Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury...Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient＇s condition and judging prognosis after traumatic brain injury.展开更多
Zinc(Zn)has recently been recognized as a promising bone repair material due to its inherent biodegradability and favorable biocompatibility.In this work,rare earth neodymium(Nd)was introduced into a Zn-based alloy fa...Zinc(Zn)has recently been recognized as a promising bone repair material due to its inherent biodegradability and favorable biocompatibility.In this work,rare earth neodymium(Nd)was introduced into a Zn-based alloy fabricated using a laser powder bed fusion(LPBF)process.Results showed that addition of Nd significantly improved the melt fluidity and reduced the evaporation of Zn,thereby achieving parts with a high densification rate of 98.71%.Significantly,the Nd alloying treatment effectively refined the grain size from 25.3 to 6.2μm.Nd Zn5 eutectics precipitated and contributed to a second-phase strengthening effect.As a result,the tensile strength increased to(119.3±5.1)MPa and the Vickers hardness to(76.2±4.1).Moreover,the Zn–Nd alloy exhibited good anti-inflammatory activity,as the Nd ions released during degradation had a strong affinity with cell membrane phospholipids and consequently inhibited the release of inflammatory cytokines.It also presented favorable cytocompatibility,showing great potential as a bone repair material.展开更多
文摘Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient＇s condition and judging prognosis after traumatic brain injury.
基金the National Natural Science Foundation of China(Nos.51935014,82072084,and 81871498)the Jiangxi Provincial Natural Science Foundation of China(Nos.20192ACB20005 and 2020ACB214004)+4 种基金the Jiangxi Provincial Key R&D Program(No.20201BBE51012)the Guangdong Provincial Higher Vocational Colleges&Schools Pearl River Scholar Funded Scheme(2018)the China Postdoctoral Science Foundation(No.2020M682114)the Open Research Fund of Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technologythe Project of Hunan Provincial Science and Technology Plan(No.2017RS3008),China。
文摘Zinc(Zn)has recently been recognized as a promising bone repair material due to its inherent biodegradability and favorable biocompatibility.In this work,rare earth neodymium(Nd)was introduced into a Zn-based alloy fabricated using a laser powder bed fusion(LPBF)process.Results showed that addition of Nd significantly improved the melt fluidity and reduced the evaporation of Zn,thereby achieving parts with a high densification rate of 98.71%.Significantly,the Nd alloying treatment effectively refined the grain size from 25.3 to 6.2μm.Nd Zn5 eutectics precipitated and contributed to a second-phase strengthening effect.As a result,the tensile strength increased to(119.3±5.1)MPa and the Vickers hardness to(76.2±4.1).Moreover,the Zn–Nd alloy exhibited good anti-inflammatory activity,as the Nd ions released during degradation had a strong affinity with cell membrane phospholipids and consequently inhibited the release of inflammatory cytokines.It also presented favorable cytocompatibility,showing great potential as a bone repair material.
