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1.
Sensors (Basel) ; 22(4)2022 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-35214240

RESUMEN

As an important field of computer vision, object detection has been studied extensively in recent years. However, existing object detection methods merely utilize the visual information of the image and fail to mine the high-level semantic information of the object, which leads to great limitations. To take full advantage of multi-source information, a knowledge update-based multimodal object recognition model is proposed in this paper. Specifically, our method initially uses Faster R-CNN to regionalize the image, then applies a transformer-based multimodal encoder to encode visual region features (region-based image features) and textual features (semantic relationships between words) corresponding to pictures. After that, a graph convolutional network (GCN) inference module is introduced to establish a relational network in which the points denote visual and textual region features, and the edges represent their relationships. In addition, based on an external knowledge base, our method further enhances the region-based relationship expression capability through a knowledge update module. In summary, the proposed algorithm not only learns the accurate relationship between objects in different regions of the image, but also benefits from the knowledge update through an external relational database. Experimental results verify the effectiveness of the proposed knowledge update module and the independent reasoning ability of our model.


Asunto(s)
Redes Neurales de la Computación , Semántica , Algoritmos , Conocimiento , Bases del Conocimiento
2.
Microsc Microanal ; 27(4): 860-877, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33993901

RESUMEN

To uncover the chewing mechanism of Cyrtotrachelus buqueti Guer, a mathematical model was created and a kinematic analysis of its rostrum mouthparts was conducted for, to our knowledge, the first time. To reduce noise and improve the quality of scanning electron micrographs of the weevil's mouthparts, nonlocal means and integral nonlocal means algorithms were proposed. Additionally, based on a comparison and analysis of five classical edge detection algorithms, a multiscale edge detection algorithm based on the B-spline wavelet was used to obtain the boundaries of structural features. The least squares method was used to analyze the data of the mouthparts to fit the mathematical model and fitted curves were obtained using Gaussian equations. The results show that curvature and concave-convex variations of the weevil's mouthparts can highlight fluctuations in friction effects when it chews bamboo shoots, which is helpful in preventing debris from bamboo shoots or other debris from sticking to the mouthpart surfaces. Moreover, this paper highlights the utility of micro-computed tomography (microCT) for three-dimensional (3D) reconstruction and a flowchart is suggested. The reconstructed slices were 9.0 µm thick and an accurate 3D rendered model was obtained from a series of microCT slices. Finally, a real model of the rostrum mouthparts was analyzed using finite-element analysis. The results provide a biological template for the design of a novel bionic drilling mechanism.

3.
Sensors (Basel) ; 21(1)2021 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-33406689

RESUMEN

Owing to insufficient illumination of the space station, the image information collected by the intelligent robot will be degraded, and it will not be able to accurately identify the tools required for the robot's on-orbit maintenance. This situation increases the difficulty of the robot's maintenance in a low-illumination environment. We proposes a novel enhancement method for images under low-illumination, namely, a deep learning algorithm based on the combination of deep convolutional and Wasserstein generative adversarial networks (DC-WGAN) in CIELAB color space. The original low-illuminance image is converted from the RGB space to the CIELAB color space which is relatively close to human vision, to accurately estimate the illumination image, and effectively reduce the effect of uneven illumination. DC-WGAN is applied to enhance the brightness component by increasing the width of the generation network to obtain more image features. Subsequently, the LAB is converted into RGB space to obtain the final enhanced image. The feasibility of the algorithm is verified by experiments on low-illuminance image under general, special, and actual conditions and comparing the experimental results with four commonly used algorithms. This study lays a technical foundation for robot target recognition and on-orbit maintenance in a space environment.

4.
Zhongguo Dang Dai Er Ke Za Zhi ; 22(3): 211-214, 2020 Mar.
Artículo en Zh | MEDLINE | ID: mdl-32204755

RESUMEN

Since December 2019, the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has occurred in Wuhan, Hubei Province, China. The infected cases were noted mostly in adults, but rarely reported in children, especially neonates. Most children with SARS-CoV-2 infection present mainly with respiratory symptoms, but less commonly with gastrointestinal symptoms, and tend to have mild clinical symptoms. A neonate with SARS-CoV-2 infection, who had vomiting and milk refusal as the first symptom, was recently admitted to Wuhan Children's Hospital. After two weeks of treatment, the patient recovered gradually and was discharged. Here, this case is reported to improve the understanding of SARS-CoV-2 infection in neonates.


Asunto(s)
Infecciones por Coronavirus , Neumonía Viral , Betacoronavirus , COVID-19 , China , Humanos , Recién Nacido , SARS-CoV-2
5.
Ecotoxicol Environ Saf ; 172: 186-193, 2019 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-30708230

RESUMEN

Fenvalerate (FEN), a representative type II pyrethroid, is a widely used pyrethroid insecticide and a potential environmental contaminant. Several studies demonstrated that gestational FEN exposure induced intrauterine growth restriction (IUGR). However, the critical time window of FEN-induced fetal IUGR remains obscure. The present study aimed to identify the critical window of FEN-induced fetal IUGR. Pregnant mice were administered corn oil or FEN (20 mg/kg) by gavage daily at the early gestational stage (GD0-GD6), middle gestational stage (GD7-GD12) or late gestational stage (GD13-GD17). The results showed that the rates of fetal IUGR were markedly increased only in the mice exposed to FEN on GD13-GD17 but not in the mice exposed to FEN on GD7-GD12 or GD0-GD6. Further analysis showed that the blood sinusoid area in the placental labyrinth layer was reduced in the mice exposed to FEN on GD13-GD17. In addition, CD34+ microvessel density in the labyrinthine region was decreased in the male and female fetuses whose mothers were exposed to FEN on GD13-GD17. Mechanistic analysis found that the glutathione level was decreased in the FEN-exposed placentas. In contrast, the levels of 3-nitrotyrosine and malondialdehyde, two oxidative stress markers, were increased in FEN-exposed placentas. Heme oxygenase-1, inducible nitric oxide synthase, catalase and peroxiredoxin-3, which are antioxidant enzymes, were upregulated in the FEN-exposed placentas. The present study suggests that the late gestational stage is a critical time window of FEN-induced fetal IUGR. Placental oxidative stress may be, at least partially, involved in the process of FEN-induced placental damage and fetal IUGR.


Asunto(s)
Retardo del Crecimiento Fetal/inducido químicamente , Insecticidas/toxicidad , Exposición Materna , Nitrilos/toxicidad , Placenta/efectos de los fármacos , Piretrinas/toxicidad , Animales , Antioxidantes/metabolismo , Femenino , Feto/efectos de los fármacos , Edad Gestacional , Masculino , Ratones , Microvasos/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Placenta/metabolismo , Embarazo , Factores de Tiempo
6.
Microsc Microanal ; 25(3): 786-797, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30898184

RESUMEN

This work focuses on the application of nanoindentation measurements and the finite element method for analyzing the mechanical properties of the rostrum of the outstanding driller Cyrtotrachelus buqueti Guer. Nanoindentation tests were carried out to measure the Young's modulus and hardness of the rostrum, with the results for the "dry" samples being 13.886 ± 0.75 and 0.368 ± 0.0445 GPa, respectively. The values for the "fresh" samples showed no clear difference from those of the "dry" ones. Moreover, field observation was conducted to determine the motion behaviors of the rostrum on the weevil. Micro-computed tomography technology was employed to obtain structural information about the rostrum, using 9 µm slices. A real three-dimensional model of the rostrum was created using the MIMICS application. Finally, the mechanical properties of the rostrum were determined by finite element analysis. It was concluded that the rostrum provides an ideal biological template for the design of biocomposite materials and lightweight tube-shaped structures. The properties determined in this study can potentially be applied in different fields, such as in the design of automotive hybrid transmission shafts, helicopter tail drive shafts, robotic arms, and other sandwich structures in aerospace engineering.


Asunto(s)
Análisis de Elementos Finitos , Gorgojos/anatomía & histología , Gorgojos/ultraestructura , Animales , Fenómenos Biomecánicos , China , Módulo de Elasticidad , Dureza , Imagenología Tridimensional/métodos , Estrés Mecánico , Gorgojos/fisiología , Microtomografía por Rayos X/métodos
7.
J Pathol ; 237(3): 307-18, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26096340

RESUMEN

Lymphangiogenesis is essential in embryonic development but is rare in adults. It occurs, however, in many disease conditions including cancers. Vascular endothelial growth factor-C/D (VEGF-C/D) and VEGF receptor-3 (Vegfr3) play a critical role in the regulation of lymphangiogenesis. We investigated how the VEGF-C/Vegfr3 signalling system is regulated by tumour necrosis factor superfamily member 15 (Tnfsf15), an endothelium-derived cytokine. We report here that Tnfsf15, which is known to induce apoptosis in vascular endothelial cells, can promote lymphatic endothelial cell (LEC) growth and migration, stimulate lymphangiogenesis, and facilitate lymphatic circulation. Treatment of mouse LECs with Tnfsf15 results in up-regulation of Vegfr3 expression; this can be inhibited by gene silencing of death domain-containing receptor-3 (DR3; Tnfrsf25), a cell surface receptor for Tnfsf15, with siRNA, or by blocking Tnfsf15-DR3 interaction with a Tnfsf15 neutralizing antibody, 4-3H. Additionally, Tnfsf15/DR3 signalling pathways in LECs include activation of NF-κB. Tnfsf15-overexpressing transgenic mice exhibit a marked enhancement of lymph drainage; this is confirmed by treatment of wild-type mice with intraperitoneal injection of recombinant Tnfsf15. Moreover, systemic treatment of pregnant Tnfsf15 transgenic mice with 4-3H leads to inhibition of embryonic lymphangiogenesis. Our data indicate that Tnfsf15, a cytokine produced largely by endothelial cells, facilitates lymphangiogenesis by up-regulating Vegfr3 gene expression in LECs, contributing to the maintenance of the homeostasis of the circulatory system. This finding also suggests that Tnfsf15 may be of potential value as a therapeutic tool for the treatment of lymphoedema.


Asunto(s)
Células Endoteliales/metabolismo , Linfangiogénesis , Vasos Linfáticos/metabolismo , Miembro 15 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/metabolismo , Receptor 3 de Factores de Crecimiento Endotelial Vascular/metabolismo , Animales , Movimiento Celular , Proliferación Celular , Células Cultivadas , Relación Dosis-Respuesta a Droga , Células Endoteliales/efectos de los fármacos , Inyecciones Intraperitoneales , Linfa/metabolismo , Linfangiogénesis/efectos de los fármacos , Vasos Linfáticos/citología , Vasos Linfáticos/efectos de los fármacos , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Transgénicos , FN-kappa B/metabolismo , Interferencia de ARN , Miembro 25 de Receptores de Factores de Necrosis Tumoral/genética , Miembro 25 de Receptores de Factores de Necrosis Tumoral/metabolismo , Proteínas Recombinantes/administración & dosificación , Transducción de Señal , Factores de Tiempo , Transfección , Miembro 15 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/administración & dosificación , Miembro 15 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/genética , Regulación hacia Arriba , Factor C de Crecimiento Endotelial Vascular/metabolismo
8.
Appl Opt ; 54(31): 9253-7, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26560579

RESUMEN

The ability to measure in vivo wall strain in embryonic hearts is important for fully understanding the mechanisms of cardiac development. Optical coherence tomography (OCT) is a powerful tool for the three-dimensional imaging of complex myocardial activities in early-stage embryonic hearts with high spatial and temporal resolutions. We describe a method to analyze periodic deformations of myocardial walls and evaluate in vivo myocardial wall strains with a high-speed spectral domain OCT system. We perform four-dimensional scanning on the outflow tract (OFT) of chick embryonic hearts and determine a special cross-section in which the OFT can be approximated as an annulus by analyzing Doppler blood-flow velocities. For each image acquired at the special cross-section, the annular myocardial wall is segmented with a semiautomatic boundary-detection algorithm, and the fluctuation myocardial wall thickness is calculated from the area and mean circumference of the myocardial wall. The experimental results shown with the embryonic chick hearts demonstrate that the proposed method is a useful tool for studying the biomechanical characteristics of embryonic hearts.


Asunto(s)
Diagnóstico por Imagen de Elasticidad/instrumentación , Corazón/embriología , Corazón/fisiología , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/instrumentación , Tomografía de Coherencia Óptica/instrumentación , Algoritmos , Animales , Embrión de Pollo , Módulo de Elasticidad/fisiología , Diagnóstico por Imagen de Elasticidad/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Corazón/anatomía & histología , Interpretación de Imagen Asistida por Computador/instrumentación , Imagenología Tridimensional/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Resistencia al Corte/fisiología , Estrés Mecánico , Tomografía de Coherencia Óptica/métodos
9.
Materials (Basel) ; 17(8)2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38673111

RESUMEN

In this paper, a one-step hot extrusion dual-stage solution treatment method is employed to fabricate high-strength and tough T-shaped complex cross-section 7055 (Al-Zn-Mg-Cu-Zr) alloy profiles, and a detailed investigation is conducted on the microstructure and mechanical properties. The results indicate that the comprehensive mechanical properties of the 7055 aluminum extruded alloy using the two-stage solution aging treatment are excellent. This is particularly evident in the balance between strength and ductility, where outstanding strength is accompanied by a plasticity that is maintained at 13.2%. During the extrusion process, the deformation textures are mainly composed of brass and copper, forming a 15.1% recrystallization texture Cube. In addition, the equilibrium phase η(MgZn2) precipitated in the grain is the main strengthening phase, and there are large discontinuous grain boundary precipitates at the grain boundary, which hinders the grain boundary dislocation movement and has great influence on the mechanical properties of alloy materials.

10.
Materials (Basel) ; 17(9)2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38730756

RESUMEN

The mechanical properties of porcupine quills have attracted the interest of researchers due to their unique structure and composition. However, there is still a knowledge gap in understanding how these properties can be utilized to design biomimetic structures with enhanced performance. This study delves into the nanomechanical and macro-mechanical properties of porcupine quills, unveiling varied elastic moduli across different regions and cross sections. The results indicated that the elastic moduli of the upper and lower epidermis were higher at 8.13 ± 0.05 GPa and 7.71 ± 0.14 GPa, respectively, compared to other regions. In contrast, the elastic modulus of the mid-dermis of the quill mid-section was measured to be 7.16 ± 0.10 GPa. Based on the micro- and macro-structural analysis of porcupine quills, which revealed distinct variations in elastic moduli across different regions and cross sections, various biomimetic porous structures (BPSs) were designed. These BPSs were inspired by the unique properties of the quills and aimed to replicate and enhance their mechanical characteristics in engineering applications. Compression, torsion, and impact tests illustrated the efficacy of structures with filled hexagons and circles in improving performance. This study showed enhancements in maximum torsional load and crashworthiness with an increase in filled structures. Particularly noteworthy was the biomimetic porous circular structure 3 (BPCS_3), which displayed exceptional achievements in average energy absorption (28.37 J) and specific energy absorption (919.82 J/kg). Finally, a response surface-based optimization method is proposed to enhance the design of the structure under combined compression-torsion loads, with the goal of reducing mass and deformation. This research contributes to the field of biomimetics by exploring the potential applications of porcupine quill-inspired structures in fields such as robotics, drive shafts, and aerospace engineering.

11.
Plant Physiol Biochem ; 210: 108626, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38615443

RESUMEN

Stomatal operation is crucial for optimising plant water and gas exchange and represents a major trait conferring abiotic stress tolerance in plants. About 56% of agricultural land around the globe is classified as acidic, and Al toxicity is a major limiting factor affecting plant performance in such soils. While most of the research work in the field discusses the impact of major abiotic stresses such as drought or salinity on stomatal operation, the impact of toxic metals and, specifically aluminium (Al) on stomatal operation receives much less attention. We aim to fill this knowledge gap by summarizing the current knowledge of the adverse effects of acid soils on plant stomatal development and operation. We summarised the knowledge of stomatal responses to both long-term and transient Al exposure, explored molecular mechanisms underlying plant adaptations to Al toxicity, and elucidated regulatory networks that alleviate Al toxicity. It is shown that Al-induced stomatal closure involves regulations of core stomatal signalling components, such as ROS, NO, and CO2 and key elements of ABA signalling. We also discuss possible targets and pathway to modify stomatal operation in plants grown in acid soils thus reducing the impact of Al toxicity on plant growth and yield.


Asunto(s)
Aluminio , Estomas de Plantas , Suelo , Aluminio/toxicidad , Estomas de Plantas/efectos de los fármacos , Estomas de Plantas/fisiología , Suelo/química , Productos Agrícolas/metabolismo , Productos Agrícolas/efectos de los fármacos , Productos Agrícolas/crecimiento & desarrollo , Adaptación Fisiológica/efectos de los fármacos
12.
Nat Prod Res ; 38(1): 85-90, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-35913407

RESUMEN

Nine diterpenoid alkaloids were isolated from Aconitum georgei Comber belonging to the genus Aconitum in Ranunculaceae family. Their structures were determinated by using HR-ESI-MS and 1 D/2D NMR spectra as geordine (1), yunaconitine (2), chasmanine (3), crassicauline A (4), forestine (5), pseudaconine (6), 14-acetylalatisamine (7), austroconitine B (8), and talatisamine (9). Among them, compound 1 is a previously undescribed aconitine-type C19-diterpenoid alkaloid, and compounds 3, and 5-9 have not previously been isolated from this species. The results of in vitro experiments indicated that new compound 1 possesses mild anti-inflammatory activity, which inhibited the production of NO in LPS-activated RAW 264.7 cells with an inhibition ratio of 29.75% at 50 µM.


Asunto(s)
Aconitum , Alcaloides , Diterpenos , Medicamentos Herbarios Chinos , Aconitum/química , Alcaloides/química , Espectroscopía de Resonancia Magnética , Medicamentos Herbarios Chinos/química , Diterpenos/química , Estructura Molecular , Raíces de Plantas/química
13.
Microsc Res Tech ; 86(5): 516-528, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36637353

RESUMEN

Benefitting from its unique helically arranged fiber structures, fish skin is a superior biological protective tissue. Reported here is a study of the microscopic morphological characteristics and mechanical properties of the skin of three species of fish, that is, Taihu white fish (Erythroculter ilishaeformis), grouper (Cichlasoma managuense), and yellowfin seabream (Ditrema temminckii Bleeker), revealing the special protective mechanisms of fish skin. Experiments involving scanning electron microscopy show that the stratum compactum is the main part of fish skin and comprises helically stacked fibers, with the helical ply angles of the fibrous layers differing significantly for the different fish species and in different regions of their bodies. Tension and penetration experiments show that fish skin provides a fish's body with considerable mechanical protection from lacerations and bites inflicted by its natural enemies. Moreover, the mechanical tests show that fish skin has two different defensive mechanisms against tension and penetration loads, thereby offering a novel idea for designing body armor that is both flexible and tough.


Asunto(s)
Peces , Piel , Animales , Peces/anatomía & histología
14.
Bioinspir Biomim ; 19(1)2023 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-37976540

RESUMEN

Inspired by the capillary transport function of plant leaf veins, this study proposes three typical leaf vein features by observing a large number of leaves, including wedge shape, branch asymmetry, as well as hierarchical arrangement, and investigates their capillary transport mechanism. Not only a preliminary theoretical analysis of capillary flow in the bio-inspired channels was carried out, but the COMSOL Multiphysics simulation software was also used to simulate gas-liquid two-phase flow in biomimetic channels. The results reveal the efficient transport mechanism of the leaf vein inspired structure and provide insight into the design of capillary transmission channels.


Asunto(s)
Hojas de la Planta , Programas Informáticos , Hojas de la Planta/anatomía & histología , Simulación por Computador
15.
Micromachines (Basel) ; 14(2)2023 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-36837956

RESUMEN

Benefiting from their unique morphological characteristics and structural properties, the ventral bony plates of the Chinese sturgeon are excellent biological protective tissue. In this work, we studied the micro- and macro-morphology and mechanical properties of the ventral bony plates of the Chinese sturgeon to elucidate the special protective mechanisms of the bony plates. Experiments involving scanning electron microscopy and energy-dispersive X-ray spectroscopy revealed that the bony plates possess a hierarchical structure and a ridge-like shape. This structure comprises a surface layer containing mineralized nanocrystals and an internal layer containing mineralized collagen fibers. From the surface layer to the internal layer, the degree of mineralization decreases gradually. Nanoindentation, tension, and compression tests demonstrated that the bony plates feature excellent mechanical properties and a high specific tensile strength comparable to that of stainless steel. Moreover, water can significantly improve the fracture toughness and deformability of the bony plates and effectively enhance the damage tolerance of the structures. The obtained results concerning the microstructure-property-function relationships of the ventral bony plates of the Chinese sturgeon may provide novel insights for designing protective structures that are both lightweight and high strength.

16.
Materials (Basel) ; 16(11)2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-37297249

RESUMEN

Inspired by the macro- and microstructures of the lotus leaf, a series of biomimetic hierarchical thin-walled structures (BHTSs) was proposed and fabricated, exhibiting improved mechanical properties. The comprehensive mechanical properties of the BHTSs were evaluated using finite element (FE) models constructed in ANSYS, which were validated by the experimental results. Light-weight numbers (LWNs) were used as an index to assess these properties. The simulation results were compared with the experimental data to validate the findings. The compression results indicated that the maximum load carried by each BHTS was very similar, with the highest bearing load being 32,571 N and the lowest being 30,183 N, resulting in only a 7.9% difference between them. In terms of the LWN-C values, the BHTS-1 exhibited the highest value at 318.51 N/g, while the BHTS-6 had the lowest value at 295.16 N/g. For the torsion and bending results, these findings suggested that increasing the bifurcation structure at the end side of the thin tube branch significantly improved the torsional resistance properties of the thin tube. For the impact characteristics of the proposed BHTSs, enhancing the bifurcation structure at the end of the thin tube branch significantly increased the energy absorption capacity and improved the energy absorption (EA) and the specific energy absorption (SEA) values of the thin tube. The BHTS-6 had the best structural design in terms of both the EA and SEA among all the BHTSs, but its CLE value was slightly lower than that of the BHTS-7, indicating slightly lower structural efficiency. This study provides a new idea and method for developing new lightweight and high-strength materials as well as designing more effective energy absorption structures. At the same time, this study has important scientific value in understanding how biological structures in nature exhibit their unique mechanical properties.

17.
Biomimetics (Basel) ; 8(2)2023 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-37366827

RESUMEN

Fish skin is a biological material with high flexibility and compliance and can provide good mechanical protection against sharp punctures. This unusual structural function makes fish skin a potential biomimetic design model for flexible, protective, and locomotory systems. In this work, tensile fracture tests, bending tests, and calculation analyses were conducted to study the toughening mechanism of sturgeon fish skin, the bending response of the whole Chinese sturgeon, and the effect of bony plates on the flexural stiffness of the fish body. Morphological observations showed some placoid scales with drag-reduction functions on the skin surface of the Chinese sturgeon. The mechanical tests revealed that the sturgeon fish skin displayed good fracture toughness. Moreover, flexural stiffness decreased gradually from the anterior region to the posterior region of the fish body, which means that the posterior region (near the tail) had higher flexibility. Under large bending deformation, the bony plates had a specific inhibition effect on the bending deformation of the fish body, especially in the posterior region of the fish body. Furthermore, the test results of the dermis-cut samples showed that the sturgeon fish skin had a significant impact on flexural stiffness, and the fish skin could act as an external tendon to promote effective swimming motion.

18.
J Gastrointest Surg ; 27(2): 373-381, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36538254

RESUMEN

PURPOSE: Transanal total mesorectal excision (taTME) is a promising surgical procedure for middle and low rectal cancer; however, it is linked to significant morbidity. This study aimed to determine the incidence of postoperative surgical complications and anastomotic leakage following taTME and to identify their associated risk factors. METHODS: The prospective clinical data of 114 patients, who underwent taTME and primary anastomosis for mid-low rectal cancer between November 2016 and June 2022, were retrospectively analyzed. Univariate and multivariate analyses were performed to identify clinical characteristics and risk factors for predicting surgical complications and anastomotic leakage. RESULTS: Surgical complications occurred in 40 (35.1%) patients within the first 30 days following surgery. Based on the Clavien-Dindo classification, minor complications (Clavien-Dindo grades I + II) accounted for 30.7%, while major complications (Clavien-Dindo grades III + IV) accounted for only 4.4%. None of the patients died within 30 days. The incidence of anastomotic leakage was 15.8%: 4.4% as grade A (5 cases), 9.6% as grade B (11 cases), and 1.8% as grade C (2 cases). Preoperative T3-4 was identified as an independent risk factor for surgical complications (p = 0.031) by multivariate analysis. American Society of Anesthesiology score ≥ 3 (P = 0.021) and incomplete total mesorectal excision specimens (P = 0.030) were significantly associated with the risk of anastomotic leakage. CONCLUSIONS: In this study, the incidence of surgical complications and anastomotic leakage in taTME aligned with previously reported rates. Preoperative T3-4 was significantly associated with surgical complications. American Society of Anesthesiology score ≥ 3 and incomplete TME specimens independently increased the risk of anastomotic leakage.


Asunto(s)
Laparoscopía , Neoplasias del Recto , Cirugía Endoscópica Transanal , Humanos , Fuga Anastomótica/epidemiología , Fuga Anastomótica/etiología , Fuga Anastomótica/cirugía , Recto/cirugía , Incidencia , Estudios Prospectivos , Estudios Retrospectivos , Neoplasias del Recto/cirugía , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Factores de Riesgo , Cirugía Endoscópica Transanal/métodos , Laparoscopía/métodos
19.
Front Psychol ; 13: 905590, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35656489

RESUMEN

The article selects socioeconomic data related to 146 prefecture-level cities included in nine city clusters from 2014 to 2018 to establish a city-level socioeconomic system in China. A sensitivity analysis of regional entrepreneurship and economic quality development based on system dynamics was conducted to explore the changes in regional entrepreneurship and economic quality development over time and their sensitivity factors. In this way, the dynamic evolution mechanism of the system can be portrayed, and the optimization of the system can be achieved through the coordination of the factors within the system. The article sets up three scenarios to explore the fluctuations in regional entrepreneurship and economic quality development when three sensitive factors, namely, business environment, financial services scale, and innovation environment, change. Findings: There are differences in the development of cities within city clusters. The business environment and high-quality economic development of the central cities within the city cluster are stronger than those of the non-central cities. Therefore, regions should focus on synergistic development within city clusters when formulating related policies. The variation of regional entrepreneurship development and economic quality development, after a factor in the system is changed, is asymmetric. Because the sensitivity of different urban clusters and the way they are affected by sensitive factors varies, the state should pay more attention to the adaptability of cities when formulating corresponding policy measures and adapt its policy measures to the sensitivity characteristics of each region according to local conditions.

20.
Ther Clin Risk Manag ; 18: 71-93, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35140468

RESUMEN

OBJECTIVE: To identify, systematically review and synthesize the evidence on the effectiveness of biofeedback therapy in patients with bowel dysfunction following rectal cancer surgery. DATA SOURCES: Four electronic databases (PubMed 1974-2021; Embase1980-2021; Cochrane databases and the trial registers) were systematically searched by reviewers from inception through March 2021. STUDY SELECTION: Randomized controlled trials (RCTs), cohort studies, and case series studies were included for adults with bowel dysfunction following rectal cancer surgery. All participants received an intervention of biofeedback treatment. Any outcomes that can evaluate the patient's bowel function were the primary research endpoint, while the quality of life was the second endpoint. The disagreements between the two reviewers were resolved after discussion and the third independent reviewer's ruling. As a result, 12 of 185 studies met selection criteria and were included in the review. DATA EXTRACTION: We designed an electronic data extraction form and data were extracted independently. The methodological quality of included studies was assessed using the Cochrane Risk of Bias, the MINORS scale, and the Institute of Health Economics scale. DATA SYNTHESIS: Meta-analyses were conducted for case series only and narrative syntheses were completed. Key findings included significant improvements in bowel function as well as health-related quality of life after biofeedback therapy. (Wexner score: t=7, MD=3.33; 95% CI [2.48, 4.18]) and (Vaizey score: t=3, MD=2.46; 95% CI [1.98, 2.93]). Subgroup analysis of Wexner score: receiving electrical stimulation therapy (t=3, MD=2.36; 95% CI [1.51, 3.22]), not receiving electrical stimulation (t=4, MD=3.79;95% CI[2.66, 4.93]); not receiving adjuvant chemoradiotherapy (t=3, MD=2.42;95% CI[1.61, 3.24]), chemotherapy and radiotherapy (t=1, MD=4.10; 95% CI [2.90, 5.30]), radiotherapy and chemotherapy on parts of patients (t=2, MD=3.46;95% CI [1.41, 5.51]), chemotherapy (t=1, MD=4.81; 95% CI [3.38, 6.24]); performing ISR (t=2, MD=3.32;95% CI [0.37, 6.27]), performing AR (t=4, MD=3.08; 95% CI [2.12, 4.04]), performing PLRAS surgery (t=1, MD=4.10;95% CI[2.90, 5.30]). CONCLUSION: Although biofeedback therapy may improve intestinal function and quality of life as well as anal function reflected by ARM after surgery, patient satisfaction is still unclear. Due to the scarcity of data, good-quality research is required to delve deeper. CLINICAL TRIAL REGISTRATION NUMBER: CRD42020192658.

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