Ozone as an alternative decontamination process for N95 facemask and biosafety gowns.

COVID-19 pandemic created a global shortage of medical protective equipment. Here, we considered ozone (O3) a disinfectant alternative due to its potent oxidative activity against biological macromolecules. The O3 decontamination assays were done using SARS-CoV-2 obtained from patients to produce artificial contamination of N95 masks and biosecurity gowns. The quantification of SARS-CoV-2 was performed before and after exposing the samples to different ozone gas concentrations for times between 5 and 30 min. Viral loads as a function of the O3 exposure time were estimated from the data obtained by the RT-PCR technique. The genetic material of the virus was no longer detected for any tested concentrations after 15 min of O3 exposure, which means a disinfection Concentration-Time above 144 ppm min. Vibrational spectroscopies were used to follow the modifications of the polymeric fibers after the O3 treatment. The results indicate that the N95 masks could be safely reused after decontamination with treatments of 15 min at the established O3 doses for a maximum of 6 cycles.

Treatment of platelet concentrates and plasma with riboflavin and UV light: Impact in bacterial reduction.

OBJECTIVES: Transfusion of hemocomponents is essential for clinical and surgical procedures and therefore their safety has increased. An option for pathogen reduction includes the combination of riboflavin and UV light. To our knowledge, there are no studies in Latin America that demonstrate the effectiveness of the pathogen reduction in hemocomponents. The objective of this work was to evaluate the efficiency of a pathogens reduction system in platelets concentrates (PC) and plasma. MATERIALS AND METHODS: PC and plasma were contaminated with Escherichia coli, Klebsiella pneumoniae, Streptococcus pyogenes and Staphylococcus epidermidis at 104 to 106 CFU and subjected to bacterial reduction. After bacterial reduction, hemocomponents were subjected to cultivation of surviving bacteria by automated method and classical colonies quantification. Additionally, quality control testing was performed in order to confirm the integrity of platelets and coagulation laboratory values in plasma before and after bacterial reduction. RESULTS: The bacterial death in PC/plasma was expressed by Logarithmic Reduction Value as follows: for both strains (E. coli and S. pyogenes) 4/4, 5/5 and 6/6; for K. pneumoniae 2.54/2.23, 2.94/2.22 and 3.44/2.98, for S. epidermidis 4/4, 3.11/5 and 3.23/4.19, for 104, 105 and 106 CFU, respectively. In PC and plasma, platelet count, pH (at 22°C), activated partial thromboplastin time (aPTT), prothrombin time (PT), fibrinogen, factor VIII and total proteins (TP) were slightly modified. CONCLUSIONS: UV light with riboflavin is able to reduce an important number of pathogens in hemocomponents; however, the bacterial reduction is influenced by the nature and quantity of the pathogen.

Applicability of the Gibbs Adsorption Isotherm to the analysis of experimental surface-tension data for ionic and nonionic surfactants.

The Gibbs Adsorption Isotherm equation is a two-dimensional analogous of the Gibbs-Duhem equation, and it is one of the cornerstones of interface science. It is also widely used to estimate the surface excess concentration (SEC) for surfactants and other compounds in aqueous solution, from surface tension measurements. However, in recent publications some authors have cast doubt on this method. In the present work, we review some of the best available surface tension experimental data, and compare estimations of the SEC, using the Gibbs isotherm method (GIM), to direct measurements reported in the literature. This is done for both nonionic and ionic surfactants, with and without added salt. Our review leads to the conclusion that the GIM has a very solid agreement with experiments, and that it does estimate accurately the SEC for surfactant concentrations smaller than the critical micellar concentration (CMC).

Onsager's irreversible thermodynamics of the dynamics of transient pores in spherical lipid vesicles.

Onsager's irreversible thermodynamics is used to perform a systematic deduction of the kinetic equations governing the opening and collapse of transient pores in spherical vesicles. We show that the edge tension has to be determined from the initial stage of the pore relaxation and that in the final state the vesicle membrane is not completely relaxed, since the surface tension and the pressure difference are about 25% of its initial value. We also show that the pore life-time is controlled by the solution viscosity and its opening is driven by the solution leak-out and the surface tension drop. The final collapse is due to a non-linear interplay between the edge and the surface tensions together with the pressure difference. We also discuss the connection with previous models.

The relationship between mood instability and depression: implications for studying and treating depression.

BACKGROUND: Most individuals with depressed mood report mood fluctuations (Mood Instability) within hours or days. This is not recognized in diagnostic criteria or standard rating scales for depression. HYPOTHESIS: That mood instability is a distinct component of the development of depression that has been omitted from criteria for depression because of reliance on retrospective recall and structured interviews. The inclusion of Mood Instability would enhance research into causes and treatment of depression. STUDIES: We examined three datasets that used retrospective and prospective measures of depressed symptom ratings and mood instability to determine the relationship between the two. Study 1 used data from the 1991 UK Health and Lifestyle Surveys (HALS). Studies 2 and 3 used clinical samples. The scales used to assess mood instability were the mood instability factor from the Eysenck Personality Inventory Neuroticism Scale, the Affective Lability Scale (ALS), and the Visual Analogue Depression Scale (VAS). The depression scales (depressive symptoms) were the General Health Questionnaire (GHQ) depression factor, the Beck Depression Inventory IA (BDI) and the mean from the Visual Analogue Depression Scale (VAS). We used partial correlation analysis to assess the association between mood instability and depression and exploratory factor analysis to determine the factor structure of items pooled from the mood instability and depression scales from studies 1 and 2. RESULTS: Mood Instability was found to be moderately associated with depressive symptoms. The Pearson's r-values ranged from 0.49 to 0.57. The correlation was lower when recalling mood in the past. The factor analytic solution supported the hypothesis that MI and depressive symptoms are related but distinct constructs. CONCLUSIONS: Reliance exclusively on the retrospective assessment of depressive symptoms has occluded the widespread occurrence of mood instability. Including Mood Instability in diagnostic and assessment criteria would enhance causal and treatment research in depression.

Effects of topical oral antiseptic rinses on bacterial counts of saliva in healthy human subjects.

Wound infections remain a significant source of morbidity in patients undergoing major head and neck operations that invade the aerodigestive tract. Infection rates have been significantly reduced by the administration of perioperative intravenous antibiotics; however, the incidence of infection remains unacceptably high. This study was undertaken to help identify an oral antiseptic that could significantly reduce the bacterial colony count of human saliva. A randomized, prospective clinical trial was conducted to analyze and compare the effects of Listerine antiseptic and Peridex oral rinse on the aerobic and anaerobic bacterial counts in healthy human subjects. Thirty healthy adult volunteers between the ages of 18 and 61 participated in the study. The patients were randomized to receive normal saline solution, Listerine antiseptic, or Peridex oral rinse. Aerobic and anaerobic bacterial colony counts of saliva were measured before treatment and at 1 and 4 hours after treatment. Both Listerine antiseptic and Peridex oral rinse significantly reduced bacterial counts at 1 hour after treatment in our volunteers. At 4 hours after treatment, Peridex oral rinse showed a further reduction in the bacterial colony count whereas Listerine antiseptic showed no difference compared with normal saline solution. At 4 hours after treatment, Peridex oral rinse reduced the total bacterial colony count by 85%.

Eagle's syndrome (elongated styloid process)

Eagle's syndrome occurs when an elongated styloid process or calcified stylohyoid ligament causes recurrent throat pain or foreign body sensation, dysphagia, or facial pain. Additional symptoms may include neck or throat pain with radiation to the ipsilateral ear. In adults, the styloid process is approximately 2.5 cm long, and its tip is located between the external and internal carotid arteries, just lateral to the tonsillar fossa. It may develop inflammatory changes or impinge on the adjacent arteries or sensory nerve endings, leading to the symptoms described. Diagnosis can usually be made on physical examination by digital palpation of the styloid process in the tonsillar fossa, which exacerbates the pain. In addition, relief of symptoms with injection of an anesthetic solution into the tonsillar fossa is highly suggestive of this diagnosis. Radiographic workup should include anterior-posterior and lateral skull films. The treatment of Eagle's syndrome is primarily surgical. The styloid process can be shortened through an intraoral or external approach. We present two cases and review the literature.