Bessel light beam for a surgical laser focusing telescope-a novel approach.

As the demand for CO[Formula: see text] laser surgeries continues to grow, the quality of their main instrument, the laser micromanipulator, becomes increasingly important. However, in many surgery systems, a large ratio of the laser power is wasted due to the reflection from the mirror of a telescopic system, like a Cassegrain telescope, back to the laser side, which not only decreases the system's efficiency but can also damage the system itself. In this article, we introduce a new design of the micromanipulator telescope for CO[Formula: see text] laser surgery, which employs a Bessel beam to improve the system efficiency. As in the propagation of a Bessel beam, the power of the light beam can be transferred from the center to a ring shape, the whole power reflected from the first mirror can reach the second mirror and no power goes back to the second mirror hole. The micromanipulator telescope design and optimization are carried out using Zemax Optics Studio, and the integration of the Bessel beam into the system is implemented using MATLAB. Our simulation results show that by applying the appropriate Bessel beam, the system efficiency can reach more than 96%, and the normalized peak irradiance can increase by 40 to 73% for various working distances. In addition to increasing the system efficiency and normalized peak irradiance, resulting in a sharper surgical blade, the use of the Bessel beam enhances the depth of focus, making the system less sensitive to depth misalignment.

Effectiveness of full Pulpotomy compared with Root canal treatment in managing teeth with signs and symptOms indicative of irreversible pulpitis: a protocol for prospectiVE meta-analysis of individual participant data of linked randomised clinical trials (PROVE).

BACKGROUND: Full pulpotomy has been proposed as an alternative to root canal treatment in teeth with signs and symptoms indicative of irreversible pulpitis (IRP), but the evidence is limited, relying on underpowered studies with a high risk of bias. The aim of this study is to conduct a prospective meta-analysis (PMA) of individual participant data of a series of individual randomised trials to provide robust evidence on the clinical and cost-effectiveness of pulpotomy compared with root canal treatment. METHODS: Individual participant data will be obtained from a series of randomised trials designed and conducted by a consortium of multi-national investigators with an interest in vital pulp treatment. These individualised trials will be conducted using a specified protocol, defined outcomes, and outcome measures. Ten parallel-group randomised trials currently being conducted in 10 countries will provide data from more than 500 participants. The primary outcome is a composite measure defined as (1) the absence of pain indicative of IRP, (2) the absence of signs and symptoms indicative of acute or chronic apical periodontitis, and (3) the absence of radiographic evidence of failure including radiolucency or resorption. Individual participant data will be obtained, assessed, and checked for quality by two independent reviewers prior to the PMA. Pooled estimates on treatment effects will be generated using a 2-stage meta-analysis approach. The first stage involves a standard regression analysis in each trial to produce aggregate data on treatment effect estimates followed by an inverse variance weighted meta-analysis to combine these aggregate data and produce summary statistics and forest plots. Cost-effectiveness analysis based on the composite outcome will be undertaken as a process evaluation to evaluate treatment fidelity and acceptability by patients and dentists. RESULTS: The research question and trial protocol were developed and approved by investigators in all 10 sites. All sites use shared resources including study protocols, data collection forms, participant information leaflets, and consent forms in order to improve flow, consistency, and reproducibility. Each site obtained its own Institutional Review Board approval, and trials were registered in appropriate open access platforms. Patient recruitment has started in most sites, as of July 2023. DISCUSSION: PMA offers a rigorous, flexible, and efficient methodology to answer this important research question and provide results with improved generalisability and external validity compared with traditional trials and retrospective meta-analyses. The results of this study will have implications for both the delivery of clinical practice and structured clinical guidelines' development. TRIAL REGISTRATION: PROSPERO CRD42023446809. Registered on 08 February 2023.

Beyond the symptoms: Personalizing giant cell arteritis care through multidimensional patient reported outcome measure.

BACKGROUND: Giant Cell Arteritis (GCA) is the commonest form of systemic vasculitis in people over the age of 50. Published research highlighted the lack of a disease-specific patient reported outcomes (PROMs) for GCA. OBJECTIVES: To assess the validity, reliability and responsiveness to change of a devised disease specific patient self-reported outcome measures questionnaire for Giant Cell Arteritis (GCA). METHODS: The GCA-PROMs was conceptualized based on frameworks outlined in the OMERACT developed core set of Outcome Measures for Large-Vessel Vasculitis and the guiding principles of the FDA guidance. Initially, cognitive interviews were conducted to identify item pool of questions. Item selection and reduction was achieved based on patients as well as an interdisciplinary group of specialists. Rasch and internal consistency reliability analyses were implemented. RESULTS: A total of 54 GCA patients completed the questionnaire. The GCA-PROMs questionnaire was reliable as demonstrated by a high standardized alpha (0.878-0.983). Content construct assessment of the GCA-PROMs functional disability and QoL revealed significant correlation (p< 0.01) with both HAQ and EQ-5D. Changes in functional disability, QoL showed significant (p< 0.01) variation with diseases activity status in response to therapy. CONCLUSIONS: The developed GCA-PROMs questionnaire is a reliable and valid instrument for assessment of GCA patients. A stratified treatment regimen depending on the individual patient's risk factors as well as preferences and associated comorbidities is the best approach to tailored patient management.

Improving productive performance, immunity, and health status of growing rabbits by using honey bee venom (Apis mellifera).

To investigate the effect of bee venom (BV) as a natural growth promotor on growing rabbits as an alternative to antibiotics, sixty 35-day-old Californian male rabbits with an average body weight of 584 ± 9 gm were randomly divided into five equal groups as follows: The 2nd group received drinking water supplied with 10 mg Oxytetracycline (OXT), while the 3rd, 4th, and 5th groups received 2, 4 and 8 mg bee venom (BV)/kg body weight/day in drinking water, and the first group was served as a control group. The growth performance features were positively impacted by adding BV (p ≤ 0.01) compared to the control, whereas LBW and BWG increased and FI reduced. Significantly improved carcass characteristics (p ≤ 0.01) as a result of the BV supplementation. Blood characteristics showed a significant reduction (p ≤ 0.01) in liver enzyme activities and Cholesterol, Triglycerides, and Low-density lipoproteins Cholesterol (LDL) as affected by BV treatment; inversely, total protein and globulin were significantly increased (p ≤ 0.01). Similarly, BV had a positive effect (p ≤ 0.01) on anti-oxidant status (Total anti-oxidant capacity (TAC), Glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT)). In contrast, the lipid peroxidation biomarker (Malondialdehyde (MDA)) was significantly decreased. The immunoglobulin (IgG and IgM) was significantly increased (p ≤ 0.01) by BV treatment. There was a positive effect of low BV levels on decreasing both cecum TBC and pathogenic bacterial count (Salmonella spp., E.coli spp., Proteus spp., and Clostridia spp.) that was significant (p ≤ 0.01). In conclusion, BV can be a natural growth promoter to enhance growth performance traits, immunological and anti-oxidative responses, and reduce pathogenic bacteria in the hindgut of growing rabbits.

In-Ovo injection of melittin into Alexandria chicken eggs: a way for early immune acceleration.

This study intended to assess the properties of in-ovo administration of Melittin (MLT) on hatchability, chick yield, hematology, immunological indices and relative organs weight of Alexandria chickens at hatch. A total of 600 eggs with an average weight of (45.12 g), were gathered and split into five groups: a non-injected group or negative control (NC), a saline injection group or positive control (PC), and three concentrations of MLT (5, 10 and 15 µg of MLT per egg, respectively). On day 18 of incubation, eggs from the injection groups were injected into the amniotic fluid from the large end with the in-ovo injection solutions (0.2 ml per egg). Results indicated that 10 µg MLT/egg positively affected the weight and yield of chicks. In addition, our findings indicated that the in-ovo administration with 10 or 15 µg MLT/egg was superior in most of the immunological indicators (spleen and bursa relative weights, immunoglobulins IgG and IgM, T cells and B cells). In conclusion, in order to improve the immune efficiency (early immune acceleration) of Alexandria chicks, which may contribute to offering a significant boost to their future performance, this study suggests injecting eggs with 5 or 10 µg MLT/egg.

Influence of α-Fe2O3, CuO and GO 2D nano-fillers on the structure, physical properties and antifungal activity of Na-CMC-PAAm blend.

The present work aims to improve the uses of the carboxymethyl cellulose-polyacrylamide (Na-CMC-PAAm) blend for energy storage, optoelectronic applications, biological control, and plant disease management. Nano-sized materials (α-Fe2O3 nanoplates (NP), CuO NP, and GO nanosheets (NS), were synthesized and incorporated into the blend. The phase purity and morphologies of the used fillers were studied by XRD and HR-TEM. The interactions and complexation between the nano-fillers and the blend chains were investigated using XRD and FTIR spectra. The chemical composition and surface morphology of the nanocomposites were studied using EDS and FE-SEM analysis. UV-vis-NIR spectra revealed that the blend shows about 95% transmittance, reduced by 10-30% after doping. The absorption and refractive indices, as well as the optical gaps of the blend, were greatly affected by the doping. The dielectric constant and loss depend on the type of filler and the applied frequency. The maximum ac conductivity of the blend at 303 K and 4.0 MHz is 21.5 × 10-4 S/m and increased to 23.5 × 10-4 S/m after doping with CuO NP. The thermal stability, activation energy, stress-strain curves, and tensile strength are dependent on the filler type. All nanocomposite solutions except the blend exhibited a wide range of antifungal properties against pre- and post-harvest phytopathogenic fungi. Aspergillus niger among the examined fungi showed high sensitivity to the tested nanocomposite solutions. Furthermore, the CuO/blend nanocomposite had the highest antifungal activity against all tested fungi. Based on that, we suggest the use of CuO/blend and GO/blend nanocomposites to control and combat pre- and post-harvest fungal plant diseases.

Performance traits and selected blood constituents of broiler chicks as influenced by early access to feed post-hatch.

The present study aimed to investigate the effect of early access to feed and water post-hatch on broiler chicks' performance. One hundred and twenty chicks were transferred from the hatchery to the rearing house and randomly divided into two groups. The first group: chicks were immediately access to feed and water (F-time 0). The second group: was held without feed and water for 24 h (F-time 24). Then, feed and water were provided ad-libitum, for both groups until 35 days of age. Results indicated that F-time 0 increased body weight and body weight gain throughout the experimental period. It increased feed intake during all experimental periods except from (22-28 days). Additionally, the F-time 0 enhanced the European production efficiency factor index. The F-time 24, increased red blood cells (RBCs) count, hemoglobin (HGB), and packed cell volume (PCV) percentage after 24 h. However, the F-time 0 had a higher RBCs count, HGB, and PCV at 35 days of age. F-time 24 increased total plasma protein, albumin, cholesterol, and triglycerides, after 24 h. In conclusion, early access to feed and water post-hatch enhances broiler chicks' performance and productivity and increases producers' revenue.

Stocking density: a clue for improving social behavior, welfare, health indices along with productivity performances of quail (Coturnix coturnix)-a review.

The quail populations are considered to be one of the largest among the poultry species. Although quail egg and meat production are growing rapidly, still, quail farming practices and welfare aspects are not well established. Stocking density is one of the factors that can significantly affect the welfare, health, and performance of birds, but according to The Expert Group for Technical Advice on Organic Production, no allowed space standards have been reported for new hybrids and different breeds of quail. This review presents an overview of 1) the benefits of egg and meat of quail, 2) the global market of quail products, 3) the factors affecting the stocking density rate, and 4) the effects of stocking density rates and housing systems on the social behavior, welfare, physiological indices, and performance parameters of broiler and laying quail. Conclusively, larger space and enriched aviaries reduce aggressive behavior, and improve the quail welfare and immunological indices. However, the effect of stocking density on some blood biochemical indices and growth performance parameters showed mixed results. A better understanding of the relationship between housing, health, growth performance, and welfare aspects would assist in the implementation of welfare-economic standards for quail production. According to available data, stocking density ranges for broiler and laying Japanese quail are suggested; however, these stocking rates should be tested under different conditions.

Garlic oil as a fight against histological and oxidative stress abnormalities in Wistar rats after oral inoculation of Anisakis spp. Type II (L3) (Nematoda) / [O uso do óleo de alho na luta contra anormalidades histológicas e de estresse oxidativo em ratos Winstar após inoculação oral de Anisakis spp. Tipo II (L3) (Nematoda)]

The consumption of inadequately thermally treated fish is a public health risk due to the possible propagation of Anisakis larvae and their antigenic proteins, the causative agent of the zoonotic disease anisakidosis. The present study demonstrated the physiological and histopathological changes that accompanied an oral inoculation of crude extracts from fresh and thermally treated Anisakis Type II (L3) in Wistar albino rats. Nematode worms were isolated from the marine fish Dicentrarchus labrax. They were examined and taxonomically identified using light and scanning electron microscopy. The study was performed in 6 rat groups: a control group (I), a garlic oil (GO) inoculated group (II), a fresh L3 inoculated group (III), a thermally treated L3 inoculated group (IV), a fresh L3 + GO inoculated group (V), and a thermally treated L3 + GO inoculated group (VI). It was observed that rats inoculated with fresh and thermally treated L3 crude extracts showed abnormal oxidative stress markers associated with the destruction of normal architecture of spleen and thymus. GO produced a protective effect in rat groups inoculated with L3 extracts + GO administration via the amelioration of oxidative stress markers, which was confirmed by the marked normal structure of the organs' histology. Cooking of L3 infected fish induced severe physiological and histopathological alterations compared to uncooked infected fish. The administration of garlic before and after fish eating is recommended to avoid the dangerous effect of anisakids, even if they are cooked.(AU)

O consumo de peixes tratados termicamente de forma inadequada é um risco à saúde pública devido à possível propagação das larvas de Anisakis e suas proteínas antigênicas, o agente causador da doença zoonótica anisakidose. O presente estudo demonstrou as alterações fisiológicas e histopatológicas que acompanharam a inoculação oral de extratos brutos de Anisakis Tipo II (L3) frescos e termicamente tratados em ratos Wistar albinos. Vermes nematoides foram isolados do peixe marinho Dicentrarchus labrax e foram examinados e identificados taxonomicamente usando microscopia óptica e eletrônica de varredura. O estudo foi realizado em 6 grupos de ratos: grupo controle (I), grupo inoculado com óleo de alho (GO) (II), grupo inoculado com L3 fresco (III), grupo inoculado com L3 tratado termicamente (IV), grupo inoculado com L3 + GO fresco (V), e grupo inoculado com L3 + GO tratado termicamente (VI). Observou-se que ratos inoculados com extrato bruto L3 fresco e tratado termicamente mostraram marcadores de estresse oxidativo anormais associados à destruição da estrutura normal do baço e do timo. GO produziu um efeito protetor em grupos de ratos inoculados com extrato L3 + administração de GO através da melhoria dos marcadores de estresse oxidativo, que foi confirmada pela marcante estrutura normal da histologia dos órgãos. O cozimento de peixes infectados com L3 induziu alterações fisiológicas e histopatológicas graves quando comparado com peixes infectados não cozidos. Recomenda-se a administração de alho antes e depois da ingestão do peixe para evitar o efeito perigoso dos anisakídeos, mesmo se cozidos.(AU)

Long non-coding RNA EGFR-AS1 in colorectal cancer: potential role in tumorigenesis and survival via miRNA-133b sponge and EGFR/STAT3 axis regulation.

BACKGROUND: Colorectal cancer is one of the most common cancers worldwide and a major cause of cancer-related death. Thus molecular biomarkers for colorectal cancer have been proposed. The role of long non-coding RNA EGFR-AS1 in colorectal cancer is still unclear. We aimed to evaluate its expression in different stages of colorectal cancer and determine any possible role in regulating the miR­133b/EGFR/STAT3 signalling pathway. MATERIALS AND METHODS: The relative expression of EGFR-AS1 and miR­133b were evaluated by quantitative real-time RT-transcription PCR in 130 colorectal cancer samples and 30 normal tissues. EGFR expression was assessed using immunohistochemistry. Furthermore, levels of p-EGFR, p-STAT3, and apoptotic proteins were determined by ELISA. RESULTS: Both EGFR-AS1 and EGFR overexpression were positively linked with colorectal cancer status (both p < 0.01), grade (both p < 0.01), and metastasis (P < 0.01 and p = 0.019 respectively). EGFR-AS1 and miR-133b were significantly inversely correlated (P < 0.01). Low expression of miR-133b was inversely associated with overexpressed EGFR and increased p-STAT3 levels. EGFR-AS1 was an independent prognostic factor for survival of colorectal cancer patients (P < 0.01, HR 2.06; 95% CI 1.32-3.19) where low EGFR-AS1 expression was associated with higher survival rate (p = 0.003). CONCLUSION: EGFR-AS1 may have a role in colorectal cancer by regulation of miR­133b/EGFR/STAT3 signalling. It may be a potential biomarker for early diagnosis and predicting the survival rate of colorectal cancer.

Influence of blood contamination on the bond strength and biointeractivity of Biodentine used as root-end filling.

AIM: To evaluate the influence of blood contamination on the bond strength and apatite forming ability of Biodentine used as root-end filling material. METHODOLOGY: Eighty (n = 80) extracted single-rooted, sound human maxillary anterior teeth were prepared and obturated. Then, the roots were resected, retrograde cavities were prepared and Biodentine was inserted as the root-end filling material. Teeth were then randomly divided into 2 equal groups (n = 40) according to the setting environment of Biodentine i.e., group A where setting took place in human blood and group B where setting took place in deionized water (control group). Teeth were incubated at 37  °C for 45 min to ensure complete setting. Root discs with the filling material in their core were prepared. Push-out bond strength test was performed using a universal testing machine and failure mode was examined. Both groups were aged in HBSS for 30 days. Apatite nucleation was evaluated at one-day, 7-days, and 30-days interval using SEM for morphological analysis and EDX for elemental analysis. Calculation of the Ca/P ratios was performed in addition to XRD for crystal phase analysis. RESULTS: Blood contamination (group A) resulted in significant reduction of bond strength values. It also affected the amount of apatite deposition on the material surface and interfacial spaces with higher Ca/P ratios than that of the normal stoichiometric hydroxyapatite. CONCLUSIONS: Blood contamination during setting of Biodentine had a detrimental effect on the bond strength and reduced the nucleation of apatite in comparison to non-contaminated group.

[Predictors of catheter-related bladder discomfort]. / Facteurs prédictifs de l'inconfort lié à la sonde vésicale.

INTRODUCTION: Establish a descriptive epidemiological profile of patients with Catheter Related Bladder Discomfort (CRBD) and identify its predictive factors. MATERIAL AND METHOD: Between June 2019 and December 2019, 300 patients have been evaluated. Different parameters were taken into account including: sex, age, body mass index (BMI), historical health data, duration and indications of the urinary catheterization, type of the transurethral catheter used, lubrication of the catheter and the existence of CRBD. We grouped our patients according to the intensity of CRBD syndrome. The various factors likely to be correlated with the occurrence of CRBD were subject of a univariate then multivariate analysis. RESULTS: 300 patients were included. The average age was 49 years (133 men and 167 women). 68 patients (22.6%) had history of urinary catheterization. 19% of patients were catheterized for acute urinary retention, while 81% were catheterized before surgery. The average duration of the urinary catheterization was 2.5 days. 54% showed CRBD symptoms, including more than 92% on the first day of the urinary catheterization. The significant risk factors in multivariate analysis were: the caliber of the catheter ≥18 Fr, the absence of lubrication, laparotomy, age <50 years, Cesarean and urinary catheterization medical history. CONCLUSION: This study identified various factors incriminated in the occurrence of CRBD. The role of the hospital practitioner is to prevent this syndrome by reducing predictive factors, particularly the technical ones. LEVEL OF EVIDENCE: 3.

Diffractometry-based vortex beams fractional topological charge measurement.

In this Letter, we investigate the Fresnel diffraction of vortex beams from a phase plate and propose a novel (to the best of our knowledge) method to determine the fractional part of the topological charge of vortex beams. When a vortex beam with a fractional topological charge illuminates the edge region of a transparent plate, the visibility of the diffraction pattern on two sides of the beam is different. Rotation of the phase plate changes the visibility on the left and right sides of the beam, periodically. By measuring three consecutive angles of the minimum visibilities, the fractional part of the topological charge is obtained. The proposed method is verified experimentally and is shown to be independent of the phase plate and vortex beam parameters. The precision of the method is obtained better than 0.01.

Diaphragm and Lung Ultrasound Indices in Prediction of Outcome of Weaning from Mechanical Ventilation in Pediatric Intensive Care Unit.

OBJECTIVE: To predict the added value of diaphragmatic and lung ultrasound indices (US) in anticipation of the outcome of mechanical ventilation of pediatric patients in the intensive care unit. METHODS: This prospective study was conducted in Zagazig University, Pediatric Hospitals, PICU; Egypt. One hundred six mechanically ventilated children aged between 1 mo to 170 mo were included in the study. All patients were candidates for weaning and have been given a chance for spontaneous breathing trial (SBT), during which diaphragmatic and lung US was performed for them. The diaphragm thickening fraction (DTF), the diaphragmatic excursion and the lung US score (LUS), that included 4 US aeration forms, were assessed. RESULTS: There were statistically significant differences between patients with failed weaning and those with successful weaning regarding DTF, diaphragmatic excursion and LUS (p < 0.001). The best cut-off value of DTF, diaphragmatic excursion, and LUS for predicting weaning failure was ≥23.175%, ≥ 6.2 mm, and ≥ 12 with an AUC (area under curve) of 0.932, 0.876, and 0.934, respectively. CONCLUSIONS: Diaphragmatic and lung US add a quick, accurate and non-invasive indices to the weaning readiness parameters compared to the other standard parameters alone. So, it is recommended to be added to the predictive parameters of weaning outcome.

Apical extrusion of debris after canal shaping with three single-file systems.

OBJECTIVES: The aim of this study was to evaluate the quantity of apically extruded debris after canal shaping with three single-file systems. MATERIALS AND METHODS: Sixty mesiobuccal canals of mandibular molars were divided into three experimental groups according to the used file systems-WaveOne Gold, RECIPROC Blue, and HyFlex EDM One file. Debris extruded during canal shaping were collected in preweighed vials. Each canal was irrigated with 5 mL of distilled water via a 30 G side-vented needle. The amount of the debris extruded from each canal was calculated by subtracting the preinstrumentation from postinstrumentation measurement. The preparation times were recorded. Data were analyzed using analysis of variance (ANOVA) and posthoc Tukey tests with α = 0.05. RESULTS: WaveOne Gold extruded the least amount of debris. Results between WaveOne Gold and HyFlex EDM were significantly different. No significant differences in canal shaping time were detected among the three groups (P > 0.05). CONCLUSION: WaveOne Gold showed the best results regarding apical debris extrusion. Difference between WaveOne Gold and HyFlex EDM suggests that file design and motion kinematics affect the quantity of debris extrusion.

Effects of supplementing broiler diets with coriander seed powder on growth performance, blood haematology, ileum microflora and economic efficiency.

A total of 480 one-day-old Arbor Acres broiler chicks were randomly assigned to four dietary groups, each including six replicates (n = 20/replicate). Broilers in the first group (G1) were fed a basal diet without any additives (control). Broilers in groups 2, 3 and 4 (G2, G3 and G4) were fed a basal diet supplemented with 0.1%, 0.2% and 0.4% coriander (Coriandrum sativum L.) seed powder (CSP) respectively. Feeding trials lasted for 42 days, and after that growth, carcass traits, haematological parameters, gut microbiota and economic efficiency (EE) were evaluated. Final body weight (FBW), total weight gain (TWG), total feed intake (TFI) and red blood cell (RBC) counts of broilers in the G4 and G3 treatment groups were significantly higher (p < .05) compared with broilers in the G1 treatment group. The feed conversion ratio (FCR) was better (p < .05) in the G4 treatment group (1.72) than in the G1 treatment group (1.84). Broilers in CSP treatment groups had significantly higher haemoglobin (Hb) concentrations, packed cell volume (PCV) and platelet counts, and had lower (p < .05) Escherichia coli and Clostridium perfringens counts compared with broilers in the G1 treatment group. Dressing, liver, pancreas, bursa and thymus percentages were higher (p < .05) in broilers in the G4 (70.30, 3.18, 0.31, 0.10 and 0.32% respectively) treatment group, compared with broilers in the control (G1) group (66.57, 2.37, 0.23, 0.04 and 0.21% respectively). Broilers in treatment groups G4 and G3 had lower percentages of abdominal fat and lower total bacterial counts (p < .05) than broilers in treatment groups G2 and G1. The highest economic efficiency (EE) was found in treatment group G4, and EE in this group was 13.06% greater than in the control (G1) group.

Root and canal morphology of maxillary premolar teeth in an Egyptian subpopulation using two classification systems: a cone beam computed tomography study.

AIM: To investigate the number of roots and root canal configurations using two coding systems and the root canal diverging and merging levels in extracted maxillary premolars in an Egyptian subpopulation using cone beam computed tomography (CBCT). METHODOLOGY: A total of 700 maxillary premolars were examined using CBCT in an Egyptian subpopulation. The number of roots was identified, and root canal configurations were classified according to Vertucci's classification and a new system for classifying root and canal morphology. In addition, the position where roots bifurcated and the levels where canals merged or diverged were identified. Fisher's exact test and independent t-test were used for statistical analysis, and the level of significance was set at 0.05 (P = 0.05). RESULTS: More than half of maxillary first premolars were double-rooted, and the majority of maxillary second premolars were single-rooted (P < 0.001). Most of the double-rooted samples had bifurcations in the middle of the root. According to the Vertucci classification, canal configuration type IV was the most common in both first and second maxillary premolars. According to the new system, the code 2 FP B1 P1 was the most common for maxillary first premolars, whilst 2 SP B1 P1 , 1 SP2 and 1 SP2-1 codes were the most common for maxillary second premolars. The three-canalled morphology in double- and three-rooted maxillary premolars had considerable variations. Root canal merging and diverging levels were comparable in both tooth types. CONCLUSION: Maxillary premolars in this Egyptian subpopulation had a wide range of root and canal anatomical variations. Clinicians should be aware of where canals merge and diverge to facilitate the treatment of all canals. The new system for classifying canal morphology describes the root and canal configurations in a more accurate and practical manner compared to the Vertucci classification.

Fecal microbiota profile in atopic asthmatic adult patients.

Summary: Background. Studies proposed a link between gut microbiota and airway tract. Objective. Study the diversity and density of gut microbiota in healthy and asthmatic patients. Method. Semi-quantitative stool cultures were performed from fecal samples collected from 80 adult asthmatic patients and 40 healthy individuals. Data on gender, age, dietetic history, clinical examination and investigations as skin prick test and pulmonary function testing were also collected. Results.Lactobacilli were found to be higher among patient group than control group. E. coli density was statistically higher in patient than control group. No significant difference was detected between male and female patients or controls. Lactobacilli were statistically more prevalent in stool culture of male cases than that of male controls. No difference was found between female cases and controls. There was no relationship between type of microbial growth and disease related parameters including age, duration of illness, number of allergens and pulmonary function test in cases. Conclusion. Atopic asthma is significantly associated with gut microbiota Lactobacilli and E. coli. It is important to determine the organism involved, to focus on microbiome-driven disease and therapies.

Focal length measurement based on Fresnel diffraction from a phase plate.

A method based on the Fresnel diffraction of light from the phase step is introduced for measuring effective focal length (EFL) and back focal length (BFL) of optical imaging systems. It is shown that, as a transparent plane-parallel plate is illuminated at a boundary region by a monochromatic beam of light, Fresnel diffraction occurs because of the abrupt change in phase imposed by the finite change in refractive index at the plate boundary. Variation of the incident angle in a convergent (or divergent) beam of light causes the periodic intensity along the central fringe of the diffraction pattern. The measurement of the extrema position of the intensity distribution accurately provides the EFL and BFL. The technique is easy to apply and can measure a wide range of both positive and negative focal lengths. The measuring setup can be very compact with low mechanical and optical noises. As examples of this technique, the EFLs of five different lenses are experimentally obtained. The results are quite consistent with the values indicated by the lens manufacturer.

Incidence of dentinal defects after preparation of severely curved root canals using the Reciproc single-file system with and without prior creation of a glide path.

AIM: To investigate the incidence of dentinal defects after preparation of severely curved root canals using the Reciproc single-file system with and without prior creation of a glide path. METHODOLOGY: Mesial roots from extracted mandibular first molars were collected and scanned with CBCT to assess the morphology of the root canal systems. Three groups of 20 anatomically comparable specimens were generated. The control group was left unprepared, whilst the experimental groups were prepared with Reciproc R25 with and without a glide path (groups RG and R, respectively). Roots were then sectioned perpendicular to the long axis at 2, 4, 6, 8 and 10 mm from the apex, and coloured photographs of the sections at 40× were obtained. Two blinded examiners registered the presence of dentinal defects twice at 2-week interval. Data were statistically analysed using the Fisher exact and Cochran's Q tests. RESULTS: No defects were observed in the control group. The overall incidence of dentinal defects was 26% in group R and 24% in group RG, with no significant differences between them (P > 0.05). Dentinal defects occurred significantly more often in the middle and coronal thirds compared to the apical third of the canals (P < 0.05). CONCLUSIONS: Prior preparation of a glide path had no impact on the incidence of dentinal defects when using Reciproc files.