Realizing a lithium sulfide(Li_(2)S)cathode with both high energy density and a long lifespan requires an innovative cathode design that maximizes electrochemical performance and resists electrode deterioration.Herein...Realizing a lithium sulfide(Li_(2)S)cathode with both high energy density and a long lifespan requires an innovative cathode design that maximizes electrochemical performance and resists electrode deterioration.Herein,a high-loading Li_(2)S-based cathode with micrometric Li_(2)S particles composed of two-dimensional graphene(Gr)and one-dimensional carbon nanotubes(CNTs)in a compact geometry is developed,and the role of CNTs in stable cycling of high-capacity Li–S batteries is emphasized.In a dimensionally combined carbon matrix,CNTs embedded within the Gr sheets create robust and sustainable electron diffusion pathways while suppressing the passivation of the active carbon surface.As a unique point,during the first charging process,the proposed cathode is fully activated through the direct conversion of Li_(2)S into S_(8) without inducing lithium polysulfide formation.The direct conversion of Li_(2)S into S_(8) in the composite cathode is ubiquitously investigated using the combined study of in situ Raman spectroscopy,in situ optical microscopy,and cryogenic transmission electron microscopy.The composite cathode demonstrates unprecedented electrochemical properties even with a high Li_(2)S loading of 10 mg cm^(–2);in particular,the practical and safe Li–S full cell coupled with a graphite anode shows ultra-long-term cycling stability over 800 cycles.展开更多
Background/Aims: Recently, endoscopic papillary large balloon dilation (EPLBD) using a large balloon (12 - 20 mm) for extraction of difficult common bile duct (CBD) stones has been widely accepted with favorable outco...Background/Aims: Recently, endoscopic papillary large balloon dilation (EPLBD) using a large balloon (12 - 20 mm) for extraction of difficult common bile duct (CBD) stones has been widely accepted with favorable outcomes. However, there is no consensus with regard to the ballooning time. The aim of our study was to evaluate the efficacy and safety of immediate balloon deflation in EPLBD for the treatment of difficult bile duct stone. Methods: This was a retrospective study of 80 consecutive patients with bile duct stones who were treated with an immediate balloon deflation method in EPLBD combined with endoscopic sphincterotomy (EST) between January 2010 and December 2012. Overall success rate, success rate at first ERCP, and the frequency of mechanical lithotripsy for complete stone removal were assessed for efficacy and safety was evaluated by assessing major complications. Results: Overall success rate for complete stone removal was high (78/80, 97.5%) and success rate for complete stone removal at first ERCP was 86.3% (69/80). The use of mechanical lithotripsy was 0% (0/80). The overall complication rate was favorable (5/80, 6.3%). PostERCP pancreatitis was observed in 3 patients (two: mild, one: moderate). In subgroup analysis, the presence of periampullary diverticulum was the only factor affecting the success rate at first ERCP. Conclusion: This study demonstrated the favorable outcome of immediate balloon deflation for treatment of difficult CBD stones and can be considered for clinical application.展开更多
AIM: To evaluate the diagnostic yield and safety of a modified technique for the histological diagnosis of subepithelial tumors (SETs). METHODS: A retrospective review of patients who underwent a modified technique fo...AIM: To evaluate the diagnostic yield and safety of a modified technique for the histological diagnosis of subepithelial tumors (SETs). METHODS: A retrospective review of patients who underwent a modified technique for the histological diagnosis of gastric SETs, consisting of a mucosal incision with a fixed flexible snare (MIF) and deep-tissue biopsy under conventional endoscopic view, from January 2012 to January 2013 was performed. Eleven patients with gastric SETs 10-30 mm in diameter and originating from the third or fourth layer on endoscopic ultrasonography were included. RESULTS: The mean age was 59.8 (range, 45-76) years, and 5 patients were male. The mean size of the SETs was 21.8 (range, 11-30) mm. The number of biopsy specimens was 6.3 (range 5-8). The mean procedure time was 9.0 min (range, 4-17 min). The diagnostic yield of MIF biopsies was 90.9% (10/11). The histological diagnoses were leiomyoma (4/11, 36.4%), aberrant pancreas (3/11, 27.3%), gastrointestinal stromal tumors (2/11, 18.2%), an inflammatory fibrinoid tumor (1/11, 9.1%); one result was non-diagnostic (1/11, 9.1%). There were six mesenchymal tumors; the specimens obtained in each case were sufficient for an immunohistochemical diagnosis. There was no major bleeding, but one perforation occurred that was successfully controlled by endoscopic clipping. CONCLUSION: The MIF biopsy was simple to perform, safe, and required a shorter procedure time, with a high diagnostic yield for small SETs.展开更多
The development of superconducting joining technology for reacted magnesium diboride(MgB_(2))conductors remains a critical challenge for the advancement of cryogen-free MgB_(2)-based magnets for magnetic resonance ima...The development of superconducting joining technology for reacted magnesium diboride(MgB_(2))conductors remains a critical challenge for the advancement of cryogen-free MgB_(2)-based magnets for magnetic resonance imaging(MRI).Herein,the fabrication of superconducting joints using reacted carbon-doped multifilament MgB_(2)wires for MRI magnets is reported.To achieve successful superconducting joints,the powder-in-mold method was employed,which involved tuning the filament protection mechanism,the powder compaction pressure,and the heat treatment condition.The fabricated joints demonstrated clear superconducting-to-normal transitions in self-field,with effective magnetic field screening up to 0.5 T at 20 K.To evaluate the interface between one of the MgB_(2)filaments and the MgB_(2)bulk within the joint,serial sectioning was conducted for the first time in this type of superconducting joint.The serial sectioning revealed space formation at the interface,potentially caused by the volume shrinkage associated with the MgB_(2)formation or the combined effect of the volume shrinkage and the different thermal expansion coefficients of the MgB_(2)bulk,the filament,the mold,and the sealing material.These findings are expected to be pivotal in developing MgB_(2)superconducting joining technology for MRI magnet applications through interface engineering.展开更多
Colorectal cancers (CRCs) with a high level of microsatellite instability (MSI-H) are clinicopathologically distinct tumors characterized by predominance in females, proximal colonic localization, poor differentiation...Colorectal cancers (CRCs) with a high level of microsatellite instability (MSI-H) are clinicopathologically distinct tumors characterized by predominance in females, proximal colonic localization, poor differentiation, mucinous histology, tumor-infiltrating lymphocytes, a Crohn’s-like lymphoid reaction and a favorable prognosis. In terms of their molecular features, MSI-H CRCs are heterogeneous tumors associated with various genetic and epigenetic alterations, including DNA mismatch repair deficiency, target microsatellite mutations, BRAF mutations, a CpG island methylator phenotype-high (CIMP-H) status, and a low level of genomic hypomethylation. The molecular heterogeneity of MSI-H CRCs also depends on ethnic differences; for example, in Eastern Asian countries, relatively low frequencies of CIMP-H and BRAF mutations have been observed in MSI-H CRCs compared to Western countries. Although the prognostic features of MSI-H CRCs include a favorable survival of patients and low benefit of adjuvant chemotherapy, there may be prognostic differences based on the molecular heterogeneity of MSI-H CRCs. Here, we have reviewed and discussed the molecular and prognostic features of MSI-H CRCs, as well as several putative prognostic or predictive molecular markers, including HSP110 expression, beta2-microglobulin mutations, myosin 1a expression, CDX2/CK20 expression, SMAD4 expression, CIMP status and LINE-1 methylation levels.展开更多
AIM: To elucidate the endoscopic features that predict the cancer following endoscopic submucosal dissection (ESD) in patients with high-grade neoplasia (HGN).
AIM:To elucidate the effects of dexamethasone on hypoxia-induced epithelial-to-mesenchymal transition(EMT) in colon cancer.METHODS:Human colon cancer HCT116 and HT29 cells were exposed to normoxic(21%) and hypoxic(1%)...AIM:To elucidate the effects of dexamethasone on hypoxia-induced epithelial-to-mesenchymal transition(EMT) in colon cancer.METHODS:Human colon cancer HCT116 and HT29 cells were exposed to normoxic(21%) and hypoxic(1%) conditions. First,the effect of dexamethasone on cell viability was examined by MTT cell proliferation assay. In order to measure the expression levels of EMT markers(Snail,Slug,Twist,E-cadherin,and integrin αVβ6) and hypoxia-related genes [Hypoxia-inducible factor-1α(HIF-1α) and vascular endothelial growth factor(VEGF)] by dexamethasone,quantitative real-time polymerase chain reaction and western blot analysis were performed. Furthermore,the morphological changes of colon cancer cells and the expression pattern of E-cadherin by dexamethasone were detected through immunocytochemistry. Finally,the effects of dexamethasone on the invasiveness and migration of colon cancer cells were elucidated using matrigel invasion,migration,and wound healing migration assays.RESULTS:Under hypoxia,dexamethasone treatment inhibited HIF-1α protein level and its downstream gene,VEGF m RNA level in the colon cancer cell lines,HCT116 and HT29. In addition,the presence of dexamethasone down-regulated the m RNA levels of hypoxia-induced Snail,Slug,and Twist,all transcriptional factors of EMT,as well as hypoxia-induced integrin αVβ6 protein level,a well-known EMT marker for colon cancer cells. Furthermore,reduced E-cadherin in hypoxic condition was found to be recoverable by treating with dexamethasone in both colon cancer cell lines. Similarly,under hypoxic conditions,dexamethasone restored the growth pattern and morphological phenotype reminiscent of colon cancer cells grown under normoxic conditions; dexamethasone blocked the migration and invasion of both colorectal cancer cell lines in hypoxia.CONCLUSION:Our study suggested that dexamethasone has inhibitory effects on cell migration and invasion by suppressing EMT of colon cancer cell lines in hypoxic condition.展开更多
BACKGROUND Increasing levels of antibiotic resistance have reduced the Helicobacter pylori(H.pylori)eradication rates afforded by the standard triple therapy.Thus,2-wk firstline four-drug regimens must be considered.A...BACKGROUND Increasing levels of antibiotic resistance have reduced the Helicobacter pylori(H.pylori)eradication rates afforded by the standard triple therapy.Thus,2-wk firstline four-drug regimens must be considered.AIM To analyze the eradication rates of modified bismuth-containing quadruple therapy(mBCQT)and concomitant therapy(CT),the associated adverse events,and compliance.METHODS Patients infected with H.pylori were prospectively randomized to receive mBCQT or CT for 2 wk.mBCQT featured a proton pump inhibitor(PPI),bismuth,metronidazole,and tetracycline,taken twice daily.CT included a PPI,clarithromycin,metronidazole,and amoxicillin,taken twice daily.The 13C-urea breath test was performed no earlier than 4 wk after therapy concluded to confirm eradication.If either the histological or rapid urease test was positive,H.pylori infection was diagnosed.RESULTS The demographic characteristics of 68 patients who received mBCQT and 68 who received CT did not differ significantly.On intention-to-treat analysis,the eradication rate was 88.2%(60/68)in the mBCQT group and 79.4%(54/68)in the CT group(P=0.162).By per-protocol analysis,the respective eradication rates were 98.4%(60/61)and 93.1%(54/58)(P=0.199).More CT than mBCQT patients experienced adverse events[33.8%(23/68)mBCQT vs 51.5%(35/58)CT patients,respectively,P=0.037].All patients showed good compliance[85.3%(58/68)mBCQT vs 82.4%(56/68)CT patients,P=0.641].CONCLUSION The H.pylori eradication rates of the 2-wk mBCQT and CT regimens are high.Most patients show good compliance,and more CT than mBCQT patients experience adverse events.展开更多
AIM: To validate the utility of Annexin A10 as a surrogate marker of the serrated neoplasia pathway in invasive colorectal cancers(CRCs).METHODS: A total of 1133 primary CRC patients who underwent surgical resection a...AIM: To validate the utility of Annexin A10 as a surrogate marker of the serrated neoplasia pathway in invasive colorectal cancers(CRCs).METHODS: A total of 1133 primary CRC patients who underwent surgical resection at Seoul National University Hospital between January 2004 and December 2007 were enrolled.Expression of Annexin A10 was evaluated by immunohistochemistry using tissue microarray and paired to our findings on clinicopathologic and molecular characteristics of each individual.Cp G island methylator phenotype was determined by Methy Light assay and microsatellite instability was determined by high performance liquid chromatography.KRAS and BRAF mutation status was evaluated by direct sequencing and allele-specific PCR.Univariate and stage-specific survival analyses were performed to reveal the prognostic value of Annexin A10 expression.RESULTS: Annexin A10 expression was observed in 66(5.8%) of the 1133 patients.Annexin A10 expression was more commonly found in females and was associated with proximal location,ulcerative gross type,advanced T category,N category and TNM stage.CRCs with Annexin A10 expression showed an absence of luminal necrosis,luminal serration and mucin production.CRCs with Annexin A10 expression were associated with Cp G island methylator phenotype,microsatellite instability and BRAF mutation.In survival analysis,Annexin A10 expression was associated with poor overall survival and progression-free survival,especially in stage Ⅳ CRCs.CONCLUSION: Annexin A10 expression is associated with poor clinical behavior and can be used a supportive surrogate marker of the serrated neoplasia pathway in invasive CRCs.展开更多
Fast interfacial kinetics derived from bicontinuous three-dimensional(3D)architecture is a strategic feature for achieving fast-charging lithium-ion batteries(LIBs).One of the main reasons is its large active surface ...Fast interfacial kinetics derived from bicontinuous three-dimensional(3D)architecture is a strategic feature for achieving fast-charging lithium-ion batteries(LIBs).One of the main reasons is its large active surface and short diffusion path.Yet,understanding of unusual electrochemical properties still remain great challenge due to its complexity.In this study,we proposed a nickel–tin compound(Ni_(3)Sn_(4))supported by 3D Nickel scaffolds as main frame because the Ni_(3)Sn_(4) clearly offers a higher reversible capacity and stable cycling performance than bare tin(Sn).In order to verify the role of Ni,atomic-scale simulation based on density functional theory systematically addressed to the reaction mechanism and structural evolution of Ni_(3)Sn_(4) during the lithiation process.Our findings are that Ni enables Ni_(3)Sn_(4) to possess higher mechanical stability in terms of reactive flow stress,subsequently lead to improve Li storage capability.This study elucidates an understanding of the lithiation mechanism of Ni_(3)Sn_(4) and provides a new perspective for the design of high-capacity and high-power 3D anodes for fast-charging LIBs.展开更多
BACKGROUND Antibiotic resistance to Helicobacter pylori(H.pylori)infection,which ultimately results in eradication failure,has been an emerging issue in the clinical field.Recently,to overcome this problem,an antibiot...BACKGROUND Antibiotic resistance to Helicobacter pylori(H.pylori)infection,which ultimately results in eradication failure,has been an emerging issue in the clinical field.Recently,to overcome this problem,an antibiotic sensitivity-based tailored therapy(TT)for H.pylori infection has received attention.AIM To investigate the efficacy and safety profiles of TT for H.pylori infection treatment compared to a non-bismuth quadruple therapy,concomitant therapy(CT)regimen.METHODS We included patients(>18 years)with an H.pylori infection and without a history of Helicobacter eradication who visited the Gil Medical Center between March 2016 and October 2020.After being randomly assigned to either the TT or CT treatment group in 1 to 1 manner,patient compliance,eradication success rate(ESR),and patient-reported side effects profiles were assessed and compared between the two groups.H.pylori infection was diagnosed using a rapid urease test,Giemsa stain,or dual priming oligonucleotide polymerase chain reaction(DPO-PCR).Tailored eradication strategy based through the presence of a 23S ribosomal RNA point mutation.For the TT group,a DPO-PCR test,which detected A2142G and/or A2143G point mutations,and a clarithromycin resistance test were performed.Patients in the clarithromycin-resistant group were treated with a bismuth-containing quadruple combination therapy,while those with sensitive results were treated with the standard triple regimen.RESULTS Of the 217 patients with a treatment naive H.pylori infection,110 patients[mean age:58.66±13.03,men,n=55(50%)]were treated with TT,and 107 patients[mean age:56.67±10.88,men,n=52(48.60%)]were treated with CT.The compliance(TT vs CT,100%vs 98.13%,P=0.30),and follow-up loss rates(8.18%vs 9.35%,P=0.95)were not significantly different between the groups.The ESR after treatment was also not statistically different between the groups(TT vs CT,82.73%vs 82.24%,P=0.95).However,the treatment-related and patient-reported side effects were significantly lower in the TT group than in the CT group(22.77%vs 50.52%,P<0.001).CONCLUSION The DPO-based TT regimen shows promising results in efficacy and safety profiles as a first-line Helicobacter eradication regimen in Korea,especially when physicians are confronted with increased antibiotic resistance rates.展开更多
AIM:To identify the epidemiologic characteristics of sportsand recreation-related eye injuries in a large metropolitan city and investigate risk factors associated with visual impairment.METHODS:We performed a multice...AIM:To identify the epidemiologic characteristics of sportsand recreation-related eye injuries in a large metropolitan city and investigate risk factors associated with visual impairment.METHODS:We performed a multicenter prospective observational study on patients using the regional eye injury registry data.This study included patients with sportsand recreation-related eye injury in four tertiary teaching hospitals in Daegu,Republic of Korea,from August 2016 to July 2018.The primary outcome was visual impairment at the first hospital visit.Distributions of sex,age,place,and causative materials were analyzed according to causative activities.To examine the association between causative activities and visual impairment,a Logistic regression analysis was used.RESULTS:Of the 349 sports-and recreation-related eye injuries,soccer was the most common causative activity,with 21.8%(n=76).Sports-and recreation-related eye injuries occurred mainly in teenagers,individuals in their 20 s,and men.Badminton and soccer were significantly associated with visual impairment at the first hospital visit compared with combat sports[(adjusted odds ratio(AOR),5.18;95%confidence interval(CI),1.67-16.09 for badminton and AOR,3.87;95%CI,1.36-10.99 for soccer].CONCLUSION:Intervention efforts such as deployment of protective eyewear in sports facilities and schools and promotion of wearing protective eyewear during these activities in teenagers and individuals in their 20 s are mandatory.展开更多
Guillain-Barre syndrome (GBS)-associated achalasia is a very rare disease of uncertain cause. We report the case of a patient diagnosed with GBS-associated type I achalasia who was successfully treated with peroral en...Guillain-Barre syndrome (GBS)-associated achalasia is a very rare disease of uncertain cause. We report the case of a patient diagnosed with GBS-associated type I achalasia who was successfully treated with peroral endoscopic myotomy (POEM). A 30-year-old man who was diagnosed with GBS 3 mo before was referred to our department with dysphagia and meal-related regurgitation. The results of esophagography, endoscopy, and high-resolution manometry (HRM) revealed type I achalasia. POEM that utilized a submucosal tunneling technique was performed to treat the GBS-associated type I achalasia. After POEM, smooth passage of a contrast agent into the stomach was shown in follow-up esophagography, and follow-up HRM revealed a decrease in the mean integrated relaxation pressure 22.9 mmHg to 9.6 mmHg. The patient remained without dysphagia for 7 mo, even though the patient’s neurological problems were not fully resolved. POEM may be a safe and effective treatment for GBS-associated type I achalasia.展开更多
Intramedullary spinal cord metastasis(ISCM) is very rare and its optimal treatment remains controversial. Pancreatic neuroendocrine tumor(pNET) is a rare tumor that usually presents with hepatic metastasis. Hepatic fa...Intramedullary spinal cord metastasis(ISCM) is very rare and its optimal treatment remains controversial. Pancreatic neuroendocrine tumor(pNET) is a rare tumor that usually presents with hepatic metastasis. Hepatic failure due to tumor progression is the major cause of death in cases of pNET. To date,no report has described a case of ISCM from pNET. Although spinal cord metastasis of a solid tumor is uncommon,it is a critical condition that can cause a potentially irreversible loss of neurologic function. Here,we report the case of a 45-year-old man who presented with leg weakness and voiding difficulty,and was found to have ISCM from pNET. Surgical treatment prevented further neurological deterioration. This is the first case report of ISCM from pNET.展开更多
BACKGROUND Bezoar is a mass of hardened external material found in the gastrointestinal(GI)tract.It may form anywhere in the GI tract,but esophageal bezoar is rare because of the short esophageal transit time.Psyllium...BACKGROUND Bezoar is a mass of hardened external material found in the gastrointestinal(GI)tract.It may form anywhere in the GI tract,but esophageal bezoar is rare because of the short esophageal transit time.Psyllium seed husk is an indigestible natural derivative that is widely used as an herbal laxative.Herein,we report a case of acute esophageal obstruction caused by a bezoar after ingestion of psyllium seed husk powder.CASE SUMMARY A 76-year-old male with Parkinson’s disease visited the emergency department with swallowing difficulty approximately 10 h after ingesting psyllium seed husk powder.Symptoms began a few hours after ingestion and progressed to severe dysphagia.There were no abnormal findings on simple radiography.However,a computed tomography scan revealed an approximately 2.0 cm×2.5 cm mass located near the gastro-esophageal junction.After grinding,the mass was removed using an endoscopic capture net.Esophageal bezoars may cause life-threatening complications.Patients with Parkinson’s disease may have esophageal motility dysfunction,which may increase esophageal transit time.Since our patient had Parkinson’s disease,this effect may have contributed to the formation of the bezoar.CONCLUSION Attention should be paid to using bulk-laxatives,and an appropriate specified regimen will be needed when marketed as a dietary supplement.展开更多
The effect of cold high pressure densification(CHPD)on anisotropy of the critical current density(Jc)in《in situ》single core binary and alloyed MgB2 tapes has been determined as a function of temperatures at 4.2 K,20...The effect of cold high pressure densification(CHPD)on anisotropy of the critical current density(Jc)in《in situ》single core binary and alloyed MgB2 tapes has been determined as a function of temperatures at 4.2 K,20 K and 25 K as well as at applied magnetic fields up to 19 T.The study includes binary and C4H6O5(malic acid)doped MgB2 tapes before and after CHPD.It is remarkable that the CHPD process not only improved the Jc values,in particular at the higher magnetic fields,but also decreased the anisotropy ratio,Г=JC^///JC^⊥In binary MgB2 tapes,the anisotropy factor F increases with higher aspect ratios,even after applying CHPD.In malic acid(C4H6O5)doped tapes,however,the application of CHPD leads only to small enhancements ofГ,even for higher aspect ratios.This is attributed to the higher carbon content in the MgB2 filaments,which in turn is a consequence of the reduced chemical reaction path in the densified filaments.At all applied field values,it was found that CHPD processed C4H6O5 doped tapes exhibit an almost isotropic behavior.This constitutes an advantage in view of industrial magnet applications using wires with square or slightly rectangular configuration.展开更多
High electrochemical stability and safety make Na+superionic conductor(NASICON)-class cathodes highly desirable for Na-ion batteries(SIBs).However,their practical capacity is limited,leading to low specific energy.Fur...High electrochemical stability and safety make Na+superionic conductor(NASICON)-class cathodes highly desirable for Na-ion batteries(SIBs).However,their practical capacity is limited,leading to low specific energy.Furthermore,the low electrical conductivity combined with a decline in capacity upon prolonged cycling(>1000 cycles)related to the loss of active material-carbon conducting contact regions contributes to moderate rate performance and cycling stability.The need for high specific energy cathodes that meet practical electrochemical requirements has prompted a search for new materials.Herein,we introduce a new carbon-coated Na_(3)VFe_(0.5)Ti_(0.5)(PO_(4))_(3)(NVFTP/C)material as a promising candidate in the NASICON family of cathodes for SIBs.With a high specific energy of∼457 Wh kg^(-1) and a high Na+insertion voltage of 3.0 V versus Na^(+)/Na,this cathode can undergo a reversible single-phase solid-solution and two-phase(de)sodiation evolution at 28 C(1 C=174.7 mAh g^(-1))for up to 10,000 cycles.This study highlights the potential of utilizing low-cost and highly efficient cathodes made from Earth-abundant and harmless materials(Fe and Ti)with enriched Na^(+)-storage properties in practical SIBs.展开更多
The suitable materials,metal nitrides,are a promising class of electrocatalyst materials for a highly efficient oxygen evolution reaction (OER) because they exhibit superior intrinsic conductivity and have higher sust...The suitable materials,metal nitrides,are a promising class of electrocatalyst materials for a highly efficient oxygen evolution reaction (OER) because they exhibit superior intrinsic conductivity and have higher sustainability than oxide-based materials.To our knowledge,for the first time,we report a designable synthesis of three-dimensional (3D) and mesoporous Co3N@ amorphous N-doped carbon (AN-C) nanocubes (NCs) with well-controlled open-framework structures via monodispersed Co3[Co(CN)6]2 Prussian blue analogue (PBA) NC precursors using in situ nitridation and calcination processes.Co3N@AN-C NCs (2 h) demonstrate better OER activity with a remarkably low Tafel plot (69.6 mV-dec-1),low overpotential of 280 mV at a current density of 10 mA-crrf2.Additionally,excellent cycling stability in alkaline electrolytes was exhibited without morphological changes and voltage elevations,superior to most reported hierarchical structures of transition-metal nitride particles.The presented strategy for synergy effects of metal-organic frameworks (MOFs)-derived transition-metal nitrides-carbon hybrid nanostructures provides prospects for developing high-performance and advanced electrocatalyst materials.展开更多
基金Korea Institute of Energy Technology Evaluation and Planning,Grant/Award Number:20214000000320Samsung Research Funding&Incubation Center of Samsung Electronics,Grant/Award Number:SRFC-MA1901-06。
文摘Realizing a lithium sulfide(Li_(2)S)cathode with both high energy density and a long lifespan requires an innovative cathode design that maximizes electrochemical performance and resists electrode deterioration.Herein,a high-loading Li_(2)S-based cathode with micrometric Li_(2)S particles composed of two-dimensional graphene(Gr)and one-dimensional carbon nanotubes(CNTs)in a compact geometry is developed,and the role of CNTs in stable cycling of high-capacity Li–S batteries is emphasized.In a dimensionally combined carbon matrix,CNTs embedded within the Gr sheets create robust and sustainable electron diffusion pathways while suppressing the passivation of the active carbon surface.As a unique point,during the first charging process,the proposed cathode is fully activated through the direct conversion of Li_(2)S into S_(8) without inducing lithium polysulfide formation.The direct conversion of Li_(2)S into S_(8) in the composite cathode is ubiquitously investigated using the combined study of in situ Raman spectroscopy,in situ optical microscopy,and cryogenic transmission electron microscopy.The composite cathode demonstrates unprecedented electrochemical properties even with a high Li_(2)S loading of 10 mg cm^(–2);in particular,the practical and safe Li–S full cell coupled with a graphite anode shows ultra-long-term cycling stability over 800 cycles.
文摘Background/Aims: Recently, endoscopic papillary large balloon dilation (EPLBD) using a large balloon (12 - 20 mm) for extraction of difficult common bile duct (CBD) stones has been widely accepted with favorable outcomes. However, there is no consensus with regard to the ballooning time. The aim of our study was to evaluate the efficacy and safety of immediate balloon deflation in EPLBD for the treatment of difficult bile duct stone. Methods: This was a retrospective study of 80 consecutive patients with bile duct stones who were treated with an immediate balloon deflation method in EPLBD combined with endoscopic sphincterotomy (EST) between January 2010 and December 2012. Overall success rate, success rate at first ERCP, and the frequency of mechanical lithotripsy for complete stone removal were assessed for efficacy and safety was evaluated by assessing major complications. Results: Overall success rate for complete stone removal was high (78/80, 97.5%) and success rate for complete stone removal at first ERCP was 86.3% (69/80). The use of mechanical lithotripsy was 0% (0/80). The overall complication rate was favorable (5/80, 6.3%). PostERCP pancreatitis was observed in 3 patients (two: mild, one: moderate). In subgroup analysis, the presence of periampullary diverticulum was the only factor affecting the success rate at first ERCP. Conclusion: This study demonstrated the favorable outcome of immediate balloon deflation for treatment of difficult CBD stones and can be considered for clinical application.
文摘AIM: To evaluate the diagnostic yield and safety of a modified technique for the histological diagnosis of subepithelial tumors (SETs). METHODS: A retrospective review of patients who underwent a modified technique for the histological diagnosis of gastric SETs, consisting of a mucosal incision with a fixed flexible snare (MIF) and deep-tissue biopsy under conventional endoscopic view, from January 2012 to January 2013 was performed. Eleven patients with gastric SETs 10-30 mm in diameter and originating from the third or fourth layer on endoscopic ultrasonography were included. RESULTS: The mean age was 59.8 (range, 45-76) years, and 5 patients were male. The mean size of the SETs was 21.8 (range, 11-30) mm. The number of biopsy specimens was 6.3 (range 5-8). The mean procedure time was 9.0 min (range, 4-17 min). The diagnostic yield of MIF biopsies was 90.9% (10/11). The histological diagnoses were leiomyoma (4/11, 36.4%), aberrant pancreas (3/11, 27.3%), gastrointestinal stromal tumors (2/11, 18.2%), an inflammatory fibrinoid tumor (1/11, 9.1%); one result was non-diagnostic (1/11, 9.1%). There were six mesenchymal tumors; the specimens obtained in each case were sufficient for an immunohistochemical diagnosis. There was no major bleeding, but one perforation occurred that was successfully controlled by endoscopic clipping. CONCLUSION: The MIF biopsy was simple to perform, safe, and required a shorter procedure time, with a high diagnostic yield for small SETs.
基金the Japan Society for the Promotion of Science(JSPS)KAKENHI Grant Number JP18F18714Cryogenic Station,Research Network and Facility Services Division,National Institute for Materials Science(NIMS),Japansupported by the ARC Linkage Project(LP200200689)。
文摘The development of superconducting joining technology for reacted magnesium diboride(MgB_(2))conductors remains a critical challenge for the advancement of cryogen-free MgB_(2)-based magnets for magnetic resonance imaging(MRI).Herein,the fabrication of superconducting joints using reacted carbon-doped multifilament MgB_(2)wires for MRI magnets is reported.To achieve successful superconducting joints,the powder-in-mold method was employed,which involved tuning the filament protection mechanism,the powder compaction pressure,and the heat treatment condition.The fabricated joints demonstrated clear superconducting-to-normal transitions in self-field,with effective magnetic field screening up to 0.5 T at 20 K.To evaluate the interface between one of the MgB_(2)filaments and the MgB_(2)bulk within the joint,serial sectioning was conducted for the first time in this type of superconducting joint.The serial sectioning revealed space formation at the interface,potentially caused by the volume shrinkage associated with the MgB_(2)formation or the combined effect of the volume shrinkage and the different thermal expansion coefficients of the MgB_(2)bulk,the filament,the mold,and the sealing material.These findings are expected to be pivotal in developing MgB_(2)superconducting joining technology for MRI magnet applications through interface engineering.
基金Supported by The National R&D Program for Cancer Control funded by the Ministry of Health and Welfare,South Korea,No.0720540the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP),No.2011-0030768+1 种基金Priority Research Centers Program through the NRF grant funded by the Ministry of Education,Science and Technology(MEST),South Korea,No.2009-0093820the Mid-career Researcher Program through the NRF grant funded by MEST,No.2011-0015646
文摘Colorectal cancers (CRCs) with a high level of microsatellite instability (MSI-H) are clinicopathologically distinct tumors characterized by predominance in females, proximal colonic localization, poor differentiation, mucinous histology, tumor-infiltrating lymphocytes, a Crohn’s-like lymphoid reaction and a favorable prognosis. In terms of their molecular features, MSI-H CRCs are heterogeneous tumors associated with various genetic and epigenetic alterations, including DNA mismatch repair deficiency, target microsatellite mutations, BRAF mutations, a CpG island methylator phenotype-high (CIMP-H) status, and a low level of genomic hypomethylation. The molecular heterogeneity of MSI-H CRCs also depends on ethnic differences; for example, in Eastern Asian countries, relatively low frequencies of CIMP-H and BRAF mutations have been observed in MSI-H CRCs compared to Western countries. Although the prognostic features of MSI-H CRCs include a favorable survival of patients and low benefit of adjuvant chemotherapy, there may be prognostic differences based on the molecular heterogeneity of MSI-H CRCs. Here, we have reviewed and discussed the molecular and prognostic features of MSI-H CRCs, as well as several putative prognostic or predictive molecular markers, including HSP110 expression, beta2-microglobulin mutations, myosin 1a expression, CDX2/CK20 expression, SMAD4 expression, CIMP status and LINE-1 methylation levels.
基金Supported by Grants of the Gachon University Gil Medical Center,No.2013-35 and 37
文摘AIM: To elucidate the endoscopic features that predict the cancer following endoscopic submucosal dissection (ESD) in patients with high-grade neoplasia (HGN).
基金Supported by A grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institutefunded by the Ministry of Health&Welfare,Republic of Korea,No.HI13C-1602-010014)grants of the Gachon University Gil Medical Center,No.2013-01,2014-11 and 2014-25
文摘AIM:To elucidate the effects of dexamethasone on hypoxia-induced epithelial-to-mesenchymal transition(EMT) in colon cancer.METHODS:Human colon cancer HCT116 and HT29 cells were exposed to normoxic(21%) and hypoxic(1%) conditions. First,the effect of dexamethasone on cell viability was examined by MTT cell proliferation assay. In order to measure the expression levels of EMT markers(Snail,Slug,Twist,E-cadherin,and integrin αVβ6) and hypoxia-related genes [Hypoxia-inducible factor-1α(HIF-1α) and vascular endothelial growth factor(VEGF)] by dexamethasone,quantitative real-time polymerase chain reaction and western blot analysis were performed. Furthermore,the morphological changes of colon cancer cells and the expression pattern of E-cadherin by dexamethasone were detected through immunocytochemistry. Finally,the effects of dexamethasone on the invasiveness and migration of colon cancer cells were elucidated using matrigel invasion,migration,and wound healing migration assays.RESULTS:Under hypoxia,dexamethasone treatment inhibited HIF-1α protein level and its downstream gene,VEGF m RNA level in the colon cancer cell lines,HCT116 and HT29. In addition,the presence of dexamethasone down-regulated the m RNA levels of hypoxia-induced Snail,Slug,and Twist,all transcriptional factors of EMT,as well as hypoxia-induced integrin αVβ6 protein level,a well-known EMT marker for colon cancer cells. Furthermore,reduced E-cadherin in hypoxic condition was found to be recoverable by treating with dexamethasone in both colon cancer cell lines. Similarly,under hypoxic conditions,dexamethasone restored the growth pattern and morphological phenotype reminiscent of colon cancer cells grown under normoxic conditions; dexamethasone blocked the migration and invasion of both colorectal cancer cell lines in hypoxia.CONCLUSION:Our study suggested that dexamethasone has inhibitory effects on cell migration and invasion by suppressing EMT of colon cancer cell lines in hypoxic condition.
基金Supported by A grant of the Korea Health Technology RD Project through the Korea Health Industry Development Institute,funded by the Ministry of Health and Fare,Republic of Korea,No.HI13C-1602-010013a grant of the Gachon University Gil Medical Center,No.2013-01 and 2013-37
文摘AIM: To identify risk factors for surgical failure after colonic stenting as a bridge to surgery in left-sided malignant colonic obstruction.
基金Supported by Grants from Korea Health Technology R&D Project through the Korea Health Industry Development Institute,Funded by the Ministry of Health and Welfare,South Korea,No.HI13C-1602-010013Gachon University Gil Medical Center,No.2013-37
文摘AIM: To evaluate the efficacy of stents in treating patients with anastomotic site obstructions due to cancer recurrence following colorectal surgery.
文摘BACKGROUND Increasing levels of antibiotic resistance have reduced the Helicobacter pylori(H.pylori)eradication rates afforded by the standard triple therapy.Thus,2-wk firstline four-drug regimens must be considered.AIM To analyze the eradication rates of modified bismuth-containing quadruple therapy(mBCQT)and concomitant therapy(CT),the associated adverse events,and compliance.METHODS Patients infected with H.pylori were prospectively randomized to receive mBCQT or CT for 2 wk.mBCQT featured a proton pump inhibitor(PPI),bismuth,metronidazole,and tetracycline,taken twice daily.CT included a PPI,clarithromycin,metronidazole,and amoxicillin,taken twice daily.The 13C-urea breath test was performed no earlier than 4 wk after therapy concluded to confirm eradication.If either the histological or rapid urease test was positive,H.pylori infection was diagnosed.RESULTS The demographic characteristics of 68 patients who received mBCQT and 68 who received CT did not differ significantly.On intention-to-treat analysis,the eradication rate was 88.2%(60/68)in the mBCQT group and 79.4%(54/68)in the CT group(P=0.162).By per-protocol analysis,the respective eradication rates were 98.4%(60/61)and 93.1%(54/58)(P=0.199).More CT than mBCQT patients experienced adverse events[33.8%(23/68)mBCQT vs 51.5%(35/58)CT patients,respectively,P=0.037].All patients showed good compliance[85.3%(58/68)mBCQT vs 82.4%(56/68)CT patients,P=0.641].CONCLUSION The H.pylori eradication rates of the 2-wk mBCQT and CT regimens are high.Most patients show good compliance,and more CT than mBCQT patients experience adverse events.
基金Supported by Grant from Basic Science Research Program through the National Research Foundation(NRF)funded by the Ministry of Education,No.2013R1A1A2059080a grant from the Korean Health Technology R&D Project,Ministry of Health&Welfare,No.HI13C1804+2 种基金Priority Research Centers Program through the NRF funded by the Ministry of Education,Science and Technology,No.2009-0093820the NRF grant funded by the Ministry of Science,ICT,and Future planning,No.2011-0030049a grant of the Korea Health Technology R&D Project,Ministry of Health&Welfare,Republic of Korea,No.HI14C1277."
文摘AIM: To validate the utility of Annexin A10 as a surrogate marker of the serrated neoplasia pathway in invasive colorectal cancers(CRCs).METHODS: A total of 1133 primary CRC patients who underwent surgical resection at Seoul National University Hospital between January 2004 and December 2007 were enrolled.Expression of Annexin A10 was evaluated by immunohistochemistry using tissue microarray and paired to our findings on clinicopathologic and molecular characteristics of each individual.Cp G island methylator phenotype was determined by Methy Light assay and microsatellite instability was determined by high performance liquid chromatography.KRAS and BRAF mutation status was evaluated by direct sequencing and allele-specific PCR.Univariate and stage-specific survival analyses were performed to reveal the prognostic value of Annexin A10 expression.RESULTS: Annexin A10 expression was observed in 66(5.8%) of the 1133 patients.Annexin A10 expression was more commonly found in females and was associated with proximal location,ulcerative gross type,advanced T category,N category and TNM stage.CRCs with Annexin A10 expression showed an absence of luminal necrosis,luminal serration and mucin production.CRCs with Annexin A10 expression were associated with Cp G island methylator phenotype,microsatellite instability and BRAF mutation.In survival analysis,Annexin A10 expression was associated with poor overall survival and progression-free survival,especially in stage Ⅳ CRCs.CONCLUSION: Annexin A10 expression is associated with poor clinical behavior and can be used a supportive surrogate marker of the serrated neoplasia pathway in invasive CRCs.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(NRF-2021M3H4A1A02045967)(NRF-2021M3H4A1A02048137)supported by the Chung-Ang University Research Scholarship Grants in 2021。
文摘Fast interfacial kinetics derived from bicontinuous three-dimensional(3D)architecture is a strategic feature for achieving fast-charging lithium-ion batteries(LIBs).One of the main reasons is its large active surface and short diffusion path.Yet,understanding of unusual electrochemical properties still remain great challenge due to its complexity.In this study,we proposed a nickel–tin compound(Ni_(3)Sn_(4))supported by 3D Nickel scaffolds as main frame because the Ni_(3)Sn_(4) clearly offers a higher reversible capacity and stable cycling performance than bare tin(Sn).In order to verify the role of Ni,atomic-scale simulation based on density functional theory systematically addressed to the reaction mechanism and structural evolution of Ni_(3)Sn_(4) during the lithiation process.Our findings are that Ni enables Ni_(3)Sn_(4) to possess higher mechanical stability in terms of reactive flow stress,subsequently lead to improve Li storage capability.This study elucidates an understanding of the lithiation mechanism of Ni_(3)Sn_(4) and provides a new perspective for the design of high-capacity and high-power 3D anodes for fast-charging LIBs.
基金National Research Foundation of Korea(NRF)funded by the Ministry of Education,No.NRF-2020R1F1A1076839。
文摘BACKGROUND Antibiotic resistance to Helicobacter pylori(H.pylori)infection,which ultimately results in eradication failure,has been an emerging issue in the clinical field.Recently,to overcome this problem,an antibiotic sensitivity-based tailored therapy(TT)for H.pylori infection has received attention.AIM To investigate the efficacy and safety profiles of TT for H.pylori infection treatment compared to a non-bismuth quadruple therapy,concomitant therapy(CT)regimen.METHODS We included patients(>18 years)with an H.pylori infection and without a history of Helicobacter eradication who visited the Gil Medical Center between March 2016 and October 2020.After being randomly assigned to either the TT or CT treatment group in 1 to 1 manner,patient compliance,eradication success rate(ESR),and patient-reported side effects profiles were assessed and compared between the two groups.H.pylori infection was diagnosed using a rapid urease test,Giemsa stain,or dual priming oligonucleotide polymerase chain reaction(DPO-PCR).Tailored eradication strategy based through the presence of a 23S ribosomal RNA point mutation.For the TT group,a DPO-PCR test,which detected A2142G and/or A2143G point mutations,and a clarithromycin resistance test were performed.Patients in the clarithromycin-resistant group were treated with a bismuth-containing quadruple combination therapy,while those with sensitive results were treated with the standard triple regimen.RESULTS Of the 217 patients with a treatment naive H.pylori infection,110 patients[mean age:58.66±13.03,men,n=55(50%)]were treated with TT,and 107 patients[mean age:56.67±10.88,men,n=52(48.60%)]were treated with CT.The compliance(TT vs CT,100%vs 98.13%,P=0.30),and follow-up loss rates(8.18%vs 9.35%,P=0.95)were not significantly different between the groups.The ESR after treatment was also not statistically different between the groups(TT vs CT,82.73%vs 82.24%,P=0.95).However,the treatment-related and patient-reported side effects were significantly lower in the TT group than in the CT group(22.77%vs 50.52%,P<0.001).CONCLUSION The DPO-based TT regimen shows promising results in efficacy and safety profiles as a first-line Helicobacter eradication regimen in Korea,especially when physicians are confronted with increased antibiotic resistance rates.
基金Supported by the Korea Centers for Disease Control and Prevention(No.2016E3300500)。
文摘AIM:To identify the epidemiologic characteristics of sportsand recreation-related eye injuries in a large metropolitan city and investigate risk factors associated with visual impairment.METHODS:We performed a multicenter prospective observational study on patients using the regional eye injury registry data.This study included patients with sportsand recreation-related eye injury in four tertiary teaching hospitals in Daegu,Republic of Korea,from August 2016 to July 2018.The primary outcome was visual impairment at the first hospital visit.Distributions of sex,age,place,and causative materials were analyzed according to causative activities.To examine the association between causative activities and visual impairment,a Logistic regression analysis was used.RESULTS:Of the 349 sports-and recreation-related eye injuries,soccer was the most common causative activity,with 21.8%(n=76).Sports-and recreation-related eye injuries occurred mainly in teenagers,individuals in their 20 s,and men.Badminton and soccer were significantly associated with visual impairment at the first hospital visit compared with combat sports[(adjusted odds ratio(AOR),5.18;95%confidence interval(CI),1.67-16.09 for badminton and AOR,3.87;95%CI,1.36-10.99 for soccer].CONCLUSION:Intervention efforts such as deployment of protective eyewear in sports facilities and schools and promotion of wearing protective eyewear during these activities in teenagers and individuals in their 20 s are mandatory.
文摘Guillain-Barre syndrome (GBS)-associated achalasia is a very rare disease of uncertain cause. We report the case of a patient diagnosed with GBS-associated type I achalasia who was successfully treated with peroral endoscopic myotomy (POEM). A 30-year-old man who was diagnosed with GBS 3 mo before was referred to our department with dysphagia and meal-related regurgitation. The results of esophagography, endoscopy, and high-resolution manometry (HRM) revealed type I achalasia. POEM that utilized a submucosal tunneling technique was performed to treat the GBS-associated type I achalasia. After POEM, smooth passage of a contrast agent into the stomach was shown in follow-up esophagography, and follow-up HRM revealed a decrease in the mean integrated relaxation pressure 22.9 mmHg to 9.6 mmHg. The patient remained without dysphagia for 7 mo, even though the patient’s neurological problems were not fully resolved. POEM may be a safe and effective treatment for GBS-associated type I achalasia.
基金Supported by Grant from Gachon University Gil Medical Center,No.2013-37
文摘Intramedullary spinal cord metastasis(ISCM) is very rare and its optimal treatment remains controversial. Pancreatic neuroendocrine tumor(pNET) is a rare tumor that usually presents with hepatic metastasis. Hepatic failure due to tumor progression is the major cause of death in cases of pNET. To date,no report has described a case of ISCM from pNET. Although spinal cord metastasis of a solid tumor is uncommon,it is a critical condition that can cause a potentially irreversible loss of neurologic function. Here,we report the case of a 45-year-old man who presented with leg weakness and voiding difficulty,and was found to have ISCM from pNET. Surgical treatment prevented further neurological deterioration. This is the first case report of ISCM from pNET.
基金Supported by the 2021 Yeungnam University Research Grant
文摘BACKGROUND Bezoar is a mass of hardened external material found in the gastrointestinal(GI)tract.It may form anywhere in the GI tract,but esophageal bezoar is rare because of the short esophageal transit time.Psyllium seed husk is an indigestible natural derivative that is widely used as an herbal laxative.Herein,we report a case of acute esophageal obstruction caused by a bezoar after ingestion of psyllium seed husk powder.CASE SUMMARY A 76-year-old male with Parkinson’s disease visited the emergency department with swallowing difficulty approximately 10 h after ingesting psyllium seed husk powder.Symptoms began a few hours after ingestion and progressed to severe dysphagia.There were no abnormal findings on simple radiography.However,a computed tomography scan revealed an approximately 2.0 cm×2.5 cm mass located near the gastro-esophageal junction.After grinding,the mass was removed using an endoscopic capture net.Esophageal bezoars may cause life-threatening complications.Patients with Parkinson’s disease may have esophageal motility dysfunction,which may increase esophageal transit time.Since our patient had Parkinson’s disease,this effect may have contributed to the formation of the bezoar.CONCLUSION Attention should be paid to using bulk-laxatives,and an appropriate specified regimen will be needed when marketed as a dietary supplement.
基金This work was supported by the Australian Research Council(Grant No.LP160101784)A.K.thanks the Researchers Supporting Project(RSP-2019/127)King Saud University,Riyadh,Saudi Arabia for the support.This work was performed in part at the Queensland node of the Australian National Fabrication Facility,a company established under the National Collaborative Research Infrastructure Strategy to provide nano-and microfabrication facilities for Australia's researchers.M.M.acknowledges an internal funding project of the University of Osijek(ZUP-2018).
文摘The effect of cold high pressure densification(CHPD)on anisotropy of the critical current density(Jc)in《in situ》single core binary and alloyed MgB2 tapes has been determined as a function of temperatures at 4.2 K,20 K and 25 K as well as at applied magnetic fields up to 19 T.The study includes binary and C4H6O5(malic acid)doped MgB2 tapes before and after CHPD.It is remarkable that the CHPD process not only improved the Jc values,in particular at the higher magnetic fields,but also decreased the anisotropy ratio,Г=JC^///JC^⊥In binary MgB2 tapes,the anisotropy factor F increases with higher aspect ratios,even after applying CHPD.In malic acid(C4H6O5)doped tapes,however,the application of CHPD leads only to small enhancements ofГ,even for higher aspect ratios.This is attributed to the higher carbon content in the MgB2 filaments,which in turn is a consequence of the reduced chemical reaction path in the densified filaments.At all applied field values,it was found that CHPD processed C4H6O5 doped tapes exhibit an almost isotropic behavior.This constitutes an advantage in view of industrial magnet applications using wires with square or slightly rectangular configuration.
基金This work was supported by the National Research Foundation of Korea(NRF)Grant funded by the Korean government(MSIT)(NRF-2018R1A5A1025224 and NRF-2021R1A4A1052051)This work was also supported by the National Research Foundation of Korea Grant funded by the Korean Government Ministry of Education and Science Technology(NRF-2021R1I1A3060193).
文摘High electrochemical stability and safety make Na+superionic conductor(NASICON)-class cathodes highly desirable for Na-ion batteries(SIBs).However,their practical capacity is limited,leading to low specific energy.Furthermore,the low electrical conductivity combined with a decline in capacity upon prolonged cycling(>1000 cycles)related to the loss of active material-carbon conducting contact regions contributes to moderate rate performance and cycling stability.The need for high specific energy cathodes that meet practical electrochemical requirements has prompted a search for new materials.Herein,we introduce a new carbon-coated Na_(3)VFe_(0.5)Ti_(0.5)(PO_(4))_(3)(NVFTP/C)material as a promising candidate in the NASICON family of cathodes for SIBs.With a high specific energy of∼457 Wh kg^(-1) and a high Na+insertion voltage of 3.0 V versus Na^(+)/Na,this cathode can undergo a reversible single-phase solid-solution and two-phase(de)sodiation evolution at 28 C(1 C=174.7 mAh g^(-1))for up to 10,000 cycles.This study highlights the potential of utilizing low-cost and highly efficient cathodes made from Earth-abundant and harmless materials(Fe and Ti)with enriched Na^(+)-storage properties in practical SIBs.
文摘The suitable materials,metal nitrides,are a promising class of electrocatalyst materials for a highly efficient oxygen evolution reaction (OER) because they exhibit superior intrinsic conductivity and have higher sustainability than oxide-based materials.To our knowledge,for the first time,we report a designable synthesis of three-dimensional (3D) and mesoporous Co3N@ amorphous N-doped carbon (AN-C) nanocubes (NCs) with well-controlled open-framework structures via monodispersed Co3[Co(CN)6]2 Prussian blue analogue (PBA) NC precursors using in situ nitridation and calcination processes.Co3N@AN-C NCs (2 h) demonstrate better OER activity with a remarkably low Tafel plot (69.6 mV-dec-1),low overpotential of 280 mV at a current density of 10 mA-crrf2.Additionally,excellent cycling stability in alkaline electrolytes was exhibited without morphological changes and voltage elevations,superior to most reported hierarchical structures of transition-metal nitride particles.The presented strategy for synergy effects of metal-organic frameworks (MOFs)-derived transition-metal nitrides-carbon hybrid nanostructures provides prospects for developing high-performance and advanced electrocatalyst materials.