Targeting Telomere Biology in Acute Lymphoblastic Leukemia

Increased cell proliferation is a hallmark of acute lymphoblastic leukemia (ALL), and genetic alterations driving clonal proliferation have been identified as prognostic factors. To evaluate replicative history and its potential prognostic value, we determined telomere length (TL) in lymphoblasts, B-, and T-lymphocytes, and measured telomerase activity (TA) in leukocytes of patients with ALL. In addition, we evaluated the potential to suppress the in vitro growth of B-ALL cells by the telomerase inhibitor imetelstat. We found a significantly lower TL in lymphoblasts (4.3 kb in pediatric and 2.3 kb in adult patients with ALL) compared to B- and T-lymphocytes (8.0 kb and 8.2 kb in pediatric, and 6.4 kb and 5.5 kb in adult patients with ALL). TA in leukocytes was 3.2 TA/C for pediatric and 0.7 TA/C for adult patients. Notably, patients with high-risk pediatric ALL had a significantly higher TA of 6.6 TA/C compared to non-high-risk patients with 2.2 TA/C. The inhibition of telomerase with imetelstat ex vivo led to significant dose-dependent apoptosis of B-ALL cells. These results suggest that TL reflects clonal expansion and indicate that elevated TA correlates with high-risk pediatric ALL. In addition, telomerase inhibition induces apoptosis of B-ALL cells cultured in vitro. TL and TA might complement established markers for the identification of patients with high-risk ALL. Moreover, TA seems to be an effective therapeutic target; hence, telomerase inhibitors, such as imetelstat, may augment standard ALL treatment.     

Effect of mechanical and air-particle cleansing protocols of provisional cement on immediate dentin sealing layer and subsequent adhesion of resin composite cement

Immediate dentin sealing (IDS) could avoid contamination of dentin from impression material and provisional cement but prior to final cementation of indirect restorations, removal of the provisional cement may damage the IDS. The objectives of this study were to investigate the effect of mechanical and air-particle cleansing protocols of provisional cement on IDS layer and subsequent adhesion of resin composite cement. The cuspal dentin surfaces of human third molars (N = 21, n_quadrant = 84) were exposed by a low-speed diamond saw under water cooling and conditioned with an adhesive system based on the three-step etch and rinse technique (OptiBond FL). Provisional cement (Freegenol) was applied on each specimen. They were then randomly divided into six subgroups where the provisional cement was removed either by (1) air-borne particle abrasion with 50-μm Al₂O₃ particles at 2 bar (AL2), (2) air-borne particle abrasion with 50-μm Al₂O₃ particles at 3.5 bar (AL3.5), (3) air-borne particle abrasion with 30-μm SiO₂ particles at 2 bar (SL2), (4) air-borne particle abrasion with 30-μm SiO₂ particles at 3.5 bar (SL3.5), (5) prophylaxy paste (Cleanic) (PP) or (6) pumice-water slurry (PW) at 1500 rpm for 15 s. The dentin surface on each tooth was assigned to four quadrants and each quadrant received the cleansing methods in a clockwise sequence. The non-contaminated and non-cleansed teeth acted as the control (C). Two separate teeth, contaminated and cleansed according to six cleansing protocols, were allocated for scanning electron microscopy (SEM) analysis (×2000). The dentin surfaces in each quadrant received resin composite luting cement (Variolink II, Ivoclar Vivadent) incrementally in a polyethylene mould (diameter: 1 mm²; height: 4 mm) and photopolymerized. The specimens were stored in distilled water for 24 h at 37 °C until the testing procedures and then shear force was applied to the adhesive interface until failure occurred in a universal testing machine (0.5 mm/min). Microshear bond (μSBS) was calculated by dividing the maximum load (N) by the bonding surface area of the resin cement. Failure types were analysed using optical microscope and SEM. Data (MPa) were analysed using one-way ANOVA (α = 0.05). Two-parameter Weibull distribution values including the Weibull modulus, scale (m) and shape (₀), values were calculated. Mean μSBS results (MPa) showed a significant difference between the experimental groups (p = 0.011) and were in a descending order as follows: C (8 ± 2.3)^a < AL2 (6.7 ± 2.4)^b < PP (6.9 ± 2)^b < PW (6.5 ± 2.1)^b < AL3.5 (5.8 ± 1.1)^b < SL2 (5.3 ± 1)^b < SL3.5 (5.2 ± 1)^b. Failure types were predominantly mixed failure type between the dentin and the adhesive resin which is a combination of adhesive and cohesive failures in the adhesive resin. Cohesive failure in the dentin was not observed in any of the groups. Weibull distribution presented lower shape (₀) for C (3.9), AL2 (3.2), PP (3.5) and PW (3.6). SEM analysis showed rough surfaces especially in the air-abraded groups whereas mechanical cleansing methods presented smoother surfaces and partially covered by particle remnants all of which occluded the dentin tubuli.     

Improvement of Interfacial Adhesion of Glass Fiber/Epoxy Composite by Using Plasma Polymerized Glass Fibers

This study intends to produce plasma polymer thin films of γ-glycidoxypropyltrimethoxysilane (γ-GPS) on glass fibers in order to improve interfacial adhesion of glass fiber-reinforced epoxy composites. A low frequency (LF) plasma generator was used for the plasma polymerization of γ-GPS on the surface of glass fibers at different plasma powers and exposure times. X-ray photoelectron spectroscopy (XPS) and SEM analyses of plasma polymerized glass fibers were conducted to obtain some information about surface properties of glass fibers. Interlaminar shear strength (ILSS) values and interfacial shear strength (IFSS) of composites reinforced with plasma polymerized glass fiber were evaluated. The ILSS and IFSS values of non-plasma polymerized glass fiber-reinforced epoxy composite were increased 110 and 53%, respectively, after plasma polymerization of γ-GPS at a plasma power of 60 W for 30 min. The improvement of interfacial adhesion was also confirmed by SEM observations of fractured surface of the composites.     

Total Antioxidant Activity and Total Phenolic Contents in Different Turkish Eggplant (Solanum Melongena L.) Cultivars

In this study, total water soluble antioxidant activity and phenolic content of 26 eggplant ( Solanum melongena L. ) cultivars were investigated. Total water soluble antioxidant activity of the cultivars varied from 2664 to 8247 μmolTrolox/kg, which is a 3.1-fold difference. Cultivars also showed significant variation for total phenolic contents ranging from 615 to 1376 mg/kg, a 2.2-fold difference. The two traits were significantly correlated and results of this study suggested that breeders can use the information to develop eggplant cultivars with high antioxidant activity.     

Photovoltaic solar cell properties of CdxZn1−xO films prepared by sol–gel method

Cd_xZn_1−xO films have been deposited by sol–gel spin-coating method onto glass substrates. The Cd/Zn ratio in solution was changed from 0 to 1. Zinc acetate dehydrates, cadmium acetate dehydrates, 2-methoxyethanol and monoethanolamine were used as a starting material (zinc and cadmium), solvent and stabilizer, respectively. The crystal structure and orientation of the films were investigated by X-ray diffraction (XRD) patterns. XRD patterns show that the films are polycrystalline nature. As x varies from 0 to 1, it was observed that the crystal structure changed from wurtzite (ZnO) to cubic (CdO) structure. The optical properties of these films have been investigated by means of the optical transmittance and reflectance spectra. A significant change in optical absorption edge, optical band gap and optical constant with variation in composition was observed.     

PET纤维纺丝中采用纳米微粒添加剂的相关问题

在许多市场和用途中采用尺寸更小的微粒材料的趋势正明显增长。在纤维纺丝中加入整个范围的添加剂（包含纳米微粒）开发具有特殊性能纺织品时存在着一些争论。纤维纺丝中的主要问题是开发低含量的添加剂。     

The behavior of chemical and electrochemical Ag deposition on FeNi‐mesh cathodes in Al‐air battery

In this study, FeNi/Ag cathode was made for aluminium air battery. For this purpose, FeNi‐mesh electrode surfaces were treated in two different ways (chemical and electrochemical deposition), with noble metal silver having a high catalytic activity. The optimum time for both methods was determined. The electrochemical properties were determined using cyclic voltammogram (CV), electrochemical impedance spectroscopy (EIS), and current‐potential (i‐t) curves. The battery performance tests were performed, and surface characteristics of the electrodes were determined with a scanning electron microscope an X‐ray diffraction method (SEM‐EDS and XRD). This study shows that FeNi mesh electrodes chemically and electrochemically deposited with silver are alternative for oxygen‐reducing cathodes for aluminium air battery because they are cheap, practical, and effective. The electrochemical (FeNi/Ag‐ED) deposition is better than the chemical (FeNi/Ag‐CD) deposition in terms of both economical and higher battery potential.     

Fabrication of basalt embedded composite fiber membrane using electrospinning method and response surface methodology

In this study, a novel basalt embedded fiber membranes was prepared by the electrospinning method. The effects of the feed rate, voltage, tip to collector distance, and the basalt content on the prepared composite fiber membranes were investigated and optimized using the response surface method. Four models were built to compare the fibers in terms of deionized water flux (DWF), activated sludge flux, chemical oxygen demand (COD) removal, and porosity of fiber membranes. All the developed models were significant and adequately precise. The maximum flux of DWF was obtained when the voltage was 17.25 kV, the tip to collector distance of 19 cm, and a basalt content in polymer of 1.25%. COD removal decreased at higher voltage values as the feed rate increased. The porosity, pore size, and the contact angle values decreased for basalt embedded fiber membrane. The increases in the basalt percentage in polymer increased the hydrophilicity of the fiber. The flux decline for the basalt embedded fiber membrane was compared with the pristine fiber membrane. The permeate fluxes of pristine and basalt embedded fiber membranes were 42.3 and 59.6 L/m²/h, respectively. The biofouling performances of pristine and basalt embedded fiber membranes were also examined. Irreversible fouling decreased from 42.9% to 8.0%, and reversible fouling increased from 56.5% to 91.1% after modification of the membrane with basalt powder. Scanning electron microscopy with energy dispersive X-ray analysis (SEM–EDX) analysis showed that basalt powder was successfully embedded into polyether sulfone polymer.     

The variational anatomy of the external aperture of the human vestibular aqueduct

A study was undertaken to demonstrate the variational anatomy of the external aperture of the vestibular aqueduct in 90 human temporal bones obtained from 58 cadavers. Topographic landmarks of the posterior surface of the petrous bone are useful for general orientation and include the external aperture of the vestibular aqueduct, internal auditory meatus, sigmoid sinus, subarcuate fossa, superior petrosal sinus and cochlear canaliculus. We determined the mean distances from the external aperture of vestibular aqueduct to the above structures to be 10.98, 11.21, 9.42, 10.27 and 13.90 mm, respectively. Furthermore, the length of the external aperture of the vestibular aqueduct revealed significant differences between the right and left sides. The distances between the EAVA and certain anatomical structures on the posterior surface of the temporal bone should be taken into consideration during surgery. Knowing the variability of the position of the external aperture of the vestibular aqueduct may help surgeons avoid traumatizing, and thus producing inadvertent lesions to the hearing mechanism.     

Intraoral repair of chipped or fractured veneered zirconia crowns and fixed dental prosthesis: clinical guidelines based on literature review

This article aimed to review the susceptibility to chipping, influencing factors, current protocols for intraoral repair and provide the clinicians with guidelines for repairing. Peer-reviewed literature in English published between 01/01/2000 and 30/06/2017 was electronically searched using PubMed and Google Scholar, followed by manual search of the scientific literature. Multiple key words and their combinations (‘Zirconium’, ‘Zirconia’, ‘Intraoral’, ‘Repair’, ‘Chipping’, ‘Fracture’, ‘Bonding’, and ‘Surface treatment’) and different search strategies were employed for sample selection. The initial search resulted in 189 articles, of which 98 were included in this review. The chipping rates of veneered zirconia-based restorations have been reported range between 0 and 44%. Researchers and clinicians were in favor of the intraoral repair of chipped veneered zirconia-based restorations. While various intraoral repair protocols were available based on the severity of chipping, decisions about intraoral repair were based on the clinical situation, availability/accessibility of repair kits, survival/success rate of repairing, and patient concerns. Intraoral repair seems to be a promising option to correct moderate size of chipping, and its success largely depends on the surface treatment methods used for the fractured surfaces. Hydrofluoric acid etching of the veneering porcelain followed by silanization and air-abrasion of the zirconia framework and then MDP priming have been recommended to create durable bonds. This review suggests that intraoral repair of chipped zirconia-based restorations offers a satisfying option for the patient when restoration replacement is not an option. Treatments for the fracture surface are the most important factors influencing the longevity of repaired zirconia-based restorations.