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1.
Front Toxicol ; 6: 1339104, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38654939

RESUMO

As a complex system governing and interconnecting numerous functions within the human body, the immune system is unsurprisingly susceptible to the impact of toxic chemicals. Toxicants can influence the immune system through a multitude of mechanisms, resulting in immunosuppression, hypersensitivity, increased risk of autoimmune diseases and cancer development. At present, the regulatory assessment of the immunotoxicity of chemicals relies heavily on rodent models and a limited number of Organisation for Economic Co-operation and Development (OECD) test guidelines, which only capture a fraction of potential toxic properties. Due to this limitation, various authorities, including the World Health Organization and the European Food Safety Authority have highlighted the need for the development of novel approaches without the use of animals for immunotoxicity testing of chemicals. In this paper, we present a concise overview of ongoing efforts dedicated to developing and standardizing methodologies for a comprehensive characterization of the immunotoxic effects of chemicals, which are performed under the EU-funded Partnership for the Assessment of Risk from Chemicals (PARC).

2.
Genes (Basel) ; 15(4)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38674438

RESUMO

The green monkey Chlorocebus sabaeus, L. 1766, native to West Africa, was introduced to the Cabo Verde Archipelago in the 16th century. Historical sources suggest that, due to the importance of Cabo Verde as a commercial entrepôt in the Atlantic slave trade, establishing the precise place of origin of this introduced species is challenging. Non-invasive fecal samples were collected from feral and captive green monkey individuals in Cabo Verde. Two mitochondrial fragments, HVRI and cyt b, were used to confirm the taxonomic identification of the species and to tentatively determine the geographic origin of introduction to the archipelago from the African continent. By comparing the new sequences of this study to previously published ones, it was shown that Cabo Verde individuals have unique haplotypes in the HVRI, while also showing affinities to several populations from north-western coastal Africa in the cyt b, suggesting probable multiple sources of introduction and an undetermined most probable origin. The latter is consistent with historical information, but may also have resulted from solely using mtDNA as a genetic marker and the dispersal characteristics of the species. The limitations of the methodology are discussed and future directions of research are suggested.


Assuntos
DNA Mitocondrial , Animais , DNA Mitocondrial/genética , Chlorocebus aethiops/genética , Cabo Verde , Filogenia , Citocromos b/genética , Haplótipos , Espécies Introduzidas , Filogeografia , Fezes/química
3.
Bioconjug Chem ; 34(12): 2337-2344, 2023 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-37948301

RESUMO

Ferroptosis is an iron-dependent lipid-peroxidation-driven mechanism of cell death and a promising therapeutic target to eradicate cancer cells. In this study, we discovered that boronic acid-derived salicylidenehydrazone (BASHY) dyes are highly efficient singlet-oxygen photosensitizers (PSs; ΦΔ up to 0.8) that induce ferroptosis triggered by photodynamic therapy. The best-performing BASHY dye displayed a high phototoxicity against the human glioblastoma multiform U87 cell line, with an IC50 value in the low nanomolar range (4.40 nM) and a remarkable phototoxicity index (PI > 22,700). Importantly, BASHY dyes were shown to accumulate in lipid droplets (LDs) and this intracellular partition was found to be essential for the enhanced phototoxicity and the induction of ferroptosis through lipid peroxidation. The safety and phototoxicity of this platform were validated using an in vivo zebrafish model (Danio rerio).


Assuntos
Ferroptose , Fármacos Fotossensibilizantes , Animais , Humanos , Fármacos Fotossensibilizantes/farmacologia , Corantes , Peroxidação de Lipídeos , Gotículas Lipídicas , Peixe-Zebra
4.
Sensors (Basel) ; 23(21)2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-37960711

RESUMO

Unmanned aerial vehicles (UAV) can be controlled in diverse ways. One of the most common is through artificial intelligence (AI), which comprises different methods, such as reinforcement learning (RL). The article aims to provide a comparison of three RL algorithms-DQN as the benchmark, SARSA as a same-family algorithm, and A2C as a different-structure one-to address the problem of a UAV navigating from departure point A to endpoint B while avoiding obstacles and, simultaneously, using the least possible time and flying the shortest distance. Under fixed premises, this investigation provides the results of the performances obtained for this activity. A neighborhood environment was selected because it is likely one of the most common areas of use for commercial drones. Taking DQN as the benchmark and not having previous knowledge of the behavior of SARSA or A2C in the employed environment, the comparison outcomes showed that DQN was the only one achieving the target. At the same time, SARSA and A2C did not. However, a deeper analysis of the results led to the conclusion that a fine-tuning of A2C could overcome the performance of DQN under certain conditions, demonstrating a greater speed at maximum finding with a more straightforward structure.

5.
Org Biomol Chem ; 21(10): 2118-2126, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36606485

RESUMO

A methodology for the synthesis of sulfonyl hydrazides mediated by hypervalent iodine is described. Taking advantage of the umpolung properties of hypervalent iodine reagents, the polarity of sodium sulfinate salts is reversed, and a key intermediate is generated and reacted with mono- and disubstituted hydrazines. To highlight the practical utility of this protocol, a diverse range of sulfonyl hydrazides were synthesized in yields up to 62%. Furthermore, a gram-scale reaction was performed, showing the robustness of the procedure. Mechanistic studies, including DFT calculations, were performed and the bioactivity of the generated compounds was evaluated.

6.
Int J Hyg Environ Health ; 248: 114099, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36528954

RESUMO

Within the EU human biomonitoring initiative (HBM4EU), a targeted, multi-national study on occupational exposure to hexavalent chromium (Cr(VI)) was performed. Cr(VI) is currently regulated in EU under REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) and under occupational safety and health (OSH) legislation. It has recently been subject to regulatory actions to improve its risk management in European workplaces. Analysis of the data obtained within the HBM4EU chromates study provides support both for the implementation of these regulatory actions and for national enforcement programs and may also contribute to the updating of occupational limit values (OELs) and biological limit values for Cr(VI). It also provides useful insights on the contribution of different risk management measures (RMMs) to further reduce the exposure to Cr(VI) and may support the evaluation of applications for authorisation under REACH. Findings on chrome platers' additional per- and polyfluoroalkyl substances (PFAS) exposure highlight the need to also pay attention to this substance group in the metals sector. A survey performed to evaluate the policy relevance of the HBM4EU chromates study findings supports the usefulness of the study results. According to the responses received from the survey, the HBM4EU chromates study was able to demonstrate the added value of the human biomonitoring (HBM) approach in assessment and management of occupational exposure to Cr(VI). For future occupational studies, we emphasise the need for engagement of policy makers and regulators throughout the whole research process to ensure awareness, relevance and uptake of the results in future policies.


Assuntos
Exposição Ocupacional , Saúde Ocupacional , Humanos , Cromatos , Exposição Ocupacional/análise , Cromo/análise , Políticas
7.
Chembiochem ; 24(4): e202200647, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36479913

RESUMO

An increasing number of novel Ru(II) polypyridyl complexes have been successfully applied as photosensitizers (PSs) for photodynamic therapy (PDT). Despite recent advances in optimized PSs with refined photophysical properties, the lack of tumoral selectivity is often a major hurdle for their clinical development. Here, classical maleimide and versatile NHS-activated acrylamide strategies were employed to site-selectively conjugate a promising Ru(II) polypyridyl complex to the N-terminally Cys-modified Bombesin (BBN) targeting unit. Surprisingly, the decreased cell uptake of these novel Ru-BBN conjugates in cancer cells did not hamper the high phototoxic activity of the Ru-containing bioconjugates and even decreased the toxicity of the constructs in the absence of light irradiation. Overall, although deceiving in terms of selectivity, our new bioconjugates could still be useful for advanced cancer treatment due to their nontoxicity in the dark.


Assuntos
Antineoplásicos , Complexos de Coordenação , Neoplasias , Fotoquimioterapia , Rutênio , Complexos de Coordenação/farmacologia , Complexos de Coordenação/efeitos da radiação , Rutênio/farmacologia , Bombesina , Fármacos Fotossensibilizantes/farmacologia , Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico
8.
Chemistry ; 28(67): e202202377, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36245264

RESUMO

N-terminal Cys modification has been intensively studied to produce homogeneous bioconjugates essentially through two modes of reaction: reversible modification with the equilibrium shifted towards the formation of the desired conjugate or stable and irreversible conjugates. Herein, we report a new method of N-terminal cysteine modification using O-salicylaldehyde esters (OSAEs) through fast conjugation and irreversible deconjugation. These reagents can rapidly react with N-terminal Cys at low-micromolar concentration to form thiazolidines with subsequent hydrolysis of the ester moiety to the phenolic derivative. These phenolic thiazolidines can be hydrolyzed at acidic pH (≈4.5) to recover the intact N-terminal Cys. Bioconjugation reactions using OSAEs offer controlled reversibility to as act as a protecting group for N-terminal cysteines, allowing the modification of in-chain residues without perturbing the N-terminal Cys, which can then be deprotected and used as a conjugation site.


Assuntos
Aldeídos , Cisteína , Cisteína/química , Tiazolidinas , Ésteres/química
9.
Plants (Basel) ; 11(20)2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36297726

RESUMO

Climate changes with global warming associated with rising atmospheric [CO2] can strongly impact crop performance, including coffee, which is one of the most world's traded agricultural commodities. Therefore, it is of utmost importance to understand the mechanisms of heat tolerance and the potential role of elevated air CO2 (eCO2) in the coffee plant response, particularly regarding the antioxidant and other protective mechanisms, which are crucial for coffee plant acclimation. For that, plants of Coffea arabica cv. Geisha 3, cv. Marsellesa and their hybrid (Geisha 3 × Marsellesa) were grown for 2 years at 25/20 °C (day/night), under 400 (ambient CO2, aCO2) or 700 µL (elevated CO2, eCO2) CO2 L-1, and then gradually submitted to a temperature increase up to 42/30 °C, followed by recovery periods of 4 (Rec4) and 14 days (Rec14). Heat (37/28 °C and/or 42/30 °C) was the major driver of the response of the studied protective molecules and associated genes in all genotypes. That was the case for carotenoids (mostly neoxanthin and lutein), but the maximal (α + ß) carotenes pool was found at 37/28 °C only in Marsellesa. All genes (except VDE) encoding for antioxidative enzymes (catalase, CAT; superoxide dismutases, CuSODs; ascorbate peroxidases, APX) or other protective proteins (HSP70, ELIP, Chape20, Chape60) were strongly up-regulated at 37/28 °C, and, especially, at 42/30 °C, in all genotypes, but with maximal transcription in Hybrid plants. Accordingly, heat greatly stimulated the activity of APX and CAT (all genotypes) and glutathione reductase (Geisha3, Hybrid) but not of SOD. Notably, CAT activity increased even at 42/30 °C, concomitantly with a strongly declined APX activity. Therefore, increased thermotolerance might arise through the reinforcement of some ROS-scavenging enzymes and other protective molecules (HSP70, ELIP, Chape20, Chape60). Plants showed low responsiveness to single eCO2 under unstressed conditions, while heat promoted changes in aCO2 plants. Only eCO2 Marsellesa plants showed greater contents of lutein, the pool of the xanthophyll cycle components (V + A + Z), and ß-carotene, compared to aCO2 plants at 42/30 °C. This, together with a lower CAT activity, suggests a lower presence of H2O2, likely also associated with the higher photochemical use of energy under eCO2. An incomplete heat stress recovery seemed evident, especially in aCO2 plants, as judged by the maintenance of the greater expression of all genes in all genotypes and increased levels of zeaxanthin (Marsellesa and Hybrid) relative to their initial controls. Altogether, heat was the main response driver of the addressed protective molecules and genes, whereas eCO2 usually attenuated the heat response and promoted a better recovery. Hybrid plants showed stronger gene expression responses, especially at the highest temperature, when compared to their parental genotypes, but altogether, Marsellesa showed a greater acclimation potential. The reinforcement of antioxidative and other protective molecules are, therefore, useful biomarkers to be included in breeding and selection programs to obtain coffee genotypes to thrive under global warming conditions, thus contributing to improved crop sustainability.

10.
Chem Commun (Camb) ; 58(57): 7928-7931, 2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35758206

RESUMO

The site-selective chemical appendage of multiple functionalities on a native peptide backbone is a highly demanding and complex tool of modern chemical biology. Here, novel NHS-activated acrylates were designed to hold various payloads in a single bioconjugation handle that is able to site-selectively and orthogonally target the N-terminal cysteine of peptides.


Assuntos
Acrilatos , Cisteína , Acrilatos/química , Cisteína/química , Peptídeos/química , Medicina Estatal
11.
Pharmaceuticals (Basel) ; 15(5)2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35631399

RESUMO

Continuing with our program to obtain new histamine H3 receptor (H3R) ligands, in this work we present the synthesis, H3R affinity and in silico studies of a series of eight new synthetically accessible purine derivatives. These compounds are designed from the isosteric replacement of the scaffold presented in our previous ligand, pyrrolo[2,3-d]pyrimidine ring, by a purine core. This design also considers maintaining the fragment of bipiperidine at C-4 and aromatic rings with electron-withdrawing groups at N-9, as these fragments are part of the proposed pharmacophore. The in vitro screening results show that two purine derivatives, 3d and 3h, elicit high affinities to the H3R (Ki values of 2.91 and 5.51 nM, respectively). Both compounds are more potent than the reference drug pitolisant (Ki 6.09 nM) and show low toxicity with in vitro models (IC50 > 30 µM on HEK-293, SH-SY5Y and HepG2 cell lines). Subsequently, binding modes of these ligands are obtained using a model of H3R by docking and molecular dynamics studies, thus determining the importance of the purine ring in enhancing affinity due to the hydrogen bonding of Tyr374 to the N-7 of this heterocycle. Finally, in silico ADME properties are predicted, which indicate a promising future for these molecules in terms of their physical−chemical properties, absorption, oral bioavailability and penetration in the CNS.

13.
Environ Res ; 204(Pt A): 111984, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34492275

RESUMO

Exposure to hexavalent chromium [Cr(VI)] may occur in several occupational activities, e.g., welding, Cr(VI) electroplating and other surface treatment processes. The aim of this study was to provide EU relevant data on occupational Cr(VI) exposure to support the regulatory risk assessment and decision-making. In addition, the capability and validity of different biomarkers for the assessment of Cr(VI) exposure were evaluated. The study involved nine European countries and involved 399 workers in different industry sectors with exposures to Cr(VI) such as welding, bath plating, applying or removing paint and other tasks. We also studied 203 controls to establish a background in workers with no direct exposure to Cr(VI). We applied a cross-sectional study design and used chromium in urine as the primary biomonitoring method for Cr(VI) exposure. Additionally, we studied the use of red blood cells (RBC) and exhaled breath condensate (EBC) for biomonitoring of exposure to Cr(VI). Personal measurements were used to study exposure to inhalable and respirable Cr(VI) by personal air sampling. Dermal exposure was studied by taking hand wipe samples. The highest internal exposures were observed in the use of Cr(VI) in electrolytic bath plating. In stainless steel welding the internal Cr exposure was clearly lower when compared to plating activities. We observed a high correlation between chromium urinary levels and air Cr(VI) or dermal total Cr exposure. Urinary chromium showed its value as a first approach for the assessment of total, internal exposure. Correlations between urinary chromium and Cr(VI) in EBC and Cr in RBC were low, probably due to differences in kinetics and indicating that these biomonitoring approaches may not be interchangeable but rather complementary. This study showed that occupational biomonitoring studies can be conducted successfully by multi-national collaboration and provide relevant information to support policy actions aiming to reduce occupational exposure to chemicals.


Assuntos
Poluentes Ocupacionais do Ar , Exposição Ocupacional , Poluentes Ocupacionais do Ar/análise , Monitoramento Biológico , Cromatos , Cromo/análise , Estudos Transversais , Monitoramento Ambiental , Humanos , Exposição Ocupacional/análise
14.
J Aging Phys Act ; 30(2): 204-216, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34412033

RESUMO

In this randomized controlled pilot trial, the authors explored the feasibility, technology compliance, and preliminary efficacy of the Education for Action (EDU-ACT), a multimodal intervention combining evidence-based strategies of physical activity (PA) education and coaching in PA levels over 4 weeks between EDU-ACT and control groups. The authors also assessed pre-post changes in neurocognitive function, functional mobility and dual-task performance, sleep and quality of life. Thirty-two sedentary older adults with memory complaints (age = 66 ± 5.3) completed the study (EDU-ACT = 18 and control = 14). The EDU-ACT adherence rate was 95%, and compliance of daily PA reporting was, on average, 22.7 days (94.6%). The EDU-ACT group demonstrated a significantly greater number of steps, processing speed, and dual-task performance when compared with controls (p < .05). In this study, a multimodal, evidence-based, low-cost intervention was feasible, well-accepted, with high adherence and compliance rates, and effective at promoting clinically meaningful increases in PA, for at least 1 month postintervention, in older adults with memory complaints.


Assuntos
Exercício Físico , Qualidade de Vida , Idoso , Cognição , Exercício Físico/psicologia , Terapia por Exercício/psicologia , Estudos de Viabilidade , Humanos
15.
Artigo em Inglês | MEDLINE | ID: mdl-34948598

RESUMO

Workers involved in the processing of electronic waste (e-waste) are potentially exposed to toxic chemicals. If exposure occurs, this may result in uptake and potential adverse health effects. Thus, exposure surveillance is an important requirement for health risk management and prevention of occupational disease. Human biomonitoring by measurement of specific biomarkers in body fluids is considered as an effective method of exposure surveillance. The aim of this study is to investigate the internal exposure of workers processing e-waste using a human biomonitoring approach, which will stimulate improved work practices and contribute to raising awareness of potential hazards. This exploratory study in occupational exposures in e-waste processing is part of the European Human Biomonitoring Initiative (HBM4EU). Here we present a study protocol using a cross sectional survey design to study worker's exposures and compare these to the exposure of subjects preferably employed in the same company but with no known exposure to industrial recycling of e-waste. The present study protocol will be applied in six to eight European countries to ensure standardised data collection. The target population size is 300 exposed and 150 controls. Biomarkers of exposure for the following chemicals will be used: chromium, cadmium and lead in blood and urine; brominated flame retardants and polychlorobiphenyls in blood; mercury, organophosphate flame retardants and phthalates in urine, and chromium, cadmium, lead and mercury in hair. In addition, the following effect biomarkers will be studied: micronuclei, epigenetic, oxidative stress, inflammatory markers and telomere length in blood and metabolomics in urine. Occupational hygiene sampling methods (airborne and settled dust, silicon wristbands and handwipes) and contextual information will be collected to facilitate the interpretation of the biomarker results and discuss exposure mitigating interventions to further reduce exposures if needed. This study protocol can be adapted to future European-wide occupational studies.


Assuntos
Resíduo Eletrônico , Exposição Ocupacional , Monitoramento Biológico , Estudos Transversais , Poeira/análise , Monitoramento Ambiental , Humanos , Exposição Ocupacional/análise , Reciclagem
16.
Chem Sci ; 12(40): 13321-13330, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34777751

RESUMO

The development of bioconjugation chemistry has enabled the combination of various synthetic functionalities to proteins, giving rise to new classes of protein conjugates with functions well beyond what Nature can provide. Despite the progress in bioconjugation chemistry, there are no reagents developed to date where the reactivity can be tuned in a user-defined fashion to address different amino acid residues in proteins. Here, we report that 2-chloromethyl acryl reagents can serve as a simple yet versatile platform for selective protein modification at cysteine or disulfide sites by tuning their inherent electronic properties through the amide or ester linkage. Specifically, the 2-chloromethyl derivatives (acrylamide or acrylate) can be obtained via a simple and easily implemented one-pot reaction based on the coupling reaction between commercially available starting materials with different end-group functionalities (amino group or hydroxyl group). 2-Chloromethyl acrylamide reagents with an amide linkage favor selective modification at the cysteine site with fast reaction kinetics and near quantitative conversations. In contrast, 2-chloromethyl acrylate reagents bearing an ester linkage can undergo two successive Michael reactions, allowing the selective modification of disulfides bonds with high labeling efficiency and good conjugate stability.

17.
Int J Hyg Environ Health ; 234: 113725, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33714856

RESUMO

The EU human biomonitoring initiative, HBM4EU, aims to co-ordinate and advance human biomonitoring (HBM) across Europe. As part of HBM4EU, we presented a protocol for a multicentre study to characterize occupational exposure to hexavalent chromium (Cr(VI)) in nine European countries (HBM4EU chromates study). This study intended to collect data on current occupational exposure and to test new indicators for chromium (Cr) biomonitoring (Cr(VI) in exhaled breath condensate and Cr in red blood cells), in addition to traditional urinary total Cr analyses. Also, data from occupational hygiene samples and biomarkers of early biological effects, including genetic and epigenetic effects, was obtained, complementing the biomonitoring information. Data collection and analysis was completed, with the project findings being made separately available. As HBM4EU prepares to embark on further European wide biomonitoring studies, we considered it important to reflect on the experiences gained through our harmonised approach. Several practical aspects are highlighted for improvement in future studies, e.g., more thorough/earlier training on the implementation of standard operating procedures for field researchers, training on the use of the data entry template, as well as improved company communications. The HBM4EU chromates study team considered that the study had successfully demonstrated the feasibility of conducting a harmonised multicentre investigation able to achieve the research aims and objectives. This was largely attributable to the engaged multidisciplinary network, committed to deliver clearly understood goals. Such networks take time and investment to develop, but are priceless in terms of their ability to deliver and facilitate knowledge sharing and collaboration.


Assuntos
Monitoramento Biológico , Exposição Ocupacional , Cromatos , Cromo/análise , Monitoramento Ambiental , Humanos
18.
Rev. Fund. Educ. Méd. (Ed. impr.) ; 24(1): 21-25, ene.-feb. 2021. tab
Artigo em Espanhol | IBECS | ID: ibc-202417

RESUMO

INTRODUCCIÓN: La tutoría clínica se define hoy como una actividad académica, que constituye un campo de transformación del conocimiento que implica a los estudiantes y docentes. El presente estudio describe las percepciones acerca de las competencias en la conducción del proceso tutorial de los protagonistas respecto a este espacio de verdadera transformación y crecimiento en este proceso educativo. Sujetos y métodos: Estudio descriptivo en el cual la variable percepción de la competencia docente del tutor clínico se evaluó en estudiantes y docentes del ciclo clínico de la Facultad de Odontología de la Universidad Finis Terrae, en Chile. La percepción se operacionalizó en tres factores y se evaluó por medio de dos instrumentos: el Council of European Chief Dental Officers (estudiantes) y el Knowledge and Prior Study Inventory (docentes). Los datos se analizaron a través de medidas de tendencia central y la prueba no paramétrica t de Student. RESULTADOS: La percepción de los docentes y la de los estudiantes respecto a las competencias para conducir la tutoría clínica presentan diferencias significativas en dos de los tres factores, como también en el desglose de ítems por factor, lo que da cuenta de los aspectos en los cuales las autopercepciones de los docentes son mejores que las percepciones de los estudiantes. CONCLUSIÓN: Se reconocen deficiencias del ejercicio del tutor que son percibidas por los estudiantes y que podrían ser mejoradas, como la autonomía, el razonamiento clínico y la efectividad de la retroalimentación, por lo que se sugiere diseñar un programa de capacitación sobre competencias docentes dirigido a tutores clínicos que responda a las debilidades percibidas


INTRODUCTION: Clinical tutoring/mentoring is defined today as an academic activity, which constitutes a transformation of knowledge field that involves students and teachers. The present study describes the perceptions about the competencies in the conduct of the tutorial process of the protagonists regarding this space of true transformation and growth of this educational process. Subjects and methods: Descriptive study in which the variable perception of the clinical tutor's teaching competence was evaluated in students and teachers of the clinical cycle of the Faculty of Dentistry of the Finis Terrae University, Chile. The perception was operationalized in three factors, and was evaluated by means of two instruments: CECD-O (students) and KPSI (teachers). The data were analyzed through measures of central tendency and the non-parametric Student's t test. RESULTS: The perception of teachers and students regarding the skills to conduct clinical tutoring, shows significant differences in two of the three factors, as well as in the breakdown of items by factor, accounting on the aspects in which the teachers'self-perceptions they are better than those perceived by students. CONCLUSION: There are recognized deficiencies in the tutor's exercise that are perceived by the students and that could be improved, such as autonomy, clinical reasoning and feedback effectiveness, which is why it is suggest designing a training program on teaching competencies aimed at clinical tutors in response to perceived weaknesses


Assuntos
Humanos , Educação em Odontologia/tendências , Capacitação de Professores/tendências , Avaliação Educacional/métodos , Mentores/estatística & dados numéricos , Estudantes de Odontologia/estatística & dados numéricos , Docentes de Odontologia/estatística & dados numéricos , Autoavaliação (Psicologia) , Estudos Transversais , Competência Profissional/estatística & dados numéricos
19.
Plants (Basel) ; 10(2)2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33513848

RESUMO

This study aimed to assess the efficiency of Ca enrichment in tubers of three genotypes of Solanum tuberosum L., through foliar spraying with CaCl2 and Ca(NO3)2 solutions. In this context, soil heterogeneity of three potato-growing fields, as well as the implications of Ca accumulation among tissues and some quality parameters were assessed. Three potato varieties (Agria, Picasso and Rossi) were grown in three production fields and during the life cycle, four pulverizations with calcium chloride (3 and 6 kg ha-1) or calcium nitrate (0.5, 2 and 4 kg ha-1) were applied. For screening the potential phytotoxicity, using Agria as a test system, the potential synthesis of photoassimilates was determined, and it was found that after the 3rd Ca application, leaf gas exchanges were moderately (net photosynthesis), to strongly (stomatal conductance) affected, although without impact on Ca accumulation in tubers. At harvest, the average Ca biofortification index varied between 5-40%, 40-35% and 4.3-13% in Agria, Picasso and Rossi, respectively. Moreover, the equatorial region of the tubers in general showed that Ca accumulation prevailed in the epidermis and, in some cases, in inner areas of the potato tubers. Biofortified tubers with Ca also showed some significant changes in total soluble solids and colorimetric parameters. It is concluded that Ca enrichment of potato tubers through foliar spraying complemented the xylem mass flow of Ca from roots, through phloem redistribution. Both fertilizers showed similar efficiency, but Rossi revealed a lower index of Ca accumulation, eventually due to different metabolic characteristics. Although affected by Ca enrichment, potato tubers maintained a high quality for industrial processing.

20.
Chembiochem ; 22(10): 1740-1742, 2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33507625

RESUMO

The development of metal-based anticancer drugs has been hampered, among other reasons, by their lack of selectivity for cancer cells. In a recent article, Zou and co-workers presented the successful intracellular activation of organogold(I) complexes for potential cancer treatment through Pd(II)-mediated transmetallation, overcoming some off-target activity of novel gold-based drugs. This unique strategy builds the perfect bridge between metallodrug usage and bioorthogonal intracellular catalysis for more advanced and selective therapies. Such an approach will hopefully pave the way for forthcoming studies in medicinal inorganic chemistry.


Assuntos
Antineoplásicos/química , Complexos de Coordenação/química , Elementos de Transição/química , Antineoplásicos/uso terapêutico , Complexos de Coordenação/uso terapêutico , Ouro/química , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Paládio/química
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