Xenopus tropicalis osteoblast-specific open chromatin regions reveal promoters and enhancers involved in human skeletal phenotypes and shed light on early vertebrate evolution.

While understanding the genetic underpinnings of osteogenesis has far-reaching implications for skeletal diseases and evolution, a comprehensive characterization of the osteoblastic regulatory landscape in non-mammalian vertebrates is still lacking. Here, we compared the ATAC-Seq profile of Xenopus tropicalis (Xt) osteoblasts to a variety of non mineralizing control tissues, and identified osteoblast-specific nucleosome free regions (NFRs) at 527 promoters and 6747 distal regions. Sequence analyses, Gene Ontology, RNA-Seq and ChIP-Seq against four key histone marks confirmed that the distal regions correspond to bona fide osteogenic transcriptional enhancers exhibiting a shared regulatory logic with mammals. We report 425 regulatory regions conserved with human and globally associated to skeletogenic genes. Of these, 35 regions have been shown to impact human skeletal phenotypes by GWAS, including one trps1 enhancer and the runx2 promoter, two genes which are respectively involved in trichorhinophalangeal syndrome type I and cleidocranial dysplasia. Intriguingly, 60 osteoblastic NFRs also align to the genome of the elephant shark, a species lacking osteoblasts and bone tissue. To tackle this paradox, we chose to focus on dlx5 because its conserved promoter, known to integrate regulatory inputs during mammalian osteogenesis, harbours an osteoblast-specific NFR in both frog and human. Hence, we show that dlx5 is expressed in Xt and elephant shark odontoblasts, supporting a common cellular and genetic origin of bone and dentine. Taken together, our work (i) unravels the Xt osteogenic regulatory landscape, (ii) illustrates how cross-species comparisons harvest data relevant to human biology and (iii) reveals that a set of genes including bnc2, dlx5, ebf3, mir199a, nfia, runx2 and zfhx4 drove the development of a primitive form of mineralized skeletal tissue deep in the vertebrate lineage.

Effect of the Addition of Fique Bagasse Cellulose Nanoparticles on the Mechanical and Structural Properties of Plastic Flexible Films from Cassava Starch.

One of the activities most representative of the agricultural sector in Colombia is the production of biodegradable fique fiber. The efficiency of the defiberization process of the fique leaves is very low since a mere 4% of the total weight of the leaf (cabuya) is used and marketed. The remaining 96%, composed of fique juice and bagasse, is considered to be waste and discarded, impacting the environment. The aim of this work was to study fique bagasse as a source of cellulose nanoparticles (CNCs). CNCs were obtained by acid hydrolysis and added at 10% to films made from cassava thermoplastic starch (TPS) by the casting method. Structural changes in the CNCs, TPS, and their mixtures were characterized by FTIR-ATR and their morphology and particle size by SEM and TEM microscopy, respectively. Thermal properties were analyzed using DSC and TGA, along with their effect on mechanical properties. Changes in the FTIR spectra indicated that the chemical method adequately removed hemicellulose and lignin from the fiber surface of fique bagasse. The CNCs showed a diameter and length of 7.5 ± 3.9 and 52.7 ± 18.1 nm, respectively, and TPS 10% CNC obtained an increase in mechanical strength of 116%. The obtainment of CNCs from lignocellulosic materials can thus be viewed as a favorable option for the subsequent reinforcement of a polymeric matrix.

Drug-Facilitated Sexual Assault: A Systematic Review.

Since the last two decades, the scientific community has made an effort to analyze drug-facilitated sexual assault (DFSA). However, a lack of understanding remains about the DFSA problem, particularly concerning the opportunistic variant. Facing this situation, a systematic review of the term DFSA is carried out from its first appearance in the scientific databases consulted (Web of Science, Scopus, and PubMed) to the current day. The search resulted in 773 publications, reduced to a final study sample composed of 19 articles. Eligible studies for this review had to meet certain inclusion criteria, in addition to providing information on DFSA prevalence, DFSA victim profile, DFSA offender profile, involved drugs, or contextual information about the assault. The results demonstrated that the assailants are men, who mostly know victims before the assault. The victims are young women under 30 years old. Alcohol is the drug involved in most DFSA cases, prevailing a voluntary use. Most assaults occur in private spaces, particularly the aggressors' own homes. Furthermore, there is a detected need for a standard definition of DFSA to allow the different actors involved in dealing with sexual violence to work effectively together, and, at the same time, it is detected that the available studies overrepresent proactive DFSA and underestimate opportunism, the most common modus operandi involved in DFSA cases.

Dissociable control of motivation and reinforcement by distinct ventral striatal dopamine receptors.

Dopamine release in striatal circuits, including the nucleus accumbens (NAc), tracks separable features of reward such as motivation and reinforcement. However, the cellular and circuit mechanisms by which dopamine receptors transform dopamine release into distinct constructs of reward remain unclear. Here, we show that dopamine D3 receptor (D3R) signaling in the NAc drives motivated behavior by regulating local NAc microcircuits. Furthermore, D3Rs co-express with dopamine D1 receptors (D1Rs), which regulate reinforcement, but not motivation. Paralleling dissociable roles in reward function, we report non-overlapping physiological actions of D3R and D1R signaling in NAc neurons. Our results establish a novel cellular framework wherein dopamine signaling within the same NAc cell type is physiologically compartmentalized via actions on distinct dopamine receptors. This structural and functional organization provides neurons in a limbic circuit with the unique ability to orchestrate dissociable aspects of reward-related behaviors that are relevant to the etiology of neuropsychiatric disorders.

Assessment of photo electro-Fenton and solar photo electro-Fenton processes for the efficient degradation of asulam herbicide.

The degradation of asulam herbicide by photo electro-Fenton (PEF) and solar photo electro-Fenton (SPEF) processes was studied using an undivided electrochemical BDD/carbon-felt cell to generate H2O2 continuously. A central composite design combined with response surface methodology was applied to determine the optimal operating conditions of current intensity = 0.30 A, [Fe2+] = 0.3 mM, and [Na2SO4] = 0.11 M at pH 3 to achieve the complete degradation of asulam by electro-Fenton. Subsequently, the SPEF process was more efficient treatment compared to PEF, achieving a complete degradation of asulam and 98% of mineralization in 180 min. Moreover, 4-aminobenzenesulfonamide, 4-aminophenol, and 4-benzoquinone were detected as aromatic intermediates, whereas acetic acid, oxalic acid, and NO3- ions were identified as final degradation by-products. Thus, the SPEF process is an efficient alternative for the complete degradation and mineralization of herbicide asulam in an aqueous solution under natural sunlight.

Co-Plasticization of Starch with Glycerol and Isosorbide: Effect on Retrogradation in Thermo-Plastic Cassava Starch Films.

Thermoplastic starch (TPS) has emerged as an essential alternative to produce environmentally friendly packaging; however, retrogradation is a disadvantage that affects its shelf life. This study analyzed the co-plasticizing effect of isosorbide on the mechanical, thermal, physicochemical, and microstructural properties and the retrogradation of films obtained by blown film extrusion from thermoplasticized starch with mixtures of glycerol and isosorbide in different ratios (3:0, 2:1, 1:2, and 0:3, respectively). The results showed that the higher concentration of isosorbide significantly increased the tensile strength; however, it reduced the elongation. Retrogradation modeled using the Avrami equation showed that the presence of isosorbide reduced the retrogradation rate (k) and modified the recrystallization mechanism (n). The relative crystallinity in the plasticized TPS films was reduced to 89%, and the adsorption significantly decreased. Isosorbide was very important in reducing the retrogradation of TPS. The best performance was obtained with the 2:1 ratio of glycerol/isosorbide due to the synergistic effect between the plasticizers. The results would allow tuning the properties of TPS films by combining glycerol/isosorbide in different ratios, which enables the design of materials tailored to potential application requirements.

Prefrontal Interneurons: Populations, Pathways, and Plasticity Supporting Typical and Disordered Cognition in Rodent Models.

Prefrontal cortex (PFC) inhibitory microcircuits regulate the gain and timing of pyramidal neuron firing, coordinate neural ensemble interactions, and gate local and long-range neural communication to support adaptive cognition and contextually tuned behavior. Accordingly, perturbations of PFC inhibitory microcircuits are thought to underlie dysregulated cognition and behavior in numerous psychiatric diseases and relevant animal models. This review, based on a Mini-Symposium presented at the 2022 Society for Neuroscience Meeting, highlights recent studies providing novel insights into: (1) discrete medial PFC (mPFC) interneuron populations in the mouse brain; (2) mPFC interneuron connections with, and regulation of, long-range mPFC afferents; and (3) circuit-specific plasticity of mPFC interneurons. The contributions of such populations, pathways, and plasticity to rodent cognition are discussed in the context of stress, reward, motivational conflict, and genetic mutations relevant to psychiatric disease.

Daily changes in light influence mood via inhibitory networks within the thalamic perihabenular nucleus.

Exposure to irregular lighting schedules leads to deficits in affective behaviors. The retino-recipient perihabenular nucleus (PHb) of the dorsal thalamus has been shown to mediate these effects in mice. However, the mechanisms of how light information is processed within the PHb remains unknown. Here, we show that the PHb contains a distinct cluster of GABAergic neurons that receive direct retinal input. These neurons are part of a larger inhibitory network composed of the thalamic reticular nucleus and zona incerta, known to modulate thalamocortical communication. In addition, PHbGABA neurons locally modulate excitatory-relay neurons, which project to limbic centers. Chronic exposure to irregular light-dark cycles alters photo-responsiveness and synaptic output of PHbGABA neurons, disrupting daily oscillations of genes associated with inhibitory and excitatory PHb signaling. Consequently, selective and chronic PHbGABA manipulation results in mood alterations that mimic those caused by irregular light exposure. Together, light-mediated disruption of PHb inhibitory networks underlies mood deficits.

Dapsone-Induced Methemoglobinemia: A Case Report.

Here, we present the case of a 64-year-old male with a rare cause of cyanosis due to dapsone-induced methemoglobinemia who was treated successfully with methylene blue and high-dose Vitamin C. Our case emphasizes the importance of history taking, knowledge, and high index of suspicion of drug-induced methemoglobinemia, especially in the presence of saturation gap. This condition can be fatal if left untreated.

Effect of the Addition of High-Protein Hydrolyzed Flour from Oncorhynchus mykiss Byproducts on the Properties of an Extruded Feed.

This work aims to evaluate the effect of the addition of a high-protein hydrolyzed (HPH) flour from the chemical silage of trout (Oncorhynchus mykiss) residues on the parameters of the extrusion system physicochemical transformations and the microstructure of the extrudate. During the extrusion process, the materials used for the study were the HPH flour obtained from trout by chemical silage, fishmeal, and cassava starch. The extrudate's microstructural changes were evaluated by determining the porosity, scanning electron microscopy, the chemical changes, the amino acid profile, residual formic and lactic acid content, the molecular mass profile, the grade of hydrolysis, and in vitro digestibility. The results showed pellets with high durability due to the cohesiveness of the hydrolyzed protein flour but at the same time with low hardness due to the high porosity achieved. The monitoring carried out to the changes in the protein, such as the degree of hydrolysis, water-soluble protein, and molecular mass profile, verify the binding effect of the high-protein hydrolyzed flour during the extrusion process. Finally, the high-resolution optical microscopy methodology presented a high correlation with the phenomena presented in the experiment.

A review of trends in the development of bionanocomposites from lignocellulosic and polyacids biomolecules as packing material making alternative: A bibliometric analysis.

Contamination caused by the accumulation of petrochemical-based plastics has reached worrying magnitudes and led to the development of biopolymers as an option to mitigate the problem. This work thus presents a bibliometric analysis of all that concerns the development of such bionanocomposite materials, using ScientoPy and SciMAT software to establish associations between the number of published documents, countries, institutions and most relevant topics. The bionanocomposites topic was found to throw up the biggest number of documents associated (2008) with the different types of raw materials and methods used to obtain nanoparticles and their combination with biopolymeric materials, the result known as a "bionancomposite*". Analysis of the documents related to the application for development of packaging materials from biological molecules, carbohydrate polymers, compounds, conjugates, gels, glucans, hydrogels, membranes, mucilage (source unspecified), mucoadhesives, paper, polymers, polysaccharide, saccharides etc, is also presented, emphasizing mechanical, thermal and barrier properties, which, due to the inclusion of nanoparticles mainly from natural sources of cellulose, show increases of up to 30%. The inclusion of nanoparticles, especially those derived from cellulose sources, generally seeks to increase the properties of bionanocomposite materials. Regarding an increase in mechanical properties, specifically tensile strength, inclusions at percentages not exceeding 10 wt% can register increases that exceed 30% were reported.

Does lumbar spine fusion predispose patients to future total hip replacement?

OBJECTIVE: Hip-spine syndrome has been well studied since it was first described by Offierski and MacNab in 1983. Today, strong evidence links symptoms of hip and spine pathology to postsurgical outcomes. Recent studies have reported increased rates of hip dislocation in patients previously treated with total hip arthroplasty (THA) who had undergone lumbar fusion procedures. However, the effect of this link on native hip-joint degeneration remains an area of ongoing research. The purpose of this study was to characterize the relationship between use of lumbar fusion procedures and acceleration of hip pathology by analyzing the rate of future THA in patients with preexisting hip osteoarthritis. METHODS: This population-level, retrospective cohort study was conducted by using the PearlDiver research program. The initial patient cohort was defined by the presence of diagnosis codes for hip osteoarthritis. Patients were categorized according to use of lumbar fusion after diagnosis of hip pathology. Survival curves with respect to THA were generated by comparison of the no lumbar fusion cohort with the lumbar fusion cohort. To assess the impact of fusion construct length, the lumbar fusion cohort was then stratified according to the number of levels treated (1-2, 3-7, or ≥ 8 levels). Hazard ratios (HRs) were then calculated for the risk factors of number of levels treated, patient age, and sex. RESULTS: A total of 2,275,683 patients matched the authors' inclusion criteria. Log-rank analysis showed no significant difference in the rates of THA over time between the no lumbar fusion cohort (2,239,946 patients) and lumbar fusion cohort (35,737 patients; p = 0.40). When patients were stratified according to number of levels treated, again no differences in the incidence rates of THA over the study period were determined (p = 0.30). Patients aged 70-74 years (HR 0.871, p < 0.001), 75-79 years (HR 0.733, p < 0.001), 80-84 years (HR 0.557, p < 0.001), and ≥ 85 years (HR = 0.275, p < 0.001) were less likely to undergo THA relative to the reference group (patients aged 65-69 years). CONCLUSIONS: Although lumbar fusion was initially hypothesized to have a significant effect on rate of THA, lumbar fusion was not associated with increased need for future THA in patients with preexisting hip osteoarthritis. Additionally, there was no relationship between fusion construct length and rate of THA. Although lumbar fusion reportedly increases the risk of hip dislocation in patients with prior THA, these data suggest that lumbar fusion may not clinically accelerate native hip degeneration.

Wikipedia: A Medical Student Educational Project to Edit Wikipedia in Preparation for Practicing Evidence-Based Pain Medicine.

OBJECTIVE: Wikipedia is commonly used to acquire information about various medical conditions such as chronic pain. Ideally, better online pain management content could reduce the burden of opioid use disorders. Our goal was to improve the quality of the content available on Wikipedia to make it more accurate and applicable to medical students and the general public while training medical students to practice evidence-based medicine and critically assess their sources of information. METHODS: An elective class in Neuroscience, Pain, and Opioids composed of 10 medical students met biweekly to discuss landmark and practice-changing research articles in the fields of acute pain, chronic pain, and opioid management. The professor chose Wikipedia articles relevant to this course. Three independent viewers analyzed the quality of citations, anecdotal medical content, and content value for both patients and medical professionals. As part of their coursework, students then edited the Wikipedia articles. RESULTS: Although some of the Wikipedia pain topic content (6.7% ± 2.0) was anecdotal, financially biased, or inconsistent with Western Medical Practice content, overall articles included primarily high-quality citations (85.6% ± 3.1). On a 0-5 Likert scale, students felt content would be moderately helpful for both medical students/professionals (3.4 ± 0.2) and laypersons (3.5 ± 0.2). Editing and adding citations was feasible, but novel material was often reverted. CONCLUSION: A significant amount of pain medicine content was relevant and amenable to student editing. Therefore, future use of this tactic could provide a unique opportunity to integrate evidence-based medicine into the medical curriculum and have a direct impact on the widely available medical information. Future refinement in the editorial process may also further improve online information.

Factores asociados a hemoptisis en pacientes con tuberculosis pulmonar en el Hospital Nacional Dos de Mayo, Lima - Perú / Associated factors with hemoptys in patients with pulmonary tuberculosis at Dos de Mayo National Hospital, Lima - Perú

RESUMEN Objetivos. Determinar los factores asociados a hemoptisis en pacientes con tuberculosis pulmonar admitidos al Hospital Nacional Dos de Mayo. Métodos. Estudio analítico de casos y controles. Se seleccionaron pacientes con baciloscopia positiva del programa de tuberculosis del Hospital Nacional Dos de Mayo, Lima - Perú. Los casos fueron pacientes con tuberculosis pulmonar con hemoptisis; y los controles, tuberculosis pulmonar sin hemoptisis. Se estudiaron variables epidemiológicas, clínicas y laboratoriales. Se empleo el software SPSS 24. Se determinaron medidas de frecuencia, medidas de tendencia central y de dispersión, así como los odds ratio con sus respectivos intervalos de confianza al 95%, se consideró estadísticamente significativo el valor de p<0,05. Resultados. La hemoptisis representó el 5,8% del total de pacientes con tuberculosis pulmonar y baciloscopia positiva, el 80% se presentó en varones menores de 60 años. El 70% de casos tuvo antecedente de hábito alcohólico (OR: 2,5 IC: 1,2-5,5); el 24% exposición a quema de biomasa (OR: 4,9 IC: 1,7-14); el 66% presentó dolor torácico (OR: 3,3 IC: 1,6-6,7); las alteraciones tomográficas estuvieron presentes en el 88% de casos (OR: 24,5 IC: 9,2-64,8); no se encontró variaciones en el perfil de coagulación. La mortalidad por hemoptisis en pacientes hospitalizados con tuberculosis pulmonar con baciloscopía positiva fue del 20,22%. Conclusiones. El alcoholismo crónico y la evidencia tomográfica de bronquiectasia estuvieron asociados a hemoptisis en pacientes hospitalizados por tuberculosis pulmonar con baciloscopia positiva.

ABSTRACT Objectives. To determine the factors associated with hemoptysis in patients with pulmonary tuberculosis admitted at Dos de Mayo National Hospital. Methods. Analytical study of cases and controls. Patients from the tuberculosis program at Dos de Mayo National Hospital, Lima- Peru, were selected. The cases were patients with pulmonary tuberculosis with hemoptysis, and controls pulmonary tuberculosis without hemoptysis. Epidemiological, clinical and laboratory variables were studied. SPSS 24 software is used. Frequency, central trend and dispersion measurements were determined, as well as odds ratios with their respective confidence intervals at 95%, the value of p<0,05 was considered statistically significant. Results. Tuberculosis hemoptysis account for 5,8% of all patients with pulmonary tuberculosis, 80% occurred in males under 60 years old. 70% of cases had a history of alcoholic habits (OR: 2,5 CI: 1,2-5,5); 24% exposure to biomass burning (OR: 4,9 CI: 1,7-14); 66% had chest pain (OR: 3,3 IC: 1,6-6,7); tomographic alterations were present in 88% of cases (OR: 24,5 IC: 9,2-64,8); however, no variations in the coagulation profile were found. Death from hemoptysis in hospitalized patients with pulmonary tuberculosis was 20,22%. Conclusions. Chronic alcoholism and tomographic evidence of bronchiectasis were associated with hemoptysis in patients hospitalized for pulmonary tuberculosis with positive smear microscopy.

Anaerobic biodegradation under slurry thermophilic conditions of poly(lactic acid)/starch blend compatibilized by maleic anhydride.

TPS/MA/PLA is a blend of thermoplastic starch (TPS) and polylactic acid (PLA) compatibilized by maleic anhydride (MA) that can be a substitute for petro-based plastics in certain applications. At the end of its life, this material must be properly disposed in treatment systems such as composting or anaerobic digestion. The biodegradability of TPS/MA/PLA, PLA, TPS and the non-compatible mixture (TPS/PLA) was evaluated in a slurry thermophilic anaerobic digestion system (STAD) according to ISO 13975-2012 standard. The anaerobic inoculum was prepared from cow manure and the organic fraction of municipal solid waste. After 31 days of incubation, the pure PLA exhibited a 12-day lag phase and 40.41% of biodegradability. TPS, TPS/PLA and TPS/MA/PLA did not exhibit lag phase and reached 92.11%, 65.48% and 64.82% of biodegradation respectively. The slow degradation rate of PLA is attributed to its high glass transition temperature and crystallinity. In TPS/MA/PLA and TPS/PLA, about 50% of PLA and 13% to 10% of the TPS remains undegraded and MA did not affect the biodegradation of TPS/MA/PLA compared to TPS/PLA. Results suggest that, in very short retention times STAD systems, PLA based materials could not exhibit enough biodegradability.

The Clinical Utility of Additional Axillary and Velpeau Radiographs in the Evaluation of Suspected Shoulder Trauma.

OBJECTIVES: To investigate the clinical utility of additional axillary or Velpeau views in evaluating potential shoulder trauma after a standard radiograph series of anteroposterior, Grashey, and/or trans-scapular views. DESIGN: Retrospective study. SETTING: Level I academic medical center. PATIENTS: All patients in a 10-year span who received an initial shoulder radiograph series followed by additional axillary/Velpeau views within 24 hours. MAIN OUTCOME MEASUREMENTS: The clinical utility of the additional axillary/Velpeau views, including the final diagnosis and treatment plan, as ascertained through examination of radiology reports, progress notes, and radiograph images. RESULTS: A total of 271 cases were reviewed, with 35 patients being excluded from the final cohort because they received post-treatment radiographs to confirm a successful therapeutic outcome. The additional axillary/Velpeau views did not affect clinical decision making in 230 (97.5%) of the remaining 236 cases. All 6 patients whose care benefitted from the additional views carried the diagnosis of shoulder instability, accounting for 40% of this diagnostic group. The additional views confirmed an equivocal finding in 5 of these 6 cases and changed the diagnosis (demonstrating a posterior dislocation that was not evident on initial radiographs) and treatment plan (leading to a closed glenohumeral reduction procedure) in the other case. CONCLUSIONS: Additional axillary/Velpeau views of suspected shoulder trauma rarely led to a change in the final treatment plan, except in patients in which a definitive diagnosis of stability or instability could not be made based on initial radiographs. A cost/benefit analysis is required to weigh the cost of additional radiographs with the benefit of capturing infrequent yet serious dislocations (usually posterior). LEVEL OF EVIDENCE: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Grado de satisfacción sobre prácticas hospitalarias en estudiantes de Medicina en una universidad peruana, 2016 / Degree of Satisfaction about Hospital Practices in Medical Students from a Peruvian University, 2016

Introducción: En las últimas dos décadas se han multiplicado las escuelas de Medicina Humana a nivel mundial y, específicamente, en Latinoamérica. Este aumento conlleva a una mayor población estudiantil que utilizará los centros hospitalarios como sus sedes de prácticas. Objetivo: Identificar el grado de satisfacción acerca de las prácticas hospitalarias en estudiantes de Medicina Humana de la universidad privada del Perú San Martín de Porres, Chiclayo, en 2016. Métodos: Estudio no experimental, observacional, descriptivo y transversal. La población estuvo constituida por estudiantes de la Facultad de Medicina Humana de cuarto, quinto y sexto años de estudios. El instrumento fue la "Escala de satisfacción de prácticas clínicas hospitalarias", constituido por 19 enunciados y estructurado en 3 dimensiones. Resultados: Se encuestó a 146 estudiantes, de los cuales el 53,4 por ciento correspondió al sexo femenino. La edad promedio fue de 23 ± 2,1 años. Se encontró que 76 estudiantes (50 por ciento) estaban "satisfechos" y "muy satisfechos" con el planeamiento, la ejecución y la evaluación de las prácticas hospitalarias. Conclusiones: Los estudiantes de Medicina Humana de la universidad privada del Perú San Martín de Porres, en 2016 se encontraron satisfechos con las prácticas hospitalarias(AU)

Introduction: In the last two decades, the schools of Human Medicine have multiplied worldwide and, specifically, in Latin America. This increase leads to a larger student population that will use the hospital centers as their practice headquarters. Objective: To identify the degree of satisfaction about hospital practices in students of Human Medicine from the Peruvian private university of San Martín de Porres, Chiclayo, in 2016. Methods: Non-experimental, observational, descriptive and cross-sectional study. The population was made up of students of the School of Human Medicine and belongin to the fourth, fifth and sixth academic years. The instrument was the Hospital Clinical Practice Satisfaction Scale, consisting of 19 statements and structured in 3 dimensions. Results: 146 students were surveyed, of which 53.4 percent corresponded to the female sex. The average age was 23±2.1 years. It was found that 76 students (50 prcent) were "satisfied" and "very satisfied" with the planning, execution and evaluation of hospital practices. Conclusions: The students of Human Medicine of the Peruvian private university of Peru San Martín de Porres, in 2016, were satisfied with the hospital practices(AU)

Structural changes of cassava starch and polylactic acid films submitted to biodegradation process.

Polylactic acid (PLA) and starch are compounds used in the manufacture of packaging to replace petroleum products as biodegradable and environmentally friendly materials. This study evaluated the structure and surface of a film manufactured by extrusion from cassava starch and PLA, which underwent a biodegradation process under compost conditions following the guidelines of ISO 4855-2:2007. Samples were taken every week for one month to perform Fourier Transform Infrared Spectroscopy (FT-IR) tests to identify functional groups on film, and High-Resolution Optical Microscopy (HROM) and Scanning Electron Microscopy (SEM) tests, from these techniques Structural changes in the film were evidenced. The addition of PLA increases the carbonyl index. The introduction of anhydrous malic acid (MA) in PLA/TPS mixtures may lead to an increase in the carbonyl index, The TPS/PLA composite film was framed in the three phases of biodegradation: disintegration, fragmentation, and mineralization. In week 4 a reduction in film size was observed with a thinning of the film with fractures that produced fragmentation and disintegration.