The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the ...The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is constructed.Based on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,China.The results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending order.The content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 years.The harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or below.This evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars.展开更多
The Songnen Plain is a crucial agricultural area in China,and in the past 20 years,a large number of dry fields have been developed into paddy fields in order to improve land output efficiency.As a result,the effectiv...The Songnen Plain is a crucial agricultural area in China,and in the past 20 years,a large number of dry fields have been developed into paddy fields in order to improve land output efficiency.As a result,the effective irrigation area of agriculture has increased annually,and the conversion mode and quantity between surface water and groundwater have changed considerably.It is essential to identify the changes in groundwater resources and their influencing factors for the sustainable development of economy and society.This study evaluates groundwater resources in the Songnen Plain using the water balance method based on meteorological,hydrological and groundwater monitoring data from 2000 to 2020.The results 3 show that the groundwater resources in the region amount to 15.945 billion m with precipitation infiltration being the most important component,accounting for 73.09%,which is followed surface water irrigation infiltration and river and ditch infiltration,constituting 14.55%and 10.32%,respectively.Different factors influence groundwater resources in different periods.Compared to 1985,the increase of surface water irrigation infiltration is the primary factor responsible for the increase of groundwater resources,while other recharge sources have decreased during the same period.Compared to 2005,all groundwater resources have increased,with the increase of surface water irrigation infiltration and river channel infiltration being the primary factors.展开更多
Current management for spinal cord injury aims to reduce secondary damage and recover sensation and movement.Acute spinal cord injury is often accompanied by spinal cord compartment syndrome.Decompression by durotomy ...Current management for spinal cord injury aims to reduce secondary damage and recover sensation and movement.Acute spinal cord injury is often accompanied by spinal cord compartment syndrome.Decompression by durotomy and/or myelotomy attempts to relieve secondary damage by completelyrelieving the compression of the spinal cord,removing the necrotic tissue,decreasing edema,reducing hemorrhage,and improving blood circulation in the spinal cord.However,it is controversial whether durotomy and/or myelotomy after spinal cord injury are beneficial to neurological recovery.This review compares the clinical effects of durotomy with those of myelotomy in the treatment of spinal cord injury.We found that durotomy has been performed more than myelotomy in the clinic,and that durotomy may be safer and more effective than myelotomy.Durotomy performed in humans had positive effects on neurological function in 92.3% of studies in this review,while durotomy in animals had positive effects on neurological function in 83.3% of studies.Myelotomy procedures were effective in 80% of animal studies,but only one clinical study of myelotomy has reported positive results,of motor and sensory improvement,in humans.However,a number of new animal studies have reported that durotomy and myelotomy are ineffective for spinal cord injury.More clinical data,in the form of a randomized controlled study,are needed to understand the effectiveness of durotomy and myelotomy.展开更多
AIM:To study the inflammatory microenvironment and expression of chemokines in hepatocellular carcinoma(HCC) in nude mice.METHODS:CBRH-7919 HCC cells were injected into the subcutaneous region of nude mice.Beginning t...AIM:To study the inflammatory microenvironment and expression of chemokines in hepatocellular carcinoma(HCC) in nude mice.METHODS:CBRH-7919 HCC cells were injected into the subcutaneous region of nude mice.Beginning two weeks after the challenge,tumor growth was measured every week for six weeks.The stromal microenvironment and inflammatory cell infiltration was assessed by immunohistochemistry in paired tumor and adjacent peritumoral samples,and macrophage phenotype was assessed using double-stain immunohistochemistry incorporating expression of an intracellular enzyme.A chemokine PCR array,comprised of 98 genes,was used to screen differential gene expressions,which were validated by Western blotting.Additionally,expression of identified chemokines was knocked-down by RNA interference,and the effect on tumor growth was assessed.RESULTS:Inflammatory cell infiltrates are a key feature of adjacent peritumoral tissues with increased macrophage,neutrophil,and T cell(specifically helperand activated subsets)infiltration.Macrophages within adjacent peritumoral tissues express inducible nitric oxide synthase,suggestive of a proinflammatory phenotype.Fifty-one genes were identified in tumor tissues during the progression period,including 50that were overexpressed(including CXCL1,CXCL2 and CXCL3)and three that were underexpressed(CXCR1,Ifg and Actb).RNA interference of CXCL1 in the CBRH-7919 cells decreased the growth of tumors in nude mice and inhibited expression of CXCL2,CXCL3and interleukin-1βprotein.CONCLUSION:These findings suggest that CXCL1plays a critical role in tumor growth and may serve as a potential molecular target for use in HCC therapy.展开更多
The widespread use of computed tomography(CT)in clinical practice has made the public focus on the cumulative radiation dose delivered to patients.Low-dose CT(LDCT)reduces the X-ray radiation dose,yet compromises qual...The widespread use of computed tomography(CT)in clinical practice has made the public focus on the cumulative radiation dose delivered to patients.Low-dose CT(LDCT)reduces the X-ray radiation dose,yet compromises quality and decreases diagnostic performance.Researchers have made great efforts to develop various algorithms for LDCT and introduced deep-learning techniques,which have achieved impressive results.However,most of these methods are directly performed on reconstructed LDCT images,in which some subtle structures and details are readily lost during the reconstruction procedure,and convolutional neural network(CNN)-based methods for raw LDCT projection data are rarely reported.To address this problem,we adopted an attention residual dense CNN,referred to as AttRDN,for LDCT sinogram denoising.First,it was aided by the attention mechanism,in which the advantages of both feature fusion and global residual learning were used to extract noise from the contaminated LDCT sinograms.Then,the denoised sinogram was restored by subtracting the noise obtained from the input noisy sinogram.Finally,the CT image was reconstructed using filtered back-projection.The experimental results qualitatively and quantitatively demonstrate that the proposed AttRDN can achieve a better performance than state-of-the-art methods.Importantly,it can prevent the loss of detailed information and has the potential for clinical application.展开更多
Demyelination of axons plays an important role in the pathology of many spinal cord diseases and injuries.Remyelination in demyelinated lesions is primarily performed by oligodendrocyte progenitor cells(OPCs),which ge...Demyelination of axons plays an important role in the pathology of many spinal cord diseases and injuries.Remyelination in demyelinated lesions is primarily performed by oligodendrocyte progenitor cells(OPCs),which generate oligodendrocytes in the developing and mature central nervous system.The efficiency of remyelination decreases with age.Many reports suggest that this decline in remyelination results from impaired OPC recruitment and differentiation during aging.Of the various molecular mechanisms involved in aging,changes in epigenetic modifications have received particular attention.Global DNA methylation is a major epigenetic modification that plays important roles in cellular senescence and organismal aging.Thus,we aimed to evaluate the dynamic changes in the global DNA methylation profiles of OPCs derived from rat spinal cords during the aging process.We separated and cultured OPCs from the spinal cords of neonatal,4-month-old,and 16-month-old rats and investigated the age-related alterations of genomic DNA methylation levels by using quantitative colorimetric analysis.To determine the potential cause of dynamic changes in global DNA methylation,we further analyzed the activity of DNA methyltransferases(DNMTs)and the expression of DNMT1,DNMT3a,DNMT3b,TET1,TET2,TET3,MBD2,and MeCP2 in the OPCs from each group.Our results showed the genomic DNA methylation level and the activity of DNMTs from OPCs derived from rat spinal cords decreased gradually during aging,and OPCs from 16-month-old rats were characterized by global hypomethylation.During OPC aging,the mRNA and protein expression levels of DNMT3a,DNMT3b,and MeCP2 were significantly elevated;those of DNMT1 were significantly down-regulated;and no significant changes were observed in those for TET1,TET2,TET3,or MBD2.Our results indicated that global DNA hypomethylation in aged OPCs is correlated with DNMT1 downregulation.Together,these data provide important evidence for partly elucidating the mechanism of age-related impaired OPC recruitment and differentiation and assist in the development of new treatments for promoting efficient remyelination.展开更多
In the visual positioning of Unmanned Ground Vehicle(UGV),the visual odometer based on direct sparse method(DSO) has the advantages of small amount of calculation,high real-time performance and high robustness,so it i...In the visual positioning of Unmanned Ground Vehicle(UGV),the visual odometer based on direct sparse method(DSO) has the advantages of small amount of calculation,high real-time performance and high robustness,so it is more widely used than the visual odometer based on feature point method.Ordinary vision sensors have a narrower viewing angle than panoramic vision sensors,and there are fewer road signs in a single frame of image,resulting in poor road sign tracking and positioning capabilities,and severely restricting the development of visual odometry.Based on these considerations,this paper proposes a binocular stereo panoramic vision positioning algorithm based on extended DSO,which can solve these problems well.The experimental results show that the binocular stereo panoramic vision positioning algorithm based on the extended DSO can directly obtain the panoramic depth image around the UGV,which greatly improves the accuracy and robustness of the visual positioning compared with other ordinary visual odometers.It will have widely application prospects in the UGV field in the future.展开更多
Pediatric acute hyperextension spinal cord injury(SCI)named as PAHSCI by us,is a special type of thoracolumbar SCI without radiographic abnormality and highly related to back-bend in dance training,which has been incr...Pediatric acute hyperextension spinal cord injury(SCI)named as PAHSCI by us,is a special type of thoracolumbar SCI without radiographic abnormality and highly related to back-bend in dance training,which has been increasingly reported.At present,it has become the leading cause of SCI in children,and brings a heavy social and economic burden.Both domestic and foreign academic institutions and dance education organizations lack a correct understanding of PAHSCI and relevant standards,specifications or guidelines.In order to provide standardized guidance,the expert team formulated this guideline based on the principles of science and practicability,starting from the diagnosis,differential diagnosis,etiology,admission evaluation,treatment,complications and prevention.This guideline puts forward 23 recommendations for 14 related issues.展开更多
Background A number of clinical trials evaluated the efficacy and adverse effects of oral propranolol in the treatment of infantile hemangioma(IH),but the treatment has not yet been standardized.This meta-analysis aim...Background A number of clinical trials evaluated the efficacy and adverse effects of oral propranolol in the treatment of infantile hemangioma(IH),but the treatment has not yet been standardized.This meta-analysis aims to reevaluate the efficacy and adverse effects of oral propranolol in comparative studies and to provide a reliable basis for clinical administration in the therapy for IH.Methods Data were obtained from PubMed,Embase,Cochrane Library,Web of Science,China National Knowledge Infra-structure and Wanfang database,from inception to December 1st,2018.The pooled risk ratios(RR)with 95%confidence intervals(95%CI)were calculated and used to evaluate the effect size.The meta-analysis was performed using the random-effects model due to heterogeneity between the studies.The Cochrane Collaboration 6 aspects of bias,methodological index for non-randomized studies and the Newcastle-Ottawa Scale were used to assess the risk for bias.Sensitivity analysis,publication bias and subgroup analysis were performed.Results Eighteen unique studies involving 2701 unique children were included in the analysis.The response rate was reported in 18 trials,which compared oral propranolol with other treatments.The heterogeneity was statistically significant(P<0.00001,P=95%).The difference in the response rate was statistically significant(RR=1.40,95%CI 1.13-1.75)while compared with the controls.However,no significant difference in the adverse events rate(RR=0.78,95%CI 0.45-1.34)and relapse rate(RR=1.45,95%CI 0.66-3.16)were found.Otherwise,the subgroup analysis indicated that the RR was 1.64(95%CI 0.24-11.36)for low-dose propranolol(1 mg/kg/day),1.42(95%CI 1.12-1.80)for medium dose(2 mg/kg/day)and 1.46(95%CI 1.17-1.82)for high dose(3 mg/kg/day),but the high dose had higher adverse events rate than medium dose,with 3.60%and 86.22%,respectively.The effectiveness of propranolol therapy among cases of treatment duration less than 6 months(RR=1.24,95%CI 1.05-1.47)was inferior to that of treatment duration greater than or equal to 6 months(RR=1.46,95%CI 1.11-1.92).Conclusions This meta-analysis reveals that oral propranolol is superior to other treatments in improving response rate of IH and can be used as the first-line therapy for IH children.A dosage of 2 mg/kg/day propranolol orally may be a good choice for IH.However,further studies are essential.展开更多
The O3-type layered oxide cathodes for sodium-ion batteries(SIBs)are considered as one of the most promising systems to fully meet the requirement for future practical application.However,fatal issues in several respe...The O3-type layered oxide cathodes for sodium-ion batteries(SIBs)are considered as one of the most promising systems to fully meet the requirement for future practical application.However,fatal issues in several respects such as poor air stability,irreversible complex multiphase evolution,inferior cycling lifespan,and poor industrial feasibility are restricting their commercialization development.Here,a stable Co-free O3-type NaNi_(0.4)Cu_(0.05)Mg_(0.05)Mn_(0.4)Ti_(0.1O2) cathode material with large-scale production could solve these problems for practical SIBs.Owing to the synergetic contribution of the multielement chemical substitution strategy,this novel cathode not only shows excellent air stability and thermal stability as well as a simple phase-transition process but also delivers outstanding battery performance in half-cell and full-cell systems.Meanwhile,various advanced characterization techniques are utilized to accurately decipher the crystalline formation process,atomic arrangement,structural evolution,and inherent effect mechanisms.Surprisingly,apart from restraining the unfavorable multiphase transformation and enhancing air stability,the accurate multielement chemical substitution engineering also shows a pinning effect to alleviate the lattice strains for the high structural reversibility and enlarges the interlayer spacing reasonably to enhance Na^(+)diffusion,resulting in excellent comprehensive performance.Overall,this study explores the fundamental scientific understandings of multielement chemical substitution strategy and opens up a new field for increasing the practicality to commercialization.展开更多
Lithium sulfur battery(LSB) is widely considered as a next-generation battery system due to its high theoretical energy density of 2567 Wh kg-1.However,several inherent issues obstruct the business application of LSB....Lithium sulfur battery(LSB) is widely considered as a next-generation battery system due to its high theoretical energy density of 2567 Wh kg-1.However,several inherent issues obstruct the business application of LSB.To address these issues,we assemble core-shell structure Fe_(3)O_(4)@C nanodots with 5 nm diameter as a valid sulfur host via a convenient organic pyrolysis treatment followed by calcination.The nanosized Fe3O4 particles could expose more chemisorption sites and inhibit the polysulfides shuttle.Moreover,the carbon layer could not only increase the conductivity but also ensure structural integrity during cyclic process.Furthermore,the mesoporous channels around Fe_(3)O_(4)@C could supply sufficient space to load sulfur and physically restrict the shuttle of polysulfides.Thus,the resultant S/Fe_(3)O_(4)@C cathode shows a highly initial capacity of 1089 mAh g^(-1) at 0.2 C,even retains 655 mAh g^(-1) over 200 cycles at 1 C.展开更多
Outbreak of COVID-19 is ongoing all over the world.Spine trauma is one of the most common types of trauma and will probably be encountered during the fight against COVID-19 and resumption of work and production.Patien...Outbreak of COVID-19 is ongoing all over the world.Spine trauma is one of the most common types of trauma and will probably be encountered during the fight against COVID-19 and resumption of work and production.Patients with unstable spine fractures or continuous deterioration of neurological function require emergency surgery.The COVID-19 epidemic has brought tremendous challenges to the diagnosis and treatment of such patients.To coordinate the diagnosis and treatment of infectious disease prevention and spine trauma so as to formulate a rigorous diagnosis and treatment plan and to reduce the disability and mortality of the disease,multidisciplinary collaboration is needed.This expert consensus is formulated in order to(1)prevent and control the epidemic,(2)diagnose and treat patients with spine trauma reasonably,and(3)reduce the risk of cross-infection between patients and medical personnel during the treatment.展开更多
Since December 2019,many patients in Wuhan sustained pneumonia with unknown causes.[1,2]A part of severe patients developed acute respiratory distress syndrome or septic shock,and even death.On January 7,2020,Chinese ...Since December 2019,many patients in Wuhan sustained pneumonia with unknown causes.[1,2]A part of severe patients developed acute respiratory distress syndrome or septic shock,and even death.On January 7,2020,Chinese researchers have for the first time detected a new coronavirus.On January 20,2020,the National Health Commission issued Announcement No.1 of 2020,which included the new coronavirus pneumonia as a Class B infectious disease,and conducted epidemic prevention and control according to the Class A infectious disease.This new kind of pneumonia has been named coronavirus disease 2019(COVID-19).The sixth edition of"Diagnosis and Treatment Scheme for New Coronavirus Infected Pneumonia"points out that the main transmission routes include respiratory droplets and close contact transmission.There is a possibility of aerosol transmission in a relatively closed environment with prolonged exposure to high concentrations of aerosol.New coronavirus pneumonia has a certain incubation period.展开更多
Background:XELOX(oxaliplatin 130mg/m^(2)iv,capecitabine 1000mg/m^(2)bid oral d1–14,q3w)chemotherapy has never been used in children.In this report,we present a case of a 12-year-old girl with colon adenocarcinoma,tre...Background:XELOX(oxaliplatin 130mg/m^(2)iv,capecitabine 1000mg/m^(2)bid oral d1–14,q3w)chemotherapy has never been used in children.In this report,we present a case of a 12-year-old girl with colon adenocarcinoma,treated with surgery and XELOX chemotherapy.Methods:On admission,the girl complained of abdominal pain and intestinal obstruction.Physical examination revealed a distended abdomen with tenderness on the left upper quadrant.Barium enema revealed a stenotic lesion at the distal end of the transverse colon,and abdominal computed tomography showed acute obstruction and a colonic mass.Laparotomy was performed after the failure of conservative treatment.Results:The mass was originated from the transverse colon.Frozen sections of the specimens revealed an adenocarcinoma.Transverse colectomy was performed and regional lymph nodes were removed.Pathological examination confirmed that the mass was a poorly differentiated adenocarcinoma,and XELOX chemotherapy was used.No evidence of recurrent or metastatic tumor was found after 18 months.Conclusion:Although complete resection is the most effective treatment,XELOX chemotherapy is beneficial to the improvement of clinical outcome of patients with colon adenocarcinoma.展开更多
基金supported by the project of China Geology Survey(12120115032801,DD20190340)。
文摘The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is constructed.Based on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,China.The results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending order.The content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 years.The harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or below.This evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars.
基金supported by Hydrogeological Survey of Songnen Plain(DD20190340)Investigation and Monitoring of Hydrogeology and Water Resources in Songliao Basin(DD20221753).
文摘The Songnen Plain is a crucial agricultural area in China,and in the past 20 years,a large number of dry fields have been developed into paddy fields in order to improve land output efficiency.As a result,the effective irrigation area of agriculture has increased annually,and the conversion mode and quantity between surface water and groundwater have changed considerably.It is essential to identify the changes in groundwater resources and their influencing factors for the sustainable development of economy and society.This study evaluates groundwater resources in the Songnen Plain using the water balance method based on meteorological,hydrological and groundwater monitoring data from 2000 to 2020.The results 3 show that the groundwater resources in the region amount to 15.945 billion m with precipitation infiltration being the most important component,accounting for 73.09%,which is followed surface water irrigation infiltration and river and ditch infiltration,constituting 14.55%and 10.32%,respectively.Different factors influence groundwater resources in different periods.Compared to 1985,the increase of surface water irrigation infiltration is the primary factor responsible for the increase of groundwater resources,while other recharge sources have decreased during the same period.Compared to 2005,all groundwater resources have increased,with the increase of surface water irrigation infiltration and river channel infiltration being the primary factors.
基金financially supported by the National Key Research and Development Program of China,No.2016YFC1100100(to XDG)
文摘Current management for spinal cord injury aims to reduce secondary damage and recover sensation and movement.Acute spinal cord injury is often accompanied by spinal cord compartment syndrome.Decompression by durotomy and/or myelotomy attempts to relieve secondary damage by completelyrelieving the compression of the spinal cord,removing the necrotic tissue,decreasing edema,reducing hemorrhage,and improving blood circulation in the spinal cord.However,it is controversial whether durotomy and/or myelotomy after spinal cord injury are beneficial to neurological recovery.This review compares the clinical effects of durotomy with those of myelotomy in the treatment of spinal cord injury.We found that durotomy has been performed more than myelotomy in the clinic,and that durotomy may be safer and more effective than myelotomy.Durotomy performed in humans had positive effects on neurological function in 92.3% of studies in this review,while durotomy in animals had positive effects on neurological function in 83.3% of studies.Myelotomy procedures were effective in 80% of animal studies,but only one clinical study of myelotomy has reported positive results,of motor and sensory improvement,in humans.However,a number of new animal studies have reported that durotomy and myelotomy are ineffective for spinal cord injury.More clinical data,in the form of a randomized controlled study,are needed to understand the effectiveness of durotomy and myelotomy.
基金Supported by Natural Science Foundation of China,No.81072954
文摘AIM:To study the inflammatory microenvironment and expression of chemokines in hepatocellular carcinoma(HCC) in nude mice.METHODS:CBRH-7919 HCC cells were injected into the subcutaneous region of nude mice.Beginning two weeks after the challenge,tumor growth was measured every week for six weeks.The stromal microenvironment and inflammatory cell infiltration was assessed by immunohistochemistry in paired tumor and adjacent peritumoral samples,and macrophage phenotype was assessed using double-stain immunohistochemistry incorporating expression of an intracellular enzyme.A chemokine PCR array,comprised of 98 genes,was used to screen differential gene expressions,which were validated by Western blotting.Additionally,expression of identified chemokines was knocked-down by RNA interference,and the effect on tumor growth was assessed.RESULTS:Inflammatory cell infiltrates are a key feature of adjacent peritumoral tissues with increased macrophage,neutrophil,and T cell(specifically helperand activated subsets)infiltration.Macrophages within adjacent peritumoral tissues express inducible nitric oxide synthase,suggestive of a proinflammatory phenotype.Fifty-one genes were identified in tumor tissues during the progression period,including 50that were overexpressed(including CXCL1,CXCL2 and CXCL3)and three that were underexpressed(CXCR1,Ifg and Actb).RNA interference of CXCL1 in the CBRH-7919 cells decreased the growth of tumors in nude mice and inhibited expression of CXCL2,CXCL3and interleukin-1βprotein.CONCLUSION:These findings suggest that CXCL1plays a critical role in tumor growth and may serve as a potential molecular target for use in HCC therapy.
基金This work was supported in part by the National Key R&D Program of China(Nos.2016YFC0104609 and 2019YFC0605203)The Fundamental Research Funds for the Central Universities(Nos.2019CDYGYB019 and 2020CDJ-LHZZ-075)。
文摘The widespread use of computed tomography(CT)in clinical practice has made the public focus on the cumulative radiation dose delivered to patients.Low-dose CT(LDCT)reduces the X-ray radiation dose,yet compromises quality and decreases diagnostic performance.Researchers have made great efforts to develop various algorithms for LDCT and introduced deep-learning techniques,which have achieved impressive results.However,most of these methods are directly performed on reconstructed LDCT images,in which some subtle structures and details are readily lost during the reconstruction procedure,and convolutional neural network(CNN)-based methods for raw LDCT projection data are rarely reported.To address this problem,we adopted an attention residual dense CNN,referred to as AttRDN,for LDCT sinogram denoising.First,it was aided by the attention mechanism,in which the advantages of both feature fusion and global residual learning were used to extract noise from the contaminated LDCT sinograms.Then,the denoised sinogram was restored by subtracting the noise obtained from the input noisy sinogram.Finally,the CT image was reconstructed using filtered back-projection.The experimental results qualitatively and quantitatively demonstrate that the proposed AttRDN can achieve a better performance than state-of-the-art methods.Importantly,it can prevent the loss of detailed information and has the potential for clinical application.
基金grants from the National Natural Science Foundation of China(No.81000520 and No.81702650)the Natural Science Foundation of Hubei Province of China(No.02.07.17040039)+1 种基金Innovation Foundation of Huazhong University of Science and Technology(No.2016YXMS229)the Innovation Foundation of Wuhan Union Hospital(No.02.03.2017-54).
文摘Demyelination of axons plays an important role in the pathology of many spinal cord diseases and injuries.Remyelination in demyelinated lesions is primarily performed by oligodendrocyte progenitor cells(OPCs),which generate oligodendrocytes in the developing and mature central nervous system.The efficiency of remyelination decreases with age.Many reports suggest that this decline in remyelination results from impaired OPC recruitment and differentiation during aging.Of the various molecular mechanisms involved in aging,changes in epigenetic modifications have received particular attention.Global DNA methylation is a major epigenetic modification that plays important roles in cellular senescence and organismal aging.Thus,we aimed to evaluate the dynamic changes in the global DNA methylation profiles of OPCs derived from rat spinal cords during the aging process.We separated and cultured OPCs from the spinal cords of neonatal,4-month-old,and 16-month-old rats and investigated the age-related alterations of genomic DNA methylation levels by using quantitative colorimetric analysis.To determine the potential cause of dynamic changes in global DNA methylation,we further analyzed the activity of DNA methyltransferases(DNMTs)and the expression of DNMT1,DNMT3a,DNMT3b,TET1,TET2,TET3,MBD2,and MeCP2 in the OPCs from each group.Our results showed the genomic DNA methylation level and the activity of DNMTs from OPCs derived from rat spinal cords decreased gradually during aging,and OPCs from 16-month-old rats were characterized by global hypomethylation.During OPC aging,the mRNA and protein expression levels of DNMT3a,DNMT3b,and MeCP2 were significantly elevated;those of DNMT1 were significantly down-regulated;and no significant changes were observed in those for TET1,TET2,TET3,or MBD2.Our results indicated that global DNA hypomethylation in aged OPCs is correlated with DNMT1 downregulation.Together,these data provide important evidence for partly elucidating the mechanism of age-related impaired OPC recruitment and differentiation and assist in the development of new treatments for promoting efficient remyelination.
基金the Project of National Natural Science Foundation of China(Grant No.61773059)the Project of National Defense Technology Foundation Program of China(Grant No.20230028) to provide fund for conducting experiments。
文摘In the visual positioning of Unmanned Ground Vehicle(UGV),the visual odometer based on direct sparse method(DSO) has the advantages of small amount of calculation,high real-time performance and high robustness,so it is more widely used than the visual odometer based on feature point method.Ordinary vision sensors have a narrower viewing angle than panoramic vision sensors,and there are fewer road signs in a single frame of image,resulting in poor road sign tracking and positioning capabilities,and severely restricting the development of visual odometry.Based on these considerations,this paper proposes a binocular stereo panoramic vision positioning algorithm based on extended DSO,which can solve these problems well.The experimental results show that the binocular stereo panoramic vision positioning algorithm based on the extended DSO can directly obtain the panoramic depth image around the UGV,which greatly improves the accuracy and robustness of the visual positioning compared with other ordinary visual odometers.It will have widely application prospects in the UGV field in the future.
基金National Natural Science Foundation of China(No.82072446 and 81873999)International Science&Technology Cooperation Program of China(No.2013DFG32690)Key R&D Program of Hubei Province(2020BCB050)。
文摘Pediatric acute hyperextension spinal cord injury(SCI)named as PAHSCI by us,is a special type of thoracolumbar SCI without radiographic abnormality and highly related to back-bend in dance training,which has been increasingly reported.At present,it has become the leading cause of SCI in children,and brings a heavy social and economic burden.Both domestic and foreign academic institutions and dance education organizations lack a correct understanding of PAHSCI and relevant standards,specifications or guidelines.In order to provide standardized guidance,the expert team formulated this guideline based on the principles of science and practicability,starting from the diagnosis,differential diagnosis,etiology,admission evaluation,treatment,complications and prevention.This guideline puts forward 23 recommendations for 14 related issues.
文摘Background A number of clinical trials evaluated the efficacy and adverse effects of oral propranolol in the treatment of infantile hemangioma(IH),but the treatment has not yet been standardized.This meta-analysis aims to reevaluate the efficacy and adverse effects of oral propranolol in comparative studies and to provide a reliable basis for clinical administration in the therapy for IH.Methods Data were obtained from PubMed,Embase,Cochrane Library,Web of Science,China National Knowledge Infra-structure and Wanfang database,from inception to December 1st,2018.The pooled risk ratios(RR)with 95%confidence intervals(95%CI)were calculated and used to evaluate the effect size.The meta-analysis was performed using the random-effects model due to heterogeneity between the studies.The Cochrane Collaboration 6 aspects of bias,methodological index for non-randomized studies and the Newcastle-Ottawa Scale were used to assess the risk for bias.Sensitivity analysis,publication bias and subgroup analysis were performed.Results Eighteen unique studies involving 2701 unique children were included in the analysis.The response rate was reported in 18 trials,which compared oral propranolol with other treatments.The heterogeneity was statistically significant(P<0.00001,P=95%).The difference in the response rate was statistically significant(RR=1.40,95%CI 1.13-1.75)while compared with the controls.However,no significant difference in the adverse events rate(RR=0.78,95%CI 0.45-1.34)and relapse rate(RR=1.45,95%CI 0.66-3.16)were found.Otherwise,the subgroup analysis indicated that the RR was 1.64(95%CI 0.24-11.36)for low-dose propranolol(1 mg/kg/day),1.42(95%CI 1.12-1.80)for medium dose(2 mg/kg/day)and 1.46(95%CI 1.17-1.82)for high dose(3 mg/kg/day),but the high dose had higher adverse events rate than medium dose,with 3.60%and 86.22%,respectively.The effectiveness of propranolol therapy among cases of treatment duration less than 6 months(RR=1.24,95%CI 1.05-1.47)was inferior to that of treatment duration greater than or equal to 6 months(RR=1.46,95%CI 1.11-1.92).Conclusions This meta-analysis reveals that oral propranolol is superior to other treatments in improving response rate of IH and can be used as the first-line therapy for IH children.A dosage of 2 mg/kg/day propranolol orally may be a good choice for IH.However,further studies are essential.
基金This work was supported by the National Postdoctoral Program for Innovative Talents(BX20200222)National Natural Science Foundation of China(Grant Nos.51772301,21878195,21805198,and 21805018)+5 种基金the National Key R&D Program of China(Grant Nos.2016YFA0202500 and 2017YFB0307504)the Distinguished Youth Science Foundation of Sichuan University(Grant 2017SCU04A08)the Distinguished Youth Foundation of Sichuan Province(Grant No.2020JDJQ0027)the Key R&D Program of Sichuan Province(Grant No.2020YFG00022)the Library of Innovation Spark Project of Sichuan University(Grant No.2018SCUH0094)the College-Enterprise Cooperation Project of Sichuan University(Grant Nos.19H0628 and 18H0357).
文摘The O3-type layered oxide cathodes for sodium-ion batteries(SIBs)are considered as one of the most promising systems to fully meet the requirement for future practical application.However,fatal issues in several respects such as poor air stability,irreversible complex multiphase evolution,inferior cycling lifespan,and poor industrial feasibility are restricting their commercialization development.Here,a stable Co-free O3-type NaNi_(0.4)Cu_(0.05)Mg_(0.05)Mn_(0.4)Ti_(0.1O2) cathode material with large-scale production could solve these problems for practical SIBs.Owing to the synergetic contribution of the multielement chemical substitution strategy,this novel cathode not only shows excellent air stability and thermal stability as well as a simple phase-transition process but also delivers outstanding battery performance in half-cell and full-cell systems.Meanwhile,various advanced characterization techniques are utilized to accurately decipher the crystalline formation process,atomic arrangement,structural evolution,and inherent effect mechanisms.Surprisingly,apart from restraining the unfavorable multiphase transformation and enhancing air stability,the accurate multielement chemical substitution engineering also shows a pinning effect to alleviate the lattice strains for the high structural reversibility and enlarges the interlayer spacing reasonably to enhance Na^(+)diffusion,resulting in excellent comprehensive performance.Overall,this study explores the fundamental scientific understandings of multielement chemical substitution strategy and opens up a new field for increasing the practicality to commercialization.
基金financially supported by the National Science Foundation of China(Nos.51772296,21878195,21805018 and 21805198)the Foundation for State Key Laboratory of Biochemical Engineering。
文摘Lithium sulfur battery(LSB) is widely considered as a next-generation battery system due to its high theoretical energy density of 2567 Wh kg-1.However,several inherent issues obstruct the business application of LSB.To address these issues,we assemble core-shell structure Fe_(3)O_(4)@C nanodots with 5 nm diameter as a valid sulfur host via a convenient organic pyrolysis treatment followed by calcination.The nanosized Fe3O4 particles could expose more chemisorption sites and inhibit the polysulfides shuttle.Moreover,the carbon layer could not only increase the conductivity but also ensure structural integrity during cyclic process.Furthermore,the mesoporous channels around Fe_(3)O_(4)@C could supply sufficient space to load sulfur and physically restrict the shuttle of polysulfides.Thus,the resultant S/Fe_(3)O_(4)@C cathode shows a highly initial capacity of 1089 mAh g^(-1) at 0.2 C,even retains 655 mAh g^(-1) over 200 cycles at 1 C.
基金National Natural Science Foundation of China(81873999,81672158)National Key R&D Program of China(2016YFC1100100).These funding agencies had no role in study design,collection/analyses of data,decision to publish,or manuscript preparation.
文摘Outbreak of COVID-19 is ongoing all over the world.Spine trauma is one of the most common types of trauma and will probably be encountered during the fight against COVID-19 and resumption of work and production.Patients with unstable spine fractures or continuous deterioration of neurological function require emergency surgery.The COVID-19 epidemic has brought tremendous challenges to the diagnosis and treatment of such patients.To coordinate the diagnosis and treatment of infectious disease prevention and spine trauma so as to formulate a rigorous diagnosis and treatment plan and to reduce the disability and mortality of the disease,multidisciplinary collaboration is needed.This expert consensus is formulated in order to(1)prevent and control the epidemic,(2)diagnose and treat patients with spine trauma reasonably,and(3)reduce the risk of cross-infection between patients and medical personnel during the treatment.
文摘Since December 2019,many patients in Wuhan sustained pneumonia with unknown causes.[1,2]A part of severe patients developed acute respiratory distress syndrome or septic shock,and even death.On January 7,2020,Chinese researchers have for the first time detected a new coronavirus.On January 20,2020,the National Health Commission issued Announcement No.1 of 2020,which included the new coronavirus pneumonia as a Class B infectious disease,and conducted epidemic prevention and control according to the Class A infectious disease.This new kind of pneumonia has been named coronavirus disease 2019(COVID-19).The sixth edition of"Diagnosis and Treatment Scheme for New Coronavirus Infected Pneumonia"points out that the main transmission routes include respiratory droplets and close contact transmission.There is a possibility of aerosol transmission in a relatively closed environment with prolonged exposure to high concentrations of aerosol.New coronavirus pneumonia has a certain incubation period.
文摘Background:XELOX(oxaliplatin 130mg/m^(2)iv,capecitabine 1000mg/m^(2)bid oral d1–14,q3w)chemotherapy has never been used in children.In this report,we present a case of a 12-year-old girl with colon adenocarcinoma,treated with surgery and XELOX chemotherapy.Methods:On admission,the girl complained of abdominal pain and intestinal obstruction.Physical examination revealed a distended abdomen with tenderness on the left upper quadrant.Barium enema revealed a stenotic lesion at the distal end of the transverse colon,and abdominal computed tomography showed acute obstruction and a colonic mass.Laparotomy was performed after the failure of conservative treatment.Results:The mass was originated from the transverse colon.Frozen sections of the specimens revealed an adenocarcinoma.Transverse colectomy was performed and regional lymph nodes were removed.Pathological examination confirmed that the mass was a poorly differentiated adenocarcinoma,and XELOX chemotherapy was used.No evidence of recurrent or metastatic tumor was found after 18 months.Conclusion:Although complete resection is the most effective treatment,XELOX chemotherapy is beneficial to the improvement of clinical outcome of patients with colon adenocarcinoma.
