The Influence of Metakaolin and Polypropylene Fiber Concrete on Mechanics Properties and Microstructure Combined Action under Multi-Salt Soaking and Freeze-Thaw.

The wide distribution of alpine saline areas in China is faced with two major problems, which are salt intrusion and freeze-thaw. In total, 216 specimens were prepared with 6 kinds of concrete mix proportions in this paper. The effects of the single and compound incorporation of metakaolin (MK) and polypropylene fiber (PPF) of different amounts on the mechanical properties and microstructure properties of concrete were investigated under the dual action of multi-salt (NaCl, MgCl2, Na2SO4, and NaHCO3) soaking and freeze-thaw. Potable water and freeze-thaw concrete were adopted as the control group. Changes in the appearance morphology, mass loss, relative dynamic elastic modulus, and compressive strength of the concrete were tested, and the microstructure of the concrete was analyzed by scanning electron microscopy (SEM). The results showed that an admixture of both MK and PPF in the potable water and freeze-thaw cycle test can improve the mechanical properties and frost resistance of concrete. The admixture of PPF can effectively improve the mechanical properties and frost resistance of concrete. However, the admixture of MK failed to improve the mechanical properties and frost resistance of concrete during multi-salt soaking and freeze-thaw. The frost resistance of concrete under multi-salt soaking and freeze-thaw was optimally improved with 10% MK and 0.6 kg/m3 PPF. Its microstructure shows that PPF can effectively inhibit crack propagation and reduce the deterioration of concrete under multi-salt soaking and freeze-thaw.

Prevalence and influencing factors of sleep disorders among preschool children in Urumqi city: a cross-sectional survey.

BACKGROUND: Sleep disorders refer to physiological and psychological states that cause adverse consequences due to the inability to fall asleep or poor sleep quality. The prevalence of sleep disorders varies greatly in different countries and regions due to different causes. This study aimed to investigate the prevalence and influencing factors of sleep disorders among preschool children in Urumqi city, China. METHODS: A cross-sectional study was conducted with stratified random cluster sampling. Children aged 3-6 years old in one kindergarten randomly selected from each of the 8 districts of Urumqi from March to July 2022, and their parents were surveyed with a sleep quality questionnaire. RESULTS: The prevalence of sleep disorders among preschool children in Urumqi was 14.29% (191/1336), and the prevalence of different symptoms was 42.81% for limb movements, 19.61% for snoring, 18.11% for bruxism, 16.39% for sleep talking, 12.57% for sweating, 11.60% for nocturnal awakening, 8.46% for nightmares, 6.89% for bed wetting, 3.74% for apnea, and 3.29% for sleepwalking. The prevalence of body movements, snoring, sweating, night-wake, nightmares, bed-wetting, apnea, and sleepwalking among different ethnicities were significantly different (P < 0.05). Multivariate analysis revealed that the major risk factors of sleep disorders were difficulty adapting to new environments, unwillingness to express emotions, inconsistent attitudes of the family toward children's education, running before bedtime, strict family education methods, etc. CONCLUSION: The prevalence of sleep disorders in preschool children in Urumqi is lower than the average level reported in other studies. Many factors affect the prevalence of sleep disorders in preschool children, but it is necessary to focus on the ability to adapt to new environments, psychological problems, and the impact of family education on sleep disorders. Further studies on the prevention and treatment of sleep disorders are needed for different ethnicities.

Plastome evolution and phylogeny of the tribe Ruteae (Rutaceae).

Rutaceae is a large family, and the genus-level classification in the subfamilies or tribes of this family is not unified based on different taxonomic treatments. Until now, phylogenetic relationships of some genera in traditional tribe Ruteae have not been clearly resolved. In this study, seven new complete plastomes of this tribe were sequenced, and a comparative analysis was performed to investigate their plastome characteristics and evolution. In addition, we inferred the phylogenetic relationships of Ruteae based on complete plastome and nuclear ITS data. All plastomes exhibited a typical quadripartite structure and were relatively conserved in their structure and gene arrangement. Their genome sizes ranged from 154,656 bp to 160,677 bp, and the size variation was found to be associated with differences in IR expansion and gene loss. A total of 112 to 114 genes were identified in the genomes, including 78 to 79 protein-coding genes, 30 tRNA genes, 4 rRNA genes, and 2 pseudogenes. Sequence divergence analysis indicated that non-coding regions exhibited a higher percentage of variable characters, and nine non-coding and six coding regions were identified as divergent hotspots. Phylogenetic results based on different datasets showed that this tribe was divided into three reciprocally exclusive groups. The phylogenetic analyses between plastome and nuclear ITS data were partly incongruent with each other. This study provides new insights into plastome evolution of Ruteae as well as Rutaceae. The availability of these plastomes provides useful genomic resources for molecular DNA barcodes and phylogenetically informative markers and deepens our understanding of the phylogeny in Ruteae.

Insights into the phylogeny and chloroplast genome evolution of Eriocaulon (Eriocaulaceae).

BACKGROUND: Eriocaulon is a wetland plant genus with important ecological value, and one of the famous taxonomically challenging groups among angiosperms, mainly due to the high intraspecific diversity and low interspecific variation in the morphological characters of species within this genus. In this study, 22 samples representing 15 Eriocaulon species from China, were sequenced and combined with published samples of Eriocaulon to test the phylogenetic resolution using the complete chloroplast genome. Furthermore, comparative analyses of the chloroplast genomes were performed to investigate the chloroplast genome evolution of Eriocaulon. RESULTS: The 22 Eriocaulon chloroplast genomes and the nine published samples were proved highly similar in genome size, gene content, and order. The Eriocaulon chloroplast genomes exhibited typical quadripartite structures with lengths from 150,222 bp to 151,584 bp. Comparative analyses revealed that four mutation hotspot regions (psbK-trnS, trnE-trnT, ndhF-rpl32, and ycf1) could serve as effective molecular markers for further phylogenetic analyses and species identification of Eriocaulon species. Phylogenetic results supported Eriocaulon as a monophyletic group. The identified relationships supported the taxonomic treatment of section Heterochiton and Leucantherae, and the section Heterochiton was the first divergent group. Phylogenetic tree supported Eriocaulon was divided into five clades. The divergence times indicated that all the sections diverged in the later Miocene and most of the extant Eriocaulon species diverged in the Quaternary. The phylogeny and divergence times supported rapid radiation occurred in the evolution history of Eriocaulon. CONCLUSION: Our study mostly supported the taxonomic treatment at the section level for Eriocaulon species in China and demonstrated the power of phylogenetic resolution using whole chloroplast genome sequences. Comparative analyses of the Eriocaulon chloroplast genome developed molecular markers that can help us better identify and understand the evolutionary history of Eriocaulon species in the future.

Characterization of the Dicranostigma leptopodum chloroplast genome and comparative analysis within subfamily Papaveroideae.

BACKGROUND: Dicranostigma leptopodum (Maxim.) Fedde is a perennial herb with bright yellow flowers, well known as "Hongmao Cao" for its medicinal properties, and is an excellent early spring flower used in urban greening. However, its molecular genomic information remains largely unknown. Here, we sequenced and analyzed the chloroplast genome of D. leptopodum to discover its genome structure, organization, and phylogenomic position within the subfamily Papaveroideae. RESULTS: The chloroplast genome size of D. leptopodum was 162,942 bp, and D. leptopodum exhibited a characteristic circular quadripartite structure, with a large single-copy (LSC) region (87,565 bp), a small single-copy (SSC) region (18,759 bp) and a pair of inverted repeat (IR) regions (28,309 bp). The D. leptopodum chloroplast genome encoded 113 genes, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. The dynamics of the genome structures, genes, IR contraction and expansion, long repeats, and single sequence repeats exhibited similarities, with slight differences observed among the eight Papaveroideae species. In addition, seven interspace regions and three coding genes displayed highly variable divergence, signifying their potential to serve as molecular markers for phylogenetic and species identification studies. Molecular evolution analyses indicated that most of the genes were undergoing purifying selection. Phylogenetic analyses revealed that D. leptopodum formed a clade with the tribe Chelidonieae. CONCLUSIONS: Our study provides detailed information on the D. leptopodum chloroplast genome, expanding the available genomic resources that may be used for future evolution and genetic diversity studies.

Dynamic evolution of the plastome in the Elm family (Ulmaceae).

MAIN CONCLUSION: This study compared the plastomes of Ulmaceae allowing analyses of the dynamic evolution, including genome structure, codon usage bias, repeat sequences, molecular mutation rates, and phylogenetic inferences. Ulmaceae is a small family in the order Rosales. This family consists of seven genera, including Ulmus, Zelkova, Planera, Hemiptelea, Phyllostylon, Ampelocera, and Holoptelea. Ulmaceae is an interesting lineage from plant biogeographic, systematic, evolutionary, and paleobotanic perspectives. It is also a good model to investigate the evolution of the plastomes in woody plants. In this study, we sequenced and assembled the complete plastomes of the six Ulmaceae genera to compare genomic structures and reveal the molecular evolutionary patterns. The size of the quadripartite plastomes ranged from 158,290 bp to 161,886 bp. The genomes contained 131 genes, including 87 coding genes, 36 tRNA, and 8 rRNA. The gene number, gene content, and genomic structure were highly consistent among the Ulmaceae genera. Nine variable regions including ndhA intron, ndhF-rpl32, ycf1, psbK-trnS, rps16-trnQ, trnT-trnL, trnT-psbD, trnS-trnG, and rpl32-trnL, were identified in Ulmaceae plastomes according to the nucleotide diversity values. Condon usage was biased among the genes and showed consistent trends in the seven genera. Molecular evolution analyses revealed that most of the genes and all gene groups were under widespread purifying selection. Twelve genes (ccsA, matK, psbH, psbK, rbcL, rpl22, rpl32, rpoA, rps12, rps15, rps16, and ycf2) were under positive selection. Phylogenetic analyses supported that Ulmaceae should be divided into two main clades, such as the temperate clade, including Ulmus, Zelkova, Planera, and Hemiptelea and the tropical clade, including Phyllostylon, Ampelocera and Holoptelea. This study reports the structure and evolutionary characteristics of the Elm family. These new genomic data will benefit assessments of genomic evolution and provide information to elucidate the phylogenetic relationships among Ulmaceae species.

[Complete chloroplast genome of Ligustrum lucidum and highly variable marker identification for Ligustrum].

Ligustri Lucidi Fructus, the sun-dried mature fruit of Ligustrum lucidum, is cool, plain, sweet, and bitter, which can be used as both food and medicine, with the effects of improving vision, blacking hair, and tonifying liver and kidney. It takes effect slowly. However, little is known about the genetic information of the medicinal plant and it is still a challenge to distinguish Ligustrum species. In this study, the complete chloroplast genome of L. lucidum was obtained by genome skimming and then compared with that of five other Ligustrum species, which had been reported. This study aims to evaluate the interspecific variation of chloroplast genome within the genus and develop molecular markers for species identification of the genus. The result showed that the chloroplast genome of L. lucidum was 162 162 bp with a circular quadripartite structure of two single-copy regions separated by a pair of inverted repeats. The Ligustrum chloroplast genomes were conserved with small interspecific difference. Comparative analysis of six Ligustrum chloroplast genomes revealed three variable regions(rbcL-accD, ycf1a, and ycf1b), and ycf1a and ycf1b can be used as the species-specific DNA barcode for Ligustrum. Phylogeny analysis provided the best resolution of Ligustrum and supported that L. lucidum was sister to L. gracile. This study clarified the genetic diversity of L. lucidum from provenance, which can serve as a reference for further analysis of pharmacological differences and breeding of excellent varieties with stable drug effects.

Complete chloroplast genome and phylogenetic analysis of Acer leipoense (Sapindaceae), a rare plant from Southwest China.

Acer leipoense is a rare and endangered species of the Sapindaceae with a very restricted distribution in Sichuan, China. In this study, the complete chloroplast genome of A. leipoense was characterized by de novo assembly using high-throughput sequencing. The chloroplast genome was 155,702 bp in length; it contained a large single copy region (85,890 bp) and a small single copy region (18,100 bp), which were separated by a pair of 25,856-bp inverted repeat regions. A total of 128 genes were predicted, including 83 protein-coding genes, 37 tRNA genes, and eight rRNA genes. A phylogenetic analysis of 23 chloroplast genome sequences from the genus Acer revealed that A. leipoense was closely related to A. yangbiense.

Chloroplast phylogenomic insights into the evolution of Distylium (Hamamelidaceae).

BACKGROUND: Most Distylium species are endangered. Distylium species mostly display homoplasy in their flowers and fruits, and are classified primarily based on leaf morphology. However, leaf size, shape, and serration vary tremendously making it difficult to use those characters to identify most species and a significant challenge to address the taxonomy of Distylium. To infer robust relationships and develop variable markers to identify Distylium species, we sequenced most of the Distylium species chloroplast genomes. RESULTS: The Distylium chloroplast genome size was 159,041-159,127 bp and encoded 80 protein-coding, 30 transfer RNAs, and 4 ribosomal RNA genes. There was a conserved gene order and a typical quadripartite structure. Phylogenomic analysis based on whole chloroplast genome sequences yielded a highly resolved phylogenetic tree and formed a monophyletic group containing four Distylium clades. A dating analysis suggested that Distylium originated in the Oligocene (34.39 Ma) and diversified within approximately 1 Ma. The evidence shows that Distylium is a rapidly radiating group. Four highly variable markers, matK-trnK, ndhC-trnV, ycf1, and trnT-trnL, and 74 polymorphic simple sequence repeats were discovered in the Distylium plastomes. CONCLUSIONS: The plastome sequences had sufficient polymorphic information to resolve phylogenetic relationships and identify Distylium species accurately.

Residual Mechanical Properties and Constitutive Model of High-Strength Seismic Steel Bars through Different Cooling Rates.

In this study, the high-temperature test (i.e., temperature to 1000 °C) is conducted on 600 MPa seismic steel bars, and its residual mechanical properties and constitutive relations are investigated though three cooling rates, i.e., under air, furnace, and water-cooling conditions. Results show that three cooling methods have significant effects on the apparent characteristics of 600 MPa steel bars, when the heating temperature is greater than 600 °C. In addition, the ultimate and yield strength of steel bars have been significantly affected by different cooling methods, with increasing heating temperature. However, the elastic modulus is significantly not affected by temperature. Furthermore, the elongation rate after fracture and the total elongation rate at the maximum force do not change significantly, when the heating temperature is less than 650 °C. The elongation rate, after fracture, and the total elongation rate, at the maximum force, have different changes for three cooling methods. The degeneration of the stress-strain curves occurs when the heating temperature is high. The two-fold line, three-fold line, and Ramberg-Osgood models are developed based on the stress-strain curve characteristics of steel bars after cooling. The fire resistance of 600 MPa steel bars of reinforced concrete structure is analyzed, which provides a basis for post-disaster damage assessment, repair, and reinforcement of the building structure.

[Spectroscopic Studies on the Host Plant Selection Mechanism of Trabala vishnou gigantina Yang (Lepidoptera: Lasiocampidae)].

Trabala vishnou gigantina Yang (Lepidoptera: Lasiocampidae) is a polyphagous forestry pest whose periodic breaking out results in great economic damage including total crop failure to forestry and fruit production in China. In this study, in order to improve the understanding of the host plant selection mechanism of T. vishnou gigantina larvae, locust, caragana, willow, poplar, apricot and sea-buckthorn were used as potential host plants for the test. Two-way choice experiment method was used to study the T. vishnou gigantina Yang feeding preferences of the six kinds of plants. Moreover, the chemical component and physical structure of six plants were analyzed with Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Among the six plants, T. vishnou gigantina larvae showed a strong preference for sea-buckthorn, followed by, apricot, willow, poplar, locust, and caragana. The FTIR analysis displayed that those six plants presented similar characteristic on absorption peak position, peak amount, and shape. The targets (1 154/1 733, 1 154/898) by FTIR showed that lipids and polysaccharide were major nutriments to affect the host plant selection of T. vishnou gigantina larvae. The XRD results showed that crystallinity index (CrI) also could affect the host plant selection of T. vishnou gigantina larvae. In this research, spectroscopy technology was firstly applied to the study of interactive relationship between insect and host, which would blaze a trail for intensive study of host plant selection mechanism of insect at molecular level.

Effect of Four Types of Chemical Pretreatment on Enzymatic Hydrolysis by SEM, XRD and FTIR Analysis.

Catalpa sawdust was respectively pretreated by NaOH, Ca(OH)2, H2SO4 and HCl solution, and the enzymatic hydrolysis of catalpa sawdust was significantly enhanced by alkaline pretreatments. In order to investigate the mechanisms of pretreatment of catalpa sawdust, the characteristics of catalpa sawdust before and after pretreatments were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. It was found that the surface of catalpa sawdust was disrupted by four kinds of chemical pretreatment, and the pretreatment with Ca(OH)2 solution resulted in the most serious damage. The XRD results showed that part of amorphous regions was damaged by alkaline pretreatments, which led to a relative increase of crystallinity Index (CrI) of catalpa sawdust; while the CrI of catalpa sawdust was insignificantly influenced by acid pretreatments. The FTIR analysis displayed that the molecular structures of hemicellulose and lignin of catalpa sawdust were damaged in different degrees by four types of pretreatment. The significant improvement of enzymatic hydrolysis of catalpa sawdust after alkaline pretreatment might be attributed to the effective delignification of alkaline.

Fluorescence enhancement effect for the determination of DNA with calcein-cetyl trimethyl ammonium bromide system.

A new spectrofluorimetric method was developed for the determination of trace amounts of DNA using the calcein as a fluorescent probe. In the presence of appropriate amounts of the cationic surfactant cetyl trimethyl ammonium bromide (CTAB), the anionic dye calcein dimerizes. The weak fluorescence intensity of the dimer was enhanced by adding DNA at pH 6-7. The interaction between calcein-CTAB and DNA was studied on the basis of this behavior and a new method was developed for determining DNA. Under the optimal conditions, the enhanced fluorescence intensity was in proportion to the concentration of DNA in the range of 4.0x10(-6) to 8.0x10(-5) g L(-1) for fsDNA and thermally denatured ctDNA (4.5x10(-6) to 9.0x10(-5) g L(-1)). The detection limits (S/N=3) were 2.0x10(-6) and 2.2x10(-6) g L(-1), respectively. This method was used for determining the concentration of DNA in synthetic samples with satisfactory results.