Circumferential variation in mechanical characteristics of porcine descending aorta

Arterial characterization of healthy descending thoracic aorta(DTA)is indispensable in determining stress distributions across wall thickness and different regions that may be responsible for aorta inhomogeneous dilation,rupture,and dissection when aneurysm occurs.Few studies have shown the inhomogeneity of DTA along the aorta tree considering changes in circumferential direction.The present study aims to clarify the circumferential regional characterization of DTA.Porcine DTA tissues were tested according to region and orientation using uniaxial tension.For axial test,results show that the difference in circumferential direction was mainly in collagen fiber modulus,where the anterior collagen fiber modulus was significantly lower than the posterior quadrant.For circumferential test,the difference in circumferential direction was mainly in the recruitment parameter,where the circumferential stiffness is significantly higher in the posterior region at physiological maximum stress.The proximal posterior quadrant and left quadrant showed significantly lower axial collagen fiber stiffness than the right and anterior quadrants,which may be a factor in aneurysm development.Furthermore,the constitutive parameters for similar detailed regions can be used by biomedical engineers to investigate improved therapies and thoroughly understand the initial stage of aneurysm development.The regional collagen fiber modulus can help improve our understanding of the mechanisms of arterial dilation and aortic dissection.

Unsteady aerodynamic noise prediction of contra-rotating open rotor using meshless method

The Contra-Rotating Open Rotor(CROR)design confronts significant noise challenges despite being one of the possible options for future green aeroengines.To efficiently estimate the noise emitted from a CROR,a three-dimensional unsteady prediction model based on the meshless method is presented.The unsteady wake flow and the aerodynamic load fluctuations on the blade are solved through the viscous vortex particle method,the blade element momentum theory and vortex lattice method.Then,the acoustic field is obtained through the Farassat’s formulation 1A.Validation of this method is conducted on a CROR,and a mesh-based method,e.g.,Nonlinear Harmonic(NLH)method,is also employed for comparison.It is found that the presented method is three times faster than NLH method while maintaining a comparable precision.A thorough parametric analysis is also carried out to illustrate the effects of rotational speed,rotor-rotor spacing and rear rotor diameter on the noise level.The rotor speed is found to be the most influencing factor,and by optimizing the speed difference between the front and rear rotors,a notable noise reduction can be expected.The current findings not only contribute to a deeper comprehension of the CROR’s aeroacoustic properties but also offer an effective tool for engineering applications.

Costunolide covalently targets NACHT domain of NLRP3 to inhibit inflammasome activation and alleviate NLRP3-driven inflammatory diseases

The NLRP3 inflammasome’s core and most specific protein,NLRP3,has a variety of functions in inflammation-driven diseases.Costunolide(COS)is the major active ingredient of the traditional Chinese medicinal herb Saussurea lappa and has anti-inflammatory activity,but the principal mechanism and molecular target of COS remain unclear.Here,we show that COS covalently binds to cysteine 598 in NACHT domain of NLRP3,altering the ATPase activity and assembly of NLRP3 inflammasome.We declare COS’s great anti-inflammasome efficacy in macrophages and disease models of gouty arthritis and ulcerative colitis via inhibiting NLRP3 inflammasome activation.We also reveal that theα-methylene-γ-butyrolactone motif in sesquiterpene lactone is the certain active group in inhibiting NLRP3 activation.Taken together,NLRP3 is identified as a direct target of COS for its anti-inflammasome activity.COS,especially theα-methylene-γ-butyrolactone motif in COS structure,might be used to design and produce novel NLRP3 inhibitors as a lead compound.

敏化型电致发光器件原理与技术

近年来,高性能荧光有机电致发光器件(FOLEDs)的开发受到了广泛关注。由于荧光材料仅能利用25%的单重态激子辐射发光,FOLEDs的外量子效率(EQE)理论极限为5%。通过能量转移,充分利用主体分子的单重态与三重态激子敏化荧光客体发光,可以提高激子利用率。目前敏化型FOLEDs(SFOLEDs)的最高EQE已达26.1%。本文详细介绍了SFOLEDs的敏化原理和机制,并根据敏化机制的不同,系统地总结了热活化延迟荧光敏化、激基复合物敏化、三重态湮灭敏化和局域电荷转移杂化激发态(HLCT)敏化等各类SFOLEDs的材料与器件结构特点及其研究进展。最后本综述对该类器件的研究前景进行了展望,期待吸引更多专业的研究人员的研究兴趣,进而推动该领域的发展。

60 Years of Development of the Journal of Integrative Plant Biology

In celebration of JIPB＇s 60th anniversary, this paper summarizes and reviews the development process of the journal. To start, we offer our heartfelt thanks to JIPB＇s pioneer Editors-in-Chief who helped get the journal off the ground and make it successful. Academic achievement is the soul of academic journals, and this paper summarizes JIPB＇s course of academic development by analyzing it in four stages： the first two stages are mostly qualitative analyses, and the latter two stages are dedicated to quantitative analyses. Most-cited papers were statistically analyzed. Improvements in editing, pub- lication, distribution and online accessibility--which are detailed in this paper--contribute to JIPB＇s sustainable development. In addition, JIPB＇s evaluation index and awards are provided with accompany- ing pictures. At the end of the paper, JIPB＇s milestones are listed chronologically. We believe that JIPB＇s development, from a national journal to an international one, parallels the development of the Chinese plant sciences.