Root Region Research Articles

The Mdm2-p53 Axis Links Cementocyte Survival to Cellular Cementum Volume.

Cementocytes are terminally differentiated cells embedded in cellular cementum, an important hard tissue covering the apical regions of tooth roots. However, the roles of cementocytes in cellular cementum remain enigmatic. Here, we show that Murine Double Minute 2 (Mdm2), an E3 ubiquitin ligase that plays vital roles in regulating cell proliferation, apoptosis, and differentiation to influence tissue or organ development, is highly expressed in the cementocytes of mice. To investigate the role of cementocyte-expressed Mdm2, Dmp1-Cre;Mdm2flox/flox (Mdm2 cKO)mice were obtained to inactivate Mdm2 in cementocytes. The results showed that Mdm2 was successfully ablated and Mdm2 cKO mice display increased cementocyte apoptosis and reduced cellular cementum volume. p53, the canonical substrate of Mdm2, was accumulated and hyperactivated in the cementocytes of Mdm2 cKO mice and in cultured IDG-CM6 cells (a cementocyte cell line) treated with Nutlin3a, an inhibitor of Mdm2. Further experiments showed that inactivation of one allele of p53 significantly rescued the increased cementocyte apoptosis and the decreased cellular cementum volume in Mdm2 cKO mice. Therefore, p53 is targeted by Mdm2 for degradation and mediates the role of Mdm2 in cementocyte survival and cellular cementum volume. Notably, Mdm2 cKO mice exhibited decreased differentiation of cementoblasts (the cell type primarily responsible for cementum deposition) and reduced rate of cellular cementum deposition. Meanwhile, OCCM-30 cells (a cementoblast cell line) showed diminished migration, proliferation, differentiation, and mineralization ability after culture with conditioned medium (CM) from Nutlin3a-pretreated IDG-CM6 cells. Intriguingly, Mdm2 cKO mice displayed significantly increased osteoclast formation and cementum resorption. Meanwhile, in vitro experiments verified that CM from Nutlin3a-pretreated IDG-CM6 cells induced osteoclast differentiation of bone marrow macrophages. Collectively, these results demonstrate that Mdm2-mediated degradation of p53 promotes cementocyte survival, and that cementocytes affect the cell behaviors of cementoblasts and osteoclasts through a paracrine mode to modulate cellular cementum volume.

Comparing Sectional and Total Dentin Bond Strengths of Three Endodontic Sealers after Using the Single-cone Obturation Technique: An In Vitro Study.

This study aimed to investigate and compare the total and sectional bond strengths of three endodontic sealers when used with the single-cone obturation technique. Forty-five human maxillary central incisors were prepared and divided into three groups according to the type of endodontic sealer: Group I (Gutta-percha/AH Plus Jet), group II (Gutta-percha/GuttaFlow 2), and group III (RealSeal/RealSeal SE). All canals were filled with the single-cone technique. Roots were sectioned and scanning electron microscope (SEM) analysis was performed on randomly selected samples from each group to assess the root canal filling interfaces. A root section from each root level was subjected to a push-out test. The sectional and total bond strengths were analyzed, then the failure modes were investigated. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey's test, and alpha was set at 0.05. Significant differences in bond strength values were observed (p < 0.05), with RealSeal SE demonstrating the highest bond strength, particularly in the middle and apical root regions. On the contrary, GuttaFlow 2 exhibited the lowest bond strength. Cohesive failure modes were more common for AH Plus Jet and GuttaFlow 2, while RealSeal SE showed cohesive and adhesive failures. The SEM analysis revealed that each sealer exhibited different levels of adaptability to dentin and core material. RealSeal SE and AH Plus Jet showed superior bond strength compared to GuttaFlow 2 when the single-cone obturation technique was used. The apical root sections exhibited the highest bond strength for all sealers, except for AH Plus Jet, which showed a higher bond strength in the coronal root sections. The current findings could guide dental professionals in choosing the most appropriate sealer for the single-cone obturation technique, potentially leading to more effective obturation procedures, especially for teeth requiring post and core restoration. How to cite this article: El Sayed M. Comparing Sectional and Total Dentin Bond Strengths of Three Endodontic Sealers after Using the Single-cone Obturation Technique: An In Vtro Study. J Contemp Dent Pract 2024;25(10):976-982.

Optimal sites for mini-implant insertion into the infrazygomatic crest according to different craniofacial morphologies: A cross-sectional cone-beam computed tomography study

The infrazygomatic bone crest and other extraalveolar regions represent a viable option for the placement of temporary anchorage devices when distalizing the maxillary arch. This approach allows for the movement of the dentition without concern for potential collisions among dental structures. Nevertheless, it is of the utmost importance to conduct a thorough examination of the anatomy of this region before the placement of mini-implants to prevent potential injuries, such as maxillary sinus perforations. The objective of this study was to quantify the depth of the infrazygomatic crest and evaluate its correlations with age, gender, skeletal classification, and vertical pattern. The study sample of this cross-sectional, retrospective study consisted of 201 cone-beam computed tomography scans collected from patients treated at the master's program in orthodontics at the University of Valencia and at a private dental clinic. The cone-beam computed tomography scans were collected for 5 years, from January 2017 to May 2022. The total and intraalveolar lengths were defined and measured at 3 points: the distal roots of the maxillary second molars, the distal roots of the maxillary first molars, and the mesial roots of the maxillary first molars. These measurements were taken on both the right and left sides using the Carestream 3D Imaging System (Atlanta, Ga). The total length (TL) at the mesiobuccal level of the first molars was found to be significantly longer on both sides (P= 0.001). The intraalveolar length exhibited statistically significant differences between the right and left sides, with those of the left side exhibiting greater length (P<0.001). The normodivergent patterns demonstrated lower TL values than hypodivergent (P= 0.006) and hyperdivergent patterns (P= 0.033). A statistically significant inverse relationship was observed between the distance from the cementoenamel junction to the vestibular bone crest and the total and intraalveolar lengths in the studied regions. The TL was greatest in the region of the mesiobuccal root of the maxillary first molars, followed by the region of the distal root of the second molars, and finally, the region of the distobuccal root of the maxillary first molars. Patients with normodivergent patterns exhibited the lowest total infrazygomatic ridge height.

Tomato roots exhibit distinct, development-specific responses to bacterial-derived peptides.

Plants possess cell-surface recognition receptors that detect molecular patterns from microbial invaders and initiate an immune response. Understanding the conservation of pattern-triggered immunity within different plant organs and across species is crucial to its sustainable and effective use in plant disease management but is currently unclear.We examined the activation and immune response patterns of three pattern recognition receptors (PRRs: SlFLS2, SlFLS3, and SlCORE) in different developmental regions of roots and in leaves of multiple accessions of domesticated and wild tomato (Solanum lycopersicum and S. pimpinellifolium) using biochemical and genetic assays.Roots from different tomato accessions differed in the amplitude and dynamics of their immune response, but all exhibited developmental-specific PTI responses in which the root early differentiation zone was the most sensitive to molecular patterns. PRR signaling pathways also showed distinct but occasionally overlapping responses downstream of each immune receptor in tomato roots.These results reveal that each PRR initiates a unique PTI pathway and suggest that the specificity and complexity of tomato root immunity are tightly linked to the developmental stage, emphasizing the importance of spatial and temporal regulation in PTI.

Optimizing Flow and Heat Transfer With Guiding Pin Fins in a Wedge-Shaped Cooling Channel for Gas Turbine Blade Trailing Edge

Abstract In this study, an innovative guiding pin-fin array optimization has been developed through three-dimensional numerical simulations to enhance the cooling efficiency of gas turbine blade trailing edge. The guiding pin-fin array is optimized using the Kriging surrogate model and Genetic Algorithm (GA), aiming to significantly improve the heat transfer rates and uniformity within the wedge-shaped channel. The design parameter chosen for optimization is the deflection angle of each guiding pin fin, and the optimization process is conducted in two rounds. The first-round optimization yields a first-optimized guiding pin-fin array, which exhibits superior overall heat transfer performance and reasonable pressure loss compared to conventional circular, oblong, and parallel pin-fin arrays. For the first-optimized guiding pin-fin (1st-OGP) channel at the Reynolds number of Re = 50,000, the total Nusselt number and pressure loss are 44.1% higher and 9.9% lower than those of the baseline circular pin-fin array (CP), respectively. An experimental validation using the transient liquid crystal (TLC) thermography method is carried out and proves the effectiveness of the optimization process. However, it is noted that the first-optimized guiding pin-fin exhibits even lower heat transfer at a low Reynolds number of Re = 10,000, particularly in the channel middle region, which is mainly due to the incapable turning flow control in the root region of the wedged channel. To address this issue and further improve the heat transfer performance at low Reynolds numbers, a second-round optimization is performed by specifically adjusting the deflection angle of the selected guiding pin fins near the root region of the wedged channel. This secondary optimization demonstrates significant heat transfer improvements over the whole studied Reynolds number range with a reasonably reduced consumption of computational resources. The total Nusselt number and pressure loss are 69.3% higher and 11.9% lower than those of the baseline circular pin-fin array, respectively, at Re = 50,000. The optimization process proposed in this paper produces a high-performance cooling structure design with elaborate guiding pin-fin arrangements in the wedge-shaped channel, which indicates high heat transfer enhancement and relatively lower pressure loss in the wedged channel for the turbine blade trailing edge.

Evaluation of hard tissue characteristics and calcifications in pulp tissue of hypomineralized permanent molars using micro-computed tomography

ObjectivesTo determine and compare pulp volume, dentin mineral density, presence of microcracks, pulp stones, and accessory canals, as well as their localizations in root regions for hypomineralized and healthy teeth. DesignThis study included 60 extracted permanent molar teeth, categorized into hypomineralized and healthy groups (n = 30 each). The hypomineralized group comprised molar teeth with limited white, yellow, or brown opacities, post-eruptive breakdown, or extensive restoration or crown damage. The healthy group included caries-free molar teeth without these characteristics. Using 3D micro-computed tomography images pulp volume, dentin mineral density, and the presence and locations of microcracks, pulp stones, and accessory canals were determined for each group. Statistical analyses were conducted using Independent T-test and Chi-square test, with significance set at p < 0.05. ResultsThere was no statistically significant difference between the groups regarding pulp volume and microcracks (p ≥ 0.05). The number of accessory canals was significantly greater in the cervical (p = 0.011; p < 0.05) and middle (p = 0.010; p < 0.05) regions of the hypomineralized teeth than healthy teeth. Dentin mineral density was statistically higher in the apical, middle, and cervical root regions (p < 0.001; p < 0.05); however, the number of pulp stones was found to be greater in the cervical regions of healthy teeth compared with those with hypomineralization (p = 0.026; p < 0.05). ConclusionThere were lower dentin mineral density measurements, a decreased number of pulp stones in the cervical region, and a greater number of accessory canals in the middle and cervical regions of hypomineralized teeth compared with healthy teeth.

First Report of Gibellulopsis nigrescens Causing Yellow Wilt on Chinese Cabbage in China.

Chinese cabbage (Brassica rapa L. ssp. pekinensis), in the family Brassicaceae, is a widely planted crop in China valued for its nutritional benefits. In May 2023, wilt symptoms on Chinese cabbage (cv. 'Dongtian118') were observed in several commercial fields located in Sheqi County, (32.47ºN, 112.46ºE), Nanyang, Henan Province, China. A disease survey noted that disease incidence on plants was approximately 20% to 50% within observed fields. Symptoms included yellowing and wilting leaves, and vascular discoloration of the stem bases. To isolate the pathogen, ten symptomatic leaves collected from different diseased cabbage in two field were cut into small pieces (5 × 5 mm), surface disinfected with 75% ethanol for 30 s, then washed three times in sterile water. After drying, tissues were transferred onto potato dextrose agar (PDA). Plates were incubated at 28℃ for 7 days in the dark. Twelve morphologically similar fungal isolates were obtained by single-spore subculture. The mycelia on PDA were originally white, later becoming dark gray due to the formation of masses of melanized chlamydospores after 15 days of culture. Conidiophores were hyaline and most had secondary branches. In addition, verticillate branches had three to four phialides in each whorl. The conidia were hyaline, elliptical or nearly circular, measuring from 3.2 to 9.5 × 2.6 to 3.8 μm (n=40). These morphological characteristics were similar to those described for Gibellulopsis nigrescens (Zare et al. 2007). The isolates were further identified based on PCR amplification. The ITS, GAPDH, and TEF1 genes were amplified using primers ITS1/ITS4, VGPDf2/VGPDr (Inderbitzin et al. 2011) and EF-2/EF1-728F (O'Donnell et al. 1998). BLAST analysis revealed 12 isolates were highly similar to G. nigrescens, with 99.82% similarity for ITS (OR818474, KJ534578), 93.17% similarity for GAPDH (JN188192.1, JN188166.1) and 91.07% similarity for TEF1 (EF543798.1, EF543804.1). Sequences of the representative isolate BC230515 were deposited into NCBI GenBank with accession nos. OR889646 for ITS and PP135039 for GAPDH. Pathogenicity of all 12 isolates was tested on potted Chinese cabbage plants (cv. 'Dongtian118'). Twenty-four healthy Chinese cabbage plants were inoculated by applying a 10 mL conidial suspension (1×107 conidial/mL) at the artificially wounded root region of each plant. Twenty-four control plants wounded similarly were treated with sterile distilled water. All plants were kept in a growth chamber at 22~25°C (day)/18~20°C (night) , 85% relative humidity and a photoperiod of 12 h per day. After 15 days, inoculated plants exhibited wilting symptoms similar to those observed in the field, whereas control plants remained healthy. The pathogenicity test was repeated three times. The associated fungus on the artificially inoculated plants was reisolated from the symptomatic leaves, and its identity was confirmed by PCR with the primers described above. Reisolated G. nigrescens had identical morphological and molecular characteristics to the original isolates, confirming Koch's postulates. To our knowledge, this is the first report of G. nigrescens causing yellowing and wilt of Chinese cabbage in China. G. nigrescens is a destructive pathogen with multiple hosts such as beet (Zhou et al. 2017), alfalfa (Hu et al. 2011), prevention and control measures should be taken in advance.

Effect of sediment erosion on pressure pulsations in a large Pelton turbine

AbstractPelton turbines functioning in sandy river environments often encounter difficulties due to the swift movement of sediment particles, leading to erosion and damage to overflow components. These challenges can result in operational instability, particularly noticeable in large turbines. Pressure pulsation is crucial for turbine stability, and alterations in overflow component profiles caused by sediment erosion can worsen pressure pulsations. This study utilizes numerical simulations to analyze turbine pressure pulsations based on surface profile changes of runner buckets after 2 and 4 years of sediment erosion in a single 500 MW large‐scale Pelton turbine. Our findings reveal that erosion leads to a gradual decrease in pressure pulsation along the bucket's splitting edge from the notch to the root. After 4 years of erosion and wear, the relative pressure pulsation amplitude in the root region increased by more than 530%. Additionally, changes occur in the thickness of the water film in the erosion area on the working surface, disrupting the flow pattern and generating more vortices. This occurrence intensifies the relative pressure pulsation amplitude and reduces bucket stability. The study findings highlight the significant impact of sediment erosion on Pelton turbine pressure pulsation, posing a considerable risk to the unit's operational stability and safety.

Gross and scanning electron microscopic features of the oral cavity (palate, tongue, and sublingual floor) of the Egyptian long-eared hedgehog (Hemiechinus auratus aegyptius)

The study was focused on the anatomical characteristics of the Egyptian long-eared hedgehog's oral cavity by using gross and scanning electron microscopic examinations. The upper lip had an elongated T-shaped snout-like structure. The hard palate had a triangular rostral part (which had a semicircular area and a caudal ridged area with the first 3 or 4 ridges) and a caudal part (which contained seven or eight slightly oblique ridges with raphae). The diamond-incisive papilla is flanked on both sides by a groove and a fissure. The hard palate surface had glandular openings and a microplicae system. The uneven, soft palate's surface had multiple grooves and folds with 12–16 Gemmal papillae. The Gemmal papillary surface had three to four taste pores with microplicae and glandular openings. The dorsal lingual surface had six filiform subtypes: pointed (on the tip, rostral border, and median apical region), triangular (on the lateral apical and circumvallate regions), bifurcated (on the median tip only), leaf-like (on the median body region), branched (on the lateral root region), and small pointed papillae (on the median root). There were two fungiform subtypes: ovals (on the rostral border and lateral region) and rounds (on the median apical region and body). The caudal root part had a triangular arrangement of three circumvallate papillae. In conclusion, the finding confirmed its oral cavity adaptation with its insectivorous feeding habits and Egyptian environment.Graphical

Measurement of Anterior Maxillary Alveolar Ridge Dimension and Assessment of Sagittal Root Position by Cone Beam Computerized Tomography (CBCT)

Maxillary anterior region is the implant site that may require the most rigorous pre-operative assessment as it will have a direct influence on aesthetic outcome and stability of the dental implant. In the present study, CBCT (cone beam computerized tomography) images were used to evaluate alveolar ridge dimension in the maxillary anterior region. This observational radiographic study was done at Nepal Medical College Teaching Hospital. The width of the alveolar bone was measured from the labial cortex to the palatal cortex of the maxillary anterior teeth in mm at the alveolar crest (L1), mid-root (L2), and apical root region (L3) for each tooth. Alveolar height was also measured from the alveolar crest to the floor of the nasal fossa. The Sagittal Root Position (SRP) of the maxillary anterior teeth was also assessed. Results showed that the maximum width of the alveolar bone was seen at L3 of canine and lateral incisor showed least width of alveolar bone width at L1. Maximum alveolar bone height was seen in canines. Males were seen to have increased width of the alveolar bone as compared to the females in all anterior teeth. The most frequent sagittal root position was class I which was seen in 270 (51.4%) of the total teeth examined, which was followed by class IV observed in 210 (40%) of the teeth examined. It could be concluded that for maxillary anterior region, additional regeneration therapy maybe required since class I is the most frequent SRP observed.

Regulation of TGF-β1-induced fibroblast differentiation of human periodontal ligament stem cells through the mutually antagonistic action of ectonucleotide pyrophosphatase/phosphodiesterase 1 and 2.

Human periodontal ligament stem cells (hPDLSCs) differentiate into periodontal ligament (PDL) fibroblasts, osteoblasts, and cementoblasts. To identify inducers of PDL fibroblastic differentiation, monoclonal antibody series were developed a series of against membrane/extracellular matrix (ECM) molecules through decoy immunization. The anti-PDL13 antibody targets ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), renowned for regulating skeletal and soft tissue mineralization. ENPP1 accumulates in the periodontal ligament region of tooth roots, and specifically localizes to the cell boundaries and elongated processes of the fibroblastic cells. As ENPP1 expression increases during fibroblastic differentiation, mineralization induced by tissue-nonspecific alkaline phosphatase (TNAP), a pyrophosphate-degrading enzyme, is completely inhibited. This is consistent with ENPP1 and TNAP acting in opposition, and TGF-β1-induced ENPP1 expression creates an essential environment for PDL fibroblast differentiation. Representative fibroblastic differentiation markers decrease with endogenous ENPP1 inhibition by siRNA and antibody blocking. ENPP2 generates lipid signaling molecules. In contrast to ENPP1, ENPP2 disappears in TGF-β1-induced PDL fibroblasts. Ectopic expression of ENPP2 hinders TGF-β1-induced PDL fibroblastic differentiation. Suppression of ENPP1 and ENPP2 leads to severe defects in undifferentiated and differentiated cells, demonstrating that these two factors play opposing roles in soft and hard tissue differentiation but can complement each other for cell survival. In conclusion, increased ENPP1 is crucial for TGF-β1-induced PDL differentiation, while ENPP2 and TNAP can inhibit ENPP1. ENPP1 and ENPP2 exhibit complementary functions in the cell survival.

Influence of Battery Levels in Cordless LED Light-curing Units on Properties of Resin Cement and Glass Fiber Post Retention.

This study aimed to assess the impact of battery levels in single-peak and multi-peak light-curing units (LCUs) on irradiance, and their effects on glass fiber post push-out bond strength to root dentin and the degree of conversion of dual-cure universal resin cement. Sixty bovine roots underwent endodontic treatment and were randomly distributed into 6 groups (n=10), formed by combining two LCUs (single-peak and multipeak) and three battery levels (100%, 50%, and 10%). A spectrophotometer measured irradiance (mW/ cm2) and spectral irradiance (mW/cm2/nm). Push-out bond strength (PBS) tests occurred at three root regions (cervical, middle, and apical), with optical and scanning electron microscopy for failure mode analysis. Degree of conversion (DC) was evaluated across the root regions. Data were analyzed using two-way repeated measures ANOVA and the Tukey HSD test. The Fisher exact test verified failure modes (α=0.05). As multipeak LCU battery levels decreased, emitted irradiance also diminished, with notable PBS reductions in the apical thirds. Failure modes were influenced by different conditions, primarily exhibiting mixed modes. Battery levels significantly impacted DC in the multipeak LCU, particularly in the cervical region, while the single-peak LCU exhibited DC reduction at the 10% battery level in the cervical region. Emitted irradiance, resin cement DC, and glass fiber post bond strength to root dentin may be influenced by varying cordless LCUs and battery levels.

Microstructural and mechanical characterizations of weld metal of S960QL ultra high strength steel joints obtained with different multi-pass laying techniques using GMAW

Abstract 15 mm thick ultra-high strength steel plates with 960MPa yield strength were welded using different multi-pass laying techniques (i.e., stringer and weaving beads) with torch manipulation. Weld metals obtained were compared using different mechanical (i.e., micro tensile tests and Vickers hardness maps) and microstructural (i.e., optical microscope, scanning electron microscope, X-ray diffraction, electron backscatter diffraction) characterization techniques. Coarser grains and acicular ferrite were observed in weld metal obtained with weaving pass procedure. There were hardness differences in face and root passes of both weld metals. Yet, hardness values were 19% and 11% higher for face and root regions of the joint obtained by stringer pass procedure, respectively. Fractographs of micro tensile test specimens revealed dimples depicting ductile network structure for both joints.

Enzymatic activity of fibroblast activation protein-α is essential for TGF-β1-induced fibroblastic differentiation of human periodontal ligament cells

Human periodontal ligament cells (hPDLCs) contain multipotent postnatal stem cells that can differentiate into PDL fibroblasts, osteoblasts, and cementoblasts. Interaction between the extracellular environment and stem cells is an important factor for differentiation into other progenitor cells. To identify cell surface molecules that induce PDL fibroblastic differentiation, we developed a series of monoclonal antibodies against membrane/ECM molecules. One of these antibodies, an anti-PDL25 antibody, recognizes approximately a 100 kDa protein, and this antigenic molecule accumulates in the periodontal ligament region of tooth roots. By mass spectrometric analysis, we found that the antigenic molecule recognized by the anti-PDL25 antibody is fibroblast activation protein α (FAPα). The expression level of FAPα/PDL25 increased in TGF-β1-induced PDL fibroblasts, and this protein was localized in the cell boundaries and elongated processes of the fibroblastic cells. Ectopic expression of FAPα induced fibroblastic differentiation. In contrast, expression of representative markers for PDL differentiation was decreased by knock down and antibody blocking of FAPα/PDL25. Inhibition of dipeptidyl peptidase activity by a potent FAPα inhibitor dramatically inhibited PDL fibroblastic marker expression but did not affect in cell proliferation and migration.

Refixation of aposterior medial root lesion in combination with centralization by ameniscotibial suture

Refixation of aposterior root lesion of the medial meniscus via atibial drill tunnel and prevention of extrusion using ameniscotibial suture (centralization). Posterior root lesion of the medial meniscus. Grade4 cartilage damage in the corresponding compartment, uncorrected varus or valgus deformities, symptomatic instabilities, extensive degenerative tears apart from the root region. Knee arthroscopy via the high anterolateral standard portal. Diagnostic arthroscopy to check indication. Locate the insertion zone on the tibial plateau and local debridement until the bone of the tibial plateau is visible. Insertion of atargeting device and drilling of atargeting wire into the center of the insertion zone in the area of the intercondylar eminence. Overdrill the target wire with a4.5 mm drill. Reinforcement of the medial meniscus posterior horn with braided suture material. The reinforcing thread is inserted into the bone tunnel via an eyelet wire with athread loop. Optional additional centralization with incision in the middle part of the meniscus. Reinforcement of the meniscus base with braided suture material using the "outside in" technique and fixation of the inner meniscus base at the edge of the tibial plateau using atransosseous extraction suture or asuture anchor. Six weeks nonweight-bearing (0kg), then gradually increased load. Range of motion: 4weeks E/F 0-0-60°, 2weeks 0-0-90°, optionally use of avalgus brace (varus of < 5°). In root lesions of the medial meniscus, transosseous refixation significantly improves knee function (Lysholm, Hospital for Special Surgery, International Knee Documentation Committee, visual analog scale for pain, Tegner, and Knee Injury and Osteoarthritis Outcome scores) and reduces osteoarthritis progression. However, atransosseous suture alone could not significantly reduce postoperative extrusion. However, previous studies have shown that additional centralization can significantly reduce extrusion.

Push-Out Bond Strength of Fiber Posts to Overflared Root Canals in Different Root Regions: Effect of Reinforcement Techniques.

Objectives: This study aimed to investigate the effect of different reinforcement techniques on the push-out bond strength of fiber posts to over-flared root canals. Materials and Methods: Forty-eight extracted human single-canal premolars were endodontically treated, over-flared, and randomly divided into four groups (N=12) including SARC: luting with self-adhesive resin cement, DCC: luting with dual-cure core build-up resin composite, CRR: relining root canal walls with bulk-fill resin composite, and DAP: relining fiber post with bulk-fill resin composite. After 24 hours, the roots were sectioned to obtain three cervical, middle, and apical 3mm slices. The push-out test was performed and failure pattern was examined. Kruskal-Wallis and post-hoc Dunn-Bonferroni tests were used for statistical analysis (P<0.05). Results: In all three regions, the lowest and highest bond strength was found in the SARC and DAP groups, respectively. In the middle region, there was a statistically significant difference between the bond strength of the SARC group and that of the DCC (P=0.044), CRR (P=0.021), and DAP (P<0.001) groups. There was no significant difference in the apical region. The lowest bond strength was observed in the apical region, and the highest was related to the cervical region. Adhesive failure was the most common failure pattern in all groups. Conclusion: Based on our results DCC, CRR and DAP methods increased bond strength in the middle and cervical sections of over-flared root regions. Considering that DCC is the easiest and most practical method, we propose that CRR and DAP can be replaced with this method in clinical procedures.

Periodic cytokinin responses in Lotus japonicus rhizobium infection and nodule development.

Host plants benefit from legume root nodule symbiosis with nitrogen-fixing bacteria under nitrogen-limiting conditions. In this interaction, the hosts must regulate nodule numbers and distribution patterns to control the degree of symbiosis and maintain root growth functions. The host response to symbiotic bacteria occurs discontinuously but repeatedly at the region behind the tip of the growing roots. Here, live-imaging and transcriptome analyses revealed oscillating host gene expression with approximately 6-hour intervals upon bacterial inoculation. Cytokinin response also exhibited a similar oscillation pattern. Cytokinin signaling is crucial to maintaining the periodicity, as observed in cytokinin receptor mutants displaying altered infection foci distribution. This periodic regulation influences the size of the root region responsive to bacteria, as well as the nodulation process progression.

Development and Measurement of a Very Thick Aerodynamic Profile for Wind Turbine Blades

We designed 60% thick airfoil to improve the aerodynamic performance in the root region of wind turbine rotor blades, taking into account current constraints. After an extensive literature review and patent research, a design methodology (including the considerations of simple manufacturing) was set up, and extensive 2D- and 3D-CFD investigations with four codes (Xfoil, MSES, ANSYS fluent, and DLR-tau) were performed, including implementation inside a generic 10 MW test-blade (CIG10MW). Comparison with results from Blade Element Momentum (BEM) methods and the estimation of 3D effects due to the rotating blade were undertaken. One specific shape (with a pronounced flat-back) was selected and tested in the Deutsche WindGuard aeroacoustic Wind Tunnel (DWAA), in Bremerhaven, Germany. A total of 34 polars were measured, included two trailing edge shapes and aerodynamic devices such as vortex generators, gurney flaps, zig-zag tape, and a splitter plate. Considerable changes in lift and drag characteristics were observed due to the use of aerodynamic add-ons. With the studies presented here, we believe we have closed an important technological gap.

Impact of calcium hydroxide and 2-hydroxyisocaproic acid on the microhardness of root dentine: an in vitro study.

To evaluate and compare the effect of calcium hydroxide [Ca(OH)2] and 2-hydroxyisocaproic acid (HICA) on the microhardness of root dentine. Fifty-one matured maxillary central incisors with straight root and type I canal configuration were decoronated to a standardized length of 16mm. The root canals were cleaned and shaped using rotary instruments up to size F5. The tooth samples were then randomly assigned into three groups (n = 17) based on the intracanal medicament placed. Group A: control group with no intracanal medicament, Group B: root canals placed with Ca(OH)2, and Group C: root canals placed with HICA. After 1week, the intracanal medicaments placed within the root canals were removed and the canals were dried. Subsequently, the specimens were split longitudinally into two halves and subjected to the Vickers microhardness test with indentations made at the coronal, middle, and apical-third root regions. The data were analyzed using one-way ANOVA and Tukey's post hoc tests. The control group showed significantly highest microhardness value (P < 0.001), followed by HICA and finally, Ca(OH)2 at the coronal, middle, and apical-third root regions, respectively. Nonetheless, there were no statistically significant differences in microhardness values across different root regions within each group. HICA was found to have a significantly lesser reduction in root dentine microhardness which could be a potential alternative to Ca(OH)2. Nevertheless, future studies are warranted to verify the present outcomes in the clinical setting.

First Report of Phytopythium litorale Causing Root Rot on Kousa Dogwood in Tennessee and the United States.

Kousa dogwood (Cornus kousa) is an economically important woody ornamental crop that exhibits creamy, white, pointed bracts in late spring, and reddish to pink drupe fruits in late summer and fall. It bears shiny dark green leaves that become reddish-purple to scarlet in the fall. In August of 2023, 3-year-old container grown C. kousa var. chinensis plants in a commercial nursery in Warren Co., Tennessee, exhibited severe yellowing, dieback and root rot symptoms (Fig. 1a and 1b). Dark brown to black lesions were observed in the root and crown region of the plants. Disease severity was 40% to 60% of root area affected, and disease incidence was approximately 40% of 1,000 plants. Surface-sterilized (10% NaOCl: 1 min) symptomatic root tissues were plated on V8-PARPH and incubated at 25°C. Sparse aerial mycelium, showing a distinct rosette or faint radiate to chrysanthemum colony pattern, was observed within four days of incubation (Fig. 2). All isolates produced ovoid or subglose, papillate, and proliferating sporangia in grass blade water cultures (Derviş et al. 2020). Sporangia measured as 19.18 to 24.80 µm X 18.08 to 22.16 µm (n = 50) with a length/width ratio of 1.06 to 1.11. Zoospores observed were between 7.07 to 9.98 µm in diameter (n = 50). Oogonia and oospores were not produced. The ribosomal internal transcribed spacer (ITS) and large subunit (LSU), as well as mitochondrial cytochrome oxidase subunit II (COX-II) genetic markers were amplified and sequenced using primer pairs ITS1/ITS4 (White et al. 1990), NL1/NL4 (Baten et al. 2014), and cox2-F/cox2-RC4 (Choi et al. 2015), respectively. The ITS, LSU, and COX-II sequences of isolates FBG6343, FBG6344 (ITS: PP458373 and PP461387; LSU: PP461390 and PP461391; COXII: PP477112 and PP477113) were 100% identical to those of MN306118, HQ643386, and MN206732, respectively. Based on the morphology (Nechwatal and Mendgen 2006) and sequence data, the isolates were identified as Phytopythium litorale (Nechw.) Abad, De Cock, Bala, Robideau, Lodhi & Lévesque. The pathogenicity test was performed on 3-year-old C. kousa var. chinensis plants grown in a 3-gal container to fulfill Koch's postulates. Kousa dogwood plants were drench inoculated (800 ml/plant) with a pathogen slurry (two plates of 7-day-old culture/liter) of isolates FBG6343 and FBG6364 (five plants per isolate). Control plants were drenched with agar slurry without the pathogen. The study was conducted in a greenhouse maintained at 21 to 23°C and 70% relative humidity with a 16-h photoperiod and irrigated twice a day for 2 min using an overhead irrigation system. Forty-five days after inoculation, plants showed dieback symptoms, and dark brown lesions developed in the roots of all inoculated plants. Isolates with morphology and sequences identical to those of FBG6343 and FBG6364 were recovered from root tissues of all inoculated plants. All control plants remained symptom-free, and P. litorale was not isolated from the root tissue. Previously, P. litorale was reported to cause disease on apple, kiwi, planatus, and rhododendron (Derviş et al. 2020; Li et al. 2021; Mert et al. 2020; Polat et al. 2023). To our knowledge, this is the first report of P. litorale causing root rot of kousa dogwood in Tennessee and the United States. Identification of this pathogen as the causal agent is crucial to developing timely management practices.