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1.
Front Microbiol ; 15: 1173637, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38741739

RESUMEN

Biological soil crusts, or biocrusts, are microbial communities found in soil surfaces in drylands and in other locations where vascular plant cover is incomplete. They are functionally significant for numerous ecosystem services, most notably in the C fixation and storage due to the ubiquity of photosynthetic microbes. Whereas carbon fixation and storage have been well studied in biocrusts, the composition, function and characteristics of other organisms in the biocrust such as heterotrophic bacteria and especially fungi are considerably less studied and this limits our ability to gain a holistic understanding of biocrust ecology and function. In this research we characterised the fungal community in biocrusts developed on Kalahari Sand soils from a site in southwest Botswana, and combined these data with previously published bacterial community data from the same site. By identifying organisational patterns in the community structure of fungi and bacteria, we found fungi that were either significantly associated with biocrust or the soil beneath biocrusts, leading to the conclusion that they likely perform functions related to the spatial organisation observed. Furthermore, we showed that within biocrusts bacterial and fungal community structures are correlated with each other i.e., a change in the bacterial community is reflected by a corresponding change in the fungal community. Importantly, this correlation but that this correlation does not occur in nearby soils. We propose that different fungi engage in short-range and long-range interactions with dryland soil surface bacteria. We have identified fungi which are candidates for further studies into their potential roles in biocrust ecology at short ranges (e.g., processing of complex compounds for waste management and resource provisioning) and longer ranges (e.g., translocation of resources such as water and the fungal loop model). This research shows that fungi are likely to have a greater contribution to biocrust function and dryland ecology than has generally been recognised.

3.
Int J Mol Sci ; 25(8)2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38673938

RESUMEN

Despite data showing that nutritional interventions high in antioxidant/anti-inflammatory properties (anthocyanin-rich foods, such as blueberries/elderberries) may decrease risk of memory loss and cognitive decline, evidence for such effects in mild cognitive impairment (MCI) is limited. This study examined preliminary effects of American elderberry (Sambucus nigra subsp. canadensis) juice on cognition and inflammatory markers in patients with MCI. In a randomized, double-blind, placebo-controlled trial, patients with MCI (n = 24, Mage = 76.33 ± 6.95) received American elderberry (n = 11) or placebo (n = 13) juice (5 mL orally 3 times a day) for 6 months. At baseline, 3 months, and 6 months, patients completed tasks measuring global cognition, verbal memory, language, visuospatial cognitive flexibility/problem solving, and memory. A subsample (n = 12, 7 elderberry/5 placebo) provided blood samples to measure serum inflammatory markers. Multilevel models examined effects of the condition (elderberry/placebo), time (baseline/3 months/6 months), and condition by time interactions on cognition/inflammation outcomes. Attrition rates for elderberry (18%) and placebo (15%) conditions were fairly low. The dosage compliance (elderberry-97%; placebo-97%) and completion of cognitive (elderberry-88%; placebo-87%) and blood-based (elderberry-100%; placebo-100%) assessments was high. Elderberry (not placebo) trended (p = 0.09) towards faster visuospatial problem solving performance from baseline to 6 months. For the elderberry condition, there were significant or significantly trending decreases over time across several markers of low-grade peripheral inflammation, including vasorin, prenylcysteine oxidase 1, and complement Factor D. Only one inflammatory marker showed an increase over time (alpha-2-macroglobin). In contrast, for the placebo, several inflammatory marker levels increased across time (L-lactate dehydrogenase B chain, complement Factor D), with one showing deceased levels over time (L-lactate dehydrogenase A chain). Daily elderberry juice consumption in patients with MCI is feasible and well tolerated and may provide some benefit to visuospatial cognitive flexibility. Preliminary findings suggest elderberry juice may reduce low-grade inflammation compared to a placebo-control. These promising findings support the need for larger, more definitive prospective studies with longer follow-ups to better understand mechanisms of action and the clinical utility of elderberries for potentially mitigating cognitive decline.


Asunto(s)
Cognición , Disfunción Cognitiva , Jugos de Frutas y Vegetales , Inflamación , Sambucus , Humanos , Masculino , Anciano , Femenino , Cognición/efectos de los fármacos , Inflamación/sangre , Método Doble Ciego , Sambucus/química , Anciano de 80 o más Años , Biomarcadores/sangre , Estudios de Factibilidad , Sambucus nigra/química
4.
PLoS One ; 19(4): e0301176, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38652707

RESUMEN

AIM: This study aims to explore regional variation and identify regions within Australia with high incidence of out-of-hospital cardiac arrest (OHCA) and low rates of bystander cardiopulmonary resuscitation (CPR). METHOD: Adult OHCAs of presumed medical aetiology occurring across Australia between 2017 and 2019 were mapped onto local government areas (LGA) using the location of arrest coordinates. Bayesian spatial models were applied to provide "smoothed" estimates of OHCA incidence and bystander CPR rates (for bystander-witnessed OHCAs) for each LGA. For each state and territory, high-risk LGAs were defined as those with an incidence rate greater than the state or territory's 75th percentile and a bystander CPR rate less than the state or territory's 25th percentile. RESULTS: A total of 62,579 OHCA cases attended by emergency medical services across 543 LGAs nationwide were included in the study. Nationally, the OHCA incidence rate across LGA ranged from 58.5 to 198.3 persons per 100,000, while bystander CPR rates ranged from 45% to 75%. We identified 60 high-risk LGAs, which were predominantly located in the state of New South Wales. Within each region, high-risk LGAs were typically located in regional and remote areas of the country, except for four metropolitan areas-two in Adelaide and two in Perth. CONCLUSIONS: We have identified high-risk LGAs, characterised by high incidence and low bystander CPR rates, which are predominantly in regional and remote areas of Australia. Strategies for reducing OHCA and improving bystander response may be best targeted at these regions.


Asunto(s)
Reanimación Cardiopulmonar , Servicios Médicos de Urgencia , Paro Cardíaco Extrahospitalario , Paro Cardíaco Extrahospitalario/epidemiología , Paro Cardíaco Extrahospitalario/terapia , Humanos , Estudios Retrospectivos , Incidencia , Australia/epidemiología , Masculino , Servicios Médicos de Urgencia/estadística & datos numéricos , Femenino , Anciano , Persona de Mediana Edad , Adulto
5.
Syst Rev ; 13(1): 114, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38671531

RESUMEN

BACKGROUND: Chronic postsurgical pain (CPSP) is common following musculoskeletal and orthopedic surgeries and is associated with impairment and reduced quality of life. Several interventions have been proposed to reduce CPSP; however, there remains uncertainty regarding which, if any, are most effective. We will perform a systematic review and network meta-analysis of randomised trials to assess the comparative benefits and harms of perioperative pharmacological and psychological interventions directed at preventing chronic pain after musculoskeletal and orthopedic surgeries. METHODS: We will search MEDLINE, Embase, PsycINFO, CINAHL, and the Cochrane Central Register of Controlled Trials from inception to present, without language restrictions. We will include randomised controlled trials that as follows: (1) enrolled adult patients undergoing musculoskeletal or orthopedic surgeries; (2) randomized them to any pharmacological or psychological interventions, or their combination directed at reducing CPSP, placebo, or usual care; and (3) assessed pain at 3 months or more after surgery. Screening for eligible trials, data extraction, and risk-of-bias assessment using revised Cochrane risk-of-bias tool (RoB 2.0) will be performed in duplicate and independently. Our main outcome of interest will be the proportion of surgical patients reporting any pain at ≥ 3 months after surgery. We will also collect data on other patient important outcomes, including pain severity, physical functioning, emotional functioning, dropout rate due to treatment-related adverse event, and overall dropout rate. We will perform a frequentist random-effects network meta-analysis to determine the relative treatment effects. When possible, the modifying effect of sex, surgery type and duration, anesthesia type, and veteran status on the effectiveness of interventions will be investigated using network meta-regression. We will use the GRADE approach to assess the certainty evidence and categorize interventions from most to least beneficial using GRADE minimally contextualised approach. DISCUSSION: This network meta-analysis will assess the comparative effectiveness of pharmacological and psychological interventions directed at preventing CPSP after orthopedic surgery. Our findings will inform clinical decision-making and identify promising interventions for future research. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42023432503.


Asunto(s)
Dolor Crónico , Metaanálisis en Red , Procedimientos Ortopédicos , Dolor Postoperatorio , Ensayos Clínicos Controlados Aleatorios como Asunto , Humanos , Procedimientos Ortopédicos/efectos adversos , Dolor Crónico/prevención & control , Dolor Postoperatorio/prevención & control , Atención Perioperativa/métodos , Calidad de Vida
6.
J Eat Disord ; 12(1): 23, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38326869

RESUMEN

This research explores experiences of compassion among 2S/LGBTQ + Canadians living with eating disorders in the context of eating disorder treatment and community support. There is a growing body of scholarship showing disparities in eating disorder care for those within 2S/LGBTQ + communities. Among the reported concerns is a potential lack of compassion in eating disorder treatment and recovery settings, something which may serve to exacerbate feelings of isolation and perpetuate misunderstandings of 2S/LGBTQ + people's experiences. In an effort to understand these dynamics more deeply, we conducted semi-structured interviews with 2S/LGBTQ + Canadians who have experienced eating disorder care. The data collected were then subjected to Foucauldian discourse analysis, which produced three interconnected discursive considerations: feeling lack of structural compassion, 2S/LGBTQ + communities as places of respite, and 2S/LGBTQ + caregiving. One of the common threads among these discursive considerations was cis-heteronormativity ingrained in eating disorder treatment settings and health care systems more broadly. Our findings underscore the critical need for more enhanced compassion for 2S/LGBTQ + patients in eating disorder care settings. We conclude that compassion, when implemented on the levels of individual clinicians, policy and procedure, and institutions, may represent an avenue toward disrupting ingrained cis-heteronormativity and the associated discursive power structures contained in health care systems.


Two-Spirit, lesbian, gay, bisexual, transgender, queer and other sexually or gender diverse (2S/LGBTQ+) are at increased risk for eating disorders often related to minority stress, discrimination, and heteronormative gender expectations. Compassion is believed to be a fundamental aspect of healthcare that builds human connections and enhances positive outcomes. Healthcare, however, is steeped in heteronormative assumptions that may further isolate many 2S/LGBTQ+ patients. This study explored how 2S/LGBTQ+ Canadians living with eating disorders felt about their care and the role of compassion in their recovery journeys. We found that these individuals often felt misunderstood and isolated during treatment. However, they often experienced understanding by connecting with other 2S/LGBTQ+ people both in care and in the community, which provided the compassionate spaces lacking in their healthcare experiences. These findings highlight a need for making healthcare more compassionate for 2S/LGBTQ+ people. This can be done by changing policies, mandatory training for healthcare professionals, and treatment that recognizes and discusses minority stresses, uses trauma-informed practices, and gender-affirming approaches. By doing such items, standard norms can be challenged and the care for 2S/LGBTQ+ people living with eating disorders can be improved.

7.
Nat Med ; 30(3): 785-796, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38365950

RESUMEN

Multiple clinical trials targeting the gut microbiome are being conducted to optimize treatment outcomes for immune checkpoint blockade (ICB). To improve the success of these interventions, understanding gut microbiome changes during ICB is urgently needed. Here through longitudinal microbiome profiling of 175 patients treated with ICB for advanced melanoma, we show that several microbial species-level genome bins (SGBs) and pathways exhibit distinct patterns from baseline in patients achieving progression-free survival (PFS) of 12 months or longer (PFS ≥12) versus patients with PFS shorter than 12 months (PFS <12). Out of 99 SGBs that could discriminate between these two groups, 20 were differentially abundant only at baseline, while 42 were differentially abundant only after treatment initiation. We identify five and four SGBs that had consistently higher abundances in patients with PFS ≥12 and <12 months, respectively. Constructing a log ratio of these SGBs, we find an association with overall survival. Finally, we find different microbial dynamics in different clinical contexts including the type of ICB regimen, development of immune-related adverse events and concomitant medication use. Insights into the longitudinal dynamics of the gut microbiome in association with host factors and treatment regimens will be critical for guiding rational microbiome-targeted therapies aimed at enhancing ICB efficacy.


Asunto(s)
Microbioma Gastrointestinal , Melanoma , Microbiota , Humanos , Microbioma Gastrointestinal/genética , Melanoma/tratamiento farmacológico , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Cognición
8.
Int J Psychol ; 59(3): 495-504, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38168745

RESUMEN

Past research suggests that reactions to research on sex differences are often less positive when the findings put men in a better light than women, especially when the lead researcher is a man. The factors underlying this effect, however, are not yet fully understood. The present study aimed to provide the first experimental test of the hypothesis that the key variable is perceived harm to women. Participants (214 men and 219 women) evaluated a bogus popular-science article reporting fictional research finding either a female- or a male-favouring sex difference in intelligence, attributed to either a female or a male lead researcher. To examine the effects of perceived harm, the introduction to the task highlighted either the potential benefits or potential drawbacks of sex-differences research in general. Consistent with past research, participants reacted less positively to the male-favouring difference, especially for male-led research. Consistent with the harm hypothesis, the effect was stronger after highlighting the potential drawbacks of sex-differences research than after highlighting the potential benefits. Our findings suggest that perceptions of harm to women underpin the aversion to male-favouring findings.


Asunto(s)
Caracteres Sexuales , Humanos , Femenino , Masculino , Adulto , Adulto Joven , Percepción Social , Adolescente , Persona de Mediana Edad , Sexismo/psicología , Investigación
9.
Eur J Public Health ; 2024 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-38276894

RESUMEN

BACKGROUND: Following years of sustained pressure on the UK health service, there is recognition amongst health professionals and stakeholders that current models of healthcare are likely to be inadequate going forward. Therefore, a fundamental review of existing social models of healthcare is needed to ascertain current thinking in this area, and whether there is a need to change perspective on current thinking. METHOD: Through a systematic research review, this paper seeks to address how previous literature has conceptualized a social model of healthcare and, how implementation of the models has been evaluated. Analysis and data were extracted from 222 publications and explored the country of origin, methodological approach, and the health and social care contexts which they were set. RESULTS: The publications predominantly drawn from the USA, UK, Australia, Canada and Europe identified five themes namely: the lack of a clear and unified definition of a social model of health and wellbeing; the need to understand context; the need for cultural change; improved integration and collaboration towards a holistic and person-centred approach; measuring and evaluating the performance of a social model of health. CONCLUSION: The review identified a need for a clear definition of a social model of health and wellbeing. Furthermore, consideration is needed on how a model integrates with current models and whether it will act as a descriptive framework or, will be developed into an operational model. The review highlights the importance of engagement with users and partner organizations in the co-creation of a model of healthcare.

10.
J Chem Theory Comput ; 20(4): 1559-1567, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-37956245

RESUMEN

Thermodynamic stability assessment of nanocrystal systems requires precise free energy calculations. This study highlights the importance of meticulous control over various factors, including the thermostat, time step, potential cutoff, initial configuration, sampling method, and overall simulation duration. Free energy computations in dry (solvent-free) systems are on the order of several hundred kBT but can be obtained with consistent accuracy. However, calculation of internal energies becomes challenging, as they are typically much larger in magnitude than free energies and exhibit significant noise and reduced reliability. To address this limitation, we propose a new internal energy estimate that drastically reduces the noise. We also present formulas that enable the optimization of the parameters of the harmonic bias potential for optimal convergence. Finally, we discuss the implications of these findings for the computation of free energies in nanocrystal clusters and superlattices.

11.
Cryobiology ; 114: 104833, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38072181

RESUMEN

Ozark chinquapin (Castanea ozarkensis Ashe) is a forest tree, endemic to the Ozark Mountain region in Eastern United States. Its nutritious nuts were consumed by Native Americans, European settlers, livestock, and wild animals and its wood was an important rot-resistant construction material. Once a significant tree in regional forest communities, the species was nearly eradicated by a chestnut blight caused by Cryphonectria parasitca (Murill) Barr fungus. Some individuals have survived as sprouts from adventitious root buds, but they rarely reach reproductive maturity. While some in situ restoration efforts are underway, the development of a viable ex situ germplasm preservation method is critical to the conservation of this important food-bearing species. Our experiment aimed to develop a cryopreservation method for C. ozarkensis dormant winter buds subjected to eight experimental treatments before desiccation, slow cooling, and storage in liquid nitrogen vapor. The highest post cryogenic viability was 91.2 % for dormant buds pretreated with 0.3 M sucrose for 16 h followed by 0.75 M sucrose for 3 h; this treatment is suggested for cryopreservation of dormant winter buds of Ozark chinquapin germplasm.


Asunto(s)
Frío , Criopreservación , Humanos , Criopreservación/métodos , Brotes de la Planta , Transición de Fase , Árboles , Sacarosa
12.
Arch Sex Behav ; 53(2): 611-627, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38030825

RESUMEN

Polygamy is a form of "one-sided" consensually non-monogamous relationship where one person has multiple committed partners, each of whom is only involved with that one person. It was likely a reoccurring feature of ancestral mating that posed adaptive problems for our ancestors. Yet polygamy, and multi-partnering more generally, is understudied in Western cultures, raising questions about the existence of polygamous interest and whether this is calibrated adaptively to personal conditions. In two studies, we examined polygamous interest in two heterosexual online samples from the UK. In Study 1 (N = 393), modest interest was found for polygamous relationships overall. Men were six times more open to polygyny than women, but there was little sex difference in openness to polyandry. Further analysis revealed that all forms of multi-partnering were undesirable relative to singlehood and monogamy; however, consensual multi-partner relationships were less undesirable than non-consensual ones. Sex differences were largest for polygyny and arrangements where men had agreed access to a casual partner alongside a committed one, yet these were two of the most acceptable forms of multi-partnering when men and women's responses were combined. Sociosexuality positively predicted interest in most forms of multi-partnering. Study 2 (N = 735) focused on polygyny and added status-linked traits as predictors. The results of Study 1 were broadly replicated, though the status-linked traits did not predict polygynous interest specifically. Instead, sociosexuality and male intrasexual competitiveness uniquely predicted general interest in multi-partner relationships. Overall, interest in polygamy appears to emerge despite social discouragement and sex differences in interest track the relative costs and benefits associated with it. However, there is no strong evidence that polygamous interest is uniquely calibrated to personal conditions when compared to other forms of multi-partnering.


Asunto(s)
Heterosexualidad , Matrimonio , Femenino , Humanos , Masculino , Estado Civil , Caracteres Sexuales , Reino Unido
13.
Nat Rev Microbiol ; 22(4): 191-205, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37968359

RESUMEN

Machine learning is increasingly important in microbiology where it is used for tasks such as predicting antibiotic resistance and associating human microbiome features with complex host diseases. The applications in microbiology are quickly expanding and the machine learning tools frequently used in basic and clinical research range from classification and regression to clustering and dimensionality reduction. In this Review, we examine the main machine learning concepts, tasks and applications that are relevant for experimental and clinical microbiologists. We provide the minimal toolbox for a microbiologist to be able to understand, interpret and use machine learning in their experimental and translational activities.


Asunto(s)
Aprendizaje Automático , Microbiota , Humanos
14.
New Phytol ; 241(1): 154-165, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37804058

RESUMEN

Potassium (K+ ) is the most abundant inorganic cation in plant cells, playing a critical role in various plant functions. However, the impacts of K on natural terrestrial ecosystems have been less studied compared with nitrogen (N) and phosphorus (P). Here, we present a global meta-analysis aimed at quantifying the response of aboveground production to K addition. This analysis is based on 144 field K fertilization experiments. We also investigate the influences of climate, soil properties, ecosystem types, and fertilizer regimes on the responses of aboveground production. We find that: K addition significantly increases aboveground production by 12.3% (95% CI: 7.4-17.5%), suggesting a widespread occurrence of K limitation across terrestrial ecosystems; K limitation is more prominent in regions with humid climates, acidic soils, or weathered soils; the effect size of K addition varies among climate zones/regions, and is influenced by multiple factors; and previous N : K and K : P thresholds utilized to detect K limitation in wetlands cannot be applied to other biomes. Our findings emphasize the role of K in limiting terrestrial productivity, which should be integrated into future terrestrial ecosystems models.


Asunto(s)
Ecosistema , Potasio , Nitrógeno , Clima , Suelo , Fósforo
16.
Sci Rep ; 13(1): 18658, 2023 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-37907572

RESUMEN

Management and design affect systems' ability to deliver ecosystem services and meet sustainable intensification needs for a growing population. Soil-plant-animal health evaluations at the systems level for conventional and silvopastoral environments are lacking and challenge adoption across temperate regions. Impacts of silvopasture on soil quality, microclimate, cattle heat stress, forage quality and yield, and cattle weight gain were compared to a conventional pasture in the mid-southern US. Here, we illustrate silvopastures have greater soil organic carbon, water content, and overall quality, with lower temperatures (soil and cattle) than conventional pastures. Forage production and cattle weight gains were similar across systems; yet, conventional pasture systems would need approximately four times more land area to yield equivalent net productivity (tree, nuts, forage, and animal weight) of one ha of silvopasture. Temperate silvopastures enhanced delivery of ecosystem services by improving soil quality and promoting animal welfare without productivity losses, thus allowing sustainable production under a changing climate.


Asunto(s)
Ecosistema , Suelo , Animales , Bovinos , Carbono , Clima , Plantas
17.
Cell Host Microbe ; 31(11): 1804-1819.e9, 2023 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-37883976

RESUMEN

The Segatella copri (formerly Prevotella copri) complex (ScC) comprises taxa that are key members of the human gut microbiome. It was previously described to contain four distinct phylogenetic clades. Combining targeted isolation with large-scale metagenomic analysis, we defined 13 distinct Segatella copri-related species, expanding the ScC complex beyond four clades. Complete genome reconstruction of thirteen strains from seven species unveiled the presence of genetically diverse large circular extrachromosomal elements. These elements are consistently present in most ScC species, contributing to intra- and inter-species diversities. The nine species-level clades present in humans display striking differences in prevalence and intra-species genetic makeup across human populations. Based on a meta-analysis, we found reproducible associations between members of ScC and the male sex and positive correlations with lower visceral fat and favorable markers of cardiometabolic health. Our work uncovers genomic diversity within ScC, facilitating a better characterization of the human microbiome.


Asunto(s)
Microbioma Gastrointestinal , Microbiota , Humanos , Masculino , Microbioma Gastrointestinal/genética , Metagenoma , Filogenia , Prevotella , Femenino
18.
Sci Rep ; 13(1): 17925, 2023 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-37864005

RESUMEN

Online X-ray Fluorescence (XRF) setup was constructed and optimized for analysing the P2O5 content in phosphate slurry (PS). Serval samples were analysed using two configurations of the setup, one with low and vertical flow and another with high and horizontal flow. The mean absolute error achieved through the first configuration was 0.87% and 0.38% using the second configuration. Reference samples were analyzed using the two configurations to construct the calibration curves. The curves cover a concentration range of P2O5 from 13.50 to 18.50% when considering the horizontal flow configuration, and a range of 14.00-15.60% when considering the vertical flow setup. An experimental study was conducted in order to optimize the measurement parameters for the online measurement of P2O5 in the phosphate slurry using the horizontal flow setup. A good signal-to-noise ratio (SNR) of [Formula: see text] was attained using an excitation energy of 20 kV or 25 kV, an excitation current of 600 µA, a distance of 18 mm between the sample and the detector, a measurement time of 60 s per spectrum and the use of an Aluminum filter between the X-ray tube and the measurement window. Online X-ray fluorescence analysis of P entails some challenges due to the low characteristic energy of P, the phosphate slurry matrix and the online analysis mode. However, the outcomes of this study indicate that XRF is a promising technology to meet the requirement for digitalization of chemical analysis of phosphate products.

19.
Artículo en Inglés | MEDLINE | ID: mdl-37890070

RESUMEN

Development of nonprecious metal-based single-atom catalysts (SACs) has provided opportunities to substitute Pt group metals and offer maximum atom utilization and unique coordination environments. Among these catalysts, Fe-N-C catalysts with atomically dispersed Fe-N4 active sites have emerged as some of the most promising oxygen reduction reaction (ORR) catalysts. However, furnace synthesis of Fe-N-C catalysts with carbon substrate derived from metal-organic framework (MOF) involves a high-temperature procedure, in which nitrogen from the carbonized MOF tends to be removed, subsequently leading to a low density of active sites. In this work, we developed a rapid and simple solid-state route to fabricate SACs through laser-induced thermal activation (LITA) of carbonized zeolitic imidazolate framework-8 (ZIF-8) adsorbed with Fe precursors. The results demonstrate that the laser process effectively avoids the loss of nitrogen in the nitrogen-doped carbon substrate and achieves a loading of Fe single atoms of 2.3 wt %, in comparison with that of 1.2 wt % from the conventional furnace treatment. The Fe-N-C catalyst synthesized in the study presents a half-wave potential of 0.91 V for ORR in alkaline media, which is higher than that of commercial Pt/C (0.87 V). When used as a cathode catalyst in zinc-air batteries (ZABs), the battery exhibits excellent electrochemical performance. This work also demonstrates the versatility of the technique through the successful synthesis of Co-N-C and Ni-N-C single atoms on nitrogen-doped carbon substrates.

20.
Rep Prog Phys ; 86(12)2023 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-37863075

RESUMEN

It is well established that a wide variety of phenomena in cellular and molecular biology involve anomalous transport e.g. the statistics for the motility of cells and molecules are fractional and do not conform to the archetypes of simple diffusion or ballistic transport. Recent research demonstrates that anomalous transport is in many cases heterogeneous in both time and space. Thus single anomalous exponents and single generalised diffusion coefficients are unable to satisfactorily describe many crucial phenomena in cellular and molecular biology. We consider advances in the field ofheterogeneous anomalous transport(HAT) highlighting: experimental techniques (single molecule methods, microscopy, image analysis, fluorescence correlation spectroscopy, inelastic neutron scattering, and nuclear magnetic resonance), theoretical tools for data analysis (robust statistical methods such as first passage probabilities, survival analysis, different varieties of mean square displacements, etc), analytic theory and generative theoretical models based on simulations. Special emphasis is made on high throughput analysis techniques based on machine learning and neural networks. Furthermore, we consider anomalous transport in the context of microrheology and the heterogeneous viscoelasticity of complex fluids. HAT in the wavefronts of reaction-diffusion systems is also considered since it plays an important role in morphogenesis and signalling. In addition, we present specific examples from cellular biology including embryonic cells, leucocytes, cancer cells, bacterial cells, bacterial biofilms, and eukaryotic microorganisms. Case studies from molecular biology include DNA, membranes, endosomal transport, endoplasmic reticula, mucins, globular proteins, and amyloids.


Asunto(s)
Modelos Teóricos , Biología Molecular , Difusión , Transporte Biológico , Procesamiento de Imagen Asistido por Computador
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