A case study is performed on the influence of the patio on the indoor environment of a traditional folk house group,named Zhangguying village in Hunan province,in the summer of 2007.Measurements include indoor and out...A case study is performed on the influence of the patio on the indoor environment of a traditional folk house group,named Zhangguying village in Hunan province,in the summer of 2007.Measurements include indoor and outdoor air temperature,indoor and outdoor illuminance,indoor and outdoor air speed,and carried out from August 5th to 10th.The results show that the patio,acting as a "buffer zone",can reduce the ambient impacts on the indoor thermal environment of rooms because the temperature of the patio is lower than that of the outdoor temperature but higher than that of the rooms.The patio can improve the indoor lighting environment because the illuminance of the patio is lower than that of outdoor and higher than that of the rooms.But the effect is too limited,because the illuminance of the rooms is lower than the national standards.This study shows that the shading design is the primary consideration in this kind of climate.The wind speed of the patio is stable and similar to that of the hall and the stack effect of the patio is not obvious.It shows that the patio is useful for natural ventilation,caused by wind pressure,in summer.展开更多
Landscape designs for modern urban open spaces are studied on the basis of traditional aesthetics, while aesthetic basis and development orientation can be provided for such designs through studies on traditional aest...Landscape designs for modern urban open spaces are studied on the basis of traditional aesthetics, while aesthetic basis and development orientation can be provided for such designs through studies on traditional aesthetics. It is hoped that landscape designs from aesthetic perspective can correct people’s aesthetic attitudes towards the city, transform their habitual aesthetic modes, so as to cultivate new aesthetic tastes.展开更多
Heat transfer,friction factor and thermal enhancement factor characteristics of a double pipe heat exchanger fitted with square-cut twisted tapes(STT) and plain twisted tapes(PTT) are investigated experimentally u...Heat transfer,friction factor and thermal enhancement factor characteristics of a double pipe heat exchanger fitted with square-cut twisted tapes(STT) and plain twisted tapes(PTT) are investigated experimentally using the water as working fluid.The tapes(STT and PTT) have three twist ratios(y=2.0,4.4 and 6.0) and the Reynolds number ranges from 2000 to 12000.The experimental results reveal that heat transfer rate,friction factor and thermal enhancement factor in the tube equipped with STT are significantly higher than those fitted with PTT. The additional disturbance and secondary flow in the vicinity of the tube wall generated by STT are higher compared to that induced by the PTT is referred as the reason for better performance.Over the range considered,the Nusselt number,friction factor and thermal enhancement factor in a tube with STT are respectively,1.03 to 1.14,1.05 to 1.25 and 1.02 to 1.06 times of those in tube with PTT.An empirical correlation is also formulated to match with experimental data of Nusselt number and friction factor for STT and PTT.展开更多
SV/IEEE 802.15.3a model has been the standard model for Ultra-wide bandwidth (UWB) indoor non-line-of-sight (NLOS) wireless propagation,but for line-of-sight (LOS) case,it is not well defined. In this paper,a new stat...SV/IEEE 802.15.3a model has been the standard model for Ultra-wide bandwidth (UWB) indoor non-line-of-sight (NLOS) wireless propagation,but for line-of-sight (LOS) case,it is not well defined. In this paper,a new statistical distribution model exclusively used for LOS environment is proposed based on investigation of the experimental data. By reducing the number of the visible random arriving clusters,the model itself and the parameters estimating of the corresponding model are simplified in comparison with SV/IEEE 802.15.3a model. The simulation result indicates that the proposed model is more accurate in modeling small-scale LOS environment than SV/IEEE 802.15.3a model when considering cumulative distribution functions (CDFs) for the three key channel impulse response (CIR) statistics.展开更多
A modified random walk model for human motion is proposed to investigate characteristics of 60GHz indoor office propagation.Compared with the classic random walk model,the movement tendency in the walking process is t...A modified random walk model for human motion is proposed to investigate characteristics of 60GHz indoor office propagation.Compared with the classic random walk model,the movement tendency in the walking process is taken into account in the modified model.Based on the proposed model,path gains of the propagation environment are simulated under a variety of settings by using a ray tracing method.Simulation results and analysis show that human motion is a major source of disturbance to the indoor office propagation and results in performance degradation in some areas.展开更多
Elaeagnus angustifolia Linn. has various ecological, medicinal and economical uses. An approach was established using RP-HPLC (reversed-phase high-performance liquid chromatography) to classify and analyse the intra...Elaeagnus angustifolia Linn. has various ecological, medicinal and economical uses. An approach was established using RP-HPLC (reversed-phase high-performance liquid chromatography) to classify and analyse the intra-specific genetic relationships of seventeen populations of E. angustifolia, collected from the Xinjiang areas of China. Chromatograms of alcohol-soluble proteins produced by seventeen populations of E. angustifolia, were compared. Each chromatogram of alcohol-soluble proteins came from a single seed of one wild plant only. The results showed that when using a Waters Delta Pak. C 18, 5μm particle size reversed phase column (150 mm×3.9mm), a linear gradient of 25%-60% solvent B with flow rate of 1 ml/min and run time of 67 min, the chromatography yielded optimum separation of E. angustifolia alcohol-soluble proteins. Representative peaks in each population were chosen according to peak area and occurrence in every seed. The converted data on the elution peaks of each population were different and could be used to represent those populations. GSC (genetic similarity coefficients) of 41% to 62% showed a medium degree of genetic diversity among the populations in these eco-areas. Cluster analysis showed that the seventeen populations orE. angustifolia could be divided into six clusters at the GSC=0.535 level and indicated the general and unique biochemical markers of these clusters. We suggest that E. angustifolia distribution in these eco-areas could be classified into six variable species. RP-HPLC was shown to be a rapid, repeatable and reliable method for E. angustifolia classification and identification and for analysis of genetic diversity.展开更多
The stress and the elastic deflection of internal ring gear in high-speed spur planetary gear units are investigated. A rim thickness parameter is defined as the flexibility of internal ring gear. Six evenly spaced li...The stress and the elastic deflection of internal ring gear in high-speed spur planetary gear units are investigated. A rim thickness parameter is defined as the flexibility of internal ring gear. Six evenly spaced linear springs are used to describe the fitting status between internal ring gear and the gearcase. The finite element model of the whole internal ring gear is established by means of Pro/E and ANSYS. The loads on meshing teeth of internal ring gear are applied according to the contact ratio and the load-sharing coefficient. With the finite element analysis (FEA), the influences of flexibility and fitting status on the stress and elastic deflection of internal ring gear are predicted. The simulation reveals that the principal stress and deflection increase with the decrease of rim thickness of internal ring gear. Moreover, larger spring stiffness helps to reduce the stress and deflection of internal ring gear. Therefore, the flexibility of internal ring gear must be considered during the design of high-speed planetary gear transmissions.展开更多
Miniaturization of electronic equipment has forced researchers to devise more effective methods for dissipating the generated heat in these devices.In this study,two methods,including porous media inserting and adding...Miniaturization of electronic equipment has forced researchers to devise more effective methods for dissipating the generated heat in these devices.In this study,two methods,including porous media inserting and adding nanoparticles to the base fluid,are used to improve heat transfer in an annulus heated on both walls.To study porous media insert,porous ribs are used on the outer and inner walls independently.The results show that when porous ribs are placed on the outer wall,although the heat transfer enhances,the pressure drop increment is so considerable that performance number (the ratio of heat transfer enhancement pressure increment,PN) is less than unity for all porous rib heights and porous media permeabilities that are studied.On the other hand,the PN of cases where porous ribs were placed on the inner wall depends on the Darcy number (Da).For example,for ribs with Da=0.1 and Da=0.0001,the maximum performance number,PN=4,occurs at the porous ribs height to hydraulic diameter ratios H/Dh=1 and H/Dh=0.25.Under these conditions,heat transfer is enhanced by two orders of magnitude.It is found that adding 5% nanoparticles to the base fluid in the two aforementioned cases improves the Nusselt number and PN by 10%–40%.展开更多
An improved on-demand multicast routing protocol(ODMRP), node classification on-demand multicast routing protocol(NC-ODMRP), which is based on node classification in mobile ad hoc networks was proposed. NC-ODMRP class...An improved on-demand multicast routing protocol(ODMRP), node classification on-demand multicast routing protocol(NC-ODMRP), which is based on node classification in mobile ad hoc networks was proposed. NC-ODMRP classifies nodes into such three categories as ordinary node, forwarding group(FG) node, neighbor node of FG node according to their history forwarding information. The categories are distinguished with different weights by a weight table in the nodes. NC-ODMRP chooses the node with the highest weight as an FG node during the setup of forwarding group, which reduces a lot of redundant FG nodes by sharing more FG nodes between different sender and receiver pairs. The simulation results show that NC-ODMRP can reduce more than 20% FG number of ODMRP, thus enhances nearly 14% data forwarding efficiency and 12% energy consumption efficiency when the number of multicast senders is more than 5.展开更多
AIM:To investigate endoscopic and histopathological findings in the duodenum of patients with Strongyloides stercoralis(S.stercoralis)hyperinfection. METHODS:Over a period of 23 years(1984-2006),we investigated 25 pat...AIM:To investigate endoscopic and histopathological findings in the duodenum of patients with Strongyloides stercoralis(S.stercoralis)hyperinfection. METHODS:Over a period of 23 years(1984-2006),we investigated 25 patients withS.stercoralis hyperinfection who had had an esophagogastroduodenoscopy before undergoing treatment for strongyloidiasis.The clinical and endoscopic findings were analyzed retrospectively. RESULTS:Twenty-four(96%)of the patients investigated were under immunocompromised condition which was mainly due to a human T lymphotropic virus type 1(HTLV-1)infection.The abnormal endoscopic findings,mainly edematous mucosa,white villi and erythematous mucosa,were observed in 23(92%) patients.The degree of duodenitis including villous atrophy/destruction and inflammatory cell infiltration corresponded to the severity of the endoscopic findings. The histopathologic yield for identifying larvae was 71.4% by duodenal biopsy.The endoscopic findings of duodenitis were more severe in patients whose biopsies were positive for larvae than those whose biopsies were negative(Endoscopic severity score:4.86±2.47vs 2.71 ±1.38,P<0.05). CONCLUSION:Our study clearly demonstrates that,in addition to stool analysis,endoscopic observation and biopsies are very important.We also emphasize that S.stercoralis and HTLV-1 infections should be ruled out before immunosuppressive therapy is administered in endemic regions.展开更多
Polar codes have become increasingly popular recently because of their capacity achieving property.In this paper,a memory efficient stage-combined belief propagation(BP) decoder design for polar codes is presented.Fir...Polar codes have become increasingly popular recently because of their capacity achieving property.In this paper,a memory efficient stage-combined belief propagation(BP) decoder design for polar codes is presented.Firstly,we briefly reviewed the conventional BP decoding algorithm.Then a stage-combined BP decoding algorithm which combines two adjacent stages into one stage and the corresponding belief message updating rules are introduced.Based on this stage-combined decoding algorithm,a memory-efficient polar BP decoder is designed.The demonstrated decoder design achieves 50%memory and decoding latency reduction in the cost of some combinational logic complexity overhead.The proposed decoder is synthesized under TSMC 45 nm Low Power CMOS technology.It achieves 0.96 Gb/s throughput with 14.2mm^2 area when code length N=2^(16)which reduces 51.5%decoder area compared with the conventional decoder design.展开更多
AIM: To compare the effect of oral erythromycin vs no preparation with prokinetics on the transit time and the image quality of capsule endoscopy (CE) in evaluating small bowel (SB) pathology. METHODS: We conducted a ...AIM: To compare the effect of oral erythromycin vs no preparation with prokinetics on the transit time and the image quality of capsule endoscopy (CE) in evaluating small bowel (SB) pathology. METHODS: We conducted a retrospective, blinded (to the type of preparation) review of 100 CE studies, 50 with no preparation with prokinetics from one medical center (Group A) and 50 from another center with administration of a single dose of 200 mg oral erythromycin 1 h prior to CE (Group B). Gastric, SB and total transit times were calculated, the presence of bile in the duodenum was scored, as was cleanliness within the proximal, middle and distal intestine. RESULTS: The erythromycin group had a slightly shorter gastric transit time (21 min vs 28 min, with no statistical significance). SB transit time was similar for both groups (all P > 0.05). Total transit time was almost identical in both groups. The rate of incomplete examination was 16% for Group A and 10% for Group B (P = 0.37). Bile and cleanliness scores in different parts of the intestine were similar for the two groups (P > 0.05). CONCLUSION: Preparation for capsule endoscopy with erythromycin does not affect SB or total transit time. It tends to reduce gastric transit time, but it does not increase the cecum-reaching rate. Erythromycin does not adversely affect image quality. We consider the routine use of oral erythromycin preparation as being unjustified, although it might be considered in patients with known prolonged gastric emptying time.展开更多
Underweight and specific nutrient deficiencies are frequent in adult patients with inflammatory bowel disease(IBD).In addition,a significant number of children with IBD,especially Crohn's disease(CD) have impaired...Underweight and specific nutrient deficiencies are frequent in adult patients with inflammatory bowel disease(IBD).In addition,a significant number of children with IBD,especially Crohn's disease(CD) have impaired linear growth.Nutrition has an important role in the management of IBD.In adults with CD,enteral nutrition(EN) is effective in inducing clinical remission of IBD,although it is less efficient than corticosteroids.Exclusive EN is an established primary therapy for pediatric CD.Limited data suggests that EN is as efficient as corticosteroids for induction of remission.Additional advantages of nutritional therapy are control of inflammation,mucosal healing,positive benefits to growth and overall nutritional status with minimal adverse effects.The available evidence suggests that supplementary EN may be effective also for maintenance of remission in CD.More studies are needed to confirm these findings.However,EN supplementation could be considered as an alternative or as an adjunct to maintenance drug therapy in CD.EN does not have a primary therapeutic role in ulcerative colitis.Specific compositions of enteral dietselemental diets or diets containing specific components-were not shown to have any advantage over standard polymeric diets and their place in the treatment of CD or UC need further evaluation.Recent theories suggest that diet may be implicated in the etiology of IBD,however there are no proven dietary approaches to reduce the risk of developing IBD.展开更多
Objective: To study the relationship of the mutation of HBV preS/S gene in HBsAg carrying pregnant women and intrauterine transmission. Methods: Polymerase chain reaction (PCR) was used to amplify HBV preS/S gene from...Objective: To study the relationship of the mutation of HBV preS/S gene in HBsAg carrying pregnant women and intrauterine transmission. Methods: Polymerase chain reaction (PCR) was used to amplify HBV preS/S gene from sera of 8 HBsAg carrying pregnant women, 4 women's neonates infected with HBV, and the other's neonates non-infected with. The PCR products were cloned and 5 clones were chosen from every woman for DNA sequencing. Results: Heterogeneity of HBV preS/S gene in HBsAg carrying pregnant women having intrauterine transmission was much higher than that from having not intrauterine transmission, and the divergence rate of nucleotide sequences also higher strikingly. Conclusion: High heterogeneity of HBV preS/S gene of HBsAg positive pregnant women may be relative to high rate of intrauterine transmis-sion展开更多
Objective A few investigations have been reported about pretectal suppressive influences on the optic tectum of frog, but characteristics of tectal activity to pretectal input are left unknown. We made intracellular r...Objective A few investigations have been reported about pretectal suppressive influences on the optic tectum of frog, but characteristics of tectal activity to pretectal input are left unknown. We made intracellular recordings to demonstrate the unexpected complexity in synaptic mechanisms involved in the suppressive influences of pretecal stimulation on the tectal cells. Methods In the present study, we investigated the neuronal activity evoked by pretectal (Lpd/P) nuclei stimulation using intracellular recording technique. Results The pretectal stimulation mainly elicited two types of responses in the ipsilateral tectum: an excitatory postsynaptic potential (EPSP) followed by an inhibitory postsynaptic potential (IPSP) and a pure IPSP. The latter predominated in the tectal cells responding to pretectal stimulation. In a few cells, biphasic hyperpolarization appeared under stronger stimulus intensities. The spikes of tecto-pretectal projecting cells elicited by antidromical stimulation were recorded in the ipsilateral tectum, which revealed reciprocal connections between the tectum and particular pretectal nuclei. The synaptic natures underlying pretecto-tectal information transformation have also been demonstrated. EPSPs with short latencies were concluded to be monosynaptic. Most IPSPs were generated through polysynaptic paths, but monosynaptic IPSPs were also recorded in the tectum. Nearly 98% of impaled tectal cells (except for antidromically projecting cells) showed inhibitory responses to pretectal stimulation. Conclusion The results provide strong evidence that pretectal cells broadly inhibit tectal neurons as that has suggested by behavioral and extracellular recording studies.展开更多
AIM: TO determine whether -1195 A→G and/or -765 G→C polymorphisms in Cyclooxygenase-2 CCOX-2) may have a risk modifying effect on the development of esophageal carcinoma in a Dutch Caucasian population. METHODS: ...AIM: TO determine whether -1195 A→G and/or -765 G→C polymorphisms in Cyclooxygenase-2 CCOX-2) may have a risk modifying effect on the development of esophageal carcinoma in a Dutch Caucasian population. METHODS: Two study groups were recruited, 252 patients with esophageal carcinoma and 240 healthy controls, matched for race, age, gender and recruiting area. DNA was isolated from whole blood and used for genotyping. PCR products were digested with restriction enzymes and products were analyzed by agarose gel electrophoresis. Odds ratios (OR) and 95% confidence intervals (CI) were estimated. RESULTS: The distribution of the -1195A→G polymorphism was significantly different in esophageal cancer patients compared to controls. The -1195 GG genotype resulted in a higher risk of developing esophageal adenocarcinoma (OR = 3.85, 95% CI: 1.45-10.3) compared with the -1195AA genotype as a reference. The -765 G→C genotype distribution was not different between the two groups. The GG/ GG haplotype was present more often in esophageal adenocarcinoma patients than in controls (OR = 3.45, 95% CI: 1.24-9.58; with AG/AG as a reference). The same trends were observed in patients with squamous cell carcinomas, however, the results did not reach statistical significance. CONCLUSION: Presence of the COX-2 -1195 GG genotype and of the GG/GG haplotype may result in a higher risk of developing esophageal carcinoma.展开更多
It is extensively approved that Channel State Information(CSI) plays an important role for synergetic transmission and interference management. However, pilot overhead to obtain CSI with enough precision is a signific...It is extensively approved that Channel State Information(CSI) plays an important role for synergetic transmission and interference management. However, pilot overhead to obtain CSI with enough precision is a significant issue for wireless communication networks with massive antennas and ultra-dense cell. This paper proposes a learning- based channel model, which can estimate, refine, and manage CSI for a synergetic transmission system. It decomposes the channel impulse response into multiple paths, and uses a learning-based algorithm to estimate paths' parameters without notable degradation caused by sparse pilots. Both indoor measurement and outdoor measurement are conducted to verify the feasibility of the proposed channel model preliminarily.展开更多
AIM:To investigate the efficacy and safety of propofol sedation for endoscopic retrograde cholangiopancreatography(ERCP).METHODS:Databases including PubMed,Embase,and the Cochrane Central Register of Controlled Trials...AIM:To investigate the efficacy and safety of propofol sedation for endoscopic retrograde cholangiopancreatography(ERCP).METHODS:Databases including PubMed,Embase,and the Cochrane Central Register of Controlled Trials updated as of October 2010 were searched.Main outcome measures were ERCP procedure duration,recovery time,incidence of hypotension and hypoxia.RESULTS:Six trials with a total of 663 patients were included.The pooled mean difference in ERCP procedure duration between the propofol and traditional sedative agents was-8.05(95%CI:-16.74 to 0.63),with no significant difference between the groups.Thepooled mean difference in the recovery time was-18.69(95%CI:-25.44 to-11.93),which showed a significant reduction with use of propofol sedation.Compared with traditional sedative agents,the pooled OR with propofol sedation for ERCP causing hypotension or hypoxia was 1.69(95%CI:0.82-3.50)and 0.90(95%CI:0.55-1.49),respectively,which indicated no significant difference between the groups.CONCLUSION:Propofol sedation during ERCP leads to shorter recovery time without an increase of cardiopulmonary side effects.Propofol sedation can provide adequate sedation during ERCP.展开更多
基金The National Key Technology R&D Program of Chinaduring the 11th Five-Year Plan Period(No.2006BAJ04A13,2006BAJ04B04,2006BAJ02A08,2006BAJ02A05,2006BAJ04A05)
文摘A case study is performed on the influence of the patio on the indoor environment of a traditional folk house group,named Zhangguying village in Hunan province,in the summer of 2007.Measurements include indoor and outdoor air temperature,indoor and outdoor illuminance,indoor and outdoor air speed,and carried out from August 5th to 10th.The results show that the patio,acting as a "buffer zone",can reduce the ambient impacts on the indoor thermal environment of rooms because the temperature of the patio is lower than that of the outdoor temperature but higher than that of the rooms.The patio can improve the indoor lighting environment because the illuminance of the patio is lower than that of outdoor and higher than that of the rooms.But the effect is too limited,because the illuminance of the rooms is lower than the national standards.This study shows that the shading design is the primary consideration in this kind of climate.The wind speed of the patio is stable and similar to that of the hall and the stack effect of the patio is not obvious.It shows that the patio is useful for natural ventilation,caused by wind pressure,in summer.
文摘Landscape designs for modern urban open spaces are studied on the basis of traditional aesthetics, while aesthetic basis and development orientation can be provided for such designs through studies on traditional aesthetics. It is hoped that landscape designs from aesthetic perspective can correct people’s aesthetic attitudes towards the city, transform their habitual aesthetic modes, so as to cultivate new aesthetic tastes.
文摘Heat transfer,friction factor and thermal enhancement factor characteristics of a double pipe heat exchanger fitted with square-cut twisted tapes(STT) and plain twisted tapes(PTT) are investigated experimentally using the water as working fluid.The tapes(STT and PTT) have three twist ratios(y=2.0,4.4 and 6.0) and the Reynolds number ranges from 2000 to 12000.The experimental results reveal that heat transfer rate,friction factor and thermal enhancement factor in the tube equipped with STT are significantly higher than those fitted with PTT. The additional disturbance and secondary flow in the vicinity of the tube wall generated by STT are higher compared to that induced by the PTT is referred as the reason for better performance.Over the range considered,the Nusselt number,friction factor and thermal enhancement factor in a tube with STT are respectively,1.03 to 1.14,1.05 to 1.25 and 1.02 to 1.06 times of those in tube with PTT.An empirical correlation is also formulated to match with experimental data of Nusselt number and friction factor for STT and PTT.
基金the Key Program of National Natural Science Foundation of China(Grant No.60432040).
文摘SV/IEEE 802.15.3a model has been the standard model for Ultra-wide bandwidth (UWB) indoor non-line-of-sight (NLOS) wireless propagation,but for line-of-sight (LOS) case,it is not well defined. In this paper,a new statistical distribution model exclusively used for LOS environment is proposed based on investigation of the experimental data. By reducing the number of the visible random arriving clusters,the model itself and the parameters estimating of the corresponding model are simplified in comparison with SV/IEEE 802.15.3a model. The simulation result indicates that the proposed model is more accurate in modeling small-scale LOS environment than SV/IEEE 802.15.3a model when considering cumulative distribution functions (CDFs) for the three key channel impulse response (CIR) statistics.
基金Supported by the National Natural Science Foundation of China(61172073)Program for New Century Excellent Talents of the Ministry of Education(NCET-12-0766)+1 种基金the Open Research Fund of National Mobile Communications Research Laboratory,Southeast University(2012D19)the Fundamental Research Funds for the Central Universities(2013JBZ001)
文摘A modified random walk model for human motion is proposed to investigate characteristics of 60GHz indoor office propagation.Compared with the classic random walk model,the movement tendency in the walking process is taken into account in the modified model.Based on the proposed model,path gains of the propagation environment are simulated under a variety of settings by using a ray tracing method.Simulation results and analysis show that human motion is a major source of disturbance to the indoor office propagation and results in performance degradation in some areas.
基金Project (Nos. 30470330 and 30100126) supported by the NationalNatural Science Foundation of China
文摘Elaeagnus angustifolia Linn. has various ecological, medicinal and economical uses. An approach was established using RP-HPLC (reversed-phase high-performance liquid chromatography) to classify and analyse the intra-specific genetic relationships of seventeen populations of E. angustifolia, collected from the Xinjiang areas of China. Chromatograms of alcohol-soluble proteins produced by seventeen populations of E. angustifolia, were compared. Each chromatogram of alcohol-soluble proteins came from a single seed of one wild plant only. The results showed that when using a Waters Delta Pak. C 18, 5μm particle size reversed phase column (150 mm×3.9mm), a linear gradient of 25%-60% solvent B with flow rate of 1 ml/min and run time of 67 min, the chromatography yielded optimum separation of E. angustifolia alcohol-soluble proteins. Representative peaks in each population were chosen according to peak area and occurrence in every seed. The converted data on the elution peaks of each population were different and could be used to represent those populations. GSC (genetic similarity coefficients) of 41% to 62% showed a medium degree of genetic diversity among the populations in these eco-areas. Cluster analysis showed that the seventeen populations orE. angustifolia could be divided into six clusters at the GSC=0.535 level and indicated the general and unique biochemical markers of these clusters. We suggest that E. angustifolia distribution in these eco-areas could be classified into six variable species. RP-HPLC was shown to be a rapid, repeatable and reliable method for E. angustifolia classification and identification and for analysis of genetic diversity.
基金Key Project of Ministry of Education of China (No.106050).
文摘The stress and the elastic deflection of internal ring gear in high-speed spur planetary gear units are investigated. A rim thickness parameter is defined as the flexibility of internal ring gear. Six evenly spaced linear springs are used to describe the fitting status between internal ring gear and the gearcase. The finite element model of the whole internal ring gear is established by means of Pro/E and ANSYS. The loads on meshing teeth of internal ring gear are applied according to the contact ratio and the load-sharing coefficient. With the finite element analysis (FEA), the influences of flexibility and fitting status on the stress and elastic deflection of internal ring gear are predicted. The simulation reveals that the principal stress and deflection increase with the decrease of rim thickness of internal ring gear. Moreover, larger spring stiffness helps to reduce the stress and deflection of internal ring gear. Therefore, the flexibility of internal ring gear must be considered during the design of high-speed planetary gear transmissions.
文摘Miniaturization of electronic equipment has forced researchers to devise more effective methods for dissipating the generated heat in these devices.In this study,two methods,including porous media inserting and adding nanoparticles to the base fluid,are used to improve heat transfer in an annulus heated on both walls.To study porous media insert,porous ribs are used on the outer and inner walls independently.The results show that when porous ribs are placed on the outer wall,although the heat transfer enhances,the pressure drop increment is so considerable that performance number (the ratio of heat transfer enhancement pressure increment,PN) is less than unity for all porous rib heights and porous media permeabilities that are studied.On the other hand,the PN of cases where porous ribs were placed on the inner wall depends on the Darcy number (Da).For example,for ribs with Da=0.1 and Da=0.0001,the maximum performance number,PN=4,occurs at the porous ribs height to hydraulic diameter ratios H/Dh=1 and H/Dh=0.25.Under these conditions,heat transfer is enhanced by two orders of magnitude.It is found that adding 5% nanoparticles to the base fluid in the two aforementioned cases improves the Nusselt number and PN by 10%–40%.
基金Project(90304010) supported by the National Natural Science Foundation of China project supported by the NewCentury Excellent Talents in University
文摘An improved on-demand multicast routing protocol(ODMRP), node classification on-demand multicast routing protocol(NC-ODMRP), which is based on node classification in mobile ad hoc networks was proposed. NC-ODMRP classifies nodes into such three categories as ordinary node, forwarding group(FG) node, neighbor node of FG node according to their history forwarding information. The categories are distinguished with different weights by a weight table in the nodes. NC-ODMRP chooses the node with the highest weight as an FG node during the setup of forwarding group, which reduces a lot of redundant FG nodes by sharing more FG nodes between different sender and receiver pairs. The simulation results show that NC-ODMRP can reduce more than 20% FG number of ODMRP, thus enhances nearly 14% data forwarding efficiency and 12% energy consumption efficiency when the number of multicast senders is more than 5.
文摘AIM:To investigate endoscopic and histopathological findings in the duodenum of patients with Strongyloides stercoralis(S.stercoralis)hyperinfection. METHODS:Over a period of 23 years(1984-2006),we investigated 25 patients withS.stercoralis hyperinfection who had had an esophagogastroduodenoscopy before undergoing treatment for strongyloidiasis.The clinical and endoscopic findings were analyzed retrospectively. RESULTS:Twenty-four(96%)of the patients investigated were under immunocompromised condition which was mainly due to a human T lymphotropic virus type 1(HTLV-1)infection.The abnormal endoscopic findings,mainly edematous mucosa,white villi and erythematous mucosa,were observed in 23(92%) patients.The degree of duodenitis including villous atrophy/destruction and inflammatory cell infiltration corresponded to the severity of the endoscopic findings. The histopathologic yield for identifying larvae was 71.4% by duodenal biopsy.The endoscopic findings of duodenitis were more severe in patients whose biopsies were positive for larvae than those whose biopsies were negative(Endoscopic severity score:4.86±2.47vs 2.71 ±1.38,P<0.05). CONCLUSION:Our study clearly demonstrates that,in addition to stool analysis,endoscopic observation and biopsies are very important.We also emphasize that S.stercoralis and HTLV-1 infections should be ruled out before immunosuppressive therapy is administered in endemic regions.
基金jointly supported by the National Nature Science Foundation of China under Grant No.61370040 and 61006018the Fundamental Research Funds for the Central Universities+1 种基金the Priority Academic Program Development of Jiangsu Higher Education InstitutionsOpen Project of State Key Laboratory of ASIC & System(Fudan University)12KF006
文摘Polar codes have become increasingly popular recently because of their capacity achieving property.In this paper,a memory efficient stage-combined belief propagation(BP) decoder design for polar codes is presented.Firstly,we briefly reviewed the conventional BP decoding algorithm.Then a stage-combined BP decoding algorithm which combines two adjacent stages into one stage and the corresponding belief message updating rules are introduced.Based on this stage-combined decoding algorithm,a memory-efficient polar BP decoder is designed.The demonstrated decoder design achieves 50%memory and decoding latency reduction in the cost of some combinational logic complexity overhead.The proposed decoder is synthesized under TSMC 45 nm Low Power CMOS technology.It achieves 0.96 Gb/s throughput with 14.2mm^2 area when code length N=2^(16)which reduces 51.5%decoder area compared with the conventional decoder design.
文摘AIM: To compare the effect of oral erythromycin vs no preparation with prokinetics on the transit time and the image quality of capsule endoscopy (CE) in evaluating small bowel (SB) pathology. METHODS: We conducted a retrospective, blinded (to the type of preparation) review of 100 CE studies, 50 with no preparation with prokinetics from one medical center (Group A) and 50 from another center with administration of a single dose of 200 mg oral erythromycin 1 h prior to CE (Group B). Gastric, SB and total transit times were calculated, the presence of bile in the duodenum was scored, as was cleanliness within the proximal, middle and distal intestine. RESULTS: The erythromycin group had a slightly shorter gastric transit time (21 min vs 28 min, with no statistical significance). SB transit time was similar for both groups (all P > 0.05). Total transit time was almost identical in both groups. The rate of incomplete examination was 16% for Group A and 10% for Group B (P = 0.37). Bile and cleanliness scores in different parts of the intestine were similar for the two groups (P > 0.05). CONCLUSION: Preparation for capsule endoscopy with erythromycin does not affect SB or total transit time. It tends to reduce gastric transit time, but it does not increase the cecum-reaching rate. Erythromycin does not adversely affect image quality. We consider the routine use of oral erythromycin preparation as being unjustified, although it might be considered in patients with known prolonged gastric emptying time.
文摘Underweight and specific nutrient deficiencies are frequent in adult patients with inflammatory bowel disease(IBD).In addition,a significant number of children with IBD,especially Crohn's disease(CD) have impaired linear growth.Nutrition has an important role in the management of IBD.In adults with CD,enteral nutrition(EN) is effective in inducing clinical remission of IBD,although it is less efficient than corticosteroids.Exclusive EN is an established primary therapy for pediatric CD.Limited data suggests that EN is as efficient as corticosteroids for induction of remission.Additional advantages of nutritional therapy are control of inflammation,mucosal healing,positive benefits to growth and overall nutritional status with minimal adverse effects.The available evidence suggests that supplementary EN may be effective also for maintenance of remission in CD.More studies are needed to confirm these findings.However,EN supplementation could be considered as an alternative or as an adjunct to maintenance drug therapy in CD.EN does not have a primary therapeutic role in ulcerative colitis.Specific compositions of enteral dietselemental diets or diets containing specific components-were not shown to have any advantage over standard polymeric diets and their place in the treatment of CD or UC need further evaluation.Recent theories suggest that diet may be implicated in the etiology of IBD,however there are no proven dietary approaches to reduce the risk of developing IBD.
基金Supported by the National Natural Science Foundation of China (No. 39970652)
文摘Objective: To study the relationship of the mutation of HBV preS/S gene in HBsAg carrying pregnant women and intrauterine transmission. Methods: Polymerase chain reaction (PCR) was used to amplify HBV preS/S gene from sera of 8 HBsAg carrying pregnant women, 4 women's neonates infected with HBV, and the other's neonates non-infected with. The PCR products were cloned and 5 clones were chosen from every woman for DNA sequencing. Results: Heterogeneity of HBV preS/S gene in HBsAg carrying pregnant women having intrauterine transmission was much higher than that from having not intrauterine transmission, and the divergence rate of nucleotide sequences also higher strikingly. Conclusion: High heterogeneity of HBV preS/S gene of HBsAg positive pregnant women may be relative to high rate of intrauterine transmis-sion
文摘Objective A few investigations have been reported about pretectal suppressive influences on the optic tectum of frog, but characteristics of tectal activity to pretectal input are left unknown. We made intracellular recordings to demonstrate the unexpected complexity in synaptic mechanisms involved in the suppressive influences of pretecal stimulation on the tectal cells. Methods In the present study, we investigated the neuronal activity evoked by pretectal (Lpd/P) nuclei stimulation using intracellular recording technique. Results The pretectal stimulation mainly elicited two types of responses in the ipsilateral tectum: an excitatory postsynaptic potential (EPSP) followed by an inhibitory postsynaptic potential (IPSP) and a pure IPSP. The latter predominated in the tectal cells responding to pretectal stimulation. In a few cells, biphasic hyperpolarization appeared under stronger stimulus intensities. The spikes of tecto-pretectal projecting cells elicited by antidromical stimulation were recorded in the ipsilateral tectum, which revealed reciprocal connections between the tectum and particular pretectal nuclei. The synaptic natures underlying pretecto-tectal information transformation have also been demonstrated. EPSPs with short latencies were concluded to be monosynaptic. Most IPSPs were generated through polysynaptic paths, but monosynaptic IPSPs were also recorded in the tectum. Nearly 98% of impaled tectal cells (except for antidromically projecting cells) showed inhibitory responses to pretectal stimulation. Conclusion The results provide strong evidence that pretectal cells broadly inhibit tectal neurons as that has suggested by behavioral and extracellular recording studies.
文摘AIM: TO determine whether -1195 A→G and/or -765 G→C polymorphisms in Cyclooxygenase-2 CCOX-2) may have a risk modifying effect on the development of esophageal carcinoma in a Dutch Caucasian population. METHODS: Two study groups were recruited, 252 patients with esophageal carcinoma and 240 healthy controls, matched for race, age, gender and recruiting area. DNA was isolated from whole blood and used for genotyping. PCR products were digested with restriction enzymes and products were analyzed by agarose gel electrophoresis. Odds ratios (OR) and 95% confidence intervals (CI) were estimated. RESULTS: The distribution of the -1195A→G polymorphism was significantly different in esophageal cancer patients compared to controls. The -1195 GG genotype resulted in a higher risk of developing esophageal adenocarcinoma (OR = 3.85, 95% CI: 1.45-10.3) compared with the -1195AA genotype as a reference. The -765 G→C genotype distribution was not different between the two groups. The GG/ GG haplotype was present more often in esophageal adenocarcinoma patients than in controls (OR = 3.45, 95% CI: 1.24-9.58; with AG/AG as a reference). The same trends were observed in patients with squamous cell carcinomas, however, the results did not reach statistical significance. CONCLUSION: Presence of the COX-2 -1195 GG genotype and of the GG/GG haplotype may result in a higher risk of developing esophageal carcinoma.
基金supported by National Basic Research Program of China (NO 2012CB316002)China’s 863 Project (NO 2014AA01A703)+2 种基金National Major Projec (NO. 2014ZX03003002-002)Program for New Century Excellent Talents in University (NCET-13-0321)Tsinghua University Initiative Scientific Research Program (2011THZ02-2)
文摘It is extensively approved that Channel State Information(CSI) plays an important role for synergetic transmission and interference management. However, pilot overhead to obtain CSI with enough precision is a significant issue for wireless communication networks with massive antennas and ultra-dense cell. This paper proposes a learning- based channel model, which can estimate, refine, and manage CSI for a synergetic transmission system. It decomposes the channel impulse response into multiple paths, and uses a learning-based algorithm to estimate paths' parameters without notable degradation caused by sparse pilots. Both indoor measurement and outdoor measurement are conducted to verify the feasibility of the proposed channel model preliminarily.
基金Supported by The grants from the Department of Anesthesiology and Intensive Care of Changhai Hospital,Shanghai,China
文摘AIM:To investigate the efficacy and safety of propofol sedation for endoscopic retrograde cholangiopancreatography(ERCP).METHODS:Databases including PubMed,Embase,and the Cochrane Central Register of Controlled Trials updated as of October 2010 were searched.Main outcome measures were ERCP procedure duration,recovery time,incidence of hypotension and hypoxia.RESULTS:Six trials with a total of 663 patients were included.The pooled mean difference in ERCP procedure duration between the propofol and traditional sedative agents was-8.05(95%CI:-16.74 to 0.63),with no significant difference between the groups.Thepooled mean difference in the recovery time was-18.69(95%CI:-25.44 to-11.93),which showed a significant reduction with use of propofol sedation.Compared with traditional sedative agents,the pooled OR with propofol sedation for ERCP causing hypotension or hypoxia was 1.69(95%CI:0.82-3.50)and 0.90(95%CI:0.55-1.49),respectively,which indicated no significant difference between the groups.CONCLUSION:Propofol sedation during ERCP leads to shorter recovery time without an increase of cardiopulmonary side effects.Propofol sedation can provide adequate sedation during ERCP.