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1.
Cell ; 178(5): 1176-1188.e15, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31442406

RESUMO

Adaptive immunity provides life-long protection by generating central and effector memory T cells and the most recently described tissue resident memory T (TRM) cells. However, the cellular origin of CD4 TRM cells and their contribution to host defense remain elusive. Using IL-17A tracking-fate mouse models, we found that a significant fraction of lung CD4 TRM cells derive from IL-17A-producing effector (TH17) cells following immunization with heat-killed Klebsiella pneumonia (Kp). These exTH17 TRM cells are maintained in the lung by IL-7, produced by lymphatic endothelial cells. During a memory response, neither antibodies, γδ T cells, nor circulatory T cells are sufficient for the rapid host defense required to eliminate Kp. Conversely, using parabiosis and depletion studies, we demonstrated that exTH17 TRM cells play an important role in bacterial clearance. Thus, we delineate the origin and function of airway CD4 TRM cells during bacterial infection, offering novel strategies for targeted vaccine design.


Assuntos
Infecções por Klebsiella/imunologia , Células Th17/imunologia , Animais , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Toxina Diftérica/farmacologia , Modelos Animais de Doenças , Feminino , Memória Imunológica , Interleucina-17/genética , Interleucina-17/metabolismo , Infecções por Klebsiella/patologia , Klebsiella pneumoniae/imunologia , Klebsiella pneumoniae/patogenicidade , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Células Th17/citologia , Células Th17/metabolismo
2.
Immunity ; 48(1): 120-132.e8, 2018 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-29343433

RESUMO

Group 3 innate lymphoid cells (ILC3s) sense environmental signals and are critical for tissue integrity in the intestine. Yet, which signals are sensed and what receptors control ILC3 function remain poorly understood. Here, we show that ILC3s with a lymphoid-tissue-inducer (LTi) phenotype expressed G-protein-coupled receptor 183 (GPR183) and migrated to its oxysterol ligand 7α,25-hydroxycholesterol (7α,25-OHC). In mice lacking Gpr183 or 7α,25-OHC, ILC3s failed to localize to cryptopatches (CPs) and isolated lymphoid follicles (ILFs). Gpr183 deficiency in ILC3s caused a defect in CP and ILF formation in the colon, but not in the small intestine. Localized oxysterol production by fibroblastic stromal cells provided an essential signal for colonic lymphoid tissue development, and inflammation-induced increased oxysterol production caused colitis through GPR183-mediated cell recruitment. Our findings show that GPR183 promotes lymphoid organ development and indicate that oxysterol-GPR183-dependent positioning within tissues controls ILC3 activity and intestinal homeostasis.


Assuntos
Colite/metabolismo , Linfócitos/metabolismo , Tecido Linfoide/metabolismo , Oxisteróis/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Movimento Celular/genética , Colite/imunologia , Colite/patologia , Colo/imunologia , Colo/patologia , Citocinas/metabolismo , Citometria de Fluxo , Imunofluorescência , Ligantes , Linfócitos/patologia , Tecido Linfoide/patologia , Camundongos , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais
3.
Immunity ; 45(6): 1219-1231, 2016 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-27913094

RESUMO

Hematopoietic stem cells (HSCs) self-renew in bone marrow niches formed by mesenchymal progenitors and endothelial cells expressing the chemokine CXCL12, but whether a separate niche instructs multipotent progenitor (MPP) differentiation remains unclear. We show that MPPs resided in HSC niches, where they encountered lineage-instructive differentiation signals. Conditional deletion of the chemokine receptor CXCR4 in MPPs reduced differentiation into common lymphoid progenitors (CLPs), which decreased lymphopoiesis. CXCR4 was required for CLP positioning near Interleukin-7+ (IL-7) cells and for optimal IL-7 receptor signaling. IL-7+ cells expressed CXCL12 and the cytokine SCF, were mesenchymal progenitors capable of differentiation into osteoblasts and adipocytes, and comprised a minor subset of sinusoidal endothelial cells. Conditional Il7 deletion in mesenchymal progenitors reduced B-lineage committed CLPs, while conditional Cxcl12 or Scf deletion from IL-7+ cells reduced HSC and MPP numbers. Thus, HSC maintenance and multilineage differentiation are distinct cell lineage decisions that are both controlled by HSC niches.


Assuntos
Diferenciação Celular/fisiologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Multipotentes/citologia , Nicho de Células-Tronco/fisiologia , Animais , Linhagem da Célula/fisiologia , Separação Celular , Quimiocina CXCL2/metabolismo , Citometria de Fluxo , Interleucina-7/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
4.
Proc Natl Acad Sci U S A ; 119(49): e2123487119, 2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36454749

RESUMO

Hexanucleotide G4C2 repeat expansions in the C9orf72 gene are the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Dipeptide repeat proteins (DPRs) generated by translation of repeat-containing RNAs show toxic effects in vivo as well as in vitro and are key targets for therapeutic intervention. We generated human antibodies that bind DPRs with high affinity and specificity. Anti-GA antibodies engaged extra- and intra-cellular poly-GA and reduced aggregate formation in a poly-GA overexpressing human cell line. However, antibody treatment in human neuronal cultures synthesizing exogenous poly-GA resulted in the formation of large extracellular immune complexes and did not affect accumulation of intracellular poly-GA aggregates. Treatment with antibodies was also shown to directly alter the morphological and biochemical properties of poly-GA and to shift poly-GA/antibody complexes to more rapidly sedimenting ones. These alterations were not observed with poly-GP and have important implications for accurate measurement of poly-GA levels including the need to evaluate all centrifugation fractions and disrupt the interaction between treatment antibodies and poly-GA by denaturation. Targeting poly-GA and poly-GP in two mouse models expressing G4C2 repeats by systemic antibody delivery for up to 16 mo was well-tolerated and led to measurable brain penetration of antibodies. Long-term treatment with anti-GA antibodies produced improvement in an open-field movement test in aged C9orf72450 mice. However, chronic administration of anti-GA antibodies in AAV-(G4C2)149 mice was associated with increased levels of poly-GA detected by immunoassay and did not significantly reduce poly-GA aggregates or alleviate disease progression in this model.


Assuntos
Genes Reguladores , Poli A , Animais , Humanos , Camundongos , Complexo Antígeno-Anticorpo , Proteína C9orf72/genética , Dipeptídeos , Modelos Animais de Doenças
5.
Hematol Oncol ; 42(2): e3257, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38415859

RESUMO

Lymphomas are a heterogeneous group of diseases that originate from T, B or natural killer cells. Lymphoma treatment is based on chemotherapy, radiotherapy, and monoclonal antibody (mAb) or other immunotherapies. The P-selectin glycoprotein ligand 1 (PSGL-1) is expressed at the surface of hematological malignant cells and has been shown to have a pro-oncogenic role in multiple myeloma and lymphoma. Here, we investigated the expression and therapeutic potential of PSGL-1 in T and B cell lymphomas. By flow cytometry analysis, we found that PSGL-1 was expressed in both T and B cell-derived lymphoma cell lines but generally at higher levels in T cell lymphoma cell lines. For most T and B cell-derived lymphoma cell lines, in vitro targeting with the PL1 mAb, which recognizes the PSGL-1 N-terminal extracellular region and blocks functional interactions with selectins, resulted in reduced cell viability. The PL1 mAb pro-apoptotic activity was shown to be dose-dependent, to be linked to increased ERK kinase phosphorylation, and to be dependent on the MAP kinase signaling pathway. Importantly, anti-PSGL-1 treatment of mice xenografted with the HUT-78 cutaneous T-cell lymphoma cell line resulted in decreased tumor growth, had no effect on in vivo proliferation, but increased the levels of apoptosis in tumors. Anti-PSGL-1 treatment of mice xenografted with a Burkitt lymphoma cell line that was resistant to anti-PSGL-1 treatment in vitro, had no impact on tumorigenesis. These findings show that PSGL-1 antibody targeting triggers lymphoma cell apoptosis and substantiates PSGL-1 as a potential target for lymphoma therapy.


Assuntos
Linfoma Cutâneo de Células T , Neoplasias Cutâneas , Humanos , Animais , Camundongos , Selectina-P , Ligantes , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Apoptose , Carcinogênese
6.
Transpl Infect Dis ; 26(1): e14204, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38010722

RESUMO

BACKGROUND: Because COVID-19 has been associated with high lethality rates among kidney transplant recipients (KTR), but also with a severe disruption and delays in overall healthcare, this study aims to evaluate the excess mortality in the pandemic era among KTR in a high-volume Brazilian transplant center. METHODS: This study used data from a single center that provides follow-up on all its transplant recipients. The population of interest included all the patients who were transplanted between August 31, 1983 and December 31, 2022 and who were live from January 1, 2014. Using the "AutoRegressive Integrated Moving Average" forecasting algorithm, the expected mortality for the pandemic era (2020-2022) was modeled from the pre-pandemic era (2014-2019). RESULTS: There were 12 077 KTRs at risk of dying in the entire observation period. In the pre-pandemic era, there were 21 deaths per 1000 patients at risk. In the pandemic era, there were 1429 observed deaths (rate of 47 deaths per 1000 patients at risk) versus the expected 587 deaths, resulting in an absolute number of 842 excess deaths, or an observed-to-expected ratio of 2.4, or an absolute rate of 26 deaths in excess per 1000 patients at risk. The excess deaths exhibited a temporal pattern mirroring that of the surges in new cases and lethality rates of COVID-19. COVID-19-related deaths drove 94% of excess mortality in the pandemic era. CONCLUSION: In this large cohort of KTR under centralized follow-up, more than twofold excess mortality was primarily driven by COVID-19-related deaths, highlighting the vulnerability of this population to the most severe presentation of SARS-CoV-2 infection.


Assuntos
COVID-19 , Transplante de Rim , Humanos , Transplantados , Transplante de Rim/efeitos adversos , Pandemias , SARS-CoV-2 , Mortalidade
7.
J Oral Pathol Med ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745372

RESUMO

BACKGROUND: To assess the influence of diagnosis and referral provided by specialists in oral diagnosis on disease-free survival and overall survival of patients with oral cancer. METHODS: A cohort of 282 patients with oral cancer treated at a regional cancer hospital from 1998 to 2016 was analyzed retrospectively. The referral register of the patients was analyzed and assigned to two groups: (1) those referred by oral diagnosis specialists (n = 129), or (2) those referred by nonspecialized professionals (n = 153). The cancer treatment evolution was assessed from the patients' records, and the outcome was registered concerning cancer recurrence and death. Sociodemographic and clinicopathological variables were explored as predictors of disease-free survival and overall survival. RESULTS: Group 1 exhibited lower T stages and a reduced incidence of regional and distant metastases. Surgery was performed in 75.2% of cases in Group 1, while in Group 2, the rate was 60.8%. Advanced T stages and regional metastases reduced the feasibility of surgery. Higher TNM stages and tumor recurrence were associated with decreased disease-free survival, while surgical intervention was a protective factor. Higher TNM stage had a negative impact on the overall survival. CONCLUSION: Specialized oral diagnosis did not directly impact disease-free survival and overall survival and did not influence the indication of surgery in oral cancer; however, it was associated with the diagnosis of early tumors and better prognosis.

8.
Metab Brain Dis ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38836947

RESUMO

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease globally, with a fast-growing prevalence. The etiology of PD exhibits a multifactorial complex nature and remains challenging. Herein, we described clinical, molecular, and integrative bioinformatics findings from a Brazilian female affected by Early-Onset PD (EOPD) harboring a recurrent homozygous pathogenic deletion in the parkin RBR E3 ubiquitin protein ligase gene (PRKN; NM_004562.3:c.155delA; p.Asn52Metfs*29; rs754809877), along with a novel heterozygous variant in the synaptojanin 1 gene (SYNJ1; NM_003895.3:c.62G > T; p.Cys21Phe; rs1486511197) found by Whole Exome Sequencing. Uncommon or unreported PRKN-related clinical features in the patient include cognitive decline, auditory and visual hallucinations, REM sleep disorder, and depression, previously observed in SYNJ1-related conditions. Moreover, PRKN interacts with endophilin A1, which is a major binding partner of SYNJ1. This protein plays a pivotal role in regulating the dynamics of synaptic vesicles, particularly in the context of endocytosis and recycling processes. Altogether, our comprehensive analyses underscore a potential synergistic effect between the PRKN and SYNJ1 variants over the pathogenesis of EOPD.

9.
Mar Drugs ; 22(6)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38921565

RESUMO

The microalgae Chlorella vulgaris and Tetraselmis chui are valued for their nutrient-rich content, including lipids and polyunsaturated fatty acids (PUFA). However, little is known about how storage and processing affect their lipid quality. This study aimed to assess the impact of domestic storage and cooking practices in dried biomass of C. vulgaris and T. chui. Four conditions were tested: control (newly opened package), light (storage at room temperature and daily light regimen for three weeks), frozen (storage in the freezer at -20 °C for three weeks), and heated (three cycles of 90 min at 100 °C). Lipid extracts were analyzed by GC-MS and LC-MS, and antioxidant activity through DPPH and ABTS radical scavenging assays. Tested storage conditions promoted a decrease in fatty acid content and in diacyl/lyso lipid species ratios of phospholipid (PC/LPC, PE/LPE) and betaine lipids (DGTS/MGTS). Lipid extracts from light treatment showed the lowest antioxidant activity in C. vulgaris (ABTS, IC40: 104.9; DPPH, IC20: 187.9 ± 15.0), while heat affected the antioxidant activity of T. chui (ABTS, IC40: 88.5 ± 2.8; DPPH, IC20 209.4 ± 10.9). These findings underscore the impact of managing storage and processing conditions to optimize the nutritional and functional benefits of C. vulgaris and T. chui in food and feed applications.


Assuntos
Antioxidantes , Chlorella vulgaris , Microalgas , Antioxidantes/farmacologia , Chlorella vulgaris/química , Microalgas/química , Lipídeos , Armazenamento de Alimentos , Ácidos Graxos/análise , Culinária
10.
J Dairy Res ; 91(1): 89-95, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38372087

RESUMO

This research paper analyzes the stability of raw cow milk in the alcohol test and seeks to understand to know the factors that influence milk stability and the occurrence of unstable non-acid milk. Milk samples were collected from the cooling tanks of rural farmers in the state of Paraná twice in summer and twice in winter. The farms were classified according to the production system: pasture with supplementation and feedlot. The following variables were analyzed: stability in the alcohol test, titratable acidity, ionized calcium concentration (iCa), chemical composition of milk, somatic cell count and standard plate count. The results showed that milk stability was greater in winter vs. summer, when the milk contained higher iCa, and in the feedlot vs. pasture system. The Pearson Correlation between variables (ethanol stability, milk composition, iCa, cooling tank temperature, milk volume, number of milking, number of cows milked, fat/protein ratio, distance and travel time) were analyzed. Stability was negatively correlated with iCa concentration and positively with lactose content. Logistic regression of the risk of unstable non-acid milk at 72% alcohol (UNAM72) showed that only iCa and lactose were determinants, while evaluation of the same risk at 78% alcohol revealed iCa, titratable acidity, lactose and milk urea nitrogen as risk factors. Under the dairy farming conditions of Paraná state, the frequency of UNAM72 was low (12.16%) and was higher in summer and in pasture systems with supplementation. In conclusion, in dairy herds bred with high technological level, with adequate nutritional and health management, the frequency of UNAM is low and is related to nutritional management abnd, perhaps, heat stress, factors that alter iCa and lactose levels.


Assuntos
Indústria de Laticínios , Leite , Estações do Ano , Animais , Leite/química , Bovinos , Feminino , Indústria de Laticínios/métodos , Cálcio/análise , Lactose/análise , Etanol/análise , Concentração de Íons de Hidrogênio , Contagem de Células/veterinária
11.
Aust Crit Care ; 2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38649316

RESUMO

BACKGROUND: Patients with critical illness often survive the intensive care unit (ICU) at a cost of prolonged length of stay (LOS) and slow recovery. This chronic critically ill disease may lead to long-term poor outcomes, especially in older or frail patients. OBJECTIVES: The main goal of this study was to address the characteristics and outcomes of patients with prolonged ICU LOS. Mainly, short- and long-term admissions were compared to identify risk factors for persistent critical illness and to characterise the impact on ICU, hospital, and long-term mortality. METHODS: Subanalysis of a retrospective, multicentric, observational study addressing the 2-year outcome of patients admitted to Portuguese ICUs (the Cimba study). Patients were segregated according to an ICU LOS of ≥14 days. RESULTS: Data from 37 118 patients were analysed, featuring a median ICU LOS of 4 days (percentile: 25-75 2-9), and a mortality of 16.1% in the ICU, 24.0% in the hospital, and 38.7% after 2 years. A total of 5334 patients (14.4%) had an ICU LOS of ≥14 days (corresponding to 48.9% of all ICU patients/days). Patients with prolonged LOS were more often younger (52.8% vs 46.4%, were ≤65 years of age , p < 0.001), although more severe (Simplified Acute Physiology Score II: 49.1 ± 16.9 vs 41.8 ± 19.5, p < 0.001), and had higher ICU and hospital mortality (18.3% vs 15.7%, and 31.2 vs 22.8%, respectively). Prolonged ICU LOS was linked to an increased risk of dying during the 2-year follow-up (adjusted Cox proportional hazard: 1.65, p < 0.001). CONCLUSION: Prolonged LOS is associated with a long-term impact on patient prognosis. More careful planning of care should incorporate these data.

12.
J Am Chem Soc ; 145(16): 8764-8769, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37037457

RESUMO

Adsorption isotherms obtained through volumetric measurements are widely used to estimate the gas adsorption performance of porous materials. Nonetheless, there is always ambiguity regarding the contributions of chemi- and physisorption processes to the overall retained gas volume. In this work, we propose, for the first time, the use of solid-state NMR (ssNMR) to generate isotherms of CO2 adsorbed onto an amine-modified silica sorbent. This method enables the separation of six individual isotherms for chemi- and physisorbed CO2 components, a feat only possible using the discrimination power of NMR spectroscopy. The adsorption mechanism for each adsorbed species was ascertained by tracking their adsorption profiles at various pressures. The proposed method was validated against conventional volumetric adsorption measurements. The isotherm curves obtained by the proposed ssNMR-assisted approach enable advanced analysis of the sorbents, revealing the potential of variable-pressure NMR experiments in gas adsorption applications.

13.
BMC Pulm Med ; 23(1): 406, 2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37884922

RESUMO

BACKGROUND: Lung function analysis in Parkinson's disease (PD) is often difficult due to the demand for adequate forced expiratory maneuvers. Respiratory oscillometry exams require onlyquiet tidal breathing and provide a detailed analysis of respiratory mechanics. We hypothesized that oscillometry would simplify the diagnosis of respiratory abnormalitiesin PD and improve our knowledge about the pathophysiological changes in these patients. MATERIALS AND METHODS: This observational study includes 20 controls and 47 individuals with PD divided into three groups (Hoehn and Yahr Scale 1-1.5; H&Y scale 2-3 and PD smokers).The diagnostic accuracy was evaluated by investigating the area under the receiver operating characteristic curve (AUC). RESULTS: Initial stages are related to increased peripheral resistance (Rp; p = 0.001). In more advanced stages, a restrictive pattern is added, reflected by reductions in dynamic compliance (p < 0.05) and increase in resonance frequency (Fr; p < 0.001). Smoking PD patients presented increased Rp (p < 0.001) and Fr (p < 0.01). PD does not introduce changes in the central airways. Oscillometric changes were correlated with respiratory muscle weakness (R = 0.37, p = 0.02). Rp showed adequate accuracy in the detection of early respiratory abnormalities (AUC = 0.858), while in more advanced stages, Fr showed high diagnostic accuracy (AUC = 0.948). The best parameter to identify changes in smoking patients was Rp (AUC = 0.896). CONCLUSION: The initial stages of PD are related to a reduction in ventilation homogeneity associated with changes in peripheral airways. More advanced stages also include a restrictive ventilatory pattern. These changes were correlated with respiratory muscle weakness and were observed in mild and moderate stages of PD in smokers and non-smokers. Oscillometry may adequately identify respiratory changes in the early stages of PD and obtain high diagnostic accuracy in more advanced stages of the disease.


Assuntos
Doença de Parkinson , Transtornos Respiratórios , Humanos , Oscilometria , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico , Espirometria , Pulmão , Mecânica Respiratória
14.
Eur Heart J ; 43(16): 1569-1577, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35139537

RESUMO

AIMS: Current risk scores do not accurately identify patients at highest risk of recurrent atherosclerotic cardiovascular disease (ASCVD) in need of more intensive therapeutic interventions. Advances in high-throughput plasma proteomics, analysed with machine learning techniques, may offer new opportunities to further improve risk stratification in these patients. METHODS AND RESULTS: Targeted plasma proteomics was performed in two secondary prevention cohorts: the Second Manifestations of ARTerial disease (SMART) cohort (n = 870) and the Athero-Express cohort (n = 700). The primary outcome was recurrent ASCVD (acute myocardial infarction, ischaemic stroke, and cardiovascular death). Machine learning techniques with extreme gradient boosting were used to construct a protein model in the derivation cohort (SMART), which was validated in the Athero-Express cohort and compared with a clinical risk model. Pathway analysis was performed to identify specific pathways in high and low C-reactive protein (CRP) patient subsets. The protein model outperformed the clinical model in both the derivation cohort [area under the curve (AUC): 0.810 vs. 0.750; P < 0.001] and validation cohort (AUC: 0.801 vs. 0.765; P < 0.001), provided significant net reclassification improvement (0.173 in validation cohort) and was well calibrated. In contrast to a clear interleukin-6 signal in high CRP patients, neutrophil-signalling-related proteins were associated with recurrent ASCVD in low CRP patients. CONCLUSION: A proteome-based risk model is superior to a clinical risk model in predicting recurrent ASCVD events. Neutrophil-related pathways were found in low CRP patients, implying the presence of a residual inflammatory risk beyond traditional NLRP3 pathways. The observed net reclassification improvement illustrates the potential of proteomics when incorporated in a tailored therapeutic approach in secondary prevention patients.


Assuntos
Aterosclerose , Isquemia Encefálica , Doenças Cardiovasculares , Acidente Vascular Cerebral , Proteína C-Reativa/análise , Doenças Cardiovasculares/prevenção & controle , Fatores de Risco de Doenças Cardíacas , Humanos , Proteômica , Medição de Risco/métodos , Fatores de Risco , Prevenção Secundária
15.
Sensors (Basel) ; 23(23)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38067936

RESUMO

This paper explores the opportunities and challenges for classifying human posture in indoor scenarios by analyzing the Frequency-Modulated (FM) radio broadcasting signal received at multiple locations. More specifically, we present a passive RF testbed operating in FM radio bands, which allows experimentation with innovative human posture classification techniques. After introducing the details of the proposed testbed, we describe a simple methodology to detect and classify human posture. The methodology includes a detailed study of feature engineering and the assumption of three traditional classification techniques. The implementation of the proposed methodology in software-defined radio devices allows an evaluation of the testbed's capability to classify human posture in real time. The evaluation results presented in this paper confirm that the accuracy of the classification can be approximately 90%, showing the effectiveness of the proposed testbed and its potential to support the development of future innovative classification techniques by only sensing FM bands in a passive mode.


Assuntos
Postura , Humanos , Previsões
16.
Sensors (Basel) ; 23(19)2023 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-37837057

RESUMO

Everyday tasks use sensors to monitor and provide information about processes in different scenarios, such as monitoring devices in manufacturing or homes. Sensors need to communicate, with or without wires, while providing secure information. Power can be derived from various energy sources, such as batteries, electrical power grids, and energy harvesting. Energy harvesting is a promising way to provide a sustainable and renewable source to power sensors by scavenging and converting energy from ambient energy sources. However, low energy is harvested through these methods. Therefore, it is becoming a challenge to design and deploy wireless sensor networks while ensuring the sensors have enough power to perform their tasks and communicate with each other through careful management and optimization, matching energy supply with demand. For this reason, data cryptography and authentication are needed to protect sensor communication. This paper studies how energy harvested with microbial fuel cells can be employed in algorithms used in data protection during sensor communication.


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Fontes Geradoras de Energia , Redes de Comunicação de Computadores , Algoritmos
17.
Sensors (Basel) ; 23(21)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37960484

RESUMO

The finite element method (FEM) was used to investigate the optical-mechanical behavior of a Fabry-Perot Interferometer (FPI) composed of a capillary segment spliced between two sections of standard optical fiber. The developed FEM model was validated by comparing it with theory and with previously published experimental data. The model was then used to show that the absolute strain on the host substrate is usually smaller than the strain measurement obtained with the sensor. Finally, the FEM model was used to propose a cavity geometry that can be produced with repeatability and that yields the correct absolute strain experienced by the host substrate, without requiring previous strain calibration.

18.
Molecules ; 28(5)2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36903471

RESUMO

In 2021, our research group published the prominent anticancer activity achieved through the successful combination of two redox centres (ortho-quinone/para-quinone or quinone/selenium-containing triazole) through a copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The combination of two naphthoquinoidal substrates towards a synergetic product was indicated, but not fully explored. Herein, we report the synthesis of 15 new quinone-based derivatives prepared from click chemistry reactions and their subsequent evaluation against nine cancer cell lines and the murine fibroblast line L929. Our strategy was based on the modification of the A-ring of para-naphthoquinones and subsequent conjugation with different ortho-quinoidal moieties. As anticipated, our study identified several compounds with IC50 values below 0.5 µM in tumour cell lines. Some of the compounds described here also exhibited an excellent selectivity index and low cytotoxicity on L929, the control cell line. The antitumour evaluation of the compounds separately and in their conjugated form proved that the activity is strongly enhanced in the derivatives containing two redox centres. Thus, our study confirms the efficiency of using A-ring functionalized para-quinones coupled with ortho-quinones to obtain a diverse range of two redox centre compounds with potential applications against cancer cell lines. Here as well, it literally takes two for an efficient tango!


Assuntos
Naftoquinonas , Quinonas , Animais , Camundongos , Quinonas/química , Benzoquinonas , Naftoquinonas/química , Oxirredução , Química Click , Reação de Cicloadição
19.
Immunol Rev ; 289(1): 142-157, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30977190

RESUMO

Studies over the last decade uncovered overlapping niches for hematopoietic stem cells (HSCs), multipotent progenitor cells, common lymphoid progenitors, and early B cell progenitors. HSC and lymphoid niches are predominantly composed by mesenchymal progenitor cells (MPCs) and by a small subset of endothelial cells. Niche cells create specialized microenvironments through the concomitant production of short-range acting cell-fate determining cytokines such as interleukin (IL)-7 and stem cell factor and the potent chemoattractant C-X-C motif chemokine ligand 12. This type of cellular organization allows for the cross-talk between hematopoietic stem and progenitor cells with niche cells, such that niche cell activity can be regulated by the quality and quantity of hematopoietic progenitors being produced. For example, preleukemic B cell progenitors and preB acute lymphoblastic leukemias interact directly with MPCs, and downregulate IL-7 expression and the production of non-leukemic lymphoid cells. In this review, we discuss a novel model of B cell development that is centered on cellular circuits formed between B cell progenitors and lymphopoietic niches.


Assuntos
Linfócitos B/fisiologia , Quimiocina CXCL12/metabolismo , Células Endoteliais/fisiologia , Células-Tronco Hematopoéticas/fisiologia , Células-Tronco Mesenquimais/fisiologia , Animais , Diferenciação Celular , Microambiente Celular , Humanos , Interleucina-7/metabolismo , Linfopoese , Nicho de Células-Tronco
20.
Opt Express ; 30(12): 20605-20613, 2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-36224801

RESUMO

Electrical corona discharge is employed in this work to deposit ions on the surface of an optical fiber, creating a strong electric field that is used for poling. Green laser light propagating in the core frees photocarriers that are displaced by the poling field. The technique presented can induce a higher optical nonlinearity than previously obtained in traditional optical poling with internal metal electrodes. To date, a maximum second order nonlinearity 0.13 pm/V has been achieved for a 15 kV corona discharge bias.

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