be used as an intermediate between thin films of metal oxides in various applications. The materials obtained from the sol-gel method are used in various optical, electronic, energy, surface engineering, biosensors, and pharmaceutical and separation technologies (such as chromatography). The sol-gel method is a conventional and industrial method for the synthesis of nanoparticles with different chemical composition. The basis of the sol-gel method is the production of a homogeneous sol from the precursors and its conversion into a gel. The solvent in the gel is then removed from the gel structure and the remaining gel is dried. The properties of the dried gel depend significantly on the drying method. In other words, the “removing solvent method” is selected according to the application in which the gel will be used. Dried gels in various ways are used in industries such as surface coating, building insulation, and the production of special clothing. It is worth mentioning that, by grinding the gel by special mills, it is possible to achieve nanoparticles.

Effect on the reduction of bacterial load after surgical hand antisepsis with triclosan 0.5% compared to triclosan 0.5% followed by 70% alcoholic solution

Triclosan 0.5% by scrubbing does not meet the UNE-EN12791 criteria to be used in the surgical hand preparation (SHP). Triclosan 0.5% by scrubbing followed by ethanol 70% hand rubbing is suitable without the additional characteristic of sustained effect. This limited effectiveness implies that triclosan should be avoided in SHP given the restrictions on its use in consumer antiseptic products. The trial was registered at ClinicalTrials.gov (ID: NCT04538365).

Causticum hahnemanni, Conium maculatum and Lycopodium clavatum highly diluted medications decreases parasitemia in mice infected by Trypanosoma cruzi

Introduction: Benznidazole is the only medicine available in Brazil for Chagas’ disease treatment, however it presents low efficacy in the chronic phase and several adverse effects [1-3]. Aim: Evaluate the effect of Causticum hahnemanni, Conium maculatum and Lycopodium clavatum [4-6] administered to mice infected with T. cruzi. Method: In blind randomized controlled trial 42 male Swiss mice, 8 weeks of age, have been grouped: GCaus –treated with C. hahnemanni 13cH (n=10), GCon –treated with C. maculatum 13 cH (n=11), GLy –treated with L. clavatum13cH (n=10) and CG – control group (n=11) treated with 7% hydro alcoholic solution 13cH. The animals were infected intraperitoneally with 1.400 blood trypomastigotes of T. cruzi - Y strain. Medications were been prepared according to Brazilian Homeopathic Pharmacopoeia [7]. Medication was diluted in water (1mL/100mL) offered ad libitum, from amber recipient during 16 hours administered 48 hours before infection and 48, 96 and 144 hours after inoculation. Parasitological parameters assessed: total parasitemia (TP), maximum peak of parasites (MPP), pre-patent period (PPP) and area under curve (AUC). Parasitemia was evaluated daily counting from the first day of infection. Clinical parameters assessed: weight, temperature, water and food intake and excreta were measured counting from the 5º day before infection until animals’ death or checking negative parasitemia for 3 consecutive days. Mortality was registered for 75 days after infection. Ethics Committee for Experiments in Animals gave approval UEM 054/11. Statistical comparison of data was performed with Kruskal-Wallis test, with 5% significance. Results and Discussion: The diluted medications have been significantly reduced the parasitological parameters: MPP (p

Towards a Mathematical Model for the Viral Progression in the Pharynx

In this work, a comprehensive model for the viral progression in the pharynx has been developed. This one-dimension model considers both Fickian diffusion and convective flow coupled with chemical reactions, such as virus population growth, infected and uninfected cell accumulation as well as virus clearance. The effect of a sterilizing agent such as an alcoholic solution on the viral progression in the pharynx was taken into account and a parametric analysis for the effect of kinetic rate parameters on virus propagation was made. Moreover, different conditions caused by further medical treatment, such as a decrease in virus yield per infected cell, were examined. It is shown that the infection fails to establish by decreasing the virus yield per infected cell. It is believed that this work could be used to further investigate the medical treatment of viral progression in the pharynx.

Preparation of silicon and alumosilicic aerogels based on the decomposition of nepheline with an alcoholic solution of sulfuric acid

The results of studies on the production of silicon and aluminum-silicon aerogels from nepheline are presented. The morphology of the obtained samples was studied. Their chemical purity was proved by the method of X-ray elemental analysis. The structural and surface properties of the resulting aerogel are presented, such as: specific surface area (843.62 и 503.99 m2/g) and pore volume (0.396 и 0.237 cm3/g), average pore size (1.870 nm). Data on the skeletal density of the obtained samples are given

Synthesis, designing, characterization and anti-microbial studies of N, N'- Bis (2 hydroxyacetophenone) Ethylenediamine metal (II) complexes

Tetra dentate Schiff base N, N’-bis [2-hydroxyacetophenone] ethylendiamine (OAcPh-en) were formed by the 2:1 molar condensation of 2-hydroxyacetophenone with ethylenediamine. Their Ni(II), Cu(II), Co(II), Mn(II), Fe(II) and Zn(II) diaquo complexes (I) were synthesized. The neutral bidentate ligand derived from benzaldehyde and ethylenediamine or o-phenylenediamine in 1:1 molar ratio in alcoholic solution yield bis[benzylidene] ethylenediamine (Ben-en) or bis [benzylidene] o-phenylinediamine (Ben-opd) (II). Further reaction between (I) and (II) in alcohol yielded mixed ligand complexes. The characterization of these newly synthesized mixed-ligand complexes were done by elemental analysis, magnetic measurements, infrared spectra and uv-visible spectra, thermo gravimetric analysis, anti-microbial studies have also been under taken

Evaluation of effects of inert vehicles proceeding from homeopathic preparation in mice’s experimental infection by Trypanosoma cruzi

Background: In experiments with homeopathic medicines is important to test the inert vehicle from succussed preparations for the treatment control. Aim: To evaluate the effect of hydro-alcoholic solutions 1cH, 6cH and 30cH in mice’s experimental infection with Trypanosoma cruzi. Methodology: In a blind, randomized, controlled test, two independent experiments with 34 and 51 swiss male mice, 8 weeks old, kept in cages micro acclimated, infected with 1400 blood trypomastigotes of the Y strain of T. cruzi (via IP), were divided: IC-untreated control; G1cH-received hydro-alcoholic solution dynamized 1cH; G6cH-received hydro-alcoholic solution dynamized 6cH and G30cH-received hydro-alcoholic solution dynamized 30cH. The solutions were prepared according to Brazilian Homeophatic Pharmacopoeia1 with alcohol 70 ° GL. Final preparations (1cH, 6cH and 30cH) were manipulated with water (Sigma-SP-Brazil). The treatment was offered diluted with water (1/100mL) ad libitum 48 hours before infection, available for 16h. After infection, the animals were treated 56h/56h for 16h until the 9th day of infection. The parasitological parameters were analyzed: Curve of Parasitemia, Total Parasitemia (TP), Peak Maximum of Parasites (PMP), Pre-Patent Period (PPP), Patent Period (PP) and Survival. The experiment was approved by the UEM’s Ethical Committee. Results: G1cH showed a higher survival (p=0.044) with a life expectancy of 2.58 times larger than the control group (Figure 1.A), as well as lower TP (p=0.002) and PMP (p = 0.018). PPP and PP showed no statistical difference, although in G1cH1 it was observed an increasing trend of PPP (p=0.065). These results are related to host’s benefit. The G6cH group presented a longer survival (p=0,045), with a life expectancy 1.94 times larger than the control group (Figure 1.B). Although no difference to TP, PMP, PP and PPP has been observed, the alcohol 6cH performed protecting animals against infection. The G30cH displayed an increasing trend of PMP (p=0.066) compared to the control group. Effects of inert vehicle succussed have been reported in studies in vitro2. However, no effects had been reported in vivo studies yet2,3. The hydro-alcoholic solution 7% 13CH, tested under the same conditions and animal model, did not change the natural evolution of the infection2. Conclusion: The hydro-alcoholic solutions 1cH and 6cH altered the course of experimental infection by T. cruzi, reducing the parasitemia and/or increasing the survival time, and can not be considered as inert vehicle in the high diluted compounds preparation.