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The current study employs numerical simulations via the SCAPS-1D platform to investigate the performance of solar cells based on perovskite, with RbGeI3 utilized as an absorber material possessing a wide bandgap of 1.31 eV. Through systematic exploration of various parameters including temperature, layer thickness, doping, and defects, the study aims to enhance the efficiency of the solar cells, considering their sensitivity to temperature variations. Results demonstrate that the proposed configuration effectively extends the absorption spectrum into the near-infrared region, with the thickness of the RbGeI3 layer emerging as a critical factor influencing device performance. Analysis reveals that the series resistance peaks at 2 Ω·см2, while the shunt resistance achieves optimal output parameters of up to 103 Ω·см2. Moreover, optimization efforts yield a solar cell exhibiting a power conversion efficiency of 24.62%, fill factor of 82.8%, open circuit voltage of 0.99V, and short circuit current density of 33.20 mA/cm2 at a RbGeI3 thickness of 0.6 um. This comprehensive numerical investigation not only enhances understanding of the intricate factors influencing perovskite solar cells but also suggests promising avenues for future advancements in the field.

Perovskite-based solar cells are currently attracting growing interest from researchers and industry alike, thanks to the advantages of this type of solar cell, particularly in terms of manufacturing simplicity and the promising power conversion efficiency, which has recently reached remarkable levels. This paper focuses on numerical simulation to improve the performance of the Formamidinium Tin Iodide (FASnI3) solar cell configuration by using Cerium Dioxide (CeO2) as ETL and Poly (Triaryl Amine) (PTAA) as HTL. The simulation has been carried out using Solar Cell Capacitance Simulator (SCAPS-1D) tool under the spectrum of AM 1.5 G. An intensive modeling has been realized to improve the output parameters of the suggested configuration based on FASnI3 as absorber. The proposed structure (ITO/CeO2/FaSnI3/PTAA/Au) achieves a tremendous power conversion efficiency (PCE) of 39.24%, an open-circuit voltage (VOC) of 1.31 V, a short-circuit current density (JSC) of 33.7 mA/cm2 and a fill factor (FF) of 90.12%.

Conjoined twins occur in an estimated one in every 200,000 live births. The etiology remains largely speculative, with genetic and environmental factors being considered. The thoraco-omphalopagus type accounts for approximately 40% of cases, making it a focal point for clinical and radiological research. Radiological imaging plays a pivotal role in delineating anatomical details, offering insights into the feasibility of surgical interventions and informing parental counselling regarding prognosis and management options. We present a case of thoracoomphalogus conjoined twins diagnosed during the third trimester of pregnancy in a 19-year-old woman. The detailed radiological assessment using ultra-sound and MRI provided crucial information on organ sharing and vascular anatomy, which is critical for management strategies. This case underscores the critical role of prenatal imaging in detecting complex congenital anomalies, facilitating informed decision-making by healthcare providers and families.

Optic nerve coloboma is a congenital defect caused by the incomplete closure of the embryonic fissure. This closure begins around the fifth week of gestation, when the embryo measures approximately 7 to 14 mm. Colobomas may appear as isolated defects or alongside other ocular and systemic abnormalities. They typically occur in the inferonasal quadrant, where the optic vesicle undergoes closure. This closure process starts centrally within the eye and progresses both anteriorly and posteriorly. The distinct nature of these closures can result in an optic nerve coloboma without an associated iris coloboma.The formation of a coloboma can be attributed to external factors affecting the fetus during pregnancy or to a genetic mutation, such as an autosomal dominant mutation in the Pax gene, which is linked to bilateral colobomas. Small colobomas generally require only clinical and radiological observation, whereas larger colobomas may need surgical intervention to remove the cyst and prevent complications related to orbital content development, thereby improving cosmetic outcomes

Skull base osteomyelitis is a rare and serious condition that primarily affects immunocompromised individuals and can be life threatening if not treated promptly. It can have various origins, with the most common being an extension of necrotizing external otitis. It is difficult to diagnose due to a wide array of clinical presentations. Imaging plays an important role in the diagnosis, identification of the possible source of infection, the extent of the disease, the pattern of spread and identification of associated complications. Early diagnosis is crucial to promptly initiate appropriate treatment. We report here a rare case of a 68-year-old patient presenting with skull base osteomyelitis resulting from bilateral otitis media, which is a rare condition.

Abstract Background This study explores the potential litholytic activity of medicinal plant infusions, specifically Arenaria rubra, Hordeum vulgare, and Zea mays, as well as a combination of these infusions, on various types of urinary calculi. Given the traditional use of these plants in managing kidney stones and the need for alternative treatments, this investigation aims to assess their efficacy in dissolving different types of calculi. Materials and methods Samples representing calcium oxalate monohydrate (COM), calcium oxalate dihydrate (COD), cystine (Cy), uric acid (UA), and calcium phosphate (CP) calculi were analyzed using FTIR and optical microscopy. Herbal infusions were prepared at a concentration of 14 g/l, and the dissolution capacity was evaluated by incubating the calculi samples in the infusions for eight weeks. Microscopic examination and statistical analysis were conducted to assess the efficacy of the infusions. Results and discussion Limited dissolution of COM and COD calculi was observed with the infusions, consistent with their known resistance to dissolution. Significant dissolution effects were observed for Cy, UA, and CP calculi, especially with infusions of A. rubra and H. vulgare. These findings suggest the potential of plant infusions as complementary therapeutic agents for certain types of kidney stones. Conclusion This study highlights the promising litholytic activity of medicinal plant infusions, specifically A. rubra and H. vulgare, which indicates a significant dissolution of various urinary calculi. While further research is needed to validate these findings, integrating plant infusions, extracts, or essential oils into clinical practice could offer additional treatment options for managing kidney stones and preventing recurrence.

Résumé : Cette étude descriptive et quantitative se penche sur l'escalade inquiétante du cyberharcèlement dans les sphères de la recherche psychologique et sociale, soulignant son expansion via les médias numériques et les contenus produits par les influenceurs. Ce phénomène préjudiciable, prévalent sur de multiples plateformes, engendre des conséquences psychosociales notables. De nature récurrente historiquement, sa prévalence s'est accentuée avec l'adoption des technologies avancées et l'essor des réseaux sociaux. Cette recherche explore les manifestations du cyberharcèlement chez les influenceurs algériens à travers une analyse de contenu de leurs vlogs pour identifier la nature et les stratégies du cyberharcèlement observé. Les analyses révèlent une présence fréquente d'humour dépréciatif visant l'apparence physique, accompagnée d'insultes intrusives et de violations de la vie privée. Contrairement aux formes traditionnelles de harcèlement, le cyberharcèlement se caractérise par une propagation rapide et une persistance accrue, une diffusion facilitée par la permanence numérique des contenus et leur impact significatif sur les utilisateurs. L'étude met également en évidence une victimisation disproportionnée des femmes, cibles de tactiques telles que la diffamation, le harcèlement électronique et l'exclusion sociale. Mots-clés : Influenceurs, Cyberharcèlement, YouTube, Vlogs, Algérie, Médias numériques.

Pin fins have the potential to improve the thermal performance of various engineering devices. Modified pin fins could further increase their thermal performance in a passive way at lower cost. This study is aimed to numerically investigate the thermal performance of trenched hemispherical pin fins heat sink (THPFHS) and the influence of parameters including the trench number (N=1, 3 and 5) and thickness (e =1 to 5 mm). The simulations are performed using a CFD software considering turbulent air flow conditions. Results show that the use of aluminum fins fitted with one trench in the middle of the hemispherical pin fin considerably increases the local heat transfer. Furthermore, all studied configurations show high thermal performance factor (HTPF) compared with the conventional CPFHS (cylindrical pin fins heat sink). For this new configuration (THPFHS), Nu increases by 45% while the thermal resistance reduces by 42%, compared to the baseline case. On the other hand, this improved performance results in 50% pressure drop penalty. Moreover, the obtained results show a significant improvement in the performance mainly at high Re.

Palatal tremor has been subdivided into essential (EPT) and symptomatic palatal tremor (SPT). Progressive ataxia and palatal tremor syndrome (PAPT) is a subgroup of symptomatic palatal tremor (SPT). It can be divided into familial and sporadic forms. Sporadic PAPT is characterized by progressive cerebellar degeneration. The cause of sporadic PAPT remains uncertain. MRI examination found an enlarged appearance of the olivary nuclei with increased signal intensity on T2 and FLAIR images. Here we report a case of a mid-adult-onset man which presents a worsening cerebellar progressive ataxia with palatal tremor, in whom imaging reveals abnormalities of the olivary nuclei with tardive cerebellar atrophy which has been diagnosed as a sporadic PAPT.

Introduction and importance The cholecystoenteric fistula, a rare complication of cholelithiasis, usually occurs as an internal biliary fistula. Our case features a cholecystoduodenal fistula presenting with severe upper gastrointestinal bleeding originating from the cystic artery. Symptoms vary, and preoperative diagnosis is uncommon. Case presentation A 63-year-old diabetic patient, who had undergone surgical treatment for a left forearm fracture, presented with persistent bleeding, hematemesis, and melena. Diagnostic esophagogastroduodenoscopy revealed an actively bleeding ulcer on the duodenal bulb, with an attempted hemostasis. Initial stabilization was achieved, but a recurrence occurred after 17 hours with hemodynamic instability. Emergency laparotomy revealed cholecystitis with a cholecystoduodenal fistula, necessitating cholecystectomy and ulcer resection. The source of bleeding was the cystic artery. The patient had a positive postoperative outcome with no recurrence of hemorrhage. Clinical discussion Cholecystoenteric fistulas, forming from obstructed cystic duct inflammation, are rare complications of biliary lithiasis. Most cases are spontaneous, linked to gallstones. Severe upper gastrointestinal bleeding from cholecystoduodenal fistulas is uncommon, often requiring surgical intervention due to cystic artery erosion. Despite advancements in laparoscopic methods, open operations are preferred for anatomical distortion and inflammation. A clear diagnosis involves hepatic angiography and may necessitate embolization. The rarity of this condition emphasizes the need for vigilant diagnosis, especially in patients with gallstone history. Conclusion Massive bleeding from cystic artery erosion by duodenal ulcer through cholecystoduodenal fistula underscores the need for clinicians’ vigilance. Recognition of gallstone disease history is crucial for timely diagnosis in this rare cause of gastrointestinal bleeding.

Lymphangiomas are rare benign neoplasms traditionally thought to result from congenital lymphatic channel malformations, though they may also be associated with other conditions. Retroperitoneal lymphangiomas account for 1% of all lymphangiomas, and fewer than 200 cases have been reported. A 42-year-old woman was admitted with symptoms of abdominal pain and distension. A computerized tomography (CT) scan showed an abdomino-pelvic mass and a giant uterine myoma. The patient underwent explorative laparotomy and the whole cyst mass was removed along with the uterine myoma. Cystic lymphangiomas are often misdiagnosed because of the vague symptoms and the absence of obvious etiology. A provisional diagnosis can be made with CT but histological examination confirms the diagnosis. Cystic lymphangioma should be included in the differential diagnosis of an ovarian cystic mass. Complete resection can be curative.

In recent years, there has been a significant trend to improve poultry zootechnical performances by biological methods to avoid the unwanted chemical growth factor's introduction into breeding process. Medicinal plants and their derivatives are good candidates to achieve this goal. Thus, this work aimed at evaluating the effect of poultry feed supplementation with the spices Curcuma longa and Zingiber officinale on the zootechnical performance, serological, and microbiological parameters of Ross 308 chicken. To achieve this purpose, 180 chicks divided into five groups and reared for 12 days. The experimental groups consisted of a control group receiving a conventional feed without antibiotics and four groups receiving a conventional feed with 0.5 and 1% turmeric and ginger doses, respectively. Results of the experiment revealed that supplementing the feed with 0.5% turmeric powder increased live weight, and average daily gain and decreased feed conversion compared to the other groups. Turmeric powder supplement (0.5 and 1%) affected blood serum parameters by decreasing triglyceride and aspartate aminotransferase (AST) concentrations. In comparison, the incorporation of 0.5% ginger in the diet decreased triglyceride concentrations, cholesterol, aspartate aminotransferases (ASAT), and alanine aminotransferases (ALAT). Cecum bacteriological analysis showed a total absence of coliforms, Salmonella sp., Clostridium sp., and lactic acid bacteria in the chick groups supplemented with different doses of turmeric and ginger (0.5 and 1%, respectively). Within this study’s limits, using these two studied spices as additives in poultry feed allowed us to conclude that supplementing with 0.5% turmeric powder positively impacted the evaluated parameters.

Cardiovascular disease such as ischemic heart disease and stroke are the most dangerous diseases in the WHO stats. Myocardial Infarction (MI), an ischemic disease of the heart, occurs due to a sudden blockage in the coronary arteries that supply blood to the heart causing a lack of oxygen and nutrients. The MI patient needs continuous monitoring using electrocardiography, the latter is always at risk of developing complications such as arrhythmias. As a solution, we proposed an internet of things (IoT) based ECG system for monitoring, the application layer was reserved for the detection of MI and arrhythmias using artificial intelligence so that the patients can keep being monitored even outside health facilities. For this purpose, this paper proposed a hybrid Convolutional Neural Network (CNN) – Bidirectional Long Short-Term Memory (BiLSTM) approach to classify ECG signals and evaluates its performance by using raw and preprocessed data, and comparing the results to related studies. Two datasets have been used in this classification. The results were promising, the model has scored 99.00% accuracy on raw data classifying 4 classes, and 99.73% accuracy on a larger preprocessed data for 3 classes classification. The proposed model is suitable to serve in our monitoring task.

Background The presence of dental caries impacts on children’s daily lives, particularly among those living in deprived areas. There are successful interventions across the United Kingdom for young children based on toothbrushing with fluoride toothpaste. However, evidence is lacking for oral health improvement programmes in secondary-school pupils to reduce dental caries and its sequelae. Objectives To determine the clinical and cost effectiveness of a behaviour change intervention promoting toothbrushing for preventing dental caries in secondary-school pupils. Design A multicentre, school-based, assessor-blinded, two-arm cluster randomised controlled trial with an internal pilot and embedded health economic and process evaluations. Setting Secondary schools in Scotland, England and Wales with above-average proportion of pupils eligible for free school meals. Randomisation occurred within schools (year-group level), using block randomisation stratified by school. Participants Pupils aged 11–13 years at recruitment, who have their own mobile telephone. Interventions Two-component intervention based on behaviour change theory: (1) 50-minute lesson delivered by teachers, and (2) twice-daily text messages to pupils’ mobile phones about toothbrushing, compared with routine education. Main outcome measures Primary outcome: presence of at least one treated or untreated carious lesion using DICDAS4–6MFT (Decayed, Missing and Filled Teeth) in any permanent tooth, measured at pupil level at 2.5 years. Secondary outcomes included: number of DICDAS4–6MFT; presence and number of DICDAS1–6MFT; plaque; bleeding; twice-daily toothbrushing; health-related quality of life (Child Health Utility 9D); and oral health-related quality of life (Caries Impacts and Experiences Questionnaire for Children). Results Four thousand six hundred and eighty pupils (intervention, n = 2262; control, n = 2418) from 42 schools were randomised. The primary analysis on 2383 pupils (50.9%; intervention 1153, 51.0%; control 1230, 50.9%) with valid data at baseline and 2.5 years found 44.6% in the intervention group and 43.0% in control had obvious decay experience in at least one permanent tooth. There was no evidence of a difference (odds ratio 1.04, 95% confidence interval 0.85 to 1.26, p = 0.72) and no statistically significant differences in secondary outcomes except for twice-daily toothbrushing at 6 months (odds ratio 1.30, 95% confidence interval 1.03 to 1.63, p = 0.03) and gingival bleeding score (borderline) at 2.5 years (geometric mean difference 0.92, 95% confidence interval 0.85 to 1.00, p = 0.05). The intervention had higher incremental mean costs (£1.02, 95% confidence interval −1.29 to 3.23) and lower incremental mean quality-adjusted life-years (−0.003, 95% confidence interval −0.009 to 0.002). The probability of the intervention being cost-effective was 7% at 2.5 years. However, in two subgroups, pilot trial schools and schools with higher proportions of pupils eligible for free school meals, there was an 84% and 60% chance of cost effectiveness, respectively, although their incremental costs and quality-adjusted life-years remained small and not statistically significant. The process evaluation revealed that the intervention was generally acceptable, although the implementation of text messages proved challenging. The COVID-19 pandemic hampered data collection. High rates of missing economic data mean findings should be interpreted with caution. Conclusions Engagement with the intervention and evidence of 6-month change in toothbrushing behaviour was positive but did not translate into a reduction of caries. Future work should include work with secondary-school pupils to develop an understanding of the determinants of oral health behaviours, including toothbrushing and sugar consumption, particularly according to free school meal eligibility. Trial registration This trial is registered as ISRCTN12139369. Funding This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 15/166/08) and is published in full in Health Technology Assessment; Vol. 28, No. 52. See the NIHR Funding and Awards website for further award information. Plain language summary What was the problem? Tooth decay has an impact on children and young people’s daily lives, particularly those living in deprived areas. For young children, programmes to improve toothbrushing with fluoride toothpaste help prevent tooth decay. The Brushing RemInder 4 Good oral HealTh trial (BRIGHT) investigated whether a secondary-school-based toothbrushing programme would work. What did we do? We developed a new programme which included a lesson and twice-daily text messages sent to pupils’ phones. In total, 4680 pupils, aged 11–13 years, from 42 secondary schools in the United Kingdom took part in the trial. At each school, one year group was randomly selected to receive the programme, while the other year group did not receive it. All pupils were followed up for 2.5 years to see whether there were any differences in levels of tooth decay, frequency of toothbrushing, plaque or quality of life. We also considered the programme’s value for money and the views of pupils and school staff. What did we find? We followed up 2383 pupils and found no difference in tooth decay, plaque or quality of life. We found those who had the programme were more likely to brush their teeth twice daily after 6 months than those who did not. The programme was not good value for money overall. However, the programme appeared to be of more benefit at preventing tooth decay in pupils eligible for free school meals compared to those not eligible. In the schools with more pupils eligible for free school meals, the chance of the programme representing good value for money increased. The programme was generally liked by the pupils and school staff. Some pupils found the text messages useful, although others said they were annoying. What does this mean? The programme helped pupils brush their teeth more frequently in the short term, but this did not lead to less tooth decay. Further research is needed to understand how to prevent tooth decay in secondary-school pupils. Scientific summary Background Reducing the high prevalence and severity of dental caries in the UK is a public health priority. Dental caries is largely preventable with several evidence-based child oral health promotion interventions including toothbrushing with fluoride toothpaste. However, evidence is lacking for interventions targeting toothbrushing practices to reduce dental caries and its sequelae (pain, infection and tooth loss) in secondary-school pupils. The Brushing RemInder 4 Good oral HealTh (BRIGHT) trial investigated a two-component behaviour change intervention (lesson and text messages) to prevent dental caries in secondary-school pupils. Objectives Conduct an internal pilot phase with feasibility components to: Tailor the intervention to young people. Test trial processes. Assess feasibility of within-school cluster randomisation (by year group). Investigate the intervention’s effect on caries prevalence, twice-daily toothbrushing, oral health-related quality of life and oral health behaviours. Investigate the intervention’s cost effectiveness. Explore implementation, mechanisms of impact and context through process evaluation. Methods Design A multicentre, school-based, assessor-blinded, two-arm cluster randomised controlled trial with an internal pilot phase, and embedded health economic and process evaluations. Criteria determining progression to the main phase were pre-specified and reviewed within the internal pilot phase. Setting Secondary schools in Scotland, England and Wales with above national average percentage of pupils eligible for free school meals (FSM) were recruited. Schools had to have pupils aged 11–16 years and at least 60 pupils per year group. Participant recruitment Pupils aged 11–13 years (Years 7 and 8 in England and Wales; S1 and S2 in Scotland) in participating schools were eligible to take part and received an information session about BRIGHT. Parents/carers had 2 weeks to decline their child’s participation. Pupils who had not been opted out were invited to participate by completing a consent form and providing their mobile telephone number. If they did not own a mobile telephone or could not provide their number, they were ineligible. Sample size We proposed to recruit 5040 pupils from 42 schools (84 year groups) to give 90% power to detect a reduction in the proportion of pupils with obvious decay experience from 34% to 26%, assuming: within-school (year-group level) randomisation, partial contamination effects (i.e. those contaminated gain half the treatment benefits) for 27% of the control group, recruiting an average of 60 pupils per year group, an intracluster correlation coefficient of 0.02% and 20% attrition at follow-up. A sample size of 10 schools was considered sufficient to test internal pilot objectives. Randomisation Year groups within schools were randomised 1 : 1 to the intervention or control arm. An allocation sequence, stratified by school using blocks of size two, was generated by an independent statistician. Once each school’s baseline assessments were completed, the year groups were randomised by allocation to the next available block. Trial interventions The intervention consisted of two components: (1) a 50-minute classroom-based session (CBS) about dental health delivered by teachers using a lesson plan and pupil-facing materials followed by (2) a series of twice-daily text messages to participants’ mobile phones about toothbrushing. Year groups allocated to the control arm received routine education only. Follow-up Assessment time points were baseline, after the lesson (internal pilot only), 12 weeks (internal pilot only), 6 months, 1, 2 (internal pilot only) and 2.5 years following lesson delivery. Pupils completed self-report questionnaires at all these time points. Dental examinations at baseline, 2 and 2.5 years included assessment of caries, plaque and gingival bleeding. Parents/carers were sent a resource use questionnaire at baseline, and 1, 2 and 2.5 years. Note, the descriptors of the time points for the assessments (e.g. 2.5 years) reflect the planned follow-up schedule and are used throughout the report; however, some of the actual average time intervals of follow-up varied from that planned (e.g. the actual average length of follow-up at the 2.5-year assessment was closer to 3 years as this was delayed due to disruptions caused by the COVID-19 pandemic). Primary outcome The primary outcome was the presence of at least one treated or untreated carious lesion in any permanent tooth, measured at the pupil level during the 2.5-year dental assessment using DICDAS4–6MFT (Decayed, Missing and Filled Teeth). Secondary outcomes Secondary outcomes assessed during the dental assessments were DICDAS4–6MFT at 2 years, and the following at 2 and 2.5 years: the presence of at least one treated or untreated carious lesion in any permanent tooth measured using DICDAS1–6MFT, the number of permanent DICDAS4–6MFT and DICDAS1–6MFT, plaque score (modified gingival index of Löe), bleeding score (gingival index) and number of teeth with bleeding gingivae. Participant-reported secondary outcome measures were: twice-daily toothbrushing, health-related quality of life measured by the Child Health Utility 9D (CHU9D) and oral health-related quality of life assessed using Caries Impacts and Experiences Questionnaire for Children (CARIES-QC). Statistical methods Both the clinical effectiveness and economic analyses were conducted to pre-specified and externally endorsed analysis plans. Analyses were conducted in STATA v17 (StataCorp LP, College Station, TX, USA) following the principles of intention to treat using two-sided statistical tests assessed at the 5% significance level. Baseline data were summarised descriptively overall and by randomised arm. The primary outcome was analysed using mixed-effect logistic regression, adjusting for the number of DICDAS4–6MFT and school year at baseline as fixed effects, and school as a random effect. Sensitivity analyses were conducted in which year group, nested within school, was additionally included as a random effect, and including additional covariates that were significantly associated with missing primary outcome data. A further sensitivity analysis excluded pupils whose dental assessments were completed outside of 3 months either side of the average length of follow-up for the 2.5-year time point. A complier-average causal effect (CACE) analysis, using a two-stage instrumental variable regression approach with the randomised group as the instrumental variable, was implemented to assess the impact of: attending the lesson; attending the lesson and receiving at least seven text messages a week for the first 12 weeks; and number of text messages sent. Subgroup analyses considered whether or not the intervention effect differed by FSM status, number of carious teeth at baseline and whether the school was recruited during the pilot or main trial phase. The secondary outcome of presence of at least one DICDAS1–6MFT was analysed as described for the primary outcome. The number of permanent DICDAS4–6MFT and DICDAS1–6MFT and number of teeth with bleeding gingivae were analysed using mixed-effect negative binomial regression, self-reported twice-daily toothbrushing via mixed-effect logistic regression and plaque, bleeding and CARIES-QC scores via mixed-effect linear regression. Models were adjusted for school year and associated baseline value of the outcome as fixed effects and school as a random effect. Attendance data, adverse events and safeguarding issues are summarised descriptively. Economic analysis The economic evaluation was undertaken using individual-level trial data, took the NHS perspective and generated quality-adjusted life-years (QALYs) using the CHU9D. The time horizon of the analysis was set to cover all relevant costs and outcomes. Parental questionnaires were used to collect data on dental treatments and child health-related quality of life. Other sources of cost data were used in relation to the text messages and the lesson. Results Clinical effectiveness results Of the 14,083 pupils approached in the 42 recruited schools, 4699 (33.4%) were eligible and consented and were asked to complete baseline data collection; however, 19 withdrew pre randomisation leaving 4680 pupils (92.9% of our target of 5040) included in the randomised sample (intervention, n = 2262; control, n = 2418). The average number of pupils recruited per school was 111.4 [standard deviation (SD) 35.9, median 107, range 46–189] and per year group was 55.7 (SD 21.6, median 53, range 13–119). The average age of pupils at recruitment was 12.7 years (SD 0.6), 54.2% were female and 21.9% were eligible for FSM. Over three-quarters (77.6%) reported brushing their teeth at least twice a day. There was a valid baseline dental assessment for 4625 pupils; 1603 (34.7%) had evidence of obvious decay experience (presence of DICDAS4–6MFT in at least one permanent tooth) and 2929 (63.3%) had at least one treated or untreated carious lesion in any permanent tooth (DICDAS1–6MFT). Baseline data were similar between the intervention and control groups. Confirmation of lesson delivery was received from 39 of the 42 schools, with an estimated 2016 (89.1%) of 2262 pupils randomised to the intervention group attending. Text messages were sent to 2258 (99.8%) intervention pupils. The other four withdrew shortly after receiving the lesson and so their messages were not commenced. Participants were sent text messages until they requested them to stop or until 12 July 2020 (when a technical error occurred with the text provider that meant texts stopped being sent). A total of 962 intervention participants (42.5%) withdrew from receiving the text messages, a median of 2.8 months after they commenced (range 1 day to 30 months). Participants were sent messages for between 0 and 127 weeks (approximately 30 months, mean 53.4 weeks, SD 35.4, median 62). This equated to between 1 and 1708 text messages (mean 694.5, SD 468.9, median 789). On average, 71.4% of the text messages sent to a participant were successfully delivered. At 2.5 years, 1043 out of 2383 pupils (43.8%; intervention 514, 44.6%; control 529, 43.0%) had obvious decay experience in at least one permanent tooth. There was no evidence of a difference between the intervention and control groups [odds ratio (OR) 1.04, 95% confidence interval (CI) 0.85 to 1.26, p = 0.72]. The sensitivity analyses produced similar results to the primary analysis. The CACE estimates of the treatment effect based on attending the CBS session and on attending the CBS session and receiving at least 50% of their messages per week for the first 12 weeks were similar to the intention to treat estimate (OR 1.05, 95% CI 0.85 to 1.31, p = 0.64, and 1.07, 95% CI 0.72 to 1.59, p = 0.74, respectively). The CACE estimate associated with the number of texts sent was OR 1.00 (95% CI 0.999 to 1.001, p = 0.93), which indicates that for every additional text message sent, there was no evidence of a decrease in likelihood of having a carious lesion. There was no significant interaction between treatment allocation and either number of carious teeth at baseline or pilot/main trial schools, but there was evidence of a qualitative interaction for FSM status, with a benefit of the intervention seen among FSM pupils (OR 0.69, 95% CI 0.44 to 1.08, p = 0.10) but not among non-FSM pupils (OR 1.17, 95% CI 0.93 to 1.46, p = 0.18). There was evidence of a statistically significant difference for twice-daily toothbrushing at 6 months (OR 1.30, 95% CI 1.03 to 1.63, p = 0.03) and borderline evidence of a difference in gingival index score between the two groups (geometric mean difference 0.92, 95% CI 0.85 to 1.00, p = 0.05) at 2.5 years. One non-serious adverse event was recorded during the trial, which was deemed possibly related and unexpected, for a pupil in the control group. No suspected serious pathologies were identified during dental assessments. Fifteen safeguarding issues arose during the course of the trial. All were dealt with according to the trial safeguarding procedure. Cost-effectiveness results Clinical results suggested that there was unlikely to be effects beyond 2.5 years, which was therefore set as the time horizon. Due to high rates of missing data, treatment costs were estimated from dental assessment data using multiple imputation. Text messages cost £32.53 per pupil on average, while mean dental costs over the 2.5-year follow-up were £20.73 and £21.02 for control and intervention groups, respectively. QALYs were similar in the control and intervention groups (2.196 and 2.193, respectively). Regression analysis estimated incremental costs and QALYs of the intervention, relative to the control group, to be £1.02 (95% CI −1.29 to 3.23) and −0.003 (95% CI −0.009 to 0.002), respectively, with a 7% chance that the intervention is cost-effective using a £20,000 per QALY gained threshold. The results were robust to the changes explored in the sensitivity analyses, except for an alternative approach to estimating QALYs using the CARIES-QC. While this only had a very small impact on incremental costs and QALYs, it was enough to generate an incremental QALY gain, which, in combination with a very small incremental cost, generates an incremental cost-effectiveness ratio (ICER) of £79 per QALY gained and an associated probability of the intervention being cost-effective of 96%. The subgroup analyses suggest that there is no evidence of a difference in the probability of the intervention being cost-effective within schools in Scotland versus England/Wales (6% in both cases). A positive QALY gain is observed in those schools with higher levels of pupils eligible for FSM than schools with lower levels of FSM eligibility. This produces an ICER of £2254 per QALY gained and a probability of the intervention being cost-effective of 60%. We also observed a QALY gain for pilot schools which leads to the intervention having an ICER of £3049 per QALY gained (and an 84% chance of it being cost-effective). Process evaluation The process evaluation showed that the BRIGHT intervention was generally implemented as intended, although there were challenges establishing the dose delivered and received for both components and technical difficulties delivering the text messages. Overall, pupils, staff members and stakeholders felt the intervention was acceptable. Conclusions At the 2.5-year follow-up, there was no evidence of a difference between the control and intervention groups in the prevalence of caries extending to dentine (primary outcome) or including enamel and dentine lesions. The proportion of participants with caries into dentine was high (intervention group 34.4% at baseline and 44.7% at the 2.5-year follow-up, and control group 34.9% at baseline and 43.1% at follow-up). There was an indication of a positive effect on short-term toothbrushing behaviour at 6 months. The subgroup analysis of participants eligible for FSM suggests a significant, qualitative interaction effect whereby the intervention appeared to be beneficial in terms of caries prevalence within pupils eligible for FSM but not for those not eligible for FSM. The process evaluation found the intervention to be broadly acceptable with some technical issues of text message delivery. The primary economic analysis shows that the intervention is not likely to be cost-effective. Further research is needed to understand how to prevent dental caries in secondary-school pupils. Trial registration This trial is registered as ISRCTN12139369. Funding This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 15/166/08) and is published in full in Health Technology Assessment; Vol. 28, No. 52. See the NIHR Funding and Awards website for further award information.