Objective:To explore the role of circROBO1 in promoting the invasion of retinal Y79 cells by targeting KLF5 and its possible regulatory mechanism.Methods:RNase R enzyme digestion and qRT-PCR experiments were used to d...Objective:To explore the role of circROBO1 in promoting the invasion of retinal Y79 cells by targeting KLF5 and its possible regulatory mechanism.Methods:RNase R enzyme digestion and qRT-PCR experiments were used to detect the structural stability of circular circROBO1 in retinal Y79 cells;cytoplasmic and nuclear RNAs of retinal Y79 cells were extracted for localization analysis of circROBO1;The expression of circROBO1 in retinal Y79 cells were silenced by siRNA.The effect of circROBO1 on the migration and invasion ability of HT-29 cells was detected by scratch assay,Transwell cell invasion and migration assay.The target binding sites of circROBO1 and its downstream miRNA and that of miRNA and its downstream target gene KLF5 were predicted by CircInteractome and TargetScan online software respectively,and the target regulation relationship between them was verified by double luciferase reporter gene experiment.Western blot was used to detect the effect of siRNA silencing the expression of circROBO1 in Y79 cells on the expression of KLF5.Results:Compared with the control group without RNase R enzyme treatment,relative circROBO1 levels did not change significantly after treatment,while relative linear ROBO1 levels decreased significantly after treatment(t=16.18,P<0.05);the content of circROBO1 in the cytoplasm was significantly higher than that in the nucleus(P<0.05);compared with si-control group,the migration rate and the invasion and migration abilities of Transwell cells were all lower in the si-circROBO1 group(t=22.54,P<0.05);circROBO1 can adsorb miR-885-5p,and there is a target binding site between miR-885-5p and KLF5(t=11.39,P<0.05);compared with the si-control group,the KLF5 protein expression in the si-circROBO1 group was significantly decreased(t=17.26,P<0.05).Conclusions:circROBO1 promotes retinalY79 cell tumor invasion by targeting KLF5.展开更多
Carbon(C),nitrogen(N),and phosphorus(P)are of fundamental importance for growth and nutrient dynamics within plant organs and deserve more attention at regional to global scales.However,our knowledge of how these nutr...Carbon(C),nitrogen(N),and phosphorus(P)are of fundamental importance for growth and nutrient dynamics within plant organs and deserve more attention at regional to global scales.However,our knowledge of how these nutrients vary with tree size,organ age,or root order at the individual level remains limited.We determined C,N,and P contents and their stoichiometric ratios(i.e.,nutrient traits)in needles,branches,and fine roots at different organ ages(0-3-year-old needles and branches)and root orders(1st-4th order roots)from 64 Pinus koraiensis of varying size(Diameter at breast height ranged from 0.3 to 100 cm)in northeast China.Soil factors were also measured.The results show that nutrient traits were regulated by tree size,organ age,or root order rather than soil factors.At a whole-plant level,nutrient traits decreased in needles and fine roots but increased in branches with tree size.At the organ level,age or root order had a negative effect on C,N,and P and a positive effect on stoichiometric ratios.Our results demonstrate that nutrient variations are closely related to organ-specific functions and ecophysiological processes at an individual level.It is suggested that the nutrient acquisition strategy by younger trees and organ fractions with higher nutrient content is for survival.Conversely,nutrient storage strategy in older trees and organ fractions are mainly for steady growth.Our results clarified the nutrient utilization strategies during tree and organ ontogeny and suggest that tree size and organ age or root order should be simultaneously considered to understand the complexities of nutrient variations.展开更多
To develop well defined in vitro cell system to test cytotoxicity of a number of model toxins, genetically engineered V79 Chinese hamster fibroblasts expressing isoenzymes of cytochrome P4501A1 XEM2 cells and V79 ce...To develop well defined in vitro cell system to test cytotoxicity of a number of model toxins, genetically engineered V79 Chinese hamster fibroblasts expressing isoenzymes of cytochrome P4501A1 XEM2 cells and V79 cells (parental), which lack cytochrome P450 enzyme activities, were used as controls. The cytotoxic effect of trans 7,8 dihydrbenzo(a)pyrene (BP 7,8 diol) on the parental cells V79 and V79 derived XEM2 cells were evaluated by two methods for cell viability. The data obtained expressed that BP 7,8 diol ranging from 1.0 μmol·L 1 to 5.0 μmol·L 1 in concentrations incubated for 24 h showed a strong cytotoxic effect in XEM2 cells (expressing rat cytochrome P4501A1) in a concentration dependent manner. Time dependent decrease for survival of XEM2 cells was also observed at 2.5 μmol·L 1 concentration. Likewise, BP 7,8 diol did not alter the survival of the parental cells V79 under the same condition. This study also showed that α naphthoflavone (αNF), a well known inhibitor of cytochrome P4501A1 might alter BP 7,8 diol induced cytotoxicity in the XEM2 cells. Our results suggested that cytochrome P4501A1 is responsible for BP 7, 8 diol induced cytotoxicity.展开更多
为了提高光伏电池转换效率、降低能量损失,有必要研究最大功率点跟踪(maximum power point tracking,MPPT)方法。针对传统扰动观察法(perturbation observation method,P&O)存在无法兼顾跟踪速度与稳态精度、在光照度发生较大变化...为了提高光伏电池转换效率、降低能量损失,有必要研究最大功率点跟踪(maximum power point tracking,MPPT)方法。针对传统扰动观察法(perturbation observation method,P&O)存在无法兼顾跟踪速度与稳态精度、在光照度发生较大变化时会产生误判现象的问题,文中提出一种能适应环境变化的变步长P&O控制策略。首先,利用光伏电池刚启动时类似恒流源的特性获取当前光照度下的短路电流,通过固定电流法推导出最大功率点(maximum power point,MPP)的参考电压;其次,当光照度突变时,提出功率修正方法,并给出突变时的变步长调整策略;最后,设计基于线性扩张状态观测器(linear extended state observer,LESO)的分数阶比例积分微分(fractional order proportion integration differentiation,FOPID)控制器,可以对算法输出的参考电压进一步进行跟踪补偿。仿真结果表明,所提控制策略可以提高稳态精度和跟踪速度,有效提高光伏电池的输出功率。展开更多
Suffcient conditions for the existence of at least one solution of two-point boundary value problems for second order nonlinear differential equations [φ(x(t))] + kx(t) + g(t,x(t)) = p(t),t ∈(0,π) x(0) = x(π) = 0 ...Suffcient conditions for the existence of at least one solution of two-point boundary value problems for second order nonlinear differential equations [φ(x(t))] + kx(t) + g(t,x(t)) = p(t),t ∈(0,π) x(0) = x(π) = 0 are established,where [φ(x)] =(|x |p-2x) with p > 1.Our result is new even when [φ(x)] = x in above problem,i.e.p = 2.Examples are presented to illustrate the effciency of the theorem in this paper.展开更多
Evaluation for the performance of learning algorithm has been the main thread of theoretical research of machine learning. The performance of the regularized regression algorithm based on independent and identically d...Evaluation for the performance of learning algorithm has been the main thread of theoretical research of machine learning. The performance of the regularized regression algorithm based on independent and identically distributed（i.i.d.） samples has been researched by a large number of references. In the present paper we provide the convergence rates for the performance of regularized regression based on the inputs of p-order Markov chains.展开更多
Using the metabelian property, regularity, p-commutativity and some properties of congruence, this paper gave the orders of automorphism groups of family Ф24, which are the groups of order p^6 determined by Rodney Ja...Using the metabelian property, regularity, p-commutativity and some properties of congruence, this paper gave the orders of automorphism groups of family Ф24, which are the groups of order p^6 determined by Rodney James, where p denotes an odd prime.展开更多
Let L = L0 ＋ V be the higher order Schrodiger type operator where L0 is a homogeneous elliptic operator of order 2m in divergence form with bounded coeffi- cients and V is a real measurable function as multiplication...Let L = L0 ＋ V be the higher order Schrodiger type operator where L0 is a homogeneous elliptic operator of order 2m in divergence form with bounded coeffi- cients and V is a real measurable function as multiplication operator （e.g., including （-△）m＋v （m∈N） as special examples）. In this paper, assume that V satisfies a strongly subcritical form condition associated with L0, the authors attempt to establish a the- HL （R） （0 〈 p ≤ 1） associated with the higher order Schrodinger ory of Hardy space P n type operator L. Specifically, we first define the molecular Hardy space Hp （JRn） by the so-called （p, q,ε, M） molecule associated to L and then establish its characterizations by the area integral defined by the heat semigroup e-tL.展开更多
A novel soluble π-conjugated polymer, poly [（3-acetylpyrrole-2, 5-diyl） p-（N, N-dimethylamino） azobenzylidene] （PAPDMAABE）, was synthesized by condensation of 3-acetylpyrrole with 4-aldehyde-4＇-dimethylaminoaz...A novel soluble π-conjugated polymer, poly [（3-acetylpyrrole-2, 5-diyl） p-（N, N-dimethylamino） azobenzylidene] （PAPDMAABE）, was synthesized by condensation of 3-acetylpyrrole with 4-aldehyde-4＇-dimethylaminoazobenzene （ADMAA）. The chemical structure of PAPDMAABE was characterized by Fourier transform infrared spectroscopy （FTIR）, ^1H-NMR, and UV-Vis-NIR spectra. Transmission electron microscope （TEM） analysis for PAPDMAABE indicates that part of PAPDMAABE is in crystal state, due to the short-range order of the polymer. Thermogravimetric analysis （TGA） curve shows that the polymer has good thermal stability and its decomposition temperature is 248℃. The optical band gap of PAPDMAABE obtained from the optical absorption spectrum is about 1.73 eV. The resonant third-order nonlinear optical property of PAPDMAABE at 532 nm was studied using degenerate four-wave mixing （DFWM） technique. The resonant third-order nonlinear optical susceptibility of the polymer is about 7.48×10^-8 esu.展开更多
基金Key Project of Hunan Provincial Department of Education(No.21A0285)。
文摘Objective:To explore the role of circROBO1 in promoting the invasion of retinal Y79 cells by targeting KLF5 and its possible regulatory mechanism.Methods:RNase R enzyme digestion and qRT-PCR experiments were used to detect the structural stability of circular circROBO1 in retinal Y79 cells;cytoplasmic and nuclear RNAs of retinal Y79 cells were extracted for localization analysis of circROBO1;The expression of circROBO1 in retinal Y79 cells were silenced by siRNA.The effect of circROBO1 on the migration and invasion ability of HT-29 cells was detected by scratch assay,Transwell cell invasion and migration assay.The target binding sites of circROBO1 and its downstream miRNA and that of miRNA and its downstream target gene KLF5 were predicted by CircInteractome and TargetScan online software respectively,and the target regulation relationship between them was verified by double luciferase reporter gene experiment.Western blot was used to detect the effect of siRNA silencing the expression of circROBO1 in Y79 cells on the expression of KLF5.Results:Compared with the control group without RNase R enzyme treatment,relative circROBO1 levels did not change significantly after treatment,while relative linear ROBO1 levels decreased significantly after treatment(t=16.18,P<0.05);the content of circROBO1 in the cytoplasm was significantly higher than that in the nucleus(P<0.05);compared with si-control group,the migration rate and the invasion and migration abilities of Transwell cells were all lower in the si-circROBO1 group(t=22.54,P<0.05);circROBO1 can adsorb miR-885-5p,and there is a target binding site between miR-885-5p and KLF5(t=11.39,P<0.05);compared with the si-control group,the KLF5 protein expression in the si-circROBO1 group was significantly decreased(t=17.26,P<0.05).Conclusions:circROBO1 promotes retinalY79 cell tumor invasion by targeting KLF5.
基金supported by the National Key R&D Program of China (2022YFD2201100)Natural Science Foundation of Heilongjiang Province of China (TD2023C006)the Fundamental Research Funds for the Central Universities (2572022DS13).
文摘Carbon(C),nitrogen(N),and phosphorus(P)are of fundamental importance for growth and nutrient dynamics within plant organs and deserve more attention at regional to global scales.However,our knowledge of how these nutrients vary with tree size,organ age,or root order at the individual level remains limited.We determined C,N,and P contents and their stoichiometric ratios(i.e.,nutrient traits)in needles,branches,and fine roots at different organ ages(0-3-year-old needles and branches)and root orders(1st-4th order roots)from 64 Pinus koraiensis of varying size(Diameter at breast height ranged from 0.3 to 100 cm)in northeast China.Soil factors were also measured.The results show that nutrient traits were regulated by tree size,organ age,or root order rather than soil factors.At a whole-plant level,nutrient traits decreased in needles and fine roots but increased in branches with tree size.At the organ level,age or root order had a negative effect on C,N,and P and a positive effect on stoichiometric ratios.Our results demonstrate that nutrient variations are closely related to organ-specific functions and ecophysiological processes at an individual level.It is suggested that the nutrient acquisition strategy by younger trees and organ fractions with higher nutrient content is for survival.Conversely,nutrient storage strategy in older trees and organ fractions are mainly for steady growth.Our results clarified the nutrient utilization strategies during tree and organ ontogeny and suggest that tree size and organ age or root order should be simultaneously considered to understand the complexities of nutrient variations.
文摘To develop well defined in vitro cell system to test cytotoxicity of a number of model toxins, genetically engineered V79 Chinese hamster fibroblasts expressing isoenzymes of cytochrome P4501A1 XEM2 cells and V79 cells (parental), which lack cytochrome P450 enzyme activities, were used as controls. The cytotoxic effect of trans 7,8 dihydrbenzo(a)pyrene (BP 7,8 diol) on the parental cells V79 and V79 derived XEM2 cells were evaluated by two methods for cell viability. The data obtained expressed that BP 7,8 diol ranging from 1.0 μmol·L 1 to 5.0 μmol·L 1 in concentrations incubated for 24 h showed a strong cytotoxic effect in XEM2 cells (expressing rat cytochrome P4501A1) in a concentration dependent manner. Time dependent decrease for survival of XEM2 cells was also observed at 2.5 μmol·L 1 concentration. Likewise, BP 7,8 diol did not alter the survival of the parental cells V79 under the same condition. This study also showed that α naphthoflavone (αNF), a well known inhibitor of cytochrome P4501A1 might alter BP 7,8 diol induced cytotoxicity in the XEM2 cells. Our results suggested that cytochrome P4501A1 is responsible for BP 7, 8 diol induced cytotoxicity.
文摘为了提高光伏电池转换效率、降低能量损失,有必要研究最大功率点跟踪(maximum power point tracking,MPPT)方法。针对传统扰动观察法(perturbation observation method,P&O)存在无法兼顾跟踪速度与稳态精度、在光照度发生较大变化时会产生误判现象的问题,文中提出一种能适应环境变化的变步长P&O控制策略。首先,利用光伏电池刚启动时类似恒流源的特性获取当前光照度下的短路电流,通过固定电流法推导出最大功率点(maximum power point,MPP)的参考电压;其次,当光照度突变时,提出功率修正方法,并给出突变时的变步长调整策略;最后,设计基于线性扩张状态观测器(linear extended state observer,LESO)的分数阶比例积分微分(fractional order proportion integration differentiation,FOPID)控制器,可以对算法输出的参考电压进一步进行跟踪补偿。仿真结果表明,所提控制策略可以提高稳态精度和跟踪速度,有效提高光伏电池的输出功率。
基金Supported by the Natural Science Foundation of Hunan Province（06JJ50008） Supported by the Natural Science Foundation of Guangdong Province（7004569）
文摘Suffcient conditions for the existence of at least one solution of two-point boundary value problems for second order nonlinear differential equations [φ(x(t))] + kx(t) + g(t,x(t)) = p(t),t ∈(0,π) x(0) = x(π) = 0 are established,where [φ(x)] =(|x |p-2x) with p > 1.Our result is new even when [φ(x)] = x in above problem,i.e.p = 2.Examples are presented to illustrate the effciency of the theorem in this paper.
基金Supported by the National Natural Science Foundation of China (10871226)the Natural Science Foundation of Zhejiang Province (Y6100096)
文摘Evaluation for the performance of learning algorithm has been the main thread of theoretical research of machine learning. The performance of the regularized regression algorithm based on independent and identically distributed（i.i.d.） samples has been researched by a large number of references. In the present paper we provide the convergence rates for the performance of regularized regression based on the inputs of p-order Markov chains.
基金The Science Research Foundation of Chongqing Municipal Education Commission of China(KJ050611)
文摘Using the metabelian property, regularity, p-commutativity and some properties of congruence, this paper gave the orders of automorphism groups of family Ф24, which are the groups of order p^6 determined by Rodney James, where p denotes an odd prime.
基金supported by NSFC(No.11301203)NSFC(No.11371057,11471033)+5 种基金NSFC(No.11371158)the Fundamental Research Funds for the Central Universities(CCNU-14A05037)the Fundamental Research Funds for the Central Universities(No.2014KJJCA10)SRFDP(No.20130003110003)the program for Changjiang ScholarsInnovative Research Team in University(No.IRT13066)
文摘Let L = L0 ＋ V be the higher order Schrodiger type operator where L0 is a homogeneous elliptic operator of order 2m in divergence form with bounded coeffi- cients and V is a real measurable function as multiplication operator （e.g., including （-△）m＋v （m∈N） as special examples）. In this paper, assume that V satisfies a strongly subcritical form condition associated with L0, the authors attempt to establish a the- HL （R） （0 〈 p ≤ 1） associated with the higher order Schrodinger ory of Hardy space P n type operator L. Specifically, we first define the molecular Hardy space Hp （JRn） by the so-called （p, q,ε, M） molecule associated to L and then establish its characterizations by the area integral defined by the heat semigroup e-tL.
基金the National Natural Science Foundation of China for financial support of this work(No.60277002).
文摘A novel soluble π-conjugated polymer, poly [（3-acetylpyrrole-2, 5-diyl） p-（N, N-dimethylamino） azobenzylidene] （PAPDMAABE）, was synthesized by condensation of 3-acetylpyrrole with 4-aldehyde-4＇-dimethylaminoazobenzene （ADMAA）. The chemical structure of PAPDMAABE was characterized by Fourier transform infrared spectroscopy （FTIR）, ^1H-NMR, and UV-Vis-NIR spectra. Transmission electron microscope （TEM） analysis for PAPDMAABE indicates that part of PAPDMAABE is in crystal state, due to the short-range order of the polymer. Thermogravimetric analysis （TGA） curve shows that the polymer has good thermal stability and its decomposition temperature is 248℃. The optical band gap of PAPDMAABE obtained from the optical absorption spectrum is about 1.73 eV. The resonant third-order nonlinear optical property of PAPDMAABE at 532 nm was studied using degenerate four-wave mixing （DFWM） technique. The resonant third-order nonlinear optical susceptibility of the polymer is about 7.48×10^-8 esu.
