A Study on the Functional Identification of Overexpressing Winter Wheat Expansin Gene TaEXPA7-B in Rice under Salt Stress.

Expansin is a cell wall relaxant protein that is common in plants and directly or indirectly participates in the whole process of plant root growth, development and morphogenesis. A well-developed root system helps plants to better absorb water and nutrients from the soil while effectively assisting them in resisting osmotic stress, such as salt stress. In this study, we observed and quantified the morphology of the roots of Arabidopsis overexpressing the TaEXPAs gene obtained by the research group in the early stage of development. We combined the bioinformatics analysis results relating to EXPA genes in five plants and identified TaEXPA7-B, a member of the EXPA family closely related to root development in winter wheat. Subcellular localization analysis of the TaEXPA7-B protein showed that it is located in the plant cell wall. In this study, the TaEXPA7-B gene was overexpressed in rice. The results showed that plant height, root length and the number of lateral roots of rice overexpressing the TaEXPA7-B gene were significantly higher than those of the wild type, and the expression of the TaEXPA7-B gene significantly promoted the growth of lateral root primordium and cortical cells. The plants were treated with 250 mM NaCl solution to simulate salt stress. The results showed that the accumulation of osmotic regulators, cell wall-related substances and the antioxidant enzyme activities of the overexpressed plants were higher than those of the wild type, and they had better salt tolerance. This paper discusses the effects of winter wheat expansins in plant root development and salt stress tolerance and provides a theoretical basis and relevant reference for screening high-quality expansin regulating root development and salt stress resistance in winter wheat and its application in crop molecular breeding.

Genome-Wide Identification and Expression Profiling of Potato (Solanum tuberosum L.) Universal Stress Proteins Reveal Essential Roles in Mechanical Damage and Deoxynivalenol Stress.

Universal stress proteins (USPs) play an important regulatory role in responses to abiotic stress. Most of the research related to USPs so far has been conducted on plant models such as Arabidopsis (Arabidopsis thaliana), rice (Oryza sativa L.), and cotton (Gossypium hirsutum L.). The potato (Solanum tuberosum L.) is one of the four major food crops in the world. The potato is susceptible to mechanical damage and infection by pathogenic fungi during transport and storage. Deoxynivalenol (DON) released by Fusarium can seriously degrade the quality of potatoes. As a result, it is of great significance to study the expression pattern of the potato StUSP gene family under abiotic stress conditions. In this study, a total of 108 USP genes were identified from the genome of the Atlantic potato, divided into four subgroups. Based on their genetic structure, the physical and chemical properties of their proteins and other aspects of their biological characteristics are comprehensively analyzed. Collinear analysis showed that the homologous genes of StUSPs and four other representative species (Solanum lycopersicum, Arabidopsis, Oryza sativa L., and Nicotiana attenuata) were highly conserved. The cis-regulatory elements of the StUSPs promoter are involved in plant hormones, environmental stress, mechanical damage, and light response. RNA-seq analysis showed that there are differences in the expression patterns of members of each subgroup under different abiotic stresses. A Weighted Gene Coexpression Network Analysis (WGCNA) of the central gene showed that the differential coexpression gene is mainly involved in the plant-pathogen response process, plant hormone signal transduction, and the biosynthesis process of secondary metabolites. Through qRT-PCR analysis, it was confirmed that StUSP13, StUSP14, StUSP15, and StUSP41 may be important candidate genes involved in the response to adversity stress in potatoes. The results of this study provide a basis for further research on the functional analysis of StUSPs in the response of potatoes to adversity stress.

Iva xanthiifolia leaf extract reduced the diversity of indigenous plant rhizosphere bacteria.

BACKGROUND: Iva xanthiifolia, native to North America, is now widely distributed in northeastern China and has become a vicious invasive plant. This article aims to probe the role of leaf extract in the invasion of I. xanthiifolia. METHODS: We collected the rhizosphere soil of Amaranthus tricolor and Setaria viridis in the invasive zone, the noninvasive zone and the noninvasive zone treated with extract from I. xanthiifolia leaf, and obtained I. xanthiifolia rhizosphere soil in the invasive zone. All wild plants were identified by Xu Yongqing. I. xanthiifolia (collection number: RQSB04100), A. tricolor (collection number: 831,030) and S. viridis (collection number: CF-0002-034) are all included in Chinese Virtual Herbarium ( https://www.cvh.ac.cn/index.php ). The soil bacterial diversity was analyzed based on the Illumina HiSeq sequencing platform. Subsequently, taxonomic analysis and Faprotax functional prediction were performed. RESULTS: The results showed that the leaf extract significantly reduced the diversity of indigenous plant rhizosphere bacteria. A. tricolor and S. viridis rhizobacterial phylum and genus abundances were significantly reduced under the influence of I. xanthiifolia or its leaf extract. The results of functional prediction showed that bacterial abundance changes induced by leaf extracts could potentially hinder nutrient cycling in native plants and increased bacterial abundance in the A. tricolor rhizosphere related to aromatic compound degradation. In addition, the greatest number of sensitive Operational Taxonomic Units (OTUs) appeared in the rhizosphere when S. viridis was in response to the invasion of I. xanthiifolia. It can be seen that A. tricolor and S. viridis have different mechanisms in response to the invasion of I. xanthiifolia. CONCLUSION: I. xanthiifolia leaves material has potential role in invasion by altering indigenous plant rhizosphere bacteria.

Hemolysin from Aeromonas hydrophila enhances the host's serum enzyme activity and regulates transcriptional responses in the spleen of Cyprinus rubrofuscus.

Aeromonas hydrophila is a conditional pathogen impacting public hygiene and safety. Hemolysin is a virulence factor of Aeromonas hydrophila that causes erythrocyte hemolysis, yet its transcriptional response to Cyprinus rubrofuscus remains unknown. Our investigation confirmed the hemolysis of hemolysin from A. hydrophila. Serum enzyme activity was evaluated weekly after C. rubrofuscus were immunized with hemolysin Ahh1. The results showed that the hemolysin enhances the serum superoxide dismutase (SOD), lysozyme (LZM), and catalase (CAT) activity, which reached a maximum on day 14. To elucidate the molecular interaction between hemolysin from A. hydrophila and the host, we performed transcriptome sequencing on the spleen of C. rubrofuscus 14 days post hemolysin infection. The total number of clean reads was 41.37 Gb, resulting in 79,832 unigenes with an N50 length of 1863 bp. There were 1982 significantly differentially expressed genes (DEGs), including 1083 upregulated genes and 899 downregulated genes. Transcript levels of the genes, such as LA6BL, CD2, and NLRC5, were significantly downregulated, while those of IL11, IL1R2, and IL8 were dramatically upregulated. The DEGs were mainly enriched in the immune disease, viral protein interaction with cytokine and cytokine receptor, and toll-like receptor pathways, suggesting that hemolysin stimulation can activate the transcriptional responses. RT-qPCR experiments results of seven genes, IL-8, STAT2, CTSK, PRF1, CXCL9, TLR5, and SACS, showed that their expression was highly concordant with RNA-seq data. We clarified for the first time the key genes and signaling pathways response to hemolysin from A. hydrophila, which offers strategies for treating and preventing diseases.

Combined Transcriptome and Metabolome Analysis Reveals Adaptive Defense Responses to DON Induction in Potato.

Phytophthora infestans poses a serious threat to potato production, storage, and processing. Understanding plant immunity triggered by fungal elicitors is important for the effective control of plant diseases. However, the role of the potato stress response to Fusarium toxin deoxynivalenol (DON)-induced stress is still not fully understood. In this study, the metabolites of DON-treated potato tubers were studied for four time intervals using UPLC-MS/MS. We identified 676 metabolites, and differential accumulation metabolite analysis showed that alkaloids, phenolic acids, and flavonoids were the major differential metabolites that directly determined defense response. Transcriptome data showed that differentially expressed genes (DEGs) were significantly enriched in phenylpropane and flavonoid metabolic pathways. Weighted gene co-expression network analysis (WGCNA) identified many hub genes, some of which modulate plant immune responses. This study is important for understanding the metabolic changes, transcriptional regulation, and physiological responses of active and signaling substances during DON induction, and it will help to design defense strategies against Phytophthora infestans in potato.

Fully digital workflow for duplicating clasp-retained removable partial dentures using three-dimensional printing: A clinical report.

This clinical report describes a fully digital workflow for replicating removable partial dentures (RPDs). The artificial teeth and denture base of existing dentures were duplicated and applied to new dentures with a redesigned framework. After the components of RPDs had been separated from the scan data of the existing dentures, they were fabricated using 3-dimensional printing and assembled to create a new denture.

Comparison of maxillary anterior mathematical proportions among 3 dental arch forms.

STATEMENT OF PROBLEM: Race and sex differences in the mathematical proportions of maxillary anterior teeth have been evaluated. However, studies exploring the relationship between the mathematical proportion of maxillary anterior teeth and maxillary dental arch form are lacking. PURPOSE: The purpose of this clinical study was to determine if a correlation exists between the mathematical proportions of maxillary anterior teeth and 3 dental arch forms. MATERIAL AND METHODS: Three hundred young participants were recruited according to predefined criteria, and images and maxillary casts were obtained. The perceived width and length of the maxillary anterior teeth were measured on the images by using a software program, and mathematical proportions, including width ratios and width-to-length ratios, were calculated for each. The casts were used to categorize each specimen into tapered, ovoid, or square groups by using a specific classification method, and the width ratios and width-to-height ratios of the 3 dental arch forms were compared. Statistical analysis was performed by using analysis of variance (ANOVA) or the Kruskal-Wallis H test to compare the mathematical proportions of maxillary anterior teeth among the 3 dental arch forms (α=.05). The intraclass correlation coefficient (ICC) was used to test the reliability of the investigators. RESULTS: Except for the width-to-length ratios of the central incisor, mathematical proportions were affected by the dental arch form. The perceived width ratios of the maxillary lateral incisor-to-central incisor gradually increased from the tapered arch to the ovoid arch and from the ovoid arch to the square arch, with mean ±standard deviation values of 0.71 ±0.04, 0.73 ±0.05, and 0.79 ±0.06, respectively. For the maxillary perceived width ratios of canine-to-lateral incisor, the ovoid arch had the maximum perceived width ratios (0.86 ±0.10), followed by the tapered (0.82 ±0.10) and square arches (0.77 ±0.11). The width-to-length ratios of the central incisor were not affected by the arch form (P=.075), and the width-to-length ratios of the lateral incisor increased as the arch form became flat, with respective values of 0.70 ±0.10, 0.74 ±0.10, and 0.76 ±0.10. For the width-to-length ratios of the canine, the ovoid arch had the maximum perceived width ratios (0.58 ±0.10), followed by the tapered (0.53 ±0.10) and square arches (0.52 ±0.10). CONCLUSIONS: The mathematical proportions varied among the 3 dental arch forms, and the dental arch form should be considered during the prosthodontic design of maxillary anterior teeth.

Pan-cancer analysis combined with experiments explores the oncogenic role of spindle apparatus coiled-coil protein 1 (SPDL1).

BACKGROUND: The function of spindle apparatus coiled-coil protein 1 (SPDL1) as a cancer-promoting gene has been reported in a number of studies. However, the pan-cancer analysis of SPDL1 is still lacking. Here, we performed this pan-cancer analysis to evaluate the expression and prognostic value of SPDL1 and gain insights into the association between SPDL1 and immune infiltration. METHODS: In this study, based on the datasets of The cancer genome atlas (TCGA), Gene expression omnibus (GEO), The Genotype-Tissue Expression (GTEx) and Clinical Proteomic Tumor Analysis Consortium (CPTAC), we used R4.1.0 software and the online tools, including TIMER2.0, GEPIA2, cBioPortal, Modbase, UALCAN, MEXPRESS, STRING, Ensembl, NCBI, HPA, Oncomine, PhosphoNET and the Kaplan-Meier plotter, to explore the potential oncogenic roles of SPDL1. The expression of SPDL1 was also further verified by immunohistochemistry (IHC) in lung adenocarcinoma (LUAD) tissues. RESULTS: SPDL1 was overexpressed in most tumors compared with adjacent normal tissues, and SPDL1 expression was significantly correlated with the prognosis in most tumor types. The main type of genetic mutation of SPDL1 was missense mutation and the frequency of R318Q/W mutation was highest (4/119). The expression of SPDL1 was closely associated with genomic instability. The SPDL1 phosphorylation levels in S555 was enhanced in ovarian cancer. The SPDL1 expression was positively correlated with the immune infiltration of CD8+ T-cells and cancer-associated fibroblasts (CAFs) in most of the tumor types. Nuclear division, organelle fission and chromosome segregation were involved in the functional mechanisms of SPDL1. CONCLUSIONS: These findings suggested that SPDL1 might serve as a biomarker for poor prognosis and immune infiltration in cancers, shedding new light on therapeutics of cancers.

Genome-Wide Identification of Expansin Genes in Wild Soybean (Glycine soja) and Functional Characterization of Expansin B1 (GsEXPB1) in Soybean Hair Root.

Wild soybean, the progenitor and close relative of cultivated soybean, has an excellent environmental adaptation ability and abundant resistance genes. Expansins, as a class of cell wall relaxation proteins, have important functions in regulating plant growth and stress resistance. In the present study, we identified a total of 75 members of the expansin family on the basis of recent genomic data published for wild soybean. The predicted results of promoter elements structure showed that wild soybean expansin may be associated with plant hormones, stress responses, and growth. Basal transcriptome data of vegetative organs suggest that the transcription of expansin members has some organ specificity. Meanwhile, the transcripts of some members had strong responses to salt, low temperature and drought stress. We screened and obtained an expansin gene, GsEXPB1, which is transcribed specifically in roots and actively responds to salt stress. The results of A. tumefaciens transient transfection showed that this protein was localized in the cell wall of onion epidermal cells. We initially analyzed the function of GsEXPB1 by a soybean hairy root transformation assay and found that overexpression of GsEXPB1 significantly increased the number of hairy roots, root length, root weight, and the tolerance to salt stress. This research provides a foundation for subsequent studies of expansins in wild soybean.

Comparative epigenomics reveals evolution of duplicated genes in potato and tomato.

The evolution of duplicated genes after polyploidization has been the subject of many evolutionary biology studies. Potato (Solanum tuberosum) and tomato (Solanum lycopersicum) are the first two sequenced genomes of asterids, and share a common polyploidization event. However, the epigenetic role of DNA methylation on the evolution of duplicated genes derived from polyploidization is not fully understood. Here, we explore the role of the DNA methylation in the evolution of duplicated genes in potato and tomato. The overall levels of DNA methylation are different, although patterns of DNA methylation are similar in potato and tomato. Different types of duplicated genes can display different methylation patterns in potato and tomato. In addition, we found that differences in the methylation levels between duplicated genes were associated with gene expression divergence. In particular, for the majority of duplicated gene pairs, one copy is always hyper- or hypo-methylated compared with the other copy across different tomato fruit ripening stages, and these genes are enriched for specific function related to transcription factor (TF) activity. Furthermore, transcription of hundreds of duplicated TFs was shown to be regulated by DNA methylation during fruit ripening stages in tomato, some of which are well-known fruit ripening TFs. Taken together, our results support the notion that DNA methylation may facilitate divergent evolution of duplicated genes and play roles in important biological processes such as tomato fruit ripening.

Mental Health Literacy Among Chinese Rural Residents: A Survey From Hubei Province in Central China on People's Perception of Mental Illnesses.

A survey was carried among 412 participants to examine mental health literacy in rural China. Two vignettes depicting schizophrenia and depression were presented, and participants were asked to reflect on their recognition and the beliefs about the causes, consequences, and the treatments of the conditions described. Results show that the recognition rates for schizophrenia and depression were 76.9% and 67.7%, respectively. Participants believed work stress, life stress, and encountered frustration were the most important reasons for mental illnesses. Participants believed that mental illnesses could cause many severe consequences to patients, such as emotional pain, bringing pain to the family, deterioration of interpersonal relationships, and destroying the individual's life. The participants were more likely to recommend nonmedical treatment for the patients in the two vignettes. Participants having a higher educational level were more likely to be aware of the consequences of the mental illnesses, and they also had a more positive attitude toward seeking professional help.

Interfacial sealing between normal dentin and caries-affected dentin with glass-ceramic and three types of bonding systems.

PURPOSE: To compare the bonding effect of normal dentin (ND) and caries-affected dentin (CAD) on the surface of glass-ceramics using three types of bonding systems. METHODS: 39 teeth with caries involving the superficial layer of dentin were randomly divided into three groups and two subgroups: nanoleakage group (n=5) and shear bond strength group (n=8). The infected dentin was removed, and the CAD was retained. The surface of the tooth was polished, and one 2 mm × 2 mm × 4 mm CAD block and one 2 mm × 2 mm × 4 mm ND block were made. The total-etch adhesive A, self-etch adhesive B, or self-adhesive resin adhesive C were used to bond the glass ceramics. The bonding specimens of the nanoleakage group were stained with ammoniated silver nitrate and observed. In the shear bond strength group, the maximum load of the loading head F (N) was recorded, and the shear bond strength of the specimen was calculated. RESULTS: The nanoleakage values were significantly lower than those in the CAD group. The nanoleakage value of group B was significantly higher than that of group C, and that of group C was significantly higher than that of group A. Both dentin type and adhesive type had an effect on shear bond strength; under the same adhesive system, normal dentin demonstrated higher shear bond strength than CAD. However, the shear bond strength of adhesive A was higher than the bond strengths of adhesives B and C, but there was no significant difference in shear bond strength between adhesives B and C. CLINICAL SIGNIFICANCE: This study showed that dentin type and bonding system influenced shear bond strength and nanoleakage. The total-etch adhesive system showed the best interfacial sealing and bonding effect.

Knockdown of Trnau1ap inhibits the proliferation and migration of NIH3T3, JEG-3 and Bewo cells via the PI3K/Akt signaling pathway.

The tRNA selenocysteine 1 associated protein 1 (Trnau1ap, initially named SECp43) is involved in Selenocysteine (Sec) biosynthesis and incorporation into selenoproteins, which play a key role in biological processes, such as embryonic development. We previously reported that downregulation of Trnau1ap inhibited proliferation of cardiomyocyte-like H9c2 cells. However, the effects of Trnau1ap on cell proliferation and migration of embryonic development are not known, and the mechanisms remain elusive. Herein, lentiviral shRNA vectors were transfected in NIH3T3, JEG-3 and Bewo cells (embryonic, trophoblast and placental cells). We found that knockdown of Trnau1ap resulted in reduced expression levels of selenoproteins. The data of Cell Count Kit-8 (CCK-8) assay and wound scratch assay revealed the proliferation and migration rates were reduced in the Trnau1ap-shRNA groups. Furthermore, western blot analysis showed that the phosphorylation level of Akt in the phosphatidylinositol 3-kinase (PI3K)/Akt pathway was attenuated. These results indicate that Trnau1ap plays an important role in regulation of cell proliferation and migration through the PI3K/Akt signaling pathway, as well as being essential for embryonic development by regulating the expression of selenoproteins.

A signal-on ratiometric fluorometric heparin assay based on the direct interaction between amino-modified carbon dots and DNA.

Amino-modified carbon dots (C-dots) with positively charged surface were prepared. They display strong blue fluorescence and are shown to act as quenchers of the green fluorescence of FAM-labeled ssDNA such as the F-probe used in this work that was immobilized on the C-dots. On the addition of highly negatively charged heparin (Hep), it will interact with the C-dots and displace the F-probe from C-dots. Once the F-probe is displaced by Hep, its green fluorescence is restored. The intrinsic blue fluorescence of the C-dots remains stable after addition of Hep. Thus, a signal-on ratiometric fluorometric assay was developed for the ultra-sensitive detection of Hep. The underlying mechanisms of quenching and recovery are discussed. Under optimized conditions, the recovery of the ratiometric fluorescence of the system composed of C-dots and quenched F-probe is proportional to the Hep concentration in the range of 0.01-2.0 µg·mL-1 (= 0.00125-0.25 U·mL-1). The method was successfully applied to the determination of Hep in spiked serum samples. Graphical abstract Schematic of a signal-on ratiometric fluorometric method for the ultra-sensitive detection of heparin on the basis of the displacement and fluorescence enhancement of adsorbed FAM-labeled ssDNA from amino-modified carbon dots (C-dots) by heparin.

The cysteine protease CEP1, a key executor involved in tapetal programmed cell death, regulates pollen development in Arabidopsis.

Tapetal programmed cell death (PCD) is a prerequisite for pollen grain development in angiosperms, and cysteine proteases are the most ubiquitous hydrolases involved in plant PCD. We identified a papain-like cysteine protease, CEP1, which is involved in tapetal PCD and pollen development in Arabidopsis thaliana. CEP1 is expressed specifically in the tapetum from stages 5 to 11 of anther development. The CEP1 protein first appears as a proenzyme in precursor protease vesicles and is then transported to the vacuole and transformed into the mature enzyme before rupture of the vacuole. cep1 mutants exhibited aborted tapetal PCD and decreased pollen fertility with abnormal pollen exine. A transcriptomic analysis revealed that 872 genes showed significantly altered expression in the cep1 mutants, and most of them are important for tapetal cell wall organization, tapetal secretory structure formation, and pollen development. CEP1 overexpression caused premature tapetal PCD and pollen infertility. ELISA and quantitative RT-PCR analyses confirmed that the CEP1 expression level showed a strong relationship to the degree of tapetal PCD and pollen fertility. Our results reveal that CEP1 is a crucial executor during tapetal PCD and that proper CEP1 expression is necessary for timely degeneration of tapetal cells and functional pollen formation.

MicroRNA-328 is involved in the effect of selenium on hydrogen peroxide-induced injury in H9c2 cells.

Oxidative stress induces apoptosis in cardiac cells, and antioxidants attenuate the injury. MicroRNAs (miRNAs) are also involved in cell death; therefore, this study aimed to investigate the role of miRNAs in the effect of selenium on oxidative stress-induced apoptosis. The effects of sodium selenite were analyzed via cell viability, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) concentration. Flow cytometry was used to evaluate cell apoptosis. Fura-2AM was used to calculate intracellular Ca2+ concentration. Sodium selenite could ameliorate hydrogen peroxide (H2 O2 )-induced cell apoptosis and improve expression levels of glutathione peroxidase and thioredoxin reductase. Pretreatment with sodium selenite improved SOD activity and reduced MDA concentration. Treatments with H2 O2 or sodium selenite decreased miR-328 levels. MiR-328 overexpression enhanced cell apoptosis, reduced ATP2A2 levels, and increased intracellular Ca2+ concentration, while inhibition produced opposite effects. MiR-328 might be involved in the effect of sodium selenite on H2 O2 -induced cell death in H9c2 cells.

Host Specificity and Phylogenetic Relationships of Chicken and Turkey Parvoviruses.

Inoculation of specific-pathogen-free chickens and turkeys with five chicken parvoviruses (ChPV) and five turkey parvoviruses (TuPV) resulted in productive virus replication only in the homologous host species. A phylogenetic tree based on nucleotide sequences of the VP1 gene segment revealed a host-specific clustering of the virus strains. These results suggest that the VP1 gene plays an essential role in host specificity of ChPV and TuPV strains and could be a relevant target sequence for strain classification.

Gastrodin improves osteoblast function and adhesion to titanium surface in a high glucose environment.

Objective: To investigate the effects of gastrodin on the biological behavior of osteoblasts and osseointegration on the surface of the titanium plate in a high glucose environment, and to explore the possible regulatory mechanisms involved. Methods: A high glucose-induced oxidative damage model of MC3T3-E1 cells was established in vitro to observe the effects of gastrodin on cellular oxidative stress, cell viability, osteogenic differentiation, mineralization, migration, and adhesion ability on the titanium surface. Results: High glucose environment can cause oxidative stress damage to MC3T3-E1 cells, leading to a decrease in cell viability, osteogenesis, migration, adhesion and other functions. Gastrodin can upregulate the expression of antioxidant enzymes (Nrf2 and HO-1) and osteogenic differentiation related proteins (RUNX2 and BMP2) in MC3T3-E1 cells in high glucose environment, thereby inhibiting the excessive production of intracellular reactive oxygen species (ROS), reversing the decrease in cell viability, and improving the osteogenic differentiation and mineralization ability of osteoblasts. And gastrodin alleviated the decline in cell migration ability, improved the morphology of the cytoskeleton and increased the adhesion ability of osteoblasts on the surface of titanium plates in high glucose environment. However, gastrodin itself did not affect the cell viability, osteogenic differentiation and mineralization ability of osteoblasts in normal environment. Conclusions: Gastrodin may protect MC3T3-E1 cells osteogenesis and osseointegration on the surface of the titanium plate in vitro by upregulating antioxidant enzymes expression, and attenuating high glucose-induced oxidative stress. Therefore, gastrodin may be a potential drug to address the problem of poor implant osseointegration in patients with diabetes.

Case studies of the load-bearing performance of shield tunnel segment with misaligned defects.

The segment misalignment is a common defect in the segment installation of a shield tunnel construction, due to the complexity and uncertainty of its construction conditions. This raises a concerning about the safety of the segment lining for the shield tunnel. In this paper, the integrated numerical models with surrounding rock, peastone grouting and segment lining were built using three-dimensional finite element method, by introducing two kinds of misaligned defects of segments. One was the misalignment that elongated the horizontal axis of the transversal ring section of segment lining, another was the misalignment between adjacent rings of segments. To eliminate the impact of boundary on numerical results, seven rings of segments are built for the three-dimensional finite element models, and the middle ring is dealt with for the results analysis under V-class surrounding rock, including the circumferential stress of outer and inner layers of the segment, the contact stress on joint surface between segments, and the stress of locating pins between adjacent rings. Results indicate that the two kinds of misaligned defects create pronounced impact on tensile stress of segment at the bottom and the crown segments, respectively, which produces a greater tensile stress to increase cracking risk even abrupt fracture of segment. However, the misaligned defects have a slight impact on the contact stress and the locating pins stress. Therefore, attention should be paid to the cracking of bottom or crown segments in the segment lining of shield tunnel.

Correlation between different points on the face and the width of maxillary anterior teeth.

Statement of problem: There is currently no consensus on the relationship between maxillary anterior teeth and different facial anthropometric measurements. Additionally, whether these relationships vary by age and sex remains unreported. Purpose: This clinical study aimed to investigate the relationship between the intercanine distance (ICaD) and intercanthal distance (ICD), interpupillary distance (IPD), interalar width (IAW), and intercommissural width (ICW), and to compare whether these relationships differ between different age and sex populations. Material and methods: Participants (n = 409) were enrolled according to the inclusion criteria, and their standardized digital images were taken to measure facial and oral segments through an image processing program. The differences between ICaD and four facial measurements and the sexual differences for all measurements were compared using the 1-sample t-test. The differences among different age groups for all measurements were compared using the one-way analysis of variance (ANOVA) test, and a least significant difference (LSD) test was used for multiple comparisons. The association between ICaD and the four facial measurements was evaluated using Pearson correlation analysis. The correlation between ICaD and four facial measurements was evaluated using linear regression. Differences in regression equations among the subgroups were evaluated through subgroup regression analysis and the significance test of the difference between the two regression coefficients. Tests of significance were two-sided, with alpha level of 0.05. The reliability of the results was evaluated by calculating intraclass correlation coefficients. Results: The ICD, IPD, ICW, and IAW significantly differed from the ICaD in both sexes (P < 0.01). All measurements were significantly greater in men than in women (P < 0.01). The differences among the age groups were statistically significant for all measurements except IPD (P < 0.05). A significant positive correlation was found between all facial measurements (r = 0.258 [ICD], r = 0.334 [IPD], r = 0.389 [ICW], and r = 0.393 [IAW]) and the ICaD in both sexes. The highest correlation was found between ICW(r = 0.345) and ICAD in men and IAW (r = 0.285) and ICAD in women. Except for the 20-29 and 50-59 age groups, the mathematical equations of ICaD and facial anthropometric measurements differed among the other age groups and sexes. Conclusions: ICD, IPD, ICW, and IAW cannot be directly used to determine ICaD in both sexes. Nevertheless, when observed from the frontal aspect, by the use of digital images, all facial measurements correlated to the intercanine distance, with a high probability. The mathematical formulae combined with facial anthropological measurements can help ensure the combined width of the six maxillary anterior teeth, but the effects of sex and age differences should be considered.