Challenges in the management of Covid-19 patients in a neurological center in Mexico City.

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Reconversion of neurosurgical practice in times of the SARS-CoV-2 pandemic: a narrative review of the literature and guideline implementation in a Mexican neurosurgical referral center.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has forced the modification of surgical practice worldwide. Medical centers have been adapted to provide an efficient arrangement of their economic and human resources. Although neurosurgeons are not in the first line of management and treatment of COVID-19 patients, they take care of patients with neurological pathology and potential severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, the authors describe their institutional actions against the pandemic and compare these actions with those in peer-reviewed publications. METHODS: The authors conducted a search using the MEDLINE, PubMed, and Google Scholar databases from the beginning of the pandemic until July 11, 2020, using the following terms: "Neurosurgery," "COVID-19/SARS-CoV-2," "reconversion/modification," "practice," "academy," and "teaching." Then, they created operational guidelines tailored for their institution to maximize resource efficiency and minimize risk for the healthcare personnel. RESULTS: According to the reviewed literature, the authors defined the following three changes that have had the greatest impact in neurosurgical practice during the COVID-19 pandemic: 1) changes in clinical practices; 2) changes in the medical care setting, including modifications of perioperative care; and 3) changes in the academic teaching methodology. CONCLUSIONS: The Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez" is one of the major referral centers for treating highly complex neurosurgical pathologies in Mexico. Its clinical and neurosurgical practices have been modified with the implementation of specific interventions against the spread of COVID-19. These practical and simple actions are remarkably relevant in the context of the pandemic and can be adopted and suited by other healthcare centers according to their available resources to better prepare for the next event.

Method To Detect Ethanol Vapor in High Humidity by Direct Reflection on a Xerogel Coating.

A simple double thin-film coating-based device is proposed to quantify the ethanol content in humid air featuring a 10 ppm resolution and spanning a dynamic range from 0 to 1000 ppm. The transduction involves the measurement of the direct optical reflection intensity, changing upon refractive index variations induced by water and ethanol adsorption within the coatings. The first thin-film coating is a microporous methyl-functionalized, silica xerogel material more sensitive to alcohol, and the second one is a microporous pure silica xerogel material more sensitive to water. The precision of the sensor is achieved through a mathematical treatment applied on the time resolved adsorption period. Reflection signals of both the ethanol- and water-sensitive coatings are taken into account in the treatment to correct for differences in ambient conditions (temperature, relative humidity, presence of volatile organic compounds) within the same chamber previous to data analysis, which corresponds to realistic operating conditions. As the adsorption mechanism is governed by molecular dynamic equilibrium, these sensors are fast and instantaneously regenerated in ambient air. The sensor is easy to assemble and was reusable for a period exceeding 1 year (maximal tested time).

Low prevalence of IgG antibodies against antigens of HEV genotypes 1 and 3 in women with a high-risk pregnancy.

The aim of the study was to assess whether high-risk pregnant women have a higher prevalence of HEV during the perinatal period. This was a cross-sectional study of 428 patients: Group 1, 127 women with a high-risk pregnancy; Group 2, 97 asymptomatic people with reactivity to HCV or HBV; Group 3, 94 patients with clinical symptoms suggestive of HEV infection; and Group 4, 110 healthy blood donors from an urban area of Mexico City. ELISA was used to measure antibody to HEV genotypes 1 and 3. The prevalence rates of anti-HEV IgG antibodies were 0.79% in Group 1, 2.1% in Group 2, 7.4% in Group 3, and 0% in Group 4. Women with a high-risk pregnancy did not have a higher prevalence of HEV infection in this clinical setting.

Mechanical energy storage performance of an aluminum fumarate metal-organic framework.

The aluminum fumarate MOF A520 or MIL-53-FA is revealed to be a promising material for mechanical energy-related applications with performances in terms of work and heat energies which surpass those of any porous solids reported so far. Complementary experimental and computational tools are deployed to finely characterize and understand the pressure-induced structural transition at the origin of these unprecedented levels of performance.

The structure of the aluminum fumarate metal-organic framework A520.

The synthesis of the commercially available aluminum fumarate sample A520 has been optimized and its structure analyzed through a combination of powder diffraction, solid-state NMR spectroscopy, molecular simulation, IR spectroscopy, and thermal analysis. A520 is an analogue of the MIL-53(Al)-BDC solid, but with a more rigid behavior. The differences between the commercial and the optimized samples in terms of defects have been investigated by in situ IR spectroscopy and correlated to their catalytic activity for ethanol dehydration.

Combined radical prostatectomy and abdominoperineal resection for locally invasive rectal cancer.

INTRODUCTION: An infiltration of urological organs is found in 5-10% of patients with colorectal carcinoma. Total pelvic exenteration is the standard procedure for locally advanced rectal cancer. In selected patients with rectal cancer involving the prostate or seminal vesicles, the bladder can be preserved and en bloc radical prostatectomy with abdominoperineal rectal resection can be performed. We report two patients who treated with this combined approach. PRESENTATION OF CASE: Two patients with symptoms of rectal bleeding and pelvic pain were investigated. Colonoscopy demonstrated a tumor in the lower rectum. Biopsies revealed adenocarcinoma. Both pelvic MRI and endorectal ultrasound showed tumors that invaded the prostate and the seminal vesicles directly but without invasion of the bladder. After neoadjuvant chemoradiation, combined radical prostatectomy and abdominoperineal amputation was performed. None has developed local recurrence, but one of them was operated on for a single lung metastasis. After a follow-up of 28 and 20 months, respectively, the patients are alive without evidence of local recurrence or distant disease. DISCUSSION: This procedure obviates the need for urinary diversion without compromising the local tumor control. Intraoperative and postoperative diagnostic difficulties, and clinical aspects in relation to postoperative anastomotic leak and survival of patients are discussed. CONCLUSION: En bloc radical prostatectomy and proctosigmoidectomy is feasible in selected patients with rectal cancer and invasion limited to the prostate or seminal vesicles because it provides good local tumor control and significantly improves the patient's quality of life in comparison to total pelvic exenteration.

Organohelium compounds: structures, stabilities and chemical bonding analyses.

This paper deals with the possibility of forming short and relatively strong carbon-helium bonds in small typical organic molecules through substitution of one or several H atoms by He(+). A structural and energetics study (based on high-level calculations) of this unusual bonding, as well as a topological characterization of the resulting cations, is undertaken. Stable species generally requires substitution of about half of the hydrogen atoms for formation. Under these conditions, the number of such species appears to be potentially unlimited. "True" C-He bonds exhibit equilibrium distances ranging from 1.327 (C2H2He2(2+)) to 1.129 Å (He2CO(2+)). The energies of neutral He releasing range from approximately 5 kcal mol(-1) [He2CO(2+), (Z)-C2H2He2(2+)] to 25 kcal mol(-1) (C2HHe3(3+)), but remain most frequently around 10 kcal mol(-1). However, most of He(+)-substituted hydrocarbons are metastable with respect to C-C cleavage, except derivatives of ethene. Atoms in molecules (AIM) and electron localization function (ELF) topological descriptors classify the C-He bond as a weak charge-shift interaction [S. Shaik, D. Danovich, B. Silvi, D. L. Lauvergnat, P. C. Hiberty, Chem. Eur. J. 2005, 11, 6358-6371] in agreement with a recent publication by Rzepa [S. H. Rzepa, Nat. Chem. 2010, 2, 390-393]. He2CO(2+) is the only investigated compound that presents a C-He bonding ELF basin, which indicates a non-negligible covalent contribution to the bond. Other modifications in the electronic structure, such as the breaking of the triple bond in ethyne derivatives or the loss of aromaticity in C6H3He3(3+), are also nicely revealed by the ELF topology.

A rare example of a porous Ca-MOF for the controlled release of biologically active NO.

A 1D-microporous 3D calcium tetracarboxylate MOF has been solvothermally prepared and its structure solved from single crystal data. It exhibits coordinatively unsaturated Ca(2+) Lewis acid sites able to trap and deliver nitric oxide at a biological level.

Clinical usefulness of mean corpuscular volume and red cell distribution width in iron deficient blood donors

Se evaluó la eficiencia diagnóstica de la amplitud de la distribución del volumen de los eritrocitos (ADE > 14.2 por ciento) y el volumen corpuscular medio (VGM < 83.5 fL) en la detección de deficiencia de hierro en mujeres candidatas a donar sangre. Empleando la saturación de la transferrina < 17 por ciento, la prevalencia de deficiencia de hierro en 296 mujeres fue de 23 por ciento, y en 635 varones donadores de 1.1 por ciento. En el grupo total de mujeres la sensibilidad y especificidad de los índices fueron de 78 por ciento y 92 por ciento respectivamente. cuando estos parámetros diagnósticos se calcularon separando las mujeres anémicas de aguéllas no anémicas, en las primera se obtuvieron valores más altos (sensibilidad 90 por ciento y valor predictivo positivo 92 por ciento) que en las no anémicas (sensibilidad 58 por ciento y valor predictivo positivo 50 por ciento). Estos resultados confirman que hay un traslape en los valores de ADE y de VGM entre los sujetos con y sin deficiencia de hierro, y que esta sobreposición parece ser mayor entre los individuos no anémicos pero con eritropoyesis deficiente en hierro. Concluimos que los índices eritrocíticos parecerían ser pruebas útiles para identificar deficiencia de hierro en las donadoras de sangre anémicas mas no en aguéllas no anémicas