Effective Coupling Model to Treat the Odd-Even Effect on the Current-Voltage Response of Saturated Linear Carbon Chains Single-Molecule Junctions.

The calculation of the electrical charge transport properties of alkanes C n H 2n S 2 with (n = 4-11) was performed to understand the odd-even effect on its current-voltage response. The extended molecule and broadband limit models were used to describe the molecular junction and covalent coupling with the electrodes. It was shown that among the participating molecular orbitals, HOMO and HOMO-1 are the ones with the most charge transport contribution. Moreover, the odd-even effect is caused by the alternation of the eigenvalues of some frontier orbitals as a function of the number of carbons, especially the HOMO that dominates the electrical transport. It could also be noted that when the current is analyzed outside the resonance, the relationship with the number of carbons exponentially decays, confirming the reports in the literature. To the best of our knowledge, a first principle study of the odd-even effect in symmetric systems composed by linear saturated carbon chains covalently coupled to electrodes has not been reported yet.

Pyridinic-N Coordination Effect on the Adsorption and Activation of CO2 by Single Vacancy Iron-Doped Graphene.

Graphene doped with different transition metals has been recently proposed to adsorb CO2 and help reduce the greenhouse effect. Iron-doped graphene is one of the most promising candidates for this task, but there is still a lack of full understanding of the adsorption mechanism. In this work, we analyze the electronic structure, geometry, and charge redistribution during adsorption of CO2 molecules by single vacancy iron-doped graphene by DFT calculations using the general gradient approximation of Perdew, Burke, and Ernzernhof functional (PBE) and the van der Waals density functional (vdW). To understand the impact of the pyridinic-N coordination of the iron atom, we gradually replaced the neighboring carbon atoms by nitrogen atoms. The analysis indicates that chemisorption and physisorption occur when the molecule is adsorbed in the side-on and end-on orientation, respectively. Adsorption is stronger when pyridinic-N coordination increases, and the vdW functional describes the chemical interactions and adsorption energy differently in relation to PBE without significant structural changes. The development of the chemical interactions with the change of coordination in the system is further investigated in this work with crystal overlap Hamilton population (COHP) analysis.

Adequate Mentorship Program for Holmium Laser Enucleation of the Prostate (HoLEP) Leads to Satisfactory Short-Term Outcomes in the Early Learning Curve of Young Urologists: First-Year Outcomes of a Newly Established Mentorship Training in Mexico.

Introduction Benign prostatic hyperplasia (BPH) is one of the most common causes of lower urinary tract symptoms in men. Holmium Laser Enucleation of the Prostate (HoLEP) has been recommended by international guidelines as an alternative to transurethral resection of the prostate (TURP). HoLEP's learning curve and the lack of adequate mentorship remains an obstacle for the worldwide adoption of this technique. Objective To report the first-year learning curve of a newly established mentorship program in young urologists without any previous HoLEP experience. Methods We report a cohort of patients with BPH, with prostate size ≥70 grams, treated with HoLEP, analyzed for perioperative data and complications, and short-term postoperative complications and functional outcomes, at three and six months after surgery. Results A total of 47 patients were managed with HoLEP. Mean total operative time was 149.8 ± 42.9 minutes. We experienced five (10.6%) intraoperative complications, including one intravesical resection of the prostate with bipolar energy, three conversions to TURP and one conversion to open prostatectomy. We experienced four postoperative complications, all of them Clavien-Dindo ≤2. Median International Prostate Symptom Score (IPSS) decrease at six months was -17 points from baseline. Mean post-void residual volume and prostate-specific antigen significantly decreased by the third postoperative month. Multiple linear regression showed that prostate size is directly related to increased surgical time during the early learning curve. Discussion Our experience adequately reflects the importance of HoLEP mentorship in young urologists seeking training in this technique. Both surgeons had perioperative and postoperative outcomes deemed satisfactory based on previously published learning curves. Conclusions HoLEP is a technically difficult procedure, however, adequate mentorship leads to satisfying short-term outcomes since the early stages of the learning curve in young urologists with no previous training on this technique.

Taller de concordancia en la evaluación de imágenes capilaroscópicas / Reliability of nailfold videocapillaroscopy workshop

Introducción: la capilaroscopia es un método no invasivo que permite observar la microvasculatura en el área periungueal. Los resultados informados pueden ser altamente variables entre distintos observadores. A lo largo del tiempo surgieron métodos cuantitativos y semicuantitativos para mejorar la reproducibilidad. Objetivos: conocer el nivel de acuerdo intra e interobservador al informar los diferentes patrones capilaroscópicos en individuos con diferente nivel de entrenamiento. Materiales y métodos: estudio de corte transversal. Participaron médicos reumatólogos especialistas y en formación que habían realizado previamente un curso virtual de capacitación en capilaroscopia. Recibieron 40 imágenes capilaroscópicas proyectadas en una presentación de PowerPoint y debían responder a través de un cuestionario digital. Se evaluó la concordancia de respuestas intra e interobservador. Resultados: se encontró un alto nivel de concordancia global con un kappa 0,66 IC 95% (0,63-0,70) p<0,0000. También en otros grupos como reumatólogos en formación: kappa 0,65 IC 95% (0,60-0,71) p=0,0000, y médicos reumatólogos: kappa 0,67 IC 95% (0,62-0,72) p=0,0000. Conclusiones: el nivel de concordancia encontrado fue globalmente alto, independientemente del nivel de entrenamiento de los profesionales, y de ser o no reumatólogo. La concordancia fue superior cuando se comparó a quienes tenían más de 4 años de experiencia en la realización de videocapilaroscopia.

Introduction: videoapillaroscopy is a non-invasive method that allows the observation of the microvasculature in the periungual area. Reported results can be highly variable between different observers. Over time, quantitative and semi-quantitative methods emerged to improve reproducibility. Objetives: to know the level of intra and interobserver agreement when reporting the different capillaroscopic patterns in individuals with different levels of training. Materials and methods: cross section study. Specialist rheumatologists and those in training who had previously completed a virtual capillaroscopy training course participated. They received 40 capillaroscopic images projected in a PowerPoint presentation and had to issue their response through a digital questionnaire. Concordance of intra and interobserver responses was evaluated. Results: a high level of global agreement was found with a kappa 0.66 CI 95% (0.63-0.70) p<0.0000, also in other groups such as rheumatologists in training: kappa 0.65 CI 95% (0.60-0.71) p=0.0000, physicians rheumatologists: kappa 0.67 95% CI (0.62-0.72) p=0.0000. Conclusions: the level of agreement found was globally high, regardless of the level of training of the professionals, and whether or not they were a rheumatologist. Concordance was higher when compared to those who had more than 4 years of experience performing videocapillaroscopy.

Treatment for T1DM patients by a neuro-fuzzy inverse optimal controller including multi-step prediction.

Diabetes Mellitus is a serious metabolic condition for global health associations. Recently, the number of adults, adolescents and children who have developed Type 1 Diabetes Mellitus (T1DM) has increased as well as the mortality statistics related to this disease. For this reason, the scientific community has directed research in developing technologies to reduce T1DM complications. This contribution is related to a feedback control strategy for blood glucose management in population samples of ten virtual adult subjects, adolescents and children. This scheme focuses on the development of an inverse optimal control (IOC) proposal which is integrated by neural identification, a multi-step prediction (MSP) strategy, and Takagi-Sugeno (T-S) fuzzy inference to shape the convenient insulin infusion in the treatment of T1DM patients. The MSP makes it possible to estimate the glucose dynamics 15 min in advance; therefore, this estimation allows the Neuro-Fuzzy-IOC (NF-IOC) controller to react in advance to prevent hypoglycemic and hyperglycemic events. The T-S fuzzy membership functions are defined in such a way that the respective inferences change basal infusion rates for each patient's condition. The results achieved for scenarios simulated in Uva/Padova virtual software illustrate that this proposal is suitable to maintain blood glucose levels within normoglycemic values (70-115 mg/dL); furthermore, this level remains less than 250 mg/dL during the postprandial event. A comparison between a simple neural IOC (NIOC) and the proposed NF-IOC is carried out using the analysis for control variability named CVGA chart included in the Uva/Padova software. This analysis highlights the improvement of the NF-IOC treatment, proposed in this article, on the NIOC approach because each subject is located inside safe zones for the entire duration of the simulation.

Overdiagnosis of Septic Shock and Loss of Potential Donors of Corneal Tissue in the Hospital General de México Dr. Eduardo Liceaga.

At the Hospital General de México Dr. Eduardo Liceaga, a large number of potential donors of corneal tissue are discarded owing to various contraindications such as shock septic. The objective of this study is to determine the number of patients with postmortem diagnosis of septic shock and analyze whether there is an overdiagnosis of it. It is a cross-sectional and descriptive study in which 144 (n = 144) medical records were reviewed between January 2018 and May 2019 and where septic shock was identified within postmortem diagnoses. Exclusion criteria were age <2 or ≥75 years; infection due to human immunodeficiency virus, hepatitis B virus, or hepatitis C virus; active tuberculosis; neuroinfection; endocarditis; or cancer. The Sequential Organ Failure Assessment (SOFA) scale was calculated, and a descriptive analysis of the data was performed. According to the third international consensus for the definition of sepsis and septic shock (SEPSIS 3) using its SOFA diagnostic tool, 46 (32%) patients did not meet the criteria for septic shock because they did not require vasopressor nor had a lactate ≥ 18 mg/dL. These were potential donors of corneal tissue that were not considered as such; 35 of them met the diagnosis of sepsis with SOFA scores of ≥2 and the suspected or documented presence of infection. Eleven patients were not considered septic. It is important to train the hospital medical staff to properly diagnose septic shock, based on international consensus, and perform all the laboratory studies that allow doctors to calculate the SOFA to confirm or rule out the presence of septic shock.

Rapid and sensitive LC-ESI-MS of gangliosides.

Gangliosides are a class of sphingolipids characterized by a ceramide lipid chain attached to an anionic oligosaccharide moiety that varies in complexity based on the level of sialylation. Heterogeneity in the oligosaccharide chain of gangliosides is a direct result of the monosaccharide structure, content, sequence, and connections. Gangliosides are highly concentrated in the central nervous system, and are cell type-specific as well as development-dependent and their quantities and species can undergo drastic changes during cell differentiation. Specific localization of gangliosides also allows for interaction with a variety of bioeffectors, including glycoproteins, antibodies, peptide hormones, and growth factors. There are currently no rapid analytical assays capable of identifying and quantifying gangliosides. The aim of this study is to establish a reliable chromatographic mass spectrometry based assay capable of profiling ganglioside levels in complex biological samples at high sensitivity. We describe here a chromatographic method using an amino column on which the separation is based on hydrophilic interaction with the sugar moiety of gangliosides. Several gangliosides, including GM1-3, GD1a,b, GD2-3, and GT1a,b, were efficiently separated in less than 10 min at a limit of detection ranging between 10-50 pg on column with a concentration dynamic range extending over 4 orders of magnitude. The developed method allowed the sensitive quantitation of gangliosides derived from the blood serum of patients with different esophagus diseases, including, adenocarcinoma, high-grade dysplasia, and Barrett's.

Sugar nucleotide quantification using multiple reaction monitoring liquid chromatography/tandem mass spectrometry.

RATIONALE: Glycosylation of proteins and lipids is reliant on the availability of monosaccharide-activated donors known as sugar nucleotides. They are responsible for glycosylation in cells. Reliable quantification of these sugar nucleotides might provide an insight into their biological roles and attributes. METHODS: Herein, a method is described for the quantification of sugar nucleotides using ultra high pressure liquid chromatography (UHPLC) tandem mass spectrometry, allowing selective detection of sugar nucleotides in a biological sample. Seven model sugar nucleotide standards commonly associated with lipid and protein glycosylation were separated on a porous graphitic carbon column using an UHPLC system coupled to a triple stage quadrupole mass spectrometer utilizing a multiple reaction monitoring approach. RESULTS: Successful baseline separation of these metabolites was attained in 6 min using an ammonium formate buffer and acetonitrile, circumventing the use of MS-unfriendly pairing reagents. The linear dynamic range of this procedure was established over almost three orders of magnitude from 20 pg to 1 ng (40 pg to 2 ng for the isomers UDP-GlcNAc/GalNAc). The limit of detection ranged from 15 pg to 30 pg while the limit of quantification ranged from 50 pg to 100 pg. Furthermore, viability of this method was tested using three different breast cancer cell lines (MDA-MB-231, MDA-MB-231-BR, and MDA-MB-361) with the successful identification and quantification of all seven targeted sugar nucleotides. CONCLUSIONS: The described method permitted the quantitative analysis of sugar nucleotides in 10 min, thus allowing the practical use of this approach in high-throughput settings. The method was also very effective for the quantification of sugar nucleotides derived from three different breast cancer cell lines. The distribution of sugar nucleotides was different among the different cell lines and unique for each cell line.

Defining putative glycan cancer biomarkers by MS.

For decades, the association between aberrant glycosylation and many types of cancers has been shown. However, defining the changes of glycan structures has not been demonstrated until recently. This has been facilitated by the major advances in MS and separation science, which allows the detailed characterization of glycan changes associated with cancer. MS glycomics methods have been successfully employed to compare the glycomic profiles of different human specimens collected from disease-free individuals and patients with cancer. Additionally, comparing the glycomic profiles of glycoproteins purified from specimen collected from disease-free individuals and patients with cancer has also been performed. These types of glycan analyses employing MS or LC-MS allow the characterization of native, labeled and permethylated glycans. This review discusses the different glycomic and glycoproteomic methods employed for defining glycans as cancer biomarkers of different organs, including breast, colon, esophagus, liver, lung, ovarian, pancreas and prostate.

Identifying cancer biomarkers by mass spectrometry-based glycomics.

Correlations between aberrant glycosylation and cancer have been established for decades. The major advances in mass spectrometry (MS) and separation science have rapidly advanced detailed characterization of the changes associated with cancer development and progression. Over the past 10 years, many reports have described MS-based glycomic methods directed toward comparing the glycomic profiles of different human specimens collected from disease-free individuals and patients with cancers. Glycomic profiling of glycoproteins isolated from human specimens originating from disease-free individuals and patients with cancers have also been performed. Profiling of native, labeled, and permethylated glycans has been acquired using MALDI-MS and LC-MS. This review focuses on describing, discussing, and evaluating the different glycomic methods employed to characterize and quantify glycomic changes associated with cancers of different organs, including breast, colon, esophagus, liver, ovarian, pancreas, and prostate.

Síndrome metabólico: primera parte / Metabolic syndrome: first part

El síndrome metabólico se define como el conjunto de factores de riesgo para enfermedad cardiovascular en ciertos individuos y su fisiopatología incluye a la resistencia insulínica. El término de síndrome de resistencia a la insulina describe las consecuencias de la insulinorresistencia y la hiperinsulinemia compensatoria. Ha habido una explosión en la investigación y el material educativo sobre el síndrome metabólico, lo cual demuestra el reconocimiento y la importancia por los clínicos. El síndrome de resistencia insulínica tiene un común denominador con la diabetes tipo 2 que va hacia la neuropatía, nefropatía y retinopatía; en cambio, en la hiperinsulinemia compensatoria, estos pacientes presentan hipertensión arterial, accidente cerebro-vascular, poliquistosis ovárica (PCOS) y esteatohepatitis no alcohólica. Realizamos una revisión de la literatura médica actual en lo referente al síndrome metabólico, su definición, resistencia a la insulina y acción insulínica, método para valorar la resistencia insulínica, consecuencias, obesidad visceral, leptina, citokinas, hormonas esteroideas, adiponectinas, relación con la Acantosis nigricans. Los clínicos debemos evaluar y tratar los factores de riesgo de enfermedad cardiovascular, sin considerar si el paciente reúne o no los criterios para el diagnóstico de síndrome metabólico, ya que lo importante es evitar que se llegue a tener una enfermedad cardiovascular.

Metabolic syndrome is defined as the set of risk factors for cardiovascular disease in certain individuals and its pathophysiology includes insulin resistance, term that describes the consequences of insulin resistance and compensatory hyperinsulinemia. There has been an esplosion of research and educational material on metabolic syndrome, all of which shows the recognition and importance syndrome and insulin resistance syndrome and insulin resistance have a common denominator with type 2 diabetes that can lead to neuropathy nephropathy; however in compensatory hiperinsulinemia, these patients, present hypertension, stroke, polycystic ovary syndrome (PCOS) and nonalcoholic steatohepatitis. We reviewed the present medical literature with regard to metabolic syndrome, its definition, insulin resistance and insulinic action, methods to evaluate insulin resistance, consequences, visceral obesity, leptin, steroid hormones, citokines, adiponectines, and relationship with Acantosis nigricans. Clinicians should evaluate and deal with risk factors of cardiovascular disease, without considering if the patient meets or not the criteria for the diagnosis of metabolic syndrome since the important thing are to avoid cardiovascular disease.

Hiperandrogenismo / Hyperandrogenism

El hiperandrogenismo en las mujeres se traduce en una serie de afecciones que van desde el simple hirsutismo hasta la franca virilización, traduciendose en signos y síntomas de la unidad pilosebácea así como del sistema reproductor femenino, además de ser precursor de graves problemas cardiovasculares y metabólicos. Los síntomas y signos, el diagnóstico, la fisiopatología y la terapia del hiperandrogenismo es revisado en el presente artículo.

Amputaciones de miembros inferiores niveles, patologías que las motivan: mortalidad - Hospital Padre Billini, 1986-1991 / Lower extremities amputation : pathogenesis, mortality - Hospital Padre Billini, 1986-1991

Se realizó un estudio retrospectivo, descriptivo y transversal sobre amputaciones de miembros inferiores en el Hospital Padre Billini, Santo Domingo, República Dominicana, incluyendo mortalidad durante el período enero, 1986-diciembre, 1991. Se encontraron 96 expedientes. El sexo masculino fue el más frecuentemente afectado (62.5 por ciento ). El grupo de edad más afectado de 41-80 años (69 por ciento ). La forma clínica más común fue diabetes mellitus (48.9 por ciento ), seguida por insuficiencia arterial periférica (30.2 por ciento ). Se realizaron 62 amputaciones supracondíleas (64.6 por ciento ). Cuatro pacientes fallecieron (4.2 por ciento )

Carcinoma epidermoide pédico: a propósito de un caso: Hospital Dr. Darío Contreras,, Sto Dgo., Rep. Dom

Presentamos un paciente masculino, meztizo, de 63 años, procedente de Barahona, que va a la emergencia del hospital Dr. Darío Contreras con historia de recibir una herida con un vidrio en la panta del pie izquierdo, tratado en un centro del ingenio de dicha población; que se infecta y se trata él mismo en su casa con medicamentos y hojas silvestres. Por el dolor intenso busca ayuda médica y es ingresado a nuestro hospital; mediante estudios de laboratorio y biopsia, realizada en dos instituciones diferentes, se determina que es un carcinoma espinocelular bien diferenciado. Se le realiza una amputación supracondilea del fémur izquierdo; luego es dado de alta en condiciones de salud adecuada y enviado al asilo San Francisco de Asis, porque no tiene familiar que le reclame