Discovery of Competent Chromatin Regions in Human Embryonic Stem Cells

The mechanisms underlying the ability of embryonic stem cells (ESCs) to rapidly activate lineage-specific genes during differentiation remain largely unknown. Through multiple CRISPR-activation screens, we discovered human ESCs have pre-established transcriptionally competent chromatin regions (CCRs) that support lineage-specific gene expression at levels comparable to differentiated cells. CCRs reside in the same topological domains as their target genes. They lack typical enhancer-associated histone modifications but show enriched occupancy of pluripotent transcription factors, DNA demethylation factors, and histone deacetylases. TET1 and QSER1 protect CCRs from excessive DNA methylation, while HDAC1 family members prevent premature activation. This "push and pull" feature resembles bivalent domains at developmental gene promoters but involves distinct molecular mechanisms. Our study provides new insights into pluripotency regulation and cellular plasticity in development and disease.

One sentence summary

We report a class of distal regulatory regions distinct from enhancers that confer human embryonic stem cells with the competence to rapidly activate the expression of lineage-specific genes.

Improvement of photocatalytic activity in the degradation of 4-chlorophenol and phenol in aqueous medium using tin-modified TiO2 photocatalysts

In this work, we present the synthesis of TiO₂ photocatalysts modified with different % mol of tin using the sol-gel method. The materials were characterized using different analytical techniques. The Rietveld refinement, XPS, Raman and UV-Vis techniques confirm the substitution of tin in the TiO₂ structural lattice due to changes in crystal lattice parameters, the low-energy shift of the Sn 3d_5/2 orbital, generation of oxygen vacancies and the decreased band gap and increased BET surface area. The material with 1 mol% tin shows superior catalytic activity compared to the references for the degradation of 40 ppm 4-chlorophenol (3 hours of reaction) and 50 ppm phenol (6 hours of reaction). Reactions fit pseudo first order kinetics in both instances. The increase in photodegradation efficiency was attributed to the generation of energy levels below the TiO₂ conduction band caused by the incorporation of 1% mol of tin, oxygen vacancies, and the heterojunction formed between the brookite-anatase-rutile, causing inhibition of the recombination of the electron (e^-) and hole (h⁺) photogenerated species. The easy synthesis, low cost and increased photodegradation efficiency of the photocatalyst with 1 mol% tin have the potential to favor the remediation of recalcitrant compounds in water.

Ethylenediamine-assisted solvothermal synthesis of ZnS/ZnO photocatalytic heterojunction for high-efficiency hydrogen production

Organic-inorganic hybrid materials have emerged as a class of novel materials over the last two decades, as they combine functional organic components and inorganic building blocks into unique materials through various chemical or physical interactions. In the present work, the importance of the use of ethylenediamine in sulfided materials applied to photocatalytic processes in the H2 production is demonstrated. The ZnS/ZnO heterojunction was prepared by the solvothermal synthesis in the presence and absence of ethylenediamine. The photocatalytic behavior showed that the addition of ethylenediamine increases the photocatalytic efficiency up to eight times compared to the photocatalyst without the organic agent. The materials were characterized by X-ray diffraction, scanning electron microscopy, infrared and UV-visible spectroscopies of solids, N2 adsorption-desorption isotherms, X-ray photoelectron spectroscopy, and photoelectrochemical characterization. The ethylenediamine plays a double role: to stabilize the cubic phase of zinc sulfide and to act as a promoter molecule of charge transfer on the surface of ZnS/ZnO/en heterojunction, slowing down the rate of recombination of the electron-hole pair, which is reflected in a decrease in the resistance to transfer of charge carriers, improving the H2 production rate until 1564 µmol h-1 g-1.

Non-convulsive status epilepticus as the initial manifestation in a family with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant small-vessel disease caused by mutations of the NOTCH3 gene. It typically presents with migraine, recurrent brain ischaemia, and cognitive disorders. Seizures rarely present as the initial manifestation, with non-convulsive status epilepticus being even less frequent. We present a series of 3 related patients with this arteriopathy, 2 of whom presented status epilepticus as a manifestation of the disease.

Blood concentrations of calcium, phosphorus and magnesium and dietary cation-anion difference in dairy cows

ABSTRACT The objective of this study was to identify the effect of pre and postpartum DCAD on serum levels of calcium, phosphorus, and magnesium in peripartum Holstein cows. Blood samples were collected from 56 cows (18 primiparous and 38 multiparous) on days -7, +7, +14 and +28 relative to parturition, to determine serum levels of total and ionized calcium, phosphorus, magnesium, and albumin; diet samples for determination of calcium, phosphorus, magnesium and DCAD were collected at the same moments and urine samples were collected at day -7 for measurement of urinary pH. Prepartum DCAD was positively correlated with total calcium (p = 0.02) and with corrected total calcium (p = 0.01) at day -7. There was a negative correlation between prepartum DCAD and magnesium levels at day -7 (p = 0.02). No influence of prepartum DCAD on phosphataemia was observed. Postpartum DCAD did not correlate with serum mineral levels at any time point. Our results demonstrate that prepartum DCAD can influence calcium and magnesium homeostasis, but not phosphorus. In addition, parity and time period should be considered when evaluating serum levels of these minerals in Holstein cows during transition period.

Photodegradation of 2,4-D (dichlorophenoxyacetic acid) with Rh/TiO2; comparative study with other noble metals (Ru, Pt, and Au)

In this work the effect of noble metal on the photodegradation of 2,4-dichlorophenoxyacetic acid herbicide using TiO₂ as support was studied. The metals and concentration were: Rh, Ru, Pt and Au and 1, 0.98, 1.89, and 1.91 wt% respectively. Rhodium was taken as reference for this experiment. The samples were characterized by X-Ray Diffraction (XRD), UV-vis absorption spectra, N₂ physisorption (BET Specific Surface Area), High Annular Angle Analysis Darkfield (HAADF) and Transmission Electron Microscopy Scanning (STEM), H₂ chemisorption, optical emission spectroscopy with inductive coupling plasma analysis (ICP-OES), solid fluorescence, X-ray Photoelectron Spectroscopy (XPS) and OH quantification. The presence of the anatase crystalline phase was mostly confirmed in all samples. The band gap decreased with the presence of metal (from 3.24 to 2.92 eV). The specific area was a function of the metal particle size. The metal particle diameter showed the following sequence Pt > Ru > Au > Rh. By XPS, TiO₂ does not manifest changes in oxidation states, but when impregnated with metals, only Pt shows the highest abundance of any oxidized state (Pt²⁺). The presence of metal reveals less electron–hole recombination compared with titanium oxide. The results of photocatalytic activity showed that Pt and Rh are the two metals with the highest mineralization (99.0 and 98.3%, respectively).

The optimum catalyst for the photocatalytic degradation of 2,4-D was Rh (1%)/TiO₂ by UV radiation. The Rh presents a strong metal-support interaction and improves the photocatalytic properties of TiO₂, modifying its band gap energy.

CDDA: extension and analysis of the discrete dipole approximation for chiral systems

Discrete dipole approximation (DDA) is a computational method broadly used to solve light scattering problems. In this work, we propose an extension of DDA that we call Chiral-DDA (CDDA), to study light-chiral matter interactions with the capability of describing the underlying physics behind. Here, CDDA is used to solve and analyze the interaction of a nanoantenna (either metallic or dielectric) with a chiral molecule located in its near field at different positions. Our method allowed to relate near field interactions with far field spectral response of the system, elucidating the role that the nanoantenna electric and magnetic polarizabilities play in the coupling with a chiral molecule. In general, this is not straightforward with other methods. We believe that CDDA has the potential to help researchers revealing some of the still unclear mechanisms responsible for the chiral signal enhancements induced by nanoantennas.

The electronic nose as a rule-out test for tuberculosis in an indigenous population

INTRODUCTION

To end the tuberculosis (TB) epidemic, efficient diagnostic tools are needed. In a previous calibration study, a portable 'point of care' electronic nose device (Aeonose^TM ) proved to be a promising tool in a hospital setting. We evaluated this technology to detect TB in an indigenous population in Paraguay.

METHODS

A total of 131 participants were enrolled. eNose results were compared with anamnesis, physical examinations, chest radiography and mycobacterial cultures in individuals with signs and symptoms compatible with TB. The eNose analysis was performed in two stages: first, the training with a combination of a previous study population plus 47 participants from the new cohort (total n = 153), and second, the 'blind prediction' of 84 participants.

RESULTS

21% of all participants (n = 131) showed symptoms and/or chest radiography abnormalities suspicious of TB. No sputum samples resulted culture positive for Mycobacterium tuberculosis complex. Only one patient had a positive smell print analysis. In the training model, the specificity was 92% (95% confidence interval (CI): 85%-96%) and the negative predictive value (NPV) was 95%. In the blind prediction model, the specificity and the NPV were 99% (95% CI: 93%-99%) and 100%, respectively. Although the sensitivity and positive predictive value of the eNose could not be assessed in this cohort due to the small sample size, no active TB cases were found during a one year of follow-up period.

CONCLUSION

The eNose showed promising specificity and negative predictive value and might therefore be developed as a rule-out test for TB in vulnerable populations.

Effect of arginine supplementation on the morphology and function of intestinal epithelia, and serum concentrations of amino acids in pigs exposed to heat stress

The exposure of pigs to heat stress (HS) appears to damage their intestinal epithelia, affecting the absorption of amino acids (AA). Arg is involved in the restoration of intestinal epithelial cells but HS reduces Arg intake. The effect of dietary supplementation with Arg on morphology of intestinal epithelia, AA transporter gene expression, and serum concentration (SC) of free AA in HS pigs were analyzed. Twenty pigs (25.3 ± 2.4 kg BW) were randomly assigned to two dietary treatments: control (0.81% Arg), wheat-soybean meal diet supplemented with L-Lys, L-Thr, DL-Met and L-Trp, and the experimental diet where 0.16% free L-Arg was supplemented to a similar control diet (+Arg). All pigs were individually housed and exposed to HS, fed at libitum with full access to water. The ambient temperature, recorded at 15-min intervals during the 21-d trial, ranged on average from 29.6 to 39.4 °C within the same day. Blood samples were collected on d18 at 1600 h (ambient temperature peak); serum was separated by centrifugation. At the end of the trial, five pigs per treatment were sacrificed to collect samples of mucosa scratched from each small intestine segment. The expression of AA transporters in intestinal mucosa and the SC of AA were analyzed. Villi height was higher (P < 0.01) in duodenum, jejunum, and ileum but the crypt depth did not differ between the control and the +Arg pigs. Supplementation of L-Arg increased the mRNA coding for the synthesis of the cationic AA transporter b 0,+ (P < 0.01) and the neutral AA transporter B 0 (P < 0.05) in duodenum by approximately five-folds and three-folds, respectively, but no effect on mRNA abundance was observed in jejunum and ileum. The supplementation of L-Arg increased serum Arg, His, Met, Thr, Trp, and urea (P < 0.05); tended to increase Val (P < 0.10), but did not affect Ile, Lys, Leu, and Phe. These results indicate that supplementing 0.16% L-Arg to the control diet may help to improve the function of the small intestine epithelium, by increasing the villi height, the abundance of AA transporters, and the SC of most indispensable AA in pigs exposed to HS conditions. However, the lack of effect of supplemental Arg on both Lys SC and weight gain of pigs suggests that increasing the Lys content in the +Arg diet might be needed to improve the performance of HS pigs.

Lipid-induced mononuclear cell cytokine secretion in the development of metabolic aberration and androgen excess in polycystic ovary syndrome

STUDY QUESTION

What is the effect of saturated fat ingestion on mononuclear cell (MNC) TNFα, IL-6 and IL-1β secretion and circulating IL-6 levels in women with polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

Women with PCOS exhibit increases in MNC-derived TNFα, IL-6 and IL-1β secretion and circulating IL-6 following saturated fat ingestion even in the absence of obesity, and these increases are linked to metabolic aberration and androgen excess.

WHAT IS KNOWN ALREADY

Cytokine excess and metabolic aberration is often present in PCOS.

STUDY DESIGN, SIZE, DURATION

A cross-sectional design was used in this study of 38 reproductive-age women.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Groups of 19 reproductive-age women with PCOS (10 lean, 9 obese) and 19 ovulatory controls (10 lean, 9 obese) participated in this study that was performed at a tertiary academic medical centre. TNFα, IL-6 and IL-1β secretion was measured from cultured MNC, and IL-6 was measured in plasma from blood sampling while fasting and 2, 3 and 5 h after saturated fat ingestion. Insulin sensitivity was determined using the Matsuda index following an oral glucose tolerance test. Androgen secretion was evaluated with blood sampling while fasting and 24, 48 and 72 h after an HCG injection.

MAIN RESULTS AND THE ROLE OF CHANCE

Lean and obese women with PCOS exhibited lipid-induced incremental AUC increases in MNC-derived TNFα (489-611%), IL-6 (333-398%) and IL-1β (560-695%) secretion and in plasma IL-6 levels (426-474%), in contrast with lean control subjects. In both PCOS groups, insulin sensitivity was lower (42-49%) and androgen secretion after HCG injection was greater (63-110%) compared with control subjects. The MNC-derived TNFα, IL-6 and IL-1β and circulating IL-6 responses were inversely associated with insulin sensitivity and directly associated with fasting lipids and androgen secretion after HCG injection.

LIMITATIONS, REASONS FOR CAUTION

The sample size of each of the four study groups was modest following group assignment of subjects by body mass.

WIDER IMPLICATIONS OF THE FINDINGS

This study showcases the unique pro-inflammatory contribution of circulating MNC in the development of metabolic aberration and androgen excess in PCOS.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by grant R01 DK107605 to F.G. from the National Institutes of Health, the Indiana Clinical and Translational Sciences Institute Clinical Research Center which is funded in part by grant UL1TR002529 from the National Institutes of Health, National Center for Advancing Translational Sciences, Clinical and Translational Sciences Award, and the Indiana University Center for Diabetes and Metabolic Diseases funded by grant P30 DK097512 from the National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. No conflicts of interest, financial or otherwise, are declared by the authors.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT01489319.

Non-convulsive status epilepticus as the initial manifestation in a family with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant small-vessel disease caused by mutations of the NOTCH3 gene. It typically presents with migraine, recurrent brain ischaemia, and cognitive disorders. Seizures rarely present as the initial manifestation, with non-convulsive status epilepticus being even less frequent. We present a series of 3 related patients with this arteriopathy, 2 of whom presented status epilepticus as a manifestation of the disease.

Oral trichomonosis: Description and severity of lesions in birds in Spain

Avian trichomonosis is a parasitic disease caused by the flagellated protozoan Trichomonas gallinae. Columbiformes are the reservoir host of the parasite, with high levels of infection, but also other domestic and wild birds from a variety of orders are susceptible to the infection and development of gross lesions. In this paper we describe the type and severity of lesions in wild birds in four avian orders (Accipitriformes, Falconiformes, Strigiformes and Columbiformes). A total of 94 clinical cases diagnosed of trichomonosis were selected for the categorization of their lesions in the upper digestive tract. The affected birds were classified into three different categories (mild, moderate and severe) based on size (in relation to the tracheal opening), depth and location of the lesions. Mild cases are those with small and superficial lesions far from the oropharyngeal opening; moderate cases possess larger and deeper lesions, and severe cases very large and deep lesions that impede swallowing or affect the skull. Mild lesions were found in 10.6 % of cases; moderate lesions were observed in 18.1 % of the birds and severe lesions in 71.3 %. Treatment outcomes in birds with either mild or moderate lesions were favorable, while severe lesions were related to poor body score, leading to death or euthanasia in most cases. A relationship between severe lesions and avian order was found, with a higher percentage of birds with this type in Falconiformes, Columbiformes and Strigiformes. Multifocal lesions were more frequent in Columbiformes and Falconiformes. In Strigiformes, 93.3 % of birds showed lesions in the upper jaw. This study seeks to further understanding of avian trichomonosis and to provide information that will be useful to veterinarians and related professionals for assessment, prognosis and treatment choice for these birds.

Variations in AXIN2 predict risk and prognosis of colorectal cancer

Objective

Colorectal cancer (CRC) and hypodontia are frequent and different diseases with common genes are involved in their etiology. The objective of this study was to identify the association between AXIN2 rs2240308 with hypodontia and CRC.

Patients and methods

This study consisted of 50 individuals with hypodontia, 50 individuals with CRC, and 155 healthy individuals from Colombia. SNP genotyping assays of rs2240308 were performed and family history of cancer in individuals with hypodontia was documented. In silico analysis was implemented to define the genomic profile of the AXIN2 gene associated with CRC. Multivariate analysis, chi square, odd ratio tests, and R software were used for statistical analysis.

Results

AXIN2 rs2240308 showed association with CRC (OR = 5.4 CI: 2.7–10.4; p < 0.001) and with other familial cancer in individuals with hypodontia (p < 0.005 OR = 1.75, 95% CI: 1.22–6.91). In silico analysis showed that variations in AXIN2 found in CRC patients, were more frequently in earlier stages of tumor and patients who carry variations in the AXIN2 gene have a worse prognosis (p < 0.05). The association between AXIN2 rs2240308 with hypodontia was not significant.

Conclusions

These results suggest that AXIN2 rs2240308 polymorphism is associated with CRC and AXIN2 could be a risk marker for predisposition and prognosis of CRC.

Characterization of the phone-calls made to a poison center related to household and cosmetics products exposition in pediatrics

INTRODUCTION

Household cleaning products and cosmetics are necessary for daily life and widely used by the population. However, their use may not be risk-free, especially when they are not used or stored as recommended. It is important to characterize exposures, as this is useful for developing stra tegies to reduce morbidity, mortality, and health costs associated, especially in the child population.

OBJECTIVE

To describe reports associated with household cleaning products and cosmetics exposure in patients under the age of 12, reported to the Poison Information Center of the Catholic University of Chile (CITUC).

PATIENTS AND METHOD

Descriptive cross-sectional study of phone calls to CITUC during 2016. The analyzed variables were age, sex, product, caller, caller and incident location, ex posure circumstances, exposure route(s), symptoms, and severity from manual records and from the WHO's electronic record software 'INTOX Data Management System'.

RESULTS

3,415 cases met the inclusion criteria. Children under the age of five represented 91% of the exposures, and 58.5% were male. 99.4% were accidental exposures, and 98.6% occurred at home. Family members (57%) and health personnel (42%) made the calls. 68.3% of the patients had no symptoms after exposure. The four products with the highest incidence were household bleach (27.6%), floor cleaners and polishers (13.1%), dish soap (7.9%), and perfume/cologne (5.8%). The main exposure route was by ingestion (89.4%).

CONCLUSIONS

Household cleaning products and cosmetics are common causes of exposures especially in children under the age of five. Although these products have a low morbidity and mortality rate, it is important to educate the population to prevent possible poisonings in the child population.

Luminescence properties of Yb3+-doped SrTiO3: the significance of the oxygen-titanium charge transfer state on photon downshifting

Ceramic powders of Sr1-1.5xYbxTiO3 (x = 0.0, 0.0125, 0.025, 0.05 and 0.075) solid solutions were synthesized by the polymeric complex method. The crystal structure, microstructure and optical properties of the powders annealed at 800 °C for 1 h were investigated by X-ray diffraction, scanning electron microscopy, and diffuse reflectance and photoluminescence spectroscopy, respectively. All the solid solutions exhibit a cubic perovskite-like structure. The reflectance spectra show a broadband below 400 nm ascribed to the ligand-to-metal charge transfer (LMCT) O2- → Ti4+ fundamental state. The Yb3+ (λem = 980 nm) excitation spectra show a broadband being also compatible with the LMCT O2- → Ti4+ state, indicating the energy transfer from the host to the Yb3+. The sample with x = 0.025 presents the highest emission intensity upon near UV excitation, which is further enhanced when the powder is treated under an oxygen-rich atmosphere. The luminescence quenching of Yb3+ is explained as due to defects associated with O2- and Sr2+ vacancies. Finally, it is shown that the solid solutions may downshift photons from UV to wavelengths where a crystalline-silicon photovoltaic solar cell has a higher spectral responsivity.

Recovery of rare earths from waste cathode ray tube (CRT) phosphor powder with organic and inorganic ligands

Cathode ray tubes (CRTs) have an appreciable amount of rare earth elements (REEs). In this document, the leaching and recovery of the REEs from CRTs, with different organic and inorganic ligands is presented. Among the complexing agents tested, the pyrophosphate ion was found to be the most advantageous for the extraction of REEs from CRTs, as an alternative to the traditional methods that use highly acidic solutions (pH < 1) and elevated temperatures. Thermodynamic analyses predict the formation of soluble REE-pyrophosphate complexes in a pH range of 2-8. Leaching solutions of 0.1 M Na₄P₂O₇ at pH 6 and room temperature were employed. REE dissolution from the untreated CRT powder under these conditions was extremely low, due to the encapsulation by other components in the powders, such as ZnS (26%), and the high content of phosphates (6%), that severely limited the solubility of the REEs. To increase extraction, pretreatments were employed to alter and remove the passivating species: roasting at 800 °C or contact with concentrated solutions of sodium hydroxide at 95 °C. The combination of these pretreatments completely eliminated the Zn and 79% of the phosphate ion, as well as other base metals, resulting in an improved exposure of REEs for subsequent leaching. Extractions for Y, Eu, Sm, and Ce of 58, 90, 90 and 87%, respectively, were achieved with the pyrophosphate solution at ambient temperature. The REEs were later recovered as oxides by adjusting the solution pH to 11. Subsequently, once the pyrophosphate solution pH is reestablished, it may be reused for leaching.

Vertical distribution and aggregation patterns of krill (Crustacea: Euphausiacea) in the Bay of Biscay: interannual and seasonal variability

Studies of krill (Crustacea: Euphausiacea) in oceanic waters of the Bay of Biscay are scarce and restricted to the epipelagic zone, overlooking vertical dynamics such as diurnal vertical migration (DVM). There is a growing interest in acoustically evaluating the biomass of krill in this area, but this requires a good knowledge of its vertical dynamics and aggregation patterns. In this work we employed acoustic data and net samples from two consecutive annual surveys covering a wide off-shelf area of the Bay of Biscay (JUVENA surveys of 2013 and 2014) and four seasonal surveys covering slope and oceanic waters in the Cantabrian Sea (SCAPA surveys of 2015). Vertical dynamics of krill were analyzed in the frame of the environmental seascape. High interannual and seasonal variations in the vertical distribution and aggregation patterns (small swarms, dense aggregations, or loose layers) of krill were observed. The vertical distribution covaried with dissolved oxygen and salinity. According to our findings, the best season to acoustically evaluate krill in the Bay of Biscay is spring, with the bulk of the biomass located above 600 m depth. Moreover, extending the acoustic recording beyond the epipelagic zone is mandatory for any season.

Znx-1CuxMn2O4 Spinels; Synthesis, Structural Characterization and Electrical Evaluation

This work presents the structural characterization and electrical evaluation of Znx-1CuxMn2O4 spinels, which are materials presented as secondary phases into the varistor ceramic systems. Samples were analyzed by X-ray diffraction, solid-state nuclear magnetic resonance, infrared spectroscopy, scanning electron microscopy and impedance spectroscopy. Although, the addition of copper to the ZnMn2O4 spinel did not produce morphological changes, the structure and electrical behaviors changed considerably. Structurally, copper addition induced the formation of partial inverse spinels, and its addition increases significantly the electrical conductivity. Therefore, the formation of Znx-1CuxMn2O4 spinels, as secondary phases into the varistor materials, may compromise significantly the varistor efficiency.   Ceramic, Impedance Spectroscopy, spinel, Varistor, XRD.

Physically meaningful Monte Carlo approach to the four-flux solution of a dense multilayered system

Due to the complexity of the radiative transfer equation, light transport problems are commonly solved using either models under restrictive assumptions, e.g., N-flux models where infinite lateral extension is assumed, or numerical methods. While the latter can be applied to more general cases, it is difficult to relate their parameters to the physical properties of the systems under study. Hence in this contribution we present, first, a review of a four-flux formalism to study the light transport problem in a plane-parallel system together with a derivation of equations to evaluate the different contributions to the total absorptance and, second, as a complementary tool, a Monte Carlo algorithm with a direct correspondence between its inputs and the properties of the system. The combination of the four-flux model and the Monte Carlo approach provides (i) all convergence warranties since the formalism has been established as a limit and (ii) new added capabilities, i.e., both temporal (transient states) and spatial (arbitrarily inhomogeneous media) resolution. The support between the theoretical model and the numerical tool is reciprocal since the model is utilized to set a Monte Carlo discretization criterion, while the Monte Carlo approach is used to validate the aforementioned model. This reinforces the parallel approach used in this work. Furthermore, we provide some examples to show its capabilities and potential, e.g., the study of the temporal distribution of a delta-like pulse of light.

[Cardiovascular Preparticipation Screening of young population. Position statement of Chilean Scientific Societies]

The Preparticipation Physical Evaluation (PPE), defined as "the health supervision of individuals, prior to the practice of physical activity and/or sports, which seeks to optimize their safe participation in sports and provide an opportunity to identify current and future risks to their health and quality of life", inclu des the Cardiovascular assessment, which aims to screen cardiovascular pathologies with the risk of worsening or sudden death during exercise. Although there is broad international consensus that the use of Pediatric Cardiovascular PPE in young athletes is useful, there is no consensus on whether this should be used in the entire pediatric population or on which is the best strategy to apply. This article presents the position of the scientific societies related to sport, physical activity and child health on the Pediatric Cardiovascular PPE.

Validación del instrumento: Competencias del personal de enfermería en Salud Pública, en el contexto mexicano

Introducción: Cuando se utilicen cuestionarios desarrollados en otros países e idiomas en estudios científicos, además de traducirlos, es necesario su adaptación cultural y validación, el objetivo de esta investigación es contar con un instrumento válido y confiable para evaluar las competencias del personal de enfermería en salud pública, para aplicarlo en el contexto mexicano. Metodología: El estudio fue de tipo descriptivo-transversal, multietápico, la población se integró en 3 grupos para las 3 diferentes etapas, en la primera, por un grupo de 10 expertos en investigación de la Facultad de Enfermería de Tampico, de la Universidad Autónoma de Tamaulipas, México y 17 profesionales que laboran en el primer nivel de atención; en la segunda, 30 profesionales de enfermería y en la tercera 177 profesionales que trabajan en el campo de la salud pública, todos ellos de tres jurisdicciones del Sur de Tamaulipas, México, el muestreo fue por conveniencia. Resultados: En cuanto a los tres procesos que se realizaron para la validación del instrumento, se mostraron resultados adecuados y satisfactorios para su aplicación, ya que en la prueba de V-Aiken se obtuvo un resultado cercano a 1, en el proceso semántico sólo se realizó modificación a una palabra; a través de la prueba piloto se obtuvo un resultado de 0.97 en el alfa de cronbach. Conclusiones: El instrumento se considera válido para iniciar con la evaluación de las mencionadas competencias, para contar con un diagnóstico inicial de las áreas de oportunidad para personal de enfermería.

DICER1 Is Essential for Self-Renewal of Human Embryonic Stem Cells

MicroRNAs (miRNAs) are the effectors of a conserved gene-silencing system with broad roles in post-transcriptional regulation. Due to functional overlaps, assigning specific functions to individual miRNAs has been challenging. DICER1 cleaves pre-miRNA hairpins into mature miRNAs, and previously Dicer1 knockout mouse embryonic stem cells have been generated to study miRNA function in early mouse development. Here we report an essential requirement of DICER1 for the self-renewal of human embryonic stem cells (hESCs). Utilizing a conditional knockout approach, we found that DICER1 deletion led to increased death receptor-mediated apoptosis and failure of hESC self-renewal. We further devised a targeted miRNA screening strategy and uncovered essential pro-survival roles of members of the mir-302-367 and mir-371-373 clusters that bear the seed sequence AAGUGC. This platform is uniquely suitable for dissecting the roles of individual miRNAs in hESC self-renewal and differentiation, which may help us better understand the early development of human embryos.

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Conditional DICER1 knockouts enable the study of its essential requirement in hESCs

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DICER1 deletion leads to increased extrinsic (receptor-mediated) apoptosis

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miRNAs rescue the DICER1 knockout apoptotic phenotype

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This work provides a platform for interrogating miRNA function in hESCs

Biodegradable multi-walled carbon nanotubes trigger anti-tumoral effects

Carbon nanotubes are of huge biotechnological interest because they can penetrate most biological barriers and, inside cells, can biomimetically interact with the cytoskeletal filaments, triggering anti-proliferative and cytotoxic effects in highly dividing cells. Unfortunately, their intrinsic properties and bio-persistence represent a putative hazard that relapses their application as therapies against cancer. Here we investigate mild oxidation treatments to improve the intracellular enzymatic digestion of MWCNTs, but preserving their morphology, responsible for their intrinsic cytotoxic properties. Cell imaging techniques and confocal Raman spectroscopic signature analysis revealed that cultured macrophages can degrade bundles of oxidized MWCNTs (o-MWCNTs) in a few days. The isolation of nanotubes from these phagocytes 96 hours after exposure confirmed a significant reduction of approximately 30% in the total length of these filaments compared to the control o-MWCNTs extracted from the cell culture medium, or the intracellular pristine MWCNTs. More interestingly, in vivo single intratumoral injections of o-MWCNTs triggered ca. 30% solid melanoma tumour growth-inhibitory effects while displaying significant signs of biodegradation at the tumoral/peri-tumoral tissues a week after the therapy has had the effect. These results support the potential use of o-MWCNTs as antitumoral agents and reveal interesting clues of how to enhance the efficient clearance of in vivo carbon nanotubes.

Electromagnetic behavior of dielectric objects on metallic periodically nanostructured substrates

In this research, we investigate the electromagnetic behavior of a metallic thin-film with a periodic array of subwavelength apertures when dielectric objects are located on it. The influence of size, geometry and optical properties of the objects on the transmission spectra is numerically analyzed. We study the sensitivity of this system to changes in the refractive index of the illuminated volume induced by the presence of objects with sizes from hundreds of nanometers (submicron-sized objects) to a few microns (micron-sized objects). Parameters such as the object volume within the penetration depth of the surface plasmon in the buffer medium or the contact surface between the object and the nanostructured substrate strongly affect the sensitivity. The proposed system models the presence of objects and their detection through the spectral shifts undergone by the transmission spectra. Also, we demonstrate that these can be used for obtaining information about the refractive index of a micron-sized object immersed in a buffer and located on the nanostructured sensitive surface. We believe that results found in this study can help biomedical researchers and experimentalists in the process of detecting and monitoring biological organisms of large sizes (notably, cells).

Las razas porcinas mediterráneas y su impacto ambiental

El cerdo Ibérico y la mayor parte las razas de cerdos Mediterráneos, han sido consideradas como cerdos autóctonos tradicionalmente vinculados al medio en los que se han desarrollado, con libertad de movimientos y alimentación basada en recursos naturales. Sin embargo, se conoce poco sobre el papel medioambiental desempeñado por estas razas, y en la actualidad, los sistemas productivos respetuosos con el medio están ganado reconocimiento. Además, en el futuro la contaminación generada por las granjas porcinas será objeto de una regulación más rígida de la que existe hoy día, debido a la rápida expansión experimentada por este tipo de producción en los países desarrollados. El 34 % de los gases de efecto invernadero generados en la producción de carne de cerdo, corresponden a las fases de cría y engorde de los animales. Para esta finalidad, España importa maíz y soja de más de 39 países diferentes. Estos flujos de mercado ocasionan una gran cantidad de CO2, y añadido a esto, los sistemas de producción porcina intensivos generan una gran cantidad de purines. En este punto, es importante remarcar los sistemas tradicionales de producción de cerdo Ibérico caracterizados por un ciclo de producción largo y una baja densidad de animales, donde los residuos orgánicos generados no son un problema medioambiental añadido. En conclusión, las implicaciones medioambientales de la producción de cerdos mediterráneos en condiciones extensivas, aún no se han cuantificado y deben ser estudiados. Por tanto, se necesita un mayor número de investigaciones que desarrollen prácticas respetuosas con el medio ambiente evitando así impactos medioambientales innecesarios.

Coumarin Derivative Directly Coordinated to Lanthanides Acts as an Excellent Antenna for UV-Vis and Near-IR Emission

A chelating coumarin-derived ligand sensitizes all emitting lanthanide ions in the solid state and gives high absolute quantum yields for ethanol solutions of complexes of Sm, Eu, Tb, and Dy, above 20% for the last two. Crystal structures of these four complexes are [Ln(Cum)₃(H₂O)(X)]·X where X = MeOH or EtOH.

Publisher Correction: TET proteins safeguard bivalent promoters from de novo methylation in human embryonic stem cells

The version of the Supplementary Text and Figures file initially posted was missing Supplementary Tables 1-6 and the Supplementary Note and used incorrect versions of the supplementary figures.

TET proteins safeguard bivalent promoters from de novo methylation in human embryonic stem cells

The TET enzymes oxidize 5-methylcytosine to 5-hydroxymethylcytosine, which can lead to DNA demethylation. However, direct connections between TET-mediated DNA demethylation and transcriptional output are difficult to establish due to challenges of distinguishing global versus locus-specific effects. Here we show that TET1/2/3 triple knockout (TKO) human embryonic stem cells (hESCs) exhibit prominent bivalent promoter hypermethylation without an overall corresponding gene expression decrease in the undifferentiated state. Focusing on the bivalent PAX6 locus, we find increased DNMT3B binding is associated with promoter hypermethylation, which precipitates a neural differentiation defect and failure of PAX6 induction during differentiation. dCas9-mediated locus-specific demethylation and global inactivation of DNMT3B in TKO hESCs partially reverses the hypermethylation at the PAX6 promoter and improves differentiation to neuroectoderm. Taken together with further genome-wide methylation and TET1 and DNMT3B ChIP-Seq analysis, we conclude that the TET proteins safeguard bivalent promoters from de novo methylation to ensure robust lineage-specific transcription upon differentiation.

Studying Kidney Disease Using Tissue and Genome Engineering in Human Pluripotent Stem Cells

Kidney morphogenesis and patterning have been extensively studied in animal models such as the mouse and zebrafish. These seminal studies have been key to define the molecular mechanisms underlying this complex multistep process. Based on this knowledge, the last 3 years have witnessed the development of a cohort of protocols allowing efficient differentiation of human pluripotent stem cells (hPSCs) towards defined kidney progenitor populations using two-dimensional (2D) culture systems or through generating organoids. Kidney organoids are three-dimensional (3D) kidney-like tissues, which are able to partially recapitulate kidney structure and function in vitro. The current possibility to combine state-of-the art tissue engineering with clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated systems 9 (Cas9)-mediated genome engineering provides an unprecedented opportunity for studying kidney disease with hPSCs. Recently, hPSCs with genetic mutations introduced through CRISPR/Cas9-mediated genome engineering have shown to produce kidney organoids able to recapitulate phenotypes of polycystic kidney disease and glomerulopathies. This mini review provides an overview of the most recent advances in differentiation of hPSCs into kidney lineages, and the latest implementation of the CRISPR/Cas9 technology in the organoid setting, as promising platforms to study human kidney development and disease.

Effectiveness of antismoking drug treatment in patients with psychiatric comorbidity compared with patients without this comorbidity

BACKGROUND

There is a relationship between smoking and some psychiatric disorders, and there is doubt whether antismoking treatment will be more complex because of psychiatric disorder.

AIM

To analyze the differences in treatment success rates among patients without psychiatric disorder and patients with psychiatric disorder who have received complete pharmacological treatment.

MATERIALS AND METHODS

A retrospective cohort study was conducted using the records of patients completely treated at Albacete University Hospital Complex during 2011. The sample comprised 293 patients seen in 2011. We treated only 73 patients and divided them into patients with or without psychiatric disorders. We analyzed the following variables: sex, age, age at smoking onset, previous quitting attempts, cigarettes per day, CO-oximetry, Fagerström test, Richmond test, alcoholism, treatment distribution, treatment failure, success, and relapse.

RESULTS

Of a total sample of 293 patients seen in 2011, 73 patients were treated: 43 were men and 30 were women. Overall, 37% had psychiatric disorder (five men and 22 women). Treatment was successful in 51 (70%) patients. There were no differences between the demographic characteristics of the two groups, except for sex (P<0.05); or regarding success, failure, or relapse; or regarding success analyzed separately according to sex distribution.

CONCLUSION

Smoking cessation treatment is equally effective in patients with and without psychiatric disorders. The characteristics of the patients with psychiatric disorders who completed the pharmacological treatment did not differ in intensity, motivation, or dependence from those with no psychiatric comorbidity. Smoking women have more psychiatric morbidity; however, the treatment is effective.

Proposal for improved mixes to produce concrete masonry units with commonly used aggregates available in the Valley of Mexico

Proposal for improved mixes to produce concrete masonry units with commonly used aggregates available in the Valley of MexicoABSTRACTIn this paper, a proposal is done to update the masonry index compressive strength design value f*m for solid concrete masonry units for the masonry guidelines of Mexico´s Federal District Code (NTCM-2004). Solid units were made by taking into account the characteristics of the most commonly used raw materials available in the Valley of Mexico to fabricate such units in the Metropolitan Area of Mexico City. Different tests were conducted for both raw materials and the obtained concrete units. Based upon test results, it is illustrated why it is much better to design masonry structures based upon the experimental data of the units to be used at the construction site rather than using index values proposed in building codes.Keywords: masonry; concrete masonry units; compressive strength.Propuesta de mejora de mezclas para producir piezas de mampostería de concreto empleando materiales comúnmente disponibles en el Valle de MéxicoRESUMENSe presenta un estudio donde se hace una propuesta para actualizar los valores índices de la resistencia a la compresión de mamposterías (f*m) elaboradas con piezas de concreto especificados en las normas de mampostería vigentes en el Distrito Federal. Se realizó un estudio de mercado, donde se tomaron en cuenta las características de los materiales comúnmente utilizados en la actualidad en el Valle de México para la fabricación de piezas de concreto sólidas, incluyendo los resultados de distintas pruebas de laboratorio realizadas a la materia prima. Con base en estos resultados, se ilustran las ventajas de diseñar a la mampostería con base experimental en lugar de utilizar los valores indicativos que se ofrecen en las normas de mampostería.Palabras clave: mampostería; piezas de concreto; resistencia a la compresión. Proposta de melhoria de traços para produzir blocos de alvenaria de concreto utilizando materiais comumente disponíveis no Vale do México RESUMOApresenta-se um estudo onde se propõe uma atualização dos valores do índice de resistência à compressão da alvenaria (f*m) elaborados com blocos de concreto especificados nas normas de alvenaria em vigor no Distrito Federal. Foi realizado um estudo de mercado, que levou em conta as características dos materiais comumente utilizados atualmente no Vale do México para a fabricação de blocos de concreto sólidos, incluindo os resultados de vários testes de laboratório nas matérias-primas disponíveis. Com base nestes resultados, são apresentadas as vantagens de projetar a alvenaria com base experimental em lugar de usar os valores indicativos oferecidos nas normas de alvenaria.Palavras chave: alvenaria; blocos de concreto; resistência à compressão.

Extension of the Kubelka-Munk theory to an arbitrary substrate: a Monte Carlo approach

In this work we review and-to some extent-upgrade one of the main theories of light flux through homogeneous isotropic media, namely, the Kubelka-Munk (K-M) theory, and in particular the later expansion made by Kubelka to obtain the reflectance of a specimen when a substrate lies underneath. We have completed this solution by calculating the transverse energy density in the specimen and the transmission of the whole. We show that this last result-compatible with Kubelka's upgrade for layered media-also allows for the calculation of the specimen/substrate absorption split. In order to validate these expressions, the results were reproduced by means of a Monte Carlo simulation working on a layered medium under the same assumptions as the K-M theory. Interestingly, the numerical procedure introduces new capabilities in the model regarding the history of any absorbed or outgoing elemental light beam, such as the recording of its time-of-flight through a given system.

Genome Editing of Lineage Determinants in Human Pluripotent Stem Cells Reveals Mechanisms of Pancreatic Development and Diabetes

Directed differentiation of human pluripotent stem cells (hPSCs) into somatic counterparts is a valuable tool for studying disease. However, examination of developmental mechanisms in hPSCs remains challenging given complex multi-factorial actions at different stages. Here, we used TALEN and CRISPR/Cas-mediated gene editing and hPSC-directed differentiation for a systematic analysis of the roles of eight pancreatic transcription factors (PDX1, RFX6, PTF1A, GLIS3, MNX1, NGN3, HES1, and ARX). Our analysis not only verified conserved gene requirements between mice and humans but also revealed a number of previously unsuspected developmental mechanisms with implications for type 2 diabetes. These include a role of RFX6 in regulating the number of pancreatic progenitors, a haploinsufficient requirement for PDX1 in pancreatic β cell differentiation, and a potentially divergent role of NGN3 in humans and mice. Our findings support use of systematic genome editing in hPSCs as a strategy for understanding mechanisms underlying congenital disorders.

Expression of MLL-AF4 or AF4-MLL fusions does not impact the efficiency of DNA damage repair

The most frequent rearrangement of the human MLL gene fuses MLL to AF4 resulting in high-risk infant B-cell acute lymphoblastic leukemia (B-ALL). MLL fusions are also hallmark oncogenic events in secondary acute myeloid leukemia. They are a direct consequence of mis-repaired DNA double strand breaks (DNA-DSBs) due to defects in the DNA damage response associated with exposure to topoisomerase-II poisons such as etoposide. It has been suggested that MLL fusions render cells susceptible to additional chromosomal damage upon exposure to etoposide. Conversely, the genome-wide mutational landscape in MLL-rearranged infant B-ALL has been reported silent. Thus, whether MLL fusions compromise the recognition and/or repair of DNA damage remains unanswered. Here, the fusion proteins MLL-AF4 (MA4) and AF4-MLL (A4M) were CRISPR/Cas9-genome edited in the AAVS1 locus of HEK293 cells as a model to study MLL fusion-mediated DNA-DSB formation/repair. Repair kinetics of etoposide- and ionizing radiation-induced DSBs was identical in WT, MA4- and A4M-expressing cells, as revealed by flow cytometry, by immunoblot for γH2AX and by comet assay. Accordingly, no differences were observed between WT, MA4- and A4M-expressing cells in the presence of master proteins involved in non-homologous end-joining (NHEJ; i.e.KU86, KU70), alternative-NHEJ (Alt-NHEJ; i.e.LigIIIa, WRN and PARP1), and homologous recombination (HR, i.e.RAD51). Moreover, functional assays revealed identical NHEJ and HR efficiency irrespective of the genotype. Treatment with etoposide consistently induced cell cycle arrest in S/G2/M independent of MA4/A4M expression, revealing a proper activation of the DNA damage checkpoints. Collectively, expression of MA4 or A4M does neither influence DNA signaling nor DNA-DSB repair.

Seroprevalence in Household Raised Pigs Indicate High Exposure to GII Noroviruses in Rural Nicaragua

Information about porcine norovirus (PoNoV), genetically similar to human NoV (HuNoV), is limited from rural areas where household-raised pigs are heavily exposed to faecal material which could facilitate transmission. Histo-blood group antigens (HBGAs) are known susceptibility factors to NoV in humans and in a germfree piglet model but their role in susceptibility in the porcine population remains unknown. This study reports: (i) the seroprevalence and antibody titres to human norovirus (NoV) VLPs in household raised pigs; (ii) the distribution of HBGAs in relation to NoV IgG antibody titres and further characterization by blocking of GII.4 VLP binding to pig gastric mucins (PGM). The majority of pigs were seropositive to all three VLPs tested (58-70%) with seropositivity and cross-reactivity increasing significantly with age. However, pig sera could not block the binding of NoV GII.4 VLPs (Dijon) to PGM suggesting no previous infection with this genotype. The majority of the pigs were H-positive (84%), a susceptibility factor for human infections. IgG antibody titres were however higher in H-negative (GMT = 247) as compared with H-positive (GMT = 57) pigs, but after age stratification, this difference in antibody titres was only observed in pigs ≤1 month of age. In conclusion, serological data show that the porcine population of Nicaragua is highly exposed to NoV infections, and the association to HBGAs warrants further investigation.

Mechanisms underlying the formation of induced pluripotent stem cells

Human pluripotent stem cells (hPSCs) offer unique opportunities for studying human biology, modeling diseases, and therapeutic applications. The simplest approach so far to generate human PSC lines is through reprogramming of somatic cells from an individual by defined factors, referred to simply as reprogramming. Reprogramming circumvents the ethical controversies associated with human embryonic stem cells (hESCs) and nuclear transfer hESCs (nt-hESCs), and the resulting induced pluripotent stem cells (hiPSCs) retain the same basic genetic makeup as the somatic cell used for reprogramming. Since the first report of iPSCs by Takahashi and Yamanaka (Cell 2006, 126:663-676), the molecular mechanisms of reprogramming have been extensively investigated. A better mechanistic understanding of reprogramming is fundamental not only to iPSC biology and improving the quality of iPSCs for therapeutic use, but also to our understanding of the molecular basis of cell identity, pluripotency, and plasticity. Here, we summarize the genetic, epigenetic, and cellular events during reprogramming, and the roles of various factors identified thus far in the reprogramming process. WIREs Dev Biol 2016, 5:39-65. doi: 10.1002/wdev.206 For further resources related to this article, please visit the WIREs website.

Induction of hyperandrogenism in lean reproductive-age women stimulates proatherogenic inflammation

We determined the effect of hyperandrogenemia as observed in polycystic ovary syndrome (PCOS) on fasting and glucose-stimulated proatherogenic inflammation markers in lean healthy reproductive-age women. Sixteen lean healthy ovulatory reproductive-age women were treated with 130 mg of DHEA or placebo (n=8 each) for 5 days. Interleukin-6 (IL-6) mRNA and IL-6 release from mononuclear cells (MNC), plasma IL-6 and C-reactive protein (CRP), and MNC-derived (matrix metalloproteinase-2) MMP-2 protein were quantified in the fasting state and 2 h after glucose ingestion, before and after treatment. Before treatment, subjects receiving dehydroepinadrosterone (DHEA) or placebo exhibited no differences in androgens, or any proatherogenic inflammation markers while fasting and after glucose ingestion. Compared with placebo, DHEA administration raised levels of testosterone, androstenedione, and DHEA-sulfate (DHEA-S), and increased the percent change from baseline in fasting IL-6 mRNA, IL-6 release, plasma IL-6, and CRP and MMP-2 protein. However, there were no differences in any of the proatherogenic inflammation markers following glucose ingestion after DHEA administration. We conclude that in lean reproductive-age women, proatherogenic inflammation in the fasting state increases after raising circulating androgens to levels observed in PCOS. However, this hyperandrogenemia-induced MNC activation does not provoke a similar response to subsequent glucose ingestion.