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1.
Sensors (Basel) ; 20(21)2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33143269

RESUMO

In this article, a compact dual-laser sensor based on an off-axis integrated-cavity output spectroscopy and time-division multiplexing method is reported. A complete dual-channel optical structure is developed and integrated on an optical cavity, which allows two distributed feedback (DFB) lasers operating at wavelengths of 1603 nm and 1651 nm to measure the concentration of CO2 and CH4, simultaneously. Performances of the dual-laser sensor are experimentally evaluated by using standard air (with a mixture of CO2 and CH4). The limit of detection (LoD) is 0.271 ppm and 1.743 ppb at a 20 s for CO2 and CH4, respectively, and the noise equivalent absorption sensitivities are 2.68 × 10-10 cm-1 Hz-1/2 and 3.88 × 10-10 cm-1 Hz-1/2, respectively. Together with a commercial instrument, the dual-laser sensor is used to measure CO2 and CH4 concentration over 120 h and verify the regular operation of the sensor for the detection of ambient air. Furthermore, a first-order exponential moving average algorithm is implemented as an effective digital filtering method to estimate the gas concentration.

2.
BMC Genomics ; 20(1): 289, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30987602

RESUMO

BACKGROUND: Dasypyrum villosum is an important wild species of wheat (Triticum aestivum L.) and harbors many desirable genes that can be used to improve various traits of wheat. Compared with other D. villosum accessions, D. villosum#4 still remains less studied. In particular, chromosomes of D. villosum#4 except 6V#4 have not been introduced into wheat by addition or substitution and translocation, which is an essential step to identify and apply the alien desired genes. RNA-seq technology can generate large amounts of transcriptome sequences and accelerate the development of chromosome-specific molecular markers and assisted selection of alien chromosome line. RESULTS: We obtained the transcriptome of D. villosum#4 via a high-throughput sequencing technique, and then developed 76 markers specific to each chromosome arm of D. villosum#4 based on the bioinformatic analysis of the transcriptome data. The D. villosum#4 sequences containing the specific DNA markers were expected to be involved in different genes, among which most had functions in metabolic processes. Consequently, we mapped these newly developed molecular markers to the homologous chromosome of barley and obtained the chromosome localization of these markers on barley genome. Then we analyzed the collinearity of these markers among D. villosum, wheat, and barley. In succession, we identified six types of T. aestivum-D. villosum#4 alien chromosome lines which had one or more than one D. villosum#4 chromosome in the cross and backcross BC3F5 populations between T. durum-D. villosum#4 amphidiploid TH3 and wheat cv. Wan7107 by employing the selected specific markers, some of which were further confirmed to be translocation or addition lines by genomic in situ hybridization (GISH). CONCLUSION: Seventy-six PCR markers specific to chromosomes of D. villosum#4 based on transcriptome data were developed in the current study and their collinearity among D. villosum, wheat, and barley were carried out. Six types of Triticum aestivum-D. villosum#4 alien chromosome lines were identified by using 12 developed markers and some of which were further confirmed by GISH. These novel T. aestivum-D. villosum#4 chromosome lines have great potential to be used for the introduction of desirable genes from D. villosum#4 into wheat by chromosomal translocation to breed new wheat varieties.


Assuntos
Cruzamento , Cromossomos de Plantas/genética , Perfilação da Expressão Gênica , Marcadores Genéticos/genética , Genômica , Poaceae/genética , Triticum/genética , Genoma de Planta/genética , Anotação de Sequência Molecular , Reação em Cadeia da Polimerase
3.
Theor Appl Genet ; 131(1): 13-25, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28887628

RESUMO

KEY MESSAGE: Transcriptome data were used to develop 134 Aegilops longissima specific PCR markers and their comparative maps were constructed by contrasting with the homologous genes in the wheat B genome. Three wheat- Ae. longissima 1BL·1S l S translocation lines were identified using the correspondence markers. Aegilops longissima is an important wild species of common wheat that harbors many genes that can be used to improve various traits of common wheat (Triticum aestivum L.). To efficiently transfer the traits conferred by these Ae. longissima genes into wheat, we sequenced the whole expression transcript of Ae. longissima. Using the transcriptome data, we developed 134 specific polymerase chain reaction markers located on the 14 chromosome arms of Ae. longissima. These novel molecular markers were assigned to specific chromosome locations based on a comparison with the homologous genes in the B genome of wheat. Annotation of these genes showed that most had functions related to metabolic processes, hydrolase activity, or catalytic activity. Additionally, we used these markers to identify three wheat-Ae. longissima 1BL·1SlS translocation lines in somatic variation populations resulting from a cross between wheat cultivar Westonia and a wheat-Ae. longissima substitution line 1Sl(1B). The translocation lines had several low molecular weight glutenin subunits encoding genes beneficial to flour processing quality that came from Ae. longissima 1SlS. The three translocation lines were also confirmed by genomic in situ hybridization. These translocation lines will be further evaluated for potential quality improvement of bread-making properties of wheat.


Assuntos
Marcadores Genéticos , Melhoramento Vegetal , Poaceae/genética , Translocação Genética , Cromossomos de Plantas , Glutens , Reação em Cadeia da Polimerase , Transcriptoma , Triticum
4.
Small ; 13(7)2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27925379

RESUMO

A Cu(OH)2 @CoCO3 (OH)2 ·nH2 O (CCHH) core-shell heterostructure nanowire array acts as robust 3D oxygen evolution reaction catalyst. It needs an overpotential of 270 mV to drive 50 mA cm-2 in 1.0 m KOH, outperforming CCHH nanowire arrays on copper foam and most reported Co-based oxygen evolution reaction catalysts in alkaline media. It is also efficient for methanol electrooxidation.

5.
Anal Chem ; 88(16): 7885-9, 2016 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-27489098

RESUMO

It is highly attractive to construct a natural enzyme-free electrode for sensitive and selective detection of glucose. In this Letter, we report that a Ni2P nanoarray on conductive carbon cloth (Ni2P NA/CC) behaves as an efficient three-dimensional catalyst electrode for glucose electrooxidation under alkaline conditions. Electrochemical measurements demonstrate that the Ni2P NA/CC, when used as a nonenzymatic glucose sensor, offers superior analytical performances with a short response time of 5 s, a wide detection range of 1 µM to 3 mM, a low detection limit of 0.18 µM (S/N = 3), a response sensitivity of 7792 µA mM(-1) cm(-2), and satisfactory selectivity, specificity, and reproducibility. Moreover, it can also be used for glucose detection in human blood serum, promising its application toward determination of glucose in real samples.


Assuntos
Glicemia/análise , Nanotecnologia , Níquel/química , Fósforo/química , Catálise , Eletrodos , Humanos , Tamanho da Partícula , Sensibilidade e Especificidade
6.
Nanotechnology ; 27(44): 44LT02, 2016 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-27671347

RESUMO

In this letter, we report on the use of a cobalt phosphide nanowall array on conductive carbon cloth (CoP NA/CC) as an efficient catalyst electrode for methanol electro-oxidation under alkaline conditions. This CoP NA/CC achieves a current density of 96 mA cm(-2) toward 0.5 M methanol at 0.5 V (versus a saturated calomel electrode (SCE)) in 1 M KOH. Moreover, this electrode exhibits superior stability and 93% of the initial anodic current density can be retained after 1000 cyclic voltammetry cycles when re-measured in new electrolyte.

7.
Nanotechnology ; 27(47): 475702, 2016 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-27767019

RESUMO

Hydrogen has been considered as an ideal energy carrier for replacing fossil fuels to mitigate global energy crises. Hydrolysis of sodium borohydride (NaBH4) is simple and effective for hydrogen production but needs active and durable catalysts to accelerate the kinetics. In this paper, we demonstrate that cobalt phosphide nanowall arrays supported on carbon cloth (CoP NAs/CC) efficiently catalyze the hydrolytic dehydrogenation of NaBH4 with an activation energy of 42.1 kJ mol-1 in alkaline media. These monolithic CoP NAs/CC show a maximum hydrogen generation rate of [Formula: see text] and are robust with superior durability and reusability. They are also excellent in activity and durability for electrochemical hydrogen evolution in 1.0 M KOH, with the need of an overpotential of only 80 mV to drive 10 mA cm-2. They offer us a promising low-cost hydrogen-generating catalyst for applications.

8.
Sci Total Environ ; 912: 169631, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38157916

RESUMO

Changes in the nitrogen cycle due to fertilizer use can cause severe environmental pollution, particularly groundwater pollution, and threaten biosphere integrity. There are many difficulties and limitations in assessing groundwater pollution and a detailed nitrogen budget in an agricultural catchment. Previous methodologies have failed in an accurate assessment of the nitrogen budget in detailed spatial patterns. Herein, we designed a new modeling approach to assess the nitrogen budget using detailed spatial patterns in an agricultural catchment in the Nara Basin. We revised the Soil and Water Assessment Tool file output format, added the results for river nutrient concentrations and ammonia volatilization to the original output file. In this study, we calibrated and validated crop harvests, paddy evapotranspiration, streamflow, and river water concentrations of nitrate-nitrogen and total nitrogen to improve model accuracy as much as possible. Among them, data for evapotranspiration was obtained from a newly released Landsat dataset. The results showed that the amount of nitrogen leaching in rice paddies was 42 kg/ha, accounting for 65 % of total leaching in the study catchment. Cambisols and Fluvic Gleysols were prone to denitrification, and nitrogen leaching or denitrification occurred relatively more readily in low-slope areas. Furthermore, a detailed analysis of nitrogen cycle processes with high spatial precision indicates that areas with severe surface water pollution may also exhibit significant groundwater pollution. Our findings provide new solutions for assessing the nitrogen budget and groundwater pollution in catchments.

9.
Polymers (Basel) ; 15(3)2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36771853

RESUMO

Muscles are capable of modulating the body and adapting to environmental changes with a highly integrated sensing and actuation. Inspired by biological muscles, coiled/twisted fibers are adopted that can convert volume expansion into axial contraction and offer the advantages of flexibility and light weight. However, the sensing-actuation integrated fish line/yarn-based artificial muscles are still barely reported due to the poor actuation-sensing interface with off-the-shelf fibers. We report herein artificial coiled yarn muscles with self-sensing and actuation functions using the commercially available yarns. Via a two-step process, the artificial coiled yarn muscles are proved to obtain enhanced electrical conductivity and durability, which facilitates the long-term application in human-robot interfaces. The resistivity is successfully reduced from 172.39 Ω·cm (first step) to 1.27 Ω·cm (second step). The multimode sense of stretch strain, pressure, and actuation-sensing are analyzed and proved to have good linearity, stability and durability. The muscles could achieve a sensitivity (gauge factor, GF) of the contraction strain perception up to 1.5. We further demonstrate this self-aware artificial coiled yarn muscles could empower non-active objects with actuation and real-time monitoring capabilities without causing damage to the objects. Overall, this work provides a facile and versatile tool in improving the actuation-sensing performances of the artificial coiled yarn muscles and has the potential in building smart and interactive soft actuation systems.

10.
Biomimetics (Basel) ; 8(2)2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37366816

RESUMO

Similar to biological muscles in nature, artificial muscles have unique advantages for driving bionic robots. However, there is still a large gap between the performance of existing artificial muscles and biological muscles. Twisted polymer actuators (TPAs) convert rotary motion from torsional to linear motion. TPAs are known for their high energy efficiency and large linear strain and stress outputs. A simple, lightweight, low-cost, self-sensing robot powered using a TPA and cooled using a thermoelectric cooler (TEC) was proposed in this study. Because TPA burns easily at high temperatures, traditional soft robots driven by TPAs have low movement frequencies. In this study, a temperature sensor and TEC were combined to develop a closed-loop temperature control system to ensure that the internal temperature of the robot was 5 °C to cool the TPAs quickly. The robot could move at a frequency of 1 Hz. Moreover, a self-sensing soft robot was proposed based on the TPA contraction length and resistance. When the motion frequency was 0.01 Hz, the TPA had good self-sensing ability and the root-mean-square error of the angle of the soft robot was less than 3.89% of the measurement amplitude. This study not only proposed a new cooling method for improving the motion frequency of soft robots but also verified the autokinetic performance of the TPAs.

11.
Artigo em Inglês | MEDLINE | ID: mdl-38051625

RESUMO

Leg properties have been involved in the broad study of human walking from mechanical energy to motion prediction of robotics. However, the variable leg elasticities and their functions during gait have not been fully explored. This study presented that the fundamental leg properties during human walking comprise axial stiffness, rest leg length, tangential stiffness and force-free leg angles. We measured the axial force-leg length and tangential force-leg angle data in eight participants (mean ± s.d. age 24.6 ± 3.0 years, mass 68.2 ± 6.8 kg, height 177.5 ± 5.2 cm) at three self-selected walking speeds (slow: 1.25 ± 0.22, normal: 1.48 ± 0.28, fast: 1.75 ± 0.32 m/s) on two different contact conditions (fixed and moving). After obtaining these gait measurements, we extracted the linear and nonlinear leg elasticities during human walking by using a minimum root-mean-square fitting. We found that the axial stiffness of nonlinear elasticity (fixed condition: 7.1-8.0, moving condition: 21.3-22.6) is higher than that of the linear elasticity (fixed condition: 5.0-5.7, moving condition: 15.2-16.5). The tangential stiffness behaves different during four stance phases of gait, with the highest (linear: 2.52-3.72, nonlinear: 1.71-2.01, in moving condition) occurred at early stance and second highest at late stance, followed by two stiffnesses in mid-stance. For both linearity and nonlinearity, the axial stiffness and rest length are independent of walking speeds in both contact conditions, while the tangential stiffness and contact angles are independent of walking speeds only in moving condition. Regardless of walking speed, elasticity and contact condition, the force-free contact angle at mid-stance is maintained at average of 82.2 °. This paper first demonstrates the mechanical walking leg property from both axial and tangential aspects. The findings provide insight into the fundamental properties including linearity and nonlinearity of human leg during locomotion for stability analysis and precise motion prediction of robotics and rehabilitation exoskeletons.


Assuntos
Perna (Membro) , Caminhada , Humanos , Adulto Jovem , Adulto , Fenômenos Biomecânicos , Marcha , Locomoção
12.
Artigo em Inglês | MEDLINE | ID: mdl-36374868

RESUMO

Understanding the distinct functions of human muscles could not only help professionals obtain insights into the underlying mechanisms that we accommodate compromised neuromuscular system, but also assist engineers in developing rehabilitation devices. This study aims to determine the contribution of major muscle and the energy flow in the human musculoskeletal system at four sub-phases (collision, rebound, preload, push-off) during the stance of walking at different speeds. Gait experiments were performed with three self-selected speeds: slow, normal, and fast. Muscle forces and mechanical work were calculated by using a subject-specified musculoskeletal model. The functions of individual muscles were characterized as four functional behaviors (strut, spring, motor, damper), which were determined based on the mechanical energy. The results showed that during collision, hip flexors (iliacus and psoas major) and ankle dorsiflexors (anterior tibialis) were the most dominant muscles in buffering the stride with energy absorption; during rebound, the posterior muscles (gluteus maximus, gastrocnemius, posterior tibialis, soleus) contributed the most to energy generation; during preload, energy for preparing push-off was mainly absorbed by the muscles surrounding knee (vastus, semimembranosus, semitendinosus); during push-off, ankle plantar flexors (gastrocnemius, soleus, posterior tibialis, peroneus muscles, flexor digitorum, flexor hallucis) mainly behaved to generate energy for forward propulsion. With increased walking speed, additional energy (almost 400%) from harder stride was mainly absorbed by the flexor muscles. Hip extensors and adductors transferred more energy (around 150%) to the distal segments during rebound. Soleus and gastrocnemius muscles generated more energy (about 75%) to the proximal segments for propulsion. Along with our previous study of joint-level energy analysis, these findings could assist better understanding of human musculoskeletal behaviors during locomotion and provide principles for the bio-design of related assistive devices from motors performance enhancement to rehabilitation such as exoskeleton and prosthesis.


Assuntos
Músculo Esquelético , Caminhada , Humanos , Caminhada/fisiologia , Músculo Esquelético/fisiologia , Marcha/fisiologia , Extremidade Inferior , Tornozelo , Fenômenos Biomecânicos
13.
Biomimetics (Basel) ; 8(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36648804

RESUMO

The human tibiofibular complex has undergone a long evolutionary process, giving its structure a high bearing-capacity. The distinct tibiofibular shape can be used in engineering to acquire excellent mechanical properties. In this paper, four types of bionic tubes were designed by extracting the dimensions of different cross-sections of human tibia-fibula. They had the same outer profiles, but different inner shapes. The concept of specific stiffness was introduced to evaluate the mechanical properties of the four tubes. Finite-element simulations and physical bending-tests using a universal testing machine were conducted, to compare their mechanical properties. The simulations showed that the type 2 bionic tube, i.e., the one closest to the human counterpart, obtained the largest specific-stiffness (ε = 6.46 × 104), followed by the type 4 (ε = 6.40 × 104) and the type 1 (ε = 6.39 × 104). The type 3 had the largest mass but the least stiffness (ε = 6.07 × 104). The specific stiffness of the type 2 bionic tube increased by approximately 25.8%, compared with that of the type 3. The physical tests depicted similar findings. This demonstrates that the bionic tube inspired by the human tibiofibular shape has excellent effectiveness and bending properties, and could be used in the fields of healthcare engineering, such as robotics and prosthetics.

14.
Sci Total Environ ; 843: 156833, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35750171

RESUMO

Phosphorus usage is irreplaceable in agriculture; however, its excessive use leads to wastage of invaluable resources and significant soil surplus. Agronomic soil phosphorus surplus in Asian regions has a much higher level than the global average. And with rapid urbanization and population growth in the recent decades, Asian countries have seen a rise in environmental pollution levels also. This study assessed the detailed phosphorus budget in the Yamato River catchment, an urbanized coastal catchment in Asia, from 1940s to 2010s using Soil and Water Assessment Tool, comprehensively analyzed the effect of anthropogenic factors on long-term phosphorus loading and agronomic soil phosphorus balance. The results showed the peak period of total phosphorus loading and agronomic soil phosphorus surplus occurred in 1970s, at 895 tons/year and 36.6 kg/ha, respectively. The major reasons for increased phosphorus loading and soil surplus during 1940-1970 were rapid population growth and increased fertilizer usage, respectively. Since the 1980s, the construction of wastewater treatment system and reduction in agricultural land contributed to environmental improvement. These anthropogenic factors had a much stronger impact on phosphorus budget than climate change in the study catchment. Soil phosphorus balance is affected by a combination of factors, such as soil properties, fertilizer usage and applied schedule, precipitation event, and crop types. And soil phosphorus surplus may be severely overestimated if the non-point source loss due to precipitation factor is not fully considered.


Assuntos
Fertilizantes , Fósforo , Agricultura/métodos , Efeitos Antropogênicos , Baías , Monitoramento Ambiental , Fósforo/análise , Solo
15.
Sci Total Environ ; 809: 151159, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-34695475

RESUMO

Forest ecosystems are critical for adjusting the dynamic balance of the hydrological cycle. This balance is affected by vegetation community types, phenology, and forest density. Previous long-term catchment-scale model studies have focused on changes in forest areas while ignoring the above factors. Since the 1980s, climate change caused by increases in atmospheric CO2 levels has enhanced forest growth. Moreover, amendments to forest management policies, including intermediate cuttings caused by economic factors, have yielded unprecedented changes in forest ecosystems. In this study, we designed a methodology and created a credible model using the Soil and Water Assessment Tool (SWAT) that can precisely reflect water balance variations caused by different ecosystem situations during long-term changes in forest density. We focused on the Yamato River catchment in Western Japan, which includes three planted forests and one primeval forest, each markedly different with respect to vegetation community composition and management policy. In the process, we examined the ratio of coniferous vegetation and broad-leaved vegetation in different forest areas, used remote sensing methods to quantify the maximum and minimum leaf area index (LAI) of each forest region over 40 years, and calibrated the model by comparing the LAI growth curve, evapotranspiration, and streamflow with observed data. Moreover, we separated the decadal canopy evaporation, transpiration, and soil evaporation from the SWAT output results. We found that (1) forest evapotranspiration has increased in recent decades because of the above reasons; (2) in young or well-managed forests, the forest water balance may have changed significantly with forest growth. For long-term studies, it is necessary to distinguish the growth characteristics of different forests during different periods, and a detailed definition of a mixed forest is required. The forest parameters and growth characteristics are critical for understanding forest ecosystems and cannot be ignored at catchment-scale.


Assuntos
Ecossistema , Florestas , Folhas de Planta , Solo , Árvores , Água
16.
Artigo em Inglês | MEDLINE | ID: mdl-35482694

RESUMO

The level of joint laxity, which is an indicator of accurate diagnosis for musculoskeletal conditions is manually determined by a physician. Studying joint laxity via artificial joints is an efficient and economical way to improve patient experience and joint proficiency. However, most of study focus on the joint geometry but are inadequate with regard to the tailored mechanical properties of soft tissues. On the basis of collagen fibril deformation, this study proposes bioinspired 3D fibers braided from polyethene multifilament for the reproduction of the controlled nonlinear behavior of ligaments and tendons. Four braided bands are designed, all showing biological behaviors. Two knot-based bands exhibit large toe strains of 10.98% and 5.33% but low linear modulus of 239.84 MPa and 826.05 MPa. The other two bands without knots exhibit lower toe strains of 1.61% and 1.52% but high linear modulus of 2605.27 MPa and 2050.74 MPa. Empirical formulas for braiding parameters (wales and courses) and mechanical properties are expressed to provide a theoretical basis for the mimicry of different tissues in the human body by artificial joints. All parameters have significant effects on the linear region of the load-displacement curve of a fiber due to braided structure, while changing the number of wales facilitates a major contribution to the toe region. A biofidelic human knee has been successfully reconstructed by using bioinspired 3D braided fibers. This study demonstrates that the nonlinear mechanical properties of soft tissues can be replicated by bioinspired 3D braided fibers, further yielding the design of more biomechanically realistic artificial joints.


Assuntos
Instabilidade Articular , Humanos , Articulação do Joelho , Ligamentos , Reprodução , Tendões
17.
Bioinspir Biomim ; 17(6)2022 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-35926484

RESUMO

The knee joint plays a key role in kinematic and kinetic performances of pedestrain locomotion. The key role of meniscus with matched ligaments in joint stability and movability has not been fully explored in current robotic knee designs. We fabricate a bioinspired robotic knee based on a kinematic model of an anatomical knee in order to reveal the relationship between the meniscus, ligaments and their stability and movability, respectively. The kinematic model was built from magnetic resonance imaging of the human knee with generated contact profiles and customized ligament fibers. Then, the bioinspired knee was designed, and its dynamic stability was maintained by ligaments and specific contact profiles, which were acquired based on the kinematic model. Finally, a monopod robot with the bioinspired knee assembled was developed for dynamic testing. The results show that (1) a smooth rolling-sliding motion can be achieved with the addition of menisci and compatible ligaments; and (2) joint stiffness can be adjusted by changing the springs and activation lengths of ligament fibers. This study gives biomimetic insights into a new design of knee joint for a robotic/prosthetic leg.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Fenômenos Biomecânicos , Humanos , Articulação do Joelho/fisiologia , Ligamentos , Modelos Biológicos
18.
Food Funct ; 13(11): 5971-5986, 2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-35546499

RESUMO

As a natural active ingredient, lactic acid bacteria have potential anti-inflammatory effects. In this study, male C57BL/6J mice were given a high-fat diet (HFD) to establish an obese mouse model. Lactobacillus plantarum 23-1 (LP23-1) with prebiotic characteristics was intervened for 8 weeks to evaluate its remission effect on obese animals and related mechanisms. The effects of LP23-1 on lipid accumulation and intestinal inflammation in HFD-fed mice were systematically evaluated by detecting lipid accumulation, blood lipid level, pathological changes in the liver and small intestine, oxidative stress and inflammatory cell level, lipid transport-related gene expression, the inflammatory signaling pathway, and intestinal tight junction (TJ) mRNA and protein expression. The results showed that LP23-1 could significantly reduce the body weight and fat index of HFD-fed mice, improve the lipid levels of serum and liver, reduce the histopathological damage to the liver and small intestine, and alleviate oxidative stress and inflammatory response caused by obesity. In addition, reverse transcription-polymerase chain reaction and western blot analysis showed that LP23-1 could regulate the mRNA expression of lipid transport-related genes; activate the TLR4/NF-κB signaling pathway; reduce intestinal inflammation; improve the mRNA and protein expression of intestinal TJ proteins zona occludens-1 (ZO-1), occludin, claudin-1, and Muc2; repair intestinal mucosal injury; and enhance intestinal barrier function. The aforementioned results showed that LP23-1 through the TLR4/NF-κB signaling pathway and intestinal barrier function reduced obesity symptoms. This study provided new insights into the mechanism of LP23-1 in reducing obesity and provided a theoretical basis for developing new functional foods.


Assuntos
Lactobacillus plantarum , Animais , Inflamação/metabolismo , Mucosa Intestinal/metabolismo , Lactobacillus plantarum/metabolismo , Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , NF-kappa B/genética , NF-kappa B/metabolismo , Obesidade/metabolismo , RNA Mensageiro/metabolismo , Transdução de Sinais , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo
19.
Int J Numer Method Biomed Eng ; 38(9): e3617, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35560814

RESUMO

Most researchers have performed finite element (FE) analysis of the human forearm fracture by exploring the strength and load transmission of the bones. However, few studies concentrated a complete simulation of the whole forearm complex including ligaments. This paper aims to investigate the load transmission through the bones, contact stress at the joints and strain in the ligaments by using an elaborate FE model, further validating the fracture condition for human forearm. The interosseous ligament was separated into three regions based on the distance to the proximal and distal ends. The FE simulation results were slightly more or less than a previous experimental data in the literature, but generally provided a close approximation of the bone and ligament behaviors. Compared with the experiment results under different loading conditions, maximum contact stress at the proximal radio ulnar joint (PRUJ) and distal radio ulnar joint (DRUJ) of the simulations was higher with an average of 13.4%, and peak strain in the interosseous ligament (IOL) was lower with an average of 11.0%. Under 10 kg load, the maximum stress in the radius (2.25 MPa) was less than double the value in the ulna (1.43 MPa). Finally, the FE model has been validated with the onset and location of the Colles' fracture in the literature. This study will provide a great benefit in terms of surgical and medical applications related to forearm fracture that require an extensive knowledge of the behavior of the bones and ligaments under various loading conditions.


Assuntos
Antebraço , Ulna , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Rádio (Anatomia)
20.
Front Bioeng Biotechnol ; 10: 950110, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36185421

RESUMO

Prosthetic knees are state-of-the-art medical devices that use mechanical mechanisms and components to simulate the normal biological knee function for individuals with transfemoral amputation. A large variety of complicated mechanical mechanisms and components have been employed; however, they lack clear relevance to the walking biomechanics of users in the design process. This article aims to bridge this knowledge gap by providing a review of prosthetic knees from a biomechanical perspective and includes stance stability, early-stance flexion and swing resistance, which directly relate the mechanical mechanisms to the perceived walking performance, i.e., fall avoidance, shock absorption, and gait symmetry. The prescription criteria and selection of prosthetic knees depend on the interaction between the user and prosthesis, which includes five functional levels from K0 to K4. Misunderstood functions and the improper adjustment of knee prostheses may lead to reduced stability, restricted stance flexion, and unnatural gait for users. Our review identifies current commercial and recent studied prosthetic knees to provide a new paradigm for prosthetic knee analysis and facilitates the standardization and optimization of prosthetic knee design. This may also enable the design of functional mechanisms and components tailored to regaining lost functions of a specific person, hence providing individualized product design.

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