Growth mechanism of strongly emitting CH3NH3PbBr3 perovskite nanocrystals with a tunable bandgap.

Metal halide perovskite nanocrystals are promising materials for a diverse range of applications, such as light-emitting devices and photodetectors. We demonstrate the bandgap tunability of strongly emitting CH3NH3PbBr3 nanocrystals synthesized at both room and elevated (60 °C) temperature through the variation of the precursor and ligand concentrations. We discuss in detail the role of two ligands, oleylamine and oleic acid, in terms of the coordination of the lead precursors and the nanocrystal surface. The growth mechanism of nanocrystals is elucidated by combining the experimental results with the principles of nucleation/growth models. The proposed formation mechanism of perovskite nanocrystals will be helpful for further studies in this field and can be used as a guide to improve the synthetic methods in the future.The development of perovskite nanocrystals is limited by poor mechanistic understanding of their growth. Here, the authors systematically study the ligand-assisted reprecipitation synthesis of CH3NH3PbBr3 nanocrystals, revealing the effect of precursor and ligand concentrations on bandgap tunability.

Antimicrobial drug use on Austrian dairy farms with special consideration of the use of "highest priority critically important antimicrobials".

The use of antibiotics in livestock production is coming under growing criticism. Beside overall antimicrobial use, specific substances listed by the WHO as "highest priority critically important antimicrobials" (HPCIAs)--these include fluoroquinolones, macrolides, 3rd and 4th generation cephalosporins, as well as glycopeptides--have been placed under specific restrictions and should only be applied in particular cases according to strict indication criteria. In this study, the consumption of antimicrobial substances on Austrian dairy farms was evaluated quantitatively. The data covered 8,027 prescription records on the use of antibiotics on 465 dairy farms. Eleven veterinary practices provided data from between four to 27 months during the period from 2008 to 2010 and the total consumption of antimicrobials was estimated. The amount of active substance(s) in grams used per livestock unit (g/LU) per year and the number of product-related daily doses used per livestock unit (n PrDD(LU)/LU) per year were determined as units of measurement. These parameters were estimated by applying Monte Carlo simulation techniques, respecting variances in annual working days of the veterinary practices as well as variances in the proportion of non-treated populations. Total antimicrobial consumption in the population-at-risk was determined to be 2.59 g/LU and 1.30 PrDD(LU)/LU per year. HPCIAs were used at a proportion of 24.6% (0.31 PrDD(LU)/LU) of the total consumption of antimicrobials for systemic and intramammary use. Of these, 3rd and 4th generation cephalosporins were most frequently administered, particularly for the treatment of mastitis and foot diseases. The total consumption of antimicrobials in Austrian dairy cattle production is negligible compared to their use in pig and poultry production systems. However, the use of HPCIAs, especially 3rd and 4th generation cephalosporins, should be minimised further.

Lactation Affects Isolated Mitochondria and Its Fatty Acid Composition but Has No Effect on Tissue Protein Oxidation, Lipid Peroxidation or DNA-Damage in Laboratory Mice.

Linking peak energy metabolism to lifespan and aging remains a major question especially when focusing on lactation in females. We studied, if and how lactation affects in vitro mitochondrial oxygen consumption and mitochondrial fatty acid composition. In addition, we assessed DNA damage, lipid peroxidation and protein carbonyls to extrapolate on oxidative stress in mothers. As model system we used C57BL/6NCrl mice and exposed lactating females to two ambient temperatures (15 °C and 22 °C) while they nursed their offspring until weaning. We found that state II and state IV respiration rates of liver mitochondria were significantly higher in the lactating animals than in non-lactating mice. Fatty acid composition of isolated liver and heart mitochondria differed between lactating and non-lactating mice with higher n-6, and lower n-3 polyunsaturated fatty acids in the lactating females. Surprisingly, lactation did not affect protein carbonyls, lipid peroxidation and DNA damage, nor did moderate cold exposure of 15 °C. We conclude that lactation increases rates of mitochondrial uncoupling and alters mitochondrial fatty acid composition thus supporting the "uncoupling to survive" hypothesis. Regarding oxidative stress, we found no impact of lactation and lower ambient temperature and contribute to growing evidence that there is no linear relationship between oxidative damage and lactation.

Estimating Ixodes ricinus densities on the landscape scale.

BACKGROUND: The study describes the estimation of the spatial distribution of questing nymphal tick densities by investigating Ixodes ricinus in Southwest Germany as an example. The production of high-resolution maps of questing tick densities is an important key to quantify the risk of tick-borne diseases. Previous I. ricinus maps were based on quantitative as well as semi-quantitative categorisations of the tick density observed at study sites with different vegetation types or indices, all compiled on local scales. Here, a quantitative approach on the landscape scale is introduced. METHODS: During 2 years, 2013 and 2014, host-seeking ticks were collected each month at 25 sampling sites by flagging an area of 100 square meters. All tick stages were identified to species level to select nymphal ticks of I. ricinus, which were used to develop and calibrate Poisson regression models. The environmental variables height above sea level, temperature, relative humidity, saturation deficit and land cover classification were used as explanatory variables. RESULTS: The number of flagged nymphal tick densities range from zero (mountain site) to more than 1,000 nymphs/100 m(2). Calibrating the Poisson regression models with these nymphal densities results in an explained variance of 72 % and a prediction error of 110 nymphs/100 m(2) in 2013. Generally, nymphal densities (maximum 374 nymphs/100 m(2)), explained variance (46 %) and prediction error (61 nymphs/100 m(2)) were lower in 2014. The models were used to compile high-resolution maps with 0.5 km(2) grid size for the study region of the German federal state Baden-Württemberg. The accuracy of the mapped tick densities was investigated by leave-one-out cross-validation resulting in root-mean-square-errors of 227 nymphs/100 m(2) for 2013 and 104 nymphs/100 m(2) for 2014. CONCLUSIONS: The methodology introduced here may be applied to further tick species or extended to other study regions. Finally, the study is a first step towards the spatial estimation of tick-borne diseases in Central Europe.

[Analysis of the impact of animal health parameters on the average daily net gain in pigs for fattening]. / Analyse des Einflusses von Tiergesundheitsparametern auf die durchschnittliche tägliche Nettozunahme von Mastschweinen.

According to regulation (EC) No. 854/2004 all pigs slaughtered in Austria are subject to a routine meat inspection at the slaughterhouse in order to detect pathological-anatomical organ alterations due to disease. This mandatory meat inspection constitutes an important contribution to ensure food safety and the resulting post-mortem findings provide a possibility to process optimization by reporting the routinely recorded results to the producers. We analyzed the impact of 18 post-mortem findings on the average daily net gain of 6119 pigs. All findings were recorded at an Austrian slaughterhouse within a quality assurance system. A linear mixed model (LMM) was applied incorporating the farm of origin as random effect in order to take non-observed farm specific risk factors (e. g. feed management, housing system, hygiene status) into account. As a result the expected average daily net gain of 490 g could be estimated and several post-mortem findings could be identified as significant factors (at the significance level 0.05) affecting the average daily net gain. The expected average daily net gain decreases significantly for pigs with at least one of the post-mortem findings arthritis (-64 g), abscess (-32 g), severe pneumonia (-13 g), visceralis pleuritis (-7 g) and hepatitis (-9 g). The expected average daily net gain increases by 5 g for pigs with post-mortem finding bursitis. The estimated random farm effect indicates the relevant impact of the farm environment on the average daily net gain. The results reinforce that there is still a great potential to improve efficiency in fattening, although the quality assurance system was implemented twelve years ago.

The use of the "highest priority critically important antimicrobials" in 75 Austrian pig farms--evaluation of on-farm drug application data.

The World Health Organization lists antimicrobial substances which are essential for the treatment of specific infections in humans as "highest priority critically important antimicrobials" (HPCIAs): macrolides, fluoroquinolones, 3rd and 4th generation cephalosporins as well as glycopeptid antibacterials. The use of these substances in livestock husbandry should be restricted in order to minimise the risk of antimicrobial resistance. To date, there is little knowledge about the amounts of HPCIAs used in animal husbandry and the different animal species and diagnoses these antimicrobials are prescribed for. In a retrospective study, drug application data recorded from 2008 until 2011 from 75 conventional pig farms were evaluated. Data were assessed directly by the farmer at farm-level. The annual antimicrobial consumption was expressed in "weight of active substance(s) in [mg]" and "number of Daily Doses". Results were referred to the animal biomass, evaluated per pig age class (piglets, weaners, fattening pigs < 60 kg biomass; fattening pigs > 60 kg biomass, sows, boars) and broken down to some variables such as the substance class and the therapy indication. The focus was especially laid on the HPCIAs. The total usage of the HPCIAs in the study population was on average 3.0 mg/ kg/year; 1.1 UDD(kg)/kg/year; 0.2 ADD(kg)/kg/year and 0.6 PrDD(kg)/kg/year. This represents about 9%, 22%, 12% and 22% of total antimicrobial consumption, respectively, depending on the unit of measurement. Fattening farms showed the highest consumption of the named substances. The main part of the HPCIAs (nADD(kg)/year) was applied to weaners, piglets and fattening pigs < 60 kg. They played an important role in the therapies of piglets (approximately 40% of the total antimicrobial consumption in piglets). Macrolides played the major role within the HPCIAs and were mainly used for digestive tract diseases. A not negligible portion of macrolides was prescribed for metaphylactic and prophylactic measures.

A rare case of infantile myofibromatosis and review of literature.

Infantile myofibromatosis is a rare benign tumor-disease (1/400,000). Four different types have been reported in literature. The most commonly affected body areas are the head, the neck, and the trunk. We would like to present a rare case of a multicentric type with singular visceral involvement and a literature review of all case series with more than five patients. A 9-month-old boy presented with a swelling on the medial side of his proximal left tibia. The lesion which was present since birth, was well palpable, indolent, hard, and mobile in relation to the surrounding tissue. Radiographic films and ultrasound examination presented a pretibial soft-tissue tumor mass with calcifications and two osteolytic lesions with a sclerotic rim. A skeletal survey showed more osteolytic lesions, but the magnetic resonance imaging showed no more soft-tissue lesions. The rapid frozen section biopsy hinted at the diagnosis of histiocytosis X. The definitive histological result 6 days later was infantile myofibromatosis. As therapy, we determined a wait-and-see policy with controls all 3 months. At 20 months follow-up, the boy showed beginning of regression of all lesions. Infantile myofibromatosis is a very rare benign tumor-disease. Radiologically often soft-tissue masses with calcifications and osteolytic lesions with sclerotic rims are described. These findings also can be interpreted as histiocytosis X, which is a potential differential diagnosis. Histopathologically, cells characteristically appear as spindle-shaped fibroblast cells with pale pink cytoplasm and elongated nuclei and the immunophenotype is defined with a positive reaction on smooth-muscle antigen vimentin and the muscle-specific antigen HHF-35. The data of the literature review underline that a wait-and-see-policy should be considered as the first treatment of choice as in most instances the bony lesions regress spontaneously. However, a thorough examination has to be carried out to exclude lesion in other organs like gastro-intestinal or cardio-pulmonary nodular tumor masses. In conclusion, the present case report and the literature review support the notion that infantile myofibromatosis should be considered as a possible differential diagnosis for soft tissue expansions and/or osteolytic lesions in a newborn.

Nonoperative treatment of tibial spine fractures in children-38 patients with a minimum follow-up of 1 year.

OBJECTIVES: The aim of this study was to determine if nonoperative treatment of fractures of the tibial spine (intercondylar eminence) in pediatric patients is the treatment of choice for these injuries. DESIGN/SETTING: Retrospective clinical analysis in a single department. PATIENTS: All patients younger than 17 years presenting with a fracture of the intercondylar eminence between January 1, 1995 and December 31, 2004 were included in this retrospective study. Patients with ossification of the growth plate (physis) at the time of accident were excluded by protocol. INTERVENTION: Nonoperative treatment with knee aspiration, reduction, and immobilization in a long leg cast. MAIN OUTCOME MEASUREMENTS: History-taking and follow-up examinations were performed using the Cincinnati Knee Score and International Knee Documentation Committee Guidelines of 2000. In addition, a magnetic resonance imaging scan of the injured knee was offered to all patients. SPSS 12.0 and Microsoft Excel 2000 were used for data processing and statistical analysis. RESULTS: Forty-three patients have been included in the study. Twenty-three were female and 20 male. The mean age at trauma was 11.5 years (6-16 years). Only 1 patient required a change of therapy and needed open reduction. Thirty-eight patients were available for follow-up at an interval of 1-7.5 years after trauma (mean 3.5 years). None of the patients reported pain, swelling, disability or giving-way, or was handicapped in their daily life. Of 26 magnetic resonance imaging examinations, we found a missing anterior cruciate ligament in 1 and a partial rupture in another patient. CONCLUSION: Based on our results, nonoperative management can still be recommended as the primary treatment for tibial spine fractures in children.