Sentinel lymph node biopsy before and after neoadjuvant chemotherapy in cN0 breast cancer patients: impact on axillary morbidity and survival-a propensity score cohort study.

PURPOSE: In patients with clinically lymph node-negative (cN0) breast cancer, performing sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NACT) has been preferentially embraced in comparison to before NACT. However, survival outcomes associated with both strategies remain understudied. We aimed to compare the axillary lymphadenectomy (ALND) rate, disease-free survival (DFS), and overall survival (OS), between two strategies. METHODS: We included 310 patients in a retrospective observational study. SNLB was performed before NACT from December 2006 to April 2014 (107 cases) and after NACT from May 2014 to May 2020 (203 patients). An inverse probability of treatment weighting (IPTW) method was applied to homogenize both groups. Hazard ratios (HR) and odd ratios (OR) are reported with 95% confidence intervals (95%CI). RESULTS: The lymphadenectomy rate was 29.9% before NACT and 7.4% after NACT (p < 0.001), with an OR of 5.35 95%CI (2.7-10.4); p = .002. After 4 years of follow-up, SLNB after NACT was associated with lower risk for DFS, HR 0.42 95%CI (0.17-1.06); p = 0.066 and better OS, HR 0.21 CI 95% (0.07-0.67); p = 0.009 than SLNB before NACT. After multivariate analysis, independent adverse prognostic factors for OS included SLNB before NACT, HR 3.095 95%CI (2.323-4.123), clinical nonresponse to NACT, HR 1.702 95% CI (1.012-2.861), and small tumors (cT1) with high proliferation index, HR 1.889 95% (1.195-2.985). CONCLUSION: Performing SLNB before NACT results in more ALND and has no benefit for patient survival. These findings support discontinuing the practice of SLNB before NACT in patients with cN0 breast cancer.

Compositional and functional analysis of the bacterial community of Mediterranean Leptosols under livestock grazing.

The composition and functioning of soil bacterial communities, as well as their responses to multiple perturbations, are not well understood in the terrestrial ecosystems. Our study focuses on the bacterial community of erosive and poorly developed soils (Haplic Leptosols) in Mediterranean rangelands of Extremadura (W Spain) with different grazing intensities. Leptosols from similar natural conditions were selected and sampled at two depths to determine the soil properties as well as the structure and activity of bacterial communities. As grazing intensified, the soil C and N content increased, as did the number and diversity of bacteria, mainly of fast-growing lineages. Aridibacter, Acidobacteria Gp6 and Gp10, Gemmatimonas, and Segetibacter increased their abundance along the grazing-intensity gradient. Firmicutes such as Romboutsia and Turicibacter from livestock microbiome also increased. In functional terms, the KEGG pathways enriched in the soils with moderate and high grazing intensity were ABC transporters, DNA repair and recombination proteins, the two-component system, and the degradation of xenobiotics. All of these proved to be related to stronger cell division and response mechanisms to environmental stressors such as drought, warming, toxic substances, and nutrient deprivation. Consequently, the bacterial community was affected by grazing, but appeared to adapt and counteract the effects of a high grazing intensity. Therefore, a clearly detrimental effect of grazing was not detected in the bacterial community of the soils studied.

Effects of grazing on soil properties in mediterranean forests (Central-Eastern Spain).

Traditional management practices, such as grazing, can have adverse impact on soils. Despite an extensive body of literature exploring the effects of grazing on soil and plants worldwide, there is a notable lack of research on its impacts in Mediterranean forests within the Iberian Peninsula Furthermore, there is a knowledge gap on the enzymatic activities and basal respiration of soil in forest after grazing. To address these gaps, this study aimed to investigate the impact of grazing on various important physicochemical and biological soil properties along with vegetation richness in a Mediterranean forest located in Castilla-La Mancha (Central Eastern Spain). Relative to undisturbed sites, grazing significantly reduced soil water content (-53%) and available water (-59%). However, soil hydraulic conductivity remained unaffected by animal trampling and the soil water repellency observed in ungrazed sites disappeared. Grazed soils experienced a slight increase in pH (+18%). Among the biochemical properties studied, only dehydrogenase showed a significant increase (+100%) while basal respiration exhibited a notable decrease (-24%). Grazing resulted in a reduction of plant species richness (-34%) indicating a loss of biodiversity in grazed areas. The observed significant alterations in key soil and plant properties due to livestock activity suggest that grazing has the potential to modify the overall soil quality of these sites. Certain variables that exhibited noteworthy differences between grazed and ungrazed sites could serve as indicators of grazing impacts in Mediterranean forests. These indicators may be considered proxies for establishing effective land management strategies to mitigate degradation in the Mediterranean forest ecosystem.

avidaR: an R library to perform complex queries on an ontology-based database of digital organisms.

Digital evolution is a branch of artificial life in which self-replicating computer programs-digital organisms-mutate and evolve within a user-defined computational environment. In spite of its value in biology, we still lack an up-to-date and comprehensive database on digital organisms resulting from evolution experiments. Therefore, we have developed an ontology-based semantic database-avidaDB-and an R package-avidaR-that provides users of the R programming language with an easy-to-use tool for performing complex queries without specific knowledge of SPARQL or RDF. avidaR can be used to do research on robustness, evolvability, complexity, phenotypic plasticity, gene regulatory networks, and genomic architecture by retrieving the genomes, phenotypes, and transcriptomes of more than a million digital organisms available on avidaDB. avidaR is already accepted on CRAN (i.e., a comprehensive collection of R packages contributed by the R community) and will make biologists better equipped to embrace the field of digital evolution.

Ontology for the Avida digital evolution platform.

The Ontology for Avida (OntoAvida) aims to develop an integrated vocabulary for the description of Avida, the most widely used computational approach for performing experimental evolution using digital organisms-self-replicating computer programs that evolve within a user-defined computational environment. The lack of a clearly defined vocabulary makes some biologists feel reluctant to embrace the field of digital evolution. This integrated framework empowers biologists by equipping them with the necessary tools to explore and analyze the field of digital evolution more effectively. By leveraging the vocabulary of Avida, researchers can gain deeper insights into the evolutionary processes and dynamics of digital organisms. In addition, OntoAvida allows researchers to make inference based on certain rules and constraints, facilitate the reproducibility of in silico evolution experiments and trace the provenance of the data stored in avidaDB-an RDF database containing the genomes, transcriptomes, and phenotypes of more than a million digital organisms. OntoAvida is part of the Open Biological and Biomedical Ontologies (OBO Foundry) and is available at http://www.obofoundry.org/ontology/ontoavida.html .

Axillary lymph node dissection versus radiotherapy in breast cancer with positive sentinel nodes after neoadjuvant therapy (ADARNAT trial).

Introduction: Breast cancer surgery currently focuses on de-escalating treatment without compromising patient survival. Axillary radiotherapy (ART) now replaces axillary lymph node dissection (ALND) in patients with limited sentinel lymph node (SLN) involvement during the primary surgery, and this has significantly reduced the incidence of lymphedema without worsening the prognosis. However, patients treated with neoadjuvant systemic treatment (NST) cannot benefit from this option despite the low incidence of residual disease in the armpit in most cases. Data regarding the use of radiotherapy instead of ALND in this population are lacking. This study will assess whether ART is non-inferior to ALND in terms of recurrence and overall survival in patients with positive SLN after NST, including whether it reduces surgery-related adverse effects. Methods and analyses: This multicenter, randomized, open-label, phase 3 trial will enroll 1660 patients with breast cancer and positive SLNs following NST in approximately 50 Spanish centers over 3 years. Patients will be stratified by NST regimen and nodal involvement (isolated tumoral cells or micrometastasis versus macrometastasis) and randomly assigned 1:1 to ART without ALND (study arm) or ALND alone (control arm). Level 3 and supraclavicular radiotherapy will be added in both arms. The primary outcome is the 5-year axillary recurrence determined by clinical and radiological examination. The secondary outcomes include lymphedema or arm dysfunction, quality of life based (EORTC QLQ-C30 and QLQ-BR23 questionnaires), disease-free survival, and overall survival. Discussion: This study aims to provide data to confirm the efficacy and safety of ART over ALND in patients with a positive SLN after NST, together with the impact on morbidity. Ethics and dissemination: The Research Ethics Committee of Bellvitge University Hospital approved this trial (Protocol Record PR148/21, version 3, 1/2/2022) and all patients must provide written informed consent. The involvement of around 50 centers across Spain will facilitate the dissemination of our results. Trial registration: ClinicalTrials.gov, identifier number NCT04889924.

Altitudinal Gradient and Soil Depth as Sources of Variations in Fungal Communities Revealed by Culture-Dependent and Culture-Independent Methods in the Negev Desert, Israel.

We examined fungal communities in soil profiles of 0-10 cm depth along the altitudinal gradient of 250-530-990 m.a.s.l. at the Central Negev Desert, Israel, which benefit from similar annual precipitation (95 mm). In the soil samples collected in the summer of 2020, a mycobiota accounting for 169 species was revealed by both culture-dependent and culture-independent (DNA-based) methodologies. The impact of soil depth on the variations in fungal communities was stronger than the impact of altitude. Both methodologies displayed a similar tendency in the composition of fungal communities: the prevalence of melanin-containing species with many-celled large spores (mainly Alternaria spp.) in the uppermost layers and the depth-wise increase in the proportion of light-colored species producing a high amount of small one-celled spores. The culturable and the DNA-based fungal communities had only 13 species in common. The differences were attributed to the pros and cons of each method. Nevertheless, despite the drawbacks, the employment of both methodologies has an advantage in providing a more comprehensive picture of fungal diversity in soils.

Intensive vegetable production under plastic mulch: A field study on soil plastic and pesticide residues and their effects on the soil microbiome.

Intensive agriculture relies on external inputs to reach high productivity and profitability. Plastic mulch, mainly in the form of Low-Density Polyethylene (LDPE), is widely used in agriculture to decrease evaporation, increase soil temperature and prevent weeds. The incomplete removal of LDPE mulch after use causes plastic contamination in agricultural soils. In conventional agriculture, the use of pesticides also leaves residues accumulating in soils. Thus, the objective of this study was to measure plastic and pesticide residues in agricultural soils and their effects on the soil microbiome. For this, we sampled soil (0-10 cm and 10-30 cm) from 18 parcels from 6 vegetable farms in SE Spain. The farms were under either organic or conventional management, where plastic mulch had been used for >25 years. We measured the macro- and micro-light density plastic debris contents, the pesticide residue levels, and a range of physiochemical properties. We also carried out DNA sequencing on the soil fungal and bacterial communities. Plastic debris (>100 µm) was found in all samples with an average number of 2 × 103 particles kg-1 and area of 60 cm2 kg-1. We found 4-10 different pesticide residues in all conventional soils, for an average of 140 µg kg-1. Overall, pesticide content was ∼100 times lower in organic farms. The soil microbiomes were farm-specific and related to different soil physicochemical parameters and contaminants. Regarding contaminants, bacterial communities responded to the total pesticide residues, the fungicide Azoxystrobin and the insecticide Chlorantraniliprole as well as the plastic area. The fungicide Boscalid was the only contaminant to influence the fungal community. The wide spread of plastic and pesticide residues in agricultural soil and their effects on soil microbial communities may impact crop production and other environmental services. More studies are required to evaluate the total costs of intensive agriculture.

Oral Sodium Chloride in the Prevention of Contrast-Associated Acute Kidney Injury in Elderly Outpatients: The PNIC-Na Randomized Non-Inferiority Trial.

OBJECTIVE: We aimed to test the non-inferiority of oral versus intravenous hydration in the incidence of contrast-associated acute kidney injury (CA-AKI) in elderly outpatients undergoing a contrast-enhanced computed tomography (CE-CT) scan. METHODS: PNIC-Na (NCT03476460) is a phase-2, single-center, randomized, open-label, non-inferiority trial. We included outpatients undergoing a CE-CT scan, >65 years having at least one risk factor for CA-AKI, such as diabetes, heart failure, or an estimated glomerular filtration rate (eGFR) of 30-59 mL/min/1.73 m². Participants were randomized (1:1) to oral sodium-chloride capsules or intravenous hydration. The primary outcome was an increase in serum creatinine >0.3 mg/dL or a reduction in eGFR >25% within 48 h. The non-inferiority margin was set at 5%. RESULTS: A total of 271 subjects (mean age 74 years, 66% male) were randomized, and 252 were considered for the main analysis (per-protocol). A total of 123 received oral hydration and 129 intravenous. CA-AKI occurred in 9 (3.6%) of 252 patients and 5/123 (4.1%) in the oral-hydration group vs. 4/129 (3.1%) in the intravenous-hydration group. The absolute difference between the groups was 1.0% (95% CI -4.8% to 7.0%), and the upper limit of the 95% CI exceeded the pre-established non-inferiority margin. No major safety concerns were observed. CONCLUSION: The incidence of CA-AKI was lower than expected. Although both regimens showed similar incidences of CA-AKI, the non-inferiority was not shown.

Management of the axilla in postmenopausal patients with cN0 hormone receptor-positive/HER2-negative breast cancer treated with neoadjuvant endocrine therapy and its prognostic impact.

PURPOSE: To evaluate the differences in nodal positivity if the sentinel lymph node biopsy (SLNB) is performed before or after neoadjuvant endocrine therapy (NET) in breast cancer patients, and its impact on prognosis. METHODS: A retrospective cohort study was performed in a single center including 91 postmenopausal cases with clinically node-negative and hormone receptor-positive/HER2-negative (HR + /HER2-) breast cancer, treated with NET and SLNB. SLNB was done pre-NET until 2014, and post-NET thereafter. Axillary lymph node dissection (ALND) was indicated only in SLNB macrometastasis, although in selected elderly patients, it was omitted. Kaplan-Meier survival curves were estimated in relation to the status of the axilla, and the differences assessed using the log-rank test. RESULTS: Between December 2006 and March 2022, SLNB was performed pre-NET in 14 cases and post-NET in 77. Both groups were similar in baseline tumor and patient characteristics. SLNB positivity was similar regardless of whether SLNB was performed before (5/14, 35.7%) or after NET (27/77, 37%), with 2/14 SLN macrometastases in the pre-NET cohort and 17/77 in the post-NET cohort. Only three patients (18.7%) with SLN macrometastasis had > 3 positive nodes following ALND. The 5-year overall survival and distant disease-free survival were 92.4% and 94.8%, respectively, with no significant differences according to SLNB status (p 0.5 and 0.8, respectively). CONCLUSION: SLN positivity did not differ according to its timing (before or after NET). Therefore, NET has no effect on lymph node clearance. Furthermore, the prognosis is good regardless of the axillary involvement. Therefore, factors other than axillary involvement may affect the prognosis in these patients.

Characteristics of the bachelor thesis in dentistry, satisfaction and motivations of the students / Características de las tesis de licenciatura en odontología, satisfacción y motivaciones de los tesistas

Objective: To describe the characteristics of under-graduate theses, satisfaction and reasons for choosing a topic of study. Materials and Methods: Cross-sectional study that included two populations, theses and thesis students who were able to support their work from 2015 to 2021 in the Faculty of Dentistry of the Universidad Nacional Mayor de San Marcos (Lima, Peru). Documentary analysis was used at first to record bibliometric data. The survey was used in a second stage to collect information related to the reasons why the thesis students chose their topic and the degree of satisfaction. Results: A total of 269 theses were examined. The theses corresponded to more women (n=142; 52.8%). All had a quantitative approach. The cross-sectional/descriptive design was the most frequent (n=207; 77%). Of the 114 respondents, the majority of them indicated that their thesis topic decision was influenced by a faculty member outside of their advisor (n= 26; 22.8%). A total of 49.1% of thesis students were in complete agreement about what they had learned about research at the end of their thesis. Conclusions: The undergraduate theses evidenced to be developed mainly by women, most of the thesis students were satisfied with the elaboration and execution of their academic work; it was evidenced that the thesis topics are mainly influenced by a teacher different from the thesis advisor, this indicates that the advisors should be more conscious when guiding the student and influencing the thematic, methodological and writing decisions together with the advised.

Objetivo: Describir las características de las tesis de licenciatura, satisfacción y motivos para la elección de un tema de estudio. Materiales y Métodos: Estudio transversal que incluyó a dos poblaciones, las tesis y a los tesistas que lograron sustentar sus trabajos desde el año 2015 al 2021 en la Facultad de Odontología de la Universidad Nacional Mayor de San Marcos (Lima, Perú). Se utilizó el análisis documental en un primer momento para registrar datos bibliométricos. La encuesta se utilizó en un segundo momento para recabar información relacionada a los motivos por los cuales escogieron su tema los tesistas y el grado de satisfacción. Resultados: Se examinaron 269 tesis. La mayoría de ellas fueron realizadas por mujeres (n=142; 52,8%). Todas tuvieron un enfoque cuantitativo. El diseño transversal/descriptivo fue el más frecuente (n=207; 77%). De los 114 encuestados, la mayoría de ellos indicó que la decisión de su tema de tesis fue influida por un docente ajeno a su asesor (n= 26; 22,8%). El 49,1% de tesistas estuvo totalmente de acuerdo respecto a lo aprendido sobre investigación al culminar su tesis. Conclusión: Las tesis de licenciatura evidenciaron ser desarrolladas principalmente por mujeres, la mayoría estuvo satisfecho con la elaboración y ejecución de su trabajo académico; se evidenció que los temas de tesis son influenciados principalmente por un docente diferente al asesor de tesis, esto indica que los asesores deben ser más conscientes al momento de guiar al estudiante e influir en las decisiones temáticas, metodológicas y de redacción junto con el asesorado

Short-term effects of post-fire soil mulching with wheat straw and wood chips on the enzymatic activities in a Mediterranean pine forest.

Soils of Mediterranean forests can be severely degraded due to wildfire. However, post-fire management techniques, such as soil mulching with vegetal residues, can limit degradation and increase functionality of burned soils. The effects of post-fire mulching on soil functionality have been little studied in Mediterranean forests, and it is still unclear whether the application of straw or wood residues is beneficial. This study explores the changes in important soil chemical and biochemical properties in a pine forest of Central Eastern Spain after a wildfire and post-fire mulching with straw or wood chips. Only basal soil respiration (BSR), dehydrogenase activity (DHA), pH and water field capacity (WFC) significantly changed after the fire and mulching. In contrast, the other enzymatic activities - urease (UA), alkaline phosphatase (Alk-PA) and ß-glucosidase (BGA), - total organic carbon (TOC) and electrical conductivity (EC) were not influenced by these soil disturbances. Time from fire and soil conditions (due to burning and management) were significant variability factors for BSR, pH, BGA, UA, TOC, EC. Mulching increased BSR compared to burned areas, especially in soils with straw (+30 %), thanks to addition of fresh organic residues, quickly incorporated in the soil. Soil pH showed a low variability among the four soil conditions, and TOC was higher in mulched soils (on average + 20 % compared to the burned soils), and this was correlated to the increased BSR. The role of mulching was essential with reference to WFC, as the post-fire management limited its reduction after the fire (on average from -30 % to -20 %). Finally, the Principal Component Analysis coupled to the Analytical Hierarchical Cluster Analysis confirmed the significant influence of the post-fire management on some enzymatic activities, although a sharp discrimination among the four soil conditions was only evident between unburned and burned sites, regardless of the management. Overall, it has been shown that mulching promotes conservation of fragile Mediterranean soils, indicating its effectiveness at preserving soil functionality in areas affected by forest fires.

Organic amendments from recycled waste promote short-term carbon sequestration of restored soils in drylands.

Soils are considered as a major reservoir for terrestrial carbon and it can act as a source or sink depending upon the land management activities. In semi-arid areas, the natural recovery of soils degraded by mining activities is complicated. A possible solution to recover soil quality and functionality, plant cover and carbon sequestration capacity could be the application of organic amendments. This work focuses on a restoration carried out in 2018 by applying with different composted organic amendments (stabilized sludge, gardening and greenhouse waste) in a limestone quarry under semi-arid climate (SE Spain). The objective was to evaluate the effects of different organic amendments on net CO2 exchange in two microcosms: soil-Stipa tenacissima and soil-spontaneous vegetation. Soil physical and chemical properties, environmental and ecological variables and their interrelationship were studied in amended and unamended soils. The results obtained under soil-forming factors in the study area showed an increase in soil organic carbon and nitrogen content, improved moisture and plant growth, and plant canopy development in amended soils. Soil moisture, soil temperature and plant cover significantly influenced net CO2 exchange. In general, microcosms with S. tenacissima showed higher carbon sequestration rates than soils with only spontaneous plant cover. Soils treated with a vegetable-only amendments showed higher plant cover and CO2 fixation rates after significant rainfall. On the other hand, the plots treated with sludge compost presented more soil respiration than photosynthesis, especially in the wet seasons. Soils with sludge and greenhouse compost mixed had higher CO2 fixation rates than soils restored with a mixture of sludge and garden compost. Soils with greenhouse waste compost showed CO2 fixation in the microcosm with plants in all campaigns, being the best treatment to promote atmospheric CO2 sequestration in soil restoration.

The Effects of a Therapeutic Strategy Guided by Lung Ultrasound on 6-Month Outcomes in Patients with Heart Failure: Results from the EPICC Randomized Controlled Trial.

Background: Pulmonary congestion (PC) is associated with an increased risk of hospitalization and death in patients with heart failure (HF). Lung ultrasound is highly sensitive for detecting PC. The aim of this study is to evaluate whether lung ultrasound-guided therapy improves 6-month outcomes in patients with HF. Methods: A randomized, multicenter, single-blind clinical trial in patients discharged after hospitalization for decompensated HF. Participants were assigned 1:1 to receive treatment guided according to the presence of lung ultrasound signs of congestion (semi-quantitative evaluation of B lines and the presence of pleural effusion) versus standard of care (SOC). The primary endpoint was the combination of cardiovascular death, readmission, or emergency department or day hospital visit due to worsening HF at 6 months. In September 2020, after an interim analysis, patient recruitment was stopped. Results: A total of 79 patients were randomized (mean age 81.2 +/− 9 years) and 41 patients (51.8%) showed a left ventricular ejection fraction >50%. The primary endpoint occurred in 11 patients (29.7%) in the SOC group and in 11 patients (26.1%) in the LUS group (log-rank = 0.83). Regarding nonserious adverse events, no significant differences were found. Conclusions: LUS-guided diuretic therapy after hospital discharge due to ADHF did not show any benefit in survival or a need for intravenous diuretics compared with SOC.

Genetic analysis of early phenology in lentil identifies distinct loci controlling component traits.

Modern-day domesticated lentil germplasm is generally considered to form three broad adaptation groups: Mediterranean, South Asian, and northern temperate, which correspond to the major global production environments. Reproductive phenology plays a key role in lentil adaptation to this diverse ecogeographic variation. Here, we dissect the characteristic earliness of the pilosae ecotype, suited to the typically short cropping season of South Asian environments. We identified two loci, DTF6a and DTF6b, at which dominant alleles confer early flowering, and we show that DTF6a alone is sufficient to confer early flowering under extremely short photoperiods. Genomic synteny confirmed the presence of a conserved cluster of three florigen (FT) gene orthologues among potential candidate genes, and expression analysis in near-isogenic material showed that the early allele is associated with a strong derepression of the FTa1 gene in particular. Sequence analysis revealed a 7.4 kb deletion in the FTa1-FTa2 intergenic region in the pilosae parent, and a wide survey of >350 accessions with diverse origin showed that the dtf6a allele is predominant in South Asian material. Collectively, these results contribute to understanding the molecular basis of global adaptation in lentil, and further emphasize the importance of this conserved genomic region for adaptation in temperate legumes generally.

The SINGLE FLOWER (SFL) gene encodes a MYB transcription factor that regulates the number of flowers produced by the inflorescence of chickpea.

Legumes usually have compound inflorescences, where flowers/pods develop from secondary inflorescences (I2), formed laterally at the primary inflorescence (I1). Number of flowers per I2, characteristic of each legume species, has important ecological and evolutionary relevance as it determines diversity in inflorescence architecture; moreover, it is also agronomically important for its potential impact on yield. Nevertheless, the genetic network controlling the number of flowers per I2 is virtually unknown. Chickpea (Cicer arietinum) typically produces one flower per I2 but single flower (sfl) mutants produce two (double-pod phenotype). We isolated the SFL gene by mapping the sfl-d mutation and identifying and characterising a second mutant allele. We analysed the effect of sfl on chickpea inflorescence ontogeny with scanning electron microscopy and studied the expression of SFL and meristem identity genes by RNA in situ hybridisation. We show that SFL corresponds to CaRAX1/2a, which codes a MYB transcription factor specifically expressed in the I2 meristem. Our findings reveal SFL as a central factor controlling chickpea inflorescence architecture, acting in the I2 meristem to regulate the length of the period for which it remains active, and therefore determining the number of floral meristems that it can produce.

Effects of technosols based on organic amendments addition for the recovery of the functionality of degraded quarry soils under semiarid Mediterranean climate: A field study.

This study aims to evaluate the effects of technosols made with different organic amendments to restore degraded soils in a semiarid limestone quarry. The effects on soil quality, functionality and organic matter dynamics of the technosols amended with waste of gardening, greenhouse horticultural, stabilized sewage sludge and two mixtures of sludge with both vegetable composts were assessed. Several physical and chemical properties, humus fractions, soil respiration and molecular composition was performed after 6 and 18 months. Un-amended soils, and nearby natural undegraded soils served as reference. Amended technosols increased water retention capacity, electrical conductivity, total organic carbon and nitrogen, respect to not amended and natural soils. Humus fraction composition was not altered over time. Un-amended soils, very poor in organic matter, did not show any pyrolyzable compounds or labile soil organic matter by thermogravimetry. In contrast, the pyrochromatograms of natural soils showed lignocellulosic materials, polypeptides and a noticeable presence of alkylic compounds. In technosols with both types vegetable compost, the organic matter structure was more complex, showing compounds from lignin-derived and long-chain alkyl, polysaccharides, chlorophyll isoprenoids and nitrogen. In sludge technosol, a set of sterols was outstanding. The mixtures showed a molecular fingerprint of materials derived from the decomposition of the organic amendments that formed them. These signs of the contribution of different organic matter forms derived from the amendments were also reported by the series exothermic peaks found in the calorimetry. This short-term study indicates a clear effect of the amendments on the recovery of soil organic matter and presumably of its functionality. After the amendments application, microbial activity and soil respiration rates increased rapidly but ceased 18 months later. The molecular composition of the organic matter of the soils amended with plant compost was very similar to that of natural, non-degraded soils in nearby areas.

Perspectivas de los graduados de Odontología sobre la supervisión (asesoría) de la tesis de licenciatura

Resumen Se identificó las perspectivas que tienen los graduados sobre los procesos de supervisión que tuvieron con sus asesores de tesis. Estudio cualitativo cuya población fueron graduados del pregrado de la Facultad de Odontología de la Universidad Nacional Mayor de San Marcos (Lima. Perú), a través de entrevistas semiestructuradas. Las categorías de estudio estuvieron relacionadas con la planificación de las actividades con el supervisor, decisiones del supervisor y percepciones generales sobre el supervisor. De los 20 entrevistados, 12 (60%) fueron mujeres. La planificación fue indicada como uno de los elementos que poco se discutió con el asesor, la mayoría indicó que nunca tuvieron una primera reunión para coordinar cómo serían las sesiones de asesoría. La percepción que se tiene de los supervisores de tesis no es adecuada por parte de los estudiantes de Odontología. Los principales aspectos negativos estuvieron relacionados a la falta de planificación de las actividades y reuniones.

Resumo Foram identificadas as perspectivas que os egressos têm sobre os processos de supervisão que tiveram com seus orientadores de tese. Estudo qualitativo cuja população foram graduandos da Faculdade de Odontologia da Universidad Nacional Mayor de San Marcos (Lima, Peru), por meio de entrevistas semiestruturadas. As categorias do estudo foram relacionadas ao planejamento das atividades com o supervisor, decisões do supervisor e percepções gerais sobre o supervisor. Dos 20 entrevistados, 12 (60%) eram mulheres. O planejamento foi apontado como um dos elementos pouco discutidos com a assessoria, a maioria indicou que nunca teve uma primeira reunião para coordenar como seriam as sessões de assessoria. A percepção dos orientadores de tese não é adequada por parte dos alunos de Odontologia. Os principais aspectos negativos foram relacionados à falta de planejamento das atividades e reuniões.

Abstract We identified graduates' views on their thesis supervision process as led by their thesis advisors. A qualitative study of graduates of the School of Dentistry of Universidad Nacional Mayor de San Marcos (Lima, Peru) included semi-structured interviews. The study categories were planning activities with the advisor, the advisor's decisions, and general views on the advisor. Of the 20 interviewees, 12 (60%) were women. Planning was insufficiently discussed with the advisor; most interviewees said that they never had a first meeting to coordinate what the advisory sessions would be like. Dental students do not have a favorable view of thesis advisors. The main negative aspects were the lack of planning of activities and meetings.

Producción científica relacionada a las Sociedades Científicas de Estudiantes en las ciencias de la salud / Scientific production about health sciences published by students scientific societies

Objetivo: Describir la producción científica mundial relacionada a las Sociedades Científicas Estudiantiles en los programas de las ciencias de la salud. Métodos: Se realizó un estudio descriptivo que incluyó a los artículos científicos publicados en las bases de datos Scopus, MedLine, ScienceDirect, SciELO, Redalyc y el buscador Google académico en el periodo 2010 a 2020. Los términos incluyeron: Sociedad Científica de Estudiantes, Sociedad Estudiantil, Sociedad Científica Estudiantil y Asociación estudiantil. De los artículos seleccionados se recolectó las categorías de: tipo de publicación, año, nombre de la revista, país de origen, colaboración internacional, programa de estudios y autoría. Los datos fueron analizados de forma descriptiva a través de frecuencias. Resultados: Se encontraron 51 publicaciones, el país que más publicaciones tuvo fue Perú (37,3 por ciento). Los principales tipos de artículos fueron las cartas al editor (41,2 por ciento) y los artículos originales (29,4 por ciento). Los investigadores Cvetkovic Vega y Mejia constituyeron los autores con mayor número de artículos. La revista con mayor cantidad de publicaciones fue Ciencia e Investigación Médica Estudiantil Latinoamericana (11,8 por ciento), mientras que la mayoría de artículos estuvieron en el programa de Medicina humana (90,2 por ciento). Conclusiones: La producción científica relacionada a las Sociedades Científicas de Estudiantes en las ciencias de la salud tiene como principal temática a la producción que realizan sus integrantes; Perú es el país con más artículos que ha publicado sobre el tema y la mayoría de fuentes de información son artículos del tipo carta al editor(AU)

Objective: Describe the scientific production published in health sciences programs by students scientific societies worldwide. Methods: A descriptive study was conducted of scientific articles published in the databases Scopus, MEDLINE, ScienceDirect, SciELO and Redalyc, and the search engine Google Scholar in the period 2010-2020. The search terms used were students scientific society, student society student scientific society and students association. The following data were collected from the articles retrieved: publication type, year, journal name, country of origin, international collaboration, syllabus and authorship. Descriptive data analysis was based on frequency estimation. Results: A total 51 publications were retrieved. The most productive country was Peru (37.3 percent). The main article types were letters to the editor (41.2 percent) and original articles (29.4 percent). Researchers Cvetkovic Vega and Mejia were the most productive authors. The journal with the largest number of publications was Ciencia e Investigación Médica Estudiantil Latinoamericana (11.8 percent), whereas most articles were related to the Human Medicine program (90.2 percent). Conclusions: Scientific production about health sciences published by students scientific societies is mainly concerned with production generated by their members. Peru is the country with the most articles published about the subject. Most information sources are articles of the letter to the editor type(AU)

Comparación del módulo de elasticidad y resistencia de la resina acrílica de termocurado y la resina flexible superpoliamida. Estudio in vitro / Comparison of the module of elasticity and resistance of thermal curing acrylic resin and flexible superpolyamide resin. An in vitro study

Objetivo: Comparar el módulo de elasticidad y resistencia de la resina acrílica de termocurado y la resina flexible superpoliamida. Métodos: Se diseñó un estudio experimental que empleó dos tipos de resinas acrílicas preparadas en cera para obtener una forma rectangular de 64 mm de largo, 10 mm de ancho y 2,5 mm de grosor, pasadas a acrílico de termocurado y resina flexible superpoliamida. Se emplearon 10 bloques de resina acrílica de cada tipo sometidas a compresión por la máquina de ensayos universal, que generó una fuerza de aproximación de 0,001 N sobre los bloques con un avance de 0,01 mm/min. El módulo de resistencia y el módulo de elasticidad se analizaron mediante la prueba de flexión de tres puntos. Resultados: El módulo de elasticidad de la resina acrílica de termocurado fue de 2501,83 ± 139,42, mientras que el módulo de resistencia fue de 78,36 ± 11,69 MPa. Por otro lado, el módulo de elasticidad de la resina flexible superpoliamida fue de 1020,59 ± 92,95, mientras que el módulo de resistencia fue de 36,04 ± 2,71 MPa. El módulo de elasticidad de la resina acrílica de termocurado fue mayor al de la resina flexible superpoliamida, esta diferencia fue de 1481,24 MPa. El módulo de resistencia de la resina acrílica de termocurado fue mayor al de la resina flexible superpoliamida. Conclusiones: Se concluyó que el módulo de elasticidad (rigidez) y resistencia fue mayor en la resina acrílica de termocurado en comparación a la resina flexible superpoliamida(AU)

Objective: Compare the module of elasticity and resistance of thermal curing acrylic resin and flexible superpolyamide resin. Methods: An experimental study was conducted of two types of acrylic resins molded in wax to obtain a 64 mm long, 10 mm wide and 2.5 mm thick rectangular shape, and then transferred to thermal curing acrylic resin and flexible superpolyamide resin. Ten acrylic resin blocks of each type were used. The blocks were compressed by the universal testing machine, which generated an approximation force of 0.001 N on the blocks at a forward speed of 0.01 mm/min. The resistance module and the elasticity module were analyzed with the three point flexural test. Results: The elasticity module of the thermal curing acrylic resin was 2501.83 ± 139.42, whereas the resistance module was 78.36 ± 11.69 MPa. The elasticity module of the flexible superpolyamide resin was 1020.59 ± 92,95, whereas the resistance module was 36.04 ± 2.71 MPa. The elasticity module of the thermal curing acrylic resin was greater than that of the flexible superpolyamide resin, the difference being 1481.24 MPa. The resistance module of the thermal curing acrylic resin was greater than that of the flexible superpolyamide resin. Conclusions: The elasticity (rigidity) and resistance module was greater in the thermal curing acrylic resin than in the flexible superpolyamide resin(AU)