BACKGROUND： Scholars have supposed to establish animal models of optic neuropathy by pressing and partially amputating optic nerve, increasing intraocular pressure and injecting vasoconstrictor, etc., but the models ...BACKGROUND： Scholars have supposed to establish animal models of optic neuropathy by pressing and partially amputating optic nerve, increasing intraocular pressure and injecting vasoconstrictor, etc., but the models are greatly different from anterior ischemia optic neuropathy. Therefore, a more ideal method is needed to establish animal model of anterior ischemic optic neuropathy （AION）. OBJECTIVE ： To establish AION models in rats, observe the functional changes of fundus, fundus fluorescein angiography （FFA）, optical coherence tomography （OCT）, flash visual evoked potential （F-VEP）, and histopathologically confirm its reliability. DESIGN： A randomized control tria SETTINGS ： Department of Ophthalmology, Xi＇an Fourth Hospital; Xi＇an Institute of Ocular Fundus Diseases MATERIALS ： The experiments were carried out in the research room of Xi＇an Institute of Ocular Fundus Diseases from February 2005 to May 2006. Thirty healthy male SD rats of 4-5 weeks old, weighing 140-160 g, were provided by the animal experimental center of the Fourth Military Medical University of Chinese PLA [SCXK （Military）2002-005], and those without eye disease examined by slit lamp and direct ophthalmoscope after mydriasis were enrolled. The conditions for feeding mice without special pathogen were strictly followed. The rats were randomly divided into blank control group （n =5）, laser group （n =5）, hematoporphyrin derivative （HPD） group and AION group （n =15）, each group was numbered randomly. For each rat, the right eye was taken as the experimental eye, and the left one as the control one. METHODS： In the AION group, the rats were injected with HPD （10 mg/kg） via caudal vein, and then the optic discs were exposed to krypton red （647 nm, 80 mV） for 120 s, and the rats were in avoidance of light for 2 weeks postoperatively. Rats in the laser group were only exposed to krypton red （647 rim, 80 mV） for 120 s, and in avoidance of light for 2 weeks postoperatively; Those in the HPD group were only injected with HPD （10 mg/kg） via caudal vein; Those in the blank control group were untouched. （1） Visual electrophysiological test： The F-VEP was used to evaluate the function of visual nerve. （2） FFA： After mydriasis and anesthesia as describe above, the fluorescein sodium parenteral solution （1 mL/kg） was injected v/a caudal vein and finished within about 3 s, the time of FFA was recorded from the beginning of injection, the video sight aimed at the optic disc and the surrounding area. （3） After mydriasis and anesthesia as describe above, the rats were examined with OCT. （4） Histological observation： After hematoxylin and eosin （HE） staining, the optic disc and surrounding blood vessels of retina were observed under light microscope at high power field. MAIN OUTCOME MEASURES： The results of fundus, FFA, visual electrophysiological test and OCT detection within 90 days after model establishment were observed. RESULTS： Of the 30 rats, 1 died after anesthesia in the laser group and 2 died in the AION group respectively, and finally 27 rats were involved in the analysis of results. （1） Changes in fundus： In the AION group, there was edema in upper optic disc and unclear boundary at 1 day after establishment, edema still could be observed at 6 days, and upper optic disc atrophied and appeared as pale at 90 days. （2） FFA results： In the AION group, early ＂low fluorescence＂, middle and late ＂high fluorescence＂ were observed in upper optic disc 1 day after model establishment, and there was ＂low fluorescence＂ at 6 days, and the low fluorescence could be observed all the time at 23 days. （3） Visual electrophysiological changes： In the AION group as compared with the control eyes, the experimental ones had prolonged F-VEP P100 latency [（71.65±8.81）, （57.58±8.38） ms, t =3.148, P =0.012], and decreased wave amplitude [（4.77±1.90）, （10.06±3.66） μV, t =4.082, P =0.003], and these changes lasted to 35 days after model establishment. （4） OCT results： In the AION group, the reflection surface of part nerve fiber layer was higher than the retina plane, the surface was rough and the thickness was increased at 6 days after model establishment. （5） Histopathological results： At 1 day after model establishment, part optic discs had highly edema, edema of nerve fibers, and loose tissue, also accompanied by the displacement of surrounding retina; At 23 days, the optic disc and surrounding nerve fiber layers became thinner, and the numbers of ganglion nuclei in the retina tissue sections were obviously decreased. These changes were not observed in the laser group, HPD group and blank control group. CONCLUSION ： The changes of fundus, FFA, OCT, visual electrophysiology and histopathology confirmed that the krypton red laser irradiation （647 nm） at 2 hours after HPD was injected via caudal vein can establish more ideal animal models of AION.展开更多
The majority of existing graph-network-based few-shot models focus on a node-similarity update mode.The lack of adequate information intensies the risk of overtraining.In this paper,we propose a novel Multihead Attent...The majority of existing graph-network-based few-shot models focus on a node-similarity update mode.The lack of adequate information intensies the risk of overtraining.In this paper,we propose a novel Multihead Attention Graph Network to excavate discriminative relation and fulll effective information propagation.For edge update,the node-level attention is used to evaluate the similarities between the two nodes and the distributionlevel attention extracts more in-deep global relation.The cooperation between those two parts provides a discriminative and comprehensive expression for edge feature.For node update,we embrace the label-level attention to soften the noise of irrelevant nodes and optimize the update direction.Our proposed model is veried through extensive experiments on two few-shot benchmark MiniImageNet and CIFAR-FS dataset.The results suggest that our method has a strong capability of noise immunity and quick convergence.The classication accuracy outperforms most state-of-the-art approaches.展开更多
Phase change memory(PCM)attracts wide attention for the memory-centric computing and neuromorphic comput-ing.For circuit and system designs,PCM compact models are mandatory and their status are reviewed in this work.M...Phase change memory(PCM)attracts wide attention for the memory-centric computing and neuromorphic comput-ing.For circuit and system designs,PCM compact models are mandatory and their status are reviewed in this work.Macro mod-els and physics-based models have been proposed in different stages of the PCM technology developments.Compact model-ing of PCM is indeed more complex than the transistor modeling due to their multi-physics nature including electrical,thermal and phase transition dynamics as well as their interactions.Realizations of the PCM operations including threshold switching,set and reset programming in these models are diverse,which also differs from the perspective of circuit simulations.For the purpose of efficient and reliable designs of the PCM technology,open issues and challenges of the compact modeling are also discussed.展开更多
In this article,the body bias dependence of the bias temperature instability(BTI)in bulk FinFETs is experimentally studied,under different test conditions for the first time.In contrast to the traditional understandin...In this article,the body bias dependence of the bias temperature instability(BTI)in bulk FinFETs is experimentally studied,under different test conditions for the first time.In contrast to the traditional understanding that changing body bias has little impact on BTI degradation in FinFETs due to its weak body effect,it is observed that it actually has non-negligible impacts.And a forward body bias(FBB)can reduce the BTI degradation in FinFETs,which is opposite with the trend in planar devices.The underlying physics is found due to the trade-off between two competing factors.The results are helpful for understanding and modeling reliability in FinFETs.展开更多
Gait recognition is a biometric technique that captures human walking pattern using gait silhouettes as input and can be used for long-term recognition.Recently proposed video-based methods achieve high performance.Ho...Gait recognition is a biometric technique that captures human walking pattern using gait silhouettes as input and can be used for long-term recognition.Recently proposed video-based methods achieve high performance.However,gait covariates or walking conditions,i.e.,bag carrying and clothing,make the recognition of intra-class gait samples hard.Advanced methods simply use triplet loss for metric learning,which does not take the gait covariates into account.For alleviating the adverse influence of gait covariates,we propose cross walking condition constraint to explicitly consider the gait covariates.Specifically,this approach designs center-based and pair-wise loss functions to decrease discrepancy of intra-class gait samples under different walking conditions and enlarge the distance of inter-class gait samples under the same walking condition.Besides,we also propose a video-based strong baseline model of high performance by applying simple yet effective tricks,which have been validated in other individual recognition fields.With the proposed baseline model and loss functions,our method achieves the state-of-the-art performance.展开更多
Purpose:To study the risk factors of increased intraocular pressure (IOP) response to triamcinolone acetonide intravitreal (IVTA) injection in eyes with macular edema associated with retinal vein occlusion. Methods:Ei...Purpose:To study the risk factors of increased intraocular pressure (IOP) response to triamcinolone acetonide intravitreal (IVTA) injection in eyes with macular edema associated with retinal vein occlusion. Methods:Eighty-nine eyes with macular edema associated with retinal vein occlusion first received periocular injection of 40 mg triamcinolone acetonide (TA) and were followed for one month. According to the diversity of IOP after periocular TA (PTA) injection, they were divided into the elevation IOP group (group A, 26 eyes) and the normal IOP group (group B,63 eyes).They then received 4 mg TA intravitreal injection.IOP measurements were recorded after PTA and IVTA injections, and were followed for six months. Results: Both PTA and IVTA injections caused a rise in IOP, but it was higher in the IVTA injection (40.45%) than in the PTA injection (29.21%). The mean rise in IOP was more significant in eyes with IVTA injection (28.08 ± 8.24 mmHg) than in eyes with PTA injection (20.87 ± 4.07 mmHg). Patients with an elevation IOP above 6 mmHg after PTA injection had a 73.08% chance of developing a pressure of 24 mmHg or higher,whereas only 12.70% of those with an elevation IOP below 6 mmHg after PTA injection experienced pressure elevation. Conclusion:IOP response to PTA injection is a good way to judge IOP response to IVTA. If the patient is highly sensitive to corticosteroid, treatments other than IVTA injection are used to avoid the increased risks associated with intravitreal corticosteroid injection.展开更多
In this work,a surface-potential based compact model focusing on the quantum confinement effects of ultimately scaled gate-all-around(GAA)MOSFET is presented.Energy quantization with sub-band formation along the radiu...In this work,a surface-potential based compact model focusing on the quantum confinement effects of ultimately scaled gate-all-around(GAA)MOSFET is presented.Energy quantization with sub-band formation along the radius direction of cylindrical GAAs or thickness direction of nanosheet GAAs leads to significant quantization effects.An analytical model of surface potentials is developed by solving the Poisson equation with incorporating sub-band effects.In combination with the existing transport model framework,charge-voltage and current-voltage formulations are developed based on the surface potential.The model formulations are then extensively validated using TCAD numerical simulations as well as Si data of nanosheet GAA MOSFETs.Simulations of typical circuits verify the model robustness and convergence for its applications in GAA technology.展开更多
In high-rise buildings with large indoor and outdoor temperature difference,neglecting the effect of stack effect in smoke exhaust shafts may cause calculation error of the fluid network model.In this paper,the mathem...In high-rise buildings with large indoor and outdoor temperature difference,neglecting the effect of stack effect in smoke exhaust shafts may cause calculation error of the fluid network model.In this paper,the mathematical model of kitchen smoke exhaust system considering the influence of stack effect was put forward and it can be inserted different range hood sub-models.Compared with the results of six working conditions of the model without considering the stack effect,the error of the proposed model were reduced by 7.6%,4.3%,4.1%,2.8%,2.4%,and 2.1%.While the indoor and outdoor temperature difference varies from−5℃ to 49℃,the effect of stack effect on the pressure in the flue and the flow rate for each user was studied for six operating rates s.The results show that under the combined effect of stack effect and flue resistance,the static pressure of the kitchen smoke exhaust system showed a low-high-low distribution,and the maximum static pressure in the flue moved toward the bottom with the increase of temperature difference.User flow rates exhibit a low-high-low-high distribution,with an increased flow rate in the bottom users and the largest flow rate in the top users.展开更多
The effects of hydrogen on the mechanical response of pure iron with randomly distributed hydrogen atoms under nanoindentation were systematically investigated by molecular dynamics simulations with the aim to further...The effects of hydrogen on the mechanical response of pure iron with randomly distributed hydrogen atoms under nanoindentation were systematically investigated by molecular dynamics simulations with the aim to further understand hydrogen embrittlement mechanism in the steels.The simulations results revealed that,for the three models with[001],[110]and[111]surface normal,hydrogen reduced the critical load of the pop-in event,promoted the dislocation slipping and reduced the plastic region size and dislocation density around the indenter compared to the hydrogen free model.Meanwhile,the different mechanical responses of the three models with different surface normal were further explained in the perspective of Schmid factor.展开更多
基金a grant from Scientific Research Fund of Shaanxi Department of Hygiene, No. 04AC1
文摘BACKGROUND： Scholars have supposed to establish animal models of optic neuropathy by pressing and partially amputating optic nerve, increasing intraocular pressure and injecting vasoconstrictor, etc., but the models are greatly different from anterior ischemia optic neuropathy. Therefore, a more ideal method is needed to establish animal model of anterior ischemic optic neuropathy （AION）. OBJECTIVE ： To establish AION models in rats, observe the functional changes of fundus, fundus fluorescein angiography （FFA）, optical coherence tomography （OCT）, flash visual evoked potential （F-VEP）, and histopathologically confirm its reliability. DESIGN： A randomized control tria SETTINGS ： Department of Ophthalmology, Xi＇an Fourth Hospital; Xi＇an Institute of Ocular Fundus Diseases MATERIALS ： The experiments were carried out in the research room of Xi＇an Institute of Ocular Fundus Diseases from February 2005 to May 2006. Thirty healthy male SD rats of 4-5 weeks old, weighing 140-160 g, were provided by the animal experimental center of the Fourth Military Medical University of Chinese PLA [SCXK （Military）2002-005], and those without eye disease examined by slit lamp and direct ophthalmoscope after mydriasis were enrolled. The conditions for feeding mice without special pathogen were strictly followed. The rats were randomly divided into blank control group （n =5）, laser group （n =5）, hematoporphyrin derivative （HPD） group and AION group （n =15）, each group was numbered randomly. For each rat, the right eye was taken as the experimental eye, and the left one as the control one. METHODS： In the AION group, the rats were injected with HPD （10 mg/kg） via caudal vein, and then the optic discs were exposed to krypton red （647 nm, 80 mV） for 120 s, and the rats were in avoidance of light for 2 weeks postoperatively. Rats in the laser group were only exposed to krypton red （647 rim, 80 mV） for 120 s, and in avoidance of light for 2 weeks postoperatively; Those in the HPD group were only injected with HPD （10 mg/kg） via caudal vein; Those in the blank control group were untouched. （1） Visual electrophysiological test： The F-VEP was used to evaluate the function of visual nerve. （2） FFA： After mydriasis and anesthesia as describe above, the fluorescein sodium parenteral solution （1 mL/kg） was injected v/a caudal vein and finished within about 3 s, the time of FFA was recorded from the beginning of injection, the video sight aimed at the optic disc and the surrounding area. （3） After mydriasis and anesthesia as describe above, the rats were examined with OCT. （4） Histological observation： After hematoxylin and eosin （HE） staining, the optic disc and surrounding blood vessels of retina were observed under light microscope at high power field. MAIN OUTCOME MEASURES： The results of fundus, FFA, visual electrophysiological test and OCT detection within 90 days after model establishment were observed. RESULTS： Of the 30 rats, 1 died after anesthesia in the laser group and 2 died in the AION group respectively, and finally 27 rats were involved in the analysis of results. （1） Changes in fundus： In the AION group, there was edema in upper optic disc and unclear boundary at 1 day after establishment, edema still could be observed at 6 days, and upper optic disc atrophied and appeared as pale at 90 days. （2） FFA results： In the AION group, early ＂low fluorescence＂, middle and late ＂high fluorescence＂ were observed in upper optic disc 1 day after model establishment, and there was ＂low fluorescence＂ at 6 days, and the low fluorescence could be observed all the time at 23 days. （3） Visual electrophysiological changes： In the AION group as compared with the control eyes, the experimental ones had prolonged F-VEP P100 latency [（71.65±8.81）, （57.58±8.38） ms, t =3.148, P =0.012], and decreased wave amplitude [（4.77±1.90）, （10.06±3.66） μV, t =4.082, P =0.003], and these changes lasted to 35 days after model establishment. （4） OCT results： In the AION group, the reflection surface of part nerve fiber layer was higher than the retina plane, the surface was rough and the thickness was increased at 6 days after model establishment. （5） Histopathological results： At 1 day after model establishment, part optic discs had highly edema, edema of nerve fibers, and loose tissue, also accompanied by the displacement of surrounding retina; At 23 days, the optic disc and surrounding nerve fiber layers became thinner, and the numbers of ganglion nuclei in the retina tissue sections were obviously decreased. These changes were not observed in the laser group, HPD group and blank control group. CONCLUSION ： The changes of fundus, FFA, OCT, visual electrophysiology and histopathology confirmed that the krypton red laser irradiation （647 nm） at 2 hours after HPD was injected via caudal vein can establish more ideal animal models of AION.
基金supported in part by the Natural Science Foundation of China under Grant 61972169 and U1536203in part by the National key research and developm program of China(2016QY01W0200)in part by the Major Scientic and Technological Project of Hubei Province(2018AAA068 and 2019AAA051).
文摘The majority of existing graph-network-based few-shot models focus on a node-similarity update mode.The lack of adequate information intensies the risk of overtraining.In this paper,we propose a novel Multihead Attention Graph Network to excavate discriminative relation and fulll effective information propagation.For edge update,the node-level attention is used to evaluate the similarities between the two nodes and the distributionlevel attention extracts more in-deep global relation.The cooperation between those two parts provides a discriminative and comprehensive expression for edge feature.For node update,we embrace the label-level attention to soften the noise of irrelevant nodes and optimize the update direction.Our proposed model is veried through extensive experiments on two few-shot benchmark MiniImageNet and CIFAR-FS dataset.The results suggest that our method has a strong capability of noise immunity and quick convergence.The classication accuracy outperforms most state-of-the-art approaches.
基金supported in part by the National Natural Science Foundation of China(62074006,91964204)in part by the Major Scientific Instruments and Equipment Development(61927901)+4 种基金the Shenzhen Science and Technology Project(GXWD20201231165807007-20200827114656001)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB44010200)Science and Technology Council of Shanghai(19JC1416801)the Shanghai Research and Innovation Functional Program(17DZ2260900)in part by the 111 Project(B18001)。
文摘Phase change memory(PCM)attracts wide attention for the memory-centric computing and neuromorphic comput-ing.For circuit and system designs,PCM compact models are mandatory and their status are reviewed in this work.Macro mod-els and physics-based models have been proposed in different stages of the PCM technology developments.Compact model-ing of PCM is indeed more complex than the transistor modeling due to their multi-physics nature including electrical,thermal and phase transition dynamics as well as their interactions.Realizations of the PCM operations including threshold switching,set and reset programming in these models are diverse,which also differs from the perspective of circuit simulations.For the purpose of efficient and reliable designs of the PCM technology,open issues and challenges of the compact modeling are also discussed.
基金supported by NSFC(61874005,61927901)the 111 Project(B18001).
文摘In this article,the body bias dependence of the bias temperature instability(BTI)in bulk FinFETs is experimentally studied,under different test conditions for the first time.In contrast to the traditional understanding that changing body bias has little impact on BTI degradation in FinFETs due to its weak body effect,it is observed that it actually has non-negligible impacts.And a forward body bias(FBB)can reduce the BTI degradation in FinFETs,which is opposite with the trend in planar devices.The underlying physics is found due to the trade-off between two competing factors.The results are helpful for understanding and modeling reliability in FinFETs.
基金This work was supported in part by the Natural Science Foundation of China under Grant 61972169 and U1536203in part by the National key research and development program of China(2016QY01W0200)in part by the Major Scientific and Technological Project of Hubei Province(2018AAA068 and 2019AAA051).
文摘Gait recognition is a biometric technique that captures human walking pattern using gait silhouettes as input and can be used for long-term recognition.Recently proposed video-based methods achieve high performance.However,gait covariates or walking conditions,i.e.,bag carrying and clothing,make the recognition of intra-class gait samples hard.Advanced methods simply use triplet loss for metric learning,which does not take the gait covariates into account.For alleviating the adverse influence of gait covariates,we propose cross walking condition constraint to explicitly consider the gait covariates.Specifically,this approach designs center-based and pair-wise loss functions to decrease discrepancy of intra-class gait samples under different walking conditions and enlarge the distance of inter-class gait samples under the same walking condition.Besides,we also propose a video-based strong baseline model of high performance by applying simple yet effective tricks,which have been validated in other individual recognition fields.With the proposed baseline model and loss functions,our method achieves the state-of-the-art performance.
文摘Purpose:To study the risk factors of increased intraocular pressure (IOP) response to triamcinolone acetonide intravitreal (IVTA) injection in eyes with macular edema associated with retinal vein occlusion. Methods:Eighty-nine eyes with macular edema associated with retinal vein occlusion first received periocular injection of 40 mg triamcinolone acetonide (TA) and were followed for one month. According to the diversity of IOP after periocular TA (PTA) injection, they were divided into the elevation IOP group (group A, 26 eyes) and the normal IOP group (group B,63 eyes).They then received 4 mg TA intravitreal injection.IOP measurements were recorded after PTA and IVTA injections, and were followed for six months. Results: Both PTA and IVTA injections caused a rise in IOP, but it was higher in the IVTA injection (40.45%) than in the PTA injection (29.21%). The mean rise in IOP was more significant in eyes with IVTA injection (28.08 ± 8.24 mmHg) than in eyes with PTA injection (20.87 ± 4.07 mmHg). Patients with an elevation IOP above 6 mmHg after PTA injection had a 73.08% chance of developing a pressure of 24 mmHg or higher,whereas only 12.70% of those with an elevation IOP below 6 mmHg after PTA injection experienced pressure elevation. Conclusion:IOP response to PTA injection is a good way to judge IOP response to IVTA. If the patient is highly sensitive to corticosteroid, treatments other than IVTA injection are used to avoid the increased risks associated with intravitreal corticosteroid injection.
基金supported in part by the Natural Science Foundation of China(62125401 and 62074006)the major scientific instruments and equipments development grant(61927901)the Shenzhen Fundamental Research Program(GXWD20200827114656001).
文摘In this work,a surface-potential based compact model focusing on the quantum confinement effects of ultimately scaled gate-all-around(GAA)MOSFET is presented.Energy quantization with sub-band formation along the radius direction of cylindrical GAAs or thickness direction of nanosheet GAAs leads to significant quantization effects.An analytical model of surface potentials is developed by solving the Poisson equation with incorporating sub-band effects.In combination with the existing transport model framework,charge-voltage and current-voltage formulations are developed based on the surface potential.The model formulations are then extensively validated using TCAD numerical simulations as well as Si data of nanosheet GAA MOSFETs.Simulations of typical circuits verify the model robustness and convergence for its applications in GAA technology.
基金supported by National Natural Science Foundation of China (Grant No.52178082)Program for Liaoning Innovative Tal-ents in University (No.SHSCXRC2017003)Shenyang Science and technology planning project (No.21-108-9-03).
文摘In high-rise buildings with large indoor and outdoor temperature difference,neglecting the effect of stack effect in smoke exhaust shafts may cause calculation error of the fluid network model.In this paper,the mathematical model of kitchen smoke exhaust system considering the influence of stack effect was put forward and it can be inserted different range hood sub-models.Compared with the results of six working conditions of the model without considering the stack effect,the error of the proposed model were reduced by 7.6%,4.3%,4.1%,2.8%,2.4%,and 2.1%.While the indoor and outdoor temperature difference varies from−5℃ to 49℃,the effect of stack effect on the pressure in the flue and the flow rate for each user was studied for six operating rates s.The results show that under the combined effect of stack effect and flue resistance,the static pressure of the kitchen smoke exhaust system showed a low-high-low distribution,and the maximum static pressure in the flue moved toward the bottom with the increase of temperature difference.User flow rates exhibit a low-high-low-high distribution,with an increased flow rate in the bottom users and the largest flow rate in the top users.
基金The authors gratefully acknowledge the support from the National Natural Science Foundation of China(Nos.52071238,&U20A20279)the National Key Research and Development Program of China(No.2022YFB3706701)the 111 Project(No.D18018).
文摘The effects of hydrogen on the mechanical response of pure iron with randomly distributed hydrogen atoms under nanoindentation were systematically investigated by molecular dynamics simulations with the aim to further understand hydrogen embrittlement mechanism in the steels.The simulations results revealed that,for the three models with[001],[110]and[111]surface normal,hydrogen reduced the critical load of the pop-in event,promoted the dislocation slipping and reduced the plastic region size and dislocation density around the indenter compared to the hydrogen free model.Meanwhile,the different mechanical responses of the three models with different surface normal were further explained in the perspective of Schmid factor.
