We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeli...We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeling. Whereas circular muscle tone generates radial closure pressure to create a local peristaltic closure wave, longitudinal muscle tone has two functions, one physiological with mechanical implications, and one purely mechanical. Each of these functions independently reduces the tension of individual circular muscle fibers to maintain closure as a consequence of shortening of longitudinal muscle locally coordinated with increasing circular muscle tone. The physiological function is deduced by combining basic laws of mechanics with concurrent measurements of intraluminal pressure from manometry, and changes in cross sectional muscle area from endoluminal ultrasound from which local longitudinal shortening (LLS) can be accurately obtained. The purely mechanical function of LLS was discovered from mathematical modeling of peristaltic esophageal transport with the axial wall motion generated by LLS. Physiologically, LLS concentrates circular muscle fibers where closure pressure is highest. However, the mechanical function of LLS is to reduce the level of pressure required to maintain closure. The combined physiological and mechanical consequences of LLS are to reduce circular muscle fiber tension and power by as much as 1/10 what would be requiredfor peristalsis without the longitudinal muscle layer, a tremendous benefit that may explain the existence of longitudinal muscle fiber in the gut. We also review what is understood of the role of longitudinal muscle in esophageal emptying, reflux and pathology.展开更多
AIM To investigate the evaluation of neogalactosylalbumin (NGA) for liver function assessment based on positron emission tomography technology. METHODS Female Kunming mice were assigned randomly to two groups: fibrosi...AIM To investigate the evaluation of neogalactosylalbumin (NGA) for liver function assessment based on positron emission tomography technology. METHODS Female Kunming mice were assigned randomly to two groups: fibrosis group and normal control group. A murine hepatic fibrosis model was generated by intraperitoneal injection of 10% carbon tetrachloride (CCl4) at 0.4 ml every 48 h for 42 d. F-18-labeled NGA ([F-18] FNGA) was synthesized and administered at a dosage of 3.7 MBq/mouse to both fibrosis mice and normal control mice. Distribution of [F-18] FNGA amongst organs was examined, and dynamic scanning was performed. Parameters were set up to compare the uptake of tracers by fibrotic liver and healthy liver. Serologic tests for liver function were also performed. RESULTS The liver function of the fibrosis model mice was significantly impaired by the use of CCl4. In the fibrosis model mice, hepatic fibrosis was verified by naked eye assessment and pathological analysis. [F-18] FNGA was found to predominantly accumulate in liver and kidneys in both control group (n = 21) and fibrosis group (n = 23). The liver uptake ability (LUA), peak time (T-p), and uptake rate (LUR) of [F-18] FNGA between healthy liver (n = 8) and fibrosis liver (n = 10) were significantly different (P < 0.05, < 0.01, and < 0.05, respectively). LUA was significantly correlated with total serum protein level (TP) (P < 0.05). T-p was significantly correlated with both TP and glucose (Glu) concentration (P < 0.05 both), and LUR was significantly correlated with both total bile acid and Glu concentration (P < 0.01 and < 0.05, respectively). CONCLUSION [F-18] FNGA mainly accumulated in liver and remained for sufficient time. Functionally-impaired liver showed a significant different uptake pattern of [F-18] FNGA compared to the controls.展开更多
A staggered impulse turbine is proposed for asymmetric air flows in Oscillating Water Column wave energy plants, which is expected to enhance the pneumatic power output in a wave cycle. The setting angle of rotor blad...A staggered impulse turbine is proposed for asymmetric air flows in Oscillating Water Column wave energy plants, which is expected to enhance the pneumatic power output in a wave cycle. The setting angle of rotor blades is set as 5°. The 3D numerical simulations were conducted under steady conditions using MRF and Mixing Plane model based on CFD software Fluent 12.0. Its mean efficiencies under different velocity amplitude ratios are studied using quasi-steady analysis, which derive corresponding data from the numerical simulation. It is found that the staggered turbine shows better performance than the conventional one under the asymmetrical air flows. Furthermore, its mean efficiency and output-work in a wave period are compared with another unsymmetrical twin impulse turbine system. The results show that the staggered turbine shows better output-work performance than the twin turbine system over the high flow coefficient domain(φ>0.7), which provides more choices to future research on turbine's optimization.展开更多
The tunable excitation patterns and emission modes associated with luminescence materials,such as downshifting luminescence(DSL),upconversion luminescence(UCL),and mechanoluminescence(ML)play an important role in info...The tunable excitation patterns and emission modes associated with luminescence materials,such as downshifting luminescence(DSL),upconversion luminescence(UCL),and mechanoluminescence(ML)play an important role in information encryption and anticounterfeiting.However,many reported luminescence materials usually show fixed excitation patterns and unimodal output,resulting in a low anticounterfeiting level.Therefore,developing luminescence materials with multitemporal,variation excitation patterns and multiple emission modes remains a considerable challenge,particularly in a single matrix.This study reports a highly integrated multifunctional material(color-tunable(DSL:amaranth→blue),tunable excitation patterns(250±380 nm)and quadrimodal(DSL,UCL,persistent luminescence(PersL),and ML)).The as-obtained versatile LaCaAl_(3)O_(7):Eu^(2+)/^(3+),Yb^(3+),Er^(3+)materials are suitable for obtaining elastomer films with the characteristics of water resistance,stretchability,and flexibility and synchronously offer multidimensional information encryptions and anticounterfeiting using common tools(ultraviolet light,nearinfrared light,and pen).These results provide a unique insight into advanced multimodal anticounterfeiting.展开更多
文摘We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeling. Whereas circular muscle tone generates radial closure pressure to create a local peristaltic closure wave, longitudinal muscle tone has two functions, one physiological with mechanical implications, and one purely mechanical. Each of these functions independently reduces the tension of individual circular muscle fibers to maintain closure as a consequence of shortening of longitudinal muscle locally coordinated with increasing circular muscle tone. The physiological function is deduced by combining basic laws of mechanics with concurrent measurements of intraluminal pressure from manometry, and changes in cross sectional muscle area from endoluminal ultrasound from which local longitudinal shortening (LLS) can be accurately obtained. The purely mechanical function of LLS was discovered from mathematical modeling of peristaltic esophageal transport with the axial wall motion generated by LLS. Physiologically, LLS concentrates circular muscle fibers where closure pressure is highest. However, the mechanical function of LLS is to reduce the level of pressure required to maintain closure. The combined physiological and mechanical consequences of LLS are to reduce circular muscle fiber tension and power by as much as 1/10 what would be requiredfor peristalsis without the longitudinal muscle layer, a tremendous benefit that may explain the existence of longitudinal muscle fiber in the gut. We also review what is understood of the role of longitudinal muscle in esophageal emptying, reflux and pathology.
基金Supported by National Natural Science Foundation of China,No.30901453 and No.81201566National Key Technology Research and Development Program of China,No.BAI06B01Youth Grant of Peking Union Medical College Hospital
文摘AIM To investigate the evaluation of neogalactosylalbumin (NGA) for liver function assessment based on positron emission tomography technology. METHODS Female Kunming mice were assigned randomly to two groups: fibrosis group and normal control group. A murine hepatic fibrosis model was generated by intraperitoneal injection of 10% carbon tetrachloride (CCl4) at 0.4 ml every 48 h for 42 d. F-18-labeled NGA ([F-18] FNGA) was synthesized and administered at a dosage of 3.7 MBq/mouse to both fibrosis mice and normal control mice. Distribution of [F-18] FNGA amongst organs was examined, and dynamic scanning was performed. Parameters were set up to compare the uptake of tracers by fibrotic liver and healthy liver. Serologic tests for liver function were also performed. RESULTS The liver function of the fibrosis model mice was significantly impaired by the use of CCl4. In the fibrosis model mice, hepatic fibrosis was verified by naked eye assessment and pathological analysis. [F-18] FNGA was found to predominantly accumulate in liver and kidneys in both control group (n = 21) and fibrosis group (n = 23). The liver uptake ability (LUA), peak time (T-p), and uptake rate (LUR) of [F-18] FNGA between healthy liver (n = 8) and fibrosis liver (n = 10) were significantly different (P < 0.05, < 0.01, and < 0.05, respectively). LUA was significantly correlated with total serum protein level (TP) (P < 0.05). T-p was significantly correlated with both TP and glucose (Glu) concentration (P < 0.05 both), and LUR was significantly correlated with both total bile acid and Glu concentration (P < 0.01 and < 0.05, respectively). CONCLUSION [F-18] FNGA mainly accumulated in liver and remained for sufficient time. Functionally-impaired liver showed a significant different uptake pattern of [F-18] FNGA compared to the controls.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51279190 and 51311140259)National High Tech Research and Development Program("863"program,Grant No.2011AA050201)
文摘A staggered impulse turbine is proposed for asymmetric air flows in Oscillating Water Column wave energy plants, which is expected to enhance the pneumatic power output in a wave cycle. The setting angle of rotor blades is set as 5°. The 3D numerical simulations were conducted under steady conditions using MRF and Mixing Plane model based on CFD software Fluent 12.0. Its mean efficiencies under different velocity amplitude ratios are studied using quasi-steady analysis, which derive corresponding data from the numerical simulation. It is found that the staggered turbine shows better performance than the conventional one under the asymmetrical air flows. Furthermore, its mean efficiency and output-work in a wave period are compared with another unsymmetrical twin impulse turbine system. The results show that the staggered turbine shows better output-work performance than the twin turbine system over the high flow coefficient domain(φ>0.7), which provides more choices to future research on turbine's optimization.
基金supported by the National Natural Science Foundation of China(21871122 and 21431002)the Fundamental Research Funds for the Central Universities(lzujbky-2021-kb17)。
文摘The tunable excitation patterns and emission modes associated with luminescence materials,such as downshifting luminescence(DSL),upconversion luminescence(UCL),and mechanoluminescence(ML)play an important role in information encryption and anticounterfeiting.However,many reported luminescence materials usually show fixed excitation patterns and unimodal output,resulting in a low anticounterfeiting level.Therefore,developing luminescence materials with multitemporal,variation excitation patterns and multiple emission modes remains a considerable challenge,particularly in a single matrix.This study reports a highly integrated multifunctional material(color-tunable(DSL:amaranth→blue),tunable excitation patterns(250±380 nm)and quadrimodal(DSL,UCL,persistent luminescence(PersL),and ML)).The as-obtained versatile LaCaAl_(3)O_(7):Eu^(2+)/^(3+),Yb^(3+),Er^(3+)materials are suitable for obtaining elastomer films with the characteristics of water resistance,stretchability,and flexibility and synchronously offer multidimensional information encryptions and anticounterfeiting using common tools(ultraviolet light,nearinfrared light,and pen).These results provide a unique insight into advanced multimodal anticounterfeiting.
