Laboratory testing on cracking characteristics and improvement mechanism of coral mud

In recent years,the development and construction of island reefs have been flourishing.Due to the remoteness of island reefs from the mainland,the scarcity of building materials,and the high transportation costs,it is imperative to use local marine resources,and the potential value and status of coral mud on island reefs,which is formed by the remains of corals and other biological entities,is becoming increasingly prominent.Utilization and optimization of natural resources on island reefs have become a brand-new research direction and challenge.This article mainly focuses on the development of a new type of green engineering material,coral mud,for use in building surface layers.Thickness effects,PVA fiber(vinylon staple fiber)modification,and HPMC(Hydroxypropyl Methyl Cellulose)adhesive modification are taken into consideration.Through laboratory tests and image processing technology,fractal theory,and electron microscopy experiments,the macro-meso-microscopic multi-scale cracking rules of the coral mud surface layer and the optimization modification rules of PVA fibers and HPMC adhesives are revealed.The results demonstrate that the performance of the coral mud surface layer is superior to that of the kaolin surface layer,and the 10 mm thickness performs better than the 5 mm and 20 mm thicknesses.As the thickness of the coral mud surface layer increases,the contact between coral mud particles becomes denser,the scale of surface micro-cracks decreases,and the number of micro-pores decreases.PVA fibers can effectively inhibit the further development of macro and micro cracks and play a good bridging role.There is a bonding and adhesion relationship between coral mud and PVA fibers,and they have a good synergistic effect in inhibiting macro and mesoscopic cracks.With the increase in HPMC adhesive content,the number of micro-cracks and the scale of micro-cracks decrease accordingly,and the structure and performance of the coral mud surface layer are further improved.Overall,PVA fibers are more effective than HPMC adhesives in inhibiting the cracking of the coral mud surface layer.This provides valuable guidance for the development and application of coral mud in wall surface materials.

Drug-loaded balloon with built-in NIR controlled tip-separable microneedles for long-effective arteriosclerosis treatment

Drug-eluting balloon(DEB)angioplasty has emerged as an effective treatment for cardiovascular and cerebrovascular diseases.However,distal embolism and late lumen restenosis could be caused by drug loss during DEB handling and rapid drug metabolization.Here,a drug-loaded balloon equipped with tip-separable microneedles on the balloon surface(MNDLB)was developed.Inbuilt near-infrared(NIR)ring laser inside the catheter inner shaft was introduced to activate the biodegradable microneedle tips for the first time.The drug-loaded tips thus could be embedded in the vasculature and then released antiproliferative drug-paclitaxel slowly via polymer degradation for more than half a year.A significant increase in drug delivery efficiency and superior therapeutic effectiveness compared with the standard DEB were demonstrated using an atherosclerosis rabbit model.

Exogenous nucleic acids aggregate in non-P-body cytoplasmic granules when transfected into cultured cells

To modulate gene expression in research studies or in potential clinical therapies,transfection of exogenous nucleic acids including plasmid DNA and small interference RNA(siRNA)are generally performed.However,the cellular processing and the fate of these nucleic acids remain elusive.By investigating the cellular behavior of transfected nucleic acids using confocal imaging,here we show that when siRNA was cotransfected into cultured cells with other nucleic acids,including single-stranded RNA oligonucleotides,single and double-stranded DNA oligonucleotides,as well as long double-stranded plasmid DNA,they all aggregate in the same cytoplasmic granules.Interestingly,the amount of siRNA aggregating in granules was found not to correlate with the gene silencing activity,suggesting that assembly of cytoplasmic granules triggered by siRNA transfection may be separable from the siRNA silencing event.Our results argue against the claim that the siRNAaggregating granules are the functional site of RNA interference(RNAi).Taken together,our studies suggest that,independent of their types or forms,extraneously transfected nucleic acids are processed through a common cytoplasmic pathway and trigger the formation of a new type of cytoplasmic granules“transfection granules”.