Additive manufactured gyroid-based cell structures under compression: design, testing and simulation for biomedical applications.

The mechanical behaviour of a DMLS Ti-6Al-4V gyroid-based cellular structure (CS), with potential application in the fabrication of implants, was studied under compressive conditions. The influence of the CS volumetric fraction on the elastic modulus was experimentally evaluated in cubic and cylindrical samples. The experimental results showed that the selected parameters allowed approximating the mechanical behaviour of the CS to that of trabecular bone. Finite element analysis was employed to study the mechanical behaviour of the CS. The model presented a good approximation of the experimental results, being useful to predict the mechanical behaviour of the CS.

Euchromatin factors HULC and Set1C affect heterochromatin organization and mating-type switching in fission yeast Schizosaccharomyces pombe.

Mating-type (P or M) of fission yeast Schizosaccharomyces pombe is determined by the transcriptionally active mat1 cassette and is switched by gene conversion using a donor, either mat2 or mat3, located in an adjacent heterochromatin region (mating-type switching; MTS). In the switching process, heterochromatic donors of genetic information are selected based on the P or M cell type and on the action of two recombination enhancers, SRE2 promoting the use of mat2-P and SRE3 promoting the use of mat3-M, leading to replacement of the content of the expressed mat1 cassette. Recently, we found that the histone H3K4 methyltransferase complex Set1C participates in donor selection, raising the question of how a complex best known for its effects in euchromatin controls recombination in heterochromatin. Here, we report that the histone H2BK119 ubiquitin ligase complex HULC functions with Set1C in MTS, as mutants in the shf1, brl1, brl2 and rad6 genes showed defects similar to Set1C mutants and belonged to the same epistasis group as set1Δ. Moreover, using H3K4R and H2BK119R histone mutants and a Set1-Y897A catalytic mutant, we found that ubiquitylation of histone H2BK119 by HULC and methylation of histone H3K4 by Set1C are functionally coupled in MTS. Cell-type biases in MTS in these mutants suggested that HULC and Set1C inhibit the use of the SRE3 recombination enhancer in M cells, thus favoring SRE2 and mat2-P. Consistent with this, imbalanced switching in the mutants was traced to compromised association of the directionality factor Swi6 with the recombination enhancers in M cells. Based on their known effects at other chromosomal locations, we speculate that HULC and Set1C control nucleosome mobility and strand invasion near the SRE elements. In addition, we uncovered distinct effects of HULC and Set1C on histone H3K9 methylation and gene silencing, consistent with additional functions in the heterochromatic domain.

Improvement of KinectTM sensor capabilities by fusion with laser sensing data using octree.

To enhance sensor capabilities, sensor data readings from different modalities must be fused. The main contribution of this paper is to present a sensor data fusion approach that can reduce Kinect(TM) sensor limitations. This approach involves combining laser with Kinect(TM) sensors. Sensor data is modelled in a 3D environment based on octrees using a probabilistic occupancy estimation. The Bayesian method, which takes into account the uncertainty inherent in the sensor measurements, is used to fuse the sensor information and update the 3D octree map. The sensor fusion yields a significant increase of the field of view of the Kinect(TM) sensor that can be used for robot tasks.

[Clinical problem solving as a measurement instrument in a diploma course for respiratory technicians]. / Manejo de la insuficiencia respiratoria a través de casos clínicos por alumnos del curso formativo profesional técnico en terapia respiratoria.

BACKGROUND: We undertook this study to consider the gaps in the training of clinical respiratory insufficiency as relates to students enrolled in a technical professional course in respiratory therapy. METHOD: An instrument was constructed and validated to evaluate clinical aptitude, integrated by four clinical cases of respiratory insufficiency. Six indicators were defined and 140 statements were elaborated, after two rounds with five technicians in respiratory therapy with experience in the care of patients with respiratory insufficiency in intensive care units, 90 statements remained. The instrument was applied in a pilot group of 31 students using Kuder Richardson formula 21 and the consistency was (0.80). Clinical aptitude of students was described on an ordinal scale from very low to very high. Categories were established from qualifications calculated for the expected chance effects. RESULTS: On comparing initial and final qualifications, there were statistically significant differences (p <0.005). CONCLUSIONS: Clinical aptitude was developed in most students enrolled in the training course. Although a promotional educational participation strategy was not planned, we are in agreement that education and training of the coordinating professors contributed to achieving the goals.

Noninvasive versus histologic detection of gastric atrophy in a Hispanic population in North America.

BACKGROUND & AIMS: Cancer risk is directly correlated with the severity and extent of mucosal atrophy, making identification of atrophy a goal in cancer prevention programs. The aim of this study was to compare targeted histology with noninvasive testing for the identification of antral and/or corpus atrophy in North America. METHODS: In a cross-sectional study of a random sample of households, 8 gastric biopsy specimens were obtained from defined locations in the antrum and corpus. Biopsies were scored for the presence of Helicobacter pylori and gastric atrophy (defined as loss of normal glandular components). Atrophy was scored by using the Sydney system and a system based on the number and location of corpus biopsies with atrophy. Patients' sera were examined for pepsinogen I, pepsinogen II, and gastrin-17 (fasting and stimulated). RESULTS: One hundred eighty volunteers, approximately 30 per age group and ranging in age from 18-82 years, participated. There were 76 men. The overall weighted prevalence of a corpus atrophy was 4.7% (95% confidence interval, 2.3-7.0). There was a significant inverse relationship between the grade of corpus atrophy and the pepsinogen I/pepsinogen II ratio (R = -0.31, P < .01). We failed to confirm the usefulness of the proposed algorithm by using gastrin-17, H. pylori serology, and serum pepsinogens to categorize the gastric histology. The Sydney system underestimated the prevalence of corpus atrophy by approximately 25%. CONCLUSION: Noninvasive testing is both possible and practical by using pepsinogen assays for the identification of the precancerous condition of moderate to severe corpus atrophy in North American Hispanic patients.

[Pulmonary mechanics, oxygenation index, and alveolar ventilation in patients with two controlled ventilatory modes. A comparative crossover study]. / Mecánica pulmonar, índice de oxigenación y ventilación alveolar en pacientes con dos modalidades de ventilación mecánica controlada. Un estudio comparativo de tipo cruzado.

OBJECTIVE: To compare in a crossover study pulmonary mechanics, oxigenation index (PaO(2)/FiO(2)), and partial pressure of CO(2) in arterial blood (PaCO(2)) in patients with mechanical ventilation in two controlled ventilatory modes. SETTING: Intensive care unit of a university affiliated hospital. DESIGN: Prospective crossover clinical trial. PATIENTS AND METHODS: A total 114 consecutive patients were admitted to the intensive care unit (ICU) under controlled mechanical ventilation with SaO(2) >90% and FiO(2) <0.5 and assigned by random allocation to either volume control (VC) and constant inspiratory flow (square flow curve) (group I) or pressure control mode (PC) (group II). Both groups were ventilated with tidal volume (Vt) of 7 ml/kg, respiratory rate (RR) 14/min, inspiratory-expiratory ratio 1:2 (I:E), PEEP 5 cm H(2)O, and FiO(2) 0.4. After 15 min of mechanical ventilation, pulmonary mechanics, oxygenation index (OI), and PaCO(2) were measured and registered, and ventilatory mode was switched to PC mode in group I and to VC in group II, maintaining the same ventilator settings. Pulmonary mechanics, OI, and PaCO(2) were again registered after 15 min of ventilation. RESULTS: Peak inspiratory pressure (PIP) was higher in VC than in PC (31.5 vs 26 cm H(2)O), which resulted in a significant increase in transpulmonary pressure amplitude difference (DP) (25 vs 19 cm H(2)O). Mean airway pressure (MAP) and OI were lower in VC than in PC (11.5 vs 12 cm H(2)O, and 198.5 vs 215, respectively). Dynamic compliance (DynC) was lower in VC than in PC (20 vs 26 ml/cm H(2)O), p < 0.05 for all values. At constant ventilator settings in the same patient, PC and not VC ventilation decreases PIP (which results in smaller transpulmonary pressure amplitude difference), increases MAP, and DynC and improves the oxygenation index.