Objectives: To compare the Ca2+ loss of enamel treated with 38% hydrogen peroxide (HP), 35% HP with light, and 10% carbamide peroxide (CP).
Method And Materials: Ten extracted premolars were sectioned buccolingually and longitudinally so that 4 specimens were obtained from each tooth. The specimens were randomly assigned to 1 of 4 groups to receive the following bleaching agents: 38% HP, 35% HP with light, 10% CP, and no agent (control). The specimens were treated with an artificial caries solution (pH 4) for 16 days; the solution was replaced on days 4, 8, 12, and 16. Calcium concentration was determined by an atomic absorption spectrophotometer. Repeated measures ANOVA was performed on concentrations on days 4, 8, 12, and 16.
Results: At the end of day 16, calcium ions released per square millimeter were calculated cumulatively as follows: 38% HP group: 27.52 +/- 5.22 microg/mL; 35% HP with light group: 25.15 +/- 4.99 microg/mL; 10% CP group: 19.53 +/- 4.03 microg/mL; control group: 18.35 +/- 4.00 microg/mL. The differences between the control group and the 35% HP with light group and between the control group and 38% HP group were statistically significant. Although demineralization differences were observed between the control group and the 10% CP group, this difference was not significant.
Conclusions: It can be concluded that 35% HP with light and 38% HP may cause significantly more loss of Ca2+ from the enamel surfaces than 10% CP. Also, 10% CP does not vary significantly from the control.
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Front Psychiatry
January 2025
School of Public Health, Suzhou Medical College of Soochow University, Suzhou, China.
Introduction: This study aimed to examine the associations of exposure to light while sleeping at night and different sleep durations with attention-deficit/hyperactivity disorder (ADHD) among preschool children in China.
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Background and objective Neck pain (NP) is a prevalent musculoskeletal disorder (MSD) among office workers (OWs) and significantly affects productivity and quality of life (QALY). However, the effect of NP on office employees in Saudi Arabia remains unclear. In light of this, we aimed to evaluate the impact of NP and its associated factors on OWs in the Jazan region, Saudi Arabia.
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Division of Plastic and Reconstructive Surgery, Icahn School of Medicine at Mount, Sinai, New York, NY, USA.
Background: Hand surgery is a competitive fellowship that draws applicants from orthopedic, plastic, and general surgery. In 2010, recommendations from the American Academy of Orthopaedic Surgeons (AAOS) Board of Specialty Societies Match Oversight Committee and the American Society of Plastic Surgeons (ASPS) Plastic Surgery Workforce Task Force led to significant reforms to their respective workforces and training. This study characterizes trends in hand fellowship applicants and programs since these recommendations (2010-2023).
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January 2024
Friedman Brain Institute, Departments of Pathology, Neuroscience, and Artificial Intelligence & Human Health, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Cryopreservation, the preservation of tissues at subzero temperatures, is a mainstay of brain banking that allows for the storage of brain tissue without the use of chemical fixatives. This is particularly important for molecular studies that are incompatible with tissue fixation. However, brain tissue is vulnerable to various forms of damage during the cryopreservation process, in particular due to the phase transition of water from a liquid to a solid state with the formation of ice crystals, which can disrupt cellular morphology.
View Article and Find Full Text PDFACS Chem Biol
January 2025
Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States.
OaPAC, the photoactivated adenylyl cyclase from , is composed of a blue light using FAD (BLUF) domain fused to an adenylate cyclase (AC) domain. Since both the BLUF and AC domains are part of the same protein, OaPAC is a model for understanding how the ultrafast modulation of the chromophore binding pocket caused by photoexcitation results in the activation of the output domain on the μs-s time scale. In the present work, we use unnatural amino acid mutagenesis to identify specific sites in the protein that are involved in transducing the signal from the FAD binding site to the ATP binding site.
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