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1.
PLoS One ; 15(6): e0234361, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32525946

RESUMO

Artificial gravity elicited through short-arm human centrifugation combined with physical exercise, such as jumping, is promising in maintaining health and performance during space travel. However, motion sickness symptoms could limit the tolerability of the approach. Therefore, we determined the feasibility and tolerability, particularly occurrence of motion sickness symptoms, during reactive jumping exercises on a short-arm centrifuge. In 15 healthy men, we assessed motion sickness induced by jumping exercises during short-arm centrifugation at constant +1Gz or randomized variable +0.5, +0.75, +1, +1.25 and +1.5 Gz along the body axis referenced to center of mass. Jumping in the upright position served as control intervention. Test sessions were conducted on separate days in a randomized and cross-over fashion. All participants tolerated jumping exercises against terrestrial gravity and on the short-arm centrifuge during 1 Gz or variable Gz at the center of mass without disabling motion sickness symptoms. While head movements markedly differed, motion sickness scores were only modestly increased with jumping on the short-arm centrifuge compared with vertical jumps. Our study demonstrates that repetitive jumping exercises are feasible and tolerable during short-arm centrifugation. Since jumping exercises maintain muscle and bone mass, our study enables further development of exercise countermeasures in artificial gravity.


Assuntos
Centrifugação/efeitos adversos , Gravidade Alterada/efeitos adversos , Enjoo devido ao Movimento/etiologia , Voo Espacial , Adaptação Fisiológica , Adulto , Medicina Aeroespacial , Centrifugação/instrumentação , Exercício Físico/fisiologia , Gravitação , Movimentos da Cabeça/fisiologia , Voluntários Saudáveis , Humanos , Masculino , Enjoo devido ao Movimento/fisiopatologia , Enjoo devido ao Movimento/prevenção & controle , Contramedidas de Ausência de Peso , Adulto Jovem
3.
Nat Commun ; 11(1): 1855, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32296057

RESUMO

Gravity sensing provides a robust verticality signal for three-dimensional navigation. Head direction cells in the mammalian limbic system implement an allocentric neuronal compass. Here we show that head-direction cells in the rodent thalamus, retrosplenial cortex and cingulum fiber bundle are tuned to conjunctive combinations of azimuth and tilt, i.e. pitch or roll. Pitch and roll orientation tuning is anchored to gravity and independent of visual landmarks. When the head tilts, azimuth tuning is affixed to the head-horizontal plane, but also uses gravity to remain anchored to the allocentric bearings in the earth-horizontal plane. Collectively, these results demonstrate that a three-dimensional, gravity-based, neural compass is likely a ubiquitous property of mammalian species, including ground-dwelling animals.


Assuntos
Encéfalo/fisiologia , Gravitação , Animais , Encéfalo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Percepção Espacial/fisiologia , Memória Espacial/fisiologia , Tálamo/metabolismo , Tálamo/fisiologia
4.
Plant Mol Biol ; 103(1-2): 197-210, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32130643

RESUMO

DEEPER ROOTING 1 (DRO1) contributes to the downward gravitropic growth trajectory of roots upstream of lateral auxin transport in monocots and dicots. Loss of DRO1 function leads to horizontally oriented lateral roots and altered gravitropic set point angle, while loss of all three DRO family members results in upward, vertical root growth. Here, we attempt to dissect the roles of AtDRO1 by analyzing expression, protein localization, auxin gradient formation, and auxin responsiveness in the atdro1 mutant. Current evidence suggests AtDRO1 is predominantly a membrane-localized protein. Here we show that VENUS-tagged AtDRO1 driven by the native AtDRO1 promoter complemented an atdro1 Arabidopsis mutant and the protein was localized in root tips and detectable in nuclei. atdro1 primary and lateral roots showed impairment in establishing an auxin gradient upon gravistimulation as visualized with DII-VENUS, a sensor for auxin signaling and proxy for relative auxin distribution. Additionally, PIN3 domain localization was not significantly altered upon gravistimulation in atdro1 primary and lateral roots. RNA-sequencing revealed differential expression of known root development-related genes in atdro1 mutants. atdro1 lateral roots were able to respond to exogenous auxin and AtDRO1 gene expression levels in root tips were unaffected by the addition of auxin. Collectively, the data suggest that nuclear localization may be important for AtDRO1 function and suggests a more nuanced role for DRO1 in regulating auxin-mediated changes in lateral branch angle. KEY MESSAGE: DEEPER ROOTING 1 (DRO1) when expressed from its native promoter is predominately localized in Arabidopsis root tips, detectable in nuclei, and impacts auxin gradient formation.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ácidos Indolacéticos/metabolismo , Proteínas Nucleares/fisiologia , Raízes de Plantas/metabolismo , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/fisiologia , Núcleo Celular/metabolismo , Teste de Complementação Genética , Gravitação , Mutação , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo
5.
Artigo em Inglês | MEDLINE | ID: mdl-32037369

RESUMO

This report highlights the usefulness and applicability of various gravimetric methods for studying earthquakes and volcanic activities. A high-resolution gravity anomaly map of Japan reveals areas with very steep horizontal gradients, where potential seismic faults are likely to be buried. Such traditional geoprospecting is coupled with novel cosmic-ray radiography to produce a fine-resolution (<100 m) three-dimensional density structure of a volcano. On the other hand, temporal gravity changes provide invaluable information about the process of earthquake faulting, volcanic eruptions, caldera formation, etc. Specifically, in this report we present our previous work on gravity research for solid earth science: (1) the first detection of coseismic gravity changes, (2) the virtual visualization of the rising and falling of magma in a conduit of Asama volcano, and (3) the large-scale lateral movement of magma during the Miyake-jima eruption in 2000.


Assuntos
Terremotos , Gravitação , Modelos Teóricos , Erupções Vulcânicas , Desastres , Planeta Terra , Japão , Cinética , Radiografia , Fatores de Tempo
6.
Curr Biol ; 30(4): R171-R174, 2020 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-32097645

RESUMO

Many animals use gravity as a spatial reference to help navigate their surroundings, but how they do so is not well understood. A new study reveals that a representative of our closest invertebrate relatives, the tunicate Ciona, processes light and gravity cues through a simple neural circuit to decide when and how to swim.


Assuntos
Ciona intestinalis , Natação , Animais , Gravitação , Sistema Nervoso , Neurobiologia
7.
Nat Commun ; 11(1): 789, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32034157

RESUMO

Place cells are spatially modulated neurons found in the hippocampus that underlie spatial memory and navigation: how these neurons represent 3D space is crucial for a full understanding of spatial cognition. We wirelessly recorded place cells in rats as they explored a cubic lattice climbing frame which could be aligned or tilted with respect to gravity. Place cells represented the entire volume of the mazes: their activity tended to be aligned with the maze axes, and when it was more difficult for the animals to move vertically the cells represented space less accurately and less stably. These results demonstrate that even surface-dwelling animals represent 3D space and suggests there is a fundamental relationship between environment structure, gravity, movement and spatial memory.


Assuntos
Células de Lugar/fisiologia , Percepção Espacial/fisiologia , Memória Espacial/fisiologia , Animais , Gravitação , Aprendizagem em Labirinto , Ratos , Telemetria/métodos
8.
PLoS One ; 15(1): e0226912, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923217

RESUMO

The target spraying effect of spray robots mainly depends on the control performance of the spraying arm during the processes of aiming and tracking. To further improve the robustness of the endpoint control and positioning accuracy of the spray arm, an improved potential field algorithm for the motion planning and control of the spray arm is proposed based on prophase research. The algorithm introduces a velocity potential field, visual field constraints and joint position limit constraints into the traditional artificial potential field method. The velocity potential field is used to ensure that the target state of the spraying arm is at the same velocity as the target crop (relative velocity) to achieve stable target tracking. The visual field constraints and joint position limit constraints are utilized to ensure the efficiency of the visual servo control and the movement of the spray arm. The algorithm can plan a feasible trajectory for the spraying arm in Cartesian space and image space, and use the speed controller to control the spraying arm movement along the trajectory for aiming and tracking. Simulation analysis shows that the algorithm can plan better motion trajectories than the servo controller based on image moments in previous studies. In addition, the experimental results show that the algorithm can effectively improve the robustness of targeting and tracking control for the spray robot.


Assuntos
Ambiente Controlado , Movimento (Física) , Robótica/instrumentação , Desenho de Equipamento , Gravitação
9.
PLoS One ; 15(1): e0227040, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31940387

RESUMO

We tested the hypothesis that the brain uses a variance-based weighting of multisensory cues to estimate head rotation to perceive which way is up. The hypothesis predicts that the known bias in perceived vertical, which occurs when the visual environment is rotated in a vertical-plane, will be reduced by the addition of visual noise. Ten healthy participants sat head-fixed in front of a vertical screen presenting an annulus filled with coloured dots, which could rotate clockwise or counter-clockwise at six angular velocities (1, 2, 4, 6, 8, 16°/s) and with six levels of noise (0, 25, 50, 60, 75, 80%). Participants were required to keep a central bar vertical by rotating a hand-held dial. Continuous adjustments of the bar were required to counteract low-amplitude low-frequency noise that was added to the bar's angular position. During visual rotation, the bias in verticality perception increased over time to reach an asymptotic value. Increases in visual rotation velocity significantly increased this bias, while the addition of visual noise significantly reduced it, but did not affect perception of visual rotation velocity. The biasing phenomena were reproduced by a model that uses a multisensory variance-weighted estimate of head rotation velocity combined with a gravito-inertial acceleration signal (GIA) from the vestibular otoliths. The time-dependent asymptotic behaviour depends on internal feedback loops that act to pull the brain's estimate of gravity direction towards the GIA signal. The model's prediction of our experimental data furthers our understanding of the neural processes underlying human verticality perception.


Assuntos
Orientação Espacial , Rotação , Vestíbulo do Labirinto , Percepção Visual , Adulto , Sinais (Psicologia) , Feminino , Gravitação , Cabeça , Humanos , Masculino , Percepção Espacial
10.
Proc Natl Acad Sci U S A ; 117(4): 2180-2186, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31932424

RESUMO

Gravity is one of the most ubiquitous environmental effects on living systems: Cellular and organismal responses to gravity are of central importance to understanding the physiological function of organisms, especially eukaryotes. Gravity has been demonstrated to have strong effects on the closed cardiovascular systems of terrestrial vertebrates, with rapidly responding neural reflexes ensuring proper blood flow despite changes in posture. Invertebrates possess open circulatory systems, which could provide fewer mechanisms to restrict gravity effects on blood flow, suggesting that these species also experience effects of gravity on blood pressure and distribution. However, whether gravity affects the open circulatory systems of invertebrates is unknown, partly due to technical measurement issues associated with small body size. Here we used X-ray imaging, radio-tracing of hemolymph, and micropressure measurements in the American grasshopper, Schistocerca americana, to assess responses to body orientation. Our results show that during changes in body orientation, gravity causes large changes in blood and air distribution, and that body position affects ventilation rate. Remarkably, we also found that insects show similar heart rate responses to body position as vertebrates, and contrasting with the classic understanding of open circulatory systems, have flexible valving systems between thorax and abdomen that can separate pressures. Gravitational effects on invertebrate cardiovascular and respiratory systems are likely to be widely distributed among invertebrates and to have broad influence on morphological and physiological evolution.


Assuntos
Gafanhotos/fisiologia , Gravitação , Adaptação Fisiológica , Animais , Pressão Sanguínea , Tamanho Corporal , Fenômenos Fisiológicos Cardiovasculares , Gafanhotos/crescimento & desenvolvimento , Fenômenos Fisiológicos Respiratórios
11.
Comput Methods Biomech Biomed Engin ; 23(5): 191-200, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31928226

RESUMO

In a highly autonomous vehicle (HAV), the rotatable seat is likely to be designed to facilitate ease of communication between the occupants. We hypothesize that the protective effects of current restraint systems vary among different seating configurations and that by using the rotational seat to alter the occupant's orientation in accordance with the direction of impact, occupants will be better protected. Moreover, in HAVs, it's likely that an imminent impact could be detected at a time of 200 ms, or even longer, prior to the initial contact. The availability of this additional time could be used strategically to actively position the occupants into a safer position for impact.Finite element simulations were performed using the THUMS model to test the hypothesis. The simulation results indicated that during a frontal impact, the backward-facing occupant is safer than occupants in other seating orientations. Moreover, 200 ms is sufficient to rotate the occupant by ±45° and ±90° without introducing additional injuries. Finally, the timing of the post-rotation impact also plays a role in injury risk of the rear-facing impact. Further studies are needed to optimize the rotating seat parameters in order to maintain occupant posture and improve crash safety in HAVs.


Assuntos
Acidentes de Trânsito , Veículos Automotores , Rotação , Fenômenos Biomecânicos , Simulação por Computador , Gravitação , Humanos , Modelos Teóricos , Fatores de Tempo
12.
World Neurosurg ; 135: 234-240, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31863889

RESUMO

BACKGROUND: In our series, the gravity-assisted ipsilateral paramedian approach was shown to be safe and advantageous for the resection of parafalcine meningioma, because it does not result in contralateral brain impingement and does not require brain retraction. We have reported the technical details of this method and the outcomes of our patients. METHODS: From September 2018 to September 2019, 10 consecutive patients with parafalcine meningioma underwent microsurgery using the gravity-assisted ipsilateral paramedian approach. The clinical data, radiological images, and surgical outcomes were collected and analyzed. RESULTS: All 10 patients (5 men and 5 women, mean age, 55.8 ± 12.5 years) underwent safe tumor resection. Of the 10 tumors, 6 were located in the frontal area, 2 in the parietal area, and 2 in frontal and parietal area. The superior sagittal sinus wall had been affected in 6 patients. Obvious perilesional edema was observed in 60% of the patients. During surgery, bridging veins were encountered in 8 patients and were preserved, except for a small branch. Brain retraction or transgression was not required, and gross total resection was achieved in all 10 patients. No major postoperative complications occurred, except for an unexpected subacute subdural hematoma 1 month postoperatively. All 10 patients had achieved a favorable outcome (Glasgow outcome scale, ≥ 4) at discharge, which remained the same after a mean follow-up of 5.8 ± 3.7 months. CONCLUSIONS: The results from the present case series have demonstrated the safety of the gravity-assisted ipsilateral paramedian approach for parafalcine meningioma resection. The approach provides good tumor exposure and clear identification and preservation of bridging veins, does not result in contralateral brain impingement, and does not require excessive brain retraction.


Assuntos
Gravitação , Neoplasias Meníngeas/cirurgia , Meningioma/cirurgia , Microcirurgia/métodos , Procedimentos Neurocirúrgicos/métodos , Posicionamento do Paciente/métodos , Adulto , Idoso , Dura-Máter , Feminino , Escala de Resultado de Glasgow , Hematoma Subdural/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia
13.
J Pediatr Orthop ; 40(1): e42-e48, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30994582

RESUMO

BACKGROUND: Although halo gravity traction (HGT) has been used to treat children with severe spinal deformity for decades, there is a distinct lack of high-quality evidence to speak to its merits or to dictate ideal manner of implementation. In addition, no guidelines exist to drive research or assist surgeons in their practice. The aim of this study was to establish best practice guidelines (BPG) using formal techniques of consensus building among a group of experienced pediatric spinal deformity surgeons to determine ideal indications and implementation of HGT for pediatric spinal deformity. METHODS: The Delphi process and nominal group technique were used to formally derive consensus among leaders in pediatric spine surgery. Initial work identified significant areas of variability in practice for which we sought to garner consensus. After review of the literature, 3 iterative surveys were administered from February through April 2018 to nationwide experts in pediatric spinal deformity. Surveys assessed anonymous opinions on ideal practices for indications, preoperative evaluation, protocols, and complications, with agreement of 80% or higher considered consensus. Final determination of consensus items and equipoise were established using the Nominal group technique in a facilitated meeting. RESULTS: Of the 42 surgeons invited, responses were received from 32, 40, and 31 surgeons for each survey, respectively. The final meeting included 14 experts with an average 10.5 years in practice and average 88 annual spinal deformity cases. Experts reached consensus on 67 items [indications (17), goals (1), preoperative evaluations (5), protocols (36), complications (8)]; these were consolidated to create final BPG in all categories, including statements to help dictate practice such as using at least 6 to 8 pins under 4 to 8 lbs of torque, with a small, tolerable starting weight and reaching goal weight of 50% TBW in ∼2 weeks. Nine items remained items of equipoise for the purposes of guiding future research. CONCLUSIONS: We developed consensus-based BPG for the use and implementation of HGT for pediatric spinal deformity. This can serve as a measure to help drive future research as well as give new surgeons a place to begin their practice of HGT. LEVEL OF EVIDENCE: Level V-expert opinion.


Assuntos
Seleção de Pacientes , Curvaturas da Coluna Vertebral/cirurgia , Tração/métodos , Tração/normas , Adolescente , Criança , Pré-Escolar , Congressos como Assunto , Consenso , Técnica Delfos , Gravitação , Humanos , Lactente , Guias de Prática Clínica como Assunto , Cuidados Pré-Operatórios/normas , Inquéritos e Questionários , Equipolência Terapêutica , Tração/efeitos adversos
14.
Spine (Phila Pa 1976) ; 45(1): E25-E36, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31842109

RESUMO

STUDY DESIGN: Prospective cross-sectional case-control study design. OBJECTIVE: This study aims to analyze the relation between balance control as well as health-related quality of life (HRQOL) in patients with adult spinal deformity (ASD), with a novel gravity line (GL)-related 3D spinal alignment parameter, the transverse gravitational deviation index (TGDI), defined to quantify the transverse plane position of any vertebra with respect to the GL. SUMMARY OF BACKGROUND DATA: Demographic data and balance control have both been identified as important determinants of HRQOL in ASD patients during a preoperative setting. Therefore, a better understanding of the relation between spinal alignment and balance is required. METHODS: After informed consent, 15 asymptomatic healthy volunteers (mean age 60.1 ±â€Š11.6 years old) and 55 ASD patients (mean age 63.5 ±â€Š10.1 years old) were included. Relation between performance on BESTest as well as core outcome measures index (COMI) with spinopelvic alignment was explored using General Linear Modeling (GLM). A P-value ≤0.05 was considered statistically significant. RESULTS: The L3 TGDI was identified to relate to balance control in the total ASD population after correction for confounding demographic factors (P = 0.001; adjusted R = 0.500) and explained 19% of the observed variance in balance performance. In addition, COMI is related to L3 TGDI in a subgroup of ASD patients with combined coronal and sagittal malalignment of L3 (P = 0.027; slope B = 0.047), despite significant influence of age (P = 0.020). CONCLUSION: In ASD patients with a combined coronal and sagittal malalignment of the L3 vertebra, both the level of balance impairment as well as HRQOL are related to the distance component of the L3 TGDI, that is, the offset between the center of the L3 vertebral body and the GL in the transverse plane. LEVEL OF EVIDENCE: 2.


Assuntos
Gravitação , Equilíbrio Postural , Qualidade de Vida/psicologia , Doenças da Coluna Vertebral/epidemiologia , Adulto , Idoso , Estudos de Casos e Controles , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Doenças da Coluna Vertebral/psicologia , Coluna Vertebral
15.
Aerosp Med Hum Perform ; 91(1): 51-55, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31852575

RESUMO

BACKGROUND: The risks associated with high positive Gz (+Gz) aerobatic flight, especially with respect to +Gz-induced loss of consciousness (G-LOC), are well known. Less appreciated is the effect of negative Gz (-Gz) flight on subsequent +Gz maneuvers, known as the "push-pull effect." This is an example involving the loss of an F-16 and pilot that was caused by the push-pull effect.CASE REPORT: The mishap pilot (MP) was killed during a training flight when his F-16 crashed without an ejection attempt. The MP, while transitioning from prolonged -Gz flight to sustained +Gz flight, maneuvered the mishap aircraft (MA) from -2.06 Gz to +8.56 Gz in less than 5 s. At this point, there were only minimal control inputs for 5 s, indicating the MP experienced transient incapacitation, most likely due to G-LOC or almost loss of consciousness (A-LOC). The MP's subsequent recovery attempt was interrupted by ground impact. The Accident Investigation Board (AIB) concluded the MP experienced G-LOC due to the push-pull effect.DISCUSSION: Since this is not the first time the push-pull effect has resulted in G-LOC mishaps, the adverse effects of such maneuvers should continue to be emphasized during military physiological training, as well as during general aviation (GA) aerobatics training. Furthermore, A-LOC, instead of being considered a discrete phenomenon, may need to be included in a broader G-LOC definition that encompasses the entire continuum of G-LOC and A-LOC.Metzler MM. G-LOC due to the push-pull effect in a fatal F-16 mishap. Aerosp Med Hum Perform. 2020; 91(1):51-55.


Assuntos
Medicina Aeroespacial , Aeronaves , Militares , Inconsciência/etiologia , Aceleração , Adulto , Evolução Fatal , Gravitação , Humanos , Masculino , Fatores de Tempo
16.
PLoS One ; 14(12): e0226013, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31809515

RESUMO

PURPOSE: The aim of this research is to establish whether, and to what extent, the tilt angle, gear ratio of the propulsion system and propulsion frequency of a wheelchair influence the position of the centre of gravity. Furthermore, it verifies the usefulness of such research using an original test stand. MATERIALS AND METHODS: The article presents the effects of three operational parameters of a wheelchair on the position of the centre of gravity of the human body. The study included 27 wheelchair propulsion tests of a wheelchair with pushrim propulsion using the following variable parameters: gear ratio of the propulsion system, propulsion frequency and wheelchair tilt angle. The position of the centre of gravity of the human body was measured in dynamic conditions at 100 Hz. The results were represented with ellipses defining the region of variability of the position of the centre of gravity of the human body. The coordinates of the centre of gravity were measured in relation to the reference system, with the start point at the centre of the axis of rotation of the rear wheelchair wheels. The measurements were taken in a horizontal plane in relation to the base on which the test stand was positioned. RESULTS: The research carried out shows that the inclination angle of the wheelchair has the greatest influence on position of the ellipse describing the position of the centre of gravity of the human body. By controlling the change in the inclination angle value in the range from 0° to 5.4°, the standard deviation of the length of the horizontal half-axis of the ellipse (SD a) equal to 31.2 mm was obtained. For comparison, by changing the frequency of pushes (40 to 50 pushes per minute) of the wheelchair at a constant inclination angle, the standard deviation of the horizontal half-axis length (SD a) equal to 8 mm was recorded. The results of the study show a change in the position of the centre of gravity of the human body in dynamic conditions. They are relative to the contact points of the wheelchair wheels with the ground. Using the dimensions of the plotted ellipses, one can determine the values of pressure that affect the wheelchair's individual wheels. Conclusions-Increasing the value of each aforementioned parameter resulted in the increase of strength required by the operator to propel the wheelchair. It directly influenced the position of the centre of gravity during the test.


Assuntos
Gravitação , Cadeiras de Rodas , Fenômenos Biomecânicos , Desenho de Equipamento , Corpo Humano , Humanos
18.
Molecules ; 25(1)2019 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-31881788

RESUMO

Microwave hydrodiffusion and gravity (MHG) and ethanolic solid-liquid extraction were compared using selected plant sources. Their bioactive profile, color features, and proximate chemical characterization were determined. MHG extracts, commercial antioxidants, and three distinct types of thermal spring water were used in a sunscreen cream formulation. Their bioactive capacity, chemical and rheological properties were evaluated. MHG Cytisus scoparius flower extract provided the highest bioactive properties. Pleurotus ostreatus MHG liquor exhibited the highest total solid extraction yield. The Brassica rapa MHG sample stood out for its total protein content and its monosaccharide and oligosaccharide concentration. Quercus robur acorns divided into quarters supplied MHG extract with the lowest energy requirements, highest DPPH inhibition percentage, total lipid content and the highest enzyme inhibition. The chemical and bioactive capacities stability of the sunscreen creams elaborated with the selected MHG extracts and the thermal spring waters showed a similar behavior than the samples containing commercial antioxidants.


Assuntos
Cosméticos/química , Gravitação , Micro-Ondas , Plantas/química , Antioxidantes/farmacologia , Carotenoides/análise , Cor , Difusão , Lipídeos/análise , Fenóis/análise , Proteínas/análise , Protetores Solares/farmacologia , Temperatura , Fatores de Tempo , Viscosidade
19.
Sci Total Environ ; 694: 133719, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31756828

RESUMO

This study investigated the performances of gravity-driven membrane (GDM) reactors integrated with granule activated carbon (GAC) biofilm process for wastewater treatment under different intermittent aeration cycles (intensity and frequency). The results showed the removal efficiencies of dissolved organic carbon, total nitrogen, ammonia were significantly improved under intermittent aeration conditions (~86-87%, ~29-37%, and ~83-99%, respectively) compared to non-aeration condition (~72% and ~18%, and ~17%, respectively). In addition, it was found that the intermittent aeration significantly reduced the cake layer resistance and therefore improved ~130-300% the permeate flux compared to control without aeration. Microbial community analysis indicated that prokaryotic and eukaryotic compositions in the cake layer biofilm were significantly influenced by aeration condition. Lastly, energy consumption analysis revealed that GAC + GDM with shorter aeration period and low aeration intensity could be promising as a decentralized wastewater treatment process in terms of water quality and operating energy.


Assuntos
Reatores Biológicos , Membranas Artificiais , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias , Purificação da Água/métodos , Amônia , Biofilmes , Carvão Vegetal , Eucariotos , Filtração/métodos , Gravitação , Nitrogênio
20.
Exp Brain Res ; 237(12): 3375-3390, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31728598

RESUMO

The perceived vanishing location of a moving target is systematically displaced forward, in the direction of motion-representational momentum-, and downward, in the direction of gravity-representational gravity. Despite a wealth of research on the factors that modulate these phenomena, little is known regarding their neurophysiological substrates. The present experiment aims to explore which role is played by cortical areas hMT/V5+, linked to the processing of visual motion, and TPJ, thought to support the functioning of an internal model of gravity, in modulating both effects. Participants were required to perform a standard spatial localization task while the activity of the right hMT/V5+ or TPJ sites was selectively disrupted with an offline continuous theta-burst stimulation (cTBS) protocol, interspersed with control blocks with no stimulation. Eye movements were recorded during all spatial localizations. Results revealed an increase in representational gravity contingent on the disruption of the activity of hMT/V5+ and, conversely, some evidence suggested a bigger representational momentum when TPJ was stimulated. Furthermore, stimulation of hMT/V5+ led to a decreased ocular overshoot and to a time-dependent downward drift of gaze location. These outcomes suggest that a reciprocal balance between perceived kinematics and anticipated dynamics might modulate these spatial localization responses, compatible with a push-pull mechanism.


Assuntos
Movimentos Oculares/fisiologia , Percepção de Movimento/fisiologia , Lobo Parietal/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Percepção Espacial/fisiologia , Lobo Temporal/fisiologia , Estimulação Magnética Transcraniana , Córtex Visual/fisiologia , Adulto , Medições dos Movimentos Oculares , Feminino , Gravitação , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
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