Versatile strategies for adult neurogenesis:avenues to repair the injured brain

Brain injuries due to trauma or stroke are major causes of adult death and disability.Unfortunately,few interventions are effective for post-injury repair of brain tissue.After a long debate on whether endogenous neurogenesis actually happens in the adult human brain,there is now substantial evidence to support its occurrence.Although neurogenesis is usually significantly stimulated by injury,the reparative potential of endogenous differentiation from neural stem/progenitor cells is usually insufficient.Alternatively,exogenous stem cell transplantation has shown promising results in animal models,but limitations such as poor long-term survival and inefficient neuronal differentiation make it still challenging for clinical use.Recently,a high focus was placed on glia-to-neuron conversion under single-factor regulation.Despite some inspiring results,the validity of this strategy is still controversial.In this review,we summarize historical findings and recent advances on neurogenesis strategies for neurorepair after brain injury.We also discuss their advantages and drawbacks,as to provide a comprehensive account of their potentials for further studies.

Gut microbial metabolite targets HDAC3-FOXK1-interferon axis in fibroblast-like synoviocytes to ameliorate rheumatoid arthritis

Rheumatoid arthritis(RA)is an autoimmune disease.Early studies hold an opinion that gut microbiota is environmentally acquired and associated with RA susceptibility.However,accumulating evidence demonstrates that genetics also shape the gut microbiota.It is known that some strains of inbred laboratory mice are highly susceptible to collagen-induced arthritis(CIA),while the others are resistant to CIA.Here,we show that transplantation of fecal microbiota of CIA-resistant C57BL/6J mice to CIA-susceptible DBA/1J mice confer CIA resistance in DBA/1J mice.C57BL/6J mice and healthy human individuals have enriched B.fragilis than DBA/1J mice and RA patients.Transplantation of B.fragilis prevents CIA in DBA/1J mice.We identify that B.fragilis mainly produces propionate and C57BL/6J mice and healthy human individuals have higher level of propionate.Fibroblast-like synoviocytes(FLSs)in RA are activated to undergo tumor-like transformation.Propionate disrupts HDAC3-FOXK1 interaction to increase acetylation of FOXK1,resulting in reduced FOXK1 stability,blocked interferon signaling and deactivation of RA-FLSs.We treat CIA mice with propionate and show that propionate attenuates CIA.Moreover,a combination of propionate with anti-TNF etanercept synergistically relieves CIA.These results suggest that B.fragilis or propionate could be an alternative or complementary approach to the current therapies.

Hard tissue stability after guided bone regeneration: a comparison between digital titanium mesh and resorbable membrane

Guided bone regeneration(GBR)uses resorbable and non-resorbable membranes as biological barriers.This study compared the differences in hard tissue stability between GBR using evidence-based digital titanium mesh and resorbable collagen membranes during implant placement.A total of 40 patients(65 implant sites)were enrolled and divided into two groups:resorbable membrane and digital titanium mesh groups.The alveolar bone was analyzed at two-and three-dimensional levels using conebeam computed tomography and by reconstructing and superimposing the hard tissues at four time points:preoperatively,postoperatively,before second-stage surgery,and 1 year after loading.The use of digital titanium mesh showed less alveolar bone resorption in vertical and horizontal directions two-dimensionally before the second-stage surgery and 1 year after loading.Regarding volumetric stability,the percentage of resorption after 6 months of healing with resorbable membrane coverage reached 37.5%.However,it was only 23.4%with titanium mesh.Although postoperative bone volume was greater at all labial sites with resorbable membrane than with digital titanium mesh,after substantial bone resorption within 1 year of loading,the labial bone thickness at the upper part of implants was thinner with resorbable membrane than with digital titanium mesh.Furthermore,digital titanium meshes made according to ideal bone arch contour reduced soft tissue irritation,and the exposure rate was only 10%.Therefore,although both resorbable membrane and digital titanium mesh in GBR were able to successfully reconstruct the bone defect,digital titanium meshes were better at maintaining the hard tissue volume in the osteogenic space.

Rapid velocity reduction and drift potential assessment of off-nozzle pesticide droplets

The droplet velocity and diameter significantly affect both the spatial drift loss and the interfacial deposition behaviors, thus determining the ultimate utilization efficiency during pesticide spraying.Investigating the spatial velocity and diameter evolutions can reveal the mechanism of drift loss and guide to design regulation strategy. Here, we explored the spatial velocity distribution of droplets after leaving the nozzle by particle image velocimetry technology and particle tracking model, considering that the effect of nozzle configuration and the air velocity. It shows that all droplets decelerate rapidly with the velocity attenuation ratio ranging from 50% to 80% within the region of 200 mm below the nozzle.The spatial velocity evolution differences between droplets in crossflow are determined by the competition of vertical drag force and net gravity, and the drag force sharply increases as the droplet diameter decreases, especially for that smaller than 150 μm. Based on the spatial evolution differences of the droplet velocity and diameter, a functional adjuvant was added to the liquid for improving the diameter distribution. And the drift loss was significantly reduced due to the reduction of the proportion of easily drifting droplets.