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Magnesium alloys, noted for their substantial mechanical strength and exceptional biocompatibility, are increasingly being considered for use in biodegradable implants. However, their rapid degradation and significant hydrogen release have limited their applications in orthopaedics. In this study, a novel Mg-RE-Sr alloy was created by friction stir processing to modify its microstructure and enhance its degradation performance. Through microstructural characterization, the friction stir processing effectively refined the grains, accelerated the re-dissolution of precipitates, and ensured a uniform distribution of these phases. The processed alloy demonstrated improved comprehensive properties, with an in vitro corrosion rate of approximately 0.4 mm/y and increases in ultimate tensile strength and elongation by 37 % and 166 %, respectively. Notably, in vivo experiments involving a rat subcutaneous implantation model revealed a slower degradation rate of 0.09 mm/y and a uniform degradation process, basically achieving the requirements for ideal performance in orthopaedic applications. The superior degradation characteristics were attributed to the synergistic effect of attenuated galvanic corrosion and the formation of a dense Y(OH)3/Y2O3 film induced by an exceptional microstructure with a highly solid-soluted matrix and uniformly refined precipitates. Meanwhile, the alloys exhibited excellent biocompatibility and did not cause undesirable inflammation or produce toxic degradation products. These improvements in biocompatibility and degradation characteristics indicate great promise for the use of this friction stir processed alloy in osteosynthesis systems in the clinical setting.
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The influence of epigallocatechin gallate (EGCG) on the physicochemical-rheological properties of silver carp surimi gel was investigated. The gel strength, texture, water-holding capacity (WHC), dynamic distribution of water, and rheological properties of surimi gels added with different levels (0, 0.02, 0.04, 0.06, 0.08, and 0.1%) of EGCG were measured. The results showed that with the increase of EGCG content, the gel strength, hardness, WHC, and immobilized water contents of surimi gels showed a trend of first increasing and then decreasing, and EGCG 0.02% and EGCG 0.04% showed better gel performance as compared with the control. EGCG 0.02% had the highest gel strength (406.62 g·cm), hardness (356.67 g), WHC (64.37%), and immobilized water contents (98.958%). The gel performance decreased significantly when the amounts of EGCG were higher than 0.06%. The viscosity, G', and Gâ³ of the rheological properties also showed the same trends. The chemical interaction of surimi gels, secondary structure of myofibrillar protein (MP), and molecular docking results of EGCG and silver carp myosin showed that EGCG mainly affected the structure and aggregation behavior of silver carp myosin through non-covalent interactions such as those of hydrogen bonds, hydrophobic interactions, and electrostatic interactions. The microstructures of EGCG 0.02% and EGCG 0.04% were compact and homogeneous, and had better gel formation ability. The lower concentrations of EGCG formed a large number of chemical interactions such as those of disulfide bonds and hydrophobic interactions inside the surimi gels by proper cross-linking with MP, and also increased the ordered ß-sheet structure of MP, which facilitated the formation of the compact three-dimensional network gel.
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We conducted an experiment of planting a dead cow and a metal-framed cage with cameras on the 1629 m deep sea floor off the southeast coast of Hainan Island in the northwestern South China Sea, using ROV diving and setting up a video camera on the cage to observe animals who came to eat the bait. The deep-sea cameras captured footage of eight Pacific sleeper sharks (Somniosus pacificus) swimming and feeding around the dead cow. To our knowledge, this is the first time the occurrence of such a shark species has been reported in the South China Sea. Eight individuals were differentiated based on the characteristic differences displayed in the images, with lengths of 1.9 to 5.1 m estimated. The video camera also recorded the predators' behavior of tearing at the dead cow on the seabed. It was discovered that Pacific sleeper sharks are not strictly solitary and exhibit queue-feeding behavior. This study is significant as it documents a record of a data-scarce shark species, for which little information is available in the literature. It also documents an expansion of the species' known habitat from the north Pacific Ocean into the South China Sea. Such sharks diving into the deep sea to predate on dead animals also suggests that occurrences of large chunks of dead organic bodies falling onto the deep sea might have been more frequent than we previously thought in the South China Sea. The findings have implications for understanding the geographic connectivity of large swimming animals between the South China Sea and the Pacific Ocean and provide scientific evidence for formulating conservation and management strategies for sharks and other large animals in the oceans.
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The electrocatalytic methanol oxidation reaction (MOR) is a viable approach for realizing high value-added formate transformation from biomass byproducts. However, usually it is restricted by the excess adsorption of intermediates (COad) and overoxidation of catalysts, which results in low product selectivity and inactivation of the active sites. Herein, a novel Cu-O-Ni electron-transfer channel was constructed by loading NiCuO x on nickel foam (NF) to inhibit the overoxidation of Ni and enhance the formate selectivity of the MOR. The optimized NiCuO x -2/NF demonstrated excellent MOR catalytic performance at industrial current density (E 500 = 1.42 V) and high faradaic efficiency of â¼100%, as well as durable formate generation up to 600 h at â¼500 mA cm-2. The directional electron transfer from Cu to Ni and enhanced lattice stability could alleviate the overoxidation of Ni(iii) active sites to guarantee reversible Ni(ii)/Ni(iii) cycles and endow NiCuO x -2/NF with high stability under increased current density, respectively. An established electrolytic cell created by coupling the MOR with the hydrogen evolution reaction could produce H2 with low electric consumption (230 mV lower voltage at 400 mA cm-2) and concurrently generated the high value-added product of formate at the anode.
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Global temperatures will continue to increase in the future. The â¼640,000-km2 Loess Plateau (LP) is a typical arid and semi-arid region in China. Similar regions cover â¼41% of the Earth, and its soils are some of the most severely eroded anywhere in the world. It is very important to understand the vegetation change and its ecological threshold under climate change on the LP for the sustainable development in the Yellow River Basin. However, little is known about how vegetation on the LP will respond to climate change and what is the sustainable threshold level of vegetation cover on the LP. Here we show that the temperature on the LP has risen 0.27 °C per decade over the past 50 years, a rate that is 30% higher than the average warming rate across China. During historical times, vegetation change was regulated by environmental factors and anthropogenic activities. Vegetation coverage was about 53% on the LP from the Xia Dynasty to the Spring and Autumn and Warring States period. Over the past 70 years, however, the environment has gradually improved and the vegetation cover had increased to â¼65% by 2021. We forecast future changes of vegetation cover on the LP in 2030s, in 2050s and in 2070s using SDM (Species Distribution Model) under Low-emission scenarios, Medium-emission scenarios and High-emission scenarios. An average value of vegetation cover under the three emission scenarios will be 64.67%, 62.70% and 61.47%, respectively. According to the historical record and SDM forecasts, the threshold level of vegetation cover on the LP is estimated to be 53-65%. Currently, vegetation cover on the LP has increased to the upper limit of the threshold value (â¼65%). We conclude that the risk of ecosystem collapse on the LP will increase with further temperature increases once the vegetated area and density exceed the threshold value. It is urgent to adopt sustainable strategies such as stopping expanding vegetation area and scientifically optimizing the vegetation structure on the LP to improve the ecological sustainability of the Yellow River Basin.
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Antifreeze peptide (AFP) including in frozen protein ink is an inevitable trend because AFP can make protein ink suitable for 3D printing after freezing. AFP-based surimi ink (ASI) was firstly investigated, and the AFP significantly enhanced 3D printability of frozen surimi ink. The rheological and textural results of ASI show that the τ0, K, and n values are 321.14 Pa, 2.2259 × 105 Pa·sn, and 0.19, respectively, and the rupture strength of the 3D structure is up to 217.67 g. Circular dichroism, intermolecular force, and differential scanning calorimeter show ASI has more undenatured protein after freezing when compared that surimi ink (SI), which was denatured, and the α-helix changed to a ß-sheet due to the destruction of hydrogen bonds and the exposure of hydrophobic groups. The water distribution, water holding capacity, and microstructure indicate that ASI effectively binds free water after freezing, while SI has weak water binding capacity and a large amount of free water is formed. ASI is suitable for 3D printing, and can print up to 40.0 mm hollow isolation column and 50.0 mm high Wuba which is not possible with SI. The application of AFP provides guidance for 3D printing frozen protein ink in food industry.
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The identification and detection of pesticides is crucial to protecting both the environment and human health. However, it can be challenging to conveniently and rapidly differentiate between different types of pesticides. We developed a supramolecular fluorescent sensor array, in which calixarenes with broad-spectrum encapsulation capacity served as recognition receptors. The sensor array exhibits distinct fluorescence change patterns for seven tested pesticides, encompassing herbicides, insecticides, and fungicides. With a reaction time of just three minutes, the sensor array proves to be a rapid and efficient tool for the discrimination of pesticides. Furthermore, this supramolecular sensing approach can be easily extended to enable real-time and on-site visual detection of varying concentrations of imazalil using a smartphone with a color scanning application. This work not only provides a simple and effective method for pesticide identification and quantification, but also offers a versatile and advantageous platform for the recognition of other analytes in relevant fields.
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Calixarenos , Plaguicidas , Calixarenos/química , Plaguicidas/análisis , Técnicas Biosensibles/métodos , Teléfono Inteligente , Espectrometría de Fluorescencia/métodosRESUMEN
In recent decades, environmental protection and energy issues have gained significant attention, and the development of efficient, environmentally friendly catalysts has become especially crucial for the advancement of photocatalytic technology. This study employs the sintering method to produce biochar. A hybrid photocatalyst for the degradation of RHB under visible light was prepared by loading varying proportions of biochar onto g-C3N4 using ultrasonic technology. Among them, 2% CGCD (2% biochar/g-C3N4) achieved a degradation rate of 91.3% for RHB after 30 minutes of visible light exposure, which was more than 25% higher than GCD (g-C3N4), and exhibited a higher photocurrent intensity and lower impedance value. The enhancement in photocatalytic activity is primarily attributed to the increased utilization efficiency of visible light and the electron transfer channel effect from a minor amount of biochar, effectively reducing the recombination of photo-generated charge carriers on the g-C3N4 surface, thereby significantly improving photocatalytic activity. The degradation of RHB is synergistically mediated by O2 -, h+ (photo-generated holes), and ËOH. The free radical capture experiment indicates that O2 - and ËOH are the primary active components, followed by h+.
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The application of electrochemical hydrogen evolution reaction (HER) for renewable energy conversion contributes to the ultimate goal of a zero-carbon emission society. Metal phosphides have been considered as promising HER catalysts in the alkaline environment, which, unfortunately, is still limited owing to the weak adsorption of H* and easy dissolution during operation. Herein, a bimetallic NiCoP-2/NF phosphide is constructed on nickel foam (NF), requiring rather low overpotentials of 150 mV and 169 mV to meet the current densities of 500 and 1000 mA cm-2, respectively, and able to operate stably for 100 h without detectable activity decay. The excellent HER performance is obtained thanks to the synergetic catalytic effect between Ni and Co, among which Ni is introduced to enhance the intrinsic activity and Co increases the electrochemically active area. Meanwhile, the protection of the externally generated amorphous phosphorus oxide layer improves the stability of NiCoP/NF. An electrolyser using NiCoP-2/NF as both cathode and anode catalysts in an alkaline solution can produce hydrogen with low electric consumption (overpotential of 270 mV at 500 mA cm-2).
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3D printing is an additive manufacturing technology that locates constructed models with computer-controlled printing equipment. To achieve high-quality printing, the requirements on rheological properties of raw materials are extremely restrictive. Given the special structure and high modifiability under external physicochemical factors, the rheological properties of proteins can be easily adjusted to suitable properties for 3D printing. Although protein has great potential as a printing material, there are many challenges in the actual printing process. This review summarizes the technical considerations for protein-based ink 3D printing. The physicochemical factors used to enhance the printing adaptability of protein inks are discussed. The post-processing methods for improving the quality of 3D structures are described, and the application and problems of fourth dimension (4D) printing are illustrated. The prospects of 3D printing in protein manufacturing are presented to support its application in food and cultured meat. The native structure and physicochemical factors of proteins are closely related to their rheological properties, which directly link with their adaptability for 3D printing. Printing parameters include extrusion pressure, printing speed, printing temperature, nozzle diameter, filling mode, and density, which significantly affect the precision and stability of the 3D structure. Post-processing can improve the stability and quality of 3D structures. 4D design can enrich the sensory quality of the structure. 3D-printed protein products can meet consumer needs for nutritional or cultured meat alternatives.
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Tinta , Impresión Tridimensional , Alimentos , Carne in Vitro , Sustitutos de la CarneRESUMEN
The circadian clock influences a wide range of biological process and controls numerous aspects of physiology to adapt to the daily environmental changes caused by Earth's rotation. The kidney clock plays an important role in maintaining tubular function, but its effect on podocytes remains unclear. Here, we found that podocytes expressed CLOCK proteins, and that 2666 glomerular gene transcripts (13.4%), including autophagy related genes, had 24-hour circadian rhythms. Deletion of Clock in podocytes resulted in 1666 gene transcripts with the loss of circadian rhythm including autophagy genes. Podocyte-specific Clock knockout mice at age three and eight months showed deficient autophagy, loss of podocytes and increased albuminuria. Chromatin immunoprecipitation (ChIP) sequence analysis indicated autophagy related genes were targets of CLOCK in podocytes. ChIP-PCR further confirmed Clock binding to the promoter regions of Becn1 and Atg12, two autophagy related genes. Furthermore, the association of CLOCK regulated autophagy with chronic sleep fragmentation and diabetic kidney disease was analyzed. Chronic sleep fragmentation resulted in the loss of glomerular Clock rhythm, inhibition of podocyte autophagy, and proteinuria. Rhythmic oscillations of Clock also disappeared in high glucose treated podocytes and in glomeruli from diabetic mice. Finally, circadian differences in podocyte autophagy were also abolished in diabetic mice. Deletion Clock in podocytes aggravated podocyte injury and proteinuria in diabetic mice. Thus, our findings demonstrate that clock-dependent regulation of autophagy may be essential for podocyte survival. Hence. loss of circadian controlled autophagy may play an important role in podocyte injury and proteinuria.
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Diabetes Mellitus Experimental , Nefropatías Diabéticas , Podocitos , Ratones , Animales , Podocitos/metabolismo , Diabetes Mellitus Experimental/complicaciones , Privación de Sueño/complicaciones , Privación de Sueño/metabolismo , Proteinuria/genética , Proteinuria/metabolismo , Nefropatías Diabéticas/genética , Nefropatías Diabéticas/complicaciones , Ratones Noqueados , AutofagiaRESUMEN
We report on the feeding ecology of two species, the short-headed lanternfish Diaphus brachycephalus and Warming's lanternfish Ceratoscopelus warmingii, using data collected over five surveys from 2015 to 2017 in the open South China Sea. D. brachycephalus feed mainly on copepods, with few differences in food composition between different-sized individuals; the diet of C. warmingii is more diverse, including crustacean zooplankton, gelatinous animals, and Mollusca, and differs significantly between fishes >55 mm in body length and smaller fishes. Interspecific competition for food between these two species is not strong, while intraspecific competition may be more intense in D. brachycephalus than in C. warmingii. Trophic levels of D. brachycephalus (3.46) and C. warmingii (3.38) identify both species as third-trophic-level lower carnivores. The diel feeding patterns of D. brachycephalus and C. warmingii differ: the former feeds actively both day and night when food is plentiful, and feeds primarily in the upper layer at night and in the mesopelagic layer during the daytime, and the latter ascends into the upper 100 m at night to feed, but stomach fullness is lower than D. brachycephalus. Dry-body-weight daily ration estimates for D. brachycephalus range from 5.19% to 16.46%, and those for C. warmingii range from 1.38% to 4.39%.
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Dieta , Conducta Alimentaria , Peces , Animales , Peces/fisiología , Dieta/veterinaria , China , Cadena Alimentaria , Tamaño CorporalRESUMEN
Nonalcoholic fatty liver (NAFL) remains relatively benign, but high-risk to end-stage liver diseases become highly prevalent when it progresses into nonalcoholic steatohepatitis (NASH). Our current understanding of the development of NAFL to NASH remains insufficient. In this study, we revealed MAP kinase (MAPK) activation as the most notable molecular signature associated with NASH progression across multiple species. Furthermore, we identified suppressor of IKKε (SIKE) as a conserved and potent negative controller of MAPK activation. Hepatocyte-specific overexpression of Sike prevented NASH progression in diet- and toxin-induced mouse NASH models. Mechanistically, SIKE directly interacted with TGF-ß-activated kinase 1 (TAK1) and TAK1-binding protein 2 (TAB2) to interrupt their binding and subsequent TAK1-MAPK signaling activation. We found that indobufen markedly up-regulated SIKE expression and effectively improved NASH features in mice and macaques. These findings identify SIKE as a MAPK suppressor that prevents NASH progression and provide proof-of-concept evidence for targeting the SIKE-TAK1 axis as a potential NASH therapy.