A new process for extracting oil and starch from tea seed was introduced. The new process included one special link compared with all of the processes used now for tea seed oil and starch production. The link was stat...A new process for extracting oil and starch from tea seed was introduced. The new process included one special link compared with all of the processes used now for tea seed oil and starch production. The link was static fermentation by which oil bodies and starch were separated naturally from tea seeds. By the process, tea seed oil and starch which were in conformity with government standards about edible oil and starch were successfully produced with 16% and 8% of production rate, respectively. The new process has many advantages, such as more simple equipments, lower production cost and whole natural products, etc..展开更多
AIM: To investigate whether the side population (SP) cells possess cancer stem cell-like characteristics in vitro and the role of SP cells in tumorigenic process in gastric cancer. METHODS: We analyzed the presence of...AIM: To investigate whether the side population (SP) cells possess cancer stem cell-like characteristics in vitro and the role of SP cells in tumorigenic process in gastric cancer. METHODS: We analyzed the presence of SP cells indifferent human gastric carcinoma cell lines, and then isolated and identified the SP cells from the KATO Ⅲ human gastric cancer cell line by flow cytometry. The clonogenic ability and self-renewal were evaluated by clone and sphere formation assays. The related genes were determined by reverse transcription polymerase chain reaction. To compare tumorigenic ability, SP and non-side population (NSP) cells from the KATO Ⅲ human gastric cancer cell line were subcutaneously injected into nude mice. RESULTS: SP cells from the total population accounted for 0.57% in KATO Ⅲ, 1.04% in Hs-746T, and 0.02% in AGS (CRL-1739). SP cells could grow clonally and have self-renewal capability in conditioned media. The expression of ABCG2, MDRI, Bmi-1 and Oct-4 was different between SP and NSP cells. However, there was no apparent difference between SP and NSP cells when they were injected into nude mice. CONCLUSION: SP cells have some cancer stem celllike characteristics in vitro and can be used for studying the tumorigenic process in gastric cancer.展开更多
Abstract: In the present study was investigated Arg-X protease-sensitive in supramolecular-genome compartments (nucleoplasm, chromatin, nuclear matrix), during the period of the transcriptional activation of chroma...Abstract: In the present study was investigated Arg-X protease-sensitive in supramolecular-genome compartments (nucleoplasm, chromatin, nuclear matrix), during the period of the transcriptional activation of chromatin when the growth processes was initiated in the mature germs of winter and transformed from it spring wheat. The germs have been separated from endosperm from 0 h (air-dry seed) up to 21 h in each 3 h after the start of seeds soaking. Cell nucleus have been allocated from germs and cleared, and then from them supramolecular-genome compartments were extracted by increasing ionic strength of solution. The Arg-X (tryptase) activity was assessed by cleavage of Arg-X bonds in the arginine-enriched protein protamine in all nuclear fractions. In the present study have shown what Arg-X protease-sensitives zones can be located on the supramolecular structures of chromatin matrix in processes of realization of ontogenetic programs of development in mature germs of the winter and transformed from it spring wheat. Arg-X protease-sensitive can translocate and coordinated in heteropolymer structures on the same genetic matrix. Questions of epigenetic mechanisms are discussed.展开更多
Gastrin is the main hormone responsible for the stimulation of gastric acid secretion;in addition,gastrin and its derivatives exert proliferative and antiapoptotic effects on several cell types.Gastrin synthesis and s...Gastrin is the main hormone responsible for the stimulation of gastric acid secretion;in addition,gastrin and its derivatives exert proliferative and antiapoptotic effects on several cell types.Gastrin synthesis and secretion are increased in certain situations,for example,when proton pump inhibitors are used.The impact of sustained hypergastrinemia is currently being investigated.In vitro experiments and animal models have shown that prolonged hypergastrinemia may be related with higher cancer rates;although,this relationship is less clear in human beings.Higher gastrin levels have been shown to cause hyperplasia of several cell types;yet,the risk for developing cancer seems to be the same in normo-and hypergastrinemic patients.Some tumors also produce their own gastrin,which can act in an autocrine manner promoting tumor growth.Certain cancers are extremely dependent on gastrin to proliferate.Initial research focused only on the effects of amidated gastrins,but there has been an interest in intermediates of gastrin in the last few decades.These intermediates aren't biologically inactive;in fact,they may exert greater effects on proliferation and apoptosis than the completely processed forms.In certain gastrin overproduction states,they are the most abundant gastrin peptides secreted.The purpose of this review is to examine the gastrin biosynthesis process and to summarize the results from different studies evaluating the production,levels,and effects of the main forms of gastrin in different overexpression states and their possible relationship with Barrett's and colorectal carcinogenesis.展开更多
Activating transcription factor 4 (ATF4) has been shown to play key roles in many physiological processes. There are no reports, however, demonstrating a direct link between ATF4 and lipid metabolism. We noticed tha...Activating transcription factor 4 (ATF4) has been shown to play key roles in many physiological processes. There are no reports, however, demonstrating a direct link between ATF4 and lipid metabolism. We noticed that Atf4- deficient mice are lean, suggesting a possible role for ATF4 in regulating lipid metabolism. The goal of our current study is to investigate the involvement of ATF4 in lipid metabolism and elucidate the underlying mechanisms. Studies using Atf4-deficient mice revealed increased energy expenditure, as measured by oxygen consumption. These mice also showed increases in lipolysis, expression of uncoupling protein 2 (UCP2) and p-oxidation genes and decreases in expression of lipogenic genes in white adipose tissue (WAT), suggesting increased utilization and decreased synthesis of fatty acids, respectively. Expression of UCP1, 2 and 3 was also increased in brown adipose tissue (BAT), suggesting increased thermogenesis. The effect of ATF4 deletion on expression of UCPs in BAT suggests that increased thermogenesis may underlie increased energy expenditure. Thus, our study identifies a possible new function for ATF4 in regulating lipid metabolism and thermogenesis.展开更多
Based on existing low-frequency water-filled impedance tube testing facilities, which is a part of the Low Frequency Facility of the Naval Undersea Warfare Center in Beijing, an improved water-filled pulse tube method...Based on existing low-frequency water-filled impedance tube testing facilities, which is a part of the Low Frequency Facility of the Naval Undersea Warfare Center in Beijing, an improved water-filled pulse tube method is presented in this short paper. This proposed study is significantly different from the conventional pulse tube method because of the capability for a single plane damped sine pulse wave to generate in the water-filled pulse tube with a regular waveform and short duration time of about 1ms. During the generation process of the pulse, an inverse filter principle was adopted to compensate the transducer response. The effect of the characteristics of tube termination can be eliminated through the generation process of the pulse. Reflection coefficient from a water/air interface was measured to verify the proposed method. When compared with the expected theoretical values, a relatively good agreement can be obtained in the low frequency range of 500-2 000 Hz.展开更多
Aiming to optimize the beer production process by improving the properties of beer and reducing production costs at the J.S.C. "Birra Peja" brewery, Peja, Kosovo, this study did an evaluation of beer produced using ...Aiming to optimize the beer production process by improving the properties of beer and reducing production costs at the J.S.C. "Birra Peja" brewery, Peja, Kosovo, this study did an evaluation of beer produced using six different malts. Four of the six studied malts were produced in four European countries: Ukraine, Croatia, Serbia and Kosovo; and, the other two malts were obtained from two (2) 30:70 proportion mixtures: one from Kosovo and Ukraine and another one from Kosovo and Croatia. Chemical, microbiological, sensory and tasting analyses were carried on beers produced by these malts. The study included three working groups from: "Birra Peja"; the Agricultural University of Tirana, Albania and "Union Brewery", Ljubljana, Slovenia. Chemical and microbiological tests were based on methods under the EBC (European Beer Convention) and MEBAK (Mitteleurop^iische Brautechnische Analysenkommision e.V.) guidelines. The analyses and assessments made for the quality of beer have come to the conclusion that beer produced by Croatian origin malt corresponds to a better quality beer.展开更多
It is impossible to plan in advance unpredictable phenomena at monitoring, diagnosis and control of industrial batch and continuous equipment and processes such as chemical composition of the raw materials, the proces...It is impossible to plan in advance unpredictable phenomena at monitoring, diagnosis and control of industrial batch and continuous equipment and processes such as chemical composition of the raw materials, the process leads to unexpected reactions and changes its parameters, etc. The agent is active, a program entity, has its own ideas how to perform the tasks of the own agenda. Agents perceive, behave "reasonably", communicate with other agents. Agents can represent equipment and operations in batch processes as recommended by the ISA $88. Jadex system is based on Java language and on FIPA org. recommendations. The description of ripening tank T406 and recipe for yogurt production in the holding of MADETA Corp. in the Czech Rep. It is described modeling and displaying of"normal" and error, fault unit state of the ripening tank. Agents are within the Jadex system and describing the behavior of ripening tank T406 with state diagrams-automata and assist in diagnosing of fault states. States are described in XML language-SCXML (State Charts XML). Jadex Control Center-JCC represents a major access point to use for operating in real time.展开更多
During the summer of 2011, a severe drought event occurred throughout the Zhujiang (Pearl) River Basin of South China. This decreased runoffinto the river, resulting in increased salinity and reduced suspended subst...During the summer of 2011, a severe drought event occurred throughout the Zhujiang (Pearl) River Basin of South China. This decreased runoffinto the river, resulting in increased salinity and reduced suspended substance. To examine the effects of this extreme drought on the distribution of nutrients and chlorophyll, we compared two surveys from 2006 and 20ll. Results show that dissolved inorganic nitrogen concentration did not change from 2006 to 2011, whereas the proportions of NOR and NH4+ to DIN in 2011 increased. PO4 3- concentration was lower in 2011 than in 2006, whereas there was no difference in SiO3 2- concentration between these years. Correlation coefficients of salinity with levels of NO3-, NO2-, NH4+, PO4 3- and SiO3 2- in 2011 were all much higher than those in 2006, suggesting greater conservation of dissolved nutrients during the extreme drought event. Furthermore, calculated amounts of regenerated nitrate and phosphorus and their proportions to observed nutrients in 2011 were much lower than in 2006, indicating that nutrient regeneration decreased during the extreme drought period. Mean concentration of chlorophyll a (Chl-a) was considerably higher in 2011 than in 2006, and a harmful algal bloom of Cochlodinium geminatum was observed in the estuary, owing to water stagnancy and lower turbidity as a consequence of drought. Therefore, the extreme drought event in 2011 changed the composition ratio of nutrients, enhanced nutrient conservative behavior, and reduced nutrient regeneration. This affected some key ecological processes in the estuary.展开更多
In this paper a class of networks with multiple connections are discussed. The multiple connections include two different types of links between nodes in complex networks. For this new model, we give a simple generati...In this paper a class of networks with multiple connections are discussed. The multiple connections include two different types of links between nodes in complex networks. For this new model, we give a simple generating procedure. Furthermore, we investigate dynamical synchronization behavior in a delayed two-layer network, giving corresponding theoretical analysis and numerical examples.展开更多
Transesterification is the most common production process for biodiesel. From this reaction, a glycerin phase is produced that is impure, thus lowering market value. However, because it is rich in carbon, it is an alt...Transesterification is the most common production process for biodiesel. From this reaction, a glycerin phase is produced that is impure, thus lowering market value. However, because it is rich in carbon, it is an alternative for generating bioproducts with a higher added value through bioconversion by microorganisms. The aim of this study was to screen parameters, such as pH (4, 5, 6, 7 and 8) and the initial glycerol concentration at 30 ± ℃ with agitation at 150 rpm for bioemulsifier and lipid synthesis in a submerged medium by Yarrowia lipolytica IMUFRJ 50678 from crude glycerin. The best conditions for bioemulsifier production were 30 ± ℃ at pH: 6 with 50 g/L of initial substrate, which produced 2.7 g/L of lipids, from which the optimum 300.5 mg/L of triglycerides was produced over 48 h of microorganism growth.展开更多
Photolysis rate (J1) and reaction rate constants (kl) for the biacetyl (butane-2,3-dione) were evaluated in aqueous phase using a continuous photolysis system with a conventional Xe-Hg arc lamp as a light source...Photolysis rate (J1) and reaction rate constants (kl) for the biacetyl (butane-2,3-dione) were evaluated in aqueous phase using a continuous photolysis system with a conventional Xe-Hg arc lamp as a light source. The OH radicals was generated by H2OE/UV process and biacetyl (CH3C(O)C(O)CH3) concentrations were monitored using 2,4-DNPH derivatization method. 2,3-butanedione molecule is widely present in the atmosphere, it have been detected in hydrometeors (fogs, rain, and clouds) and at a significant yield (up to 10μmolar). The measurements were performed at 294 K and with free pH values. Our results lead to the following obtained values: J1= 3×10^-4 S^-1 and k1 = (6.17±0.95)×10^8 M^-1·s^-1.The uncertainty listed above is ±15%.展开更多
Seasonal variations in the nitrogen isotopic composition of dissolved nitrate (δ15NO3) were investigated in the surface waters of the Changjiang River estuary in 2009 and 2010. δ15NO3 varied between -4.6‰ and 8.9...Seasonal variations in the nitrogen isotopic composition of dissolved nitrate (δ15NO3) were investigated in the surface waters of the Changjiang River estuary in 2009 and 2010. δ15NO3 varied between -4.6‰ and 8.9%0 with changes in temperature, salinity, dissolved oxygen concentrations, and the composition of the dissolved inorganic nitrogen pool. In February, biological processes decreased because of low temperature, and the mean δ15NO3 near the river mouth was 2.4%0. In May, δ15NO3 was the highest in the surface waters among all seasons. Analysis on the conservative mixing revealed assimilation, and this finding is supported by positive relationship between Chl a and δ15NO3. The fractionation factor of assimilation was estimated to be 2.0‰ by the Rayleigh equation. Nitrification was supported based on the mixing behaviors in November 2010 and the low δ15NO3 values in May and November 2009. The high ammonium concentrations in the adjacent marine area and positive relationships between total organic nitrogen and δ15NO3 in November 2010 indicated that mineralization was taking place.展开更多
文摘A new process for extracting oil and starch from tea seed was introduced. The new process included one special link compared with all of the processes used now for tea seed oil and starch production. The link was static fermentation by which oil bodies and starch were separated naturally from tea seeds. By the process, tea seed oil and starch which were in conformity with government standards about edible oil and starch were successfully produced with 16% and 8% of production rate, respectively. The new process has many advantages, such as more simple equipments, lower production cost and whole natural products, etc..
文摘AIM: To investigate whether the side population (SP) cells possess cancer stem cell-like characteristics in vitro and the role of SP cells in tumorigenic process in gastric cancer. METHODS: We analyzed the presence of SP cells indifferent human gastric carcinoma cell lines, and then isolated and identified the SP cells from the KATO Ⅲ human gastric cancer cell line by flow cytometry. The clonogenic ability and self-renewal were evaluated by clone and sphere formation assays. The related genes were determined by reverse transcription polymerase chain reaction. To compare tumorigenic ability, SP and non-side population (NSP) cells from the KATO Ⅲ human gastric cancer cell line were subcutaneously injected into nude mice. RESULTS: SP cells from the total population accounted for 0.57% in KATO Ⅲ, 1.04% in Hs-746T, and 0.02% in AGS (CRL-1739). SP cells could grow clonally and have self-renewal capability in conditioned media. The expression of ABCG2, MDRI, Bmi-1 and Oct-4 was different between SP and NSP cells. However, there was no apparent difference between SP and NSP cells when they were injected into nude mice. CONCLUSION: SP cells have some cancer stem celllike characteristics in vitro and can be used for studying the tumorigenic process in gastric cancer.
文摘Abstract: In the present study was investigated Arg-X protease-sensitive in supramolecular-genome compartments (nucleoplasm, chromatin, nuclear matrix), during the period of the transcriptional activation of chromatin when the growth processes was initiated in the mature germs of winter and transformed from it spring wheat. The germs have been separated from endosperm from 0 h (air-dry seed) up to 21 h in each 3 h after the start of seeds soaking. Cell nucleus have been allocated from germs and cleared, and then from them supramolecular-genome compartments were extracted by increasing ionic strength of solution. The Arg-X (tryptase) activity was assessed by cleavage of Arg-X bonds in the arginine-enriched protein protamine in all nuclear fractions. In the present study have shown what Arg-X protease-sensitives zones can be located on the supramolecular structures of chromatin matrix in processes of realization of ontogenetic programs of development in mature germs of the winter and transformed from it spring wheat. Arg-X protease-sensitive can translocate and coordinated in heteropolymer structures on the same genetic matrix. Questions of epigenetic mechanisms are discussed.
基金Supported by Instituto de Salud Carlos Ⅲ with Grants FIS 08/1047 and CIBERehdInstituto de Salud Carlos Ⅲ FI10/00167, to Chueca E
文摘Gastrin is the main hormone responsible for the stimulation of gastric acid secretion;in addition,gastrin and its derivatives exert proliferative and antiapoptotic effects on several cell types.Gastrin synthesis and secretion are increased in certain situations,for example,when proton pump inhibitors are used.The impact of sustained hypergastrinemia is currently being investigated.In vitro experiments and animal models have shown that prolonged hypergastrinemia may be related with higher cancer rates;although,this relationship is less clear in human beings.Higher gastrin levels have been shown to cause hyperplasia of several cell types;yet,the risk for developing cancer seems to be the same in normo-and hypergastrinemic patients.Some tumors also produce their own gastrin,which can act in an autocrine manner promoting tumor growth.Certain cancers are extremely dependent on gastrin to proliferate.Initial research focused only on the effects of amidated gastrins,but there has been an interest in intermediates of gastrin in the last few decades.These intermediates aren't biologically inactive;in fact,they may exert greater effects on proliferation and apoptosis than the completely processed forms.In certain gastrin overproduction states,they are the most abundant gastrin peptides secreted.The purpose of this review is to examine the gastrin biosynthesis process and to summarize the results from different studies evaluating the production,levels,and effects of the main forms of gastrin in different overexpression states and their possible relationship with Barrett's and colorectal carcinogenesis.
文摘Activating transcription factor 4 (ATF4) has been shown to play key roles in many physiological processes. There are no reports, however, demonstrating a direct link between ATF4 and lipid metabolism. We noticed that Atf4- deficient mice are lean, suggesting a possible role for ATF4 in regulating lipid metabolism. The goal of our current study is to investigate the involvement of ATF4 in lipid metabolism and elucidate the underlying mechanisms. Studies using Atf4-deficient mice revealed increased energy expenditure, as measured by oxygen consumption. These mice also showed increases in lipolysis, expression of uncoupling protein 2 (UCP2) and p-oxidation genes and decreases in expression of lipogenic genes in white adipose tissue (WAT), suggesting increased utilization and decreased synthesis of fatty acids, respectively. Expression of UCP1, 2 and 3 was also increased in brown adipose tissue (BAT), suggesting increased thermogenesis. The effect of ATF4 deletion on expression of UCPs in BAT suggests that increased thermogenesis may underlie increased energy expenditure. Thus, our study identifies a possible new function for ATF4 in regulating lipid metabolism and thermogenesis.
基金Supported by the National Natural Science Foundation of China under Grant No. 11204242 China Postdoctoral Foundation under Grant No. 2011M501477
文摘Based on existing low-frequency water-filled impedance tube testing facilities, which is a part of the Low Frequency Facility of the Naval Undersea Warfare Center in Beijing, an improved water-filled pulse tube method is presented in this short paper. This proposed study is significantly different from the conventional pulse tube method because of the capability for a single plane damped sine pulse wave to generate in the water-filled pulse tube with a regular waveform and short duration time of about 1ms. During the generation process of the pulse, an inverse filter principle was adopted to compensate the transducer response. The effect of the characteristics of tube termination can be eliminated through the generation process of the pulse. Reflection coefficient from a water/air interface was measured to verify the proposed method. When compared with the expected theoretical values, a relatively good agreement can be obtained in the low frequency range of 500-2 000 Hz.
文摘Aiming to optimize the beer production process by improving the properties of beer and reducing production costs at the J.S.C. "Birra Peja" brewery, Peja, Kosovo, this study did an evaluation of beer produced using six different malts. Four of the six studied malts were produced in four European countries: Ukraine, Croatia, Serbia and Kosovo; and, the other two malts were obtained from two (2) 30:70 proportion mixtures: one from Kosovo and Ukraine and another one from Kosovo and Croatia. Chemical, microbiological, sensory and tasting analyses were carried on beers produced by these malts. The study included three working groups from: "Birra Peja"; the Agricultural University of Tirana, Albania and "Union Brewery", Ljubljana, Slovenia. Chemical and microbiological tests were based on methods under the EBC (European Beer Convention) and MEBAK (Mitteleurop^iische Brautechnische Analysenkommision e.V.) guidelines. The analyses and assessments made for the quality of beer have come to the conclusion that beer produced by Croatian origin malt corresponds to a better quality beer.
文摘It is impossible to plan in advance unpredictable phenomena at monitoring, diagnosis and control of industrial batch and continuous equipment and processes such as chemical composition of the raw materials, the process leads to unexpected reactions and changes its parameters, etc. The agent is active, a program entity, has its own ideas how to perform the tasks of the own agenda. Agents perceive, behave "reasonably", communicate with other agents. Agents can represent equipment and operations in batch processes as recommended by the ISA $88. Jadex system is based on Java language and on FIPA org. recommendations. The description of ripening tank T406 and recipe for yogurt production in the holding of MADETA Corp. in the Czech Rep. It is described modeling and displaying of"normal" and error, fault unit state of the ripening tank. Agents are within the Jadex system and describing the behavior of ripening tank T406 with state diagrams-automata and assist in diagnosing of fault states. States are described in XML language-SCXML (State Charts XML). Jadex Control Center-JCC represents a major access point to use for operating in real time.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA11020205)the National Natural Science Foundation of China(Nos.41076069,40776086)+1 种基金the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-YW-Q07)the National 908 Special Project of China(No.GD908-JC-06)
文摘During the summer of 2011, a severe drought event occurred throughout the Zhujiang (Pearl) River Basin of South China. This decreased runoffinto the river, resulting in increased salinity and reduced suspended substance. To examine the effects of this extreme drought on the distribution of nutrients and chlorophyll, we compared two surveys from 2006 and 20ll. Results show that dissolved inorganic nitrogen concentration did not change from 2006 to 2011, whereas the proportions of NOR and NH4+ to DIN in 2011 increased. PO4 3- concentration was lower in 2011 than in 2006, whereas there was no difference in SiO3 2- concentration between these years. Correlation coefficients of salinity with levels of NO3-, NO2-, NH4+, PO4 3- and SiO3 2- in 2011 were all much higher than those in 2006, suggesting greater conservation of dissolved nutrients during the extreme drought event. Furthermore, calculated amounts of regenerated nitrate and phosphorus and their proportions to observed nutrients in 2011 were much lower than in 2006, indicating that nutrient regeneration decreased during the extreme drought period. Mean concentration of chlorophyll a (Chl-a) was considerably higher in 2011 than in 2006, and a harmful algal bloom of Cochlodinium geminatum was observed in the estuary, owing to water stagnancy and lower turbidity as a consequence of drought. Therefore, the extreme drought event in 2011 changed the composition ratio of nutrients, enhanced nutrient conservative behavior, and reduced nutrient regeneration. This affected some key ecological processes in the estuary.
基金Supported by National Natural Science Foundation of China under Grant No. 10672146the Key Disciplines of Shanghai Municipality under Grant No. S30104
文摘In this paper a class of networks with multiple connections are discussed. The multiple connections include two different types of links between nodes in complex networks. For this new model, we give a simple generating procedure. Furthermore, we investigate dynamical synchronization behavior in a delayed two-layer network, giving corresponding theoretical analysis and numerical examples.
文摘Transesterification is the most common production process for biodiesel. From this reaction, a glycerin phase is produced that is impure, thus lowering market value. However, because it is rich in carbon, it is an alternative for generating bioproducts with a higher added value through bioconversion by microorganisms. The aim of this study was to screen parameters, such as pH (4, 5, 6, 7 and 8) and the initial glycerol concentration at 30 ± ℃ with agitation at 150 rpm for bioemulsifier and lipid synthesis in a submerged medium by Yarrowia lipolytica IMUFRJ 50678 from crude glycerin. The best conditions for bioemulsifier production were 30 ± ℃ at pH: 6 with 50 g/L of initial substrate, which produced 2.7 g/L of lipids, from which the optimum 300.5 mg/L of triglycerides was produced over 48 h of microorganism growth.
文摘Photolysis rate (J1) and reaction rate constants (kl) for the biacetyl (butane-2,3-dione) were evaluated in aqueous phase using a continuous photolysis system with a conventional Xe-Hg arc lamp as a light source. The OH radicals was generated by H2OE/UV process and biacetyl (CH3C(O)C(O)CH3) concentrations were monitored using 2,4-DNPH derivatization method. 2,3-butanedione molecule is widely present in the atmosphere, it have been detected in hydrometeors (fogs, rain, and clouds) and at a significant yield (up to 10μmolar). The measurements were performed at 294 K and with free pH values. Our results lead to the following obtained values: J1= 3×10^-4 S^-1 and k1 = (6.17±0.95)×10^8 M^-1·s^-1.The uncertainty listed above is ±15%.
基金Supported by the National Natural Science Foundation of China(No.41276116)the Fund for Creative Research Groups by NSFC(No.41121064)the National Basic Research Program of China(973 Program)(No.2010CB428706)
文摘Seasonal variations in the nitrogen isotopic composition of dissolved nitrate (δ15NO3) were investigated in the surface waters of the Changjiang River estuary in 2009 and 2010. δ15NO3 varied between -4.6‰ and 8.9%0 with changes in temperature, salinity, dissolved oxygen concentrations, and the composition of the dissolved inorganic nitrogen pool. In February, biological processes decreased because of low temperature, and the mean δ15NO3 near the river mouth was 2.4%0. In May, δ15NO3 was the highest in the surface waters among all seasons. Analysis on the conservative mixing revealed assimilation, and this finding is supported by positive relationship between Chl a and δ15NO3. The fractionation factor of assimilation was estimated to be 2.0‰ by the Rayleigh equation. Nitrification was supported based on the mixing behaviors in November 2010 and the low δ15NO3 values in May and November 2009. The high ammonium concentrations in the adjacent marine area and positive relationships between total organic nitrogen and δ15NO3 in November 2010 indicated that mineralization was taking place.