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Recently, a [Na.sup.+]-binding aptamer was reported to be embedded in a few RNA-cleaving DNAzymes, including NaA43, Ce13d, and NaH1. The [Na.sup.+] aptamer consists of multiple GG stretches, which is a prerequisite for the formation of G-quadruplex (G4) structures. These DNAzymes require [Na.sup.+] for activity but show no activity in the presence of [K.sup.+] or other metal ions. Given that DNA can selectively bind [K.sup.+] by forming a G4 structure, this work aims to answer whether this [Na.sup.+] aptamer also uses a G4 to bind [Na.sup.+]. Through comparative ThT fluorescence spectrometry studies, while a control G4 DNA exhibited notable fluorescence enhancement up to 5 mM [K.sup.+] with a [K.sub.d] of 0.28 [+ or -] 0.06 mM, the Ce13d DNAzyme fluorescence was negligibly perturbed with similar concentrations of [K.sup.+]. Opposed to this, Ce13d displayed specific remarkable fluorescence decrease with low millimolar concentrations of [Na.sup.+]. NMR experiments at two different pH values suggest that Ce13d adopts a significantly different conformation or equilibrium of conformations in the presence of [Na.sup.+] versus [K.sup.+] and has a more stable structure in the presence of [Na.sup.+]. Additionally, absence of characteristic G4 peaks in one-dimensional [.sup.1]HNMR suggest that G4 is not responsible for the [Na.sup.+] binding. This hypothesis is confirmed by the absence of characteristic peaks in the CD spectra of this sequence. Therefore, we concluded that the aptamer must be selective for [Na.sup.+] and that it binds [Na.sup.+] using a structural element that does not contain G4. Key words: aptamers, DNAzymes, sodium, fluorescence, NMR. Recemment, on rapportait qu'un aptamere liant le [Na.sup.+] s'incorporait dans quelques ADNzymes de clivage de l'ARN, dont NaA43, Ce13d et NaH1. L'aptamere a [Na.sup.+] se compose de plusieurs sequences GG, qui sont essentielles a la formation de structures G-quadruplexe (G4). La presence de l'ion [Na.sup.+] est necessaire a l'activite de ces ADNzymes. En effet ces dernieres ne montrent aucune activite en presence de [K.sup.+] ou d'autres ions metalliques. Etant donne que l'ADN peut lier selectivement au [K.sup.+] en formant une structure G4, le but de ces travaux consiste a verifier si cet aptamere a [Na.sup.+] forme aussi une structure G4 pour se lier au [Na.sup.+]. Par des etudes comparatives de spectrometrie de fluorescence a la thioflavine T (ThT), nous avons montre que bien qu'un ADN de structure G4 a titre de temoin presente une amplification notable de la fluorescence a des concentrations allant jusqu'a de 5 mM de [K.sup.+] avec une constante [K.sub.d] de 0,28 [+ or -] 0,06 mM, la perturbation de la fluorescence de l'ADNzyme Ce13d etait negligeable a des concentrations de [K.sup.+] similaires. Au contraire, le Ce13d a affiche une diminution particulierement marquee de la fluorescence aux concentrations millimolaires inferieures de [Na.sup.+]. Les experiences de RMN a deux valeurs de pH differentes semblent indiquer qu'en presence de [Na.sup.+], le Ce13d adopte une conformation ou des conformations a l'equilibre substantiellement differentes par rapport a celles adoptees en presence de [K.sup.+], et que sa structure est plus stable en presence de [Na.sup.+]. De plus, l'absence de pics caracteristiques de la structure G4 en RMN [.sup.1]H 1D laisse supposer que la structure G4 n'est pas responsable de la liaison avec le [Na.sup.+]. Cette hypothese est confirmee par l'absence de pics caracteristiques dans les spectres de dichroisme circulaire de cette sequence. Par consequent, nous avons conclu que l'aptamere doit etre selectif pour l'ion [Na.sup.+] et qu'il se lie au [Na.sup.+] au moyen d'un element structural qui ne comporte pas de structure G4. [Traduit par la Redaction] Mots-cles: aptameres, ADNzymes, sodium, fluorescence, RMN., 1. Introduction Understanding metal binding to DNA is important not only for studying the biological functions of DNA, but also for biosensor development, (1,2) drug development, (3) and nanotechnology. (4) [...]

This study aims to evaluate the incidence of low birth weight (LBW) and related maternal risk factors (during pregnancy or childbirth) and neonatal outcomes. A retrospective cross-sectional study design was used to select 7,421 pregnant women who gave birth in our hospital from January 2018 to June 2021. The data were analyzed using STATA 14.1, and the dependent variable (LBW) and risk were analyzed by the chi-square test of independence. The association between factors is used to determine the factors related to LBW through bivariate and multivariate logistic regression. The incidence of LBW in this study was 4.77%. Compared with single pregnant women, the probability of newborn LBW in married pregnant women is 40% lower (AOR = 0.60 95%CI: 0.40–0.90, p = 0.013). Compared with gestational age less than 37 weeks, the LBW probability of gestational age 37–42 and 42 weeks or older is 85 and 81% lower respectively (AOR = 0.15 95% CI: 0.10–0.24, p = 0.001; AOR = 0.19 95 %CI: 0.09–38, p = 0.001), compared with normal pregnant women, the probability of neonatal LBW among pregnant women with hypertension is 94% higher [AOR = 1.94 (95% CI: 1.39–2.74, p = 0.001). Compared with neonates with normal birth weight, neonates with LBW are at Apgar 1 min And Apgar 5 min score is lower than 7 (AOR = 0.52 95%CI: 0.37–0.73, p = 0.001, AOR = 0.54 95%CI: 0.38–0.75, p = 0.001) higher risk. In conclusion, women’s marital status (single), gestational age (

Aimed at the problems of unmanned marine exploration vessels, such as the short voyage time and the limited sensing ability caused by sensor failure under complex marine environments, a long-range unmanned ocean-air stereo exploration vessel driven by wind and solar energy is developed. An elevating ducted wind turbine is designed for high efficiency and low starting wind speed, and a deployable solar photovoltaic power generation system is developed. Therefore, wind power and solar energy can be utilized to realize a hybrid system, which overcomes the instability of single energy power supply, and effectively ensures the endurance of unmanned exploration vessel. Then, a ship-borne tethered ummanned aerial vehicle (UAV) system is developed with an autonomous takeoff and landing control section. Finally, the information fusion technology of ship borne and airborne sensors is adopted to greatly improve the perception ability of the unmanned ship to the surrounding environment and the function of three-dimension detection of sea and air. The unmanned surface vessel (USV) proposed in this paper is permitted to perform the assigned task with different types of loading equipment according to the scenarios.

To realize the practical scale application of the spar-type floating offshore wind turbine (FOWT) in the medium depth sea areas, a novel 6 MW spar-type floating offshore wind turbine is analyzed by model test and numerical simulation under extreme conditions. The response of main freedom degrees, the mooring tense and the stress at the danger point are explored by a 1∶65.3 scale model at the State Key Laboratory of Ocean Engineering in Shanghai JiaoTong University. Coupled motion response of the spar-type floating wind turbine is calculated by using numerical simulation software in time domain. The results of the numerical simulation and model test are compared and analyzed in time and frequency domain. The maximum deviation between numerical simulation and model test is less than 12%, which shows that the numerical simulation results are in good agreement with the model test results. The dynamic response energy of the FOWT is mainly concentrated at low frequency and wave frequency. Moreover, the whole FOWT system has an excellent survivability under extreme conditions. Finally, the ultimate load of the wind turbine is predicted, which provides the necessary theoretical basis and calculation parameters for the structural strength calculation.

Porous copper (Cu), with varying porosities, has been made using carbamide as a space holder through the powder metallurgy route. Two shapes of carbamide particles were used, (i) needlelike and (ii) spherical, in order to investigate the effect of the space holder shape on the pore structure and mechanical properties of porous Cu. The compressive deformation behavior of porous Cu was studied under a compression test. The pores' structural characteristics and mechanical properties of the porous Cu varied significantly with the shape of the space holder. Although the effect of the space holder shape on the porosity was not regular, the effect on the mechanical properties was regular. The stress increased monotonically with the increase in the strain, and strain hardening occurred at the plastic yield stage. The elastic modulus and yield strength followed the power law, with the relative density irrespective of the space holder shape. The empirical constants associated with different empirically developed power law relations were different, according to the shape of space holder. A quantitative relationship between the elastic modulus and yield strength and the spacer content was obtained to control the mechanical properties of the present porous Cu or other porous metals and metal foams using the well-known space holder method. [ABSTRACT FROM AUTHOR]