Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 98
Filtrar
1.
Proc Natl Acad Sci U S A ; 120(41): e2309952120, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37782810

RESUMO

Earth's inner core is predominantly composed of solid iron (Fe) and displays intriguing properties such as strong shear softening and an ultrahigh Poisson's ratio. Insofar, physical mechanisms to explain these features coherently remain highly debated. Here, we have studied longitudinal and shear wave velocities of hcp-Fe (hexagonal close-packed iron) at relevant pressure-temperature conditions of the inner core using in situ shock experiments and machine learning molecular dynamics (MLMD) simulations. Our results demonstrate that the shear wave velocity of hcp-Fe along the Hugoniot in the premelting condition, defined as T/Tm (Tm: melting temperature of iron) above 0.96, is significantly reduced by ~30%, while Poisson's ratio jumps to approximately 0.44. MLMD simulations at 230 to 330 GPa indicate that collective motion with fast diffusive atomic migration occurs in premelting hcp-Fe primarily along [100] or [010] crystallographic direction, contributing to its elastic softening and enhanced Poisson's ratio. Our study reveals that hcp-Fe atoms can diffusively migrate to neighboring positions, forming open-loop and close-loop clusters in the inner core conditions. Hcp-Fe with collective motion at the inner core conditions is thus not an ideal solid previously believed. The premelting hcp-Fe with collective motion behaves like an extremely soft solid with an ultralow shear modulus and an ultrahigh Poisson's ratio that are consistent with seismic observations of the region. Our findings indicate that premelting hcp-Fe with fast diffusive motion represents the underlying physical mechanism to help explain the unique seismic and geodynamic features of the inner core.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38558156

RESUMO

Metastasis is a major contributor to treatment failure and death in urological cancers, representing an important biomedical challenge at present. Metastases form as a result of cancer cells leaving the primary site, entering the vasculature and lymphatic vessels, and colonizing clones elsewhere in the body. However, the specific regulatory mechanisms of action underlying the metastatic process of urological cancers remain incompletely elucidated. With the deepening of research, circular RNAs (circRNAs) have been found to not only play a significant role in tumor progression and prognosis but also show aberrant expression in various tumor metastases, consequently impacting tumor metastasis through multiple pathways. Therefore, circRNAs are emerging as potential tumor markers and treatment targets. This review summarizes the research progress on elucidating how circRNAs regulate the urological cancer invasion-metastasis cascade response and related processes, as well as their role in immune microenvironment remodeling and circRNA vaccines. This body of work highlights circRNA regulation as an emerging therapeutic target for urological cancers, which should motivate further specific research in this regard.

3.
Plant Cell ; 34(10): 3577-3610, 2022 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-35766883

RESUMO

Moso bamboo (Phyllostachys edulis) shows remarkably rapid growth (114.5 cm/day), but the underlying biological mechanisms remain unclear. After examining more than 12,750 internodes from more than 510 culms from 17 Moso populations, we identified internode 18 as a representative internode for rapid growth. This internode includes a 2-cm cell division zone (DZ), a cell elongation zone up to 12 cm, and a secondary cell wall (SCW) thickening zone. These zones elongated 11.8 cm, produced approximately 570,000,000 cells, and deposited ∼28 mg g-1 dry weight (DW) lignin and ∼44 mg g-1 DW cellulose daily, far exceeding vegetative growth observed in other plants. We used anatomical, mathematical, physiological, and genomic data to characterize development and transcriptional networks during rapid growth in internode 18. Our results suggest that (1) gibberellin may directly trigger the rapid growth of Moso shoots, (2) decreased cytokinin and increased auxin accumulation may trigger cell DZ elongation, and (3) abscisic acid and mechanical pressure may stimulate rapid SCW thickening via MYB83L. We conclude that internode length involves a possible tradeoff mediated by mechanical pressure caused by rapid growth, possibly influenced by environmental temperature and regulated by genes related to cell division and elongation. Our results provide insight into the rapid growth of Moso bamboo.


Assuntos
Giberelinas , Transcriptoma , Ácido Abscísico/farmacologia , Citocininas , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Lignina , Poaceae/genética , Transcriptoma/genética
4.
Phys Chem Chem Phys ; 26(8): 7001-7009, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38345314

RESUMO

Layered VS2 has been widely used as a battery anode material owing to its large specific surface area and controllable ion-transport channel. However, its semiconductor properties and poor cycling stability seriously limit its further applications. Herein, a two-dimensional BN/VS2 heterostructure (BVH) was constructed as an anode material for rechargeable metal-ion batteries (RMIBs). Demonstrated using first principles calculations, BVH exhibits a metallic property due to lattice stress between monolayer BN and VS2. BVH displays low ion diffusion energy barriers (0.13, 0.43, and 0.56 eV) and high theoretical capacities (447, 553.5, and 340.7 mA h g-1) for Li+, Na+, and Mg2+ storage. In BVH, the VS2 layer as the main redox center supports charge transfer, while the inactive BN layer enables high structural stability. This synergistic effect is expected to simultaneously achieve a high rate, high capacity, and long life. This design provides an important insight into developing new anode materials for RMIBs.

5.
BMC Med Imaging ; 24(1): 12, 2024 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-38182987

RESUMO

BACKGROUND: Lung cancer remains a leading cause of death among cancer patients. Computed tomography (CT) plays a key role in lung cancer screening. Previous studies have not adequately quantified the effect of scanning protocols on the detected tumor size. The aim of this study was to assess the effect of various CT scanning parameters on tumor size and densitometry based on a phantom study and to investigate the optimal energy and mA image quality for screening assessment. METHODS: We proposed a new model using the LUNGMAN N1 phantom multipurpose anthropomorphic chest phantom (diameters: 8, 10, and 12 mm; CT values: - 100, - 630, and - 800 HU) to evaluate the influence of changes in tube voltage and tube current on the size and density of pulmonary nodules. In the LUNGMAN N1 model, three types of simulated lung nodules representing solid tumors of different sizes were used. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were used to evaluate the image quality of each scanning combination. The consistency between the calculated results based on segmentation from two physicists was evaluated using the interclass correlation coefficient (ICC). RESULTS: In terms of nodule size, the longest diameters of ground-glass nodules (GGNs) were closest to the ground truth on the images measured at 100 kVp tube voltage, and the longest diameters of solid nodules were closest to the ground truth on the images measured at 80 kVp tube voltage. In respect to density, the CT values of GGNs and solid nodules were closest to the ground truth when measured at 80 kVp and 100 kVp tube voltage, respectively. The overall agreement demonstrates that the measurements were consistent between the two physicists. CONCLUSIONS: Our proposed model demonstrated that a combination of 80 kVp and 140 mA scans was preferred for measuring the size of the solid nodules, and a combination of 100 kVp and 100 mA scans was preferred for measuring the size of the GGNs when performing lung cancer screening. The CT values at 80 kVp and 100 kVp were preferred for the measurement of GGNs and solid nodules, respectively, which were closest to the true CT values of the nodules. Therefore, the combination of scanning parameters should be selected for different types of nodules to obtain more accurate nodal data.


Assuntos
Neoplasias Pulmonares , Nódulos Pulmonares Múltiplos , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Detecção Precoce de Câncer , Nódulos Pulmonares Múltiplos/diagnóstico por imagem , Imagens de Fantasmas , Cintilografia
6.
Food Microbiol ; 119: 104459, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38225037

RESUMO

Lemon essential oil (LEO) is a common natural antibacterial substance, and encapsulating LEO into nanoemulsions (NEs) can improve their stability and broaden its application. Our study aimed to investigate the bacterial inhibitory effect of LEO-NEs against Escherichia coli (E. coli). Results showed that the minimum inhibitory concentration (MIC) of LEO-NEs was 6.25 mg/mL, and the time-kill curve showed that E. coli were significantly killed by LEO-NEs after 5 h of treatment at 1MIC. Flow-cytometry analysis showed that LEO-NEs adversely affected the cell-membrane depolarisation, cell-membrane integrity, and efflux pump function of E. coli. Confocal laser scanning microscopy demonstrated that 8MIC of LEO-NEs induced changes in the cell-membrane permeability and cell-wall integrity of E. coli. Proteomic results suggested that the mode of action LEO-NEs against E. coli was to enhance bacterial chemotaxis and significantly inhibit ribosomal assembly. They may also affect butyric acid, ascorbic acid and aldehyde metabolism, and sulphur-relay system pathways. In conclusion, LEO-NEs had potential application as a natural antibacterial agent for the control of E. coli in the food industry.


Assuntos
Escherichia coli , Óleos Voláteis , Proteômica , Antibacterianos/farmacologia , Óleos Voláteis/farmacologia , Membrana Celular , Bactérias
7.
Int J Mol Sci ; 25(3)2024 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-38339154

RESUMO

Increasingly globally prevalent obesity and related metabolic disorders have underscored the demand for safe and natural therapeutic approaches, given the limitations of weight loss drugs and surgeries. This study compared the phytochemical composition and antioxidant activity of five different varieties of citrus physiological premature fruit drop (CPFD). Untargeted metabolomics was employed to identify variations in metabolites among different CPFDs, and their antilipidemic effects in vitro were assessed. The results showed that Citrus aurantium L. 'Daidai' physiological premature fruit drop (DDPD) and Citrus aurantium 'Changshan-huyou' physiological premature fruit drop (HYPD) exhibited higher levels of phytochemicals and stronger antioxidant activity. There were 97 differential metabolites identified in DDPD and HYPD, including phenylpropanoids, flavonoids, alkaloids, organic acids, terpenes, and lipids. Additionally, DDPD and HYPD demonstrated potential antilipidemic effects against oleic acid (OA)-induced steatosis in HepG2 hepatocytes and 3T3-L1 adipocytes. In conclusion, our findings reveal the outstanding antioxidant activity and antilipidemic effects of CPFD, indicating its potential use as a natural antioxidant and health supplement and promoting the high-value utilization of this resource.


Assuntos
Antioxidantes , Citrus , Fenilenodiaminas , Antioxidantes/metabolismo , Citrus/metabolismo , Frutas/química , Flavonoides/farmacologia , Extratos Vegetais/química
8.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 41(3): 469-475, 2024 Jun 25.
Artigo em Zh | MEDLINE | ID: mdl-38932532

RESUMO

Accurately evaluating the local biomechanics of arterial wall is crucial for diagnosing and treating arterial diseases. Indentation measurement can be used to evaluate the local mechanical properties of the artery. However, the effects of the indenter's geometric structure and the analysis theory on measurement results remain uncertain. In this paper, four kinds of indenters were used to measure the pulmonary aorta, the proximal thoracic aorta and the distal thoracic aorta in pigs, and the arterial elastic modulus was calculated by Sneddon and Sirghi theory to explore the influence of the indenter geometry and analysis theory on the measured elastic modulus. The results showed that the arterial elastic modulus measured by cylindrical indenter was lower than that measured by spherical indenter. In addition, compared with the calculated results of Sirghi theory, the Sneddon theory, which does not take adhesion forces in account, resulted in slightly larger elastic modulus values. In conclusion, this study provides parametric support for effective measurement of arterial local mechanical properties by millimeter indentation technique.


Assuntos
Aorta Torácica , Módulo de Elasticidade , Artéria Pulmonar , Animais , Suínos , Fenômenos Biomecânicos , Aorta Torácica/fisiologia , Aorta Torácica/anatomia & histologia , Artéria Pulmonar/fisiologia , Estresse Mecânico , Artérias/fisiologia
9.
Exp Eye Res ; 233: 109541, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37321365

RESUMO

Ocular diseases and treatment related to rhegmatogenous retinal detachment (RRD) are highly correlated with retinal adhesion behavior. Therefore, this paper proposes to study the adhesion behavior of the intact retina. This can provide theoretical guidance for the treatment and research of retinal detachment (RD) related diseases. To systematically analyze this aspect, two experiments were performed on the porcine retina. The pull-off test combined with the modified JKR theory was used to study the adhesion behavior of the vitreoretinal interface, while the peeling test was used to study the adhesion behavior of the chorioretinal interface. In addition, the adhesion phase involved in the pull-off test was simulated and analyzed by building the corresponding finite element method (FEM). The experimental results of adhesion force on the vitreoretinal interface were obtained by pull-off test with five sizes of rigid punch. The experimental value of the pull-off force FPO tends to increase gradually with increasing punch radius in the range of 0.5-4 mm. A comparison of the experimental results with the simulation results shows that they are in a well agreement. And there is no statistical difference between the experimental and theoretical values of the pull-off force FPO. In addition, the values of retinal adhesion work were also obtained by pull-off test. Interestingly, there is a significant scale effect of the retinal work of adhesion. Finally, the peeling test gave a maximum peeling strength TMax of about 13 mN/mm and a stable peeling strength TD of about 11 mN/mm between the retina and the choroid. The pull-off test well shows the process of retinal traction by the diseased vitreous at the beginning of RRD. A comparison of the experimental results with the finite element results verifies the accuracy of the simulation. The peeling test well investigated the adhesion behavior between the retina and the choroid and obtained key biomechanical data (peeling strength, etc.). The combination of the two experiments allows a more systematic study of the whole retina. This research can provide more complete material parameters for finite element modeling of retina-related diseases, and it also can provide the theoretical guidance for individualized design of retinal repair surgery.


Assuntos
Descolamento Retiniano , Doenças Retinianas , Animais , Suínos , Descolamento Retiniano/cirurgia , Descolamento Retiniano/patologia , Vitrectomia/métodos , Retina/patologia , Doenças Retinianas/patologia , Corpo Vítreo/patologia , Aderências Teciduais
10.
Phys Chem Chem Phys ; 25(38): 26289-26297, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37747069

RESUMO

Rechargeable magnesium batteries (RMBs) are considered as highly promising energy storage systems. However, the lack of cathode materials with fast Mg2+ diffusion kinetics and high energy density severely hinders the development of RMBs. Herein, a two-dimensional (2D) VO2/VS2 heterostructure as a RMB cathode material is proposed by introducing an O-V-O layer in VS2 to improve the discharge voltage and specific capacity while keeping the fast Mg2+ diffusion kinetics. Based on first principle calculations, the geometric structures, electronic characteristics of the VO2/VS2 heterostructure, and the adsorption properties and diffusion behaviors of Mg2+ in VO2/VS2 are systematically studied. The metallic properties of VO2/VS2 and a relatively low diffusion barrier of Mg2+ (0.6 eV) in VO2/VS2 enable a large potential in delivering high rate performance in actual RMBs. Compared with traditional VS2 materials (1.25 V), the average discharge platform of VO2/VS2 could be increased to 1.7 V. The theoretical capacities of the layered VS2 and VO2/VS2 are calculated as 233 and 301 mA h g-1, respectively. Thus, the VO2/VS2 heterostructure exhibits a high theoretical energy density of 511.7 W h kg-1, significantly surpassing that of VS2 (291.3 W h kg-1). This work provides important guidance for designing high-energy and high-rate 2D heterostructure cathode materials for RMBs and other multivalent ion batteries.

11.
J Nanobiotechnology ; 21(1): 412, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37936120

RESUMO

The immune system is closely associated with the pathogenesis of polycystic ovary syndrome (PCOS). Macrophages are one of the important immune cell types in the ovarian proinflammatory microenvironment, and ameliorate the inflammatory status mainly through M2 phenotype polarization during PCOS. Current therapeutic approaches lack efficacy and immunomodulatory capacity, and a new therapeutic method is needed to prevent inflammation and alleviate PCOS. Here, octahedral nanoceria nanoparticles with powerful antioxidative ability were bonded to the anti-inflammatory drug resveratrol (CeO2@RSV), which demonstrates a crucial strategy that involves anti-inflammatory and antioxidative efficacy, thereby facilitating the proliferation of granulosa cells during PCOS. Notably, our nanoparticles were demonstrated to possess potent therapeutic efficacy via anti-inflammatory activities and effectively alleviated endocrine dysfunction, inflammation and ovarian injury in a dehydroepiandrosterone (DHEA)-induced PCOS mouse model. Collectively, this study revealed the tremendous potential of the newly developed nanoparticles in ameliorating the proinflammatory microenvironment and promoting the function of granulosa cells, representing the first attempt to treat PCOS by using CeO2@RSV nanoparticles and providing new insights in combating clinical PCOS.


Assuntos
Nanocompostos , Síndrome do Ovário Policístico , Camundongos , Animais , Feminino , Humanos , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/tratamento farmacológico , Síndrome do Ovário Policístico/metabolismo , Inflamação/tratamento farmacológico , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Microambiente Tumoral
12.
Int J Mol Sci ; 24(16)2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37628727

RESUMO

The dynamic adaptation of bacteria to environmental changes is achieved through the coordinated expression of many genes, which constitutes a transcriptional regulatory network (TRN). Bradyrhizobium diazoefficiens USDA110 is an important model strain for the study of symbiotic nitrogen fixation (SNF), and its SNF ability largely depends on the TRN. In this study, independent component analysis was applied to 226 high-quality gene expression profiles of B. diazoefficiens USDA110 microarray datasets, from which 64 iModulons were identified. Using these iModulons and their condition-specific activity levels, we (1) provided new insights into the connection between the FixLJ-FixK2-FixK1 regulatory cascade and quorum sensing, (2) discovered the independence of the FixLJ-FixK2-FixK1 and NifA/RpoN regulatory cascades in response to oxygen, (3) identified the FixLJ-FixK2 cascade as a mediator connecting the FixK2-2 iModulon and the Phenylalanine iModulon, (4) described the differential activation of iModulons in B. diazoefficiens USDA110 under different environmental conditions, and (5) proposed a notion of active-TRN based on the changes in iModulon activity to better illustrate the relationship between gene regulation and environmental condition. In sum, this research offered an iModulon-based TRN for B. diazoefficiens USDA110, which formed a foundation for comprehensively understanding the intricate transcriptional regulation during SNF.


Assuntos
Bradyrhizobium , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Bradyrhizobium/genética , Aclimatação
13.
Environ Geochem Health ; 45(5): 2611-2627, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36063240

RESUMO

Chronic kidney disease of unknown etiology (CKDu) has posed a serious threat to human health around the world. The link between the prevalence of CKDu and groundwater geochemistry is not well understood. To identify the potential geogenic risk factors, we collected 52 groundwater samples related to CKDu (CKDu groundwater) and 18 groundwater samples related to non-CKDu (non-CKDu groundwater) from the typical CKDu prevailing areas in Sri Lanka. Results demonstrated that CKDu groundwater had significantly higher Si (average 30.1 mg/L, p < 0.05) and F- (average 0.80 mg/L, p < 0.05) concentrations than those of non-CKDu groundwater (average 21.0 and 0.45 mg/L, respectively), indicating that Si and F- were the potential risk factors causing CKDu. The principal hydrogeochemical process controlling local groundwater chemistry was chemical weathering of silicates in Precambrian metamorphic rocks. Groundwater samples were mostly undersaturated with respect to amorphous silica and clay minerals such as talc and sepiolite, which was conducive to silicate weathering and elevated Si concentrations in groundwater. Decreased Ca2+ being facilitated by calcite precipitation and cation exchange between Ca2+ and Na+ favored fluorite dissolution and thus led to high groundwater F- concentrations. Competitive adsorption between [Formula: see text] and F- also enhanced the release of F- from solid surfaces. This study highlights the CKDu potential risk factors regarding groundwater geochemistry and their enrichment factors, which helps in preventing the prevalence of CKDu.


Assuntos
Água Subterrânea , Insuficiência Renal Crônica , Poluentes Químicos da Água , Humanos , Doenças Renais Crônicas Idiopáticas , Minerais/análise , Sódio/análise , Insuficiência Renal Crônica/epidemiologia , Carbonato de Cálcio , Sri Lanka/epidemiologia , Poluentes Químicos da Água/análise , Fluoretos/análise , Monitoramento Ambiental
14.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 40(3): 522-528, 2023 Jun 25.
Artigo em Zh | MEDLINE | ID: mdl-37380392

RESUMO

The bionic optic nerve can mimic human visual physiology and is a future treatment for visual disorders. Photosynaptic devices could respond to light stimuli and mimic normal optic nerve function. By modifying (Poly(3,4-ethylenedioxythio-phene):poly (styrenesulfonate)) active layers with all-inorganic perovskite quantum dots, with an aqueous solution as the dielectric layer in this paper, we developed a photosynaptic device based on an organic electrochemical transistor (OECT). The optical switching response time of OECT was 3.7 s. To improve the optical response of the device, a 365 nm, 300 mW·cm -2 UV light source was used. Basic synaptic behaviors such as postsynaptic currents (0.225 mA) at a light pulse duration of 4 s and double pulse facilitation at a light pulse duration of 1 s and pulse interval of 1 s were simulated. By changing the way light stimulates, for example, by adjusting the intensity of the light pulses from 180 to 540 mW·cm -2, the duration from 1 to 20 s, and the number of light pulses from 1 to 20, the postsynaptic currents were increased by 0.350 mA, 0.420 mA, and 0.466 mA, respectively. As such, we realized the effective shift from short-term synaptic plasticity (100 s recovery of initial value) to long-term synaptic plasticity (84.3% of 250 s decay maximum). This optical synapse has a high potential for simulating the human optic nerve.


Assuntos
Pontos Quânticos , Humanos , Biônica , Óxidos , Nervo Óptico
15.
Zhongguo Yi Liao Qi Xie Za Zhi ; 47(4): 442-444, 2023 Jul 30.
Artigo em Zh | MEDLINE | ID: mdl-37580298

RESUMO

OBJECTIVE: To improve the electromagnetic compatibility (EMC) quality of medical devices, improve the efficiency of EMC testing, and promote the speed of market approval. METHODS: The unqualified cases of EMC test items of medical devices in recent years were statistically analyzed, and the reasons of low EMC quality of medical devices were analyzed from the perspective of test. RESULTS: Based on the analysis of the reasons, the suggestions were given from the perspectives of medical device manufacturers and testing organizations. CONCLUSIONS: In order to ensure the quality of EMC of medical devices, medical device manufacturers, regulatory authorities and inspection and testing institutions should strengthen the monitoring and evaluation of medical device electromagnetic compatibility, to ensure the safety of products work together to promote the development of the medical device industry healthily and orderly.


Assuntos
Fenômenos Eletromagnéticos , Indústrias , Campos Eletromagnéticos
16.
Physiol Plant ; 174(6): e13822, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36335549

RESUMO

The exact developmental roadmaps of bamboo leaf epidermis and the regulating genes are largely unknown. In this study, we comprehensively investigated the morphological features of the leaf epidermis of bamboo, Pseudosasa japonica. We also established the developmental roadmaps of the abaxial epidermis along the linearly growing leaf. A variant of P. japonica, P. japonica var. tsutsumiana, with smaller stomata and higher stomata density, was identified. Further analysis revealed that the higher stomata density of the variant was due to the abnormal increase in stomata columns within the single stomata band. This abnormal development of stomata bands was observed as early as the guard mother cell stage in the leaf division zone (DZ). Interestingly, the developmental pattern of the single stomata was similar in P. japonica and the variant. Molecular data showed that PjDLT (Dwarf and Low Tillering) was significantly downregulated in leaves DZ of the variant. Overexpression of PjDLT in Arabidopsis and rice results in smaller plants with lower stomata density, whereas downregulation or mutation of OsDLT results in increased stomata density. Our results highlight the morphological features and developmental schedule of the leaf epidermis of bamboo and provide evidence that DLT plays an important role in regulating stomata in bamboo and rice.


Assuntos
Oryza , Folhas de Planta , Epiderme Vegetal/genética , Poaceae , Epiderme , Oryza/genética , Estômatos de Plantas/genética
17.
Med Sci Monit ; 28: e935448, 2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35450978

RESUMO

BACKGROUND This study describes the use of closed reduction percutaneous intramedullary fixation with Kirschner wires in 4 children with displaced metaphyseal-diaphyseal junction (MDJ) fractures of the distal humerus. MATERIAL AND METHODS Between August 2016 and August 2019, 4 patients (3 boys and 1 girl), whose mean age was 4 years 5 months (range: 3 years 6 months to 5 years 4 months), with displaced MDJ fractures of the distal humerus were treated using closed reduction percutaneous intramedullary fixation with Kirschner wires. Three of the fractures were oblique and 1 was transverse. The operation time and the frequency of intraoperative fluoroscopy were recorded. All children were followed up for greater than 18 months, taking anteroposterior and lateral radiographs of the elbow joint to evaluate the outcomes. At the last follow-up, the Flynn elbow joint function score was used to evaluate clinical outcomes, and complications were recorded. RESULTS The mean operation time was 37.5 min (range: 35-40 min) and the frequency of intraoperative fluoroscopy was 11.7 times (range: 8-15 times). All of the fractures were confirmed to be healed based on radiographic results at 4 weeks after surgery. At the last follow-up, 4 children had normal elbow joint motion without elbow deformity. The Flynn score showed their outcomes were excellent. CONCLUSIONS Closed reduction percutaneous intramedullary fixation using Kirschner wires was an effective treatment for displaced MDJ fractures of the distal humerus in the 4 children described and was shown to be easy to perform with a short operation time.


Assuntos
Articulação do Cotovelo , Fraturas do Úmero , Fios Ortopédicos , Criança , Diáfises , Articulação do Cotovelo/cirurgia , Feminino , Fixação Interna de Fraturas , Humanos , Fraturas do Úmero/diagnóstico por imagem , Fraturas do Úmero/cirurgia , Úmero/cirurgia , Lactente , Masculino , Resultado do Tratamento
18.
J Anim Physiol Anim Nutr (Berl) ; 106(5): 1139-1148, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35023236

RESUMO

Melatonin has been reported to affect intestinal function by targeting microbiome, morphological structure, barrier integrity and nutrient absorptive system. While the effect of melatonin on intestinal development in newborn infants is obscure, thus, this study firstly attempted to investigate the hypothesis that melatonin treatment improves intestinal development in sucking piglets. 14 healthy newborn piglets received 10 ml melatonin solution (1 mg/ml) or drinking water (n = 7) for 21 days. The results showed that oral administration of melatonin increased liver relative weight (p < 0.05) but failed to affect growth performance in sucking piglets (p > 0.05). Immunostaining jejunal samples from melatonin group showed high expressions of nnos and claudin1, indicating that melatonin improved intestinal neural development and barrier integrity. Also, melatonin promoted intestinal absorptive function evidenced by the increased serum proline concentration in melatonin-treated piglets compared with the control (p < 0.05). Gut microbiota compositions were tested by 16S rDNA sequencing and the results showed that melatonin increased the relative abundance of Actinobacteria compared with the control (p < 0.05) at the phylum level. However, Selenomonadales was markedly reduced compared with the control at the order level (p < 0.05). Gut and faecal volatile fatty acids were tested to evaluate the microbiota metabolism, but no difference was noticed in volatile fatty acid concentrations (p > 0.05). Melatonin improved intestinal development by affecting neural development, barrier integrity, nutrient absorption and microbiota in sucking piglets.


Assuntos
Microbioma Gastrointestinal , Melatonina , Microbiota , Animais , Bactérias , Ingestão de Alimentos , Ácidos Graxos Voláteis/farmacologia , Humanos , Melatonina/farmacologia , Suínos
19.
Int J Psychol ; 57(4): 475-482, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33978957

RESUMO

Amid the ongoing international tensions surrounding China, Chinese international students (CISs) in Western countries have become targets of political suspicion. Against discriminatory voices that make sweeping generalisations about CISs, this research argues that their political identities are in fact diverse and malleable. Using theories of postmodernism and transnationalism, this study applies thematic analysis and discourse analysis to interviews with 28 CISs, yielding four major findings. First, it identifies three distinct patterns of political identity: Chinese nationalists who endorse conservative politics in the West; advocates of liberal democracy; and transnational neoliberals who avoid political participation. Second, it argues that CISs undergo identity changes depending on a range of individual and social characteristics. Among these characteristics, third, it highlights the role of socioeconomic status in shaping the political identities of CISs, and in so doing, reflects on the inadequacy of race and nationality as identity markers. Fourth, it suggests that the political identities of CISs are transnationally hinged on both China and the host countries. On the practical front, the study may inform professions working with CISs such as education and policymaking. Theoretically, it suggests that the political identities of CISs are heterogenous, impressionable and transnationally contingent.


Assuntos
Política , Classe Social , China , Humanos , Estudantes
20.
Exp Eye Res ; 209: 108670, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34129848

RESUMO

In this study, a macro-indentation test on the submillimeter scale was performed to analyze the indentation behavior of an intact cornea under physiological pressures. The Hertz and Johnson-Kendall-Roberts (JKR) models were employed to solve the elastic modulus (E) of the intact cornea. The relevant detailed analysis showed that the JKR model, which accounted for the contribution from the adhesion energy, could be used to obtain the E values that were more than two-folds of those obtained from the Hertz model, which only considered the external force. Compared with the uniaxial tension test in vitro, unlike the elastic Hertz-model, the E values under physiological pressures that were obtained with the JKR model were between the lower and upper limits of corneal material. This phenomenon indicated that the JKR model could be used to obtain reasonably effective E values of an intact cornea under physiological pressures.


Assuntos
Córnea/fisiologia , Pressão Intraocular/fisiologia , Modelos Biológicos , Animais , Córnea/diagnóstico por imagem , Módulo de Elasticidade , Microscopia de Força Atômica , Modelos Animais , Suínos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA