After brain damage,regenerative angiogenesis and neurogenesis have been shown to occur simultaneously in mammals,suggesting a close link between these processes.However,the mechanisms by which these processes interact...After brain damage,regenerative angiogenesis and neurogenesis have been shown to occur simultaneously in mammals,suggesting a close link between these processes.However,the mechanisms by which these processes interact are not well understood.In this work,we aimed to study the correlation between angiogenesis and neurogenesis after a telencephalic stab wound injury.To this end,we used zebrafish as a relevant model of neuroplasticity and brain repair mechanisms.First,using the Tg(fli1:EGFP×mpeg1.1:mCherry)zebrafish line,which enables visualization of blood vessels and microglia respectively,we analyzed regenerative angiogenesis from 1 to 21 days post-lesion.In parallel,we monitored brain cell proliferation in neurogenic niches localized in the ventricular zone by using immunohistochemistry.We found that after brain damage,the blood vessel area and width as well as expression of the fli1 transgene and vascular endothelial growth factor(vegfaa and vegfbb)were increased.At the same time,neural stem cell proliferation was also increased,peaking between 3 and 5 days post-lesion in a manner similar to angiogenesis,along with the recruitment of microglia.Then,through pharmacological manipulation by injecting an anti-angiogenic drug(Tivozanib)or Vegf at the lesion site,we demonstrated that blocking or activating Vegf signaling modulated both angiogenic and neurogenic processes,as well as microglial recruitment.Finally,we showed that inhibition of microglia by clodronate-containing liposome injection or dexamethasone treatment impairs regenerative neurogenesis,as previously described,as well as injury-induced angiogenesis.In conclusion,we have described regenerative angiogenesis in zebrafish for the first time and have highlighted the role of inflammation in this process.In addition,we have shown that both angiogenesis and neurogenesis are involved in brain repair and that microglia and inflammation-dependent mechanisms activated by Vegf signaling are important contributors to these processes.This study paves the way for a better understanding of the effect of Vegf on microglia and for studies aimed at promoting angiogenesis to improve brain plasticity after brain injury.展开更多
A stab-resistant substrate was designed and realized with a triangular pyramidal structure, inspired by the biological armor model in nature. The stab-resistance behavior and dynamic response mechanisms were studied t...A stab-resistant substrate was designed and realized with a triangular pyramidal structure, inspired by the biological armor model in nature. The stab-resistance behavior and dynamic response mechanisms were studied through numerical simulation and experimental testing of a knife impacting a substrate,and an optimal structural design was obtained accordingly, with a tilted angle of 22.5and optimal thickness of 1.2 mm. It was shown that the triangular pyramidal structure generated twice the internal energy of the knife than the flat substrate due to the dispersing effect of the structure. The force parallel to the inclination caused a significant scratch on the substrate surface, while the force perpendicular caused obvious substrate deformation. A new riveting method was used to form the total layer, which passed the GA 68-2008 standard. The stab-resistant clothing coupled with the reduced wearing burden could provide effective protection and avoid fatal injuries on security personnel working in dangerous environments. The method provided may enlighten the future design and manufacturing of stabresistant clothing.展开更多
Thoracic spinal cord stab injuries are rare lesions. A 17-year-old boy was stabbed on his back by his classmate when he bent forward to pick up his cloth from the ground. On admission, he presented with: complete para...Thoracic spinal cord stab injuries are rare lesions. A 17-year-old boy was stabbed on his back by his classmate when he bent forward to pick up his cloth from the ground. On admission, he presented with: complete paraplegia with muscle strength of zero on all muscle groups, complete anesthesia from dermatome 10 and below, acute urinary retention, and a four-centimeter wound on the thoracolumbar region from which cerebrospinal fluid mixed with blood was oozing out. A high-dose methylprednisolone protocol was started (30 mg/kg in one hour and then 5.4 mg/kg over 23 hours) an indwelling urinary catheter placed and sterile dressing of the wound done. Antibiotics and analgesics were also administered. The computed tomography scanning revealed a spinal cord transection at T10-T11 level with incarceration of the broken knife blade. An emergency thoracic laminectomy was performed. Removal of the broken knife blade revealed complete spinal cord transection with a compressive hematoma within the spinal cord which was removed by smooth suction. The spinal dura was sutured and the wound closed in many layers. On day 14 after surgery, sensitivity was recovered with 3 on 5 muscle strength in both lower limbs except for both feet where motor function remained null. Urinary retention and fecal incontinence persisted. The patient was discharged from our service for a rehabilitation center. At 32-month follow-up, neurological examination was unchanged although patient noticed a slight improvement of sphincter disturbances.展开更多
Despite numerous research investigations to understand the influences of various structural parameters,to the authors'knowledge,no research has been the effect of different angles of incidence on stab response and...Despite numerous research investigations to understand the influences of various structural parameters,to the authors'knowledge,no research has been the effect of different angles of incidence on stab response and performance of different types of protective textiles.Three distinct structures of 3D woven textiles and 2D plain weave fabric made with similar high-performance fiber and areal density were designed and manufactured to be tested.Two samples,one composed of a single and the other of 4-panel layers,from each fabric type structure,were prepared,and tested against stabbing at[0○],[22.5○],and[45○]angle of incidence.A new stabbing experimental setup that entertained testing of the specimens at various angles of incidence was engineered and utilized.The stabbing bench is also equipped with magnetic sensors and a UK Home Office Scientific Development Branch(HOSDB)/P1/B sharpness engineered knives to measure the impact velocity and exerted impact energy respectively.A silicon compound was utilized to imprint the Back Face Signature(BFS)on the backing material after every specimen test.Each silicon print was then scanned,digitized,and precisely measured to evaluate the stab response and performance of the specimen based on different performance variables,including Depth of Trauma(DOT),Depth of Penetration(DOP),and Length of Penetration(LOP).Besides,the post-impact surface failure modes of the fabrics were also measured using Image software and analyzed at the microscale level.The results show stab angle of incidence greatly influences the stab response and performance of protective textiles.The outcome of the study could provide not only valuable insights into understanding the stab response and capabilities of protective textiles under different angle of incidence,but also provide valuable information for protective textile manufacturer,armor developer and stab testing and standardizing organizations to consider the angle of incidence while developing,testing,optimizing,and using protective textiles in various applications.展开更多
Traumatic brain injury is a global health crisis,causing significant death and disability worldwide.Neuroinflammation that follows traumatic brain injury has serious consequences for neuronal survival and cognitive im...Traumatic brain injury is a global health crisis,causing significant death and disability worldwide.Neuroinflammation that follows traumatic brain injury has serious consequences for neuronal survival and cognitive impairments,with astrocytes involved in this response.Following traumatic brain injury,astrocytes rapidly become reactive,and astrogliosis propagates from the injury core to distant brain regions.Homeostatic astroglial proteins are downregulated near the traumatic brain injury core,while pro-inflammatory astroglial genes are overexpressed.This altered gene expression is considered a pathological remodeling of astrocytes that produces serious consequences for neuronal survival and cognitive recovery.In addition,glial scar formed by reactive astrocytes is initially necessary to limit immune cell infiltration,but in the long term impedes axonal reconnection and functional recovery.Current therapeutic strategies for traumatic brain injury are focused on preventing acute complications.Statins,cannabinoids,progesterone,beta-blockers,and cerebrolysin demonstrate neuroprotective benefits but most of them have not been studied in the context of astrocytes.In this review,we discuss the cell signaling pathways activated in reactive astrocytes following traumatic brain injury and we discuss some of the potential new strategies aimed to modulate astroglial responses in traumatic brain injury,especially using cell-targeted strategies with miRNAs or lncRNA,viral vectors,and repurposed drugs.展开更多
High performance fibers impregnated by shear thickening fluids(STFs) have been recognized as a kind of latent stab-resistant materials. In our work, the rheological properties of various nano-silica particles in diffi...High performance fibers impregnated by shear thickening fluids(STFs) have been recognized as a kind of latent stab-resistant materials. In our work, the rheological properties of various nano-silica particles in diffierent carriers were first investigated, some of which showed the typical characteristic of shear thickening phenomena.And then, the effiects of add-on and surface hydrophilicity of silica particles, the type and concentration of the carriers were discussed in detail. It was found that the systems of hydrophilic silica in ethylene glycol, butylenes glycol and polyethylene glycol(PEG) demonstrated shear thickening; moreover, the reversibility of rheological behaviors of hydrophilic silica-PEG300 suspensions indicated energy dissipation existed within a circulation of shear stress. Furthermore, the detail mechanism of STF based nano-silica particles was explored and a process diagram was presented. Finally, the stab-resistance and morphology of cutting edge of ultra high molecular weight polyethylene(UHMWPE) fabric impregnated STF composites were investigated and the results were analyzed.The higher silica add-on was benefit to the improvement of the stab resistance of the composites.展开更多
Knives are among the weapons most frequently involved in criminal cases.They represent the most encountered category of weapons in Swiss homicide cases(completed and attempted homicides considered)and are also frequen...Knives are among the weapons most frequently involved in criminal cases.They represent the most encountered category of weapons in Swiss homicide cases(completed and attempted homicides considered)and are also frequently employed in assault cases,notably bodily injuries.Whenever a knife is involved in a stabbing event,DNA and fingerprints may be sought.When garments are damaged,fibres can also be investigated.Fibres from the victim's garments might transfer onto the blade of the knife used in the assault and can thus provide useful infbnnation to determine whether a particular weapon could have be used to stab the victim.This study simulates vertical stabbings into garments with the use of a special holding device.Different types ofknives and blades straight or serrated were used as weapons.Two garments presenting different shedding capacities and garment structures were also considered for the simulations.The distribution of fibres transferred onto the blade(number and position)was recorded for each simulation performed.Sequences of stabbings into the two garments were also carried out to assess whether the order of the stabs could be determined.Several parameters were considered,notably the distribution of fibres transferred onto the blade.The transfer of fibres inside the stab damage ballistic soap was used in this study and on the area near the second damage was also investigated.This study provides new insight into the interpretation of fibres transferred onto knives after a single stab or a sequence of stabbings and into determining the stabbing sequence.Finally,the study brings some guidelines for the search and recovery of fibres on the crime scene and on the blades ofknives.展开更多
Single-atom catalysts(SACs)are promising in some reactions typically promoted by homogeneous catalysts.However,the leaching of active species from the support in liquid-phase reactions hinders their potential applicat...Single-atom catalysts(SACs)are promising in some reactions typically promoted by homogeneous catalysts.However,the leaching of active species from the support in liquid-phase reactions hinders their potential applications.Herein,taking the hydroformylation reaction as an example,we report ionic liquid(IL)-induced stabilization of single Rh atoms against leaching.Among the ILs examined.展开更多
基金supported by European Regional Development Funds RE0022527 ZEBRATOX(EU-Région Réunion-French State national counterpart,to Nicolas Diotel and Jean-Loup Bascands).
文摘After brain damage,regenerative angiogenesis and neurogenesis have been shown to occur simultaneously in mammals,suggesting a close link between these processes.However,the mechanisms by which these processes interact are not well understood.In this work,we aimed to study the correlation between angiogenesis and neurogenesis after a telencephalic stab wound injury.To this end,we used zebrafish as a relevant model of neuroplasticity and brain repair mechanisms.First,using the Tg(fli1:EGFP×mpeg1.1:mCherry)zebrafish line,which enables visualization of blood vessels and microglia respectively,we analyzed regenerative angiogenesis from 1 to 21 days post-lesion.In parallel,we monitored brain cell proliferation in neurogenic niches localized in the ventricular zone by using immunohistochemistry.We found that after brain damage,the blood vessel area and width as well as expression of the fli1 transgene and vascular endothelial growth factor(vegfaa and vegfbb)were increased.At the same time,neural stem cell proliferation was also increased,peaking between 3 and 5 days post-lesion in a manner similar to angiogenesis,along with the recruitment of microglia.Then,through pharmacological manipulation by injecting an anti-angiogenic drug(Tivozanib)or Vegf at the lesion site,we demonstrated that blocking or activating Vegf signaling modulated both angiogenic and neurogenic processes,as well as microglial recruitment.Finally,we showed that inhibition of microglia by clodronate-containing liposome injection or dexamethasone treatment impairs regenerative neurogenesis,as previously described,as well as injury-induced angiogenesis.In conclusion,we have described regenerative angiogenesis in zebrafish for the first time and have highlighted the role of inflammation in this process.In addition,we have shown that both angiogenesis and neurogenesis are involved in brain repair and that microglia and inflammation-dependent mechanisms activated by Vegf signaling are important contributors to these processes.This study paves the way for a better understanding of the effect of Vegf on microglia and for studies aimed at promoting angiogenesis to improve brain plasticity after brain injury.
基金supported by the National Natural Science Foundation of China [51874041 and 71861167002]。
文摘A stab-resistant substrate was designed and realized with a triangular pyramidal structure, inspired by the biological armor model in nature. The stab-resistance behavior and dynamic response mechanisms were studied through numerical simulation and experimental testing of a knife impacting a substrate,and an optimal structural design was obtained accordingly, with a tilted angle of 22.5and optimal thickness of 1.2 mm. It was shown that the triangular pyramidal structure generated twice the internal energy of the knife than the flat substrate due to the dispersing effect of the structure. The force parallel to the inclination caused a significant scratch on the substrate surface, while the force perpendicular caused obvious substrate deformation. A new riveting method was used to form the total layer, which passed the GA 68-2008 standard. The stab-resistant clothing coupled with the reduced wearing burden could provide effective protection and avoid fatal injuries on security personnel working in dangerous environments. The method provided may enlighten the future design and manufacturing of stabresistant clothing.
文摘Thoracic spinal cord stab injuries are rare lesions. A 17-year-old boy was stabbed on his back by his classmate when he bent forward to pick up his cloth from the ground. On admission, he presented with: complete paraplegia with muscle strength of zero on all muscle groups, complete anesthesia from dermatome 10 and below, acute urinary retention, and a four-centimeter wound on the thoracolumbar region from which cerebrospinal fluid mixed with blood was oozing out. A high-dose methylprednisolone protocol was started (30 mg/kg in one hour and then 5.4 mg/kg over 23 hours) an indwelling urinary catheter placed and sterile dressing of the wound done. Antibiotics and analgesics were also administered. The computed tomography scanning revealed a spinal cord transection at T10-T11 level with incarceration of the broken knife blade. An emergency thoracic laminectomy was performed. Removal of the broken knife blade revealed complete spinal cord transection with a compressive hematoma within the spinal cord which was removed by smooth suction. The spinal dura was sutured and the wound closed in many layers. On day 14 after surgery, sensitivity was recovered with 3 on 5 muscle strength in both lower limbs except for both feet where motor function remained null. Urinary retention and fecal incontinence persisted. The patient was discharged from our service for a rehabilitation center. At 32-month follow-up, neurological examination was unchanged although patient noticed a slight improvement of sphincter disturbances.
文摘Despite numerous research investigations to understand the influences of various structural parameters,to the authors'knowledge,no research has been the effect of different angles of incidence on stab response and performance of different types of protective textiles.Three distinct structures of 3D woven textiles and 2D plain weave fabric made with similar high-performance fiber and areal density were designed and manufactured to be tested.Two samples,one composed of a single and the other of 4-panel layers,from each fabric type structure,were prepared,and tested against stabbing at[0○],[22.5○],and[45○]angle of incidence.A new stabbing experimental setup that entertained testing of the specimens at various angles of incidence was engineered and utilized.The stabbing bench is also equipped with magnetic sensors and a UK Home Office Scientific Development Branch(HOSDB)/P1/B sharpness engineered knives to measure the impact velocity and exerted impact energy respectively.A silicon compound was utilized to imprint the Back Face Signature(BFS)on the backing material after every specimen test.Each silicon print was then scanned,digitized,and precisely measured to evaluate the stab response and performance of the specimen based on different performance variables,including Depth of Trauma(DOT),Depth of Penetration(DOP),and Length of Penetration(LOP).Besides,the post-impact surface failure modes of the fabrics were also measured using Image software and analyzed at the microscale level.The results show stab angle of incidence greatly influences the stab response and performance of protective textiles.The outcome of the study could provide not only valuable insights into understanding the stab response and capabilities of protective textiles under different angle of incidence,but also provide valuable information for protective textile manufacturer,armor developer and stab testing and standardizing organizations to consider the angle of incidence while developing,testing,optimizing,and using protective textiles in various applications.
基金supported by grants PICT 2019-08512017-2203,UBACYT and PIP CONICET(to AJR).
文摘Traumatic brain injury is a global health crisis,causing significant death and disability worldwide.Neuroinflammation that follows traumatic brain injury has serious consequences for neuronal survival and cognitive impairments,with astrocytes involved in this response.Following traumatic brain injury,astrocytes rapidly become reactive,and astrogliosis propagates from the injury core to distant brain regions.Homeostatic astroglial proteins are downregulated near the traumatic brain injury core,while pro-inflammatory astroglial genes are overexpressed.This altered gene expression is considered a pathological remodeling of astrocytes that produces serious consequences for neuronal survival and cognitive recovery.In addition,glial scar formed by reactive astrocytes is initially necessary to limit immune cell infiltration,but in the long term impedes axonal reconnection and functional recovery.Current therapeutic strategies for traumatic brain injury are focused on preventing acute complications.Statins,cannabinoids,progesterone,beta-blockers,and cerebrolysin demonstrate neuroprotective benefits but most of them have not been studied in the context of astrocytes.In this review,we discuss the cell signaling pathways activated in reactive astrocytes following traumatic brain injury and we discuss some of the potential new strategies aimed to modulate astroglial responses in traumatic brain injury,especially using cell-targeted strategies with miRNAs or lncRNA,viral vectors,and repurposed drugs.
文摘High performance fibers impregnated by shear thickening fluids(STFs) have been recognized as a kind of latent stab-resistant materials. In our work, the rheological properties of various nano-silica particles in diffierent carriers were first investigated, some of which showed the typical characteristic of shear thickening phenomena.And then, the effiects of add-on and surface hydrophilicity of silica particles, the type and concentration of the carriers were discussed in detail. It was found that the systems of hydrophilic silica in ethylene glycol, butylenes glycol and polyethylene glycol(PEG) demonstrated shear thickening; moreover, the reversibility of rheological behaviors of hydrophilic silica-PEG300 suspensions indicated energy dissipation existed within a circulation of shear stress. Furthermore, the detail mechanism of STF based nano-silica particles was explored and a process diagram was presented. Finally, the stab-resistance and morphology of cutting edge of ultra high molecular weight polyethylene(UHMWPE) fabric impregnated STF composites were investigated and the results were analyzed.The higher silica add-on was benefit to the improvement of the stab resistance of the composites.
文摘Knives are among the weapons most frequently involved in criminal cases.They represent the most encountered category of weapons in Swiss homicide cases(completed and attempted homicides considered)and are also frequently employed in assault cases,notably bodily injuries.Whenever a knife is involved in a stabbing event,DNA and fingerprints may be sought.When garments are damaged,fibres can also be investigated.Fibres from the victim's garments might transfer onto the blade of the knife used in the assault and can thus provide useful infbnnation to determine whether a particular weapon could have be used to stab the victim.This study simulates vertical stabbings into garments with the use of a special holding device.Different types ofknives and blades straight or serrated were used as weapons.Two garments presenting different shedding capacities and garment structures were also considered for the simulations.The distribution of fibres transferred onto the blade(number and position)was recorded for each simulation performed.Sequences of stabbings into the two garments were also carried out to assess whether the order of the stabs could be determined.Several parameters were considered,notably the distribution of fibres transferred onto the blade.The transfer of fibres inside the stab damage ballistic soap was used in this study and on the area near the second damage was also investigated.This study provides new insight into the interpretation of fibres transferred onto knives after a single stab or a sequence of stabbings and into determining the stabbing sequence.Finally,the study brings some guidelines for the search and recovery of fibres on the crime scene and on the blades ofknives.
基金from the Singapore National Research Foundation(ANR-17-CE06-001701 and WBS:R-279-000-530-281)for their finiancial support.The XAS were collected at the beamline BL01B1 at the SPring-8(Japan Synchrotron Radiation Research Institute,Hyogo,Japan)under the approval of JASRI(Proposal No.2019A1398).Q.H.thanks the NRF Fellowship(NRF-NRFF11-2019-0002)from the National Research Foundation of Singapore.M.G.and J.H.acknowledge the MEXT Project of Integrated Research Consortium on Chemical Science(IRCCS),the Photoexcitonix Project at Hokkaido University,and JSPS KAKENHI(JP20K05217).Some of the computations were performed at RCCS(Okazaki,Japan).
文摘Single-atom catalysts(SACs)are promising in some reactions typically promoted by homogeneous catalysts.However,the leaching of active species from the support in liquid-phase reactions hinders their potential applications.Herein,taking the hydroformylation reaction as an example,we report ionic liquid(IL)-induced stabilization of single Rh atoms against leaching.Among the ILs examined.
