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The taro harvesting process is affected by a complex system composed of particle mechanics system and multi-body dynamics system. The discrete element method(DEM) can effectively solve the nonlinear problem of the interaction between harvesting components and working materials. Therefore, the discrete element model of taro tiller plants is of great importance for taro harvesting. This paper proposes a simulation method to establish a discrete element flexible plant model and dynamic clamping and pulling process of taro tiller plant. Discrete Element models of taro corm and flexible tiller petiole and leaf were established using DEM method, and the discrete element flexible model of the taro plant was established. Taro clamping and pulling force testing platform was designed and built. The single factor and Plackett-Burman experiments were used to determine the simulation parameters and optimize the taro plant model by taking the correlation coefficient of clamping force and correlation coefficient of pulling force collected from the simulation and the bench experiment as the experiment index. The parameter calibration results of discrete element model of taro plant are as follows: petiole-petiole method/tangential contact stiffness was 8.15×109 N·m-3, and normal/tangential critical stress was 6.65×106 Pa. The contact stiffness of pseudostem- corm method was 1.22×109 N·m-3, the critical stress of normal/tangential was 1.18×105 Pa, and the energy of soil surface was 4.15×106J·m-3. When the pulling speed is 0.1, 0.2, 0.3, 0.4 and 0.5 m·s-1, the correlation coefficients between the simulation experiment and the bench experiment are 0.812, 0.850, 0.770, 0.697 and 0.652, respectively. The average value of correlation coefficient is 0.756, indicating that the simulated discrete element plant model is close to the real plant model. The discrete element model of taro plant established in this paper has high reliability. The final purpose of this paper is to provide a model reference for the design and optimization of taro harvester by discrete element method.
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Objective:To study the epidemiological features of local influenza A(H1N1)pdm09 epidemic strains through analyzing the changes in lineages and to analyze how well the vaccine strains were matched to the circulating strains in Hangzhou.Methods:Of 1 112 clinical specimens from laboratory-confirmed A(H1N1)pdm09 infections in Hangzhou in consecutive seasons from 2009 to 2020, 208 (18.7%) with high viral load (Ct value <30) were randomly selected from 10 influenza epidemics for full-length hemagglutinin gene ( HA) gene sequencing. Genetic variation, evolution and lineage changes of these representative local strains were analyzed by comparison with vaccine strains and reference strains. Results:Since the 2009 pandemic, A(H1N1)pdm09 had become one of the predominant viruses causing seasonal influenza and been reported to co-circulate with influenza A(H3N2) and influenza B viruses in Hangzhou in the past decade. It caused 10 local influenza epidemics in the 12 consecutive seasons from 2009 to 2020. HA gene sequencing revealed complex sources and rapid variation of the local A(H1N1)pdm09 strains. The main epidemic strains often genetically drifted from the recommended northern hemisphere vaccine strains due to lineage changes. Conclusions:This study suggested that it was essential to update the recommended vaccine strains year by year. Besides, enhanced periodic monitoring of influenza A(H1N1)pdm09 strains circulating in the region was important for the prevention and control of influenza A(H1N1)pdm09 infection in the next epidemic season.
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Objective:To analyze the epidemiological and etiological characteristics of dengue fever in Hangzhou in 2018.Methods:RT-PCR was used to detect the nucleic acids and analyze the serotypes of dengue viruses (DENV) in serum samples collected from dengue fever cases. Phylogenetic trees based on the E gene sequences of DENV isolated from the serum samples were then constructed and analyzed. Epidemiological characteristics of these dengue fever cases were analyzed. Results:A total of 80 cases of dengue fever were detected in Hangzhou in 2018 with 55 imported cases and 25 indigenous cases (24 caused by DENV-1 and one by DENV-3). These indigenous cases mainly occurred during late July to early October with people above 50 years old accounting for 68%. Phylogenetic analysis showed that DENV-1 strains isolated from the indigenous cases in Yuhang, Jianggan-Shangcheng and Qiantang districts all belonged to genotype Ⅰ, and were respectively closely related to the strains from Indonesia in 2015, Myanmar in 2017, Ningbo in 2018 and Hangzhou imported cases from Thailand in 2018. The indigenous DENV-3 strain belonged to genotype Ⅲ, and shared 99.5% homology with the Singapore strain in 2013.Conclusions:Imported cases accounted for a large fraction of the dengue fever cases in Hangzhou, which brought a high risk to indigenous outbreak. Due to multiple imported cases, the current epidemic presented a characteristic of multiple small-scale outbreaks.
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BACKGROUND@#The good prognosis of lepidic predominant invasive adenocarcinoma (LPA) and adenocarcinoma in situ (AIS)/microinvasive adenocarcinoma (MIA) in the pathological subtypes of early lung adenocarcinoma is similar, and the means to distinguish LPA from non-LPA is urgently needed in clinical practice. This study intends to analyze the correlation between positron emission computed tomography (PET)/computed tomography (CT) maximal standard uptake value (SUVmax) with CT three-dimensional reconstruction parameters and the pathological subtypes of early lung adenocarcinoma with part-solid nodules (PSNs) in preoperative imaging.@*METHODS@#The data of early lung adenocarcinoma patients who underwent anatomical pneumonectomy at the Department of Thoracic Surgery of Northern Jiangsu People's Hospital from January 2016 to January 2019 retrospectively analyzed and subsolid nodules on imaging were showed. All patients with enhanced chest CT and PET/CT data can be obtained completely, using Mimics software to perform three-dimensional reconstruction to obtain tumor volume, 3-dimensional mean-CT value (3Dm-CT) of tumor and SUVmax, using SPSS 25.0 for statistical analysis and GraphPad Prism 8.3.0 for drawing receiver operating curve (ROC). P0.7 were included in the multivariate ROC curve analysis, and the joint predictor (AUC=0.835) was obtained with medium or above predictive value.@*CONCLUSIONS@#PET/CT SUVmax and CT three-dimensional reconstruction parameters have a significant correlation with the different pathological subtypes of early lung adenocarcinoma with PSNs in imaging. The combination of SUVmax, tumor volume, ground glass component volume and 3Dm-CT of solid/ground glass component CT value has certain value in identifying the pathological subtype of early stage lung adenocarcinoma with PSNs nodules in imaging.
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The adaptive immunity that protects patients from coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is not well characterized. In particular, the asymptomatic patients have been found to induce weak and transient SARS-CoV-2 antibody responses, but the underlying mechanisms remain unknown; meanwhile, the protective immunity that guide the recovery of these asymptomatic patients is also not well studied. Here, we characterized SARS-CoV-2-specific B-cell and T-cell responses in 10 asymptomatic patients and 49 patients with other disease severity (mild, n = 10, moderate, n = 32, severe, n = 7) and found that asymptomatic or mild symptomatic patients failed to mount virus-specific germinal center (GC) B cell responses that result in robust and long-term humoral immunity, assessed by GC response indicators including follicular helper T (TFH) cell and memory B cell responses as well as serum CXCL13 levels. Alternatively, these patients mounted potent virus-specific TH1 and CD8+ T cell responses. In sharp contrast, patients of moderate or severe disease induced vigorous virus-specific GC B cell responses and associated TFH responses; however, the virus-specific TH1 and CD8+ T cells were minimally induced in these patients. These results therefore uncovered the protective immunity in COVID-19 patients and revealed the strikingly dichotomous and incomplete adaptive immunity in COVID-19 patients with different disease severity, providing important insights into rational design of COVID-19 vaccines.
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COVID-19 patients exhibit differential disease severity after SARS-CoV-2 infection. It is currently unknown as to the correlation between the magnitude of neutralizing antibody (NAb) responses and the disease severity in COVID-19 patients. In a cohort of 59 recovered patients with disease severity including severe, moderate, mild and asymptomatic, we observed the positive correlation between serum neutralizing capacity and disease severity, in particular, the highest NAb capacity in sera from the patients with severe disease, while a lack of ability of asymptomatic patients to mount competent NAbs. Furthermore, the compositions of NAb subtypes were also different between recovered patients with severe symptoms and with mild-to-moderate symptoms. These results reveal the tremendous heterogeneity of SARS-CoV-2-specific NAb responses and their correlations to disease severity, highlighting the needs of future vaccination in COVID-19 patients recovered from asymptomatic or mild illness.
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Lung cancer is one of the most common cancers in the world,which seriously affects people's physical and mental health.About 85％ of them are non-small cell lung cancers.In recent years,with the rapid development of low-dose computed tomography,Da Vinci robotic surgery and targeted therapy,the therapeutic effect of lung cancer has been greatly improved.However,due to the lack of early diagnosis of biomarkers,therapeutic targets and signs of prognosis,most patients have metastases when they are at the time of treatment.Lung cancer remains the leading cause of cancer-related death.CircRNA is a special endogenous non coding RNA,which is formed by the reverse splicing of the 3'splice donor site and the 5'splice acceptor site to form a covalent closed loop.It is highly conservative and stable.The expression level of circRNA in non-small cell lung cancer is obviously abnormal,which is closely related to the occurrence,development and metastasis of non-small cell lung cancer.It is expected to become an ideal biomarker,which is used for early diagnosis of non-small cell lung cancer,and provides new therapeutic targets and prognostic markers.
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Tissue engineering has already become an important research direction of trachea substitute; the construction of the scaffold is one of the key factors for a tissue engineering trachea .With the development and the maturity of the technology of 3D-printing, the design and manufacture of the tissue engineered scaffold is widely broadened, various types of 3D-printed scaffold are researched constantly.This review aims to summarize and evaluates the latest progress of the experiments about 3D-printed tissue engineering scaffold.
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Objective@#To explored the bio-compatibility and cartilage regeneration of the rabbits genipin cross-linked decellularized scaffold, to provide experimental and theoretical support for the clinical application of genipin cross-linked decellularized scaffold.@*Methods@#Detergent-enzyme method was used to prepare decellularized tracheal scaffolds. Cellular content of native trachea and decellularized trachea were compared by 4′, 6-diamidino-2-phenylindole(DAPI) staining. Masson trichrome staining was used to compare the histological structure of the progenitor tube, decellularized trachea, and genipin cross-linked decellularized trachea. Nine adult New Zealand white rabbits were randomly divided into autologous tracheal transplantation group (negative control group), allogeneic tracheal transplantation group (positive control group), and genipin cross-linked decellularized tracheal transplantation group (experimental group). Autologous bone marrow mesenchymal stem cells were implanted on the surface of trachea in each group. The blood cells and type II collagen were detected to compare the inflammatory response and chondrocyte regeneration after tracheal orthotopic transplantation in the three groups.@*Results@#After DAPI staining and light microscope observation (×200), the cell content of the acellular 7-cycle trachea [(143.0 ± 71.1) cells/field] was significantly lower than that of the native trachea [(853.5 ± 149.6) cells/field], and the difference was statistically significant (P<0.001). Masson′s trichrome staining showed that the tissue structure of genipin cross-linked decellularized trachea was more complete. Blood cell analysis and type II collagen test results showed that genipin cross-linked decellularized trachea transplanted with bone marrow mesenchymal stem cells after transplantation in situ has little rejection and can be converted into chondrocytes by the action of related growth factors in vivo.@*Conclusions@#Genipin cross-linked decellularized tracheal scaffold combined with stem cell transplantation can successfully construct a tracheal in situ replacement model. This study provides a strong support for the research of tissue engineering trachea.
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Objective To explored the bio-compatibility and cartilage regeneration of the rabbits genipin cross-linked decellularized scaffold, to provide experimental and theoretical support for the clinical application of genipin cross-linked decellularized scaffold. Methods Detergent-enzyme method was used to prepare decellularized tracheal scaffolds. Cellular content of native trachea and decellularized trachea were compared by 4', 6-diamidino-2-phenylindole(DAPI) staining. Masson trichrome staining was used to compare the histological structure of the progenitor tube, decellularized trachea, and genipin cross-linked decellularized trachea. Nine adult New Zealand white rabbits were randomly divided into autologous tracheal transplantation group (negative control group), allogeneic tracheal transplantation group (positive control group), and genipin cross-linked decellularized tracheal transplantation group (experimental group). Autologous bone marrow mesenchymal stem cells were implanted on the surface of trachea in each group. The blood cells and type II collagen were detected to compare the inflammatory response and chondrocyte regeneration after tracheal orthotopic transplantation in the three groups. Results After DAPI staining and light microscope observation (×200), the cell content of the acellular 7-cycle trachea [(143.0 ± 71.1) cells/field] was significantly lower than that of the native trachea [(853.5 ± 149.6) cells/ field], and the difference was statistically significant (P<0.001). Masson's trichrome staining showed that the tissue structure of genipin cross -linked decellularized trachea was more complete. Blood cell analysis and type II collagen test results showed that genipin cross-linked decellularized trachea transplanted with bone marrow mesenchymal stem cells after transplantation in situ has little rejection and can be converted into chondrocytes by the action of related growth factors in vivo. Conclusions Genipin cross-linked decellularized tracheal scaffold combined with stem cell transplantation can successfully construct a tracheal in situ replacement model. This study provides a strong support for the research of tissue engineering trachea.
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Objective To investigate the safety and short-term effectiveness of the hybrid operation for the treatment of intracranial complex ruptured aneurysms.Methods From December 2014 to March 2017,14 consecutive patients with complex ruptured aneurysm treated with hybrid operation at the Department of Neurosurgery,Nanfang Hospital,Southern Medical University were enrolled retrospectively,including 13 with acute spontaneous aneurismal subarachnoid hemorrhage and 1 with hemorrhage in the recurrent aneurysm embolization.Twelve aneurysms were treated with shape clipping.Digital subtraction angiography (DSA) was used to evaluate the clipping effect of aneurysms.Two patients with aneurysm were treated with extracranial-intracranial (EC-IC) bypass and aneurysm trapping.Endovascular balloon occlusion for trapping aneurysms was performed after DSA evaluation of the patency of bridge vessel.Results Of the 14 patients,11 were treated with emergency hybrid operation after angiography,2 were treated with elective surgery,and 1 with emergency surgery for rescue because of bleeding during embolization.DSA revealed that the aneurysm clips in 3 of 12 patients needed to be adjusted,including 2 parent artery stenosis and 1 with incomplete clipping.After adjustment,the clipping was satisfactory.In intracranial and extracranial bypass surgery,angiography revealed that the blood vessels were patent.Trapping of the aneurysms was performed in the one-stage operation.One patient discharged voluntarily after procedure because of serious vasospasm.Onepatient had perfusion pressure breakthrough after surgery and received hematoma evacuation and decompression.The Glasgow outcome scale (GOS) score was 3 at discharge.Other patients had no new neurological dysfunction after operation.Thirteen patients were followed up for 3-24 months after operation.There were no new neurological dysfunction,including GOS 5 in 8 cases and 4 in 5 cases.Six patients underwent DSA examination,in 4 of them the aneurysm clipping did not show aneurysm recurrence,and the parent arteries were patent.Two patients treated with vascular bypass.There were no recurrence of aneurysms,and the parent arteries and anastomotic vessels were patent.Conclusion After preliminary observation,using hybrid operation for the treatment of complicated intracranial ruptured aneurysms was safe and effective.
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Alcohol exposure Often observed in the process of traumatic brain injury (TBI), which is closely related to the death of traumatic brain injury. At home and abroad this area research is complex. This paper summarizes the relevant domestic and foreign experimental studies in recent ten years, from the clinical experimental study, animal model application, brain damage identification and other aspects of different serum alcohol levels (BAC) on the impact of brain injury related research progress. This review provides a reference for further research at first, it also has reference for the identification of related deaths.
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Objective T o observe cardiac ultrastructure and the expression of heat shock protein 70 (H SP70) and hypoxia inducible factor-1α (H IF-1α) in electric shock death rats and to explore the application of these indexes as the basis of m edical identification in electric shock death. Methods Seventy-tw o SD rats w ere random ly divided into electric shock death group, postm ortem electric shock group and the control group. T he changes of m yocardial ultrastructure w ere observed by transm ission electron m icro-scope, and the expressions of m yocardial H SP70 and H IF-1α w ere observed by im m unohistochem ical technology. Results M yocardial m yofibril fracture, m itochondrial cristae and m em brane dissolution, and disordered arrangem ent of Z lines and M lines w ere observed in electric shock rats. H SP70 and H IF-1αw ere strong positive expressions in the electric shock death group, significantly com pared w ith the con-trol and postm ortem electric shock groups (P<0.05). Conclusion T he expressions of H SP70 and H IF-1αw ere obviously increased in electric shock death group, w hich m ay be used as the diagnostic indicator of electric shock death.
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Objective To investigate the process of apoptosis in lungs and liver induced by crushing hindlimbs of rat, and study the mechanismof crush injury. Methods The rat experimental model of hindlimbs crush injury was established. The cell apoptosis in lungs and liver was detected by TUNEL assay, and the expression of Bax, Bcl-2 and caspase-3 apoptin was examined by immunohistochemistry. Results C ompared with the control group, the partial muscle injury of rat’s hindlimbs was more serious with more apoptosis observed in lungs and liver (P<0.05). The expression of Bax was up-regulated and Bcl-2 was down-regulated, whereas caspase-3 expression was activated (P<0.05). Conclusion The cell apoptosis has increased significantly in lungs and liver after crush injury of hindlimbs in rat. The corre-lation factor released during tissue injury may mediate apoptosis process.
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Objective To observe the therapeutic effect ofYiqi-Fumai injection andShenshao capsule in the treatment of angina pectoris and the influence on vascular endothelial cell function and serum MPO. Methods 90 cases of angina pectoris of coronary heart disease were randomly divided into a treatment group and a control group. 50 cases in the treatment group were treated withYiqi-Fumai injection and Shenshao capsule; 40 cases in the control group were treated with Plavix and metoprolol; clinical symptoms were observed before and after treatment, the indexes of endothelial cell function and electrocardiogram blood serum nitric oxide (NO), endothelin (ET), NOS and serum MPO, SOD, GSH changes were compared.Results The content of nitric oxide (NO), 6-keto-PGFLa and NOS of the treatment group were increased than the control group, while ET was reduced. In the treatment group, NO was (78.09 ± 88.71)μmol/L 6-keto-PGFL was 32.04 ± 25.82 pg/ml and NOS was 27.88 ± 9.08 U/MI before the treatment,; after the treatment, the NO was 127.11 ± 103.60μmol/L, 6-keto-PGFLa was 50.03 ± 60.87 pg/ml and NOS was 35.12 ± 22.18 U/MI. In the control group, NO was 96.98 ± 82.45μmol/L, 6-keto-PGFLa was 40.31 ± 51.92 pg/ml and NOS was 28.12 ± 5.11 U/MI before the treatment; After the treatment, NO was 95.62 ± 6.31μmol/L, 6-keto-PGFLa was 29.09 ± 42.01 pg/ml and NOS was 30.11 ± 7.51 U/MI. In the treatment group, ET was 58.81 ± 33.18 pg/ml before the treatment and 42.47 ± 40.5 pg/ml. after the treatment. In the control group, ET was 56.81 ± 32.76 pg/ml before the treatment and 60.67 ± 12.81 pg/ml after the treatment. In terms of resistance to oxidative stress and MPO, the SOD ,GSH and MPO improvement rate of the treatment group was significantly better than the control group (P<0.05). In the treatment group, SOD was 48.36 ± 17.38 U/MI, GSH was 126.68 ± 19.93 g/L and MPO was 57.33 ± 8.34 mmol/L before the treatment, after the treatment, SOD was 62.45 ± 15.76 U/MI, GSH was 135.98 ± 28.99 g/L and MPO was 17.11 ± 3.60 mmol/L. In the control group, SOD was 48.44 ± 19.37 U/MI, GSH was 29.44 ± 21.66 g/L and MPO was 56.35 ± 14.44 mmol/L before the treatment, after the treatment, SOD was 57.35 ± 14.44 U/MI, GSH was 28.56 ± 24.06 g/L and MPO was 48.62 ± 6.31 mmol/L.ConclusionYiqi-Fumai injection combined with Shenshao capsule has curative effect on angina pectoris of coronary heart disease, being worth of clinical use.
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Spontaneous complete thrombosis with parent artery occlusion of giant intracranial aneurysms is rare.We report a patient with a rare giant vertebral artery aneurysm with spontaneous complete thrombosis and parent artery occlusion,and review the related literature,discuss its incidence,clinical presentation,pathogenesis,diagnosis,and treatment.
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Objective To investigate the difficulty, safety and clinical efficacy of the pterional approach from the side of open A2 plane vs the approach from the side of closed A2 plane for anterosuperior-pointing anterior communicat?ing artery aneurysms (ACoAA). Methods Forty-two patients with anterosuperior-pointing ACoAA treated by microsurgi?cal clipping were divided into two groups of the approach from the side of open A2 plane (n=22) and the approach from the side of closed A2 plane (n=20). Primary objective endpoints were rates of gyrus rectus aspiration, displacement of the ipsilateral A2 and surgical-related complications, clipping results, incidence of cognitive function impairment and Glasgow Outcome Scale (GOS) at 6 months after treatment. Results The incidence of gyrus rectus aspiration and dis?placement of the ipsilateral A2, cognitive impairment at 6 months after treatment and the surgical-related complications was also significant lower in the approach from the side of open A2 plane than in the approach from the side of closed A2 plane [4(18.2%) cases vs. 11(55.0%) cases, χ2=6.185, P0.05). Conclusions The pterional approach from the side of open A2 plane in patients with anterosuperior-pointing ACoAA allows the aneurysmal necks to be secured safely, decreases operation difficulty and prevents surgical-related complications.
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Objective:To explore the clinical effect of Qizhi Weitong granules combined with rabeprazole in the treatment of reflux esophagitis and the influence on the levels of gastrin and motilin. Methods:Totally 80 cases of patients with reflux esophagitis were se-lected, and then randomly divided into the observation group and the control group with 40 cases in each. The control group was treated with rabeprazole, and the observation group was treated with Qizhi Weitong granules additionally. After 4-week treatment, the clinical effect and the influence on the levels of gastrin and motilin in the two groups were compared. Results:By comparing the clinical effect and endoscopic curative in the two groups, the total effective rate of the observation group was 95. 0% and 92. 5%, which was obvious-ly higher than that of the control group. Compared with those before the treatment, the levels of gastrin and motilin in the two groups were significantly improved after the treatment, and the improvement of the observation group was obviously higher than that of the con-trol group with statistically significant difference (P<0. 05). Conclusion: Qizhi Weitong granules combined with rabeprazole in the treatment of reflux esophagitis is effective, which can greatly improve the levels of gastrin and motilin and is worthy of further clinical application.
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Objective: The compare the safety and efficacy between cryoablation (CRYO) and radiofrequency catheter ablation (RFCA) for treating the patients with atrio-ventricular nodal reentrant tachycardia (AVNRT) by meta-analysis. Methods: We systemically searched the Medline, Cochrane library and Embase database to fulifll our pre-deifned criteria until the publication of May 2014. Results: There were 5 randomized controlled trials (RCTs) and 14 retrospective trials enrolled in our study with 2900 patients. The patients were allocated into 2 groups:CRYO group, n=1384 and RFCA group, n=1516. The overall pool-analysis demonstrated that compared with RFCA group, CRYO group had the lower risk of permanent atrio-ventricular nodal block (OR:0.27, 95%CI 0.11 to 0.62, P Conclusion: Although CRYO could decrease the risk of permanent atrio-ventricular nodal block, while its effectiveness was lower than RFCA for AVNRT treatment in relevant patients.
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Aphasia is a common complication of stroke.Transcranial magnetic stimulation is a noninvasive brain stimulation approach.Some case studies and randomized controlled trials have confirmed the effectiveness of repetitive transcranial magnetic stimulation for the treatment of poststroke aphasia,but its specific mechanism remains unclear.