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Multiphonon emission model of spin-dependent exciton formation in organic semiconductors

The maximum efficiency in organic light-emitting diodes (OLEDs) depends on the ratio, $r=k_S/k_T$, where $k_S$ ($k_T$) is the singlet (triplet) exciton formation rate. Several recent experiments found that r increases with increasing oligomer length from a value $r \approx 1$ in monomers and short oligomers. Here, we model exciton formation as a multi-phonon emission process. Our model is based on two assertions: (i) More phonons are emitted in triplet formation than in singlet formation. (ii) The Huang-Rhys parameter for this phonon emission is smaller in long oligomers than in short ones. We justify these assertions based on recent experimental and theoretical data.Comment: 8 pages, 7 figure

Resistance status of European grapevine moth [Lobesia botrana Denis & Schiffmüller (Lep.: Tortricidae)] againts to some insecticides

Salkım güvesi (Lobesia botrana Lepidoptera: Tortricidae) en önemli bağ zararlılarından biridir. Türkiye üzüm üretiminin % 35'inin gerçekleştiği Manisa ilinde önemli zararlara sebep olmakta ve mücadelesi için kimyasal mücadele uygulanmaktadır. Yoğun kimyasal kullanımın getirdiği önemli sorunlardan birisi direnç oluşumudur. Manisa ilinde salkım güvesinin insektisitlere karşı direnç durumunun araştırılması ve hangi enzimlerin bundan sorumlu olduğunun belirlenmesi, elde edilen sonuçlara göre ilaçlama programlarının hazırlanması bu çalışmada amaçlanmıştır. Bölgede en yaygın kullanılan insektisitlerden Emamectin benzoate, Spinosad, Lambda-cyhalothrin, Indoxacarb, Chlorpyrifos-ethyl etkili maddeleri larvalara uygulanarak bioassay ve biyokimyasal analizleri yapılarak LD50 değerleri belirlenmiştir. Toksikolojik testler sonucunda Alaşehir popülasyonda Lambda-cyhalothrin ve Indoxacarb LD50 ve LD90 değerleri Sarıgöl popülasyonuna göre yüksek bulunmuştur. Sarıgöl popülasyonunda ise Chlorpyriofs-ethyl, Emamectin benzoate ve Spinosad LD50 değerleri diğer popülasyona göre daha yüksek değerde saptanmıştır. Yapılan enzim analizi sonucunda ise EST enzimi Alaşehir popülasyonu için 9.48 nmol ' -naphtol mg protein-1 dakika-1 değeri ile Sarıgöl popülasyonuna göre daha yüksek bulunmuştur. GST enzimi ise SP'de 0.041 mM glutathione konjugat mg protein-1 dakika-1 olduğu belirlenmiştir. Sonuç olarak salkım güvesinin direnç miktarını belirlemede ileri çalışmaların yapılması gerektiği düşünülmektedir.European Grapevine Moth is one of the most important pest in vineyards. It causes very high production losses and must be applied with insecticide for control of European grapevine moth in province Manisa where 35 % table grape of product in Turkey. One of the important problems of insecticide use is occurence of resistance. For this reason we selected Manisa region where extensive viticulture area in Turkey and we aimed to the determine the resistance status in European grapevine moth and which insecticide become resistance and which enzyme system is responsible for this resistance. In this study we collected larvae from Sarıgöl and Alaşehir district of Manisa province and larvae were reared in laboratory. ' Emamectin benzoate, Spinosad, Lambda-cyhalothrin, Indoxacarb, Chlorpyrifos-ethyl were applied to neonate larvae stage to determine the LD50 values with bioassay and biochemical methods. Bioassay methods showed that Lambda-cyhalothrin and Indoxacarb LD50 values were higher in AP than SP. Also the other insecticides LD50 values were higher in SP than AP. Therefore the results of enzymatic assay showed that EST activities of AP and SP were found 9.48 and 6.36 nmol ' -naphtol mg protein-1 min-1 respectively. GST activities showed that SP activities was found higher than AP but there is no significantly different between two populations. As a result, the further studies are needed to determine the amount of resistance of European grapevine moth to insecticides

Depression Screening for Adolescents in Primary Care

Depression is a serious problem in the United States with suicide the potential catastrophic result of this disease. Suicide is the third leading cause of death for youth between the ages of 10 and 24. At any one time, 5% to 6% of adolescents experience major depressive symptoms, with lifetime rates of major depression among adolescents reaching up to 20%. Adolescents see their primary care providers on average once or twice a year making this the ideal setting for identification of adolescent depression. A review of the literature supports the use of instruments to identify depression that can be incorporated during routine health exams and the need for depression screening in primary care. The goal of this quality improvement project was to implement depression screening into a pediatric primary care setting. This was accomplished through the development of a process to disseminate and score PHQ-9 questionnaires at all health maintenance visits

Large magnetoresistance at room-temperature in semiconducting polymer sandwich devices

We report on the discovery of a large, room temperature magnetoresistance (MR) effect in polyfluorene sandwich devices in weak magnetic fields. We characterize this effect and discuss its dependence on voltage, temperature, film thickness, electrode materials, and (unintentional) impurity concentration. We usually observed negative MR, but positive MR can also be achieved under high applied electric fields. The MR effect reaches up to 10% at fields of 10mT at room temperature. The effect shows only a weak temperature dependence and is independent of the sign and direction of the magnetic field. We find that the effect is related to the hole current in the devices.Comment: 3 pages, 4 figure

Correlation between postpartum depression and omega-3, micronutrients

In recent years, attention has been called to the link between nutrition and mental health. Postpartum depression is an important depressive disorder which often arises 6 to 12 weeks after giving birth and can happen at any time within one year. Postpartum depression prevalence is around 20% worldwide. Genetic predisposition and environmental factors, as well as certain social, psychological and biological factors constitute risk factors for postpartum depression. While malnutrition is among the biological factors, there is a correlation between nutrients such as folic acid, vitamin B₁₂, vitamin D, iron, selenium, zinc, and n-3 fatty acids and psychological state. The nutrients that claim most attention relating to postpartum depression are n-3 essential fatty acids. Insufficient intake of n-3, folic acid, vitamins B and iron is observed in pregnant women. Failing to meet the needs of the mother due to malnutrition during pregnancy can increase the risk of depleting the body’s nutrient reserves and developing postpartum. This risk factor needs to be kept in check by determining and keeping track of the nutrient needs of the mother during the perinatal period

The role of obesity in male fertility

Obesity causes many health problems as well as having negative effects on fertility. There is a multifaceted relationship between obesity and male infertility. Male fertility is associated with sperm concentration, motility and morphology. Testosterone (total and free) and gonadotropin levels were low and estrogen levels were found to be high in obese men. The decrease in androgen levels varies based on the degree of obesity. High body mass index is inversely related to total sperm count, sperm concentration, sperm morphology and number of motile sperm. Leptin and ghrelin are hormones that influence body weight regulation and eating behaviors. Serum leptin level, which is high in obese infertile men, showed a significant positive correlation with abnormal sperm morphology, serum FSH, LH, prolactin level and showed a significant negative correlation with sperm concentration, sperm motility and serum testosterone level. Further research is needed on the effects of ghrelin levels on male infertility. The relationship between obesity and erectile dysfunction can be explained by decreased testosterone levels and elevation of some proinflammatory cytokine levels. Decreased physical activity due to obesity, long-term sitting increases testicular temperature and affects sperm production negatively. There is a multifaceted relationship between obesity, metabolic syndrome and type 2 diabetes and serum testosterone and SHBG. Diet and exercise showed improvement in testosterone levels and sperm concentration due to decreased body weight. However, studies on this subject are extremely limited. The possible effects of weight loss on successful infertility treatment of obese men should not be ignored