Ruthenium-Encapsulated Porphyrinic Organic Polymer as a Photoresponsive Oxidoreductase Mimetic Nanozyme for Colorimetric Sensing.

The advantages of porosity and stable unpaired electrons of porphyrinic organic polymers (POPs) with free radicals are exclusive and potentially practical functionalities and combining the semiconductor-like characteristics of these materials and metal ions has been an effective way to assemble an efficient photocatalytic system. Herein, a new ruthenium (Ru) ion-encapsulated porphyrinic organic polymer (POP/Ru) is facilely synthesized as a proper photoresponsive nanozyme with unique photo-oxidase properties. Surprisingly, the proposed POP/Ru revealed outstanding photoresponsive oxidase-mimicking activity due to the synergetic effect of the integration of Ru and π-electrons of POP, which boosts charge separation and transport. POP/Ru was applied to the oxidation of o-phenylenediamine (o-PDA) as a chromogenic probe for producing a colorimetric signal. The kinetic study reveals that these photo-oxidase mimics have a significant affinity for the o-PDA chromogenic agent owing to a lower Km and superior Vmax. Further findings demonstrate that the presence of the l-arginine (l-Arg) target causes an inhibition effect on the photo-nanozymatic colorimetry of POP/Ru. This research develops the applications of the comprehensive colorimetric strategy for ultrasensitive l-Arg monitoring with a limit of detection (LOD) of 15.2 nM in the dynamic range of 4.0 nM-340 µM and illuminates that the proposed photo-oxidase nanozyme as a visual strategy is feasible in l-Arg environmentally friendly colorimetric detection in juice samples.

Viability and Reproducibility of Periodontal Ligament Cells on Avulsed Teeth Stored in Ham's F-10 Solution.

OBJECTIVES: The purpose of the present study was to evaluate the efficacy of Ham's F-10 in maintaining the viability and reproducibility of PDL cells on avulsed teeth. STUDY DESIGN: Sixty mature, healthy extracted premolars were used. The experimental media used were Ham's F-10, Hank's balanced salt solution (HBSS), skim milk, and tap water (n = 15 specimens each). Cell viability was tested after 1, 3, 6, and 24 h storage in medium. Cell reproducibility was assessed by methyl-thiazol-tetrazolium (MTT) assay after1, 3, and 6 h storage in Ham's F-10, HBSS, and tap water. RESULTS: The viability of PDL cells stored in Ham's F-10 and HBSS was significantly greater than that of samples stored in milk and tap water at all-time points (P<0.001). A significant difference in cell viability between samples stored in Ham's F-10 and HBSS (favoring the former) was observed only at 6h (P=0.04). MTT assay results were significantly better for samples stored in Ham's F-10 and HBSS than for those stored in tap water (P<0.001), with a significant difference between Ham's F-10 and HBSS observed only at 3h (P<0.001). CONCLUSIONS: Ham's F-10 is capable of preserving PDL cells viable and reproducible better than milk and tap water and similar to HBSS.

Atezolizumab and Bevacizumab Targeted-Therapy in Advanced Hepatocellular Carcinoma: A Systematic Review of Cost-effectiveness Analyses.

BACKGROUND: Atezolizumab (ATZ) plus bevacizumab (BVC) co-administration is one of the newest systemic interventions in advanced hepatocellular carcinoma (AHCC). This treatment approach is more costly and effective than other therapeutic interventions, significantly improving AHCC survival and health-related quality of life. AIM: This economic study aimed to systematically review all cost-effectiveness analyses of ATZ/BVC combination in AHCC. METHOD: A comprehensive search in scientific databases was performed using a highly sensitive syntax to find all related economic evaluations. The target population was AHCC patients. The intervention was ATZ/BVC, which was compared with sorafenib, nivolumab, and other anticancer strategies. We included studies that reported quality-adjusted life-years (QALYs) and/or life-years, costs, and incremental cost-effectiveness ratio (ICER), and finally, the characteristics of included studies were categorized. RESULTS: Out of 315 identified records, 12 cost-effectiveness analyses were eligible for inclusion in the systematic review. Treatment costs were significantly higher with ATZ/BVC in all studies (from 61,397 to 253,687 USD/patient compared to sorafenib and nivolumab, respectively). Incremental QALYs/patient varied from 0.35 to 0.86 compared to sintilimab/BVC and sorafenib. Although ICERs for drugs varied widely, all were united in the lack of cost-effectiveness of the ATZ/BVC. The willingness-to-pay threshold in all studies was lower than the ICER, which indicated a reluctance to pay for this treatment strategy by the health systems. CONCLUSION: The ATZ/BVC combination is an expensive targeted immunotherapy in AHCC. Significant discounts in ATZ and BVC prices are essential for this novel approach to be cost-effective and extensively used.

Photo-responsive oxidase-like nanozyme based on a vanadium-docked porphyrinic covalent organic framework for colorimetric L-Arginine sensing.

This study reports the development of a vanadium-docked porphyrinic covalent organic framework as a novel class of highly polar photoactive materials. Thanks to its extended π-electron conjugation and high chemical stabilities, this framework can serve as an oxidase-Like photo-nanozyme for photocatalytic oxidation of o-phenylenediamine (o-PDA) and a colorimetric substrate for the production of the yellow-colored oxidized o-PDA (o-PDAox). The physicochemical properties of the as-prepared photo-nanozyme were characterized by several analytical techniques. Its enhanced light harvesting and charge separation and transfer were also verified by electrochemical and spectroscopic analysis. This photo-nonenzymatic colorimetric assay was applied for the sensitive L-Arginine (L-Arg) detection as a typical amino acid in the linear range of 8.1 nM-330 µM with a limit of detection (LOD) of 3.5 nM. The findings of this research confirmed the safety and feasibility of the proposed photo-nonenzymatic colorimetric sensing strategy for the detection of L-Arg and other similar biomolecules in food samples. Kinetic investigation revealed that the photo-responsive oxidase mimic exhibits satisfactory Km (0.47 mM) and Vmax (42.0 µM/s) values. This work broadened our insight into the development of modified porphyrinic-COF-based visible light-responsive oxidase-like photo-nanozyme for environmentally friendly colorimetric biosensing.

The relationship between fear of Covid-19 and obsessive-compulsive disorder.

BACKGROUND: The coronavirus pandemic and health measures related to it have led to an increase in mental health problems. The relatively high incidence of the disease and its mortality rate created anxiety in society. This study aimed to determine the prevalence of fear of the coronavirus (COVID-19) and its relationship with obsessive-compulsive disorder in patients who attended the outpatient clinic of Besat Hospital in Hamadan. METHODS: In this cross-sectional descriptive study, 320 patients who attended the outpatient clinic of Besat Hospital in Hamadan were selected by random sampling method in 2021. Data were collected using the Fear of the coronavirus (COVID-19) questionnaire and obsessive-compulsive disorder scale and analyzed using SPSS software (V16). They were analyzed using Pearson correlation coefficient and independent t-test. RESULTS: The mean ± SD age of the subjects was 34.14 ± 9.30 years and 65% of the study subjects were women. The mean ± SD score on the obsessive-compulsive disorder scale was 32.90 ± 19.87 and the mean ± SD score for fear of coronavirus was 16.82 ± 5.79. The contamination dimension of OCD had the highest score of 9.04 ± 5.46 and stealing had the lowest score of 0.10 ± 0.49. The mean fear of COVID-19 in people who had a history of obsessive-compulsive disorder before the quarantine was significantly higher than in those who did not have it (P = 0.002). Along with the increasing fear of coronavirus scale score, the score of obsessive-compulsive disorders increased except for the stealing dimension (P < 0.001). CONCLUSIONS: The results of the study showed that there was a moderate level of fear of COVID-19 among the study population. Also, a relatively high proportion of study subjects had a weak manifestation of OCD. It seems that two years after the beginning of the Covid-19 coronavirus pandemic, people have adapted to the conditions, and their fear of the disease is reduced.

Regression equations for predicting the size of unerupted canines and premolars in an Iranian population: a pilot study.

AIM: The aim of this pilot study was to evaluate equations for predicting the size of unerupted canines and premolars during the mixed dentition period in an Iranian population. METHODS AND MATERIALS: This cross-sectional analysis was performed on 106 subjects (52 girls, 54 boys, aged 13-15 years). Data were obtained from dental cast by making direct measurements of the maximum mesiodistal widths of all mandibular and maxillary incisors, canines, premolars, and first molars with an electronic digital sliding caliper, with an accuracy of ± 0.02 mm and repeatability of ± 0.01 mm. The results were statistically analyzed using Student t tests, Pearson product-moment coefficients, and ANOVA tests. Correlation coefficients (r) and error variance of estimates were determined using a significance level of p<0.05. RESULTS: No significant differences were found between the mesiodistal tooth widths of males and females in this Iranian population. The highest correlation was between the sum of the mesiodistal width of canines and premolars in the maxilla with the mesiodistal width of the mandibular first molars and maxillary central incisors (r = 0.742). A moderate correlation was obtained in the mandible (r = 0.665). Approximations were developed to predict the size of the unerupted canines and premolars in both jaws (in the maxilla, Y = 0.740X + 14.271, or the simplified formula, Y = 3/4X + 14; for the mandibular arch, Y = 0.658X + 16.353, or the simplified formula, Y = 2/3 X + 16). CONCLUSION: The strongest correlation was found for the sum of the mesiodistal width of canines and premolars in the maxilla with the mesiodistal width of the mandibular first molars and maxillary central incisors in the maxillary analysis (r = 0.742). A moderate correlation was found in the mandible for the sum of the mesiodistal width of canines and premolars with the mesiodistal width of the mandibular first molars and maxillary central incisors (r = 0.665). CLINICAL SIGNIFICANCE: The simplified equations proposed for the maxillary arch (Y = 3/4 X + 14) and for the mandibular arch (Y = 2/3 X + 16) offer an easy and practical way to predict the size of unerupted canines and premolars in the maxillary and mandibular arches of Iranian children.

Numerical investigation of natural convection heat transfer in a cylindrical enclosure due to ultrasonic vibrations.

Application of ultrasonic waves for heat transfer augmentation has been proposed in the last few decades. Due to limited researches on acoustic streaming induced by ultrasonic oscillation, the effect of ultrasonic waves on natural convection heat transfer is the main purpose of this paper. At first, natural convection on up-ward-facing heating surface in a cylindrical enclosure filled with air is investigated numerically by the finite difference method, then the effect of upper surface oscillation on convection heat transfer is considered. The conservation equations in Lagrangian approach and compressible fluid are assumed for the numerical simulation. Results show that acoustic pressure will become steady after some milliseconds also pressure oscillation amplitude and acoustic velocity components will be constant therefore steady state velocity is used for solving energy equation. Results show that Enhancement of heat transfer coefficient can be up to 175% by induced ultrasonic waves. In addition, the effect of different parameters on acoustic streaming and heat transfer has been studied.

A Simplified Method for the Restoration of Severely Decayed Primary Incisors.

OBJECTIVES: Caries and dental trauma are common reasons for primary anterior teeth restorations in children. This non-control clinical trial was designed to evaluate crown restorations reinforced with a sectioned file post for the restoration of severely damaged primary maxillary incisors. MATERIALS AND METHODS: Thirty-eight primary maxillary incisors of 12 children (3-5 years old) with early childhood caries (ECC) received composite restorations with a custom made post. The restorations were evaluated using the modified United State Public Health Service (USPHS) criteria. The results were statistically analyzed by descriptive -analytical tests. RESULTS: In this trial, the quality of marginal adaptation decreased after three and 12 months intervals. Recurrent carious lesions were observed during intervals. In terms of restoration retention, only one patient lost both the post and the restoration at the 12-month follow up. CONCLUSION: The sectioned file post technique showed good retention and aesthetics for restoring severely damaged primary maxillary anterior teeth.

Natural model training, an alternative way to enhance learning in pediatric dentistry.

OBJECTIVE: Educational teaching of the diagnosis of resorbed root for pulpectomy in deciduous teeth radiography has always been a big challenge in pediatric dentistry. The purpose of the study was to propose a new practical methodology to improve the quality of learning in students of dentistry. MATERIALS AND METHODS: Extracted deciduous teeth were molded in the transparent epoxy resin as their real position in the jawbone. Then, their own pre-extraction radiographs were attached to them. Forty dental students were randomly allocated to the control group of conventional teaching and experimental group of natural model training. All participants were attended in a validated exam and the data were analyzed. A questionnaire was designed with an answer choice in Lickert scale to measure the students' attitude towards the new method and finally the data were reported with descriptive statistics. RESULTS: The mean of the learning degree in the experimental group was graded 9.2± 3.2 and was significantly higher than 5.8± 1.1 which belongs to the participants of the conventional method as control (p= 0.04 <0.05). CONCLUSION: Considering the limitation of this study, using natural models in radiography training will improve the diagnostic competency and the student's educational satisfaction in pediatric dentistry.

In vitro investigation of heat transfer phenomenon in human immature teeth.

Background and aims. Heat generated within tooth during clinical dentistry can cause thermally induced damage to hard and soft components of the tooth (enamel, dentin and pulp). Geometrical characteristics of immature teeth are different from those of mature teeth. The purpose of this experimental and theoretical study was to investigate thermal changes in immature permanent teeth during the use of LED light-curing units (LCU). Materials and methods. This study was performed on the second mandibular premolars. This experimental investiga-tion was carried out for recording temperature variations of different sites of tooth and two dimensional finite element models were used for heat transfer phenomenon in immature teeth. Sensitivity analysis and local tests were included in the model validation phase. Results. Overall, thermal stimulation for 30 seconds with a low-intensity LED LCU increased the temperature from 28°C to 38°C in IIT (intact immature tooth) and PIT (cavity-prepared immature tooth). When a high-intensity LED LCU was used, tooth temperature increased from 28°C to 48°C. The results of the experimental tests and mathematical modeling illustrated that using LED LCU on immature teeth did not have any detrimental effect on the pulp temperature. Conclusion. Using LED LCU in immature teeth had no effect on pulp temperature in this study. Sensitivity analysis showed that variations of heat conductivity might affect heat transfer in immature teeth; therefore, further studies are required to determine thermal conductivity of immature teeth.

Sodium hypochlorite vs formocresol as pulpotomy medicaments in primary molars: 1-year follow-up.

PURPOSE: The study evaluated the effects of 3 percent sodium hypochlorite (NaOCl) and formocresol (FC) as pulp dressing agents in pulpotomized primary molars. METHODS: One hundred children between three and six years each with at least one primary mandibular second molar requiring pulpotomy were randomly allocated to two groups (of 50 each). All the teeth received stainless steel crown after conventional pulpotomy procedure with either NaOCI (applied for 15 second) or FC (applied for one minute). Clinical and radiographic signs/symptoms were blindly recorded at zero, six. and 12 months. The differences were statistically analyzed using the Fisher's exact test. RESULTS: At six months, 100 percent clinical success was found with both NaOCl, and FC. Radiographic success rates for NaOCl were 98 percent and 92 percent at 6- and 12-month recalls respectively. FC group showed 94 percent and 93 percent radiographic success rates at the same periods respectively. There was no statistically significant difference between the groups. CONCLUSION: NaOCl can be suggested as a pulpotomy agent for primary teeth pulpotomies. However further clinical studies with long-term follow-ups are needed to test the efficacy of NaOCl as a pulpotomy medicament in primary teeth.

The parents' knowledge and behavior towards the effects of using iron supplements on tooth staining and dental caries in Mashhad, Iran.

BACKGROUND: Iron deficiency is estimated to be the most common nutritional deficiency in both developed and underdeveloped nations. Iron supplements at early age may prevent iron deficiency. The aim of this study was to assess the knowledge and management of parents about using iron supplements related to dental caries and staining among Iranian children (6 months to 2 year-old) and to identify some factors underlying these attitudes. MATERIALS AND METHODS: This randomized cross sectional study was carried out on the parents of 220 children (6 months to 2-year-old) evaluated in health services centers in Mashhad in 2008. Parents filled questionnaires assessing their opinions on the risk of using iron supplement on tooth staining and dental caries. The results were statistically analyzed by descriptive-analytical, Mann Whitney and Kruscal Wallis tests. RESULTS: According to this study the relation between iron supplement application with tooth staining and its effect on dental caries, it must be noted that most parents (82.7%) had a moderate range of knowledge. Major of the parents (72.7%) had a moderate level of behavior. There was a significant difference between the knowledge level of fathers with their level of education (P = 0.01). CONCLUSION: The finding of this study indicates that parental knowledge about consumption of iron supplements by their children (6 months to 2-year-old) has been moderate. But their behavior was poor and needs more attention.

Management of physiological hyperpigmentation of oral mucosa by cryosurgical treatment: a case report.

Melanin hyperpigmentation is the result of melanin granules. "Black gums" may cause esthetic problems. Different treatment modalities have been used with the aim of removing pigmentations for esthetic reasons, all of which have some advantages and disadvantages. Recurrent lesions are the most important concept in all of these treatments. Cryotherapy is a method of tissue destruction by rapid freezing. It is an atraumatic, cost-effective and simple method for treating oral pigmentation. This report presents the effects of cryotherapy on physiologic pigmentations of oral mucosa in a 9-year-old boy. In this case no recurrent lesions were observed after 12 months.

Treatment of gingival physiologic pigmentation in adolescents by liquid nitrogen cryosurgery: 24-month follow-up.

Although gingival pigmentation is physiologic in most cases, esthetic concerns regarding "black gums" are common among adolescents. Numerous procedures have been suggested to treat this problem. The aim of this study was to evaluate the efficacy of cryosurgery with liquid nitrogen for the removal of physiologic gingival pigmentation (PGP) in adolescents. Melanin pigmentation of the anterior segments in 15 patients was treated using liquid nitrogen. Standard digital photographs were taken preoperatively and at 3, 12, and 24 months postoperatively. Photographs were analyzed digitally and showed significant differences in gingival color between the preoperative and postoperative follow-ups. Cryosurgery successfully removed PGP in adolescents.

Major differences in oral health knowledge and behavior in a group of Iranian pre-university students: a cross-sectional study.

To establish efficient methods for self-prevention of oral diseases, assessment of dental health behavior and knowledge in various social classes is necessary. The main purpose of this study was to determine the major differences in oral health knowledge and behavior in a group of Iranian pre-university students. In this cross-sectional study, 591 pre-university students from different regions of Mashhad, Iran were randomly selected to complete a questionnaire consisting of two parts including dental health behavior and knowledge. Scores were recorded and statistical analyses performed to determine the correlation between dental health behavior and knowledge. Data was analyzed with Student's t-test, one-way analysis of variance and Pearson correlation. The mean score of dental health knowledge was significantly lower than the dental health behavior (2.95 ± 0.02 vs. 3.31 ± 0.05, P < 0.001). This difference was observed with gender, birth location and major subject of study. The dental health behavior of Iranian pre-university students was inadequate and their dental health knowledge was at a lower level compared to their behavior. Experimental science students had better oral health behavior compared to other students.

Bi-rooted Primary Maxillary Canines: A Case Report.

This report presents a rare case of bi-rooted primary maxillary canines. A 6-year-old girl presented at the Department of Pediatric Dentistry, Faculty of Dentistry, Mashhad University of Medical Sciences, Iran, with the chief complaint of pain in the lower right quadrant of her dentition. Radiographic examination revealed bifurcation of primary maxillary canine roots. This report discusses the possible etiology of bi-rooted canines, implications for the developing dentition, and treatment options for these teeth.

A study on oral health of children with cardiac diseases in mashhad, iran in 2004.

BACKGROUND AND AIMS: Preventing oral disease is the most desirable way of ensuring good dental health for children with heart disease. Dental and gingival infections in patients with cardiac problems may lead to infective endocarditis. The aim of this study was to evaluate oral and dental health status in children with heart disease referred to a cardiac center compared with the control group. MATERIALS AND METHODS: In this descriptive cross-sectional study, case group consisting of 100 patients 2-12 years old with heart disease were examined for oral and dental status in Pediatric Cardiac Center in Mashhad, Iran, in 2004. Fifty healthy children with the same age as the case group referring to the Department of Pedodontics, Mashhad Faculty of Dentistry served as the control group. For each patient, dental and medical history, dmft, DMFT, debris index, tooth brushing status as well as parental knowledge of infective endocarditis and their economic status was registered on a questionnaire. Statistical analysis was performed using Kruskal-Wallis, chi-square and t-tests. RESULTS: There were no significant differences between case and control groups in dmft (3.92 ± 3.99 and 3.54 ± 3.33, respectively), DMFT (3.7 ± 4 and 1.47 ± 1.72, respectively) and their components. Tooth brushing status and debris index were significantly worse in the study group (P = 0.001 and P = 0.008, respectively). 35% of parents were aware of the importance of good oral health in cardiac children although none of them knew about infective endocarditis. Most of the parents in study group had low (30%) to medium (53%) economic status. CONCLUSION: In this study, the children with cardiac disease did not have a good oral and dental health status. Developing strategies toward preventive dental care of children with cardiac problems and informing their parents is suggested.