838 research outputs found
A Generalization of the Tang-Ding Binary Cyclic Codes
Cyclic codes are an interesting family of linear codes since they have
efficient decoding algorithms and contain optimal codes as subfamilies.
Constructing infinite families of cyclic codes with good parameters is
important in both theory and practice. Recently, Tang and Ding [IEEE Trans.
Inf. Theory, vol. 68, no. 12, pp. 7842--7849, 2022] proposed an infinite family
of binary cyclic codes with good parameters. Shi et al. [arXiv:2309.12003v1,
2023] developed the binary Tang-Ding codes to the -ary case. Inspired by
these two works, we study -ary Tang-Ding codes, where . Good
lower bounds on the minimum distance of the -ary Tang-Ding codes are
presented. As a by-product, an infinite family of -ary duadic codes with a
square-root like lower bound is presented
In situ synthesis of zeolitic imidazolate frameworks/carbon nanotube composites with enhanced CO2 adsorption
A series of ZIF-8 and hydroxyl-functionalized carbon nanotube (CNT) composites were successfully synthesized by the solvothermal method. The obtained ZIF-8/CNT composites were characterized by XRD, SEM, TGA and N2 adsorption at 77 K. The contents of ZIF-8 and CNTs in the composites were calculated from thermal analysis data. CO2 and N2 adsorption at 273 K on the composites was also investigated and compared. The ZIF-8 particles in the composites exhibit similar crystal structures and morphology to those of pure ZIF-8, but display enhanced thermal stability. The surface areas and pore volumes of the ZIF-8/CNT composites are higher than the values calculated for hypothetical physical mixtures, and the synergetic effect between ZIF-8 and CNTs can be proposed. This phenomenon demonstrates that the incorporation of CNTs into ZIF-8 can facilitate the nucleation and crystallization of ZIF-8. As a result, the composites with an optimal CNT content (3.63 wt%) show improved CO2 adsorption capacity and higher relative selectivity for CO2/N2 compared with pure ZIF-8
Cr-doped La-Ni-O catalysts derived from\ua0perovskite precursors for CH4-CO2 reforming under microwave irradiation
The nickel catalysts derived from Cr-doped LaNiO perovskite-like precursors were characterized by X-ray diffraction, high-resolution transmission electron microscopy, temperature-programmed oxidation, temperature-programmed reduction, and X-ray photoelectron spectroscopy. Their catalytic performance in CO reforming of methane under microwave irradiation was investigated. It was found that the structure and morphology of the oxide composites in this research were influenced by the ratio of Ni and Cr, and the mismatch of La, Ni, and Cr may cause phase segregation. The catalytic performance of the Ni catalysts is dependent on the oxygen mobility of the perovskite oxide matrix, the content of the reduced Ni, and the content of the remaining perovskite structure. The mobile oxygen in the perovskite matrix in the catalyst may enhance the conversion of CO during the reaction
Follow-up management service and health outcomes of hypertensive patients in China: A cross-sectional analysis from the national health service survey in Jiangsu province
BackgroundHypertension is a major cause of early mortality worldwide. Health follow-up management services can encourage patients with hypertension to improve their health behavior and outcomes. However, a lack of studies on the relationship between specific factors of follow-up management and both subjective and objective health outcome among hypertensive patients exists. The current study investigated the relationship between service content, frequency, mode, and institutions of follow-up management and health outcomes among Chinese hypertensives.MethodsData were obtained from the sixth National Health Service Survey (NHSS) of Jiangsu Province, which was conducted in 2018. Descriptive statistics were used to analyze the sample characteristics and the utilization of follow-up management services. Both multiple linear regression and logistic regression were used to estimate the association of follow-up management service and other factors with hypertensives' subjective and objective health outcomes.ResultSome respondents (19.30%) reported hypertension, and 75.36% of these patients obtained follow-up management services. Hypertensive patients' subjective health outcome self-reported health status and objective health outcome blood pressure (BP) control were found to be significantly associated with follow-up management services. The outcomes were both significantly improved by a high frequency of management services, a high level of follow-up providers, the mode of visiting healthcare facilities and/or calling, and receiving instructions on medication use. However, inquiring about patients' symptoms was negatively associated with self-reported health status and BP control. In addition, BP measurement was significantly and positively associated with hypertensive patients' self-reported health status; the patients receiving lifestyle guidance were more likely to have their BP levels under control.ConclusionsHypertension management strategies should further focus on the frequency of healthcare follow-up management via categorization of the follow-up services and appropriate adjustment of service delivery modes to optimize health follow-up management for hypertensives further improve their outcomes. Meanwhile, complementary policies are also needed to address other socioeconomic factors that can promote good health conditions for hypertension patients
4′-Chloro-3′,5′-dimethoxyacetanilide
The title compound, C10H12ClNO3, crystallizes with four independent molecules in the asymmetric unit which are linked by intermolecular N—H⋯O hydrogen bonds
Divergence in function and expression of the NOD26-like intrinsic proteins in plants
<p>Abstract</p> <p>Background</p> <p>NOD26-like intrinsic proteins (NIPs) that belong to the aquaporin superfamily are plant-specific and exhibit a similar three-dimensional structure. Experimental evidences however revealed that functional divergence should have extensively occurred among NIP genes. It is therefore intriguing to further investigate the evolutionary mechanisms being responsible for the functional diversification of the NIP genes. To better understand this process, a comprehensive analysis including the phylogenetic, positive selection, functional divergence, and transcriptional analysis was carried out.</p> <p>Results</p> <p>The origination of NIPs could be dated back to the primitive land plants, and their diversification would be no younger than the emergence time of the moss <it>P. patens</it>. The rapid proliferation of NIPs in plants may be primarily attributed to the segmental chromosome duplication produced by polyploidy and tandem duplications. The maximum likelihood analysis revealed that <it>NIPs </it>should have experienced strong selective pressure for adaptive evolution after gene duplication and/or speciation, prompting the formation of distinct <it>NIP </it>groups. Functional divergence analysis at the amino acid level has provided strong statistical evidence for shifted evolutionary rate and/or radical change of the physiochemical properties of amino acids after gene duplication, and DIVERGE2 has identified the critical amino acid sites that are thought to be responsible for the divergence for further investigation. The expression of plant NIPs displays a distinct tissue-, cell-type-, and developmental specific pattern, and their responses to various stress treatments are quite different also. The differences in organization of <it>cis</it>-acting regulatory elements in the promoter regions may partially explain their distinction in expression.</p> <p>Conclusion</p> <p>A number of analyses both at the DNA and amino acid sequence levels have provided strong evidences that plant NIPs have suffered a high divergence in function and expression during evolution, which is primarily attributed to the strong positive selection or a rapid change of evolutionary rate and/or physiochemical properties of some critical amino acid sites.</p
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