Assessing the usability and reliability of a web-based teledentistry tool for remote diagnosis of oral lesions: a cross-sectional study.

BACKGROUND: Oral mucosa lesions are the third most prevalent oral pathology, following caries and periodontal diseases. Teledentistry offers an effective way to manage patients with these lesions. The accuracy of remote diagnoses and consultations relies heavily on the quality of the information and photos sent to remote specialists. This study aims to evaluate the usability and reliability of a teledentistry tool for the remote diagnosis of oral lesions. METHODS: The cross-sectional study included both usability evaluation and reliability assessment. The teledentistry platform, "OralMedTeledent", facilitated synchronous and asynchronous interactions, allowing for patient consultations, remote follow-ups, and doctor-to-doctor consultations. Usability was evaluated by 5 experts using the Nielsen heuristic checklist. Reliability was assessed from August 2022 to September 2023 with 109 patients, using Cohen's kappa coefficient to measure agreement between examiners and the gold standard in diagnosing oral lesions. RESULTS: The findings revealed 66 usability issues, most of which were related to helping users recognize, diagnose, and recover from errors, as well as issues with help and documentation. Among these, 11 issues were of minor severity. The reliability test, conducted with 109 participants (57.8% female, 42.2% male) showed that the web-based teleconsultation system performed significantly well. The system demonstrated significant substantial performance (0.81 ≤ κ < 1; P > 0.05). CONCLUSION: Overall, the web-based teleconsultation system has proven to be reliable for the remote diagnosis of oral lesions, making it a valuable alternative during emergencies such as the COVID-19 pandemic. However, several usability issues have been identified and need to be addressed.

Intracellular bactericidal activity and action mechanism of MDP1 antimicrobial peptide against VRSA and MRSA in human endothelial cells.

Introduction: Staphylococcus aureus is a prominent cause of postoperative infections, often persisting within host cells, leading to chronic infections. Conventional antibiotics struggle to eliminate intracellular S. aureus due to poor cell penetration. Antimicrobial peptides are a new hope for tackling intracellular bacteria. Accordingly, this study examines the antimicrobial peptide MDP1, derived from melittin, for its efficacy against intracellular S. aureus. Methods: In this study, the physiochemical properties (Prediction of three-dimensional structure, circular dichroism and helical wheel projection analysis) were investigated. Extracellular antibacterial activity and cytotoxicity of MDP1 were also assessed. The mechanism of interaction of MDP1 with S. aureus was evaluated by molecular dynamic simulation, atomic force and confocal microscopy. Bacterial internalization into an endothelial cell model was confirmed through culture and transmission electron microscopy. The effect of the peptide on intracellular bacteria was investigated by culture and epi-fluorescence microscopy. Results and discussion: 3D structural prediction proved the conformation of MDP1 as an α-helix peptide. Helical-wheel projection analysis indicated the proper orientation of hydrophobic amino acid residues for membrane interaction. CD spectroscopy of MDP1 showed that MDP1 in SDS 10 and 30 mM adopted 87 and 91% helical conformation. Atomic force and confocal microscopy assessments as well as molecular dynamics studies revealed the peptide-bacterial membrane interaction. MDP1, at the concentration of 0.32 µg mL-1, demonstrated a fold reduction of 21.7 ± 1.8, 1.7 ± 0.2, and 7.3 ± 0.8 in intracellular bacterial load for ATCC, VRSA, and MRSA, respectively. Molecular dynamics results demonstrate a preferential interaction of MDP1 with POPG/POPE membranes, primarily driven by electrostatic forces and hydrogen bonding. In POPC systems, two out of four MDP1 interacted effectively, while all four MDP1 engaged with POPG/POPE membranes. Gathering all data together, MDP1 is efficacious in the reduction of intracellular VRSA and MRSA proved by culture and epi-fluorescent microscopy although further studies should be performed to increase the intracellular activity of MDP1.

Technological aspects and recommendations for applying teledentistry in oral medicine: a scoping review.

BACKGROUND: Teledentistry is applied in oral medicine to help dental practitioners and specialists manage complex oral conditions. This scoping review aims to synthesize the available evidence regarding the technical requirements and the provision of security services, as well as the recommendations on standard oral cavity photography methods for using teledentistry in oral medicine. METHOD: The present scoping review was conducted in 2022 according to the Joanna Briggs Institute (JBI) manual. Four databases were systematically searched, including ISI Web of Science, PubMed, Scopus, and ProQuest, from January 1999 to December 2021. After finalizing the search strategy, all the original articles, reviews, editorials, letters, comments, and book chapters were included. All the dissertations uploaded in English with a full-text electronic file were also included to achieve a comprehensive picture of the available literature. Two types of analysis were applied: the quantitative descriptive analysis applying Excel 2016 and the qualitative thematic analysis using MAXQDA version 10. RESULTS: The included papers were published during 1999-2021. Most of the included articles were from Brazil (n = 9, 21.43%), India (n = 6, 14.28%), the USA (n = 6, 14.28%), and the UK (n = 5, 11.90%). Social media usage as a teledentistry platform increased considerably between 2019 and 2021. Teledentistry platforms have been classified into four categories, including email, telephone, social network applications (WhatsApp, zoom, Google Meeting, Instagram, line Application, Viber, and Messenger), and teledentistry systems (teledentistry systems, which were designed specially to perform a teledentistry project). Teledentistry has been conducted to store and forward (n = 15, 30.71%), real-time (n = 9, 21.43%), or both (n = 12, 35.71%). According to the thematic results, basic technical requirements have been categorized into four, including teledentistry platform, type of interactions, internet connection, and photography tool. Other thematic results demonstrate seven categories of recommendations, including general factors, light, patient position, phone position, setting of a mobile phone camera, photo sending requirements, and photo visualization. CONCLUSION: According to the results, over the past 7 years, especially during the COVID-19 pandemic, social network applications such as WhatsApp and Zoom have been used more frequently. Also, photography recommendations with a mobile phone camera depend on several factors such as general factors, light, patient position, phone position, setting of the mobile phone camera, and photo-sending requirements. Given the increased use of mobile cameras for oral photography, these recommendations can help improve the quality of images and subsequently improve the reliability of clinical decision-making in managing patients' conditions.

Tele-dentistry, its trends, scope, and future framework in oral medicine; a scoping review during January 1999 to December 2021.

BACKGROUND: Tele-dentistry has been increasingly used for different purposes of visit, consultation, triage, screening, and training in oral medicine. This study aims to determine the main facilitators, barriers, and participants` viewpoints of applying tele-dentistry in oral medicine and develop a framework indicating the input, process, output, and feedback. METHOD: This was a scoping review conducted in 2022 applying Arksey and O'Malley (2005) approach. Four databases including ISI web of science, PubMed, Scopus, and ProQuest were searched from January 1999 to December 2021. Inclusion criteria consisted of all original and non-original articles (reviews, editorials, letters, comments, and book chapters), and dissertations in English with a full text electronic file. Excel2016 was used for descriptive quantitative analysis and MAXQDA version 10 was applied for qualitative thematic analysis. A thematic framework was developed customizing the results of the review in a virtual mini expert panel. RESULTS: Descriptive results show that among 59 included articles, 27 (46%) have addressed the various applications of tele-dentistry during COVID-19 pandemic in the field of oral medicine. From geographical distribution perspective, most of the papers were published in Brazil (n = 13)/ 22.03%, India (n = 7)/11.86% and USA (n = 6)/10.17%. Thematic analysis shows that seven main themes of "information", "skill", "human resource", 'technical", "administrative', 'financial', and 'training and education' are explored as facilitators. 'Individual', 'environmental', 'organizational', 'regulation', 'clinical', and 'technical barriers' are also identified as main barriers of tele-dentistry in oral medicine. CONCLUSION: According to the results for using tele-dentistry services in oral medicine, a diverse category of facilitators should be considered and at the same time, different barriers should be managed. Users` satisfaction and perceived usefulness of tele-dentistry as final outcomes can be increased considering the system`s feedback and applying facilitator incentives as well as decreasing the barriers.

Investigation of physicochemical properties, antimicrobial and antioxidant activity of edible films based on chitosan/casein containing Origanum vulgare L. essential oil and its effect on quality maintenance of cherry tomato.

Edible coatings prevent physicochemical and biological food deterioration. Using bioactive compounds like essential oils can enrich films. In this study, edible films from chitosan (C), casein (Z) and oregano (OEO) were developed, and their physicochemical, barrier, antimicrobial, antioxidant, and structural properties (FTIR, SEM) were investigated. The C1Z3 ratio had good mechanical and inhibitory properties, and OEO improves flexibility, barrier, hydrophobic, antimicrobial, and antioxidant properties. The physicochemical and microbiological properties of cherry tomatoes were affected by C1Z3 and C1Z3O1.5 coatings. Coated fruits were stored at 4 °C for 32 days. The best results for weight loss, shrinkage, and titratable acidity were found to be 17.88%, 31.12%, and 0.15% in C1Z3O1.5 coated cherry tomatoes, respectively.The TMAB of C1Z3O1.5 coated fruits was less than detectable and the fungal growth was inhibited for 28 days. Accordingly, by adding OEO to chitosan/casein coatings, the spoilage process of cherry tomatoes was delayed for long-term storage.

Fast killing kinetics, significant therapeutic index, and high stability of melittin-derived antimicrobial peptide.

The emergence of multidrug-resistant (MDR) bacteria is a major challenge for antimicrobial chemotherapy. Concerning this issue, antimicrobial peptides (AMPs) have been presented as novel promising antibiotics. Our previous de novo designed melittin-derived peptides (MDP1 and MDP2) indicated their potential as peptide drug leads. Accordingly, this study was aimed to evaluate the kinetics of activity, toxicity, and stability of MDP1 and MDP2 as well as determination of their structures. The killing kinetics of MDP1 and MDP2 demonstrate that all bacterial strains were rapidly killed. MDP1 and MDP2 were ca. 100- and 26.6-fold less hemolytic than melittin and found to be respectively 72.9- and 41.6-fold less cytotoxic than melittin on the HEK293 cell line. MDP1 and MDP2 showed 252- and 132-fold improvement in their therapeutic index in comparison to melittin. MDP1 and MDP2 sustained their activities in the presence of human plasma and were found to be ca. four to eightfold more stable than melittin. Spectropolarimetry analysis of MDP1 and MDP2 indicates that the peptides adopt an alpha-helical structure predominantly. According to the fast killing kinetics, significant therapeutic index, and high stability of MDP1, it could be considered as a drug lead in a mouse model of septicemia infections.

Eradication of vancomycin-resistant Staphylococcus aureus on a mouse model of third-degree burn infection by melittin: An antimicrobial peptide from bee venom.

Third-degree burn infections caused by antibiotic-resistant bacteria are of high clinical concern. Chemical antibiotics are not promising in eradication of bacterial infections. In this challenging condition, antimicrobial peptides (AMPs) are recently introduced as novel promising agents to overcome the issue. Accordingly, our study aimed to evaluate the efficiency of 'melittin' as natural peptide in bee venom, in eradicating vancomycin resistant Staphylococcus aureus (VRSA) on a mouse model of third-degree burn infection. In vitro pharmacological value of melittin was determined by examining its inhibitory and killing activities on VRSA isolates at different doses and time periods. The action mechanism of 'melittin' was evaluated by fluorescent release assay and Field Emission Scanning Electron Microscopy (FE-SEM) analyses. In vivo activity and toxicity of melittin were also examined on a mouse model of third-degree burn infection. The Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) of melittin on all isolates ranged from '0.125-2 µg/mL' and '0.125-4 µg/mL', respectively. Rapid antibacterial activity of melittin on VRSA isolates was demonstrated by killing kinetics assays. Fluorometric and FE-SEM analyses indicated the membranolytic effects of melittin on VRSA isolates. The colonized VRSA bacteria were eradicated by melittin at 16 µg, in a single dose. No dermal toxicity and in vivo hemolysis were observed in the examined mice. The lack of in vivo toxicity of melittin along with its potent antibacterial activity indicated its promising therapeutic value as a topical drug against S. aureus associated third-degree burn infections.

The Antifungal Peptide MCh-AMP1 Derived From Matricaria chamomilla Inhibits Candida albicans Growth via Inducing ROS Generation and Altering Fungal Cell Membrane Permeability.

The rise of antifungal drug resistance in Candida species responsible for life threatening candidiasis is considered as an increasing challenge for the public health. MCh-AMP1 has previously been reported as a natural peptide from Matricaria chamomilla L. flowers with broad-spectrum antifungal activity against human pathogenic molds and yeasts. In the current study, the mode of action of synthetic MCh-AMP1 was investigated against Candida albicans, the major etiologic agent of life-threatening nosocomial candidiasis at cellular and molecular levels. Candida albicans ATCC 10231 was cultured in presence of various concentrations of MCh-AMP1 (16-64 µg/mL) and its mode of action was investigated using plasma membrane permeabilization assays, reactive oxygen species (ROS) induction, potassium ion leakage and ultrastructural analyses by electron microscopy. MCh-AMP1 showed fungicidal activity against Candida albicans at the concentrations of 32 and 64 µg/mL. The peptide increased fungal cell membrane permeability as evidenced by elevating of PI uptake and induced potassium leakage from the yeast cells. ROS production was induced by the peptide inside the fungal cells to a maximum of 64.8% at the concentration of 64 µg/mL. Scanning electron microscopy observations showed cell deformation as shrinkage and folding of treated yeast cells. Transmission electron microscopy showed detachment of plasma membrane from the cell wall, cell depletion and massive destruction of intracellular organelles and cell membrane of the fungal cells. Our results demonstrated that MCh-AMP1 caused Candida albicans cell death via increasing cell membrane permeability and inducing ROS production. Therefore, MCh-AMP1 could be considered as a promising therapeutic agent to combat Candida albicans infections.

Highly Synergistic Effects of Melittin with Conventional Antibiotics Against Multidrug-Resistant Isolates of Acinetobacter baumannii and Pseudomonas aeruginosa.

BACKGROUND: Morbidity and mortality due to multidrug-resistant (MDR) bacteria are of great concern in burn patients. In this critical condition, synergism between antimicrobial peptides and conventional antibiotics would be a promising strategy. Accordingly, this study aimed to determine the therapeutic value of melittin as a natural peptide by examining its synergistic effect with conventional antibiotics against MDR isolates of Acinetobacter baumannii and Pseudomonas aeruginosa. MATERIALS AND METHODS: Fifteen clinical isolates for each kind of bacteria were collected from burn patients. Antibiotic susceptibility of all isolates was evaluated by disk diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration for melittin, colistin, doripenem, doxycycline, and ceftazidime were also examined. Fractional inhibitory concentration (FIC) of melittin in combination with the antibiotics was determined for six MDR isolates. The cytotoxicity of melittin in combination with the antibiotics was examined on a normal human cell line. RESULTS: The geometric means of MIC (GMMIC) for melittin and doripenem after combination were reduced to 61.5- and 51.5-fold, respectively, against MDR A. baumannii isolates. These reductions for melittin-doripenem and melittin-ceftazidime against MDR P. aeruginosa isolates were (63.5 and 58)-fold and (16 and 11)-fold, respectively. FIC for melittin-doripenem against A. baumannii and FIC for melittin-doripenem and melittin-ceftazidime against P. aeruginosa strains were ≤0.5. This issue caused a decrease of up to 104-, 68-, and 17-fold, respectively, in the cytotoxicity of melittin. CONCLUSION: In conclusion, the synergism of melittin at its nontoxic dose with doripenem and ceftazidime could be of great therapeutic value as a topical drug against burn infections caused by MDR bacteria.

Single dose eradication of extensively drug resistant Acinetobacter spp. In a mouse model of burn infection by melittin antimicrobial peptide.

Bacterial infections caused by antibiotic resistant bacteria are the leading cause of morbidity and mortality after burn injuries. This issue has driven the need for promising antimicrobial drugs to eradication of bacterial pathogens. Accordingly, we aimed to determine the therapeutic value of melittin, as a natural Antimicrobial peptide (AMP), in eradication of extensively drug-resistant (XDR) Acinetobacter spp. on a mouse model of third degree burn infection. Melittin killed all examined XDR isolates at 4 µg/mL up to 3 h. Melittin caused significant fluorescence release from XDR isolates at the minimum dose of 0.062 µg/mL. Vesicle formation on the membrane and squeezing of bacteria followed by cell lysis indicated the membranolytic effect of melittin. Melittin at 32 µg/mL completely eradicated the colonized XDR bacteria on infected burn mice during 2 h. No toxicity was observed on injured or healthy derma, as well as circulating Red Blood Cells (RBCs) in the examined mice. Potent promising antibacterial activity of melittin and the lack of toxicity at the therapeutic dose can clarify that melittin can be implemented as a topical drug lead in a preclinical trial of third degree burn infections.

Action mechanism of melittin-derived antimicrobial peptides, MDP1 and MDP2, de novo designed against multidrug resistant bacteria.

The emergence and dissemination of multidrug resistant (MDR) bacteria are major challenges for antimicrobial chemotherapy of bacterial infections. In this critical condition, cationic antimicrobial peptides are 'novel' promising candidate antibiotics to overcome the issue. In this study, we investigated the antibacterial mechanism of new melittin-derived peptides (i.e., MDP1 and MDP2) against multidrug resistant Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. MDP1 was designed with deletion of three amino acid residues, i.e., S18, W19, and I20, from the end of second hydrophobic motif of melittin. In the next step, VLTTG in MDP1 sequence was substituted with tryptophan residue. MDP1 and MDP2 had a high-antibacterial activity against MDR and reference strains of S. aureus, E. coli, and P. aeruginosa. DNA and calcein release and flow cytometry assays indicate a time-dependent antibacterial activity on the examined bacteria affected by both MDP1 and MDP2. Finally, SEM analyses highlighted dose- and time-dependent effects of MDP1 and MDP2 on S. aureus and E. coli bacteria by induction of vesicle or pore formation as well as cell lysis. In this study we successfully showed that rational truncation of large hydrophobic motifs can lead to significant reduction in toxicity against human RBCs and improving the antibacterial activity as well. Analyses of data from DNA release, fluorometry, flow cytometry, and morphological assays demonstrated that the MDP1 and MDP2 altered the integrity of both Gram-positive and Gram-negative bacterial membranes and killed the bacteria via membrane damages.

High-power diode-pumped Kerr-lens mode-locked bulk Yb:KGW laser.

A high-power (>1 W) pure Kerr-lens mode-locked bulk Yb:KGW laser with multimode fiber-coupled diode pumping was demonstrated. The laser delivered 240 fs pulses with 2.3 W of average output power at 86.8 MHz, corresponding to 97 kW of peak power and 26 nJ of pulse energy. The shortest generated pulse duration was 120 fs with 1.2 W of output power. The self-starting regime was also observed with a background continuous-wave component. The laser exhibited more than an order of magnitude higher output power when compared to the previously reported bulk Yb-ion-doped lasers with multimode laser diode pumping systems.

Green Synthesis of Palladium/Titanium Dioxide Nanoparticles and their Application for the Reduction of Methyl Orange, Congo Red and Rhodamine B in Aqueous Medium.

OBJECTIVE: Palladium nanoparticles (Pd NPs) supported on the TiO2 NPs were prepared using Euphorbia thymifolia L. leaf extract. The Pd/TiO2 NPs were characterized by FESEM, EDS, TEM and XRD analysis and were used as nanocatalysts for the reduction of a variety of organic dyes. To the best of the author's knowledge, this study explains the first report to the synthesis of Pd/TiO2 NPs using Euphorbia thymifolia L. leaf extract. METHOD: 1.0 G of TiO2 was dispersed in 40 mL of 0.3 Mm PdCl2 solution and sonicated for 30 min. Then, 20 mL of the plant extract was mixed under continuous stirring at 60°C for 2 h. The prepared Pd/TiO2 NPs were centrifuged, washed and then dried. RESULTS: FESEM imaging showed the formation of NPs in the size range of 19-29 nm. The Pd/TiO2 NPs exhibited high activity towards the reduction of Methyl Orange, Congo red and Rhodamine B in the presence of NaBH4 in aqueous medium during 4, 1 and 54 s, respectively. CONCLUSION: The synthesis of the Pd/TiO2 NPs by this route is rapid, simple, less time consuming, environmentally safe and compatibility for medical and pharmaceutical applications because of minimizing the use of toxic or hazardous organic solvents and reagents. Furthermore, the biosyenthesized nanocatalyst can catalyze the reduction of organic dyes during short-time and can be recovered and recycled several times without significant loss of activity.

ZnO-nanoparticles as an Efficient Catalyst for the Synthesis of Functionalized Benzenes: Multicomponent Reactions of Sulfonoketenimides.

OBJECTIVE: Functionalized benzenes are prepared from the reaction of sulfonoketenimides that is produced from the Copper catalyzed reaction of terminal alkynes and sulfonyl azides with zwitterionic intermediate that is generated from the reaction of dialkyl acetylenedicarboxylates, alkyl bromides and triphenylphosphine in the presence of ZnO-nanoparticles in good yields. MATERIAL AND METHODS: All chemicals employed in this work were prepared from Fluka (Buchs, Switzerland) and were used without further purification. Nanoparticles of ZnO were synthesized according to literature report. Melting points were measured on an Electrothermal 9100 apparatus. Elemental analyses for C, H, and N were performed using a Heraeus CHN­O-Rapid analyzer. Mass spectra were recorded on a FINNIGAN-MAT 8430 spectrometer operating at an ionization potential of 70 eV. IR spectra were measured on a Shimadzu IR-460 spectrometer. 1H, and 13C NMR spectra were measured with a BRUKER DRX-500 AVANCE spectrometer at 500.1 and 125.8 MHz, respectively. RESULTS: In these reactions, the first step is optimization of reaction conditions for achieving best conditions. For this reason, solvent, catalyst, and reaction time is changed so that the best result is obtained. For optimization, several catalysts such as CuI, CuBr, CuCl, ZnO-nanoparticles, CM-ZnO, pyridine, piperidine, CuO-NPs, TiO2-NPs and copper powder were checked. Among them CuI and ZnO-NPs give the best results. Also, several solvents such as CH3CN, H2O, solvent-free conditions, toluene and diethyl ether are employed and CH3CN is the best solvent. CONCLUSION: In summary, sulfonoketenimides react with intermediate that is generated from the reaction of dialkyl acetylenedicarboxylate, alkyl bromides and triphenylphosphine in the presence of ZnO-NPs (10 mol%) to produce benzene derivatives in good yields.

Sex differences in stroke: a socioeconomic perspective.

BACKGROUND: A number of studies have explored the issue of sex differences in stroke from biomedical perspective; however, there are still large gaps in the existing knowledge. The purpose of this study was to assess whether the differences in socioeconomic status and living conditions between men and women may explain the part of the sex differences in incidence and outcomes of stroke. METHODS: All stroke participants aged ≥60 years admitted in Vaseie Hospital in Sabzevar, Iran, from March 21, 2013, until March 20, 2014, were included in this study. Computerized tomography and magnetic resonance imaging were used to confirm stroke. A series of χ2 tests were performed and Statistical Program for Social Sciences, Version 21.0, was used to investigate the potential differences between older men and women in stroke incidence and outcomes. RESULTS: A total of 159 incident stroke cases were documented during 1 year. The annual rate of stroke was statistically significantly higher in elderly women than in elderly men (401 vs 357 per 100,000; P<0.001). Female elderly participants had significantly lower socioeconomic status, poorer living conditions, and higher lifetime history of depression, hypertension, and diabetes mellitus than their male counterparts. CONCLUSION: The findings from this study showed that elderly women are more adversely affected by stroke in terms of incidence and outcomes of stroke than elderly men. The most noticeable result is that sex differences in socioeconomic status and living conditions may result in increased incidence of stroke and poorer outcomes in elderly women. Therefore, it is imperative to identify vulnerable elderly women and provide them appropriate treatment and services.

Femtosecond Kerr-lens mode-locked Alexandrite laser.

The generation of 170 fs pulses at 755 nm from a Kerr-lens mode-locked Alexandrite laser was demonstrated. The laser was pumped at 532 nm and produced 780 mW of average output power with 9.8% of optical-to-optical efficiency. To the best of our knowledge, these are the shortest pulses that have been produced from a mode-locked Alexandrite laser to date.

High-power continuous-wave dual-wavelength operation of a diode-pumped Yb:KGW laser.

High-power dual-wavelength diode-pumped Yb:KGW laser using a single birefringent filter plate was demonstrated. Two oscillating wavelengths maintained the same polarization and stable dual-wavelength operation at 1014.6 and 1041.3 nm (7.57 THz of frequency offset) with 3.4 W of average output power and a diffraction-limited beam profile was obtained. Dual-wavelength laser operation at shorter- or longer-wavelength pairs with lower average output power could also be realized for other output-coupling transmissions.

Mathematical modeling of transmission dynamics and optimal control of vaccination and treatment for hepatitis B virus.

Hepatitis B virus (HBV) infection is a worldwide public health problem. In this paper, we study the dynamics of hepatitis B virus (HBV) infection which can be controlled by vaccination as well as treatment. Initially we consider constant controls for both vaccination and treatment. In the constant controls case, by determining the basic reproduction number, we study the existence and stability of the disease-free and endemic steady-state solutions of the model. Next, we take the controls as time and formulate the appropriate optimal control problem and obtain the optimal control strategy to minimize both the number of infectious humans and the associated costs. Finally at the end numerical simulation results show that optimal combination of vaccination and treatment is the most effective way to control hepatitis B virus infection.

Phenotypic characterization and PCR-Ribotypic profile of Pseudomonas aeruginosa isolated from cystic fibrosis patients in Iran.

BACKGROUND: Pseudomonas aeruginosa, is the most common pathogen in patients with cystic fibrosis (CF) that shows various resistance to antibiotics, acquires mucoidity and multiple genotypes. This survey was performed to study phenotypic and genotypic variations among P. aeruginosa isolates in CF patients at Alzahra Hospital in Isfahan, Iran. MATERIALS AND METHODS: The isolates of Pseudomonas aeruginosa from CF patients at Alzahra Hospital was identified by appropriate biochemical and microscopic tests, then performed antibiotic resistance tests and mucoid colony morphotyping. The genum of isolates extracted and confirmed on 16S rDNA-based PCR assay and typed on 16S rDNA-23SrDNA spacer, restricted with Hinf1 restriction enzyme. RESULTS: P. aeruginosa was isolated from 21 of the 59 CF patients (35.5%), Out of 21 isolates 9 (42.8%) strains were revealed mucoid morphotype. 81.8% isolates of mucoid strains were resistance to at least one of four antibiotics (GM, AN, PIP and CP). Most of the isolates (86%) showed resistance to ceftazidime. Ribotyping revealed two patterns (P1, P5). CONCLUSION: The isolates of P. aeruginosa showed meaningful difference between drug resistance to antibiotics. The majority of P. aeruginosa isolated from CF patients showed pattern1 of PCR-Ribotyping.