Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
New Phytol ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38887135

RESUMO

Bamboo, a renewable resource with rapid growth and an impressive height-to-diameter ratio, faces mechanical instability due to its slender structure. Despite this, bamboo maintains its posture without breaking in its battle against environmental and gravitational forces. But what drives this motor function in bamboo? This study subjected Moso bamboo (Phyllostachys edulis) to gravitational stimulation, compelling it to grow at a 45° angle instead of upright. Remarkably, the artificially inclined bamboo exhibited astonishing shape control and adjustment capabilities. The growth strain was detected at both macroscopic and microscopic levels, providing evidence for the presence of internal stress, namely growth stress. The high longitudinal tensile stress on the upper side, along with a significant asymmetry in stress distribution in tilted bamboo, plays a pivotal role in maintaining its mechanical stability. Drawing upon experimental findings, it can be deduced that the growth stress primarily originates from the broad layers of fiber cells. Bamboo could potentially regulate the magnitude of growth stress by modifying the number of fiber cell layers during its maturation process. Additionally, the microfibril angle and lignin disposition may decisively influence the generation of growth stress.

2.
Lasers Med Sci ; 38(1): 33, 2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36598586

RESUMO

Femtosecond laser is a promising surface treatment tool for zirconia implant. In this study, the fatigue behavior of zirconia specimens with microgrooved surfaces formed by femtosecond laser is reported. One hundred sixty CAD/CAM zirconia bars (20 mm × 4 mm × 1.4 mm) were evenly divided into four groups with different surface: as sintered; sandblasted with 110 µm Al2O3; femtosecond laser produced microgrooves having 50 µm width, 30 µm depth, and 100 µm pitch; microgrooves having 30 µm width, 20 µm depth, and 60 µm pitch. The femtosecond laser formed micro/nanostructured microgrooves with precise size on zirconia surfaces. XRD analysis indicated that microgrooved surface showed no obvious tetragonal-to-monoclinic phase transformation. The fatigue strength of sandblasted specimens (728 MPa) was significantly higher than that of as sintered specimens (570 MPa). However, the fatigue strength of specimens with microgrooved surface decreased to about 360-380 MPa. The results suggest femtosecond laser is an effective technique to regulate the surface microtopography of zirconia, while further investigations are needed to improve its fatigue behavior.


Assuntos
Lasers , Zircônio , Propriedades de Superfície , Microscopia Eletrônica de Varredura , Teste de Materiais , Cerâmica , Materiais Dentários
3.
Sensors (Basel) ; 22(14)2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35891051

RESUMO

In this letter, we propose a nonlinear Magnetoelastic Energy (ME) with a material parameter related to electron interactions. An attenuating term is contained in the formula of the proposed nonlinear ME, which can predict the variation in the anisotropic magneto-crystalline constants induced by external stress more accurately than the classical linear ME. The domain wall velocity under stress and magnetic field can be predicted accurately based on the nonlinear ME. The proposed nonlinear ME model is concise and easy to use. It is important in sensor analysis and production, magneto-acoustic coupling motivation, magnetoelastic excitation, etc.

4.
Int J Mol Sci ; 23(10)2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-35628638

RESUMO

Polylactic acid-glycolic acid (PLGA) has been widely used in bone tissue engineering due to its favorable biocompatibility and adjustable biodegradation. 3D printing technology can prepare scaffolds with rich structure and function, and is one of the best methods to obtain scaffolds for bone tissue repair. This review systematically summarizes the research progress of 3D-printed, PLGA-based scaffolds. The properties of the modified components of scaffolds are introduced in detail. The influence of structure and printing method change in printing process is analyzed. The advantages and disadvantages of their applications are illustrated by several examples. Finally, we briefly discuss the limitations and future development direction of current 3D-printed, PLGA-based materials for bone tissue repair.


Assuntos
Engenharia Tecidual , Alicerces Teciduais , Osso e Ossos , Glicolatos , Poliésteres , Impressão Tridimensional , Engenharia Tecidual/métodos , Alicerces Teciduais/química
5.
J BUON ; 21(1): 118-24, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27061539

RESUMO

PURPOSE: The aim of this study was to compare the surgical and long-term outcomes of laparoscopic and open gastrectomy with radical intent for locally advanced gastric carcinoma in case-controlled patient groups using the propensity score. METHODS: Between January 2009 and December 2014, 389 patients who underwent gastrectomy with radical intent for locally advanced gastric carcinoma were enrolled. These patients were divided into two groups according to the method of operation: the laparoscopy group (patients who underwent laparoscopic gastrectomy) and the open group (patients who underwent open gastrectomy). To correct different demographic and clinical factors in the two groups, a propensity score matching was used at a 1:1 ratio, and, finally, 184 patients were enrolled in this study, 92 patients in each group. Preoperative characteristics, surgical results, and long-term results were analyzed. RESULTS: Preoperative baseline variables were well balanced in both groups. There were no differences of the extent of surgery between the two groups. With the exception of shorter postoperative hospital stay and less blood loss in the laparoscopy group as compared with the open group, there were no significant differences in surgical, pathological, and long-term outcomes. The 5-year overall survival rates were 57% in the laparoscopy group and 50% in the open group (p=0.606). The 5-year disease-free survival rates were 48% in the laparoscopy group and 42% in the open group (p=0.515). CONCLUSION: Laparoscopic gastrectomy for locally advanced gastric carcinoma is safe, and long-term outcomes were comparable to those who underwent open resection.


Assuntos
Gastrectomia/métodos , Laparoscopia/métodos , Pontuação de Propensão , Neoplasias Gástricas/cirurgia , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias Gástricas/mortalidade , Taxa de Sobrevida
6.
Math Biosci Eng ; 21(3): 4669-4697, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38549344

RESUMO

Segmenting plant organs is a crucial step in extracting plant phenotypes. Despite the advancements in point-based neural networks, the field of plant point cloud segmentation suffers from a lack of adequate datasets. In this study, we addressed this issue by generating Arabidopsis models using L-system and proposing the surface-weighted sampling method. This approach enables automated point sampling and annotation, resulting in fully annotated point clouds. To create the Arabidopsis dataset, we employed Voxel Centroid Sampling and Random Sampling as point cloud downsampling methods, effectively reducing the number of points. To enhance the efficiency of semantic segmentation in plant point clouds, we introduced the Plant Stratified Transformer. This network is an improved version of the Stratified Transformer, incorporating the Fast Downsample Layer. Our improved network underwent training and testing on our dataset, and we compared its performance with PointNet++, PAConv, and the original Stratified Transformer network. For semantic segmentation, our improved network achieved mean Precision, Recall, F1-score and IoU of 84.20, 83.03, 83.61 and 73.11%, respectively. It outperformed PointNet++ and PAConv and performed similarly to the original network. Regarding efficiency, the training time and inference time were 714.3 and 597.9 ms, respectively, which were reduced by 320.9 and 271.8 ms, respectively, compared to the original network. The improved network significantly accelerated the speed of feeding point clouds into the network while maintaining segmentation performance. We demonstrated the potential of virtual plants and deep learning methods in rapidly extracting plant phenotypes, contributing to the advancement of plant phenotype research.


Assuntos
Arabidopsis , Fontes de Energia Elétrica , Redes Neurais de Computação , Fenótipo , Projetos de Pesquisa
7.
World J Gastrointest Surg ; 16(6): 1548-1557, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38983331

RESUMO

BACKGROUND: Laparoscopic low anterior resection (LLAR) has become a mainstream surgical method for the treatment of colorectal cancer, which has shown many advantages in the aspects of surgical trauma and postoperative rehabilitation. However, the effect of surgery on patients' left coronary artery and its vascular reconstruction have not been deeply discussed. With the development of medical imaging technology, 3D vascular reconstruction has become an effective means to evaluate the curative effect of surgery. AIM: To investigate the clinical value of preoperative 3D vascular reconstruction in LLAR of rectal cancer with the left colic artery (LCA) preserved. METHODS: A retrospective cohort study was performed to analyze the clinical data of 146 patients who underwent LLAR for rectal cancer with LCA preservation from January to December 2023 in our hospital. All patients underwent LLAR of rectal cancer with the LCA preserved, and the intraoperative and postoperative data were complete. The patients were divided into a reconstruction group (72 patients) and a nonreconstruction group (74 patients) according to whether 3D vascular reconstruction was performed before surgery. The clinical features, operation conditions, complications, pathological results and postoperative recovery of the two groups were collected and compared. RESULTS: A total of 146 patients with rectal cancer were included in the study, including 72 patients in the reconstruction group and 74 patients in the nonreconstruction group. There were 47 males and 25 females in the reconstruction group, aged (59.75 ± 6.2) years, with a body mass index (BMI) (24.1 ± 2.2) kg/m2, and 51 males and 23 females in the nonreconstruction group, aged (58.77 ± 6.1) years, with a BMI (23.6 ± 2.7) kg/m2. There was no significant difference in the baseline data between the two groups (P > 0.05). In the submesenteric artery reconstruction group, 35 patients were type I, 25 patients were type II, 11 patients were type III, and 1 patient was type IV. There were 37 type I patients, 24 type II patients, 12 type III patients, and 1 type IV patient in the nonreconstruction group. There was no significant difference in arterial typing between the two groups (P > 0.05). The operation time of the reconstruction group was 162.2 ± 10.8 min, and that of the nonreconstruction group was 197.9 ± 19.1 min. Compared with that of the reconstruction group, the operation time of the two groups was shorter, and the difference was statistically significant (t = 13.840, P < 0.05). The amount of intraoperative blood loss was 30.4 ± 20.0 mL in the reconstruction group and 61.2 ± 26.4 mL in the nonreconstruction group. The amount of blood loss in the reconstruction group was less than that in the control group, and the difference was statistically significant (t = -7.930, P < 0.05). The rates of anastomotic leakage (1.4% vs 1.4%, P = 0.984), anastomotic hemorrhage (2.8% vs 4.1%, P = 0.672), and postoperative hospital stay (6.8 ± 0.7 d vs 7.0 ± 0.7 d, P = 0.141) were not significantly different between the two groups. CONCLUSION: Preoperative 3D vascular reconstruction technology can shorten the operation time and reduce the amount of intraoperative blood loss. Preoperative 3D vascular reconstruction is recommended to provide an intraoperative reference for laparoscopic low anterior resection with LCA preservation.

8.
Adv Sci (Weinh) ; 11(25): e2401330, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38634564

RESUMO

The energy loss induced open-circuit voltage (VOC) deficit hampers the rapid development of state-of-the-art organic solar cells (OSCs), therefore, it is extremely urgent to explore effective strategies to address this issue. Herein, a new volatile solid additive 1,4-bis(iodomethyl)cyclohexane (DIMCH) featured with concentrated electrostatic potential distribution is utilized to act as a morphology-directing guest to reduce energy loss in multiple state-of-art blend system, leading to one of highest efficiency (18.8%) at the forefront of reported binary OSCs. Volatile DIMCH decreases radiative/non-radiative recombination induced energy loss (ΔE2/ΔE3) by rationally balancing the crystallinity of donors and acceptors and realizing homogeneous network structure of crystal domain with reduced D-A phase separation during the film formation process and weakens energy disorder and trap density in OSCs. It is believed that this study brings not only a profound understanding of emerging volatile solid additives but also a new hope to further reduce energy loss and improve the performance of OSCs.

9.
Bioact Mater ; 24: 361-375, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36632506

RESUMO

Long-term nonunion of bone defects has always been a major problem in orthopedic treatment. Artificial bone graft materials such as Poly (lactic-co-glycolic acid)/ß-tricalcium phosphate (PLGA/ß-TCP) scaffolds are expected to solve this problem due to their suitable degradation rate and good osteoconductivity. However, insufficient mechanical properties, lack of osteoinductivity and infections after implanted limit its large-scale clinical application. Hence, we proposed a novel bone repair bioscaffold by adding zinc submicron particles to PLGA/ß-TCP using low temperature rapid prototyping 3D printing technology. We first screened the scaffolds with 1 wt% Zn that had good biocompatibility and could stably release a safe dose of zinc ions within 16 weeks to ensure long-term non-toxicity. As designed, the scaffold had a multi-level porous structure of biomimetic cancellous bone, and the Young's modulus (63.41 ± 1.89 MPa) and compressive strength (2.887 ± 0.025 MPa) of the scaffold were close to those of cancellous bone. In addition, after a series of in vitro and in vivo experiments, the scaffolds proved to have no adverse effects on the viability of BMSCs and promoted their adhesion and osteogenic differentiation, as well as exhibiting higher osteogenic and anti-inflammatory properties than PLGA/ß-TCP scaffold without zinc particles. We also found that this osteogenic and anti-inflammatory effect might be related to Wnt/ß-catenin, P38 MAPK and NFkB pathways. This study lay a foundation for the follow-up study of bone regeneration mechanism of Zn-containing biomaterials. We envision that this scaffold may become a new strategy for clinical treatment of bone defects.

10.
Front Optoelectron ; 16(1): 8, 2023 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-37087536

RESUMO

Single perylene diimide (PDI) used as a non-fullerene acceptor (NFA) in organic solar cells (OSCs) is enticing because of its low cost and excellent stability. To improve the photovoltaic performance, it is vital to narrow the bandgap and regulate the stacking behavior. To address this challenge, we synthesize soluble perylenetetracarboxylic bisbenzimidazole (PTCBI) molecules with a bulky side chain at the bay region, by replacing the widely used "swallow tail" type alkyl chains at the imide position of PDI molecules with a planar benzimidazole structure. Compared with PDI molecules, PTCBI molecules exhibit red-shifted UV-vis absorption spectra with larger extinction coefficient, and one magnitude higher electron mobility. Finally, OSCs based on one soluble PTCBI-type NFA, namely MAS-7, exhibit a champion power conversion efficiency (PCE) of 4.34%, which is significantly higher than that of the corresponding PDI-based OSCs and is the highest PCE of PTCBI-based OSCs reported. These results highlight the potential of soluble PTCBI derivatives as NFAs in OSCs.

11.
Adv Sci (Weinh) ; 10(7): e2206580, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36592412

RESUMO

Hybrid cycloalkyl-alkyl side chains are considered a unique composite side-chain system for the construction of novel organic semiconductor materials. However, there is a lack of fundamental understanding of the variations in the single-crystal structures as well as the optoelectronic and energetic properties generated by the introduction of hybrid side chains in electron acceptors. Herein, symmetric/asymmetric acceptors (Y-C10ch and A-C10ch) bearing bilateral and unilateral 10-cyclohexyldecyl are designed, synthesized, and compared with the symmetric acceptor 2,2'-((2Z,2'Z)-((12,13-bis(2-butyloctyl)-3,9 bis(ethylhexyl)-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″':4',5']thieno[2',3':4,5] pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10- diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (L8-BO). The stepwise introduction of 10-cyclohexyldecyl side chains decreases the optical bandgap, deepens the energy level, and enables the acceptor molecules to pack closely in a regular manner. Crystallographic analysis demonstrates that the 10-cyclohexyldecyl chain endows the acceptor with a more planar skeleton and enforces more compact 3D network packing, resulting in an active layer with higher domain purity. Moreover, the 10-cyclohexyldecyl chain affects the donor/acceptor interfacial energetics and accelerates exciton dissociation, enabling a power conversion efficiency (PCE) of >18% in the 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″':4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (Y6) (PM6):A-C10ch-based organic solar cells (OSCs). Importantly, the incorporation of Y-C10ch as the third component of the PM6:L8-BO blend results in a higher PCE of 19.1%. The superior molecular packing behavior of the 10-cyclohexyldecyl side chain is highlighted here for the fabrication of high-performance OSCs.

12.
Polymers (Basel) ; 14(2)2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35054649

RESUMO

Bamboo is much more easily attacked by fungus compared with wood, resulting in shorter service life and higher loss in storage and transportation. It has been long accepted that the high content of starch and sugars in bamboo is mainly responsible for its low mould resistance. In this paper, acetic acid, propionic acid, oxalic acid, citric acid, and hydrochloric acid were adopted to hydrothermally hydrolyze the starch in bamboo, with the aims to investigate their respective effect on the mould and blue-stain resistance of bamboo, and the optimized citric acid in different concentrations were studied. The starch content, glucose yields, weight loss, and colour changes of solid bamboo caused by the different acidic hydrolysis were also compared. The results indicated that weak acidic hydrolysis treatment was capable of improving mould-resistant of bamboo. The mould resistance increased with the increased concentration of citric acid. Bamboo treated with citric acid in the concentration of 10% could reduce the infected area ranging to 10-17%, the growth rating of which could reach 1 resistance. The content of soluble sugar and starch remained in bamboo decreased significantly from 43 mg/g to 31 mg/g and 46 mg/g to 23 mg/g, respectively, when the citric acid concentration varied from 4% to 10%. Citric acid treatments of 10% also caused a greatest surface colour change and weight loss. The results in this study demonstrated citric acid treatment can effectively reduce the starch grain and soluble sugars content and improve mould resistance of bamboo, which can be attributed to the reduction of starch grain and soluble carbohydrates (such as glucose, fructose, and sucrose, etc.) in bamboo.

13.
Polymers (Basel) ; 14(6)2022 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-35335580

RESUMO

Color is one of the most important characteristics of a material's appearance, which affects the additional value of bamboo and psychological feelings of users. Previous studies have shown that the dimensional stability, mildew resistance and durability of bamboo were improved after tung oil thermal treatment. In this study, the effects of tung oil thermal treatment on bamboo color at different temperatures and durations of time were investigated. The results show that the lightness (L*) of bamboo decreased as the tung oil temperature or duration of time increased. The red-green coordinates (a*) and color saturation (C*) of bamboo were gradually increased as the tung oil temperature rose from 23 °C to 160 °C, while the a* and C* were gradually decreased when the temperature continued to rise from 160 °C to 200 °C. There was no significant difference in the yellow-blue coordinates (b*) of bamboo when the duration was prolonged from 0.5 h to 3 h with tung oil thermal treatment at 140 °C. Eye movement data show that the popularity of bamboo furniture was significantly improved at 23-100 °C and slightly improved at 160-180 °C with tung oil treatment. Therefore, tung oil thermal treatment plays a positive role in improving visual effects and additional value of bamboo.

14.
Polymers (Basel) ; 14(19)2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36235998

RESUMO

The effect of humidity and heat environmental conditions on the durability of conventional bamboo materials is a pressing issue in the reserving phase of biomass materials. In this study, the relationship between the main physicochemical, pyrolytic, and mechanical properties of bamboo before and after ageing has been investigated. Exposure of engineered bamboo raw materials with moisture content up to 10% to alternating humidity and heat cycles (20 °C 98% RH-30 °C 64% RH-40 °C 30% RH) of ageing (HHT) causes degradation of the chemical polymer matrix. Byk Gardner 6840 color difference meter, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), compression intensity, thermogravimetric-infrared spectroscopy (TG-IR), and density changes are used to assess the quality of the material before and after ageing. No significant changes in the moisture content within the range of 6.12 ± 0.327 after two weeks of the engineered bamboo during wet thermal cyclic ageing were determined. However, there were significant differences in mass loss (7.75-9.93 g), cellulose crystallinity, chemical changes, compression strength, and pyrolytic properties. Differences in specimen colors were observed during 10 weeks of the accelerated humidity heat cycling ageing, and TCD variations ranged from 3.75 to 20.08 and from 0.25 and 3.24, respectively. Reduced cellulose crystallinity (36.459-22.638%), axial compressive strength (63.07-88.09 MPa), and modulus of rupture (2409-4286 MPa) were found during aging, whereas deformation and ductility properties were improved. Both natural and humidity heat ageing improve thermal stability and peak pyrolysis rates (0.739-0.931; 0.731-0.797). Humidity heat cyclic ageing will assist in the design and risk assessment of warehousing environments for industrial applications.

15.
Sci Rep ; 12(1): 8610, 2022 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-35597801

RESUMO

One of the excellent characteristics of bamboo is the deformation stability. However, the reasons for the good bending stability of bamboo have not been well studied. In this study, we examined the pathways that controls bending deformation in bamboo. A hand-bent phyllostachys iridescens member was chosen to examine continuous density distribution, microfibril angle (MFA) and modulus of elasticity (MOE) along radial direction using SilviScan analysis. Our results show that in bent bamboo, MFA is lower in tension sample and higher in compression sample than neutral sample. There is a strong linear positive correlation between density and MOE, while negative linear correlation between MOE and MFA and no obvious linear correlation between MFA and density. Increased bending was influential in primarily changing the MOE, while also altering the density distribution and MFA. Our results demonstrate variation in density, MOE and MFA distribution along radial direction of tension, neutral and compression samples, which play an important role in maintaining the bending characteristics of bamboo.


Assuntos
Microfibrilas , Poaceae , Módulo de Elasticidade
16.
Adv Healthc Mater ; 11(20): e2201596, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35920510

RESUMO

Myelin sheath reconstruction plays an important role in peripheral nerve regeneration. But the hindered reconstruction of myelin sheath, due to the inadequate repair phenotypes of macrophages and Schwann cells after peripheral nerve injury, often causes poor functional nerve recovery. Here, biomechanically-adapted immunohydrogels are prepared as the FK506-loaded platforms and nerve tissue engineering scaffolds to reconstruct myelin sheath for peripheral nerve regeneration. By immunofluorescent staining, an increase in the proportion of F4/80+ markers reveals that the biomechanically-adapted scaffolds facilitate recruitment of macrophages. Furthermore, the high Interleukin 10 (IL-10) mRNA expression level suggests the anti-inflammation learning effects of FK506 in vitro, which is further confirmed by a high CD206/TNF-α ratio in the FK506 Gel group in vivo. The immune learning effects are positively related to the increase in compactness and thickness of myelin sheath, indicating the synergy of structural reconstruction of myelin sheath and M2 phenotype polarization of macrophages. All these data indicate that the biomechanically-adapted immunohydrogels enhance recruitment of macrophages, educate M2 polarization of macrophages and promote a neuroprotective environment, which in consequence reconstructs myelin sheath for peripheral nerve regeneration.


Assuntos
Interleucina-10 , Bainha de Mielina , Bainha de Mielina/metabolismo , Interleucina-10/metabolismo , Tacrolimo/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Regeneração Nervosa/fisiologia , Células de Schwann/metabolismo , RNA Mensageiro/metabolismo
17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(6): 1717-9, 2011 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-21847965

RESUMO

The microfibril angle and crystallinity of bamboo treated with gamma rays were tested by X-ray diffraction (XRD). The result indicated that crystallinity in bamboo increased when irradiation dose was less than 100 kGy, while the irradiation dose was raised to about 100 kGy, crystallinity in bamboo reduced. But during the whole irradiation process, the influence on microfibril angle was not obvious, so it was not the dominant factors on variation in physical-mechanical properties of bamboo during the process of irradiation.


Assuntos
Bambusa/efeitos da radiação , Raios gama , Difração de Raios X
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(7): 1922-4, 2011 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-21942052

RESUMO

The structures and qualities of main chemical compositions in cell wall of bamboo treated with gamma rays were tested by nuclear magnetic resonance spectrometer (NMR) and X-ray Diffraction (XRD). The result indicated that the bamboo crystallinity increased at the beginning of irradiation process, while the crystallinity reduced when the irradiation dose was raised to about 100 kGy. During the whole irradiation process, hemicellulose degraded, and with the irradiation doses increased the non-phenolic lignin changed to the phenolic.


Assuntos
Bambusa/química , Bambusa/efeitos da radiação , Raios gama , Lignina/química , Lignina/efeitos da radiação , Espectroscopia de Ressonância Magnética , Polissacarídeos/química , Polissacarídeos/efeitos da radiação , Difração de Raios X
19.
Adv Mater ; 33(6): e2000688, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32705727

RESUMO

Discontinuously reinforced titanium matrix composites (DRTMCs), as one of the most important metal matrix composites (MMCs), are expected to exhibit high strength, elastic modulus, high-temperature endurability, wear resistance, isotropic property, and formability. Recent innovative research shows that tailoring the reinforcement network distribution totally differently from the conventional homogeneous distribution can not only improve the strengthening effect but also resolve the dilemma of DRTMCs with poor tensile ductility. Based on the network architecture, multiscale architecture, for example, two-scale network and laminate-network microstructure can further inspire superior strength, creep, and oxidation resistance at elevated temperatures. Herein, the most recent developments, which include the design, fabrication, microstructure, high-temperature performance, strengthening mechanisms, and future research opportunities for DRTMCs with multiscale architecture, are captured. In this regard, the service temperature can be increased by 200 °C, and the creep rupture time by 59-fold compared with those of conventional titanium alloys, which can meet the urgent demands of lightweight nickel-based structural materials and potentially replace nickel base superalloys at 600-800 °C to reduce weight by 45%. In fact, multiscale architecture design strategy will also favorably open a new era in the research of extensive metallic materials for improved performances.

20.
Zhonghua Zhong Liu Za Zhi ; 32(11): 845-9, 2010 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-21223691

RESUMO

OBJECTIVE: To investigate whether the single nucleotide polymorphisms (SNPs) at -1082, -819 and -592 of interleukin-10 gene and its haplotype are associated with cachexia in patients with gastric cancer. METHODS: Radioimmunoassay was used to examine the serum levels of IL-10 in 223 patients with gastric cancer. The single nucleotide polymorphisms (SNPs) of IL-10 gene -1082G/A, -819T/C and -592A/C were analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: The serum levels of IL-10 were significantly higher in patients with cachexia than those without (P < 0.001). An increased frequency of -1082G allele was noted in patients with cachexia (P = 0.049). The frequencies of -1082AG and -819CC genotypes were elevated in patients with cachexia than those without (P = 0.036, 0.024). In a logistic regression analysis adjusted for actual weight, carcinoma location and stage, the -1082AG genotype was associated with an odds ratio of 1.989 (95%CI, 1.041 - 3.802, P = 0.037), and the -819CC genotype with an odds ratio of 3.393 (95%CI, 1.298 - 8.871, P = 0.013) for cachexia. Furthermore, haplotype analysis revealed that G1082C819C592 haplotype was associated with a significantly increased risk of cachexia (OR = 2.21; 95%CI, 1.14 - 4.30; P = 0.02). CONCLUSION: Our results suggest that the gene haplotype of IL-10 contributes to the occurrence of cachexia in patients with gastric cancer in Chinese population.


Assuntos
Caquexia/genética , Haplótipos , Interleucina-10/genética , Polimorfismo de Nucleotídeo Único , Neoplasias Gástricas/genética , Idoso , Alelos , Povo Asiático/genética , Caquexia/sangue , Caquexia/complicações , Feminino , Predisposição Genética para Doença , Humanos , Interleucina-10/sangue , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Neoplasias Gástricas/sangue , Neoplasias Gástricas/complicações
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa