Pacing-induced cardiomyopathy (PICM) resultsf rom the detrimental effect of frequent right ventricular pacing.^([1]) The diagnosis relies on a combination of pacing-associated ventricular dyschrony manifested with ECG...Pacing-induced cardiomyopathy (PICM) resultsf rom the detrimental effect of frequent right ventricular pacing.^([1]) The diagnosis relies on a combination of pacing-associated ventricular dyschrony manifested with ECG wide LBBB-pattern QRS duration and clinical assessment, imaging studies. Conduction system pacing (CSP), such as His bundle pacing (HBP)and left bundle branch pacing (LBBP), may help to prevent PICM,^([2]) but the criteria for optimal patient selection remain inadequately defined.展开更多
The case report presented in this edition by Mu et al.The report presents a case of atrial septal defect(ASD)associated with electrocardiographic changes,noting that the crochetage sign resolved after Selective His Bu...The case report presented in this edition by Mu et al.The report presents a case of atrial septal defect(ASD)associated with electrocardiographic changes,noting that the crochetage sign resolved after Selective His Bundle Pacing(S-HBP)without requiring surgical closure.The mechanisms behind the appearance and resolution of the crochetage sign remain unclear.The authors observed the dis-appearance of the crochetage sign post-S-HBP,suggesting a possible correlation between these specific R waves and the cardiac conduction system.This editorial aims to explore various types of ASD and their relationship with the cardiac con-duction system,highlighting the diagnostic significance of the crochetage sign in ASD.展开更多
BACKGROUND Cardiac conduction disorders and electrocardiographic(ECG)changes may occur as a manifestation of coronavirus disease 2019(COVID-19),especially in severe cases.AIM To describe conduction system disorders an...BACKGROUND Cardiac conduction disorders and electrocardiographic(ECG)changes may occur as a manifestation of coronavirus disease 2019(COVID-19),especially in severe cases.AIM To describe conduction system disorders and their association with other electrocardiographic parameters in patients who died of COVID-19.METHODS In this cross-sectional study,electrocardiographic and clinical data of 432 patients who expired from COVID-19 between August 1st,2021,and December 1st,2021,in a tertiary hospital were reviewed.RESULTS Among 432 patients who died from COVID-19,atrioventricular block(AVB)was found in 40(9.3%).Among these 40 patients,28(6.5%)suffered from 1st degree AVB,and 12(2.8%)suffered from complete heart block(CHB).Changes in ST-T wave,compatible with myocardial infarction or localized myocarditis,appeared in 189(59.0%).Findings compatible with myocardial injury,such as fragmented QRS and prolonged QTc,were found in 91 patients(21.1%)and 28 patients(6.5%),respectively.In patients who died of COVID-19,conduction disorder was unrelated to any underlying medical condition.Fragmented QRS,axis deviation,and ST-T changes were significantly related to conduction system disorder in patients who died of COVID-19(P value<0.05).CONCLUSION Conduction system disorders are associated with several other ECG abnormalities,especially those indicative of myocardial ischemia or inflammation.Most patients(73.14%)who died of COVID-19 demonstrated at least one ECG abnormality parameter.Since a COVID-19 patient's ECG gives important information regarding their cardiac health,our findings can help develop a risk stratification method for at-risk COVID-19 patients in future studies.展开更多
Objective：To isolate ceils of cardiac conduction system （CCS） with laser capture microdissec tion （LCM） and extract and evaluate quality of small amount of RNA from ceils of CCS. Methods： Cryo star sections were...Objective：To isolate ceils of cardiac conduction system （CCS） with laser capture microdissec tion （LCM） and extract and evaluate quality of small amount of RNA from ceils of CCS. Methods： Cryo star sections were followed by H-E staining. 20 pieces of H-E stained eryostat sections were scraped and its RNA was assessed to insure that RNA didn＇t degrade in dyeing and dehydration process. Ceils of CCS were captured with LCM and quality of small amount of RNA was verified with RT-PCR. Results： Ceils of CCS isolated with LCM had clear morphology after staining. High quality RNA was extracted from LCM samples and scraped tissues; 18S rRNA and 28S rRNA were seen distinctly on gel eleetrophoresis. Low level of small amount of RNA extracted from LCM sample was below the limit of detection on gel eleetrophoresis or ultraviolet speetrophotometer. The housekeeping genes β-aetin and GAPDH were successfully amplified with small amount of RNA. Conclusion ：This study resolves the problem of acquiring material of CCS precisely that hinders gene research of CCS. It is found out that the method is easy and reliable to extract and assess the quality of small amount of RNA from mierodisseeted ceils of CCS.展开更多
Cardiac tumors are well described in the literature. The first reports of cardiac tumors date back hundreds of years.The prevalence of primary cardiac tumors at autopsy ranges from 0.001% to 0.3% with secondary tu... Cardiac tumors are well described in the literature. The first reports of cardiac tumors date back hundreds of years.The prevalence of primary cardiac tumors at autopsy ranges from 0.001% to 0.3% with secondary tumors more common than in primary tumors. ……展开更多
Anatomical features of portions of the conduction system in connection with parameters and shape of the heart, ventricles and parts of the IVS （interventricular septum） were studied on 501 specimens oh human hearts ...Anatomical features of portions of the conduction system in connection with parameters and shape of the heart, ventricles and parts of the IVS （interventricular septum） were studied on 501 specimens oh human hearts of both sexes and different ages using common morphological methods. In prenatal and postnatal periods of ontogenesis are similar variants of the structure of the ventricles of the heart with certain proportions of the linear dimensions inflow and outflow sections, parameters parts of IVS. Each of options of structural organization of heart ventricles and its IVS corresponds to set of specific features of portions of cardiac conduction system, signifying change of the positional angles, linear dimensions and shape.展开更多
Objectives This randomized study was designed to compare the safety and efficacy of intravenous diltiazem versus intravenous cedilanid-D （deslanoside） for ventricular rate control in patients with atrial fibrillati...Objectives This randomized study was designed to compare the safety and efficacy of intravenous diltiazem versus intravenous cedilanid-D （deslanoside） for ventricular rate control in patients with atrial fibrillation （AF）. Analysis of the effect on conduction system of these drugs was also performed. Methods Forty three patients with AF were randomly assigned to receive intravenous therapy with 0.25mg/kg diltiazem （n = 21） or 0.4rag cedilanid-D （n = 22）. If not effective at 120 minutes （〈 20% decrease in pretreatment ventricular rate or can not convert to sinus rhythm= another dose of diltiazem or 0.2mg cedilanid-D was administered. Blood pressure and electrocardiographic recordings were performed before and after 5, 10, 20, 30, 60 minutes of drug administration. Further recordings were performed at 120 minutes in noneffective patients, and at 180 minutes in patients who received second time drug administration. To evaluate the effect on conduction system of these two drugs by measuring PA, AH and HV intervals using His bundle electrogram test another nineteen sinus rhythm patients were randomized to dihiazem （n=9） and cedilanid （n= 10） group. His bundle electrogram recordings were performed before and after 5, 10, 20 and 30 minutes of drug administration. Statistical significance was assessed with the use of t test, Fisher＇s exact test, ANOVA and LSD methodology. Results At baseline and after 5, 10, 20, 30, 60 minutes of drug administration the heart rates （mean±SD） were（133±15）, （92±20）, （87±22）, （85 ±20）, （85±21）, （85 ±23）beats/minute in diltiazem group respectively and（ 140±21 ）, （ 122±24）, （118±25）, （110±26）, （112±25）, （110±28） beats/ minute in cedilanid-D group respectively. Heart rate reduction was higher in diltiazem group than cedilanid group during 5 （41±20 vs 17±14,P 〈 0.01）; 10 （46±21 vs 22±20, P〈0.01）; 20 （48±21 vs 29±22, P〈0.01 ） ; 30（48±22 vs 27±22,P〈0.01 ）and 60 minutes （48±23 vs 29±24, P〈 0.05）. Both drugs had no effect on both systolic and diastolic blood pressure （P 〉0.05） and no major side effects were noticed. Diltiazem maintained effective ventrieular rate in 20 patients, whereas eedilanid-D maintained in 15 patients within 180 minutes （95.2%vs 68.2%,P〈 0.05）. There were no statistical significance in baseline heart rate, age and weight between the two groups. Both diltiazem and cedilanid-D can increase AH interval, but have no effect on HV and PA intervals in sinus rhythm patients. Conclusions Both dihiazem and eedilanid-D decrease ventrieular heart rate, but heart rate reduction is significantly higher in diltiazem group, thus should be considered as a drug of choice for emergency control of ventrieular rate. Under clinical monitoring this dose of diltiazem seems to be safe and applicable in AF patients with congestive heart failure. Both drugs have no effect on PA and HV intervals but increase the AH interval thereby can reduce ventricular rate.展开更多
Taking the Lindemann model as a sample system in which there exist chemical reactions, diffusion and heat conduction, we found the theoretical framework of linear stability analysis for a unidimensional nonhomogeneous...Taking the Lindemann model as a sample system in which there exist chemical reactions, diffusion and heat conduction, we found the theoretical framework of linear stability analysis for a unidimensional nonhomogeneous two-variable system with one end subject to Dirichlet conditions, while the other end no-flux conditions. Furthermore, the conditions for the emergence of temperature waves are found out by the linear stability analysis and verified by a diagram for successive steps of evolution of spatial profile of temperature during a period that is plotted by numerical simulations on a computer. Without doubt, these results are in favor of the heat balance in chemical reactor designs.展开更多
BACKGROUND Recurrence of atrial fibrillation(AF)is common in patients with persistent AF even after multiple ablation procedures.His-Purkinje conduction system pacing(HPCSP)combined with atrioventricular node ablation...BACKGROUND Recurrence of atrial fibrillation(AF)is common in patients with persistent AF even after multiple ablation procedures.His-Purkinje conduction system pacing(HPCSP)combined with atrioventricular node ablation(AVNA)is effective in managing patients with AF and heart failure.This study aimed to determine whether HPCSP combined with AVNA can improve quality of life and alleviate symptoms in older patients with symptomatic persistent AF refractory to multiple ablation procedures,as well as evaluate the feasibility and safety of this therapy.METHODS Older patients(≥65 years)with symptomatic persistent AF refractory to at least two ablation procedures were treated with combined HPCSP and AVNA.The success rates and complications were recorded.Pacing parameters,European Heart Rhythm Association(EHRA)scores,and Atrial Fibrillation Effect on Quality-of-Life(AFEQT)scores obtained perioperatively were compared with those recorded at the 6-month follow-up examination.RESULTS Thirty-one patients were enrolled;of those,only thirty patients were eventually treated with AVNA because one patient developed a complete atrioventricular block following the withdrawal of the His bundle pacing lead.The success rates were 100%for HPCSP(22 cases with His bundle pacing,and 9 cases with left bundle branch pacing)and 93.3%(28/30)for AVNA,respectively.By the 6-month follow-up examination,EHRA scores improved significantly(3.00±0.73 vs.2.44±0.63,P=0.014)and AFEQT scores increased markedly(49.6±20.6 vs.70.9±14.0,P=0.001).No severe complications developed.CONCLUSIONS When used in older patients with symptomatic persistent AF refractory to multiple ablation procedures,HPCSP combined with AVNA significantly alleviated symptoms and improved quality of life during short-term follow-up.This therapy was proved to be safe and effective in this patient population.展开更多
Tumors of the cardiac conduction system(CCS) have rarely been reported. The CCS from 198 cardiac-related deaths(Group Ⅰ) ,and 838 deaths from non-cardiovascular diseases or trauma(Group Ⅱ) ,were studied. Sampling wa...Tumors of the cardiac conduction system(CCS) have rarely been reported. The CCS from 198 cardiac-related deaths(Group Ⅰ) ,and 838 deaths from non-cardiovascular diseases or trauma(Group Ⅱ) ,were studied. Sampling was done of the sinoatrial node(SAN) and atrio-ventricular node(AVN) along their long axis of each node as a single block and the His bundle(HB) perpendicular to its long axis in 2-4 blocks. Five-micron serial sections were made;tissue slices were taken intermittently,every 20th from the SAN,every 10th from the AVN,and every 30th from the HB and bundle branches(BB) ,by continuous slices three times. Tumors in the CCS were found in 12 cases(1.155 %) ,where 10(0.965%) were primary tumors,and 2(0.193%) were metastatic tumors. The primary tumors included 4 fibromata compressing the HB(0.386 %) ,4 hemangiomata(0.386%) ,1 AVN tumor(0.097 %) ,and 1 rhabdomyoma(0.097 %) . In 8 of the 10 cases,the tumors were located in the AVN or HB. The metastatic tumors originated from lymphocytic leukemia and malignant lymphoma(histiocytic type) in lung,and were all found in the SAN. Of the 12 cases,2 were from the group Ⅰ. Tumors in the CCS are the smallest tumors in different parts of the body,which can cause sudden death.展开更多
By means of a stochastic model suggested in this paper for the systems with local non-equilibrium excited thermal fluctuations, the famous Shannon entropy is extended to include the heat conduction processes controlle...By means of a stochastic model suggested in this paper for the systems with local non-equilibrium excited thermal fluctuations, the famous Shannon entropy is extended to include the heat conduction processes controlled externally by boundary constraints of constant temperature gradients at two sides.Meanwhile,using the description of master equation for the continuous Markov processes a balance equation of stochastic entropy production valid for one dimension gaseous heat conduction systems with high values of Prandtl number has been also established.Based on it,a general expression for both the stochastic entropy production and the entropy production of fluctuations have been further deduced by theΩ-expansions.In this formalism,all kinds of stochastic contributions to the dissipation from the non-equilibrium thermal fluctuation and internal noise turn explicit.展开更多
Gels and conductive polymer composites,including hydrogen bonds(HBs),have emerged as promising materials for electro-magnetic wave(EMW)absorption across various applications.However,the relationship between conduction...Gels and conductive polymer composites,including hydrogen bonds(HBs),have emerged as promising materials for electro-magnetic wave(EMW)absorption across various applications.However,the relationship between conduction loss in EMW-absorbing materials and charge transfer in HB remains to be fully understood.In this study,we developed a series of deep eutectic gels to fine-tune the quantity of HB by adjusting the molar ratio of choline chloride(ChCl)and ethylene glycol(EG).Owing to the unique properties of deep eutectic gels,the effects of magnetic loss and polarization loss on EMW attenuation can be disregarded.Our results indicate that the quantity of HB initially increases and then decreases with the introduction of EG,with HB-induced conductive loss following similar pat-terns.At a ChCl and EG molar ratio of 2.4,the gel labeled G22-CE2.4 exhibited the best EMW absorption performance,characterized by an effective absorption bandwidth of 8.50 GHz and a thickness of 2.54 mm.This superior performance is attributed to the synergistic ef-fects of excellent conductive loss and impedance matching generated by the optimal number of HB.This work elucidates the role of HB in dielectric loss for the first time and provides valuable insights into the optimal design of supramolecular polymer absorbers.展开更多
A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety problems.Our study addresses the...A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety problems.Our study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves conductivity.mPR-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain dispersion.Integrating this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 cycles.In situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen reactions.Ex situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability tests.The present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.展开更多
To develop proton-conducting materials with high hydrothermal and acid-base stability and to elucidate the proton-transport mechanism through visualized structural analysis,two new lanthanum phosphite-oxalates with 3D...To develop proton-conducting materials with high hydrothermal and acid-base stability and to elucidate the proton-transport mechanism through visualized structural analysis,two new lanthanum phosphite-oxalates with 3D frameworks,designated as[La(HPO_(3))(C_(2)O_(4))0.5(H_(2)O)_(2)](La‑1)and(C_(6)H_(16)N_(2))(H_(3)O)[La_(2)(H_(2)PO_(3))_(3)(C_(2)O_(4))_(3)(H_(2)O)](La‑2)(C_(6)H_(14)N_(2)=cis-2,6-dimethylpiperazine),were prepared by hydrothermal and solvothermal conduction,respectively.La‑1 was constructed with lanthanum phosphite 2D layers and C_(2)O_(4)^(2-)groups,whereas La‑2 was constructed with lanthanum oxalate 2D layers and H_(2)PO^(3-)groups.Alternating current(AC)impedance spectra indicate that the pro-ton conductivities of both compounds could reach 10^(-4)S·cm^(-1)and remain highly durable at 75℃and 98%of rela-tive humidity(RH).Due to the abundance of H-bonds in La‑2,theσof La‑2 was higher than that of La‑1.La‑1 exhibited excellent water and pH stability.CCDC:2439965,La‑1;443776,La‑2.展开更多
The incidence of new-onset cardiac conduction disturbances following transcatheter aortic valve implantation(TAVI)has not decreased compared to other complications,and nowadays is by far the most frequent drawback fol...The incidence of new-onset cardiac conduction disturbances following transcatheter aortic valve implantation(TAVI)has not decreased compared to other complications,and nowadays is by far the most frequent drawback following the procedure.Meanwhile,the global management of TAVI recipients has led to a minimalist approach with short postprocedural length of stay,which may be limited by the occurrence of late arrhythmic events in patients at high-risk.This review focuses on those strategies to overcome the conundrum between early discharge and new-onset conduction disturbances in elderly TAVI candidates and provides a perspective on future improvements in this field.展开更多
Objective:Arrhythmia-induced cardiomyopathy(AIC)is a reversible dilated cardiomyopathy induced by rapid or irregular heartbeat.Acupuncture has a long history of use in the treatment of cardiac diseases,and Xinshu(BL15...Objective:Arrhythmia-induced cardiomyopathy(AIC)is a reversible dilated cardiomyopathy induced by rapid or irregular heartbeat.Acupuncture has a long history of use in the treatment of cardiac diseases,and Xinshu(BL15)is a key acupoint.However,the underlying mechanism of acupuncture at BL15 in the treatment of AIC has not yet been elucidated.Methods:AIC was induced in adult male Sprague-Dawley(SD)rats by continuous administration of acetylcholine(ACh)-CaCl2 and treatment with electroacupuncture(EA)at bilateral BL15.Echocardiography was used to evaluate cardiac function;the rotarod test for motor coordination and performance;hematoxylin and eosin(HE)staining for the morphology of ventricles;electrocardiogram for susceptibility,inducibility,and duration of atrial fibrillation(AF);and electrical and optical mapping in isolated rat hearts maintained by the Langendorff perfusion system for electrical conduction and intracellular handling,respectively.Reverse transcription quantitative polymerase chain reaction(RT-qPCR)and Western blotting were used to determine the levels of cardiac conduction and intracellular calcium-handling proteins in the ventricle.Results:The results showed that EA improved the ejection factor and morphological indices on echocardiography,restored motor coordination and performance,and alleviated ventricular dilation and AF onset.EA alleviates atrial conduction disorders,shortens APD80,and decreases calcium handling in rats with AIC.Cx43 was downregulated and CaMKII was upregulated,and both effects were reversed by EA treatment.Conclusion:Our study provides a novel AIC model with abnormal electrical propagation and calcium handling that can be protected by EA at BL15.This potential mechanism may be associated with the modulation of Cx43 and CaMKII expression.展开更多
Exploring a new and robust material for proton conduction is of significant importance to the scientific interest and technological importance.Polyoxometalates(POMs)are a class of molecular anion metal oxide clusters ...Exploring a new and robust material for proton conduction is of significant importance to the scientific interest and technological importance.Polyoxometalates(POMs)are a class of molecular anion metal oxide clusters with well-defined structures and diverse properties.Therefore,the design and synthesis of a POM-based material for proton conduction is extremely vital.Herein,a dimeric four tartaric acid-bridged tetra-Zr-incorporated arsenotungstate.展开更多
After millions of years of natural evolution,horsetails have evolved unique stem structures that enable survival in harsh environments.Inspired by the cross-sectional characteristics of horsetail stems,a series of bio...After millions of years of natural evolution,horsetails have evolved unique stem structures that enable survival in harsh environments.Inspired by the cross-sectional characteristics of horsetail stems,a series of bioinspired sandwich structures were designed and fabricated using the laser powder bed fusion(LPBF)process.By combining experimental and finite element simulation methods,the formability,mechanical properties,deformation behavior,and thermal conduction performance of these structures were determined.Results show that the surface morphology of the bioinspired sandwich structures was smooth,with no cracks observed.The bioinspired sandwich structure with an inner tube diameter of 1.9 mm(D_(1.9))exhibited optimal comprehensive mechanical properties,with a specific strength of 64.2 MPa/(g/cm^(3)),and specific energy absorption of 3.3 J/g.Stress distribution results revealed that the D_(1.9)structures had the most uniform stress distribution.Furthermore,increasing the internal conduction paths improved heat transfer;therefore,the thermal conductivities of the D_(1.4),D_(1.9),and D_(2.4)structures were higher than that of the D0 structure.This study demonstrates that a bioinspired design approach,combined with additive manufacturing technology,enables the development of high-performance structures with both load-bearing and thermally insulating capabilities.展开更多
Aiming at the problem that the bit error rate(BER)of asymmetrically clipped optical orthogonal frequency division multiplexing(ACO-OFDM)space optical communication system is significantly affected by different turbule...Aiming at the problem that the bit error rate(BER)of asymmetrically clipped optical orthogonal frequency division multiplexing(ACO-OFDM)space optical communication system is significantly affected by different turbulence intensities,the deep learning technique is proposed to the polarization code decoding in ACO-OFDM space optical communication system.Moreover,this system realizes the polarization code decoding and signal demodulation without frequency conduction with superior performance and robustness compared with the performance of traditional decoder.Simulations under different turbulence intensities as well as different mapping orders show that the convolutional neural network(CNN)decoder trained under weak-medium-strong turbulence atmospheric channels achieves a performance improvement of about 10^(2)compared to the conventional decoder at 4-quadrature amplitude modulation(4QAM),and the BERs for both 16QAM and 64QAM are in between those of the conventional decoder.展开更多
Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)is considered to be the most potential light-absorbing material to replace CuInGaSe_(2)(CIGS),but the actual photoelectric conversion efficiency of such cells is much lower than that of CIG...Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)is considered to be the most potential light-absorbing material to replace CuInGaSe_(2)(CIGS),but the actual photoelectric conversion efficiency of such cells is much lower than that of CIGS.One of the reasons is the high recombination rate of carriers at the interface.In this paper,in order to reduce the carrier recombination,a new solar cell structure with double absorber layers of Al-doped ZnO(AZO)/intrinsic(i)-ZnO/CdS/CZTS_(x1)Se_(1−x1)(CZTSSe_(1))/CZTS_(x2)Se_(1−x2)(CZTSSe_(2))/Mo was proposed,and the optimal conduction band offsets(CBOs)of CdS/CZTSSe_(1) interface and CZTSSe_(1)/CZTSSe_(2) interface were determined by changing the S ratio in CZTSSe_(1) and CZTSSe_(2),and the effect of thickness of CZTSSe_(1) on the performance of the cell was studied.The efficiencies of the optimized single and double absorber layers reached 17.97%and 23.4%,respectively.Compared with the single absorber layer structure,the proposed structure with double absorber layers has better cell performance.展开更多
文摘Pacing-induced cardiomyopathy (PICM) resultsf rom the detrimental effect of frequent right ventricular pacing.^([1]) The diagnosis relies on a combination of pacing-associated ventricular dyschrony manifested with ECG wide LBBB-pattern QRS duration and clinical assessment, imaging studies. Conduction system pacing (CSP), such as His bundle pacing (HBP)and left bundle branch pacing (LBBP), may help to prevent PICM,^([2]) but the criteria for optimal patient selection remain inadequately defined.
基金Supported by Guangzhou Municipal Science and Technology Bureau's 2024 Basic and Applied Basic Research Topic,China,No.2024A04J4491,and No.2024A04J4254the Scientific Research Project of Guangdong Provincial Bureau of Traditional Chinese Medicine,China,No.2022ZYYJ01the Soft Science Research Program of Luohu District,Shenzhen,China,No.LX202402016.
文摘The case report presented in this edition by Mu et al.The report presents a case of atrial septal defect(ASD)associated with electrocardiographic changes,noting that the crochetage sign resolved after Selective His Bundle Pacing(S-HBP)without requiring surgical closure.The mechanisms behind the appearance and resolution of the crochetage sign remain unclear.The authors observed the dis-appearance of the crochetage sign post-S-HBP,suggesting a possible correlation between these specific R waves and the cardiac conduction system.This editorial aims to explore various types of ASD and their relationship with the cardiac con-duction system,highlighting the diagnostic significance of the crochetage sign in ASD.
文摘BACKGROUND Cardiac conduction disorders and electrocardiographic(ECG)changes may occur as a manifestation of coronavirus disease 2019(COVID-19),especially in severe cases.AIM To describe conduction system disorders and their association with other electrocardiographic parameters in patients who died of COVID-19.METHODS In this cross-sectional study,electrocardiographic and clinical data of 432 patients who expired from COVID-19 between August 1st,2021,and December 1st,2021,in a tertiary hospital were reviewed.RESULTS Among 432 patients who died from COVID-19,atrioventricular block(AVB)was found in 40(9.3%).Among these 40 patients,28(6.5%)suffered from 1st degree AVB,and 12(2.8%)suffered from complete heart block(CHB).Changes in ST-T wave,compatible with myocardial infarction or localized myocarditis,appeared in 189(59.0%).Findings compatible with myocardial injury,such as fragmented QRS and prolonged QTc,were found in 91 patients(21.1%)and 28 patients(6.5%),respectively.In patients who died of COVID-19,conduction disorder was unrelated to any underlying medical condition.Fragmented QRS,axis deviation,and ST-T changes were significantly related to conduction system disorder in patients who died of COVID-19(P value<0.05).CONCLUSION Conduction system disorders are associated with several other ECG abnormalities,especially those indicative of myocardial ischemia or inflammation.Most patients(73.14%)who died of COVID-19 demonstrated at least one ECG abnormality parameter.Since a COVID-19 patient's ECG gives important information regarding their cardiac health,our findings can help develop a risk stratification method for at-risk COVID-19 patients in future studies.
文摘Objective：To isolate ceils of cardiac conduction system （CCS） with laser capture microdissec tion （LCM） and extract and evaluate quality of small amount of RNA from ceils of CCS. Methods： Cryo star sections were followed by H-E staining. 20 pieces of H-E stained eryostat sections were scraped and its RNA was assessed to insure that RNA didn＇t degrade in dyeing and dehydration process. Ceils of CCS were captured with LCM and quality of small amount of RNA was verified with RT-PCR. Results： Ceils of CCS isolated with LCM had clear morphology after staining. High quality RNA was extracted from LCM samples and scraped tissues; 18S rRNA and 28S rRNA were seen distinctly on gel eleetrophoresis. Low level of small amount of RNA extracted from LCM sample was below the limit of detection on gel eleetrophoresis or ultraviolet speetrophotometer. The housekeeping genes β-aetin and GAPDH were successfully amplified with small amount of RNA. Conclusion ：This study resolves the problem of acquiring material of CCS precisely that hinders gene research of CCS. It is found out that the method is easy and reliable to extract and assess the quality of small amount of RNA from mierodisseeted ceils of CCS.
文摘 Cardiac tumors are well described in the literature. The first reports of cardiac tumors date back hundreds of years.The prevalence of primary cardiac tumors at autopsy ranges from 0.001% to 0.3% with secondary tumors more common than in primary tumors. ……
文摘Anatomical features of portions of the conduction system in connection with parameters and shape of the heart, ventricles and parts of the IVS （interventricular septum） were studied on 501 specimens oh human hearts of both sexes and different ages using common morphological methods. In prenatal and postnatal periods of ontogenesis are similar variants of the structure of the ventricles of the heart with certain proportions of the linear dimensions inflow and outflow sections, parameters parts of IVS. Each of options of structural organization of heart ventricles and its IVS corresponds to set of specific features of portions of cardiac conduction system, signifying change of the positional angles, linear dimensions and shape.
文摘Objectives This randomized study was designed to compare the safety and efficacy of intravenous diltiazem versus intravenous cedilanid-D （deslanoside） for ventricular rate control in patients with atrial fibrillation （AF）. Analysis of the effect on conduction system of these drugs was also performed. Methods Forty three patients with AF were randomly assigned to receive intravenous therapy with 0.25mg/kg diltiazem （n = 21） or 0.4rag cedilanid-D （n = 22）. If not effective at 120 minutes （〈 20% decrease in pretreatment ventricular rate or can not convert to sinus rhythm= another dose of diltiazem or 0.2mg cedilanid-D was administered. Blood pressure and electrocardiographic recordings were performed before and after 5, 10, 20, 30, 60 minutes of drug administration. Further recordings were performed at 120 minutes in noneffective patients, and at 180 minutes in patients who received second time drug administration. To evaluate the effect on conduction system of these two drugs by measuring PA, AH and HV intervals using His bundle electrogram test another nineteen sinus rhythm patients were randomized to dihiazem （n=9） and cedilanid （n= 10） group. His bundle electrogram recordings were performed before and after 5, 10, 20 and 30 minutes of drug administration. Statistical significance was assessed with the use of t test, Fisher＇s exact test, ANOVA and LSD methodology. Results At baseline and after 5, 10, 20, 30, 60 minutes of drug administration the heart rates （mean±SD） were（133±15）, （92±20）, （87±22）, （85 ±20）, （85±21）, （85 ±23）beats/minute in diltiazem group respectively and（ 140±21 ）, （ 122±24）, （118±25）, （110±26）, （112±25）, （110±28） beats/ minute in cedilanid-D group respectively. Heart rate reduction was higher in diltiazem group than cedilanid group during 5 （41±20 vs 17±14,P 〈 0.01）; 10 （46±21 vs 22±20, P〈0.01）; 20 （48±21 vs 29±22, P〈0.01 ） ; 30（48±22 vs 27±22,P〈0.01 ）and 60 minutes （48±23 vs 29±24, P〈 0.05）. Both drugs had no effect on both systolic and diastolic blood pressure （P 〉0.05） and no major side effects were noticed. Diltiazem maintained effective ventrieular rate in 20 patients, whereas eedilanid-D maintained in 15 patients within 180 minutes （95.2%vs 68.2%,P〈 0.05）. There were no statistical significance in baseline heart rate, age and weight between the two groups. Both diltiazem and cedilanid-D can increase AH interval, but have no effect on HV and PA intervals in sinus rhythm patients. Conclusions Both dihiazem and eedilanid-D decrease ventrieular heart rate, but heart rate reduction is significantly higher in diltiazem group, thus should be considered as a drug of choice for emergency control of ventrieular rate. Under clinical monitoring this dose of diltiazem seems to be safe and applicable in AF patients with congestive heart failure. Both drugs have no effect on PA and HV intervals but increase the AH interval thereby can reduce ventricular rate.
文摘Taking the Lindemann model as a sample system in which there exist chemical reactions, diffusion and heat conduction, we found the theoretical framework of linear stability analysis for a unidimensional nonhomogeneous two-variable system with one end subject to Dirichlet conditions, while the other end no-flux conditions. Furthermore, the conditions for the emergence of temperature waves are found out by the linear stability analysis and verified by a diagram for successive steps of evolution of spatial profile of temperature during a period that is plotted by numerical simulations on a computer. Without doubt, these results are in favor of the heat balance in chemical reactor designs.
基金the Beijing Natural Science Foundation(No.7202050)the Project of Hebei Province Medical Science Research(No.20210483).
文摘BACKGROUND Recurrence of atrial fibrillation(AF)is common in patients with persistent AF even after multiple ablation procedures.His-Purkinje conduction system pacing(HPCSP)combined with atrioventricular node ablation(AVNA)is effective in managing patients with AF and heart failure.This study aimed to determine whether HPCSP combined with AVNA can improve quality of life and alleviate symptoms in older patients with symptomatic persistent AF refractory to multiple ablation procedures,as well as evaluate the feasibility and safety of this therapy.METHODS Older patients(≥65 years)with symptomatic persistent AF refractory to at least two ablation procedures were treated with combined HPCSP and AVNA.The success rates and complications were recorded.Pacing parameters,European Heart Rhythm Association(EHRA)scores,and Atrial Fibrillation Effect on Quality-of-Life(AFEQT)scores obtained perioperatively were compared with those recorded at the 6-month follow-up examination.RESULTS Thirty-one patients were enrolled;of those,only thirty patients were eventually treated with AVNA because one patient developed a complete atrioventricular block following the withdrawal of the His bundle pacing lead.The success rates were 100%for HPCSP(22 cases with His bundle pacing,and 9 cases with left bundle branch pacing)and 93.3%(28/30)for AVNA,respectively.By the 6-month follow-up examination,EHRA scores improved significantly(3.00±0.73 vs.2.44±0.63,P=0.014)and AFEQT scores increased markedly(49.6±20.6 vs.70.9±14.0,P=0.001).No severe complications developed.CONCLUSIONS When used in older patients with symptomatic persistent AF refractory to multiple ablation procedures,HPCSP combined with AVNA significantly alleviated symptoms and improved quality of life during short-term follow-up.This therapy was proved to be safe and effective in this patient population.
文摘Tumors of the cardiac conduction system(CCS) have rarely been reported. The CCS from 198 cardiac-related deaths(Group Ⅰ) ,and 838 deaths from non-cardiovascular diseases or trauma(Group Ⅱ) ,were studied. Sampling was done of the sinoatrial node(SAN) and atrio-ventricular node(AVN) along their long axis of each node as a single block and the His bundle(HB) perpendicular to its long axis in 2-4 blocks. Five-micron serial sections were made;tissue slices were taken intermittently,every 20th from the SAN,every 10th from the AVN,and every 30th from the HB and bundle branches(BB) ,by continuous slices three times. Tumors in the CCS were found in 12 cases(1.155 %) ,where 10(0.965%) were primary tumors,and 2(0.193%) were metastatic tumors. The primary tumors included 4 fibromata compressing the HB(0.386 %) ,4 hemangiomata(0.386%) ,1 AVN tumor(0.097 %) ,and 1 rhabdomyoma(0.097 %) . In 8 of the 10 cases,the tumors were located in the AVN or HB. The metastatic tumors originated from lymphocytic leukemia and malignant lymphoma(histiocytic type) in lung,and were all found in the SAN. Of the 12 cases,2 were from the group Ⅰ. Tumors in the CCS are the smallest tumors in different parts of the body,which can cause sudden death.
文摘By means of a stochastic model suggested in this paper for the systems with local non-equilibrium excited thermal fluctuations, the famous Shannon entropy is extended to include the heat conduction processes controlled externally by boundary constraints of constant temperature gradients at two sides.Meanwhile,using the description of master equation for the continuous Markov processes a balance equation of stochastic entropy production valid for one dimension gaseous heat conduction systems with high values of Prandtl number has been also established.Based on it,a general expression for both the stochastic entropy production and the entropy production of fluctuations have been further deduced by theΩ-expansions.In this formalism,all kinds of stochastic contributions to the dissipation from the non-equilibrium thermal fluctuation and internal noise turn explicit.
基金supported by the National Nat-ural Science Foundation of China(Nos.51872238,52074227,and 21806129)the Fundamental Research Funds for the Central Universities,China(Nos.3102018zy045 and 3102019AX11)+2 种基金the Guangdong Basic and Applied Basic Research Foundation,China(No.2024A1515010298)the Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2017JQ5116 and 2020JM-118)the Key Laboratory of Icing and Anti/De-icing of CARDC(No.IADL20220401).
文摘Gels and conductive polymer composites,including hydrogen bonds(HBs),have emerged as promising materials for electro-magnetic wave(EMW)absorption across various applications.However,the relationship between conduction loss in EMW-absorbing materials and charge transfer in HB remains to be fully understood.In this study,we developed a series of deep eutectic gels to fine-tune the quantity of HB by adjusting the molar ratio of choline chloride(ChCl)and ethylene glycol(EG).Owing to the unique properties of deep eutectic gels,the effects of magnetic loss and polarization loss on EMW attenuation can be disregarded.Our results indicate that the quantity of HB initially increases and then decreases with the introduction of EG,with HB-induced conductive loss following similar pat-terns.At a ChCl and EG molar ratio of 2.4,the gel labeled G22-CE2.4 exhibited the best EMW absorption performance,characterized by an effective absorption bandwidth of 8.50 GHz and a thickness of 2.54 mm.This superior performance is attributed to the synergistic ef-fects of excellent conductive loss and impedance matching generated by the optimal number of HB.This work elucidates the role of HB in dielectric loss for the first time and provides valuable insights into the optimal design of supramolecular polymer absorbers.
基金supported by a National Research Foundation of Korea(NRF)Grant funded by the Ministry of Science and ICT(2021R1A2C1014294,2022R1A2C3003319)the BK21 FOUR(Fostering Outstanding Universities for Research)through the National Research Foundation(NRF)of Korea.
文摘A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety problems.Our study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves conductivity.mPR-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain dispersion.Integrating this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 cycles.In situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen reactions.Ex situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability tests.The present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.
文摘To develop proton-conducting materials with high hydrothermal and acid-base stability and to elucidate the proton-transport mechanism through visualized structural analysis,two new lanthanum phosphite-oxalates with 3D frameworks,designated as[La(HPO_(3))(C_(2)O_(4))0.5(H_(2)O)_(2)](La‑1)and(C_(6)H_(16)N_(2))(H_(3)O)[La_(2)(H_(2)PO_(3))_(3)(C_(2)O_(4))_(3)(H_(2)O)](La‑2)(C_(6)H_(14)N_(2)=cis-2,6-dimethylpiperazine),were prepared by hydrothermal and solvothermal conduction,respectively.La‑1 was constructed with lanthanum phosphite 2D layers and C_(2)O_(4)^(2-)groups,whereas La‑2 was constructed with lanthanum oxalate 2D layers and H_(2)PO^(3-)groups.Alternating current(AC)impedance spectra indicate that the pro-ton conductivities of both compounds could reach 10^(-4)S·cm^(-1)and remain highly durable at 75℃and 98%of rela-tive humidity(RH).Due to the abundance of H-bonds in La‑2,theσof La‑2 was higher than that of La‑1.La‑1 exhibited excellent water and pH stability.CCDC:2439965,La‑1;443776,La‑2.
文摘The incidence of new-onset cardiac conduction disturbances following transcatheter aortic valve implantation(TAVI)has not decreased compared to other complications,and nowadays is by far the most frequent drawback following the procedure.Meanwhile,the global management of TAVI recipients has led to a minimalist approach with short postprocedural length of stay,which may be limited by the occurrence of late arrhythmic events in patients at high-risk.This review focuses on those strategies to overcome the conundrum between early discharge and new-onset conduction disturbances in elderly TAVI candidates and provides a perspective on future improvements in this field.
基金supported by the National Key R&D Program of China(2022YFC3500405,2019YFC1712105)The National Science Foundation of China(82374075)+1 种基金The National Comprehensive Traditional Chinese Medicine Reform Demonstration Zone Science and Technology Collaborative Development Project(GZY-KJS-SD-2024-046)Taishan Scholar Youth Project of Shandong Province(tsqn202306188).
文摘Objective:Arrhythmia-induced cardiomyopathy(AIC)is a reversible dilated cardiomyopathy induced by rapid or irregular heartbeat.Acupuncture has a long history of use in the treatment of cardiac diseases,and Xinshu(BL15)is a key acupoint.However,the underlying mechanism of acupuncture at BL15 in the treatment of AIC has not yet been elucidated.Methods:AIC was induced in adult male Sprague-Dawley(SD)rats by continuous administration of acetylcholine(ACh)-CaCl2 and treatment with electroacupuncture(EA)at bilateral BL15.Echocardiography was used to evaluate cardiac function;the rotarod test for motor coordination and performance;hematoxylin and eosin(HE)staining for the morphology of ventricles;electrocardiogram for susceptibility,inducibility,and duration of atrial fibrillation(AF);and electrical and optical mapping in isolated rat hearts maintained by the Langendorff perfusion system for electrical conduction and intracellular handling,respectively.Reverse transcription quantitative polymerase chain reaction(RT-qPCR)and Western blotting were used to determine the levels of cardiac conduction and intracellular calcium-handling proteins in the ventricle.Results:The results showed that EA improved the ejection factor and morphological indices on echocardiography,restored motor coordination and performance,and alleviated ventricular dilation and AF onset.EA alleviates atrial conduction disorders,shortens APD80,and decreases calcium handling in rats with AIC.Cx43 was downregulated and CaMKII was upregulated,and both effects were reversed by EA treatment.Conclusion:Our study provides a novel AIC model with abnormal electrical propagation and calcium handling that can be protected by EA at BL15.This potential mechanism may be associated with the modulation of Cx43 and CaMKII expression.
基金supported by the National Natural Science Foundation of China(Nos.22071043 and 22203027)Shanxi Province Science Foundation(No.202303021211194)the program for the(Reserved)Discipline Leaders of Taiyuan Institute of Technology.
文摘Exploring a new and robust material for proton conduction is of significant importance to the scientific interest and technological importance.Polyoxometalates(POMs)are a class of molecular anion metal oxide clusters with well-defined structures and diverse properties.Therefore,the design and synthesis of a POM-based material for proton conduction is extremely vital.Herein,a dimeric four tartaric acid-bridged tetra-Zr-incorporated arsenotungstate.
基金supported by National Key Research and Development Program of China(Grant No.2021YFB1715400)National Natural Science Foundation of China(Grant No.52225503)+3 种基金Key Research and Development Program of Jiangsu Province(Grant Nos.BE2022069,BE2022069-1)Fundamental Research Funds for the Central Universities(Grant No.NI2024003)National Natural Science Foundation of China for Creative Research Groups(Grant No.51921003)the 15th Batch of“Six Talents Peaks”Innovative Talents Team Program(Grant No.TD-GDZB-001).
文摘After millions of years of natural evolution,horsetails have evolved unique stem structures that enable survival in harsh environments.Inspired by the cross-sectional characteristics of horsetail stems,a series of bioinspired sandwich structures were designed and fabricated using the laser powder bed fusion(LPBF)process.By combining experimental and finite element simulation methods,the formability,mechanical properties,deformation behavior,and thermal conduction performance of these structures were determined.Results show that the surface morphology of the bioinspired sandwich structures was smooth,with no cracks observed.The bioinspired sandwich structure with an inner tube diameter of 1.9 mm(D_(1.9))exhibited optimal comprehensive mechanical properties,with a specific strength of 64.2 MPa/(g/cm^(3)),and specific energy absorption of 3.3 J/g.Stress distribution results revealed that the D_(1.9)structures had the most uniform stress distribution.Furthermore,increasing the internal conduction paths improved heat transfer;therefore,the thermal conductivities of the D_(1.4),D_(1.9),and D_(2.4)structures were higher than that of the D0 structure.This study demonstrates that a bioinspired design approach,combined with additive manufacturing technology,enables the development of high-performance structures with both load-bearing and thermally insulating capabilities.
基金supported by the National Natural Science Foundation of China(No.12104141).
文摘Aiming at the problem that the bit error rate(BER)of asymmetrically clipped optical orthogonal frequency division multiplexing(ACO-OFDM)space optical communication system is significantly affected by different turbulence intensities,the deep learning technique is proposed to the polarization code decoding in ACO-OFDM space optical communication system.Moreover,this system realizes the polarization code decoding and signal demodulation without frequency conduction with superior performance and robustness compared with the performance of traditional decoder.Simulations under different turbulence intensities as well as different mapping orders show that the convolutional neural network(CNN)decoder trained under weak-medium-strong turbulence atmospheric channels achieves a performance improvement of about 10^(2)compared to the conventional decoder at 4-quadrature amplitude modulation(4QAM),and the BERs for both 16QAM and 64QAM are in between those of the conventional decoder.
基金supported by the Science and Technology Innovation Development Program(No.70304901).
文摘Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)is considered to be the most potential light-absorbing material to replace CuInGaSe_(2)(CIGS),but the actual photoelectric conversion efficiency of such cells is much lower than that of CIGS.One of the reasons is the high recombination rate of carriers at the interface.In this paper,in order to reduce the carrier recombination,a new solar cell structure with double absorber layers of Al-doped ZnO(AZO)/intrinsic(i)-ZnO/CdS/CZTS_(x1)Se_(1−x1)(CZTSSe_(1))/CZTS_(x2)Se_(1−x2)(CZTSSe_(2))/Mo was proposed,and the optimal conduction band offsets(CBOs)of CdS/CZTSSe_(1) interface and CZTSSe_(1)/CZTSSe_(2) interface were determined by changing the S ratio in CZTSSe_(1) and CZTSSe_(2),and the effect of thickness of CZTSSe_(1) on the performance of the cell was studied.The efficiencies of the optimized single and double absorber layers reached 17.97%and 23.4%,respectively.Compared with the single absorber layer structure,the proposed structure with double absorber layers has better cell performance.
