196 research outputs found

    Development of polarization-resolved optical scanning microscopy imaging techniques to study biomolecular organizations

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    Light, as electromagnetic radiation, conveys energy through space and time via fluctuations in electric and magnetic fields. This thesis explores the interaction of light and biological structures through polarization-resolved imaging techniques. Light microscopy, and polarization analysis enable the examination of biological entities. Biological function often centers on chromatin, the genetic material composed of DNA wrapped around histone proteins within cell nuclei. This structure's chiral nature gives rise to interactions with polarized light. This research encompasses three main aspects. Firstly, an existing multimodal Circular Intensity Differential Scattering (CIDS) and fluorescence microscopy are upgraded into an open configuration to be integrated with other modalities. Secondly, a novel cell classification method employing CIDS and a phasor representation is introduced. Thirdly, polarization analysis of fluorescence emission is employed for pathological investigations. Accordingly, the thesis is organized into three chapters. Chapter 1 lays the theoretical foundation for light propagation and polarization, outlining the Jones and Stokes-Mueller formalisms. The interaction between light and optical elements, transmission, and reflection processes are discussed. Polarized light's ability to reveal image contrast in polarizing microscopes, linear and nonlinear polarization-resolved microscopy, and Mueller matrix microscopy as a comprehensive technique for studying biological structures are detailed. Chapter 2 focuses on CIDS, a label-free light scattering method, including a single point angular spectroscopy mode and scanning microscopy imaging. A significant upgrade of the setup is achieved, incorporating automation, calibration, and statistical analysis routines. An intuitive phasor approach is proposed, enabling image segmentation, cell discrimination, and enhanced interpretation of polarimetric contrast. As a result, image processing programs have been developed to provide automated measurements using polarization-resolved laser scanning microscopy imaging integrated with confocal fluorescence microscopy of cells and chromatin inside cell nuclei, including the use of new types of samples such as progeria cells. Chapter 3 applies a polarization-resolved two-photon excitation fluorescence (2PEF) microscopy to study multicellular cancerous cells. A homemade 2PEF microscope is developed for colon cancer cell analysis. The integration of polarization and fluorescence techniques leads to a comprehensive understanding of the molecular orientation within samples, particularly useful for cancer diagnosis. Overall, this thesis presents an exploration of polarization-resolved imaging techniques for studying biological structures, encompassing theory, experimental enhancements, innovative methodologies, and practical applications

    Enamel Surface Roughness after Orthodontic Bracket Debonding and Composite Resin Removal by Two Types of Burs

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    Objective: Increased enamel surface roughness following orthodontic bracket debonding leads to increased plaque accumulation and enamel decalcification. Therefore, different methods are employed to achieve smoother enamel surfaces after bracket debonding. This study  compared enamel surface roughness following orthodontic bracket debonding and composite resin removal using white stone and tungsten carbide burs.Methods: In this in-vitro, experimental study, 20 first and second premolars of 10-20 year-olds were collected and their crowns were mounted in acrylic blocks. Roughness of the buccal surfaces of teeth was determined by atomic force microscopy (AFM) and the brackets were bonded to the teeth. After bracket debonding, composite remnants were removed using white stone and tungsten carbide burs. Parameters of enamel surface roughness were determined by AFM and time required for composite removal was also calculated. Repeated measures ANOVA was used to assess the changes in parameters based on the time of measurement, type of bur and their interaction effect. Time required for composite resin removal by bur was analyzed using one-way ANOVA and Tukey’s multiple comparisons.Results: Resin removal increased enamel surface roughness compared to the baseline values in all groups. However, no significant differences were noted between the two types of burs regarding arithmetic average of the roughness profile (Ra), the root mean square roughness (Rq) and the maximum peak-to-valley height in the sampling length (Rt) after resin removal. Time required for resin removal with tungsten carbide bur (34.2 seconds) was significantly shorter than with white stone bur (56.6 seconds)(both ps<0.0001).Conclusion: Considering the similar enamel surface roughness values achieved by the two burs, tungsten carbide burs are recommended for resin removal following orthodontic bracket debonding

    Wound healing Benefits of Curcumin for Perineal Repair after Episiotomy: Results of an Iranian Randomized Controlled Trial

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    Pain and discomfort related to episiotomy have been reported to interfere with women's daily activities postpartum, such as sitting, walking and lifting the baby. To compare the effects of curcumin and Povidone-iodine solutions for episiotomy healing in primiparous women. 120 healthy primiparous women with a vaginal delivery at term were evaluated in this double-blind randomized clinical trial. Randomization was done using a table of random list numbers. Perineal healing was evaluated by research midwives blinded to random allocation at 24-48 hours and 10 days postpartum. Pain was assessed via a visual analogue scale and wound healing via the REEDA scale. Analysis was done on the intention-to-treat principle. The main outcome measure was the changes in wound healing between the two groups as measured by the REEDA Scale. Secondary outcome measures were perineal pain and wound healing 24-48 hours and 10 days after delivery. There was a greater decrease in the total scores of the REEDA in the curcumin group than in the Povidone-iodine (P < 0.001), however; there weren't significant differences between the groups on the VAS scores. The application of curcumin may assist in the episiotomy healing process and could be suitable replacement for Povidone-iodine. Esmaeili Vardanjani SA, Sehati Shafai F, Mohebi P, Deyhimi M, Delazar A, Ghojazadeh M, Malekpour M. Wound healing Benefits of Curcumin for Perineal Repair after Episiotomy: Results of an Iranian Randomized Controlled Trial. Life Sci J 2012;9(4):5536-5541] (ISSN:1097-8135). http://www.lifesciencesite.com. 82

    Up-to-date Treatments of Primary Hyperhidrosis with Focus on Sympathectomy and Sympathicotomy; a Narrative Review

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    Background: Primary hyperhidrosis (PH) refers to excessive sweating, beyond normal physiological levels, in specific sites of the body for unknown reasons. It is usually bilateral and is most prominent in the palms, axillae, feet, and face. PH prevalence is estimated to be 0%-6.1% in different populations. It usually begins in childhood and is more frequent in women. In 57% of cases, there is a positive family history. It is an autosomal dominant disorder with variable penetration in chromosomes 5, 14, or both. Objective: The aim of this study was to illustrate current treatments of PH while focusing on surgical therapies through a narrative review. Methods: A complete search of online articles from 2007 to 2014 in PubMed, Scopus, and the Cochrane Library was performed. A free search and a search in the MeSH database for the study’s keywords were also done. More than 600 relevant articles were found, of which 51 were chosen for this study. This article is based on those articles. Results: Surgery is the best and more permanent therapy for PH. The most common consequences of surgery are compensatory sweating and gustatory sweating. There is controversy concerning whether lowering the level and limiting the number of ganglia on which surgery is performed reduces compensatory sweating. Conclusion: It seems that ramicotomy (selective division of the sympathetic postganglionic fibers) reduces compensatory sweating, but this theory should be confirmed with more studies

    Employee Mental Absence Diagnosing and Analysis of Digital Mental Health Platforms (Case study: Iran Tobacco Company)

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    Purpose: The purpose of this study is to investigate the diagnosis of employees' mental absence and to provide a suitable model for the Iranian Tobacco Company. Method: This research was conducted with a qualitative-inductive approach and the method of Strauss-Corbin's grounded theory. The research tool (data collection) is a semi-structured interview that analyzes the data obtained from interviews with 10 qualified elites and experts of the Iranian Tobacco Company in three stages of open, axial, and selective coding in ATLAS TI software using the grounded theory method. Findings: 13 general categories in the form of a paradigm model in which these factors include causal conditions (individual factors; factors of group behavior; organizational factors; environmental factors), axial phenomenon (diagnosis of the mental absence of employees), contextual conditions (environmental and physical context), intervening conditions (individual factors ), and strategies (organizational strategy; job-related strategy; career development strategy), and consequences (individual outcomes; effectiveness; group outcomes) were identified. Conclusion: In a business environment with digital disruption from competitors and customers who have more choices through the availability of digital applications and information, it is important to ensure that organizations can quickly understand and adapt to new information. The need for mindfulness and control of mental absence is a prerequisite for digital transformation

    The Prevalence of ESBLs Producing Klebsiella pneumoniae Isolates in Some Major Hospitals, Iran

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    Aims of this study were to investigate on antibiotic resistance and molecular epidemiology of K.pneumoniae producing ESBLs isolates of respiratory tract infections in some major hospitals in Iran. K.pneumonaie were obtained of patients with RTI. K. pneumoniae producing ESBLs detected by screening, confirming and PCR methods. During the 12-month period, a total of one hundred and thirteen of K.pneumoniae were found from RTI in three cities in different region of Iran which Sixty seven strains (59.2%) were ESBLs producer. In Ilam hospitals, seventeen strains (43.6%), in Milad hospital, thirty-seven strains (74%) and in Emam Reza hospital, thirteen strains (54.2%) were ESBLs producer. The findings showed that among sixty-seven K.pneumoniae producing ESBLs, Sixty-three strains (94%) were positive for blaSHV, eleven strains (16.4%) contained blaTEM and sixteen strains (23.9%) harbored blaCTX-M. Imipenem was found as an effectiveness antibiotic. In the current study, Majority of the ESBLs production had occurred in Milad hospital in Tehran (74%). In conclusion, spreading ESBL-producing strains is a concern, as it causes limitations to the antimicrobial agents for optimal treatment of patients

    Is a Single dose of Prophylactic Antibiotics Sufficient in Patients with Acute Non-Complicated Appendicitis?

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    Background: Acute appendicitis is one of the most common acute surgery events. Its main treatment is surgery. However medical management before and after the surgery has an important impact on the treatment. Objective: The aim of study was evaluating the outcomes of single dose and quadruple doses of prophylactic antibiotic therapy in patients with acute non-complicated appendicitis. Methods: This randomized double blind clinical trial was carried out on 294 patients in single dose (136 patients) and the quadruple doses (158 patients) groups. In single dose group, a dose of 1g Cefazolin + 500mg Metronidazole was prescribed intravenously about half an hour before surgery. The quadruple doses group received three more doses after surgery.  Two groups were followed for fever, erythema, seroma, wound infection, intra-abdominal abscess formation and readmissions within one month after discharge. Results: The mean age of patients was 31±5.14 years. 203(69%) of patients were men while 91(31%) were women. There were no significant statistical differences between groups in age, sex and body mass index (BMI) variables. No significant statistical differences were observed during surgery and hospitalization period between two groups. In the single dose group, wound infection was 8(5.9%), while it was 6(3.8%) in the quadruple doses group; hence, there were no significant statistical differences in this regard. There was no abdominal abscess in groups. There were significant statistical differences regarding erythema, seroma and antibiotics consumption costs between groups. Conclusion: A single dose of prophylactic antibiotics is sufficient in patients with acute suppurative non-complicated appendicitis

    Evaluation of an immunocapture-agglutination test (Brucellacapt) for serodiagnosis of human brucellosis, Ilam, Iran

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    Brucellosis is common health problem in some Middle Eastern, Mediterranean countries and Iran. The present investigation was carried out to investigate the prevalence of brucella antibodies through Rose bengal test (RBT), Wright and Coombs and comparison with Brucella Capt Test. A total of 754 different suspected to brucellosis were tested during the period from March 2008 to February 2009. They assayed by Brucellacapt, Coombs tests and SAT. Our results had shown that of 754 serum samples, 125 samples were positive by Rosbangal test. Thus, frequency of brucellosis by Rosbangal test was 16.5%. The results in 1/40 and 1/80 were equal for Brucellacapt and Coombs test and different for SAT. The other titers results were different for all testes which used in our study. The results from the present study showed a high sensitivity and specificity of Brucellacapt for the diagnosis of human brucellosis
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