1,044 research outputs found

    Porphyrin-containing polyimide films deposited by high vacuum co-evaporation

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    Abstract Thin films of porphyrin-containing polyimide were produced by high vacuum co-evaporation of 4,4′-hexafluoroisopropylidene diphthalic anhydride (6FDA), 3,3′-diaminodiphenyl sulfone (DDS) and 5,10,15,20 meso-tetraphenyl porphyrin (TPP). The films were characterized by FT-IR analysis, optical absorption and emission spectroscopy. FT-IR analysis shows that the film matrix is comprised of only unreacted monomers. The conversion of monomers to polyamic acid and the following condensation to polyimide were studied by curing the samples at temperatures up to 240 °C. The amount of polyamic acid increases from room temperature to 120 °C, while at higher temperature it starts to condense to polyimide. Optical analysis shows that TPP is incorporated in the film matrix and its chemical state is determined by the interaction with the monomers, polyamic acid and polyimide. After curing the TPP molecules are finely dispersed in the polyimide matrix and their absorption and fluorescence properties are wholly preserved

    An unusual interplay among disorder, Kondo-effect and spin-glass behavior in the Kondo lattices, Ce2_2Au1x_{1-x}Cox_xSi3_3

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    We report the results of magnetic measurements for the solid solution Ce2_2Au1x_{1-x}Cox_xSi3_3. The results reveal that this solid solution is characterized by a magnetic phase diagram (plot of magnetic transition temperature versus xx) unusual for Kondo lattices. In particular, the spin-glass freezing induced by disorder is observed only for the compositions at the weak coupling limit; as one approaches the quantum critical point by a gradual replacement of Au by Co, this disorder effect is surprisingly suppressed in favor of long range antiferro-magnetic ordering in contrast to expectations. This unusual interplay between disorder, spin-glass freezing and the Kondo-effect calls for further refinement of theories on competition between magnetism and the Kondo effect.Comment: 4 pages, 3 figure

    How shift work influences anxiety, depression, stress and insomnia conditions in Italian nurses: an exploratory study

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    Background and aim of the work. Evidence suggest that the nursing profession is a very complex profession. The aim of the present study is to investigate how nursing shift work influences nurses’ health, particularly if shift work impacts on anxiety, depression, stress and insomnia conditions Methods. An on-line cohort observational study has been conducted during May 2022 and 408 nurses have been enrolled. Results. Most of the nurses recruited are employed also during the night shift (73.3%) and are very young (p<0.001), as ageing less than 30 years (29.2%) and between 31-40 years (29%). Significant difference has been reported in smoking habit, as nurses who are employed also during the night shift report higher smoking habit than the other comparing groups (p=0.020). No further significant differences according to sex, age, work experience, nursing education, nursing activity, BMI and shift have been found. Finally, no differences have been assessed between anxiety, depression, stress and insomnia conditions according to shift work typologies. Conclusions. The present study highlights research results already explored in the current literature; however, it collects further information and assesses additional differences, in order to defibe a more complete picture of the nursing profession. (www.actabiomedica.it

    Effects of telmisartan and ramipril on adiponectin and blood pressure in patients with type 2 diabetes

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    &lt;b&gt;Background:&lt;/b&gt; Adiponectin is secreted by adipose tissue and may play a role in cardiovascular disease. We examined adiponectin levels in patients with type 2 diabetes who participated in the Telmisartan vs. Ramipril in Renal Endothelial Dysfunction (TRENDY) study. &lt;b&gt;Methods&lt;/b&gt; A total of 87 patients were assessed at baseline and following 9 weeks treatment with the angiotensin-receptor blocker telmisartan (final dose, 80 mg; n = 45) or the angiotensin-converting enzyme inhibitor ramipril (final dose, 10 mg; n = 42). Adiponectin levels were measured in plasma by radioimmunoassay. &lt;b&gt;Results:&lt;/b&gt; Adiponectin levels were inversely correlated with systolic (SBP; r = -0.240, P &#60; 0.05) and diastolic (DBP; r = -0.227, P &#60; 0.05) blood pressure at baseline and following treatment with telmisartan or ramipril (SBP: r = -0.228, P &#60; 0.05; DBP: r = -0.286, P &#60; 0.05). Changes in adiponectin levels were related to changes in SBP (r = -0.357, P &#60; 0.01) and DBP (r = -0.286, P &#60; 0.01). There was a significant increase in adiponectin levels in the telmisartan (0.68 (95% confidence interval (CI), 0.27 to 1.10) &lt;sup&gt;&#181;&lt;/sup&gt;g/ml, P &#60; 0.01) but not in the ramipril group (0.17 (95% CI, -0.56 to 0.90) &lt;sup&gt;&#181;&lt;/sup&gt;g/ml, P = 0.67). Blood pressure reduction in the telmisartan group (DeltaSBP: -13.5 (95% CI, -17.0 to -10.0) mm Hg; &#916;DBP: -7.6 (95% CI, -9.8 to -5.3) mm Hg, each P &#60; 0.001) was significantly (P less than or equal to 0.01 for SBP and P &#60; 0.01 for DBP) greater than in the ramipril group (&#916;SBP: -6.1 (95% CI, -6.2 to -2.0) mm Hg; &#916;DBP: -2.7 (95% CI, -5.0 to -0.5) mm Hg; P &#60; 0.01 and P &#60; 0.05, respectively). &lt;b&gt;Conclusion:&lt;/b&gt; Adiponectin is correlated with blood pressure in patients with type 2 diabetes. Whether increased adiponectin contributes to the blood pressure–lowering effect of telmisartan needs further study

    Estimating offsets for avian displacement effects of anthropogenic impacts

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    Biodiversity offsetting, or compensatory mitigation, is increasingly being used in temperate grassland ecosystems to compensate for unavoidable environmental damage from anthropogenic developments such as transportation infrastructure, urbanization, and energy development. Pursuit of energy independence in the United States will expand domestic energy production. Concurrent with this increased growth is increased disruption to wildlife habitats, including avian displacement from suitable breeding habitat. Recent studies at energy-extraction and energy-generation facilities have provided evidence for behavioral avoidance and thus reduced use of habitat by breeding waterfowl and grassland birds in the vicinity of energy infrastructure. To quantify and compensate for this loss in value of avian breeding habitat, it is necessary to determine a biologically based currency so that the sufficiency of offsets in terms of biological equivalent value can be obtained. We describe a method for quantifying the amount of habitat needed to provide equivalent biological value for avifauna displaced by energy and transportation infrastructure, based on the ability to define five metrics: impact distance, impact area, pre-impact density, percent displacement, and offset density. We calculate percent displacement values for breeding waterfowl and grassland birds and demonstrate the applicability of our avian-impact offset method using examples for wind and oil infrastructure. We also apply our method to an example in which the biological value of the offset habitat is similar to the impacted habitat, based on similarity in habitat type (e.g., native prairie), geographical location, land use, and landscape composition, as well as to an example in which the biological value of the offset habitat is dissimilar to the impacted habitat. We provide a worksheet that informs potential users how to apply our method to their specific developments and a framework for developing decision-support tools aimed at achieving landscape-level conservation goals

    Natural Language Processing to extract SNOMED-CT codes from pathological reports

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    Objective. The use of standardized structured reports (SSR) and suitable terminologies like SNOMED-CT can enhance data retrieval and analysis, fostering large-scale studies and collaboration. However, the still large prevalence of narrative reports in our laboratories warrants alternative and automated labeling approaches. In this project, natural language processing (NLP) methods were used to associate SNOMED-CT codes to structured and unstructured reports from an Italian Digital Pathology Department. Methods. Two NLP-based automatic coding systems (support vector machine, SVM, and long-short term memory, LSTM) were trained and applied to a series of narrative reports. Results. The 1163 cases were tested with both algorithms, showing good performances in terms of accuracy, precision, recall, and F1 score, with SVM showing slightly better performances as compared to LSTM (0.84, 0.87, 0.83, 0.82 vs 0.83, 0.85, 0.83, 0.82, respectively). The integration of an explainability allowed identification of terms and groups of words of importance, enabling fine-tuning, balancing semantic meaning and model performance. Conclusions. AI tools allow the automatic SNOMED-CT labeling of the pathology archives, providing a retrospective fix to the large lack of organization of narrative reports

    Snake prices and crocodile appetites: Aquatic wildlife supply and demand on Tonle Sap Lake, Cambodia

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    Commercial trade is a major driver of over-exploitation of wild species, but the pattern of demand and how it responds to changes in supply is poorly understood. Here we explore the markets for snakes from Tonle Sap Lake in Cambodia to evaluate future exploitation scenarios, identify entry points for conservation and, more generally, to illustrate the value of multi-scale analysis of markets to traded wildlife conservation. In Cambodia, the largest driver of snake exploitation is the domestic trade in snakes as crocodile food. We estimate that farmed crocodiles consume between 2.7 and 12.2 million snakes per year. The market price for crocodiles has been in decline since 2003, which, combined with rising prices for their food, has led to a reduced frequency of feeding and closure of small farms. The large farms that generate a disproportionate amount of the demand for snakes continue to operate in anticipation of future market opportunities, and preferences for snakes could help maintain demand if market prices for crocodiles rise to pre 2003 levels. In the absence of a sustained demand from crocodile farms, it is also possible that alternative markets will develop, such as one for human snack food. The demand for snakes, however, also depends on the availability of substitute resources, principally fish. The substitutability and low price elasticity of demand offers a relatively sustainable form of consumerism. Given the nature of these market drivers, addressing consumer preferences and limiting the protection of snakes to their breeding season are likely to be the most effective tools for conservation. This study highlights the importance of understanding the structure of markets and the behaviour of consumer demand prior to implementing regulations on wildlife hunting and trade

    Effects of microplastics and drought on soil ecosystem functions and multifunctionality

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    1. Microplastics in soils have become an important threat for terrestrial systems as they may potentially alter the geochemical/biophysical soil environment and can interact with drought. As microplastics may affect soil water content, this could exacerbate the well-known negative effects of drought on ecosystem functionality. Thus, functions including litter decomposition, soil aggregation or those related with nutrient cycling can be altered. Despite this potential interaction, we know relatively little about how microplastics, under different soil water conditions, affect ecosystem functions and multifunctionality. 2. To address this gap, we performed an experiment using grassland plant communities growing in microcosms. Microplastic fibres (absent, present) and soil water conditions (well-watered, drought) were applied in a fully factorial design. At harvest, we measured soil ecosystem functions related to nutrient cycling (beta-glucosaminidase, beta-D-cellobiosidase, phosphatase, beta-glucosidase enzymes), respiration, nutrient retention, pH, litter decomposition and soil aggregation (water stable aggregates). As terrestrial systems provide these functions simultaneously, we also assessed ecosystem multifunctionality, an index that encompasses the array of ecosystem functions measured here. 3. We found that the interaction between microplastic fibres and drought affected ecosystem functions and multifunctionality. Drought had negatively affected nutrient cycling by decreasing enzymatic activities by up to similar to 39%, while microplastics increased soil aggregation by similar to 18%, soil pH by similar to 4% and nutrient retention by up to similar to 70% by diminishing nutrient leaching. Microplastic fibres also impacted soil enzymes, respiration and ecosystem multifunctionality, but importantly, the direction of these effects depended on soil water status. That is, under well-watered conditions, these functions decreased with microplastic fibres by up to similar to 34% while under drought they had similar values irrespective of the microplastic presence, or tended to increase with microplastics. Litter decomposition had a contrary pattern increasing with microplastics by similar to 6% under well-watered conditions while decreasing to a similar percentage under drought. 4. Synthesis and applications. Single ecosystem functions can be positively or negatively affected by microplastics fibres depending on soil water status. However, our results suggest that microplastic fibres may cause negative effects on ecosystem soil multifunctionality of a similar magnitude as drought. Thus, strategies to counteract this new global change factor are necessary

    Itinerant electron metamagnetism in LaCo9_9Si4_4

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    The strongly exchange enhanced Pauli paramagnet LaCo9_9Si4_4 is found to exhibit an itinerant metamagnetic phase transition with indications for metamagnetic quantum criticality. Our investigation comprises magnetic, specific heat, and NMR measurements as well as ab-initio electronic structure calculations. The critical field is about 3.5 T for HcH||c and 6 T for HcH\bot c, which is the lowest value ever found for rare earth intermetallic compounds. In the ferromagnetic state there appears a moment of about 0.2 μB\mu_B/Co at the 16k16k Co-sites, but sigificantly smaller moments at the 4d and 16l16l Co-sites.Comment: 11 pages, 5 figures, PRB Rapid Communication, in prin
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