Anoxic nitrification with carbon-based materials as terminal electron acceptors.

This study investigates the potential of humic substances (HS) and graphene oxide (GO), as extracellular electron acceptors (EEA) for nitrification, aiming to explore alternatives to sustain this process in wastewater treatment systems. Experimental results demonstrate the conversion of ammonium to nitrate (up to 87 % of conversion) coupled to the reduction of either HS or GO by anaerobic consortia. Electron balance confirmed the contribution of HS and GO to ammonium oxidation. Tracer analysis in incubations performed with 15NH4+ demonstrated 15NO3- as the main product with a minor fraction ending as 29N2. Phylogenetic analysis identified Firmicutes, Euryarchaeota, and Chloroflexi as the microbial lineages potentially involved in anoxic nitrification linked to HS reduction. This study introduces a new avenue for research in which carbon-based materials with electron-accepting capacity may support the anoxic oxidation of ammonium, for instance in bioelectrochemical systems in which carbon-based anodes could support this novel process.

The consensus of the Asociación Mexicana de Gastroenterología on the diagnosis and treatment of gastroesophageal reflux and gastroesophageal reflux disease in infants.

Gastroesophageal reflux (GER) is a frequent normal phenomenon in children of any age. It is more common in infants, in whom the majority of episodes are short-lived and cause no other symptoms or complications, differentiating it from gastroesophageal reflux disease (GERD). The diagnosis and management of GER and GERD continue to be a challenge for the physician. Therefore, the aim of the Asociación Mexicana de Gastroenterología was to adapt international documents to facilitate their adoption by primary care physicians, with the goal of standardizing quality of care and reducing the number of diagnostic tests performed and inappropriate medication use. The ADAPTE methodology was followed, and the recommendations were approved utilizing the Delphi strategy. The executive committee carried out the review of the guidelines, position papers, and international reviews that met the a priori quality criteria and possible applicability in a local context. The recommendations were taken from those sources and adapted, after which they were approved by the working group. The consensus consists of 25 statements and their supporting information on the diagnosis and treatment of GER and GERD in infants. The adapted document is the first systematic effort to provide an adequate consensus for use in Mexico, proposing a practical approach to and management of GER and GERD for healthcare providers.

The COVID-19 pandemic and non-COVID-19 healthcare utilization in Mexico.

OBJECTIVES: This study aimed to analyze the effects of the COVID-19 pandemic on non-COVID-19 healthcare utilization in Mexico, including oral health, mental health, communicable disease visits, health checkups, chronic degenerative disease visits, postpartum care, prenatal care, and family planning visits. STUDY DESIGN: This was a retrospective ecological analysis during the COVID-19 pandemic. During the pandemic, the Mexican government recommended non-essential consultations be suspended or rescheduled to accommodate the new demand for healthcare services from COVID-19 patients. METHODS: This study uses administrative data from Mexico's Ministry of Health from January 2017 to December 2022. These data cover 14,299 consultation units and 775 hospitals from the 32 Mexican States, all of which are public institutions. A difference-in-differences strategy and an event study specification are used to study the impacts of the pandemic on non-COVID-19 healthcare utilization. RESULTS: The findings reveal a decrease in the utilization of all healthcare services: oral health (69%), mental health (27%), communicable diseases (46%), chronic degenerative diseases (36%), health checkups (62%), family planning (45%), prenatal care (36%), and postpartum care (44%). Furthermore, the event study indicates that most services follow a U-shaped trend, although only mental health services clearly return to prepandemic levels. The remainder of services remain below prepandemic levels at the end of 2022. CONCLUSIONS: The 2020 pandemic had detrimental effects on non-COVID-19 healthcare utilization. The healthcare interruptions will likely impact short- and long-term morbidity and mortality. Programs intended to remediate these negative consequences may be of interest to public health policymakers.

Anammox with alternative electron acceptors: perspectives for nitrogen removal from wastewaters.

In the context of the anaerobic ammonium oxidation process (anammox), great scientific advances have been made over the past two decades, making anammox a consolidated technology widely used worldwide for nitrogen removal from wastewaters. This review provides a detailed and comprehensive description of the anammox process, the microorganisms involved and their metabolism. In addition, recent research on the application of the anammox process with alternative electron acceptors is described, highlighting the biochemical reactions involved, its advantages and potential applications for specific wastewaters. An updated description is also given of studies reporting the ability of microorganisms to couple the anammox process to extracellular electron transfer to insoluble electron acceptors; particularly iron, carbon-based materials and electrodes in bioelectrochemical systems (BES). The latter, also referred to as anodic anammox, is a promising strategy to combine the ammonium removal from wastewater with bioelectricity production, which is discussed here in terms of its efficiency, economic feasibility, and energetic aspects. Therefore, the information provided in this review is relevant for future applications.

Biocatalyst developed with recovered iron-rich minerals enhances the biotransformation of SARS-CoV-2 antiviral drugs in anaerobic bioreactors.

The biotransformation of the SARS-CoV-2 antiviral drugs, ribavirin and tenofovir, was studied in methanogenic bioreactors. The role of iron-rich minerals, recovered from a metallurgic effluent, on the biotransformation process was also assessed. Enrichment of anaerobic sludge with recovered minerals promoted superior removal efficiency for both antivirals (97.4 % and 94.7 % for ribavirin and tenofovir, respectively) as compared to the control bioreactor lacking minerals, which achieved 58.5 % and 37.9 % removal for the same drugs, respectively. Further analysis conducted by liquid chromatography coupled to mass spectroscopy revealed several metabolites derived from the biotransformation of both antivirals. Interestingly, tracer analysis with 13CH4 revealed that anaerobic methane oxidation coupled to Fe(III) reduction occurred in the enriched bioreactor, which was reflected in a lower content of methane in the biogas produced from this system, as compared to the control bioreactor. This treatment proposal is suitable within the circular economy concept, in which recovered metals from an industrial wastewater are applied in bioreactors to create a biocatalyst for promoting the biotransformation of emerging pollutants. This strategy may be appropriate for the anaerobic treatment of wastewaters originated from hospitals, as well as from the pharmaceutical and chemical sectors.

Enhanced anaerobic treatment of synthetic protein-rich wastewater promoted by organic xerogels.

Carbon-based materials have been shown to enhance anaerobic digestion processes by promoting direct interspecies electron transfer in methanogenic consortia. However, little is known on their effects during the treatment of complex substrates, such as those derived from protein-rich wastewaters. Here, organic xerogels (OX) are tested, for the first time, as accelerators of the methanogenic activity of an anaerobic consortium treating a synthetic protein-rich wastewater. Three OX with distinct pore size distribution (10 and 1000 nm for OX-10 and OX-1000, respectively) and structural conformation (graphene oxide integration into OX-10-GO polymeric matrix) were synthesized. OX-1000 promoted the highest methane production rate (5.21 mL/g*h, 13.5% increase with respect to the control incubated without OX) among the synthesized OX. Additionally, batch bioreactors amended with OX achieved higher chemical oxygen demand (COD) removal (up to 88%) as compared to the control, which only showed 50% of COD removal. Interestingly, amendment of bioreactors with OX also triggered the production of medium-chain fatty acids, including caprylate and caproate. Moreover, OX decreased the accumulation of ammonium, derived from proteins hydrolysis, partly explained by their adsorption capacities, and probably involving their electron-accepting capacity promoting anaerobic ammonium oxidation. This is the first time that OX were successfully applied as methanogenic accelerators for the anaerobic treatment of synthetic protein-rich wastewater, increasing the methane production rate and COD removal as well as triggering the production of medium chain fatty acids and attenuating the accumulation of ammonium. Therefore, OX are proposed as suitable materials to boost the efficiency of anaerobic systems to treat complex industrial wastewaters.

New bimetallic adsorbent material based on cerium-iron nanoparticles highly selective and affine for arsenic(V).

Bimetallic oxy(hydroxides) have gain great interest in water treatment systems based on adsorption processes. Their high OH groups density, in addition to inheriting the oxides properties make them highly promising adsorbents of anions. In this work, highly affine and selective bimetallic oxyhydroxides of cerium and iron (Ce:Fe-P's) for arsenic(V) were synthesized by implementing an assisted microwave methodology. The Ce:Fe-P's were characterized by various techniques (SEM, FTIR, XRD and XPS) and the As(V) adsorption capacity and kinetics as well as the effect of pH and the presence of coexisting anions were determined. The results showed that Ce:Fe-P's have an outstanding As(V) adsorption capacity (179.8 mg g-1 at Ce = 3 mg L-1) even at low concentrations (120 mg g-1 at Ce = 37 µg L-1). Moreover, the adsorption equilibrium was reached very fast, just in 3 min, with an adsorption rate of 0.123 mg min-1, that is, 80% of the initial As(V) concentration of 5 mg L-1 was removed in the first 3 min. The arsenic adsorption capacity decreased only up to 20% at pH above 7, attributed to electrostatic repulsions due to the adsorbent's pHPZC, which was 6.8. On the other hand, the arsenic adsorption capacity of Ce:Fe-P's decreased just 21% in the presence of 10 mg L-1 of each of the following competing anions: F-, Cl-, SO42-, NO3-, PO43- and CO32-, which usually coincide in contaminated water with As(V). Ce:Fe-P's has proven to be one of the most promising As(V) adsorbent materials reported so far in the literature, because it presented an outstanding adsorption capacity and at the same time a very fast adsorption speed. Furthermore, the pH and the concentration of coexisting anions caused little interference in the adsorption processes. Due to the above, the Ce:Fe-P's is already in the process of intellectual protection.

Monitoring of RAS mutant clones in plasma of patients with RAS mutant metastatic colorectal cancer.

PURPOSE: Some patients with histologically confirmed primary mCRC and mutated RAS reported undetectable RAS mutant clones in plasma after receiving anti-VEGF treatment. The aim was to prospectively assess it with its potential therapeutic implications. METHODS: RAS mutant genes in solid biopsy (before first-line treatment: FOLFOX/CAPOX + bevacizumab) were compared in liquid biopsy (before second-line treatment: panitumumab + FOLFIRI), using Idylla™ system. Discordant results between solid/liquid biopsies were assessed by the next-generation sequencing (NGS) test (solid/liquid biopsies). RESULTS: Twenty-three patients were assessed (seven had RAS mutant discrepancies between solid/liquid biopsies). The NGS test confirmed that 3/23 (13%) patients had undetectable RAS mutant clones in liquid biopsy and 3/23 (13%) presented discrepancies in solid biopsy (Idylla™ system vs. NGS test). CONCLUSION: Thirteen percentage of patients had undetectable RAS mutant clones in liquid biopsy after first-line treatment. However, some discrepancies between solid and liquid biopsies have been observed. These results suggest a need to improve accuracy of RAS analyses, especially in solid biopsies.

DNA damage modeled with Geant4-DNA: effects of plasmid DNA conformation and experimental conditions.

The chemical stage of the Monte Carlo track-structure (MCTS) code Geant4-DNA was extended for its use in DNA strand break (SB) simulations and compared against published experimental data. Geant4-DNA simulations were performed using pUC19 plasmids (2686 base pairs) in a buffered solution of DMSO irradiated by60Co or137Csγ-rays. A comprehensive evaluation of SSB yields was performed considering DMSO, DNA concentration, dose and plasmid supercoiling. The latter was measured using the super helix density value used in a Brownian dynamics plasmid generation algorithm. The Geant4-DNA implementation of the independent reaction times method (IRT), developed to simulate the reaction kinetics of radiochemical species, allowed to score the fraction of supercoiled, relaxed and linearized plasmid fractions as a function of the absorbed dose. The percentage of the number of SB after •OH + DNA and H• + DNA reactions, referred as SSB efficiency, obtained using MCTS were 13.77% and 0.74% respectively. This is in reasonable agreement with published values of 12% and 0.8%. The SSB yields as a function of DMSO concentration, DNA concentration and super helix density recreated the expected published experimental behaviors within 5%, one standard deviation. The dose response of SSB and DSB yields agreed with published measurements within 5%, one standard deviation. We demonstrated that the developed extension of IRT in Geant4-DNA, facilitated the reproduction of experimental conditions. Furthermore, its calculations were strongly in agreement with experimental data. These two facts will facilitate the use of this extension in future radiobiological applications, aiding the study of DNA damage mechanisms with a high level of detail.

Early transcriptional responses in Solanum peruvianum and Solanum lycopersicum account for different acclimation processes during water scarcity events.

Cultivated tomato Solanum lycopersicum (Slyc) is sensitive to water shortages, while its wild relative Solanum peruvianum L. (Sper), an herbaceous perennial small shrub, can grow under water scarcity and soil salinity environments. Plastic Sper modifies the plant architecture when suffering from drought, which is mediated by the replacement of leaf organs, among other changes. The early events that trigger acclimation and improve these morphological traits are unknown. In this study, a physiological and transcriptomic approach was used to understand the processes that differentiate the response in Slyc and Sper in the context of acclimation to stress and future consequences for plant architecture. In this regard, moderate (MD) and severe drought (SD) were imposed, mediating PEG treatments. The results showed a reduction in water and osmotic potential during stress, which correlated with the upregulation of sugar and proline metabolism-related genes. Additionally, the senescence-related genes FTSH6 protease and asparagine synthase were highly induced in both species. However, GO categories such as "protein ubiquitination" or "endopeptidase inhibitor activity" were differentially enriched in Sper and Slyc, respectively. Genes related to polyamine biosynthesis were induced, while several cyclins and kinetin were downregulated in Sper under drought treatments. Repression of photosynthesis-related genes was correlated with a higher reduction in the electron transport rate in Slyc than in Sper. Additionally, transcription factors from the ERF, WRKY and NAC families were commonly induced in Sper. Although some similar responses were induced in both species under drought stress, many important changes were detected to be differentially induced. This suggests that different pathways dictate the strategies to address the early response to drought and the consequent episodes in the acclimation process in both tomato species.

Calpain Participates in Cortical Cytoskeleton Modification and DNA Release during Neutrophil Extracellular Trap Formation.

INTRODUCTION: The formation of neutrophil extracellular traps (NETs) is a process in which several kinds of enzymes participate generating posttranslational modifications of proteins. NETs have been associated with infectious, autoimmune, and inflammatory diseases. Inhibition of several proteases reduces the formation of NETs. In the present work, we analyzed the role of several broad-acting and specific inhibitors of proteases in the formation of NETs. METHODS: Neutrophils were isolated from peripheral blood of healthy individuals by density gradient. The neutrophils were quantified and seeded into cell culture plates. Phorbol myristate acetate and A23187 were used as NETs inducers, and several specific inhibitors of proteases were used. The cells were stained for cytoskeleton or DNA. The cell-free supernatants were used to assess DNA release. Statistical analysis was carried out by a Kruskal-Wallis or ANOVA test. RESULTS: We observed marked changes in actin organization after the induction of NETs, suggesting that the cytoskeleton is being actively regulated. When we used protease inhibitors, the release of DNA was reduced, suggesting the participation of actin remodeling in the process. Further characterization of the specific proteases revealed that calpain modulates the reorganization of actin cytoskeleton and DNA release. Preservation of part of the actin cytoskeleton suggests that DNA release is not only a mechanic process associated to the chromatin decondensation; rather the process is highly regulated by active proteases that promote cytoskeleton reorganization and chromatin decondensation that culminates in DNA release. CONCLUSION: Calpain mediates the DNA release in the NET formation process by the modification of cortical actin cytoskeleton in a calcium-dependent manner.

Uso de Peróxido de Hidrógeno como Enjuague Bucal Previo a la Consulta Dental para Disminuir la Carga Viral de COVID-19. Revisión de la Literatura / Use of Hydrogen Peroxide as a Dental Pre-consultation Mouthwash to Decrease the Viral Load of COVID-19. Literature Review

RESUMEN: La utilización de enjuagues antisépticos previo a la atención odontológica favorecería la disminución del virus en la cavidad oral. Se ha planteado el uso de peróxido de hidrógeno preconsulta dental. Se revisaron las bases de datos PubMed, Cochrane y Elsevier publicados desde Enero 2019 a junio 2020. Los estudios que cumplieron los criterios de inclusión fueron revisados por 2 autores individualmente. Se realizó una revisión cualitativa de los datos. No existen ensayos controlados aleatorios o estudios de observación clínica sobre el efecto curativo o preventivo del peróxido de hidrógeno contra el COVID-19, pero si protocolos de ensayos clínicos que están en proceso de reclutamiento. El enjuague bucal con peróxido de hidrógeno podría ser una solución viable pre consulta dental que debe ser estudiada para reducir la carga viral del COVID-19.

ABSTRACT: The use of antiseptic rinses prior to dental care would favor the reduction of the virus in the oral cavity. The use of hydrogen peroxide prior to dental consultation has been proposed. PubMed, Cochrane and Elsevier databases published from January 2019 to June 2020 were reviewed. Studies that met the inclusion criteria were reviewed by 2 authors individually. A qualitative review of the data was performed. There are no randomized controlled trials or clinical observation studies on the curative or preventive effect of hydrogen peroxide against COVID-19, but there are clinical trial protocols that are in the process of recruitment. Hydrogen peroxide mouthwash could be a viable solution prior to dental consultation that should be studied, to reduce COVID-19 viral load.

Synthesis of Bamboo-like Multiwall Carbon Nanotube-Poly(Acrylic Acid-co-Itaconic Acid)/NaOH Composite Hydrogel and its Potential Application for Electrochemical Detection of Cadmium(II).

A poly(acrylic acid-co-itaconic acid) (PAA-co-IA)/NaOH hydrogel containing bamboo-type multiwall carbon nanotubes (B-MWCNTs) doped with nitrogen (PAA-co-IA/NaOH/B-MWCNTs) was synthesized and characterized by SEM, absorption of water, point of zero charges, infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The possible use of the PAA-co-IA/NaOH/B-MWCNT hydrogel as an electrode modifier and pre-concentrator agent for Cd(II) sensing purposes was then evaluated using carbon paste electrodes via differential pulse voltammetry. The presence of the B-MWCNTs in the hydrogel matrix decreased its degree of swelling, stabilized the structure of the swollen gel, and favored the detection of 3 ppb Cd(II), which is comparable to the World Health Organization's allowable maximum value in drinking water. A calibration curve was obtained in the concentration range of 2.67 × 10-8 to 6.23 × 10-7 M (i.e., 3 and 70 ppb) to determine a limit of detection (LOD) of 19.24 µgL-1 and a sensitivity of 0.15 µC ppb-1. Also, the Zn(II), Hg(II), Pb(II) and Cu(II) ions interfered moderately on the determination of Cd(II).

Plasmocitoma mamario y cáncer de mama: a propósito de un caso / Breast Plasmacytoma and breast cancer: a case report

El plasmocitoma mamario es una neoplasia de células plasmáticas extremadamente infrecuente, con menos de cincuenta casos descritos en el último siglo. Por este motivo, apenas se dispone de datos acerca del abordaje, tratamiento y seguimiento más convenientes. Presentamos el caso de una paciente de 70 años que debutó con un plasmocitoma mamario y que un año después fue diagnosticada de un carcinoma mamario lobulillar ipsilateral. La asociación entre plasmocitoma y cáncer de mama no está descrita en la literatura, por lo que es muy complicado establecer un vínculo entre ambas entidades. Sin embargo, el abordaje terapéutico del plasmocitoma podría comprometer el tratamiento ulterior de un cáncer de mama, por lo que el tratamiento idóneo en estos casos sea probablemente la cirugía.

Breast plasmocytoma is an extremely rare plasma cell neoplasm, with less than 50 cases reported in the last century. This is the reason why we barely have data about optimal management, treatment and follow-up. We hereby report the case of a 70 year old woman diagnosed with breast plasmocytoma that developed lobular breast cancer a year later. The link between plasmocytoma and breast cancer has not been previously established. However, breast plasmocytoma treatment could compromise latter breast cancer approach, so probably the most suitable strategy in these cases should be breast surgery.Conclusions: There are clinical characteristics associated with complications in women with surgical management abortion in our center, such as admission diagnosis, unplanned pregnancy, previous abortion and type of evacuation. There are limitations regarding the quantity and quality of information, however, our results allow us to know the profile of patients treated for abortion in our center.

Subclinical inflammation in the preclinical phase of rheumatoid arthritis might contribute to articular joint damage.

The first degree relatives of rheumatoid arthritis (RA) patients have a higher risk of developing RA, which is related to the expression of autoantibodies against citrullinated proteins (ACPA). Remarkably, prior to the onset of RA, cartilage damage is already initiated, whereas ACPA autoantibodies are already expressed. Here we show that both TNF-α and IL-6 are also increased prior to the onset of RA. Furthermore, when the levels of DKK1 and Sclerostin were evaluated in first degree relatives of RA patients, we found that the serum levels of TNF- α correlate with the expression levels of both DKK1 and Sclerostin. Interestingly, when the disease is already established, the correlation of TNF- α with DKK1 is lost in RA patients, whereas the correlation of Sclerostin with both TNF- α and IL-6 is further increased. Our data suggest a subclinical inflammation in patients at high risk of developing RA, which might lead to an increase in the levels of both DKK1 and Sclerostin, contributing to joint damage in the preclinical phase of the disease linked to the expression of ACPA autoantibodies.

Erratum: Flores, J., et al. Effective Parameters for 1D Photonic Crystals with Isotropic and Anisotropic Magnetic Inclusions: Coherent Wave Homogenization Theory. Materials 2020, 13, 1475.

The authors wish to make the following corrections to this paper [1]: replace: (37) 1 ε z = f ε m = 1 - f ε d and (39) 1 µ z = f µ m = 1 - f µ d with the correct expressions: (37) 1 ε z = f ε m + 1 - f ε d and (39) 1 µ z = f µ m + 1 - f µ d [...].

Metabolic Syndrome, a Real Barrier for Living Kidney Donor Transplant.

INTRODUCTION: Renal transplantation is the optimal renal replacement therapy. In Mexico, most of the kidney transplants are from living donors. It is essential to identify conditions that increase the risk of developing chronic kidney disease (CKD) in donors, such as metabolic syndrome (MS). MATERIALS AND METHODS: In retrospect from January 2008 to December 2018, the donation protocols for renal transplantation of the Hospital Central Sur Alta Especialidad "Picacho" were reviewed, classifying all the cases of donors by nephrectomy or no nephrectomy and describing the demographic characteristics, prevalence of metabolic diseases, and cause of rejection of the protocol. RESULTS: A total of 178 donors were studied: 82 women (46%), 96 men (54%), mean age of 42 years, average body mass index (BMI) 27.9 kg/m2, glomerular filtration rate (GFR) by Chronic Kidney Disease Epidemiology Collaboration 99 mL/min, 59 patients with grade I and II obesity (BMI ≥ 30 kg/m2), and 1 patient with morbid obesity (BMI ≥ 40 kg/m2). A total of 39 patients (22%) underwent nephrectomy and 139 (78%) did not. The following characteristics and alterations were found: Of the 139 patients who did not undergo nephrectomy, 91 had metabolic disorders, 20 had low GFR, 21 had albuminuria, and 4 recipients received cadaveric transplants, 3 due to critical conditions of the recipient. The metabolic alterations in the rejected donors were as follows: MS 54 (59%), prediabetes 55 (39%), newly diagnosed hypertension 70 (76%), diabetes mellitus 20 (14%), obesity 47 (51.6%), dyslipidemia 76 (83%), hyperuricemia 17 (12%). DISCUSSION: The prevalence of MS in apparently healthy donors is similar to that of other studies in Mexico. Both MS and its components are independently associated with an increased risk of cardiovascular disease and CKD. It has been shown that these donors have a greater degree of glomerular and interstitial fibrosis; therefore, diagnosis, prevention, and timely treatment in this group are important.

Efecto de gas de formalina sobre el recuento de mesófilos en nailon comercial destinado a procedimientos quirúrgicos / Effect of formaline gas on the counting of mesophiles in commercial nylon destined to surgical procedures

RESUMEN La investigación se realizó a fin de evaluar el efecto del gas de formalina sobre el recuento de mesófilos en nailon comercial (poliamida) destinado a procedimientos quirúrgicos. En primer lugar, se evaluó la contaminación de una muestra del material comercial de 1 g expuesta al ambiente de quirófano por 72 horas, a través de la técnica de recuento en placa para mesófilos; se obtuvieron 850 UFC/g. Una vez comprobada la contaminación de la poliamida comercial, esta se sometió a gases de formalina en comprimidos. Se colocaron 5 muestras (n=5) de nailon de 1 g cada una en 5 recipientes herméticos de 1 litro con 1 gramo de formalina cada uno; estos recipientes se almacenaron en un mueble en sala de esterilización a un metro de altura del piso y posteriormente, fueron abiertos y cultivados a través de la técnica de recuento en placa para mesófilos, uno por día a lo largo de 5 días a intervalos de 24 horas. Los resultados obtenidos no registraron crecimientos de microorganismos a partir de las 24 horas y durante los 5 días posteriores y se encontraron diferencias estadísticamente significativas (p < 0,05). Se concluye que bajo las condiciones del presente estudio el tiempo de esterilización de la formalina sobre nailon comercial es de 24 horas.

ABSTRACT Hie present research work was carried out with the purpose of evaluating the effect of formalin gas on the count of mesophiles in commercial nylon (polyamide) destined to surgical procedures. Firstly, the contamination of a 1 g commercial nylon sample, exposed to the operating room environment for 72 hours, was evaluated through the plate counting technique for mesophiles; it yielded a result of 850 CFU / gram. Once the contamination of the commercial polyamide was checked, it was subjected to formalin gases in tablets. Five nylon samples (n=5) of 1 gram each were placed in 5 1 liter airtight containers containing 1 gram of formalin; Hese containers were stored in a cabinet in the sterilization room one meter above the floor, and later opened and cultivated through the plate counting technique for mesophiles, one per day for 5 days at 24 hour intervals. The results obtained after being exposed to formalin gases in tablets did not register growths of microorganisms after 24 hours and during the 5 days after the study, finding statistically significant differences (p < 0.05) in relation to the studied times concluding under the conditions of the present study that the sterilization time of the formalin on commercial nylon is equal to 24 hours.

Leptospirosis in an asplenic patient -case report.

BACKGROUND: The presentation of clinical leptospirosis has been historically associated with animal workers, slaughterhouse workers and medical veterinarians. This association has shifted to be related to flooding events and outdoor activities; few cases are related to high-risk factors found in immunosuppressed patients. Scarcely a handful of cases have serological evidence of immune response against Leptospira serovar Bratislava representing serogroup Australis, a serovar associated with poor reproductive performance in swine and horses, and recently with cats. CASE PRESENTATION: Herein, we describe a rare clinical presentation of disseminated Leptospira infection in an immunosuppressed 65-year-old woman. She was admitted to the emergency room with fever, bacteraemia, bilateral uveitis and pulmonary involvement. The patient denied outdoor activities; she only had wide exposure to faeces and urine from cats living in her home. Her medical history included idiopathic thrombocytopenic purpura (ITP) diagnosed at the age of 18. She did not respond to medical treatment, and a splenectomy was performed. At age 60, she was diagnosed with Chronic Myeloid Leukemia (CML), and was treated with a tyrosine kinase inhibitor (TKI) -Imatinib. The patient voluntarily discontinued the treatment for the last 6 months. After extensive workup, no microorganisms were identified by the commonly used stains in microbiology. The diagnosis was performed through dark-field microscopy, microagglutination test (MAT), Leptospira genus-specific PCR, the IS1500 PCR for identification of pathogenic species, and 16S based sequencing for the genus identification. CONCLUSION: Immunosuppressed patients may acquire uncommon infections from ubiquitous microorganisms. In this case, serology evidence of exposure to Leptospira serovar Bratislava by MAT and the presence of the Leptospira genus were identified. It should be on mind for the diagnosis in otherwise healthy patients, and thoroughly search on splenectomised patients exposed to animals. Additionally, this report highlights the usefulness of PCR for diagnosis of this potentially life-threatening illness.

Effects of graphene oxide and reduced graphene oxide on acetoclastic, hydrogenotrophic and methylotrophic methanogenesis.

This study describes the effects of graphene oxide (GO) and reduced graphene oxide (rGO) on the acetoclastic, hydrogenotrophic and methylotrophic pathways of methanogenesis by an anaerobic consortium. The results showed that GO negatively affected the hydrogenotrophic and acetoclastic pathways at a concentration of 300 mg/L, causing a decrease of ~ 38% on the maximum specific methanogenic activity (MMA) with respect to the controls lacking GO. However, the presence of rGO (300 mg/L) promoted an improvement of the MMA (> 45%) achieved with all substrates, except for the hydrogenotrophic pathway, which was relatively insensitive to rGO. The presence of either rGO or GO enhanced the methylotrophic pathway and resulted in an increase of the MMA of up to 55%. X-ray photoelectron spectroscopy (XPS) analysis revealed that GO underwent microbial reduction during the incubation period. Electrons derived from substrates oxidation were deviated from methanogenesis towards the reduction of GO, which may explain the MMA decreased observed in the presence of GO. Furthermore, XPS evidence indicated that the extent of GO reduction depended on the metabolic pathway triggered by a given substrate.