P-and SV-wave dispersion and attenuation have been extensively investigated in saturated poroelastic media with aligned fractures.However,there are few existing models that incorporate the multiple wave attenuation me...P-and SV-wave dispersion and attenuation have been extensively investigated in saturated poroelastic media with aligned fractures.However,there are few existing models that incorporate the multiple wave attenuation mechanisms from the microscopic scale to the macroscopic scale.Hence,in this work,we developed a unified model to incorporate the wave attenuation mechanisms at different scales,which includes the microscopic squirt flow between the microcracks and pores,the mesoscopic wave-induced fluid flow between fractures and background(FB-WIFF),and the macroscopic Biot's global flow and elastic scattering(ES)from the fractures.Using Tang's modified Biot's theory and the mixed-boundary conditions,we derived the exact frequency-dependent solutions of the scattering problem for a single penny-shaped fracture with oblique incident P-and SV-waves.We then developed theoretical models for a set of aligned fractures and randomly oriented fractures using the Foldy approximation.The results indicated that microcrack squirt flow considerably influences the dispersion and attenuation of P-and SV-wave velocities.The coupling effects of microcrack squirt flow with the FB-WIFF and ES of fractures cause much higher velocity dispersion and attenuation for P waves than for SV waves.Randomly oriented fractures substantially reduce the attenuation caused by the FB-WIFF and ES,particularly for the ES attenuation of SV waves.Through a comparison with existing models in the limiting cases and previous experimental measurements,we validated our model.展开更多
Background:Chinese medicine is widely applied in Asian and Western countries for its outstanding therapeutic effect,but there are still unsolved problems such as unclear active ingredients and pharmacological effects....Background:Chinese medicine is widely applied in Asian and Western countries for its outstanding therapeutic effect,but there are still unsolved problems such as unclear active ingredients and pharmacological effects.The application of nano/microparticle technology in Chinese medicine may become a promising strategy to solve this problem in the near future(provided that more efforts are made to in-depth exploration).In this work,a comprehensive analysis of the field was carried out from a bibliometrics perspective,and further the publishing trends and research hotspots were figured out.Methods:The articles or reviews from 2000 to 2020 were retrieved in the database of Web of Science Core Collection.The documents were processed by Clarivate Analytic,Visualization of Similarities viewer,Statistical Analysis Toolkit for Informetrics and bibliometric online platform,and the data were visualized.Finally,a bibliometric summary,citation analysis results and research trends were described.Results:A bibliometric analysis of 773 articles of interest showed that research in this field had continued to grow in recent years,with a high degree of interdisciplinary integration.Secondly,this field attached great importance to the quantitative analysis of Chinese medicine combined with nano/micro particle technology.Chinese medicine,nanoparticles and liposomes were the most accessed keywords.China was the main contributing country,and the top-10 contributing organizations were all located in China.Co-authorship was a common phenomenon in this field.Conclusion:The published literature on the application of nano/micro particle technology in Chinese medicine was summarized.The results suggested that bibliometric analysis could predict possible directions for future research in this field.展开更多
Objective To explore the safety and efficacy of frameless stereotactic brain biopsy.Methods Diagnostic accuracy was calculated by comparing biopsy diagnosis with definitive pathology in 62 patients who underwent frame...Objective To explore the safety and efficacy of frameless stereotactic brain biopsy.Methods Diagnostic accuracy was calculated by comparing biopsy diagnosis with definitive pathology in 62 patients who underwent frameless stereotactic brain biopsy between January 2008 and December 2010 in Xiamen University Southeast Hospital.Preoperative characteristics and histological diagnosis were reviewed and then information was analysed to identify factors associated with the biopsy not yielding a diagnosis and complications.Results Diagnostic yield was 93.5%.No differences were found between pathological diagnosis and frozen pathological diagnosis.The most common lesions were astrocytic lesions,included 16 cases of low-grade glioma and 12 cases of malignant glioma.Remote hemorrhage,metastasis,and lymphoma were following in incidence.Multiple brain lesions were found in 17 cases (27.4%).Eleven cases were frontal lesions (17.7%),8 were frontotemporal (12.9%),6 were frontoparietal (9.7%),and 5 each were temporal,parietal,and parietotemporal lesions (8.1%).Postoperative complications occurred in 21.0% of the patients after biopsies,including 10 haemorrhages (16.1%) and 3 temporary neurological deficits (1 epilepsy,1 headache,and 1 partial hemiparesis).No patient required operation for hematoma evacuation.Conclusion Frameless stereotactic biopsy is an effective and safe technique for histologic diagnosis of brain lesions,particularly for multifocal and frontal lesions.展开更多
BACKGROUND Gastric glomus tumor(GGT)is rare submucosal mesenchymal tumor that lacks specific clinical manifestations and is usually treated mainly by traditional surgical resection.This paper presents a case of a GGT,...BACKGROUND Gastric glomus tumor(GGT)is rare submucosal mesenchymal tumor that lacks specific clinical manifestations and is usually treated mainly by traditional surgical resection.This paper presents a case of a GGT,exhibited both intraluminally and extraluminally growth that was removed by laparoscopy-gastroscopy cooperative surgery.CASE SUMMARY A 52-year-old male presented with epigastric discomfort accompanied by a sense of fullness for 3 mo.Upper gastrointestinal endoscopy identified a submucosal lump located in the gastric antrum.Endoscopic ultrasonography identified a 2.4 cm×1.8 cm lump located in the gastric antrum.It originated from the muscularis propria and exhibited both intraluminally and extraluminally growth,with hypoechoicity on the periphery,hyperechoicity in the middle,and unclear boundaries.Computed tomography showed nodular thickening of 3.0 cm×2.2 cm in the gastric wall of the gastric antrum,and after enhancement,the lesion exhibited obvious enhancement We suspected that it was a gastrointestinal stromal tumor(glomus tumor and schwannoma were not excluded)and planned to perform laparoscopy-gastroscopy cooperative surgery.Immunohistochemical staining after the operation revealed that spinal muscular atrophy(+),hcaldesmon(+),cluster of differentiation 34(CD34)(+),2%Ki-67-positive rate,CD56,melanoma antigen,CD117,discovered on GIST-1,leukocyte common antigen,caudal type homeobox 2,cytokeratin,and S-100 were all negative.The tumor was finally diagnosed as a GGT.CONCLUSION GGTs are rare submucosal tumors of the stomach and should be considered in the differential diagnosis of gastric submucosal tumors.Laparoscopy-gastroscopy cooperative surgery is less invasive and more precise and could be an effective method for the treatment of GGTs.展开更多
In order to investigate the microstructure evolution during a hot extrusion process,a cellular automata(CA)coupled with finite element method(FEM)was developed to numerically simulate the dynamic recrystallization(DRX...In order to investigate the microstructure evolution during a hot extrusion process,a cellular automata(CA)coupled with finite element method(FEM)was developed to numerically simulate the dynamic recrystallization(DRX).Firstly,the cellular automata model was modified by introducing thermomechanical parameters under the isothermal hot compression conditions.Then,the modified CA was verified by the experimental average grain size which was obtained by the hot compression of cylindrical specimens.After that,the modified CA was used to predict the microstructure evolution during a double cup extrusion by combining with the finite element method.The results showed that the strain rate and the temperature are sensitive to the average grain size while the strain can affect the DRX fraction greatly.In addition,the CA model can predict the final microstructure successfully and is able to simulate the DRX phenomenon for a wide range of deformation conditions.It also revealed that the results obtained by CA model are consistent with the ones acquired by finite element analysis.展开更多
Graphene quantum dots(GQDs)doped InGaO(IGO)thin film transistors(TFTs)have been fabricated based on solution-driven ZrO_(x) as gate dielectrics.Compare to pure IGO TFTs,superior electrical performance of the GQDs-IGO ...Graphene quantum dots(GQDs)doped InGaO(IGO)thin film transistors(TFTs)have been fabricated based on solution-driven ZrO_(x) as gate dielectrics.Compare to pure IGO TFTs,superior electrical performance of the GQDs-IGO TFTs can be achieved by adjusting the doping concentration.It has been demonstrated that GQDs-modified IGO TFTs devices with GQDs doping content of0.3 mg·ml^(-1)have the optimized performances,including field-effect mobility(μ_(FE))of 22.02 cm^(2)·V^(-1)·s^(-1),on/off current ratio(I_(on)/I_(off))of 7.06×10^(7),subthreshold swing(SS)of 0.09 V·dec^(-1),hysteresis of 0.04 V and interfacial trap states(D_(it))of 1.03×10^(12)cm^(-2).In addition,bias stress and illumination stress tests have been performed and excellent stability has been achieved for optimized GQDs-IGO-TFTs.The GQDs-IGO TFTs device showed smaller threshold voltage shift of 0.12 and 0.04 V under positive bias stress(PBS)test and negative bias stress(NBS)test for 3600 s,respectively.And it showed smaller threshold voltage shift of 0.27 and 0.34 V for red light under the PBS and NBS test for 3600 s,respectively.Meanwhile,it showed smaller threshold voltage shift of0.20 and 0.22 V for green light under PBS and NBS test for3600 s,respectively.It also showed smaller threshold voltage shift of 0.17 and 0.12 V for blue under the positive bias illumination stress(PBIS)test and negative bias illumination stress(NBIS)test for 3600 s,respectively.Lowfrequency noise(LFN)characteristics of GQDs-IGO/ZrO_(x)TFTs indicated that the noise source came from the fluctuations in mobility.Finally,a low voltage resistor-loaded unipolar inverter has been built based on GQDs-IGO/ZrO_(x)TFT,demonstrating good dynamic response behavior and a maximum gain of 7.4.These experimental results have suggested that solution-processed GQDs-IGO/ZrO_(x)TFT may envision potential applications in low-cost and large-area electronics.展开更多
Chimera states,a symmetry-breaking spatiotemporal pattern in nonlocally coupled dynamical units,prevail in a variety of systems.However,the interaction structures among oscillators are static in most of studies on chi...Chimera states,a symmetry-breaking spatiotemporal pattern in nonlocally coupled dynamical units,prevail in a variety of systems.However,the interaction structures among oscillators are static in most of studies on chimera state.In this work,we consider a population of agents.Each agent carries a phase oscillator.We assume that agents perform Brownian motions on a ring and interact with each other with a kernel function dependent on the distance between them.When agents are motionless,the model allows for several dynamical states including two different chimera states (the type-Ⅰ and the type-Ⅱ chimeras).The movement of agents changes the relative positions among them and produces perpetual noise to impact on the model dynamics.We find that the response of the coupled phase oscillators to the movement of agents depends on both the phase lag α,determining the stabilities of chimera states,and the agent mobility D.For low mobility,the synchronous state transits to the type-Ⅰ chimera state for α close to π/2 and attracts other initial states otherwise.For intermediate mobility,the coupled oscillators randomly jump among different dynamical states and the jump dynamics depends on α.We investigate the statistical properties in these different dynamical regimes and present the scaling laws between the transient time and the mobility for low mobility and relations between the mean lifetimes of different dynamical states and the mobility for intermediate mobility.展开更多
基金This work was supported by the Laoshan National Laboratory Science and Technology Innovation Project(No.LSKJ202203407)the National Natural Science Foundation of China(Grant Nos.42174145,41821002,42274146)+1 种基金Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology(2022B1212010002)Shenzhen Stable Support Plan Program for Higher Education Institutions(20220815110144003).
文摘P-and SV-wave dispersion and attenuation have been extensively investigated in saturated poroelastic media with aligned fractures.However,there are few existing models that incorporate the multiple wave attenuation mechanisms from the microscopic scale to the macroscopic scale.Hence,in this work,we developed a unified model to incorporate the wave attenuation mechanisms at different scales,which includes the microscopic squirt flow between the microcracks and pores,the mesoscopic wave-induced fluid flow between fractures and background(FB-WIFF),and the macroscopic Biot's global flow and elastic scattering(ES)from the fractures.Using Tang's modified Biot's theory and the mixed-boundary conditions,we derived the exact frequency-dependent solutions of the scattering problem for a single penny-shaped fracture with oblique incident P-and SV-waves.We then developed theoretical models for a set of aligned fractures and randomly oriented fractures using the Foldy approximation.The results indicated that microcrack squirt flow considerably influences the dispersion and attenuation of P-and SV-wave velocities.The coupling effects of microcrack squirt flow with the FB-WIFF and ES of fractures cause much higher velocity dispersion and attenuation for P waves than for SV waves.Randomly oriented fractures substantially reduce the attenuation caused by the FB-WIFF and ES,particularly for the ES attenuation of SV waves.Through a comparison with existing models in the limiting cases and previous experimental measurements,we validated our model.
基金the financial supports from the Fundamental Research Funds for the Central Universities(No.21621012)the National Natural Science Foundation of China(No.82104070).
文摘Background:Chinese medicine is widely applied in Asian and Western countries for its outstanding therapeutic effect,but there are still unsolved problems such as unclear active ingredients and pharmacological effects.The application of nano/microparticle technology in Chinese medicine may become a promising strategy to solve this problem in the near future(provided that more efforts are made to in-depth exploration).In this work,a comprehensive analysis of the field was carried out from a bibliometrics perspective,and further the publishing trends and research hotspots were figured out.Methods:The articles or reviews from 2000 to 2020 were retrieved in the database of Web of Science Core Collection.The documents were processed by Clarivate Analytic,Visualization of Similarities viewer,Statistical Analysis Toolkit for Informetrics and bibliometric online platform,and the data were visualized.Finally,a bibliometric summary,citation analysis results and research trends were described.Results:A bibliometric analysis of 773 articles of interest showed that research in this field had continued to grow in recent years,with a high degree of interdisciplinary integration.Secondly,this field attached great importance to the quantitative analysis of Chinese medicine combined with nano/micro particle technology.Chinese medicine,nanoparticles and liposomes were the most accessed keywords.China was the main contributing country,and the top-10 contributing organizations were all located in China.Co-authorship was a common phenomenon in this field.Conclusion:The published literature on the application of nano/micro particle technology in Chinese medicine was summarized.The results suggested that bibliometric analysis could predict possible directions for future research in this field.
文摘Objective To explore the safety and efficacy of frameless stereotactic brain biopsy.Methods Diagnostic accuracy was calculated by comparing biopsy diagnosis with definitive pathology in 62 patients who underwent frameless stereotactic brain biopsy between January 2008 and December 2010 in Xiamen University Southeast Hospital.Preoperative characteristics and histological diagnosis were reviewed and then information was analysed to identify factors associated with the biopsy not yielding a diagnosis and complications.Results Diagnostic yield was 93.5%.No differences were found between pathological diagnosis and frozen pathological diagnosis.The most common lesions were astrocytic lesions,included 16 cases of low-grade glioma and 12 cases of malignant glioma.Remote hemorrhage,metastasis,and lymphoma were following in incidence.Multiple brain lesions were found in 17 cases (27.4%).Eleven cases were frontal lesions (17.7%),8 were frontotemporal (12.9%),6 were frontoparietal (9.7%),and 5 each were temporal,parietal,and parietotemporal lesions (8.1%).Postoperative complications occurred in 21.0% of the patients after biopsies,including 10 haemorrhages (16.1%) and 3 temporary neurological deficits (1 epilepsy,1 headache,and 1 partial hemiparesis).No patient required operation for hematoma evacuation.Conclusion Frameless stereotactic biopsy is an effective and safe technique for histologic diagnosis of brain lesions,particularly for multifocal and frontal lesions.
基金Key Program of Shandong Provincial Natural Science Foundation,No.ZR2020KE018The Project of Shandong Province Higher Educational Science and Technology Program,No.J17KA253+1 种基金The Medical Science and Technology Development Project of Shandong,No.2018WS062Weifang Science and Technology Development Plan,No.2020YX040.
文摘BACKGROUND Gastric glomus tumor(GGT)is rare submucosal mesenchymal tumor that lacks specific clinical manifestations and is usually treated mainly by traditional surgical resection.This paper presents a case of a GGT,exhibited both intraluminally and extraluminally growth that was removed by laparoscopy-gastroscopy cooperative surgery.CASE SUMMARY A 52-year-old male presented with epigastric discomfort accompanied by a sense of fullness for 3 mo.Upper gastrointestinal endoscopy identified a submucosal lump located in the gastric antrum.Endoscopic ultrasonography identified a 2.4 cm×1.8 cm lump located in the gastric antrum.It originated from the muscularis propria and exhibited both intraluminally and extraluminally growth,with hypoechoicity on the periphery,hyperechoicity in the middle,and unclear boundaries.Computed tomography showed nodular thickening of 3.0 cm×2.2 cm in the gastric wall of the gastric antrum,and after enhancement,the lesion exhibited obvious enhancement We suspected that it was a gastrointestinal stromal tumor(glomus tumor and schwannoma were not excluded)and planned to perform laparoscopy-gastroscopy cooperative surgery.Immunohistochemical staining after the operation revealed that spinal muscular atrophy(+),hcaldesmon(+),cluster of differentiation 34(CD34)(+),2%Ki-67-positive rate,CD56,melanoma antigen,CD117,discovered on GIST-1,leukocyte common antigen,caudal type homeobox 2,cytokeratin,and S-100 were all negative.The tumor was finally diagnosed as a GGT.CONCLUSION GGTs are rare submucosal tumors of the stomach and should be considered in the differential diagnosis of gastric submucosal tumors.Laparoscopy-gastroscopy cooperative surgery is less invasive and more precise and could be an effective method for the treatment of GGTs.
基金Sponsored by the Chongqing Natural Science Foundation(Grant No.CSTC2009BA4065)the Fundamental Research Funds for the CentralUniversities of China(Grant No.CDJZR11130003)
文摘In order to investigate the microstructure evolution during a hot extrusion process,a cellular automata(CA)coupled with finite element method(FEM)was developed to numerically simulate the dynamic recrystallization(DRX).Firstly,the cellular automata model was modified by introducing thermomechanical parameters under the isothermal hot compression conditions.Then,the modified CA was verified by the experimental average grain size which was obtained by the hot compression of cylindrical specimens.After that,the modified CA was used to predict the microstructure evolution during a double cup extrusion by combining with the finite element method.The results showed that the strain rate and the temperature are sensitive to the average grain size while the strain can affect the DRX fraction greatly.In addition,the CA model can predict the final microstructure successfully and is able to simulate the DRX phenomenon for a wide range of deformation conditions.It also revealed that the results obtained by CA model are consistent with the ones acquired by finite element analysis.
基金financially supported by the National Natural Science Foundation of China(No.11774001)Anhui Project(No.Z010118169)Open Fund Project of Zhejiang Engineering Research Center of MEMS in Shaoxing University(No.MEMSZJERC2202)。
文摘Graphene quantum dots(GQDs)doped InGaO(IGO)thin film transistors(TFTs)have been fabricated based on solution-driven ZrO_(x) as gate dielectrics.Compare to pure IGO TFTs,superior electrical performance of the GQDs-IGO TFTs can be achieved by adjusting the doping concentration.It has been demonstrated that GQDs-modified IGO TFTs devices with GQDs doping content of0.3 mg·ml^(-1)have the optimized performances,including field-effect mobility(μ_(FE))of 22.02 cm^(2)·V^(-1)·s^(-1),on/off current ratio(I_(on)/I_(off))of 7.06×10^(7),subthreshold swing(SS)of 0.09 V·dec^(-1),hysteresis of 0.04 V and interfacial trap states(D_(it))of 1.03×10^(12)cm^(-2).In addition,bias stress and illumination stress tests have been performed and excellent stability has been achieved for optimized GQDs-IGO-TFTs.The GQDs-IGO TFTs device showed smaller threshold voltage shift of 0.12 and 0.04 V under positive bias stress(PBS)test and negative bias stress(NBS)test for 3600 s,respectively.And it showed smaller threshold voltage shift of 0.27 and 0.34 V for red light under the PBS and NBS test for 3600 s,respectively.Meanwhile,it showed smaller threshold voltage shift of0.20 and 0.22 V for green light under PBS and NBS test for3600 s,respectively.It also showed smaller threshold voltage shift of 0.17 and 0.12 V for blue under the positive bias illumination stress(PBIS)test and negative bias illumination stress(NBIS)test for 3600 s,respectively.Lowfrequency noise(LFN)characteristics of GQDs-IGO/ZrO_(x)TFTs indicated that the noise source came from the fluctuations in mobility.Finally,a low voltage resistor-loaded unipolar inverter has been built based on GQDs-IGO/ZrO_(x)TFT,demonstrating good dynamic response behavior and a maximum gain of 7.4.These experimental results have suggested that solution-processed GQDs-IGO/ZrO_(x)TFT may envision potential applications in low-cost and large-area electronics.
基金supported by the National Natural Science Foundation of China (Grant Nos.11575036,11805021, and 11505016).Compliance with ethical standards. The authors declare that they have no conflict of interest concerning the publication of this manuscript.
文摘Chimera states,a symmetry-breaking spatiotemporal pattern in nonlocally coupled dynamical units,prevail in a variety of systems.However,the interaction structures among oscillators are static in most of studies on chimera state.In this work,we consider a population of agents.Each agent carries a phase oscillator.We assume that agents perform Brownian motions on a ring and interact with each other with a kernel function dependent on the distance between them.When agents are motionless,the model allows for several dynamical states including two different chimera states (the type-Ⅰ and the type-Ⅱ chimeras).The movement of agents changes the relative positions among them and produces perpetual noise to impact on the model dynamics.We find that the response of the coupled phase oscillators to the movement of agents depends on both the phase lag α,determining the stabilities of chimera states,and the agent mobility D.For low mobility,the synchronous state transits to the type-Ⅰ chimera state for α close to π/2 and attracts other initial states otherwise.For intermediate mobility,the coupled oscillators randomly jump among different dynamical states and the jump dynamics depends on α.We investigate the statistical properties in these different dynamical regimes and present the scaling laws between the transient time and the mobility for low mobility and relations between the mean lifetimes of different dynamical states and the mobility for intermediate mobility.
