To the Editor:A 62-year-old woman presented to the dermatology department with a 5-month history of multiple painless cutaneous abscesses and ulcers[Figure 1A],occurring 1 month after a transvaginal hysterectomy due t...To the Editor:A 62-year-old woman presented to the dermatology department with a 5-month history of multiple painless cutaneous abscesses and ulcers[Figure 1A],occurring 1 month after a transvaginal hysterectomy due to uterine prolapse.Her general condition was good before and after the surgery,with no abnormal physical signs apart from metroptosis.She reported no fever,night sweat,cough,or abdominal pain,but 10 kg weight-loss.She has no history of diabetes,autoimmune diseases,or chronic infectious diseases.There was no similar illness in her family.展开更多
The development of negative permittivity materials in multifunctional applications requests expansion of their operating frequency and improvement of stability of negative permittivity.Low electron density is benefici...The development of negative permittivity materials in multifunctional applications requests expansion of their operating frequency and improvement of stability of negative permittivity.Low electron density is beneficial to reduce plasma frequency so that negative permittivity is achieved in kHz region.Negative permittivity achieved by percolating composites is restricted in practicality due to its instability nature at high temperatures.To achieve temperature-stable negative permittivity in kHz region,monophase La_(1-x)Ba_(x)CoO_(3)ceramics were prepared,and the transition from dielectric to metal was elaborated in the perspective of electrical conductivity and negative permittivity.The plasma-like negative permittivity is attained in kHz region,which is interpreted by the collective oscillation of low electron density.The temperature-stable negative permittivity is based on the fact that the plasmonic state will not be undermined at high temperatures.In addition,zero-crossing behavior of real permittivity is observed in La_(0.9)Ba_(0.1)CoO_(3)sample,which provides a promising alternative to designing epsilon-near-zero materials.This work makes the La_(1-x)Ba_(x)CoO_(3)system a source material for achieving effective negative permittivity.展开更多
文摘To the Editor:A 62-year-old woman presented to the dermatology department with a 5-month history of multiple painless cutaneous abscesses and ulcers[Figure 1A],occurring 1 month after a transvaginal hysterectomy due to uterine prolapse.Her general condition was good before and after the surgery,with no abnormal physical signs apart from metroptosis.She reported no fever,night sweat,cough,or abdominal pain,but 10 kg weight-loss.She has no history of diabetes,autoimmune diseases,or chronic infectious diseases.There was no similar illness in her family.
基金supported by the National Natural Science Foundation of China(Nos.51771104,51871146,51971119)the Natural Science Foundation of Shandong Province(No.ZR2020YQ32)the Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-10-E00053)。
文摘The development of negative permittivity materials in multifunctional applications requests expansion of their operating frequency and improvement of stability of negative permittivity.Low electron density is beneficial to reduce plasma frequency so that negative permittivity is achieved in kHz region.Negative permittivity achieved by percolating composites is restricted in practicality due to its instability nature at high temperatures.To achieve temperature-stable negative permittivity in kHz region,monophase La_(1-x)Ba_(x)CoO_(3)ceramics were prepared,and the transition from dielectric to metal was elaborated in the perspective of electrical conductivity and negative permittivity.The plasma-like negative permittivity is attained in kHz region,which is interpreted by the collective oscillation of low electron density.The temperature-stable negative permittivity is based on the fact that the plasmonic state will not be undermined at high temperatures.In addition,zero-crossing behavior of real permittivity is observed in La_(0.9)Ba_(0.1)CoO_(3)sample,which provides a promising alternative to designing epsilon-near-zero materials.This work makes the La_(1-x)Ba_(x)CoO_(3)system a source material for achieving effective negative permittivity.
