28 research outputs found
Multilevel unilateral versus bilateral pedicular percutaneous vertebroplasty for osteoporotic vertebral compression fractures
Study designRetrospective study.ObjectiveControversy exists over the need for unilateral vs. bilateral pedicular percutaneous vertebroplasty (PVP) for patients with osteoporotic vertebral compression fractures (OVCFs). Clinical research is scarce comparing two approaches for multi-level PVP. This study aimed at evaluating the clinical and radiographic outcomes of multi-level PVP using two approaches for OVCFs.MethodsSeventy-eight patients with OVCFs undergoing multi-level PVP were enrolled including 36 patients undergoing unilateral PVP and 42 undergoing bilateral PVP. The clinical and radiological assessments including the Visual Analogue Scale (VAS), sagittal and coronal segmental Cobb, vertebral compression ratio (VCR), and vertebral sides ratio (VSR) were evaluated preoperatively and postoperatively.ResultsAll patients achieved a minimum 2-year follow-up. A total of 164 fractured vertebrae were enrolled. Regarding clinical efficacy, the VAS score improved in both groups after surgery, but the two groups did not differ significantly. The changes tendency in Sagittal Segmental Cobb, VSR, and VCR were similar postoperatively, and no statistically significant difference between groups. As for the Coronal Segmental Cobb angle, patients in unilateral and bilateral groups were shown to have 5.0Ā°āĀ±ā4.0Ā° and 2.6Ā°āĀ±ā2.2Ā° degrees loss of correction at a minimum 2-years follow-up duration, respectively. The loss of correction in the Coronal Segmental Cobb of unilateral group was significantly greater than that of bilateral group.ConclusionBoth multi-level unilateral and bilateral pedicular PVP achieved significant pain reduction and vertebral height restoration. Moreover, the bilateral PVP has shown advantages in stabilizing Coronal Cobb angle in patients with OVCFs
<i>IlAP2</i>, an AP2/ERF Superfamily Gene, Mediates Cadmium Tolerance by Interacting with <i>IlMT2a</i> in <i>Iris lactea</i> var. <i>chinensis</i>
Cadmium (Cd) stress has a major impact on ecosystems, so it is important to find suitable Cd-tolerant plants while elucidating the responsible molecular mechanism for phytoremediation to manage Cd soil contamination. Iris lactea var. chinensis is an ornamental perennial groundcover plant with strong tolerance to Cd. Previous studies found that IlAP2, an AP2/ERF superfamily gene, may be an interacting partner of the metallothionein gene IlMT2a, which plays a key role in Cd tolerance. To study the role of IlAP2 in regulating Cd tolerance in I. lactea, we analyzed its regulation function and mechanism based on a yeast two-hybrid assay, a bimolecular fluorescence complementation test, quantitative real-time PCR, transgenics and transcriptome sequencing. The results showed that IlAP2 interacts with IlMT2a and may cooperate with other transcription factors to regulate genes involved in signal transduction and plant hormones, leading to reduced Cd toxicity by hindering Cd transport. These findings provide insights into the mechanism of IlAP2-mediated stress responses to Cd and important gene resources for improving plant stress tolerance in phytoremediation
Transcriptome Profiling of Louisiana iris Root and Identification of Genes Involved in Lead-Stress Response
Louisiana iris is tolerant to and accumulates the heavy metal lead (Pb). However, there is limited knowledge of the molecular mechanisms behind this feature. We describe the transcriptome of Louisiana iris using Illumina sequencing technology. The root transcriptome of Louisiana iris under control and Pb-stress conditions was sequenced. Overall, 525,498 transcripts representing 313,958 unigenes were assembled using the clean raw reads. Among them, 43,015 unigenes were annotated and their functions classified using the euKaryotic Orthologous Groups (KOG) database. They were divided into 25 molecular families. In the Gene Ontology (GO) database, 50,174 unigenes were categorized into three GO trees (molecular function, cellular component and biological process). After analysis of differentially expressed genes, some Pb-stress-related genes were selected, including biosynthesis genes of chelating compounds, metal transporters, transcription factors and antioxidant-related genes. This study not only lays a foundation for further studies on differential genes under Pb stress, but also facilitates the molecular breeding of Louisiana iris
Transcriptome Analysis Reveals Regulatory Framework for Salt and Drought Tolerance in Hibiscus hamabo Siebold & Zuccarini
Hibiscus hamabo Siebold & Zuccarini (H. hamabo) is tolerant to salt and drought conditions, but the molecular mechanisms that underlie this stress tolerance remain unclear. In this study, the transcriptome of H. hamabo roots was investigated under NaCl or PEG treatment. A total of 20,513 and 27,516 significantly changed known genes at 6 h and 24 h, respectively, were detected between the salt or drought treatments and the control libraries. Among these, there were 3845 and 7430 overlapping genes under the two stresses at 6 h and 24 h, respectively. Based on the analysis of enriched KEGG pathways and clustering of expression patterns, the DEGs that were continuously up- or down-regulated under both salt and drought treatments were mainly enriched in MAPK signaling pathway, transcription factors, transporters and other pathways. The transcriptome expression profiles of H. hamabo provide a genetic resource for identifying common regulatory factors involved in responses to different abiotic stresses. In addition, the identified factors may be useful to developing genetic breeding strategies for the Malvaceae
Output-Only Parameters Identification of Earthquake-Excited Building Structures with Least Squares and Input Modification Process
Damage detection and system identification with output-only information is an important but challenging task for ensuring the safety and functionality of civil structures during their service life. In this paper, a relatively simple and efficient iteration identification method consisting of the least squares estimation (LSE) technique and an input modification process is proposed for the simultaneous identification of structural parameters and the unknown ground motion. The spatial distribution characteristics of ground acceleration on earthquake-excited building structures are considered as additional information for parameters identification in each iterative step. First, the unknown input is estimated using the measured responses and the initial guesses of the structural parameters. The estimated input is then modified on the basis of the property of its spatial distribution. This modified input is further employed for providing the updated estimation of structural parameters. The iterative procedure would continue until the preset convergence criterion is satisfied. The accuracy of the proposed approach is numerically validated via a shear building model under the El Centro earthquake. The effects of signal noise, the number of sample points, and the initial guesses of structural parameters are discussed. The results show that the proposed approach can satisfactorily identify the structural parameters and unknown earthquakes
Axial Compression Behavior of Symmetrical Full-Scale Concrete Filled Double Skin Steel Tube Stub Columns
To investigate the bearing behavior of symmetrical full-scale different strength concrete filled double skin steel tube (CFDST) stub columns, 19 full-scale specimens were designed, considering the slenderness ratio (λ); the compression strength of core concrete and sandwich concrete (fcki, fcko), the thickness of the inner and outer steel tubes (ti, to); the diameter of inner and outer steel tubes (Di, Do); and the tensile strength of the inner and outer steel tubes (fyki, fyko) as the main parameters. Nonlinear constitutive models for concrete considering constraint effect were adopted, and a finite element (FE) model was established using ABAQUS software. By comparing the results between simulations and experiments, the rationality of the modeling method was verified. Based on the FE model, the parameter analysis for CFDST columns were conducted, and the force mechanism, stress distribution, and deformation process were analyzed. The results showed that the axial compression bearing capacity (Nsu) increased significantly with an increase in fcki, to, Do, and fcko, while Nsu decreased gradually with an increase in λ. Finally, according to the calculated results of the specimens, the calculation formula for Nsu of full-scale composite columns was statistically regressed using 1stOpt software and showed a good agreement with the FE
Genome-Wide Identification and Characterization of NAC Family in Hibiscus hamabo Sieb. et Zucc. under Various Abiotic Stresses
NAC transcription factor is one of the largest plant gene families, participating in the regulation of plant biological and abiotic stresses. In this study, 182 NAC proteins (HhNACs) were identified based on genomic datasets of Hibiscus hamabo Sieb. et Zucc (H. hamabo). These proteins were divided into 19 subfamilies based on their phylogenetic relationship, motif pattern, and gene structure analysis. Expression analysis with RNA-seq revealed that most HhNACs were expressed in response to drought and salt stress. Research of quantitative real-time PCR analysis of nine selected HhNACs supported the transcriptome data’s dependability and suggested that HhNAC54 was significantly upregulated under multiple abiotic stresses. Overexpression of HhNAC54 in Arabidopsis thaliana (A. thaliana) significantly increased its tolerance to salt. This study provides a basis for a comprehensive analysis of NAC transcription factor and insight into the abiotic stress response mechanism in H. hamabo
Axial Compression Behavior of Symmetrical Full-Scale Concrete Filled Double Skin Steel Tube Stub Columns
To investigate the bearing behavior of symmetrical full-scale different strength concrete filled double skin steel tube (CFDST) stub columns, 19 full-scale specimens were designed, considering the slenderness ratio (Ī»); the compression strength of core concrete and sandwich concrete (fcki, fcko), the thickness of the inner and outer steel tubes (ti, to); the diameter of inner and outer steel tubes (Di, Do); and the tensile strength of the inner and outer steel tubes (fyki, fyko) as the main parameters. Nonlinear constitutive models for concrete considering constraint effect were adopted, and a finite element (FE) model was established using ABAQUS software. By comparing the results between simulations and experiments, the rationality of the modeling method was verified. Based on the FE model, the parameter analysis for CFDST columns were conducted, and the force mechanism, stress distribution, and deformation process were analyzed. The results showed that the axial compression bearing capacity (Nsu) increased significantly with an increase in fcki, to, Do, and fcko, while Nsu decreased gradually with an increase in Ī». Finally, according to the calculated results of the specimens, the calculation formula for Nsu of full-scale composite columns was statistically regressed using 1stOpt software and showed a good agreement with the FE
ERĪ² modulation and non-modulation of ERĪ± by administration of geniposide and panax notoginseng saponins in SH-SY5Y cells
Objective: To illustrate the effect of geniposide (GP) and panax notoginseng saponins (PNS) on estrogen receptors (ER) including ERĪ± and ERĪ² within the cytoplasm and nucleus of SH-SY5Y cells. Methods: Immunofluorescence was used to observe the distribution of ERĪ± and ERĪ² in cytoplasm and nucleus, but Western blot was only for ERĪ² detection. q-PCR was applied to detect NR3C1, S100A6 and LGALS1downstream mRNA gene expression levels of ER. Results: Through analyzing fluorescence intensity under the administration of GP and PNS in SH-SY5Y cells, we found that the distribution of ERĪ± has not been affected. We also discovered that GP and/or PNS significantly stimulated the transportation of ERĪ² into the nucleus in a time-dependent manner (all PĀ <Ā .001). When SH-SY5Y cells were treated with supplements of GP, PNS, GPĀ +Ā PNS at 15Ā minutes, 30Ā minutes and 45Ā minutes, the distribution of ERĪ² in the nucleus significantly increased compared with that in control group (all PĀ <Ā .001). Evidently, treatment with GP, PNS, GPĀ +Ā PNS was able to significantly increase the levels of ERĪ² protein within the nucleus compared with control group at both 30Ā minutes and 45Ā minutes intervals (all PĀ <Ā .001). Furthermore, GP and PNS showed signs of activating to NR3C1 and LGALS1, two genes downstream of ER. It is possible that the S100A6 gene mainly encoded the downstream gene in ERĪ±'s signaling pathway, which was not affected after the treatment of GP and/or PNS. Conclusion: The distribution and expression of ERĪ² has been modulated under the administration of GPĀ +Ā PNS within the SH-SY5Y cells, whereas ERĪ± has not. GP and PNS in combination may play an estrogenic-like effect with selectivity on ERĪ² modulation. Keywords: Geniposide, Panax notoginseng saponins, Estrogen receptor, SH-SY5Y cel