Using a Novel Transfer Learning Method for Designing Thin Film Solar Cells with Enhanced Quantum Efficiencies.

In this study a new method for design optimization is proposed that is based on "transfer learning". The proposed framework improves the accuracy and efficiency of surrogate-based optimization. A surrogate model is an approximation to a costly black-box function that can be used for more efficient search of optimal points. When design specifications change, the objective function changes too. Therefore, there is a need for a new surrogate model. However, the concept of transfer learning can be applied to refit the new surrogate more efficiently. In other words insights from previous experiences can be applied to learning and optimizing the new function. We use the proposed method in a particular problem pertaining to the design of "thin film multilayer solar cells", where the goal is to maximize the external quantum efficiency of photoelectric conversion. The results show that the accuracy of the surrogate model is improved by 2-3 times using the transfer learning approach, using only half as many training data points as the original model. In addition, by transferring the design knowledge from one particular set of materials to another similar set of materials in the thin film structure, the surrogate-based optimization is improved, and is it obtained with far less computational time.

Rapid Optimization of External Quantum Efficiency of Thin Film Solar Cells Using Surrogate Modeling of Absorptivity.

This paper uses surrogate modeling for very fast design of thin film solar cells with improved solar-to-electricity conversion efficiency. We demonstrate that the wavelength-specific optical absorptivity of a thin film multi-layered amorphous-silicon-based solar cell can be modeled accurately with Neural Networks and can be efficiently approximated as a function of cell geometry and wavelength. Consequently, the external quantum efficiency can be computed by averaging surrogate absorption and carrier recombination contributions over the entire irradiance spectrum in an efficient way. Using this framework, we optimize a multi-layer structure consisting of ITO front coating, metallic back-reflector and oxide layers for achieving maximum efficiency. Our required computation time for an entire model fitting and optimization is 5 to 20 times less than the best previous optimization results based on direct Finite Difference Time Domain (FDTD) simulations, therefore proving the value of surrogate modeling. The resulting optimization solution suggests at least 50% improvement in the external quantum efficiency compared to bare silicon, and 25% improvement compared to a random design.

Oral L-arginine protects against cyclosporine-induced hepatotoxicity in rats.

Cyclosporine A (CyA) leads to liver injury, probably by causing the production of free radicals and resulting in nitric oxide (NO) deficiency. We evaluated CyA-mediated liver damage histopathologically to determine the possible beneficial effects of L-arginine (L-Arg). In this study, 7 groups of Sprague-Dawley rats; (1) Control group; (2) 0.9% NaCl group; (3) CyA group: 7.5mg/kg/day; (4) L-Arg group: 2g/lt/day; (5) l-NAME (N-nitro-L-arginine methyl ester) group: 5mg/100ml/day; (6) CyA+L-Arg group: L-Arg (2g/lt/day)+CyA (7.5mg/kg/day); and (7) CyA+L-NAME group: CyA (7.5mg/kg/day)+L-NAME (5mg/100ml/day) were included. At the end of the treatments, animals were killed and hepatic tissues were treated for morphological (hematoxylin and eosin) and biochemical (NO and malondialdehyde, MDA) analyses, and serum was processed for biochemical (alanine transaminase (ALT), aspartate transaminase (AST), bilirubin, alkaline phosphatase (ALP) and total protein) study. The results indicated that CyA-induced hepatotoxicity was characterized by sinusoidal dilatation, hepatocellular vacuolization, neutrophilic infiltration and hepatocellular necrosis. These findings were less pronounced in the CyA+L-Arg group than CyA alone group. L-NAME group showed moderate changes. The CyA+L-NAME (Group 7) had more severe changes. We found changes in tissue NO and MDA levels. We think that the tissue damage caused by CyA is mild and reversible at the period when biochemical parameters are just starting to become abnormal and that L-Arg may have a protective effect against CyA damage on liver.

[Prevalence of depressive symptoms, ways of coping, and related factors among medical school and health services higher education students]. / Tip Fakültesi ve Saglik Yüksekokulu Ogrencilerinde Depresif Belirti Yayginligi, Stresle Basaçikma Tarzlari ve Etkileyen Faktörler.

OBJECTIVE: The aims of this study were to explore the prevalence of depressive symptoms, ways of coping, and their relationships to sociodemographic variables among students of the Medical Faculty (MF) and the Health Services Higher Education School (HSHES) at Inönü University. METHOD: The Beck Depression Inventory (BDI), Styles of Coping Inventory (SCI), and a sociodemographic questionnaire were used. RESULTS: Among the HSHES students (n = 128), the prevalence of depressive symptoms was higher. The MF students whose fathers had a higher level of education had higher BDI scores. The MF students from families with lower levels of income had a higher frequency of depressive symptoms. In both groups, the students with previous histories of psychiatric and physical ilness had higher BDI scores. Among the MF students, older age (OR = 2.72), and among the HSHES students, having a previous history of psychiatric disorder (OR = 5.25) and female gender (OR = 1.85) affected the prevalence of depressive symptoms. The HSHES students used passive styles of coping more frequently. Active coping styles were used more frequently by the male students in both groups. The HSHES students whose mothers had lower levels of education, had higher passive coping style scores; active coping styles and higher family income correlated positively. In both groups, BDI and active styles scores correlated positively. Passive styles were used more frequently by male and female students that had a higher frequency of depressive symptoms. CONCLUSION: The rate of mental health problems was quite high among the students. Preventive mental health programs should be developed and implemented.

Review of forensic assessments of female referrals to the branch of legal medicine, Malatya region, Turkey--1996-2000.

It is well recognized that the most pervasive form in gender violence is violence against women by their intimate male partners. Domestic violence (DV) crosses all cultures, races, and socioeconomic levels, affecting people of all ages and both sexes, but particularly women and children. DV refers to the chronic physical, sexual and psychological maltreatment of one family member against another in order to control. DV represents a significant health threat to women. It may also be an important precipitating factor of female suicide. As the literature has begun to document the extent of interfamilial violence, attention has focused on forensic documentation. The aim of this study is to review female victims presented at the Branch of Legal Medicine of Malatya, Turkey, regarding gender-based violence and DV in relation towards sexual offenses and suicide attempts. Accordingly, recommendations were presented to increase the awareness of DV by setting policies and in response legislative recommendations. The legal reports of women (n=2245) were reviewed. In respect of the Turkish Penal Code (TPC), paragraph 456/1, 2, 3 and 4, which covers the act of assault and battery, the severity of the injuries have been categorized into three groups according to the Turkish Injury Scale (TIS) covered by TPC 456/1, 2 and 4, into the issues of functional incapacitation according to TPC 456/2 and 3, and with regard to the presence of a mark of an injury on the face according to TPC 456/2 tables. Because of incomplete data, not all results be categorized as positive for DV. Despite the large number of blunt force injuries (699 cases out of 2245) and the high percentage of external lesions, 76% of 1796 files, found, recognition of DV was uncommon. According to TPC 456/4, in cases of small trauma-related injuries, legal proceedings are dependent upon a victim's making a complaint. The percentage of 80.4% (n=2245) represents the need for information regarding legal requirements. The frequency of sexual assault cases, 144 victims out of 162, and in suicide attempts, 95 women out of 145, in the 15-24 year age span may also reflect a society's accusative approach towards women based on moral values. Unless prosecuting DV cases purely on the evidence in regard to victim's safety, withdrawal of complaints will continue. It is essential to identify to 'name' DV when it occurs. Recognizing the serious immediate and future long-term implications for health, multifaceted intervention is important. DV has to undergo some fundamental and far-reaching reformation in Turkey regarding how the legal system deals with it appropriately.

Psychiatric disorders and large interdialytic weight gain in patients on chronic haemodialysis.

AIMS: Psychiatric disorders have been considered in terms of non-compliant behaviour and low life quality in haemodialysis patients. The aim of this study is to investigate the potential association of psychiatric disorders with compliance of fluid restriction and nutritional status and to measure the effects of psychiatric disorders on the life quality in chronic renal failure patients on haemodialysis. METHODS: The study was conducted between April 2002 and December 2002 at a University hospital haemodialysis unit. The study population included 40 chronic renal failure patients (15 females/25 males). The Hamilton Depression Rating Scale (HDRS), Hamilton Anxiety Rating Scale (HARS) and Primary Care Evaluation of Mental Disorders (PRIME-MD), The Mini Mental State Examination (MMSE) and Short Form Health Survey 36 (SF-36) were used for patient assessment by a trained psychiatrist. The subjects' medical charts were reviewed by a physician who was unaware of the the results of the psychiatric assesments. Interdialytic weight gain (IDWG %) and nutritional status were used as an index of diet compliance. Nutrition was assessed by using subjective global assessment (SGA), serum albumin, predialysis phosphorus and potassium levels. RESULTS: All patients' MMSE were normal. A diagnosis of a depressive or anxiety or somatoform disorder by the PRIME MD was made in 65% of the patients. Fourteen (35%) of the patients had a depressive disorder, 13 (32.5%) of the patients had a somatoform disorder, and 12 (30%) had an anxiety disorder. We found no relationship between any psychiatric disorder and age, sex, duration of dialysis therapy, education, marital status, employment, socioeconomic status, serum albumin, phosphorus, potassium or SGA (P > 0.05). In patients with depression or a somatoform disorder, the interdialytic weight (%) was significantly higher than those of the patients without these disorders (P < 0.05). All indices of quality of life decreased in patients diagnosed with a psychiatric disorder. CONCLUSION: Depressive symptoms are important determinants of patients' large interdialytic weight gain and psychiatric disorders that effect a patients' overall quality of life. Evaluation of psychiatric status should be part of the care provided to haemodialysis patients.

[Family functioning in patients with schizophrenia, bipolar affective disorder and epilepsy]. / Sizofreni, Iki Uçlu Duygudurum Bozuklugu ve Epilepsi Hastalarinda Aile Islevlerinin Karsilastirilmasi.

OBJECTIVE: To evaluate the impact of illness progression on the family functioning of patients with schizophrenia, bipolar affective disorder and epilepsy showing chronic relapsing progress and affecting functionality. METHOD: A total of 75 patients who were diagnosed according to DSM-IV criteria as having schizophrenia (n: 25), bipolar affective disorder (n: 25) or epilepsy (n: 25) and their 134 family members were included in the study. A socio-demographical data form was completed by consulting the patient and family members, and a Family Assessment Device (FAD) was used. RESULTS: The general functionality level was low in patients with schizophrenia. Families of patients with bipolar affective disorder had healthier functioning than families of patients with schizophrenia and epilepsy. Subscales of "communication" and "behavioral control" were reported as highly ineffective by the schizophrenia patients. The epilepsy patients have family dysfunction in "behavioral control" and "roles" subscales. The families of bipolar affective disorder patients evaluated their "problem solving" and "general functioning" as problematic. CONCLUSION: The family's experience of disease and adaptation is a dynamic and ongoing process. Our data suggest that chronic psychiatric and neurological diseases may cause some specific difficulties in family functions.

Interdialytic weight gain and pulmonary membrane diffusing capacity in patients on hemodialysis.

BACKGROUND: Measurement of pulmonary diffusion capacity for carbon monoxide (DLCO) may be useful for assessing disease affecting the alveolar-capillary bed or the pulmonary vasculature. It was reported that hemodialysis (HD) therapy causes DLCO reduction via decrease of pulmonary capillary blood volume components. The aim of the study was to evaluate the effect of interdialytic weight gain on pulmonary function and especially DLCO. We further determined whether intravascular volume status, assessed by inferior vena cava diameter (IVCD) contributes to DLCO in patients on HD. METHODS: Routine pulmonary function testing including forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC, forced mid-expiratory flow rate (FEF25-75), DLCO IVCD index and other echocardiographic parameters were evaluated in 20 patients (mean age 48.6+/-18.3 years, mean dialysis duration 17.4+/-19.2 months) on chronic HD, 1 hour after HD and after an interdialytic period (1 hour before HD therapy). Single-breath DLCO measurements were corrected for hemoglobin concentration (cDLCO). RESULTS: Routine pulmonary function tests (spirometry) showed no significant changes in FEV1, FVC and FEF25-75 whereas a statistically significant fall in FEV/FVC was found. At the end of the interdialytic period a statistically significant increase in weight, IVCD index, left ventriculer diastolic diameter (LVDD), and diastolic blood pressure (DBP) were observed (P < 0.05). Using the single-breath DLCO, we found unchanged cDLCO at the end of the interdialytic period. There was no correlation of cDLCO with increases in weight, DBP, IVCD index, LVDD (P > 0.05). CONCLUSION: The accumulation of body water between dialyses has no significant influence on DLCO.