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1.
Acta Trop ; 257: 107315, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38969320

ABSTRACT

Tick-borne pathogens are a significant threat to human and animal health. Exposing the microbial composition of ticks elucidates their potential role in transmitting pathogens and causing disease as well as uncovering their potential interaction with the hosting tick. Our study focused on characterizing the tick microbiome of adult females and their lab-reared larval offspring of two prevalent tick species found on dogs in Nigeria [Rhipicephalus sanguineus s.l. tropical lineage (R. linnaei) and Haemaphysalis leachi]. We investigated the relative phyla abundance, the alpha and beta diversities of microbial communities comparing tick species, and different development stages (adults versus larvae). To the best of our knowledge, this is the first analysis on H. leachi microbiome described from West Africa. Our findings revealed a diverse microbiome with significant differences across species and their developmental stages, highlighting the dominance of the Proteobacteria phylum, followed by Firmicutes and Actinobacteriota. In contrast to H. leachi, for R. linnaei we observed significant differences in the alpha and beta diversities of the microbiome of larvae and adult females. Predominant bacterial genera were identified in R. linnaei, particularly Arsenophonus and Coxiella, which showed increased abundance in adult ticks. In H. leachi, other predominant genera were detected, including Sphingomonas, Comamonas, and Williamsia. Our results contribute to the understanding of microbiome dynamics within ticks and offers insights of tick physiology for addressing public health concerns and developing effective strategies for pathogen control.

2.
Curr Health Sci J ; 50(1): 20-28, 2024.
Article in English | MEDLINE | ID: mdl-38846470

ABSTRACT

BACKROUND: Pancreaticojejunal anastomosis has a high risk of pancreatic leakage, which several surgical techniques have been described. Our main objective is to determine what is the association of postoperative pancreatic leakage in patients undergoing pancreaticoduodenectomy according to the pancreaticojejunal anastomosis technique used (Cattel vs Blumgart)? MATERIAL AND METHODS: Historical cohort, all cancer patients undergoing pancreaticoduodenectomy were included. From April 2020 to May 2021, Cattel technique was used; from June 2021 to June 2022, Blumgart technique was used. All procedures were performed by a single board-certified surgical oncologist at Oncology Hospital. RESULTS: 24 patients (11 men and 13 women). The first 9 procedures were performed with the Cattel technique, starting from procedure 10, the Blumgart technique was used. No differences were observed regarding the consistency of the pancreas (p=0.28) or the size of the duct (p=0.51) between the two groups. Pancreatic leakage was observed in 100% with the Cattel technique and in 6.7% with the Blumgart technique (p= 0.0001). An amylase value was observed in the left drainage at 6 days > 200 U/L with the Cattel technique and < 200 U/L with Blumgart (p=0.0001). Intraoperative bleeding (Cattel 1200 ml vs. Blumgart 400 ml, p= 0.03) and 90-day mortality (Cattel 33.3% vs. Blumgart 0%, Log-Rank: 0.022) also showed a difference in favor of Blumgart technique. Blumgart technique is a protective factor for the presence of pancreatic leakage (RR 0.06, 95% CI 0.01-0.44, p=0.0001). DISCUSSION: A lower risk of pancreatic leakage was found using the Blumgart technique, compared to the Cattel technique.

3.
Med Mycol Case Rep ; 44: 100650, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38711546

ABSTRACT

Phaeoacremonium is a genus of dematiaceous fungi that rarely causes human infections. We describe a case of subcutaneous infection in a 70-year-old diabetic man with lesions on the dorsum of the one foot. The agent was isolated, and for the final identification we performed matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and DNA sequencing. After diagnosis, the patient underwent curettage of the cyst and received 100mg of Itraconazole, twice daily for 6 months. Clinical resolution of the lesion was observed after treatment. This is the first case of infection by Phaeoacremonium venezuelense reported in Costa Rica.

4.
Biomedicines ; 12(2)2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38397861

ABSTRACT

Intussusceptive angiogenesis (IA) and intussusceptive lymphangiogenesis (IL) play a key role in the growth and morphogenesis of vessels. However, there are very few studies in this regard in vessel tumors (VTs). Our objective is to assess the presence, characteristics, and possible mechanisms of the formation of intussusceptive structures in a broad spectrum of VTs. For this purpose, examples of benign and malignant blood and lymphatic VTs were studied via conventional procedures, semithin sections, and immunochemistry and immunofluorescence microscopy. The results demonstrated intussusceptive structures (pillars, meshes, and folds) in benign (lobular capillary hemangioma or pyogenic granuloma, intravascular papillary endothelial hyperplasia or Masson tumor, sinusoidal hemangioma, cavernous hemangioma, glomeruloid hemangioma, angiolipoma, and lymphangiomas), low-grade malignancy (retiform hemangioendothelioma and Dabska tumor), and malignant (angiosarcoma and Kaposi sarcoma) VTs. Intussusceptive structures showed an endothelial cover and a core formed of connective tissue components and presented findings suggesting an origin through vessel loops, endothelialized thrombus, interendothelial bridges, and/or splitting and fusion, and conditioned VT morphology. In conclusion, the findings support the participation of IA and IL, in association with sprouting angiogenesis, in VTs, and therefore in their growth and morphogenesis, which is of pathophysiological interest and lays the groundwork for in-depth molecular studies with therapeutic purposes.

5.
Parasit Vectors ; 17(1): 77, 2024 Feb 20.
Article in English | MEDLINE | ID: mdl-38378676

ABSTRACT

BACKGROUND: Nematodes of the Ascarididae, Ancylostomatidae and Onchocercidae families are parasites of human and veterinary importance causing infections with high prevalence worldwide. Molecular tools have significantly improved the diagnosis of these helminthiases, but the selection of genetic markers for PCR or metabarcoding purposes is often challenging because of the resolution these may show. METHODS: Nuclear 18S rRNA, internal transcribed spacers 1 (ITS-1) and 2 (ITS-2), mitochondrial gene cytochrome oxidase 1 (cox1) and mitochondrial rRNA genes 12S and 16S loci were studied for 30 species of the mentioned families. Accordingly, their phylogenetic interspecies resolution, pairwise nucleotide p-distances and sequence availability in GenBank were analyzed. RESULTS: The 18S rRNA showed the least interspecies resolution since separate species of the Ascaris, Mansonella, Toxocara or Ancylostoma genus were intermixed in phylogenetic trees as opposed to the ITS-1, ITS-2, cox1, 12S and 16S loci. Moreover, pairwise nucleotide p-distances were significantly different in the 18S compared to the other loci, with an average of 99.1 ± 0.1%, 99.8 ± 0.1% and 98.8 ± 0.9% for the Ascarididae, Ancylostomatidae and Onchocercidae families, respectively. However, ITS-1 and ITS-2 average pairwise nucleotide p-distances in the three families ranged from 72.7% to 87.3%, and the cox1, 12S and 16S ranged from 86.4% to 90.4%. Additionally, 2491 cox1 sequences were retrieved from the 30 analyzed species in GenBank, whereas 212, 1082, 994, 428 and 143 sequences could be obtained from the 18S, ITS-1, ITS-2, 12S and 16S markers, respectively. CONCLUSIONS: The use of the cox1 gene is recommended because of the high interspecies resolution and the large number of sequences available in databases. Importantly, confirmation of the identity of an unknown specimen should always be complemented with the careful morphological examination of worms and the analysis of other markers used for specific parasitic groups.


Subject(s)
Nematoda , Sarcocystis , Sarcocystosis , Humans , Animals , RNA, Ribosomal, 18S/genetics , Sarcocystosis/veterinary , Phylogeny , Nematoda/genetics , Nucleotides
6.
Phys Rev Lett ; 131(22): 227201, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-38101363

ABSTRACT

Dynamical fluctuations or rare events associated with atypical trajectories in chaotic maps due to specific initial conditions can crucially determine their fate, as the may lead to stability islands or regions in phase space otherwise displaying unusual behavior. Yet, finding such initial conditions is a daunting task precisely because of the chaotic nature of the system. In this Letter, we circumvent this problem by proposing a framework for finding an effective topologically conjugate map whose typical trajectories correspond to atypical ones of the original map. This is illustrated by means of examples which focus on counterbalancing the instability of fixed points and periodic orbits, as well as on the characterization of a dynamical phase transition involving the finite-time Lyapunov exponent. The procedure parallels that of the application of the generalized Doob transform in the stochastic dynamics of Markov chains, diffusive processes, and open quantum systems, which in each case results in a new process having the prescribed statistics in its stationary state. This Letter thus brings chaotic maps into the growing family of systems whose rare fluctuations-sustaining prescribed statistics of dynamical observables-can be characterized and controlled by means of a large-deviation formalism.

7.
PLoS Negl Trop Dis ; 17(11): e0011733, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37917733

ABSTRACT

BACKGROUND: Leptospirosis is a complex zoonotic disease mostly caused by a group of eight pathogenic species (L. interrogans, L. borgpetersenii, L. kirschneri, L. mayottensis, L. noguchii, L. santarosai, L. weilii, L. alexanderi), with a wide spectrum of animal reservoirs and patient outcomes. Leptospira interrogans is considered as the leading causative agent of leptospirosis worldwide and it is the most studied species. However, the genomic features and phylogeography of other Leptospira pathogenic species remain to be determined. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated the genome diversity of the main pathogenic Leptospira species based on a collection of 914 genomes from strains isolated around the world. Genome analyses revealed species-specific genome size and GC content, and an open pangenome in the pathogenic species, except for L. mayottensis. Taking advantage of a new set of genomes of L. santarosai strains isolated from patients in Costa Rica, we took a closer look at this species. L. santarosai strains are largely distributed in America, including the Caribbean islands, with over 96% of the available genomes originating from this continent. Phylogenetic analysis showed high genetic diversity within L. santarosai, and the clonal groups identified by cgMLST were strongly associated with geographical areas. Serotype identification based on serogrouping and/or analysis of the O-antigen biosynthesis gene loci further confirmed the great diversity of strains within the species. CONCLUSIONS/SIGNIFICANCE: In conclusion, we report a comprehensive genome analysis of pathogenic Leptospira species with a focus on L. santarosai. Our study sheds new light onto the genomic diversity, evolutionary history, and epidemiology of leptospirosis in America and globally. Our findings also expand our knowledge of the genes driving O-antigen diversity. In addition, our work provides a framework for understanding the virulence and spread of L. santarosai and for improving its surveillance in both humans and animals.


Subject(s)
Leptospira , Leptospirosis , Animals , Humans , Phylogeny , O Antigens , Leptospirosis/epidemiology
8.
Parasit Vectors ; 16(1): 315, 2023 Sep 04.
Article in English | MEDLINE | ID: mdl-37667323

ABSTRACT

BACKGROUND: Pathogens face strong selection from host immune responses, yet many host populations support pervasive pathogen populations. We investigated this puzzle in a model system of Bartonella and rodents from Israel's northwestern Negev Desert. We chose to study this system because, in this region, 75-100% of rodents are infected with Bartonella at any given time, despite an efficient immunological response. In this region, Bartonella species circulate in three rodent species, and we tested the hypothesis that at least one of these hosts exhibits a waning immune response to Bartonella, which allows reinfections. METHODS: We inoculated captive animals of all three rodent species with the same Bartonella strain, and we quantified the bacterial dynamics and Bartonella-specific immunoglobulin G antibody kinetics over a period of 139 days after the primary inoculation, and then for 60 days following reinoculation with the same strain. RESULTS: Contrary to our hypothesis, we found a strong, long-lasting immunoglobulin G antibody response, with protective immunological memory in all three rodent species. That response prevented reinfection upon exposure of the rodents to the same Bartonella strain. CONCLUSIONS: This study constitutes an initial step toward understanding how the interplay between traits of Bartonella and their hosts influences the epidemiological dynamics of these pathogens in nature.


Subject(s)
Bartonella Infections , Bartonella , Animals , Bartonella Infections/epidemiology , Bartonella Infections/veterinary , Immunoglobulin G , Kinetics , Immunity
9.
Int J Mol Sci ; 24(15)2023 Jul 28.
Article in English | MEDLINE | ID: mdl-37569493

ABSTRACT

Telocytes/CD34+ stromal cells (TCs/CD34+ SCs) have been studied in numerous organs and tissues, but their presence and characteristics in the parathyroid glands have not been explored. Using immunological and ultrastructural procedures, we assess the location, arrangement, and behavior of TCs/CD34+ SCs in normal human parathyroids, during their development and in their most frequent pathologic conditions. In normal parathyroids, TCs/CD34+ SCs show a small somatic body and long thin processes with a moniliform aspect, form labyrinthine systems, connect other neighboring TCs/CD34+ SCs, vessels, adipocytes, and parenchymal cells directly or by extracellular vesicles, and associate with collagen I. TCs/CD34+ SCs and collagen I are absent around vessels and adipocytes within parenchymal clusters. In developing parathyroids, TCs/CD34+ SC surround small parenchymal nests and adipocytes. In hyperplastic parathyroids, TCs/CD34+ SCs are prominent in some thickened internodular septa and surround small extraglandular parenchymal cell nests. TCs/CD34+ SCs are present in delimiting regions with compressed parathyroids and their capsule in adenomas but absent in most adenomatous tissue. In conclusion, TCs/CD34+ SCs are an important cellular component in the human parathyroid stroma, except around vessels within parenchymal nests. They show typical characteristics, including those of connecting cells, are present in developing parathyroids, and participate in the most frequent parathyroid pathology, including hyperplastic and adenomatous parathyroids.


Subject(s)
Adenoma , Parathyroid Neoplasms , Telocytes , Humans , Parathyroid Glands , Stromal Cells/ultrastructure , Antigens, CD34 , Hyperplasia , Cell Adhesion Molecules , Collagen
10.
Biology (Basel) ; 12(7)2023 Jun 29.
Article in English | MEDLINE | ID: mdl-37508360

ABSTRACT

This paper aims to review, systematically synthesize, and analyze fragmented information about the importance of coat color in local goats and its relationship with productivity and other important traits. Topics on current research on color expression are addressed, the relationship that has as a mechanism of environmental adaptation, its relationship with the production of meat, milk, and derivates, and the economic value of this characteristic. The use of this attribute as a tool to establish selection criteria in breeding programs based on results reported in the scientific literature is significant, particularly for low-income production systems, where the implementation of classic genetic improvement schemes is limited due to the lack of productive information, which is distinctive of extensive marginal or low scaled production systems around the world.

11.
Sensors (Basel) ; 23(11)2023 Jun 01.
Article in English | MEDLINE | ID: mdl-37299979

ABSTRACT

This paper presents the development of an instrumented exoskeleton with baropodometry, electromyography, and torque sensors. The six degrees of freedom (Dof) exoskeleton has a human intention detection system based on a classifier of electromyographic signals coming from four sensors placed in the muscles of the lower extremity together with baropodometric signals from four resistive load sensors placed at the front and rear parts of both feet. In addition, the exoskeleton is instrumented with four flexible actuators coupled with torque sensors. The main objective of the paper was the development of a lower limb therapy exoskeleton, articulated at hip and knees to allow the performance of three types of motion depending on the detected user's intention: sitting to standing, standing to sitting, and standing to walking. In addition, the paper presents the development of a dynamical model and the implementation of a feedback control in the exoskeleton.


Subject(s)
Exoskeleton Device , Humans , Electromyography , Lower Extremity/physiology , Knee , Movement/physiology , Biomechanical Phenomena
12.
Waste Manag Res ; 41(11): 1674-1683, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37265168

ABSTRACT

The management of solid waste is one of the biggest challenges for sustainability. Aiming at gains of scale, guaranteeing universal access and the technical and economic viability of the services, intermunicipal cooperation has been implemented in several countries, and in Brazil, it presents itself as one of the main instruments of public policies in the sector of sanitation. The main objective of this article is to propose a set of indicators and the construction of an index to evaluate the performance of regionalized management of urban solid waste, applying them to intermunicipal public consortia operating in Brazil. Based on the Delphi methodology, a total of 15 indicators were defined, divided into 5 sustainability dimensions, used for the construction of the Regionalized Urban Solid Waste Management Performance Index (IDGRSU). In Brazil, the performance of regionalized management was classified as Regular for most of the operating consortia analysed. The adequacy of the final disposal in regional sanitary landfills is the common practice among the municipalities, and consequently, the reduction of the areas of dumps represents the main advance in the management. The index developed proved to be an important instrument to support municipalities and consortia for waste management, contributing to the implementation of sustainable strategies and to the development of policies, and its application in other countries is feasible, regardless of the size of the municipalities.


Subject(s)
Refuse Disposal , Waste Management , Solid Waste , Waste Disposal Facilities , Brazil , Cities
13.
Front Robot AI ; 10: 1032748, 2023.
Article in English | MEDLINE | ID: mdl-36860557

ABSTRACT

A few years ago, powered prostheses triggered new technological advances in diverse areas such as mobility, comfort, and design, which have been essential to improving the quality of life of individuals with lower limb disability. The human body is a complex system involving mental and physical health, meaning a dependant relationship between its organs and lifestyle. The elements used in the design of these prostheses are critical and related to lower limb amputation level, user morphology and human-prosthetic interaction. Hence, several technologies have been employed to accomplish the end user's needs, for example, advanced materials, control systems, electronics, energy management, signal processing, and artificial intelligence. This paper presents a systematic literature review on such technologies, to identify the latest advances, challenges, and opportunities in developing lower limb prostheses with the analysis on the most significant papers. Powered prostheses for walking in different terrains were illustrated and examined, with the kind of movement the device should perform by considering the electronics, automatic control, and energy efficiency. Results show a lack of a specific and generalised structure to be followed by new developments, gaps in energy management and improved smoother patient interaction. Additionally, Human Prosthetic Interaction (HPI) is a term introduced in this paper since no other research has integrated this interaction in communication between the artificial limb and the end-user. The main goal of this paper is to provide, with the found evidence, a set of steps and components to be followed by new researchers and experts looking to improve knowledge in this field.

14.
Microorganisms ; 11(2)2023 Jan 30.
Article in English | MEDLINE | ID: mdl-36838305

ABSTRACT

Rodents and bats are the most diverse mammal group that host Bartonella species. In the Americas, they were described as harboring Bartonella species; however, they were mostly characterized to the genotypic level. We describe here Bartonella isolates obtained from blood samples of one rodent (Peromyscus yucatanicus from San José Pibtuch, Yucatan) and two bat species (Desmodus rotundus from Progreso, and Pteronotus parnellii from Chamela-Cuitzmala) from Mexico. We sequenced and described the genomic features of three Bartonella strains and performed phylogenomic and pangenome analyses to decipher their phylogenetic relationships. The mouse-associated genome was closely related to Bartonella vinsonii. The two bat-associated genomes clustered into a single distinct clade in between lineages 3 and 4, suggesting to be an ancestor of the rodent-associated Bartonella clade (lineage 4). These three genomes showed <95% OrthoANI values compared to any other Bartonella genome, and therefore should be considered as novel species. In addition, our analyses suggest that the B. vinsonii complex should be revised, and all B. vinsonii subspecies need to be renamed and considered as full species. The phylogenomic clustering of the bat-associated Bartonella strains and their virulence factor profile (lack of the Vbh/TraG conjugation system remains of the T4SS) suggest that it should be considered as a new lineage clade (L5) within the Bartonella genus.

15.
Int J Mol Sci ; 24(4)2023 Feb 14.
Article in English | MEDLINE | ID: mdl-36835203

ABSTRACT

Kaposi sarcoma (KS) is an angioproliferative lesion in which two main KS cell sources are currently sustained: endothelial cells (ECs) and mesenchymal/stromal cells. Our objective is to establish the tissue location, characteristics and transdifferentiation steps to the KS cells of the latter. For this purpose, we studied specimens of 49 cases of cutaneous KS using immunochemistry and confocal and electron microscopy. The results showed that delimiting CD34+ stromal cells/Telocytes (CD34+SCs/TCs) in the external layer of the pre-existing blood vessels and around skin appendages form small convergent lumens, express markers for ECs of blood and lymphatic vessels, share ultrastructural characteristics with ECs and participate in the origin of two main types of neovessels, the evolution of which gives rise to lymphangiomatous or spindle-cell patterns-the substrate of the main KS histopathological variants. Intraluminal folds and pillars (papillae) are formed in the neovessels, which suggests they increase by vessel splitting (intussusceptive angiogenesis and intussusceptive lymphangiogenesis). In conclusion, delimiting CD34+SCs/TCs are mesenchymal/stromal cells that can transdifferentiate into KS ECs, participating in the formation of two types of neovessels. The subsequent growth of the latter involves intussusceptive mechanisms, originating several KS variants. These findings are of histogenic, clinical and therapeutic interest.


Subject(s)
Sarcoma, Kaposi , Skin Neoplasms , Stromal Cells , Telocytes , Humans , Antigens, CD34/metabolism , Endothelial Cells/metabolism , Sarcoma, Kaposi/pathology , Skin Neoplasms/pathology , Stromal Cells/metabolism , Stromal Cells/pathology , Telocytes/metabolism , Telocytes/pathology , Neovascularization, Pathologic/metabolism , Neovascularization, Pathologic/pathology
16.
Histol Histopathol ; 38(1): 29-46, 2023 Jan.
Article in English | MEDLINE | ID: mdl-35775452

ABSTRACT

The microvasculature of angiolipoma frequently presents thrombi. Our objectives are to assess whether intussusceptive angiogenesis (IA) participates in vasculature formation in non-infiltrating angiolipoma and, if so, to explore how thrombi are involved in the IA process. For this purpose, we studied angiolipoma specimens (n: 52), using immunohistochemistry, and confocal and electron microscopy. The results showed the presence of folds and pillars, hallmarks of IA, dividing the vessel lumen. Folds showed a cover formed by reoriented endothelial cells from the vessel wall, or from newly formed folds, and a core initially formed by thrombus fragments (clot components as transitional core), which was replaced by extracellular matrix and invaginating pericytes establishing numerous peg-and-socket junctions with endothelial cells (mature core). A condensed plasmatic electron-dense material surrounded and connected folds and pillars with each other and with the vascular wall, which suggests a clot role in fold/pillar arrangement. In conclusion, we contribute to IA participation in capillary network formation in angiolipoma and the immunohistochemical and ultrastructural events by which microthrombosis facilitates IA. Therefore, in addition to the histogenesis of angiolipoma, we provide an easily obtainable substrate for future studies on clot component action in IA, of clinical and therapeutic interest.


Subject(s)
Angiolipoma , Thrombosis , Humans , Endothelial Cells , Morphogenesis , Neovascularization, Physiologic
17.
Liberabit ; 29(1): 683, 2023.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1538148

ABSTRACT

Antecedentes: el estrés percibido hace referencia al grado en que las personas perciben las demandas de su entorno como impredecibles e incontrolables. Las escalas PSS-14 y PSS-10 son los instrumentos más utilizados a nivel mundial para evaluar este constructo. Objetivo: describir las propiedades psicométricas de la EEP de 14 y 10 ítems en docentes chilenos, e indagar la invarianza estructural de sus modelos según el sexo de los/as docentes. Método: se efectuó un estudio instrumental en una muestra de 206 profesores. Resultados: el análisis factorial confirmatorio, a través de un método de máxima verosimilitud robusto (MLR), mostró los mejores indicadores de ajuste en los modelos de dos factores relacionados: en el PSS-14 (χ² = 166.693, gl = 76, p < .001; CFI = .918; TLI = .901; RMSEA = .076) y en el PSS-10 (χ² = 59.979, gl = 34, p < .001; CFI = .968; TLI = .957; RMSEA = .061). Los coeficientes ω de McDonald fueron favorables para los factores de ambas escalas. Asimismo, se constató la invarianza de la estructura de dos factores para hombres y mujeres en los dos instrumentos. Conclusión: se concluye que estos antecedentes avalarían el uso de estos instrumentos en docentes chilenos. Palabras claves: estrés; profesores; validez; confiabilidad; invarianza; Chile.


Background: Perceived stress refers to the degree to which people perceive the demands of their environment as unpredictable and uncontrollable. The PSS-14 and PSS-10 scales are the most widely used instruments worldwide to assess this construct. Objective: To describe the psychometric properties of the EEP 14 and 10 items in Chilean teachers, and to investigate the structural invariance of its models according to teachers' gender. Method: An instrumental study was carried out in a sample of 206 teachers. Results: Confirmatory factor analysis, using a robust maximum likelihood (MLR) method, showed the best fit indicators in the models of two related factors: in the PSS-14 (χ² = 166.693, df = 76, p < .001; CFI = .918; TLI = .901; RMSEA = .076) and in the PSS-10 (χ² = 59.979, df = 34, p < .001; CFI = .968; TLI = .957; RMSEA = .061). The McDonald's ω coefficients were favorable for the factors of both scales. Likewise, the invariance of the two-factor structure for men and women in the two instruments was verified. Conclusion: It is concluded that these antecedents would support the use of these instruments in Chilean teachers. Keywords: stress; teachers; validity; reliability; comparison of invariances; Chile.

18.
Article in English | MEDLINE | ID: mdl-36554756

ABSTRACT

The growing problem of mental health in the university population, as a consequence of the COVID-19 pandemic, has generated the need to consider positive variables to address this situation. Life satisfaction and academic engagement are two constructs that emerge as conceptual tools oriented in this direction. The present study sought to describe the effect of academic engagement on life satisfaction in a sample of Chilean university students. A cross-sectional co-relational design was used. A total of 370 university students participated, 72.4% female and 27.6% male, aged beitive effect of engagement on life satisfaction was demonstrated, where the dimensions vigor (ß = 0.462; p < 0.01) and dedication (ß = 0.465; p < 0.01) acted as significant predictors (χ2 = 87.077, gl = 32, p < 0.01; χ2/gl = 2.721; CFI = 975; TLI = 0.964; RMSEA = 0.068). The proposed model showed factorial invariance according to sex. The usefulness of employing these constructs as a way to manage the well-being and mental health of students in university institutions is discussed.


Subject(s)
COVID-19 , Pandemics , Aged , Female , Humans , Male , Chile , COVID-19/epidemiology , Cross-Sectional Studies , Personal Satisfaction , Students/psychology , Universities
19.
Int J Mol Sci ; 23(16)2022 Aug 12.
Article in English | MEDLINE | ID: mdl-36012273

ABSTRACT

Perivascular cells in the pericytic microvasculature, pericytes and CD34+ stromal cells/telocytes (CD34+SCs/TCs), have an important role in angiogenesis. We compare the behavior of these cells depending on whether the growth of endothelial cells (ECs) from the pre-existing microvasculature is toward the interstitium with vascular bud and neovessel formation (sprouting angiogenesis) or toward the vascular lumen with intravascular pillar development and vessel division (intussusceptive angiogenesis). Detachment from the vascular wall, mobilization, proliferation, recruitment, and differentiation of pericytes and CD34+SCs/TCs, as well as associated changes in vessel permeability and functionality, and modifications of the extracellular matrix are more intense, longer lasting over time, and with a greater energy cost in sprouting angiogenesis than in intussusceptive angiogenesis, in which some of the aforementioned events do not occur or are compensated for by others (e.g., sparse EC and pericyte proliferation by cell elongation and thinning). The governing mechanisms involve cell-cell contacts (e.g., peg-and-socket junctions between pericytes and ECs), multiple autocrine and paracrine signaling molecules and pathways (e.g., vascular endothelial growth factor, platelet-derived growth factor, angiopoietins, transforming growth factor B, ephrins, semaphorins, and metalloproteinases), and other factors (e.g., hypoxia, vascular patency, and blood flow). Pericytes participate in vessel development, stabilization, maturation and regression in sprouting angiogenesis, and in interstitial tissue structure formation of the pillar core in intussusceptive angiogenesis. In sprouting angiogenesis, proliferating perivascular CD34+SCs/TCs are an important source of stromal cells during repair through granulation tissue formation and of cancer-associated fibroblasts (CAFs) in tumors. Conversely, CD34+SCs/TCs have less participation as precursor cells in intussusceptive angiogenesis. The dysfunction of these mechanisms is involved in several diseases, including neoplasms, with therapeutic implications.


Subject(s)
Pericytes , Telocytes , Antigens, CD34/metabolism , Endothelial Cells/metabolism , Neovascularization, Physiologic/physiology , Pericytes/metabolism , Stromal Cells/metabolism , Telocytes/metabolism , Vascular Endothelial Growth Factor A/analysis
20.
J Bionic Eng ; 19(5): 1374-1391, 2022.
Article in English | MEDLINE | ID: mdl-35756166

ABSTRACT

This paper presents an upper limb exoskeleton that allows cognitive (through electromyography signals) and physical user interaction (through load cells sensors) for passive and active exercises that can activate neuroplasticity in the rehabilitation process of people who suffer from a neurological injury. For the exoskeleton to be easily accepted by patients who suffer from a neurological injury, we used the ISO9241-210:2010 as a methodology design process. As the first steps of the design process, design requirements were collected from previous usability tests and literature. Then, as a second step, a technological solution is proposed, and as a third step, the system was evaluated through performance and user testing. As part of the technological solution and to allow patient participation during the rehabilitation process, we have proposed a hybrid admittance control whose input is load cell or electromyography signals. The hybrid admittance control is intended for active therapy exercises, is easily implemented, and does not need musculoskeletal modeling to work. Furthermore, electromyography signals classification models and features were evaluated to identify the best settings for the cognitive human-robot interaction.

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