BACKGROUND：Endogenous neural progenitor cells play a beneficial role for cognitive recovery following traumatic brain injury.However,there are few classification-control studies aimed at varying graded brain trauma.O...BACKGROUND：Endogenous neural progenitor cells play a beneficial role for cognitive recovery following traumatic brain injury.However,there are few classification-control studies aimed at varying graded brain trauma.OBJECTIVE：To observe the effects of adult endogenous neurogenesis on cognitive function repair and regeneration of neural progenitor cells following varying graded traumatic hippocampal injury to determine the significance of endogenous neurogenesis in the repair of brain injury.DESIGN,TIME AND SETTING：A randomized,controlled,animal experiment was performed at the Key Laboratory of Injuries,Variations and Regeneration of Nervous System,Tianjin Medical University General Hospital,from February to October 2009.MATERIALS：Mouse anti-rat 5-bromodeoxyuridine （BrdU） and neuronal nuclei （NeuN） monoclonal antibodies were purchased from Millipore Corporation,USA.METHODS：A total of 45 Wistar rats were randomly assigned to three groups.Mild and severe injury groups were respectively subjected to （182 ± 2） kPa and （284 ± 4） kPa lateral fluid percussion to establish models of brain injury,and the control group was subjected to surgery with no lateral fluid percussion.MAIN OUTCOME MEASURES：Cognitive function was estimated using the Morris water maze.Proliferation,survival,and differentiation of newly generated cells in the injured hippocampus were observed through the use of immunofluorescent staining.RESULTS：At 7 days post-injury,the number of BrdU＋ cells in the hippocampal dentate gyrus significantly increased in the mild and severe injury groups compared with the control group （P〈0.01）.At 61 days post-injury,the number of BrdU7NeuN＋ cells in the hippocampal dentate gyrus was significantly greater in the mild injury group compared with the severe injury and control groups （P〈 0.01）.In addition,the control group exhibited the greatest proportion of surviving cells that differentiated into mature neurons compared with the injury groups （P〈 0.01）.Moreover,at 61 days post-injury,cognitive function in rats with mild injury recovered to normal levels,whereas the severe injury group exhibited cognitive deficits （P〈 0.01）.CONCLUSION：Traumatic brain injury may be a stimulation factor for proliferation of neural progenitor cells in the adult hippocampus but severe brain trauma does not lead to an increased number of newly generated cells.Endogenous adult neurogenesis repairs neurological functions to an extent.However,recovery of neurological function remains limited following severe traumatic brain injury.展开更多
Little work has been done on the effect of being overweight on the wireless narrowband radio propagation of wearable medical instruments.In this paper,by applying a finite-difference time-domain technique and a statis...Little work has been done on the effect of being overweight on the wireless narrowband radio propagation of wearable medical instruments.In this paper,by applying a finite-difference time-domain technique and a statistical learning method,the authors find that being overweight might be an obstacle to body-surface wireless communication.The findings have certain instructive meanings for those engineers who are designing on-body medical instruments for patients,especially those patients who are overweight.展开更多
Doping is a critically important strategy to modulate the properties of organic semiconductors(OSCs) to improve their optoelectrical performances. Conventional bulk doping involves the incorporation of foreign molecul...Doping is a critically important strategy to modulate the properties of organic semiconductors(OSCs) to improve their optoelectrical performances. Conventional bulk doping involves the incorporation of foreign molecular species(i.e., dopants) into the lattice of the host OSCs, and thus disrupts the packing of the host OSCs and induces structural defects, which tends to reduce the mobility and(or) the on/off ratio in organic field-effect transistors(OFETs). In this article, we report a highly efficient and highly controllable surface doping strategy utilizing 2D molecular crystals(2DMCs) as dopants to boost the mobility and to modulate the threshold voltage of OFETs. The amount of dopants, i.e., the thickness of the 2DMCs, is controlled at monolayer precision, enabling fine tuning of the electrical properties of the OSCs at unprecedented accuracy. As a result, a prominent increase of the average mobility from 1.31 to 4.71 cm2 V-1 s-1 and a substantial reduction of the threshold voltage from -18.5 to -1.8 V are observed. Meanwhile, high on/off ratios of up to 108 are retained.展开更多
In this paper,we propose a new directional multi-resolution ridgelet network(DMRN)based on the ridgelet frame theory,which uses the ridgelet as the activation function in a hidden layer.For the multi-resolution proper...In this paper,we propose a new directional multi-resolution ridgelet network(DMRN)based on the ridgelet frame theory,which uses the ridgelet as the activation function in a hidden layer.For the multi-resolution properties of the ridgelet function in the direction besides scale and position,DMRN has great capabilities in catching essential features of direction-rich data.It proves to be able to approximate any multivariate function in a more stable and efficient way,and optimal in approximating functions with spatial inhomogeneities.Besides,using binary ridgelet frame as the mathematical foundation in its construction,DMRN is more flexible with a simple structure.The construction and the learning algorithm of DMRN are given.Its approximation capacity and approximation rate are also analyzed in detail.Possibilities of applications to regression and recognition are included to demonstrate its superiority to other methods and feasibility in practice.Both theory analysis and simulation results prove its high efficiency.展开更多
基金the National Natural Science Foundation of China,No. 30973090the Natural Science Foundation of Tianjin,No.09JCZDJC17200
文摘BACKGROUND：Endogenous neural progenitor cells play a beneficial role for cognitive recovery following traumatic brain injury.However,there are few classification-control studies aimed at varying graded brain trauma.OBJECTIVE：To observe the effects of adult endogenous neurogenesis on cognitive function repair and regeneration of neural progenitor cells following varying graded traumatic hippocampal injury to determine the significance of endogenous neurogenesis in the repair of brain injury.DESIGN,TIME AND SETTING：A randomized,controlled,animal experiment was performed at the Key Laboratory of Injuries,Variations and Regeneration of Nervous System,Tianjin Medical University General Hospital,from February to October 2009.MATERIALS：Mouse anti-rat 5-bromodeoxyuridine （BrdU） and neuronal nuclei （NeuN） monoclonal antibodies were purchased from Millipore Corporation,USA.METHODS：A total of 45 Wistar rats were randomly assigned to three groups.Mild and severe injury groups were respectively subjected to （182 ± 2） kPa and （284 ± 4） kPa lateral fluid percussion to establish models of brain injury,and the control group was subjected to surgery with no lateral fluid percussion.MAIN OUTCOME MEASURES：Cognitive function was estimated using the Morris water maze.Proliferation,survival,and differentiation of newly generated cells in the injured hippocampus were observed through the use of immunofluorescent staining.RESULTS：At 7 days post-injury,the number of BrdU＋ cells in the hippocampal dentate gyrus significantly increased in the mild and severe injury groups compared with the control group （P〈0.01）.At 61 days post-injury,the number of BrdU7NeuN＋ cells in the hippocampal dentate gyrus was significantly greater in the mild injury group compared with the severe injury and control groups （P〈 0.01）.In addition,the control group exhibited the greatest proportion of surviving cells that differentiated into mature neurons compared with the injury groups （P〈 0.01）.Moreover,at 61 days post-injury,cognitive function in rats with mild injury recovered to normal levels,whereas the severe injury group exhibited cognitive deficits （P〈 0.01）.CONCLUSION：Traumatic brain injury may be a stimulation factor for proliferation of neural progenitor cells in the adult hippocampus but severe brain trauma does not lead to an increased number of newly generated cells.Endogenous adult neurogenesis repairs neurological functions to an extent.However,recovery of neurological function remains limited following severe traumatic brain injury.
基金supported by the National Natural Science Foundation of China(52073206,52273193)the Fundamental Research Funds for the Central UniversitiesTianjin University 2021 Postgraduate Education Special Fund(B2-2021-005)。
基金supported by the Fundamental Research Funds for the Central Universities (K5051310004,JB140219,and K5051302033)the National Natural Science Foundation of China (61301175)
文摘Little work has been done on the effect of being overweight on the wireless narrowband radio propagation of wearable medical instruments.In this paper,by applying a finite-difference time-domain technique and a statistical learning method,the authors find that being overweight might be an obstacle to body-surface wireless communication.The findings have certain instructive meanings for those engineers who are designing on-body medical instruments for patients,especially those patients who are overweight.
基金the National Natural Science Foundation of China(61674116,51873148,51633006,and 52003190)the Ministry of Science and Technology of China(2016YFA0202302)the Natural Science Foundation of Tianjin(18JC-YBJC18400)。
基金supported by the National Natural Science Foundation of China (51873148, 61674116, 51633006)the Ministry of Science and Technology of China (2016YFA0202302)the Natural Science Foundation of Tianjin City (18JC-YBJC18400)。
文摘Doping is a critically important strategy to modulate the properties of organic semiconductors(OSCs) to improve their optoelectrical performances. Conventional bulk doping involves the incorporation of foreign molecular species(i.e., dopants) into the lattice of the host OSCs, and thus disrupts the packing of the host OSCs and induces structural defects, which tends to reduce the mobility and(or) the on/off ratio in organic field-effect transistors(OFETs). In this article, we report a highly efficient and highly controllable surface doping strategy utilizing 2D molecular crystals(2DMCs) as dopants to boost the mobility and to modulate the threshold voltage of OFETs. The amount of dopants, i.e., the thickness of the 2DMCs, is controlled at monolayer precision, enabling fine tuning of the electrical properties of the OSCs at unprecedented accuracy. As a result, a prominent increase of the average mobility from 1.31 to 4.71 cm2 V-1 s-1 and a substantial reduction of the threshold voltage from -18.5 to -1.8 V are observed. Meanwhile, high on/off ratios of up to 108 are retained.
基金supported by the National Natural Science Foundation of China (Grant No.60601029)the National Basic Research Program of China (No.A 50105020025).
文摘In this paper,we propose a new directional multi-resolution ridgelet network(DMRN)based on the ridgelet frame theory,which uses the ridgelet as the activation function in a hidden layer.For the multi-resolution properties of the ridgelet function in the direction besides scale and position,DMRN has great capabilities in catching essential features of direction-rich data.It proves to be able to approximate any multivariate function in a more stable and efficient way,and optimal in approximating functions with spatial inhomogeneities.Besides,using binary ridgelet frame as the mathematical foundation in its construction,DMRN is more flexible with a simple structure.The construction and the learning algorithm of DMRN are given.Its approximation capacity and approximation rate are also analyzed in detail.Possibilities of applications to regression and recognition are included to demonstrate its superiority to other methods and feasibility in practice.Both theory analysis and simulation results prove its high efficiency.
