Peristaltic motion of Jeffrey fluid with nonlinear mixed convection.

Since previous few decays the consideration of non-Newtonian liquids motion due to its immense usages in medicine, biology, industrial procedures, chemistry of catalysts and in environment. Various studies examine the significance of bio-materials flow in physiological procedures to explore the cure of diagnosed symptoms of disease appearing during movement in a human physiological system. To illustrate the characteristics of physiological liquids various non-Newtonian models have been proposed, but yet no such single liquid model is exploited which describes all the properties of nonlinear behaving liquids. Among these several non-Newtonian models, Jeffery liquid model should be reduced to its base fluid case (i.e. viscous liquid) by choosing λ1 = λ2 = 0. Various physiological materials which represents both linear and nonlinear characteristics respectively blood is one of these. Jeffery fluid and peristaltic motion have some common properties such as radii, relaxation time and retardation time. Moreover heat and mass transfer is also an important phenomenon which is suitable for various physiological processes such as hemodialysis and oxygenation etc. Thus due to such motivating facts this research is conducted to investigate the peristaltic motion of electrically conducting Jeffery liquid. The peristaltic propagating channel walls are asymmetric and inclined. Joule heating and magnetic field effects are considered by applying magnetic field in transverse direction to the flow. Further conservation laws modelled the flow situation via considering quadric mix convection, thermos diffusion and diffusion-thermos, heat generation and absorption, chemical reaction with activation energy features. Moreover, creeping flow and long wavelength assumptions are used to simplify the mathematical modelling. The reduced system of equation is solved numerically through built-in technique in Mathematica software. This built-in technique is working through ND Solve command and shooting and RK-Felburg numerical schemes are behind this technique. These numerical results are used to discuss the flow quantities i.e., velocity, temperature and concentration against the sundry dimensionless quantities. Examining the results it comes to know that both thermal and concentration nonlinear mix convection have oppositely affecting the axial velocity. Both heat and mass transfer are escalating function of thermo-diffusion/diffusion-thermo aspects.

Comparison of fracture resistance of fiber-reinforced post and core with different cementation techniques: in vitro study.

OBJECTIVE: The current study aimed to inspect the fracture resistance of fiber post to canal dentin using a different technique of cementation. MATERIALS AND METHODS: 60 sound single-rooted central incisors with comparable size and length were stored in normal saline. Each tooth was immersed in 5% sodium hypochlorite (NaOCl). The specimens were randomly divided into 6 groups of 10 specimens each. All included specimens received root canal treatment (RCT). Post-space preparation was done using Gates Glidden drills. Post space was standardized with 10 mm length, keeping 3 to 5 mm as an apical seal. Based on the cementation technique samples were divided into six study groups. Group A: One step-Monoblock; Group B: One step- Monoblock-NA-FP; Group C: One step-Monoblock-RX-MC; Group D: Two-step- RX-MC; Group E: Two-step- RX-FZ; Group F: Two-step- RX-FZ-Custom post. Following cementation, all teeth will be prepared to receive a monolithic zirconia crown with a finish line of 1 mm above the CEJ. Each specimen was mounted in auto-polymerizing clear acrylic resin using a preformed tube. All samples were subjected to pushing forces to measure the fracture strength of the specimen using a universal testing machine. To compare the means among different experimental groups Post Hoc Tukey multiple comparison tests and analysis of variance (ANOVA) were adopted. RESULTS: The highest fracture resistance was observed in group A. Whereas, the lowest fracture resistance was observed in group D samples. Fracture strength in group A samples showed significantly higher fracture resistance values compared to all other groups (p < 0.05). Fracture resistance values in group F specimens were significantly higher than specimens in groups B, C, D, and E respectively (p < 0.05). CONCLUSIONS: Monoblock technique using single cementation and core material (Multicore Flow) when polymerized simultaneously exhibited the highest fracture resistance of glass fiber post compared to other cementation techniques.

Awareness of current mobile apps for smoking cessation among the dental and medical practitioners in Saudi Arabia.

OBJECTIVE: This study aimed at assessing whether the dental and medical practitioners in Saudi Arabia are aware of the smoking cessation smartphone applications and their opinions about this method used in smoking cessation. MATERIALS AND METHODS: A self-reporting questionnaire was designed to assess the level of knowledge and awareness among the dental and medical practitioners regarding the smartphone mobile applications for smoking cessation. The content of the questionnaire was validated and sent to individual physicians through email, WhatsApp, Twitter and other social media platforms, which also contained a consent form and explanation of the study. Responses were summarized using descriptive statistics by frequencies and percentages. A Chi-square test was used to observe the differences in opinions of smoking cessation apps between smokers and non-smokers among all the participants. RESULTS: A total of 420 responses were obtained from the dental and medical professionals (291 males and 129 females) in different ranks. Among all the participants, 46.7% were in the age range of 30-40 years. The profession of the participants was divided into four groups and general dental practitioners are the most respondents compared to other practitioners. Among all the participants, 31% were smokers and the rest were non-smokers. Overall, 12.6% of participants and 20.8% of participants who were smokers were aware of the mobile applications which are used for smoking cessation. CONCLUSIONS: The dental and medical practitioners in Saudi Arabia are not relatively acquainted with mobile apps for smoking cessation.

Labial alveolar bone thickness and its correlation with buccolingual maxillary incisors angulation: a CBCT based study.

OBJECTIVE: Understanding the labial alveolar bone thickness (ABT) and buccolingual teeth angulation may reduce the complication that might arise during or post-operative treatment. The operator could determine the precise method to ensure long-term treatment success. This study aimed to evaluate the ABT with buccolingual upper incisor teeth angulation based on the maxillary plane by using the cone-beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 371 CBCT radiographs were initially assessed and 100 CBCT radiographs were included. On the maxillary incisors, the labial alveolar bone thickness is evaluated at three points (Point A: Four mm below from CEJ, Point B: Midpoint from the labial alveolar-palatal alveolar crest plane and root apex. Point C: Root Apex of the tooth). The distance from these points to labial alveolar bone was measured for the ABT. Moreover, buccolingual angulation of the tooth was measured by the angle formed by the maxillary plane and the long axis of the tooth. RESULTS: There is no significant difference observed between genders in the labial alveolar bone thickness. The labial alveolar bone thickness grew gradually from the cementoenamel junction (CEJ) level to the apical level. Moreover, there was a statistically significant positive correlation observed between labial alveolar bone thickness at the apical level (Point C) and angulation (p<0.05). CONCLUSIONS: The labial bone thickness was less than 2 mm in the majority of cases at the three points among maxillary incisors. In addition, there is a correlation between buccolingual angulation of the maxillary incisors and labial alveolar bone thickness.

Comparative assessment of periodontal treatment needs among the electronic cigarette users and traditional smokers.

OBJECTIVE: It is currently presumptuous that electric cigarettes are less harmful than the conventional ones; this is increasing the consumption of electric cigarettes. Therefore, this study intended to evaluate the periodontal treatment needs among conventional smokers, electronic cigarette smokers and non-smokers. This cross-sectional designed study involved 150 patients with a mean age of 29.88±7.81 years. PATIENTS AND METHODS: Among all patients, 50 patients were recruited in each group. The periodontal condition and the treatment need for the patients were assessed using the community periodontal index treatment need (CPITN). Fisher exact test was used to find the significant association of all three groups with the periodontal status and the treatment need. Female patients (12.5%) showed better periodontal status than the male patients (87.5%) and required less complicated periodontal treatment independently from smoking type. RESULTS: Furthermore, deeper pocket depth ≥6 mm (75%) has been found among the conventional cigarette smokers whereas the majority of the electric cigarette smokers (50%) have calculus deposition. Thus, 50% of the electric smokers require professional scaling whereas 57.1% of conventional smokers prerequisite complex periodontal treatment. CONCLUSIONS: Besides, there was a significant difference (p≤0.05) observed among all groups in periodontal health index and treatment need. Conventional cigarette consumers need more complicated periodontal treatment compared to the patients who consume electric cigarettes.

Effect of tonsillectomy on humeral and cellular immunity: a systematic review of published studies from 2009 to 2019.

BACKGROUND: Although tonsillectomy is the most commonly performed surgical operation for children, its postoperative effect on the immune response was a source of debate among physicians. PURPOSE: The aim of this systemic review was study the effect of tonsillectomy on children immune response. DATA SOURCES: PubMed, Medline, Embase and Cochrane Library. REVIEW METHODS: All relevant articles published English language addressing the effect of tonsillectomy on the immune system were included. One investigators extracted data regarding: year of the study, sample size, study design, sample size, timing of analysis, studied immune factors, result and conclusion were identified. Another investigator independently reviewed data accuracy. RESULTS: Ten articles published between from January 2009 to January 2019 in about this issue that included 404 children were reviewed. All reviewed studies showed a non-significant difference between levels of indicators of the humeral immunity (IgA, IgG, IgM, C3 and C4) pre- and postoperatively. Studies that measured these indicators only after surgery, showed a non-significant difference in their levels between patients and healthy controls. Levels of indicators of cellular immunity (CD4+ , CD3+ , CD8+ , CD19+ , CD25+ , CD16+ , CD+ 56) showed slight reduction or increase in some studies but without a significant difference compared to their levels preoperatively, postoperatively at different intervals or with healthy controls. Other studies found no changes in these indicators postoperatively. CONCLUSION: There was enough evidence to conclude that tonsillectomy has no negative affect on both humeral and cellular immunity of children.

The effect of human interferon alpha on replication of different bovine viral diarrhea virus strains.

Bovine viral diarrhea virus (BVDV) exists in two main biotypes: cytopathic (cp) and noncytopathic (ncp). Although some studies were done on the effect of interferon alpha (IFN-α) on BVDV, the effect of exogenous IFN against BVDV biotypes remains unclear. In the present study, we evaluated the comparative effect of exogenous human IFN-α (HuIFN-α) on different BVDV biotypes and genotypes. The results showed that exogenous HuIFN-α greatly inhibited the growth of different BVDV biotypes and genotypes. However, HuINF-α has a significant inhibitory effect on cp biotype compared to ncp one without significant variation between different genotypes. The effect of HuIFN-α on BVDV reached the maximum level at early stages of infection (0-20 h post infection) and increased in a dose-dependent manner (10-500 U/ml). Quantitative real-time RT-PCR was used to evaluate the effect of exogenous HuIFN-α on RNA synthesis of both BVDV biotypes. HuIFN-α reduced RNA production of cp by 4 logs compared to only 2 logs for ncp strains. Additionally, the antiviral effect of IFN-α against both BVDV biotypes seems to be independent of the RNA-dependent protein kinase (PKR) activation as assayed by direct analysis of in vivo phosphorylation of eIF2-α and by 2-aminopurine (2-AP) treatment. Collectively, these results indicated that the exogenous HuIFN-α treatment has an inhibitory effect not only on cp BVDV biotype but also on the ncp BVDV. The antiviral effect of exogenous HuIFN-α was biotype, time, dose but not genotype dependent. PKR has no role in the inhibitory effect suggesting that other IFN-antiviral pathways were involved. Keywords: BVDV biotypes; HuIFN-α; RNA synthesis; PKR-independent.

Comparison of mesiodistal tooth width in individuals from three ethnic groups in Southern Saudi Arabia.

OBJECTIVE: The aim of this study was to compare the mesiodistal tooth sizes and to see the gender dimorphism among three ethnic groups of southern part of Saudi Arabia, that is, Asir, Najran, and Jizan region. SUBJECTS AND METHODS: The sample composed of 90 individuals (45 of each gender) from 3 different regions of southern Saudi Arabia, having mean age of 26.9 years. The measurements were done directly on the models with the aid of the digital calliper measuring the largest mesiodistal measure of incisors, canines, premolars, and molars in both sides. RESULTS: Almost all the mesiodistal tooth widths were statistically significant between the groups except maxillary and mandibular permanent third molars. Regarding sexual dimorphism, the groups were combined; almost all the mesiodistal tooth widths were not shown statistically significant difference between the males and females except that right first permanent premolars were significantly larger in the females than in the males. CONCLUSION: The present study has provided norms of the mesiodistal permanent tooth diameters of a Saudi population that are newer and more complete than the previously published norms. There appear to be some secular trends in the mesiodistal diameter of the Saudi permanent teeth toward sexual dimorphism.

Effect of Tdap upon antibody response to meningococcal polysaccharide when administered before, with or after the quadrivalent meningococcal TT-conjugate vaccine (coadministered with the 13-valent pneumococcal CRM197-conjugate vaccine) in adult Hajj pilgrims: A randomised controlled trial.

Hajj pilgrims are susceptible to several serious infections and are required to receive multiple vaccinations. Polysaccharide-protein conjugate vaccines contain carrier proteins such as tetanus toxoid (TT), diphtheria toxoid or a mutant of diphtheria toxoid (CRM197). These carrier proteins may interact with other conjugate or combination vaccines containing tetanus or diphtheria on concurrent or sequential administration. We examined the immune interaction of separate and concomitant administration of a tetanus/diphtheria/acellular pertussis (Tdap) vaccine with a TT-conjugated quadrivalent meningococcal vaccine (MCV4) (coadministered with 13-valent pneumococcal CRM197-conjugate vaccine [PCV13]) in adult Australian pilgrims before attending Hajj in 2015. We randomly assigned each participant to one of three vaccination schedules. Group 1 received Tdap 3-4 weeks before receiving MCV4 coadministered with PCV13. Group 2 received all three vaccines concomitantly. Group 3 received MCV4 and PCV13 3-4 weeks before Tdap. Blood samples were collected at baseline, at each vaccination visit and 3-4 weeks after vaccination and tested for response to meningococcal serogroups C, W and Y using a serum bactericidal antibody (rSBA) assay with baby rabbit complement, and to diphtheria and tetanus toxoid, measuring IgG antibodies by ELISA. Participants completed symptom diaries after each vaccination. A total of 166 participants aged 18-64 (median 42) years were recruited, of whom 160 completed the study. Compared to the other groups, Group 1 (given Tdap first) had significantly lower proportion of subjects achieving a ≥4-fold rise in rSBA for serogroup W. No difference was detected across the three groups in achieving protection threshold (rSBA ≥8 post vaccination) or SBA geometric mean titre (GMT) post vaccination. Group 3, which was given MCV4/PCV13 first, had high levels of antibody against diphtheria and tetanus than the other groups, when tested prior to receipt of Tdap; Only the anti-tetanus responses remained significantly higher after Tdap administration. No serious adverse events were reported. In conclusion, when multiple vaccination is required for Hajj pilgrims, administering Tdap concurrently with MCV4/PCV13 produces adequate immune responses, and avoids meningococcal immune interference, in the convenience of a single consultation. However, giving Tdap 3-4 weeks after MCV4/PCV13 has the advantage of an enhanced tetanus toxoid response. The trial is Trials Registry (ANZCTR): ACTRN12613000536763.

Effect of Tdap when administered before, with or after the 13-valent pneumococcal conjugate vaccine (coadministered with the quadrivalent meningococcal conjugate vaccine) in adults: A randomised controlled trial.

Sequential or co-administration of vaccines has potential to alter the immune response to any of the antigens. Existing literature suggests that prior immunisation of tetanus/diphtheria-containing vaccines can either enhance or suppress immune response to conjugate pneumococcal or meningococcal vaccines. We examined this interaction among adult Australian travellers before attending the Hajj pilgrimage 2014. We also investigated tolerability of these vaccines separately and concomitantly. We randomly assigned each participant to one of three vaccination schedules. Group A received adult tetanus, diphtheria and acellular pertussis vaccine (Tdap) 3-4weeks before receiving CRM197-conjugated 13-valent pneumococcal vaccine (PCV13) and CRM197-conjugated quadrivalent meningococcal vaccine (MCV4). Group B received all three vaccines on one day. Group C received PCV13 and MCV4 3-4weeks before Tdap. Blood samples collected at baseline, each vaccination visit and 3-4weeks after vaccination were tested using the pneumococcal opsonophagocytic assay (OPA) and by ELISA for diphtheria and tetanus antibodies. Funding for meningococcal serology was not available. Participants completed symptom diaries after each vaccination. A total of 111 participants aged 18-64 (median 40) years were recruited. No statistically significant difference was detected across the three groups in achieving OPA titre ⩾1:8 post vaccination. However, compared to other groups, Group A had a statistically significant lower number of subjects achieving ⩾4-fold rise in serotype 3, and also significantly lower geometric mean titres (GMTs) to six (of 13) pneumococcal serotypes (3, 5, 18C, 4, 19A and 9V). Group C (given prior PCV13 and MVC4) had statistically significant higher pre-Tdap geometric mean concentration (GMC) of anti-diphtheria IgG; however, there was no difference across the three groups following Tdap. Anti-tetanus IgG GMCs were similar across the groups before and after Tdap. No serious adverse events were reported. In conclusion, Tdap vaccination 3-4weeks before concomitant administration of PCV13 and MCV4 significantly reduced the antibody response to six of the 13 pneumococcal serotypes in adults. The trial is registered at the Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12613000536763.

Australian Hajj pilgrims' knowledge, attitude and perception about Ebola, November 2014 to February 2015.

Upon return from Hajj 2014, 150 Australian pilgrims were interviewed about their understanding of the Ebola epidemic. Most (89%, 134/150) knew of the epidemic before travelling and 60% (80/134) of those knew Ebola transmits through body fluids. Pilgrims who received pre-travel health advice were more conscious of Ebola (69% vs 31%, p = 0.01) and adhered better to hand hygiene after touching an ill person (68% vs 31%, p < 0.01). Mass media was the main information source (78%).

Vaccinations against respiratory tract infections at Hajj.

The transmission of respiratory tract infections (RTIs) is very high among the Hajj congregation in Mecca, Saudi Arabia. Despite recommendations for vaccinations, pilgrims remain at increased risk of RTIs. In this paper we systematically reviewed available studies assessing the uptake and effectiveness of vaccinations against RTIs among Hajj pilgrims and enumerated important demographic factors, if described, associated with vaccine uptake. Of the 42 included studies, 29 reported on the uptake and effectiveness of influenza vaccine among pilgrims, eight studies reported the uptake of other vaccines, notably pneumococcal, diphtheria and bacillus Calmette-Guérin vaccines, and the remaining five studies described both influenza and non-influenza vaccines. The uptake of seasonal influenza vaccine ranged from 0.7% to 100% across the study populations, with coverage highest in the elderly and those with pre-existing co-morbidities. The effectiveness of influenza vaccine was variable across studies but was significantly effective against laboratory-confirmed influenza (risk ratio 0.56; 95% CI 0.41-0.75; p <0.001) in pooled metadata from six studies. Uptake of diphtheria and pneumococcal vaccines was low, and the only study reporting pertussis among Hajj pilgrims found the presence of pre-Hajj immunity to be significantly protective against disease. Despite favourable evidence of effectiveness, our review shows variable uptake of vaccines across a number of studies with few data available on the uptake of non-influenza vaccines. Mixed-method studies are needed to gauge knowledge, attitudes and practices of Hajj pilgrims regarding vaccination, and randomized controlled trials are required to confirm the efficacy of vaccines and improve uptake in this vulnerable travelling population.