In vivo astrocyte-to-neuron reprogramming for central nervous system regeneration:a narrative review

The inability of damaged neurons to regenerate within the mature central nervous system(CNS)is a significant neuroscientific challenge.Astrocytes are an essential component of the CNS and participate in many physiological processes including blood-brain barrier formation,axon growth regulation,neuronal support,and higher cognitive functions such as memory.Recent reprogramming studies have confirmed that astrocytes in the mature CNS can be transformed into functional neurons.Building on in vitro work,many studies have demonstrated that astrocytes can be transformed into neurons in different disease models to replace damaged or lost cells.However,many findings in this field are controversial,as the source of new neurons has been questioned.This review summarizes progress in reprogramming astrocytes into neurons in vivo in animal models of spinal cord injury,brain injury,Huntington’s disease,Parkinson’s disease,Alzheimer’s disease,and other neurodegenerative conditions.

Task assignment in ground-to-air confrontation based on multiagent deep reinforcement learning

The scale of ground-to-air confrontation task assignments is large and needs to deal with many concurrent task assignments and random events.Aiming at the problems where existing task assignment methods are applied to ground-to-air confrontation,there is low efficiency in dealing with complex tasks,and there are interactive conflicts in multiagent systems.This study proposes a multiagent architecture based on a one-general agent with multiple narrow agents(OGMN)to reduce task assignment conflicts.Considering the slow speed of traditional dynamic task assignment algorithms,this paper proposes the proximal policy optimization for task assignment of general and narrow agents(PPOTAGNA)algorithm.The algorithm based on the idea of the optimal assignment strategy algorithm and combined with the training framework of deep reinforcement learning(DRL)adds a multihead attention mechanism and a stage reward mechanism to the bilateral band clipping PPO algorithm to solve the problem of low training efficiency.Finally,simulation experiments are carried out in the digital battlefield.The multiagent architecture based on OGMN combined with the PPO-TAGNA algorithm can obtain higher rewards faster and has a higher win ratio.By analyzing agent behavior,the efficiency,superiority and rationality of resource utilization of this method are verified.

Association between brain N-acetylaspartate levels and sensory and motor dysfunction in patients who have spinal cord injury with spasticity:an observational case-control study

Spinal cord injury is a severe and devastating disease,and spasticity is a common and severe complication that is notoriously refractory to treatment.However,the pathophysiological mechanisms underlying spasticity and its development remain largely unknown.The goal of the present study was to find differences,if any,in metabolites of the left precentral gyrus and basal ganglia of patients who have spinal cord injury with or without spasticity,and to explore the relationship between the brain metabolite concentrations and clinical status.Thirty-six participants were recruited for magnetic resonance spectroscopic examination:23 with spinal cord injury(12 with spasticity and 11 without spasticity)and 13 healthy controls.We acquired localized proton spectra from the precentral gyrus and basal ganglia via 10 mm^(3) voxels.Notably,univariate linear regression analysis demonstrated that the lower that the N-acetylaspartate concentration(a marker for neuronal loss)was in the precentral gyrus of the patients,the lower their ASIA(American Spinal Injury Association)light-touch scores,pinprick scores,and motor scores.Additionally,longer durations of injury were associated with higher N-acetylaspartate levels in the precentral gyrus.Compared with the healthy participants and patients without spasticity,N-acetylaspartate levels in the patients with spasticity were significantly lower in both the precentral gyrus and basal ganglia.Lower N-acetylaspartate levels also correlated with greater sensory and motor dysfunction in the patients who had spinal cord injury with spasticity.

Roasting and leaching behaviors of vanadium and chromium in calcification roasting–acid leaching of high-chromium vanadium slag

Calcification roasting–acid leaching of high-chromium vanadium slag(HCVS)was conducted to elucidate the roasting and leaching behaviors of vanadium and chromium.The effects of the purity of Ca O,molar ratio between Ca O and V_2O_5(n(Ca O)/n(V_2O_5)),roasting temperature,holding time,and the heating rate used in the oxidation–calcification processes were investigated.The roasting process and mechanism were analyzed by X-ray diffraction(XRD),scanning electron microscopy(SEM),and thermogravimetry–differential scanning calorimetry(TG–DSC).The results show that most of vanadium reacted with Ca O to generate calcium vanadates and transferred into the leaching liquid,whereas almost all of the chromium remained in the leaching residue in the form of(Fe_(0.6)Cr_(0.4))_2O_3.Variation trends of the vanadium and chromium leaching ratios were always opposite because of the competitive reactions of oxidation and calcification between vanadium and chromium with Ca O.Moreover,Ca O was more likely to combine with vanadium,as further confirmed by thermodynamic analysis.When the HCVS with Ca O added in an n(Ca O)/n(V_2O_5)ratio of 0.5 was roasted in an air atmosphere at a heating rate of 10°C/min from room temperature to 950°C and maintained at this temperature for 60 min,the leaching ratios of vanadium and chromium reached91.14%and 0.49%,respectively;thus,efficient extraction of vanadium from HCVS was achieved and the leaching residue could be used as a new raw material for the extraction of chromium.Furthermore,the oxidation and calcification reactions of the spinel phases occurred at 592and 630°C for n(Ca O)/n(V_2O_5)ratios of 0.5 and 5,respectively.

Omental mass combined with indirect inguinal hernia leads to a scrotal mass: A case report

BACKGROUND Primary omental tumors are uncommon,and omental fibromas account for 2%of these tumors.Due to the low incidence of omental fibromas and the limited relevant literature,it is challenging for clinicians to make an accurate diagnosis of this condition,especially before surgery.CASE SUMMARY A 30-year-old man was admitted to the hospital because of a left epididymal mass with vague discomfort for more than 1 mo.A physical examination was performed,and the findings showed that the epididymal mass may have entered the abdominal cavity.Pelvic computed tomography was performed in our hospital and revealed a left inguinal hernia with a mass in the hernial contents,and no masses were found in the left epididymis.A traditional inguinal hernia incision was made.Intraoperative hernia contents were found to be of the greater omentum,and a 2.5 cm-diameter mass was found at the distal end of the greater omentum.The scrotum and epididymis did not exhibit other masses.Then,the mass of the greater omentum was excised.Intraoperative frozen pathological examination suggested a spindle cell tumor.The postoperative pathological examination suggested that the mass was an omental angiofibroma.Postoperatively,the patient recovered well and was discharged.Outpatient re-examinations were performed at 1 mo and half a year after the operation and showed no obvious abnormalities.CONCLUSION Due to the low morbidity rate associated with and latent nature of omental tumors,these tumors are difficult to diagnose preoperatively;thorough medical history taking,detailed physical examinations,and necessary imaging auxiliary examinations can help clinicians diagnose and treat these cases.

Multiparameter magnetic resonance imaging of liver fibrosis in a bile duct ligation mouse model

BACKGROUND Bile duct ligation(BDL)in animals is a classical method for mimicking cholestatic fibrosis.Although different surgical techniques have been described in rats and rabbits,mouse models can be more cost-effective and reproducible for investigating cholestatic fibrosis.Magnetic resonance imaging(MRI)has made great advances for noninvasive assessment of liver fibrosis.More comprehensive liver fibrotic features of BDL on MRI are important.However,the utility of multiparameter MRI to detect liver fibrosis in a BDL mouse model has not been assessed.AIM To evaluate the correlation between the pathological changes and multiparameter MRI characteristics of liver fibrosis in a BDL mouse model.METHODS Twenty-eight healthy adult male balb/c mice were randomly divided into four groups:sham,week 2 BDL,week 4 BDL,and week 6 BDL.Multiparameter MRI sequences,included magnetic resonance cholangiopancreatography,T1-weighted,T2-weighted,T2 mapping,and pre-and post-enhanced T1 mapping,were performed after sham and BDL surgery.Peripheral blood and liver tissue were collected after MRI.For statistical analysis,Student’s t-test and Pearson’s correlation coefficient were used.RESULTS Four mice died after BDL surgery;seven,six,five and six mice were included separately from the four groups.Signal intensities of liver parenchyma showed no difference on TI-and T2-weighted images.Bile duct volume,ΔT1 value,T2 value,and the rate of liver fibrosis increased steadily in week 2 BDL,week 4 BDL and week 6 BDL groups compared with those in the sham group(P<0.01).Alanine aminotransferase and aspartate transaminase levels initially surged after surgery,followed by a gradual decline over time.Strong correlations were found between bile duct volume(r=0.84),T2 value(r=0.78),ΔT1 value(r=0.62),and hepatic fibrosis rate(all P<0.01)in the BDL groups.CONCLUSION The BDL mouse model induces changes that can be observed on MRI.The MRI parameters correlate with the hepatic fibrosis rate and allow for detection of cholestatic fibrosis.

Shearing-force-driven delamination of waste residue into oxidatively stable MXene composites for high-performance Si anode

The low yield of MXene is normally related to the delaminating step,contributing to the key technical challenges in moving toward industrial applications.Here,a shearing-force-driven strategy is proposed for re-exfoliating waste MXene residue to prepare oxidatively stable MXene composites in a low-cost manner,where the strong shear stress in the assisted solvent,such as carbon nanotubes(CNTs),chitosan(CS),and polyacrylamide(PAM)aqueous solutions,acts on the surface of MXene(Ti_(3)C_(2)T_(x))through coordination between hydroxyl and Ti atoms,resulting in a rapid and efficient exfoliation of waste Ti_(3)C_(2)T_(x)residue under stirring.Furthermore,this formed coordinate bond helps to stabilize the low-valent Ti atoms on the surface of MXene,thereby enhancing the oxidative stability of Ti_(3)C_(2)T_(x).Besides,the CNT@MXene composite is selected to construct a free-standing membrane to encapsulate Si nanoparticles,achieving a high and reversible capacity after 50 cycles.This work supports the concept of valorizing waste and adopts a fluid shear forceassisted method to re-exfoliate waste residues,which greatly reduces the cost of processing and improves the chemical stability of MXene.More importantly,this work has uncovered a new direction for the commercialization of MXene composites and has significantly improved the realworld applications of MXene-based materials.