248 research outputs found

    Two-step versus Single Application of Mitomycin-C in Photorefractive Keratectomy for High Myopia

    Get PDF
    Purpose: To evaluate the long-term outcomes of two-step versus single application of mitomycin-C (MMC) during photorefractive keratectomy (PRK) for high myopia. Methods: This randomized clinical trial included consecutive patients with high myopia (exceeding 7 D). Patients underwent PRK and were randomized to two methods of MMC 0.02% application as follows: in the single application group, MMC was applied for 45 seconds followed by irrigation; in the two-step group MMC was used identically followed by repeat application for another 15 seconds and corneal surface irrigation. Visual acuity, refractive error, pachymetry, topography, corneal haze and complications were compared between the two groups 18 months after surgery. Results: One hundred and forty patients (70 subjects in either study arm) underwent PRK according to the study protocol. Mean spherical equivalent refractive error was significantly reduced from baseline to -1.16΁0.39 D in the single application group and to -1.07΁0.39 D in the two-step group. Sixteen (11.5%) versus 8 (5.7%) eyes lost one or more line(s) of best corrected visual acuity in the single application group as compared to the two-step group (P=0.05). Corneal haze was observed in 18 (12.9%) and 8 (5.7%) eyes in the single application versus two-step group, respectively (P=0.04). Grade 3 corneal haze was not observed in the two-step group but occurred in five eyes (3.6%) in the single application group (P=0.03). No eyes developed corneal ectasia during the follow-up period. Conclusion: Two-step intraoperative application of MMC 0.02% in highly myopic eyes undergoing PRK can reduce the frequency and severity of haze formation

    The Relationship between Self-Esteem and Coping Styles in Patients Undergoing Hemodialysis‏

    Get PDF
    This paper is a report of a study of The Relationship between Self-Esteem and Coping Styles in patients undergoing hemodialysis in Iran. Hemodialysis patients face with multiple physical and psychological stressful factors; they use coping styles in order to cope with the challenges. A descriptive-correlation study was conducted based on the data collected from patients undergoing hemodialysis by census method in the city of Kerman using the Endler and Parker coping style, Self-esteem and demographic information questionnaires. The mean age of patients was 56.21 ± 1.45 years and 58.5% were male. The statistically positive relationship between self-esteem and problem-oriented coping style (p=0.05) and inverse relationship between self-esteem and emotion-oriented style (p<0.001). The patients with higher and lower self-esteem used problem-oriented and emotion-oriented styles, respectively. According to the results, it is necessary for nurses to enhance their role in promoting self-esteem and help patients undergoing hemodialysis while using problem-oriented style

    Design and Performance of Microstrip Diplexers: A Review

    Get PDF
    The radiofrequency microstrip diplexers are widely demanded nowadays by modern wireless communication systems. Hence, several types of previously reported microstrip diplexers are reviewed and investigated in this work. Microstrip diplexers are three ports devices used for separating desired signals and delivering them through two (or more) different channels. The diplexers are investigated in three categories of dual-channel bandpass-bandpass diplexers, multichannel diplexers, and lowpassbandpass diplexers. The investigated multi-channel diplexers include a number of four-channel, six-channel, and eight-channel diplexers. Due to the hard design process, the number of reported diplexers with more than four channels is limited. The layout structures and theory design methods of the previously reported diplexers are studied. Moreover, their size and performance are compared while some explanations about their advantages and disadvantages are presented. This comparison includes insertion loss, return loss, fractional bandwidths, isolation, selectivity, and gaps between channels

    White blood cell count to mean platelet volume ratio as a novel non-invasive marker predicting long-term outcomes in patients with non-ST elevation acute coronary syndrome

    Get PDF
    Background: Total white blood cell (WBC) count and mean platelet volume have previously been shown to predict outcomes in acute coronary syndrome (ACS) patients. In this prospective study, we sought to determine the prognostic value of baseline WBC count to mean platelet volume ratio (WMR) in patients with non-ST elevation acute coronary syndrome (NSTE-ACS). Methods: A total of 490 patients with NSTE-ACS were prospectively enrolled. The relationship between baseline WMR and major adverse cardiovascular events (MACE) incidence was assessed during a mean follow-up of 330.8 ± 38 days. Results: The patients’ mean age was 60.4 ± 12.9 year, 59% of them were male. The patients were categorized into two groups based on WMR values, high- and low-WMR groups (&lt; 755 vs. ≄ 755). The incidence of MACE was significantly higher in high-WMR compared with that of low-WMR group (22.4% vs. 10.7%, p &lt; 0.001). Total WBC counts (median 7.9 vs. 6.9 ×103/ÎŒL, p = 0.004), neutrophil count (median 4.6 vs. 4.2 ×103/ÎŒL, p = 0.021), and WMR (median 863.2 vs. 731.5, p = 0.001) were significantly higher in the MACE-positive than MACE-negative group. The high-WMR was found to be significantly associated with the MACE-free survival rate (p &lt; 0.001). In an adjusted cox regression model, the elevated WMR was independently predicted the incidence of MACE (hazard ratio 2.419, 95% CI 1.515–3.862, p &lt; 0.001). Conclusions: The elevated baseline WMR independently predicted the MACE incidence in patients with NSTE-ACS during long-term follow-up.

    Prevalence of Color Blindness in Iranian Students: A Meta-analysis

    Get PDF
    Color blindness (color vision deficiency) is a disorder that impairs the true perception of colors. Using the information in this study, appropriate policy can be made to identify high-risk groups, as well as educational policies for families to perform more effective genetic diagnosis methods. This study aims to examine the prevalence of color blindness in Iranian students through a meta-analysis. Articles related to color blindness published between January 1990 and December 2020 were searched in Scopus, Cochrane Library, Web of Science (WoS), Science Direct, Embase, SID, MagIran, IranDoc, Medline, and Google Scholar databases. The keywords used were based on medical subject topics (MeSH Terms) and, after careful review, articles were selected according to varied sections of Participants, Exposure, Comparison, and Outcomes (PECO). Participants: students; Exposure: students with color blindness were examined; Comparison: Students from multiple provinces and regions of Iran were surveyed for color blindness; Outcomes: the pooled prevalence of color blindness in Iranian students reported from different provinces. The prevalence of color blindness in Iranian students was 3.8% (95% CI: 2.7–5.4%). The pooled prevalence of color blindness in Iranian male and female students was 4.7% (95% CI: 3.5–6.4%) and 0.7% (95% CI: 0.3–1.3%), respectively. The pooled prevalence of red–green color blindness (Tritan) was 41.7% (95% CI: 18.9–68.8%). The pooled prevalence of red color blindness (Protan) was 13.9% (95% CI: 7.8–23.8%), and the pooled prevalence of green color blindness (Deutan) based on meta-analysis was 45.3% (95% CI: 29–62.7%). Due to the high prevalence of color blindness in students, especially male students, it is necessary to be screened for through genetic tests in couples before having children

    Seawater reverse osmosis membrane fouling causes in a full scale desalination plant; through the analysis of environmental issues: raw water quality

    Get PDF
    Background: Membrane clogging is one of the most important problem for desalination plant operators in Iran, therefore, this study was conducted to investigate the main causes of this problem using field analysis. Methods: In this study, six continuous membranes in a reverse osmosis (RO) pressure vessel under the 33-month service period (April 2017 to November 2019) were selected. The membranes were analyzed through visual evaluation of the outer and inner membrane surface, analyzing the damages and physical harms, oxidative stress tests, iron spot test, fouling chemical analysis using loss on ignition (LOI) tests, X-ray fluorescence (XRF), and Fourier-transform infrared (FTIR) spectroscopy. Results: Particle size distribution in raw seawater (EC = 55 000 Όs/cm, turbidity = 11 NTU) was 66.4% smaller than 1 Ό and 28.3% between 1 to 1.9 Όm. Physical damages were not seen on the membranes but telescopic damages were observed which was due to membrane fouling. Removal efficiencies of turbidity and silt density index (SDI) were 84% and 18%, respectively. Membrane oxidation was also seen. Most of the sediments compositions on the membranes were SiO2, Al2O3, MgO, and Fe2O3. Biological fouling was detected on the membranes surface. Conclusion: Inaccurate use of chlorine neutralizer caused the residual chlorine to be present in the membrane entering water, which damaged the membrane. Accumulation of clogging agents on membrane surface showed malfunction of pretreatment function, therefore, revision of design and operation of units is necessary. Biological fouling is due to non-effective pre-chlorination of drinking water. Metallic compounds sedimentation on the membrane is due to improper use of anti-fouling chemicals. High SDI in the influent shows the need to change the cartridge filters. Keywords: Seawater, Drinking, Chlorides, Particle size, Chloride, Spectroscopy, Fourier transform infrared, Ira

    Pattern and Visual Prognostic Factors of Behcet’s Uveitis in Northwest Iran

    Get PDF
    Purpose: To investigate the pattern of ocular involvement in Behcet’s disease (BD) with predictors of patients’ final state of vision. Methods: This historical cohort encompassed the clinical records of 200 patients diagnosed according to the International Criteria for BD (ICBD), over a period of 17 years between 2004 and 2021. Results: The prevalence of Behcet’s uveitis (BU) was more common in females and patients in the fourth decade of life. Ninety-five patients (47.5%) had evidence of ocular involvement in the initial ophthalmologic evaluation, and 171 patients (85.5%) manifested evidence of BU during the follow-up visits of which bilateral non-granulomatous panuveitis was the most common anatomical pattern of involvement (32.9%) followed by posterior (27.6%), anterior (26.5%), and intermediate (13.8%) uveitis. The prevalent accompanying signs were oral aphthous (67%), skin lesions (29%), and genital ulcers (19.5%). Cystoid macular edema (CME) was the most frequent ocular complication (62%), followed by cataract (57.5%) and epiretinal membranes (ERM) (36.5%). Univariate analysis showed the following determinants: male gender, younger age at onset, panuveitis, posterior uveitis, retinal vasculitis, and longer duration of uveitis as poorer visual prognostic factors of the disease. Multivariate analysis demonstrated a higher chance of poor visual prognosis of BD in patients with panuveitis, posterior uveitis, retinal vasculitis, and longer duration of uveitis. Conclusion: This cohort study demonstrated an overview on epidemiological patterns of BU along with the visual prognostic factors in Iranian patients

    Thermodynamic Study of Comfarol Binding to Urease

    Get PDF
    Isothermal Titration Calorimetry, ITC, was used to study of Jack Bean urease, JBU, binding with comfarol in phosphate buffer at pH 7.4. Data analyzing of comfarol interaction with JBU was performed by the extended solvation model and the positive cooperativity of comfarol with JBU indicates that comfarol causes stabilization of the JBU structure. DOI:&nbsp;http://dx.doi.org/10.17807/orbital.v11i3.136

    Bilateral Angle-Closure Glaucoma in a Young Female Receiving Cabergoline: A Case Report

    Get PDF
    Purpose: To report a case of bilateral acute angle-closure glaucoma after oral administration of cabergoline for the treatment of galactorrhea. Methods: A diagnosis of secondary drug-induced angle-closure glaucoma was made in a patient with elevated intraocular pressure (IOP) and myopic refractive shift, which was confirmed by ultrasound biomicroscopy (UBM) of the ciliary body and anterior segment, sonography, and optical coherence tomography. The treatment included the discontinuation of the culprit drug and the administration of topical anti-glaucoma drops. The treatment course was followed with serial measurements of the IOP and refraction, and with performing UBM. Results: Five hours after he received a single 0.5-mg oral cabergoline tablet, the patient suffered from acute secondary angle-closure glaucoma and myopic refractive error. UBM demonstrated both effusion of the ciliary body and an anterior rotation of the iris-ciliary body. IOP was reduced 8 h after cessation of the causative agent and administration of anti-glaucoma drops. Refractive errors returned to normal levels after 8 days. Conclusion: Secondary acute angle-closure glaucoma has been reported to occur after the administration of some drugs. In this report, an attempt has been made to describe this adverse reaction after oral cabergoline intake

    Design and fabrication of a compact microstrip triplexer for wimax and wireless applications

    Get PDF
    A novel structure to design a microstrip triplexer for wireless and WiMAX applications is presented. To obtain a compact microstrip layout, step impedance resonators and coupled lines are used. The introduced triplexer has a size of 0.35λg×0.26λg, where λg is calculated at 2.3 GHz. Also, the obtained insertion losses are 0.78 dB, 1.1 dB and 0.62 dB at 2.3 GHz, 3.2 GHz and 3.6 GHz, respectively. The LC model of the presented resonator is investigated to tune three resonance frequencies by calculating numerical values of inductors and capacitors. Finally, the designed triplexer is simulated and measured
    • 

    corecore