AIM To study the genetic susceptibility of HLA-DQA1 alleles to duodenal ulcer in Wuhan Hans.METHODS Seventy patients with duodenalulcer and fifty healthy controls were examinedfor HLA-DQA1 genotypes.HLA-DQA1 typing wa...AIM To study the genetic susceptibility of HLA-DQA1 alleles to duodenal ulcer in Wuhan Hans.METHODS Seventy patients with duodenalulcer and fifty healthy controls were examinedfor HLA-DQA1 genotypes.HLA-DQA1 typing wascarried out by digesting the locus specificpolymerase chain reaction amplified productswith alleles specific restriction enzymes(PCR-RFLP),i.e.,Apal Ⅰ,Bsaj Ⅰ,Hph Ⅰ,Fok Ⅰ,Mbo Ⅱ and Mnl Ⅰ.RESULTS The allele frequencies of DQA1 * 0301and DQA1 * 0102 in patients with duodenal ulcerwere significantly higher and lower respectivelythan those in healthy controls(0.40 vs 0.20,P = 0.003,mcorret = 0.024)and(0.05 vs 0.14,P = 0.012,but Pcorret】0.05),respectively.CONCLUSION DQA1 * 0301 is a susceptiblegene for duodenal ulcer in Wuhan Hans,andthere are immunogenetic differences in HLA-DQA1 locus between duodenal ulcer patients andhealthy controls.展开更多
Based on the analyses on amplitudes of historical variation of temperature and precipitation in the past 500 years and latest 100 years,according to the regional climate change scenarios for China estimated by composi...Based on the analyses on amplitudes of historical variation of temperature and precipitation in the past 500 years and latest 100 years,according to the regional climate change scenarios for China estimated by composite GCM,the potential impacts of climate change on cropping systems in China in future are simulated and assessed using the cropping system model development specially for the Chinese cropping patterns.It is shown that under the projected future climate change by 2050 the most parts of the present double cropping area would be replaced by the different triple cropping patterns while the current double cropping area would shift towards the central part of the present single cropping area.More explicitly,the northern boundary of triple cropping area would shift from its current border at the Changjing River to the Huanghe River,a shift of more than 5 degrees of latitude.And the shift of multiple cropping areas leads to a significant decrease of single cropping area. Furthermore,considering the changes mentioned above in combination with the likely negative balance of precipitation and evapotranspiration and,therefore,increase of moisture stress(i.e. less water availability),as well as the possible increase of heat stress disaster and decrease of LGS (length of growing season),the potential implication of climate change for agriculture in China are also analyzed roughly in this paper. As a result,however,it is still very difficult to reach a specific conclusion that the future climate change will he favorable or unfavorable to farm in China because of the complicated Chinese farming patterns,the complex-various social and economic environment of agricultural development and,especially,a great scientific uncertainties in the investigation/prediction of climate change.展开更多
AIM:To evaluate the impact of enhanced recovery after surgery(ERAS) programs in comparison with traditional care on liver surgery outcomes.METHODS:The Pub Med,EMBASE,CNKI and Cochrane Central Register of Controlled Tr...AIM:To evaluate the impact of enhanced recovery after surgery(ERAS) programs in comparison with traditional care on liver surgery outcomes.METHODS:The Pub Med,EMBASE,CNKI and Cochrane Central Register of Controlled Trials databases were searched for randomized controlled trials(RCTs) comparing the ERAS program with traditional care in patients undergoing liver surgery. Studies selected for the meta-analysis met all of the following inclusion criteria:(1) evaluation of ERAS in comparison to traditional care in adult patients undergoing elective open or laparoscopic liver surgery;(2) outcome measures including complications,recovery of bowel function,and hospital length of stay; and(3) RCTs. The following exclusion criteria were applied:(1) the study was not an RCT;(2) the study did not compare ERAS with traditional care;(3) the study reported on emergency,non-elective or transplantation surgery; and(4) the study consisted of unpublished studies with only the abstract presented at a national or international meeting. The primary outcomes were complications. Secondary outcomes were length of hospital stay and time to first flatus.RESULTS:Five RCTs containing 723 patients were included in the meta-analysis. In 10/723 cases,patients presented with benign diseases,while the remaining 713 cases had liver cancer. Of the five studies,three were published in English and two were published in Chinese. Three hundred and fifty-four patients were in the ERAS group,while 369 patients were in the traditional care group. Compared with traditional care,ERAS programs were associated with significantly decreased overall complications(RR = 0.66; 95%CI:0.49-0.88; P = 0.005),grade?Ⅰ?complications(RR = 0.51; 95%CI:0.33-0.79; P = 0.003),and hospitallength of stay [WMD =-2.77 d,95%CI:-3.87-(-1.66); P < 0.00001]. Similarly,ERAS programs were associated with decreased time to first flatus [WMD =-19.69 h,95%CI:-34.63-(-4.74); P < 0.0001]. There was no statistically significant difference in grade Ⅱ-Ⅴ complications between the two group展开更多
The flexible contact and machining with wide strip are two prominent advantages for the robotic belt grinding system, which can be widely used to improve the surface quality and machining efficiency while finishing th...The flexible contact and machining with wide strip are two prominent advantages for the robotic belt grinding system, which can be widely used to improve the surface quality and machining efficiency while finishing the workpieces with sculptured surfaces. There lacks research on grinding path planning with the constraint of curvature. With complicated contact between the contact wheel and the workpiece, the grinding paths for robot can be obtained by the theory of contact kinematics. The grinding process must satisfy the universal demands of the belt grinding technologies, and the most important thing is to make the contact wheel conform to the local geometrical features on the contact area. For the local surfaces with small curvature, the curve length between the neighboring cutting locations becomes longer to ensure processing efficiency. Otherwise, for the local areas with large curvature, the curve length becomes shorter to ensure machining accuracy. A series of planes are created to intersect with the target surface to be ground, and the corresponding sectional profile curves are obtained. For each curve, the curve length between the neighboring cutting points is optimized by inserting a cutter location at the local area with large curvatures. A method of generating the grinding paths including curve length spacing optimization is set up. The validity is completely approved by the off-line simulation, and during the grinding experiments with the method, the quality of surface is improved. The path planning method provides a theoretical support for the smooth and accuracy path of robotic surface grinding.展开更多
The variation in nitrogen （N） uptake by rice has been widely studied but differences in rice root morphology that may contribute to this variation are not completely understood. Field and greenhouse experiments were...The variation in nitrogen （N） uptake by rice has been widely studied but differences in rice root morphology that may contribute to this variation are not completely understood. Field and greenhouse experiments were carried out to study N accumulation, root dry weights, total root lengths, root surface areas, and root bleeding rates of two rice cultivars, Elio with low N-use efficiency and Nanguang with high N-use efficiency. Low （1 mmol N L^-1） and high （5 mmol N L^-1） N applications were established in the greenhouse experiment, and the N rates were 0, 120, and 240 kg ha^-1 in the field experiments at Jiangning and Jiangpu farms, Nanjing, China. The results showed that the N accumulation, root dry weight, total root length, and root surface area increased with an increase in N application. At the heading stage, N accumulation in the shoots and roots of Nanguang was greater than that of Elio in the field experiments and that of Elio at 5 mmol N L^-1 in the greenhouse experiment. After the heading stage, N accumulation was higher for Nanguang at both 1 and 5 mmol N L^-1 in the greenhouse experiment. The total root length and root surface area were significantly different between the two cultivars. Over the range of the fertilizer application rates, the root lengths of Nanguang at Jiangning Farm were 49%-6170 greater at booting and 26%-39% greater at heading than those of Elio, and at Jiangpu Farm they were 22%-42% and 26%-38% greater, respectively. Nanguang had a greater root bleeding rate than Elio. It was concluded that the N-use efficiency of the two rice cultivars studied depended to a great extent on the root morphological parameters and root physiological characteristics at different growth stages.展开更多
A residual heterozygous line （RHL） carrying a heterozygous segment between two S SR loci RM 11 and RM134 on the rice chromo- some 7 was selected from a set of recombinant inbred lines from the cross D50 （javanica）...A residual heterozygous line （RHL） carrying a heterozygous segment between two S SR loci RM 11 and RM134 on the rice chromo- some 7 was selected from a set of recombinant inbred lines from the cross D50 （javanica）/HB277 （indica）. The former parent produces much longer grains than the latter. Selfed progenies of this selection were analyzed genotypically （SSRs） and phenotypically （grain length）. Grain length was discontinuously variable in the mapping populations, allowing for the placement of this QTL qGL7-2 within a -4.8 cM interval defined by RM351 and RM234. A set of new markers within this region were developed, which narrowed the QTL to a 278 kb region defined by the markers Indell and RM21945. This region contains 49 predicted genes. The results also suggest that the novel allele for grain length will be used for the application of marker assisted selection for the improvement of grain length.展开更多
Imbalanced application of nitrogen(N) and phosphorus(P) fertilizers can result in reduced crop yield,low nutrient use efficiency,and high loss of nutrients and soil nitrate nitrogen(NO_3^--N) accumulation decreases wh...Imbalanced application of nitrogen(N) and phosphorus(P) fertilizers can result in reduced crop yield,low nutrient use efficiency,and high loss of nutrients and soil nitrate nitrogen(NO_3^--N) accumulation decreases when N is applied with P and/or manure;however,the effect of applications of N with P and/or manure on root growth and distribution in the soil profile is not fully understood.The aim of this study was to investigate the combined effects of different N and P fertilizer application rates with or without manure on maize(Zea mays L.) yield,N uptake,root growth,apparent N surplus,Olsen-P concentration,and mineral N(N_(min)) accumulation in a fluvo-aquic calcareous soil from a long-term(28-year) experiment.The experiment comprised twelve combinations of chemical N and P fertilizers,either with or without chicken manure,as treatments in four replicates.The yield of maize grain was 82%higher,the N uptake 100%higher,and the N_(min) accumulation 39%lower in the treatments with combined N and P in comparison to N fertilizer only.The maize root length density in the 30-60 cm layer was three times greater in the treatments with N and P fertilizers than with N fertilizer only.Manure addition increased maize yield by 50%and N uptake by 43%,and reduced N_(min)(mostly NO_3^--N) accumulation in the soil by 46%.The long-term application of manure and P fertilizer resulted in significant increases in soil Olsen-P concentration when no N fertilizer was applied.Manure application reduced the apparent N surplus for all treatments.These results suggest that combined N and P fertilizer applications could enhance maize grain yield and nutrient uptake via stimulating root growth,leading to reduced accumulation of potentially leachable NO_3^--N in soil,and manure application was a practical way to improve degraded soils in China and the rest of the world.展开更多
There are well coherences between annual averaged air temperatures at every meteorological station along the Qinghai-Xizang railway, and its 10-year moving average correlation coefficient is 0.92. Thus, the regional a...There are well coherences between annual averaged air temperatures at every meteorological station along the Qinghai-Xizang railway, and its 10-year moving average correlation coefficient is 0.92. Thus, the regional averaged annual mean temperature series along the Qinghai-Xizang railway (Trw) from 1935 to 2000 are constructed. The investigation is suggested that: Trw had significant responses to the 5-year lagged sunspot cycle length (SCL) and 15-year lagged concentration of atmospheric carbon dioxide (CO2), and the correlation coefficients between them are -0.76 (SCL) and 0.88 (CO2), respectively. The future SCL is predicted by the model of average generated function constructed with its main cycles of 76a, 93a, 108a, 205a and 275a. The result shows that the SCL would be becoming longer in the first half of the 21st century, and then it could be becoming shorter in the second half of the 21st century. Based on the natural change of SCL and the effect of double CO2 concentration, Trw in the 21st century is forecasted. It could warm up about 0.50℃ in the first half of the 21st century compared with the last decade of last century. The mean maximum air temperature could be likely about 0.20℃ in July and from 0.40℃ to 1.10℃ in January. The annual air temperature difference would likely reduce 0.3-1.00℃. The probability of above predictions ranges from 0.64 to 0.73.展开更多
The article summarizes previous studies on the flow in open channels with rigid vegetation, and constructs a mathematical model for submerged and emerged rigid vegetation. The model involves the forces balance in the ...The article summarizes previous studies on the flow in open channels with rigid vegetation, and constructs a mathematical model for submerged and emerged rigid vegetation. The model involves the forces balance in the control volume in one-dimensional steady uniform flow. For submerged vegetation, the whole flow is divided into four regions： external region, upper vegetated region, transition region and viscous region. According to the Karrnan similarity theory, the article improves the mixing length expression, and then gives an analytical solution to predict the vertical distribution of stream-wise velocity in the external region. For emerged vegetation, the flow is divided into two region： outer region and viscous region. In the two circumstances, the thicknesses of each region are determined respectively. The comparison between the calculated results and our experimental data and other researchers＇ data proves that the proposed model is effective.展开更多
文摘AIM To study the genetic susceptibility of HLA-DQA1 alleles to duodenal ulcer in Wuhan Hans.METHODS Seventy patients with duodenalulcer and fifty healthy controls were examinedfor HLA-DQA1 genotypes.HLA-DQA1 typing wascarried out by digesting the locus specificpolymerase chain reaction amplified productswith alleles specific restriction enzymes(PCR-RFLP),i.e.,Apal Ⅰ,Bsaj Ⅰ,Hph Ⅰ,Fok Ⅰ,Mbo Ⅱ and Mnl Ⅰ.RESULTS The allele frequencies of DQA1 * 0301and DQA1 * 0102 in patients with duodenal ulcerwere significantly higher and lower respectivelythan those in healthy controls(0.40 vs 0.20,P = 0.003,mcorret = 0.024)and(0.05 vs 0.14,P = 0.012,but Pcorret】0.05),respectively.CONCLUSION DQA1 * 0301 is a susceptiblegene for duodenal ulcer in Wuhan Hans,andthere are immunogenetic differences in HLA-DQA1 locus between duodenal ulcer patients andhealthy controls.
文摘Based on the analyses on amplitudes of historical variation of temperature and precipitation in the past 500 years and latest 100 years,according to the regional climate change scenarios for China estimated by composite GCM,the potential impacts of climate change on cropping systems in China in future are simulated and assessed using the cropping system model development specially for the Chinese cropping patterns.It is shown that under the projected future climate change by 2050 the most parts of the present double cropping area would be replaced by the different triple cropping patterns while the current double cropping area would shift towards the central part of the present single cropping area.More explicitly,the northern boundary of triple cropping area would shift from its current border at the Changjing River to the Huanghe River,a shift of more than 5 degrees of latitude.And the shift of multiple cropping areas leads to a significant decrease of single cropping area. Furthermore,considering the changes mentioned above in combination with the likely negative balance of precipitation and evapotranspiration and,therefore,increase of moisture stress(i.e. less water availability),as well as the possible increase of heat stress disaster and decrease of LGS (length of growing season),the potential implication of climate change for agriculture in China are also analyzed roughly in this paper. As a result,however,it is still very difficult to reach a specific conclusion that the future climate change will he favorable or unfavorable to farm in China because of the complicated Chinese farming patterns,the complex-various social and economic environment of agricultural development and,especially,a great scientific uncertainties in the investigation/prediction of climate change.
文摘AIM:To evaluate the impact of enhanced recovery after surgery(ERAS) programs in comparison with traditional care on liver surgery outcomes.METHODS:The Pub Med,EMBASE,CNKI and Cochrane Central Register of Controlled Trials databases were searched for randomized controlled trials(RCTs) comparing the ERAS program with traditional care in patients undergoing liver surgery. Studies selected for the meta-analysis met all of the following inclusion criteria:(1) evaluation of ERAS in comparison to traditional care in adult patients undergoing elective open or laparoscopic liver surgery;(2) outcome measures including complications,recovery of bowel function,and hospital length of stay; and(3) RCTs. The following exclusion criteria were applied:(1) the study was not an RCT;(2) the study did not compare ERAS with traditional care;(3) the study reported on emergency,non-elective or transplantation surgery; and(4) the study consisted of unpublished studies with only the abstract presented at a national or international meeting. The primary outcomes were complications. Secondary outcomes were length of hospital stay and time to first flatus.RESULTS:Five RCTs containing 723 patients were included in the meta-analysis. In 10/723 cases,patients presented with benign diseases,while the remaining 713 cases had liver cancer. Of the five studies,three were published in English and two were published in Chinese. Three hundred and fifty-four patients were in the ERAS group,while 369 patients were in the traditional care group. Compared with traditional care,ERAS programs were associated with significantly decreased overall complications(RR = 0.66; 95%CI:0.49-0.88; P = 0.005),grade?Ⅰ?complications(RR = 0.51; 95%CI:0.33-0.79; P = 0.003),and hospitallength of stay [WMD =-2.77 d,95%CI:-3.87-(-1.66); P < 0.00001]. Similarly,ERAS programs were associated with decreased time to first flatus [WMD =-19.69 h,95%CI:-34.63-(-4.74); P < 0.0001]. There was no statistically significant difference in grade Ⅱ-Ⅴ complications between the two group
文摘The flexible contact and machining with wide strip are two prominent advantages for the robotic belt grinding system, which can be widely used to improve the surface quality and machining efficiency while finishing the workpieces with sculptured surfaces. There lacks research on grinding path planning with the constraint of curvature. With complicated contact between the contact wheel and the workpiece, the grinding paths for robot can be obtained by the theory of contact kinematics. The grinding process must satisfy the universal demands of the belt grinding technologies, and the most important thing is to make the contact wheel conform to the local geometrical features on the contact area. For the local surfaces with small curvature, the curve length between the neighboring cutting locations becomes longer to ensure processing efficiency. Otherwise, for the local areas with large curvature, the curve length becomes shorter to ensure machining accuracy. A series of planes are created to intersect with the target surface to be ground, and the corresponding sectional profile curves are obtained. For each curve, the curve length between the neighboring cutting points is optimized by inserting a cutter location at the local area with large curvatures. A method of generating the grinding paths including curve length spacing optimization is set up. The validity is completely approved by the off-line simulation, and during the grinding experiments with the method, the quality of surface is improved. The path planning method provides a theoretical support for the smooth and accuracy path of robotic surface grinding.
基金Supported by the National Key Basic Research Program (973 Program) of China (No.2007CB109304)the NationalNatural Science Foundation of China (Nos.30771290 and 30671234)
文摘The variation in nitrogen （N） uptake by rice has been widely studied but differences in rice root morphology that may contribute to this variation are not completely understood. Field and greenhouse experiments were carried out to study N accumulation, root dry weights, total root lengths, root surface areas, and root bleeding rates of two rice cultivars, Elio with low N-use efficiency and Nanguang with high N-use efficiency. Low （1 mmol N L^-1） and high （5 mmol N L^-1） N applications were established in the greenhouse experiment, and the N rates were 0, 120, and 240 kg ha^-1 in the field experiments at Jiangning and Jiangpu farms, Nanjing, China. The results showed that the N accumulation, root dry weight, total root length, and root surface area increased with an increase in N application. At the heading stage, N accumulation in the shoots and roots of Nanguang was greater than that of Elio in the field experiments and that of Elio at 5 mmol N L^-1 in the greenhouse experiment. After the heading stage, N accumulation was higher for Nanguang at both 1 and 5 mmol N L^-1 in the greenhouse experiment. The total root length and root surface area were significantly different between the two cultivars. Over the range of the fertilizer application rates, the root lengths of Nanguang at Jiangning Farm were 49%-6170 greater at booting and 26%-39% greater at heading than those of Elio, and at Jiangpu Farm they were 22%-42% and 26%-38% greater, respectively. Nanguang had a greater root bleeding rate than Elio. It was concluded that the N-use efficiency of the two rice cultivars studied depended to a great extent on the root morphological parameters and root physiological characteristics at different growth stages.
基金supported by the National High-tech R&D Program (863 Program) (No. 2009AA101101)the National S&T Major Project (No. 2008ZX08001)the Central Level, Non-profit, Scientific Research Insti-tutes’ Basic R&D Operations Special Fund (No. 2009RG002-3)
文摘A residual heterozygous line （RHL） carrying a heterozygous segment between two S SR loci RM 11 and RM134 on the rice chromo- some 7 was selected from a set of recombinant inbred lines from the cross D50 （javanica）/HB277 （indica）. The former parent produces much longer grains than the latter. Selfed progenies of this selection were analyzed genotypically （SSRs） and phenotypically （grain length）. Grain length was discontinuously variable in the mapping populations, allowing for the placement of this QTL qGL7-2 within a -4.8 cM interval defined by RM351 and RM234. A set of new markers within this region were developed, which narrowed the QTL to a 278 kb region defined by the markers Indell and RM21945. This region contains 49 predicted genes. The results also suggest that the novel allele for grain length will be used for the application of marker assisted selection for the improvement of grain length.
基金supported by the Beijing Higher Education Young Elite Teacher Project (No. YETP0313)the Chinese Universities Scientific Fund (No. 2014JD073)+1 种基金the National Natural Science Foundation of China (Nos. 31330070, 30925024, 31121062, 41173083, and 41473068)the Introducing International Advanced Agricultural Science and Technology Program of the Ministry of Agriculture of China (948 Program) (No. 2011-G18)
文摘Imbalanced application of nitrogen(N) and phosphorus(P) fertilizers can result in reduced crop yield,low nutrient use efficiency,and high loss of nutrients and soil nitrate nitrogen(NO_3^--N) accumulation decreases when N is applied with P and/or manure;however,the effect of applications of N with P and/or manure on root growth and distribution in the soil profile is not fully understood.The aim of this study was to investigate the combined effects of different N and P fertilizer application rates with or without manure on maize(Zea mays L.) yield,N uptake,root growth,apparent N surplus,Olsen-P concentration,and mineral N(N_(min)) accumulation in a fluvo-aquic calcareous soil from a long-term(28-year) experiment.The experiment comprised twelve combinations of chemical N and P fertilizers,either with or without chicken manure,as treatments in four replicates.The yield of maize grain was 82%higher,the N uptake 100%higher,and the N_(min) accumulation 39%lower in the treatments with combined N and P in comparison to N fertilizer only.The maize root length density in the 30-60 cm layer was three times greater in the treatments with N and P fertilizers than with N fertilizer only.Manure addition increased maize yield by 50%and N uptake by 43%,and reduced N_(min)(mostly NO_3^--N) accumulation in the soil by 46%.The long-term application of manure and P fertilizer resulted in significant increases in soil Olsen-P concentration when no N fertilizer was applied.Manure application reduced the apparent N surplus for all treatments.These results suggest that combined N and P fertilizer applications could enhance maize grain yield and nutrient uptake via stimulating root growth,leading to reduced accumulation of potentially leachable NO_3^--N in soil,and manure application was a practical way to improve degraded soils in China and the rest of the world.
文摘There are well coherences between annual averaged air temperatures at every meteorological station along the Qinghai-Xizang railway, and its 10-year moving average correlation coefficient is 0.92. Thus, the regional averaged annual mean temperature series along the Qinghai-Xizang railway (Trw) from 1935 to 2000 are constructed. The investigation is suggested that: Trw had significant responses to the 5-year lagged sunspot cycle length (SCL) and 15-year lagged concentration of atmospheric carbon dioxide (CO2), and the correlation coefficients between them are -0.76 (SCL) and 0.88 (CO2), respectively. The future SCL is predicted by the model of average generated function constructed with its main cycles of 76a, 93a, 108a, 205a and 275a. The result shows that the SCL would be becoming longer in the first half of the 21st century, and then it could be becoming shorter in the second half of the 21st century. Based on the natural change of SCL and the effect of double CO2 concentration, Trw in the 21st century is forecasted. It could warm up about 0.50℃ in the first half of the 21st century compared with the last decade of last century. The mean maximum air temperature could be likely about 0.20℃ in July and from 0.40℃ to 1.10℃ in January. The annual air temperature difference would likely reduce 0.3-1.00℃. The probability of above predictions ranges from 0.64 to 0.73.
基金support by the National Natural Science Foundation of China (Grant Nos.50679061,50709025 and 10972163)
文摘The article summarizes previous studies on the flow in open channels with rigid vegetation, and constructs a mathematical model for submerged and emerged rigid vegetation. The model involves the forces balance in the control volume in one-dimensional steady uniform flow. For submerged vegetation, the whole flow is divided into four regions： external region, upper vegetated region, transition region and viscous region. According to the Karrnan similarity theory, the article improves the mixing length expression, and then gives an analytical solution to predict the vertical distribution of stream-wise velocity in the external region. For emerged vegetation, the flow is divided into two region： outer region and viscous region. In the two circumstances, the thicknesses of each region are determined respectively. The comparison between the calculated results and our experimental data and other researchers＇ data proves that the proposed model is effective.
