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1.
Eur Rev Med Pharmacol Sci ; 27(6): 2385-2393, 2023 03.
Article in English | MEDLINE | ID: mdl-37013757

ABSTRACT

OBJECTIVE: The electromechanical window (EMW) was investigated as a new predictor of arrhythmia in the presence of long QT. However, the use of EMW to predict idiopathic frequent ventricular premature complexes (PVCs) in those with normal QT intervals has not been clarified. PATIENTS AND METHODS: This single-center study included consecutive patients who presented to the Cardiology Clinic with palpitations and were found to have idiopathic PVC on 24-hour Holter monitoring. Those with a PVC/24-hour frequency of < 1% were defined as group 1, 1-10% as group 2, and > 10% as group 3. The EMW was defined as the time difference (in ms) between the aortic valve closure and the end of the QT interval, measured from an ECG on the concurrent echocardiogram. RESULTS: A total of 148 patients were included in the study, 64% (n = 94) of which were female. The patients' mean age was 50.11 ± 14.7. The groups were similar in terms of the patients' age, BMI, and comorbidities. There was a statistically significant difference between the three groups in terms of the EMW measurements (group 1: 3.78 ± 19.6, group 2: -7 ± 30.9, group 3: -34.83 ± 55.2 ms: p < 0.001). In the multivariate regression analysis, the EMW (OR 0.971, p = 0.007) and every 10-ms decrease in the EMW (OR 1.254, p = 0.011) were thus determined to be independent predictors of PVC > 10%. An EMW value of ≤ -15 ms was associated with the frequency of 24-h PVC > 10%, with a sensitivity of 70% and a specificity of 70% (AUC 0.716, 95% CI: 0.636-0.787 p < 0.001). CONCLUSIONS: The results showed that a negative increase in the EMW may be associated with frequent idiopathic PVCs.


Subject(s)
Long QT Syndrome , Ventricular Premature Complexes , Humans , Female , Adult , Middle Aged , Male , Ventricular Premature Complexes/diagnosis , Ventricular Premature Complexes/complications , Electrocardiography , Echocardiography , Multivariate Analysis , Electrocardiography, Ambulatory
2.
Util Policy ; 76: 101359, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35250191

ABSTRACT

The rapid spread of COVID-19 has severely impacted many sectors, including the electricity sector. The reliability of the electricity sector is critical to the economy, health, and welfare of society; therefore, supply and demand need to be balanced in real-time, and the impact of unexpected factors should be analyzed. During the pandemic, behavioral restrictions such as lockdowns, closure of factories, schools, and shopping malls, and changing habits, such as shifted work and leisure hours at home, significantly affected the demand structure. In this research, the restrictions and their corresponding timing are classified and mapped with the Turkish electricity demand data to analyze the estimated impact of the restrictions on total demand and daily demand profile. A modulated Fourier Series Expansion evaluates deviations from normal conditions in the aggregate demand and the daily consumption profile. The aggregate demand shows a significant decrease in the early phase of the pandemic, during the period March-June 2020. The shape of the daily demand curve is analyzed to estimate how much demand shifted from daytime to night-time. A population-based restriction index is proposed to analyze the relationship between the strength and coverage of the restrictions and the total demand. The persistency of the changes in the daily demand curve in the post-contingency period is analyzed. These findings imply that new scheduling approaches for daily and weekly loads are required to avoid supply-demand mismatches in the future. The long-term policy implications for the energy transition and lessons learned from the COVID-19 pandemic experience are also presented.

3.
Pharm Dev Technol ; 24(10): 1200-1209, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31343377

ABSTRACT

This article summarizes the critical factors involved in product development of a single dosage form formulated by compacting ethyl cellulose (EC) coated controlled release pellets into a tablet. The greatest challenge associated with this type of complex system is to minimize the effect of compression on the drug release. The effects of compression on the drug release were optimized with combination of the following factors (1) particle size of the core pellets, (2) the selection of the coating polymer's viscosity grade, and (3) emergence of cushioning agents. The optimization of these factors provided superior protection for the controlled release coated pellets; therefore, the desired drug release from the tablet was successfully achieved as designed. However, the drug release rates from the coated pellets before and after the compression were minimized and exhibited only a slight difference.


Subject(s)
Cellulose/analogs & derivatives , Models, Chemical , Pharmaceutical Preparations/chemistry , Technology, Pharmaceutical/methods , Cellulose/chemistry , Delayed-Action Preparations , Drug Liberation , Solubility , Tablets
4.
Arch. endocrinol. metab. (Online) ; 61(6): 633-636, Dec. 2017. graf
Article in English | LILACS | ID: biblio-887602

ABSTRACT

SUMMARY Isolated growth hormone deficiency (IGHD) is the most common pituitary hormone deficiency and, clinically, patients have delayed bone age. High sequence similarity between CYP21A2 gene and CYP21A1P pseudogene poses difficulties for exome sequencing interpretation. A 7.5 year-old boy born to second-degree cousins presented with severe short stature (height SDS −3.7) and bone age of 6 years. Clonidine and combined pituitary stimulation tests revealed GH deficiency. Pituitary MRI was normal. The patient was successfully treated with rGH. Surprisingly, at 10.8 years, his bone age had advanced to 13 years, but physical exam, LH and testosterone levels remained prepubertal. An ACTH stimulation test disclosed a non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency explaining the bone age advancement and, therefore, treatment with cortisone acetate was added. The genetic diagnosis of a homozygous mutation in GHRHR (p.Leu144His), a homozygous CYP21A2 mutation (p.Val282Leu) and CYP21A1P pseudogene duplication was established by Sanger sequencing, MLPA and whole-exome sequencing. We report the unusual clinical presentation of a patient born to consanguineous parents with two recessive endocrine diseases: non-classic congenital adrenal hyperplasia modifying the classical GH deficiency phenotype. We used a method of paired read mapping aided by neighbouring mis-matches to overcome the challenges of exome-sequencing in the presence of a pseudogene.


Subject(s)
Humans , Male , Infant , Child , Bone Diseases, Developmental/genetics , Steroid 21-Hydroxylase/genetics , Receptors, Neuropeptide/genetics , Adrenal Hyperplasia, Congenital/genetics , Dwarfism, Pituitary/genetics , Pedigree , Phenotype , Bone Diseases, Developmental/etiology , Receptors, Pituitary Hormone-Regulating Hormone/genetics , Adrenal Hyperplasia, Congenital/complications , Consanguinity , Dwarfism, Pituitary/complications , Mutation
5.
Acta Chir Orthop Traumatol Cech ; 84(5): 391-395, 2017.
Article in English | MEDLINE | ID: mdl-29351542

ABSTRACT

PURPOSE OF THE STUDY The purpose of the current study is to assess the efficacy of anti-adhesion gel on the symptom severity and functional outcomes after mini incision open surgery for carpal tunnel syndrom (CTS). MATERIAL AND METHODS A total of 200 CTS patients (154 women, 46 men) were included in this study. Group I (n = 100; 78 women, 22 men) did not receive local administration of anti-adhesion gel, while anti-adhesion gel consisting of hyaluronic acid-carboxymethylcellulose (Seprafilm®, SanofiBiosurgery, Bridgewater, NJ, USA) was locally applied to patients in Group II (n = 100; 76 women, 24 men). All patients recruited in this study had received conservative treatment comprised of non-steroidal antiinflammatory drugs, steroid injection, replacement of vitamin B and stabilization with splints. Cases that did not benefit from these therapeutic options during one year were assigned as candidates for surgical treatment. RESULTS There was no significant difference between two groups in terms of mean age, gender distribution, preoperative and postoperative Boston questionnaire (BQ) scores, difference of BQ scores after the operation, and the presence of the disease on the left or right side. According to postoperative 1. Year results, there was no significant difference between two groups. CONCLUSIONS Results of the current study demonstrated that use of anti-adhesion gel during mini incision open surgery for CTS did not bring about significant advantages in terms of functional or symptomatic outcomes. Further, controlled trials on larger series are warranted to understand the beneficial effects of anti-adhesive materials during the surgical treatment of CTS. Key words: anti-adhesion gel, Boston questionnaire, carpal tunnel syndrome.


Subject(s)
Carpal Tunnel Syndrome/surgery , Hyaluronic Acid/therapeutic use , Female , Gels , Humans , Intraoperative Care/methods , Male , Postoperative Complications/prevention & control , Tissue Adhesions/etiology , Tissue Adhesions/prevention & control , Treatment Outcome
6.
Arch Endocrinol Metab ; 61(6): 633-636, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29412390

ABSTRACT

Isolated growth hormone deficiency (IGHD) is the most common pituitary hormone deficiency and, clinically, patients have delayed bone age. High sequence similarity between CYP21A2 gene and CYP21A1P pseudogene poses difficulties for exome sequencing interpretation. A 7.5 year-old boy born to second-degree cousins presented with severe short stature (height SDS -3.7) and bone age of 6 years. Clonidine and combined pituitary stimulation tests revealed GH deficiency. Pituitary MRI was normal. The patient was successfully treated with rGH. Surprisingly, at 10.8 years, his bone age had advanced to 13 years, but physical exam, LH and testosterone levels remained prepubertal. An ACTH stimulation test disclosed a non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency explaining the bone age advancement and, therefore, treatment with cortisone acetate was added. The genetic diagnosis of a homozygous mutation in GHRHR (p.Leu144His), a homozygous CYP21A2 mutation (p.Val282Leu) and CYP21A1P pseudogene duplication was established by Sanger sequencing, MLPA and whole-exome sequencing. We report the unusual clinical presentation of a patient born to consanguineous parents with two recessive endocrine diseases: non-classic congenital adrenal hyperplasia modifying the classical GH deficiency phenotype. We used a method of paired read mapping aided by neighbouring mis-matches to overcome the challenges of exome-sequencing in the presence of a pseudogene.


Subject(s)
Adrenal Hyperplasia, Congenital/genetics , Bone Diseases, Developmental/genetics , Dwarfism, Pituitary/genetics , Receptors, Neuropeptide/genetics , Receptors, Pituitary Hormone-Regulating Hormone/genetics , Steroid 21-Hydroxylase/genetics , Adrenal Hyperplasia, Congenital/complications , Bone Diseases, Developmental/etiology , Child , Consanguinity , Dwarfism, Pituitary/complications , Humans , Infant, Newborn , Male , Mutation , Pedigree , Phenotype
7.
Mem Cognit ; 45(1): 63-80, 2017 01.
Article in English | MEDLINE | ID: mdl-27600699

ABSTRACT

The mental rotation literature commonly reports a sex difference, almost always favoring men. Two strategies have been proposed in the literature to account for this difference: holistic and piecemeal. However, there is great variability in rotation performance suggesting other possible contributing factors. This study investigated the effects of stimuli characteristics and habitual spatial thinking on mental rotation performance. In three experiments, participants completed a mental rotation task with two modifications: (1) 3-D figures were presented with their cut versions to promote piecemeal strategy, and (2) block figures were either presented within a frame or none, in light of reference framework model or perceptual grouping model. Overall, whole figures generated faster responses than cut figures and this was more pronounced with greater angular disparity. Shape or the presence of a frame affected rotation performance. Having a frame seemed to impede overall rotation, especially for cut figures, supporting an object-based reference frame. However, a 3-D frame did not have the same effect, possibly suggesting the unitary configuration idea. Men rotated more accurately than women, but still sex was not as robust as it was suggested in the literature. Interestingly, there were similarities between possible strategy use and habitual spatial thinking. People who were categorized as having landmark-centered representations and who preferred verbal directions showed a pattern suggesting the use of a piecemeal strategy, and survey-centered representations and map preference seemed to reflect a holistic strategy.


Subject(s)
Imagination/physiology , Space Perception/physiology , Thinking/physiology , Adult , Female , Humans , Male , Rotation , Young Adult
8.
Eur Rev Med Pharmacol Sci ; 19(6): 1086-91, 2015.
Article in English | MEDLINE | ID: mdl-25855936

ABSTRACT

OBJECTIVE: T-wave peak to end interval (TPE) is a measure of repolarization dispersion, which has been reported as a major arrhythmogenic factor post acute myocardial infarction. The aim of our study was to investigate the changes in TPE in this patient population with regard to peri-procedural intracoronary ECG findings. PATIENTS AND METHODS: Forty-four patients (34 male and mean age of 54.9 ± 10.9 years) with acute STEMI were included. Intracoronary ECG was performed during primary PCI. TPE indices were calculated before and after the procedure. Measurement of the intracoronary ST-segment was carried out before and just after coronary blood flow was established in the infarct related artery. Intracoronary ST-segment resolution (IC-STR) was defined as ≥ 1 mm compared to baseline. RESULTS: There was no difference with respect to baseline characteristics when patients with IC-STR were compared with patients without IC-STR. TPE values decreased significantly after primary PCI in patients with IC-STR (80.9 ± 22.8 ms vs. 65.8 ± 14.4 ms; p < 0.001) whereas they did not change significantly after PCI in patients without IC-STR (79.2 ± 20.9 ms vs. 68.5 ± 16.3 ms; p = 0.18). CONCLUSIONS: TPE measured from surface ECG recordings is significantly reduced in STEMI patients with successful reperfusion after primary PCI, as determined by IC-ECG recordings.


Subject(s)
Electrocardiography/trends , Myocardial Infarction/physiopathology , Myocardial Infarction/surgery , Percutaneous Coronary Intervention/trends , Recovery of Function/physiology , Adult , Aged , Arrhythmias, Cardiac/diagnosis , Arrhythmias, Cardiac/physiopathology , Arrhythmias, Cardiac/surgery , Brugada Syndrome , Cardiac Conduction System Disease , Female , Heart Conduction System/abnormalities , Heart Conduction System/physiopathology , Heart Conduction System/surgery , Humans , Male , Middle Aged , Myocardial Infarction/diagnosis , Prospective Studies , Treatment Outcome
9.
Orthop Traumatol Surg Res ; 99(2): 208-15, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23428315

ABSTRACT

PURPOSE: External fixation has been associated with a high incidence of complications and poor outcomes due to the instability and difficulty in treating open tibia fractures. We use intramedullary (IM) elastic nails to supplement the external fixator. We compared the results of fractures treated by external fixation with and without IM-elastic nail. HYPOTHESIS: The combination of external fixation with IM-elastic nails may be used as an alternative to solve problems due to the external fixators alone in open tibia fractures. METHODS: Group 1 included prospectively 26 cases (15 males and 11 females, mean age 37.5 ± 12.4 years) treated with external fixation and IM-elastic nails, whereas group 2 consisted of 28 cases (23 males and five females, mean age 30.7 ± 14.0 years) treated with standard external fixation. Functional and bone results were made using the criteria proposed by ASAMI. RESULTS: The mean follow-up period was 3.96 ± 2.0 years in group 1 and 3.32 ± 2.1 years in group 2. The mean duration to external fixation and mean time to union were significantly lower in group 1 (P<0.001). In addition, bone and functional results were significantly higher in group 1 (P<0.01), however, pin track infections were lower in group 1 (P<0.01). CONCLUSION: Our results showed the improvement in outcomes with IM-elastic nails: decreased duration of external fixation need and decreased bone healing delay. Therefore, this method may be a superior alternative for preventing complications related to external fixation in open tibia fractures. LEVEL OF EVIDENCE: Level III: prospective comparative study.


Subject(s)
Fracture Fixation/methods , Fractures, Open/surgery , Tibial Fractures/surgery , Adolescent , Adult , Aged , Bone Nails , Female , Humans , Male , Middle Aged , Prospective Studies , Surgical Wound Infection/epidemiology , Treatment Outcome , Wound Healing , Young Adult
11.
Acta Cardiol ; 66(4): 523-5, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21894812

ABSTRACT

Neurocardiogenic syncope is a relatively common cause of syncope and is diagnosed by head-up tilt testing. A 21-year-old man was examined for frequent syncope episodes which occurred after episodes of blood drawing and standing in queue. Syncope developed in tilt table testing. After about 68 seconds, sinus rhythm returned. Recent reports have shown that tilt training is a very effective therapy for recurrent neurocardiogenic syncope. In our case, the patient was treated with midodrine 2.5 mg once a day and a tilt training programme. Therapy resulted in improvement and during a follow-up of six months, no major events occurred.


Subject(s)
Heart Arrest/therapy , Midodrine/therapeutic use , Physical Therapy Modalities , Syncope, Vasovagal/diagnosis , Tilt-Table Test/adverse effects , Vasoconstrictor Agents/therapeutic use , Combined Modality Therapy , Electrocardiography , Humans , Male , Posture , Young Adult
12.
Pancreas ; 40(7): 1024-8, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21775920

ABSTRACT

OBJECTIVES: Endoscopic ultrasound (EUS) may offer a diagnostic tool through the combination of imaging and guided fine-needle aspiration of pancreatic cysts. The purpose of this investigation was to determine the most accurate test for differentiating mucinous from nonmucinous cysts. METHODS: The results of EUS imaging, cytology, and cyst fluid biochemical markers were prospectively collected and compared in a large single-center study (776 patients) using histology or malignant cytology as the final diagnostic standard in 198 patients. RESULTS: The mean cyst fluid carcinoembryonic antigen (CEA) was greater in mucinous cysts (4703.0 ng/mL) compared with nonmucinous cysts (25.8 ng/mL) (P = 0.008). When using the optimal cutoff value of 109.9 ng/mL, the CEA was more accurate (86%, receiver operating characteristic area = 0.928) than EUS imaging (48%) and cytology (58%) in predicting a mucinous cyst (P < 0.0001). Malignant cysts had a mean cyst fluid CEA value (2558.2 ng/mL) similar to benign cysts (4700.2 ng/mL). Cytology (75%) more accurately diagnosed malignant cysts than EUS (66%) and CEA (62%) (P < 0.05). CONCLUSIONS: Cyst fluid CEA concentration provides a highly accurate test for the diagnosis of a mucinous cyst, but does not distinguish benign from malignant cysts. Cytology is the most accurate test for the diagnosis of a malignant cyst.


Subject(s)
Biomarkers, Tumor/analysis , Carcinoembryonic Antigen/analysis , Cyst Fluid/chemistry , Neoplasms, Cystic, Mucinous, and Serous/diagnosis , Pancreatic Cyst/diagnosis , Pancreatic Neoplasms/diagnosis , Aged , Biopsy, Fine-Needle , Boston , Diagnosis, Differential , Endosonography , Female , Humans , Male , Middle Aged , Neoplasms, Cystic, Mucinous, and Serous/chemistry , Neoplasms, Cystic, Mucinous, and Serous/diagnostic imaging , Neoplasms, Cystic, Mucinous, and Serous/pathology , Pancreatic Cyst/chemistry , Pancreatic Cyst/diagnostic imaging , Pancreatic Cyst/pathology , Pancreatic Neoplasms/chemistry , Pancreatic Neoplasms/diagnostic imaging , Pancreatic Neoplasms/pathology , Predictive Value of Tests , Prospective Studies , ROC Curve , Radioimmunoassay , Sensitivity and Specificity
13.
J Psychiatr Ment Health Nurs ; 17(8): 692-9, 2010 Oct.
Article in English | MEDLINE | ID: mdl-21050335

ABSTRACT

The research was designed with a descriptive purpose to compare the alexithymic characteristics, trait anger and anger expression styles of those who are diagnosed with insomnia with those who are not. It was conducted with 96 patients who applied to Department of Sleep Disorders and were diagnosed with insomnia and 96 volunteers were not diagnosed with any psychiatric diagnosis and had not any sleep disorders in two Medical Faculty Hospitals in west of Turkey. Three types of forms were used to collect research data. The first form is the Sociodemographic Characteristics Form, the second one is The Toronto Alexithymia Scale and the third one is the Trait Anger-Anger Expression Scale. It was determined that the patients diagnosed with insomnia had displayed much more alexithymic characteristics than control group. Insomniac patients had higher level of anger and anger expression-in than the control group was found. In accordance with the findings, it is suggested that more comprehensive data should be obtained from the patients having sleeping problems and, that the nursing interventions on the patients' recognition, expression and anger management should be reflected on the nursing holistic care.


Subject(s)
Affective Symptoms/psychology , Anger , Sleep Initiation and Maintenance Disorders/psychology , Adult , Affective Symptoms/complications , Cross-Sectional Studies , Emotions , Female , Humans , Male , Psychiatric Status Rating Scales , Psychological Tests , Sleep Initiation and Maintenance Disorders/etiology
14.
Br J Ophthalmol ; 93(1): 79-82, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18829635

ABSTRACT

AIMS: The aim of the study was to compare the results of short-wavelength (SW) and near-infrared (NIR) autofluorescence (AF) in acute central serous chorioretinopathy (CSC). METHODS: Twenty-six eyes of the 26 patients diagnosed with CSC (mean age 37.4 years) were included in this retrospective study. AF images were evaluated and compared with angiographic and ophthalmoscopic findings. Fluorescein angiography and AF imaging were performed using a confocal scanning laser ophthalmoscope. RESULTS: Focally decreased AF at the leakage site was seen in most of the cases with acute CSC (20 of 26 eyes in SW-AF; 20 of 20 eyes in NIR-AF). Twenty-four of the 26 cases had decreased SW-AF corresponding to the area of the serous retinal detachment, while 19 of the available 20 cases had decreased NIR-AF corresponding to the area of the serous retinal detachment. Increased granular AF corresponding to the extent of the former retinal detachment was seen earlier with SW-AF imaging, but disappeared later in the course of disease with NIR-AF imaging. CONCLUSIONS: AF imaging in CSC demonstrates different patterns according to the course of the disease, reflecting RPE and outer retinal changes. Combining two different methods of AF imaging could predict recent or former CSC episodes and may be a non-invasive technique for monitoring CSC and performing differential diagnosis.


Subject(s)
Choroid Diseases/diagnosis , Fluorescein Angiography , Microscopy, Confocal , Ophthalmoscopy , Retinal Detachment/diagnosis , Adult , Disease Progression , Female , Fovea Centralis , Fundus Oculi , Humans , Infrared Rays , Male , Middle Aged , Reproducibility of Results , Retrospective Studies , Treatment Outcome , Young Adult
15.
J Fr Ophtalmol ; 31(7): 699-704, 2008 Sep.
Article in French | MEDLINE | ID: mdl-18971855

ABSTRACT

AIM: To study the efficacy and safety of topical ciclosporin A (CsA) as an adjunctive therapy after surgical treatment of primary pterygium including excision and limbal conjunctival autograft (LCA) with respect to postoperative pain and complications. PATIENTS AND METHOD: A prospective randomized clinical study was conducted in 60 consecutive patients with primary pterygium. Sixty eyes were operated on using the same surgical technique including excision and LCA. Thirty eyes were randomly treated with topical 0.05% CsA for 3 months after the surgery as a supplement to the standard topical therapy. All patients were followed for postoperative pain using the visual analog scale (VAS) for 1 week after surgery and for complications including recurrences for a period of 1 year. RESULTS: The average VAS was significantly lower in the CsA group (p=0.034). There was only one recurrence (3.4%) in the CsA group (n=28) and five recurrences (17.9%) in the control group (n=29). The other complications were substantial graft scarring (one in the CsA group, three in the control group), Tenon's granuloma (0/2), and fibrovascular proliferation (1/3). The ratio of the cases with no complications was statistically significantly higher in the CsA group (p=0.017). CONCLUSION: This study shows that topical CsA therapy after pterygium surgery may reduce postoperative pain and also decreases complications including recurrences.


Subject(s)
Corneal Transplantation , Cyclosporine/administration & dosage , Immunosuppressive Agents/administration & dosage , Pain, Postoperative/prevention & control , Pterygium/surgery , Administration, Topical , Adolescent , Adult , Cicatrix/epidemiology , Cicatrix/etiology , Cyclosporine/therapeutic use , Female , Granuloma/epidemiology , Granuloma/etiology , Humans , Immunosuppressive Agents/therapeutic use , Limbus Corneae/surgery , Male , Middle Aged , Pain Measurement , Pain, Postoperative/epidemiology , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Prospective Studies , Recurrence , Transplantation, Autologous/immunology , Young Adult
16.
Br J Ophthalmol ; 92(9): 1241-3, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18617545

ABSTRACT

AIM: To investigate the excitation-time-dependent increment in luminescence of fundus autofluorescence. METHODS: Fundus autofluorescence (FAF) images were obtained with a confocal scanning laser ophthalmoscope. Consecutive 60 images of each eye were taken at 1 s time intervals immediately after the beginning of argon laser excitation. Twenty-one eyes of 21 normal subjects were enrolled in the study. To analyse the luminescence of fundus autofluorescence, an 80 x 80 pixel square selection was placed in a relatively avascular fundus area of each consecutive image. Individual grey-scale values of the selected areas were recorded, and the time slope was plotted. RESULTS: The time-dependent increment of the autofluorescence was observed in all subjects. The average luminosity value of subjects at the beginning was calculated as 32.5 mean grey value (MGV), and luminosity reached its maximum (45.4 MGV) between 25 and 30 s. CONCLUSION: The excitation-time-dependent increment in FAF luminosity should be taken into account while acquiring FAF images for quantitative, comparative and longitudinal studies.


Subject(s)
Ophthalmoscopy/methods , Retinal Diseases/diagnosis , Adult , Analysis of Variance , Female , Fluorescein Angiography/methods , Humans , Luminescence , Male , Ophthalmoscopes , Time Factors
18.
J Phys Chem B ; 112(4): 1104-11, 2008 Jan 31.
Article in English | MEDLINE | ID: mdl-18181606

ABSTRACT

A comprehensive study has been undertaken of the electronic spectral and photophysical properties of two oligophenyl (BPH and BPHF) and one oligothienyl (BTF) swivel cruciforms involving measurements of absorption, fluorescence, and phosphorescence spectra, quantum yields of fluorescence (phiF), phosphorescence (phiPh) and triplet formation (phiT), lifetimes of fluorescence (tauF) and of the triplet state (tauT), and quantum yields of singlet oxygen production (phiDelta). From these, all radiative kF and radiationless rate constants, kIC and kISC, have been obtained in solution. The energies of the lowest lying singlet and triplet excited states were also determined at 293 K. Several of the above properties have also been obtained at low temperature and in the solid state (thin films). In general, for the phenyl oligophenyl (BPH) and for the oligothienyl (BTF) compounds, the radiationless decay channels (phiIC+phiISC) are the dominant pathway for the excited-state deactivation, whereas with the fluorene based oligophenyl BPHF the radiative route prevails. In contrast to the general rule found for related oligomers (and polymers) where radiative emission from T1 is absent, with the compounds studied, phosphorescence has been observed for all of the compounds, indicating that this type of functionalization can lead to emissive triplets. Time-resolved fluorescence decays with picosecond resolution revealed multiexponential (bi- and triexponential) decay laws compatible with the existence of more than one species or conformation in the excited state. These results are discussed on the basis of conformational flexibility in the excited state.

19.
Eur J Ophthalmol ; 16(6): 785-90, 2006.
Article in English | MEDLINE | ID: mdl-17191182

ABSTRACT

PURPOSE: To investigate the effects of artificial tear application on contrast sensitivity in dry and normal eyes. METHODS: A total of 55 patients with normal (10/10) corrected or uncorrected visual acuity referring to GATA Gulhane Military Medical Academy Haydarpasa Ophthalmology Outpatient Clinic were evaluated in regard to dry eye diagnostic criteria, and assigned into the dry eye group (Group 1; 35 patients) and the control group (Group 2; 20 patients). All patients were given a contrast sensitivity testing at low and high spatial frequencies using the gradual contrast sensitivity chart before and at 5 minutes after application of artificial tears, and the two groups were compared. Wilcoxon test was used in statistical analysis, accepting a p value of <0.05 as significant. RESULTS: In the dry eye group, there was a statistically significant increase in contrast sensitivity scores both at low and high frequencies after application of artificial tears (p<0.05). In the control group, although there was a significant increase in low frequency scores after artificial tear application (p< 0.05), there was not a significant change in high frequency scores (p>0.05). CONCLUSIONS: The decreased contrast sensitivity in dry eyes improves with application of artificial tears. Therefore, the impeded quality of vision seen in dry eye patients could be restored closer to normal with artificial tear therapy. Besides, contrast sensitivity testing could be used in the follow-up of artificial tear therapy.


Subject(s)
Contrast Sensitivity/drug effects , Dry Eye Syndromes/drug therapy , Ophthalmic Solutions/administration & dosage , Adult , Aged , Contrast Sensitivity/physiology , Dry Eye Syndromes/physiopathology , Female , Humans , Male , Middle Aged , Military Personnel , Vision Tests , Visual Acuity
20.
J Phys Chem B ; 110(31): 15100-6, 2006 Aug 10.
Article in English | MEDLINE | ID: mdl-16884222

ABSTRACT

The photophysical and spectroscopic properties of a new class of oligothiophene derivatives, designated as cruciform oligomers, have been investigated in solution (room and low temperature) and in the solid state (as thin films in Zeonex matrixes). The study comprises absorption, emission, and triplet-triplet absorption spectra, together with quantitative measurements of quantum yields (fluorescence, intersystem crossing, internal conversion, and singlet oxygen formation) and lifetimes. The overall data allow the determination of the rate constants for all decay processes. From these, several conclusions are drawn. First, in solution, the main deactivation channels for the compounds are the radiationless processes: S(1) --> S(0) internal conversion and S(1) --> T(1) intersystem crossing. Second, in general, in the solid state, the fluorescence quantum yields decrease relative to solution. A comparison is made with the analogous linear alpha-oligothiophenes, revealing a lower fluorescence quantum efficiency and, in contrast to the normal oligothiophenes, that internal conversion is an important channel for the deactivation of the singlet excited state. Replacement of thiophene by 1,4-phenylene units in the longer-sized cruciform oligomer increases the fluorescence efficiency. The highly efficient generation of singlet oxygen through energy transfer from the triplet state (S(Delta) approximately 1) provides support for the measured intersystem crossing quantum yields and suggests that reaction with this may be an important pathway to consider for degradation of devices produced with these compounds.


Subject(s)
Combinatorial Chemistry Techniques/methods , Thiophenes/chemistry , Molecular Structure , Oxygen/chemistry , Photochemistry , Sensitivity and Specificity , Solutions/chemistry , Spectrometry, Fluorescence/methods , Spectrophotometry, Ultraviolet/methods
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