Endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA)is a means to procure adequate specimens for histological and cytologic analysis.The ideal EUS-FNA should be safe,accurate,and have a high sample adequacy ra...Endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA)is a means to procure adequate specimens for histological and cytologic analysis.The ideal EUS-FNA should be safe,accurate,and have a high sample adequacy rate and low adverse events rate.In recent years,many guidelines and trials on EUS-FNA have been published.The purpose of this article is to provide an update on the influence of some of the main factors on the diagnostic efficiency of EUS-FNA as well as a rare but serious complication known as needle tract seeding.展开更多
Covalent organic frameworks(COFs),as a novel class of functional polymers,exhibit versatile applica-tions due to their crystalline porous structures and conjugated skeletons.However,synthesis of COFs with high crystal...Covalent organic frameworks(COFs),as a novel class of functional polymers,exhibit versatile applica-tions due to their crystalline porous structures and conjugated skeletons.However,synthesis of COFs with high crystallinity still faces great challenges,especially for scale-up preparation.Herein we report a two-step solvothermal process to improve crystallinity of COFs.The first step focuses on polycondensa-tion of monomers with no need for optimizing crystallization conditions.In the second step,appropriate solvothermal conditions are used to facilitate crystallization of the COFs through defects correction and structural repairing.Furthermore,this strategy could also be applicable to scale-up synthesis of high qual-ity COFs,which lays a foundation for their practical applications.展开更多
In this paper we mainly concern the persistence of invariant tori in generalized Hamiltonian systems. Here the generalized Hamiltonian systems refer to the systems which may admit a distinct number of action and angle...In this paper we mainly concern the persistence of invariant tori in generalized Hamiltonian systems. Here the generalized Hamiltonian systems refer to the systems which may admit a distinct number of action and angle variables. In particular, system under consideration can be odd dimensional. Under the Riissmann type non-degenerate condition, we proved that the majority of the lower-dimension invariant tori of the integrable systems in generalized Hamiltonian system are persistent under small perturbation. The surviving lower-dimensional tori might be elliptic, hyperbolic, or of mixed type.展开更多
文摘Endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA)is a means to procure adequate specimens for histological and cytologic analysis.The ideal EUS-FNA should be safe,accurate,and have a high sample adequacy rate and low adverse events rate.In recent years,many guidelines and trials on EUS-FNA have been published.The purpose of this article is to provide an update on the influence of some of the main factors on the diagnostic efficiency of EUS-FNA as well as a rare but serious complication known as needle tract seeding.
基金the National Natural Science Foundation of China(No.21632004)the Science and Technology Commission of Shang-hai Municipality(No.19XD1404900)for financial support.
文摘Covalent organic frameworks(COFs),as a novel class of functional polymers,exhibit versatile applica-tions due to their crystalline porous structures and conjugated skeletons.However,synthesis of COFs with high crystallinity still faces great challenges,especially for scale-up preparation.Herein we report a two-step solvothermal process to improve crystallinity of COFs.The first step focuses on polycondensa-tion of monomers with no need for optimizing crystallization conditions.In the second step,appropriate solvothermal conditions are used to facilitate crystallization of the COFs through defects correction and structural repairing.Furthermore,this strategy could also be applicable to scale-up synthesis of high qual-ity COFs,which lays a foundation for their practical applications.
基金Partially supported by the Talent Foundation (522-7901-01140418) of Northwest A & FUniversity.
文摘In this paper we mainly concern the persistence of invariant tori in generalized Hamiltonian systems. Here the generalized Hamiltonian systems refer to the systems which may admit a distinct number of action and angle variables. In particular, system under consideration can be odd dimensional. Under the Riissmann type non-degenerate condition, we proved that the majority of the lower-dimension invariant tori of the integrable systems in generalized Hamiltonian system are persistent under small perturbation. The surviving lower-dimensional tori might be elliptic, hyperbolic, or of mixed type.
