| 1. |
- Kristan, Matej, et al.
(författare)
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The Sixth Visual Object Tracking VOT2018 Challenge Results
- 2019
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Ingår i: Computer Vision – ECCV 2018 Workshops. - Cham : Springer Publishing Company. - 9783030110086 - 9783030110093 ; , s. 3-53
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2018 is the sixth annual tracker benchmarking activity organized by the VOT initiative. Results of over eighty trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in the recent years. The evaluation included the standard VOT and other popular methodologies for short-term tracking analysis and a “real-time” experiment simulating a situation where a tracker processes images as if provided by a continuously running sensor. A long-term tracking subchallenge has been introduced to the set of standard VOT sub-challenges. The new subchallenge focuses on long-term tracking properties, namely coping with target disappearance and reappearance. A new dataset has been compiled and a performance evaluation methodology that focuses on long-term tracking capabilities has been adopted. The VOT toolkit has been updated to support both standard short-term and the new long-term tracking subchallenges. Performance of the tested trackers typically by far exceeds standard baselines. The source code for most of the trackers is publicly available from the VOT page. The dataset, the evaluation kit and the results are publicly available at the challenge website (http://votchallenge.net).
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| 2. |
- Wang, Zhihang, 1989, et al.
(författare)
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Chip-scale solar thermal electrical power generation
- 2022
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Ingår i: Cell Reports Physical Science. - : Elsevier BV. - 2666-3864. ; 3:3
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Tidskriftsartikel (refereegranskat)abstract
- There is an urgent need for alternative compact technologies that can derive and store energy from the sun, especially the large amount of solar heat that is not effectively used for power generation. Here, we report a combination of solution- and neat-film-based molecular solar thermal (MOST) systems, where solar energy can be stored as chemical energy and released as heat, with microfabricated thermoelectric generators to produce electricity when solar radiation is not available. The photophysical properties of two MOST couples are characterized both in liquid with a catalytical cycling setup and in a phase-interconvertible neat film. Their suitable photophysical properties let us combine them individually with a microelectromechanical ultrathin thermoelectric chip to use the stored solar energy for electrical power generation. The generator can produce, as a proof of concept, a power output of up to 0.1 nW (power output per unit volume up to 1.3 W m−3). Our results demonstrate that such a molecular thermal power generation system has a high potential to store and transfer solar power into electricity and is thus potentially independent of geographical restrictions.
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| 3. |
- Andronis, Christos, et al.
(författare)
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Molecular basis of mood and cognitive adverse events elucidated via a combination of pharmacovigilance data mining and functional enrichment analysis
- 2020
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Ingår i: Archives of Toxicology. - : Springer Nature. - 0340-5761 .- 1432-0738. ; 94:8, s. 2829-2845
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Tidskriftsartikel (refereegranskat)abstract
- Drug-induced Mood- and Cognition-related adverse events (MCAEs) are often only detected during the clinical trial phases of drug development, or even after marketing, thus posing a major safety concern and a challenge for both pharmaceutical companies and clinicians. To fill some gaps in the understanding and elucidate potential biological mechanisms of action frequently associated with MCAEs, we present a unique workflow linking observational population data with the available knowledge at molecular, cellular, and psychopharmacology levels. It is based on statistical analysis of pharmacovigilance reports and subsequent signaling pathway analyses, followed by evidence-based expert manual curation of the outcomes. Our analysis: (a) ranked pharmaceuticals with high occurrence of such adverse events (AEs), based on disproportionality analysis of the FDA Adverse Event Reporting System (FAERS) database, and (b) identified 120 associated genes and common pathway nodes possibly underlying MCAEs. Nearly two-thirds of the identified genes were related to immune modulation, which supports the critical involvement of immune cells and their responses in the regulation of the central nervous system function. This finding also means that pharmaceuticals with a negligible central nervous system exposure may induce MCAEs through dysregulation of the peripheral immune system. Knowledge gained through this workflow unravels putative hallmark biological targets and mediators of drug-induced mood and cognitive disorders that need to be further assessed and validated in experimental models. Thereafter, they can be used to substantially improve in silico/in vitro/in vivo tools for predicting these adversities at a preclinical stage.
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| 4. |
- Balayssac, David, et al.
(författare)
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Neurofilament light chain in plasma as a sensitive diagnostic biomarker of peripheral neurotoxicity : In Vivo mouse studies with oxaliplatin and paclitaxel - NeuroDeRisk project
- 2023
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Ingår i: Biomedicine and Pharmacotherapy. - : Elsevier. - 0753-3322 .- 1950-6007. ; 167
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Tidskriftsartikel (refereegranskat)abstract
- Identifying compounds that are neurotoxic either toward the central or the peripheral nervous systems (CNS or PNS) would greatly benefit early stages of drug development by derisking liabilities and selecting safe compounds. Unfortunately, so far assays mostly rely on histopathology findings often identified after repeated-dose toxicity studies in animals. The European NeuroDeRisk project aimed to provide comprehensive tools to identify compounds likely inducing neurotoxicity. As part of this project, the present work aimed to identify diagnostic non-invasive biomarkers of PNS toxicity in mice. We used two neurotoxic drugs in vivo to correlate functional, histopathological and biological findings. CD1 male mice received repeated injections of oxaliplatin or paclitaxel followed by an assessment of drug exposure in CNS/PNS tissues. Functional signs of PNS toxicity were assessed using electronic von Frey and cold paw immersion tests (oxaliplatin), and functional observational battery, rotarod and cold plate tests (paclitaxel). Plasma concentrations of neurofilament light chain (NF-L) and vascular endothelial growth factor A (VEGF-A) were measured, and histopathological evaluations were performed on a comprehensive list of CNS and PNS tissues. Functional PNS toxicity was observed only in oxaliplatin-treated mice. Histopathological findings were observed dose-dependently only in paclitaxel groups. While no changes of VEGF-A concentrations was recorded, NF-L concentrations were increased only in paclitaxel-treated animals as early as 7 days after the onset of drug administration. These results show that plasma NF-L changes correlated with microscopic changes in the PNS, thus strongly suggesting that NF-L could be a sensitive and specific biomarker of PNS toxicity in mice.
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| 5. |
- Felsberg, Michael, 1974-, et al.
(författare)
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The Thermal Infrared Visual Object Tracking VOT-TIR2016 Challenge Results
- 2016
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Ingår i: Computer Vision – ECCV 2016 Workshops. ECCV 2016.. - Cham : SPRINGER INT PUBLISHING AG. - 9783319488813 - 9783319488806 ; , s. 824-849
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Konferensbidrag (refereegranskat)abstract
- The Thermal Infrared Visual Object Tracking challenge 2016, VOT-TIR2016, aims at comparing short-term single-object visual trackers that work on thermal infrared (TIR) sequences and do not apply pre-learned models of object appearance. VOT-TIR2016 is the second benchmark on short-term tracking in TIR sequences. Results of 24 trackers are presented. For each participating tracker, a short description is provided in the appendix. The VOT-TIR2016 challenge is similar to the 2015 challenge, the main difference is the introduction of new, more difficult sequences into the dataset. Furthermore, VOT-TIR2016 evaluation adopted the improvements regarding overlap calculation in VOT2016. Compared to VOT-TIR2015, a significant general improvement of results has been observed, which partly compensate for the more difficult sequences. The dataset, the evaluation kit, as well as the results are publicly available at the challenge website.
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| 6. |
- Hu, Yang, 1989-, et al.
(författare)
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Analysis of the contributing role of drug transport across biological barriers in the development and treatment of chemotherapy-induced peripheral neuropathy
- 2024
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Ingår i: Fluids and Barriers of the CNS. - : Springer Nature. - 2045-8118. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Chemotherapy-induced peripheral neuropathy (CIPN) represents a major unmet medical need that currently has no preventive and/or curative treatment. This is, among others, driven by a poor understanding of the contributive role of drug transport across biological barriers to target-site exposure. Methods Here, we systematically investigated the transport of 11 small-molecule drugs, both, associated and not with CIPN development, at conventional (dorsal root ganglia, sciatic nerve) and non-conventional (brain, spinal cord, skeletal muscle) CIPN sites. We developed a Combinatory Mapping Approach for CIPN, CMA-CIPN, combining in vivo and in vitro elements. Results Using CMA-CIPN, we determined the unbound tissue-to-plasma concentration ratio (K-p,K-uu) and the unbound intracellular-to-extracellular concentration ratio (K-p,K-uu,K-cell), to quantitatively assess the extent of unbound drug transport across endothelial interfaces and parenchymal cellular barriers of investigated CIPN-sites, respectively, in a rat model. The analysis revealed that unique pharmacokinetic characteristics underly time-dependent accumulation of the CIPN-positive drugs paclitaxel and vincristine at conventional (dorsal root ganglia and sciatic nerve) and non-conventional (skeletal muscle) CIPN sites. Investigated CIPN-positive drugs displayed intracellular accumulation contrary to CIPN-negative drugs nilotinib and methotrexate, which lacked this feature in all investigated tissues. Conclusions Hence, high unbound drug intracellular and extracellular exposure at target sites, driven by an interplay of drug transport across the endothelial and parenchymal cellular barriers, is a predisposing factor to CIPN development for CIPN-positive drugs. Critical drug-specific features of unbound drug disposition at various CIPN- sites provide invaluable insights into understanding the pharmacological/toxicological effects at the target-sites which will inform new strategies for monitoring and treatment of CIPN.
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| 7. |
- Hu, Yang, 1989-
(författare)
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Drug Delivery to the Brain by Liposomes : Understanding Factors Governing Delivery Outcomes In Vivo
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The blood-brain barrier (BBB) is the primary obstacle for efficient drug delivery to the central nervous system (CNS). One promising strategy to enhance brain delivery is to utilize nanocarriers (NC), e.g., liposomes, encapsulating CNS drugs. However, there is still a lack of understanding of how carrier- and payload-associated factors with liposomal brain delivery may influence brain drug uptake and ultimately therapeutic performance. In this thesis, the impact of factors including the liposomal formulation, the addition of a BBB-targeting ligand and the BBB transport properties of the payload itself on brain drug delivery were quantitatively investigated in vivo with microdialysis. Furthermore, by using a model-based approach, the benefits of NCs with different properties to increase the therapeutic index of CNS drugs were studied and key parameters influencing the therapeutic performance were identified.The formulation of PEGylated (PEG) liposomes could significantly influence brain delivery of methotrexate (MTX). Compared to free MTX, PEG liposomes based on egg-yolk phosphatidylcholine (EYPC) increased brain uptake of MTX by 3-fold, while the formulation based on hydrogenated soy phosphatidylcholine (HSPC) did not affect the uptake at all. Also, PEG liposomes could influence the BBB transport of payloads differently, depending on if the payload itself show active uptake or efflux at the BBB. For diphenhydramine (DPH), a drug with active uptake at the BBB, PEG-EYPC liposomes significantly reduced its uptake into the brain. Moreover, the brain-targeting effect of glutathione (GSH)-tagged PEG liposomal MTX was highly dependent on the liposomal formulation that is combined with GSH. Compared to the PEG control formulations, GSH-PEG-HSPC liposomes increased brain delivery of MTX 4-fold, while GSH-coating on PEG-EYPC liposomes did not further enhance the uptake. In the last simulation study, two independent processes of nanodelivery to the brain were identified. A NC only prolonging circulation time increases the therapeutic index by reducing peripheral toxicity, while a NC with increased circulation time and brain uptake improves the therapeutic index due to both elevated central effect and decreased peripheral toxicity. Faster in vivo drug release and faster systemic elimination of the intact NC reduce the therapeutic performance. A drug with shorter half-life will obtain more therapeutic benefit from NC-encapsulation.In summary, this thesis work contributes to a better understanding of factors governing the success of liposomal brain delivery and gives important insights on what needs to be considered and how to optimize the properties of a NC when developing NC-based strategies for treating CNS diseases.
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| 8. |
- Hu, Yang, 1989-, et al.
(författare)
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In Vivo Quantitative Understanding of PEGylated Liposome’s Influence on Brain Delivery of Diphenhydramine
- 2018
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Ingår i: Molecular Pharmaceutics. - : American Chemical Society (ACS). - 1543-8384 .- 1543-8392. ; 15:12, s. 5493-5500
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Tidskriftsartikel (refereegranskat)abstract
- Despite the promising features of liposomes as brain drug delivery vehicles, it remains uncertain how they influence the brain uptake in vivo. In order to gain a better fundamental understanding of the interaction between liposomes and the blood–brain barrier (BBB), it is indispensable to test if liposomes affect drugs with different BBB transport properties (active influx or efflux) differently. The aim of this study was to quantitatively evaluate how PEGylated (PEG) liposomes influence brain delivery of diphenhydramine (DPH), a drug with active influx at the BBB, in rats. The brain uptake of DPH after 30 min intravenous infusion of free DPH, PEG liposomal DPH, or free DPH + empty PEG liposomes was compared by determining the unbound DPH concentrations in brain interstitial fluid and plasma with microdialysis. Regular blood samples were taken to measure total DPH concentrations in plasma. Free DPH was actively taken up into the brain time-dependently, with higher uptake at early time points followed by an unbound brain-to-plasma exposure ratio (Kp,uu) of 3.0. The encapsulation in PEG liposomes significantly decreased brain uptake of DPH, with a reduction of Kp,uu to 1.5 (p < 0.05). When empty PEG liposomes were coadministered with free drug, DPH brain uptake had a tendency to decrease (Kp,uu 2.3), and DPH was found to bind to the liposomes. This study showed that PEG liposomes decreased the brain delivery of DPH in a complex manner, contributing to the understanding of the intricate interactions between drug, liposomes, and the BBB.
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| 9. |
- Hu, Yang, 1989-, et al.
(författare)
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Perspectives on Nanodelivery to the Brain : Prerequisites for Successful Brain Treatment
- 2020
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Ingår i: Molecular Pharmaceutics. - : AMER CHEMICAL SOC. - 1543-8384 .- 1543-8392. ; 17:11, s. 4029-4039
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Tidskriftsartikel (refereegranskat)abstract
- Nanocarriers (NCs) are promising tools to improve drug delivery across the blood-brain barrier (BBB) for more effective treatment of brain disorders, although there is a scarcity of clinical translation of brain-directed NCs. In order to drive the development of brain-oriented NCs toward clinical success, it is essential to understand the prerequisites for nanodelivery to be successful in brain treatment. In this Perspective, we present how pharmacokinetic/pharmacodynamic (PK/PD), formulation and nanotoxicity factors impact the therapeutic success of brain-specific nanodelivery. Properties including high loading efficiency, slow in vivo drug release, long systemic circulation, an increase in unbound brain-to-plasma concentration/exposure ratio (K-p,K-uu,K-brain), high drug potency, and minimal nanotoxicity are prerequisites that should preferably be combined to maximize the therapeutic potential of a brain-targeted NC. The PK of brain-directed NCs needs to be evaluated in a more therapeutically relevant manner, focusing on the released, unbound drug. It is more crucial to increase the K-p,K-uu,K-brain than to improve the ability of the NC to cross the BBB in its intact form. Brain-targeted NCs, which are mostly developed for treating brain tumors, including metastases, should aim to enhance drug delivery not just to tumor regions with disrupted BBB, but equally important to regions with intact BBB where the drugs themselves have problems reaching. This article provides critical insights into how a brain-targeted nanoformulation needs to be designed and optimized to achieve therapeutic success in the brain.
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| 10. |
- Hu, Yang, 1989-, et al.
(författare)
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Targeted Brain Delivery of Methotrexate by Glutathione PEGylated Liposomes : How can the Formulation Make a Difference?
- 2019
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Ingår i: European journal of pharmaceutics and biopharmaceutics. - : Elsevier BV. - 0939-6411 .- 1873-3441. ; 139, s. 197-204
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to quantitatively investigate how conjugation of GSH to different liposomal formulations influence the brain delivery of methotrexate (MTX) in rats. GSH-PEG liposomal MTX based on hydrogenated soy phosphatidylcholine (HSPC) or egg yolk phosphatidylcholine (EYPC) and their corresponding PEG control liposomes were prepared. The brain delivery of MTX after intravenously administering free MTX, four liposomal formulations or free MTX + empty GSH-PEG-HSPC liposomes was evaluated by performing microdialysis in brain interstitial fluid and blood. Compared to free MTX with a steady-state unbound brain-toplasma concentration ratio (K-p,K-uu) of 0.10, PEG-HSPC liposomes did not affect the brain uptake of MTX, while PEG-EYPC liposomes improved the uptake (K-p,(uu) 1.5, p < 0.05). Compared to PEG control formulations, GSHPEG-HSPC liposomes increased brain delivery of MTX by 4-fold (K-p,(uu) 0.82, p < 0.05), while GSH-coating on PEG-EYPC liposomes did not result in a further enhancement in uptake. The co-administration of empty GSHPEG-HSPC liposomes with free MTX did not influence the uptake of MTX into the brain. This work showed that the brain-targeting effect of GSH-PEG liposomal MTX is highly dependent on the liposomal formulation that is combined with GSH, providing insights on formulation optimization of this promising brain delivery platform.
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| 11. |
- Hu, Yang, 1989-, et al.
(författare)
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Understanding the Influence of Nanocarrier-Mediated Brain Delivery on Therapeutic Performance Through Pharmacokinetic-Pharmacodynamic Modeling.
- 2019
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Ingår i: Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0022-3549 .- 1520-6017. ; 108:10, s. 3425-3433
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed at evaluating how encapsulation in a regular nanocarrier (NC) (providing extended circulation time) or in a brain-targeting NC (providing prolonged circulation time and increased brain uptake) may influence the therapeutic index compared with the unformulated drug and to explore the key parameters affecting therapeutic performance using a model-based approach. Pharmacokinetic (PK) models were built with chosen PK parameters. For a scenario where central effect depends on area under the unbound brain concentration curve and peripheral toxicity relates to peak unbound plasma concentration, dose-effect and drug-side effect curves were constructed, and the therapeutic index was evaluated. Regular NC improved the therapeutic index compared with the unformulated drug due to reduced peripheral toxicity, while brain-targeting NC enhanced the therapeutic index by lowering peripheral toxicity and increasing central effect. Decreasing drug release rate or systemic clearance of NC with drug still encapsulated could increase the therapeutic index. Also, a drug with shorter half-life would therapeutically benefit more from a NC encapsulation. This work provides insights into how a NC for brain delivery should be optimized to maximize the therapeutic performance and is helpful to predict if and to what extent a drug with certain PK properties would obtain therapeutic benefit from nanoencapsulation.
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| 12. |
- Lozano, Rafael, et al.
(författare)
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Measuring progress from 1990 to 2017 and projecting attainment to 2030 of the health-related Sustainable Development Goals for 195 countries and territories: a systematic analysis for the Global Burden of Disease Study 2017
- 2018
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Ingår i: The Lancet. - : Elsevier. - 1474-547X .- 0140-6736. ; 392:10159, s. 2091-2138
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Tidskriftsartikel (refereegranskat)abstract
- Background: Efforts to establish the 2015 baseline and monitor early implementation of the UN Sustainable Development Goals (SDGs) highlight both great potential for and threats to improving health by 2030. To fully deliver on the SDG aim of “leaving no one behind”, it is increasingly important to examine the health-related SDGs beyond national-level estimates. As part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017), we measured progress on 41 of 52 health-related SDG indicators and estimated the health-related SDG index for 195 countries and territories for the period 1990–2017, projected indicators to 2030, and analysed global attainment. Methods: We measured progress on 41 health-related SDG indicators from 1990 to 2017, an increase of four indicators since GBD 2016 (new indicators were health worker density, sexual violence by non-intimate partners, population census status, and prevalence of physical and sexual violence [reported separately]). We also improved the measurement of several previously reported indicators. We constructed national-level estimates and, for a subset of health-related SDGs, examined indicator-level differences by sex and Socio-demographic Index (SDI) quintile. We also did subnational assessments of performance for selected countries. To construct the health-related SDG index, we transformed the value for each indicator on a scale of 0–100, with 0 as the 2·5th percentile and 100 as the 97·5th percentile of 1000 draws calculated from 1990 to 2030, and took the geometric mean of the scaled indicators by target. To generate projections through 2030, we used a forecasting framework that drew estimates from the broader GBD study and used weighted averages of indicator-specific and country-specific annualised rates of change from 1990 to 2017 to inform future estimates. We assessed attainment of indicators with defined targets in two ways: first, using mean values projected for 2030, and then using the probability of attainment in 2030 calculated from 1000 draws. We also did a global attainment analysis of the feasibility of attaining SDG targets on the basis of past trends. Using 2015 global averages of indicators with defined SDG targets, we calculated the global annualised rates of change required from 2015 to 2030 to meet these targets, and then identified in what percentiles the required global annualised rates of change fell in the distribution of country-level rates of change from 1990 to 2015. We took the mean of these global percentile values across indicators and applied the past rate of change at this mean global percentile to all health-related SDG indicators, irrespective of target definition, to estimate the equivalent 2030 global average value and percentage change from 2015 to 2030 for each indicator. Findings: The global median health-related SDG index in 2017 was 59·4 (IQR 35·4–67·3), ranging from a low of 11·6 (95% uncertainty interval 9·6–14·0) to a high of 84·9 (83·1–86·7). SDG index values in countries assessed at the subnational level varied substantially, particularly in China and India, although scores in Japan and the UK were more homogeneous. Indicators also varied by SDI quintile and sex, with males having worse outcomes than females for non-communicable disease (NCD) mortality, alcohol use, and smoking, among others. Most countries were projected to have a higher health-related SDG index in 2030 than in 2017, while country-level probabilities of attainment by 2030 varied widely by indicator. Under-5 mortality, neonatal mortality, maternal mortality ratio, and malaria indicators had the most countries with at least 95% probability of target attainment. Other indicators, including NCD mortality and suicide mortality, had no countries projected to meet corresponding SDG targets on the basis of projected mean values for 2030 but showed some probability of attainment by 2030. For some indicators, including child malnutrition, several infectious diseases, and most violence measures, the annualised rates of change required to meet SDG targets far exceeded the pace of progress achieved by any country in the recent past. We found that applying the mean global annualised rate of change to indicators without defined targets would equate to about 19% and 22% reductions in global smoking and alcohol consumption, respectively; a 47% decline in adolescent birth rates; and a more than 85% increase in health worker density per 1000 population by 2030. Interpretation: The GBD study offers a unique, robust platform for monitoring the health-related SDGs across demographic and geographic dimensions. Our findings underscore the importance of increased collection and analysis of disaggregated data and highlight where more deliberate design or targeting of interventions could accelerate progress in attaining the SDGs. Current projections show that many health-related SDG indicators, NCDs, NCD-related risks, and violence-related indicators will require a concerted shift away from what might have driven past gains—curative interventions in the case of NCDs—towards multisectoral, prevention-oriented policy action and investments to achieve SDG aims. Notably, several targets, if they are to be met by 2030, demand a pace of progress that no country has achieved in the recent past. The future is fundamentally uncertain, and no model can fully predict what breakthroughs or events might alter the course of the SDGs. What is clear is that our actions—or inaction—today will ultimately dictate how close the world, collectively, can get to leaving no one behind by 2030.
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| 13. |
- Pagnin, Elena, 1989, et al.
(författare)
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HB+DB: Distance bounding meets human based authentication
- 2018
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Ingår i: Future Generation Computer Systems. - : Elsevier BV. - 0167-739X. ; 80, s. 627-639
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Tidskriftsartikel (refereegranskat)abstract
- Authentication for resource-constrained devices is seen as one of the major challenges in current wireless communication networks. The HB + protocol by Juels and Weis provides device authentication based on the learning parity with noise (LPN) problem and is appropriate for resource-constrained devices, but it has been shown to be vulnerable to a simple man-in-the-middle attack. Subsequent work has focused on modifying the cryptographic properties of the original protocol to mitigate this problem. We propose that this attack could be mitigated using physical layer measure s from distance-bounding protocols and simple modifications to devices’ radio receivers. We take the HB + as a reference protocol and combine it with distance-bounding techniques. This hybrid solution, the HB + DB protocol is shown to provide resistance against the man-in-the-middle attacks on HB + as a result of the additional physical-layer mechanisms. We analyze the security of the proposed HB + DB protocol against active man-in-the-middle attacks and present experiments showing how it is practically possible to limit the success of a practical man-in-the-middle attack. We also briefly discuss the possibility that HB + DB could provide some resistance to basic threats scenarios meant to be mitigated by distance-bounding protocols. We make a practical implementation to verify that our proposed method is feasible. Finally, we discuss a proof-of-concept channel for our scheme implemented on a platform equivalent in resources to a contactless smart card/NFC device.
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| 14. |
- Powell, Diana, et al.
(författare)
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Sulfur dioxide in the mid-infrared transmission spectrum of WASP-39b
- 2024
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Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 626:8001, s. 979-983
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Tidskriftsartikel (refereegranskat)abstract
- The recent inference of sulfur dioxide (SO2) in the atmosphere of the hot (approximately 1,100 K), Saturn-mass exoplanet WASP-39b from near-infrared JWST observations1–3 suggests that photochemistry is a key process in high-temperature exoplanet atmospheres4. This is because of the low (<1 ppb) abundance of SO2 under thermochemical equilibrium compared with that produced from the photochemistry of H2O and H2S (1–10 ppm)4–9. However, the SO2 inference was made from a single, small molecular feature in the transmission spectrum of WASP-39b at 4.05 μm and, therefore, the detection of other SO2 absorption bands at different wavelengths is needed to better constrain the SO2 abundance. Here we report the detection of SO2 spectral features at 7.7 and 8.5 μm in the 5–12-μm transmission spectrum of WASP-39b measured by the JWST Mid-Infrared Instrument (MIRI) Low Resolution Spectrometer (LRS)10. Our observations suggest an abundance of SO2 of 0.5–25 ppm (1σ range), consistent with previous findings4. As well as SO2, we find broad water-vapour absorption features, as well as an unexplained decrease in the transit depth at wavelengths longer than 10 μm. Fitting the spectrum with a grid of atmospheric forward models, we derive an atmospheric heavy-element content (metallicity) for WASP-39b of approximately 7.1–8.0 times solar and demonstrate that photochemistry shapes the spectra of WASP-39b across a broad wavelength range.
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| 15. |
- Wang, Zhihang, 1989, et al.
(författare)
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Storing energy with molecular photoisomers
- 2021
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Ingår i: Joule. - : Elsevier BV. - 2542-4351. ; 5:12, s. 3116-3136
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Forskningsöversikt (refereegranskat)abstract
- Some molecular photoisomers can be isomerized to a metastable high-energy state by exposure to light. These molecules can then be thermally or catalytically converted back to their initial state, releasing heat in the process. Such a reversible photochemical process has been considered for developing molecular solar thermal (MOST) systems. In this review, we introduce the concept, criteria, and state-of-the-art of MOST systems, with an emphasis on the three most promising molecular systems: norbornadiene/quadricyclane, E/Z-azobenzene, and dihydroazulene/vinylheptafulvene. After discussing the fundamental working principles, we focus on molecular design strategies for improving solar energy storage performance, remaining challenges, and potential focus areas. Finally, we summarize the current molecular incorporation into functional devices and conclude with a perspective on challenges and future directions.
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| 16. |
- Yang, Jianping, et al.
(författare)
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Iridium-Catalyzed Double Convergent 1,3-Rearrangement/Hydrogenation of Allylic Alcohols
- 2023
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 145:1, s. 626-633
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Tidskriftsartikel (refereegranskat)abstract
- Enantioconvergent catalysis has the potential to convert different isomers of a starting material to a single highly enantioenriched product. Here we report a novel enantioselective double convergent 1,3-rearrangement/hydrogenation of allylic alcohols using an Ir-N,P catalyst. A variety of allylic alcohols, each consisting of a 1:1:1:1 mixture of four isomers, were converted to the corresponding tertiary alcohols with two contiguous stereogenic centers, in up to 99% ee and 99:1 d.r. DFT calculations, and control experiments suggest that the 1,3-rearrangement is the crucial stereodetermining element of the reaction.
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| 17. |
- Zeng, S., et al.
(författare)
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Discovery of an Orally Active and Long-Acting DPP-IV Inhibitor through Property-Based Optimization with an in Silico Biotransformation Prediction Tool
- 2020
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Ingår i: ChemMedChem. - : John Wiley and Sons Ltd. - 1860-7179 .- 1860-7187. ; 15:16, s. 1608-1617
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Tidskriftsartikel (refereegranskat)abstract
- Long-acting dipeptidyl peptidase IV inhibitors have emerged as promising molecules for interventions for type 2 diabetes. Once weekly dosing brings greater patient compliance and more stable glycemic control. Starting from our previous highly potent compound with a thienoprimidine scaffold, which is unfortunately severely hit by hepatic biotransformation, a lead compound was rapidly generated by drawing on the experience of our previously discovered long-acting compounds with pyrrolopyrimidine scaffold. With the aid of an in silico biotransformation prediction tool, (R)-2-((2-(3-aminopiperidin-1-yl)-4-oxo-6-(pyridin-3-yl)thieno[3,2-d]pyrimidin-3(4H)-yl)methyl)-4-fluorobenzonitrile was eventually generated and determined to have high potency, a fine pharmacokinetic profile, and a long-acting in vivo efficacy.
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