Chirality hold broad applications in life sciences,quantum devices,and various other areas.Traditionally,molecular chirality can be characterized by using steady-state circular dichroism spectroscopy.However,the techn...Chirality hold broad applications in life sciences,quantum devices,and various other areas.Traditionally,molecular chirality can be characterized by using steady-state circular dichroism spectroscopy.However,the techniques that can characterize excited state chirality are progressively capturing the public interest as it can provide the dynamic information for chirality generation and transfer.In this review,we focus on the theoretical background and the developmental history of femtosecond time-resolved circular dichroism spectroscopy(TRCD)techniques around the world.Additionally,we provide examples to showcase the utility of these techniques in the analysis of the dynamical molecular chemical structures,the investigation of molecular chirality generation,and the detection of electron spin dynamics in semiconductor quantum dots.展开更多
Schwannomas are peripheral nerve tumors that are typically solitary and benign.Their diagnosis is largely based on surgically resected specimens.Recently,a number of case reports have indicated that retroperitoneal sc...Schwannomas are peripheral nerve tumors that are typically solitary and benign.Their diagnosis is largely based on surgically resected specimens.Recently,a number of case reports have indicated that retroperitoneal schwannomas could be diagnosed with endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA).We report the diagnosis of three cases of schwannoma using EUS-FNA.Subjects were two males and one female,ages 22,40,and 46 years,respectively,all of whom were symptom-free.Imaging findings showed well-circumscribed round tumors.However,as the tumors could not be diagnosed using these findings alone,EUS-FNA was performed.Hematoxylin-eosin staining of the resulting tissue fragments revealed bland spindle cells with nuclear palisading.There was no disparity in nuclear sizes.Immunostaining revealed S-100 protein positivity and all cases were diagnosed as schwannomas.Ki-67 indexes were 3%-15%,2%-3%,and 3%,respectively.No case showed any signs of malignancy.As most schwannomas are benign tumors and seldom become malignant,we observed these patients without therapy.All tumors demonstrated no enlargement and no change in characteristics.Schwannomas are almost always benign and can be observed following diagnosis by EUS-FNA.展开更多
In order to gain circularly polarized light of left-handed and right-handed rotation by using a fixed device, a left-handed and right-handed rotation double function circular polarizer is designed with two λ/4 retard...In order to gain circularly polarized light of left-handed and right-handed rotation by using a fixed device, a left-handed and right-handed rotation double function circular polarizer is designed with two λ/4 retarders and one polarizer, and its operating principle is analysed by matrix optical means. The result indicates that when the monochromatic light enters this circular polarizer in the positive direction and the negative direction,the emergent light should be circularly polarized light,of left-handed and right-handed rotation respectively. The testing system has been established to verify the above results.展开更多
基金funded by the National Natural Science FoundationofChina(No.92156024and No.92356307 to Jinquan Chen)Menghui Jia thanks the Materials Characterization Center and the Office of Laboratory and Equipment of East China Normal University for funding support(ECNUETR2023-13).
文摘Chirality hold broad applications in life sciences,quantum devices,and various other areas.Traditionally,molecular chirality can be characterized by using steady-state circular dichroism spectroscopy.However,the techniques that can characterize excited state chirality are progressively capturing the public interest as it can provide the dynamic information for chirality generation and transfer.In this review,we focus on the theoretical background and the developmental history of femtosecond time-resolved circular dichroism spectroscopy(TRCD)techniques around the world.Additionally,we provide examples to showcase the utility of these techniques in the analysis of the dynamical molecular chemical structures,the investigation of molecular chirality generation,and the detection of electron spin dynamics in semiconductor quantum dots.
文摘Schwannomas are peripheral nerve tumors that are typically solitary and benign.Their diagnosis is largely based on surgically resected specimens.Recently,a number of case reports have indicated that retroperitoneal schwannomas could be diagnosed with endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA).We report the diagnosis of three cases of schwannoma using EUS-FNA.Subjects were two males and one female,ages 22,40,and 46 years,respectively,all of whom were symptom-free.Imaging findings showed well-circumscribed round tumors.However,as the tumors could not be diagnosed using these findings alone,EUS-FNA was performed.Hematoxylin-eosin staining of the resulting tissue fragments revealed bland spindle cells with nuclear palisading.There was no disparity in nuclear sizes.Immunostaining revealed S-100 protein positivity and all cases were diagnosed as schwannomas.Ki-67 indexes were 3%-15%,2%-3%,and 3%,respectively.No case showed any signs of malignancy.As most schwannomas are benign tumors and seldom become malignant,we observed these patients without therapy.All tumors demonstrated no enlargement and no change in characteristics.Schwannomas are almost always benign and can be observed following diagnosis by EUS-FNA.
文摘In order to gain circularly polarized light of left-handed and right-handed rotation by using a fixed device, a left-handed and right-handed rotation double function circular polarizer is designed with two λ/4 retarders and one polarizer, and its operating principle is analysed by matrix optical means. The result indicates that when the monochromatic light enters this circular polarizer in the positive direction and the negative direction,the emergent light should be circularly polarized light,of left-handed and right-handed rotation respectively. The testing system has been established to verify the above results.
