A novel alpha function for Peng-Robinson equation of state was proposed and generalized with acentric factor and dipole moment for predicting thermodynamic properties of non-polar,weakly polar,and polar compounds.The ...A novel alpha function for Peng-Robinson equation of state was proposed and generalized with acentric factor and dipole moment for predicting thermodynamic properties of non-polar,weakly polar,and polar compounds.The parameters of new alpha function were fitted with vapor pressures of 70 compounds.Six different methods were investigated for the correlation of parameters of new alpha function and Heyen alpha function.The generalized new alpha function passed the consistency test.The results indicated that the predictive accuracy of generalized new alpha function and generalized Heyen alpha function was improved for the estimation of vapor pressure of 11 kinds of compounds,with the average relative deviations(ARDs)being 2.60%and 2.76%.The ARDs of the two generalized alpha functions were 2.04%and 2.09%for the enthalpy of vaporization.However,the generalized new alpha function and the other alpha functions had great deviations for the prediction of liquid volumes and isobaric heat capacities.The alpha function that was generalized with acentric factor and reduced dipole moment was more accurate than that was generalized with acentric factor,especially for the prediction of vapor pressure and enthalpy of vaporization of polar compounds.展开更多
Effect factors of the absorption of the source,air,entrance window,and dead layer of a detector must be considered in the measurement of monoenergetic alpha particles,along with statistical noise and other factors tha...Effect factors of the absorption of the source,air,entrance window,and dead layer of a detector must be considered in the measurement of monoenergetic alpha particles,along with statistical noise and other factors that collectively cause the alpha spectrum to exhibit a well-known low-energy tail.Therefore,the estabUshment of an alpha spectrum detector response function from the perspective of a signaling system must consider the various factors mentioned above.The detector response function is the convolution of an alphaparticle pulse function,two exponential functions,and a Gaussian function,followed by calculation of the parameters of the detector response function using the weighted leastsquares fitting method as proposed in this paper.In our experiment,^(239)Pu alpha spectra were measured by a highresolution,passivated implanted planar silicon(PIPS)detector at 10 levels of vacuum and 10 source-detector distances.The spectrum-fitting results were excellent as evaluated by reduced Chi-square(x^2) and correlation coefficients.Finally,the variation of parameters with vacuum level and source-detector distance was studied.Results demonstrate that σ,τ_1,and τ_2 exhibit no obvious trend of variation with vacuum in the range 2000-20,000 mTorr,and at a confidence level of 95%,the values of τ_1 and τ_2 decline in a similar fashion with source-detector distance by the power exponential function,while the value of a declines linearly.展开更多
Spontaneous alpha oscillations are a ubiquitous phenomenon in the brain and play a key role in neural information processing and various cognitive functions.Jansen＇s neural mass model（NMM） was initially proposed to...Spontaneous alpha oscillations are a ubiquitous phenomenon in the brain and play a key role in neural information processing and various cognitive functions.Jansen＇s neural mass model（NMM） was initially proposed to study the origin of alpha oscillations.Most of previous studies of the spontaneous alpha oscillations in the NMM were conducted using numerical methods.In this study,we aim to propose an analytical approach using the describing function method to elucidate the spontaneous alpha oscillation mechanism in the NMM.First,the sigmoid nonlinear function in the NMM is approximated by its describing function,allowing us to reformulate the NMM and derive its standard form composed of one nonlinear part and one linear part.Second,by conducting a theoretical analysis,we can assess whether or not the spontaneous alpha oscillation would occur in the NMM and,furthermore,accurately determine its amplitude and frequency.The results reveal analytically that the interaction between linearity and nonlinearity of the NMM plays a key role in generating the spontaneous alpha oscillations.Furthermore,strong nonlinearity and large linear strength are required to generate the spontaneous alpha oscillations.展开更多
Mild traumatic brain injury（TBI）, also called concussion, initiates sequelae leading to motor deficits, cognitive impairments and subtly compromised neurobehaviors. While the acute phase of TBI is associated with ne...Mild traumatic brain injury（TBI）, also called concussion, initiates sequelae leading to motor deficits, cognitive impairments and subtly compromised neurobehaviors. While the acute phase of TBI is associated with neuroinflammation and nitroxidative burst, the chronic phase shows a lack of stimulation of the neurorepair process and regeneration. The deficiency of nitric oxide（NO）, the consequent disturbed NO metabolome, and imbalanced mechanisms of S-nitrosylation are implicated in blocking the mechanisms of neurorepair processes and functional recovery in the both phases. Hypoxia inducible factor-1 alpha（HIF-1α）, a master regulator of hypoxia/ischemia, stimulates the process of neurorepair and thus aids in functional recovery after brain trauma. The activity of HIF-1α is regulated by NO via the mechanism of S-nitrosylation of HIF-1α. S-nitrosylation is dynamically regulated by NO metabolites such as S-nitrosoglutathione（GSNO） and peroxynitrite. GSNO stabilizes, and peroxynitrite destabilizes HIF-1α. Exogenously administered GSNO was found not only to stabilize HIF-1α and to induce HIF-1α-dependent genes but also to stimulate the regeneration process and to aid in functional recovery in TBI animals.展开更多
Post-hepatectomy liver failure(PHLF) is a leading cause of morbidity and mortality following major liver resection. The development of PHLF is dependent on the volume of the remaining liver tissue and hepatocyte funct...Post-hepatectomy liver failure(PHLF) is a leading cause of morbidity and mortality following major liver resection. The development of PHLF is dependent on the volume of the remaining liver tissue and hepatocyte function. Without effective pre-operative assessment, patients with undiagnosed liver disease could be at increased risk of PHLF. We report a case of a 60-year-old male patient with PHLF secondary to undiagnosed alpha-1-antitrypsin deficiency(AATD) following major liver resection. He initially presented with acute large bowel obstruction secondary to a colorectal adenocarcinoma, which had metastasized to the liver. There was no significant past medical history apart from mild chronic obstructive pulmonary disease. After colonic surgery and liver directed neo-adjuvant chemotherapy, he underwent a laparoscopic partially extended right hepatectomy and radio-frequency ablation. Post-operatively he developed PHLF. The cause of PHLF remained unknown, prompting reanalysis of the histology, which showed evidence of AATD. He subsequently developed progressive liver dysfunction, portal hypertension, and eventually an extensive parastomal bleed, which led to his death; this was ultimately due to a combination of AATD and chemotherapy. This case highlights that formal testing for AATD in all patients with a known history of chronic obstructive pulmonary disease, heavy smoking, or strong family history could help prevent the development of PHLF in patients undergoing major liver resection.展开更多
OBJECTIVE Oleoylethanolamide(OEA) is an endogenous peroxisome proliferatoractivated receptor alpha(PPARα) agonist that acts on the peripheral control of energy metabolism.Previous studies have shown that OEA exerts n...OBJECTIVE Oleoylethanolamide(OEA) is an endogenous peroxisome proliferatoractivated receptor alpha(PPARα) agonist that acts on the peripheral control of energy metabolism.Previous studies have shown that OEA exerts neuroprotection after cerebral ischemia.However,whether OEA affects the outcomes of diabetes-induced encephalopathy(DE) requires further study.METHODS The chronic effects of OEA on DE were evaluated in C57BL/6 and PPARαknockout mice,individually.The cognitive function was assessed with Morris water maze.The expression of receptor for advanced glycation end products(RAGE) and phosphorylation of Tau in mice hippocampus were determined using Western blotting.The influence of OEA in neuron loss and neuroplasticity were assessed with immunofluorescent staining and Western blotting.RESULTS OEA markedly ameliorated performance in the Morris water maze,which was correlated with its capabilities of suppressing glycometabolism and phosphorylation of Tau in the hippocampus.OEA offered protection from diabetes-induced impairments in hippocampal neuroplasticity.Furthermore,the changes in Morris water maze performance and neuron loss could not be observed in PPARα knockout mouse models with OEA administration.CONCLUSION The ability of OEA to control PPARα signaling can serve as a novel neuroprotective approach for the treatment of diabetes-induced encephalopathy.展开更多
Purpose: Several studies have demonstrated that the measurement of salivary alpha-amylase (sAA) levels is a useful tool for evaluating the autonomic nervous system. Psychosocial stress increases the release of sAA as ...Purpose: Several studies have demonstrated that the measurement of salivary alpha-amylase (sAA) levels is a useful tool for evaluating the autonomic nervous system. Psychosocial stress increases the release of sAA as a useful marker for autonomic nervous system (ANS). To our knowledge, although some studies have evaluated sAA levels under psychosocial stress, no studies have investigated the changes in sAA activity that occur in junior high school students who are not attending school due to social anxiety disorder (SAD). We aimed to investigate the relationship between the sAA levels and psychiatric states of such patients. Methods: The study subjects consisted of SAD patients (n = 39) and healthy controls (n = 57). We used a portable hand-held monitor to measure the level of sAA and State-Trait Anxiety Index (STAI) to evaluate the psychiatric state. Results: The patients’ sAA activity was significantly higher than that of the controls (n = 57) (p < 0.001). Significant differences in heart rate (HR) (76.10 ± 11.96 vs. 68.69 ± 10.61, respectively, p < 0.01) and STAI scores (both the STAI-State and STAI-Trait scores) (49.35 ± 10.57 vs. 41.24 ± 8.59, respectively, p < 0.01;55.69 ± 10.44 vs. 45.61 ± 9.36, respectively, p < 0.001) were detected between the patients and healthy controls. Conclusions: These results indicated that junior high school students with SAD exhibit a higher state of anxiety and high autonomic activity, probably due to changes in the sympathetic nervous system. As a result, junior high school students with SAD are expected to exhibit high levels of sAA accompanied by anxiety symptoms.展开更多
基金supported by National Natural Science Foundation of China(22008129,22108138)。
文摘A novel alpha function for Peng-Robinson equation of state was proposed and generalized with acentric factor and dipole moment for predicting thermodynamic properties of non-polar,weakly polar,and polar compounds.The parameters of new alpha function were fitted with vapor pressures of 70 compounds.Six different methods were investigated for the correlation of parameters of new alpha function and Heyen alpha function.The generalized new alpha function passed the consistency test.The results indicated that the predictive accuracy of generalized new alpha function and generalized Heyen alpha function was improved for the estimation of vapor pressure of 11 kinds of compounds,with the average relative deviations(ARDs)being 2.60%and 2.76%.The ARDs of the two generalized alpha functions were 2.04%and 2.09%for the enthalpy of vaporization.However,the generalized new alpha function and the other alpha functions had great deviations for the prediction of liquid volumes and isobaric heat capacities.The alpha function that was generalized with acentric factor and reduced dipole moment was more accurate than that was generalized with acentric factor,especially for the prediction of vapor pressure and enthalpy of vaporization of polar compounds.
基金supported by the National Natural Science Foundation of China(Nos.41374130 and 41604154)Opening Foundation of Sichuan Provincial Key Lab of Applied Nuclear Techniques in Geosciences(No.gnzds2014003)the Open Fund of Robot Technology Used for Special Environment Key Laboratory of Sichuan Province(13zxtk04)
文摘Effect factors of the absorption of the source,air,entrance window,and dead layer of a detector must be considered in the measurement of monoenergetic alpha particles,along with statistical noise and other factors that collectively cause the alpha spectrum to exhibit a well-known low-energy tail.Therefore,the estabUshment of an alpha spectrum detector response function from the perspective of a signaling system must consider the various factors mentioned above.The detector response function is the convolution of an alphaparticle pulse function,two exponential functions,and a Gaussian function,followed by calculation of the parameters of the detector response function using the weighted leastsquares fitting method as proposed in this paper.In our experiment,^(239)Pu alpha spectra were measured by a highresolution,passivated implanted planar silicon(PIPS)detector at 10 levels of vacuum and 10 source-detector distances.The spectrum-fitting results were excellent as evaluated by reduced Chi-square(x^2) and correlation coefficients.Finally,the variation of parameters with vacuum level and source-detector distance was studied.Results demonstrate that σ,τ_1,and τ_2 exhibit no obvious trend of variation with vacuum in the range 2000-20,000 mTorr,and at a confidence level of 95%,the values of τ_1 and τ_2 decline in a similar fashion with source-detector distance by the power exponential function,while the value of a declines linearly.
基金Project supported by the National Natural Science Foundation of China(Grant No.61473208)the Tianjin Research Program of Application Foundation and Advanced Technology,China(Grant No.15JCYBJC47700)+1 种基金the National Institutes of Health,USA(Grant Nos.R01DA040990 and R01EY027544)the Project of Humanities and Social Sciences from the Ministry of Education,China(Grant No.17YJAZH092)
文摘Spontaneous alpha oscillations are a ubiquitous phenomenon in the brain and play a key role in neural information processing and various cognitive functions.Jansen＇s neural mass model（NMM） was initially proposed to study the origin of alpha oscillations.Most of previous studies of the spontaneous alpha oscillations in the NMM were conducted using numerical methods.In this study,we aim to propose an analytical approach using the describing function method to elucidate the spontaneous alpha oscillation mechanism in the NMM.First,the sigmoid nonlinear function in the NMM is approximated by its describing function,allowing us to reformulate the NMM and derive its standard form composed of one nonlinear part and one linear part.Second,by conducting a theoretical analysis,we can assess whether or not the spontaneous alpha oscillation would occur in the NMM and,furthermore,accurately determine its amplitude and frequency.The results reveal analytically that the interaction between linearity and nonlinearity of the NMM plays a key role in generating the spontaneous alpha oscillations.Furthermore,strong nonlinearity and large linear strength are required to generate the spontaneous alpha oscillations.
基金supported by grants from VA merit awards(BX3401 and RX2090)
文摘Mild traumatic brain injury（TBI）, also called concussion, initiates sequelae leading to motor deficits, cognitive impairments and subtly compromised neurobehaviors. While the acute phase of TBI is associated with neuroinflammation and nitroxidative burst, the chronic phase shows a lack of stimulation of the neurorepair process and regeneration. The deficiency of nitric oxide（NO）, the consequent disturbed NO metabolome, and imbalanced mechanisms of S-nitrosylation are implicated in blocking the mechanisms of neurorepair processes and functional recovery in the both phases. Hypoxia inducible factor-1 alpha（HIF-1α）, a master regulator of hypoxia/ischemia, stimulates the process of neurorepair and thus aids in functional recovery after brain trauma. The activity of HIF-1α is regulated by NO via the mechanism of S-nitrosylation of HIF-1α. S-nitrosylation is dynamically regulated by NO metabolites such as S-nitrosoglutathione（GSNO） and peroxynitrite. GSNO stabilizes, and peroxynitrite destabilizes HIF-1α. Exogenously administered GSNO was found not only to stabilize HIF-1α and to induce HIF-1α-dependent genes but also to stimulate the regeneration process and to aid in functional recovery in TBI animals.
文摘Post-hepatectomy liver failure(PHLF) is a leading cause of morbidity and mortality following major liver resection. The development of PHLF is dependent on the volume of the remaining liver tissue and hepatocyte function. Without effective pre-operative assessment, patients with undiagnosed liver disease could be at increased risk of PHLF. We report a case of a 60-year-old male patient with PHLF secondary to undiagnosed alpha-1-antitrypsin deficiency(AATD) following major liver resection. He initially presented with acute large bowel obstruction secondary to a colorectal adenocarcinoma, which had metastasized to the liver. There was no significant past medical history apart from mild chronic obstructive pulmonary disease. After colonic surgery and liver directed neo-adjuvant chemotherapy, he underwent a laparoscopic partially extended right hepatectomy and radio-frequency ablation. Post-operatively he developed PHLF. The cause of PHLF remained unknown, prompting reanalysis of the histology, which showed evidence of AATD. He subsequently developed progressive liver dysfunction, portal hypertension, and eventually an extensive parastomal bleed, which led to his death; this was ultimately due to a combination of AATD and chemotherapy. This case highlights that formal testing for AATD in all patients with a known history of chronic obstructive pulmonary disease, heavy smoking, or strong family history could help prevent the development of PHLF in patients undergoing major liver resection.
基金Fun-damental Research Funds for the Central Universities (20720180042)Health Science ResearchPersonnel Training Program of Fujian Province(2018-CXB-30)+2 种基金Natural Science Foundation of Fujian, China (2016J014152016D024)Science and Technology Project of Xi
文摘OBJECTIVE Oleoylethanolamide(OEA) is an endogenous peroxisome proliferatoractivated receptor alpha(PPARα) agonist that acts on the peripheral control of energy metabolism.Previous studies have shown that OEA exerts neuroprotection after cerebral ischemia.However,whether OEA affects the outcomes of diabetes-induced encephalopathy(DE) requires further study.METHODS The chronic effects of OEA on DE were evaluated in C57BL/6 and PPARαknockout mice,individually.The cognitive function was assessed with Morris water maze.The expression of receptor for advanced glycation end products(RAGE) and phosphorylation of Tau in mice hippocampus were determined using Western blotting.The influence of OEA in neuron loss and neuroplasticity were assessed with immunofluorescent staining and Western blotting.RESULTS OEA markedly ameliorated performance in the Morris water maze,which was correlated with its capabilities of suppressing glycometabolism and phosphorylation of Tau in the hippocampus.OEA offered protection from diabetes-induced impairments in hippocampal neuroplasticity.Furthermore,the changes in Morris water maze performance and neuron loss could not be observed in PPARα knockout mouse models with OEA administration.CONCLUSION The ability of OEA to control PPARα signaling can serve as a novel neuroprotective approach for the treatment of diabetes-induced encephalopathy.
文摘Purpose: Several studies have demonstrated that the measurement of salivary alpha-amylase (sAA) levels is a useful tool for evaluating the autonomic nervous system. Psychosocial stress increases the release of sAA as a useful marker for autonomic nervous system (ANS). To our knowledge, although some studies have evaluated sAA levels under psychosocial stress, no studies have investigated the changes in sAA activity that occur in junior high school students who are not attending school due to social anxiety disorder (SAD). We aimed to investigate the relationship between the sAA levels and psychiatric states of such patients. Methods: The study subjects consisted of SAD patients (n = 39) and healthy controls (n = 57). We used a portable hand-held monitor to measure the level of sAA and State-Trait Anxiety Index (STAI) to evaluate the psychiatric state. Results: The patients’ sAA activity was significantly higher than that of the controls (n = 57) (p < 0.001). Significant differences in heart rate (HR) (76.10 ± 11.96 vs. 68.69 ± 10.61, respectively, p < 0.01) and STAI scores (both the STAI-State and STAI-Trait scores) (49.35 ± 10.57 vs. 41.24 ± 8.59, respectively, p < 0.01;55.69 ± 10.44 vs. 45.61 ± 9.36, respectively, p < 0.001) were detected between the patients and healthy controls. Conclusions: These results indicated that junior high school students with SAD exhibit a higher state of anxiety and high autonomic activity, probably due to changes in the sympathetic nervous system. As a result, junior high school students with SAD are expected to exhibit high levels of sAA accompanied by anxiety symptoms.
