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Brain rhythms provide the timing for recruitment of brain activity required for linking together neuronal ensembles engaged in specific tasks. The γ-oscillations (30 to 120 Hz) orchestrate neuronal circuits underlying cognitive processes and working memory. These oscillations are reduced in numerous neurological and psychiatric disorders, including early cognitive decline in Alzheimer's disease (AD). Here, we report on a potent brain-permeable small molecule, DDL-920 that increases γ-oscillations and improves cognition/memory in a mouse model of AD, thus showing promise as a class of therapeutics for AD. We employed anatomical, in vitro and in vivo electrophysiological, and behavioral methods to examine the effects of our lead therapeutic candidate small molecule. As a novel in central nervous system pharmacotherapy, our lead molecule acts as a potent, efficacious, and selective negative allosteric modulator of the γ-aminobutyric acid type A receptors most likely assembled from α1ß2δ subunits. These receptors, identified through anatomical and pharmacological means, underlie the tonic inhibition of parvalbumin (PV) expressing interneurons (PV+INs) critically involved in the generation of γ-oscillations. When orally administered twice daily for 2 wk, DDL-920 restored the cognitive/memory impairments of 3- to 4-mo-old AD model mice as measured by their performance in the Barnes maze. Our approach is unique as it is meant to enhance cognitive performance and working memory in a state-dependent manner by engaging and amplifying the brain's endogenous γ-oscillations through enhancing the function of PV+INs.
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Doença de Alzheimer , Cognição , Modelos Animais de Doenças , Ritmo Gama , Animais , Doença de Alzheimer/tratamento farmacológico , Camundongos , Cognição/efeitos dos fármacos , Ritmo Gama/efeitos dos fármacos , Memória/efeitos dos fármacos , Receptores de GABA-A/metabolismo , Camundongos Transgênicos , Humanos , Masculino , Memória de Curto Prazo/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Alanina/análogos & derivados , AzepinasRESUMO
The initial colonization of the Americas remains a highly debated topic1, and the exact timing of the first arrivals is unknown. The earliest archaeological record of Mexico-which holds a key geographical position in the Americas-is poorly known and understudied. Historically, the region has remained on the periphery of research focused on the first American populations2. However, recent investigations provide reliable evidence of a human presence in the northwest region of Mexico3,4, the Chiapas Highlands5, Central Mexico6 and the Caribbean coast7-9 during the Late Pleistocene and Early Holocene epochs. Here we present results of recent excavations at Chiquihuite Cave-a high-altitude site in central-northern Mexico-that corroborate previous findings in the Americas10-17of cultural evidence that dates to the Last Glacial Maximum (26,500-19,000 years ago)18, and which push back dates for human dispersal to the region possibly as early as 33,000-31,000 years ago. The site yielded about 1,900 stone artefacts within a 3-m-deep stratified sequence, revealing a previously unknown lithic industry that underwent only minor changes over millennia. More than 50 radiocarbon and luminescence dates provide chronological control, and genetic, palaeoenvironmental and chemical data document the changing environments in which the occupants lived. Our results provide new evidence for the antiquity of humans in the Americas, illustrate the cultural diversity of the earliest dispersal groups (which predate those of the Clovis culture) and open new directions of research.
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Migração Humana/história , Camada de Gelo , Altitude , Arqueologia , Teorema de Bayes , Cavernas , Diversidade Cultural , DNA Antigo/análise , História Antiga , Humanos , MéxicoRESUMO
Avoiding microbial contamination and biofilm formation on the surfaces of aircraft fuel tanks is a major challenge in the aviation industry. The inevitable presence of water in fuel systems and nutrients provided by the fuel makes an ideal environment for bacteria, fungi, and yeast to grow. Understanding how microbes grow on different fuel tank materials is the first step to control biofilm formation in aviation fuel systems. In this study, biofilms of Pseudomonas putida, a model Gram-negative bacterium previously found in aircraft fuel tanks, were characterized on aluminum 7075-T6 surfaces, which is an alloy used by the aviation industry due to favorable properties including high strength and fatigue resistance. Scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX) showed that extracellular polymeric substances (EPS) produced by P. putida were important components of biofilms with a likely role in biofilm stability and adhesion to the surfaces. EDX analysis showed that the proportion of phosphorus with respect to nitrogen is higher in the EPS than in the bacterial cells. Additionally, different morphologies in biofilm formation were observed in the fuel phase compared to the water phase. Micro-Fourier transform infrared spectroscopy (micro-FTIR) analysis suggested that phosphoryl and carboxyl functional groups are fundamental for the irreversible attachment between the EPS of bacteria and the aluminum surface, by the formation of hydrogen bonds and inner-sphere complexes between the macromolecules and the aluminum surface. Based on the hypothesis that nucleic acids (particularly DNA) are an important component of EPS in P. putida biofilms, the impact of degrading extracellular DNA was tested. Treatment with the enzyme DNase I affected both water and fuel phase biofilmsâwith the cell structure disrupted in the aqueous phase, but cells remained attached to the aluminum coupons.
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Low-grade gliomas are primary brain tumors that arise from glial cells and are usually treated with temozolomide (TMZ) as a chemotherapeutic option. They are often incurable, but patients have a prolonged survival. One of the shortcomings of the treatment is that patients eventually develop drug resistance. Recent findings show that persisters, cells that enter a dormancy state to resist treatment, play an important role in the development of resistance to TMZ. In this study we constructed a mathematical model of low-grade glioma response to TMZ incorporating a persister population. The model was able to describe the volumetric longitudinal dynamics, observed in routine FLAIR 3D sequences, of low-grade glioma patients acquiring TMZ resistance. We used the model to explore different TMZ administration protocols, first on virtual clones of real patients and afterwards on virtual patients preserving the relationships between parameters of real patients. In silico clinical trials showed that resistance development was deferred by protocols in which individual doses are administered after rest periods, rather than the 28-days cycle standard protocol. This led to median survival gains in virtual patients of more than 15 months when using resting periods between two and three weeks and agreed with recent experimental observations in animal models. Additionally, we tested adaptive variations of these new protocols, what showed a potential reduction in toxicity, but no survival gain. Our computational results highlight the need of further clinical trials that could obtain better results from treatment with TMZ in low grade gliomas.
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Neoplasias Encefálicas , Glioma , Humanos , Antineoplásicos Alquilantes/farmacologia , Antineoplásicos Alquilantes/uso terapêutico , Dacarbazina/efeitos adversos , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Glioma/tratamento farmacológico , Glioma/patologia , Temozolomida/farmacologia , Temozolomida/uso terapêuticoRESUMO
This study aimed to compare performance, kinematic, and physiological variables between open water and pool swimming conditions in elite triathletes and to examine the associations between conditions on these variables. Fourteen elite triathletes (10 males and 4 females [23.4 ± 3.8 years]) performed two 1500-m swimming tests in open water and in a 25-m pool. Swimming speed, stroke rate (SR), length (SL) and index (SI), heart rate (HR), blood lactate concentrations [La-], and end-exercise oxygen uptake (EEVÌO2) were assessed in both conditions. Lower SL and SI and higher SR were obtained in open water compared with pool swimming (p < 0.05). Moreover, kinematic variables changed as a function of distance in both conditions (p < 0.05). No differences were found in the main physiological variables (HR, [La-], and EEVÌO2) between conditions. Respiratory exchange ratio presented lower values in open water than in pool conditions (p < 0.05), while time constant was higher in open water (p = 0.032). The fastest triathletes in open water obtained the best performance in the pool (r = 0.958; p < 0.001). All kinematic variables, HR and peak [La-] presented positive associations between conditions (r > 0.6; p < 0.05). Despite physiological invariance, triathletes and coaches should monitor specific open water training to adapt their swimming technique to the competitive environment.
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Desempenho Atlético , Frequência Cardíaca , Ácido Láctico , Consumo de Oxigênio , Natação , Água , Humanos , Natação/fisiologia , Masculino , Feminino , Desempenho Atlético/fisiologia , Frequência Cardíaca/fisiologia , Adulto Jovem , Consumo de Oxigênio/fisiologia , Adulto , Ácido Láctico/sangue , Fenômenos Biomecânicos , PiscinasRESUMO
This study aimed to determine the prevalence of V. parahaemolyticus in oysters from the northwestern coast of Mexico and to identify the serotypes, virulence factors, and antibiotic resistance of the strains. Oyster samples were collected from 2012 to 2020 from the northwest coast of Mexico; biochemical and molecular methods were used to identify V. parahaemolyticus from oysters; antiserum reaction to determine V. parahaemolyticus serotypes, and PCR assays were performed to identify pathogenic (tdh and/or trh) or pandemic (toxRS/new, and/or orf8) strains and antibiotic resistance testing. A total of 441 oyster samples were collected and tested for V. parahaemolyticus. Forty-seven percent of oyster samples were positive for V. parahaemolyticus. Ten different O serogroups and 72 serovars were identified, predominantly serotype O1:KUT with 22.2% and OUT:KUT with 17.3%. Twenty new serotypes that had not been previously reported in our region were identified. We detected 4.3% of pathogenic clones but no pandemic strains. About 73.5% of strains were resistant to at least one antibiotic, mainly ampicillin and ciprofloxacin; 25% were multi-drug resistant. In conclusion, the pathogenic strains in oysters and antibiotic resistance are of public health concern, as the potential for outbreaks throughout northwestern Mexico is well established.
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Antibacterianos , Ostreidae , Frutos do Mar , Vibrio parahaemolyticus , Fatores de Virulência , Animais , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/efeitos dos fármacos , Vibrio parahaemolyticus/isolamento & purificação , México/epidemiologia , Ostreidae/microbiologia , Fatores de Virulência/genética , Antibacterianos/farmacologia , Frutos do Mar/microbiologia , Farmacorresistência Bacteriana , Sorogrupo , Virulência/genética , Testes de Sensibilidade MicrobianaRESUMO
Human cancers are biologically and morphologically heterogeneous. A variety of clonal populations emerge within these neoplasms and their interaction leads to complex spatiotemporal dynamics during tumor growth. We studied the reshaping of metabolic activity in human cancers by means of continuous and discrete mathematical models and matched the results to positron emission tomography (PET) imaging data. Our models revealed that the location of increasingly active proliferative cellular spots progressively drifted from the center of the tumor to the periphery, as a result of the competition between gradually more aggressive phenotypes. This computational finding led to the development of a metric, normalized distance from 18F-fluorodeoxyglucose (18F-FDG) hotspot to centroid (NHOC), based on the separation from the location of the activity (proliferation) hotspot to the tumor centroid. The NHOC metric can be computed for patients using 18F-FDG PET-computed tomography (PET/CT) images where the voxel of maximum uptake (standardized uptake value [SUV]max) is taken as the activity hotspot. Two datasets of 18F-FDG PET/CT images were collected, one from 61 breast cancer patients and another from 161 non-small-cell lung cancer patients. In both cohorts, survival analyses were carried out for the NHOC and for other classical PET/CT-based biomarkers, finding that the former had a high prognostic value, outperforming the latter. In summary, our work offers additional insights into the evolutionary mechanisms behind tumor progression, provides a different PET/CT-based biomarker, and reveals that an activity hotspot closer to the tumor periphery is associated to a worst patient outcome.
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Neoplasias da Mama/diagnóstico , Carcinogênese/genética , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Modelos Teóricos , Adulto , Idoso , Biomarcadores Tumorais/genética , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células/genética , Feminino , Fluordesoxiglucose F18/farmacologia , Heterogeneidade Genética/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons/métodos , PrognósticoRESUMO
This study aimed (i) to analyze the 1500 m open water swimming performance, (ii) to examine the associations between physiological and biomechanical variables with swimming performance, and (iii) to determine which variables can predict swimming performance in triathletes. Fourteen elite triathletes (23.4±3.8 y) performed a 1500 m test in open water swimming conditions. Swimming performance was assessed using World Aquatics Points Scoring, and data were obtained from the 1500 m open water swimming test. Heart rate, end-exercise oxygen uptake (EEËVO2) and blood lactate concentrations were measured. The initial 250 m of the 1500 m swimming test presented the highest values of biomechanical variables in males (i. e. swimming speed, stroke rate (SR), length (SL), index (SI)). A decrease in SL was observed in the last 250 m in both sexes. Positive association were found between EEËVO2 (r=0.513; p=0.030), swimming speed (r=0.873; p<0.001) and SI (r=0.704; p=0.002) with swimming performance. In contrast, time constant of the oxygen uptake (r=-0.500; p=0.034) and buoy-turn times (r=-0.525; p=0.027) were negatively associated with performance. SI was the main predictor (R 2=0.495) of open water swimming performance in triathletes. In conclusion, triathletes and coaches must conduct open water training sessions to maximize SI (i. e. swimming efficiency).
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Desempenho Atlético , Frequência Cardíaca , Ácido Láctico , Consumo de Oxigênio , Natação , Humanos , Natação/fisiologia , Masculino , Consumo de Oxigênio/fisiologia , Desempenho Atlético/fisiologia , Adulto Jovem , Ácido Láctico/sangue , Frequência Cardíaca/fisiologia , Fenômenos Biomecânicos , Feminino , Adulto , Teste de EsforçoRESUMO
Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 2016) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 2016). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.
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Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia , Zika virus/isolamento & purificação , América/epidemiologia , Número Básico de Reprodução , Brasil/epidemiologia , Variação Genética , Genoma Viral/genética , Humanos , Microcefalia/epidemiologia , Microcefalia/virologia , Epidemiologia Molecular , Filogeografia , Análise Espaço-Temporal , Zika virus/genética , Infecção por Zika virus/epidemiologiaRESUMO
OBJECTIVE: Among service members (SMs) with mild traumatic brain injury (mTBI) admitted to an intensive outpatient program (IOP), we identified qualitatively distinct subgroups based on post-concussive symptoms (PCSs) and characterized changes between subgroups from admission to discharge. Further, we examined whether co-morbid posttraumatic stress disorder (PTSD) influenced changes between subgroups. DESIGN: Quasi-experimental. Latent transition analysis identified distinctive subgroups of SMs and examined transitions between subgroups from admission to discharge. Logistic regression examined the effect of PTSD on transition to the Minimal subgroup (low probability of any moderate-very severe PCS) while adjusting for admission subgroup designation. SETTING: National Intrepid Center of Excellence (NICoE) at Walter Reed National Military Medical Center. PARTICIPANTS: 1141 active duty SMs with persistent PCS despite prior treatment (N=1141). INTERVENTIONS: NICoE 4-week interdisciplinary IOP. MAIN OUTCOME MEASURE(S): Subgroups identified using Neurobehavioral Symptom Inventory items at admission and discharge. RESULTS: Model fit indices supported a 7-class solution. The 7 subgroups of SMs were distinguished by diverging patterns of probability for specific PCS. The Minimal subgroup was most prevalent at discharge (39.4%), followed by the Sleep subgroup (high probability of sleep problems, low probability of other PCS; 26.8%). 41% and 25% of SMs admitted within the Affective (ie, predominantly affective PCS) and Sleep subgroups remained within the same group at discharge, respectively. The 19% of SMs with co-morbid PTSD were less likely to transition to the Minimal subgroup (odds ratio=0.28; P<.001) and were more likely to remain in their admission subgroup at discharge (35.5% with PTSD vs 22.2% without). CONCLUSIONS: Most of SMs achieved symptom resolution after participation in the IOP, with most transitioning to subgroups characterized by reduced symptom burden. SMs admitted in the Affective and Sleep subgroups, as well as those with PTSD, were most likely to have continuing clinical needs at discharge, revealing priority targets for resource allocation and follow-up treatment.
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Concussão Encefálica , Lesões Encefálicas Traumáticas , Militares , Síndrome Pós-Concussão , Transtornos de Estresse Pós-Traumáticos , Humanos , Síndrome Pós-Concussão/psicologia , Concussão Encefálica/diagnóstico , Pacientes Ambulatoriais , Militares/psicologia , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Lesões Encefálicas Traumáticas/psicologiaRESUMO
This research aimed to evaluate the antimicrobial activity of essential oils (EOs) against clinically and environmentally isolated Salmonella serotypes. Oregano, thyme, and grapefruit EO compounds were identified, and the antimicrobial activity was evaluated against the S. Saintpaul, Oranienburg, and Infantis serotypes. In addition, molecular docking was performed to explore the possible mechanisms between compounds of EOs with microbial enzymes. Thymol was the main compound identified in oregano (44.0%) and thyme (31%) EOs, while d-limonene was present in a greater proportion in grapefruit EO. Oregano EO had the highest antimicrobial activity, followed by thyme and grapefruit EOs. Oregano and thyme EOs illustrated a greater inhibitory capacity to all serotypes, particularly with the environmental S. Saintpaul. Oregano EO presented values of minimum inhibitory concentration (MIC) and minimum bactericidal concentration of 0.1 µL/mL for all serotypes, while thyme and grapefruit EOs presented MIC values of 0.1 µL/mL for the clinical serotypes S. Infantis and S. Oranienburg, respectively. Molecular docking analysis showed the optimal binding free energies for thymol and carvacrol with glucokinase, ATP-dependent-6-fructokinase, outer membrane porin C, and topoisomerase IV. Our results indicate that these EOs can inhibit clinically and environmentally isolated Salmonella serotypes and can be used as alternatives for developing natural food preservatives.
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Anti-Infecciosos , Óleos Voláteis , Salmonella enterica , Thymus (Planta) , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Óleos de Plantas/farmacologia , Timol/farmacologia , Simulação de Acoplamento Molecular , Sorogrupo , Testes de Sensibilidade Microbiana , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Thymus (Planta)/químicaRESUMO
Leishmania mexicana is one of the causal agents of cutaneous leishmaniasis. Current antileishmanial chemotherapeutics have demonstrated adverse side effects; thus, alternative treatments are needed. In this study, we performed in silico and in vitro analyses of the leishmanicidal potential of the most abundant phenolic compounds identified in black sesame sprouts biostimulated with Bacillus clausii. The molecular docking analysis showed strong interactions (binding free energies between -6.5 and -9.5 kcal/mol) of sesaminol 2-O-triglucoside, pinoresinol dihexoside, isoverbascoside, and apigenin with the arginase, leishmanolysin, cysteine peptidase B, and pyruvate kinase leishmanial enzymes. Furthermore, almost all phenolic compounds interacted with the active site residues of L. mexicana enzymes. In vitro, the B. clausii-biostimulated sprout phenolic extracts and apigenin inhibited the growth of promastigotes with IC50 values of 0.08 mg gallic acid equivalent/mL and 6.42 µM (0.0017 mg/mL), respectively. Additionally, in the macrophage infection model, cells treated with B. clausii-biostimulated sprout phenolic extracts and infected with L. mexicana exhibited significantly (P < 0.05) reduced nitric oxide production and decreased parasite burden. Altogether, our study provides important data related to high efficacy and less toxic natural antileishmanial candidates against promastigotes of L. mexicana.
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Antiprotozoários , Leishmania mexicana , Leishmaniose Cutânea , Sesamum , Animais , Camundongos , Simulação de Acoplamento Molecular , Apigenina/farmacologia , Apigenina/uso terapêutico , Leishmaniose Cutânea/tratamento farmacológico , Antiprotozoários/farmacologia , Camundongos Endogâmicos BALB CRESUMO
Many of the studies on the sex ratio at birth (SRB) are based on a small number of cases over a short period of time. Taking a multivariate approach to a dataset consisting of nearly 199 million birth records in the United States from 1968 to 2019, we present a detailed analysis of several possible factors that might affect the sex ratio at birth (SRB) and its patterns of variation. We found that race/ethnicity is the variable with the strongest influence on this index. Parental age, birth order and solar radiation also have a bearing on the SRB, albeit only to a moderate degree. The historical evolution of the SRB among Black and American Indian and Alaska Native populations remains unexplained.
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Our aim was to establish the determinants explaining the wetsuit advantages in middle-distance swimming efforts. Thirty-one triathletes and open water swimmers performed two 400 m front crawl bouts in a 25 m swimming pool with swim and wetsuits (with 48 h rest in-between). Anthropometric, kinematic and physiological variables were measured and Pearson correlation coefficients and stepwise linear regression analysis were used to determine their relationships. Associations observed in the 400 m front crawl included time improved using wetsuit with swimmers age (r=0.38; p=0.017), cross-sectional area (r=0.33; p=0.034), wetsuit upper limbs thickness (r=-0.49; p=0.010), ΔInternational Swimming Federation Points (r=-0.39;p=0.016), Δstroke rate (SR, r=0.48; p=0.003), Δstroke length (SL, r=-0.39; p=0.015), Δpropelling efficiency (r=-0.37; p=0.019) and Δblood lactate concentrations (r=0.30; p=0.048) in the total sample. In females, associations were found between the time improved and wetsuit upper and lower limbs thickness (both r=-0.78; p=0.011), and in males associations were found between time improved and age (r=0.43; p=0.030), ΔSR (r=0.56; p=0.005) and ΔSL (r=-0.44; p=0.026). Furthermore, 48% of the 400 m front crawl time improved was explained by wetsuit upper limbs thickness and SR changes (total sample), 62% explained by the wetsuit lower limbs thickness (females) and 48% of this enhancement was related to age and SR changes (males). Therefore, faster upper and lower limbs actions and wetsuit upper and lower limbs thickness are beneficial for 400 m front crawl performance improvement.
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Natação , Extremidade Superior , Humanos , Masculino , Feminino , Natação/fisiologia , Fenômenos Biomecânicos , Análise de Regressão , AntropometriaRESUMO
This research presents a simple method to additively manufacture Cone 5 porcelain clay ceramics by using the direct ink-write (DIW) printing technique. DIW has allowed the application of extruding highly viscous ceramic materials with relatively high-quality and good mechanical properties, which additionally allows a freedom of design and the capability of manufacturing complex geometrical shapes. Clay particles were mixed with deionized (DI) water at different ratios, where the most suitable composition for 3D printing was observed at a 1:5 w/c ratio (16.2 wt.%. of DI water). Differential geometrical designs were printed to demonstrate the printing capabilities of the paste. In addition, a clay structure was fabricated with an embedded wireless temperature and relative humidity (RH) sensor during the 3D printing process. The embedded sensor read up to 65% RH and temperatures of up to 85 °F from a maximum distance of 141.7 m. The structural integrity of the selected 3D printed geometries was confirmed through the compressive strength of fired and non-fired clay samples, with strengths of 70 MPa and 90 MPa, respectively. This research demonstrates the feasibility of using the DIW printing of porcelain clay with embedded sensors, with fully functional temperature- and humidity-sensing capabilities.
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Molecular techniques are an alternative for the diagnosis of strongyloidiasis, produced by Strongyloides stercoralis. However, it is necessary to determine the best amplification target for the populations of this parasite present in a geographical area and standardize a polymerase chain reaction (PCR) protocol for its detection. The objectives of this work were the comparison of different PCR targets for molecular detection of S. stercoralis and the standardization of a PCR protocol for the selected target with the best diagnostic results. DNA extraction was performed from parasite larvae by saline precipitation. Three amplification targets of the genes encoding ribosomal RNA 18S (18S rDNA) and 5.8S (5.8S rDNA) and cytochrome oxidase 1 (COX1) of S. stercoralis were compared, and the PCR reaction conditions for the best target were standardized (concentration of reagents and template DNA, hybridization temperature, and number of cycles). The analytical sensitivity and specificity of the technique were determined. DNA extraction by saline precipitation made it possible to obtain DNA of high purity and integrity. The ideal target was the 5.8S rDNA, since the 18S rDNA yielded non-reproducible results and COX1 never amplified under any condition tested. The optimal conditions for the 5.8S rDNA-PCR were: 1.5 mM MgCl2, 100 µM dNTPs, 0.4 µM primers, and 0.75 U DNA polymerase, using 35 cycles and a hybridization temperature of 60 °C. The analytical sensitivity of the PCR was 1 attogram of DNA, and the specificity was 100%. Consequently, the 5.8S rDNA was shown to be highly sensitive and specific for the detection of S. stercoralis DNA.
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Strongyloides stercoralis , Estrongiloidíase , Animais , Strongyloides stercoralis/genética , Estrongiloidíase/diagnóstico , Estrongiloidíase/parasitologia , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 18S/genética , DNA Ribossômico/genética , Fezes/parasitologiaRESUMO
Photonic crystals can be engineered so that the flow of optical power and the phase of the field are independently controlled. The concept is demonstrated by creating a self-collimating lattice with an embedded cylindrical lens. The device is fabricated in a photopolymer by multi-photon lithography with the lattice spacing chosen for operation around the telecom wavelength of 1550 nm. The lattice is based on a low-symmetry rod-in-wall unit cell that strongly self-collimates light. The walls are varied in thickness to modulate the effective refractive index so light acquires a spatially quadratic phase profile as it propagates through the device. Although the phase of the field is altered, the light does not focus within the device because self-collimation forces power to flow parallel to the principal axes of the lattice. Upon exiting the device, ordinary propagation resumes in free space and the curved phase profile causes the light to focus. An analysis of the experimentally observed optical behavior shows that the device behaves like a thin lens, even though the device is considerably thick.
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OBJECTIVE: The purpose of this study was to evaluate the prognostic value of novel geometric variables obtained from pre-treatment [18F]FDG PET/CT with respect to classical ones in patients with non-small cell lung cancer (NSCLC). METHODS: Retrospective study including stage I-III NSCLC patients with baseline [18F]FDG PET/CT. Clinical, histopathologic, and metabolic parameters were obtained. After tumor segmentation, SUV and volume-based variables, global texture, sphericity, and two novel parameters, normalized SUVpeak to centroid distance (nSCD) and normalized SUVmax to perimeter distance (nSPD), were obtained. Early recurrence (ER) and short-term mortality (STM) were used as end points. Univariate logistic regression and multivariate logistic regression with respect to ER and STM were performed. RESULTS: A cohort of 173 patients was selected. ER was detected in 49/104 of patients with recurrent disease. Additionally, 100 patients died and 53 had STM. Age, pathologic lymphovascular invasion, lymph nodal infiltration, TNM stage, nSCD, and nSPD were associated with ER, although only age (aOR = 1.06, p = 0.002), pathologic lymphovascular invasion (aOR = 3.40, p = 0.022), and nSPD (aOR = 0.02, p = 0.018) were significant independent predictors of ER in multivariate analysis. Age, lymph nodal infiltration, TNM stage, nSCD, and nSPD were predictors of STM. Age (aOR = 1.05, p = 0.006), lymph nodal infiltration (aOR = 2.72, p = 0.005), and nSPD (aOR = 0.03, p = 0.022) were significantly associated with STM in multivariate analysis. Coefficient of variation (COV) and SUVmean/SUVmax ratio did not show significant predictive value with respect to ER or STM. CONCLUSION: The geometric variables, nSCD and nSPD, are robust biomarkers of the poorest outcome prediction of patients with NSCLC with respect to classical PET variables. KEY POINTS: ⢠In NSCLC patients, it is crucial to find prognostic parameters since TNM system alone cannot explain the variation in lung cancer survival. ⢠Age, lymphovascular invasion, lymph nodal infiltration, and metabolic geometrical parameters were useful as prognostic parameters. ⢠The displacement grade of the highest point of metabolic activity towards the periphery assessed by geometric variables obtained from [18F]FDG PET/CT was a robust biomarker of the poorest outcome prediction of patients with NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/patologia , Fluordesoxiglucose F18 , Humanos , Neoplasias Pulmonares/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Tomografia por Emissão de Pósitrons , Prognóstico , Compostos Radiofarmacêuticos , Estudos RetrospectivosRESUMO
BACKGROUND: The period fertility in China has declined to very low levels, and the completed cohort fertility rate (CFR) has also decreased significantly. However, the exact fertility rate remains controversial. While the tempo effect has played a significant role in China's period fertility decline, child underreporting has to be taken into consideration in China's fertility research. METHODS: By using the census data from 1982 to 2010, and the 1% population sample survey data from 1995 to 2015, we systematically analyzed China's fertility and its trends since the 1980s using period fertility measures, adjusted period fertility measures, cohort fertility measures, and indirect estimation methods. RESULTS: The results show that marriage postponement significantly affects the TFR decline. Even after eliminating the tempo and parity structure effect, the adjusted TFR has fallen below 1.5, and the first-order fertility rate dropped to 0.9 in 2015. The CFR for women aged 45-49 declined from 5.37 in 1982 to 1.62 in 2015 mainly because of a decrease in fourth and higher-order births from 1982 to 1990, a decrease in second and third births from 1990 to 2000, and a decrease in second births from 2000 to 2015. Indirect estimation methods yielded a TFR in the range of 1.5-1.6 for the period 2000-2010 and an average TFR of 1.49 for the period 2011-2020. CONCLUSIONS: The traditional norm of universal marriage and childbearing for Chinese women is changing. China's fertility has been steadily declining, as measured by both period and cohort indicators. Following the historical change, fertility may continue to decline even after introducing the universal three-child policy in China in 2021.
Assuntos
Países em Desenvolvimento , Fertilidade , China , Feminino , Humanos , Casamento , Pessoa de Meia-Idade , Dinâmica Populacional , GravidezRESUMO
The CACNA1C and the ZNF804A genes are among the most relevant schizophrenia GWAS findings. Recent evidence shows that the interaction of these genes with the schizophrenia diagnosis modulates brain functional response to a verbal fluency task. To better understand how these genes might influence the risk for schizophrenia, we aimed to study the interplay between CACNA1C and ZNF804A on working memory brain functional correlates. The analyses included functional and behavioural N-back task data (obtained from an fMRI protocol) and CACNA1C-rs1006737 and ZNF804A-rs1344706 genotypes for 78 healthy subjects and 78 patients with schizophrenia (matched for age, sex and premorbid IQ). We tested the effects of the epistasis between these genes as well as of the three-way interaction (CACNA1C × ZNAF804A × diagnosis) on working memory-associated activity (N-back: 2-back vs 1-back). We detected a significant CACNA1C × ZNAF804A interaction on working memory functional response in regions comprising the ventral caudate medially and within the left hemisphere, the superior and inferior orbitofrontal gyrus, the superior temporal pole and the ventral-anterior insula. The individuals with the GWAS-identified risk genotypes (CACNA1C-AA/AG and ZNF804A-AA) displayed a reduced working memory modulation response. This genotypic combination was also associated with opposite brain activity patterns between patients and controls. While further research will help to comprehend the neurobiological mechanisms of this interaction, our data highlight the role of the epistasis between CACNA1C and ZNF804A in the functional mechanisms underlying the pathophysiology of schizophrenia.