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1.
N Biotechnol ; 84: 9-23, 2024 Sep 07.
Article in English | MEDLINE | ID: mdl-39245322

ABSTRACT

Polyhydroxyalkanoates (PHAs) are a well-known group of biodegradable and biocompatible bioplastics that are synthesised and stored by microorganisms as carbon and energy reservoirs. Extracellular PHA depolymerases (ePhaZs), secreted by a limited range of microorganisms, are the main hydrolytic enzymes responsible for their environmental degradation. Pseudomonas sp. GK13, initially identified as P. fluorescens GK13, produces PHA and a prototypic ePhaZ that specifically degrades mcl-PHA. In this study, a comprehensive characterization of strain GK13 was performed. The whole genomic sequence of GK13 was consolidated into one complete chromosome, leading to its reclassification as P. solani GK13. We conducted a detailed in silico examination of the bacteria genomic sequence, specifically targeting PHA metabolic functions. From the different growth conditions explored, PHA accumulation occurred only under carbon/nitrogen (C/N) imbalance, whereas ePhaZ production was induced even at balanced C/N ratios in mineral media. We extend our study to other bacteria belonging to the Pseudomonas genus revealing that the ePhaZ production capacity is closely associated with mcl-PHA synthesis capacity, as also suggested by metagenomic samples. This finding suggests that these types of microorganisms could contribute to the carbon economy of the microbial community, by storing PHA in carbon-rich times, and sharing it with the rest of the population during times of carbon scarcity through PHA hydrolysis. The conclusion pointed that carbon cycle metabolism performed by P. solani GK13 may contribute to the environmental circular economy at a microscopic scale.

2.
ACS EST Air ; 1(9): 1084-1095, 2024 Sep 13.
Article in English | MEDLINE | ID: mdl-39295741

ABSTRACT

In 2018, the ATHLETIC campaign was conducted at the University of Colorado Dal Ward Athletic Center and characterized dynamic indoor air composition in a gym environment. Among other parameters, inorganic particle and gas-phase species were alternatingly measured in the gym's supply duct and weight room. The Indoor Model of Aerosols, Gases, Emissions, and Surfaces (IMAGES) uses the inorganic aerosol thermodynamic equilibrium model, ISORROPIA, to estimate the partitioning of inorganic aerosols and corresponding gases. In this study herein, measurements from the ATHLETIC campaign were used to evaluate IMAGES' performance. Ammonia emission rates, nitric acid deposition, and particle deposition velocities were related to observed occupancy, which informed these rates in IMAGES runs. Initially, modeled indoor inorganic aerosol concentrations were not in good agreement with measurements. A parametric investigation revealed that lowering the temperature or raising the relative humidity used in the ISORROPIA model drove the semivolatile species more toward the particle phase, substantially improving modeled-measured agreement. One speculated reason for these solutions is that aerosol water was enhanced by increasing the RH or decreasing the temperature. Another is that thermodynamic equilibrium was not established in this indoor setting or that the thermodynamic parametrizations in ISORROPIA are less accurate for typical indoor settings. This result suggests that applying ISORROPIA indoors requires further careful experimental validation.

3.
J Therm Biol ; 125: 103969, 2024 Sep 12.
Article in English | MEDLINE | ID: mdl-39299099

ABSTRACT

The gradient between core and skin temperature is a relevant factor in heat exchange between the human body and the environment, but people with spinal cord injury (SCI), due to their autonomic dysfunction, have impaired mechanisms that condition skin temperature response. This study aimed to determine how SCI affects skin temperature response in different ROIs during a graded exercise test in a moderate temperature environment. 32 participants were included in the study [SCI (N = 16); Non-SCI (N = 16)]. A graded exercise test was conducted on an arm crank ergometer, with a staged duration of 3 min separated by 1 min of rest. Skin temperature was measured using infrared thermography at rest, after each interval and during recovery. Individuals with SCI exhibited lower skin temperature in the anterior leg during exercise than Non-SCI (p < 0.001). During recovery, SCI athletes experienced a lower skin temperature restoration in the anterior arm, posterior arm and anterior leg (p < 0.05). The anterior leg is an interesting region to measure during exercise in people with SCI for assessing the physiological effect of the injury, probably for the autonomic dysfunction in skin temperature regulation, but the effect observed during recovery in the arms suggests the presence of different mechanisms involved in skin temperature regulation.

4.
Muscle Nerve ; 2024 Sep 07.
Article in English | MEDLINE | ID: mdl-39243146

ABSTRACT

INTRODUCTION/AIMS: Noninvasive ventilation (NIV) has been shown to improve survival and symptom burden in patients with amyotrophic lateral sclerosis (ALS). However, limited data exist regarding the clinical and physiological parameters at the time of NIV initiation. This study aimed to describe the clinical characteristics and respiratory physiological markers in a cohort of ALS patients with chronic respiratory failure. METHODS: This is a single-center retrospective cohort study of patients with ALS assessed for NIV initiation between February 2012 and January 2021. NIV was initiated based on insurance eligibility criteria: daytime hypercapnia, defined by partial pressure of carbon dioxide (PaCO2) >45 mm Hg using diurnal transcutaneous CO2 (TcCO2) as a surrogate, a maximal inspiratory pressure (MIP) <60 cmH2O or forced vital capacity (FVC) <50% predicted normal. RESULTS: We identified 335 patients with ALS and chronic respiratory failure referred to an outpatient home ventilation clinic for NIV initiation. The mean age was 64 years ±11; 151 (45%) were female, 326 (97%) were white, and 100 (29%) had bulbar-onset ALS. At the time of NIV initiation, the mean FVC was 64% ± 19%, the mean MIP; 41 cmH2O ± 17, and diurnal TcCO2; 40 ± 6 mmHg. The most common reasons for NIV initiation were MIP <60 cmH2O (58%) and multiple concomitant indications (28%). Within 1 year of NIV initiation, 126 (37%) patients were deceased. DISCUSSION: We found that impairment in inspiratory force was the most common reason for NIV initiation and often preceded significant declines in FVC.

6.
Materials (Basel) ; 17(15)2024 Aug 03.
Article in English | MEDLINE | ID: mdl-39124509

ABSTRACT

In this study, the maximum CO2 capture capacity of an ordered mesoporous carbon (CMK-3) was evaluated at high pressure (35 atm) and several temperatures (0, 10, 20, and 35 °C). CMK-3 was synthesized with the hard template method (silica SBA-15) using furfuryl alcohol and toluene as carbon sources. The CO2 adsorption isotherms were fitted to the following adsorption theories: Freundlich, Langmuir, Sips, Toth, Dubinin-Radushkevich, and Temkin. The maximum capture capacity (726.7 mg·g-1) was achieved at 0 °C and 34 atm. The results of the study of successive adsorption-desorption cycles showed that multi-cycle reversible gas capture processes could be used in optimal temperature and pressure conditions. It was determined that 0.478 g of CMK-3 would be required to reduce the CO2 concentration in 1 m3 of air to pre-industrial levels (280 ppm). The obtained results may contribute to technological developments for the mitigation of human impacts on the environment through the capture of atmospheric CO2.

7.
Foods ; 13(16)2024 Aug 22.
Article in English | MEDLINE | ID: mdl-39200567

ABSTRACT

Insects have recently received much attention as sustainable protein sources due to their nutritional value and eco-friendliness. Unlike conventional livestock, insects require minimal resources and produce fewer greenhouse gas emissions. Moreover, insects offer high-quality protein, essential amino acids, and various vitamins and minerals. This study in Spain, specifically in Castilla y León, investigated insect consumption acceptance across age groups, particularly among older individuals, shedding light on factors influencing adoption. The findings inform strategies to address global protein deficiencies and advocate sustainable food practices, with implications for broader European research amidst challenges like water scarcity. Methods: A survey-based research approach collected data on attitudes, preferences, and motivations regarding insect consumption. Statistical analyses were conducted to identify demographic trends and significant associations. Results: Elderly participants expressed reluctance towards insect consumption but showed openness in survival scenarios. Younger individuals exhibited greater willingness to try insects, influenced by factors such as education and previous experiences. Conclusion: Understanding demographic variations in attitudes towards entomophagy is vital for fostering its acceptance. This study demonstrated that older individuals exhibit greater resistance to incorporating insects into their diets compared with younger individuals. Recommended strategies include incorporating insects discreetly into familiar foods and highlighting their nutritional advantages. Collaboration between researchers and stakeholders is essential for harnessing the potential of insects as a sustainable protein source.

8.
Sci Rep ; 14(1): 20021, 2024 08 28.
Article in English | MEDLINE | ID: mdl-39198503

ABSTRACT

The internal iliac artery arises as a terminal extension of the common iliac artery and supplies blood to the pelvic region. This study aims to identify the anatomic variations of the internal iliac artery (IIA) in a Mexican population sample. This is a retrospective cross-sectional observational study. A total of 81 angiographies via the femoral artery approach performed on patients undergoing various medical procedures were included. Variations in the IIA branching patterns were identified by evaluating the angiographic images and grouped according to Adachi's classification into five types (I-V). A total of 139 hemipelvises were analyzed (78 right and 61 left). The frequencies of each type of variation were as follows: Type I (71.2%), Type II (10.79%), Type III (0 cases), Type IV (0.7%), Type V (12.94%), and unclassified (4.31%). The most frequent anatomical variants of the IIA in the western Mexican population sample were Type I, followed by Types V and II. Even though Type V is rare in most populations, it was the second most frequent variant in this study. Understanding the variants of the IIA branching pattern is necessary for performing invasive procedures in the pelvic region with precision and minimizing complications.


Subject(s)
Anatomic Variation , Iliac Artery , Humans , Mexico , Iliac Artery/anatomy & histology , Iliac Artery/diagnostic imaging , Female , Male , Middle Aged , Cross-Sectional Studies , Retrospective Studies , Prevalence , Adult , Aged , Angiography , Aged, 80 and over
9.
J Environ Manage ; 368: 122162, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39128352

ABSTRACT

Husks of rice (RH), coffee (CH), and cholupa (CLH) were used to produce natural adsorbents. The natural adsorbents were used to remove pharmaceuticals such as diclofenac, ciprofloxacin, and acetaminophen in a mixture of distilled water. However, CH stood out for its efficiency in removing ciprofloxacin (74%) due to the higher concentration of acidic groups, as indicated by the Boehm method. In addition, CH removed 86% of ciprofloxacin individually. Therefore, CH was selected and used to remove other fluoroquinolones, such as levofloxacin and Norfloxacin. Although electrostatic interactions favored removals, better removal was observed for ciprofloxacin due to its smaller molecular volume. Then, ciprofloxacin was selected, and the effect of pH, matrix, and adsorbent doses were evaluated. In this way, using a pH of 6.2 in urine with a dose of 1.5 g L-1, it is possible to adsorb CIP concentrations in the range (0.0050-0.42 mmol L-1). Subsequently, the high R2 values and low percentages of APE and Δq indicated better fits for pseudo-second-order kinetics, suggesting a two-stage adsorption. At the same time, the Langmuir isotherm recommends a monolayer adsorption with a Qm of 25.2 mg g-1. In addition, a cost of 0.373 USD/g CIP was estimated for the process, where the material can be reused up to 4 times with a CIP removal in the urine of 51%. Consequently, thermodynamics analysis showed an exothermic and spontaneous process with high disorder. Furthermore, changes in FTIR analysis after adsorption suggest that CH in removing CIP in urine involves electrostatic attractions, hydrogen bonds and π-π interactions. In addition, the life cycle analysis presents, for the 11 categories evaluated, a lower environmental impact of the CIP removal in urine with CH than for the preparation of adsorbent, confirming that the adsorption process is more environmentally friendly than materials synthesis or other alternatives of treatments. Furthermore, future directions of the study based on real applications were proposed.


Subject(s)
Water Pollutants, Chemical , Adsorption , Kinetics , Water Pollutants, Chemical/chemistry , Hydrogen-Ion Concentration , Ciprofloxacin/chemistry , Ciprofloxacin/urine , Pharmaceutical Preparations/chemistry , Pharmaceutical Preparations/analysis , Pharmaceutical Preparations/urine
10.
ACS EST Air ; 1(7): 725-733, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-39021671

ABSTRACT

Since the 1930s, germicidal ultraviolet (GUV) irradiation has been used indoors to prevent the transmission of airborne diseases, such as tuberculosis and measles. Recently, it has received renewed attention due to the COVID-19 pandemic. While GUV radiation has been shown to be effective in inactivating airborne bacteria and viruses, few studies on the impact of GUV on indoor air quality have been published. In this work, we evaluate the effects of GUV222 (GUV at 222 nm) on the chemistry of a common indoor volatile organic compound (VOC), limonene. We found that the production of O3 by the GUV222 lamps caused the formation of particulate matter (PM) and oxygenated volatile organic compounds (VOCs). We also found that the chemistry proceeds through the ozonolysis of limonene as well as the reaction with secondary OH, and that the presence of GUV light led to observable but small perturbations to this chemistry. Understanding the effects of GUV222 on indoor air quality is important in evaluating the safety of these devices.

11.
BMC Psychol ; 12(1): 392, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39010177

ABSTRACT

BACKGROUND: Examination and understanding of neural hyperactivity are some of the greatest scientific challenges faced in the present day. For this reason, the present study aimed to examine this phenomenon in the context of higher education. METHOD: Likewise, this work will enable an instrument to be created to appropriately and reliably estimate neural hyperactivity associated with chronic stress in university students undertaking a Physiotherapy degree. RESULTS: Analysis of content validity was carried out according to agreement and consensus between nineteen experts with Education Science or Psychology degrees, via the Delphi method. On the other hand, face validity was established by administering the questionnaire to a sample of 194 university students aged between 18 and 45 years (M = 30.48%; SD = 13.152). CONCLUSION: The final self-report measure, denominated mental hyperactivity, was composed of 10 items which showed adequate fit with regards to face and content validity (α = 0.775). Confirmatory factor analysis confirmed that the questionnaire was unidimensional.


Subject(s)
Stress, Psychological , Students , Humans , Female , Male , Adult , Young Adult , Adolescent , Stress, Psychological/psychology , Reproducibility of Results , Surveys and Questionnaires/standards , Students/psychology , Students/statistics & numerical data , Middle Aged , Universities , Psychometrics/instrumentation , Self Report , Chronic Disease/psychology
12.
Nutrients ; 16(14)2024 Jul 10.
Article in English | MEDLINE | ID: mdl-39064645

ABSTRACT

Bioelectrical impedance analysis (BIA) is a method used to estimate body composition, and it relies mainly on the body's water content. Insufficient body water can introduce bias to body composition scores. PURPOSE: To determine the effect of body weight loss elicited by passive dehydration on body composition scores, including phase angle (PhA). METHODS: Twenty-five euhydrated apparently healthy and physically active men's (age = 22.6 ± 3.3 yr.; body mass = 76.7 ± 15.9 kg; height = 172.0 ± 6.3 cm) body composition variables and PhA were measured before and after sitting quietly for 5 h in a controlled environment (26.6 ± 1.7 °C, 72 ± 4.9%RH). RESULTS: It was found that five hours of passive dehydration caused a loss in body weight (Δ = 0.76 ± 0.34 kg, p < 0.05) and a decrease in body fat estimation (Δ = 0.90 ± 0.87 kg, p < 0.001). Additionally, an increase in ECW (Δ = 0.12 ± 0.30 L, p < 0.021) and PhA (Δ = 0.10 ± 0.15°, p < 0.005) was observed. CONCLUSION: Body weight loss due to passive dehydration decreased BIA-derived fat mass, and increased extracellular water and PhA in physically active and apparently healthy men. Nonetheless, these changes had a negligible effect on the accuracy of the equipment, rendering them clinically insignificant.


Subject(s)
Body Composition , Body Water , Dehydration , Electric Impedance , Weight Loss , Humans , Male , Dehydration/physiopathology , Adult , Weight Loss/physiology , Young Adult
13.
Sensors (Basel) ; 24(14)2024 Jul 13.
Article in English | MEDLINE | ID: mdl-39065931

ABSTRACT

The aim of the present study was to evaluate skin temperature (Tsk) asymmetries, using infrared thermography, in professional padel players before (PRE), after (POST) and 10 min after training (POST10), and their relationship with perceptual variables and training characteristics. Thermal images were taken of 10 players before, after and 10 min after a standardized technical training. After training, Tsk of the dominant side was higher than before training in the anterior forearm (30.8 ± 0.4 °C vs. 29.1 ± 1.2 °C, p < 0.01; ES = 1.9), anterior shoulder (31.6 ± 0.6 °C vs. 30.9 ± 0.6 °C, p < 0.05; ES = 1.0) posterior arm (29.5 ± 1.0 °C vs. 28.3 ± 1.2 °C, p < 0.05; ES = 1.0), and posterior forearm (30.8 ± 0.9 °C vs. 29.3 ± 1.6 °C, p < 0.05; ES = 1.1). Likewise, these differences were significant POST10 in the anterior arm, anterior forearm, anterior shoulder, posterior arm and posterior forearm. Comparing the different moments of measurement (PRE, POST and POST10), the temperature was higher POST10 in all the regions analyzed except for the shoulder, abdominals, and lower back. Also, correlations were found between fatigue variation and temperature variation between limbs (Tsk dominance), and no correlation was found except between age and posterior thigh (|r| = 0.69; p < 0.05), and between the racket mass and anterior knee (|r| = 0.81; p < 0.01). In conclusion, infrared thermography allows monitoring of skin asymmetries between limbs in professional padel players, but these asymmetries were not related to overall fatigue variation, overall pain variation, years of experience and training hours.


Subject(s)
Skin Temperature , Thermography , Humans , Skin Temperature/physiology , Thermography/methods , Male , Adult , Infrared Rays , Young Adult , Forearm/physiology , Athletes
14.
Eur J Investig Health Psychol Educ ; 14(7): 1881-1889, 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-39056639

ABSTRACT

Violent behaviour in the secondary education stage is a serious concern that comes from low emotional control. Judo is a sport that requires self-control and high emotional competence to mitigate aggressive behaviours. This research presents the objectives of analysing the correlations of different types of aggressive behaviours before an intervention program with those after said program, as well as study the effect of emotions on aggressive behaviours before and after the intervention program through multigroup structural equation modelling. A quasi-experimental study was planned. It used a pre-test-post-test design in a population of 139 secondary school students (M = 15.76; SD = 1.066). The instruments were an ad hoc questionnaire, the Schutte Self-Report Inventory and the Violent Behaviour at School Scale. The data show that the intervention decreased the correlations between different types of violent behaviours. The results show an increase in the effect of emotional intelligence on mitigating aggressive attitudes. The promotion and use of contact sports is necessary to prevent the emergence of aggressive behaviours within a school environment.

15.
Adicciones ; 0(0): 1903, 2024 Jun 27.
Article in English, Spanish | MEDLINE | ID: mdl-39033526

ABSTRACT

Alcohol consumption among Spanish undergraduates during their university time has increased exponentially in recent years. In addition, this lifestyle change is associated with abandoning the Mediterranean diet, increasing the risk of suffering some kind of injury and affecting their quality of life. The study was carried out with a sample of 1,057 Spanish university students, 12.1% (n = 127) of them women and 87.9% (n= 930) men. The SF-36 questionnaire was used to measure health-related quality of life, the MEDAS test to check adherence to the Mediterranean diet, and the AUDIT test to measure alcohol consumption. The results show an inverse relationship between injury and quality of life (ß= -0.020) and adherence to the Mediterranean diet (ß= -0.042) among students who have suffered some kind of injury. On the other hand, there was a positive relationship with alcohol consumption (ß= -0.046). The main conclusion is that lower alcohol consumption and higher adherence to the Mediterranean diet was associated with a better quality of life and a reduced risk of injury in undergraduates in southern Spain.


El consumo de alcohol de la juventud durante el periodo universitario ha aumentado exponencialmente en los últimos años. Además, el cambio de estilo de vida se asocia al abandono de la dieta mediterránea, aumentando el riesgo de sufrir algún tipo de lesión y afectando a su calidad de vida. El estudio se realizó con una muestra de 1057 estudiantes universitarios españoles, el 12,1% (n = 127) de mujeres y el 87,9% (n = 930) de hombres. Se utilizó el cuestionario SF-36 para medir la calidad de vida relacionada con la salud; el test MEDAS para comprobar la adherencia a la dieta mediterránea; y el test AUDIT para medir el consumo de alcohol. Los resultados muestran una relación inversa entre la lesión y la calidad de vida (ß= -0,020) y la adherencia a la dieta mediterránea (ß= -0,042) entre los estudiantes que han sufrido algún tipo de lesión. Por otro lado, se observa una relación positiva con el consumo de alcohol (ß= -0,046). La principal conclusión es que un menor consumo de alcohol y una mayor adherencia a la dieta mediterránea se asociaron con una mejor calidad de vida y un menor riesgo de lesiones en los estudiantes universitarios del sur de España.

16.
Obes Surg ; 34(8): 2766-2777, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39023675

ABSTRACT

INTRODUCTION: Intragastric balloon (IGB) is a minimally invasive and reversible option for obesity treatment. There is a worldwide growing number of different IGB models. The efficacy and safety profile for each model must be demonstrated. We aim to evaluate IGB safety profile according to the experience of the Spanish Bariatric Endoscopy Group (GETTEMO). METHODS: A survey of 37 IGBs safety-related questions was sent to all GETTEMO members, to retrospectively collect a multicenter Spanish registry. Incidence, causes, and resolution of both major and minor complications and adverse events (AEs), including legal consequences, differentiated for each balloon model were evaluated. Secondary outcome was weight loss data to confirm efficacy. RESULTS: Twenty-one Spanish hospitals experienced in IGBs responded. The overall data encompassed 20,680 IGBs, including 12 different models. Mean %TBWL of 17.66 ± 2.5% was observed. Early removal rate due to intolerance was 3.62%. Mean major complications rate was 0.70% (> 1% in Spatz2, HB, and Spatz3 models), mainly complicated gastric ulcer. Minor AEs rate was 6.37%, mainly esophagitis. Nine cases (0.04%) required surgery. A single case of mortality (0.0048%) occurred. Seven lawsuits (0.0034%) were received, all with favorable resolution. CONCLUSIONS: In the Spanish experience accumulating 20,680 IGBs and including 12 different balloon models, a low incidence rate of major complications and minor AEs are observed (0.70% and 6.37%, respectively), mostly resolved with medical/endoscopic management. IGB shows good tolerance and efficacy profile. These safety data are within the accepted quality standards.


Subject(s)
Gastric Balloon , Obesity, Morbid , Weight Loss , Humans , Spain/epidemiology , Retrospective Studies , Female , Obesity, Morbid/surgery , Male , Adult , Middle Aged , Treatment Outcome , Postoperative Complications/epidemiology , Registries
17.
ACS Phys Chem Au ; 4(4): 363-374, 2024 Jul 24.
Article in English | MEDLINE | ID: mdl-39069979

ABSTRACT

This work reports on various properties and analysis of optical interactions in phosphate glasses containing red-emitting Mn2+ and near-infrared (NIR)-emitting Nd3+ ions, which are of interest for energy applications and solar spectral converters. The glasses were made by melting with 50P2O5-(48 - x)BaO-2MnO-xNd2O3 (x = 0, 0.5, 1.0, and 2.0 mol %) nominal compositions and characterized by X-ray diffraction, density and related physical properties, differential scanning calorimetry, dilatometry, UV-vis-NIR optical absorption, and photoluminescence spectroscopy with decay kinetics analysis. The glasses were X-ray amorphous, wherein the physical and thermal properties of the Mn2+/Nd3+-codoped glasses were largely impacted by Nd2O3 contents. The optical absorption spectra supported the occurrence of Mn2+ ions and the lack of Mn3+ in the codoped glasses, while the absorption due to Nd3+ ions increased steadily with Nd2O3 contents. Analyzing the glass absorption edges via Tauc and Urbach plots was further pursued for a comparison. The photoluminescence evaluation showed a consistent suppression of the emission from Mn2+ ions with increasing Nd3+ concentration, while the decay kinetics revealed shorter lifetimes in connection with increased Mn2+ → Nd3+ transfer efficiencies. Excitation of Mn2+ at 410 nm, however, led to the Nd3+ NIR emission being most intense for 1.0 mol % Nd2O3, despite the 4F3/2 emission decay analysis showing lifetime shortening throughout. Considering the compromise between red and NIR emissions, the Mn-containing glass doped with 0.5 mol % Nd2O3 is put in perspective with the concept of solar spectral conversion.

18.
Sci Rep ; 14(1): 15168, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38956121

ABSTRACT

The lithium cycling in the supra-subduction mantle wedge is crucial for understanding the generation of Li-rich magmas that may potentially source ore deposition in continental arcs. Here, we look from the mantle source perspective at the geological processes controlling the Li mobility in convergent margins, by characterizing a set of sub-arc mantle xenoliths from the southern Andes (Coyhaique, western Patagonia). The mineral trace element signatures and oxygen fugacity estimates (FMQ > + 3) in some of these peridotite xenoliths record the interaction with arc magmas enriched in fluid-mobile elements originally scavenged by slab dehydration. This subduction-related metasomatism was poorly effective on enhancing the Li inventory of the sub-arc lithospheric mantle, underpinning the inefficiency of slab-derived fluids on mobilizing Li through the mantle wedge. However, major and trace element compositions of mantle minerals in other xenoliths also record transient thermal and chemical anomalies associated with the percolation of slab window-related magmas, which exhibit an "adakite"-type geochemical fingerprint inherited by slab-derived melts produced during ridge subduction and slab window opening event. As these melts percolated through the shallow (7.2-16.8 kbar) and hot (952-1054 °C) lithospheric mantle wedge, they promoted the crystallization of metasomatic clinopyroxene having exceptionally high Li abundances (6-15 ppm). Numerical modeling shows that low degrees (< 10%) of partial melting of this Li-rich and fertile sub-arc lithospheric mantle generates primitive melts having two-fold Li enrichment (~13 ppm) compared with average subduction-zone basalts. Prolonged fractional crystallization of these melts produces extremely Li-enriched silicic rocks, which may stoke the Li inventory of mineralizing fluids in the shallow crust.

19.
ACS Org Inorg Au ; 4(3): 338-349, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38855337

ABSTRACT

Near-infrared (NIR)-emitting phosphate glasses containing Nd3+ ions are attractive for applications in laser materials and solar spectral converters. The composition-structure-property relation in this type of glass system is thus of interest from fundamental and applied perspectives. In this work, Nd3+-containing glasses were made by melting with 50P2O5-(50 - x)BaO-xNd2O3 (x = 0, 0.5, 1.0, 2.0, 3.0, 4.0 mol %) nominal compositions and studied comprehensively by density and related physical properties, X-ray diffraction (XRD), Raman spectroscopy, O 1s X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), dilatometry, ultraviolet-visible (UV-vis)-NIR optical absorption, and photoluminescence (PL) spectroscopy with decay dynamics assessment. The densities and molar volumes of the Nd3+-containing glasses generally increased with Nd2O3 concentration also resulting in shorter Nd3+-Nd3+ distances. XRD supported the amorphous nature of the glasses, whereas the Raman spectra evolution was indicative of glass depolymerization being induced by Nd3+ ions. Oxygen (1s) and phosphorus (2p) analysis by XPS for the glass with 4.0 mol % Nd2O3 agreed with the increase in nonbridging oxygens relative to the undoped host. DSC results showed that the glass transition temperatures increased with Nd3+ concentration, with the glasses also displaying a decreased tendency toward crystallization. Dilatometry showed trends of increasing softening temperatures and decreasing thermal expansion coefficients with increasing Nd2O3 content. A glass strengthening/tightening effect was then indicated to be induced by Nd3+ with higher field strength compared to Ba2+ ions. The UV-vis-NIR absorption by Nd3+ ions increased consistently with Nd3+ concentration. The UV-vis absorption edges of the Nd-containing glasses were also analyzed via Tauc and Urbach plots for comparison with the undoped host. Concerning the PL behavior, the Nd3+ NIR emission intensity was highest for 1.0 mol % Nd2O3 and decreased thereafter. The decay kinetics of the 4F3/2 emitting state in Nd3+ ions analyzed revealed decreasing lifetimes where the decay rate analysis pointed to the prevalence of ion-ion excitation migration leading to PL quenching at high Nd3+ concentrations.

20.
Materials (Basel) ; 17(11)2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38893933

ABSTRACT

The CO2 adsorption of a phenylene-bridged ordered mesoporous organosilica (PMO-benzene) was analyzed. The maximum capture capacity was 638.2 mg·g-1 (0 °C and 34 atm). Approximately 0.43 g would be enough to reduce the amount of atmospheric CO2 in 1 m3 to pre-industrial levels. The CO2 adsorption data were analyzed using several isotherm models, including Langmuir, Freundlich, Sips, Toth, Dubinin-Radushkevich, and Temkin models. This study confirmed the capability of this material for use in reversible CO2 capture with a minimal loss of capacity (around 1%) after 10 capture cycles. Various techniques were employed to characterize this material. The findings from this study can help mitigate the greenhouse effect caused by CO2.

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