The Scope of Virtual Reality Simulators in Radiology Education: Systematic Literature Review.

Background: In recent years, virtual reality (VR) has gained significant importance in medical education. Radiology education also has seen the induction of VR technology. However, there is no comprehensive review in this specific area. This review aims to fill this knowledge gap. Objective: This systematic literature review aims to explore the scope of VR use in radiology education. Methods: A literature search was carried out using PubMed, Scopus, ScienceDirect, and Google Scholar for articles relating to the use of VR in radiology education, published from database inception to September 1, 2023. The identified articles were then subjected to a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)-defined study selection process. Results: The database search identified 2503 nonduplicate articles. After PRISMA screening, 17 were included in the review for analysis, of which 3 (18%) were randomized controlled trials, 7 (41%) were randomized experimental trials, and 7 (41%) were cross-sectional studies. Of the 10 randomized trials, 3 (30%) had a low risk of bias, 5 (50%) showed some concerns, and 2 (20%) had a high risk of bias. Among the 7 cross-sectional studies, 2 (29%) scored "good" in the overall quality and the remaining 5 (71%) scored "fair." VR was found to be significantly more effective than traditional methods of teaching in improving the radiographic and radiologic skills of students. The use of VR systems was found to improve the students' skills in overall proficiency, patient positioning, equipment knowledge, equipment handling, and radiographic techniques. Student feedback was also reported in the included studies. The students generally provided positive feedback about the utility, ease of use, and satisfaction of VR systems, as well as their perceived positive impact on skill and knowledge acquisition. Conclusions: The evidence from this review shows that the use of VR had significant benefit for students in various aspects of radiology education. However, the variable nature of the studies included in the review reduces the scope for a comprehensive recommendation of VR use in radiology education.

A new fluorescence probe for sofosbuvir analysis in dosage form and spiked human plasma.

A simple, rapid, and low-cost technique was developed to allow reliable analysis of the anti-hepatitis C drug sofosbuvir in bulk, tablet form, and spiked human plasma. This method depends on the ability of sofosbuvir to quench the fluorescence of the newly synthesized 2-amino-3-cyano-4,6-dimethylpyridine (reagent 3). Elemental analysis and spectral data were used to validate the structure of the synthesized reagent. The newly synthesized reagent exhibited a satisfactory level of fluorescence emission at 365 nm after excitation at 247 nm. All experimental variables that might affect the quenching process were analyzed and optimized. Linearity, range, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ) were all validated in accordance with the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. The concentration range was shown to be linear between 0.1 and 1.5 µg/mL. The technique was effectively utilized for sofosbuvir analysis in both its tablet dosage form and spiked human plasma, with mean percentage recoveries of 100.13 ± 0.35 and 94.26 ± 1.69, respectively.

In-lab synthesized turn-off fluorescence sensor for estimation of Gemigliptin and Rosuvastatin polypill appraised by Spider diagram, AGREE and whiteness metrics.

Gemigliptin-Rosuvastatin single-pill combination is a promising therapeutic tool in the effective control of hyperglycemia and hypercholesterolemia. Organic sensors with high quantum yields have profoundly significant applications in the pharmaceutical industry, such as routine quality control of marketed formulations. Herein, the fluorescence sensor, 2-Morpholino-4,6-dimethyl nicotinonitrile 3, (λex; 226 nm, λem; 406 nm), was synthesized with a fluorescence quantum yield of 56.86% and fully characterized in our laboratory. This sensor showed high efficiency for the determination of Gemigliptin (GEM) and Rosuvastatin (RSV) traces through their stoichiometric interactions and simultaneously fractionated by selective solvation. The interaction between the stated analytes and sensor 3 was a quenching effect. Various experimental parameters and the turn-off mechanism were addressed. The adopted approach fulfilled the ICH validation criteria and showed linear satisfactory ranges, 0.2-2 and 0.1-1 µg/mL for GEM and RSV, respectively with nano-limits of detection less than 30 ng/mL for both analytes. The synthesized sensor has been successfully applied for GEM and RSV co-assessment in their synthetic polypill with excellent % recoveries of 98.83 ± 0.86 and 100.19 ± 0.64, respectively. No statistically significant difference between the results of the proposed and reported spectrophotometric methods in terms of the F- and t-tests. Ecological and whiteness appraisals of the proposed study were conducted via three novel approaches: the Greenness Index via Spider Diagram, the Analytical Greenness Metric, and the Red-Green-Blue 12 model. The aforementioned metrics proved the superiority of the adopted approach over the previously published one regarding eco-friendliness and sustainability. Our devised fluorimetric turn-off sensing method showed high sensitivity, selectivity, feasibility, and rapidity with minimal cost and environmental burden over other sophisticated techniques, making it reliable in quality control labs.

An artificial intelligence model for the radiographic diagnosis of osteoarthritis of the temporomandibular joint.

The interpretation of the signs of Temporomandibular joint (TMJ) osteoarthritis on cone-beam computed tomography (CBCT) is highly subjective that hinders the diagnostic process. The objectives of this study were to develop and test the performance of an artificial intelligence (AI) model for the diagnosis of TMJ osteoarthritis from CBCT. A total of 2737 CBCT images from 943 patients were used for the training and validation of the AI model. The model was based on a single convolutional network while object detection was achieved using a single regression model. Two experienced evaluators performed a Diagnostic Criteria for Temporomandibular Disorders (DC/TMD)-based assessment to generate a separate model-testing set of 350 images in which the concluded diagnosis was considered the golden reference. The diagnostic performance of the model was then compared to an experienced oral radiologist. The AI diagnosis showed statistically higher agreement with the golden reference compared to the radiologist. Cohen's kappa showed statistically significant differences in the agreement between the AI and the radiologist with the golden reference for the diagnosis of all signs collectively (P = 0.0079) and for subcortical cysts (P = 0.0214). AI is expected to eliminate the subjectivity associated with the human interpretation and expedite the diagnostic process of TMJ osteoarthritis.

Impact of fully guided implant planning software training on the knowledge acquisition and satisfaction of dental undergraduate students.

BACKGROUND: A majority of dental school students do not undergo hands-on clinical training in implantology in the undergraduate curriculum. Training is usually restricted to pre-implant evaluation and post-implant prostheses. Virtual implant planning software (VIPS) provides an alternative opportunity for undergraduate students to experience implant planning much before gaining hands-on experience. However, not many studies have the contribution of VIPS to the knowledge acquisition of students. We conducted a preliminary study to evaluate the knowledge acquisition of the students when exposed to a hands-on session of VIPS. We also evaluated students' satisfaction levels, when exposed to hands-on training in fully guided implant planning software. METHODS: A two-part theory lecture on fully guided implant planning was delivered to 90, 5th (final)-year dental undergraduate students by the oral radiology faculty. The students were then randomly divided into three groups. Group A was exposed to didactic lectures only. Group B was shown a video for fully guided implant planning in addition to the didactic lecture. Group C was shown a video for fully guided implant planning in addition to a didactic lecture and then performed a hands-on session of virtual implant planning under faculty guidance. Students from all groups were given an MCQ-based test. After the completion of the test students from group A and B also received VIPS hands-on training. Students from all three groups answered and a feedback questionnaire regarding their satisfaction levels with VIPS. RESULTS: The overall test score of students in Group C was higher than their colleagues in both Groups A and B and the differences were statistically significant (p = 0.01). More than 85% of the students were satisfied with the teaching approach. CONCLUSIONS: The utilization of VIPS in the training of dental undergraduate students improves their performance confirming better knowledge acquisition and content mastery.

Chromatographic reversed HPLC and TLC-densitometry methods for simultaneous determination of serdexmethylphenidate and dexmethylphenidate in presence of their degradation products-with computational assessment.

Two Chromatographic methods have been established and optimized for simultaneous determination of serdexmethylphenidate (SER.DMP) and dexmethylphenidate (DMP) in the presence of their degradation products. The first method is a reversed phase high performance liquid chromatography with diode array detection (HPLC-DAD). Isocratic separation was carried out on Waters X-bridge Shield RP18 column (150×3.9×5 µm particle size) using a mixture of 5 mM phosphate buffer (pH 5.5): acetonitrile (40:60, v/v) as a mobile phase, flow rate 1 mL/min and detection at 220 nm. The second method is a thin-layer chromatography (TLC)-densitometry method using methanol: chloroform (70:30, v/v) as a mobile phase and UV scanning at 220 nm. In HPLC method, the linearity range of SER.DMP was (2.5-25 µg/mL); with LOD (0.051 µg/mL) and LOQ (0.165 µg/mL) while for DMP was (2.5-25 µg/mL); with LOD and LOQ of (0.098 µg/mL) and (0.186 µg/mL), respectively. For TLC method the sensitivity range of SER.DMP was (5-25 µg/mL), LOD was (0.184 µg/spot), while LOQ was (0.202 µg/ spot) whereas for DMP the sensitivity range was (5-25 µg/mL) with LOD of (0.115 µg/ spot) and LOQ of (0.237 µg/ spot), respectively. SER.DMP was found to be equally labile to acidic and alkaline hydrolysis, whereas DMP was sensitive to acidic hydrolysis only. Both drugs were successfully determined in presence of acidic and basic degradants by the two developed methods (stability indicating assay method). Chromatographic separation of the degradation products was carried out on TLC aluminum silica plates 60 F254, as a stationary phase, using methanol: dichloroethane: acetonitrile (60:20:20 v/v), as a mobile phase. The degradation pathway was confirmed using TLC, IR, 1H-NMR and mass spectroscopy; moreover, the separation power was correlated to the computational results by applying molecular dynamic simulation. The developed methods were validated according to the International Conference on Harmonization (ICH) guidelines demonstrating good accuracy and precision. They were successfully applied for quantitation of SER.DMP and DMP in pure and capsule forms. The results were statistically compared with those obtained by the reported method in terms of accuracy, precision and robustness, and no significant difference was found.

Acceptability of fully guided virtual implant planning software among dental undergraduate students.

BACKGROUND: Fully guided implant surgery as a technique is gaining popularity. It has been observed that use of surgical guides improves precision and predictability for dental implant placement. However, like any other newer technology, the acceptance of fully guided dental implant technology among users is based upon its perceived usability. This study aimed at evaluating the perception about using Virtual Implant Planning Software (VIPS) among undergraduate dental students at the university of Sharjah. METHODS: Ninety-Six dental surgery students from the University of Sharjah were included in the study. One week after the Virtual Implant Planning Software (Planmeca Romexis version 6.2 procedure, students were asked to complete a Combined technology acceptance model and the theory of planned behaviour (C-TAM TPB) questionnaire. Sixty-six students responded to the questionnaire. RESULTS: Cronbach's alpha surpassed 0.7 for perceived usefulness, perceived ease of use, perceived behavioral control, and subjective norm. Attitude and behavioural intention reported Cronbach's alpha values less than 0.7. Spearman's correlation coefficient was significant for all the constructs. Perceived ease of use explained 49%, 33%, and 42% of the variance of perceived usefulness (R2 = 0.49), attitude (R2 = 0.33), and perceived behavioral control (R2 = 0.42) respectively. Perceived usefulness explained 25%, 18%, and 23% of the variance of attitude (R2 = 0.25), behavioral intention (R2 = 0.18), and perceived behavioral control (R2 = 0.23) respectively. Attitude accounted for 25%, 33%, and 29% of the variance of behavioral intention (R2 = 0.25), perceived behavioral control (R = 0.33), and subjective norm (R = 0.29) respectively. CONCLUSION: The fully guided VIPS was acceptable by dental students specifically because of its usability. This makes VIPS a very effective tool for teaching implantology for dental students. VIPS also allows students to perform multiple repetitions of the implant planning procedure which enhances understanding and content retention.

Carbon dots as fluorescent nanoprobes for assay of some non-fluorophoric nitrogenous compounds of high pharmaceutical interest.

Background: Carbon dots, CDs, have excellent photoluminescence properties, good biocompatibility, low toxicity and good light stability. The optical, magnetic and electronic properties of CDs make them a hugely relevant tool to be used in pharmaceutical analysis, bioimaging, drug delivery, and other fields. The fluorescence of carbon nanodots makes it suitable for assay of some nitrogenous compounds of high pharmaceutical interest. In this work, we develop simple, fast and green spectrophotometric methods for quantification of Azithromycin and Rasagiline mesilate using synthesized fluorescent CDs from garlic peels. Results: The spectrometric methods depend on stoichiometric reactions of both drugs with fluorescent CDs. Carbon dots exhibit a declared absorption peak λmax at 238 nm and potent fluorimetric emission at λem 528 nm, upon excitation at λex 376 nm. Drugs' concentrations in ppm are efficiently calculated using Stern-Volmer Equation. Decrease in fluorescence (ΔF = F o - F) and the F-ratio values are linearly correlated to molar concentration of each quencher (drug). A significant linear diminish in the dots' measured absorbance and fluorimetric emission values was observed. Validation of all the developed methods was according to the ICH guidelines. Conclusions: In a new way, this work successfully indicates, spectrometric methods for rapid detection of two non-fluorophoric nitrogenous compounds using potent carbon nanodots. Consequently, these green developed methods offer several benefits as simplicity, ease of quantification, accuracy and precision that encourage the application of the developed methods in routine analysis of Azithromycin and Rasagiline mesilate in quality control laboratories as analytical tool. Supplementary Information: The online version contains supplementary material available at 10.1186/s43088-023-00346-z.

Determination of rivaroxaban by utilizing its quenching effect on acetoxymercuric fluorescein reagent in pharmaceutical preparations and in spiked biological matrices.

A simple, precise and inexpensive spectrofluorimetric method has been developed for assay of rivaroxaban raw material and its tablets. The method depends on the quenching effect of rivaroxaban on the fluorescence intensity of acetoxymercuric fluorescein (AMF). Parameters that may affect the reaction such as pH, AMF solution concentration, reaction time and diluting solvents were studied and optimized. The proposed method was applied for determination of rivaroxaban in tablets with percentage recovery of 100.4 ± 0.28, and in organic extract of spiked plasma samples with percentage recovery of 98.40 ± 1.08. The developed method was validated according to ICH guidelines in terms of accuracy, precision, linearity, range, limit of detection (LOD) and limit of quantification (LOQ).

Computer-aided finite element model for biomechanical analysis of orthodontic aligners.

OBJECTIVES: To design a finite element (FE) model that might facilitate understanding of the complex mechanical behavior of orthodontic aligners. The designed model was validated by comparing the generated forces - during 0.2-mm facio-lingual translation of upper left central incisor (Tooth 21) - with the values reported by experimental studies in literature. MATERIALS AND METHODS: A 3D digital model, obtained from scanning of a typodont of upper jaw, was imported into 3-matic software for designing of aligners with different thicknesses: 0.4, 0.5, 0.6, 0.7 mm. The model was exported to Marc/Mentat FE software. Suitable parameters for FE simulation were selected after a series of sensitivity analyses. Different element classes of the model and different rigidity values of the aligner were also investigated. RESULTS: The resultant maximum forces generated on facio-lingual translation of Tooth 21 were within the range of 1.3-18.3 N. The force was direction-dependent, where lingual translation transmitted higher forces than facial translation. The force increases with increasing the thickness of the aligner, but not linearly. We found that the generated forces were almost directly proportional to the rigidity of the aligner. The contact normal stress map showed an uneven but almost repeatable distribution of stresses all over the facial surface and concentration of stresses at specific points. CONCLUSIONS: A validated FE model could reveal a lot about mechanical behavior of orthodontic aligners. CLINICAL RELEVANCE: Understanding the force systems of clear aligner by means of FE will facilitate better treatment planning and getting optimal outcomes.

Comparative study of extension area based methods for spectrophotometric determination of desmopressin acetate in the presence of its acid-induced degradation products.

Desmopressin acetate (DPA) is a synthetic analogue of vasopressin used in the treatment of diabetes insipidus, bedwetting, hemophilia A, and elevated levels of urea in the blood. Sensitive and selective stability-indicating methods are needed to be developed and validated for its assay pure and pharmaceutical dosage forms in the presence of its degradation products as no method has been reported for its determination in the presence of its degradants. This work describes a comparative study of five simple stability-indicating spectrophotometric techniques for determination of DPA in presence of its acid-degradation products (acid-degradants) without prior separation. The proposed spectrophotometric techniques (First derivative, Derivative ratio, Ratio difference, Mean centering and Dual wavelength) were developed and validated according to ICH guidelines. Acid degradation was carried out with 0.1 N HCl; the acid-degradants were separated on TLC plates and the acidic degradation pathway was established by IR, H-NMR and MS techniques. The TLC method was based on the separation of DPA and its acid-induced degradation products on silica gel plates using methanol: water (80:20, v/v) as a developing system and UV detection at 254 nm. All assay suggested methods were successfully applied for quantitation of DPA in pure and tablet forms. They are specific, sensitive, precise and accurate. They showed good linearity in the concentration range of 1-14 µg/mL with good correlation coefficients, and limit of detection (LOD) of 0.304, 0.274, 0.167, 0.248 and 0.199 and limit of quantitation (LOQ) of 0.920, 0.829, 0.506, 0.751 and 0.604) for each method, respectively. These methods were successfully applied for the simultaneous determination of DPA in its pure and tablet dosage form in the presence of its acid-degradants. The results obtained were statistically comparable with those of reported HPLC assay method; no significant differences were observed with relevance to accuracy and precision. All the methods are sensitive, selective and can be used for the routine analysis of DPA in its pure and dosage forms.

Selective Sensing of Darolutamide and Thalidomide in Pharmaceutical Preparations and in Spiked Biofluids.

Selective spectrofluorometric sensing is introduced for the analysis of non-steroidal anti-androgens, darolutamide, and thalidomide in pharmaceutical preparations and biofluids. An organic fluorophore, 2,4,8,10-tetramethylpyrido[2',3':3,4]pyrazolo[1,5-a]pyrimidine 2 was synthesized in our laboratories by new simple methods to act as a fluorescent reagent for the analysis of the studied drugs. Elemental and spectral analyses were performed to approve the fluorophore structure. The fluorophore possesses a fluorescence at λem 422 nm when excited at 328 nm. The interaction between the studied drugs and the fluorophore was found to be quenching. The quenching mechanisms were studied and interpreted through the Stern-Volmer relationship. Moreover, the Stern-Volmer constants were calculated for the quenching interactions of both drugs. The introduced method was validated for the estimation of darolutamide and thalidomide in dosage forms, plasma, and urine, offering good percentage recoveries.

Prevalence and characteristics of referred pain in patients diagnosed with temporomandibular disorders according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) in Sharjah, United Arab Emirates.

BACKGROUND: Referred pain often complicates and delays the diagnosis of temporomandibular disorders (TMD). Elaborating the prevalence and characteristics of TMD-associated referred pain as well as the distribution of referred pain in different TMD classes will significantly improve the diagnostic process. The objectives of the present study were to assess the prevalence and to evaluate the characteristics of referred pain associated with TMD diagnosed according to the DC/TMD. METHODS: A total of 252 patients were evaluated using the DC/TMD Axes-I and -II assessment tools. Different modalities were used to treat the diagnosed TMD. Referred pain was diagnosed when the location of the perceived pain in response to palpation extended beyond the boundary of the structure that was examined. For pain locations that were perceived as deep, patients were asked to locate the surface of the area of pain. The result of the assessment was identified as positive if the patient described his perceived pain during the clinical examination as being familiar pain that was experienced in the same location in the last 30 days.  Results: TMD-associated referred pain was recorded in 153 patients (60.7%). The most common referred pain location was the temporal area (45.2%), followed by the ear (42.1%). The referred pain was recorded in disc displacement with reduction with intermittent locking and myofascial pain with referral in all patients (100%). The proportion of patients with referred pain was significantly different between the different TMD diagnostic subgroups (P < 0.001).  The recorded percentage of improvement in the referred pain following the treatment was 50.41% after 3 months and 56.65% after 6 months. CONCLUSIONS: Referred pain is a prominent feature of TMD. More studies are required with longer follow-up periods and bigger sample sizes to support the findings of the present study.

Analysis of the Volumetric Asymmetry of the Mandibular Condyles Using CBCT.

OBJECTIVES: The aim of this study was to analyse volumetric asymmetries between the right and left condyles in relation to age, gender, and dental status. MATERIALS AND METHODS: A retrospective analysis of 150 cone beam computed tomography (CBCT) scans was conducted. A single investigator performed the volumetric analysis of the CBCT scans using Vesalius 3D software. The volumetric data were analysed in relation to the gender, age, and dental status. RESULTS: The mean right condylar volume was significantly higher (P < .01) than the left condylar volume. Right and left condylar volumes were significantly higher (P < .01) in male study participants when compared to female study participants. There was no significant difference (P = .47) in the volumetric asymmetry between the male and female study participants. The volumetric asymmetry was significantly higher (P < .01) in the older age groups when compared to the younger age groups. The volumetric asymmetry was significantly higher (P < .01) in the partially and completely edentulous patients when compared to the dentate study participants. The condylar volume on the side having a partially edentulous area was significantly lower than the condylar volume of the contralateral dentate side (P < .001). CONCLUSIONS: The volumetric asymmetry between the right and left condyle significantly increases with age and edentulousness. The result of the study encourages the clinicians to perform volumetric evaluation of the condyles in cases of radiographically evident condylar asymmetries to obtain a more accurate diagnosis.

Electrochemical determination of dinitolmide in poultry product samples using a highly sensitive Mn2O3/MCNTs-NPs carbon paste electrode aided by greenness assessment tools.

In this paper, chemically modified carbon paste Mn2O3/MCNTs-NPs electrode for estimation of dinitolmide (DOM) utilizing square wave voltammetry method (SWV) was developed. The study investigated the electrochemical behavior of DOM, and the morphology of the modified electrode was evaluated by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The voltammetric behavior of DOM at modified electrode was recorded at a scan rate of 100 mVs-1 against Ag/AgCl reference electrode in phosphate buffer pH 4.0 within linearity range 2-12 µM, LOQ, and LOD of 1.8 and 0.594 µM, respectively, with average % recovery of (100.89 ± 0.795). GAPI and Analytical Eco-Scale tools were applied for greenness assessment. Specificity and interference study was valid for the proposed method; allowing DOM to be determined in its acidic degradation and its major interference drug. The proposed method was successfully employed to quantify DOM in bulk powder, egg, and frozen cuts-up chicken muscle samples.

Selective sensing of the nucleoside analogue, trifluridine and tipiracil in dosage form and biological matrices.

A new fluorescent sensor is introduced to analyze nucleoside analogue, trifluridine and tipiracil in tablets and biological fluids. The synthesized fluorophore exhibits good fluorescence at 446 nm after excitation at 257 nm. The interaction between the studied drugs and the reagent was a quenching effect. Different experimental parameters and the mechanism of quenching were discussed. The present method was utilized to analyze trifluridine and tipiracil raw materials and tablets over the concentration range of 20-1000 ng/mL and spiked biological fluids over the range of 30-1000 ng/mL. The method is selective, specific, and possesses good accuracy and high precision. The method is highly sensitive, with detection limits of 5.8 and 6.0 ng/mL for trifluridine and tipiracil, respectively, and quantitation limits of 17.7 and 18.1 ng/mL for trifluridine and tipiracil, respectively. In vivo analysis of trifluridine was achieved selectively and the mean pharmacokinetic parameters were studied.

The consequences and outcomes associated with dental implants encroaching on adjacent teeth.

BACKGROUND: Dental implant placement carries a risk of iatrogenic damage to adjacent root surfaces. PURPOSE: To classify and understand different types of trauma to the tooth root body by dental implants. MATERIALS AND METHODS: This prospective case series included 43 implants placed between February 2017 and June 2020 that had primary stability and were in a position that accidentally invaded the adjacent teeth. The type and degree of the injury were evaluated clinically and radiographically. Tenderness, mobility, and sensitivity tests of the injured teeth were conducted at different visits. Implant failure was confirmed by the presence of implant mobility during the healing period. RESULTS: Overall, 43 patients had root injuries due to dental implant surgeries. Regarding the 43 injured roots, 32 developed transient tenderness to percussion, 16 developed variable degrees of resorption in the cementum, three lost pulp sensitivity and one had persistent tenderness to percussion. No injured teeth were lost. In three patients, implant periapical lesions were confirmed radiographically as radiolucency near the apex of the involved implants. Out of the 43 implants, 11 failed and were removed within 6 months, with an implant failure rate of (25%). CONCLUSIONS: Root damage after implant surgery varies depending on the type and severity of injury. Periodic clinical and radiographical examination is necessary to monitor root resorption and implant integration and to rule out pulp necrosis.

Thermography as a non-ionizing quantitative tool for diagnosing periapical inflammatory lesions.

BACKGROUND: Thermography is a contemporary imaging modality based on acquiring and analyzing thermal data using non-contact devices. The aim of the present study was to assess the validity of thermography, compared with that of the reference-standard, for the diagnosis of periapical inflammatory lesions and to evaluate the temperature ranges for acute pulpitis with apical periodontitis (AAP), acute periapical abscess (AA) and chronic periapical abscess (CA). METHODS: AAP, AA and CA were diagnosed based on clinical and radiographic criteria. Thermographic data were acquired using the FLIR E-5 Infrared Camera. Extraoral thermal images were taken from the front and right and left sides of patients whose mouths were closed, and one intraoral thermal image was taken from the palatal perspective. Agreement in the diagnoses based on the combination of clinical and radiographic assessments and the thermographic evaluation was calculated. The temperature ranges of the three diagnostic subgroups were also measured. RESULTS: A total of 80 patients were enrolled in this study. The mean intraoral thermal image temperature for AA was 37.26 ± 0.36, that for CA was 35.03 ± 0.63 and that for AAP was 36.07 ± 0.45. The differences between the mean intraoral thermal temperatures of the three diagnostic groups were statistically significant (P < 0.001). The result of the Kappa coefficient of agreement between the combination of clinical and radiographic assessments and the thermographic evaluation was significant (P < 0.001). CONCLUSIONS: Thermography is an effective, quantitative and nonionizing approach that can be used for the diagnosis of periapical inflammatory lesions. The results of the present study indicated that the highest thermal image temperatures were recorded for AA. Thermography might be able to detect inflammatory reactions during the preclinical stage, leading to early diagnosis.

Determination and structural characterization of ravidasvir metabolites by LC coupled to triple quadrupole linear ion trap MS: Application to pharmacokinetics and phase I metabolism in rats.

Hepatitis C virus (HCV) is an infectious disease that has become a global clinical issue because of its significant morbidity and mortality. Novel anti-hepatitis C drugs are continuously developed to decrease the pervasiveness of the infection globally. A synthetic ravidasvir, benzimidazole-naphthylene-imidazole derivatives, has been used as an anti-HCV drug. This study determined the metabolites of ravidasvir and its pharmacokinetics in rats using information-dependent acquisition and multiple reaction monitoring scanning modes in linear ion trap LC-MS/MS instrument, respectively. Two time-programming linear-gradient chromatographic methods were employed using a Kinetex C18 column (50 × 3 mm, 2.6 µm) and a Luna HILIC column (100 × 4.6 mm, 3 µm) for the qualitative and quantitative determination of ravidasvir and its metabolites, respectively. In silico prediction where sites in a molecule are susceptible to metabolism by cytochrome P450 was implemented, which helped in proposing the metabolic pathway of ravidasvir. The most dominant metabolite in rat liver microsomal samples was oxidative ravidasvir, where one O-demethylated metabolite and eight isomers of the oxidative ravidasvir metabolites were identified. The study provides essential data for proposing the metabolic pathway and successfully applied it to determine the pharmacokinetics of ravidasvir in rat plasma.

Fluorescent sensing for some nitric oxide donors in dosage forms and biological matrices.

New fluorescent sensing of some nitric oxide donors, nitroglycerin and isosorbide dinitrate was developed in our laboratories. Two fluorescent reagents, 2-(2-hydroxyethylamino)-4,6-dimethylpyridine-3-carbonitrile, 3a and 2-(3-chloro-phenylamino)-4,6-dimethylpyridine-3-carbonitrile, 3b were synthesized in our laboratories and a comparative study was performed between them from the point of fluorescence intensity. The fluorophore, 3a, was selected for the analytical study as it exhibit higher quantum yield value. The interaction between the selected drugs and the fluorophore was noticed to be quenching. The mechanism of quenching was studied and it was supposed to be collisional quenching through photo induced electron transfer process. The proposed sensing method was applied successfully for the analysis of nitroglycerin and isosorbide dinitrate in dosage forms within concentration range of (0.05-0.5 µg/mL) with percentage recoveries of 99.9 ± 0.5 and 99.9 ± 0.7 respectively. The studied drugs, nitroglycerin and isosorbide dinitrate, were also probed in spiked biological matrices such as plasma samples with percentage recoveries of 99.1 ± 1.97 and 100.7 ± 1.96 and urine samples with percentage recoveries of 100.4 ± 1.8 and 100.3 ± 1.7 respectively. In vivo analysis of both drugs in real plasma was also investigated. The sensing method exhibit well intra-day and inter day precision with %RSD < 2%.