Microplastics are ubiquitous in various ocean areas and have aroused global concern. This study investigated the abundance and characteristics of microplastic pollution in the Nordic Seas. In the sea ...area affected by the East Greenland Current, the abundance of microplastics was 1.19 ± 0.28 items/L, with fiber (76.1%), transparent (76.2%), and small microplastics (0.1–0.5 mm, 48.1%) being the most abundant types present. The abundance of microplastics in the cold basin affected by the Greenland Sea Gyre was 2.43 ± 0.84 items/L. Fiber accounted for 87.2% of the total microplastics, and the proportions of transparent and 0.1–0.5 mm particles were 87.6% and 63.9%, respectively. Principal component analysis (PCA) based on size spectrum data revealed that the spatial pattern of microplastics was closely related to ocean currents and the station position in the ocean current. Furthermore, scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS) analysis illustrated that the microplastics had many weathering and exfoliation sites and adsorbed heavy metals onto their surfaces. The Fourier Transform Infrared Spectrometer (FTIR) analysis showed that the microplastics in the Nordic Seas were mainly polyester and polyethylene. These results not only provide the latest data on microplastic pollution in the Nordic Seas, but also give evidence that ocean currents affect the transport of marine microplastics.
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•Microplastic pollution in the Nordic Seas was compared based on ocean currents.•Abundance of microplastics in the East Greenland Current was 1.19 ± 0.28 items/L.•Abundance of microplastics in the Greenland Sea Gyre (GSG) was 2.43 ± 0.84 items/L.•Microplastics in group GSG showed higher homogeneity of size, shape, and color.•Greenland Sea Gyre increases microplastic pollution in the seawater of this sea area.
The trade effect, in this article, mainly refers to the trade impacts of member countries and non-member states. This article first summarises the empirical analysis methods of trade effects of ...regional economic integration and then combines the methods widely used in the current research, proposes research methods suitable for Trans-Pacific Partnership (TPP) trade effect analysis, establishes models and conducts empirical analysis and then analyses empirical evidence, by which to predict the trend of post-TPP and its future influence.
The outbreak of Newcastle Pneumonia is characterised by its pandemic nature and uncertainty, which makes the prevention, control and management of the epidemic much more difficult. The epidemic ...prevention and control model of “community + volunteers” was implemented in the community to effectively improve the efficiency of epidemic prevention and control. This model is community-led and identifies the needs of the community: social organisations are the main actors, organising volunteers and integrating public resources to provide efficient and low-cost epidemic prevention and control services for the community. The paper analyses the effectiveness and problems of the “community + volunteers” epidemic prevention and control practice in community H in Bayannur, summarises the experience and makes feasible recommendations to improve community epidemic prevention and control governance.
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•Low-density PLLA foams were produced by supercritical CO2 foaming.•Pressure-induce flow method could enhance PLLA’s crystallization.•PLLA foams exhibited open-cellular structure and ...high compressive strength.•The high-through PLLA scaffolds lead better long-term culture results.
Porous poly (l-lactic acid) (PLLA) scaffold has been widely used as substitutes for tissue engineering. However, PLLA is intrinsically difficult to be produced for low-density and high porosity by physical foaming procedure, due to its weak melt strength, slow crystallization kinetic, and low heterogeneous nucleation efficiency in bulk. For the sake of enhancing the PLLA’s crystallization and heterogeneous nucleation in supercritical CO2 (ScCO2) foaming, a pressure-induced flow (PIF) method was applied on neat PLLA. As a result, the PLLA’s crystallinity and its spherulite size increased from original 15.3% and 5.0nm to 42.1% and 28.5nm, respectively. High-strength and low-density PLLA foams with uniform and controlled cellular morphology were feasibly produced, varying the foaming temperature from 100 to 140°C in a ScCO2 batch foaming process. The closed cellular structure was transformed to high-interconnected porous structure, when reducing the foaming temperature. The open-cellular PLLA scaffolds foams, with a relatively high open pore content of 77.3%, prepared using this approach can achieve a high porosity up to 92.5%, and exhibit excellent compressive stress. To evaluate its tissue engineering application, long-term culture of mouse embryonic fibroblast cells (MEFs) demonstrated that the selected open-cellular PLLA scaffold provided prominent advantages ranging from enhanced cell adhesion and proliferation to facilitated nutrient transport. The combination of PIF and CO2 foaming process can produce a great promising PLLA scaffold for tissue engineering with desirable open-cellular structure, high-strength, low-cost and easy production capacity.
has simultaneously emerged on five continents as a fungal pathogen causing nosocomial outbreaks. The challenges in the treatment of
infections are the variable antifungal susceptibility profiles ...among clinical isolates and the development of resistance to single or multiple classes of available antifungal drugs. Here, the
susceptibility to echinocandin antifungal drugs was determined and
sequencing was performed on 106
clinical isolates. Four isolates were identified to be resistant to all tested echinocandins (MIC ≥ 4 mg/liter) and harbored an S639F mutation in
hot spot region 1. All remaining isolates were
wild type (WT) and echinocandin susceptible, with micafungin being the most potent echinocandin (MIC
= 0.125 mg/liter). Antifungal susceptibility testing with caspofungin was challenging due to the fact that all
WT isolates exhibited an Eagle effect (also known as the paradoxical growth effect), which occurred at various intensities. To assess whether the Eagle effect resulted in pharmacodynamic resistance, 8 representative isolates were evaluated for their
drug response in a murine model of invasive candidiasis. All isolates were susceptible to caspofungin at a human therapeutic dose, except for those harboring the S639F mutation. The data suggest that only isolates carrying mutations in
are echinocandin resistant and that routine
testing of
isolates for susceptibility to caspofungin by the broth microdilution method should be viewed cautiously or avoided.
River stage fluctuation (RSF) is one of the most important factors influencing the physical, chemical, and ecological aspects of rivers. Despite widespread interest in river stage variations, there ...is currently no global benchmark of RSF and their spatial patterns. Our understanding of these characteristics remains limited. We used Sentinel‐3 altimetry data to establish a benchmark data set for RSF in wide rivers (width >1 km). We conducted an initial investigation of the spatial patterns and inter‐annual variability associated with RSF. The results show a wide range of fluctuation amplitudes spanning from a mere 1 to 18 m. Notably, rivers in semi‐arid regions exhibit more pronounced fluctuations. Further analyses indicate that human activities play a significant role in RSF. The results are of substantial interest to the scientific community, as they are closely linked to critical hydrological processes, including floods, river‐floodplain dynamics, river‐groundwater interaction, greenhouse gas emissions, and river restoration.
Plain Language Summary
Rivers show a seasonal rhythm over time due to multiple processes. A critical aspect of the rhythm is the river stage, which resembles the pulse of a river as it rises and falls. Traditionally, river stages have been monitored using gauging stations. However, these local monitoring networks fall short in providing a comprehensive global perspective on river stage fluctuations, which are directly linked to significant events like floods and droughts. Advanced Earth Observation techniques now offer a means to better understand the pulse of rivers on broader scales. Specifically, satellite radar altimetry serves as a valuable tool for river stage records by measuring water surface elevation, thereby providing insights into the normality or abnormality of river conditions. This study represents one of the first global‐scale investigations into the patterns of river stage fluctuations and inter‐annual variability spanning from 2016 to 2022. Moreover, this new data set holds practical value for related studies, such as the validation of the average depth of the channel when the river is full, the assessment of river channel storage variation, the facilitation of river navigation, stepwise ecological restoration, and more.
Key Points
Stage fluctuations of large rivers were estimated globally for the first time using satellite radar altimetry
Rivers in semi‐arid regions have larger fluctuations than those in other climate regions
The top five river basins with the highest stage fluctuations (>7 m) are the Orinoco, Mississippi, Yangtze, Irrawaddy, and Amazon basins
Phlorotannins are a type of natural active substance extracted from brown algae, which belong to a type of important plant polyphenol. Phloroglucinol is the basic unit in its structure. Phlorotannins ...have a wide range of biological activities, such as antioxidant, antibacterial, antiviral, anti-tumor, anti-hypertensive, hypoglycemic, whitening, anti-allergic and anti-inflammatory, etc. Phlorotannins are mainly used in the fields of medicine, food and cosmetics. This paper reviews the research progress of extraction, separation technology and biological activity of phlorotannins, which will help the scientific community investigate the greater biological significance of phlorotannins.
The task of semantic segmentation of maize and weed images using fully supervised deep learning models requires a large number of pixel-level mask labels, and the complex morphology of the maize and ...weeds themselves can further increase the cost of image annotation. To solve this problem, we proposed a Scrawl Label-based Weakly Supervised Semantic Segmentation Network (SL-Net). SL-Net consists of a pseudo label generation module, encoder, and decoder. The pseudo label generation module converts scrawl labels into pseudo labels that replace manual labels that are involved in network training, improving the backbone network for feature extraction based on the DeepLab-V3+ model and using a migration learning strategy to optimize the training process. The results show that the intersection over union of the pseudo labels that are generated by the pseudo label module with the ground truth is 83.32%, and the cosine similarity is 93.55%. In the semantic segmentation testing of SL-Net for image seedling of maize plants and weeds, the mean intersection over union and average precision reached 87.30% and 94.06%, which is higher than the semantic segmentation accuracy of DeepLab-V3+ and PSPNet under weakly and fully supervised learning conditions. We conduct experiments to demonstrate the effectiveness of the proposed method.
is an emerging multidrug-resistant fungal pathogen causing nosocomial and invasive infections associated with high mortality.
is commonly misidentified as several different yeast species by ...commercially available phenotypic identification platforms. Thus, there is an urgent need for a reliable diagnostic method. In this paper, we present fast, robust, easy-to-perform and interpret PCR and real-time PCR assays to identify
and related species:
,
, and
Targeting rDNA region nucleotide sequences, primers specific for
only or
and related species were designed. A panel of 140 clinical fungal isolates was used in both PCR and real-time PCR assays followed by electrophoresis or melting temperature analysis, respectively. The identification results from the assays were 100% concordant with DNA sequencing results. These molecular assays overcome the deficiencies of existing phenotypic tests to identify
and related species.