Our next generation of industry-lndustry 4.0-holds the promise of increased flexibility in manufacturing, along with mass customization, better quality, and improved productivity. It thus enables companies to cope wit...Our next generation of industry-lndustry 4.0-holds the promise of increased flexibility in manufacturing, along with mass customization, better quality, and improved productivity. It thus enables companies to cope with the challenges of producing increasingly individualized products with a short lead-time to market and higher quality. Intelligent manufacturing plays an important role in Industry 4.0. Typical resources are converted into intelligent objects so that they are able to sense, act, and behave within a smart environment. In order to fully understand intelligent manufacturing in the context of Industry 4.0, this paper provides a comprehensive review of associated topics such as intelligent manufacturing, Internet of Things （IoT）- enabled manufacturing, and cloud manufacturing. Similarities and differences in these topics are highlighted based on our analysis. We also review key technologies such as the loT, cyber-physical systems （CPSs）, cloud computing, big data analytics （BDA）, and information and communications technology （ICT） that are used to enable intelligent manufacturing. Next, we describe worldwide movements in intelligent manufacturing, including governmental strategic plans from different countries and strategic plans from major international companies in the European Union, United States, Japan, and China. Finally, we present current challenges and future research directions. The concepts discussed in this paper will spark new ideas in the effort to realize the much-anticipated Fourth Industrial Revolution.展开更多
Abscisic acid(ABA)is an important phytohormone regulating plant growth,development,and stress responses.It has an essential role in multiple physiological processes of plants,such as stomatal closure,cuticular wax acc...Abscisic acid(ABA)is an important phytohormone regulating plant growth,development,and stress responses.It has an essential role in multiple physiological processes of plants,such as stomatal closure,cuticular wax accumulation,leaf senescence,bud dormancy,seed germination,osmotic regulation,and growth inhibition among many others.Abscisic acid controls downstream responses to abiotic and biotic environmental changes through both transcriptional and posttranscriptional mechanisms.During the past 20 years,ABA biosynthesis and many of its signaling pathways have been well characterized.Here we review the dynamics of ABA metabolic pools and signaling that affects many of its physiological functions.展开更多
INTRODUCTION Sleep disturbance is one of the most common nonmotor symptoms in Parkinson's disease (PD).Sleep disturbance affects 40-98% of PD patients in the world. In China, the prevalence of PD patients with sle...INTRODUCTION Sleep disturbance is one of the most common nonmotor symptoms in Parkinson's disease (PD).Sleep disturbance affects 40-98% of PD patients in the world. In China, the prevalence of PD patients with sleep disturbance ranges from 47.66% to 89.10%. Sleep disturbance usually has adverse impact on the quality of life of PD patients. Apossible pathogenesis of PD with sleep disturbance include thalamocortical pathway degeneration and changes of neurotransmitter systems. The etiology of sleep disturbance is multifactorial,involving degeneration of areas regulating sleep,sleep structure affected by drugs,sleep disturbance induced by drug,and sleep fragmentation by multiple factors.展开更多
针对玛湖地区致密油藏衰竭式开发后期采油速度快速递减的问题,提出利用超临界CO_(2)驱替开发致密油藏的研究思路,通过开展超临界CO_(2)萃取致密油实验、最小混相压力实验及长岩心驱替实验,探究了超临界CO_(2)驱替提高致密油采收率的作...针对玛湖地区致密油藏衰竭式开发后期采油速度快速递减的问题,提出利用超临界CO_(2)驱替开发致密油藏的研究思路,通过开展超临界CO_(2)萃取致密油实验、最小混相压力实验及长岩心驱替实验,探究了超临界CO_(2)驱替提高致密油采收率的作用机理、开发特征及影响因素,优选了注气速度、CO_(2)转注时机等重要操作参数。实验结果表明:CO_(2)萃取轻质组分能力随萃取次数的增加而减弱;注气速度对最终采收率影响较大,最优注气速度为0.10 cm 3/min;原油与超临界CO_(2)最小混相压力为34.18 MPa;当前油藏压力条件为最佳CO_(2)转注时机。该研究成果对致密油藏高效开发具有一定指导意义。展开更多
To investigate the effect of arsenic on spermatogenesis. Methods: Mature (4 months old) Wistar rats were intraperitoneally administered sodium arsenite at doses of 4, 5 or 6 mg-kg^-day1 for 26 days. Different varietie...To investigate the effect of arsenic on spermatogenesis. Methods: Mature (4 months old) Wistar rats were intraperitoneally administered sodium arsenite at doses of 4, 5 or 6 mg-kg^-day1 for 26 days. Different varieties of germ cells at stage VII seminiferous epithelium cycle, namely, type A spermatogonia (ASg), preleptotene spermatocytes (pLSc), midpachytene spermatocytes (mPSc) and step 7 spermatids (7Sd) were quantitatively evaluated, along with radioimmunoassay of plasma follicle-stimulating hormone (FSH), lutuneizing hormone (LH), testosterone and assessment of the epididymal sperm count. Results: In the 5 and 6 mg/kg groups, there were significant dose-dependent decreases in the accessory sex organ weights, epididymal sperm count and plasma concentrations of LH, FSH and testosterone with massive degeneration of all the germ cells at stage VII. The changes were insignificant in the 4 mg/kg group. Conclusion: Arsenite has a suppressive influence on spermatogenesis and gonadotrophin and testosterone release in rats.展开更多
Soil salinity is a growing problem around the world with special relevance in farmlands. The ability to sense and respond to environmental stimuli is among the most fundamental processes that enable plants to survive....Soil salinity is a growing problem around the world with special relevance in farmlands. The ability to sense and respond to environmental stimuli is among the most fundamental processes that enable plants to survive. At the cellular level, the Salt Overly Sensitive （SOS） signaling pathway that comprises SOS3, SOS2, and SOS1 has been proposed to mediate cellular signaling under salt stress, to maintain ion homeostasis. Less well known is how cellularly heterog- enous organs couple the salt signals to homeostasis maintenance of different types of cells and to appropriate growth of the entire organ and plant. Recent evidence strongly indicates that different regulatory mechanisms are adopted by roots and shoots in response to salt stress. Several reports have stated that, in roots, the SOS proteins may have novel roles in addition to their functions in sodium homeostasis. SOS3 plays a critical role in plastic development of lateral roots through modulation of auxin gradients and maxima in roots under mild salt conditions. The SOS proteins also play a role in the dynamics of cytoskeleton under stress. These results imply a high complexity of the regulatory networks involved in plant response to salinity. This review focuses on the emerging complexity of the SOS signaling and SOS protein functions, and highlights recent understanding on how the SOS proteins contribute to different responses to salt stress besides ion homeostasis.展开更多
Transferring foreign DNA into plant cells by biolistic and Agrobacterium _mediated methods may result in random integration of different copy numbers of the transgene, and different proportions of intact vs. rearra...Transferring foreign DNA into plant cells by biolistic and Agrobacterium _mediated methods may result in random integration of different copy numbers of the transgene, and different proportions of intact vs. rearranged copies of the transgene. This may, in turn, affect transgene expression levels. To test the above hypothesis, we first introduced the same plasmid, pAc1PG_CAM, into rice (Oryza sativa L.) calli separately by the biolistic method and by the Agrobacterium _mediated method. To show whether different plasmids may affect the results, we also introduced pTOK233 by the Agrobacterium _mediated method and pJPM44 by the biolistic method. Transgene expression of R0 plants was monitored by histochemical analysis of GUS activity. Transgene copy number was determined by Southern blot analysis after digesting genomic DNA with an enzyme that has a unique cutting site within the input plasmid. The total genomic DNA was also digested by a two_cut enzyme (the cuts are located at two sides of a given transgene expression cassette), followed by Southern blotting analysis, for determining the number of intact transgene expression cassettes. Our data showed that Agrobacterium _mediated transformation resulted in lower transgene copy number (average between 2.1 and 2.3) in transgenic rice plants, compared with those plants obtained by the biolistic method (average between 4.2 and 5.6). The frequency of DNA rearrangement in expression cassettes is lower in transgenic rice plants obtained by the Agrobacterium _ mediated method than those obtained by the biolistic method. The average rearrangement frequency is 0.07 to 0.106 for the Agrobacterium _mediated method, and 0.57 to 0.66 for the biolistic method. Our results suggest that it is better to compare the number of intact expression cassettes instead of the total copy number of the transgene in demonstrating their influence on the level of transgene expression. This is the first report on the frequency of expression cassette rearrangemen展开更多
Information and communication technology is undergoing rapid development, and many disruptive technologies, such as cloud computing, Internet of Things, big data, and artificial intelligence, have emerged. These techn...Information and communication technology is undergoing rapid development, and many disruptive technologies, such as cloud computing, Internet of Things, big data, and artificial intelligence, have emerged. These technologies are permeating the manufacturing industry and enable the fusion of physical and virtual worlds through cyber-physical systems （CPS）, which mark the advent of the fourth stage of industrial production （i.e., Industry 4.0）. The widespread application of CPS in manufacturing environments renders manufacturing sys- tems increasingly smart. To advance research on the implementation of Industry 4.0, this study examines smart manufacturing systems for Industry 4.0. First, a conceptual framework of smart manufacturing systems for Industry 4.0 is presented. Second, demonstrative scenarios that pertain to smart design, smart machining, smart control, smart monitoring, and smart scheduling, are presented. Key technologies and their possible applications to Industry 4.0 smart manufacturing systems are reviewed based on these demonstrative scenarios. Finally, challenges and future perspectives are identified and discussed.展开更多
Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for produci...Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for producing pig iron from red mud waste fines. The smelting reduction of red mud was carried out in a 35 kW DC extended arc thermal plasma reactor. Red mud was properly mixed with fluxes and graphite （fixed carbon, 99%） as a reductant as per stoichiometric requirement. The effect of various process parameters like a reductant, fluxes and smelting time on iron recovery was studied and optimized. An optimum condition for the maximum recovery of iron was obtained. A new thermal plasma process applicable to direct iron making from red mud waste fines that would achieve significant utilization of red mud was proposed.展开更多
Indole-3-acetic acid （IAA）, a major plant auxin, is produced in both tryptophan-dependent and tryptophan-independent pathways. A major pathway in Arabidopsis thaliana generates IAA in two reactions from tryptophan. ...Indole-3-acetic acid （IAA）, a major plant auxin, is produced in both tryptophan-dependent and tryptophan-independent pathways. A major pathway in Arabidopsis thaliana generates IAA in two reactions from tryptophan. Step one converts tryptophan to indole-3-pyruvic acid （IPA） by tryptophan aminotransferases followed by a rate-limiting step converting IPA to IAA catalyzed by YUCCA proteins. We identified eight putative StYUC （Solanum tuberosum YUCCA） genes whose deduced amino acid sequences share 50%-70% identity with those of Arabidopsis YUCCA proteins. All include canonical, conserved YUCCA sequences： FATGY motif, FMO signature sequence, and FAD-binding and NADP-binding sequences. In addition, five genes were found with -50% amino acid sequence identity to Arabidopsis trypto-phan aminotransferases. Transgenic potato （Solanum tuberosum cv. Jowon） constitutively overexpressing Arabidopsis AtYUC6 displayed high-auxin phenotypes such as narrow downward-curled leaves, increased height, erect stature, and longevity. Transgenic potato plants overexpressing AtYUC6 showed enhanced drought tolerance based on reduced water loss. The phenotype was correlated with reduced levels of reactive oxygen species in leaves. The results suggest a func-tional YUCCA pathway of auxin biosynthesis in potato that may be exploited to alter plant responses to the environment.展开更多
Insertion mutations that disrupt the function of PHT4;6 （At5g44370） cause NaCI hypersensitivity of Arabidopsis seedlings that is characterized by reduced growth of the primary root, enhanced lateral branching, and s...Insertion mutations that disrupt the function of PHT4;6 （At5g44370） cause NaCI hypersensitivity of Arabidopsis seedlings that is characterized by reduced growth of the primary root, enhanced lateral branching, and swelling of root tips. Mutant phenotypes were exacerbated by sucrose, but not by equiosmolar concentrations of mannitol, and attenuated by low inorganic phosphate in the medium. Protein PHT4;6 belongs to the Major Facilitator Superfamily of permeases that shares significant sequence similarity to mammalian type-I Pi transporters and vesicular glutamate transporters, and is a member of the PHT4 family of putative intracellular phosphate transporters of plants. PHT4;6 localizes to the Golgi membrane and transport studies indicate that PHT4;6 facilitates the selective transport of Pi but not of chloride or inorganic anions. Phenotypic similarities with other mutants displaying root swelling suggest that PHT4;6 likely functions in protein N-glycosylation and cell wall biosynthesis, which are essential for salt tolerance. Together, our results indicate that PHT4;6 transports Pi out of the Golgi lumenal space for the re-cycling of the Pi released from glycosylation processes.展开更多
The phytohormone abscisic acid （ABA） regulates many key processes in plants, such as seed germina- tion, seedling growth, and abiotic stress tolerance. In recent years, a minimal set of core components of a major AB...The phytohormone abscisic acid （ABA） regulates many key processes in plants, such as seed germina- tion, seedling growth, and abiotic stress tolerance. In recent years, a minimal set of core components of a major ABA signaling pathway has been discovered. These components include a RCAR/PYR/PYL family of ABA receptors, a group of PP2C phosphatases, and three SnRK2 kinases. However, how the interactions between the receptors and their targets are regulated by other proteins remains largely unknown. In a companion paper published in this issue, we showed that ROP11, a member of the plant- specific Rho-like small GTPase family, negatively regulates multiple ABA responses in Arabidopsis. The current work demonstrated that the constitutively active ROP11 （CA-ROP11） can modulate the RCAR1/PYL9-mediated ABA signaling pathway based on reconstitution assays in Arabidopsis thaliana protoplasts. Furthermore, using luciferase complementation imaging, yeast two-hybrid assays, co- immunoprecipitation assays in Nicotiana benthamiana and bimolecular fluorescence complementation assays, we demonstrated that CA-ROP11 directly interacts with ABI1, a signaling component downstream of RCAR1/PYL9. Finally, we provided biochemical evidence that CA-ROP11 protects ABI1 phosphatase activity from inhibition by RCAR1/PYL9 and thus negatively regulates ABA signaling in plant cells. A model of how ROP11 acts to negatively regulate ABA signaling is presented.展开更多
This paper considers the robust delay-dependent stability problem of a class of linear uncertain system with interval time-varying delay and proposes less conservative stability criteria for computing the maximum allo...This paper considers the robust delay-dependent stability problem of a class of linear uncertain system with interval time-varying delay and proposes less conservative stability criteria for computing the maximum allowable bound of the delay range. Less conservatism of the proposed stability criteria is attributed to the delay-central point method of stability analysis, wherein the delay interval is partitioned into two subintervals of equal length, and the time derivative of a candidate Lyapunov-Krasovskii functional based on delay decomposition technique is evaluated in each of these delay segments. In deriving the stability conditions in LMI framework, neither model transformations nor bounding techniques using free-weighting matrix variables are employed for dealing the cross-terms that emerge from the time derivative of the Lyapunov-Krasovskii functional; instead, they are dealt using tighter integral inequalities. The proposed analysis subsequently yields a stability condition in convex LMI framework that can be solved using standard numerical packages. For deriving robust stability conditions, two categories of system uncertainties, namely, time-varying structured and polytopic-type uncertainties, are considered. The effectiveness of the proposed stability criteria is validated through standard numerical examples.展开更多
AIM： To investigate the expression of cyclooxygenase-2 （COX-2） and epithelial growth factor receptor （EGFR） throughout the progression of Barrett＇s esophagus （BE）. METHODS： COX-2 and EGFR protein expressions ...AIM： To investigate the expression of cyclooxygenase-2 （COX-2） and epithelial growth factor receptor （EGFR） throughout the progression of Barrett＇s esophagus （BE）. METHODS： COX-2 and EGFR protein expressions were detected by using immunohistochemical method. A detailed cytomorphological changes were determined. Areas of COX-2 and EGFR expression were quantified by using computer Imaging System. RESULTS： The expressions of both COX-2 and EGFR increased along with the progression from BE to esophagus adenocarcinoma （EAC）. A positive correlation was found between COX-2 expression and EGFR expression. CONCLUSION： COX-2 and EGFR may be cooperative in the stepwise progression from BE to EAC, thereby leading to carcinogenesis.展开更多
文摘Our next generation of industry-lndustry 4.0-holds the promise of increased flexibility in manufacturing, along with mass customization, better quality, and improved productivity. It thus enables companies to cope with the challenges of producing increasingly individualized products with a short lead-time to market and higher quality. Intelligent manufacturing plays an important role in Industry 4.0. Typical resources are converted into intelligent objects so that they are able to sense, act, and behave within a smart environment. In order to fully understand intelligent manufacturing in the context of Industry 4.0, this paper provides a comprehensive review of associated topics such as intelligent manufacturing, Internet of Things （IoT）- enabled manufacturing, and cloud manufacturing. Similarities and differences in these topics are highlighted based on our analysis. We also review key technologies such as the loT, cyber-physical systems （CPSs）, cloud computing, big data analytics （BDA）, and information and communications technology （ICT） that are used to enable intelligent manufacturing. Next, we describe worldwide movements in intelligent manufacturing, including governmental strategic plans from different countries and strategic plans from major international companies in the European Union, United States, Japan, and China. Finally, we present current challenges and future research directions. The concepts discussed in this paper will spark new ideas in the effort to realize the much-anticipated Fourth Industrial Revolution.
基金supported by the Shanghai Center for Plant Stress Biology from the Chinese Academy of Sciences, the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB27040107)the National Natural Science Foundation of China (31970293)the Shanghai Pujiang Program (18PJ1410900)
文摘Abscisic acid(ABA)is an important phytohormone regulating plant growth,development,and stress responses.It has an essential role in multiple physiological processes of plants,such as stomatal closure,cuticular wax accumulation,leaf senescence,bud dormancy,seed germination,osmotic regulation,and growth inhibition among many others.Abscisic acid controls downstream responses to abiotic and biotic environmental changes through both transcriptional and posttranscriptional mechanisms.During the past 20 years,ABA biosynthesis and many of its signaling pathways have been well characterized.Here we review the dynamics of ABA metabolic pools and signaling that affects many of its physiological functions.
文摘INTRODUCTION Sleep disturbance is one of the most common nonmotor symptoms in Parkinson's disease (PD).Sleep disturbance affects 40-98% of PD patients in the world. In China, the prevalence of PD patients with sleep disturbance ranges from 47.66% to 89.10%. Sleep disturbance usually has adverse impact on the quality of life of PD patients. Apossible pathogenesis of PD with sleep disturbance include thalamocortical pathway degeneration and changes of neurotransmitter systems. The etiology of sleep disturbance is multifactorial,involving degeneration of areas regulating sleep,sleep structure affected by drugs,sleep disturbance induced by drug,and sleep fragmentation by multiple factors.
文摘针对玛湖地区致密油藏衰竭式开发后期采油速度快速递减的问题,提出利用超临界CO_(2)驱替开发致密油藏的研究思路,通过开展超临界CO_(2)萃取致密油实验、最小混相压力实验及长岩心驱替实验,探究了超临界CO_(2)驱替提高致密油采收率的作用机理、开发特征及影响因素,优选了注气速度、CO_(2)转注时机等重要操作参数。实验结果表明:CO_(2)萃取轻质组分能力随萃取次数的增加而减弱;注气速度对最终采收率影响较大,最优注气速度为0.10 cm 3/min;原油与超临界CO_(2)最小混相压力为34.18 MPa;当前油藏压力条件为最佳CO_(2)转注时机。该研究成果对致密油藏高效开发具有一定指导意义。
文摘To investigate the effect of arsenic on spermatogenesis. Methods: Mature (4 months old) Wistar rats were intraperitoneally administered sodium arsenite at doses of 4, 5 or 6 mg-kg^-day1 for 26 days. Different varieties of germ cells at stage VII seminiferous epithelium cycle, namely, type A spermatogonia (ASg), preleptotene spermatocytes (pLSc), midpachytene spermatocytes (mPSc) and step 7 spermatids (7Sd) were quantitatively evaluated, along with radioimmunoassay of plasma follicle-stimulating hormone (FSH), lutuneizing hormone (LH), testosterone and assessment of the epididymal sperm count. Results: In the 5 and 6 mg/kg groups, there were significant dose-dependent decreases in the accessory sex organ weights, epididymal sperm count and plasma concentrations of LH, FSH and testosterone with massive degeneration of all the germ cells at stage VII. The changes were insignificant in the 4 mg/kg group. Conclusion: Arsenite has a suppressive influence on spermatogenesis and gonadotrophin and testosterone release in rats.
基金We would like to acknowledge support from the National Science Foundation of China，the National Program on Key Basic Research Project，the Key Basic Research Project of Applied Basic Research Program of Hebei Province，the National Transgenic Key Project of MOA，the Ministry of Science and Innovation of Spain，the International Exchange Program of the University of Naples ‘Federico Ⅱ' to G.B.No conflict of interest declared
文摘Soil salinity is a growing problem around the world with special relevance in farmlands. The ability to sense and respond to environmental stimuli is among the most fundamental processes that enable plants to survive. At the cellular level, the Salt Overly Sensitive （SOS） signaling pathway that comprises SOS3, SOS2, and SOS1 has been proposed to mediate cellular signaling under salt stress, to maintain ion homeostasis. Less well known is how cellularly heterog- enous organs couple the salt signals to homeostasis maintenance of different types of cells and to appropriate growth of the entire organ and plant. Recent evidence strongly indicates that different regulatory mechanisms are adopted by roots and shoots in response to salt stress. Several reports have stated that, in roots, the SOS proteins may have novel roles in addition to their functions in sodium homeostasis. SOS3 plays a critical role in plastic development of lateral roots through modulation of auxin gradients and maxima in roots under mild salt conditions. The SOS proteins also play a role in the dynamics of cytoskeleton under stress. These results imply a high complexity of the regulatory networks involved in plant response to salinity. This review focuses on the emerging complexity of the SOS signaling and SOS protein functions, and highlights recent understanding on how the SOS proteins contribute to different responses to salt stress besides ion homeostasis.
文摘Transferring foreign DNA into plant cells by biolistic and Agrobacterium _mediated methods may result in random integration of different copy numbers of the transgene, and different proportions of intact vs. rearranged copies of the transgene. This may, in turn, affect transgene expression levels. To test the above hypothesis, we first introduced the same plasmid, pAc1PG_CAM, into rice (Oryza sativa L.) calli separately by the biolistic method and by the Agrobacterium _mediated method. To show whether different plasmids may affect the results, we also introduced pTOK233 by the Agrobacterium _mediated method and pJPM44 by the biolistic method. Transgene expression of R0 plants was monitored by histochemical analysis of GUS activity. Transgene copy number was determined by Southern blot analysis after digesting genomic DNA with an enzyme that has a unique cutting site within the input plasmid. The total genomic DNA was also digested by a two_cut enzyme (the cuts are located at two sides of a given transgene expression cassette), followed by Southern blotting analysis, for determining the number of intact transgene expression cassettes. Our data showed that Agrobacterium _mediated transformation resulted in lower transgene copy number (average between 2.1 and 2.3) in transgenic rice plants, compared with those plants obtained by the biolistic method (average between 4.2 and 5.6). The frequency of DNA rearrangement in expression cassettes is lower in transgenic rice plants obtained by the Agrobacterium _ mediated method than those obtained by the biolistic method. The average rearrangement frequency is 0.07 to 0.106 for the Agrobacterium _mediated method, and 0.57 to 0.66 for the biolistic method. Our results suggest that it is better to compare the number of intact expression cassettes instead of the total copy number of the transgene in demonstrating their influence on the level of transgene expression. This is the first report on the frequency of expression cassette rearrangemen
文摘Information and communication technology is undergoing rapid development, and many disruptive technologies, such as cloud computing, Internet of Things, big data, and artificial intelligence, have emerged. These technologies are permeating the manufacturing industry and enable the fusion of physical and virtual worlds through cyber-physical systems （CPS）, which mark the advent of the fourth stage of industrial production （i.e., Industry 4.0）. The widespread application of CPS in manufacturing environments renders manufacturing sys- tems increasingly smart. To advance research on the implementation of Industry 4.0, this study examines smart manufacturing systems for Industry 4.0. First, a conceptual framework of smart manufacturing systems for Industry 4.0 is presented. Second, demonstrative scenarios that pertain to smart design, smart machining, smart control, smart monitoring, and smart scheduling, are presented. Key technologies and their possible applications to Industry 4.0 smart manufacturing systems are reviewed based on these demonstrative scenarios. Finally, challenges and future perspectives are identified and discussed.
文摘Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for producing pig iron from red mud waste fines. The smelting reduction of red mud was carried out in a 35 kW DC extended arc thermal plasma reactor. Red mud was properly mixed with fluxes and graphite （fixed carbon, 99%） as a reductant as per stoichiometric requirement. The effect of various process parameters like a reductant, fluxes and smelting time on iron recovery was studied and optimized. An optimum condition for the maximum recovery of iron was obtained. A new thermal plasma process applicable to direct iron making from red mud waste fines that would achieve significant utilization of red mud was proposed.
文摘Indole-3-acetic acid （IAA）, a major plant auxin, is produced in both tryptophan-dependent and tryptophan-independent pathways. A major pathway in Arabidopsis thaliana generates IAA in two reactions from tryptophan. Step one converts tryptophan to indole-3-pyruvic acid （IPA） by tryptophan aminotransferases followed by a rate-limiting step converting IPA to IAA catalyzed by YUCCA proteins. We identified eight putative StYUC （Solanum tuberosum YUCCA） genes whose deduced amino acid sequences share 50%-70% identity with those of Arabidopsis YUCCA proteins. All include canonical, conserved YUCCA sequences： FATGY motif, FMO signature sequence, and FAD-binding and NADP-binding sequences. In addition, five genes were found with -50% amino acid sequence identity to Arabidopsis trypto-phan aminotransferases. Transgenic potato （Solanum tuberosum cv. Jowon） constitutively overexpressing Arabidopsis AtYUC6 displayed high-auxin phenotypes such as narrow downward-curled leaves, increased height, erect stature, and longevity. Transgenic potato plants overexpressing AtYUC6 showed enhanced drought tolerance based on reduced water loss. The phenotype was correlated with reduced levels of reactive oxygen species in leaves. The results suggest a func-tional YUCCA pathway of auxin biosynthesis in potato that may be exploited to alter plant responses to the environment.
文摘Insertion mutations that disrupt the function of PHT4;6 （At5g44370） cause NaCI hypersensitivity of Arabidopsis seedlings that is characterized by reduced growth of the primary root, enhanced lateral branching, and swelling of root tips. Mutant phenotypes were exacerbated by sucrose, but not by equiosmolar concentrations of mannitol, and attenuated by low inorganic phosphate in the medium. Protein PHT4;6 belongs to the Major Facilitator Superfamily of permeases that shares significant sequence similarity to mammalian type-I Pi transporters and vesicular glutamate transporters, and is a member of the PHT4 family of putative intracellular phosphate transporters of plants. PHT4;6 localizes to the Golgi membrane and transport studies indicate that PHT4;6 facilitates the selective transport of Pi but not of chloride or inorganic anions. Phenotypic similarities with other mutants displaying root swelling suggest that PHT4;6 likely functions in protein N-glycosylation and cell wall biosynthesis, which are essential for salt tolerance. Together, our results indicate that PHT4;6 transports Pi out of the Golgi lumenal space for the re-cycling of the Pi released from glycosylation processes.
基金supported by the 973National Basic Research Program of the Ministry of Science and Technology of China(2009CB119100)the National Natural Science Foundation of China(90717121)
文摘The phytohormone abscisic acid （ABA） regulates many key processes in plants, such as seed germina- tion, seedling growth, and abiotic stress tolerance. In recent years, a minimal set of core components of a major ABA signaling pathway has been discovered. These components include a RCAR/PYR/PYL family of ABA receptors, a group of PP2C phosphatases, and three SnRK2 kinases. However, how the interactions between the receptors and their targets are regulated by other proteins remains largely unknown. In a companion paper published in this issue, we showed that ROP11, a member of the plant- specific Rho-like small GTPase family, negatively regulates multiple ABA responses in Arabidopsis. The current work demonstrated that the constitutively active ROP11 （CA-ROP11） can modulate the RCAR1/PYL9-mediated ABA signaling pathway based on reconstitution assays in Arabidopsis thaliana protoplasts. Furthermore, using luciferase complementation imaging, yeast two-hybrid assays, co- immunoprecipitation assays in Nicotiana benthamiana and bimolecular fluorescence complementation assays, we demonstrated that CA-ROP11 directly interacts with ABI1, a signaling component downstream of RCAR1/PYL9. Finally, we provided biochemical evidence that CA-ROP11 protects ABI1 phosphatase activity from inhibition by RCAR1/PYL9 and thus negatively regulates ABA signaling in plant cells. A model of how ROP11 acts to negatively regulate ABA signaling is presented.
文摘This paper considers the robust delay-dependent stability problem of a class of linear uncertain system with interval time-varying delay and proposes less conservative stability criteria for computing the maximum allowable bound of the delay range. Less conservatism of the proposed stability criteria is attributed to the delay-central point method of stability analysis, wherein the delay interval is partitioned into two subintervals of equal length, and the time derivative of a candidate Lyapunov-Krasovskii functional based on delay decomposition technique is evaluated in each of these delay segments. In deriving the stability conditions in LMI framework, neither model transformations nor bounding techniques using free-weighting matrix variables are employed for dealing the cross-terms that emerge from the time derivative of the Lyapunov-Krasovskii functional; instead, they are dealt using tighter integral inequalities. The proposed analysis subsequently yields a stability condition in convex LMI framework that can be solved using standard numerical packages. For deriving robust stability conditions, two categories of system uncertainties, namely, time-varying structured and polytopic-type uncertainties, are considered. The effectiveness of the proposed stability criteria is validated through standard numerical examples.
基金Supported by the University of Louisville Hospital the Society for Surgery of the Alimentary Tract Career Development Award
文摘AIM： To investigate the expression of cyclooxygenase-2 （COX-2） and epithelial growth factor receptor （EGFR） throughout the progression of Barrett＇s esophagus （BE）. METHODS： COX-2 and EGFR protein expressions were detected by using immunohistochemical method. A detailed cytomorphological changes were determined. Areas of COX-2 and EGFR expression were quantified by using computer Imaging System. RESULTS： The expressions of both COX-2 and EGFR increased along with the progression from BE to esophagus adenocarcinoma （EAC）. A positive correlation was found between COX-2 expression and EGFR expression. CONCLUSION： COX-2 and EGFR may be cooperative in the stepwise progression from BE to EAC, thereby leading to carcinogenesis.
