Inertial piezoelectric actuators are widely applied in precision devices with simple structure and accurate movement.However,existing inertial piezoelectric actuators still face the challenges of rollback motion and b...Inertial piezoelectric actuators are widely applied in precision devices with simple structure and accurate movement.However,existing inertial piezoelectric actuators still face the challenges of rollback motion and bulky power supply.In this work,an alternate excitation strategy and a customized small power supply for a bimorph rotary piezoelectric actuator(BRPA)are proposed to solve the problems.The BRPA prototype is designed with a bipedal symmetrical structure,measuring 35 mm in height and 32 mm in diameter,which has a maximum rotation velocity of 0.247 rad/s and a resolution of 0.66μrad.Thanks to the bipedal symmetrical structure,the friction directions between the driving feet and the rotor can be coordinated to suppress the rollback.The rollback ratio is almost zero when the phase difference of the exciting signal is set as 180°.The customized power supply is designed and manufactured,whose size is 58 mm×56 mm×46 mm.It can output signals for the single step mode and the continuous mode,and they are adopted to excite BRPA to achieve a small stroke with one single step and a large stroke with continuous step,respectively.Then,an experimental system for optical fiber alignment is developed based on the BRPA and the customized small power supply,the experiment has verified the practicability of this work in the precision fields,especially in the miniaturized precision systems.展开更多
The neovascularization of ischemic tis- sue is a crucial initial step for the functional rehabili- tation and wound healing. However, the short of seed cell candidate for the foundation of vascular network is still a ...The neovascularization of ischemic tis- sue is a crucial initial step for the functional rehabili- tation and wound healing. However, the short of seed cell candidate for the foundation of vascular network is still a big issue. Human adipose tissue derived mesenchymal stem cells (hADSCs), which possess multilineage potential, are capable of adipogenic, osteogenic, and chondrogenic differentiation. We examined whether this kind of stem cells could dif- ferentiate into endothelial-like cells and participate in blood vessel formation, and whether they could be used as an ideal cell source for therapeutic angio- genesis in ischemic diseases or vascularization of tissue constructs. The results showed that hADSCs, grown under appropriately induced conditions, dis- played characteristics similar to those of vessel en- dothelium. The differentiated cells expressed endo- thelial cell markers CD34 and vWF, and had high metabolism of acetylated low-density lipoprotein and prostacyclin. In addition, the induced cells were able to form tube-like structures when cultured on matrigel. Our data indicated that induced hADSCs could ex- hibit characteristics of endothelial cells. Therefore, these cells, as a source of human endothelial cells, may find many applications in such realms as engi- neering blood vessels, endothelial cell transplantation for myocardial regeneration, and induction of angio- genesis for treatment of regional ischemia.展开更多
Antibacterial wound dressing can benefit the wound healing by preventing bacterial infection,especially for the electrospun ones due to their porous structures and easily loading antibacterial drugs.However,it is chal...Antibacterial wound dressing can benefit the wound healing by preventing bacterial infection,especially for the electrospun ones due to their porous structures and easily loading antibacterial drugs.However,it is challenging to apply the antibacterial electrospun wound dressing to covering the wound conveniently and safely.Here,we presented one step fabrication and application of antibacterial electrospun zein/cinnamon oil wound dressing via a handheld electrospinning setup.The prepared zein/cinnamon oil wound dressing showed gas permeability of(76.1-5.45)mm/s,hydrophilicity with zero body fluid contact angle,swelling stability after 24 h as well as antibacterial zones over 5 cm against both E.coli and S.aureus bacteria.Moreover,in situ electrospinning process can deposit the electrospun zein/cinnamon oil fibers directly onto the wound,meantime forming a wound dressing.The mice cut-wound model experiment demonstrated that the one step in situ fabrication and application of zein/cinnamon oil wound dressing could nearly heal the wound within 11 d.展开更多
For a long time,I took photos in arandom and purposeless way,focusing solely on the techniques that could create beautiful but worthless visuals.Gradually,I started to hope that I could record the valuable items that ...For a long time,I took photos in arandom and purposeless way,focusing solely on the techniques that could create beautiful but worthless visuals.Gradually,I started to hope that I could record the valuable items that I cared about.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52105015 and 52225501)the China Postdoctoral Science Foundation(Grant No.2021M690830)the Postdoctoral Science Foundation of Heilongjiang Province,China(Grant No.LBH-Z21018)。
文摘Inertial piezoelectric actuators are widely applied in precision devices with simple structure and accurate movement.However,existing inertial piezoelectric actuators still face the challenges of rollback motion and bulky power supply.In this work,an alternate excitation strategy and a customized small power supply for a bimorph rotary piezoelectric actuator(BRPA)are proposed to solve the problems.The BRPA prototype is designed with a bipedal symmetrical structure,measuring 35 mm in height and 32 mm in diameter,which has a maximum rotation velocity of 0.247 rad/s and a resolution of 0.66μrad.Thanks to the bipedal symmetrical structure,the friction directions between the driving feet and the rotor can be coordinated to suppress the rollback.The rollback ratio is almost zero when the phase difference of the exciting signal is set as 180°.The customized power supply is designed and manufactured,whose size is 58 mm×56 mm×46 mm.It can output signals for the single step mode and the continuous mode,and they are adopted to excite BRPA to achieve a small stroke with one single step and a large stroke with continuous step,respectively.Then,an experimental system for optical fiber alignment is developed based on the BRPA and the customized small power supply,the experiment has verified the practicability of this work in the precision fields,especially in the miniaturized precision systems.
文摘The neovascularization of ischemic tis- sue is a crucial initial step for the functional rehabili- tation and wound healing. However, the short of seed cell candidate for the foundation of vascular network is still a big issue. Human adipose tissue derived mesenchymal stem cells (hADSCs), which possess multilineage potential, are capable of adipogenic, osteogenic, and chondrogenic differentiation. We examined whether this kind of stem cells could dif- ferentiate into endothelial-like cells and participate in blood vessel formation, and whether they could be used as an ideal cell source for therapeutic angio- genesis in ischemic diseases or vascularization of tissue constructs. The results showed that hADSCs, grown under appropriately induced conditions, dis- played characteristics similar to those of vessel en- dothelium. The differentiated cells expressed endo- thelial cell markers CD34 and vWF, and had high metabolism of acetylated low-density lipoprotein and prostacyclin. In addition, the induced cells were able to form tube-like structures when cultured on matrigel. Our data indicated that induced hADSCs could ex- hibit characteristics of endothelial cells. Therefore, these cells, as a source of human endothelial cells, may find many applications in such realms as engi- neering blood vessels, endothelial cell transplantation for myocardial regeneration, and induction of angio- genesis for treatment of regional ischemia.
基金This work was supported by the Postdoctoral Science Foundation of China(No.2020M671998)the Fund of the State Key Laboratory of Bio-Fibers and Eco-Textiles(Qingdao University)of China(No.ZKT35)the National Natural Science Foundation of China(No.51703102).
文摘Antibacterial wound dressing can benefit the wound healing by preventing bacterial infection,especially for the electrospun ones due to their porous structures and easily loading antibacterial drugs.However,it is challenging to apply the antibacterial electrospun wound dressing to covering the wound conveniently and safely.Here,we presented one step fabrication and application of antibacterial electrospun zein/cinnamon oil wound dressing via a handheld electrospinning setup.The prepared zein/cinnamon oil wound dressing showed gas permeability of(76.1-5.45)mm/s,hydrophilicity with zero body fluid contact angle,swelling stability after 24 h as well as antibacterial zones over 5 cm against both E.coli and S.aureus bacteria.Moreover,in situ electrospinning process can deposit the electrospun zein/cinnamon oil fibers directly onto the wound,meantime forming a wound dressing.The mice cut-wound model experiment demonstrated that the one step in situ fabrication and application of zein/cinnamon oil wound dressing could nearly heal the wound within 11 d.
文摘For a long time,I took photos in arandom and purposeless way,focusing solely on the techniques that could create beautiful but worthless visuals.Gradually,I started to hope that I could record the valuable items that I cared about.