Neural network models of mechanical properties prediction for wrought magnesium alloys were improved by using more reasonable parameters, and were used to develop new types of magnesium alloys. The parameters were con...Neural network models of mechanical properties prediction for wrought magnesium alloys were improved by using more reasonable parameters, and were used to develop new types of magnesium alloys. The parameters were confirmed by comparing prediction errors and correlation coefficients of models, which have been built with all the parameters used commonly with training of all permutations and combinations. The application was focused on Mg-Zn-Mn and Mg-Zn-Y-Zr alloys. The prediction of mechanical properties of Mg-Zn-Mn alloys and the effects of mole ratios of Y to Zn on the strengths in Mg-Zn-Y-Zr alloys were investigated by using the improved models. The predicted results are good agreement with the experimental values. A high strength extruded Mg-Zn-Zr-Y alloy was also developed by the models. The applications of the models indicate that the improved models can be used to develop new types of wrought magnesium alloys.展开更多
The workpieces of A357 alloy were routinely heat treated to the T6 state in order to gain an adequate mechanical property.The mechanical properties of these workpieces depend mainly on solid-solution temperature,solid...The workpieces of A357 alloy were routinely heat treated to the T6 state in order to gain an adequate mechanical property.The mechanical properties of these workpieces depend mainly on solid-solution temperature,solid-solution time,artificial aging temperature and artificial aging time.An artificial neural network(ANN) model with a back-propagation(BP) algorithm was used to predict mechanical properties of A357 alloy,and the effects of heat treatment processes on mechanical behavior of this alloy were studied.The results show that this BP model is able to predict the mechanical properties with a high accuracy.This model was used to reflect the influence of heat treatments on the mechanical properties of A357 alloy.Isograms of ultimate tensile strength and elongation were drawn in the same picture,which are very helpful to understand the relationship among aging parameters,ultimate tensile strength and elongation.展开更多
Uniaxial compressive experiments of ultrafine-grained Al fabricated by equal channel angular pressing(ECAP) method were performed at wide temperature and strain rate range. The influence of temperature on flow stress,...Uniaxial compressive experiments of ultrafine-grained Al fabricated by equal channel angular pressing(ECAP) method were performed at wide temperature and strain rate range. The influence of temperature on flow stress, strain hardening rate and strain rate sensitivity was investigated experimentally. The results show that both the effect of temperature on flow stress and its strain rate sensitivity of ECAPed Al is much larger than those of the coarse-grained Al. The temperature sensitivity of ultrafine-grained Al is comparatively weaker than that of the coarse-grained Al. Based on the experimental results, the apparent activation volume was estimated at different temperatures and strain rates. The forest dislocation interactions is the dominant thermally activated mechanism for ECAPed Al compressed at quasi-static strain rates, while the viscous drag plays an important role at high strain rates.展开更多
Based on potted plant experiment, BP-artifieial neural network was used to simulate crop evapotranspiration and 3 kinds of artificial neural network models were constructed as ET1 (meteorological factors), ET2( met...Based on potted plant experiment, BP-artifieial neural network was used to simulate crop evapotranspiration and 3 kinds of artificial neural network models were constructed as ET1 (meteorological factors), ET2( meteorological factors and sowing days) and ET3 (meteorological factors, sowing days and water content). And the predicted result was compared with actual value ET that was obtained by weighing method. The results showed that the ET3 model had higher calculation precision and an optimum BP-artificial neural network model for calculating crop evapotranspiration.展开更多
Objective: to obtain the high purified and active nerve growth factor (NGF) from mouse submaxillary glands. Methods: NGF was prepared from mouse submaxillary glands by the way of elution with CM 52 column. The molecul...Objective: to obtain the high purified and active nerve growth factor (NGF) from mouse submaxillary glands. Methods: NGF was prepared from mouse submaxillary glands by the way of elution with CM 52 column. The molecular weight and purification of NGF were detected by SDS-PAGE polyacrylamide gel electrophoresis. The biological activity of NGF was verified thorough culturing DRG. Results: About 14 kDa stained band was observed on SDS-PAGE and it promoted proliferation of dorsal root gang lia (DRG). Conclusion: Good quality of NGF could be obtained with these methods.展开更多
[Objective] The aim was to explore tobacco varieties which satisfy tobacco formula and is suitable to be grown in ecotopes simultaneously. [Method] Interior and exterior qualities of tobacco were compared and identifi...[Objective] The aim was to explore tobacco varieties which satisfy tobacco formula and is suitable to be grown in ecotopes simultaneously. [Method] Interior and exterior qualities of tobacco were compared and identified based on agronomic and economic characters of tobacco in fields. [Result] Yunshai No.1 was better in both agronomic and economic characters. Specifically, the fragrance was dominated by empyreumatique and aroma; the highly-qualified variety is fragrant and sweet, with little irritation, which gives the tobacco smoke a light, mild flavor. As for Virgini- a934, economic characters were better, but agronomic characters were just ordinary. Similar to Yunshai No.l, dominated by empyreumatique and aroma, the variety was with distinctive resin and herbaceous fragrance. What's more, it tasted good with high quality and usability. Cunsanpi was ordinary in agronomic characters, and poor in economic characters, with coordinated quality and chemical composition. It is fra- grant and the smoke is clean. However, the quality was not so high and it tasted not so good. Tengruan No.2 was good in agronomic characters, but poor in eco- nomic characters, which gives delicate fragrance, but not clean enough. Waiweiba and Mijie Qinggeng neither taste well nor smell sweet, performing ordinary in agro- nomic and economic characters. Hence, the two varieties seem bad in quality and ranks poorly. [Conclusion] In terms of sensory quality, the varieties from high to low were Yunshai No.1, Virginia 934, Cunsanpi, Tengruan No.2, Waiweiba and Mijie Qinggeng.展开更多
Some noclassical properties in electromagnetic field are investigated for the interaction of two-modes initially taken in coherent-state representation with the three-level -type atom, such as squeezing properties an...Some noclassical properties in electromagnetic field are investigated for the interaction of two-modes initially taken in coherent-state representation with the three-level -type atom, such as squeezing properties and violation of the Cauchy-Schwartz inequality. The enhancement of field squeezing is found by selective atomic measurement. The Cauchy-Schwartz inequality is violated by the application of the classical field followed by detection in excited state.展开更多
Experimental evidence indicates that chronic mechanical sub-occlusion of the intestine may damage the enteric nervous system (ENS), although data in humans are lacking. We here describe the first case of enteric deg...Experimental evidence indicates that chronic mechanical sub-occlusion of the intestine may damage the enteric nervous system (ENS), although data in humans are lacking. We here describe the first case of enteric degenerative neuropathy related to a congenital obstruction of the gut. A 3-year and 9-mo old girl began to complain of vomiting, abdominal distension, constipation with air-fluid levels at plane abdominal radiology. Her subsequent medical history was characterized by 3 operations: the first showed dilated duodeno-jejunal loops in the absence of occlusive lesions; the second (2 years later) was performed to obtain full-thickness biopsies of the dilated intestinal loops and revealed hyperganglionosis at histopathology; the third (9 years after the hyperganglionosis was identified) disclosed a Ladd's band which was removed and the associated gut malrotation was corrected. Repeated intraoperative full-thickness biopsies showed enteric degenerative neuropathy along with reduced interstitial cells of Cajal network in dilated loops above the obstruction and a normal neuromuscular layer below the Ladd's band. One year after the latest surgery the patient tolerated oral feeding and did well, suggesting that congenital (partial) mechanical obstruction of the small bowel in humans can evoke progressive adaptive changes of the ENS which are similar to those found in animal models of intestinal mechanical occlusion. Such ENS changes mimic neuronal abnormalities observed in intestinal pseudoobstruction.展开更多
AIM: To investigate that both the neuronal function of the contractile system and structural apparatus of the gastrointestinal tract are affected in patients with longstanding diabetes and auto mic neuropathy. METHODS...AIM: To investigate that both the neuronal function of the contractile system and structural apparatus of the gastrointestinal tract are affected in patients with longstanding diabetes and auto mic neuropathy. METHODS: The evoked esophageal and duodenal contractile activity to standardized bag distension was assessed using a specialized ultrasound-based probe. Twelve type-1 diabetic patients with autonomic neuropathy and severe gastrointestinal symptoms and 12 healthy controls were studied. The geometry and biomechanical parameters (strain, tension/stress, and stiffness) were assessed. RESULTS: The diabetic patients had increased frequency of distension-induced contractions (6.0 ± 0.6 vs 3.3 ± 0.5, P < 0.001). This increased reactivity was correlated with the duration of the disease (P = 0.009). Impaired coordination of the contractile activity in diabetic patients was demonstrated as imbalance between the time required to evoke the first contraction at the distension site and proximal to it (1.5 ± 0.6 vs 0.5 ± 0.1, P = 0.03). The esophageal wall and especially the mucosa-submucosa layer had increased thickness in the patients (P < 0.001), and the longitudinal and radial compressive stretch was less in diabetics (P <0.001). The esophageal and duodenal wall stiffness and circumferential deformation induced by the distensions were not affected in the patients (all P > 0.14). CONCLUSION: The impaired contractile activity with an imbalance in the distension-induced contractions likely reflects neuronal abnormalities due to autonomic neuropathy. However, structural changes and remodeling of the gastrointestinal tract are also evident and may add to the neuronal changes. This may contribute to the pathophysiology of diabetic gut dysfunction and impact on future management of diabetic patients with gastrointestinal symptoms.展开更多
Perilla frutescens L. is a traditional medicinal plant in china. In recent years, with more and more attention is paid to the nutritional and health values of Perilla frutescens L, it has become a potential medicinal ...Perilla frutescens L. is a traditional medicinal plant in china. In recent years, with more and more attention is paid to the nutritional and health values of Perilla frutescens L, it has become a potential medicinal and edible crop. Two Per- ilia frutescens cultivars, Qisu No.1 (oil type) and Qisu No.3 (leaf and seed-using type), bred by Rapeseed Research Institute of Guizhou Academy of Agricultural Sciences, were used as test material for studying the effects of different planting density on the economic yield and agronomic characters of Perilla frutescens L. under moderate fertility level. The results showed the variation tendency of agro- nomic characters with the change of planting density was similar for the two Perilla frutescens cultivars. Among them, the plant height, main-stem nods, first effective branch length, first effective branch height, spikes per plant, and yield per plant were negatively related to the planting density; and main spike length and main- spike grains were positively related to the planting density. The effects of planting density on kilo-grain weight were not significant. The yield of the two cuitivars all increased first and then decreased with the increase of planting density. The re- gression analysis of planting density versus yield of Perilla frutescens L. was per- formed for obtaining the regression equations (Qisu No.l: y=54.046 5+96.777 lx- 45.719 8x2, r=0.999 4; Qisu No.3:y=38.717 6+42.111 3x-16.757 7x2, r=0.999 8). Based on the regression equations, the optimal planting density for Qisu No.1 was 158 745 plants/hm2 with peak yield of 1 578.90 kg/hm2, and for Qisu No.3 was 188 745 plants/hm2 with peak yield of 977.55 kg/hm2. Under the optimal planting density, Qisu No.3 could also harvest 3 000 kg/hm2 of Perilla frutescens dry leaves and 2 400 kg/hm2 of Perilla frutescens stems. This research would provide an important reference for the promotion, high-yield cultivation and comprehensive utilization of Perilla frutescens L.展开更多
Safety incentive mechanism and corresponding motivation avenues are helpful and important for the scientific safety management in coal mine. With the help of modern systematic analysis method, the efficacy of safety i...Safety incentive mechanism and corresponding motivation avenues are helpful and important for the scientific safety management in coal mine. With the help of modern systematic analysis method, the efficacy of safety incentive mechanisms is discussed in detail. The research shows that more effective avenue to reduce accident is to differently use motivation measures in practice.展开更多
AIM: To determine the most cost-effective hemofiltration modality for early management of severe acute pancreatitis (SAP) in China. METHODS: We carried out a search of Pub-Medline and Chinese Biomedical Disk datab...AIM: To determine the most cost-effective hemofiltration modality for early management of severe acute pancreatitis (SAP) in China. METHODS: We carried out a search of Pub-Medline and Chinese Biomedical Disk database. Controlled clinical trials on Chinese population were included in the analysis. The four decision branches that were analyzed were: continuous or long-term veno-venous hemofiltration (CVVH/LVVH), short-term veno-venous hemofiltration (SVVH), SVVH plus peritoneal dialysis (PD), and non-hemofiltration control group. The effectiveness of the technique was determined by survival rate, complications prevention and surgery preservation. The total cost of hospitalization was also assessed. RESULTS: The SVVH only technique was the least costly modality, $5809 (44449 RMB), and was selected as the baseline treatment modality. SVVH only arm achieved the lowest C/E ratio in terms of overall survival, complications prevention and surgery preservation. In incremental cost-effectiveness analysis, the CWH/ LVVH only and the control arms were inferior to other techniques. Sensitivity analysis showed SVVH only and SVVH plus PD arms overlapped in C/survival ratio. CONCLUSION: The role of early veno-venous hemofiltration as an alternative therapy for SAP remains controversial. However, we propose that early use of short-term high-volume veno-venous hemofiltration would have a beneficial impact on the management of SAP.展开更多
As a new neural network model,extreme learning machine(ELM)has a good learning rate and generalization ability.However,ELM with a single hidden layer structure often fails to achieve good results when faced with large...As a new neural network model,extreme learning machine(ELM)has a good learning rate and generalization ability.However,ELM with a single hidden layer structure often fails to achieve good results when faced with large-scale multi-featured problems.To resolve this problem,we propose a multi-layer framework for the ELM learning algorithm to improve the model’s generalization ability.Moreover,noises or abnormal points often exist in practical applications,and they result in the inability to obtain clean training data.The generalization ability of the original ELM decreases under such circumstances.To address this issue,we add model bias and variance to the loss function so that the model gains the ability to minimize model bias and model variance,thus reducing the influence of noise signals.A new robust multi-layer algorithm called ML-RELM is proposed to enhance outlier robustness in complex datasets.Simulation results show that the method has high generalization ability and strong robustness to noise.展开更多
This study was conducted to investigate the effect of feeding different fibre feedstuffs on the performance, nutrient utilization and economics of production of weaning/growing pigs. Five fibre feedstuffs--palm kernel...This study was conducted to investigate the effect of feeding different fibre feedstuffs on the performance, nutrient utilization and economics of production of weaning/growing pigs. Five fibre feedstuffs--palm kernel cake (PKC), wheat offal (WO), corn bran (CB), rice bran (RB) and brewers' dried grain (BDG) were used at 25% in each of the five experimental diets that were formulated in this study. Twenty weaner pigs (12.75 ± 0.6 kg) were used for the growth study while 15 pigs (14.95 ± 0.57 kg) were used for the digestibility study. The design of the experiment was completely randomized. The results of the study showed that the performance of the experimental animals were significantly influenced (P 〈 0.05) by the dietary treatments. The apparent digestibility of the crude protein, crude fiber and ether extract showed significant differences (P 〈 0.05) while there was no significant difference (P 〉 0.05) in the apparent digestibility of their dry matter, ash and nitrogen free extract. The diet that contained WO had the best growth response and apparent nutrient digestibility. Results of economics of production also showed that diet with WO gave the best (P 〈 0.05) value in feed cost/'kg gain and net profit/animal. It can be concluded from this study that although all the animals fed the different fibre feedstuffs performed satisfactorily on all the parameters monitored, but for optimum growth, apparent nutrients digestibility and economics of production. WO should be used as a fibre feedstuff in the diets of weaning/growing pigs in the tropics.展开更多
AIM: To investigate the endoscopic ampullectomy practices of expert biliary endoscopists. METHODS: An anonymous expert biliary endoscopists practices. survey was mailed to 79 to assess ampullectomy RESULTS: Forty s...AIM: To investigate the endoscopic ampullectomy practices of expert biliary endoscopists. METHODS: An anonymous expert biliary endoscopists practices. survey was mailed to 79 to assess ampullectomy RESULTS: Forty six (58%) biliary endoscopists returned the questionnaire. Of these, 63% were in academia and in practice for an average of 16.4 years (± 8.6). Endoscopists performed an average of 1.1 (± 0.8) ampullectomies per month. Prior to ampullectomy, endoscopic ultrasound was "always" utilized by 67% of respondents vs "sometimes" in 31% of respondents. Empiric biliary sphincterotomy was not utilized uniformly, only 26% "always" and 37% "sometimes" performed it prior to resection. Fifty three percent reported "never" performing empiric pancreatic sphincterotomy prior to ampullectomy. Practitioners with high endoscopic retrograde cholangiopancreatography volumes were the most likely to perform a pancreatic sphincterotomy (OR = 10.9; P = 0.09). Participants overwhelmingly favored "always" placing a prophylactic pancreatic stent, with 86% placing it after ampullectomy rather than prior to resection (23%). Argon plasma coagulation was the favored adjunct modality (83%) for removal of residual adenomatous tissue. Practitioners uniformly (100%) preferred follow-up examination to be within 6 mo postmpullectomy.CONCLUSION: Among biliary experts, there is less variation in ampultectomy practices than is reflected in the literature.展开更多
Purpose: The relationship between acute exercise and executive functions in college students with attention deficit hyperactivity disorder (ADHD) has not been clearly established. The purpose of this preliminary st...Purpose: The relationship between acute exercise and executive functions in college students with attention deficit hyperactivity disorder (ADHD) has not been clearly established. The purpose of this preliminary study was to examine the difference in cognitive performance between college students with and without ADHD and to explore the effects of acute exercise on multiple aspects of executive functions and on serum brain derived neurotrophic factor (BDNF). Methods: College students (normal: n = 10; ADHD: n = 10) performed the Stroop Test, Trail Making Test, and Digit Span Test prior to and after an acute exercise intervention. Blood samples were obtained prior to the pre-test cognitive test performance and then again after exercise and prior to the post-test cognitive test performance. Results: Students with ADHD exhibited impaired executive functions, particularly on inhibition. Additionally, while acute exercise improved all aspects of executive functions in those without ADHD, acute exercise only improved inhibitory performance for those with ADHD. Further, BDNF was not influenced by acute exercise regardless of the subjects' ADHD status. Conclusion: These results provide preliminary evidence for exercise as a potential adjunct treatment for benefitting inhibition in college students with ADHD.展开更多
A scheme to implement of 1 →3 economic phase-covariant cloning machine for unknown equator state in cavity-QED is proposed. The scheme requires cavity-assisted collision processes between atoms, which cross through n...A scheme to implement of 1 →3 economic phase-covariant cloning machine for unknown equator state in cavity-QED is proposed. The scheme requires cavity-assisted collision processes between atoms, which cross through nonresonant cavity fields in the vacuum states. The cavity fields are only virtually excited so that the cavity quality factor can be loosened.展开更多
基金Project(50725413)supported by the National Natural Science Foundation of ChinaProject(2007CB613704)supported by the National Basic Research Program of ChinaProject(2010CSTC-BJLKR)supported by Chongqing Science and Technology Commission,China
文摘Neural network models of mechanical properties prediction for wrought magnesium alloys were improved by using more reasonable parameters, and were used to develop new types of magnesium alloys. The parameters were confirmed by comparing prediction errors and correlation coefficients of models, which have been built with all the parameters used commonly with training of all permutations and combinations. The application was focused on Mg-Zn-Mn and Mg-Zn-Y-Zr alloys. The prediction of mechanical properties of Mg-Zn-Mn alloys and the effects of mole ratios of Y to Zn on the strengths in Mg-Zn-Y-Zr alloys were investigated by using the improved models. The predicted results are good agreement with the experimental values. A high strength extruded Mg-Zn-Zr-Y alloy was also developed by the models. The applications of the models indicate that the improved models can be used to develop new types of wrought magnesium alloys.
文摘The workpieces of A357 alloy were routinely heat treated to the T6 state in order to gain an adequate mechanical property.The mechanical properties of these workpieces depend mainly on solid-solution temperature,solid-solution time,artificial aging temperature and artificial aging time.An artificial neural network(ANN) model with a back-propagation(BP) algorithm was used to predict mechanical properties of A357 alloy,and the effects of heat treatment processes on mechanical behavior of this alloy were studied.The results show that this BP model is able to predict the mechanical properties with a high accuracy.This model was used to reflect the influence of heat treatments on the mechanical properties of A357 alloy.Isograms of ultimate tensile strength and elongation were drawn in the same picture,which are very helpful to understand the relationship among aging parameters,ultimate tensile strength and elongation.
基金Projects(11272267,11102168,10932008)supported by the National Natural Science Foundation of ChinaProject(B07050)supported by Northwestern Polytechnical University
文摘Uniaxial compressive experiments of ultrafine-grained Al fabricated by equal channel angular pressing(ECAP) method were performed at wide temperature and strain rate range. The influence of temperature on flow stress, strain hardening rate and strain rate sensitivity was investigated experimentally. The results show that both the effect of temperature on flow stress and its strain rate sensitivity of ECAPed Al is much larger than those of the coarse-grained Al. The temperature sensitivity of ultrafine-grained Al is comparatively weaker than that of the coarse-grained Al. Based on the experimental results, the apparent activation volume was estimated at different temperatures and strain rates. The forest dislocation interactions is the dominant thermally activated mechanism for ECAPed Al compressed at quasi-static strain rates, while the viscous drag plays an important role at high strain rates.
基金Supported by the National Natural Science Foundation of China(50609022)~~
文摘Based on potted plant experiment, BP-artifieial neural network was used to simulate crop evapotranspiration and 3 kinds of artificial neural network models were constructed as ET1 (meteorological factors), ET2( meteorological factors and sowing days) and ET3 (meteorological factors, sowing days and water content). And the predicted result was compared with actual value ET that was obtained by weighing method. The results showed that the ET3 model had higher calculation precision and an optimum BP-artificial neural network model for calculating crop evapotranspiration.
文摘Objective: to obtain the high purified and active nerve growth factor (NGF) from mouse submaxillary glands. Methods: NGF was prepared from mouse submaxillary glands by the way of elution with CM 52 column. The molecular weight and purification of NGF were detected by SDS-PAGE polyacrylamide gel electrophoresis. The biological activity of NGF was verified thorough culturing DRG. Results: About 14 kDa stained band was observed on SDS-PAGE and it promoted proliferation of dorsal root gang lia (DRG). Conclusion: Good quality of NGF could be obtained with these methods.
基金Supported by China Tobacco Yunnan Industrial Co.,Ltd(2010YL02)~~
文摘[Objective] The aim was to explore tobacco varieties which satisfy tobacco formula and is suitable to be grown in ecotopes simultaneously. [Method] Interior and exterior qualities of tobacco were compared and identified based on agronomic and economic characters of tobacco in fields. [Result] Yunshai No.1 was better in both agronomic and economic characters. Specifically, the fragrance was dominated by empyreumatique and aroma; the highly-qualified variety is fragrant and sweet, with little irritation, which gives the tobacco smoke a light, mild flavor. As for Virgini- a934, economic characters were better, but agronomic characters were just ordinary. Similar to Yunshai No.l, dominated by empyreumatique and aroma, the variety was with distinctive resin and herbaceous fragrance. What's more, it tasted good with high quality and usability. Cunsanpi was ordinary in agronomic characters, and poor in economic characters, with coordinated quality and chemical composition. It is fra- grant and the smoke is clean. However, the quality was not so high and it tasted not so good. Tengruan No.2 was good in agronomic characters, but poor in eco- nomic characters, which gives delicate fragrance, but not clean enough. Waiweiba and Mijie Qinggeng neither taste well nor smell sweet, performing ordinary in agro- nomic and economic characters. Hence, the two varieties seem bad in quality and ranks poorly. [Conclusion] In terms of sensory quality, the varieties from high to low were Yunshai No.1, Virginia 934, Cunsanpi, Tengruan No.2, Waiweiba and Mijie Qinggeng.
基金The project supported by the Natural Science Foundation of Fujian Province under Grant .No. W0650011 and Funds from Fujian Department of Education under Grant No. JB06041
文摘Some noclassical properties in electromagnetic field are investigated for the interaction of two-modes initially taken in coherent-state representation with the three-level -type atom, such as squeezing properties and violation of the Cauchy-Schwartz inequality. The enhancement of field squeezing is found by selective atomic measurement. The Cauchy-Schwartz inequality is violated by the application of the classical field followed by detection in excited state.
基金Supported by the Italian Ministry of Education, University and Research (CCOFIN Project No. 2004062155 to RDeG,2004055120 to GB and 2003064378 to RDeG, GB and VS)
文摘Experimental evidence indicates that chronic mechanical sub-occlusion of the intestine may damage the enteric nervous system (ENS), although data in humans are lacking. We here describe the first case of enteric degenerative neuropathy related to a congenital obstruction of the gut. A 3-year and 9-mo old girl began to complain of vomiting, abdominal distension, constipation with air-fluid levels at plane abdominal radiology. Her subsequent medical history was characterized by 3 operations: the first showed dilated duodeno-jejunal loops in the absence of occlusive lesions; the second (2 years later) was performed to obtain full-thickness biopsies of the dilated intestinal loops and revealed hyperganglionosis at histopathology; the third (9 years after the hyperganglionosis was identified) disclosed a Ladd's band which was removed and the associated gut malrotation was corrected. Repeated intraoperative full-thickness biopsies showed enteric degenerative neuropathy along with reduced interstitial cells of Cajal network in dilated loops above the obstruction and a normal neuromuscular layer below the Ladd's band. One year after the latest surgery the patient tolerated oral feeding and did well, suggesting that congenital (partial) mechanical obstruction of the small bowel in humans can evoke progressive adaptive changes of the ENS which are similar to those found in animal models of intestinal mechanical occlusion. Such ENS changes mimic neuronal abnormalities observed in intestinal pseudoobstruction.
文摘AIM: To investigate that both the neuronal function of the contractile system and structural apparatus of the gastrointestinal tract are affected in patients with longstanding diabetes and auto mic neuropathy. METHODS: The evoked esophageal and duodenal contractile activity to standardized bag distension was assessed using a specialized ultrasound-based probe. Twelve type-1 diabetic patients with autonomic neuropathy and severe gastrointestinal symptoms and 12 healthy controls were studied. The geometry and biomechanical parameters (strain, tension/stress, and stiffness) were assessed. RESULTS: The diabetic patients had increased frequency of distension-induced contractions (6.0 ± 0.6 vs 3.3 ± 0.5, P < 0.001). This increased reactivity was correlated with the duration of the disease (P = 0.009). Impaired coordination of the contractile activity in diabetic patients was demonstrated as imbalance between the time required to evoke the first contraction at the distension site and proximal to it (1.5 ± 0.6 vs 0.5 ± 0.1, P = 0.03). The esophageal wall and especially the mucosa-submucosa layer had increased thickness in the patients (P < 0.001), and the longitudinal and radial compressive stretch was less in diabetics (P <0.001). The esophageal and duodenal wall stiffness and circumferential deformation induced by the distensions were not affected in the patients (all P > 0.14). CONCLUSION: The impaired contractile activity with an imbalance in the distension-induced contractions likely reflects neuronal abnormalities due to autonomic neuropathy. However, structural changes and remodeling of the gastrointestinal tract are also evident and may add to the neuronal changes. This may contribute to the pathophysiology of diabetic gut dysfunction and impact on future management of diabetic patients with gastrointestinal symptoms.
基金Supported by National Natural Science Foundation of China(31360067)Guiyang Science and Technology Plan Project(Cultivation Plan of Innovative Talents-Young Science and Technology Talents Training Subsidy)(ZKHT[2012HK]209-36)+1 种基金Agriculture Animal and Plant Breeding Special of Guizhou Province(QNYZ[2013]019)Special Fund of Guizhou Academy of Agricultural Sciences(QKH[2011]017)~~
文摘Perilla frutescens L. is a traditional medicinal plant in china. In recent years, with more and more attention is paid to the nutritional and health values of Perilla frutescens L, it has become a potential medicinal and edible crop. Two Per- ilia frutescens cultivars, Qisu No.1 (oil type) and Qisu No.3 (leaf and seed-using type), bred by Rapeseed Research Institute of Guizhou Academy of Agricultural Sciences, were used as test material for studying the effects of different planting density on the economic yield and agronomic characters of Perilla frutescens L. under moderate fertility level. The results showed the variation tendency of agro- nomic characters with the change of planting density was similar for the two Perilla frutescens cultivars. Among them, the plant height, main-stem nods, first effective branch length, first effective branch height, spikes per plant, and yield per plant were negatively related to the planting density; and main spike length and main- spike grains were positively related to the planting density. The effects of planting density on kilo-grain weight were not significant. The yield of the two cuitivars all increased first and then decreased with the increase of planting density. The re- gression analysis of planting density versus yield of Perilla frutescens L. was per- formed for obtaining the regression equations (Qisu No.l: y=54.046 5+96.777 lx- 45.719 8x2, r=0.999 4; Qisu No.3:y=38.717 6+42.111 3x-16.757 7x2, r=0.999 8). Based on the regression equations, the optimal planting density for Qisu No.1 was 158 745 plants/hm2 with peak yield of 1 578.90 kg/hm2, and for Qisu No.3 was 188 745 plants/hm2 with peak yield of 977.55 kg/hm2. Under the optimal planting density, Qisu No.3 could also harvest 3 000 kg/hm2 of Perilla frutescens dry leaves and 2 400 kg/hm2 of Perilla frutescens stems. This research would provide an important reference for the promotion, high-yield cultivation and comprehensive utilization of Perilla frutescens L.
文摘Safety incentive mechanism and corresponding motivation avenues are helpful and important for the scientific safety management in coal mine. With the help of modern systematic analysis method, the efficacy of safety incentive mechanisms is discussed in detail. The research shows that more effective avenue to reduce accident is to differently use motivation measures in practice.
基金Supported by The National Natural Science Foundation of China, No.30500684 and Clinical Research Foundation for Residency Granted by the Cooperative Project of West China Hospital and Daiichi Pharmaceutical Co. Ltd., the level Ⅰ
文摘AIM: To determine the most cost-effective hemofiltration modality for early management of severe acute pancreatitis (SAP) in China. METHODS: We carried out a search of Pub-Medline and Chinese Biomedical Disk database. Controlled clinical trials on Chinese population were included in the analysis. The four decision branches that were analyzed were: continuous or long-term veno-venous hemofiltration (CVVH/LVVH), short-term veno-venous hemofiltration (SVVH), SVVH plus peritoneal dialysis (PD), and non-hemofiltration control group. The effectiveness of the technique was determined by survival rate, complications prevention and surgery preservation. The total cost of hospitalization was also assessed. RESULTS: The SVVH only technique was the least costly modality, $5809 (44449 RMB), and was selected as the baseline treatment modality. SVVH only arm achieved the lowest C/E ratio in terms of overall survival, complications prevention and surgery preservation. In incremental cost-effectiveness analysis, the CWH/ LVVH only and the control arms were inferior to other techniques. Sensitivity analysis showed SVVH only and SVVH plus PD arms overlapped in C/survival ratio. CONCLUSION: The role of early veno-venous hemofiltration as an alternative therapy for SAP remains controversial. However, we propose that early use of short-term high-volume veno-venous hemofiltration would have a beneficial impact on the management of SAP.
基金Project(21878081)supported by the National Natural Science Foundation of ChinaProject(222201917006)supported by the Fundamental Research Funds for the Central Universities,China。
文摘As a new neural network model,extreme learning machine(ELM)has a good learning rate and generalization ability.However,ELM with a single hidden layer structure often fails to achieve good results when faced with large-scale multi-featured problems.To resolve this problem,we propose a multi-layer framework for the ELM learning algorithm to improve the model’s generalization ability.Moreover,noises or abnormal points often exist in practical applications,and they result in the inability to obtain clean training data.The generalization ability of the original ELM decreases under such circumstances.To address this issue,we add model bias and variance to the loss function so that the model gains the ability to minimize model bias and model variance,thus reducing the influence of noise signals.A new robust multi-layer algorithm called ML-RELM is proposed to enhance outlier robustness in complex datasets.Simulation results show that the method has high generalization ability and strong robustness to noise.
文摘This study was conducted to investigate the effect of feeding different fibre feedstuffs on the performance, nutrient utilization and economics of production of weaning/growing pigs. Five fibre feedstuffs--palm kernel cake (PKC), wheat offal (WO), corn bran (CB), rice bran (RB) and brewers' dried grain (BDG) were used at 25% in each of the five experimental diets that were formulated in this study. Twenty weaner pigs (12.75 ± 0.6 kg) were used for the growth study while 15 pigs (14.95 ± 0.57 kg) were used for the digestibility study. The design of the experiment was completely randomized. The results of the study showed that the performance of the experimental animals were significantly influenced (P 〈 0.05) by the dietary treatments. The apparent digestibility of the crude protein, crude fiber and ether extract showed significant differences (P 〈 0.05) while there was no significant difference (P 〉 0.05) in the apparent digestibility of their dry matter, ash and nitrogen free extract. The diet that contained WO had the best growth response and apparent nutrient digestibility. Results of economics of production also showed that diet with WO gave the best (P 〈 0.05) value in feed cost/'kg gain and net profit/animal. It can be concluded from this study that although all the animals fed the different fibre feedstuffs performed satisfactorily on all the parameters monitored, but for optimum growth, apparent nutrients digestibility and economics of production. WO should be used as a fibre feedstuff in the diets of weaning/growing pigs in the tropics.
文摘AIM: To investigate the endoscopic ampullectomy practices of expert biliary endoscopists. METHODS: An anonymous expert biliary endoscopists practices. survey was mailed to 79 to assess ampullectomy RESULTS: Forty six (58%) biliary endoscopists returned the questionnaire. Of these, 63% were in academia and in practice for an average of 16.4 years (± 8.6). Endoscopists performed an average of 1.1 (± 0.8) ampullectomies per month. Prior to ampullectomy, endoscopic ultrasound was "always" utilized by 67% of respondents vs "sometimes" in 31% of respondents. Empiric biliary sphincterotomy was not utilized uniformly, only 26% "always" and 37% "sometimes" performed it prior to resection. Fifty three percent reported "never" performing empiric pancreatic sphincterotomy prior to ampullectomy. Practitioners with high endoscopic retrograde cholangiopancreatography volumes were the most likely to perform a pancreatic sphincterotomy (OR = 10.9; P = 0.09). Participants overwhelmingly favored "always" placing a prophylactic pancreatic stent, with 86% placing it after ampullectomy rather than prior to resection (23%). Argon plasma coagulation was the favored adjunct modality (83%) for removal of residual adenomatous tissue. Practitioners uniformly (100%) preferred follow-up examination to be within 6 mo postmpullectomy.CONCLUSION: Among biliary experts, there is less variation in ampultectomy practices than is reflected in the literature.
文摘Purpose: The relationship between acute exercise and executive functions in college students with attention deficit hyperactivity disorder (ADHD) has not been clearly established. The purpose of this preliminary study was to examine the difference in cognitive performance between college students with and without ADHD and to explore the effects of acute exercise on multiple aspects of executive functions and on serum brain derived neurotrophic factor (BDNF). Methods: College students (normal: n = 10; ADHD: n = 10) performed the Stroop Test, Trail Making Test, and Digit Span Test prior to and after an acute exercise intervention. Blood samples were obtained prior to the pre-test cognitive test performance and then again after exercise and prior to the post-test cognitive test performance. Results: Students with ADHD exhibited impaired executive functions, particularly on inhibition. Additionally, while acute exercise improved all aspects of executive functions in those without ADHD, acute exercise only improved inhibitory performance for those with ADHD. Further, BDNF was not influenced by acute exercise regardless of the subjects' ADHD status. Conclusion: These results provide preliminary evidence for exercise as a potential adjunct treatment for benefitting inhibition in college students with ADHD.
基金The project supported by National Natural Science Foundation of China under Grant No.10574001the Science Foundation of Education Department of Anhui Province under Grant No.KJ2007A002
文摘A scheme to implement of 1 →3 economic phase-covariant cloning machine for unknown equator state in cavity-QED is proposed. The scheme requires cavity-assisted collision processes between atoms, which cross through nonresonant cavity fields in the vacuum states. The cavity fields are only virtually excited so that the cavity quality factor can be loosened.