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1.
Small ; : e2406012, 2024 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-39394916

RESUMO

The application of thermodynamically more favorable sulfur oxidation reaction (SOR) to replace oxygen evolution reaction (OER) in electrocatalytic water electrolysis is an appealing strategy to achieve low-energy hydrogen production while removing toxic sulfur ions from wastewater. However, the study of SOR catalysts with both activity and stability still faces great challenges. Herein, this study prepares partially amorphous Ru-doped CoSe (pa-Ru-CoSe) nanoparticles for SOR. The doping of Ru keeps Co in an electron-deficient state, which enhances the adsorption of SOR intermediates and improves the catalytic activity. Meanwhile, the partially amorphous selenide possesses great corrosion resistance to sulfur species, thus ensuring stability in long-term SOR. In addition, the pa-Ru-CoSe requires only 0.566 V to reach a current density of 100 mA cm-2 in the SOR-HER coupled system and remains stable for 200 h. This work provides a promising partially amorphous strategy for SOR catalysts with both catalytic activity and long-term stability, enabling hydrogen production with low energy consumption and simultaneous sulfur production.

2.
Small ; 20(30): e2311217, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38396321

RESUMO

Amidst the escalating quest for clean energy, the hydrogen evolution reaction (HER) in acidic conditions has taken center stage, catalyzing the search for advanced electrocatalysts. The efficacy of these materials is predominantly dictated by the active site density on their surfaces. The propensity is leveraged for monolayer architectures to introduce defects, enhancing surface area, and increasing active sites. Doping enhances defects and fine-tunes catalyst activity. In this vein, defect-enriched monolayer nanosheets doped with nickel and a trace amount of ruthenium in VS2 (SL-Ni-Ru-VS2) are engineered and characterized. Evaluation in 0.5 m H2SO4 solution unveils that the catalyst achieves overpotentials as low as 20 and 41 mV at current densities of -10 and -100 mA cm⁻2. Impressively, the catalyst maintains a mass activity of 13.08 A mg⁻¹Ru, even with minimal Ru incorporation, indicating exceptional catalytic efficiency. This monolayer catalyst sustains its high activity at lower overpotentials, demonstrating its practical applicability. The comprehensive analysis, which combines experimental data and computational simulations, indicates that the co-doping of Ni and Ru enhances the electrocatalytic properties of VS2. This research offers a strategic framework for crafting cutting-edge electrocatalysts specifically designed for enhanced performance in the HER.

3.
Angew Chem Int Ed Engl ; 63(15): e202400582, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38308672

RESUMO

Large-scale deployment of proton exchange membranes water electrolysis (PEM-WE) requires a substantial reduction in usage of platinum group metals (PGMs) as indispensable electrocatalyst for cathodic hydrogen evolution reaction (HER). Ultra-fine PGMs nanocatalysts possess abundant catalytic sites at lower loading, but usually exhibit reduced stability in long-term operations under corrosive acidic environments. Here we report grafting the ultra-fine PtRu crystalline nanoalloys with PtxRuySez "amorphous skin" (c-PtRu@a-PtxRuySez) by in situ atomic layer selenation to simultaneously improve catalytic activity and stability. We found that the c-PtRu@a-PtxRuySez-1 with ~0.6 nm thickness amorphous skin achieved an ultra-high mass activity of 26.7 A mg-1 Pt+Ru at -0.07 V as well as a state-of-the-art durability maintained for at least 1000 h at -10 mA cm-2 and 550 h at -100 mA⋅cm-2 for acid HER. Experimental and theoretical investigations suggested that the amorphous skin not only improved the electrochemical accessibility of the catalyst surface and increasing the intrinsic activity of the catalytic sites, but also mitigated the dissolution/diffusion of the active species, thus resulting in improved catalytic activity and stability under acidic electrolyte. This work demonstrates a direction of designing ultra-fine PGMs electrocatalysts both with high utilization and robust durability, offers an in situ "amorphous skin" engineering strategy.

4.
Environ Sci Technol ; 57(5): 2186-2196, 2023 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-36693338

RESUMO

Taking the world's largest green tide caused by the macroalga Ulva prolifera in the South Yellow Sea as a natural case, it is studied here if macroalgae can perform inorganic carbon sequestration in the ocean. Massive macroalgae released large amounts of organic carbon, most of which were transformed by microorganisms into dissolved inorganic carbon (DIC). Nearshore field investigations showed that, along with seawater deoxygenation and acidification, both DIC and total alkalinity (TAlk) increased significantly (both >50%) in the areas covered by dense U. prolifera at the late-bloom stage. Offshore mapping cruises revealed that DIC and TAlk were relatively higher at the late-bloom stage than at the before-bloom stage. Laboratory cultivation of U. prolifera at the late-bloom stage further manifested a significant enhancement effect on DIC and TAlk in seawater. Sulfate reduction and/or denitrification likely dominated the production of TAlk. Notably, half of the generated DIC and almost all the TAlk could persist in seawater under varying conditions, from hypoxia to normoxia and from air-water CO2 disequilibrium to re-equilibrium. The enhancement of TAlk allowed more DIC to remain in the seawater rather than escape into the atmosphere, thus having the long-term legacy effect of increasing DIC pool in the ocean.


Assuntos
Eutrofização , Ulva , Água do Mar , Carbono , Oceanos e Mares , China
5.
Nature ; 542(7640): 232-236, 2017 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-28146472

RESUMO

Both humans and animals seek primary rewards in the environment, even when such rewards do not correspond to current physiological needs. An example of this is a dissociation between food-seeking behaviour and metabolic needs, a notoriously difficult-to-treat symptom of eating disorders. Feeding relies on distinct cell groups in the hypothalamus, the activity of which also changes in anticipation of feeding onset. The hypothalamus receives strong descending inputs from the lateral septum, which is connected, in turn, with cortical networks, but cognitive regulation of feeding-related behaviours is not yet understood. Cortical cognitive processing involves gamma oscillations, which support memory, attention, cognitive flexibility and sensory responses. These functions contribute crucially to feeding behaviour by unknown neural mechanisms. Here we show that coordinated gamma (30-90 Hz) oscillations in the lateral hypothalamus and upstream brain regions organize food-seeking behaviour in mice. Gamma-rhythmic input to the lateral hypothalamus from somatostatin-positive lateral septum cells evokes food approach without affecting food intake. Inhibitory inputs from the lateral septum enable separate signalling by lateral hypothalamus neurons according to their feeding-related activity, making them fire at distinct phases of the gamma oscillation. Upstream, medial prefrontal cortical projections provide gamma-rhythmic inputs to the lateral septum; these inputs are causally associated with improved performance in a food-rewarded learning task. Overall, our work identifies a top-down pathway that uses gamma synchronization to guide the activity of subcortical networks and to regulate feeding behaviour by dynamic reorganization of functional cell groups in the hypothalamus.


Assuntos
Comportamento Alimentar/fisiologia , Ritmo Gama/fisiologia , Hipotálamo/fisiologia , Animais , Ingestão de Alimentos/fisiologia , Ingestão de Alimentos/psicologia , Metabolismo Energético/fisiologia , Comportamento Alimentar/psicologia , Hipotálamo/citologia , Aprendizagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/fisiologia , Recompensa , Somatostatina/metabolismo
6.
Int J Hyperthermia ; 36(1): 1122-1128, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31739695

RESUMO

Purpose: This study assessed the efficacy and safety of computed tomography (CT)-guided percutaneous thermal ablation for hepatocellular carcinoma adjacent to the second porta hepatis.Methods: From January 2011 to June 2018, 59 consecutive patients (51 men and 8 women aged 29-85 years) with 65 tumors (mean maximum tumor diameter: 20.5 ± 1.2 mm; range: 5-50 cm) adjacent to the second porta hepatis underwent percutaneous CT-guided thermal ablation. The complete ablation rate, local progression-free survival (LPFS), progression-free survival (PFS), prognostic factors for local progression, and safety of this technique were assessed.Results: No more than three sessions were performed to complete a patient's treatment. Technical success was achieved for all tumors. In the median follow-up of 18.5 months, local tumor progression occurred in 32.2% (19/59) of patients, while tumor progression occurred in 71.2% (42/59). The median LPFS was 37.4 months. The 1-, 2-, and 3-year LPFS rates were 86.2%, 66.5%, and 66.5%, respectively. The median PFS was 11.0 months. The 1-, 2-, and 3-year PFS rates were 47.9%, 27.0%, and 20.2%, respectively. The tumor size (P = .007) and distance between the tumor and inferior vena cava (P = 0.018) were the independent prognostic factors for local tumor progression.Conclusion: We showed that CT-guided percutaneous microwave ablation and radiofrequency ablation are effective and safe treatments for tumors adjacent to the second porta hepatis, particularly in patients with lesions less than 3 cm and a distance between the tumor and inferior vena cava of more than 5 mm.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/cirurgia , Ablação por Cateter/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/cirurgia , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/patologia , Feminino , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade
7.
Front Neurosci ; 18: 1366761, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39165340

RESUMO

Background: Research has shown disrupted structural network measures related to cognitive decline and future cortical atrophy during the progression of Alzheimer's disease (AD). However, evidence regarding the individual variability of gray matter network measures and the associations with concurrent cognitive decline and cortical atrophy related to AD is still sparse. Objective: To investigate whether alterations in single-subject gray matter networks are related to concurrent cognitive decline and cortical gray matter atrophy during AD progression. Methods: We analyzed structural MRI data from 185 cognitively normal (CN), 150 mild cognitive impairment (MCI), and 153 AD participants, and calculated the global network metrics of gray matter networks for each participant. We examined the alterations of single-subject gray matter networks in patients with MCI and AD, and investigated the associations of network metrics with concurrent cognitive decline and cortical gray matter atrophy. Results: The small-world properties including gamma, lambda, and sigma had lower values in the MCI and AD groups than the CN group. AD patients had reduced degree, clustering coefficient, and path length than the CN and MCI groups. We observed significant associations of cognitive ability with degree in the CN group, with gamma and sigma in the MCI group, and with degree, connectivity density, clustering coefficient, and path length in the AD group. There were significant correlation patterns between sigma values and cortical gray matter volume in the CN, MCI, and AD groups. Conclusion: These findings suggest the individual variability of gray matter network metrics may be valuable to track concurrent cognitive decline and cortical atrophy during AD progression. This may contribute to a better understanding of cognitive decline and brain morphological alterations related to AD.

8.
Front Cardiovasc Med ; 11: 1412104, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39185135

RESUMO

Out-of-hospital cardiac arrest (OHCA) mostly occurs in crowded public places outside hospitals, such as public sports facilities, airports, railway stations, subway stations, and shopping malls. The emergency department of Liaocheng People's Hospital in Shandong Province admitted one patient with OHCA in August 2021, who suddenly suffered a loss of consciousness and cardiac arrest during exercise after dinner. Witnesses immediately gave continuous chest compressions and artificial respiration and called our hospital's emergency department (at 120). Arriving at the emergency department, we continued to provide chest compressions and ventilator-assisted ventilation after performing endotracheal intubation. We administered adrenaline for cardiac excitation, dopamine for maintained blood pressure, sodium bicarbonate to correct the acidosis, and multiple electric defibrillations. However, the patient's cardiac Doppler ultrasound indicated poor cardiac contractions, and extracorporeal membrane oxygenation (ECMO) was started immediately. We performed coronary angiography for the patient with ECMO support, indicating that the patient had an 80% critical stenosis of the left main coronary artery and an 80%-90% stenosis in the middle section of the left anterior descending artery with an aneurysm. Fortunately, there was no obvious stenosis in the right coronary artery. The patient was transferred to the intensive care unit and received comprehensive treatment, including anticoagulation, myocardial nutritional support, improvement of cardiac function, continuous renal replacement therapy, organ function protection, anti-inflammatory treatment, and rehabilitation. Coronary artery bypass grafting was performed after the patient's condition stabilized, and he was finally discharged. ECMO support therapy for patients with cardiac arrest can be considered when economic conditions permit. It is very important to conduct the necessary examinations in the early stage of resuscitation with ECMO support to clarify the cause of the cardiac arrest and to treat it accordingly.

9.
Mar Environ Res ; 201: 106708, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39208767

RESUMO

Ocean alkalinity enhancement is considered as an effective atmospheric CO2 removal approach, but currently, little is known about the carbon sequestration potential of implementing olivine addition in offshore waters. We investigated the effect of olivine addition on the seawater carbonate system by carrying out a deck incubation experiment in the Northern Yellow Sea; the dissolution rate of olivine was calculated based on the increase in seawater alkalinity (TA), and the CO2 sequestration potential was evaluated. The results showed that the dissolution of olivine increased seawater TA and decreased partial pressure of CO2, resulting in oceanic CO2 uptake from the atmosphere through sea-air exchange; it also increased seawater pH and mitigated ocean acidification to a certain extent. The addition of 1 ‰ olivine had a more significant effect on the seawater carbonate system than 0.5 ‰ olivine addition. The average dissolution rate constant of olivine was 1.44 ± 0.15 µmol m-2 d-1. Assuming that olivine settles completely on the seabed due to gravity, the theoretically maximum amount of CO2 removed by applying 1 tonne of olivine per square meter area in the Northern Yellow Sea is only 2.0 × 10-4 t/m2. Therefore, when olivine addition is implemented in the offshore waters, it is necessary to consider reducing the olivine size, prolonging the settling time of olivine in the water column; and spreading olivine in well-mixed waters to prolong the residence time through repeated resuspension, thus increasing its potential in carbon sequestration.


Assuntos
Dióxido de Carbono , Sequestro de Carbono , Compostos de Ferro , Compostos de Magnésio , Água do Mar , Silicatos , Dióxido de Carbono/análise , Água do Mar/química , Silicatos/química , Compostos de Magnésio/química , Compostos de Ferro/química , Navios , Concentração de Íons de Hidrogênio , Carbonatos/química
10.
Crit Rev Anal Chem ; : 1-23, 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39264749

RESUMO

Hypochlorous acid (HClO) is widely used in everyday life for bleaching and disinfecting tap water, and also in human metabolism, where it plays an important role in destroying foreign bacterial invaders and pathogens as well as immune defense and cellular functioning maintenance. Abnormal levels of hypochlorous acid have the potential to cause joint inflammation, neuronal degeneration, and even life-threatening cancer. Specific identification and effective detection of hypochlorous acid are important for monitoring human health and the environment. In recent years, organic fluorescent probes have attracted much attention because of their simple synthesis, easy operation, high sensitivity, and high specificity, and a variety of hypochlorous acid fluorescent probes based on low-cost, easy-to-operate, and rapid identification have been developed. In this paper, we review the fluorescent probes that have been developed in the past five years for the specific recognition of hypochlorous acid based on different fluorophores, such as triphenylamine, coumarin, 1,8-naphthalize, etc., as well as recognition units, such as N-N dimethyl thiosemicarbazone, and describe how the probes and hypochlorous acid interact for identification in the same manner as other fluorescent probes. In addition, the reaction mechanism between the probe and hypochlorous acid, the fluorescence change of the probe, and the detection limit are described to illustrate the progress in the detection of hypochlorous acid in recent years and to provide ideas for the development of hypochlorous acid fluorescent probes in the future.

11.
Mar Pollut Bull ; 201: 116252, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38479328

RESUMO

Ocean acidification (OA) is a global environmental concern, and submarine groundwater discharge (SGD) is a potentially process that enhances OA. This review summarizes the relationship between two types of constituents carried by SGD into China's seawater and OA. 1) Current research predominantly concentrates on constituent fluxes from SGD, neglecting its ecological impacts on carbon and nutrients budgets, as well as the mechanisms between carbon and nutrients. 2) Uncertainties persist in SGD research methods and acidification characterization. 3) There's a need to enhance quantitative research methods of SGD-OA, particularly in areas with intricate biogeochemical processes. Effective identification methods are crucial to quantify SGD's contribution to OA. Investigating core scientific questions, including SGD's impact on OA rates and scales, is paramount. While the primary focus is on SGD-OA research in China, insights gained from novel perspectives could have broader value for coastal management globally.


Assuntos
Água Subterrânea , Água do Mar , Concentração de Íons de Hidrogênio , Acidificação dos Oceanos , Monitoramento Ambiental , Água Subterrânea/química , China , Carbono
12.
Artigo em Inglês | MEDLINE | ID: mdl-39150803

RESUMO

The reconstruction of indoor scenes from multi-view RGB images is challenging due to the coexistence of flat and texture-less regions alongside delicate and fine-grained regions. Recent methods leverage neural radiance fields aided by predicted surface normal priors to recover the scene geometry. These methods excel in producing complete and smooth results for floor and wall areas. However, they struggle to capture complex surfaces with high-frequency structures due to the inadequate neural representation and the inaccurately predicted normal priors. This work aims to reconstruct high-fidelity surfaces with fine-grained details by addressing the above limitations. To improve the capacity of the implicit representation, we propose a hybrid architecture to represent low-frequency and high-frequency regions separately. To enhance the normal priors, we introduce a simple yet effective image sharpening and denoising technique, coupled with a network that estimates the pixel-wise uncertainty of the predicted surface normal vectors. Identifying such uncertainty can prevent our model from being misled by unreliable surface normal supervisions that hinder the accurate reconstruction of intricate geometries. Experiments on the benchmark datasets show that our method outperforms existing methods in terms of reconstruction quality. Furthermore, the proposed method also generalizes well to real-world indoor scenarios captured by our hand-held mobile phones. Our code is publicly available at: https://github.com/yec22/Fine-Grained-Indoor-Recon.

13.
Science ; 385(6709): 647-651, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39116246

RESUMO

Flexible integration spurs diverse applications in metal-organic frameworks (MOFs). However, current configurations suffer from the trade-off between MOF loadings and mechanical compliance. We report a wrinkled configuration of MOF thin films. We established an interfacial synthesis confined and controlled by a polymer topcoat and achieved multiple Turing motifs in the wrinkled thin films. These films have complete MOF surface coverage and exhibit strain tolerance up to 53.2%. The enhanced mechanical properties allow film transfer onto various substrates. We obtained membranes with large H2/CO2 selectivity (41.2) and high H2 permeance (8.46 × 103 gas permeation units), showcasing negligible defects after transfer. We also achieved soft humidity sensors on delicate electrodes by avoiding exposure to harsh MOF synthesis conditions. These results highlight the potential of wrinkled MOF thin films for plug-and-play integration.

14.
Mar Pollut Bull ; 189: 114826, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36931156

RESUMO

Ocean acidification has emerged as a major challenge affecting the development of the marine aquaculture. Seasonal variations of seawater pH and aragonite saturation (Ωarag) were investigated in the Muping Marine Ranch, Yantai. The results showed that the seasonal variations of pH and Ωarag were distinct. The temperature exerted opposite effects on pH and Ωarag and played a dominant role in pH variation, while limited role in Ωarag. The air-sea exchange had a syntropic effect on pH and Ωarag but less impact on their seasonal variations. Biological activities affected seasonal variations of surface seawater pH and Ωarag, but they largely canceled each other out with other non-temperature effects; while bottom seawater Ωarag was mainly controlled by biological respiration in summer. This study demonstrates that pH is primarily controlled by seasonal temperature changes, whereas Ωarag would be a better indicator for ocean acidification caused by non-temperature processes.


Assuntos
Carbonato de Cálcio , Água do Mar , Concentração de Íons de Hidrogênio , Estações do Ano , Carbonato de Cálcio/análise , China , Dióxido de Carbono/análise
15.
Front Aging Neurosci ; 15: 1287122, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38149170

RESUMO

Background: It has been well documented that atrophy of hippocampus and hippocampal subfields is closely linked to cognitive decline in normal aging and patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, evidence is still sparce regarding the atrophy of hippocampus and hippocampal subfields in normal aging adults who later developed MCI or AD. Objective: To examine whether atrophy of hippocampus and hippocampal subfields has occurred in normal aging before a diagnosis of MCI or AD. Methods: We analyzed structural magnetic resonance imaging (MRI) data of cognitively normal (CN, n = 144), MCI (n = 90), and AD (n = 145) participants obtained from the Alzheimer's Disease Neuroimaging Initiative. The CN participants were categorized into early dementia converters (CN-C) and non-converters (CN-NC) based on their scores of clinical dementia rating after an average of 36.2 months (range: 6-105 months). We extracted the whole hippocampus and hippocampal subfields for each participant using FreeSurfer, and analyzed the differences in volumes of hippocampus and hippocampal subfields between groups. We then examined the associations between volume of hippocampal subfields and delayed recall scores in each group separately. Results: Hippocampus and most of the hippocampal subfields demonstrated significant atrophy during the progression of AD. The CN-C and CN-NC groups differed in the left hippocampus-amygdala transition area (HATA). Furthermore, the volume of presubiculum was significantly correlated with delayed recall scores in the CN-NC and AD groups, but not in the CN-C and MCI groups. Conclusion: Hippocampal subfield atrophy (i.e., left HATA) had occurred in cognitively normal elderly individuals before clinical symptoms were recognized. Significant associations of presubiculum with delayed recall scores in the CN-NC and AD groups highlight the essential role of the hippocampal subfields in both early dementia detection and AD progression.

16.
Mater Today Bio ; 22: 100735, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37576868

RESUMO

Astrocytes are multifunctional glial cells that are essential for brain functioning. Most existing methods to induce astrocytes from stem cells are inefficient, requiring couples of weeks. Here, we designed an alginate hydrogel-based method to realize high-efficiency astrocytic differentiation from human neural stem cells. Comparing to the conventional tissue culture materials, the hydrogel drastically promoted astrocytic differentiation within three days. We investigated the regulatory mechanism underlying the enhanced differentiation, and found that the stretch-activated ion channels and Yes-associated protein (YAP), a mechanosensitive transcription coactivator, were both indispensable. In particular, the Piezo1 Ca2+ channel, but not transient receptor potential vanilloid 4 (TRPV4) channel, was necessary for promoting the astrocytic differentiation. The stretch-activated channels regulated the nuclear localization of YAP, and inhibition of the channels down-regulated the expression of YAP as well as its target genes. When blocking the YAP/TEAD-mediated transcription, astrocytic differentiation on the hydrogel significantly declined. Interestingly, cells on the hydrogel showed a remarkable filamentous actin assembly together with YAP nuclear translocation during the differentiation, while a progressive gel rupture at the cell-hydrogel interface along with a change in the gel elasticity was detected. These findings suggest that spontaneous decrosslinking of the hydrogel alters its mechanical properties, delivering mechanical stimuli to the cells. These mechanical signals activate the Piezo1 Ca2+ channel, facilitate YAP nuclear transcription via actomyosin cytoskeleton, and eventually provoke the astrocytic differentiation. While offering an efficient approach to obtain astrocytes, our work provides novel insights into the mechanism of astrocytic development through mechanical regulation.

17.
Mar Environ Res ; 192: 106196, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37751645

RESUMO

Temperature plays an important role in affecting the physiological traits of marine plankton. In this study, we conducted an outdoor incubation experiment to investigate the effects of elevated temperature on Chl a, photosynthetic carbon fixation and the composition of plankton communities in the surface seawater around Pingtan Island, the northwest Taiwan Strait in Autumn 2022. After 3-4 days of incubation, elevated temperature (1-4 °C higher than ambient temperature) led to a decrease in Chl a concentration across all three stations, did not result in significant increases in the particulate organic carbon (POC) and nitrogen (PON) concentrations in seawater with high nitrate concentrations, whereas increased POC and PON concentrations in nitrate-limited seawater. These findings suggest that the effect of temperature on the POC and PON contents of plankton is affected by the availability of nitrate. Diatoms were the dominant phytoplankton group in all three stations. Our results indicate that ocean warming has a potential to increase the POC contents of marine plankton per volume of seawater, which may increase the ability of phytoplankton to absorb atmospheric CO2 and to alleviate global warming.


Assuntos
Nitratos , Plâncton , Fitoplâncton/fisiologia , Água do Mar , Fotossíntese , China , Oceanos e Mares , Carbono
18.
Microorganisms ; 11(1)2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36677400

RESUMO

Climate change has led to frequent cold surges in mid-latitudes, resulting in sudden temperature drops and icing of nearshore seawater, which may be affecting the eukaryotic microalgal community. In this paper, we investigated the differences between a eukaryotic microalgal community in sea ice and in seawater during the seawater freezing, due to the cold surge in Aoshan Bay, Qingdao, China, in January 2021. The results showed that the eukaryotic microalgal community in the sea ice and in the seawater was similar in composition at the phylum and genus levels, but that its relative abundances differed. In the seawater, the eukaryotic microalgal genera were dominated by Chaetoceros, while its relative abundance was significantly lower in the sea ice, probably because the cold-surge-induced seawater icing existed only for a short period of time, and Chaetoceros had not yet adapted to the rapid environmental changes in the sea ice. The relative abundance of Bathycoccus in the sea ice was higher, and showed a significant positive correlation with nitrite and silicate, while the relative abundance of Micromonas in the sea ice was also significantly higher than in the seawater, which may be related to the elevated CO2 concentration in the sea ice. This study demonstrates that although the seawater icing due to the cold surge was short, it may have affected the seawater eukaryotic microalgal community, to a certain extent.

19.
World J Gastrointest Oncol ; 14(9): 1727-1738, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36187402

RESUMO

BACKGROUND: In microwave ablation (MWA), although computed tomography (CT) scanning can overcome gas interference, it cannot achieve real-time localization. Therefore, the puncture technique is more important in CT-guided ablation. AIM: To compare the fine needle-assisted puncture (FNP) positioning technique and the conventional puncture (CP) technique for the safety and efficacy of CT-guided MWA in treating hepatocellular carcinoma (HCC). METHODS: This retrospective study included 124 patients with 166 tumor nodules from February 2018 and June 2021. Seventy patients received CT-guided MWA under the FNP technique (FNP group), and 54 patients received MWA under the CP technique (CP group). Intergroup comparisons were made regarding local tumor progression (LTP), recurrence-free survival (RFS), overall survival (OS), and complications. The influencing variables of LTP and RFS were analyzed through univariate and multivariate regressions. RESULTS: The 1-, 2-, and 3-year cumulative incidences of LTP in the FNP group were significantly lower than those in the CP group (7.4%, 12.7%, 21.3% vs 13.7%, 32.9%, 36.4%; P = 0.038). The 1-, 2-, and 3-year RFS rates in the FNP group were significantly higher than those in the CP group (80.6%, 73.3%, 64.0% vs 83.3%, 39.4%, and 32.5%, respectively; P = 0.008). The FNP technique independently predicted LTP and RFS. Minor complications in the FNP group were lower than those in the CP group (P < 0.001). The difference in median OS was insignificant between the FNP and CP groups (P = 0.229). CONCLUSION: The FNP technique used in CT-guided MWA may improve outcomes in terms of LTP, RFS, and procedure-related complications for HCC.

20.
Front Microbiol ; 12: 805361, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35222305

RESUMO

Spreading olivine powder in seawater to enhance alkalinity through weathering reactions has been proposed as a potential solution to control atmospheric CO2 concentration. Attention has usually been paid to the chemical properties of seawater after the addition of olivine within lab and modeling studies. However, both microbial acclimation and evolution in such manipulated natural environments are often overlooked, yet they are of great importance for understanding the biological consequences of whether olivine addition is a feasible approach to mitigating climate change. In this study, an olivine addition experiment was conducted to investigate variation in bacterial diversity and community composition in the surface and bottom seawater of a representative marine ranch area in the Muping, Yantai. The results show that the composition of the particle-attached microbial community was particularly affected by the application of olivine. The relative abundance of biofilm-forming microbes in particle-attached fraction increased after the addition of olivine, while no significant variation in the free-living bacterial community was observed. Our study suggests that olivine addition would reshape the bacterial community structure, especially in particle-attached microenvironments. Therefore, the risk evaluation of alkalinity enhancement should be further studied before its large-scale application as a potential ocean geoengineering plan.

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