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1.
Malar J ; 23(1): 188, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38880870

RESUMO

BACKGROUND: Effective testing for malaria, including the detection of infections at very low densities, is vital for the successful elimination of the disease. Unfortunately, existing methods are either inexpensive but poorly sensitive or sensitive but costly. Recent studies have shown that mid-infrared spectroscopy coupled with machine learning (MIRs-ML) has potential for rapidly detecting malaria infections but requires further evaluation on diverse samples representative of natural infections in endemic areas. The aim of this study was, therefore, to demonstrate a simple AI-powered, reagent-free, and user-friendly approach that uses mid-infrared spectra from dried blood spots to accurately detect malaria infections across varying parasite densities and anaemic conditions. METHODS: Plasmodium falciparum strains NF54 and FCR3 were cultured and mixed with blood from 70 malaria-free individuals to create various malaria parasitaemia and anaemic conditions. Blood dilutions produced three haematocrit ratios (50%, 25%, 12.5%) and five parasitaemia levels (6%, 0.1%, 0.002%, 0.00003%, 0%). Dried blood spots were prepared on Whatman™ filter papers and scanned using attenuated total reflection-Fourier Transform Infrared (ATR-FTIR) for machine-learning analysis. Three classifiers were trained on an 80%/20% split of 4655 spectra: (I) high contrast (6% parasitaemia vs. negative), (II) low contrast (0.00003% vs. negative) and (III) all concentrations (all positive levels vs. negative). The classifiers were validated with unseen datasets to detect malaria at various parasitaemia levels and anaemic conditions. Additionally, these classifiers were tested on samples from a population survey in malaria-endemic villages of southeastern Tanzania. RESULTS: The AI classifiers attained over 90% accuracy in detecting malaria infections as low as one parasite per microlitre of blood, a sensitivity unattainable by conventional RDTs and microscopy. These laboratory-developed classifiers seamlessly transitioned to field applicability, achieving over 80% accuracy in predicting natural P. falciparum infections in blood samples collected during the field survey. Crucially, the performance remained unaffected by various levels of anaemia, a common complication in malaria patients. CONCLUSION: These findings suggest that the AI-driven mid-infrared spectroscopy approach holds promise as a simplified, sensitive and cost-effective method for malaria screening, consistently performing well despite variations in parasite densities and anaemic conditions. The technique simply involves scanning dried blood spots with a desktop mid-infrared scanner and analysing the spectra using pre-trained AI classifiers, making it readily adaptable to field conditions in low-resource settings. In this study, the approach was successfully adapted to field use, effectively predicting natural malaria infections in blood samples from a population-level survey in Tanzania. With additional field trials and validation, this technique could significantly enhance malaria surveillance and contribute to accelerating malaria elimination efforts.


Assuntos
Malária Falciparum , Plasmodium falciparum , Humanos , Malária Falciparum/diagnóstico , Malária Falciparum/sangue , Malária Falciparum/parasitologia , Plasmodium falciparum/isolamento & purificação , Parasitemia/diagnóstico , Parasitemia/parasitologia , Anemia/diagnóstico , Anemia/sangue , Anemia/parasitologia , Espectrofotometria Infravermelho/métodos , Aprendizado de Máquina , Carga Parasitária , Adulto , Inteligência Artificial , Sensibilidade e Especificidade , Feminino , Adulto Jovem , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Adolescente , Masculino , Pessoa de Meia-Idade , Programas de Rastreamento/métodos
2.
Liver Int ; 44(3): 838-847, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38263707

RESUMO

BACKGROUND AND AIMS: Haemochromatosis is characterized by progressive iron overload affecting the liver and can cause cirrhosis and hepatocellular carcinoma. Most haemochromatosis patients are homozygous for p.C282Y in HFE, but only a minority of individuals with this genotype will develop the disease. The aim was to assess the penetrance of iron overload, fibrosis, hepatocellular carcinoma and life expectancy. METHODS: A total of 8839 individuals from the Austrian region of Tyrol were genotyped for the p.C282Y variant between 1997 and 2021. Demographic, laboratory parameters and causes of death were assessed from health records. Penetrance, survival, and cancer incidence were ascertained from diagnosed cases, insurance- and cancer registry data. Outcomes were compared with a propensity score-matched control population. RESULTS: Median age at diagnosis in 542 p.C282Y homozygous individuals was 47.8 years (64% male). At genotyping, the prevalence of iron overload was 55%. The cumulative penetrance of haemochromatosis defined as the presence of provisional iron overload was 24.2% in males and 10.5% in females aged 60 years or younger. Among p.C282Y homozygotes of the same ages, the cumulative proportion of individuals without fibrosis (FIB-4 score < 1.3) was 92.8% in males and 96.7% in females. Median life expectancy was reduced by 6.8 years in individuals homozygous for p.C282Y when compared with population-matched controls (p = .001). Hepatocellular carcinoma incidence was not significantly higher in p.C282Y homozygotes than in controls matched for age and sex. CONCLUSION: Reduced survival and the observed age-dependent increase in penetrance among p.C282Y homozygotes call for earlier diagnosis of haemochromatosis to prevent complications.


Assuntos
Carcinoma Hepatocelular , Hemocromatose , Sobrecarga de Ferro , Neoplasias Hepáticas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hemocromatose/epidemiologia , Hemocromatose/genética , Hemocromatose/complicações , Penetrância , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/complicações , Estudos de Coortes , Incidência , Antígenos de Histocompatibilidade Classe I/genética , Proteína da Hemocromatose/genética , Sobrecarga de Ferro/complicações , Homozigoto , Cirrose Hepática/complicações , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/complicações , Mutação
3.
JDR Clin Trans Res ; 9(2): 185-189, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37565570

RESUMO

KNOWLEDGE TRANSFER STATEMENT: The EU DELIVER project aims to enhance the quality of oral health care through codevelopment and coproduction of solutions together with citizens/patients, providers, and policymakers. The unique multicountry nature of the project will facilitate fast-track prototype development and testing of innovative QI approaches in select countries. Reflective learning regarding the transferability of findings between different countries and settings offers unique opportunities to drive progress toward context-specific implementation of innovative oral health care QI approaches. The collective knowledge gained from the 7 European countries involved in DELIVER can also generate knowhow for improving the quality of oral health care in other countries around the globe.


Assuntos
Aprendizagem , Qualidade da Assistência à Saúde , Humanos , Europa (Continente)
4.
Hypertension ; 81(2): 319-329, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38018457

RESUMO

BACKGROUND: The chronic hypoxia of high-altitude residence poses challenges for tissue oxygen supply and metabolism. Exposure to high altitude during pregnancy increases the incidence of hypertensive disorders of pregnancy and fetal growth restriction and alters placental metabolism. High-altitude ancestry protects against altitude-associated fetal growth restriction, indicating hypoxia tolerance that is genetic in nature. Yet, not all babies are protected and placental pathologies associated with fetal growth restriction occur in some Andean highlanders. METHODS: We examined placental metabolic function in 79 Andeans (18-45 years; 39 preeclamptic and 40 normotensive) living in La Paz, Bolivia (3600-4100 m) delivered by unlabored Cesarean section. Using a selection-nominated approach, we examined links between putatively adaptive genetic variation and phenotypes related to oxygen delivery or placental metabolism. RESULTS: Mitochondrial oxidative capacity was associated with fetal oxygen delivery in normotensive but not preeclamptic placenta and was also suppressed in term preeclamptic pregnancy. Maternal haplotypes in or within 200 kb of selection-nominated genes were associated with lower placental mitochondrial respiratory capacity (PTPRD [protein tyrosine phosphatase receptor-δ]), lower maternal plasma erythropoietin (CPT2 [carnitine palmitoyl transferase 2], proopiomelanocortin, and DNMT3 [DNA methyltransferase 3]), and lower VEGF (vascular endothelial growth factor) in umbilical venous plasma (TBX5 [T-box transcription factor 5]). A fetal haplotype within 200 kb of CPT2 was associated with increased placental mitochondrial complex II capacity, placental nitrotyrosine, and GLUT4 (glucose transporter type 4) protein expression. CONCLUSIONS: Our findings reveal novel associations between putatively adaptive gene regions and phenotypes linked to oxygen delivery and placental metabolic function in highland Andeans, suggesting that such effects may be of genetic origin. Our findings also demonstrate maladaptive metabolic mechanisms in the context of preeclampsia, including dysregulation of placental oxygen consumption.


Assuntos
Placenta , Pré-Eclâmpsia , Humanos , Gravidez , Feminino , Placenta/metabolismo , Cesárea , Retardo do Crescimento Fetal , Fator A de Crescimento do Endotélio Vascular/metabolismo , Hipóxia/metabolismo , Oxigênio/metabolismo , Fenótipo , Genômica
5.
Energy Adv ; 2(11): 1893-1904, 2023 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-38013932

RESUMO

CO2 electrolysis might be a key process to utilize intermittent renewable electricity for the sustainable production of hydrocarbon chemicals without relying on fossil fuels. Commonly used carbon-based gas diffusion electrodes (GDEs) enable high Faradaic efficiencies for the desired carbon products at high current densities, but have limited stability. In this study, we explore the adaption of a carbon-free GDE from a Chlor-alkali electrolysis process as a cathode for gas-fed CO2 electrolysis. We determine the impact of electrowetting on the electrochemical performance by analyzing the Faradaic efficiency for CO at industrially relevant current density. The characterization of used GDEs with X-ray photoelectron spectroscopy (XPS) and X-Ray diffraction (XRD) reveals a potential-dependent degradation, which can be explained through chemical polytetrafluorethylene (PTFE) degradation and/or physical erosion of PTFE through the restructuring of the silver surface. Our results further suggest that electrowetting-induced flooding lets the Faradaic efficiency for CO drop below 40% after only 30 min of electrolysis. We conclude that the effect of electrowetting has to be managed more carefully before the investigated carbon-free GDEs can compete with carbon-based GDEs as cathodes for CO2 electrolysis. Further, not only the conductive phase (such as carbon), but also the binder (such as PTFE), should be carefully selected for stable CO2 reduction.

6.
Parasit Vectors ; 16(1): 342, 2023 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-37789458

RESUMO

BACKGROUND: Pyrethroid resistance in the key malaria vectors threatens the success of pyrethroid-treated nets. To overcome pyrethroid resistance, Interceptor® G2 (IG2), a 'first-in-class' dual insecticidal net that combines alpha-cypermethrin with chlorfenapyr, was developed. Chlorfenapyr is a pro-insecticide, requiring bio-activation by oxidative metabolism within the insect's mitochondria, constituting a mode of action preventing cross-resistance to pyrethroids. Recent epidemiological trials conducted in Benin and Tanzania confirm IG2's public health value in areas with pyrethroid-resistant Anopheles mosquitoes. As chlorfenapyr might also interfere with the metabolic mechanism of the Plasmodium parasite, we hypothesised that chlorfenapyr may provide additional transmission-reducing effects even if a mosquito survives a sub-lethal dose. METHODS: We tested the effect of chlorfenapyr netting to reduce Plasmodium falciparum transmission using a modified WHO tunnel test with a dose yielding sub-lethal effects. Pyrethroid-resistant Anopheles gambiae s.s. with L1014F and L1014S knockdown resistance alleles and expression levels of pyrethroid metabolisers CYP6P3, CYP6M2, CYP4G16 and CYP6P1 confirmed by quantitative reverse transcription polymerase chain reaction (RT-qPCR) prior to conducting experiments were exposed to untreated netting and netting treated with 200 mg/m3 chlorfenapyr for 8 h overnight and then fed on gametocytemic blood meals from naturally infected individuals. Prevalence and intensity of oocysts and sporozoites were determined on day 8 and day 16 after feeding. RESULTS: Both prevalence and intensity of P. falciparum infection in the surviving mosquitoes were substantially reduced in the chlorfenapyr-exposed mosquitoes compared to untreated nets. The odds ratios in the prevalence of oocysts and sporozoites were 0.33 (95% confidence interval; 95% CI 0.23-0.46) and 0.43 (95% CI 0.25-0.73), respectively, while only the incidence rate ratio for oocysts was 0.30 (95% CI 0.22-0.41). CONCLUSION: We demonstrated that sub-lethal exposure of pyrethroid-resistant mosquitoes to chlorfenapyr substantially reduces the proportion of infected mosquitoes and the intensity of the P. falciparum infection. This will likely also contribute to the reduction of malaria in communities beyond the direct killing of mosquitoes.


Assuntos
Anopheles , Mosquiteiros Tratados com Inseticida , Inseticidas , Malária Falciparum , Malária , Parasitos , Piretrinas , Animais , Humanos , Anopheles/fisiologia , Plasmodium falciparum , Resistência a Inseticidas , Controle de Mosquitos , Mosquitos Vetores/fisiologia , Piretrinas/farmacologia , Inseticidas/farmacologia , Malária Falciparum/prevenção & controle , Malária/prevenção & controle , Probabilidade
7.
Diabetologia ; 66(12): 2320-2331, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37670017

RESUMO

AIMS/HYPOTHESIS: Metformin is increasingly used therapeutically during pregnancy worldwide, particularly in the treatment of gestational diabetes, which affects a substantial proportion of pregnant women globally. However, the impact on placental metabolism remains unclear. In view of the association between metformin use in pregnancy and decreased birthweight, it is essential to understand how metformin modulates the bioenergetic and anabolic functions of the placenta. METHODS: A cohort of 55 placentas delivered by elective Caesarean section at term was collected from consenting participants. Trophoblasts were isolated from the placental samples and treated in vitro with clinically relevant doses of metformin (0.01 mmol/l or 0.1 mmol/l) or vehicle. Respiratory function was assayed using high-resolution respirometry to measure oxygen concentration and calculated [Formula: see text]. Glycolytic rate and glycolytic stress assays were performed using Agilent Seahorse XF assays. Fatty acid uptake and oxidation measurements were conducted using radioisotope-labelled assays. Lipidomic analysis was conducted using LC-MS. Gene expression and protein analysis were performed using RT-PCR and western blotting, respectively. RESULTS: Complex I-supported oxidative phosphorylation was lower in metformin-treated trophoblasts (0.01 mmol/l metformin, 61.7% of control, p<0.05; 0.1 mmol/l metformin, 43.1% of control, p<0.001). The proton efflux rate arising from glycolysis under physiological conditions was increased following metformin treatment, up to 23±5% above control conditions following treatment with 0.1 mmol/l metformin (p<0.01). There was a significant increase in triglyceride concentrations in trophoblasts treated with 0.1 mmol/l metformin (p<0.05), particularly those of esters of long-chain polyunsaturated fatty acids. Fatty acid oxidation was reduced by ~50% in trophoblasts treated with 0.1 mmol/l metformin compared with controls (p<0.001), with no difference in uptake between treatment groups. CONCLUSIONS/INTERPRETATION: In primary trophoblasts derived from term placentas metformin treatment caused a reduction in oxidative phosphorylation through partial inactivation of complex I and potentially by other mechanisms. Metformin-treated trophoblasts accumulate lipids, particularly long- and very-long-chain polyunsaturated fatty acids. Our findings raise clinically important questions about the balance of risk of metformin use during pregnancy, particularly in situations where the benefits are not clear-cut and alternative therapies are available.


Assuntos
Metformina , Placenta , Humanos , Feminino , Gravidez , Metformina/farmacologia , Metformina/uso terapêutico , Metformina/metabolismo , Trofoblastos/metabolismo , Cesárea , Ácidos Graxos/metabolismo , Ácidos Graxos Insaturados/metabolismo
8.
Ann Telecommun ; 78(5-6): 277-295, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37593439

RESUMO

ICT hold significant potential to increase resource and energy efficiencies and contribute to a circular economy. Yet unresolved is whether the aggregated net effect of ICT overall mitigates or aggravates environmental burdens. While the savings potentials have been explored, drivers that prevent these and possible counter measures have not been researched thoroughly. The concept digital sufficiency constitutes a basis to understand how ICT can become part of the essential environmental transformation. Digital sufficiency consists of four dimensions, each suggesting a set of strategies and policy proposals: (a) hardware sufficiency, which aims for fewer devices needing to be produced and their absolute energy demand being kept to the lowest level possible to perform the desired tasks; (b) software sufficiency, which covers ensuring that data traffic and hardware utilization during application are kept as low as possible; (c) user sufficiency, which strives for users applying digital devices frugally and using ICT in a way that promotes sustainable lifestyles; and (d) economic sufficiency, which aspires to digitalization supporting a transition to an economy characterized not by economic growth as the primary goal but by sufficient production and consumption within planetary boundaries. The policies for hardware and software sufficiency are relatively easily conceivable and executable. Policies for user and economic sufficiency are politically more difficult to implement and relate strongly to policies for environmental transformation in general. This article argues for comprehensive policies for digital sufficiency, which are indispensible if ICT are to play a beneficial role in overall environmental transformation.

9.
ACS Sustain Chem Eng ; 11(28): 10430-10440, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37476421

RESUMO

Electrochemical CO2 reduction poses a promising pathway to produce hydrocarbon chemicals and fuels without relying on fossil fuels. Gas diffusion electrodes allow high selectivity for desired carbon products at high current density by ensuring a sufficient CO2 mass transfer rate to the catalyst layer. In addition to CO2 mass transfer, the product selectivity also strongly depends on the local pH at the catalyst surface. In this work, we directly visualize for the first time the two-dimensional (2D) pH profile in the catholyte channel of a gas-fed CO2 electrolyzer equipped with a bipolar membrane. The pH profile is imaged with operando fluorescence lifetime imaging microscopy (FLIM) using a pH-sensitive quinolinium-based dye. We demonstrate that bubble-induced mixing plays an important role in the Faradaic efficiency. Our concentration measurements show that the pH at the catalyst remains lower at -100 mA cm-2 than at -10 mA cm-2, implying that bubble-induced advection outweighs the additional OH- flux at these current densities. We also prove that the pH buffering effect of CO2 from the gas feed and dissolved CO2 in the catholyte prevents the gas diffusion electrode from becoming strongly alkaline. Our findings suggest that gas-fed CO2 electrolyzers with a bipolar membrane and a flowing catholyte are promising designs for scale-up and high-current-density operation because they are able to avoid extreme pH values in the catalyst layer.

10.
Parasit Vectors ; 16(1): 217, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37391770

RESUMO

BACKGROUND: Asymptomatic malaria infections (Plasmodium falciparum) are common in school-aged children and represent a disease transmission reservoir as they are potentially infectious to mosquitoes. To detect and treat such infections, convenient, rapid and reliable diagnostic tools are needed. In this study, malaria rapid diagnostic tests (mRDT), light microscopy (LM) and quantitative polymerase chain reaction (qPCR) were used to evaluate their performance detecting asymptomatic malaria infections that are infectious to mosquitoes. METHODS: One hundred seventy asymptomatic school-aged children (6-14 years old) from the Bagamoyo district in Tanzania were screened for Plasmodium spp. infections using mRDT (SD BIOLINE), LM and qPCR. In addition, gametocytes were detected using reverse transcription quantitative polymerase chain reaction (RT-qPCR) for all qPCR-positive children. Venous blood from all P. falciparum positive children was fed to female Anopheles gambiae sensu stricto mosquitoes via direct membrane feeding assays (DMFAs) after serum replacement. Mosquitoes were dissected for oocyst infections on day 8 post-infection. RESULTS: The P. falciparum prevalence in study participants was 31.7% by qPCR, 18.2% by mRDT and 9.4% by LM. Approximately one-third (31.2%) of asymptomatic malaria infections were infectious to mosquitoes in DMFAs. In total, 297 infected mosquitoes were recorded after dissections, from which 94.9% (282/297) were derived from infections detected by mRDT and 5.1% (15/297) from subpatent mRDT infections. CONCLUSION: The mRDT can be used reliably to detect children carrying gametocyte densities sufficient to infect high numbers of mosquitoes. Subpatent mRDT infections contributed marginally to the pool of oocyts-infected mosquitoes.


Assuntos
Anopheles , Malária Falciparum , Malária , Animais , Humanos , Criança , Feminino , Adolescente , Plasmodium falciparum/genética , Testes de Diagnóstico Rápido , Malária Falciparum/diagnóstico , Infecções Assintomáticas
11.
ACS Sens ; 8(5): 2050-2059, 2023 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-37128994

RESUMO

Spatiotemporal pH imaging using fluorescence lifetime imaging microscopy (FLIM) is an excellent technique for investigating dynamic (electro)chemical processes. However, probes that are responsive at high pH values are not available. Here, we describe the development and application of dedicated pH probes based on the 1-methyl-7-amino-quinolinium fluorophore. The high fluorescence lifetime and quantum yield, the high (photo)stability, and the inherent water solubility make the quinolinium fluorophore well suited for the development of FLIM probes. Due to the flexible fluorophore-spacer-receptor architecture, probe lifetimes are tunable in the pH range between 5.5 and 11. An additional fluorescence lifetime response, at tunable pH values between 11 and 13, is achieved by deprotonation of the aromatic amine at the quinolinium core. Probe lifetimes are hardly affected by temperature and the presence of most inorganic ions, thus making FLIM imaging highly reliable and convenient. At 0.1 mM probe concentrations, imaging at rates of 3 images per second, at a resolution of 4 µm, while measuring pH values up to 12 is achieved. This enables the pH imaging of dynamic electrochemical processes involving chemical reactions and mass transport.


Assuntos
Corantes Fluorescentes , Imagem Óptica , Microscopia de Fluorescência/métodos , Concentração de Íons de Hidrogênio , Água
12.
J Med Chem ; 66(9): 6122-6148, 2023 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-37114951

RESUMO

Avoidance of apoptosis is critical for the development and sustained growth of tumors. The pro-survival protein myeloid cell leukemia 1 (Mcl-1) is an anti-apoptotic member of the Bcl-2 family of proteins which is overexpressed in many cancers. Upregulation of Mcl-1 in human cancers is associated with high tumor grade, poor survival, and resistance to chemotherapy. Therefore, pharmacological inhibition of Mcl-1 is regarded as an attractive approach to treating relapsed or refractory malignancies. Herein, we disclose the design, synthesis, optimization, and early preclinical evaluation of a potent and selective small-molecule inhibitor of Mcl-1. Our exploratory design tactics focused on structural modifications which improve the potency and physicochemical properties of the inhibitor while minimizing the risk of functional cardiotoxicity. Despite being in the "non-Lipinski" beyond-Rule-of-Five property space, the developed compound benefits from exquisite oral bioavailability in vivo and induces potent pharmacodynamic inhibition of Mcl-1 in a mouse xenograft model.


Assuntos
Antineoplásicos , Neoplasias Hematológicas , Humanos , Camundongos , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos/química , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Linhagem Celular Tumoral , Apoptose , Neoplasias Hematológicas/tratamento farmacológico , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo
13.
Patterns (N Y) ; 4(2): 100679, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36873905

RESUMO

Innovations and efficiencies in digital technology have lately been depicted as paramount in the green transition to enable the reduction of greenhouse gas emissions, both in the information and communication technology (ICT) sector and the wider economy. This, however, fails to adequately account for rebound effects that can offset emission savings and, in the worst case, increase emissions. In this perspective, we draw on a transdisciplinary workshop with 19 experts from carbon accounting, digital sustainability research, ethics, sociology, public policy, and sustainable business to expose the challenges of addressing rebound effects in digital innovation processes and associated policy. We utilize a responsible innovation approach to uncover potential ways forward for incorporating rebound effects in these domains, concluding that addressing ICT-related rebound effects ultimately requires a shift from an ICT efficiency-centered perspective to a "systems thinking" model, which aims to understand efficiency as one solution among others that requires constraints on emissions for ICT environmental savings to be realized.

14.
ACS Sustain Chem Eng ; 11(7): 2840-2852, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36844750

RESUMO

The use of gas diffusion electrodes that supply gaseous CO2 directly to the catalyst layer has greatly improved the performance of electrochemical CO2 conversion. However, reports of high current densities and Faradaic efficiencies primarily come from small lab scale electrolysers. Such electrolysers typically have a geometric area of 5 cm2, while an industrial electrolyser would require an area closer to 1 m2. The difference in scales means that many limitations that manifest only for larger electrolysers are not captured in lab scale setups. We develop a 2D computational model of both a lab scale and upscaled CO2 electrolyser to determine performance limitations at larger scales and how they compare to the performance limitations observed at the lab scale. We find that for the same current density larger electrolysers exhibit much greater reaction and local environment inhomogeneity. Increasing catalyst layer pH and widening concentration boundary layers of the KHCO3 buffer in the electrolyte channel lead to higher activation overpotential and increased parasitic loss of reactant CO2 to the electrolyte solution. We show that a variable catalyst loading along the direction of the flow channel may improve the economics of a large scale CO2 electrolyser.

15.
Cells ; 12(3)2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36766814

RESUMO

Chronic wounds represent a major therapeutic challenge. Lymphatic vessel function is impaired in chronic ulcers but the role of lymphangiogenesis in wound healing has remained unclear. We found that lymphatic vessels are largely absent from chronic human wounds as evaluated in patient biopsies. Excisional wound healing studies were conducted using transgenic mice with or without an increased number of cutaneous lymphatic vessels, as well as antibody-mediated inhibition of lymphangiogenesis. We found that a lack of lymphatic vessels mediated a proinflammatory wound microenvironment and delayed wound closure, and that the VEGF-C/VEGFR3 signaling axis is required for wound lymphangiogenesis. Treatment of diabetic mice (db/db mice) with the F8-VEGF-C fusion protein that targets the alternatively spliced extra domain A (EDA) of fibronectin, expressed in remodeling tissue, promoted wound healing, and potently induced wound lymphangiogenesis. The treatment also reduced tissue inflammation and exerted beneficial effects on the wound microenvironment, including myofibroblast density and collagen deposition. These findings indicate that activating the lymphatic vasculature might represent a new therapeutic strategy for treating chronic non-healing wounds.


Assuntos
Diabetes Mellitus Experimental , Linfangiogênese , Camundongos , Humanos , Animais , Diabetes Mellitus Experimental/patologia , Fator C de Crescimento do Endotélio Vascular/metabolismo , Cicatrização/fisiologia , Pele/patologia , Camundongos Transgênicos
16.
J Low Temp Phys ; 209(3-4): 464-472, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36439908

RESUMO

We present Monte Carlo simulations of radiative transfer within the absorbers of X-ray microcalorimeters, utilizing a numerical model for the photon propagation and photon absorption process within the absorber structure. In our model, we include effects of Compton scattering off bound electrons and fluorescence. Scattered or fluorescence photons as well as Auger and photoelectrons escaping the absorber can result in partial energy depositions. By implementing a simplified description of the physical processes compared to existing comprehensive particle transport software frameworks, our model aims to provide representative results at a small computational effort. This approach makes it possible to use our model for quick assessments, parametric studies, and application in other Monte Carlo-based instrument simulators like SIXTE, a software package for X-ray astronomical instrumentation. To study the impact of the energy loss effects on the spectral response of a microcalorimeter, we apply our model to the sensors of the cryogenic X-ray spectrometer X-IFU onboard the future Athena X-ray observatory.

17.
PLoS One ; 17(7): e0269309, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35895618

RESUMO

BACKGROUND: Anemia is present in up to two-thirds of patients undergoing colorectal surgery mainly caused by iron deficiency and inflammation. As anemia is associated with increased risk of perioperative death, diagnosis and treatment of preoperative anemia according to etiology have been recommended. OBJECTIVE: The aim of the present study was to assess if the association between anemia and survival in patients undergoing colorectal surgery was determined by the severity of anemia alone or also by anemia etiology. METHODS: To determine the prevalence of anemia and etiology, preoperative hematological parameters, C-reactive protein, ferritin and transferrin saturation were retrospectively assessed and correlated with outcome in a cohort of patients undergoing colorectal surgery between 2005 and 2019 at the University Hospital of Innsbruck. Anemia was defined as hemoglobin <120 g/L in females and <130 g/L in males. The etiology of anemia was classified on the basis of serum iron parameters, as iron deficiency anemia, anemia of inflammation or other anemia etiologies. RESULTS: Preoperative anemia was present in 54% (1316/2458) of all patients. Anemia was associated with iron deficiency in 45% (134/299) and classified as anemia of inflammation in 32% (97/299) of patients with available serum iron parameters. The etiology of anemia was a strong and independent predictor of survival, where iron deficiency and anemia of inflammation were associated with better postoperative survival than other anemia etiologies. One year survival rates were 84.3%, 77.3% and 69.1% for patients with iron deficiency anemia, anemia of inflammation and other anemia types. Inflammation indicated by high C-reactive protein is a strong negative predictor of overall survival. CONCLUSIONS: Anemia has a high prevalence among patients undergoing colorectal surgery and rational treatment requires early assessment of serum iron parameters and C-reactive protein.


Assuntos
Anemia Ferropriva , Anemia , Cirurgia Colorretal , Deficiências de Ferro , Anemia/complicações , Anemia/epidemiologia , Anemia Ferropriva/complicações , Anemia Ferropriva/epidemiologia , Proteína C-Reativa/metabolismo , Estudos de Coortes , Feminino , Hemoglobinas/metabolismo , Humanos , Inflamação , Ferro , Masculino , Estudos Retrospectivos
18.
J Extracell Vesicles ; 11(5): e12225, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35585651

RESUMO

Extracellular vesicles (EVs) have shown promise as biological delivery vehicles, but therapeutic applications require efficient cargo loading. Here, we developed new methods for CRISPR/Cas9 loading into EVs through reversible heterodimerization of Cas9-fusions with EV sorting partners. Cas9-loaded EVs were collected from engineered Expi293F cells using standard methodology, characterized using nanoparticle tracking analysis, western blotting, and transmission electron microscopy and analysed for CRISPR/Cas9-mediated functional gene editing in a Cre-reporter cellular assay. Light-induced dimerization using Cryptochrome 2 combined with CD9 or a Myristoylation-Palmitoylation-Palmitoylation lipid modification resulted in efficient loading with approximately 25 Cas9 molecules per EV and high functional delivery with 51% gene editing of the Cre reporter cassette in HEK293 and 25% in HepG2 cells, respectively. This approach was also effective for targeting knock-down of the therapeutically relevant PCSK9 gene with 6% indel efficiency in HEK293. Cas9 transfer was detergent-sensitive and associated with the EV fractions after size exclusion chromatography, indicative of EV-mediated transfer. Considering the advantages of EVs over other delivery vectors we envision that this study will prove useful for a range of therapeutic applications, including CRISPR/Cas9 mediated genome editing.


Assuntos
Vesículas Extracelulares , Edição de Genes , Sistemas CRISPR-Cas/genética , Células HEK293 , Humanos , Pró-Proteína Convertase 9/genética
19.
Nat Commun ; 13(1): 3018, 2022 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-35641497

RESUMO

The dysregulated physical interaction between two intracellular membrane proteins, the sarco/endoplasmic reticulum Ca2+ ATPase and its reversible inhibitor phospholamban, induces heart failure by inhibiting calcium cycling. While phospholamban is a bona-fide therapeutic target, approaches to selectively inhibit this protein remain elusive. Here, we report the in vivo application of intracellular acting antibodies (intrabodies), derived from the variable domain of camelid heavy-chain antibodies, to modulate the function of phospholamban. Using a synthetic VHH phage-display library, we identify intrabodies with high affinity and specificity for different conformational states of phospholamban. Rapid phenotypic screening, via modified mRNA transfection of primary cells and tissue, efficiently identifies the intrabody with most desirable features. Adeno-associated virus mediated delivery of this intrabody results in improvement of cardiac performance in a murine heart failure model. Our strategy for generating intrabodies to investigate cardiac disease combined with modified mRNA and adeno-associated virus screening could reveal unique future therapeutic opportunities.


Assuntos
Proteínas de Ligação ao Cálcio , Insuficiência Cardíaca , Animais , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Dependovirus/genética , Dependovirus/metabolismo , Coração , Camundongos , RNA Mensageiro
20.
ACS Sustain Chem Eng ; 10(14): 4683-4693, 2022 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-35433135

RESUMO

Electrochemical CO2 reduction is a promising process to store intermittent renewable energy in the form of chemical bonds and to meet the demand for hydrocarbon chemicals without relying on fossil fuels. Researchers in the field have used gas diffusion electrodes (GDEs) to supply CO2 to the catalyst layer from the gas phase. This approach allows us to bypass mass transfer limitations imposed by the limited solubility and diffusion of CO2 in the liquid phase at a laboratory scale. However, at a larger scale, pressure differences across the porous gas diffusion layer can occur. This can lead to flooding and electrolyte breakthrough, which can decrease performance. The aim of this study is to understand the effects of the GDE structure on flooding behavior and CO2 reduction performance. We approach the problem by preparing GDEs from commercial substrates with a range of structural parameters (carbon fiber structure, thickness, and cracks). We then determined the liquid breakthrough pressure and measured the Faradaic efficiency for CO at an industrially relevant current density. We found that there is a trade-off between flooding resistance and mass transfer capabilities that limits the maximum GDE height of a flow-by electrolyzer. This trade-off depends strongly on the thickness and the structure of the carbon fiber substrate. We propose a design strategy for a hierarchically structured GDE, which might offer a pathway to an industrial scale by avoiding the trade-off between flooding resistance and CO2 reduction performance.

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