Enhancing the Interaction of Carbon Nanotubes by Metal-Organic Decomposition with Improved Mechanical Strength and Ultra-Broadband EMI Shielding Performance

The remarkable properties of carbon nanotubes(CNTs)have led to promising applications in the field of electromagnetic inter-ference(EMI)shielding.However,for macroscopic CNT assemblies,such as CNT film,achieving high electrical and mechanical properties remains challenging,which heavily depends on the tube-tube interac-tions of CNTs.Herein,we develop a novel strategy based on metal-organic decomposition(MOD)to fabricate a flexible silver-carbon nanotube(Ag-CNT)film.The Ag particles are introduced in situ into the CNT film through annealing of MOD,leading to enhanced tube-tube interactions.As a result,the electrical conductivity of Ag-CNT film is up to 6.82×10^(5) S m^(-1),and the EMI shielding effectiveness of Ag-CNT film with a thickness of~7.8μm exceeds 66 dB in the ultra-broad frequency range(3-40 GHz).The tensile strength and Young’s modulus of Ag-CNT film increase from 30.09±3.14 to 76.06±6.20 MPa(~253%)and from 1.12±0.33 to 8.90±0.97 GPa(~795%),respectively.Moreover,the Ag-CNT film exhibits excellent near-field shield-ing performance,which can effectively block wireless transmission.This innovative approach provides an effective route to further apply macroscopic CNT assemblies to future portable and wearable electronic devices.

Secondary coronary artery ostial lesions:Three case reports

BACKGROUND Atherosclerosis is one of the main causes of coronary artery ostial lesions seen clinically.Secondary coronary artery ostial lesions are rare,and cases reported previously were associated with syphilitic vasculitis and aortic dissection.Here,we report three rare cases of secondary coronary ostial lesions.Due to their rareness,these lesions can easily be neglected,which may lead to misdiagnosis and missed diagnosis.CASE SUMMARY We present three patients with acute myocardial infarction and unstable angina caused by secondary coronary artery ostial lesions.In Case 1,coronary angiography(CAG)revealed 90%stenosis of the left main coronary ostium.Chest contrast computed tomography(CT)suggested thymic carcinoma invading the left main coronary ostium.Coronary artery bypass grafting and tumor resection were performed.In Case 2,echocardiography revealed a sinus of Valsalva aneurysm(SVA)-like dilatation.CAG showed a right coronary sinus giant aneurysm and complete obstruction of the right coronary artery(RCA)ostium.Aortic contrast CT confirmed these findings.The Bentall procedure was performed.In Case 3,CT CAG identified an anomalous origin of the right coronary artery(AORCA)from the left sinus of Valsalva coursing between the aorta and pulmonary trunk,causing severe RCA ostium stenosis by compression.Surgical correction of the AORCA was performed.CONCLUSION The cases reported here suggest that we should consider other causes of coronary ostial lesions other than atherosclerosis.