Consistent formulation of the crossover from density to velocity dependent recombination in organic solar cells

Carrier recombination is a central process in bulk heterojunction organic solar cells. Based on the competition of hopping rates that either implies escape in a broad density of states or recombination across the interface, we formulate a general theory of recombination flux that distinguishes reaction or transport limited recombination according to charge density. The Langevin picture is valid only in the low charge density limit, and a crossover to the reaction controlled regime occurs at higher densities. We present results from impedance spectroscopy of poly(3-hexylthiophene):methanofullerene solar cell that exhibit this crossoverThe work was supported by Generalitat Valenciana (Project No. ISIC/2012/008)

Effect of electromagnetic field (3mT frequency) on heart ulatrastructure in mice

زمینه و هدف: شرایط زندگی مدرن سبب شده است که انسان به طور مداوم در معرض میدان های الکترومغناطیس قرار گیرد. مطالعات اپیدمیولوژیک و آزمایشگاهی حیوانی اثر سوء میدان های الکترومغناطیس را بر سیستم های بیولوژیک نشان داده است. این مطالعه با هدف تعیین اثرات میدان های الکترومغناطیس بر فرا ساختمان سلول های قلبی انجام شد. روش بررسی: در این مطالعه تجربی 30 سر رت ماده نژاد ویستار به دو گروه آزمایش و کنترل (در هر گروه پانزده سر) تقسیم شدند. رت های گروه آزمایش به مدت 4 ماه و روزانه 4 ساعت در معرض میدان الکترومغناطیس با شدت 3 میلی تسلا قرار گرفتند. پس از اتمام این مدت حیوانات گروه آزمایش و کنترل کشته و نمونه های قلب جهت مطالعه با میکروسکوپ الکترونی آماده شدند. سلول ها از نظر کمی و تعداد در دو گروه کنترل و آزمایش با استفاده از آزمون t-test تجریه و تحلیل شدند. یافته ها: یافته ها نشان داد که هسته سلول های عضله قلبی کوچک، متراکم و هتروکروماتیک شده اند به طوری که میانگین قطر هسته در گروه کنترل و آزمایش به ترتیب 005/±085/0 و 009/0±057/0 میلی متر (001/0

Theoretical study of equilibrium and nonequilibrium exciton dynamics in disordered semiconductors

We develop a temperature-dependent theory for singlet exciton hopping transport in disordered semiconductors. It draws on the transport level concept within a Förster transfer model and bridges the gap in describing the transition from equilibrium to nonequilibrium time-dependent spectral diffusion.We test the validity range of the developed model using kinetic Monte Carlo simulations and find agreement over a broad range of temperatures. It reproduces the scaling of the diffusion length and spectral shift with the dimensionless disorder parameter and describes in a unified manner the transition from equilibrium to nonequilibrium transport regime. We find that the diffusion length in the nonequilibrium regime does not scale with the the third power of the Förster radius. The developed theory provides a powerful tool for interpreting time-resolved and steady state spectroscopy experiments in a variety of disordered materials, including organic semiconductors and colloidal quantum dots.This project has received funding from the Universidad Carlos III de Madrid, the European Union’s Seventh Frame- work Programme for research, technological development, and demonstration under Grant Agreement No. 600371, el Ministerio de Economía, Industria y Competitividad (COFUND2014-51509), el Ministerio de Educación, cultura y Deporte (CEI-15-17), and Banco Santander

Insight into Photon Recycling in Perovskite Semiconductors from the Concept of Photon Diffusion

Photon recycling has been proven to be an important process in metal halide perovskite thin films. We propose a model of photon recycling based on the photon diffusion concept that can interpret experimental observations on the photoluminescence and transient spectroscopy in perovskite layers. Our model shows how the photon recycling can enhance the apparent photocarrier lifetime and thereby slow down the photoluminescence decay dynamics. We also discuss the interplay between photon recycling and the photocarriers diffusive transport and demonstrate that at high carrier concentrations, photon recycling dominates the diffusion, conveying the carriers inside the absorbing layer over long distances. We also provide a quantitative determination of a diffusion length that is considerably expanded by the photon recycling process. The effect of the photon recycling process on the Auger recombination rate is also addressed here. The results provide insights for both interpreting the experimental observations and also designing experimental schemes

Bridging clinic: The initial medical management of patients with newly diagnosed pancreatic cancer

Pancreatic cancer is the 11th most common cancer in the UK and has the worst prognosis of any tumour with minimal improvements in survival over recent decades. As most patients are either ineligible for surgery or may decline chemotherapy, the emphasis is on control of symptoms and management of complications such as poor nutritional status. The time period between informing the patient of their diagnosis and commencing cancer treatments presents a valuable opportunity to proactively identify and treat symptoms to optimise patients’ overall well-being. The ‘bridging clinic’, delivered by a range of healthcare professionals from gastroenterologists to nurse practitioners, can provide this interface where patients are first informed of their diagnosis and second supportive therapies offered. In this article, we provide a structure for instituting such supportive therapies at the bridging clinic. The components of the clinic are summarised using the mnemonic INDASH (Information/Nutrition/Diabetes and Depression/Analgesia/Stenting/Hereditary) and each is discussed in detail below

Fostering the internationalization of family firms : the role of foreign participation, R&D, and import of goods

LAUREA MAGISTRALEQuesta tesi di laurea studia le relazioni tra le aziende familiari e l’andamento delle esportazioni come proxy dell’internazionalizzazione. La prevalente visione accademica mostra come le aziende familiari, spesso, hanno un andamento delle esportazioni inferiori causa il loro interesse nel “familiness”, le risorse limitate, la mancanza di abilità ed una conoscenza che induce ad un’elevata avversione al rischio. Data l’importanza delle aziende familiari nell’attuale economia globale, lo scopo principale di questo lavoro rimanda alla ricerca di possibili soluzioni che favoriscano la loro espansione nel panorama internazionale. La struttura teorica ci rimanda all’identificazione di tre possibili strategie in grado di mitigare l’andamento negativo delle aziende familiari. Le ipotesi di effetti positivi riguardanti le proprietà straniere, R&D e l’importazione di beni sono empiricamente testati tramite modelli FGLS e controllati per consistenza, con modelli GEE, usando il database spagnolo ESEE che include oltre 5000 aziende monitorate in un arco temporale che spazia tra il 1990 ed il 2016. Il nostro risultato espone un effetto di moderazione positivo per le proprietà straniere e l’importo di beni, ma non è stata trovata nessuna prova rigardo un effetto positivo dello R&D e dell’andamento dell’export delle aziende familiari.This master thesis studies the relationship between family firms and export performance as a proxy of internationalization. The prevalent view of scholar’s state that family firms often have inferior export performance, due to their concern on familiness, limited resources, lack of skills, and knowledge that leads to higher risk aversion. Given the importance of family firms in today’s global economy, the main aim of this work is to find possible strategies that can foster their international expansion. The theoretical framework leads us to the find three possible strategies that can moderate the negative export performance of family firms. The hypotheses of positive moderation effects of foreign ownership, R&D, and import of goods are empirically tested, with FGLS model and checked for robustness, with the GEE model, using the Spanish ESEE database that includes over 5000 firms observed from 1990 to 2016. Our result shows a positive moderation effect of foreign ownership and import of goods, but no evidence was found for the positive moderation effect of R&D on the export performance of family firms

Association of the Myocilin Gene Polymorphism With Primary Open Angle Glaucoma

Glaucoma is the second cause of irreversible blindness, and the Primary Open Angle Glaucoma (POAG) subtype is the most common type of glaucoma. It has been shown that genetic mutations increase the risk of POAG used for early detection. The aim of the current study was to determine the association between genetic variations of Myocilin (MYOC) gene and susceptibility to POAG in the Iranian population. This case-control study was conducted on patients with POAG, referred to Khatam-al Anbia Eye Hospital, Mashhad, Iran. The control group was selected from healthy patients with a refractive disorder, who had referred to this hospital. After extracting the DNA from the whole blood sample, the Polymerase Chain Reaction-Single-Strand Conformation Polymorphisms (PCR-SSCP) method was used to discriminate variability in sequences in three exons of MYOC gene locus, known as GLC1A. Clinical characteristics of the subjects, comprised of visual acuity, Cup to Disc Ratio (CDR), and Intra-Ocular Pressure (IOP) were statistically compared between the wild and mutant type of the MYOC gene using independent samples t-test, Chi-square, and logistic regression test with SPSS version 15.0 software. P-values of < 0.05 were considered significant. One hundred and forty participants (75.1% males) were studied in two groups of case (n = 70) and control (n = 70). The frequency of mutant alleles in patients and healthy groups was statistically significant (40% versus 11.5%, Odd’s Ratio (OR): 5.1, CI 95% for OR: 2.1 to 12.4, P-value < 0.001). Also, the detected mutation in the case group was significantly higher in exon 1 and 3 (15.7% versus 0%, P-value = 0.001, and 11.5% versus 2.8%, P-value = 0.049, respectively). Based on the result of the current study, it seems that the MYOC gene polymorphisms increased the risk of POAG in the Iranian population

Adenosine Deaminase 1 as a Biomarker for Diagnosis and Monitoring of Patients with Acute Lymphoblastic Leukemia

Background: Acute lymphoblastic leukemia (ALL) is known as the most prevalent pediatric malignancy all around the world. Identification of specific biomarker is necessary for early diagnosis and effective therapy. It is believed that Adenosine deaminase (ADA) as an enzyme involved in the purine salvage pathway increases in ALL patients. Herein, the quantity and pattern of ADA isoenzymes were surveyed among ALL patients in comparison to healthy subjects. Methods: Serum and RBC samples of three different groups of ALL patients, including newly diagnosed cases without any drugs administration, subjects with the relapsed disease, patients in the remission stage after therapy, and the healthy subjects were enrolled in the study. Then, the activity and pattern of ADA1, ADA2 and ADA1+cp were determined using ADA kit and electrophoresis on SDS-PAGE, respectively. To confirm the presence of ADA enzyme, the fresh serums, extractions from erythrocytes, JM cell line as a human T lymphocyte line and J774 A.1 as mouse monocyte line were electrophoresed on 1.2 agarose gel and stained with the specific dye. Results: The activities of ADA1 isoenzyme and total ADA in new cases and subjects with the relapsed disease were significantly higher than their activities in the patients in the remission stage and healthy controls (p<0.001). The unbounded ADA1 isoenzyme was found to exist in the erythrocyte, lymphocyte and monocyte. But in serum, all the ADA1 was bounded to the cp protein. Conclusions: ADA1 is the key isoenzyme elevating in ALL patients, therefore this isoenzyme could be a useful biomarker to diagnose ALL patients and monitor their therapies. © 2017 Mina Ebrahimi-Rad et al

Adenosine Deaminase 1 as a Biomarker for Diagnosis and Monitoring of Patients with Acute Lymphoblastic Leukemia

Background: Acute lymphoblastic leukemia (ALL) is known as the most prevalent pediatric malignancy all around the world. Identification of specific biomarker is necessary for early diagnosis and effective therapy. It is believed that Adenosine deaminase (ADA) as an enzyme involved in the purine salvage pathway increases in ALL patients. Herein, the quantity and pattern of ADA isoenzymes were surveyed among ALL patients in comparison to healthy subjects. Methods: Serum and RBC samples of three different groups of ALL patients, including newly diagnosed cases without any drugs administration, subjects with the relapsed disease, patients in the remission stage after therapy, and the healthy subjects were enrolled in the study. Then, the activity and pattern of ADA1, ADA2 and ADA1+cp were determined using ADA kit and electrophoresis on SDS-PAGE, respectively. To confirm the presence of ADA enzyme, the fresh serums, extractions from erythrocytes, JM cell line as a human T lymphocyte line and J774 A.1 as mouse monocyte line were electrophoresed on 1.2 agarose gel and stained with the specific dye. Results: The activities of ADA1 isoenzyme and total ADA in new cases and subjects with the relapsed disease were significantly higher than their activities in the patients in the remission stage and healthy controls (p<0.001). The unbounded ADA1 isoenzyme was found to exist in the erythrocyte, lymphocyte and monocyte. But in serum, all the ADA1 was bounded to the cp protein. Conclusions: ADA1 is the key isoenzyme elevating in ALL patients, therefore this isoenzyme could be a useful biomarker to diagnose ALL patients and monitor their therapies. © 2017 Mina Ebrahimi-Rad et al