The modified Zakharov-Kuznetsov equation with the initial value problem is studied numerically by means of homotopy perturbation method. The analytical approximate solutions of the modified Zakharov-Kuznetsov equation...The modified Zakharov-Kuznetsov equation with the initial value problem is studied numerically by means of homotopy perturbation method. The analytical approximate solutions of the modified Zakharov-Kuznetsov equation are obtained. Choosing the form of the initial value, the single solitary wave, two solitary waves and rational solutions are presented, some of which are shown by the plots.展开更多
[ Objective ] This study aimed to investigate the optimal method for extracting RNA from roots of medicinal plant herba violae by comparing the effects of liquid nitrogen grinding method and low-temperature sectioning...[ Objective ] This study aimed to investigate the optimal method for extracting RNA from roots of medicinal plant herba violae by comparing the effects of liquid nitrogen grinding method and low-temperature sectioning method on RNA extraction. [ Method] Roots of herba violae were respectively crushed by using liquid nitrogen grinding method and low-temperature sectioning method to extract RNA. The extraction effects of these two methods were compared based on detec- tion of RNA concentration, purity and integrity and amplification of GAPDH gene by RT-PCR. [Result] The concentration of RNA extracted by liquid nitrogen grinding method and low-temperature sectioning method was 1.21 and 3.57 p^g/~, respectively. Both RNA extracted by these two methods showed two distinct bands after agarose gel electrophoresis. The ratio of brightness of the 28S rRNA to the 18S rRNA bands was greater than 1. PCR amplification showed that the length of GAPDH gene was about 230 bp, which was consistent with the expected result. [ Conclusion ] The experimental results indicated that using low-tempera ture sectioning method to crush the roots of herba violae can meet the needs of most molecular biological experiments including gene cloning and expression analysis, which is an effective and simple method for extracting RNA from plant roots.展开更多
A Fock-Darwin system in noncommutative quantum mechanics is studied. By constructing Heisenberg algebra we obtain the levels on noncommutative space and noncommutative phase space, and give the corrections to the resu...A Fock-Darwin system in noncommutative quantum mechanics is studied. By constructing Heisenberg algebra we obtain the levels on noncommutative space and noncommutative phase space, and give the corrections to the results in usual quantum mechanics. Moreover, to search the difference among the three spaces, the degeneracy is analysed by two ways, the value of ω/ωe and certain algebra realization （SU（2）and SU（1,1））, and some interesting properties in the magnetic field limit are exhibited, such as totally different degeneracy and magic number distribution for the given frequency or mass of a system in strong magnetic field.展开更多
In view of long-term transformer insulation resistance and dielectric loss measurement, measurement and according to the national standard formula conversion values are not completely consistent, in this paper, a vari...In view of long-term transformer insulation resistance and dielectric loss measurement, measurement and according to the national standard formula conversion values are not completely consistent, in this paper, a variety of transformers are studied, and the applicable scope of the conversion formula is discussed emphatically, combined with the test results are analyzed of transformer insulation resistance value to temperature and oiliness and dielectric loss tangent to temperature and oiliness, and puts forward suggestions on how to improve the insulation performance of transformer.展开更多
Background:Hypertension is a major risk factor for cardiovascular diseases,including AF,which is one of the most common cardiac arrhythmias globally.AF is strongly associated with an increased risk of stroke,heart fai...Background:Hypertension is a major risk factor for cardiovascular diseases,including AF,which is one of the most common cardiac arrhythmias globally.AF is strongly associated with an increased risk of stroke,heart failure(HF),and cardiovascular mortality.Although intensive blood pressure lowering has been shown to reduce adverse cardiovascular events,its effect on the risk of AF remains debated.Some studies suggest a beneficial effect,whereas others are inconclusive.Therefore,a comprehensive review and meta-analysis are needed to clarify these effects.Objective:This study aims to evaluate the impact of intensive blood pressure lowering on the incidence of atrial fibrillation(AF)in hyper-tensive patients.Methods:We performed a systematic review and meta-analysis by searching PubMed,EMBASE,Scopus,Web of Science,and the Cochrane Library up to September 2,2024,for randomized controlled trials comparing intensive blood pressure lowering with standard treatment in hypertensive patients.Studies were included if participants were 40 year or older with systolic blood pressure between 130 and 180 mm Hg(1 mm Hg≈0.133 kPa).Data extraction was conducted by 2 independent researchers,and statistical analysis was performed using Review Manager(RevMan)5.4.Risk ratios(RRs)and 95%confidence intervals(CIs)were calculated.A random-effects model was applied if heterogeneity was detected(I^(2)>50%).Results:A total of 6 randomized controlled trials involving 34,824 participants were included in the analysis.Intensive blood pressure lowering significantly reduced the risk of new-onset AF compared with standard treatment(RR=0.76,95%CI=0.62–0.93,p<0.01,I^(2)=0%).Reductions were also observed in stroke(RR=0.71,95%CI=0.58–0.87,p<0.005,I^(2)=7%),HF(RR=0.67,95%CI=0.45–0.99,p=0.05,I^(2)=53%),and nonfatal coronary events(RR=0.80,95%CI=0.70–0.92,p<0.005,I^(2)=39%).However,intensive blood pressure lowering had no significant effect on cardiovascular mortality or all-cause mortality compared with standard treatment.Discussion:Intensive blood pressure lowering significantly reduces the risk of AF and other cardiovascular events,such as stroke,HF,and nonfatal coronary events,particularly among high-risk hypertensive patients.These findings support the potential benefits of inten-sive blood pressure management in reducing AF incidence and improving overall cardiovascular outcomes,but the evidence is limited.展开更多
文摘The modified Zakharov-Kuznetsov equation with the initial value problem is studied numerically by means of homotopy perturbation method. The analytical approximate solutions of the modified Zakharov-Kuznetsov equation are obtained. Choosing the form of the initial value, the single solitary wave, two solitary waves and rational solutions are presented, some of which are shown by the plots.
基金Supported by National Natural Science Foundation of China(81001700)Project of Sichuan Provincial Education Department(11ZB227,11ZB124)Research Project for the Application Foundation of Sichuan Provincial Science and Technology Department(2012JY0081)
文摘[ Objective ] This study aimed to investigate the optimal method for extracting RNA from roots of medicinal plant herba violae by comparing the effects of liquid nitrogen grinding method and low-temperature sectioning method on RNA extraction. [ Method] Roots of herba violae were respectively crushed by using liquid nitrogen grinding method and low-temperature sectioning method to extract RNA. The extraction effects of these two methods were compared based on detec- tion of RNA concentration, purity and integrity and amplification of GAPDH gene by RT-PCR. [Result] The concentration of RNA extracted by liquid nitrogen grinding method and low-temperature sectioning method was 1.21 and 3.57 p^g/~, respectively. Both RNA extracted by these two methods showed two distinct bands after agarose gel electrophoresis. The ratio of brightness of the 28S rRNA to the 18S rRNA bands was greater than 1. PCR amplification showed that the length of GAPDH gene was about 230 bp, which was consistent with the expected result. [ Conclusion ] The experimental results indicated that using low-tempera ture sectioning method to crush the roots of herba violae can meet the needs of most molecular biological experiments including gene cloning and expression analysis, which is an effective and simple method for extracting RNA from plant roots.
基金Supported by the National Natural Science Foundation of China under Grant No 10575026, and the Natural Science Foundation of Zhejiang Provence under Grant No Y607437.
文摘A Fock-Darwin system in noncommutative quantum mechanics is studied. By constructing Heisenberg algebra we obtain the levels on noncommutative space and noncommutative phase space, and give the corrections to the results in usual quantum mechanics. Moreover, to search the difference among the three spaces, the degeneracy is analysed by two ways, the value of ω/ωe and certain algebra realization （SU（2）and SU（1,1））, and some interesting properties in the magnetic field limit are exhibited, such as totally different degeneracy and magic number distribution for the given frequency or mass of a system in strong magnetic field.
文摘In view of long-term transformer insulation resistance and dielectric loss measurement, measurement and according to the national standard formula conversion values are not completely consistent, in this paper, a variety of transformers are studied, and the applicable scope of the conversion formula is discussed emphatically, combined with the test results are analyzed of transformer insulation resistance value to temperature and oiliness and dielectric loss tangent to temperature and oiliness, and puts forward suggestions on how to improve the insulation performance of transformer.
基金funded by grants from the Central High-Level Traditional Chinese Medicine Hospital Project of Eye Hospital China Academy of Chinese Medical Sciences(GSP2-02)Science and Technology Innovation Project of China Academy of Chinese Medical Sciences(CI2021A00906)Beijing Natural Science Foundation(7232324).
文摘Background:Hypertension is a major risk factor for cardiovascular diseases,including AF,which is one of the most common cardiac arrhythmias globally.AF is strongly associated with an increased risk of stroke,heart failure(HF),and cardiovascular mortality.Although intensive blood pressure lowering has been shown to reduce adverse cardiovascular events,its effect on the risk of AF remains debated.Some studies suggest a beneficial effect,whereas others are inconclusive.Therefore,a comprehensive review and meta-analysis are needed to clarify these effects.Objective:This study aims to evaluate the impact of intensive blood pressure lowering on the incidence of atrial fibrillation(AF)in hyper-tensive patients.Methods:We performed a systematic review and meta-analysis by searching PubMed,EMBASE,Scopus,Web of Science,and the Cochrane Library up to September 2,2024,for randomized controlled trials comparing intensive blood pressure lowering with standard treatment in hypertensive patients.Studies were included if participants were 40 year or older with systolic blood pressure between 130 and 180 mm Hg(1 mm Hg≈0.133 kPa).Data extraction was conducted by 2 independent researchers,and statistical analysis was performed using Review Manager(RevMan)5.4.Risk ratios(RRs)and 95%confidence intervals(CIs)were calculated.A random-effects model was applied if heterogeneity was detected(I^(2)>50%).Results:A total of 6 randomized controlled trials involving 34,824 participants were included in the analysis.Intensive blood pressure lowering significantly reduced the risk of new-onset AF compared with standard treatment(RR=0.76,95%CI=0.62–0.93,p<0.01,I^(2)=0%).Reductions were also observed in stroke(RR=0.71,95%CI=0.58–0.87,p<0.005,I^(2)=7%),HF(RR=0.67,95%CI=0.45–0.99,p=0.05,I^(2)=53%),and nonfatal coronary events(RR=0.80,95%CI=0.70–0.92,p<0.005,I^(2)=39%).However,intensive blood pressure lowering had no significant effect on cardiovascular mortality or all-cause mortality compared with standard treatment.Discussion:Intensive blood pressure lowering significantly reduces the risk of AF and other cardiovascular events,such as stroke,HF,and nonfatal coronary events,particularly among high-risk hypertensive patients.These findings support the potential benefits of inten-sive blood pressure management in reducing AF incidence and improving overall cardiovascular outcomes,but the evidence is limited.
