Attenuation of Cross-Flow Fan Noise Using Porous Stabilizers

This paper presents a qualitative analysis of controlling the cross-flow fan noise by using porous stabilizers. The stabilizer was originally a folded plate. It is changed into a porous structure which has a plenum chamber and vent holes on the front wall. In order to investigate the influences of using the porous stabilizers, experiments are carried out to measure the cross-flow fan aerodynamic performances and sound radiation. Meanwhile, the internal flow field of the fan is numerically simulated. The results show that the porous stabilizers have not produced considerable effect on the cross-flow fan's performance curve, but the noise radiated from the fan is strongly affected. This indicates the feasibility of controlling the cross-flow fan noise by using the porous stabilizers with selected porosity

Effect of implant placement depth on the peri-implant bone defect configurations in ligature-induced peri-implantitis : an experimental study in dogs

The subcrestal placement of implant platform has been considered a key factor in the preservation of crestal bone, but the influence of implant placement depth on bone remodeling combined with peri-implantitis is not fully understood. The aim of this study was to assess the effect of the crestal or subcrestal placement of implants on peri-implant bone defects of ligature-induced peri-implantitis in dogs. Eight weeks after tooth extraction in six beagle dogs, two different types of implants (A: OsseoSpeed?, Astra, Mölndal, Sweden; B: Integra-CP?, Bicon, Boston, USA) were placed at either crestal or subcrestal (-1.5 mm) positions on one side of the mandible. Ligature-induced peri-implantitis was initiated four weeks after the installation of the healing abutment connections. After 12 weeks, tissue biopsies were processed for histological analyses. Supra-alveolar bone loss combined with a shallow infrabony defect was observed in crestal level implants while deep and wide infrabony defects were present in subcrestal level groups. Subcrestal groups showed significantly greater ridge loss, depths and widths of infrabony defects when compared to crestal groups (P<0.001). Within the limitations of the animal study, it can be stated that the implants at subcrestal position displayed greater infra-osseous defect than implants at crestal position under an experimental ligature-induced peri-implantitis

GC Gene Polymorphisms and Vitamin D-Binding Protein Levels Are Related to the Risk of Generalized Aggressive Periodontitis

Objective. To explore whether GC (group-specific component) rs17467825, rs4588, and rs7041 polymorphisms are associated with generalized aggressive periodontitis. Methods. This case-control study recruited 372 patients with generalized aggressive periodontitis (group AgP) and 133 periodontal healthy subjects (group HP). GC rs17467825, rs4588, and rs7041 genotypes and plasmatic vitamin D-binding protein (DBP) were measured. Analysis of single SNP and multiple SNPs was performed and relevance between plasmatic DBP and haplotypes was analyzed. Results. GC rs17467825 GG genotype was statistically associated with lower risk for generalized aggressive periodontitis under the recessive model (OR = 0.52, 95% CI: 0.30–0.92, p=0.028). GC rs17467825 and rs4588 had strong linkage disequilibrium with r2≥0.8 and D′≥0.8. Haplotype (GC rs17467825, rs4588) GC was associated with the less risk for generalized aggressive periodontitis (OR = 0.29, 95% CI: 0.09–0.96, p=0.043). In group AgP, individuals with combined genotype (GC rs17467825, rs4588) AG+CA had significantly lower plasmatic DBP level than those with the other two combined genotypes (AG+CA versus AA+CC p=0.007; AG+CA versus GG+AA p=0.026). Conclusions. GC rs17467825 genotype GG and haplotype (GC rs17467825, rs4588) GC are associated with generalized aggressive periodontitis. The association may be acquired through regulating DBP levels. The functions of GC gene and DBP in inflammatory disease need to be further studied

Research Progress on the molecular mechanism of the Utilization of Human Milk Oligosaccharides in Bifidobacterium longum subsp. infantis and Its probiotic effect

Human milk is the most important source of nutrition in early infancy, which can meet all the nutritional needs in the first 6 months after birth. It contains many bioactive substances that can regulate the intestinal flora, promote the development of the immune system, and enhance the intestinal barrier. Human milk oligosaccharides (HMOs) are one of the active substances in human milk. They cannot be directly digested and absorbed by infants, but can be used as a prebiotic to stimulate the establishment and evolution of the gut microbiota. Bifidobacterium longum subsp. infantis is a dominant microorganism in the gut of breastfed infants, which has almost all gene clusters required for metabolizing the major HMOs, and its interaction with HMOs plays a key role in the early intestinal health of infants. This review summarizes the composition and structure of HMOs, describes the utilization of HMOs by B. longum subsp. infantis and summarizes the beneficial effects B. longum subsp. infantis exerts in infants by metabolizing HMOs, which will lay the foundation for exploring the interaction mechanism between HMOs and the gut microbiota, as well as its role in infant intestinal development and maturation

MOF-Derived Robust and Synergetic Acid Sites Inducing C-N Bond Disruption for Energy-Efficient CO₂Desorption

Amine-based scrubbing technique is recognized as a promising method of capturing CO2 to alleviate climate change. However, the less stability and poor acidity of solid acid catalysts (SACs) limit their potential to further improve amine regeneration activity and reduce the energy penalty. To address these challenges, here, we introduce two-dimensional (2D) cobalt-nitrogen-doped carbon nanoflakes (Co-N-C NSs) driven by a layered metal-organic framework that work as SACs. The designed 2D Co-N-C SACs can exhibit promising stability, superhydrophilic surface, and acidity. Such 2D structure also contains well-confined Co-N4 Lewis acid sites and -OH Brønsted acid sites to have a synergetic effect on C-N bond disruption and significantly increase CO2 desorption rate by 281% and reduce the reaction temperatures to 88 °C, minimizing water evaporation by 20.3% and subsequent regeneration energy penalty by 71.7% compared to the noncatalysis.</p

Characterization of the Autocrine/Paracrine Function of Vitamin D in Human Gingival Fibroblasts and Periodontal Ligament Cells

Background: We previously demonstrated that 25-hydroxyvitamin D-3, the precursor of 1 alpha,25-dihydroxyvitamin D-3, is abundant around periodontal soft tissues. Here we investigate whether 25-hydroxyvitamin D-3 is converted to 1 alpha,25-dihydroxyvitamin D-3 in periodontal soft tissue cells and explore the possibility of an autocrine/paracrine function of 1 alpha,25-dihydroxyvitamin D-3 in periodontal soft tissue cells. Methodology/Principal Findings: We established primary cultures of human gingival fibroblasts and human periodontal ligament cells from 5 individual donors. We demonstrated that 1 alpha-hydroxylase was expressed in human gingival fibroblasts and periodontal ligament cells, as was cubilin. After incubation with the 1 alpha-hydroxylase substrate 25-hydroxyvitamin D-3, human gingival fibroblasts and periodontal ligament cells generated detectable 1 alpha,25-dihydroxyvitamin D-3 that resulted in an up-regulation of CYP24A1 and RANKL mRNA. A specific knockdown of 1 alpha-hydroxylase in human gingival fibroblasts and periodontal ligament cells using siRNA resulted in a significant reduction in both 1 alpha, 25-dihydroxyvitamin D-3 production and mRNA expression of CYP24A1 and RANKL. The classical renal regulators of 1 alpha-hydroxylase (parathyroid hormone, calcium and 1 alpha,25-dihydroxyvitamin D-3) and Porphyromonas gingivalis lipopolysaccharide did not influence 1 alpha-hydroxylase expression significantly, however, interleukin-1 beta and sodium butyrate strongly induced 1 alpha-hydroxylase expression in human gingival fibroblasts and periodontal ligament cells. Conclusions/Significance: In this study, the expression, activity and functionality of 1 alpha-hydroxylase were detected in human gingival fibroblasts and periodontal ligament cells, raising the possibility that vitamin D acts in an autocrine/paracrine manner in these cells.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000305781700070&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Multidisciplinary SciencesSCI(E)PubMed13ARTICLE6e39878

Relationship of central incisor implant placement to the ridge configuration anterior to the nasopalatine canal in dentate and partially edentulous individuals: a comparative study

Background. The aims of this study were to investigate the ridge contour anterior to the nasopalatine canal, and the difference between the incidences of the nasopalatine canal perforation in dentate and partially edentulous patients by cone-beam computed tomography.Methods. Cone-beam computed tomography scan images from 72 patients were selected from database and divided into dentate and partially edentulous groups. The configuration of the ridge anterior to the canal including palatal concavity depth, palatal concavity height, palatal concavity angle, bone height coronal to the incisive foramen, and bone width anterior to the canal was measured. A virtual implant placement procedure was used, and the incidences of perforation were evaluated after implant placement in the cingulum position with the long axis along with the designed crown.Results. Comparing with variable values from dentate patients, the palatal concavity depth and angle were greater by 0.9 mm and 4°, and bone height was shorter by 1.1 mm in partially edentulous patients, respectively. Bone width in edentulous patients was narrower than in dentate patients by 1.2 mm at incisive foramen level and 0.9 mm at 8 mm subcrestal level, respectively. After 72 virtual cylindrical implants (4.1 × 12 mm) were placed, a total of 12 sites (16.7%) showed a perforation and three-fourths occurred in partially edentulous patients. After replacing with 72 tapered implants (4.3 × 13 mm), only 6 implants (8.3%) broke into the canal in the partially edentulous patient group.Conclusions. The nasopalatine canal may get close to the implant site and the bone width anterior to the canal decreases after the central incisor extraction. The incidence of nasopalatine canal perforation may occur more commonly during delayed implant placement in central incisor missing patients

The effect of supragingival glycine air polishing on periodontitis during maintenance therapy: a randomized controlled trial

Background Glycine air polishing has been proved to be safe, comfortable and time-saving. Whether it could substitute ultrasonic scaling to remove dental plaque biofilm during periodontal maintenance remains unclear. The purposes of this study were to evaluate the effect of supragingival glycine air polishing (SGAP) on the subgingival periodontal pathogens during maintenance therapy and to check the association of periodontal pathogens and clinical parameters. Methods Twenty-three chronic periodontitis patients during their maintenance therapy were enrolled in the 12-week study. According to randomized split-mouth design, the test side was treated with SGAP (65 μm), while the control side was treated with supragingival ultrasonic scaling and polishing (SUSP) with rubber cup. Clinical examination including plaque index (PLI), probing depth (PD), bleeding index (BI) were performed at baseline and 12 weeks post-treatment. Sampling of the subgingival plaque at each investigational site (mesiobuccal site of the mandibular first molar) was performed at baseline and 2, 4, 8, 12 weeks after maintenance treatment. Four periodontal pathogens including Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola and Fusobacterium nucleatum were detected by 16S rDNA polymerase chain reaction. Results Clinical status generally improved after treatment in both groups. PLI in both groups, PD in SGAP group and bleeding on probing (%) in SUSP group significantly decreased after treatment (p < 0.05). There was no significant difference of clinical parameters between two groups before and after treatment. The detection rates of P. gingivalis, T. denticola in both groups, T. forsythia in SUSP group and F. nucleatum in SGAP group decreased after maintenance treatment in both groups, although no significant difference was found, and it rebound to baseline level at 12 weeks after maintenance treatment. There was no significant difference between SGAP group and SUSP group at any time point. T. denticola-positive sites had significantly greater BI than T. denticola-negative sites (p < 0.05). Discussion Supragingival glycine air polishing had a reliable effect in removing subgingival dental plaque biofilm during maintenance period, and three months may be a proper maintenance interval for pockets not more than 5 mm

Effect of knockdown of 25-hydroxylases on 25OHD₃ generation.

<p>hGF and hPDLC from donors 2, 4 and 5 were treated with vitamin D₃ at various concentrations indicated in the figure for 12 h after transfection with a siRNA oligonucleotide for CYP27A1, a siRNA oligonucleotide for CYP2R1, or a non-silencing control. 25OHD₃ production was measured in supernatants of hGF (A), supernatants of hPDLC (B), cell lysates of hGF (C), and cell lysates of hPDLC (D). When CYP27A1 or CYP2R1 was not knocked down, the production of 25OHD₃ increased with an increasing concentration of 25OHD₃. When CYP27A1 was knocked down in hGF and hPDLC, the generation of 25OHD₃ decreased significantly compared to when CYP27A1 was not knocked down. When CYP2R1 was knocked down in hGF (A, C), the generation of 25OHD₃ was not significantly different from that when CYP2R1 was not knocked down. When CYP2R1 was knocked down in hPDLC (B, D), the generation of 25OHD₃ was only slightly different at some time points from that when CYP2R1 was not knocked down. The data are presented as the mean ± SE. * hGF or hPDLC generated significantly less 25OHD₃ with the same amount of added vitamin D₃ when CYP27A1 or CYP2R1 was knocked down (<i>p</i><0.05). # hGF or hPDLC generated significantly more 25OHD₃ with the same amount of added vitamin D₃ when CYP27A1 or CYP2R1 was knocked down (<i>p</i><0.05).</p