Exosomes derived from stem cells as an emerging therapeutic strategy for intervertebral disc degeneration

Intervertebral disc(IVD)degenerative diseases are a common problem in the world,and they cause substantial social and economic burdens for people.The current methods for treating IVD degenerative diseases mainly include surgery and conservative treatment,which cannot fundamentally restore the normal structure of the disc.With continuous research on the mechanism of degeneration and the development of regenerative medicine,rapid progress has been made in the field of regenerative medicine regarding the use of stem cell-derived exosomes,which are active biological substances used in intercellular communication,because they show a strong effect in promoting tissue regeneration.The study of exosomes in the field of IVD degeneration has just begun,and many surprising achievements have been made.This paper mainly reviews the biological characteristics of exosomes and highlights the current status of exosomes in the field of IVD degeneration,as well as future developments regarding exosomes.

针刺治疗癌症相关症状临床研究的文献计量学分析

Background:Acupuncture has been recommended as a nonpharmacological intervention for managing cancer-related symptoms.However,there are few bibliometric analysis-based studies concerning the overall trends and characteristics in acupuncture therapy for cancer management.This study aims to summarize the status and bibliometric characteristics of acupuncture as an intervention for cancer-related symptoms.Methods:All clinical research papers on acupuncture for the management of cancer-related symptoms published up to October 1,2020 were collected from the PubMed and Web of Science databases.Data on the included studies were extracted to reflect the following items:publication year,journal,country or region,institution,clinical indications,and acupuncture prescriptions.Characteristics were analyzed using bibliometric methods.Results:A total of 226 papers were included.The number of such publications has increased steadily since 2004.The 226 articles were published in 94 English journals,with Integrative Cancer Therapies(18 articles) and Acupuncture in Medicine(14 articles) being the most prolific.The included studies are distributed across 20 countries and regions,among which the top two are the United States of America(68 articles) and China(60 articles).The types of cancer the studies addressed include breast,gastric,head and neck,etc.Acupuncture is mainly employed in the treatment of complications and side effects,among which nausea and vomiting,pain,hot flashes,and fatigue are the most frequently treated cancer-related symptoms.Acupuncture is the most commonly used treatment therapy,and the four most frequently used acupoints used are Neiguan(内关 PC6),Sanyinjiao(三阴交 SP6),Zusanli(足三里 ST36),and Hegu(合 LI4).The specific acupuncture prescription depends on individual patients’ symptoms.Conclusion:Research on acupuncture as an adjunctive therapy for cancer-related symptoms is developing steadily,with results being reported in a growing number of mainstream medical journals.Hence,this field is expected to receive more attention in the future.

Macroscopic Regulation of Hierarchical Nanostructures in Liquid-crystalline Block Copolymers towards Functional Materials

The great potential of liquid-crystalline block copolymers(LCBCs)containing photoresponsive mesogens toward novel applications in photonics and nanotechnology has been attracting increasing attention,due to the combination of the inherent property of microphase separation of block copolymers and the hierarchically-assembled structures of liquid-crystalline polymers(LCPs).The periodically ordered nanostructures in bulk film of LCBCs can be acquired by supramolecular cooperative motion,derived from the interaction between liquid-crystalline elastic deformation and microphase separation,which are able to improve physical properties of polymer film toward advanced functional applications.Moreover,various micro/nano-patterned structures have been fabricated via light manipulation of photoresponsive LCBCs with good reproducibility and mass production.Thanks to recent developments in synthesis and polymerization techniques,diverse azobenzene-containing LCBCs have been designed,resulting in the creation of a wide variety of novel functions.This review illustrates recent progresses in macroscopic regulation of hierarchical nanostructures in LCBCs towards functional materials.The existing challenges are also discussed,showing perspectives for future studies.

A Liutex-based subgrid stress model for large-eddy simulation

The concept of vortex is crucial in both understanding and modeling of turbulence.For large eddy simulation(LES),the effect of small-scale eddies onto the large scales or the resolved flow field is modeled by subgrid stress models.Even though the rotating motions of fluids,i.e.,vortices or eddies are central in developing turbulent models,vortex identification methods are seldom used in these models.In this study,we develop a new subgrid model based on the Liutex vector,a new quantity introduced to decompose fluid motions into rigid rotation,pure shear and stretching,and thus identify vortices.The new model is then applied in a decaying homogeneous isotropic turbulence(DHIT)and a turbulent channel flow at Reynolds number Reτ=180.It is shown that the new model can predict accurate energy spectra compared with experiments in DHIT and give a well-matched velocity profile in turbulent channel flow without changing the form of the model.Future directions include improvement of the Liutex based model,for example developing anisotropic subgrid models,and its applications in various turbulent flows.

In-situ synchrotron high energy X-ray diffraction study of spontaneous reorientation of R phase upon cooling in nanocrystalline Ti_(50)Ni_(45.5)Fe_(4.5)alloy

This study investigated a peculiar phenomenon of self-reorientation of thermally formed R phase in nanocrystalline Ti_(50)Ni_(45.5)Fe_(4.5)by means of in-situ syn-chrotron high energy X-ray diffraction(HE-XRD).Two samples with different average grain sizes of 40 and 90 nm were investigated.R phase in the 40-nm grain size sample was found to self-reorient gradually upon cooling,whereas the same phenomenon did not occur in the 90-nm grain size sample.This self-reorientation process is attributed to the development and evolution of an internal stress anisotropy caused by the second order continuous lattice distortion of R phase upon further cooling in the small nanograined matrix,which lacks the self-accommodation mechanism for internal stress cancellation.