| 51. |
- Kronenberg, Linda M., et al.
(författare)
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Coping styles in substance use disorder (SUD) patients with and without co-occurring attention deficit/hyperactivity disorder (ADHD) or autism spectrum disorder (ASD)
- 2015
-
Ingår i: BMC Psychiatry. - : Springer Science and Business Media LLC. - 1471-244X. ; 15
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Patients with a substance use disorder (SUD) and co-occurring attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) often start using substances in an attempt to cope with the stress related to their ADHD or ASD. To improve treatment for these patient groups, it is important to identify and compare the various coping styles between SUD patients with and without ADHD or ASD and with subjects from a general population sample. Methods: Cross-sectional study using the Utrecht Coping List (UCL) in 50 SUD patients, 41 SUD + ADHD patients, 31 SUD + ASD patients and 1,200 railway employees. Results: Compared with the reference group, all three SUD groups showed a significant higher mean on the Palliative reaction, Avoidance, and Passive reaction subscales of the UCL. The scores for all UCL subscales of the SUD and the SUD + ADHD groups were very similar. However, the SUD + ASD group scored higher on Passive reaction and lower on Reassuring thoughts than the SUD and the SUD + ADHD groups and lower on Expression of emotions subscale in comparison with the SUD + ADHD group. Conclusions: Regardless of the presence of a co-occurring disorder, SUD patients reported more palliative, avoidant and passive coping when confronted than people in the general population. In addition, SUD patients with co-occurring ASD were different from other SUD patients in their coping and professionals should take this into account when working on more adaptive coping strategies with these patients.
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| 52. |
- van den Brink, W., et al.
(författare)
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Efficacy and safety of sodium oxybate in alcohol-dependent patients with a very high drinking risk level
- 2018
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Ingår i: Addiction Biology. - : Wiley. - 1355-6215 .- 1369-1600. ; 23:4, s. 969-986
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Tidskriftsartikel (refereegranskat)abstract
- Medication development for alcohol relapse prevention or reduction of consumption is highly challenging due to methodological issues of pharmacotherapy trials. Existing approved medications are only modestly effective with many patients failing to benefit from these therapies. Therefore, there is a pressing need for other effective treatments with a different mechanism of action, especially for patients with very high (VH) drinking risk levels (DRL) because this is the most severely affected population of alcohol use disorder patients. Life expectancy of alcohol-dependent patients with a VH DRL is reduced by 22 years compared with the general population and approximately 90000 alcohol-dependent subjects with a VH DRL die prematurely each year in the EU (Rehm et al. 2018). A promising new medication for this population is sodium oxybate, a compound that acts on GABA(B) receptors and extrasynaptic GABA(A) receptors resulting in alcohol-mimetic effects. In this article, a European expert group of alcohol researchers and clinicians summarizes data (a) from published trials, (b) from two new-as yet unpublished-large clinical trials (GATE 2 (n = 314) and SMO032 (n = 496), (c) from post hoc subgroup analyses of patients with different WHO-defined DRLs and (d) from multiple meta-analyses. These data provide convergent evidence that sodium oxybate is effective especially in a subgroup of alcohol-dependent patients with VH DRLs. Depending on the study, abstinence rates are increased up to 34 percent compared with placebo with risk ratios up to 6.8 in favor of sodium oxybate treatment. These convergent data are supported by the clinical use of sodium oxybate in Austria and Italy for more than 25years. Sodium oxybate is the sodium salt of gamma-hydroxybutyric acid that is also used as a recreational (street) drug suggestive of abuse potential. However, a pharmacovigilance database of more than 260000 alcohol-dependent patients treated with sodium oxybate reported very few adverse side effects and only few cases of abuse. We therefore conclude that sodium oxybate is an effective, well-tolerated and safe treatment for withdrawal and relapse prevention treatment, especially in alcohol-dependent patients with VH DRL.
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| 53. |
- Crunelle, CL, et al.
(författare)
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International Consensus Statement on Screening, Diagnosis and Treatment of Substance Use Disorder Patients with Comorbid Attention Deficit/Hyperactivity Disorder
- 2018
-
Ingår i: European addiction research. - : S. Karger AG. - 1421-9891 .- 1022-6877. ; 24:1, s. 43-51
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Tidskriftsartikel (refereegranskat)abstract
- Adult attention deficit/hyperactivity disorder (ADHD) often co-occurs with substance use disorders (SUD) and is associated with early onset and more severe development of SUD and with reduced treatment effectiveness. Screening tools allow for a good recognition of possible ADHD in adults with SUD and should be used routinely, followed by an ADHD diagnostic process initiated as soon as possible. Simultaneous and integrated treatment of ADHD and SUD, using a combination of pharmaco- and psychotherapy, is recommended. Long-acting methylphenidate, extended-release amphetamines, and atomoxetine with up-titration to higher dosages may be considered in patients unresponsive to standard doses. This paper includes evidence- and consensus-based recommendations developed to provide guidance in the screening, diagnosis and treatment of patients with ADHD-SUD comorbidity.
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| 54. |
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| 55. |
- Kemppinen, Julia, et al.
(författare)
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Microclimate, an important part of ecology and biogeography
- 2024
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Ingår i: GLOBAL ECOLOGY AND BIOGEOGRAPHY. - 1466-822X .- 1466-8238. ; 33:6
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Tidskriftsartikel (refereegranskat)abstract
- Brief introduction: What are microclimates and why are they important?Microclimate science has developed into a global discipline. Microclimate science is increasingly used to understand and mitigate climate and biodiversity shifts. Here, we provide an overview of the current status of microclimate ecology and biogeography in terrestrial ecosystems, and where this field is heading next.Microclimate investigations in ecology and biogeographyWe highlight the latest research on interactions between microclimates and organisms, including how microclimates influence individuals, and through them populations, communities and entire ecosystems and their processes. We also briefly discuss recent research on how organisms shape microclimates from the tropics to the poles.Microclimate applications in ecosystem managementMicroclimates are also important in ecosystem management under climate change. We showcase new research in microclimate management with examples from biodiversity conservation, forestry and urban ecology. We discuss the importance of microrefugia in conservation and how to promote microclimate heterogeneity.Methods for microclimate scienceWe showcase the recent advances in data acquisition, such as novel field sensors and remote sensing methods. We discuss microclimate modelling, mapping and data processing, including accessibility of modelling tools, advantages of mechanistic and statistical modelling and solutions for computational challenges that have pushed the state-of-the-art of the field.What's next?We identify major knowledge gaps that need to be filled for further advancing microclimate investigations, applications and methods. These gaps include spatiotemporal scaling of microclimate data, mismatches between macroclimate and microclimate in predicting responses of organisms to climate change, and the need for more evidence on the outcomes of microclimate management.
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| 56. |
- Kronenberg, Linda M., et al.
(författare)
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Everyday life consequences of substance use in adult patients with a substance use disorder (SUD) and co-occurring attention deficit/hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) : a patient's perspective
- 2014
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Ingår i: BMC Psychiatry. - : Springer Science and Business Media LLC. - 1471-244X. ; 14, s. 264-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although the prevalence of substance use disorder (SUD) with co-occurring attention deficit/hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) is relatively high in adult patients, there is hardly any knowledge about these dual diagnoses. A recent study reported met-and unmet needs for several life domains regarding these patient groups. To improve treatment, it is necessary to identify the everyday life consequences of SUD and co-occurring ADHD or ASD in adult patients. Methods: Qualitative study using in-depth interviews. 11 SUD + ADHD and 12 SUD + ASD patients participated in the study. The interview transcripts were coded and analysed according to the seven steps for descriptive phenomenology by Colaizzi. Results: Both patients with ADHD and patients with ASD can get caught in a jumble of thoughts and emotions which can often lead to agitation and impulsivity in the case of ADHD or passivity and melancholia in the case of ASD with co-occurring SUD in both cases. Initially substance use ameliorates the symptoms and related problems, but both patient groups can later experience even greater problems: difficulties with the structuring of daily life due to a lack of planning (SUD + ADHD) or due to a lack of initiative (SUD + ASD). Both groups indicate that structure helps them function better. They also recognize that substance use disorganizes their lives and that an absence of structure contributes to substance use in what becomes a vicious circle which needs to be broken for effective treatment and care. Conclusions: This study provides insight into the daily life consequences of SUD with a co-occurring ADHD or ASD. Substance use is reported to solve some ADHD- or ASD-related problems in the short run but have negative consequences in the long run (i.e., contribute to already impaired cognitive functioning). Insight is provided into what clinicians can do to break this vicious circle and thus help ADHD patients to refrain from action and ASD patients to take action.
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| 57. |
- Kronenberg, Linda M., et al.
(författare)
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Personal Recovery in Individuals Diagnosed with Substance use Disorder (SUD) and Co-Occurring Attention Deficit/Hyperactivity Disorder (ADHD) or Autism Spectrum Disorder (ASD)
- 2015
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Ingår i: Archives of Psychiatric Nursing. - : Elsevier BV. - 0883-9417 .- 1532-8228. ; 29:4, s. 242-248
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Tidskriftsartikel (refereegranskat)abstract
- The process of personal recovery in people diagnosed with substance use disorder and comorbid attention deficit/hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) was mapped. Four general themes representing four consecutive stages in the recovery process were identified in both client groups: (1) crisis and diagnosis; (2) dealing with agitation, symptoms, and burden; (3) reorganization of life; and (4) meaningful life. However, the personal recovery outcomes and the need for support were different for the two clients groups. Based on these findings, mental health nurses can offer recovery supporting care tailored to the challenging needs of these clients. For the SUD + ADHD group, overall, a coaching attitude is preferred. For the SUD + ASD group, overall, instructional, supportive and directive attitude is needed.
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| 58. |
- Parma, Valentina, et al.
(författare)
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More Than Smell—COVID-19 Is Associated With Severe Impairment of Smell, Taste, and Chemesthesis
- 2020
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Ingår i: Chemical Senses. - : Oxford University Press (OUP). - 0379-864X .- 1464-3553. ; 45:7, s. 609-622
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Tidskriftsartikel (refereegranskat)abstract
- Recent anecdotal and scientific reports have provided evidence of a link between COVID-19 and chemosensory impairments, such as anosmia. However, these reports have downplayed or failed to distinguish potential effects on taste, ignored chemesthesis, and generally lacked quantitative measurements. Here, we report the development, implementation, and initial results of a multilingual, international questionnaire to assess self-reported quantity and quality of perception in 3 distinct chemosensory modalities (smell, taste, and chemesthesis) before and during COVID-19. In the first 11 days after questionnaire launch, 4039 participants (2913 women, 1118 men, and 8 others, aged 19–79) reported a COVID-19 diagnosis either via laboratory tests or clinical assessment. Importantly, smell, taste, and chemesthetic function were each significantly reduced compared to their status before the disease. Difference scores (maximum possible change ±100) revealed a mean reduction of smell (−79.7 ± 28.7, mean ± standard deviation), taste (−69.0 ± 32.6), and chemesthetic (−37.3 ± 36.2) function during COVID-19. Qualitative changes in olfactory ability (parosmia and phantosmia) were relatively rare and correlated with smell loss. Importantly, perceived nasal obstruction did not account for smell loss. Furthermore, chemosensory impairments were similar between participants in the laboratory test and clinical assessment groups. These results show that COVID-19-associated chemosensory impairment is not limited to smell but also affects taste and chemesthesis. The multimodal impact of COVID-19 and the lack of perceived nasal obstruction suggest that severe acute respiratory syndrome coronavirus strain 2 (SARS-CoV-2) infection may disrupt sensory-neural mechanisms.
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| 59. |
- Adewumi, Oluseun, et al.
(författare)
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Characterization of human embryonic stem cell lines by the International Stem Cell Initiative
- 2007
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Ingår i: Nature Biotechnology. - : Springer Science and Business Media LLC. - 1087-0156 .- 1546-1696. ; 25:7, s. 803-816
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Tidskriftsartikel (refereegranskat)abstract
- The International Stem Cell Initiative characterized 59 human embryonic stem cell lines from 17 laboratories worldwide. Despite diverse genotypes and different techniques used for derivation and maintenance, all lines exhibited similar expression patterns for several markers of human embryonic stem cells. They expressed the glycolipid antigens SSEA3 and SSEA4, the keratan sulfate antigens TRA-1-60, TRA-1-81, GCTM2 and GCT343, and the protein antigens CD9, Thy1 (also known as CD90), tissue- nonspecific alkaline phosphatase and class 1 HLA, as well as the strongly developmentally regulated genes NANOG, POU5F1 (formerly known as OCT4), TDGF1, DNMT3B, GABRB3 and GDF3. Nevertheless, the lines were not identical: differences in expression of several lineage markers were evident, and several imprinted genes showed generally similar allele-specific expression patterns, but some gene-dependent variation was observed. Also, some female lines expressed readily detectable levels of XIST whereas others did not. No significant contamination of the lines with mycoplasma, bacteria or cytopathic viruses was detected.
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| 60. |
- Amid, C., et al.
(författare)
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Additive effects of the herbicide glyphosate and elevated temperature on the branched coral Acropora formosa in Nha Trang, Vietnam
- 2018
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 25:14, s. 13360-13372
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Tidskriftsartikel (refereegranskat)abstract
- The combined effects of the herbicide glyphosate and elevated temperature were studied on the tropical staghorn coral Acropora formosa, in Nha Trang bay, Vietnam. The corals were collected from two different reefs, one close to a polluted fish farm and one in a marine-protected area (MPA). In the laboratory, branches of the corals were exposed to the herbicide glyphosate at ambient (28 degrees C) and at 3 degrees C elevated water temperatures (31 degrees C). Effects of herbicide and elevated temperature were studied on coral bleaching using photography and digital image analysis (new colorimetric method developed here based on grayscale), chlorophyll a analysis, and symbiotic dinoflagellate (Symbiodinium, referred to as zooxanthellae) counts. All corals from the MPA started to bleach in the laboratory before they were exposed to the treatments, indicating that they were very sensitive, as opposed to the corals collected from the more polluted site, which were more tolerant and showed no bleaching response to temperature increase or herbicide alone. However, the combined exposure to the stressors resulted in significant loss of color, proportional to loss in chlorophyll a and zooxanthellae. The difference in sensitivity of the corals collected from the polluted site versus the MPA site could be explained by different symbiont types: the resilient type C3u and the stress-sensitive types C21 and C23, respectively. The additive effect of elevated temperatures and herbicides adds further weight to the notion that the bleaching of coral reefs is accelerated in the presence of multiple stressors. These results suggest that the corals in Nha Trang bay have adapted to the ongoing pollution to become more tolerant to anthropogenic stressors, and that multiple stressors hamper this resilience. The loss of color and decrease of chlorophyll a suggest that bleaching is related to concentration of chloro-pigments. The colorimetric method could be further fine-tuned and used as a precise, non-intrusive tool for monitoring coral bleaching in situ.
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| 61. |
- Fleck, M., et al.
(författare)
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Quasiparticle broadening in insulating copper oxides
- 1999
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Ingår i: Physica B. ; 259-261, s. 729-731
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Tidskriftsartikel (refereegranskat)abstract
- We calculate the spectral function of the half-filled two-dimensional Hubbard model with realistic hopping integrals for Sr2CuO2Cl2 within the dynamical mean-field theory at finite temperatures. It is shown that precursor effects of incommensurate spin dynamics lead to an incoherent broadening of the quasiparticle peaks on an energy scale that depends on local spin order. This might serve as an indirect method of detecting changes of local spin order under doping.
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| 62. |
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| 63. |
- Lam, BYK, et al.
(författare)
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The global burden of cerebral small vessel disease in low- and middle-income countries: A systematic review and meta-analysis
- 2023
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Ingår i: International journal of stroke : official journal of the International Stroke Society. - : SAGE Publications. - 1747-4949. ; 18:1, s. 15-27
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Tidskriftsartikel (refereegranskat)abstract
- Cerebral small vessel disease (cSVD) is a major cause of stroke and dementia. Previous studies on the prevalence of cSVD are mostly based on single geographically defined cohorts in high-income countries. Studies investigating the prevalence of cSVD in low- and middle-income countries (LMICs) are expanding but have not been systematically assessed. Aim: This study aims to systematically review the prevalence of cSVD in LMICs. Results: Articles were searched from the Ovid MEDLINE and EMBASE databases from 1 January 2000 to 31 March 2022, without language restrictions. Title/abstract screening, full-text review, and data extraction were performed by two to seven independent reviewers. The prevalence of cSVD and study sample size were extracted by pre-defined world regions and health status. The Risk of Bias for Non-randomized Studies tool was used. The protocol was registered on PROSPERO (CRD42022311133). A meta-analysis of proportion was performed to assess the prevalence of different magnetic resonance imaging markers of cSVD, and a meta-regression was performed to investigate associations between cSVD prevalence and type of study, age, and male: female ratio. Of 2743 studies identified, 42 studies spanning 12 global regions were included in the systematic review. Most of the identified studies were from China (n = 23). The median prevalence of moderate-to-severe white matter hyperintensities (WMHs) was 20.5%, 40.5%, and 58.4% in the community, stroke, and dementia groups, respectively. The median prevalence of lacunes was 0.8% and 33.5% in the community and stroke groups. The median prevalence of cerebral microbleeds (CMBs) was 10.7% and 22.4% in the community and stroke groups. The median prevalence of moderate-to-severe perivascular spaces was 25.0% in the community. Meta-regression analyses showed that the weighted median age (51.4 ± 0.0 years old; range: 36.3–80.2) was a significant predictor of the prevalence of moderate-to-severe WMH and lacunes, while the type of study was a significant predictor of the prevalence of CMB. The heterogeneity of studies was high (>95%). Male participants were overrepresented. Conclusions: This systematic review and meta-analysis provide data on cSVD prevalence in LMICs and demonstrated the high prevalence of the condition. cSVD research in LMICs is being published at an increasing rate, especially between 2010 and 2022. More data are particularly needed from Sub-Saharan Africa and Central Europe, Eastern Europe, and Central Asia.
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| 64. |
- Van de Glind, G, et al.
(författare)
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The International Collaboration on ADHD and Substance Abuse (ICASA): Mission, Results, and Future Activities
- 2020
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Ingår i: European addiction research. - : S. Karger AG. - 1421-9891 .- 1022-6877. ; 26:4-5, s. 173-178
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Tidskriftsartikel (refereegranskat)abstract
- <b><i>Background:</i></b> The <i>International Collaboration on ADHD and Substance Abuse</i> (ICASA) is a network of 28 centers from 16 countries initiated to investigate the link between attention deficit-hyperactivity disorder (ADHD) and substance use disorder (SUD). In this article, we present the mission, the results of finished studies, and the current and future research projects of ICASA. Methods: During the past 10 years, 3 cross-sectional studies were conducted: two International ADHD in Substance use disorders Prevalence (IASP-1 and IASP-2) studies, directed at the screening, diagnosis, and the prevalence of adult ADHD in treatment-seeking patients with SUD, and the Continuous performance test for ADHD in SUD Patients (CASP) study, testing a novel continuous performance test in SUD patients with and without adult ADHD. Recently, the prospective International Naturalistic Cohort Study of ADHD and Substance Use Disorders (INCAS) was initiated, directed at treatment provision and treatment outcome in SUD patients with adult ADHD. <b><i>Results:</i></b> The IASP studies have shown that approximately 1 in 6 adult treatment-seeking SUD patients also have ADHD. In addition, those SUD patients with adult ADHD compared to SUD patients without ADHD report more childhood trauma exposure, slower infant development, greater problems controlling their temperament, and lower educational attainment. Comorbid patients also reported more risk-taking behavior, and a higher rate of other psychiatric disorders compared to SUD patients without ADHD. Screening, diagnosis, and treatment of this patient group are possible even before abstinence has been achieved. The results of the CASP study are reported separately in this special issue. <b><i>Conclusions:</i></b> The ICASA research to date has demonstrated a high prevalence of comorbid ADHD and SUD, associated with elevated rates of additional comorbidities and risk factors for adverse outcomes. More research is needed to find the best way to treat these patients, which is the main topic of the ongoing INCAS study.
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| 65. |
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| 66. |
- Arias-Andrés, M., et al.
(författare)
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Lower tier toxicity risk assessment of agriculture pesticides detected on the Rio Madre de Dios watershed, Costa Rica
- 2018
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 25:14, s. 13312-13321
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Tidskriftsartikel (refereegranskat)abstract
- Costa Rica is a tropical country with one of the highest biodiversity on Earth. It also has an intensive agriculture, and pesticide runoff from banana and pineapple plantations may cause a high toxicity risk to non-target species in rivers downstream the plantations. We performed a first tier risk assessment of the maximum measured concentrations of 32 pesticides detected over 4 years in the River Madre de Dios (RMD) and its coastal lagoon on the Caribbean coast of Costa Rica. Species sensitivity distributions (SSDs) were plotted in order to derive HC5 values for each pesticide, i.e., hazard concentrations for 5 % of the species, often used as environmental criteria values in other countries. We also carried out toxicity tests for selected pesticides with native Costa Rican species in order to calculate risk coefficients according to national guidelines in Costa Rica. The concentrations of herbicides diuron and ametryn and insecticides carbofuran, diazinon, and ethoprophos exceeded either the HC5 value or the lower limit of its 90 % confidence interval suggesting toxic risks above accepted levels. Risk coefficients of diuron and carbofuran derived using local guidelines indicate toxicity risks as well. The assessed fungicides did not present acute toxic risks according to our analysis. Overall, these results show a possible toxicity of detected pesticides to aquatic organisms and provide a comparison of Costa Rican national guidelines with more refined methods for risk assessment based on SSDs. Further higher tier risk assessments of pesticides in this watershed are also necessary in order to consider pesticide water concentrations over time, toxicity from pesticide mixtures, and eventual effects on ecosystem functions.
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| 67. |
- Baalousha, M., et al.
(författare)
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Modeling nanomaterial fate and uptake in the environment: current knowledge and future trends
- 2016
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Ingår i: Environmental Science-Nano. - : Royal Society of Chemistry (RSC). - 2051-8153 .- 2051-8161. ; 3:2, s. 323-345
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Tidskriftsartikel (refereegranskat)abstract
- Modeling the environmental fate of nanomaterials (NMs) and their uptake by cells and organisms in the environment is essential to underpin experimental research, develop overarching theories, improve our fundamental understanding of NM exposure and hazard, and thus enable risk assessment of NMs. Here, we critically review the state-of-the-art of the available models that can be applied/adapted to quantify/predict NM fate and uptake in aquatic and terrestrial systems and make recommendations regarding future directions for model development. Fate models have evolved from substance flow analysis models that lack nano-specific processes to more advanced mechanistic models that (at least partially) take nano-specific (typically non-equilibrium, dynamic) processes into account, with a focus on key fate processes such as agglomeration, sedimentation and dissolution. Similarly, NM uptake by organisms is driven by dynamic processes rather than by equilibrium partitioning. Hence, biokinetic models are more suited to model NM uptake, compared with the simple bio-accumulation factors used for organic compounds. Additionally, biokinetic models take speciation processes (e.g. particulate versus ionic uptake) into account, although identifying essential environment-specific processes to include in models remains a challenge. The models developed so far require parameterization, calibration and validation with available data, e.g. field data (if available), or experimental data (e.g. aquatic and terrestrial mesocosms), rather than extension to more complex and sophisticated models that include all possible transformation processes. Collaborative efforts between experimentalists and modelers to generate appropriate ground-truth data would advance the field most rapidly.
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| 68. |
- Braicovich, Lucio, et al.
(författare)
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Determining the electron-phonon coupling in superconducting cuprates by resonant inelastic x-ray scattering: Methods and results on Nd1+xBa2-xCu3O7-δ
- 2020
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Ingår i: Physical Review Research. - 2643-1564. ; 2:2
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Tidskriftsartikel (refereegranskat)abstract
- The coupling between lattice vibration quanta and valence electrons can induce charge-density modulations and decisively influence the transport properties of materials, e.g., leading to conventional superconductivity. In high-critical-temperature superconductors, where electronic correlation is the main actor, the actual role of electron-phonon coupling (EPC) is being intensely debated theoretically and investigated experimentally. We present an in-depth study of how the EPC strength can be obtained directly from resonant inelastic x-ray scattering (RIXS) data through the theoretical approach derived by Ament et al. [Europhys. Lett. 95, 27008 (2011)]. The role of the model parameters (e.g., phonon energy ω0, intermediate state lifetime 1/Γ, EPC matrix element M, and detuning energy Ω) is thoroughly analyzed, providing general relations among them that can be used to make quantitative estimates of the dimensionless EPC g=(M/ω0)2 without detailed microscopic modeling. We then apply these methods to very high-resolution Cu L3-edge RIXS spectra of three Nd1+xBa2−xCu3O7−δ films. For the insulating antiferromagnetic parent compound, the value of M as a function of the in-plane momentum transfer is obtained for Cu-O bond-stretching (breathing) and bond-bending (buckling) phonon branches. For the underdoped and the nearly optimally doped samples, the effects of Coulomb screening and of charge-density-wave correlations on M are assessed. In light of the anticipated further improvements of the RIXS experimental resolution, this work provides a solid framework for an exhaustive investigation of the EPC in cuprates and other quantum materials.
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| 69. |
- Rossi, Matteo, et al.
(författare)
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Experimental Determination of Momentum-Resolved Electron-Phonon Coupling
- 2019
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 123:2
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Tidskriftsartikel (refereegranskat)abstract
- We provide a novel experimental method to quantitatively estimate the electron-phonon coupling and its momentum dependence from resonant inelastic x-ray scattering (RIXS) spectra based on the detuning of the incident photon energy away from an absorption resonance. We apply it to the cuprate parent compound NdBa2Cu3O6 and find that the electronic coupling to the oxygen half-breathing phonon branch is strongest at the Brillouin zone boundary, where it amounts to ∼0.17 eV, in agreement with previous studies. In principle, this method is applicable to any absorption resonance suitable for RIXS measurements and will help to define the contribution of lattice vibrations to the peculiar properties of quantum materials.
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