Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 438
Filtrar
1.
Opt Lett ; 49(8): 2177-2180, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38621105

RESUMO

Advancements in photonic integration technology have enabled the effective excitation of simulated Brillouin scattering (SBS) on a single chip, boosting Brillouin-based applications such as microwave photonic signal processing, narrow-linewidth lasers, and optical sensing. However, on-chip circuits still require large pump power and centimeter-scale waveguide length to achieve a considerable Brillouin gain, making them both power-inefficient and challenging for integration. Here, we exploit the slow-light effect to significantly enhance SBS, presenting the first, to the best of our knowledge, demonstration of a slow-light Brillouin-active waveguide on the silicon-on-insulator (SOI) platform. By integrating a Bragg grating with a suspended ridge waveguide, a 2.1-fold enhancement of the forward Brillouin gain coefficient is observed in a 1.25 mm device. Furthermore, this device shows a Brillouin gain coefficient of 1,693 m-1W-1 and a mechanical quality factor of 1,080. The short waveguide length reduces susceptibility to inhomogeneous broadening, enabling the simultaneous achievement of a high Brillouin gain coefficient and a high mechanical quality factor. This approach introduces an additional dimension to enhance acousto-optic interaction efficiency in the SOI platform and holds significant potential for microwave photonic filters and high spatial resolution sensing.

2.
Pest Manag Sci ; 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38482986

RESUMO

BACKGROUND: The discovery of agricultural fungicide candidates from natural products is one of the key strategies for developing environment friendly agricultural fungicides with high efficiency, high selectivity and unique modes-of-action. Based on previous work, a series of novel α-methylene-γ-butyrolactone (MBL) derivatives containing benzothiophene moiety were designed and synthesized. RESULTS: The majority of the proposed compounds displayed moderate to considerable antifungal efficacy against the tested pathogenic fungi and oomycetes, some exhibiting broad spectrum antifungal activity. Notably, compounds 2 (3-F-Ph) and 7 (4-Cl-Ph) showed excellent antifungal activity against Rhizoctonia with half maximal effective concentration (EC50) values of 0.94 and 0.99 mg L-1, respectively, comparable to the commercial fungicide tebuconazole (EC50 = 0.96 mg L-1), and also displayed significant inhibitory effects against V alsa mali with EC50 values of 2.26 and 1.67 mg L-1, respectively - better than famoxadone and carabrone. The in vivo protective and curative effects against R. solani of compound 2 were 57.2% and 53.7% at 100 mg L-1, respectively, which were equivalent to tebuconazole (51.6% and 52.4%). Further investigations found that compound 2 altered the ultrastructure of R. solani cell, significantly increased the relative conductivity of the cells, and reduced the activity of complex III in a dose-dependent manner. Molecular docking results showed that compound 2 matched well with the Qo pocket. CONCLUSION: The results revealed that MBL derivatives containing benzothiophene moiety are promising antifungal candidates and provide a new backbone structure for further optimization of novel fungicides. © 2024 Society of Chemical Industry.

3.
Int J Biol Macromol ; 264(Pt 1): 130536, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38432273

RESUMO

Tremella fuciformis polysaccharide (TFPS) is a natural mushroom mucopolysaccharide widely used in health foods, medical care, cosmetic and surgical materials. In this study, we developed an efficient strategy for the repeated batch production of highly bioactive TFPS from the agro-industrial residue cane molasses. Cane molasses contained 39.92 % sucrose (w/w), 6.36 % fructose and 3.53 % glucose, all of which could be utilized by T. fuciformis spores, whereas, the TFPS production efficiency only reached 0.74 g/L/d. Corn cobs proved to be the best immobilized carrier that could tightly absorb spores and significantly shorten the fermentation lag period. The average yield of TFPS in eight repeated batch culture was 5.52 g/L with a production efficiency of 2.04 g/L/d. The average fermentation cycle after optimization was reduced by 61.61 % compared with the initial conditions. Compared to glucose as a carbon source, cane molasses significantly increased the proportion of low-molecular-weight TFPS (TFPS-2) in total polysaccharides from 3.54 % to 17.25 % (w/w). Moreover, TFPS-2 exhibited potent antioxidant capacity against four free radicals (O2-, ABTS+, OH, and DPPH). In conclusion, this study lays the foundation for the efficient conversion of cane molasses and production of TFPS with high bioactivity.


Assuntos
Basidiomycota , Técnicas de Cultura Celular por Lotes , Melaço , Bengala , Polissacarídeos/farmacologia , Polissacarídeos/química , Fermentação , Glucose
4.
Sheng Wu Gong Cheng Xue Bao ; 40(3): 921-930, 2024 Mar 25.
Artigo em Chinês | MEDLINE | ID: mdl-38545987

RESUMO

Pantoea alhagi NX-11 exopolysaccharide (PAPS) is a novel microbial biostimulant that enhances crop resistance to salt and drought stress. It is biodegradable and holds promising applications in improving agricultural yield and efficiency. However, the fermentation process of PAPS exhibits a high viscosity due to low oxygen transfer efficiency, which hinders yield improvement and downstream processing. This study aimed to investigate the effects of seven oxygen carriers (Span 80, Span 20, Tween 80, Tween 20, glycerin, olive oil, and soybean oil) on fermentation yield. The results showed that the addition of 0.5% (V/V) Tween 20 significantly enhanced the production of PAPS. Moreover, the introduction of 0.5% (V/V) Tween 20 in a 7.5 L fermenter resulted in a PAPS titer of (16.85±0.50) g/L, which was 17.70% higher than that of the control group. Furthermore, the rheological characterization and the microstructure analysis of the polysaccharide products revealed that the characteristic structure of polysaccharides remained unchanged in the oxygen carrier treated group, but their viscosity increased. These findings may facilitate enhancing the biosynthesis efficiency of other polymer products.


Assuntos
Pantoea , Polissorbatos , Polissorbatos/química , Polissacarídeos , Oxigênio
5.
Opt Lett ; 49(6): 1465-1468, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38489426

RESUMO

The acousto-optic interaction known as stimulated Brillouin scattering (SBS) has emerged as a fundamental principle for realizing crucial components and functionalities in integrated photonics. However, the main challenge of integrating Brillouin devices is how to effectively confine both optical and acoustic waves. Apart from that, the manufacturing processes for these devices need to be compatible with standard fabrication platforms and streamlined to facilitate their large-scale integration. Here, we demonstrate a novel, to the best of our knowledge, suspended nanowire structure that can tightly confine photons and phonons. Furthermore, tailored for this structure, we introduce a loading-effect-based three-dimensional microfabrication technique, compatible with complementary metal-oxide-semiconductor (CMOS) technology. This innovative technique allows for the fabrication of the entire structure using a single-step lithography exposure, significantly streamlining the fabrication process. Leveraging this structure and fabrication scheme, we have achieved a Brillouin gain coefficient of 1100 W-1m-1 on the silicon-on-insulator platform within a compact footprint. It can support a Brillouin net gain over 4.1 dB with modest pump powers. We believe that this structure can significantly advance the development of SBS on chip, unlocking new opportunities for a large-scale integration of Brillouin-based photonic devices.

6.
Microbiol Spectr ; : e0018624, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38511949

RESUMO

Inoculation with plant growth-promoting rhizobacteria (PGPR) strains has promoted plant growth and decreased nitrous oxide (N2O) emissions from agricultural soils simultaneously. However, limited PGPR strains can mitigate N2O emissions from agricultural soils, and the microbial ecological mechanisms underlying N2O mitigation after inoculation are poorly understood. In greenhouse pot experiments, the effects of inoculation with Stutzerimonas stutzeri NRCB010 and NRCB025 on tomato growth and N2O emissions were investigated in two vegetable agricultural soils with contrasting textures. Inoculation with NRCB010 and NRCB025 significantly promoted tomato growth in both soils. Moreover, inoculation with NRCB010 decreased the N2O emissions from the fine- and coarse-textured soils by 38.7% and 52.2%, respectively, and inoculation with NRCB025 decreased the N2O emissions from the coarse-textured soil by 76.6%. Inoculation with NRCB010 and NRCB025 decreased N2O emissions mainly by altering soil microbial community composition and the abundance of nitrogen-cycle functional genes. The N2O-mitigating effect might be partially explained by a decrease in the (amoA + amoB)/(nosZI + nosZII) and (nirS + nirK)/(nosZI + nosZII) ratios, respectively. Soil pH and organic matter were key variables that explain the variation in abundance of N-cycle functional genes and subsequent N2O emission. Moreover, the N2O-mitigating effect varied depending on soil textures and individual strain after inoculation. This study provides insights into developing biofertilizers with plant growth-promoting and N2O-mitigating effects. IMPORTANCE: Plant growth-promoting rhizobacteria (PGPR) have been applied to mitigate nitrous oxide (N2O) emissions from agricultural soils, but the microbial ecological mechanisms underlying N2O mitigation are poorly understood. That is why only limited PGPR strains can mitigate N2O emissions from agricultural soils. Therefore, it is of substantial significance to reveal soil ecological mechanisms of PGPR strains to achieve efficient and reliable N2O-mitigating effect after inoculation. Inoculation with Stutzerimonas stutzeri strains decreased N2O emissions from two soils with contrasting textures probably by altering soil microbial community composition and gene abundance involved in nitrification and denitrification. Our findings provide detailed insight into soil ecological mechanisms of PGPR strains to mitigate N2O emissions from vegetable agricultural soils.

7.
Org Lett ; 26(11): 2309-2314, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38466078

RESUMO

2-Alkylpyridines are a privileged scaffold throughout the realm of organic synthesis and play a key role in natural products, pharmaceuticals, and agrochemicals. Herein, we report the first B-alkyl Suzuki cross-coupling of 2-pyridyl ammonium salts to access functionalized 2-alkylpyridines. The use of well-defined, operationally simple Pd-NHCs permits for an exceptionally broad scope of the challenging B-alkyl C-N cross-coupling with organoboranes containing ß-hydrogen, representing a novel method for the discovery of highly sought-after molecules for plant protection.

8.
Adv Sci (Weinh) ; 11(15): e2306399, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38348540

RESUMO

Traumatic brain injury (TBI) leads to progressive neurodegeneration that may be caused by chronic traumatic encephalopathy (CTE). However, the precise mechanism remains unclear. Herein, the study identifies a crucial protein, axonemal dynein light intermediate polypeptide 1 (DNALI1), and elucidated its potential pathogenic role in post-TBI neurodegeneration. The DNALI1 gene is systematically screened through analyses of Aging, Dementia, and TBI studies, confirming its elevated expression both in vitro and in vivo. Moreover, it is observed that altered DNALI1 expression under normal conditions has no discernible effect. However, upon overexpression, DNALI1 inhibits autophagosome-lysosome fusion, reduces autophagic flux, and exacerbates cell death under pathological conditions. DNALI1 silencing significantly enhances autophagic flux and alleviates neurodegeneration in a CTE model. These findings highlight DNALI1 as a potential key target for preventing TBI-related neurodegeneration.


Assuntos
Lesões Encefálicas Traumáticas , Encefalopatia Traumática Crônica , Humanos , Autofagossomos/metabolismo , Autofagossomos/patologia , Lesões Encefálicas Traumáticas/complicações , Encefalopatia Traumática Crônica/etiologia , Encefalopatia Traumática Crônica/patologia , Autofagia , Lisossomos/metabolismo
9.
Int J Biol Macromol ; 263(Pt 2): 130425, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38412938

RESUMO

Liquid fermentation could revolutionize mushroom polysaccharide production, but the low temperature constraint hampers the process. This study implemented adaptive laboratory evolution (ALE) to enhance the thermotolerance of Naematelia aurantialba strains and increase expolysaccharide production. After 75 ALE cycles at 30 °C, the adaptive strain surpassed the wild-type strain by 5 °C. In a 7.5 L fermentor at 30 °C, the ALE strain yielded 17 % more exopolysaccharide than the wild type strain at 25 °C. Although the exopolysaccharide synthesized by both strains shares a consistent monosaccharide composition, infrared spectrum, and glycosidic bond composition, the ALE strain's exopolysaccharide has a larger molecular weight. Furthermore, the ALE strain's exopolysaccharide exhibits superior cryoprotection performance compared to that produced by the original strain. The adapted strain demonstrated lower ROS levels and increased activity of antioxidant enzymes, indicating improved performance. Fatty acid profiling and transcriptomics revealed reconfiguration of carbohydrate metabolism, amino acid metabolism, and membrane lipid synthesis in thermophilic strains, maintaining cellular homeostasis and productivity. This study provides efficient strains and fermentation methods for high-temperature mushroom polysaccharide production, reducing energy consumption and costs.


Assuntos
Basidiomycota , Reatores Biológicos , Polissacarídeos , Temperatura , Fermentação
10.
Nat Aging ; 4(3): 414-433, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38321225

RESUMO

The incidence of intestinal diseases increases with age, yet the mechanisms governing gut aging and its link to diseases, such as colorectal cancer (CRC), remain elusive. In this study, while considering age, sex and proximal-distal variations, we used a multi-omics approach in non-human primates (Macaca fascicularis) to shed light on the heterogeneity of intestinal aging and identify potential regulators of gut aging. We explored the roles of several regulators, including those from tryptophan metabolism, in intestinal function and lifespan in Caenorhabditis elegans. Suggesting conservation of region specificity, tryptophan metabolism via the kynurenine and serotonin (5-HT) pathways varied between the proximal and distal colon, and, using a mouse colitis model, we observed that distal colitis was more sensitive to 5-HT treatment. Additionally, using proteomics analysis of human CRC samples, we identified links between gut aging and CRC, with high HPX levels predicting poor prognosis in older patients with CRC. Together, this work provides potential targets for preventing gut aging and associated diseases.


Assuntos
Colite , Serotonina , Animais , Humanos , Idoso , Serotonina/metabolismo , Triptofano/metabolismo , Multiômica , Colite/metabolismo , Envelhecimento/genética , Caenorhabditis elegans/metabolismo , Primatas/metabolismo
11.
Artigo em Inglês | MEDLINE | ID: mdl-38381637

RESUMO

Salient object ranking (SOR) aims to segment salient objects in an image and simultaneously predict their saliency rankings, according to the shifted human attention over different objects. The existing SOR approaches mainly focus on object-based attention, e.g., the semantic and appearance of object. However, we find that the scene context plays a vital role in SOR, in which the saliency ranking of the same object varies a lot at different scenes. In this paper, we thus make the first attempt towards explicitly learning scene context for SOR. Specifically, we establish a large-scale SOR dataset of 24,373 images with rich context annotations, i.e., scene graphs, segmentation, and saliency rankings. Inspired by the data analysis on our dataset, we propose a novel graph hypernetwork, named HyperSOR, for context-aware SOR. In HyperSOR, an initial graph module is developed to segment objects and construct an initial graph by considering both geometry and semantic information. Then, a scene graph generation module with multi-path graph attention mechanism is designed to learn semantic relationships among objects based on the initial graph. Finally, a saliency ranking prediction module dynamically adopts the learned scene context through a novel graph hypernetwork, for inferring the saliency rankings. Experimental results show that our HyperSOR can significantly improve the performance of SOR.

12.
J Neurochem ; 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38382918

RESUMO

Ferroptosis has been implicated in several neurological disorders and may be therapeutically targeted. However, the susceptibility to ferroptosis varies in different cells, and inconsistent results have been reported even using the same cell line. Understanding the effects of key variables of in vitro studies on ferroptosis susceptibility is of critical importance to facilitate drug discoveries targeting ferroptosis. Here, we showed that increased cell seeding density leads to enhanced resistance to ferroptosis by reducing intracellular iron levels. We further identified iron-responsive protein 1 (IRP1) as the key protein affected by cell density, which affects the expression of ferroportin or transferrin receptor and results in altered iron levels. Such observations were consistent across different cell lines, indicating that cell density should be tightly controlled in studies of ferroptosis. Since cell densities vary in different brain regions, these results may also shed light on selective regional vulnerability observed in neurological disorders.

13.
Sci Total Environ ; 917: 170395, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38307277

RESUMO

In the mangrove growth area, the availability of high-quality optical images is limited throughout the year due to cloud cover, precipitation, and sensor revisiting cycles. In the worst-case scenario, severe conditions may lead to the unavailability of, causing variations in monitoring times for mangroves across different years. This significantly impacts the accuracy of long-term sequence monitoring of mangrove dynamics. To monitor long-term dynamic changes in mangrove spatial distribution, area, and ecology we reconstructed comprehensive time series images from 2000 to 2020 based on Landsat, Sentinel-2, and moderate-resolution imaging spectroradiometer (MODIS) images. We employed neighborhood-similar pixel interpolator (NSPI) strip filling, Fmask and temporal NSPI cloud-removal and filling, and FSDAF model to monitor the long-term dynamic changes in mangrove spatial distribution, area, and ecology. All three methods effectively reconstructed the images, with the FSDAF model exhibiting the greatest accuracy. The reconstructed images suggested that the mangroves demonstrated an overall growth trend from 2000 to 2020, with an increase from 3796.74 ha to 7676.89 ha, an increase of approximately 3880.15 ha over 20 years. Despite this growth, the number of patches gradually increased, the degree of fragmentation consistently worsened, and the landscape shape gradually became irregular. The study area demonstrated pronounced overall heterogeneity, with a gradually increase in the degree of dispersion, indicating evident overall instability. Additionally, the centroid of the mangroves moved towards the ocean, which complicated their growth environment and posed a serious threat to their growth and recovery. Anthropogenic disturbance is the main factor driving changes in mangrove areas. Driving factors that affected the change in mangrove areas were ranked as follows: GDP > highway mileage > population density > precipitation > humidity > wind speed > sunshine > temperature. The results of this study provide comprehensive data for the protection and restoration of mangroves.

14.
Angew Chem Int Ed Engl ; 63(11): e202320036, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38191990

RESUMO

The striking aesthetic appeal of fullerene-like clusters has captured the interest of researchers. Nevertheless, the assembly of fullerene-like polyoxovadanadate (POV) cages remains a significant challenge due to the scarcity of suitable pentagonal motif. Herein, we have successfully synthesized the first fullerene-like all-inorganic POV cage, {(V2 O)V30 Nb12 O102 (H2 O)12 } (V30 Nb12 ), by introducing Nb into the POVs. V30 Nb12 is assembled by 12 heterometallic {(Nb)V5 } pentagons through sharing V centers with Ih symmetry, reminiscent of C60 . To our knowledge, the fullerene-like V30 Nb12 not only represents the highest-nuclearity POV cage but also stands as the first niobovanadate cluster. Notably, V30 Nb12 exhibits excellent solution stability, as confirmed by ESI-MS, FT-IR and UV/Vis spectra. As there is no protection organic ligand on its outer surface, V30 Nb12 can be further modified with Cu-complexes to form a fullerene-like cluster based zigzag chain (Cu-V30 Nb12 ).

15.
Int J Biol Macromol ; 261(Pt 1): 129756, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38286376

RESUMO

Mushroom polysaccharides exhibit numerous health-enhancing attributes that are intricately linked to the breakdown, assimilation, and exploitation of polysaccharides within the organism. Naematelia aurantialba polysaccharides (NAPS-A), highly prized polysaccharides derived from mushrooms, remain shrouded in uncertainty regarding their characteristics pertaining to gastrointestinal digestion and gut microbial fermentation. The study aimed to understand the digestion and fecal fermentation patterns of NAPS-A. After simulated digestion, NAPS-A's physicochemical properties remained unchanged. However, during in vitro fecal fermentation, indigestible NAPS-A underwent significant changes in various properties, such as reducing sugar, chemical composition, constituent monosaccharides, Molecular weight, apparent viscosity, FT-IR spectra, and microscopic morphology. Notably, NAPS-A was effectively utilized by the gut microbiota, with unchanged properties after digestion but altered after fermentation. It influenced gut microbe composition by increasing beneficial bacteria (Lactobacillus, Faecalibacterium, and Roseburia), lowering pH, and producing short-chain fatty acids. NAPS-A fermentation enriches carbohydrate, fatty acid, and amino acid metabolic pathways through PICRUSt prediction analysis. Overall, these findings emphasize NAPS-A's role in regulating gut bacteria and their metabolic functions, despite its challenging digestibility.


Assuntos
Agaricales , Basidiomycota , Digestão , Fermentação , Espectroscopia de Infravermelho com Transformada de Fourier , Ácidos Graxos Voláteis/metabolismo , Polissacarídeos/metabolismo , Agaricales/metabolismo , Bactérias/metabolismo
16.
Int J Biol Macromol ; 261(Pt 1): 129809, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38290633

RESUMO

Diabetes is one of the foremost chronic non-communicable diseases worldwide, which significantly impacts people's quality of life. This study aimed to investigate the hypoglycemic effects of γ-polyglutamic acid (γ-PGA) on STZ-induced type II diabetes mice and its potential mechanisms. The results indicated that γ-PGA intervention contributed to reducing fasting blood glucose levels in diabetic mice, regulating lipid metabolism in type II diabetes mice, and improving insulin resistance. Additionally, γ-PGA could alleviate liver inflammation, enhancing the activity of hepatic antioxidant enzymes. Investigation into the insulin signaling pathway revealed that γ-PGA significantly increased the expression of INSR, IRS-1, Akt, PI3K in diabetic mice, thereby enhancing insulin sensitivity and improving insulin resistance to regulate glucose metabolism. High-throughput sequencing of mouse gut microbiota using 16S rRNA showed that γ-PGA increased the abundance and evenness of beneficial bacteria in the intestines of type II diabetic mice, inhibited the growth of harmful bacteria, and may exerted hypoglycemic effects by modulating and improving relevant metabolic pathways associated with diabetes symptoms. This study provides new insights into the treatment of type II diabetes and highlights the significant potential of γ-PGA in treating type II diabetes.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Resistência à Insulina , Ácido Poliglutâmico/análogos & derivados , Humanos , Camundongos , Animais , Hipoglicemiantes/efeitos adversos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , RNA Ribossômico 16S , Qualidade de Vida , Insulina/metabolismo , Glicemia/metabolismo
17.
J Agric Food Chem ; 72(5): 2492-2500, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38271672

RESUMO

Structural diversity derivatization from natural products is an important and effective method of discovering novel green pesticides. Cinnamic acids are abundant in plants, and their unparalleled structures endow them with various excellent biological activities. A series of novel cinnamic oxime esters were designed and synthesized to develop high antifungal agrochemicals. The antifungal activity, structure-activity relationship, and action mechanism were systematically studied. Compounds 7i, 7u, 7v, and 7x exhibited satisfactory activity against Gaeumannomyces graminis var. tritici, with inhibition rates of ≥90% at 50 µg/mL. Compounds 7z and 7n demonstrated excellent activities against Valsa mali and Botrytis cinerea, with median effective concentration (EC50) values of 0.71 and 1.41 µg/mL, respectively. Compound 7z exhibited 100% protective and curative activities against apple Valsa canker at 200 µg/mL. The control effects of 7n against gray mold on tomato fruits and leaves were all >96%, exhibiting superior or similar effects to those of the commercial fungicide boscalid. Furthermore, the quantitative structure-activity relationship was established to guide the further design of higher-activity compounds. The preliminary results on the action mechanism revealed that 7n treatment could disrupt the function of the nucleus and mitochondria, leading to reactive oxygen species accumulation and cell membrane damage. Its primary biochemical mechanism may be inhibiting fungal ergosterol biosynthesis. The novel structure, simple synthesis, and excellent activity of cinnamic oxime esters render them promising potential fungicides.


Assuntos
Ascomicetos , Cinamatos , Fungicidas Industriais , Fungicidas Industriais/química , Antifúngicos/farmacologia , Relação Estrutura-Atividade , Relação Quantitativa Estrutura-Atividade , Oximas/farmacologia , Botrytis
18.
Int J Biol Macromol ; 256(Pt 2): 128438, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38042318

RESUMO

We here describe the isolation of a novel exopolysaccharide from Acinetobacter rhizosphaerae, named ArEPS. The structure of ArEPS was characterized by analysis of the monosaccharide composition, molecular weight, infrared spectrum, methylation, and nuclear magnetic resonance spectrum. ArEPS was found to be an acidic heteropolysaccharide composed of glucose, galactose, galacturonic acid, glucuronic acid, mannose, and glucosamine; the molecular weight was 1533 kDa. Structural analysis showed that the main-chain structure of ArEPS predominantly comprised 1,3,6-ß-Glcp, 1,3,4-α-Galp, 1,2-ß-Glcp, 1,4-ß-GlcpA, 1,4-ß-GalpA, and the side-chain structure comprised 1,6-ß-Glcp, 1,3-ß-Galp, 1-α-Glcp, 1-ß-Galp, 1-α-Manp, 1,4,6-α-Glcp, 1,2,4-ß-Glcp, 1,2,3-ß-Glcp, and 1,3-ß-GlcpN. ArEPS significantly enhanced the tolerance of rice seedlings to salt stress. Specifically, plant height, fresh weight, chlorophyll content, and the K+/Na+ ratio increased by 51 %, 63 %, 29 %, and 162 %, respectively, and the malondialdehyde content was reduced by 45 % after treatment with 100 mg/kg ArEPS compared to treatment with 100 mM NaCl. Finally, based on the quadratic regression between fresh weight and ArEPS addition, the optimal ArEPS addition level was estimated to be 135.12 mg/kg. These results indicate the prospects of ArEPS application in agriculture.


Assuntos
Acinetobacter , Oryza , Plântula , Plântula/química , Monossacarídeos/análise , Galactose/análise , Polissacarídeos/química , Peso Molecular
19.
Sci Total Environ ; 912: 169600, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38151126

RESUMO

The coexistence of multi-component dissolved organic chemicals causes tremendous challenge in purifying petrochemical wastewater, and stepwise selective adsorption holds the most promise for enhanced treatments. This study is designed to enhance the removal of multiple dissolved organic chemicals by stepwise adsorption. Special attention is given to the selective removal mechanisms for the major pollutant N,N-dimethylformamide (DMF), the sensitive pollutant fluorescent dissolved organic matter (FDOM) and other components. The results indicated that the combination of coal activated carbon and aluminum silica gel produced a synergistic effect and broke the limitation of removing only certain pollutants. Combined removal rates of 80.5 % for the dissolved organic carbon and 86.7 % for the biotoxicity in petrochemical wastewater were obtained with the enhanced two-step adsorption. The adsorption performance of both adsorbents remained stable even after five cycles. The selective adsorption mechanism revealed that hydrophobic organics such as DMF was adsorbed by the macropores of coal activated carbon, while the FDOM was eliminated by π-π stacking, electrostatic interaction and hydrophobic interaction. The hydrophilic organics were removed by the mesopores of aluminum silica gel, the silica hydroxyl groups and hydrophilic interaction. This study provides a comprehensive understanding of the selective adsorption mechanism and enhanced stepwise removal of multiple pollutants in petrochemical wastewater, which will guide the deep treatment of complex wastewater.

20.
World J Gastroenterol ; 29(43): 5804-5817, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-38074914

RESUMO

BACKGROUND: Surgical resection is the primary treatment for hepatocellular carcinoma (HCC). However, studies indicate that nearly 70% of patients experience HCC recurrence within five years following hepatectomy. The earlier the recurrence, the worse the prognosis. Current studies on postoperative recurrence primarily rely on postoperative pathology and patient clinical data, which are lagging. Hence, developing a new pre-operative prediction model for postoperative recurrence is crucial for guiding individualized treatment of HCC patients and enhancing their prognosis. AIM: To identify key variables in pre-operative clinical and imaging data using machine learning algorithms to construct multiple risk prediction models for early postoperative recurrence of HCC. METHODS: The demographic and clinical data of 371 HCC patients were collected for this retrospective study. These data were randomly divided into training and test sets at a ratio of 8:2. The training set was analyzed, and key feature variables with predictive value for early HCC recurrence were selected to construct six different machine learning prediction models. Each model was evaluated, and the best-performing model was selected for interpreting the importance of each variable. Finally, an online calculator based on the model was generated for daily clinical practice. RESULTS: Following machine learning analysis, eight key feature variables (age, intratumoral arteries, alpha-fetoprotein, pre-operative blood glucose, number of tumors, glucose-to-lymphocyte ratio, liver cirrhosis, and pre-operative platelets) were selected to construct six different prediction models. The XGBoost model outperformed other models, with the area under the receiver operating characteristic curve in the training, validation, and test datasets being 0.993 (95% confidence interval: 0.982-1.000), 0.734 (0.601-0.867), and 0.706 (0.585-0.827), respectively. Calibration curve and decision curve analysis indicated that the XGBoost model also had good predictive performance and clinical application value. CONCLUSION: The XGBoost model exhibits superior performance and is a reliable tool for predicting early postoperative HCC recurrence. This model may guide surgical strategies and postoperative individualized medicine.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Estudos Retrospectivos , Fatores de Risco , Aprendizado de Máquina
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...