社会加速视域下大学生学习异化风险的现实表征、生成逻辑及应对

社会加速深刻地改写了现代社会中的时间结构,身处其中的个体对时间结构的变化有着深切的感知。技术发展加速、社会变迁加速以及生活节奏加速影响了当下大学生学习的节奏、内容与目标等诸多方面。大学生身处班级集体、学校组织与社会之中,其行为和实践的节奏、速度、期限和顺序不自觉地受到社会加速所引发的竞争漩涡、时间焦虑和不确定性的影响,进而出现了与学习空间、与学习内容、与学习行为、与学习时间、与自我关系相异化的倾向。为应对大学生学习中的异化风险,大学生自身可以通过确定适己时间、设定长远目标、延迟满足等路径尝试找寻逆俗生存的力量;学校层面可以从评价体系方面进行改革以弱化同侪竞争的压力,为大学生创设慢慢成长、深度思考的学习文化,并为大学生提供完善的心理支持体系。

价值与功用:本科生成绩单与教学管理

本科教育是高等教育体系的基础,本科生是接受高等教育人群中最大的学生群体,本科生成绩单是反映人才培养模式和教学质量的载体之一,有独特的使用价值和适用范围。本科生成绩单是一个历史现象,其中的每一个符号和要素都是值得研究的课题,蕴藏着极大的研究空间和研究价值。高等教育进入大众化和普及化阶段以来,成绩单的价值与功用遇到挑战,在我国本科生成绩单中出现了一些令人费解的现象,诸如“价值理念”缺失和“管理功用”失范等。这些现象亟须得到关注和纠正。研究本科生成绩单就是探讨如何遵循本科教育教学规律和学生成长规律,深化人才培养模式和教学改革,重振成绩单的价值与功用。

Regulating Blood Clot Fibrin Films to Manipulate Biomaterial-Mediated Foreign Body Responses

The clinical efficacy of implanted biomaterials is often compromised by host immune recognition and subsequent foreign body responses(FBRs).During the implantation,biomaterials inevitably come into direct contact with the blood,absorbing blood protein and forming blood clot.Many studies have been carried out to regulate protein adsorption,thus manipulating FBR.However,the role of clot surface fibrin films formed by clotting shrinkage in host reactions and FBR is often ignored.Because of the principle of fibrin film formation being relevant to fibrinogen or clotting factor absorption,it is feasible to manipulate the fibrin film formation via tuning the absorption of fibrinogen and clotting factor.As biological hydroxyapatite reserved bone architecture and microporous structure,the smaller particle size may expose more microporous structures and adsorb more fibrinogen or clotting factor.Therefore,we set up 3 sizes(small,<0.2 mm;medium,1 to 2 mm;large,3 to 4 mm)of biological hydroxyapatite(porcine bone-derived hydroxyapatite)with different microporous structures to investigate the absorption of blood protein,the formation of clot surface fibrin films,and the subsequent FBR.We found that small group adsorbed more clotting factors because of more microporous structures and formed the thinnest and sparsest fibrin films.These thinnest and sparsest fibrin films increased inflammation and profibrosis of macrophages through a potential signaling pathway of cell adhesion-cytoskeleton-autophagy,leading to the stronger FBR.Large group adsorbed lesser clotting factors,forming the thickest and densest fibrin films,easing inflammation and profibrosis of macrophages,and finally mitigating FBR.Thus,this study deepens the understanding of the role of fibrin films in host recognition and FBR and demonstrates the feasibility of a strategy to regulate FBR by modulating fibrin films via tuning the absorption of blood proteins.

Improving hard metal implant and soft tissue integration by modulating the“inflammatory-fibrous complex”response

Soft tissue integration is one major difficulty in the wide applications of metal materials in soft tissue-related areas.The inevitable inflammatory response and subsequent fibrous reaction toward the metal implant is one key response for metal implant-soft tissue integration.It is of great importance to modulate this inflammatory-fibrous response,which is mainly mediated by the multidirectional interaction between fibroblasts and macrophages.In this study,macrophages are induced to generate M1 and M2 macrophage immune microenvironments.Their cytokine profiles have been proven to have potentially multi-regulatory effects on fibroblasts.The multi-reparative effects of soft tissue cells(human gingival fibroblasts)cultured on metal material(titanium alloy disks)in M1 and M2 immune microenvironments are then dissected.Fibroblasts in the M1 immune microenvironment tend to aggravate the inflammatory response in a pro-inflammatory positive feedback loop,while M2 immune microenvironment enhances multiple functions of fibroblasts in soft tissue integration,including soft tissue regeneration,cell adhesion on materials,and contraction to immobilize soft tissue.Enlighted by the close interaction between macrophages and fibroblasts,we propose the concept of an“inflammatory-fibrous complex”to disclose possible methods of precisely and effectively modulating inflammatory and fibrous responses,thus advancing the development of metal soft tissue materials.

Nanotopographic micro-nano forces finely tune the conformation of macrophage mechanosensitive membrane protein integrinβ_(2)to manipulate inflammatory responses

Finely tuning mechanosensitive membrane proteins holds great potential in precisely controlling inflammatory responses.In addition to macroscopic force,mechanosensitive membrane proteins are reported to be sensitive to micro-nano forces.Integrinβ_(2),for example,might undergo a piconewton scale stretching force in the activation state.High-aspect-ratio nanotopographic structures were found to generate nN-scale biomechanical force.Together with the advantages of uniform and precisely tunable structural parameters,it is fascinating to develop low-aspect-ratio nanotopographic structures to generate micro-nano forces for finely modulating their conformations and the subsequent mechanoimmiune responses.In this study,low-aspect-ratio nanotopographic structures were developed to finely manipulate the conformation of integrinβ_(2).The direct interaction of forces and the model molecule integrinαXβ_(2)was first performed.It was demonstrated that pressing force could successfully induce conformational compression and deactivation of integrinαXβ_(2),and approximately 270 to 720 pN may be required to inhibit its conformational extension and activation.Three low-aspect-ratio nanotopographic surfaces(nanohemispheres,nanorods,and nanoholes)with various structural parameters were specially designed to generate the micro-nano forces.It was found that the nanorods and nanohemispheres surfaces induce greater contact pressure at the contact interface between macrophages and nanotopographic structures,particularly after cell adhesion.These higher contact pressures successfully inhibited the conformational extension and activation of integrinβ_(2),suppressing focal adhesion activity and the downstream PI3K-Akt signaling pathway,reducing NF-κB signaling and macrophage inflammatory responses.Our findings suggest that nanotopographic structures can be used to finely tune mechanosensitive membrane protein conformation changes,providing an effective strategy for precisely modulating inflammatory responses.