Synaptic dysfunction is an important pathological hallmark and cause of Alzheimer's disease(AD).High-frequency stimulation(HFS)-induced long-term potentiation(LTP)has been widely used to study synaptic plasticity,...Synaptic dysfunction is an important pathological hallmark and cause of Alzheimer's disease(AD).High-frequency stimulation(HFS)-induced long-term potentiation(LTP)has been widely used to study synaptic plasticity,with impaired LTP found to be associated with AD.However,the exact molecular mechanism underlying synaptic plasticity has yet to be completely elucidated.Whether genes regulating synaptic plasticity are altered in AD and contribute to disease onset also remains unclear.Herein,we induced LTP in the hippocampal CA1 region of wildtype(WT)and AD model mice by administering HFS to the CA3 region and then studied transcriptome changes in the CA1 region.We identified 89 genes that may participate in normal synaptic plasticity by screening HFS-induced differentially expressed genes(DEGs)in mice with normal LTP,and 43 genes that may contribute to synaptic dysfunction in AD by comparing HFS-induced DEGs in mice with normal LTP and AD mice with impaired LTP.We further refined the 43 genes down to 14 by screening for genes with altered expression in pathological-stage AD mice without HFS induction.Among them,we found that the expression of Pygm,which catabolizes glycogen,was also decreased in AD patients.We further demonstrated that down-regulation of PYGM in neurons impaired synaptic plasticity and cognition in WT mice,while its overexpression attenuated synaptic dysfunction and cognitive deficits in AD mice.Moreover,we showed that PYGM directly regulated energy generation in neurons.Our study not only indicates that PYGM-mediated energy production in neurons plays an important role in synaptic function,but also provides a novel LTP-based strategy to systematically identify genes regulating synaptic plasticity under physiological and pathological conditions.展开更多
The increasing severity of ground subsidence,ground fissure and other disasters caused by the excessive exploitation of deep underground resources has highlighted the pressing need for effective management.A significa...The increasing severity of ground subsidence,ground fissure and other disasters caused by the excessive exploitation of deep underground resources has highlighted the pressing need for effective management.A significant contributing factor to the challenges faced is the inadequacy of existing soil mechanics experimental instruments in providing effective indicators,creating a bottleneck in comprehensively understanding the mechanisms of land subsidence.It is urgent to develop a multi-field and multi-functional soil mechanics experimental system to address this issue.Based soil mechanics theories,the existing manufacturing capabilities of triaxial apparatus and the practical demands of the test system,a set of multi-field coupled high-pressure triaxial system is developed tailored for testing deep soils(at depths of approximately 3000 m)and soft rock.This system incorporates specialized design elements such as high-pressure chamber and horizontal deformation testing devices.In addition to the conventional triaxial tester functions,its distinctive feature encompass a horizontal deformation tracking measuring device,a water release testing device and temperature control device for the sample.This ensemble facilitates testing of horizontal and vertical deformation water release and other parameters of samples under a specified stress conditions,at constant or varying temperature ranging from-40℃–90℃.The accuracy of the tested parameters meets the requirements of relevant current specifications.The test system not only provides scientifically robust data for revealing the deformation and failure mechanism of soil subjected to extreme temperature,but also offers critical data support for major engineering projects,deep exploration and mitigation efforts related to soil deformation-induced disaster.展开更多
BACKGROUND The incidence of acute kidney injury(AKI)in patients with sepsis is high,and the prognosis of patients with septic AKI is poor.The early diagnosis and treatment of septic AKI is of great significance in imp...BACKGROUND The incidence of acute kidney injury(AKI)in patients with sepsis is high,and the prognosis of patients with septic AKI is poor.The early diagnosis and treatment of septic AKI is of great significance in improving the prognosis of patients with sepsis.AIM To explore the value of contrast-enhanced ultrasound(CEUS),serum creatinine(Scr),and other indicators in the early diagnosis of septic AKI.METHODS Ninety patients with sepsis during hospitalization at Tongji Hospital of Tongji University were recruited as subjects.Each patient was recorded with relevant basic data,clinical indicators,and CEUS results.The patients were divided into AKI group and non-AKI group according to the results of renal function diagnosis after 48 h.On the 7th day,the renal function of the non-AKI group was re-evaluated and the patients were further divided into AKI subgroup and non-AKI subgroup.The differences of the indicators in different groups were compared,and the diagnostic value of each indicator and their combination for septic AKI was analyzed.RESULTS Systemic inflammatory response score(2.58±0.75),blood lactic acid(3.01±1.33 mmol/L),Scr(141.82±27.19μmol/L),blood urea nitrogen(4.41±0.81mmol/L),and rise time(10.23±2.63 s)in the AKI group were higher than those in the non-AKI group.Peak intensity(PI)(10.78±3.98 dB)and wash in slope(WIS)(1.07±0.53 dB/s)were lower than those in the non-AKI group.The differences were statistically significant(P<0.05).The PI(12.83±3.77 dB)and WIS(1.22±0.68 dB/s)in the AKI subgroup were lower than those in the non-AKI subgroup,and the differences were statistically significant(P<0.05).The area under curve(AUC)of Scr for the diagnosis of septic AKI was 0.825 with a sensitivity of 56.76% and a specificity of 100%.The AUCs of WIS and PI(0.928 and 0.912)were higher than those of Scr.Their sensitivities were 100%,but the specificities were 71.70% and 75.47%.The AUC of the combination of three indicators for the diagnosis of septic AKI was 0.943,which was significantly higher than the AUC diagnosed by each single indicator.The sensitivity was 94.59%,and the specificity was 81.13%.CONCLUSION The combination of Scr,PI,and WIS can improve the diagnostic accuracy of septic AKI.PI and WIS are expected to predict the occurrence of early septic AKI.展开更多
AIM To analyze the incidence of hepatocellular carcinoma (HCC) in a population that underwent health checkups and had high serum miR-106b levels. METHODS A total of 335 subjects who underwent checkups in the Digestive...AIM To analyze the incidence of hepatocellular carcinoma (HCC) in a population that underwent health checkups and had high serum miR-106b levels. METHODS A total of 335 subjects who underwent checkups in the Digestive and Liver Disease Department of our hospital were randomly selected. RT-PCR was used to detect the level of miR-106b in serum samples. Laboratory and imaging examinations were carried out to confirm the HCC diagnosis in patients who had a > 2-fold change in miR-106b levels. Ultrasound-guided biopsy was also used for HCC diagnosis when necessary. On this basis, the clinical data of these subjects, including history of hepatitis virus infection, obesity, long-term history of alcohol use and stage of HCC, were collected. Then, the impact of these factors on the level of miR1-06b in serum was analyzed. Furthermore, receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic efficacy of miR-106b for HCC. RESULTS A total of 35 subjects had abnormal serum miR-106b levels, of which 20 subjects were diagnosed with HCC. t-test revealed that the difference in serum miR-106b level in terms of sex, age, history of hepatitis virus infection, obesity and long-term history of alcohol use was not statistically significant. However, serum miR-106b levels in patients with advanced HCC (stage. /.) was higher than in patients with early HCC (stage./.), and the difference was statistically significant (P = 0.000). Moreover, the ROC curve revealed that the area under the curve value for miR-106b was 0.885, which shows that serum miR-106b level has a certain clinical value for HCC diagnosis. CONCLUSION The random sampling survey shows that serum miR-106b level is a valuable diagnostic marker for HCC. However, the diagnostic threshold value needs to be further researched.展开更多
AIM: To determine the correlation between portal hemodynamics and spleen function among different grades of cirrhosis and verify its significance in cirrhosis staging.METHODS: The portal and splenic vein hemodynamics ...AIM: To determine the correlation between portal hemodynamics and spleen function among different grades of cirrhosis and verify its significance in cirrhosis staging.METHODS: The portal and splenic vein hemodynamics and spleen size were investigated by ultrasonography in consecutive 38 cirrhotic patients with cirrhosis (Child's grades A to C) and 20 normal controls. The differences were compared in portal vein diameter and flow velocity between patients with and without ascites and between patients with mild and severe esophageal varices. The correlation between peripheral blood cell counts and Child's grades was also determined.RESULTS: The portal flow velocity and volume were significantly lower in patients with Child's C (12.25±1.67 cm/s vs 788.59±234 mm/min, respectively) cirrhosis compared to controls (19.55±3.28 cm/s vs 1254.03±410 mm/min,respectively) and those with Child's A (18.5±3.02 cm/s vs1358.48±384 mm/min, respectively) and Child's B (16.0±3.89cm/s vs 1142.23±390 mm/min, respectively)cirrhosis.Patients with ascites had much lower portal flow velocity and volume (13.0±1.72 cm/s vs 1078±533 mm/min) than those without ascites (18.6±2.60 cm/s vs 1394±354 mm/min).There was no statistical difference between patients with mild and severe esophageal varices. The portal vein diameter was not significantly different among the above groups.There were significant differences in splenic vein diameter,flow velocity and white blood cell count, but not in spleen size, red blood cell and platelet counts among the various grades of cirrhosis. The spleen size was negatively correlated with red blood cell and platelet counts (r= -0.620and r = -0.8.34, respectively).CONCLUSION: An optimal system that includes parameters representing the portal hemodynamics and spleen function should be proposed for cirrhosis staging.展开更多
Theoretical studies of F atom reaction with trans-1,3-butadiene were carried out at the CCSD（T）/6- 311G（d,p）/B3LYP/6-311G（d,p） levels. Energies and structures for all reactants, products and transition states we...Theoretical studies of F atom reaction with trans-1,3-butadiene were carried out at the CCSD（T）/6- 311G（d,p）/B3LYP/6-311G（d,p） levels. Energies and structures for all reactants, products and transition states were determined. Two reaction pathways involving the formation of the complexes CH2CHCHFCH2 and CH2CHCHCH2F were found in this reaction. Theoretical results suggest that the H atom channel observed in previous crossed beam experiment occurs likely via these two long-lived complex formation pathways. For the complex CH2CHCHFCH2 pathway, another reaction channel （C2H3＋C2H3F） is also accessible. Relative importance of the C2H3＋C2H3F channel versus the H formation channel via the same reaction pathway has also been estimated, suggesting that it would be difficult to observe the C2H3＋C2H3F channel in a crossed molecular beam experiment. Theoretical analysis also shows that the HF formation proceeds via direct abstraction mechanisms, though it is likely a minor process in this reaction.展开更多
The radical-molecule reaction F＋propene （CH2CHCH3） was studied in detail by using the Becke＇s three parameter Lee-Yang-Parr-B3LYP/6-311G（d,p） and coupled cluster with single, double, and triple excitationsCCSD（...The radical-molecule reaction F＋propene （CH2CHCH3） was studied in detail by using the Becke＇s three parameter Lee-Yang-Parr-B3LYP/6-311G（d,p） and coupled cluster with single, double, and triple excitationsCCSD（T）/6-311＋G（2d,2p）. It is shown that F＋propene reaction mainly occurs through complex-formation mechanism： F attacks the double bond of propene leading to the formation of complex 1 and complex 2. As the two radical complexes are metastable, they can quickly dissociate to H＋C3HsF, CH3＋C2H3F and HF＋C3H5. Based on the ab initio calculations, the CH3＋C2H3F is the main channel, and the H elimination and HF forming channels also provide some contribution to products. The calculated values are in good agreement with the recently reported experimental results.展开更多
Sliced velocity mapping ion imaging technique was employed to investigate the dynamics of the hydroxyl elimination channel in the photodissociaiton of nitric acid in the ultraviolet region. The OH product was detected...Sliced velocity mapping ion imaging technique was employed to investigate the dynamics of the hydroxyl elimination channel in the photodissociaiton of nitric acid in the ultraviolet region. The OH product was detected by （2＋1） resonance enhanced multiphoton ionization via the D^2∑^- electronic state. The total kinetic energy spectra of the OH＋NO2 channel from the photolysis of HONO2 show that both ：NO2（X2A1） and NO2（A2B2） channels are present, suggesting that both 1^1A″ and 2^1A″ excited electronic states of HONO2 are involved in the excitation. The parallel angular distributions suggest that the dissociation of the nitric acid is a fast process in comparison with the rotational period of the HNO3 molecule. The anisotropy parameter β for the hydroxyl elimination channel is found to be dependent on the OH product rotational state as well as the photolysis energy.展开更多
Objective: To investigate the significance of vascular endothelial growth factor (VEGF) in the pathogene- sis of liver cirrhosis and the correlation between VEGF and proto-oncogene c-fos and c-myc in cir- rhotic liver...Objective: To investigate the significance of vascular endothelial growth factor (VEGF) in the pathogene- sis of liver cirrhosis and the correlation between VEGF and proto-oncogene c-fos and c-myc in cir- rhotic liver. Methods: The proteins of VEGF, c-fos, and c-myc were identified immunohistochemically in each tissue section of 53 cases of liver cirrhosis. The correlations between VEGF, c-fos and c-myc were analyzed. The levels of VEGF protein in different Child gradings were also compared. Results: The proteins of VEGF were more highly ex- pressed in Child A and B patients than in Child C patients and controls. The expressions of both c-fos and c-myc were not statistically significant between VEGF positive and negative patients. Conclusions: The protein level of VEGF can reflect the compensation status of cirrhosis patients and may act as an anti-cirrhotic factor. The proto-oncogene c- fos, c-myc and VEGF may have different mecha- nisms in the course of cirrhosis or hepatic tumorigen- esis.展开更多
Crossed beams scattering study was carried out on the F＋HD→DF＋H reaction using high- resolution H-atom Rydberg tagging time-of-flight technique. Vibrational state-resolved differential cross sections were measured,...Crossed beams scattering study was carried out on the F＋HD→DF＋H reaction using high- resolution H-atom Rydberg tagging time-of-flight technique. Vibrational state-resolved differential cross sections were measured, with partial rotational state resolution, at eight collision energies in the range of 2.51-5.60 kJ/mol. Experimental results indicated that the product angular distributions are predominantly backward scattered. As the collision energy increases, the backward scattered peak becomes broader gradually. Dependence of product vibration branching ratios on the collision energy was also determined. The experimental results show that the DF products are highly inverted in the vibrational state distribution and the DF （v＇=3） product is the most populated state. Furthermore, the DF （v＇=l） product has also been observed at collision energy above 3.97 kJ/mol.展开更多
Quasi-classical trajectory （QCT） calculations on the H^＋＋H2 reaction system were carried out on a new potential energy surface （PES）. Theoretical calculations show that the angular distribution of the forward an...Quasi-classical trajectory （QCT） calculations on the H^＋＋H2 reaction system were carried out on a new potential energy surface （PES）. Theoretical calculations show that the angular distribution of the forward and backward products is roughly symmetric for the title reaction. The product rotational state distribution was also determined at a few collision energies. In t, he collision energy range from 0.124 eV to 1.424 eV, the integral cross section for this system monotonically decreases with the collision energy. A comparison with the experimental result of the ion-molecule reaction was also made, the agreement is generally good.展开更多
Based on the formation and development analysis of the environmental geological disaster of land subsidence, earth fissures and other geological disasters in the North China,it showed these disasters caused a very ser...Based on the formation and development analysis of the environmental geological disaster of land subsidence, earth fissures and other geological disasters in the North China,it showed these disasters caused a very serious problem in some areas of the North China, such as the deep groundwater exploitation cone, which is accumulated with great damage and loss and is hard to be controlled, therefore, great attention should be paid. It is considered that the formation of the deep groundwater cone is the root of various geological environmental problems, and the groundwater cone recovery is the key to solve other environmental problems.展开更多
The chemical weathering can consume atmosphere/soil CO2. Human activities such as pollution, fertilization and acid precipitation have exerted a large impact on CO2 intake by carbonate weathering. Thus, based on the a...The chemical weathering can consume atmosphere/soil CO2. Human activities such as pollution, fertilization and acid precipitation have exerted a large impact on CO2 intake by carbonate weathering. Thus, based on the analysis on chemical component change of the karst groundwater in the karst ridge watershed of Conglin Village, Fuling District of Chongqing City, the influence of human activities such as fertilization, sewage discharges from mustard tuber processing, breeding industry and acid rain precipitation on carbonate weathering and CO2 intake in 1980, 2003 and 2006 was studied. The results showed that CO2 intake by carbonate rock declined with year. Because H+ derived from acid sewage discharge, fertilization and acid precipitation reacted with carbonate rock when mustard tuber production and swine breeding were developed fleetly after 2000 as well as the burning amount of high-sulfur coal augmented persistently, which led to the increase of(Ca2++Mg2+)/HCO3-. The difference on charge between Ca2++Mg2+ and HCO3- was balanced by NO3-+SO42-. The control on pollution and acid rain, especially the pre-neutralization of acid waste water, would rejuvenate the atmospheric CO2 intake strength of carbonate weathering besides the protection of water and soil environment.展开更多
基金supported by the National Natural Science Foundation of China (U21A20361 and 82130039 to Y.W.Z.)Fundamental Research Funds for the Central Universities (20720220133 to Y.W.Z.)+2 种基金Natural Science Foundation of Fujian Province (2021J02057 to Q.L.M.)Science and Technology Plan Projects of Fujian Province (2020Y2015 to Z.X.W.)2020 Joint Support of Key Projects on Health Care (3502Z20209005 to Z.X.W.)。
文摘Synaptic dysfunction is an important pathological hallmark and cause of Alzheimer's disease(AD).High-frequency stimulation(HFS)-induced long-term potentiation(LTP)has been widely used to study synaptic plasticity,with impaired LTP found to be associated with AD.However,the exact molecular mechanism underlying synaptic plasticity has yet to be completely elucidated.Whether genes regulating synaptic plasticity are altered in AD and contribute to disease onset also remains unclear.Herein,we induced LTP in the hippocampal CA1 region of wildtype(WT)and AD model mice by administering HFS to the CA3 region and then studied transcriptome changes in the CA1 region.We identified 89 genes that may participate in normal synaptic plasticity by screening HFS-induced differentially expressed genes(DEGs)in mice with normal LTP,and 43 genes that may contribute to synaptic dysfunction in AD by comparing HFS-induced DEGs in mice with normal LTP and AD mice with impaired LTP.We further refined the 43 genes down to 14 by screening for genes with altered expression in pathological-stage AD mice without HFS induction.Among them,we found that the expression of Pygm,which catabolizes glycogen,was also decreased in AD patients.We further demonstrated that down-regulation of PYGM in neurons impaired synaptic plasticity and cognition in WT mice,while its overexpression attenuated synaptic dysfunction and cognitive deficits in AD mice.Moreover,we showed that PYGM directly regulated energy generation in neurons.Our study not only indicates that PYGM-mediated energy production in neurons plays an important role in synaptic function,but also provides a novel LTP-based strategy to systematically identify genes regulating synaptic plasticity under physiological and pathological conditions.
基金supported by National Natural Science Foundation(No.41272301 and No.42007171)Nature Fund of Hebei(No.D2021504034)Chinese Academy of Geological Sciences(No.YYWF201628).
文摘The increasing severity of ground subsidence,ground fissure and other disasters caused by the excessive exploitation of deep underground resources has highlighted the pressing need for effective management.A significant contributing factor to the challenges faced is the inadequacy of existing soil mechanics experimental instruments in providing effective indicators,creating a bottleneck in comprehensively understanding the mechanisms of land subsidence.It is urgent to develop a multi-field and multi-functional soil mechanics experimental system to address this issue.Based soil mechanics theories,the existing manufacturing capabilities of triaxial apparatus and the practical demands of the test system,a set of multi-field coupled high-pressure triaxial system is developed tailored for testing deep soils(at depths of approximately 3000 m)and soft rock.This system incorporates specialized design elements such as high-pressure chamber and horizontal deformation testing devices.In addition to the conventional triaxial tester functions,its distinctive feature encompass a horizontal deformation tracking measuring device,a water release testing device and temperature control device for the sample.This ensemble facilitates testing of horizontal and vertical deformation water release and other parameters of samples under a specified stress conditions,at constant or varying temperature ranging from-40℃–90℃.The accuracy of the tested parameters meets the requirements of relevant current specifications.The test system not only provides scientifically robust data for revealing the deformation and failure mechanism of soil subjected to extreme temperature,but also offers critical data support for major engineering projects,deep exploration and mitigation efforts related to soil deformation-induced disaster.
基金National Natural Science Foundation of China,No.81873609
文摘BACKGROUND The incidence of acute kidney injury(AKI)in patients with sepsis is high,and the prognosis of patients with septic AKI is poor.The early diagnosis and treatment of septic AKI is of great significance in improving the prognosis of patients with sepsis.AIM To explore the value of contrast-enhanced ultrasound(CEUS),serum creatinine(Scr),and other indicators in the early diagnosis of septic AKI.METHODS Ninety patients with sepsis during hospitalization at Tongji Hospital of Tongji University were recruited as subjects.Each patient was recorded with relevant basic data,clinical indicators,and CEUS results.The patients were divided into AKI group and non-AKI group according to the results of renal function diagnosis after 48 h.On the 7th day,the renal function of the non-AKI group was re-evaluated and the patients were further divided into AKI subgroup and non-AKI subgroup.The differences of the indicators in different groups were compared,and the diagnostic value of each indicator and their combination for septic AKI was analyzed.RESULTS Systemic inflammatory response score(2.58±0.75),blood lactic acid(3.01±1.33 mmol/L),Scr(141.82±27.19μmol/L),blood urea nitrogen(4.41±0.81mmol/L),and rise time(10.23±2.63 s)in the AKI group were higher than those in the non-AKI group.Peak intensity(PI)(10.78±3.98 dB)and wash in slope(WIS)(1.07±0.53 dB/s)were lower than those in the non-AKI group.The differences were statistically significant(P<0.05).The PI(12.83±3.77 dB)and WIS(1.22±0.68 dB/s)in the AKI subgroup were lower than those in the non-AKI subgroup,and the differences were statistically significant(P<0.05).The area under curve(AUC)of Scr for the diagnosis of septic AKI was 0.825 with a sensitivity of 56.76% and a specificity of 100%.The AUCs of WIS and PI(0.928 and 0.912)were higher than those of Scr.Their sensitivities were 100%,but the specificities were 71.70% and 75.47%.The AUC of the combination of three indicators for the diagnosis of septic AKI was 0.943,which was significantly higher than the AUC diagnosed by each single indicator.The sensitivity was 94.59%,and the specificity was 81.13%.CONCLUSION The combination of Scr,PI,and WIS can improve the diagnostic accuracy of septic AKI.PI and WIS are expected to predict the occurrence of early septic AKI.
文摘AIM To analyze the incidence of hepatocellular carcinoma (HCC) in a population that underwent health checkups and had high serum miR-106b levels. METHODS A total of 335 subjects who underwent checkups in the Digestive and Liver Disease Department of our hospital were randomly selected. RT-PCR was used to detect the level of miR-106b in serum samples. Laboratory and imaging examinations were carried out to confirm the HCC diagnosis in patients who had a > 2-fold change in miR-106b levels. Ultrasound-guided biopsy was also used for HCC diagnosis when necessary. On this basis, the clinical data of these subjects, including history of hepatitis virus infection, obesity, long-term history of alcohol use and stage of HCC, were collected. Then, the impact of these factors on the level of miR1-06b in serum was analyzed. Furthermore, receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic efficacy of miR-106b for HCC. RESULTS A total of 35 subjects had abnormal serum miR-106b levels, of which 20 subjects were diagnosed with HCC. t-test revealed that the difference in serum miR-106b level in terms of sex, age, history of hepatitis virus infection, obesity and long-term history of alcohol use was not statistically significant. However, serum miR-106b levels in patients with advanced HCC (stage. /.) was higher than in patients with early HCC (stage./.), and the difference was statistically significant (P = 0.000). Moreover, the ROC curve revealed that the area under the curve value for miR-106b was 0.885, which shows that serum miR-106b level has a certain clinical value for HCC diagnosis. CONCLUSION The random sampling survey shows that serum miR-106b level is a valuable diagnostic marker for HCC. However, the diagnostic threshold value needs to be further researched.
基金Supported by the National Science Fund or Foundation for Postdoctoral Fellows in China,No.2001.6the Medical Science Found of Shandong Province,No.1999CA2BJBA1.
文摘AIM: To determine the correlation between portal hemodynamics and spleen function among different grades of cirrhosis and verify its significance in cirrhosis staging.METHODS: The portal and splenic vein hemodynamics and spleen size were investigated by ultrasonography in consecutive 38 cirrhotic patients with cirrhosis (Child's grades A to C) and 20 normal controls. The differences were compared in portal vein diameter and flow velocity between patients with and without ascites and between patients with mild and severe esophageal varices. The correlation between peripheral blood cell counts and Child's grades was also determined.RESULTS: The portal flow velocity and volume were significantly lower in patients with Child's C (12.25±1.67 cm/s vs 788.59±234 mm/min, respectively) cirrhosis compared to controls (19.55±3.28 cm/s vs 1254.03±410 mm/min,respectively) and those with Child's A (18.5±3.02 cm/s vs1358.48±384 mm/min, respectively) and Child's B (16.0±3.89cm/s vs 1142.23±390 mm/min, respectively)cirrhosis.Patients with ascites had much lower portal flow velocity and volume (13.0±1.72 cm/s vs 1078±533 mm/min) than those without ascites (18.6±2.60 cm/s vs 1394±354 mm/min).There was no statistical difference between patients with mild and severe esophageal varices. The portal vein diameter was not significantly different among the above groups.There were significant differences in splenic vein diameter,flow velocity and white blood cell count, but not in spleen size, red blood cell and platelet counts among the various grades of cirrhosis. The spleen size was negatively correlated with red blood cell and platelet counts (r= -0.620and r = -0.8.34, respectively).CONCLUSION: An optimal system that includes parameters representing the portal hemodynamics and spleen function should be proposed for cirrhosis staging.
基金V. ACKN0WLEDGMENT This work was supported by the Chinese Academy of Sciences, the Ministry of Science and Technology of China, and the National Natural Science Foundation of China.
文摘Theoretical studies of F atom reaction with trans-1,3-butadiene were carried out at the CCSD（T）/6- 311G（d,p）/B3LYP/6-311G（d,p） levels. Energies and structures for all reactants, products and transition states were determined. Two reaction pathways involving the formation of the complexes CH2CHCHFCH2 and CH2CHCHCH2F were found in this reaction. Theoretical results suggest that the H atom channel observed in previous crossed beam experiment occurs likely via these two long-lived complex formation pathways. For the complex CH2CHCHFCH2 pathway, another reaction channel （C2H3＋C2H3F） is also accessible. Relative importance of the C2H3＋C2H3F channel versus the H formation channel via the same reaction pathway has also been estimated, suggesting that it would be difficult to observe the C2H3＋C2H3F channel in a crossed molecular beam experiment. Theoretical analysis also shows that the HF formation proceeds via direct abstraction mechanisms, though it is likely a minor process in this reaction.
基金Ⅴ. ACKN0WLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20328304, No.10574068, No.20533060 and No.20525313）.
文摘The radical-molecule reaction F＋propene （CH2CHCH3） was studied in detail by using the Becke＇s three parameter Lee-Yang-Parr-B3LYP/6-311G（d,p） and coupled cluster with single, double, and triple excitationsCCSD（T）/6-311＋G（2d,2p）. It is shown that F＋propene reaction mainly occurs through complex-formation mechanism： F attacks the double bond of propene leading to the formation of complex 1 and complex 2. As the two radical complexes are metastable, they can quickly dissociate to H＋C3HsF, CH3＋C2H3F and HF＋C3H5. Based on the ab initio calculations, the CH3＋C2H3F is the main channel, and the H elimination and HF forming channels also provide some contribution to products. The calculated values are in good agreement with the recently reported experimental results.
基金Ⅴ. ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China, the Ministry of Sciences and Technology, and the Chinese Academy of Sciences.
文摘Sliced velocity mapping ion imaging technique was employed to investigate the dynamics of the hydroxyl elimination channel in the photodissociaiton of nitric acid in the ultraviolet region. The OH product was detected by （2＋1） resonance enhanced multiphoton ionization via the D^2∑^- electronic state. The total kinetic energy spectra of the OH＋NO2 channel from the photolysis of HONO2 show that both ：NO2（X2A1） and NO2（A2B2） channels are present, suggesting that both 1^1A″ and 2^1A″ excited electronic states of HONO2 are involved in the excitation. The parallel angular distributions suggest that the dissociation of the nitric acid is a fast process in comparison with the rotational period of the HNO3 molecule. The anisotropy parameter β for the hydroxyl elimination channel is found to be dependent on the OH product rotational state as well as the photolysis energy.
文摘Objective: To investigate the significance of vascular endothelial growth factor (VEGF) in the pathogene- sis of liver cirrhosis and the correlation between VEGF and proto-oncogene c-fos and c-myc in cir- rhotic liver. Methods: The proteins of VEGF, c-fos, and c-myc were identified immunohistochemically in each tissue section of 53 cases of liver cirrhosis. The correlations between VEGF, c-fos and c-myc were analyzed. The levels of VEGF protein in different Child gradings were also compared. Results: The proteins of VEGF were more highly ex- pressed in Child A and B patients than in Child C patients and controls. The expressions of both c-fos and c-myc were not statistically significant between VEGF positive and negative patients. Conclusions: The protein level of VEGF can reflect the compensation status of cirrhosis patients and may act as an anti-cirrhotic factor. The proto-oncogene c- fos, c-myc and VEGF may have different mecha- nisms in the course of cirrhosis or hepatic tumorigen- esis.
基金V. ACKNOWLEDGMENTS This work was supported by the Chinese Academy of Sciences, the Ministry of Science and Technology, and the National Natural Science Foundation of China.
文摘Crossed beams scattering study was carried out on the F＋HD→DF＋H reaction using high- resolution H-atom Rydberg tagging time-of-flight technique. Vibrational state-resolved differential cross sections were measured, with partial rotational state resolution, at eight collision energies in the range of 2.51-5.60 kJ/mol. Experimental results indicated that the product angular distributions are predominantly backward scattered. As the collision energy increases, the backward scattered peak becomes broader gradually. Dependence of product vibration branching ratios on the collision energy was also determined. The experimental results show that the DF products are highly inverted in the vibrational state distribution and the DF （v＇=3） product is the most populated state. Furthermore, the DF （v＇=l） product has also been observed at collision energy above 3.97 kJ/mol.
基金Ⅴ. ACKN0WLEDGEMENTS This work was supported by the Chinese Academy of Sciences, the Ministry of Science and Technology and the National Natural Science Foundation of China （No.20328304, No.10574068, No.20533060 and No.20525313）.
文摘Quasi-classical trajectory （QCT） calculations on the H^＋＋H2 reaction system were carried out on a new potential energy surface （PES）. Theoretical calculations show that the angular distribution of the forward and backward products is roughly symmetric for the title reaction. The product rotational state distribution was also determined at a few collision energies. In t, he collision energy range from 0.124 eV to 1.424 eV, the integral cross section for this system monotonically decreases with the collision energy. A comparison with the experimental result of the ion-molecule reaction was also made, the agreement is generally good.
文摘Based on the formation and development analysis of the environmental geological disaster of land subsidence, earth fissures and other geological disasters in the North China,it showed these disasters caused a very serious problem in some areas of the North China, such as the deep groundwater exploitation cone, which is accumulated with great damage and loss and is hard to be controlled, therefore, great attention should be paid. It is considered that the formation of the deep groundwater cone is the root of various geological environmental problems, and the groundwater cone recovery is the key to solve other environmental problems.
文摘The chemical weathering can consume atmosphere/soil CO2. Human activities such as pollution, fertilization and acid precipitation have exerted a large impact on CO2 intake by carbonate weathering. Thus, based on the analysis on chemical component change of the karst groundwater in the karst ridge watershed of Conglin Village, Fuling District of Chongqing City, the influence of human activities such as fertilization, sewage discharges from mustard tuber processing, breeding industry and acid rain precipitation on carbonate weathering and CO2 intake in 1980, 2003 and 2006 was studied. The results showed that CO2 intake by carbonate rock declined with year. Because H+ derived from acid sewage discharge, fertilization and acid precipitation reacted with carbonate rock when mustard tuber production and swine breeding were developed fleetly after 2000 as well as the burning amount of high-sulfur coal augmented persistently, which led to the increase of(Ca2++Mg2+)/HCO3-. The difference on charge between Ca2++Mg2+ and HCO3- was balanced by NO3-+SO42-. The control on pollution and acid rain, especially the pre-neutralization of acid waste water, would rejuvenate the atmospheric CO2 intake strength of carbonate weathering besides the protection of water and soil environment.
