Our recent study demonstrated that knockout of microRNA-301a attenuates migration and phagocytosis in macrophages.Considering that macrophages and Schwann cells synergistically clear the debris of degraded axons and m...Our recent study demonstrated that knockout of microRNA-301a attenuates migration and phagocytosis in macrophages.Considering that macrophages and Schwann cells synergistically clear the debris of degraded axons and myelin during Wallerian degeneration,which is a prerequisite for nerve regeneration,we hypothesized that microRNA-301a regulates Wallerian degeneration and nerve regeneration via impacts on Schwann cell migration and phagocytosis.Herein,we found low expression of microRNA-301a in intact sciatic nerves,with no impact of the microRNA-301a knockout on nerve structure and function.By contrast,we found significant upregulation of microRNA-301a in injured sciatic nerves.We established a sciatic nerve crush model in microRNA-301a knockout mice,which exhibited attenua9ted morphological and functional regeneration following sciatic nerve crush injury.The microRNA-301a knockout also led to significantly inhibited Wallerian degeneration in an in vivo sciatic nerve-transection model and in an in vitro nerve explant block model.Schwann cells with the microRNA-301a knockout showed inhibition of phagocytosis and migration,which was reversible under transfection with microRNA-301a mimics.Rescue experiments involving transfection of microRNA-301a-knockout Schwann cells with microRNA-301a mimics or treatment with the C-X-C motif receptor 4 inhibitor WZ811 indicated the mechanistic involvement of the Yin Yang 1/C-X-C motif receptor 4 pathway in the role of microRNA-301a.Combined with our previous findings in macrophages,we conclude that microRNA-301a plays a key role in peripheral nerve injury and repair by regulating the migratory and phagocytic capabilities of Schwann cells and macrophages via the Yin Yang 1/C-X-C motif receptor 4 pathway.展开更多
A soft X-ray energy materials research beamline(BL20U2),a branch of energy materials beamline(E-line),has been constructed in the Shanghai Synchrotron Radiation Facility(SSRF)Phase-Ⅱ project.It is now operational for...A soft X-ray energy materials research beamline(BL20U2),a branch of energy materials beamline(E-line),has been constructed in the Shanghai Synchrotron Radiation Facility(SSRF)Phase-Ⅱ project.It is now operational for soft X-ray resonant emission spectroscopy(RXES)and soft X-ray resonant elastic scattering(REXS)investigations.Optical optimization was implemented for high performance,e.g.,photon flux,energy-resolving power,and focus spot size.RXES experiments show that the energy range extends from 150 to 1500 eV.The elastic peak measured near titanium absorption edge(@445 eV)indicates an energy resolution of the RXES spectrometer of 65 meV.The measured photon flux is 3×10^(12)photons/s at 244 eV at the RXES sample position for an SSRF electron energy of 3.5 GeV and a projected ring current as 300 mA.The spot size at the RXES sample position is 23μm in the horizontal direction and 7.9μm in the vertical direction,respectively.Moreover,the angular resolution of elastic REXS scatterometer reaches 0.005°through measurement of X-ray reflection from the single-crystal silicon wafers.A sample of the REXS scatterometer is vibrationally decoupled from its chamber and cooled using copper braids connected from an open cycle liquid helium cryo reservoir,whereas the minimum sample temperature is below 15 K.展开更多
Fetal skeletal dysplasia(FSD)encompasses diverse clinical features and complicates prenatal diagnosis and perinatal care.In this retrospective study,we integrate prenatal deep phenotyping with exome or genome sequenci...Fetal skeletal dysplasia(FSD)encompasses diverse clinical features and complicates prenatal diagnosis and perinatal care.In this retrospective study,we integrate prenatal deep phenotyping with exome or genome sequencing(ES/GS)to elucidate comprehensive genotype and phenotype landscapes,diagnostic outcomes,genotype-phenotype correlations,and postnatal follow-up findings and to refine genetic counseling and clinical decision-making.The study includes a cohort of 152 fetuses with FSD in China.All fetuses undergo prenatal deep phenotyping followed by ES/GS analysis.Prenatal deep phenotyping enables classification into isolated and non-isolated FSD groups and identifies previously unrecognized prenatal features associated with KBG syndrome and Segawa syndrome.Among skeletal anomalies,limb bone anomalies are the most common(72.4%).Genetic testing yields positive diagnoses in 88 fetuses(57.9%).Notably,fetuses with cranial and limb bone abnormalities demonstrate a higher diagnostic yield.Comparative analysis of prenatal and postnatal genotypes and phenotypes in individuals harboring pathogenic variants in four hotspot genes provides a deeper understanding of skeletal dysplasia phenotypes.Genetic findings from this cohort directly inform reproductive decisions in 16 subsequent pregnancies.Our findings significantly enhance genotype-phenotype correlations and contribute to improved prenatal counseling,informed clinical decision-making,and optimized perinatal care,and advance precision medicine strategies for FSD-affected families.展开更多
The most widely used bisphenol A-type epoxy resin(DGEBA)in electrical engineering demonstrates excellent mechanical and electrical properties.However,the insoluble and infusible characteristics of cured DGEBA make it ...The most widely used bisphenol A-type epoxy resin(DGEBA)in electrical engineering demonstrates excellent mechanical and electrical properties.However,the insoluble and infusible characteristics of cured DGEBA make it difficult to efficiently degrade and recycle decommissioned electrical equipment.In this study,a degradable itaconic acid-based epoxy resin incorporating dynamic covalent bonds was prepared through the integration of ester bonds and disulfide bonds,with itaconic acid as the precursor.The covalent bonding effects on the mechanical,thermal,electrical,and degradation characteristics were systematically evaluated.The experimental results revealed that the introduction of dynamic ester bonds enhanced the mechanical properties and thermal stability of the resin system,achieving a flexural strength of 141.57 MPa and an initial decomposition temperature T_(5%)of up to 344.9℃.The resin system containing dynamic disulfide bonds exhibited a dielectric breakdown strength of 41.11 k V/mm.Simultaneously,the incorporation of disulfide bonds endowed the epoxy resin with remarkable degradability,enabling complete dissolution within 1.5 h at 90℃ in a mixed solution of dithiothreitol(DTT)and N-methylpyrrolidone(NMP).This research provides a valuable reference for the application of itaconic acid-based vitrimer with dynamic covalent bonds in electrical materials,contributing to the development and utilization of environmentally friendly electrical equipment.展开更多
目的:探讨心脏死亡供体器官捐献(donation after cardiac death,DCD)来源角膜植片术后排斥反应与角膜内皮细胞的相关性。方法:用角膜内皮显微镜对心脏死亡供体来源角膜植片行穿透性角膜移植术后发生排斥反应的28例28眼角膜植片分别于术...目的:探讨心脏死亡供体器官捐献(donation after cardiac death,DCD)来源角膜植片术后排斥反应与角膜内皮细胞的相关性。方法:用角膜内皮显微镜对心脏死亡供体来源角膜植片行穿透性角膜移植术后发生排斥反应的28例28眼角膜植片分别于术后<1、2~3、4~6、7~12mo行角膜内皮镜检查。结果:28例患者术后<1、2~3、4~6、7~12mo的角膜内皮细胞变异系数分别为38.23%、49.56%、57.18%、65.04%;角膜内皮细胞密度分别为2071.15±311.47、1771.33±348.18、1626.59±353.92、1553.14±307.31个/mm2;角膜内皮细胞变异系数与排斥反应呈正相关关系(r=0.95,P<0.05);术后角膜内皮细胞密度与排斥反应呈负相关关系(r=-0.93,P<0.05)。结论:DCD穿透性角膜移植术后发生排斥反应时有角膜内皮细胞变异系数逐步增高,角膜内皮细胞密度逐步降低的趋势;角膜内皮细胞变异系数、角膜内皮细胞密度可作为早期检测术后排斥反应的指标。展开更多
Aim: To investigate the relationship between sudomotor dysfunction and various body composition analysis indices in type 2 diabetic patients. Methods: Between January 2016 and April 2021, 136 diabetic participants who...Aim: To investigate the relationship between sudomotor dysfunction and various body composition analysis indices in type 2 diabetic patients. Methods: Between January 2016 and April 2021, 136 diabetic participants who had undergone body composition analysis (BCA) were recruited for this cross-sectional study. Sudomotor functions were assessed using SUDOSCAN, and participants were grouped into patients with normal (Group 1, n = 51), mildly reduced (Group 2, n = 46) and severely reduced (Group 3, n = 39) foot electrochemical skin conductance (FESC) levels. Results: The mean age was 60.4 ± 10.1 years, median diabetes duration was 12 (6 - 19) years, and 52.2% of participants were males. Among BCA parameters, the significant differences were found in total fat (TF) (p = 0.023), percentage of TF (%TF) (p = 0.025), percentage of android fat (%AF) (p = 0.048), fat mass (FM) in arms (p = 0.016), FM in legs (p = 0.002), appendicular fat mass (aFM) (p = 0.002), appendicular fat mass/body mass index (aFM/BMI) ratio (p = 0.009) between three groups. In Spearman correlation analysis, FESC was correlated with RBC, ESR and homocysteine (r = 0.171, r = −0.190, r = −0.192, p β =0.161, 0.155, 0.165, 0.185, p Conclusion: The progressive decline of sudomotor function is positively associated with loss of subcutaneous fat in arms and legs, suggesting that subcutaneous fat of extremities may be necessary to prevent DPN progression in type 2 diabetic patients.展开更多
AIM: To evaluate the role of baicalin in ulcerative colitis (UC) with regard to the CD4<sup>+</sup>CD29<sup>+</sup> T helper cell, its surface markers and serum inflammatory cytokines.
AIM: To study differences in the visceral sensitivity of the colonic mucosa between patients with diarrheapredominant irritable bowel syndrome(IBS-D) and those with ulcerative colitis(UC) in remission and to relate th...AIM: To study differences in the visceral sensitivity of the colonic mucosa between patients with diarrheapredominant irritable bowel syndrome(IBS-D) and those with ulcerative colitis(UC) in remission and to relate these differences with changes in the 5-hydroxytryptophan(5-HT) signaling pathway. METHODS: Gastrointestinal symptoms were used to determine the clinical symptom scores and rectal visceral sensitivity of patients with IBS-D and patients with UC in remission. Blood levels of 5-HT and5-hydroxyindoleacetic acid(5-HIAA) were measured using an HPLC-electrochemical detection system. The levels of 5-HT 3 receptor(3R), 4R, and 7R m RNAs in colonic biopsy samples were detected using reverse transcription-polymerase chain reaction. The protein expression of TPH1 was analyzed by Western blot and immunohistochemistry.RESULTS: Abdominal pain or discomfort, stool frequency, and the scores of these symptoms in combination with gastrointestinal symptoms were higher in the IBS-D and UC groups than in the control groups. However, no significant differences were observed between the IBS-D and UC remission groups. With respect to rectal visceral sensitivity, the UC remission and IBS-D groups showed a decrease in the initial perception threshold, defecating threshold and pain threshold. However, these groups exhibited significantly increased anorectal relaxation pressure. Tests examining the main indicators of the 5-HT signaling pathway showed that the plasma 5-HT levels, 5-HIAA concentrations, TPH1 expression in the colonic mucosa, and 5-HT3 R and 5-HT5 R expression were increased in both the IBS-D and the UC remission groups; no increases were observed with respect to 5-HT7 R expression.CONCLUSION: The IBS-D and UC groups showed similar clinical symptom scores, visceral sensitivity, and levels of serotonin signaling pathway indicators in the plasma and colonic mucosa. However, the pain threshold and 5-HT7 R expression in the colonic mucosa were significantly different between these groups. The results reveal that(1) IBS-D and UC are related to visceral sensitivity pathogenesis and the clinical manifestations of these conditions and(2) the observed differences in visceral hypersensitivity are possibly due to differences in levels of the 5-HT7 receptor, a component of the 5-HT signaling pathway.展开更多
BACKGROUND Ectopic expression of miRNAs promotes tumor development and progression.miRNA(miR)-320a is downregulated in many cancers,including gastric cancer(GC).However,the mechanism underlying its downregulation and ...BACKGROUND Ectopic expression of miRNAs promotes tumor development and progression.miRNA(miR)-320a is downregulated in many cancers,including gastric cancer(GC).However,the mechanism underlying its downregulation and the role of miR-320a in GC are unknown.AIM To determine expression and biological functions of miR-320a in GC and investigate the underlying molecular mechanisms.METHODS Quantitative real-time polymerase chain reaction(PCR)was used to determine expression of miR-320a in GC cell lines and tissues.TargetScanHuman7.1,miRDB,and microRNA.org were used to predict the possible targets of miR-320a,and a dual luciferase assay was used to confirm the findings.Western blotting was used to detect the protein levels of pre-B-cell leukemia homeobox 3(PBX3)in GC cells and tissue samples.Cell Counting Kit-8 proliferation,Transwell,wound healing,and apoptosis assays were performed to analyze the biological functions of miR-320a in GC cells.Methylation-specific PCR was used to analyze the methylation level of the miR-320a promoter CpG islands.5-Aza-2’-deoxycytidine(5-Aza-CdR)and trichostatin A(TSA)were used to treat GC cells.RESULTS miR-320a expression was lower in GC cell lines and tissues than in the normal gastric mucosa cell line GES-1 and matched adjacent normal tissues.miR-320a overexpression suppressed GC cell proliferation,invasion and migration,and induced apoptosis.PBX3 was a target of miR-320a in GC.The methylation level of the miR-320a promoter CpG islands was elevated and this was partly reversed by 5-Aza-CdR and TSA.CONCLUSION miR-320a acts as a tumor suppressor and inhibits malignant behavior of GC cells,partly by targeting PBX3.DNA methylation is an important mechanism associated with low expression of miR-320a.展开更多
We report the design of a wide-range energy material beamline(E-line) with multiple experimental techniques at the Shanghai Synchrotron Radiation Facility.The undulators consisted of an elliptically polarizing undulat...We report the design of a wide-range energy material beamline(E-line) with multiple experimental techniques at the Shanghai Synchrotron Radiation Facility.The undulators consisted of an elliptically polarizing undulator and in-vacuum undulator that generate the soft and hard X-rays, respectively. The beamline covered a wide energy range from 130 to 18 ke V with both a high photon flux([ 10^(12) phs/s with exit silt 30 lm in soft X-ray and [ 5 9 10^(12) phs/s in hard X-ray within 0.1%BW bandwidth) and promising resolving power(maximum E/DE [ 15,000 in soft X-ray with exit silt 30 lm and [6000 in hard X-ray). Moreover, the beam spots from the soft and hard X-rays were focused to the same sample position with a high overlap ratio, so that the surfaces, interfaces, and bulk properties were characterized in situ by changing the probing depth.展开更多
Dendrites play irreplaceable roles in the nerve conduction pathway and are vulnerable to various insults.Peripheral axotomy of motor neurons results in the retraction of dendritic arbors,and the dendritic arbor can be...Dendrites play irreplaceable roles in the nerve conduction pathway and are vulnerable to various insults.Peripheral axotomy of motor neurons results in the retraction of dendritic arbors,and the dendritic arbor can be re-expanded when reinnervation is allowed.RhoA is a target that regulates the cytoskeleton and promotes neuronal survival and axon regeneration.However,the role of RhoA in dendrite degeneration and regeneration is unknown.In this study,we explored the potential role of RhoA in dendrites.A line of motor neuronal conditional knockout mice was developed by crossbreeding HB9~(Cre+)mice with RhoA~(flox/flox)mice.We established two models for assaying dendrite degeneration and regeneration,in which the brachial plexus was transection or crush injured,respectively.We found that at 28 days after brachial plexus transection,the density,complexity,and structural integrity of dendrites in the ventral horn of the spinal cord of RhoA conditional knockout mice were slightly decreased compared with that in Cre mice.Dendrites underwent degeneration at 7 and 14 days after brachial plexus transection and recovered at 28–56 days.The density,complexity,and structural integrity of dendrites in the ventral horn of the spinal cord of RhoA conditional knockout mice recovered compared with results in Cre mice.These findings suggest that RhoA knockout in motor neurons attenuates dendrite degeneration and promotes dendrite regeneration after peripheral nerve injury.展开更多
Wallerian degeneration,the progressive disintegration of distal axons and myelin that occurs after peripheral nerve injury,is essential for creating a permissive microenvironment for nerve regeneration,and involves cy...Wallerian degeneration,the progressive disintegration of distal axons and myelin that occurs after peripheral nerve injury,is essential for creating a permissive microenvironment for nerve regeneration,and involves cytoskeletal reconstruction.However,it is unclear whether microtubule dynamics play a role in this process.To address this,we treated cultured sciatic nerve explants,an in vitro model of Wallerian degeneration,with the microtubule-targeting agents paclitaxel and nocodazole.We found that paclitaxel-induced microtubule stabilization promoted axon and myelin degeneration and Schwann cell dedifferentiation,whereas nocodazole-induced microtubule destabilization inhibited these processes.Evaluation of an in vivo model of peripheral nerve injury showed that treatment with paclitaxel or nocodazole accelerated or attenuated axonal regeneration,as well as functional recovery of nerve conduction and target muscle and motor behavior,respectively.These results suggest that microtubule dynamics participate in peripheral nerve regeneration after injury by affecting Wallerian degeneration.This study was approved by the Animal Care and Use Committee of Southern Medical University,China(approval No.SMUL2015081) on October 15,2015.展开更多
The thirteen mother alloys,C%+1/3Si%=4.45%,differing in their Si,Ce,Sb and Sn contents,were prepared.Seventy grams of these alloys was remelted in a high purity alumina crucible at 1,450oC under an Ar atmosphere,and t...The thirteen mother alloys,C%+1/3Si%=4.45%,differing in their Si,Ce,Sb and Sn contents,were prepared.Seventy grams of these alloys was remelted in a high purity alumina crucible at 1,450oC under an Ar atmosphere,and then cooled at 30 K/min for obtaining their cooling curves.Their graphite morphologies were observed using an optical microscope and an SEM.Their three-dimensional graphite shapes were observed by the SEM using the samples whose matrices were etched off with an acid-aqua solution,to confirm the chunky graphite.For discussing the influence of the Si and Ce contents on the chunky graphite formation,two experiments were carried out.In the first one,the Si contents were changed from 0 to 4% in the 0.15%Ce alloys,and for the second one,the 3.5%Si and 4%Si samples that differed in the Ce contents of 0.1 and 0.2% were used.In the third experiment,the influence of Sb and Sn on the chunky graphite formation was investigated by using the 4%Si and 0.1%Ce samples.The results showed that with the increase of the Si content,the volume fraction of the chunky graphite increases,while the volume fraction of the ledeburite decreases,and the chunky graphite volume fraction in the 0.2%Ce samples is higher than that of the 0.1%Ce samples.The effect of the Sb and Sn additions on the prevention of chunky graphite formation cannot be confirmed due to their high Si contents.Therefore,further studies will be needed in this field.展开更多
This paper reviews the original work of the authors published recently,describing the influence of B on the matrix of the Cuadded spheroidal graphite cast iron.The effect of Cu has been corrected as a ferrite formatio...This paper reviews the original work of the authors published recently,describing the influence of B on the matrix of the Cuadded spheroidal graphite cast iron.The effect of Cu has been corrected as a ferrite formation promoter in the matrix of the grey cast iron by the usage of high-purity material.Also,this paper focuses on the ferrite formation and the observation of the Cu distribution in the B-added and B-free Cu-containing spheroidal graphite cast iron.The Cu film on the spheroidal graphite can be successfully observed in the B-free sample using a special etching method.However,in the B-added sample,no Cu film could be found,while the secondary graphite was formed on the surface of the spheroidal graphite.The interaction between B and Cu is stressed as a peculiar phenomenon by the employment of a contrast experiment of B and Mn.The heat treatment could make Cu precipitate more significantly in the eutectic cells and in the matrix in the form of large Cu particles because of the limited solubility of Cu.展开更多
BACKGROUND Cases of depression among adolescents are gradually increasing.The study of the physiological basis of cognitive function from a biochemical perspective has therefore been garnering increasing attention.Dep...BACKGROUND Cases of depression among adolescents are gradually increasing.The study of the physiological basis of cognitive function from a biochemical perspective has therefore been garnering increasing attention.Depression has been hypothesized to be associated with the brain biochemical metabolism of the anterior cingulate gyrus,frontal lobe white matter,and the thalamus.AIM To explore the application of proton magnetic resonance spectroscopy(1H-MRS)in the metabolic alterations in the prefrontal white matter(PWM)and gray matter(GM)in adolescents with depression.METHODS 1H-MRS was performed for semi-quantitative analysis of the biochemical metabolites N-acetylaspartate(NAA),choline(Cho)complexes,creatine(Cr),and myoinositol(mI)in bilateral PWM,anterior cingulate GM,and thalami of 31 adolescent patients with depression(research group)and 35 healthy adolescents(control group),and the NAA/Cr,Cho/Cr,and mI/Cr ratios were calculated.Meanwhile,Hamilton Depression Scale(HAMD)and Wechsler Memory Scale were used to assess the degree of depression and memory function in all adolescents.The correlation of brain metabolite levels with scale scores was also analyzed.RESULTS The research group had markedly higher HAMD-24 scores and lower memory quotient(MQ)compared with the control group(P<0.05).Adolescents with depression were found to have lower bilateral PWM NAA/Cr and Cho/Cr ratios compared with healthy adolescents(P<0.05).The mI/Cr ratios were found to be similar in both groups(P>0.05).The bilateral anterior cingulate GM NAA/Cr,Cho/Cr,and mI/Cr also did not demonstrate marked differences(P>0.05).No statistical inter-group difference was determined in NAA/Cr of the bilateral thalami(P>0.05),while bilateral thalamic Cho/Cr and mI/Cr were reduced in teenagers with depression compared with healthy adolescents(P<0.05).A significant negative correlation was observed between the HAMD-24 scores in adolescents with depression with bilateral PWM NAA/Cr and Cho/Cr and were inversely linked to bilateral thalamic Cho/Cr and mI/Cr(P<0.05).In adolescents with depressions,MQ positively correlated with right PWH NAA/Cr,left PWH Cho/Cr,and bilateral thalamic Cho/Cr and mI/Cr.CONCLUSION PWM and thalamic metabolic abnormalities might influence teen depression,and the reduction in bilateral PWM NAA/Cr and Cho/Cr could be related to the neuropathology of adolescents with depression suffering from memory impairment.There exists a possibility of dysfunction of nerve cell membrane phospholipids in the thalami of adolescent patients with depression.展开更多
Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental results.The synthesis of superheavy elements Z=121 was systematically studied through co...Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental results.The synthesis of superheavy elements Z=121 was systematically studied through combinations of stable projectiles with Z=21-30 and targets with half-lives exceeding 50 d.The influence of mass asymmetry and isotopic dependence on the projectile and target nuclei was investigated in detail.The reactions^(254)Es(^(46)Ti,3n)^(297)121 and^(252)Es(^(46)Ti,3n)^(295)121 were found to be experimentally feasible for synthesizing superheavy element Z=121,with maximal evaporation residue cross sections of 6.619 and 4.123 fb at 219.9 and 223.9 MeV,respectively.展开更多
Based on the dinuclear system model,the synthesis of the predicted double-magic nuclei^(298)Fl and 304120 was investigated via neutron-rich radioactive beam-induced fusion reactions.The reaction^(58)Ca+^(244)Pu is pre...Based on the dinuclear system model,the synthesis of the predicted double-magic nuclei^(298)Fl and 304120 was investigated via neutron-rich radioactive beam-induced fusion reactions.The reaction^(58)Ca+^(244)Pu is predicted to be favorable for producing^(298)Fl with a maximal ER cross section of 0.301 pb.Investigations of the entrance channel effect reveal that the^(244)Pu target is more promising for synthesizing^(298)Fl than the neutron-rich targets^(248)Cm and^(249)Bk,because of the influence of the Coulomb barrier.For the synthesis of 304120,the maximal ER cross section of 0.046 fb emerges in the reaction^(58)V+^(249)Bk,indicating the need for further advancements in both experimental facilities and reaction mechanisms.展开更多
基金supported by the National Natural Science Foundation of China,No.82071386(to JG).
文摘Our recent study demonstrated that knockout of microRNA-301a attenuates migration and phagocytosis in macrophages.Considering that macrophages and Schwann cells synergistically clear the debris of degraded axons and myelin during Wallerian degeneration,which is a prerequisite for nerve regeneration,we hypothesized that microRNA-301a regulates Wallerian degeneration and nerve regeneration via impacts on Schwann cell migration and phagocytosis.Herein,we found low expression of microRNA-301a in intact sciatic nerves,with no impact of the microRNA-301a knockout on nerve structure and function.By contrast,we found significant upregulation of microRNA-301a in injured sciatic nerves.We established a sciatic nerve crush model in microRNA-301a knockout mice,which exhibited attenua9ted morphological and functional regeneration following sciatic nerve crush injury.The microRNA-301a knockout also led to significantly inhibited Wallerian degeneration in an in vivo sciatic nerve-transection model and in an in vitro nerve explant block model.Schwann cells with the microRNA-301a knockout showed inhibition of phagocytosis and migration,which was reversible under transfection with microRNA-301a mimics.Rescue experiments involving transfection of microRNA-301a-knockout Schwann cells with microRNA-301a mimics or treatment with the C-X-C motif receptor 4 inhibitor WZ811 indicated the mechanistic involvement of the Yin Yang 1/C-X-C motif receptor 4 pathway in the role of microRNA-301a.Combined with our previous findings in macrophages,we conclude that microRNA-301a plays a key role in peripheral nerve injury and repair by regulating the migratory and phagocytic capabilities of Schwann cells and macrophages via the Yin Yang 1/C-X-C motif receptor 4 pathway.
文摘A soft X-ray energy materials research beamline(BL20U2),a branch of energy materials beamline(E-line),has been constructed in the Shanghai Synchrotron Radiation Facility(SSRF)Phase-Ⅱ project.It is now operational for soft X-ray resonant emission spectroscopy(RXES)and soft X-ray resonant elastic scattering(REXS)investigations.Optical optimization was implemented for high performance,e.g.,photon flux,energy-resolving power,and focus spot size.RXES experiments show that the energy range extends from 150 to 1500 eV.The elastic peak measured near titanium absorption edge(@445 eV)indicates an energy resolution of the RXES spectrometer of 65 meV.The measured photon flux is 3×10^(12)photons/s at 244 eV at the RXES sample position for an SSRF electron energy of 3.5 GeV and a projected ring current as 300 mA.The spot size at the RXES sample position is 23μm in the horizontal direction and 7.9μm in the vertical direction,respectively.Moreover,the angular resolution of elastic REXS scatterometer reaches 0.005°through measurement of X-ray reflection from the single-crystal silicon wafers.A sample of the REXS scatterometer is vibrationally decoupled from its chamber and cooled using copper braids connected from an open cycle liquid helium cryo reservoir,whereas the minimum sample temperature is below 15 K.
基金the National Key Research and Development Program of China(2022YFC2703100 to S.Z.,2024YFC2707100 for Q.Q.,2022YFC2703901 to Z.W.,2022YFC2703102 to N.W.)National Natural Science Foundation of China(82172525 to G.Q.,82172382 to J.Z.)+2 种基金CAMS Innovation Fund for Medical Sciences(CIFMS,2021-I2M-1-051 to J.Z.and N.W.,2021-I2M-1-052 and 2022-I2M-2-001 to Z.W.,2023-I2M-C&T-A-003 to J.Z.)National High Level Hospital Clinical Research Funding(2022-PUMCH-D-004 to J.Z.and N.W.,2022-PUMCH-C-033 to N.W.,2022-PUMCH-D-002 to Z.W.)Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(2019PT320025 to N.W.).
文摘Fetal skeletal dysplasia(FSD)encompasses diverse clinical features and complicates prenatal diagnosis and perinatal care.In this retrospective study,we integrate prenatal deep phenotyping with exome or genome sequencing(ES/GS)to elucidate comprehensive genotype and phenotype landscapes,diagnostic outcomes,genotype-phenotype correlations,and postnatal follow-up findings and to refine genetic counseling and clinical decision-making.The study includes a cohort of 152 fetuses with FSD in China.All fetuses undergo prenatal deep phenotyping followed by ES/GS analysis.Prenatal deep phenotyping enables classification into isolated and non-isolated FSD groups and identifies previously unrecognized prenatal features associated with KBG syndrome and Segawa syndrome.Among skeletal anomalies,limb bone anomalies are the most common(72.4%).Genetic testing yields positive diagnoses in 88 fetuses(57.9%).Notably,fetuses with cranial and limb bone abnormalities demonstrate a higher diagnostic yield.Comparative analysis of prenatal and postnatal genotypes and phenotypes in individuals harboring pathogenic variants in four hotspot genes provides a deeper understanding of skeletal dysplasia phenotypes.Genetic findings from this cohort directly inform reproductive decisions in 16 subsequent pregnancies.Our findings significantly enhance genotype-phenotype correlations and contribute to improved prenatal counseling,informed clinical decision-making,and optimized perinatal care,and advance precision medicine strategies for FSD-affected families.
基金financially supported by the National Natural Science Foundation of China(No.52377025)。
文摘The most widely used bisphenol A-type epoxy resin(DGEBA)in electrical engineering demonstrates excellent mechanical and electrical properties.However,the insoluble and infusible characteristics of cured DGEBA make it difficult to efficiently degrade and recycle decommissioned electrical equipment.In this study,a degradable itaconic acid-based epoxy resin incorporating dynamic covalent bonds was prepared through the integration of ester bonds and disulfide bonds,with itaconic acid as the precursor.The covalent bonding effects on the mechanical,thermal,electrical,and degradation characteristics were systematically evaluated.The experimental results revealed that the introduction of dynamic ester bonds enhanced the mechanical properties and thermal stability of the resin system,achieving a flexural strength of 141.57 MPa and an initial decomposition temperature T_(5%)of up to 344.9℃.The resin system containing dynamic disulfide bonds exhibited a dielectric breakdown strength of 41.11 k V/mm.Simultaneously,the incorporation of disulfide bonds endowed the epoxy resin with remarkable degradability,enabling complete dissolution within 1.5 h at 90℃ in a mixed solution of dithiothreitol(DTT)and N-methylpyrrolidone(NMP).This research provides a valuable reference for the application of itaconic acid-based vitrimer with dynamic covalent bonds in electrical materials,contributing to the development and utilization of environmentally friendly electrical equipment.
文摘目的:探讨心脏死亡供体器官捐献(donation after cardiac death,DCD)来源角膜植片术后排斥反应与角膜内皮细胞的相关性。方法:用角膜内皮显微镜对心脏死亡供体来源角膜植片行穿透性角膜移植术后发生排斥反应的28例28眼角膜植片分别于术后<1、2~3、4~6、7~12mo行角膜内皮镜检查。结果:28例患者术后<1、2~3、4~6、7~12mo的角膜内皮细胞变异系数分别为38.23%、49.56%、57.18%、65.04%;角膜内皮细胞密度分别为2071.15±311.47、1771.33±348.18、1626.59±353.92、1553.14±307.31个/mm2;角膜内皮细胞变异系数与排斥反应呈正相关关系(r=0.95,P<0.05);术后角膜内皮细胞密度与排斥反应呈负相关关系(r=-0.93,P<0.05)。结论:DCD穿透性角膜移植术后发生排斥反应时有角膜内皮细胞变异系数逐步增高,角膜内皮细胞密度逐步降低的趋势;角膜内皮细胞变异系数、角膜内皮细胞密度可作为早期检测术后排斥反应的指标。
文摘Aim: To investigate the relationship between sudomotor dysfunction and various body composition analysis indices in type 2 diabetic patients. Methods: Between January 2016 and April 2021, 136 diabetic participants who had undergone body composition analysis (BCA) were recruited for this cross-sectional study. Sudomotor functions were assessed using SUDOSCAN, and participants were grouped into patients with normal (Group 1, n = 51), mildly reduced (Group 2, n = 46) and severely reduced (Group 3, n = 39) foot electrochemical skin conductance (FESC) levels. Results: The mean age was 60.4 ± 10.1 years, median diabetes duration was 12 (6 - 19) years, and 52.2% of participants were males. Among BCA parameters, the significant differences were found in total fat (TF) (p = 0.023), percentage of TF (%TF) (p = 0.025), percentage of android fat (%AF) (p = 0.048), fat mass (FM) in arms (p = 0.016), FM in legs (p = 0.002), appendicular fat mass (aFM) (p = 0.002), appendicular fat mass/body mass index (aFM/BMI) ratio (p = 0.009) between three groups. In Spearman correlation analysis, FESC was correlated with RBC, ESR and homocysteine (r = 0.171, r = −0.190, r = −0.192, p β =0.161, 0.155, 0.165, 0.185, p Conclusion: The progressive decline of sudomotor function is positively associated with loss of subcutaneous fat in arms and legs, suggesting that subcutaneous fat of extremities may be necessary to prevent DPN progression in type 2 diabetic patients.
基金Supported by National Natural Science Foundation of Chinunder Grant No.30772701
文摘AIM: To evaluate the role of baicalin in ulcerative colitis (UC) with regard to the CD4<sup>+</sup>CD29<sup>+</sup> T helper cell, its surface markers and serum inflammatory cytokines.
基金Supported by The Natural Science Foundation of Guangdong,No.S2012040006557
文摘AIM: To study differences in the visceral sensitivity of the colonic mucosa between patients with diarrheapredominant irritable bowel syndrome(IBS-D) and those with ulcerative colitis(UC) in remission and to relate these differences with changes in the 5-hydroxytryptophan(5-HT) signaling pathway. METHODS: Gastrointestinal symptoms were used to determine the clinical symptom scores and rectal visceral sensitivity of patients with IBS-D and patients with UC in remission. Blood levels of 5-HT and5-hydroxyindoleacetic acid(5-HIAA) were measured using an HPLC-electrochemical detection system. The levels of 5-HT 3 receptor(3R), 4R, and 7R m RNAs in colonic biopsy samples were detected using reverse transcription-polymerase chain reaction. The protein expression of TPH1 was analyzed by Western blot and immunohistochemistry.RESULTS: Abdominal pain or discomfort, stool frequency, and the scores of these symptoms in combination with gastrointestinal symptoms were higher in the IBS-D and UC groups than in the control groups. However, no significant differences were observed between the IBS-D and UC remission groups. With respect to rectal visceral sensitivity, the UC remission and IBS-D groups showed a decrease in the initial perception threshold, defecating threshold and pain threshold. However, these groups exhibited significantly increased anorectal relaxation pressure. Tests examining the main indicators of the 5-HT signaling pathway showed that the plasma 5-HT levels, 5-HIAA concentrations, TPH1 expression in the colonic mucosa, and 5-HT3 R and 5-HT5 R expression were increased in both the IBS-D and the UC remission groups; no increases were observed with respect to 5-HT7 R expression.CONCLUSION: The IBS-D and UC groups showed similar clinical symptom scores, visceral sensitivity, and levels of serotonin signaling pathway indicators in the plasma and colonic mucosa. However, the pain threshold and 5-HT7 R expression in the colonic mucosa were significantly different between these groups. The results reveal that(1) IBS-D and UC are related to visceral sensitivity pathogenesis and the clinical manifestations of these conditions and(2) the observed differences in visceral hypersensitivity are possibly due to differences in levels of the 5-HT7 receptor, a component of the 5-HT signaling pathway.
基金Supported by the Natural Science Foundation of Liaoning Province,No.201602817
文摘BACKGROUND Ectopic expression of miRNAs promotes tumor development and progression.miRNA(miR)-320a is downregulated in many cancers,including gastric cancer(GC).However,the mechanism underlying its downregulation and the role of miR-320a in GC are unknown.AIM To determine expression and biological functions of miR-320a in GC and investigate the underlying molecular mechanisms.METHODS Quantitative real-time polymerase chain reaction(PCR)was used to determine expression of miR-320a in GC cell lines and tissues.TargetScanHuman7.1,miRDB,and microRNA.org were used to predict the possible targets of miR-320a,and a dual luciferase assay was used to confirm the findings.Western blotting was used to detect the protein levels of pre-B-cell leukemia homeobox 3(PBX3)in GC cells and tissue samples.Cell Counting Kit-8 proliferation,Transwell,wound healing,and apoptosis assays were performed to analyze the biological functions of miR-320a in GC cells.Methylation-specific PCR was used to analyze the methylation level of the miR-320a promoter CpG islands.5-Aza-2’-deoxycytidine(5-Aza-CdR)and trichostatin A(TSA)were used to treat GC cells.RESULTS miR-320a expression was lower in GC cell lines and tissues than in the normal gastric mucosa cell line GES-1 and matched adjacent normal tissues.miR-320a overexpression suppressed GC cell proliferation,invasion and migration,and induced apoptosis.PBX3 was a target of miR-320a in GC.The methylation level of the miR-320a promoter CpG islands was elevated and this was partly reversed by 5-Aza-CdR and TSA.CONCLUSION miR-320a acts as a tumor suppressor and inhibits malignant behavior of GC cells,partly by targeting PBX3.DNA methylation is an important mechanism associated with low expression of miR-320a.
基金supported by the National Development and Reform Commission(NDRC) of Chinathe National Natural Science Foundation of China(No.11505280)+1 种基金the Shanghai Youth Foundation(No.14YF1407500)the National Science Foundation of China(Nos.11475251,11225527)
文摘We report the design of a wide-range energy material beamline(E-line) with multiple experimental techniques at the Shanghai Synchrotron Radiation Facility.The undulators consisted of an elliptically polarizing undulator and in-vacuum undulator that generate the soft and hard X-rays, respectively. The beamline covered a wide energy range from 130 to 18 ke V with both a high photon flux([ 10^(12) phs/s with exit silt 30 lm in soft X-ray and [ 5 9 10^(12) phs/s in hard X-ray within 0.1%BW bandwidth) and promising resolving power(maximum E/DE [ 15,000 in soft X-ray with exit silt 30 lm and [6000 in hard X-ray). Moreover, the beam spots from the soft and hard X-rays were focused to the same sample position with a high overlap ratio, so that the surfaces, interfaces, and bulk properties were characterized in situ by changing the probing depth.
基金the Ministry of Science and Technology China Brain Initiative Grant,No.2022ZD0204701the National Natural Science Foundation of China,Nos.82071386&81870982(all to JG)。
文摘Dendrites play irreplaceable roles in the nerve conduction pathway and are vulnerable to various insults.Peripheral axotomy of motor neurons results in the retraction of dendritic arbors,and the dendritic arbor can be re-expanded when reinnervation is allowed.RhoA is a target that regulates the cytoskeleton and promotes neuronal survival and axon regeneration.However,the role of RhoA in dendrite degeneration and regeneration is unknown.In this study,we explored the potential role of RhoA in dendrites.A line of motor neuronal conditional knockout mice was developed by crossbreeding HB9~(Cre+)mice with RhoA~(flox/flox)mice.We established two models for assaying dendrite degeneration and regeneration,in which the brachial plexus was transection or crush injured,respectively.We found that at 28 days after brachial plexus transection,the density,complexity,and structural integrity of dendrites in the ventral horn of the spinal cord of RhoA conditional knockout mice were slightly decreased compared with that in Cre mice.Dendrites underwent degeneration at 7 and 14 days after brachial plexus transection and recovered at 28–56 days.The density,complexity,and structural integrity of dendrites in the ventral horn of the spinal cord of RhoA conditional knockout mice recovered compared with results in Cre mice.These findings suggest that RhoA knockout in motor neurons attenuates dendrite degeneration and promotes dendrite regeneration after peripheral nerve injury.
基金supported by the National Natural Science Foundation of China,Nos.82071386 (to JS),81870982 (to JS)&81571182 (to JS)the National Key Basic Research Program of China,No.2014CB542202 (to JS)+3 种基金the Program for Changjiang Scholars and Innovative Research Team in University of China,No.IRT-16R37 (to JS)Key Research&Development Program of Guangzhou Regenerative Medicine and Health Guangdong Laboratory of China,No.2018GZR110104008 (to HZ)Research Grant of Guangdong Province Key Laboratory of Psychiatric Disorders of China,No.N201904 (to JS)Natural Science Foundation of Guangdong Province of China,No.2017A030312009 (to JS)。
文摘Wallerian degeneration,the progressive disintegration of distal axons and myelin that occurs after peripheral nerve injury,is essential for creating a permissive microenvironment for nerve regeneration,and involves cytoskeletal reconstruction.However,it is unclear whether microtubule dynamics play a role in this process.To address this,we treated cultured sciatic nerve explants,an in vitro model of Wallerian degeneration,with the microtubule-targeting agents paclitaxel and nocodazole.We found that paclitaxel-induced microtubule stabilization promoted axon and myelin degeneration and Schwann cell dedifferentiation,whereas nocodazole-induced microtubule destabilization inhibited these processes.Evaluation of an in vivo model of peripheral nerve injury showed that treatment with paclitaxel or nocodazole accelerated or attenuated axonal regeneration,as well as functional recovery of nerve conduction and target muscle and motor behavior,respectively.These results suggest that microtubule dynamics participate in peripheral nerve regeneration after injury by affecting Wallerian degeneration.This study was approved by the Animal Care and Use Committee of Southern Medical University,China(approval No.SMUL2015081) on October 15,2015.
文摘The thirteen mother alloys,C%+1/3Si%=4.45%,differing in their Si,Ce,Sb and Sn contents,were prepared.Seventy grams of these alloys was remelted in a high purity alumina crucible at 1,450oC under an Ar atmosphere,and then cooled at 30 K/min for obtaining their cooling curves.Their graphite morphologies were observed using an optical microscope and an SEM.Their three-dimensional graphite shapes were observed by the SEM using the samples whose matrices were etched off with an acid-aqua solution,to confirm the chunky graphite.For discussing the influence of the Si and Ce contents on the chunky graphite formation,two experiments were carried out.In the first one,the Si contents were changed from 0 to 4% in the 0.15%Ce alloys,and for the second one,the 3.5%Si and 4%Si samples that differed in the Ce contents of 0.1 and 0.2% were used.In the third experiment,the influence of Sb and Sn on the chunky graphite formation was investigated by using the 4%Si and 0.1%Ce samples.The results showed that with the increase of the Si content,the volume fraction of the chunky graphite increases,while the volume fraction of the ledeburite decreases,and the chunky graphite volume fraction in the 0.2%Ce samples is higher than that of the 0.1%Ce samples.The effect of the Sb and Sn additions on the prevention of chunky graphite formation cannot be confirmed due to their high Si contents.Therefore,further studies will be needed in this field.
文摘This paper reviews the original work of the authors published recently,describing the influence of B on the matrix of the Cuadded spheroidal graphite cast iron.The effect of Cu has been corrected as a ferrite formation promoter in the matrix of the grey cast iron by the usage of high-purity material.Also,this paper focuses on the ferrite formation and the observation of the Cu distribution in the B-added and B-free Cu-containing spheroidal graphite cast iron.The Cu film on the spheroidal graphite can be successfully observed in the B-free sample using a special etching method.However,in the B-added sample,no Cu film could be found,while the secondary graphite was formed on the surface of the spheroidal graphite.The interaction between B and Cu is stressed as a peculiar phenomenon by the employment of a contrast experiment of B and Mn.The heat treatment could make Cu precipitate more significantly in the eutectic cells and in the matrix in the form of large Cu particles because of the limited solubility of Cu.
基金Supported by the General Scientific Research Project of Zhejiang Provincial Department of Education,No.Y202248840 and No.Y201942374。
文摘BACKGROUND Cases of depression among adolescents are gradually increasing.The study of the physiological basis of cognitive function from a biochemical perspective has therefore been garnering increasing attention.Depression has been hypothesized to be associated with the brain biochemical metabolism of the anterior cingulate gyrus,frontal lobe white matter,and the thalamus.AIM To explore the application of proton magnetic resonance spectroscopy(1H-MRS)in the metabolic alterations in the prefrontal white matter(PWM)and gray matter(GM)in adolescents with depression.METHODS 1H-MRS was performed for semi-quantitative analysis of the biochemical metabolites N-acetylaspartate(NAA),choline(Cho)complexes,creatine(Cr),and myoinositol(mI)in bilateral PWM,anterior cingulate GM,and thalami of 31 adolescent patients with depression(research group)and 35 healthy adolescents(control group),and the NAA/Cr,Cho/Cr,and mI/Cr ratios were calculated.Meanwhile,Hamilton Depression Scale(HAMD)and Wechsler Memory Scale were used to assess the degree of depression and memory function in all adolescents.The correlation of brain metabolite levels with scale scores was also analyzed.RESULTS The research group had markedly higher HAMD-24 scores and lower memory quotient(MQ)compared with the control group(P<0.05).Adolescents with depression were found to have lower bilateral PWM NAA/Cr and Cho/Cr ratios compared with healthy adolescents(P<0.05).The mI/Cr ratios were found to be similar in both groups(P>0.05).The bilateral anterior cingulate GM NAA/Cr,Cho/Cr,and mI/Cr also did not demonstrate marked differences(P>0.05).No statistical inter-group difference was determined in NAA/Cr of the bilateral thalami(P>0.05),while bilateral thalamic Cho/Cr and mI/Cr were reduced in teenagers with depression compared with healthy adolescents(P<0.05).A significant negative correlation was observed between the HAMD-24 scores in adolescents with depression with bilateral PWM NAA/Cr and Cho/Cr and were inversely linked to bilateral thalamic Cho/Cr and mI/Cr(P<0.05).In adolescents with depressions,MQ positively correlated with right PWH NAA/Cr,left PWH Cho/Cr,and bilateral thalamic Cho/Cr and mI/Cr.CONCLUSION PWM and thalamic metabolic abnormalities might influence teen depression,and the reduction in bilateral PWM NAA/Cr and Cho/Cr could be related to the neuropathology of adolescents with depression suffering from memory impairment.There exists a possibility of dysfunction of nerve cell membrane phospholipids in the thalami of adolescent patients with depression.
基金the National Key R&D Program of China(No.2023YFA1606401)the National Natural Science Foundation of China(Nos.12135004,11635003 and 11961141004).
文摘Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental results.The synthesis of superheavy elements Z=121 was systematically studied through combinations of stable projectiles with Z=21-30 and targets with half-lives exceeding 50 d.The influence of mass asymmetry and isotopic dependence on the projectile and target nuclei was investigated in detail.The reactions^(254)Es(^(46)Ti,3n)^(297)121 and^(252)Es(^(46)Ti,3n)^(295)121 were found to be experimentally feasible for synthesizing superheavy element Z=121,with maximal evaporation residue cross sections of 6.619 and 4.123 fb at 219.9 and 223.9 MeV,respectively.
基金supported by the National Key R&D Program of China(No.2023YFA1606401)the National Natural Science Foundation of China(Nos.12135004,11635003 and 11961141004)the Guangxi Natural Science Foundation(No.2022GXNSFBA035549).
文摘Based on the dinuclear system model,the synthesis of the predicted double-magic nuclei^(298)Fl and 304120 was investigated via neutron-rich radioactive beam-induced fusion reactions.The reaction^(58)Ca+^(244)Pu is predicted to be favorable for producing^(298)Fl with a maximal ER cross section of 0.301 pb.Investigations of the entrance channel effect reveal that the^(244)Pu target is more promising for synthesizing^(298)Fl than the neutron-rich targets^(248)Cm and^(249)Bk,because of the influence of the Coulomb barrier.For the synthesis of 304120,the maximal ER cross section of 0.046 fb emerges in the reaction^(58)V+^(249)Bk,indicating the need for further advancements in both experimental facilities and reaction mechanisms.
