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The group-IV monochalcogenide monolayers, GeSe, are interesting and novel two-dimensional (2D) semiconductor materials due to their highly anisotropic physical properties. Monolayers of the different GeSe polymorphs have already had their physical properties and potential applications extensively investigated. However, few-layer homostructures, which can also be approximated as 2D systems in many cases, have not received the same attention. For this reason, in this work, we investigate the optical properties of a free-standing few-layer ß-GeSe system and use this information to investigate their performance in the near-field radiative heat transfer (NFRHT). The required optical conductivity of the few-layer 2D material is calculated by using density functional theory (DFT), including spin-orbit coupling. The band structure is investigated for up to five layers, and the effective electron masses are calculated correspondingly. Using this information, both the intraband transitions due to the presence of free electrons introduced by doping and the interband transitions are considered. The contribution of the ionic vibrations is also included in calculating the optical properties because of its relevance to NFRHT through the resulting active optical phonons. With all these contributions included, more realistic predictions of the NFRHT between the layered 2D ß-GeSe materials can be obtained. It is found that the heat transfer attainable with the layered system is similar to that of a single layer of ß-GeSe we have obtained previously.

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OBJECTIVE: To describe changes in fetal Doppler parameters during a novel technique for open fetal microneurosurgery for open spina bifida (OSB) repair. METHODS: This was a prospective study of 44 fetuses undergoing open fetal surgery for OSB repair using a novel microneurosurgery approach that is characterized by a mini-hysterotomy (diameter of 15 mm), minimal fetal manipulation and maintenance of a constant normal amniotic fluid volume throughout the procedure. Doppler velocimetry of the umbilical artery (UA), fetal middle cerebral artery (MCA) and ductus venosus (DV) was performed before the start of surgery and at prespecified timepoints during fetal surgery. UA pulsatility index (PI) > 95th percentile, DV-PI > 95th percentile, MCA-PI < 5th percentile and cerebroplacental ratio (CPR) < 5th percentile were considered abnormal. RESULTS: Median gestational age at fetal surgery was 25.2 weeks (range, 22.9-27.9 weeks). Doppler recordings were successfully obtained in all cases during all timepoints throughout the surgery. As compared with Doppler values before surgery, there was a significant increase in the proportion of fetuses with MCA-PI < 5th percentile (63.6% vs 13.6%; P < 0.001), CPR < 5th percentile (65.9% vs 15.9%; P < 0.001) and DV-PI > 95th percentile (22.7% vs 0%; P = 0.01) and a non-significant increase in the proportion of fetuses with UA-PI > 95th percentile (11.4% vs 0%; P = 0.12) during fetal surgery. None of the fetuses showed absent or reversed end-diastolic velocity in the UA or absent or reversed DV a-wave at any stage during OSB repair. All abnormal Doppler parameters returned to normal after surgery. CONCLUSIONS: During open fetal surgery for OSB repair, a small hysterotomy, reduced fetal manipulation and maintenance of a normal amniotic fluid volume seem to prevent severe fetal Doppler abnormalities. The mild Doppler changes observed during fetal surgery could be a manifestation of fetal adaptation to the stress of fetal surgery. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

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We present a general unfolding method for the electronic bands of systems with double-periodicity. Within density functional theory with atomic orbitals as basis-set, our method takes into account two symmetry operations of the primitive cell: a standard expansion and a single rotation, letting to elucidate the physical effects associated to the mutual interactions between systems with more than one periodicity. As a result, our unfolding method allows studying the electronic properties of vertically stacked two-dimensional homo- or heterostructures. We apply our method to study [Formula: see text] single-layer graphene, [Formula: see text] twisted single-layer graphene, and [Formula: see text] graphene- [Formula: see text] tungsten disulfide heterostructure with an interlayer angle of [Formula: see text]. Our unfolding method allows observing typical mini gaps reported in heterostructures, as well as other electronic deviations from pristine structures, impossible to distinguish without an unfolding method. We anticipate that this unfolding method can be useful to compare with experiments to elucidate the electronic properties of two-dimensional homo- or heterostructures, where the interlayer angle can be considered as an additional parameter.

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A systematic investigation is performed on the electronic transport properties of armchair-graphene nanoribbon (AGNR) heterojunctions using spin-polarized density functional theory calculations in combination with the non-equilibrium Green's function formalism. 9-AGNR and 5-AGNR structures are used to form a single-well configuration by sandwiching a 5-AGNR between two 9-AGNRs. At the same time, these 9-AGNRs are matched at the left and right to electrodes, 9 and 5 being the number of carbon dimers as width. This heterojunction mimics an electronic device with two potential barriers (9-AGNR) and one quantum well (5-AGNR) where quasi-bound states are confined. First, we study the ground state properties, and then we calculate the electron transport properties of this device as a function of the well width. We show the presence of electronic tunnelling resonances between the barriers by delocalized electron density inside the well's structure. This is corroborated by transmission curves, localized densities of states (LDOS), current-vs.-bias voltage results, and the trend of the resonances as a function of the well width. This work shows that carbon AGNRs may be used as resonant-tunnelling devices for applications in nanoelectronics.

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Microbial desulfurization or biodesulfurization (BDS) is an attractive low-cost and environmentally friendly complementary technology to the hydrotreating chemical process based on the potential of certain bacteria to specifically remove sulfur from S-heterocyclic compounds of crude fuels that are recalcitrant to the chemical treatments. The 4S or Dsz sulfur specific pathway for dibenzothiophene (DBT) and alkyl-substituted DBTs, widely used as model S-heterocyclic compounds, has been extensively studied at the physiological, biochemical and genetic levels mainly in Gram-positive bacteria. Nevertheless, several Gram-negative bacteria have been also used in BDS because they are endowed with some properties, e.g., broad metabolic versatility and easy genetic and genomic manipulation, that make them suitable chassis for systems metabolic engineering strategies. A high number of recombinant bacteria, many of which are Pseudomonas strains, have been constructed to overcome the major bottlenecks of the desulfurization process, i.e., expression of the dsz operon, activity of the Dsz enzymes, retro-inhibition of the Dsz pathway, availability of reducing power, uptake-secretion of substrate and intermediates, tolerance to organic solvents and metals, and other host-specific limitations. However, to attain a BDS process with industrial applicability, it is necessary to apply all the knowledge and advances achieved at the genetic and metabolic levels to the process engineering level, i.e., kinetic modelling, scale-up of biphasic systems, enhancing mass transfer rates, biocatalyst separation, etc. The production of high-added value products derived from the organosulfur material present in oil can be regarded also as an economically viable process that has barely begun to be explored.

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Shimwellia blattae ATCC 33430 as biocatalyst in the conversion of 1,3-propanediol from glycerol is herein evaluated. Several operational conditions in batch cultivations, employing pure and raw glycerol as sole carbon source, were studied. Temperature was studied at shaken bottle scale, while pH control strategy, together with the influence of raw glycerol and its impurities during fermentation were studied employing a 2L STBR. Thereafter, fluid dynamic conditions were considered by changing the stirring speed and the gas supply (air or nitrogen) in the same scale-up experiments. The best results were obtained at a temperature of 37°C, an agitation rate of 200rpm, with free pH evolution from 6.9 and subsequent control at 6.5 and no gas supply during the fermentation, employing an initial concentration of 30g/L of raw glycerol. Under these conditions, the biocatalyst is competitive, leading to results in line with other previous works in the literature in batch conditions, reaching a final concentration of 1,3-propanediol of 13.84g/L, with a yield of 0.45g/g and a productivity of 1.19g/(Lh) from raw glycerol.

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The specific growth and the xanthan production rates by the bacterium Xanthomonas campestris under different shear levels in shake flasks and in a stirred and sparged tank bioreactor have been studied. The shake flask has been used as a reference for studying the shear effects. An effectiveness factor expressed by the ratio of the observed growth rate and the growth rate without oxygen limitation or cell damage was calculated in both modes of cultures. It was observed that the effectiveness factor was strongly dependent on the operational conditions. A strong oxygen transfer limitation at low stirring rates, indicated by a 54 % decrease in the effectiveness factor was observed. In contrast, at higher stirrer speed, cell damage was caused by hydrodynamic stress in the turbulent bulk of the broth, yielding again a decrease in the effectiveness factor values for stirrer speeds higher than 500 rpm. Cell morphological changes were also observed depending on the agitation conditions, differences in morphology being evident at high shear stress.

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El uso de esteroide está reconocido en el tratamiento crítico del paciente quemado y es útil en el choque séptico que no responde a vasopresores. Este grupo de medicamentos ayuda a regular la respuesta hemodinámica mejorando el aporte de sangre a la piel, aunque sabemos que tienen un efecto nocivo en el proceso de cicatrización. Evaluamos el efecto histopatológico del empleo de esteroides en quemaduras usando un modelo animal. Empleamos 2 grupos de 10 ratas (Wistar) en las que colocamos un cilindro de metal en el dorso durante 15 segundos a 95oC, produciendo una quemadura. En ese momento, uno de los grupos recibió esteroide a dosis de estrés (hidrocortisona 5 mg/kg) y el otro no recibió ningún medicamento. Al quinto día resecamos la escara y cubrimos el defecto con cultivo de queratinocitos. Los animales fueron sacrificadas a los 14 días. Realizamos análisis histopatológico. Macroscópicamente evaluamos la (..) (AU)

The use of steroids is well recognized in critical care specially in septic shock. There are some reports of their utility in severe burns. It helps to regulate the hemodynamic response in order to improve the blood supply to the skin, although it is well known their negative effect in wound healing. Our objective is to know the hystopathologic effect of steroids in burn healing. We used 2 groups of 10 rats (Wistar). Both groups were exposed in their backs to a metallic cylinder at 95 oC for 15 seconds. At the moment of the burn, one group was given steroid (hydrocortisone at stress dose 5 mg/kg) and the other group didn't received any medication. The scar was removed at the 5th day and the burn injury was covered with queratinocyte culture. The rats were sacrificed at 14th day. We evaluated the presence of clinical signs of infection and the percentage of new epithelium. In the microscope we evaluated the following parameters: fibrosis, inflammatory process, presence of fibroblast and vascular proliferation. We compared both groups using Chi2 test (SPSS program version 10). A p =/<. 05 was considered as statistical significant. We found no difference between each group in fibrosis (p .47), inflammatory process (p .27), or fibroblast presence (p.16). But there was a difference in vascular proliferation (p .05) against the first group (steroid group). There were no signs of infection and all of them were epithelised at the 14th day. In conclusion, the use of steroids in burns in an animal model could have a final effect in wound healing. In humans it is important to say that they can be helpful in those cases with clear evidence of benefit, as for example failure to vassopresor response in septic shock. We are not sure about the final effect in wound healing in the steroid group as for example wound contracture in long term (AU)

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BACKGROUND/AIMS: In Argentina, hemolytic uremic syndrome (HUS) constitutes the most frequent cause of acute renal failure in children. The aim of our study was to analyze the early tubular response under the effect of Shiga toxin type 2 (Stx2) in a rat experimental model of HUS. METHODS: Adult male Sprague-Dawley rats were injected intraperitoneally with culture supernatant from recombinant Escherichia coli expressing Stx2. Functional, histological, immunohistochemical and Western blot studies were performed at 48 h postinoculation. RESULTS: Renal tubules showed the loss of the epithelial markers E-cadherin and ß-catenin, and an increase in transforming growth factor-ß1 expression. We detected the expression of α-smooth muscle actin in the interstitium and fibrosis in the periglomerular areas. CONCLUSION: Our results indicate that the early tubular response to the effects of Stx2 is related to an immunophenotype change of tubular cells and the presence of mild fibrosis in the interstitium.

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BACKGROUND: Surveys of cardiac pacing and implantable cardiovertor defibrillators (ICD) have been reported since 1969 and 1993 respectively. Increasing costs of medical technology, budget constraints and emergent new clinical indications prompted our committee to conduct the first survey of cardiac rhythm management and device implant patterns in Puerto Rico. METHOD: Clinical and demographic data were obtained for all cardiac devices sold and implanted from 2000 to 2006, through a joint agreement with official representatives of the 2 largest manufacturers and distributors of cardiac pacemakers and ICD in Puerto Rico. RESULTS: 13,854 cardiac devices were implanted from 2000 to 2006. The number of permanent pacemakers (PP) implanted per million population has varied from 430 in the year 2000 to 482 in the year 2006. A significant greater number of males received PP than females (P < .05). Yearly increases in implant rates for cardiac resynchronization therapy (CRT) and ICD were observed, mainly due to new emergent clinical indications, appropriate insurance coverage and availability of implanting electrophysiologists. CONCLUSIONS: Sales figures from PP and ICD manufacturers are a reliable system to calculate and analyze changes in cardiac device implant patterns. The rate of 482 PP per million population positions Puerto Rico as the third largest implant market in North and South America. This finding should be useful to insurance health providers since 76% of the implants are performed in patients over 65 years old. In the year 2006, Puerto Rico was the 10th largest implant market in the world with 67 CRT implanted per million population. A significant greater number of CRT and ICD were implanted in males than females. This gender difference has increased in spite of strict requirements to include more females in clinical trials and intensive, educational and awareness efforts conducted among physicians and patients. A summary of the current guidelines and...

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Catalytic abatement of solutions of 1,000 mg/L in phenol, ortho and para nitrophenol and ortho and para cresols was acomplished by using two catalytic systems. Fenton's reagent was used at 50 degrees C by adding 10 mg/L of ferrous cation and different dosages of H2O2. The mixture was reacting isothermically in a batch way during 3 hours. Catalytic wet oxidation (CWO) was carried out by using a commercial Activated Carbon, Industrial React FE01606A, CWO runs were carried out in a fixed bed reactor (FBR) with concurrent upflow. Temperature and oxygen pressure of the reactor were set to 160 degrees C and 16 bar, respectively. While phenols are quicky oxidised by the Fenton reagent higher mineralisation was obtained in the CWO process.

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Catalytic wet oxidation (CWO) of a phenolic mixture containing phenol, o-cresol and p-cresol (500mg/L on each pollutant) has been carried out using a commercial activated carbon (AC) as catalyst, placed in a continuous three-phase reactor. Total pressure was 16 bar and temperature was 127 degrees C. Pollutant conversion, mineralization, intermediate distribution, and toxicity were measured at the reactor outlet. Under these conditions no detoxification of the inlet effluent was found even at the highest catalyst weight (W) to liquid flow rate (Q(L)) ratio used. On the other hand, some Fenton Runs (FR) have been carried out in a batch way using the same phenolic aqueous mixture previously cited. The concentration of Fe(2+) was set to 10mg/L. The influence of the H(2)O(2) amount (between 10 and 100% of the stoichiometric dose) and temperature (30, 50, and 70 degrees C) on phenols conversion, mineralization, and detoxification have been analyzed. Phenols conversion was near unity at low hydrogen peroxide dosage but mineralization and detoxification achieved an asymptotic value at each temperature conditions. The integration of Fenton reagent as pretreatment of the CWO process remarkably improves the efficiency of the CWO reactor and allows to obtain detoxified effluents at mild temperature conditions and relatively low W/Q(L) values. For a given phenolic mixture a temperature range of 30-50 degrees C in the Fenton pretreatment with a H(2)O(2) dosage between 20 and 40% of the stoichiometric amount required can be proposed.

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OBJECTIVE: To assess pregnancy outcomes in a population of renal transplant recipients in Mexico. METHOD: A total of 75 pregnancies in 60 patients managed at the National Institute of Perinatology, Mexico City, Mexico, were reviewed. RESULT: The mean age at conception was 26.97+/-5.42 years and the mean time from transplantation to pregnancy was 5.49+/-3.6 years. Prepregnancy renal function was determined by serum creatinine level (mean, 1.32+/-0.73 mg/dL). Prepregnancy hypertension was noted in 45.3% of the patients. Urinary tract infection was the most common complication, followed by pregnancy-induced hypertension. The pregnancy resulted in abortion in 11 patients and in live birth for the remaining 64 participants. The mean+/-SD gestational age at birth was 37.1+/-3 weeks, and intrauterine growth restriction was noted in 12 newborns. A serum creatinine level of 1.5 mg/dL or higher prior to pregnancy was associated with delivery before the 34th week and low birth weight. CONCLUSION: In this study, pregnancy ended in a live birth in 84% of women with a renal transplant.

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Tomando en cuenta que en la actualidad se acepta y reconoce plenamente la necesidad de la educación del paciente que sufre de diabetes mellitus. Se realizó una investigación diagnóstica, de corte trasversal, en pacientes diabéticos tipo 2 en el hospital Patrocinio Peñuela Ruíz. Para determinar el grado de conocimientos sobre su enfermedad, aplicamos una entrevista con preguntas referentes a la misma. Los resultados obtenidos fueron expresados en tablas y porcentajes concluyendo que estos pacientes están muy carentes de conocimiento sobre esta enfermedad tan agresiva, por lo que consideramos es urgente crear conciencia en el personal de la salud, paciente y familiar para lograr mantener un mejor control metabólico del paciente y por lo tanto un mejoramiento de su estado de salud integral.

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El Síndrome de Ramsay Hunt es una parálisis facial periférica (PFP) aguda asociada a otalgia y ampollas herpéticas en piel del pabellón de la oreja y del conducto auditivo externo. Debida a inflamación del nervio facial ocasionada por reactivación del virus de la varicela zoster. (VVZ). Es más frecuente en inmunodeprimidos y después de los 50 años. Enfermedad rara, autolimitada y su pronóstico es bueno. El diagnóstico es básicamente clínico. Paciente masculino de 27 años de edad, con enfermedad de dos semanas de evolución, caracterizada por debilidad, sensación de ardor en región temporal izquierda; posteriormente otalgia, aparición de eritema maculopapular, que evolucionó a vesículas en región temporo-parieto-occipital, hemicuello y hombro izquierdo. Luego presentó PFP. Antecedente de varicela a los 8 años. Se demostró VVZ a través de inmunofluorescencia directa de muestra de suero y biopsia de piel. El paciente fue tratado con: Aciclovir, Prednisona, Ketoprofeno. Nuestro caso corresponde a un síndrome de Ramsay Hunt tipo 2, consiste en PFP, dolor periauricular, lesiones herpéticas en pabellón auricular, conducto auditivo externo, cara, cuero cabelludo o cuello, sin afectación del VIII Par craneal. Para confirmar la clínica, la inmunofluorescencia directa se escogió como método diagnóstico por ser más sensible que el cultivo, de costo accesible y procesamiento rápido. El VVZ es muy lábil y d¡fícil de aislar. El paciente respondió bien al tratamiento, desapareciendo la neuralgia postherpetica y la parálisis facial completamente a los 27 días de su egreso.

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A conformational study has been performed for galphimines A and B, which differ from each other only in an acetate moiety on ring B of galphimine A. Mechanical molecular calculations showed that the predominant conformers in a Boltzman distribution are those which establish an intramolecular hydrogen bond between the hydroxyls on rings A and B, keeping a similar conformation on the rest of the molecule. The existence of these conformers was confirmed by NMR spectroscopy in (D6) DMSO solution. Furthermore, an unbound hydrogen conformation was found. These types of conformations very probably coexist in solution, for both types of galphimines A and B. Additional experiments suggest that the acetate group on galphimine A does not distort rings B and A, neither does it disturb the intramolecular hydrogen bond formation that also shows galphimine B. Finally, it does not present a steric effect on ring A to avoid any type of interaction of the functional groups on this ring with the biological receptor. The acetate group, which is responsible for the lost of activity of galphimine A very probably prevent that the hydroxyls OH4 and OH7 from interacting, either in a hydrogen bounded or free form, with the receptor, indicating the importance that these hydroxyls play in the biological activity of the molecule.

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This work reports on the evolution of the toxicity of phenol-containing simulated wastewater upon catalytic wet oxidation with a commercial copper-based catalyst (Engelhard Cu-0203T). The results of the study show that this catalyst enhances detoxification, in addition to its effect on the oxidation rate. The EC50 values of the intermediates identified throughout the oxidation route of phenol have been determined and used to predict the evolution of toxicity upon oxidation. The predicted values have been compared with the ones measured directly from the aqueous solution during the oxidation process. To learn about the evolution of toxicity through out the routes of phenol oxidation, experiments have been performed with simulated wastewaters containing separately phenol, catechol, and hydroquinone as original pollutants. The significant increase of toxicity observed during the early stages of phenol oxidation is not directly related to the development of the brown color that derives mainly from catechol oxidation. This increase of toxicity is caused by the formation of hydroquinone and p-benzoquinone as intermediates, the former showing the highest toxicity. Furthermore, synergistic effects, giving rise to a significant increase of toxicity, have been observed. These effects derive from the interactions among copper leached from the catalyst and catechol, hydroquinone, and p-benzoquinone and demand that close attention be paid to this potential problem in catalytic wet oxidation.

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The hydrolysis of lactose by a beta-galactosidase from the thermophilic microorganism Thermus sp. strain T2, both in solution and immobilized on a commercial silica-alumina, has been studied. The enzyme has been previously produced by Escherichia coli JM101 harboring the plasmid pBGT1, which contains the codifying gene under the promoters lpp(P) and lac(PQ). The enzyme was immobilized on the support activated with tris-hydroxymethylphosphine (THP). Activity and stability of the free and the immobilized enzyme towards pH and temperature were tested. To study the activity at different pH and temperature values, lactose was used as substrate. To check the stability, the enzyme was incubated either in buffer BP or in a solution of lactose in buffer BM at different pH and temperatures, being the remaining activity tested by withdrawing samples and determining their activity toward ONPG at 70 degrees C in buffer BP. Afterward, runs were performed to obtain kinetic models adequate for the description of the hydrolysis of lactose by the free and the immobilized enzyme. These data were fitted to the kinetic models proposed (all based on the Michaelis-Menten mechanism) by non-linear regression, being the models and their parameters compared to determine the effect of the immobilization on the kinetic behavior of the enzyme. Both the free and the immobilized enzyme are competitively inhibited by galactose, while glucose inhibited only the action of the free enzyme, in an uncompetitive way. The immobilization step seems to eliminate the inhibition by glucose. Moreover, the immobilization reduced to a half the inhibitory action of galactose. In general, the immobilization reduced the activity of the enzyme, but increased its thermal stability. Finally, a comparison between the kinetic behavior of this thermophilic enzyme and enzymes of mesophile microorganisms previously studied by us (E. coli and K. fragilis) and by other authors (Aspergillus niger) is performed.

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Organic extracts from fresh and smoked yellowtail fish (Seriola lalandi), lisa fish (Mugil cephalus) and cazon fish (Mustelus lunulatus) were tested for mutagenicity using Ames Salmonella tester strains TA98 and TA100 with metabolic activation (S9). Also, the antimutagenicity of the organic extract from yellowtail fish was tested against aflatoxin B1 (AFB1). Yellowtail fish extract was sequentially fractionated by thin-layer chromatography (TLC) and each fraction was also tested for antimutagenicity. None of the fresh species showed mutagenicity. Extract from smoked yellowtail showed the highest mutagenic potential among the smoked species tested. Organic extract from fresh yellowtail reduced the number of revertants caused by AFB1 showing a dose response type of relationship. Sequential TLC fractionation of the antimutagenic extract produced four antimutagenic fractions from fresh yellowtail fish. These results that the lipidic fraction of the species tested contains at least four compounds with chemoprotective properties that reduce the mutagenicity of AFB1.

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