Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
Int J Mol Sci ; 24(7)2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37047570

RESUMO

The gills are the major organ for Na+ uptake in teleosts. It was proposed that freshwater (FW) teleosts adopt Na+/H+ exchanger 3 (Nhe3) as the primary transporter for Na+ uptake and Na+-Cl- co-transporter (Ncc) as the backup transporter. However, convincing molecular physiological evidence to support the role of Ncc in branchial Na+ uptake is still lacking due to the limitations of functional assays in the gills. Thus, this study aimed to reveal the role of branchial Ncc in Na+ uptake with an in vivo detection platform (scanning ion-selective electrode technique, SIET) that has been recently established in fish gills. First, we identified that Ncc2-expressing cells in zebrafish gills are a specific subtype of ionocyte (NCC ionocytes) by using single-cell transcriptome analysis and immunofluorescence. After a long-term low-Na+ FW exposure, zebrafish increased branchial Ncc2 expression and the number of NCC ionocytes and enhanced gill Na+ uptake capacity. Pharmacological treatments further suggested that Na+ is indeed taken up by Ncc, in addition to Nhe, in the gills. These findings reveal the uptake roles of both branchial Ncc and Nhe under FW and shed light on osmoregulatory physiology in adult fish.


Assuntos
Simportadores , Peixe-Zebra , Animais , Peixe-Zebra/metabolismo , Simportadores/metabolismo , Transporte Biológico , Transporte de Íons/fisiologia , Brânquias/metabolismo , Trocador 3 de Sódio-Hidrogênio/metabolismo , Água Doce
2.
Int J Mol Sci ; 23(8)2022 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-35457237

RESUMO

Molecular and physiological analyses in ionoregulatory organs (e.g., adult gills and embryonic skin) are essential for studying fish ion regulation. Recent progress in the molecular physiology of fish ion regulation was mostly obtained in embryonic skin; however, studies of ion regulation in adult gills are still elusive and limited because there are no direct methods for in vivo functional assays in the gills. The present study applied the scanning ion-selective electrode technique (SIET) in adult gills to investigate branchial H+-excreting functions in vivo. We removed the opercula from zebrafish and then performed long-term acid acclimation experiments. The results of Western blot and immunofluorescence showed that the protein expression of H+-ATPase (HA) and the number of H+-ATPase-rich ionocytes were increased under acidic situations. The SIET results proved that the H+ excretion capacity is indeed enhanced in the gills acclimated to acidic water. In addition, both HA and Na+/H+ exchanger (Nhe) inhibitors suppressed the branchial H+ excretion capacity, suggesting that H+ is excreted in association with HA and Nhe in zebrafish gills. These results demonstrate that SIET is effective for in vivo detection in fish gills, representing a breakthrough approach for studying the molecular physiology of fish ion regulation.


Assuntos
Brânquias , Peixe-Zebra , Aclimatação/fisiologia , Ácidos/farmacologia , Animais , Brânquias/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Peixe-Zebra/metabolismo
3.
Int J Mol Sci ; 21(11)2020 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-32486459

RESUMO

Arginine vasopressin (Avp) is a conserved pleiotropic hormone that is known to regulate both water reabsorption and ion balance; however, many of the mechanisms underlying its effects remain unclear. Here, we used zebrafish embryos to investigate how Avp modulates ion and acid-base homeostasis. After incubating embryos in double-deionized water for 24 h, avp mRNA expression levels were significantly upregulated. Knockdown of Avp protein expression by an antisense morpholino oligonucleotide (MO) reduced the expression of ionocyte-related genes and downregulated whole-body Cl- content and H+ secretion, while Na+ and Ca2+ levels were not affected. Incubation of Avp antagonist SR49059 also downregulated the mRNA expression of sodium chloride cotransporter 2b (ncc2b), which is a transporter responsible for Cl- uptake. Correspondingly, avp morphants showed lower NCC and H+-ATPase rich (HR) cell numbers, but Na+/K+-ATPase rich (NaR) cell numbers remained unchanged. avp MO also downregulated the numbers of foxi3a- and p63-expressing cells. Finally, the mRNA expression levels of calcitonin gene-related peptide (cgrp) and its receptor, calcitonin receptor-like 1 (crlr1), were downregulated in avp morphants, suggesting that Avp might affect Cgrp and Crlr1 for modulating Cl- balance. Together, our results reveal a molecular/cellular pathway through which Avp regulates ion and acid-base balance, providing new insights into its function.


Assuntos
Equilíbrio Ácido-Base , Arginina Vasopressina/farmacologia , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Íons/química , Simportadores de Cloreto de Sódio/metabolismo , Vasopressinas/metabolismo , Animais , Cálcio/química , Cloretos/química , DNA Complementar/metabolismo , Regulação para Baixo , Eletrodos , Homeostase , Hibridização In Situ , Transporte de Íons , Oligonucleotídeos Antissenso/farmacologia , RNA Mensageiro/metabolismo , Pele/metabolismo , Sódio/química , Peixe-Zebra , Proteínas de Peixe-Zebra/genética
4.
Mol Biol Rep ; 41(4): 2143-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24442318

RESUMO

Clodronate liposome injection is an effective approach to selectively and specifically depleting macrophages. Macrophages play a crucial role in cutaneous wound healing and are associated with excessive scar formation. Use of clodronate liposomes to enhance cutaneous wound healing and reduce scar formation could represent a major advance in wound therapy and hypertrophic scar treatment. This study aimed to investigate the effects of subcutaneous or intraperitoneal injection of clodronate liposomes on cutaneous wound healing and scar formation. A burn injury mouse model was used. Mice were treated with subcutaneous or intraperitoneal injection of clodronate liposomes. Wound healing time was analyzed and scar tissues were harvested for hematoxylin and eosin (HE) staining, reverse transcription polymerase chain reaction (RT-PCR) and Western blot analyses. Wound healing time in treated mice was extended. HE showed that the basal layer of the epidermis in treated scars was flattened, the dermis layer was not significantly thickened, and collagen fibers were well arranged, with few cells and micro vessels. RT-PCR and Western blot analyses showed that the levels of TGF-ß1 and collagen I-α2 were decreased in treated mice. Clodronate liposomes reduce excessive scar formation and delay cutaneous wound healing possibly by reducing collagen deposition and macrophage-derived TGF-ß1 expression.


Assuntos
Queimaduras/metabolismo , Queimaduras/patologia , Cicatriz/metabolismo , Ácido Clodrônico/administração & dosagem , Colágeno/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Queimaduras/tratamento farmacológico , Cicatriz/tratamento farmacológico , Cicatriz/patologia , Colágeno Tipo I/metabolismo , Modelos Animais de Doenças , Lipossomos , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Fatores de Tempo , Cicatrização/efeitos dos fármacos , Cicatrização/imunologia
5.
Nanoscale ; 16(12): 6176-6189, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38445353

RESUMO

A new type of embedded composite material health monitoring nano-sensor is designed to ensure that the unique material advantages of nanofillers can be maximized. The carbon nanotubes (CNTs)/polysulfone (PSF)/polyimide (PI) thin film sensor in this paper is obtained by the self-assembly of a PSF/PI asymmetric porous membrane which is prepared by a phase inversion method through vacuum filtration of SWCNTs. It is a new structure for a practical CNT sensor that can take into account both 'composite health monitoring and damage warning' and 'composite mechanical enhancement'. The new structure of the CNTs/PSF/PI film sensor is divided into two parts. The upper part consists of small-aperture finger-like holes filled with SWCNTs (the SWCNT content is 0.0127 mg cm-2). The lower part consists of large-aperture cavities conducive to resin infiltration, which enhance the interface bonding force between the sensor and the composite material. This unique structure allows the CNTs/PSF/PI film sensor to change the influence of the embedded sensor from 'introducing defects' to 'local enhancement', and the mechanical strength of the enhanced specimen can reach up to 1.68 times that of the original specimen, and the service interval can reach 2.01 times that of the original specimen. In addition, the CNTs/PSF/PI film sensor also has good sensitivity (GF = 2.54) and extremely high linearity (R2 = 0.9995), and has excellent follow-up and interface bonding ability. It can also maintain excellent fatigue resistance and stability over 46 500 vibration cycles, which provides new research ideas and research methods for the field of composite-life monitoring sensors.

6.
Biology (Basel) ; 13(3)2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38534463

RESUMO

To uncover the internal mechanisms of various drought stress intensities affecting the soluble sugar content in organs and its regulation by endogenous abscisic acid (ABA), we selected the saplings of Platycladus orientalis, a typical tree species in the Beijing area, as our research subject. We investigated the correlation between tree soluble sugars and endogenous ABA in the organs (comprised of leaf, branch, stem, coarse root, and fine root) under two water treatments. One water treatment was defined as T1, which stopped watering until the potted soil volumetric water content (SWC) reached the wilting coefficient and then rewatered the sapling. The other water treatment, named T2, replenished 95% of the total water loss of one potted sapling every day and irrigated the above-mentioned sapling after its SWC reached the wilt coefficients. The results revealed that (1) the photosynthetic physiological parameters of P. orientalis were significantly reduced (p < 0.05) under fast and slow drought processes. The photosynthetic physiological parameters of P. orientalis in the fast drought-rehydration treatment group recovered faster relative to the slow drought-rehydration treatment group. (2) The fast and slow drought treatments significantly (p < 0.05) increased the ABA and soluble sugar contents in all organs. The roots of the P. orientalis exhibited higher sensitivity in ABA and soluble sugar content to changes in soil moisture dynamics compared to other organs. (3) ABA and soluble sugar content of P. orientalis showed a significant positive correlation (p < 0.05) under fast and slow drought conditions. During the rehydration stage, the two were significantly correlated in the T2 treatment (p < 0.05). In summary, soil drought rhythms significantly affected the photosynthetic parameters, organ ABA, and soluble sugar content of P. orientalis. This study elucidates the adaptive mechanisms of P. orientalis plants to drought and rehydration under the above-mentioned two water drought treatments, offering theoretical insights for selecting and cultivating drought-tolerant tree species.

7.
ACS Appl Mater Interfaces ; 15(51): 59655-59670, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38085975

RESUMO

Designing flexible wearable sensors with a wide sensing range, high sensitivity, and high stability is a vulnerable research direction with a futuristic field to study. In this paper, Ti3C2Tx MXene/carbon nanotube (CNT)/thermoplastic polyurethane (TPU)/polysulfone (PSF) composite films with excellent sensor performance were obtained by self-assembly of conductive fillers in TPU/PSF porous films with an asymmetric structure through vacuum filtration, and the porous films were prepared by the phase inversion method. The composite films consist of the upper part with finger-like "cavities" filled by MXene/CNTs, which reduces the microcracks in the conductive network during the tensile process, and the lower part has smaller apertures of a relatively dense resin cortex assisting the recovery process. The exclusive layer structure of the MXene/CNTs/TPU/PSF film sensor, with a thickness of 46.95 µm, contains 0.0339 mg/cm2 single-walled carbon nanotubes (SWNTs) and 0.348 mg/cm2 MXene only, providing functional range (0-80.7%), high sensitivity (up to 1265.18), and excellent stability and durability (stable sensing under 2300 fatigue tests, viable to the initial resistance), endurably cycled under large strains with serious damage to the conductive network. Finally, the MXene/CNTs/TPU/PSF film sensor is usable for monitoring pulse, swallow, tiptoe, and various joint bends in real time and distributing effective electrical signals. This paper implies that the MXene/CNTs/TPU/PSF film sensor has broad prospects in pragmatic applications.


Assuntos
Nanotubos de Carbono , Humanos , Poliuretanos , Córtex Cerebral
8.
J Mol Histol ; 54(1): 25-39, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36344754

RESUMO

More and more studies have shown that Branched chain amino acid transaminase 1 (BCAT1) is involved in the occurrence and development of a variety of tumors. However, the mechanism of its occurrence and development in hepatocellular carcinoma (HCC) remains unclear. Here, we demonstrated the relationship between BCAT1 and AKT signaling pathway, as well as EMT, and the clinical significance of BCAT1 by using BCAT1 expression in 5 cell lines and 113 liver cancer and non-liver cancer tissue samples. The results showed that the expression of AKT was positively correlated with BCAT1 in HCC tissues, and BCAT1 could promote the progression of HCC cells through the AKT signaling pathway. Clinical analysis and Bioinformatics technology analysis revealed that BCAT1 was correlated with poor prognosis, and BCAT1 expression in the HCC tissues was evidently correlated with tumor number, vascular invasion, Edmondson grade and TNM stage (P < 0.05). In vitro studies showed that BCAT1 increased the invasion and migration of in MHCC-97H cells a d Huh7 cells. By inhibiting the expression of the BCAT1 gene, we detected the corresponding changes in the expression levels of Twist, E-cadherin and Vimentin, confirming that BCAT1 may promote the invasion and migration of HCC cells through epithelial-mesenchymal transformation (EMT). Overall, BCAT1 can activate AKT signaling pathway and EMT to promote the development and metastasis of HCC cells. this study may provide new ideas and directions for cancer diagnosis and treatment.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Prognóstico , Transição Epitelial-Mesenquimal/genética , Linhagem Celular Tumoral , Transdução de Sinais , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Transaminases/genética , Transaminases/metabolismo
9.
Plants (Basel) ; 12(15)2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37570989

RESUMO

To explore whether there were differences among the patterns of response of grasslands with different levels of degradation to extreme drought events and nitrogen addition, three grasslands along a degradation gradient (extremely, moderately, and lightly degraded) were selected in the Bashang area of northern China using the human disturbance index (HDI). A field experiment with simulated extreme spring drought, nitrogen addition, and their interaction was conducted during the growing seasons of 2020 and 2021. The soil moisture, aboveground biomass, and composition of the plant community were measured. The primary results were as follows. (1) Drought treatment caused soil drought stress, with moderately degraded grassland being the most affected, which resulted in an 80% decrease in soil moisture and a 78% decrease in aboveground biomass. The addition of nitrogen did not mitigate the impact of drought. Moreover, the aboveground net primary production (ANPP) in 2021 was less sensitive to spring drought than in 2020. (2) The community composition changed after 2 years of drought treatment, particularly for the moderately degraded grasslands with annual forbs, such as Salsola collina, increasing significantly in biomass proportion, which led to a trend of exacerbated degradation (higher HDI). This degradation trend decreased under the addition of nitrogen. (3) The variation in drought sensitivities of the ANPP was primarily determined by the proportion of plants based on the classification of degradation indicators in the community, with higher proportions of intermediate degradation indicator species exhibiting more sensitivity to spring drought. These findings can help to provide scientific evidence for the governance and restoration of regional degraded grassland under frequent extreme weather conditions.

10.
ACS Appl Mater Interfaces ; 14(13): 15504-15516, 2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35344347

RESUMO

The universal application of wearable strain sensors in various situations for human-activity monitoring is considerably limited by the contradiction between high sensitivity and broad working range. There still remains a huge challenge to design sensors featuring simultaneous broad working range and high sensitivity. Herein, a typical bilayer-conductive structure Ti3C2Tx MXene/carbon nanotubes (CNTs)/thermoplastic polyurethane (TPU) composite film was developed by a simple and scalable vacuum filtration process utilizing a porous electrospun thermoplastic polyurethane (TPU) mat as a skeleton. The MXene/CNTs/TPU strain sensor is composed of two parts: a brittle densely stacked MXene upper lamella and a flexible MXene/CNT-decorated fibrous network lower layer. Benefiting from the synergetic effect of the two parts along with hydrogen-bonding interactions between the porous TPU fiber mat and MXene sheets, the MXene/CNTs/TPU strain sensor possesses both a broad working range (up to 330%) and high sensitivity (maximum gauge factor of 2911) as well as superb long-term durability (2600 cycles under the strain of 50%). Finally, the sensor can be successfully employed for human movement monitoring, from tiny facial expressions, respiration, and pulse beat to large-scale finger and elbow bending, demonstrating a promising and attractive application for wearable devices and human-machine interaction.


Assuntos
Nanotubos de Carbono , Dispositivos Eletrônicos Vestíveis , Condutividade Elétrica , Humanos , Movimento (Física) , Nanotubos de Carbono/química , Poliuretanos
11.
Ying Yong Sheng Tai Xue Bao ; 33(6): 1466-1474, 2022 Jun.
Artigo em Zh | MEDLINE | ID: mdl-35729121

RESUMO

In this study, we examined the regularity of phenological rhythmical change of plant water-soluble compound δ13C (δ13Cwsc) in spring for two typical tree species in the warm temperate zone of China, Pinus tabuliformis and Robinia pseudoacacia. The δ13Cwsc in each organ of those two species in the spring phenological period were measured to explore the relationship between δ13Cwsc and related environmental factors. The results showed that there were significant differences in δ13Cwsc values of each organ between P. tabuliformis and R. pseudoacacia, with higher δ13Cwsc(-25.03‰±0.01‰) in the new shoot of P. tabuliformis. The δ13Cwsc value in the non-photosynthetic organs were 0.83‰-1.8‰ higher than that in the photosynthetic organs, while the δ13Cwsc value in the aboveground part was generally lower than that in the underground part. As spring progressing, different carbon storage strategies were found between two species. When the terminal bud of P. tabuliformis opened, the carbon was obtained from the proximal old leaves. At the beginning of leaf development, photosynthetic products accumulated by old leaves could not meet the growth requirements for new leaves and roots, with 90% of which depending on the carbon reserve in branches and stems. When full leaf having developed, the photosynthetic function of both new and old leaves recovered and the carbon consumed by branches and stems was gradually replenished. For R. pseudoacacia, at the beginning of leaf bud opening and leaf spreading, branches were the main carbon source for new leaves and roots. When leaves were fully unfolded, mature leaves with high capacity of carbon sequestration became the primary carbon source. Results of principal component analysis showed that temperature during observation period, ≥10 ℃ accumulated temperature, sunshine duration and solar radiation were the main factors influencing δ13Cwsc, which could explained 86.3% of the total variation. The δ13Cwsc values of both species was negatively correlated with temperature and relative humidity, but positively correlated with the difference of saturated water pressure, ≥10 ℃ accumulated temperature and sunshine duration. The main environmental factors affecting plant δ13Cwsc varied during the phenological process. Our results could provide a reference for more accurate estimation of spring organ carbon distribution pattern of regional typical tree species, and also a theoretical basis for formulating scientific and reasonable forest management strategy.


Assuntos
Árvores , Água , Carbono , Isótopos de Carbono , Florestas , Folhas de Planta , Estações do Ano
12.
Ying Yong Sheng Tai Xue Bao ; 33(8): 2153-2160, 2022 Aug.
Artigo em Zh | MEDLINE | ID: mdl-36043822

RESUMO

Based on community investigation data from grasslands on two different soil parent material types (loess and sand parent materials) and under three human utilization modes in the Saihan Ullah Reserve, we calculated human disturbance index (HDI) and biodiversity indices and analyzed the interactions between species diversity and degradation levels. The results showed that degradation status varied across different soil parent material types and human utilization modes, and that degradation levels of loess and sand parent materials both increased with the enhancement of human utilization intensification. HDI of loess parent material grasslands (mean value of 1.21) was lower than sand parent material grasslands (mean value of 1.48) in the same human utilization. Biodiversity indices declined with soil sandy degree and the utilization intensification. The mean values of Margarlef richness index, Shannon diversity index, Simpson dominance index and Pielou evenness index were between 1.57-4.27, 1.16-2.39, 0.76-0.87, and 0.71-0.80, respectively. The Margalef richness index, Shannon diversity index and Simpson dominance index decreased with increasing HDI, while Pielou evenness index increased. Overgrazing could lead to serious threat on both grasslands with soil parent material types, and the optimum utilization mode of loess and sand parent material grasslands were enclosure with mowing and seasonal grazing. In the future works of biodiversity conservation, it is important to consider the influence of both different soil patent material and human utilization modes of grassland. It is urgent to develop different utilization modes for grassland under different soil parent material types, which would enhance the matchness of grassland restoration and management with local conditions.


Assuntos
Pradaria , Solo , Biodiversidade , Humanos , Plantas/metabolismo , Areia
13.
Biosensors (Basel) ; 12(5)2022 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-35624613

RESUMO

An exoskeleton, a wearable device, was designed based on the user's physical and cognitive interactions. The control of the exoskeleton uses biomedical signals reflecting the user intention as input, and its algorithm is calculated as an output to make the movement smooth. However, the process of transforming the input of biomedical signals, such as electromyography (EMG), into the output of adjusting the torque and angle of the exoskeleton is limited by a finite time lag and precision of trajectory prediction, which result in a mismatch between the subject and exoskeleton. Here, we propose an EMG-based single-joint exoskeleton system by merging a differentiable continuous system with a dynamic musculoskeletal model. The parameters of each muscle contraction were calculated and applied to the rigid exoskeleton system to predict the precise trajectory. The results revealed accurate torque and angle prediction for the knee exoskeleton and good performance of assistance during movement. Our method outperformed other models regarding the rate of convergence and execution time. In conclusion, a differentiable continuous system merged with a dynamic musculoskeletal model supported the effective and accurate performance of an exoskeleton controlled by EMG signals.


Assuntos
Exoesqueleto Energizado , Simulação por Computador , Eletromiografia/métodos , Movimento , Torque
14.
Rev Sci Instrum ; 92(1): 015005, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33514220

RESUMO

Intravascular ultrasound (IVUS) has become a useful tool in the detection of coronary artery disease. However, non-uniform rotation distortion (NURD) reduces the image quality. In order to suppress the influence of NURD, a piezoelectric motor that can meet the requirements of IVUS catheters has been proposed. The motor has a diameter of 1 mm and a length of 10 mm using the new polarization direction proposed in the paper. A 45° mirror is fixed on the top of the motor to reflect the ultrasound transmitted from the transducer. The manufacture and drive of the piezoelectric motor is simple, and the maximum speed of the piezoelectric motor can reach 6450 rpm under the voltage of 20Vp-p. The minimum power required by the rotating motor is only 0.038 W, which can be directly driven by the signal generator without a power amplifier. The motor can operate at a low voltage and still has a high and stable speed. Meanwhile, the speed of the motor is controllable and has a satisfactory stability with a maximum angular error of 8°. The images detected by the cooperation of the motor and the ultrasonic transducer are also shown, which indicates that the motor has the rotational stability that meets the imaging requirements and the potential for application in the IVUS catheter to help improve the image quality of the coronary arteries and prevent and help treat potential diseases.


Assuntos
Catéteres , Vasos Coronários/diagnóstico por imagem , Desenho de Equipamento , Ultrassonografia/instrumentação , Eletricidade , Humanos
15.
Environ Pollut ; 281: 117009, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33813194

RESUMO

Air pollution caused by PM2.5 particles is a critical issue for public health that adversely affects people living in urban cities. Short-term Mega-events such as international meetings, sports tournaments, and traditional festivals can profoundly influence the local air quality. However, the extent of these influences and their role in improving or deteriorating the local air quality is still unclear. By collecting relative research from 75 publications based on more than 37 cities worldwide, we conducted a systematic review and meta-analysis. We calculated the log response ratio (RR) of the treatment (during) and control periods (before and after) of the Mega-events. The short-term policy control measures enacted during the Mega-Events consisting of meetings caused a significant decline (by -44.06%) in the ambient PM2.5 concentration. The mean daily PM2.5 concentration reduced from more than 100.00 µg/m3 before the events to 60.39 µg/m3, which is below the WHO (World Health Organization) interim target - 1 (75 µg/m3). On the contrary, setting off fireworks during the festival increased the ambient PM2.5 concentrations by 89.57% on average, with a mean daily value of 254.22 µg/m3. The variations in the effects of all event types on the air quality were primarily influenced by the background PM2.5 concentrations, with a negative correlation throughout. Moreover, the impact of events with policy control measures was also influenced by the year of the event, level of control, and location (suburban/urban) of the monitoring sites. Our findings provide evidence of the potential of human intervention on PM2.5 pollution reduction. We further highlight the crucial role of background pollution level in implementing policies during the Mega-events, which can benefit the environmental governance of developing countries.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Cidades , Conservação dos Recursos Naturais , Monitoramento Ambiental , Política Ambiental , Humanos , Material Particulado/análise
16.
J Neural Eng ; 18(6)2021 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-34706357

RESUMO

Objective. Hyperscanning is an emerging technology that concurrently scans the neural dynamics of multiple individuals to study interpersonal interactions. In particular, hyperscanning with electroencephalography (EEG) is increasingly popular owing to its mobility and its ability to allow studying social interactions in naturalistic settings at the millisecond scale.Approach.To align multiple EEG time series with sophisticated event markers in a single time domain, a precise and unified timestamp is required for stream synchronization. This study proposes a clock-synchronized method that uses a custom-made RJ45 cable to coordinate the sampling between wireless EEG amplifiers to prevent incorrect estimation of interbrain connectivity due to asynchronous sampling. In this method, analog-to-digital converters are driven by the same sampling clock. Additionally, two clock-synchronized amplifiers leverage additional radio frequency channels to keep the counter of their receiving dongles updated, which guarantees that binding event markers received by the dongle with the EEG time series have the correct timestamp.Main results.The results of two simulation experiments and one video gaming experiment reveal that the proposed method ensures synchronous sampling in a system with multiple EEG devices, achieving near-zero phase lag and negligible amplitude difference between the signals.Significance.According to all of the signal-similarity metrics, the suggested method is a promising option for wireless EEG hyperscanning and can be utilized to precisely assess the interbrain couplings underlying social-interaction behaviors.


Assuntos
Encéfalo , Eletroencefalografia , Amplificadores Eletrônicos , Mapeamento Encefálico/métodos , Eletroencefalografia/métodos , Humanos , Relações Interpessoais
17.
Int J Mol Sci ; 11(5): 2039-55, 2010 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-20559500

RESUMO

Stem cells, a special subset of cells derived from embryo or adult tissues, are known to present the characteristics of self-renewal, multiple lineages of differentiation, high plastic capability, and long-term maintenance. Recent reports have further suggested that neural stem cells (NSCs) derived from the adult hippocampal and subventricular regions possess the utilizing potential to develop the transplantation strategies and to screen the candidate agents for neurogenesis, neuroprotection, and neuroplasticity in neurodegenerative diseases. In this article, we review the roles of NSCs and other stem cells in neuroprotective and neurorestorative therapies for neurological and psychiatric diseases. We show the evidences that NSCs play the key roles involved in the pathogenesis of several neurodegenerative disorders, including depression, stroke and Parkinson's disease. Moreover, the potential and possible utilities of induced pluripotent stem cells (iPS), reprogramming from adult fibroblasts with ectopic expression of four embryonic genes, are also reviewed and further discussed. An understanding of the biophysiology of stem cells could help us elucidate the pathogenicity and develop new treatments for neurodegenerative disorders. In contrast to cell transplantation therapies, the application of stem cells can further provide a platform for drug discovery and small molecular testing, including Chinese herbal medicines. In addition, the high-throughput stem cell-based systems can be used to elucidate the mechanisms of neuroprotective candidates in translation medical research for neurodegenerative diseases.


Assuntos
Células-Tronco Adultas/transplante , Hipocampo/metabolismo , Células-Tronco Neurais/transplante , Doenças Neurodegenerativas/terapia , Medicina Regenerativa/métodos , Transplante de Células-Tronco , Células-Tronco Adultas/metabolismo , Células-Tronco Adultas/patologia , Animais , Hipocampo/patologia , Humanos , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologia , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia
18.
PLoS One ; 15(12): e0244198, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33373388

RESUMO

High temperatures induce early bolting in lettuce (Lactuca sativa L.), which decreases both quality and production. However, knowledge of the molecular mechanism underlying high temperature promotes premature bolting is lacking. In this study, we compared lettuce during the bolting period induced by high temperatures (33/25 °C, day/night) to which raised under controlled temperatures (20/13 °C, day/night) using iTRAQ-based phosphoproteomic analysis. A total of 3,814 phosphorylation sites located on 1,766 phosphopeptides from 987 phosphoproteins were identified after high-temperature treatment,among which 217 phosphoproteins significantly changed their expression abundance (116 upregulated and 101 downregulated). Most phosphoproteins for which the abundance was altered were associated with the metabolic process, with the main molecular functions were catalytic activity and transporter activity. Regarding the functional pathway, starch and sucrose metabolism was the mainly enriched signaling pathways. Hence, high temperature influenced phosphoprotein activity, especially that associated with starch and sucrose metabolism. We suspected that the lettuce shorten its growth cycle and reduce vegetative growth owing to changes in the contents of starch and soluble sugar after high temperature stress, which then led to early bolting/flowering. These findings improve our understanding of the regulatory molecular mechanisms involved in lettuce bolting.


Assuntos
Resposta ao Choque Térmico , Lactuca/metabolismo , Fosfoproteínas/metabolismo , Proteoma/metabolismo , Amido/metabolismo , Sacarose/metabolismo , Lactuca/crescimento & desenvolvimento , Fosfoproteínas/genética , Proteoma/genética
19.
Nat Commun ; 11(1): 4611, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32929072

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) and cancer-associated cachexia (CAC) are multifactorial and characterized by dysregulated inflammatory networks. Whether the proinflammatory cytokine IL-20 is involved in the complex networks of PDAC and CAC remains unclear. Here, we report that elevated IL-20 levels in tumor tissue correlate with poor overall survival in 72 patients with PDAC. In vivo, we establish a transgenic mouse model (KPC) and an orthotopic PDAC model and examine the therapeutic efficacy of an anti-IL-20 monoclonal antibody (7E). Targeting IL-20 not only prolongs survival and attenuates PD-L1 expression in both murine models but also inhibits tumor growth and mitigates M2-like polarization in the orthotopic PDAC model. Combination treatment with 7E and an anti-PD-1 antibody shows better efficacy in inhibiting tumor growth than either treatment alone in the orthotopic PDAC model. Finally, 7E mitigates cachexic symptoms in CAC models. Together, we conclude IL-20 is a critical mediator in PDAC progression.


Assuntos
Anticorpos Monoclonais/farmacologia , Antígeno B7-H1/metabolismo , Interleucinas/antagonistas & inibidores , Modelos Biológicos , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Animais , Linfócitos T CD8-Positivos/metabolismo , Caquexia , Carcinoma Pulmonar de Lewis/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Interleucinas/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos Endogâmicos C57BL , Neoplasias Pancreáticas/imunologia , Análise de Sobrevida , Resultado do Tratamento , Triglicerídeos/sangue , Regulação para Cima/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
20.
RSC Adv ; 8(39): 22078-22085, 2018 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-35541750

RESUMO

This paper proposes a flexible and highly sensitive carbon nanotube buckypaper as a sensing layer embedded within a composite for cure monitoring applications. The buckypaper was fabricated with mono-dispersion of multi-wall carbon nanotubes by a spray-vacuum filtration method. Six different curing conditions (with maximum heating temperatures of 120 °C, 108 °C, 95 °C, 90 °C, 85 °C and 75 °C) were designed to characterize and analyze the electromechanical response of the BP sensor to the composite structure, and the results indicated that the temperature coefficient of resistance of buckypaper is associated to the resin curing behavior. The critical value (-7.18 × 10-4 °C-1) of the temperature coefficient of resistance was determined. Experimental results also show that a stable three-dimensional network of resin molecular chains is formed and that the polymer presents a glassy state when the value of the temperature coefficient of resistance is greater than the critical value. Based on this relationship, a hypothesis was raised that for the complete curing of the resin, the temperature coefficient of resistance of the buckypaper sensor should meet the critical value condition, which was also consistent with the differential scanning calorimetry testing of the curing degree. The buckypaper sensor was found to be sensitive to the curing degree of the resin, and has a promising future in applications in composite manufacturing processes. Moreover, the properties of composite components are indeed able to be improved via the monitoring and optimization of the curing parameters.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA