Provision of choline chloride to the bovine preimplantation embryo alters postnatal body size and DNA methylation.

Choline is a vital micronutrient that can be utilized in the formation of betaine and multiple phospholipids. In this study, we aimed to confirm, and expand on previous findings, how choline impacts embryos from the first 7 days of development to affect postnatal phenotype. Bos indicus embryos were cultured in a choline-free medium (termed vehicle) or medium supplemented with 1.8 mM choline Blastocyst-stage embryos were transferred into crossbred recipients. Once born, calves were evaluated at birth, 94 d, 178 d and at weaning (average age = 239 d). Following weaning, all calves were enrolled into a feed efficiency trial before being separated by sex, with males being slaughtered at approximately 580 d of age and females followed until their first pregnancy check. Results confirm that exposure of 1.8 mM choline chloride during the first 7 d of development alters postnatal characteristics of the resultant calves. Calves of both sexes from choline-treated embryos were consistently heavier through weaning and males had heavier testes at 3 mo of age. There were sex-dependent alterations in DNA methylation in whole blood caused by choline treatment. After weaning, feed efficiency was affected by an interaction with sex, with choline calves being more efficient for females and less efficient for males. Calves from choline-treated embryos were heavier, or tended to be heavier, than calves from vehicle embryos at all observations after weaning. Carcass weight was heavier for choline calves and the cross-sectional area of the Longissumus thoracis muscle was increased by choline. Few females became pregnant during the experiment although numerically more choline females were pregnant than vehicle females. Results confirm that exposure of the preimplantation embryo to 1.8 mM choline can alter phenotypes of the resultant calves through the first 19 months after birth.

Uso de la determinación transcutánea de co2 en pacientes con déficit de timidina quinasa 2 y costes de su uso en una consulta de ventilación mecánica no invasiva / Use of transcutaneous co2 determination in patients with thymidine kinase 2 deficit and costs of its use in a noninvasive mechanical ventilation consultation

Objetivo: Describir el uso de la capnografía transcutánea en una población adulta y pediátrica de pacientes con déficit de timidina quinasa 2 y hacer un estudio comparativo de costes de una determinación de gasometría arterial y capnografía en la población de nuestra consulta de VMNI. Metodología: Se realizó una anamnesis y unas pruebas funcionales respiratorias para valorar afectación de la musculatura respiratoria y calidad del sueño. Para determinar la hipoventilación, se midió la pCO2 transcutánea en vigilia y/o durante el sueño. Se realizó un estudio económico para comparar el coste de una determinación de ptcCO2 frente a la determinación mediante GSA. El estudio económico se realizó estimando la población total de pacientes que se valoraba en la consulta de VMNI de manera anual. Resultados: 9 pacientes con déficit de TK2 (4 adultos y 5 niños). A 4 pacientes se les realizó una poligrafía respiratoria basal. A la población pediátrica se les realizó un registro continuo de ptcCO2 con pulsioximetria anual. Se realizaron 4 registros con ptcCO2 y VMNI. Elcoste de la determinación de ptCO2 en comparación con la GSA fue de 6,29 euros frente a 5,37 euros. Conclusiones: La medición de la ptcCO2 es útil en la consulta de VMNI para la realización de medidas puntuales en la consulta como para monitorización continua durante el sueño. Con el uso que realizamos en nuestra consulta de la capnografía transcutánea, la determinación puntual de la pCO2 transcutánea es más económica que la realización de la GSA. (AU)

Objective: to describe the use of transcutaneous capnography in an adult and pediatric population of patients with Thymidine inase 2 deficiency and to compare the costs between blood gases by arterial gasometry (BGA) and capnography in our population. Material and methods: an anamnesis, and respiratory functional tests to assess respiratory muscle involvement, sleep quality were performed.To assess the presence of alveolar hypoventilation the determination of transcutaneous pCO2while awake and/or during sleepwas performed. An economic study has been done to compare the cost of a determination of ptcCO2 versus the determination by BGA. Results: 9 patients with TK2 deficiency (4 adults and 5 children). 4 patients underwent baseline respiratory polygraphy. The pediatric patients underwent at least one continuous recording of ptcCO2 with pulse oximetry each year.4 studies of ptcCO2 duringNIV were performed. The cost in the adult population of a punctual determination of pCO2 by BGA was 6,29 euros while for capnography was 5,37 euros. Conclusions: the measurement of ptcCO2 is useful in the consultation of NIV for the realization of specific measurements in the consultation as for continuous monitoring of this parameter. In our practice of transcutaneous capnography, the punctual determination of transcutaneous pCO2 is cheaper than the BGA. (AU)

Network structure of avian mixed-species flocks decays with elevation and latitude across the Andes.

Birds in mixed-species flocks benefit from greater foraging efficiency and reduced predation, but also face costs related to competition and activity matching. Because this cost-benefit trade-off is context-dependent (e.g. abiotic conditions and habitat quality), the structure of flocks is expected to vary along elevational, latitudinal and disturbance gradients. Specifically, we predicted that the connectivity and cohesion of flocking networks would (i) decline towards tropical latitudes and lower elevations, where competition and activity matching costs are higher, and (ii) increase with lower forest cover and greater human disturbance. We analysed the structure of 84 flock networks across the Andes and assessed the effect of elevation, latitude, forest cover and human disturbance on network characteristics. We found that Andean flocks are overall open-membership systems (unstructured), though the extent of network structure varied across gradients. Elevation was the main predictor of structure, with more connected and less modular flocks upslope. As expected, flocks in areas with higher forest cover were less cohesive, with better defined flock subtypes. Flocks also varied across latitude and disturbance gradients as predicted, but effect sizes were small. Our findings indicate that the unstructured nature of Andean flocks might arise as a strategy to cope with harsh environmental conditions. This article is part of the theme issue 'Mixed-species groups and aggregations: shaping ecological and behavioural patterns and processes'.

Cycloaddition between nitrogen-doped graphene (6π-component) and benzene (4π-component): a theoretical approach using density functional theory with vdW-DF correction.

The interaction between nitrogen-doped graphene defects (N3V1 and N4V2 pyridinic, and N3V1 and N3V3 pyrrolic) and benzene have been investigated by applying density functional theory (DFT), together with the vdW-DF correction. We discovered that only the N3V3 pyrrolic defect is a reactive site (6π-component), forming a cycloadduct with benzene (4π-component) that has energy barriers below 154.38 kJ mol-1 (1.60 eV). The conduction and valence bands (HOMO and LUMO) for N3V3 form a degenerate pair of orbitals at the gamma point, with the same ionization potential (IP) and electron affinity (EA). Likewise, inspection of the orbital symmetries for both systems confirms that these must undergo concerted reactions based on the Woodward and Hoffmann principles of orbital symmetry, with the appropriate orbital occupancies. This is the first time that substitutionally doped graphene has been demonstrated to participate as a 6π-component for cycloaddition reactions with benzene.

Chimeric antigen receptor T cell therapy in oncology - Pipeline at a glance: Analysis of the ClinicalTrials.gov database.

There is a rapid growth of published data associated with chimeric antigen receptor (CAR) T-cells, and its evaluation is becoming challenging. We performed a review of the ClinicalTrials.gov database, searching for clinical trials using CAR T-cell therapy in oncology (cut-off December 2019). 593 trials were found. 48 % of trials are from China and 39 % from the USA. 63 % percent focused on hematologic malignancies, while gastrointestinal cancer, breast cancer, and nervous system were the top 3 solid tumors addressed. Common targets in hematologic malignancies are CD19 and BCMA; while mesothelin and CD171 in solid tumors. Second-generation CAR T designs predominate with CD28 or 41BB co-stimulation. Mixed sponsors supported 45 % of trials, and only 19 % received funding exclusively from industry. Current trends suggest that 900 CAR T-cell therapy clinical trials will be registered during 2020-2025. We estimate a two-fold increase in trials that study allogeneic cell products in the next five years.

QSAR and molecular docking modelling of anti-leishmanial activities of organic selenium and tellurium compounds.

Leishmaniasis affects mainly rural areas and the poorest people in the world. A computational study of the antileishmanial activity of organic selenium and tellurium compounds was performed. The 3D structures of the compounds were optimized at the wb97xd/lanl2dz level and used in the quantitative structure-activity relationship (QSAR) analysis. The antileishmanial activity was measured by L. donovani ß carbonic anhydrase inhibition (Ki) and the half-maximal inhibitory concentration (IC50) against L. infantum amastigotes. The dataset was divided into training (75%) and test sets (25%) by using a k-means clustering algorithm. For pKi prediction, model M3 with seven 3D topographic descriptors was characterized by the following statistical parameters: r 2 = 0.879, Q 2 LOO = 0.822, and Q 2 ext = 0.840. For pIC50 prediction, model M12 with six attributes was characterized by the following statistical parameters: r 2 = 0.907, Q 2 LOO = 0.824, and Q 2 ext = 0.795. Both models met all the requirements of Tropsha´s test, which implies predictions of pIC50 and pKi activities with high accuracy. Concomitantly, favourable interactions of the sulphonamide group with the Zn atom in the protein were revealed by the docking analysis.

Effect of ultrasonic irradiation power on sonochemical synthesis of gold nanoparticles.

In this work, optimized size distribution and optical properties in the colloidal synthesis of gold nanoparticles (GNPs) were obtained using a proposed ultrasonic irradiation assisted Turkevich-Frens method. The effect of three nominal ultrasound (20 kHz) irradiation powers: 60, 150, and 210 W have been analyzed as size and shape control parameters. The GNPs colloidal solutions were obtained from chloroauric acid (HAuCl4) and trisodium citrate (C6H5Na3O7·2H2O) under continuous irradiation for 1 h without any additional heat or stirring. The surface plasmon resonance (SPR) was monitored in the UV-Vis spectra every 10 min to found the optimal time for localized SPR wavelength (λLSPR), and the 210 sample procedure has reduced the λLSPR localization at 20 min, while 150 and 60 samples have showed λLSPR at 60 min. The nucleation and growth of GNPs showed changes in shape and size distribution associated with physical (cavitation, temperature) and chemical (radical generation, pH) conditions in the aqueous solution. The results showed quasi-spherical GNPs as pentakis dodecahedron (λLSPR = 560 nm), triakis icosahedron (λLSPR = 535 nm), and tetrakis hexahedron (λLSPR = 525 nm) in a size range from 12 to 16 nm. Chemical effects of ultrasound irradiation were suggested in the disproportionation process, electrons of AuCl2- are rapidly exchanged through the gold surface. After AuCl4- and Cl- were desorbed, a tetrachloroaurate complex was recycled for the two-electron reduction by citrate, aurophilic interaction between complexes AuCl2-, electrons exchange, and gold seeds, the deposition of new gold atoms on the surface promoting the growth of GNPs. These mechanisms are enhanced by the effects of ultrasound, such as cavitation and transmitted energy into the solution. These results show that the plasmonic response from the reported GNPs can be tuned using a simple methodology with minimum infrastructure requirements. Moreover, the production method could be easily scalable to meet industrial manufacturing needs.

Actions of putative embryokines on development of the preimplantation bovine embryo to the blastocyst stage.

Once it enters the uterus at d 4 to 5 after ovulation, the preimplantation bovine embryo is controlled in its development by regulatory signaling molecules from the mother called embryokines. Here, several cell-signaling molecules whose genes are expressed in the endometrium during d 5 to 7 after estrus were tested for the ability to affect the competence of the embryo for further development and the characteristics of the resultant blastocysts. Molecules tested were C-natriuretic peptide (CNP), IL-8, bovine morphogenetic protein 4 (BMP-4), IL-6, and leukemia inhibitory factor (LIF). None of the cell-signaling molecules tested improved the competence of the embryo to become a blastocyst; in fact, BMP-4 decreased development. All molecules modified attributes of the blastocyst formed in culture. In particular, CNP increased the number of cells in the ICM, whereas IL-8 decreased inner cell mass cell numbers and tended to increase the proportion of blastocysts that were hatching or hatched. In addition, BMP-4 decreased the proportion of blastocysts that were hatching. Interleukin-6 and, to a lesser extent, LIF activated the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in the inner cell mass, and LIF increased the percent of cells in the blastocyst that were positive for both NANOG and phosphorylated (activated) STAT3. In conclusion, our results indicate that CNP, IL-8, IL-6, LIF, and BMP-4 can modify embryonic development of the cow in a manner that affects characteristics of the resultant blastocyst. Further research is required to understand how these changes in characteristics of the blastocyst would affect competence of the embryo to establish and maintain pregnancy.

Effects of choline on the phenotype of the cultured bovine preimplantation embryo.

Choline is a precursor of acetylcholine, phosphatidylcholine, and the methyl-donor betaine. Reports indicate that supplementation with rumen-protected choline improves postpartum reproductive function of dairy cows. The objective was to determine whether addition of choline to culture medium of in vitro-produced embryos alters the phenotype of the resultant blastocysts. Treatments were choline chloride (ChCl; 0.004, 1.3, 1.8, and 6.37 mM) and phosphatidylcholine (1.3 mM). Treatment with 0.004 mM ChCl improved development to the blastocyst stage, increased blastocyst cell number, and increased the percentage of blastocysts that were hatching or hatched. Development was not affected by higher concentrations of ChCl but was reduced by 1.3 mM phosphatidylcholine. Treatment of embryos with 1.3 mM ChCl (but not other concentrations) increased expression in blastocysts of 11 of 165 genes examined (AMOT, NANOG, HDAC8, HNF4A, STAT1, MBNL3, SOX2, STAT3, KDM2B, SAV1, and GPAM) and decreased expression of one gene (ASS1). Treatment with 1.3 mM ChCl decreased global DNA methylation at d 3.5 of development and increased DNA methylation at d 7.5 in blastocysts. Treatment with 1.8 mM ChCl also increased methylation in blastocysts. In conclusion, addition of choline to the culture medium alters the phenotype of preimplantation bovine embryos produced in vitro. Choline chloride can act in a concentration-dependent manner to alter development, expression of specific genes, and DNA methylation.

Comparison of the defined daily dose and days of treatment methods for evaluating the consumption of antibiotics and antifungals in the intensive care unit / Comparación de la dosis diaria definida y los días de tratamiento para evaluar el consumo de antibióticos y antifúngicos en la unidad de cuidados intensivos

OBJECTIVE: To compare the measurement of antimicrobial consumption by defined daily dose (DDD) versus by days of therapy (DOT). DESIGN: Retrospective analysis of clinical and administrative data from patients admitted to a polyvalent ICU. SETTING: ICU at a University Hospital in Spain. PATIENTS: All patients admitted to the ICU. INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: For the DDD method, the World Health Organization (WHO)-assigned DDD was determined for the all the prescribed antimicrobials. For the DOT method, one DOT represented the administration of a single agent on a given day regardless of the number of doses administered. To express aggregate use, total DDDs and total DOTs were normalized to 100 patient-days. RESULTS: During the study period, 2393 adult patients were admitted to the ICU. Total median antimicrobial drugs measured by DDDs was 535.3 (IQR 319.8-845.5) vs. 344.0 (IQR 117.2-544.5) when measured by DOTs, p < 0.001. When antimicrobial consumption was normalized to 100 patient-days, median antimicrobial consumption was also higher when measured by DDDs [2.98/100 patient-days (IQR 1.76-5.25) vs. 1.89/100 patient-days (IQR 0.64-3.0) when measured by DOTs, p < 0.001]. CONCLUSIONS: For most antibacterial and antifungal drugs used in critically ill patients, estimates of aggregate antibiotic use by DDDs per 100 patient-days and DOTs per 100 patient-days are discordant because the administered dose is dissimilar from the WHO-assigned DDD. DOT methods should be recommended to avoid the overestimation that occurs with DDDs in adult critically ill patients

OBJETIVO: Comparar la medición del consumo de antimicrobianos por dosis diarias definidas (DDD) y por días de tratamiento (DOT). DISEÑO: Análisis retrospectivo de datos clínicos y administrativos de los pacientes ingresados en una unidad de cuidados intensivos (UCI) polivalente. Ámbito: La UCI de un hospital universitario de España. PACIENTES: Todos los pacientes ingresados en la UCI.: INTERVENCIONES: Ninguna. PRINCIPALES VARIABLES DE INTERÉS: Se determinó la DDD asignada por la Organización Mundial de la Salud (OMS) para todos los antimicrobianos prescritos. La DOT representó los días de utilización de cada antimicrobiano independientemente del número de dosis administradas cada día. Las DDD totales y los DOT totales se normalizaron por cada 100 estancias. RESULTADOS: Durante el período de estudio, 2.393 pacientes adultos ingresaron en la UCI. La mediana de los antimicrobianos medidos por DDD fue de 535,3 (RIQ: 319,8-845,5) frente a 344,0 (RIQ: 117,2-544,5) cuando se midió mediante DOT; p < 0,001. Cuando el consumo de antimicrobianos se normalizó por 100 estancias, el consumo de antimicrobianos también fue mayor cuando se midió con DDD (2,98/100 estancias [RIQ: 1,76-5,25] vs. 1,89/100 estancias [RIQ: 0,64-3,0] cuando se midió por DOT; p < 0,001). CONCLUSIONES: Para la mayoría de los antimicrobianos utilizados en la UCI, el consumo global y medido por DDD/100 estancias y DOT/100 estancias son discordantes porque la dosis administrada es diferente de la DDD asignada por la OMS. Se debe recomendar la utilización de las DOT para evitar la sobreestimación que se produce con las DDD en pacientes adultos críticamente enfermos

Comparison of the defined daily dose and days of treatment methods for evaluating the consumption of antibiotics and antifungals in the intensive care unit.

OBJECTIVE: To compare the measurement of antimicrobial consumption by defined daily dose (DDD) versus by days of therapy (DOT). DESIGN: Retrospective analysis of clinical and administrative data from patients admitted to a polyvalent ICU. SETTING: ICU at a University Hospital in Spain. PATIENTS: All patients admitted to the ICU. INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: For the DDD method, the World Health Organization (WHO)-assigned DDD was determined for the all the prescribed antimicrobials. For the DOT method, one DOT represented the administration of a single agent on a given day regardless of the number of doses administered. To express aggregate use, total DDDs and total DOTs were normalized to 100 patient-days. RESULTS: During the study period, 2393 adult patients were admitted to the ICU. Total median antimicrobial drugs measured by DDDs was 535.3 (IQR 319.8-845.5) vs. 344.0 (IQR 117.2-544.5) when measured by DOTs, p<0.001. When antimicrobial consumption was normalized to 100 patient-days, median antimicrobial consumption was also higher when measured by DDDs [2.98/100 patient-days (IQR 1.76-5.25) vs. 1.89/100 patient-days (IQR 0.64-3.0) when measured by DOTs, p<0.001]. CONCLUSIONS: For most antibacterial and antifungal drugs used in critically ill patients, estimates of aggregate antibiotic use by DDDs per 100 patient-days and DOTs per 100 patient-days are discordant because the administered dose is dissimilar from the WHO-assigned DDD. DOT methods should be recommended to avoid the overestimation that occurs with DDDs in adult critically ill patients.

Central venous-to-arterial carbon dioxide difference combined with arterial-to-venous oxygen content difference (PcvaCO2/CavO2) reflects microcirculatory oxygenation alterations in early septic shock.

PURPOSE: To explore the relationship between central venous-to-arterial carbon dioxide difference (PcvaCO2), PcvaCO2/arterial-venous oxygen content difference ratio (PcvaCO2/CavO2) and the microcirculatory status, evaluated by using near-infrared spectroscopy, in septic shock patients. METHODS: Observational study in a 30-bed mixed ICU. Fifty septic shock patients within the first 24 h of ICU admission were studied. After restoration of mean arterial pressure, hemodynamic, metabolic and microcirculatory parameters were simultaneously evaluated. Local tissue oxygen saturation (StO2), and local hemoglobin index (THI) were measured on the thenar eminence by means of near-infrared spectroscopy. A transient vascular occlusion test was performed in order to obtain StO2 deoxygenation rate (DeO2), local oxygen consumption (nirVO2), and reoxgenation rate (ReO2). RESULTS: At inclusion, increased PcvaCO2 values were associated with lower StO2 and THI, whereas increased PcvaCO2/CavO2 values were associated with lower DeO2, nirVO2, and ReO2. Multiple regression models confirmed the association between PcvaCO2/CavO2 and nirVO2, while PcvaCO2 was only related to CI, and not to microcirculatory parameters. CONCLUSIONS: In a population of early septic shock patients, increases in PcvaCO2 and PcvaCO2/CavO2 reflected different alterations at the microcirculatory level. While PcvaCO2 was related to global flow, the PcvaCO2/CavO2 ratio was associated to impaired local oxygen utilization and diminished microvascular reactivity.

Effects of intrauterine infusion of seminal plasma at artificial insemination on fertility of lactating Holstein cows.

An inflammatory response is induced in the reproductive tract by deposition of semen during natural mating. This response might facilitate establishment and maintenance of pregnancy and alter the phenotype of the offspring by modifying the microenvironment of the reproductive tract. Here, we hypothesized that intrauterine infusion of 0.5 mL of seminal plasma at the time of artificial insemination (AI) in first-service lactating Holstein cows will improve pregnancy success after insemination. Cows were inseminated (511 primiparous cows inseminated with X-sorted semen, 554 multiparous cows inseminated with X-sorted semen, and 627 multiparous cows inseminated with conventional semen) using the Double-Ovsynch protocol. Cows were randomly assigned to receive intrauterine infusion of either 0.5 mL of seminal plasma or saline immediately after AI. There was no overall effect of seminal plasma infusion on the percentage of inseminated cows diagnosed pregnant at d 32 or 60 after AI, pregnancy loss, or percent of inseminated cows calving. If cows were inseminated with conventional semen, seminal plasma reduced pregnancies at d 32 and tended to reduce calvings. There was no effect of seminal plasma if cows were inseminated with X-sorted semen. Seminal plasma infusion increased the birth weight of heifer calves born using X-sorted semen but not conventional semen. These results do not support a beneficial effect of seminal plasma on pregnancy success after AI, but exposure to seminal plasma may program fetal development to affect phenotype at birth.

Interactions of human chorionic gonadotropin with genotype and parity on fertility responses of lactating dairy cows.

Fertility-promoting effects of treatment of lactating dairy cattle with human chorionic gonadotropin (hCG) after artificial insemination (AI) have been variable. Here, we tested whether fertility response to hCG in lactating Holstein cows interacts with genotype and parity. Primiparous (n = 538) and multiparous (n = 613) cows were treated with hCG (3,300 IU) or vehicle 5 d after AI. Pregnancy was diagnosed on d 32 and 60 after AI. A subset of cows (n = 593-701) was genotyped for 4 single nucleotide polymorphisms (SNP) previously associated with fertility. Treatment with hCG increased progesterone concentration on d 12 after AI regardless of genotype or parity. Pregnancy per AI was improved by hCG in primiparous cows but not in multiparous cows. Moreover, hCG treatment interacted with a SNP in coenzyme Q9 (COQ9) to affect fertility. Fertility of cows treated with vehicle was greatest for the AA allele, whereas fertility was lowest for the same genotype among cows treated with hCG. Pregnancy per AI was also affected by genotype for heat shock protein A1-like (HSPA1L) and progesterone receptor (PGR), but no interactions were observed with treatment. Genotype for a SNP in prostate androgen-regulated mucin-like protein 1 (PARM1) was not associated with fertility. Overall, results show that variation in response to hCG treatment on fertility depends on parity and interacts with a SNP in COQ9.

Study of the porosity of calcified chicken eggshell using atomic force microscopy and image processing.

In this work, the porosity of the layers of calcified chicken eggshell (vertical crystal layer VCL, palisade layer PL and mammillary layer ML) was evaluated using atomic force microscopy (AFM) and image processing (IP). AFM topographic images were obtained from different locations for each layer and along the cross-section of calcified eggshell. Roughness parameters, surface area values, pore size and shape, surface porosity, area occupied by pores and pore density were obtained from AFM and IP. It was observed that the thickest layer (PL) exhibited the highest degree of porosity (surface porosity = 2.75 ± 1.68%, pore density = 162 ± 60 pores/µm2) when compared to the other two layers. In general, the pores located in all layers ("bubble pores") had circular shape and similar sizes. Measurements revealed a porosity gradient along the cross-section which varied with position, i.e., increasing surface porosity from the VCL towards the region of the PL closer to the ML, and decreasing surface porosity from this location towards the ML innermost surface. This suggests that the calcified eggshell has a sandwich-like structure where porosity may influence gas exchange and mechanical properties. The combination of AFM with IP presented here provides a simple and precise method to study porosity in calcified chicken eggshell, and this methodology could be used to examine other types of porous biological materials.

Changes to the dissociation barrier of H2 due to buckling induced by a chemisorbed hydrogen on a doped graphene surface.

An effectiveway of enhancing hydrogen storage on adsorbent materials can be induced by the hydrogen spill-over mechanism, although to date there is no general consensus which satisfactorily explains the mechanism. In this work, a possible reaction path to explain hydrogen adsorption is shown. Density-functional calculations were used to study the dissociation of molecular hydrogen near to a stressed region, as a consequence of chemisorbed hydrogen at the graphene-nitrogen surface. We found that as a result of the buckling induced by the chemisorbed hydrogen, the dissociation barrier of molecular hydrogen diminished by 0.84 eV. The chemisorbed hydrogen is the final state in the spill-over mechanism on a graphene-nitrogen decorated with palladium clusters. This effect helps to create hydrogen nanoislands that may change the diffusion and detrapping of H. An electronic structure analysis suggests that these systems occasionally present metallic or semiconductor behavior. Graphical Abstract Hydrogen dissociation and adsorption process via buckling defect.

Respiratory quotient estimations as additional prognostic tools in early septic shock.

Central venous-to-arterial carbon dioxide difference (PcvaCO2), and its correction by the arterial-to-venous oxygen content difference (PcvaCO2/CavO2) have been proposed as additional tools to evaluate tissue hypoxia. Since the relationship between pressure and content of CO2 (CCO2) might be affected by several factors, some authors advocate for the use of CcvaCO2/CavO2. The aim of the present study was to explore the factors that might intervene in the difference between PcvaCO2/CavO2 and CcvaCO2/CavO2, and to analyze their association with mortality. Observational study in a 30-bed mixed ICU. Fifty-two septic shock patients within the first 24 h of ICU admission were studied. After restoration of mean arterial pressure, hemodynamic and metabolic parameters were evaluated. A total of 110 sets of measurements were performed. Simultaneous PcvaCO2/CavO2 and CcvaCO2/CavO2 values were correlated, but agreement analysis showed a significant proportional bias. The difference between PcvaCO2/CavO2 and CcvaCO2/CavO2 was independently associated with pH, ScvO2, baseline CcvaCO2/CavO2 and hemoglobin. A stepwise regression analysis showed that pH was the single best predictor for the magnitude of such difference, with very limited effect of other variables. At inclusion, variables associated with ICU-mortality were lactate, pH, PcvaCO2/CavO2, and the difference between PcvaCO2/CavO2 and CcvaCO2/CavO2. Initial ScvO2, PcvaCO2, CcvaCO2/CavO2, and cardiac index were not different in survivors and non-survivors. In a population of early septic shock patients, simultaneous values of PcvaCO2/CavO2 and CcvaCO2/CavO2 were not equivalent, and the main determinant of the magnitude of the difference between these two parameters was pH. The PcvaCO2/CavO2 ratio was associated with ICU mortality, whereas CcvaCO2/CavO2 was not.

Matrix stiffness induces epithelial-mesenchymal transition and promotes chemoresistance in pancreatic cancer cells.

Increased matrix rigidity associated with the fibrotic reaction is documented to stimulate intracellular signalling pathways that promote cancer cell survival and tumour growth. Pancreatic cancer is one of the stiffest of all human solid carcinomas and is characterised by a remarkable desmoplastic reaction. Here we use mouse models, genetically engineered to recapitulate human pancreatic cancer, and several pancreatic cancer cell lines as a model to investigate the effect of matrix stiffness in epithelial-mesenchymal transition (EMT) and resistance to chemotherapeutics. We found that recapitulation of the fibrotic rigidities found in pancreatic cancer tissues promote elements of EMT, including increases in vimentin expression, decreases in E-cadherin expression, nuclear localisation of ß-catenin, YAP and TAZ and changes in cell shape towards a mesenchymal phenotype. We also report that stiffness induces chemoresistance to paclitaxel, but not to gemcitabine, both commonly used therapeutics, suggesting that environmental rigidity underlies an aspect of chemoresistance.