Mental health problems and help-seeking behaviours of Syrian refugee adolescents: mediating role of self-stigma.

BACKGROUND: Although common mental health problems have been widely studied with self-stigma, few studies have focused on the mediating effect of self-stigma in the relationship between mental health problems and help-seeking behaviours of refugee adolescents. Therefore, the purpose of the present study was to examine whether self-stigma mitigates the adverse effects of stress, anxiety, and depression symptoms on the help-seeking behaviours of Syrian adolescents living in Turkey. METHODS: The participants of this study included 488 Syrian refugee adolescents (boys, 63.73%; girls, 3627%) living in Turkey. Participants completed the Depression Anxiety Stress Scale and General Help-Seeking Scale and Self-Stigma of Seeking Psychology Help Scale. RESULTS: The findings revealed that stress (ß = 0.19, p < 0.01), anxiety (ß = 0.12, p < 0.05), and depression (ß = 0.17, p < 0.01) had significant and positive predictive effects on self-stigma, but not on help-seeking behaviours. Also, self-stigma (ß = -0.12, p < 0.01) had a significant negative predictive effect on help-seeking behaviours. With regard to the indirect effects, the findings showed that self-stigma fully mediated the associations between stress - help-seeking [effect = -0.05, 95% confidence interval (CI) -0.11 to -0.01], anxiety - help-seeking (effect = -0.04, 95% CI -0.09 to -0.01)], and depression - help-seeking (effect = -0.05, 95% CI -0.12 to -0.01). CONCLUSIONS: Our findings highlight the potential negative effects of self-stigma on the help-seeking behaviours of Syrian refugee adolescents, both directly and indirectly. These results can be used to develop and implement effective and efficient interventions to address the unmet mental health needs of refugee adolescents.

BMP Stimulation Differentially Affects Phosphorylation and Protein Stability of ß-Catenin in Breast Cancer Cell Lines.

Increased expression and nuclear translocation of ß-CATENIN is frequently observed in breast cancer, and it correlates with poor prognosis. Current treatment strategies targeting ß-CATENIN are not as efficient as desired. Therefore, detailed understanding of ß-CATENIN regulation is crucial. Bone morphogenetic proteins (BMP) and Wingless/Integrated (WNT) pathway crosstalk is well-studied for many cancer types including colorectal cancer, whereas it is still poorly understood for breast cancer. Analysis of breast cancer patient data revealed that BMP2 and BMP6 were significantly downregulated in tumors. Since mutation frequency in genes enhancing ß-CATENIN protein stability is relatively low in breast cancer, we aimed to investigate whether decreased BMP ligand expression could contribute to a high protein level of ß-CATENIN in breast cancer cells. We demonstrated that downstream of BMP stimulation, SMAD4 is required to reduce ß-CATENIN protein stability through the phosphorylation in MCF7 and T47D cells. Consequently, BMP stimulation reduces ß-CATENIN levels and prevents its nuclear translocation and target gene expression in MCF7 cells. Conversely, BMP stimulation has no effect on ß-CATENIN phosphorylation or stability in MDA-MB-231 and MDA-MB-468 cells. Likewise, SMAD4 modulation does not alter the response of those cells, indicating that SMAD4 alone is insufficient for BMP-induced ß-CATENIN phosphorylation. While our data suggest that considering BMP activity may serve as a prognostic marker for understanding ß-CATENIN accumulation risk, further investigation is needed to elucidate the differential responsiveness of breast cancer cell lines.

Less bleeding by omitting aspirin in non-ST-segment elevation acute coronary syndrome patients: Rationale and design of the LEGACY study.

BACKGROUND: Early aspirin withdrawal, also known as P2Y12-inhibitor monotherapy, following percutaneous coronary intervention (PCI) for non-ST-segment elevation acute coronary syndrome (NSTE-ACS) can reduce bleeding without a trade-off in efficacy. Still the average daily bleeding risk is highest during the first months and it remains unclear if aspirin can be omitted immediately following PCI. METHODS: The LEGACY study is an open-label, multicenter randomized controlled trial evaluating the safety and efficacy of immediate P2Y12-inhibitor monotherapy versus dual antiplatelet therapy (DAPT) for 12 months in 3,090 patients. Patients are randomized immediately following successful PCI for NSTE-ACS to 75-100 mg aspirin once daily versus no aspirin. The primary hypothesis is that immediately omitting aspirin is superior to DAPT with respect to major or minor bleeding defined as Bleeding Academic Research Consortium type 2, 3, or 5 bleeding, while maintaining noninferiority for the composite of all-cause mortality, myocardial infarction and stroke compared to DAPT. CONCLUSIONS: The LEGACY study is the first randomized study that is specifically designed to evaluate the impact of immediately omitting aspirin, and thus treating patients with P2Y12-inhibitor monotherapy, as compared to DAPT for 12 months on bleeding and ischemic events within 12 months following PCI for NSTE-ACS.

Is diagnostic performance of SARS-CoV-2 detection dogs reduced -due to virus variation- over the time?

Medical detection dogs have a high potential for use as alternative diagnostic tools not only for organic diseases, but also for infectious diseases. However, new variants emerging over time may affect the accuracy and sensitivity of diagnostic methods including medical detection dogs in case of viral pandemics. To the best of our knowledge, this is a pioneer study aimed to investigate diagnostic performances and generalization ability of SARS-CoV-2 detection dogs against the new variant after being trained with the original virus. Two SARS-CoV-2 detection dogs were used in this study. In total, 1002 samples including the Omicron variant were introduced to the dogs using a double-blinded design. Two different refresher training sessions were conducted to train the dogs to identify the scent of the Omicron variant. In the first refreshment training, mixed samples (original virus and Omicron variant) were used. The diagnostic performances of the dogs were significantly increased only after the second refreshment training where only the Omicron variant was introduced. This study illustrates that diagnostic performances of SARS-CoV-2 detection dogs were not consistent over time with the emerging new variants. Thus, refreshment training with new variant(s) should be conducted with every new variant which may affect the diagnostic performances of those dogs in such infectious outbreaks.

Platelet glycoprotein IIb/IIIa inhibitor tirofiban in clopidogrel-naïve patients undergoing elective percutaneous coronary intervention.

BACKGROUND: The safety of administration of tirofiban, a platelet glycoprotein IIb/IIIa inhibitor, followed by a clopidogrel loading dose in clopidogrel-naïve patients undergoing ad-hoc percutaneous coronary intervention (PCI) is not yet clear. METHODS: In a retrospective observational cohort analysis, clopidogrel-naïve patients undergoing ad-hoc PCI who received a high-dose bolus of tirofiban (25 µg/kg) followed by a 600-mg clopidogrel loading dose (group 1) were compared with patients undergoing elective PCI who were pretreated with clopidogrel (group 2), between September 2014 and October 2021. The primary outcome was major adverse cardiovascular events (MACE) defined as the composite of death, myocardial infarction, stroke, target-lesion revascularisation and bleeding at 30 days. Secondary outcomes were MACE at 7 days and individual components of the primary outcome at 7 and 30 days. RESULTS: A total of 1404 patients were included: 432 (31%) in group 1 and 972 (69%) in group 2. Median age was 69 years, and 28% were female. At 7­day follow-up, MACE occurred in 1.4% in group 1 versus 3.0% in group 2 (p = 0.08). 30-day MACE were observed in 1.9% in group 1 and 4.2% in group 2 (p = 0.03). Secondary outcomes were comparable between the groups. Cox regression analysis, corrected for baseline differences, revealed no significant difference in the primary outcome (hazard ratio: 1.8; 95% confidence interval: 0.8-3.9). CONCLUSION: Ad-hoc PCI in clopidogrel-naïve patients who were treated with high-dose bolus of tirofiban followed by a clopidogrel loading dose immediately after the procedure appeared to be safe.

Organic pollutant exposure and health effects of cooking emissions on kitchen staff in food services.

This study was conducted to determine the exposure and health risk to cooking fumes of a total of 88 volunteer kitchen staff aged between 18 and 65 years working in five different kitchens in Ankara. Gas- and particle-phase polycyclic aromatic hydrocarbons (PAHs), and volatile organic compound (VOCs) concentrations were evaluated in the indoor air of 5 kitchens. Serum malondialdehyde (MDA) and superoxide dismutase (SOD) levels were analyzed to determine the oxidative damage as a result of the exposure to cooking fumes among the cooks and waiters. Significant positive relationships were found between serum MDA levels of the hot kitchen workers and indoor chrysene (Chr), indeno(1,2,3-c,d)pyrene (Ind), and total VOC levels. Although the carcinogenic risks estimated for the exposed population were between the acceptable/tolerable levels, the hazard quotient (HQ) estimated for the exposure to indoor benzene exceeded the safe level. The results of the study revealed that exposure to organic pollutants in indoor air may be a risk factor for the development of oxidative stress, especially in hot kitchen workers. The importance of efficient ventilation in the kitchen has been pointed out to reduce health risks caused by cooking fumes.

Non-metabolic functions of pyruvate kinase M2: PKM2 in tumorigenesis and therapy resistance.

Cancer is the disease of uncontrollably dividing cells in the body. As cancer cells proliferate at higher rates, they need more energy in a short time necessitating deregulation of energy-generating pathways for their benefit. Although oxidative phosphorylation generates more energy from a glucose molecule, cancer cells have a tendency to enhance aerobic glycolysis by consuming more glucose and producing lactate as a by-product even if oxygen is present. In addition to the generation of rapid energy to fulfill their increasing demands, this strategy also provides the use of glucose metabolites such as lactate as a source for the synthesis of anabolic molecules, such as nucleotides, amino acids, and lipids during the rapid phase of the proliferation. Pyruvate kinase M2 (PKM2) is an isoform of pyruvate kinase, which mediates the balancing of energy generation mechanisms during the anabolic and catabolic events. Due to its vital role in glycolysis, PKM2 has been investigated to target cancer cell metabolism for several years. However, recent studies demonstrate that PKM2 may also promote cancer progression by regulating core steps in metastasis such as migration, angiogenesis, and stemness. Of note, it is estimated that 90% of cancer-related deaths are due to metastasis. This review is intended to summarize the recent advances in the non-metabolic roles of PKM2 in cancer progression and to indicate its potential uses for the development of new treatment strategies.

Determination of epidemiological characteristics of addicts treated in drug addiction clinics in Kabul.

According to the Afghanistan Ministry of Health, 3.5 million people use drugs, 2.4 million of which are regular users. In this cross-sectional study, it was aimed to determine epidemiological characteristics of addicts in a treatment center in Kabul. Eight hundred people were included. Statistical analysis was done with SPSS 22.0. The average age was 30.74 years, 88.9% were male, and 50.6% were married. Further, 35.9% have never been trained, 60.5% of participants were living in urban areas, 62.8% were refugees, 17.5% were unemployed, and 30.3% of them had monthly income below 147.1 USD. The average age of starting substance use was 19.9 years. "Friendship environment" was the leading reason to start (36.6%), followed by "reduce troubles" with 22.3%. The most preferred substance was cannabis (46.0%), followed by opium (25.3%) and heroin (17.0%). Heroin was the most commonly used substance lifelong (87.1%), followed by cannabis (66.3%) and opium (65.5%). When compared to individuals younger than 18, heroin use rates were 3.52 times higher in the 18-to-30 age range, 5.49 times higher in the 31-to-45 age range, and 1.86 times higher in urban residents than rural. Cannabis use was 12.24 times more among men than women, 2.79 times higher among divorced or widowed individuals than singles, 1.68 times higher among refugees than non-refugees, and 2.26 times higher among drug traffickers than non-traffickers. Opium use was 1.63 times higher for refugees than non-refugees and 3.24 times higher in those who worked in drug fields than those who did not. Periodic assessment of prevalence of drug use and the establishment of drug use monitoring systems are recommended.

Long-term outcome after deferred revascularization due to negative fractional flow reserve in intermediate coronary lesions.

OBJECTIVES: The aim was to assess long-term outcome after deferring intervention of coronary lesions with a fractional flow reserve (FFR) value of >0.80 in a real-world patient population and then to identify factors associated with deferred target lesion failure (DTLF). BACKGROUND: Deferring coronary interventions of intermediate lesions based on FFR measurement is safe, irrespective of the extent of coronary artery disease. However, FFR values near the cut-off of >0.80 may have less favorable outcome. METHODS: A retrospective analysis was performed in patients with deferred coronary intervention based on FFR value >0.80. The primary endpoint was DTLF, a composite of acute coronary syndrome (ACS) and any coronary revascularization, related to the initially deferred stenosis. RESULTS: A total of 600 patients, mean age of 66 ± 10 years, and 751 coronary lesions with negative FFR values (mean 0.88 ± 0.04) were included. The mean follow-up was 27 ± 15 months. DTLF occurred in 44 patients (7.3%), revascularization in 42 (7%), and ACS without revascularization in 2 patients (0.3%). Patients with DTLF more often had diabetes mellitus, previous coronary artery bypass grafting, multivessel disease (MVD), and lower FFR at inclusion. Multivariable regression analysis showed that lower deferred FFR values [FFR 0.81-0.85: hazard ratio (HR) 2.79 (95% CI [confidence interval]; 1.46-5.32), p .002], MVD [HR 1.98 (95% CI; 1.05-3.75), p .036], distal lesions [HR 2.43 (95% CI; 1.29-4.57), p .006], and lesions located in a saphenous vein graft (SVG) [HR 6.35 (95% CI; 1.81-22.28), p .004] were independent predictors for DTLF. CONCLUSIONS: The long-term rate of DTLF of initially deferred coronary lesions was 7.3%. Independent predictors for DTLF are lower deferred FFR value, the presence of MVD, distal lesions, and lesions in SVG.

Sleep disturbances in children with cystic fibrosis, primary ciliary dyskinesia and typically developing children during COVID-19 pandemic.

AIM: We aimed to investigate sleep disturbances in children with cystic fibrosis (CF) and primary ciliary dyskinesia (PCD) and typically developing (TD) children during the COVID-19 pandemic. METHODS: Primary care givers of children with CF and PCD aged 3-16 years were asked to enrol in the study. Primary care givers of TD children were included as control group. The Sleep Disturbance Scale for Children (SDSC) was used, and questions related to sleep habits during the pandemic were asked. Results of the three groups were compared. RESULTS: Primary care givers of 33 children with CF, 16 children with PCD and 66 TD children were included in the study. There were no differences in terms of age and gender between the three groups. Changes in sleep patterns during the pandemic were more common among TD children and their families, with 75% of the children and 80% of their families sleeping later than before. The sleep initiation and maintenance disorder scores were higher in TD children (P = 0.001), whereas the sleep breathing disorder scores were higher in children with PCD (P = 0.001), and the sleep hyperhidrosis scores were higher in children with CF and PCD (P = 0.011). No relationships were found between sleep parameters and clinical findings of children with lung disease. CONCLUSIONS: Children's sleep habits have changed during the pandemic. Children with chronic lung diseases and even TD children may experience sleep disturbances during this period.

Nonpharmaceutical interventions in Turkey and worldwide during COVID-19 pandemic

Nonpharmaceutical interventions (NPIs) are actions apart from getting vaccinated and medications, in order to promote deceleration of the spread of illness among people and communities during pandemic. In this article, we aim to examine NPIs applied in Turkey and worldwide due to the COVID-19 pandemic. Some of the NPIs such as isolation, quarantine, and contact tracing were maintained with updates of the Ministry of Health guidelines in Turkey. Some NPIs including travel and partial or full curfew mobilization restrictions were set in accordance with the various periods by the number of cases. Periods of restrictions at autumn 2021 to summer 2022 are national partial curfews, national extended curfews, local decision-making phase, revised local decision-making phase, partial lockdown, full lockdown and gradual normalization. Mitigation and suppression have been implemented in Turkey with restrictions of varying severity throughout the course of the epidemic. It is seen that the restrictions implemented in Turkey contributed to the flattening of the epidemic curve. Even some countries mainly applied the suppression method, and others applied the mitigation method, in general, it is seen that similar methods were applied with different weights. Examples of different countries demonstrated that NPIs are effective for flattening epidemic curve. NPI have been the main instrument for a year and a half from the beginning of the epidemic to mid-2021 in Turkey as well as worldwide.

Is cervical swab an efficient method for developing a new noninvasive prenatal diagnostic test for numerical and structural chromosome anomalies?

Background/aim: Prenatal diagnosis is vital to obtain healthy generation for risky pregnancies. There have been several approaches, some of which are routinely applied in clinics to evaluate the possible prenatal deficiencies and/or diseases. In the present study, we aimed to isolate the fetal cells from endocervical samples and try to identify possible anomalies which were proved by Amniocentesis (AS) and chorionic villus sampling (CVS) methods. Materials and methods: Endoservical specimens were collected from 100 pregnant women. Cells were separated in parallel by fluorescence-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS) using human leukocyte antigen (HLA) G233 and placental alkaline phosphatase (PLAP) antibodies. CMA (comprehensive meta-analysis) were carried out and male fetuses were confirmed with Sex determining region Y (SRY) amplification. Results: The percent of HLA G233 and placental and placental alkaline phosphatase (PLAP) positive cells were 4.55% and 84.59%, respectively. The percent of cells positive for both markers was 14.75%. CMA analyses were not informative. (SRY) was amplified in 67% of the samples. Conclusion: However, the success rate of the both cell sorting and scanning of DNA anomalies by aCGH and/or RT-PCR was limited, preventing the applicability of this proposal in the clinics. Still, the success of the proposed method depends on the development of the novel fetal cell-specific antibodies and the improvements in the sorting systems.

Analysis of Judd-Ofelt parameters and radioluminescence results of SrNb2O6:Dy3+ phosphors synthesized via molten salt method.

In this work, Dy3+-doped SrNb2O6 phosphors were fabricated by the molten salt process, which avoids high sintering temperatures, prolonged reaction time and poor compositional homogeneity. All samples crystallized to the orthorhombic columbite structure with space group, P21/c, while a rod-like morphology was observed by scanning electron microscopy (SEM). PL (photoluminescence) and RL (radioluminescence) spectra of SrNb2O6:Dy3+ exhibited a strong blue emission peak at 576.0 nm related to 4F9/2 → 6H15/2 transition of Dy. The high RL emission of the 4F9/2 → 6H15/2 (electric dipole) transition upon X-ray-induced excitation led to a decrease in Dy3+ local environmental symmetry. The Judd-Ofelt (J-O) theory was applied to the PL excitation spectra for the calculation of optical data such as Ω2, Ω4, and Ω6 parameters, radiative transition probability (Ar), branching ratios (ß, ßexp) and stimulated emission cross-section (σe). The quantum efficiencies (ηQE) varied between 35.47 and 31.93%, which are compatible with theoretical quantum efficiencies based on the Einstein relation. The CIE chromaticity coordinates (x, y) and CCT (correlated color temperature) parameter for 3 mol% phosphor were defined (0.385, 0.432) and 4209 K, respectively.

Alcohol consumption and alcohol policy

Alcohol is a unique addictive substance used by many people for different reasons. Alcohol use affects not only the users but also the family and the whole society in a negative way. Alcohol is one of the most commonly used substances for entertainment purposes in the world and 1 in 3 people is a current drinker. 2348 billion people (43% of the population) aged 15 and over are current drinkers and males drink about 2 times more frequently than females (53.6%/32.3%). According to the Global Alcohol and Health Report published by the World Health Organization (WHO) (2018), total alcohol per capita consumption (APC) worldwide aged 15 and over increased from 5.7 liters in 2000 to 6.4 liters in 2016. Harmful alcohol consumption is a major public health problem and it is known to be associated with more than 200 diseases and injuries. Policies and measures to prevent alcohol use are not implemented adequately and the burden of alcohol-related illnesses continues to increase tremendously. In order to prevent and reduce the harmful effects of alcohol, alcohol policies should be formulated based on the best evidence from a public health perspective.

Fundamental Characteristics, Attitudes and Behaviors Regarding Substance Use Focusing on Cannabis: Findings from the General Population Survey in Turkey, 2011.

Cannabis is the most prevalent illicit drug used in the world. We aimed to determine prevalence and some characteristics of cannabis use in Turkey. The study was based on a cross-sectional survey conducted with a nationally representative sample of 8045 individuals with in-house interviews. The life-time prevalence of substance use was found as 2.8%. Cannabis with 0.7% life-time prevalence, was the most commonly used substance. Cannabis users were concerned about some adverse outcomes such as anxiety with withdrawal (14%), losing control about using the drug (14%), daily performance problems (10.9%) and problems about interpersonal violence (6.9%). 35.1% of them wanted to quit and 18% regretted using cannabis. Prevalence of cannabis use is lower in Turkey compared with most of the other countries in the world. Nevertheless, it is a significant health concern. Identifying characteristics and attitudes related with cannabis use may help to improve policies about protective measures.

Visual and Postural Motion-Evoked Dizziness Symptoms Are Predominant in Vestibular Migraine Patients.

Background: Vestibular migraine (VM) is one of the most common underdiagnosed disorders. We aimed to study the clinical characteristics of VM patients who were referred to a neurology-headache unit by otolaryngology after exclusion of peripheral causes of vertigo. Methods: One hundred and one patients diagnosed with VM in the headache unit were included. Description of vestibular symptoms, demographic and clinical features, trigger factors, accompanying diseases, and response to vestibular-suppressant medications and prophylactic migraine treatment were evaluated. Results: Vestibular symptoms were triggered by daily head and body movements and mainly consisted of brief attacks lasting seconds (60.4% of patients) although the total duration of the vestibular episode lasted hours or days. Other aggravating factors were moving visual stimuli, passive motion, and visually busy environments. Visually induced vestibular symptoms were defined by 71.3% of the patients, and positional motion-induced vestibular symptoms were described by 82.2% of the patients. Vestibular symptoms were mainly defined as feeling the ground slipping from under their feet (40.6%), feeling like there is an earthquake or swaying (27.7%), sensation of rocking on a boat (26.7%), and sensation as if stepping on empty space (24.8%). The majority of the patients (83.2%) previously used vestibular-suppressant drugs, and these drugs were effective temporarily only in 12.9%. Conclusions: Chronic recurrent dizziness symptoms, rather than internal or external vertigo, are predominant in our VM patients. Recurrent brief dizziness attacks induced upon routine visual and/or postural motion, longstanding symptoms with limited response to vestibular suppressants, and precipitation by typical migraine triggers are suggestive of VM.

Microstructural and Radioluminescence Characteristics of Nd3+ Doped Columbite-Type SrNb2O6 Phosphor.

Undoped and different concentration Nd3+ doped SrNb2O6 powders with columbite structure were synthesized by molten salt process using a mixture of strontium nitrate and niobium (V) oxide and NaCl-KCl salt mixture as a flux under relatively low calcining temperature. X-ray diffraction analysis results indicated that SrNb2O6 phases found to be orthorhombic columbite single phase for undoped, 0.5 and 3 mol% Nd3+ doping concentrations. Phase composition of the powders was examined by SEM-EDS analyses. Radioluminescence properties of Nd3+ doped samples from UV to near-IR spectral region were studied. The emissions increased with the doping concentration of up to 3 mol%, and then decreased due to concentration quenching effect. There is a sharp emission peak around 880 nm associated with 4F5/2 â†’ 4I9/2 transition in the Nd3+ ion between 300 and 1100 nm. The broad emission band intensity was observed from 400 to 650 nm where the peak intensities increased by increasing Nd3+ doping concentration. All the measurements were taken under the room temperature.

Structural and Near-Infrared Properties of Nd3+ Activated Lu3NbO7 Phosphor.

Undoped and Nd3+ doped lutetium niobate phases have been prepared by a conventional solid state reaction method using lutetium acetate and niobium oxide at 1250 °C for 6 h. X-ray diffraction patterns of the 6 mol% Lu3NbO7 sample exhibited a cubic fluorite single phase. Phase structure exhibited interesting crystallization behaviour depending on increasing Nd3+ concentration which led to a Lu3NbO7 single phase formation during the heat treatment process. SEM investigations were also in agreement with the XRD results. Morphologies of Nd3+ doped lutetium niobate powders exhibited oval like shapes and grain sizes varied between 0.3 and 5 µm. Near-infrared luminescence properties of Nd3+ doped Lu3NbO7 were also studied. 1.06 µm laser transition characteristics of Nd3+ doped lutetium niobate have been observed. Concentration quenching phenomenon was not detected depending on increasing Nd3+ doping concentrations at room temperature.

Synthesis and Optical Properties of Novel Red-Emitting PbNb2O6: Eu(3+) Phosphors.

Undoped and PbNb2O6:Eu(3+) (1.0 ≤ x ≤ 6.0 mol%) phosphors were synthesized at 1100 °C for 3.5 h by the conventional solid state reaction method. Synthesized PbNb2O6:Eu(3+) phosphors were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS) and Photoluminescence (PL) analyses. The PL spectra showed series of excitation peaks between 350 and 430 nm due to the 4f-4f transitions of Eu(3+). For 395.0 nm excitation, emission spectra of Eu(3+) doped samples were observed at 591 nm (orange) and 614 nm (red) due to the (5)D0 â†’ (7)F1 transitions and (5)D0 â†’ (7)F2 transitions, respectively. PL analysis results also showed that the emission intensity increased by increasing Eu(3+) ion content. No concentration quenching effect was observed. The CIE chromaticity color coordinates (x,y) of the PbNb2O6:Eu(3+) phosphors were found to be in the red region of the chromaticity diagram.

Synthesis and Optical Characterization of Red-Emitting BaTa2O6:Eu(3+) Phosphors.

Undoped and Eu(3+) doped BaTa2O6 phosphors were synthesized via solid state reaction method and characterized by using XRD, SEM-EDS and photoluminescence (PL) analyses. The XRD results revealed that the crystal structure of BaTa2O6 allowed up to 10 mol% levels of Eu(3+) ions due to the TTB characteristic network of adjacent octahedrals. SEM-EDS analyses confirmed the formation of BaTa2O6 structure and EuTaO4 secondary phase. BaTa2O6:Eu(3+) phosphors exhibited orange and red emissions at 592.2 nm and 615.7 nm in the visible region respectively. The Commission Internationale d'Eclairage (CIE) chromaticity coordinates of the BaTa2O6:Eu(3+) phosphors that excited at λ ex = 400 nm ranged from orangish-red to pinkish-red depending on increasing Eu(3+) concentration.