Impact of Auxiliary Features on Retention of Short Dental Crowns: An In-Vitro Analysis of Box and Groove Preparations.

BACKGROUND Several auxiliary features have been proposed to achieve sustainable retention for short-prepared dental crowns; however, achieving retention is challenging. This study aimed to assess the impact of increased total occlusal convergence and auxiliary preparation factors like box and groove on the retention form of short tooth preparations. MATERIAL AND METHODS Eighty resin machine-milled dies with a height of 3 mm and a deep chamfer margin of 1 mm were prepared to mimic the short-prepared molar. Initially, 2 teeth were prepared following the guidelines, and the total occlusal convergence was kept at 10° and 20°, respectively. Auxiliary features such as the proximal box and buccal groove were prepared on separate 20° dies. Eighty dies were prepared with 10 samples each for 10°, 20°, 20° with proximal box and 20° with buccal groove for zirconia (n=40) and metal crowns (n=40). Cementation was done with glass ionomer luting cement, and a pull-off test was conducted. Data were analyzed using one-way analysis of variance and post hoc fisher least significant difference test (P<0.05). RESULTS The highest mean was observed in the proximal box group with the metal crown (14.59), and the lowest in the group with 20° zirconia crowns (9.12). Within groups, the highest retentive values were found for the 20° taper with proximal box preparation; the lowest was for the 20° taper group. CONCLUSIONS Within the study limitations, it could be concluded that incorporating a proximal box or buccal groove in short tooth preparations with an increased total occlusal convergence improved retentive values.

Cheminformatics and machine learning approaches for repurposing anti-viral compounds against monkeypox virus thymidylate kinase.

One of the emerging epidemic concerns is Monkeypox disease which is spreading globally. This disease is caused by the monkeypox virus (MPXV), with an increasing global incidence with an outbreak in 2022. One of the novel targets for monkeypox disease is thymidylate kinase, which is involved in pyrimidine metabolism. In this study, docking-based virtual screening and molecular dynamics techniques were employed in addition to the machine learning (ML) model to investigate the potential anti-viral natural small compounds to inhibit thymidylate kinase of MPXV. Several potential hits were identified through high-throughput virtual screening, and further top three candidates were selected, which ranked using the ML model. These three compounds were then examined under molecular dynamics simulation and MM/GBSA-binding free energy analysis. Among these, Chlorhexidine HCl showed high potential for binding to the thymidylate kinase with stable and consistent conformation with RMSD < 0.3 nm. The MM/GBSA analysis also showed the minimum binding free energy (ΔGTOTAL) of -62.41 kcal/mol for this compound. Overall, this study used structure-based drug design complemented by machine learning-guided ligand-based drug design to screen potential hit compounds from the anti-viral natural compound database.

CM-CPPA: Chaotic Map-Based Conditional Privacy-Preserving Authentication Scheme in 5G-Enabled Vehicular Networks.

The security and privacy concerns in vehicular communication are often faced with schemes depending on either elliptic curve (EC) or bilinear pair (BP) cryptographies. However, the operations used by BP and EC are time-consuming and more complicated. None of the previous studies fittingly tackled the efficient performance of signing messages and verifying signatures. Therefore, a chaotic map-based conditional privacy-preserving authentication (CM-CPPA) scheme is proposed to provide communication security in 5G-enabled vehicular networks in this paper. The proposed CM-CPPA scheme employs a Chebyshev polynomial mapping operation and a hash function based on a chaotic map to sign and verify messages. Furthermore, by using the AVISPA simulator for security analysis, the results of the proposed CM-CPPA scheme are good and safe against general attacks. Since EC and BP operations do not employ the proposed CM-CPPA scheme, their performance evaluation in terms of overhead such as computation and communication outperforms other most recent related schemes. Ultimately, the proposed CM-CPPA scheme decreases the overhead of computation of verifying the signatures and signing the messages by 24.2% and 62.52%, respectively. Whilst, the proposed CM-CPPA scheme decreases the overhead of communication of the format tuple by 57.69%.

Asymmetric Design of Spin-Crossover Complexes to Increase the Volatility for Surface Deposition.

A mononuclear complex [Fe(tBu2qsal)2] has been obtained by a reaction between an Fe(II) precursor salt and a tridentate ligand 2,4-di(tert-butyl)-6-((quinoline-8-ylimino)methyl)phenol (tBu2qsalH) in the presence of triethylamine. The complex exhibits a hysteretic spin transition at 117 K upon cooling and 129 K upon warming, as well as light-induced excited spin-state trapping at lower temperatures. Although the strongly cooperative spin transition suggests substantial intermolecular interactions, the complex is readily sublimable, as evidenced by the growth of its single crystals by sublimation at 573 → 373 K and ∼10-3 mbar. This seemingly antagonistic behavior is explained by the asymmetric coordination environment, in which the tBu substituents and quinoline moieties appear on opposite sides of the complex. As a result, the structure is partitioned in well-defined layers separated by van der Waals interactions between the tBu groups, while the efficient cooperative interactions within the layer are provided by the quinoline-based moieties. The abrupt spin transition is preserved in a 20 nm thin film prepared by sublimation, as evidenced by abrupt and hysteretic changes in the dielectric properties in the temperature range comparable to the one around which the spin transition is observed for the bulk material. The changes in the dielectric response are in excellent agreement with differences in the dielectric tensor of the low-spin and high-spin crystal structures evaluated by density functional theory calculations. The substantially higher volatility of [Fe(tBu2qsal)2], as compared to a similar complex without tBu substituents, suggests that asymmetric molecular shapes offer an efficient design strategy to achieve sublimable complexes with strongly cooperative spin transitions.

A 12-20 GHz Wideband High-Power SP2T Switch Based on Gap Waveguide Technology.

A novel wideband high-power single-pole two-throw (SP2T) switch based on gap waveguide technology is presented in this article. The proposed switch has a SP2T structure and consists of three standard WR62 waveguide ports. Due to the advantage of gap waveguide technology, the switch design structure requires no electrical contact between its different parts, and the leakage of the electromagnetic wave is suppressed. The proposed switch has an air gap between its parts. As a result, the sliding part of the switch can be moved freely to change the switch states. Consequently, a low-precision and low-cost fabrication can be utilized. The simulation and measurement of the proposed switch indicate that a 50% operating frequency bandwidth covering the range of 12-20 GHz can be achieved. The switch input return-loss is better than 15 dB within the frequency bandwidth, whereas the insertion loss and isolation levels of the proposed design are above 0.15 dB and better than 65 dB, respectively.

Bi-Directional Mutual Energy Trade between Smart Grid and Energy Districts Using Renewable Energy Credits.

A central authority, in a conventional centralized energy trading market, superintends energy and financial transactions. The central authority manages and controls transparent energy trading between producer and consumer, imposes a penalty in case of contract violation, and disburses numerous rewards. However, the management and control through the third party pose a significant threat to the security and privacy of consumers'/producers' (participants) profiles. The energy transactions between participants involving central authority utilize users' time, money, and impose a computational burden over the central controlling authority. The Blockchain-based decentralized energy transaction concept, bypassing the central authority, is proposed in Smart Grid (SG) by researchers. Blockchain technology braces the concept of Peer-to-Peer (P2P) energy transactions. This work encompasses the SolarCoin-based digital currency blockchain model for SG incorporating RE. Energy transactions from Prosumer (P) to Prosumer, Energy District to Energy District, and Energy District to SG are thoroughly investigated and analyzed in this work. A robust demand-side optimized model is proposed using Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) to maximize Prosumer Energy Surplus (PES), Grid revenue (GR), percentage energy transactions accomplished, and decreased Prosumer Energy Cost (PEC). Real-time averaged energy data of Australia are employed, and a piece-wise energy price mechanism is implemented in this work. The graphical analysis and tabular statistics manifest the efficacy of the proposed model.

Is intra-arterial hepatic chemotherapy painful?

BACKGROUND: Liver metastases are mainly supplied by the hepatic artery, allowing the administration of intra-arterial hepatic chemotherapy (IAHC) while preserving normal parenchyma. The progression-free survival and response rate are prolonged by IAHC which can improve the rate of secondary resectability. Severe abdominal pain requiring high-dose opioids can appear during HIAC administration. This pain is related to extrahepatic infusion and gastroduodenal ulceration. However, intense abdominal pain was observed under oxaliplatin IAHC specifically without any extrahepatic infusion. METHOD: We retrospectively reviewed the charts of 68 patients who received IAHC in our center between 2011 and 2015. Patient's demographics and disease characteristics were collected. Other variables such as the type, duration, and dosage of the chemotherapy administered, as well as the usage of painkillers before, during, or after intra-arterial administration, were also registered. RESULTS: The mean age of the patients was 59 years. 61.7% were male (n = 42). The mean dose of oxaliplatin administered was 162 mg per cure over 6.7-h course. Fifty percent were diagnosed with a left colon cancer, and 85.2% had synchronous liver metastasis. While 47% of patients received IAHC as a third-line therapy, the main chemotherapeutic drug was oxaliplatin (85.2% of cases; n = 58), then OPTILIV protocol (5FU, irinotecan, oxaliplatin) (13.3%; n = 9), and mitomycin C (1.5%; n = 1). A dose reduction of 23.6% had been noted in 58.8% (n = 40) cases due to adverse effects. Among patients who received opioids during IAHC (n = 40), 20% required opioids in intercure. Before, during, and after IAHC administration, patients complained of abdominal pain in 8.8%, 58.8%, and 19.1%, and opioids were used in 10.2%, 57.3%, and 19.1%, respectively. The main onset of pain occurs during the third cycle of chemotherapy. Among our patients, 11.7% and 22% had ulcer and extrahepatic perfusion, respectively, while 7.3% of them were asymptomatic. The mean occurrence of these signs was during the fourth cycle of IAHC. 33.8% and 52.9% of patients had abdominal pain while an extended and short infusion time, respectively. CONCLUSION: Lengthening of the infusion time did not prevent the occurrence of abdominal pain significantly but was nonetheless decreased compared with patients undergoing short infusion durations. Pain was more common in patients who did not have a dose reduction and who presented with ulcer and extrahepatic perfusion. Abdominal pain occurred on average one cycle before ulcer or extrahepatic perfusion diagnosis. In current practice, pain should be an alarming indicator in patients receiving IAHC, as it may be associated with ulcer or extrahepatic perfusion and thus requiring opioids.

The use of magnetic resonance phase-contrast cine in Chiari malformation with syringomyelia.

INTRODUCTION: Chiari malformation (CM) is a disorder of mesodermal origin and is commonly associated with syringomyelia. Foramen magnum decompression is the first-line of standard treatment in symptomatic patients with a confirmed radiographic diagnosis. Magnetic resonance (MR) cine allows accurate evaluation of cerebrospinal fluid (CSF) physiology at the craniovertebral junction but often this is under-utilised in Malaysia. METHODS: In this series, we looked into nine cases of CM with syringomyelia from clinical and radiological perspective before and after surgery. The radiological parameters were herniated tonsillar length, syrinx: cord ratio, syrinx length and diameter. Flow velocity and morphologic changes in Chiari were illustrated. RESULTS: Seven patients showed either reduction in syrinx length, syrinx: cord ratio or both postoperatively. Clinical recovery somewhat varied in motor and sensory symptoms. Four patients gained better functional grade in modified Rankin scale (MRS) while the rest remained similar. The study highlighted the advantage of CSF flow dynamics information over MR anatomical radiographic improvement in addressing the neurologic and functional recovery. We also discussed the practicality of cine sequence in preoperative patient selection, syrinx analysis and postoperative flow evaluation in anticipation of clinical outcome. CONCLUSION: Phase-contrast cine MRI is a useful tool dictated by resource availability. We recommend its routine use in preoperative analysis and subsequent observational follow-up after surgery.

Voltammetric determination of iodide in iodized table salt using cetyltrimethylammonium bromide as ion-pairing.

In this work, voltammetric study based on cetyltrimethylammonium bromide (CTAB) as an ion-pairing agent for the determination of iodine level in iodized table salt has been explored. CTAB was used as an intermediate compound between iodide (I-) and the electrode due to its ability to dissociate to produce cetyltrimethylammonium ions ([CTA]+). The [CTA]+ with a long hydrophobic alkyl chain can be directly adsorbed onto the surface of the working electrode, and this in turns coated the electrode with cationic charge and enhance the electrode ability to bind to iodide (I-) and other molecular iodine ions. A mixture of iodide and CTAB ([CTA]+I-) was prepared and potential of 1.0 V for 60.0 s was applied to pre-concentrate the solution on the working electrode causing the [CTA]+I- to oxidize to iodine (I2). The produced I2 immediately react with chloride ion (Cl-) from the electrolyte of hydrochloric acid (HCl) to produce I2Cl- and form ion-pair with CTA+ as [CTA]+I2Cl-. The linear calibration curve of the developed method towards iodide was in the concentration range of 0.5-4.0 mg/L with sensitivity of - 1.383 µA mg/L-1 cm-2 (R2 = 0.9950), limit of detection (LOD) of 0.3 mg/L and limit of quantification (LOQ) of 1.0 mg/L, respectively. The proposed method indicates good agreement with the standard method for iodine determination with recovery range from 95.0 to 104.3%. The developed method provided potential application as a portable on-site iodine detector.

Hepatitis C virus infection in Jeddah city, Saudi Arabia: Seroprevalence and knowledge.

The infection rate of the hepatitis C virus (HCV) in Saudi Arabia is among the lowest in the world. However, it is likely that poor knowledge and awareness of HCV infection could minimize the effectiveness of prevention and control programs in the kingdom. Thus, the study objective was to estimate the prevalence of HCV infection, and to assess current knowledge about it, in the targeted population. Data on 5482 Saudi people attending primary healthcare centers in Jeddah City in 2014/2015 were analyzed in this cross-sectional study. Questions that covered the natural history, risk behavior, and prevention, and treatment of HCV were collected using a predesigned questionnaire. HCV seroprevalence was assessed using an enzyme-linked immunosorbent assay. HCV prevalence of 0.38% (95% confidence interval: 0.22-0.54) was found. The level of knowledge of the natural history, risk behavior, and prevention and treatment of HCV was poor among the participants. The lowest level of knowledge for all participants pertained to its prevention and treatment. The prevalence of HCV was low in Saudi Arabia (0.38%). However, adequate knowledge of HCV was lacking. Thus, the need to increase knowledge and awareness of HCV in the Saudi population is warranted.

Human infection with MERS coronavirus after exposure to infected camels, Saudi Arabia, 2013.

We investigated a case of human infection with Middle East respiratory syndrome coronavirus (MERS-CoV) after exposure to infected camels. Analysis of the whole human-derived virus and 15% of the camel-derived virus sequence yielded nucleotide polymorphism signatures suggestive of cross-species transmission. Camels may act as a direct source of human MERS-CoV infection.

Bilateral subtentorial empyema complicated with nosocomial acinectobacter ventriculitis: a case report.

Subtentorial subdural empyema is a rare and life threatening intracranial suppuration. It is usually an intracranial complication of otogenic infections. Early diagnosis and surgical drainage are the most important factors determining prognosis. The high mortality reported in the literature reflects the severity of subtentorial subdural empyema if proper management is delayed. Intracranial infections usually require between 4 to 6 weeks of intravenous antibiotics therapy. However, the prolonged duration of hospitalization as well as requirement for neurosurgically inserted indwelling devices may predispose these patients to new nosocomial infections.

Tactile working length determination for root canal therapy in underserved settings.

DESIGN: Multicentre randomised controlled clinical trial in a rural underserved African setting. INTERVENTION: The technical and electrical infrastructure still remains unstable in Gambia. Therefore, block randomisation was chosen. Patients included in 2010 were treated according to the original BRT method with tactile working length determination, whereas patients included in 2011 were treated with radiographic working length control. During the latter study period and the 24-month evaluation, a generator was provided to ensure sufficient power supply to run a radiographic unit. OUTCOME MEASURE: The primary end point was the apical extension score of the radiographic quality parameter of root canal fillings. The secondary radiographic end point was the periapical index, and the secondary clinical end point was tooth tender to percussion. The safety end point was tooth loss as a consequence of endodontic failure. RESULTS: BRT with tactile working length determination compared with standard radiographic working length control did not significantly differ in terms of radiographic and clinical outcomes after 24 months. The apical extension of the root canal fillings and the periapical anatomic structures showed no significant differences according to radiographic analyses (P = 0.5). Corresponding results were found in clinical aspects of tooth tender to percussion (P = 0.6) and tooth loss (P = 0.7). CONCLUSIONS: Within the limits of this randomised controlled trial it was shown that tactile working length determination in BRT resulted in comparable treatment outcomes in radiographic and clinical aspects compared with standard endodontic treatment with radiographic working length determination. Tactile working length determination turned out to be an accurate method in BRT.

Predictability of Insulin Resistance Based on the Clinical Manifestations Among Male Medical Students of a Private College in Saudi Arabia.

Background Numerous clinical signs and symptoms are thought to be associated with insulin resistance. The purpose of this study was to examine the prevalence of insulin resistance among male medical students attending a private Saudi Arabian institution, based on clinical indications. Methods A convenient non-probability sample consisting of 241 male medical students was used to conduct cross-sectional research. Each participant had an in-person interview as well as anthropometric measurements. The interview consisted of a questionnaire that was used to assess demographic data and clinical manifestations related to insulin resistance. Results The study demonstrated the connection between a few dermatological symptoms and waist circumference as an indicator of insulin resistance. In both the high and normal waist circumference groups, acne was the most common symptom. There was no correlation found between waist circumference and psoriasis, hidradenitis suppurativa, androgenic alopecia, alopecia areata, or vitiligo. Nevertheless, as an indicator of insulin resistance, waist circumference was statistically significantly correlated with both skin tags and acanthosis nigricans. Most students had excessive day sleep, foggy brains, struggled with planning and solving problems, and had a memory that became worse in the past few years. In addition, many students feel hungry even after eating some sweets and usually have extreme thirst. Conclusion Among medical students, skin tags, acanthosis nigricans, and acne were the most prevalent dermatological manifestations. Clinicians need to be aware that skin conditions, sleep difficulties throughout the day, changes in cognition, and food cravings might all be indicators of internal changes and/or illnesses such as diabetes and prediabetes.

Efficacy of Faculty Development Training Workshops (FDTWs) on Writing High-Quality Multiple-Choice Questions at Northern Border University (NBU) in the Kingdom of Saudi Arabia (KSA).

BACKGROUND: A multiple-choice question (MCQ) is a frequently used assessment tool in medical education for both certification and competitive examinations. Well-constructed MCQs impact the utility of the assessment and, thus, the fate of the examinee. AIMS AND OBJECTIVES: To analyze the basic science faculty perceptions of writing high-quality MCQs, to create awareness of item-writing flaws in constructing high-quality MCQs, and to determine the impact of faculty development training workshops (FDTWs) on MCQ writing skills. MATERIAL AND METHODS: An online workshop was held over two weeks for basic science faculty to learn high-quality MCQ construction. Faculty-made MCQs were analyzed for flaws, and a questionnaire assessed the impact of the workshop on MCQ construction. Pre- and post-workshop responses were compared to evaluate the necessity of such workshops for improving faculty skills in MCQ assessments. RESULTS: A total of 47 (83.2%) of participating faculty believed the workshop could reduce MCQ construction errors. The participants agreed that a series of workshops were needed for lasting improvements in MCQ construction. CONCLUSIONS: One-day short-duration workshops, such as the current one alone, cannot achieve the objectives of training participants to write high-quality MCQs. To improve student assessment through high-quality MCQs, the faculty needs to be exposed to continuous and frequent sessions that will help them.

Awareness and Hygiene Practices Among Contact Lens Wearers: A Population-Based Cross-Sectional Survey.

Background More than 150 million individuals worldwide wear contact lenses (CL) for therapeutic as well as cosmetic purposes. Researchers have linked failure to adhere to CL care instructions with outbreaks of serious eye infections. In the current study, we assess the consequences of inadequate cleanliness as well as awareness of and adherence to appropriate CL hygiene. Methods This is a cross-sectional descriptive study conducted in the Jazan region, southwest Saudi Arabia, during the period between October 2022 and April 2023. Results Out of a total of 718 participants, 391 (54.4%) were wearing CL. Of these, 318 (81.33%) CL wearers were female, while 73 (18.67%) were male. Among the CL wearers, 196 (50%) were aged 24 and younger. The overall knowledge was higher in females, with 320 (74.6%) having a high level of knowledge, compared to 195 (67.5%) males (p-value = 0.044). The level of knowledge was higher in those who had had an eye examination before using CL. Regarding practice, 202 (63.5%) females demonstrated better practices, while only 32 (43.8%) males did (p-value = 0.002). Variations in the adequacy of practice regarding CLs were identified according to the duration of CL use and the risk of suffering from eye dryness (p-values <0.05). Conclusions The participants' overall knowledge and practices were good. This should be encouraged by performing an eye examination before wearing CL and demonstrating good wearing habits in terms of hygiene behavior.

Publications in Plastic Surgery and Reconstruction: A Review from a Developing Country, Sudan.

Background: Plastic and reconstructive surgery services need to be improved in developing African countries. Research and article publications from those countries are limited. This review was conducted to identify published articles from Sudan in the area of plastic and reconstructive surgery. Methods: This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines were used for the preparation of this systematic review. A comprehensive systematic search was performed using PubMed, ScienceDirect, and Web of Science databases. Articles published in Sudan, specifically in the area of plastic and reconstructive surgery, and written in English were included in this review. Results: The total number of articles that fulfilled the inclusion criteria was 23. The articles were written from 1969 to 2023. Only two articles were published in the 20th century. The most common study type was a retrospective study of eight articles, and the most common study area was Khartoum Teaching Hospital. Regarding the publishing journals, the number of subscription journals was six (30%), whereas open access was 17 (70%). Conclusion: This review demonstrates the lack of articles published on plastic surgery in Sudan. Further investigation is needed to determine the challenges and problems associated with possible clarifications.

Serological markers of transfusion transmissible infections and ABO blood groups in Najran, Saudi Arabia.

OBJECTIVES: To ascertain the prevalence of transfusion transmissible infections (TTIs) across diverse donor groups in the Najran province. Additionally, to establish a potential association between the development of TTI and the donors' blood group, as determined by the ABO/Rh blood grouping system. METHODS: Blood donation data of 4120 donors, spanning from January to December 2020, were retrospectively reviewed. The blood were screened for TTI markers, including hepatitis B surface antigen (HBsAg), anti-hepatitis B core (anti-HBc), anti-hepatitis C virus (anti-HCV), anti-human immunodeficiency viruses 1 and 2 (anti-HIV1&2), anti-human T-lymphotropic virus types 1 and 2 (anti-HTLV-1&2), and syphilis antigen. RESULTS: Positive TTI markers were detected in 10.9% of the donors. The most detected TTI marker was anti-HBc (8.9%), followed by HBsAg (0.7%). Other markers were individually detected in <1% of the donors. Anti-HBc-positive was significantly elevated among non-Saudi blood donors. There was an association between age groups and anti-HCV (p=0.002), anti-HTLV (p=0.004) and syphilis antigen (p=0.02) markers positivity. The AB positive blood group exhibited the most positivity for TTI markers, followed by O positive blood group. Similarly, association was found between ABO group and HBsAg (p=0.01), anti-HBc (p=0.001), and anti-HCV (p<0.001) markers positivity. CONCLUSION: Emphasis on implementing robust screening measures for donated blood is underscored by this study. There is the need for future study to extensively evaluate TTI status to enhance our understanding of the trend in TTI.

Retraction: Mesenteric Panniculitis and COVID-19: A Rare Association.

[This retracts the article DOI: 10.7759/cureus.21314.].

Retraction: A Rare Case of Solitary Schwannoma of Submandibular Gland.

[This retracts the article DOI: 10.7759/cureus.21373.].