Evaluation of Tooth Surface Irradiated With Erbium: Yttrium Aluminum Garnet and Carbon Dioxide Lasers by Atomic Force Microscopy

Introduction: T Laser irradiation of dentin surface can affect its surface topography and roughness. Atomic force microscopy (AFM) is among the most efficient tools for determination of surface topography of natural biomolecules in nano-scales. Surface roughness affects plaque retention especially in the cervical region. This study aimed to assess and compare the obstruction of dentinal tubules and dentin surface roughness after irradiation of erbium: yttrium aluminum garnet (Er:YAG )and CO2 lasers for treatment of dentin hypersensitivity (DH) .Methods: Five disc-shaped samples measuring 3 mm in thickness were fabricated by horizontal sectioning of the cervical area of five extracted human molars using a low speed saw. Each disc was divided into 3 segments by a bur under water coolant. The three segments of each disc were placed on a glass slide. First segment: No intervention (control group). Second segment: Er:YAG laser irradiation (2940 nm, 50 mJ, 10 Hz and 0.5 W, 30 seconds) along with water coolant. Third segment: CO2 laser irradiation (10600 nm, 80 Hz, 0.3 W, 30 seconds) along with water coolant. After that, the surfaces underwent non-contact AFM. The diameters of dentinal tubules as well as surface roughness were then measured and statistically analyzed using repeated measures ANOVA.Results: The surface roughness parameters (Ra, Rq) showed increased roughness after laser irradiation and this increase in roughness after Er:YAG laser application was significant compared to the control group (P = 0.048). However, CO2 laser caused no significant change in surface roughness. Also, after Er:YAG laser application, fewer open dentinal tubules were observed and the remaining open tubules had a smaller diameter.Conclusion: Based on the results, Er:YAG laser irradiation obstructs the dentinal tubules and increases the dentin surface roughness. This increase in surface roughness can cause microbial plaque retention and increase the risk of caries and periodontal disease. Application of CO2 laser (compared to Er:YAG) lead to slight but clinically significant obstruction of dentinal tubules and surface roughnes

In Vitro Anti-tumor Effects of Photodynamic Therapy on Oral Squamous Cell Carcinoma: A Review

Background: Due to the increasing prevalence and high mortality rate of oral cancer and problems of routine treatments, more recent modalities like photodynamic therapy (PDT) have been developed. PDT can effectively destroy tumor cells with minimum side effects. Research on the in vitro effects of PDT may be helpful in determining the molecular mechanisms responsible for its effectiveness, and can lead to development of more efficient techniques. The aim of this study was to review the use of PDT on oral cancer among in-vitro studies. Materials and methods: A literature search for English articles on photodynamic therapy in oral squamous cell carcinoma (SCC) was performed using PubMed, Scopus, Google Scholar, and Web of Science databases. The search string included both MeSH terms and relevant text words. Data extraction was performed based on the inclusion/exclusion criteria. Results: Forty-one studies were selected after reviewing 567 articles. According to the extracted data, the tongue, 5-aminolevulinic acid, viability/cytotoxicity and apoptosis, laser, 600-700nm, were the most common cell-line-source, photosensitizer, assessed outcome, light source, and wavelength respectively used in the studies. Reduced viability and increase apoptosis were the most reported outcomes. Conclusion: PDT showed generally promising effects on reducing the viability of different oral cancer cells. Different cell lines, from various sources or even those originating from the same location, sometimes responded differently to the same protocol. Due to the favorable results obtained from using natural photosensitizers and considering their additional health-promoting properties, their use in future investigations with different cell lines and light specifications is recommended

Evaluation of Hemoglobin A1c Criteria to Assess Preoperative Diabetes Risk in Cardiac Surgery Patients

Objective: Hemoglobin A1c (A1C) has recently been recommended for diagnosing diabetes mellitus and diabetes risk (prediabetes). Its performance compared with fasting plasma glucose (FPG) and 2-h post-glucose load (2HPG) is not well delineated. We compared the performance of A1C with that of FPG and 2HPG in preoperative cardiac surgery patients. Methods: Data from 92 patients without a history of diabetes were analyzed. Patients were classified with diabetes or prediabetes using established cutoffs for FPG, 2HPG, and A1C. Sensitivity and specificity of the new A1C criteria were evaluated. Results: All patients diagnosed with diabetes by A1C also had impaired fasting glucose, impaired glucose tolerance, or diabetes by other criteria. Using FPG as the reference, sensitivity and specificity of A1C for diagnosing diabetes were 50% and 96%, and using 2HPG as the reference they were 25% and 95%. Sensitivity and specificity for identifying prediabetes with FPG as the reference were 51% and 51%, respectively, and with 2HPG were 53% and 51%, respectively. One-third each of patients with prediabetes was identified using FPG, A1C, or both. When testing A1C and FPG concurrently, the sensitivity of diagnosing dysglycemia increased to 93% stipulating one or both tests are abnormal; specificity increased to 100% if both tests were required to be abnormal. Conclusions: In patients before cardiac surgery, A1C criteria identified the largest number of patients with diabetes and prediabetes. For diagnosing prediabetes, A1C and FPG were discordant and characterized different groups of patients, therefore altering the distribution of diabetes risk. Simultaneous measurement of FGP and A1C may be a more sensitive and specific tool for identifying high-risk individuals with diabetes and prediabetes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90436/1/dia-2E2011-2E0074.pd

Comparative Evaluation of Microtensile Bond Strength of Three Adhesive Systems

Objectives: The aim of this study was to assess the microtensile bond strength of three universal adhesives to dentin and enamel. Materials and Methods: Sixty extracted human third molar teeth were chosen and divided into six groups regarding the adhesive (G-Premio Bond, Clearfil S3 Bond or Single Bond) and tooth surface. All the applied bonding agents were universal adhesives. The teeth were polished and the adhesives were applied; then the teeth were restored with composite resin. The samples were mounted in acrylic resin and sectioned. The specimens were subjected to a universal testing machine and the microtensile bond strength was measured. The failure mode of each specimen was determined under a stereomicroscope. Data were analyzed using two-way ANOVA (α=0.05). Results: The microtensile bond strength of G-Premio Bond to enamel and dentin was 11.79±8.27 and 17.55±9.47 MPa, respectively which was not significantly different from the values in Single Bond group (15.59±10.66 and 17.19±10.09 MPa to enamel and dentin, respectively; P>0.05). However, the values for Clearfil S3 Bond were 7.11±4.23 and 7.88±8.83 MPa to enamel and dentin, respectively, which were significantly lower than the values for G-Premio Bond (P<0.05). Scanning electron microscopic (SEM) images showed that the adhesive failure was dominant in both enamel and dentin groups and in all adhesive systems. Conclusion: G-Premio Bond and Single Bond provided higher microtensile bond strength compared with Clearfil S3 Bond. Universal adhesives with their acceptable performance can be applied in self-etch mode on both enamel and dentin

The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. VI. The Star Formation History and Dust Production in Andromeda IX

We present a photometric study of the resolved stellar populations in Andromeda IX (And IX), the closest satellite to M31, a metal-poor and low-mass dwarf spheroidal galaxy. We estimate a distance modulus of $24.56^{+0.05}_{-0.15}$ mag based on the tip of the red giant branch. By probing the variability of asymptotic giant branch stars, we study the star formation history of And IX. We identified 50 long-period variables (LPVs) in And IX using the Isaac Newton Telescope in two filters, the Sloan $i'$ and Harris $V$. In this study, we selected LPVs within two half-light radii with amplitudes in the range of 0.2–2.20 mag. It is found that the peak of star formation reaches ${\sim}8.2 {\pm} 3.1 {\times} 10{^-4}M_{\odot} yr^{-1}$ at ≈6 Gyr ago. Our findings suggest an outside-in galaxy formation scenario for And IX with a quenching occurring $3.65^{+1.52}_{-0.13}$ Gyr ago with a star formation rate (SFR) in the order of $2.0 {\times} 10^{-4}M_{\odot} yr^{-1}$ at redshift <0.5. We calculate the total stellar mass by integrating the SFR within two half-light radii ${\sim}3.0 {\times} 10^{5}M_{\odot}$. By employing spectral energy distribution fitting for the observed LPVs in And IX, we evaluate a mass-loss rate in the range of $10^{-7} ≤ M ≤ 10^{-5} M_{\odot} yr^{-1}$. Finally, we show that the total mass deposition to the interstellar medium (ISM) is ${\sim}2.4 {\times} 10^{-4} M_{\odot} yr^{-1}$ from the C- and O-rich types of dust-enshrouded LPVs. The ratio of the total mass returned to the ISM by LPVs to the total stellar mass is ${\sim}8.0 {\times} 10^{-10} yr^{-1}$, and so at this rate it would take ∼1 Gyr to reproduce this galaxy

Stridor Due to an Unsuspected Parathyroid Cyst in a Thirty-Two-Year-Old Woman with Goiter

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85084/1/thy_2009_0413.pd

Characteristics and performance of Cd, Ni, and Pb bio-adsorption using Callinectes sapidus biomass: real wastewater treatment

In the current study, the bio-adsorption potential of Callinectes sapidus biomass for control of cadmium, nickel, and lead from the aqueous stream was assessed. Spectrum analysis of FTIR, AFM, EDAX, mapping, SEM, TEM, and XRF was used to study the properties of the C. sapidus biomass. The XRF analysis revealed that C. sapidus bio-adsorbent has various effective metal oxides that can be useful to adsorb pollutants. The best model to describe the equilibrium data was Freundlich isotherm. The Langmuir bio-adsorption capacity was reported at 31.44 mg g −1 , 29.23 mg g −1 , and 29.15 mg g −1 for lead, cadmium, and nickel ions, respectively. Pseudo-first-order and pseudo-second-order kinetic models were studied to test the kinetic behavior of the process. An intra-particle diffusion model was used to determine the effective mechanisms involved in the bio-adsorption. Based on t 1/2 , it can be concluded that the equilibrium speed of the bio-adsorption process is high. The thermodynamic study showed that the metal bio-adsorption process using C. sapidus biomass is exothermic and spontaneous. The field applicability of the crab bio-adsorbent for eliminating concurrently several contaminants (metal ions, antibiotics, sulfate, nitrate, and ammonium) from an actual wastewater was successfully examine

Neurochemical Insights Into COVID-19-related Anosmia: A Commentary Study

In the wake of the COVID-19 pandemic, anosmia, the loss of the sense of smell, has emerged as a curious and widespread symptom. While the sense of smell in many individuals has eventually recovered, some grapple with anosmia for extended periods. In our recent study entitled "Magnetic Resonance Spectroscopy Findings of Brain Olfactory Areas in Patients With COVID-19-Related Anosmia," we embarked on a journey to explore the neurochemical underpinnings of anosmia in COVID-19 patients. This commentary extends our original research, providing insights into the evolving landscape of COVID-19-related anosmia and its implications