Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 223
Filtrar
1.
Med ; 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38986608

RESUMEN

BACKGROUND: Gastric cancer is the fifth most common cancer and the fourth most common cause of cancer death worldwide, yet the prognosis of advanced disease remains poor. METHODS: This was a randomized, double-blinded, phase 2 trial (ClinicalTrials.gov: NCT04908813). Patients with locally advanced/metastatic HER2-positive gastric/gastroesophageal junction cancer and no prior systemic antitumor therapy were randomized 1:1:1 to 25 mg/kg HLX22 (a novel anti-HER2 antibody) + HLX02 (trastuzumab biosimilar) + oxaliplatin and capecitabine (XELOX) (group A), 15 mg/kg HLX22 + HLX02 + XELOX (group B), or placebo + HLX02 + XELOX (group C) in 3-week cycles. Primary endpoints were progression-free survival (PFS) and objective response rate (ORR) assessed by independent radiological review committee (IRRC). FINDINGS: Between November 29, 2021, and June 6, 2022, 82 patients were screened; 53 were randomized to group A (n = 18), B (n = 17), and C (n = 18). With 14.3 months of median follow-up, IRRC-assessed median PFS was prolonged with the addition of HLX22 (A vs. C, 15.1 vs. 8.2 months, hazard ratio [HR] 0.5 [95% confidence interval (CI) 0.17-1.27]; B vs. C, not reached vs. 8.2 months, HR 0.1 [95% CI 0.04-0.52]). Confirmed ORR was comparable among groups (A vs. B vs. C, 77.8% vs. 82.4% vs. 88.9%). Treatment-related adverse events (TRAEs) were observed in 18 (100%), 16 (94.1%), and 17 (94.4%) patients, respectively. One (5.6%) patient in group C reported a grade 5 TRAE. CONCLUSIONS: Adding HLX22 to HLX02 and XELOX prolonged PFS and enhanced antitumor response in the first-line treatment of HER2-positive gastric cancer, with manageable safety. FUNDING: Shanghai Henlius Biotech, Inc.

2.
Sci Total Environ ; 946: 174188, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38925393

RESUMEN

Rice-crayfish farming systems (RCs) can help mitigate climate change by enhancing soil organic carbon (SOC) sequestration. However, the mechanisms that govern the responses of microbial residues carbon (MRC), a key component of SOC, in RCs are not fully understood. We conducted a 6-year field experiment comparing RCs and rice monoculture systems (RMs). Specifically, we explored how MRC formation and stabilization differ between the two systems and how those differences are linked to changes in the metabolic processes of microbes. Results showed that MRC levels in RCs were 5.2 % and 40.0 % higher in the topsoil and subsoil, respectively, compared to RMs, indicating depth-dependent effects. Notably, MRC accumulation and stabilization in RCs were promoted through a cascade of processes of dissolved organic carbon (DOC) accessibility-microbial metabolism-mineral protection. In addition, the mechanism of MRC accumulation in subsoil differed between the two systems. Specifically, RMs improved accessibility of DOC by reducing humification and aromaticity of subsoil DOC, which helped microbes access to resources at lower cost. This decreased the respiration rate of microbes, thereby increasing microbial carbon pump (MCP) efficiency and thus promoting MRC accumulation. By contrast, the crayfish in RCs facilitated carbon exchange between topsoil and subsoil through their burrowing behaviors. This increased carbon allocation for microbial metabolism in the subsoil, supporting a larger microbial population and thus enhancing the MCP capacity, while reducing MRC re-decomposition via enhanced mineral protection, further increasing subsoil MRC accumulation. That is, MRC accumulation in the subsoil of RCs was predominantly driven by microbial population numbers (MCP capacity) whereas that of RMs was mostly driven by microbial anabolic efficacy (MCP efficiency). Our findings reveal a key mechanism by which RCs promoted soil MRC accumulation and stabilization, highlighting the potential role of DOC accessibility-microbial metabolism-mineral protection pathway in regulating MRC accumulation and stabilization.

3.
Polymers (Basel) ; 16(9)2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38732739

RESUMEN

Developing high-performance and low-cost protein purification materials is of great importance to meet the demands for highly purified proteins in biotechnological industries. Herein, a facile strategy was developed to design and construct high-efficiency protein absorption and separation media by combining aerogels' molding techniques and impregnation processes. Poly (ethylene-co-vinyl alcohol) (EVOH) nanofibrous aerogels (NFAs) were modified by grafting butane tetracarboxylic acid (BTCA) over them in situ. This modification was carried out using polyphosphoric acid as a catalyst. The resulting EVOH/BTCA NFAs exhibited favorable comprehensive properties. Benefiting from the highly interconnected porous structure, good underwater compressive properties, and abundant absorption ligands, the obtained EVOH/BTCA NFAs possessed a high static absorption capacity of 1082.13 mg/g to lysozyme and a short absorption equilibrium time of about 6 h. A high saturated dynamic absorption capacity for lysozyme (716.85 mg/g) was also realized solely by gravity. Furthermore, EVOH/BTCA NFAs displayed excellent reusability, good acid and alkaline resistance, and unique absorption selectivity performance. The successful synthesis of such aerogels can provide a potential candidate for next-generation protein absorbents for bio-separation and purification engineering.

4.
Physiol Plant ; 176(3): e14360, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38797869

RESUMEN

Potassium (K+) is an essential macronutrient for appropriate plant development and physiology. However, little is known about the mechanisms involved in the regulation of leaf water relations by K under water deficit. A pot experiment with two K supplies of 0.45 and 0 g K2O per pot (3 kg soil per pot) and two watering conditions (well-watered and water-deficit) was conducted to explore the effects of K deficiency on canopy transpiration characteristics, leaf water status, photosynthesis, and hydraulic traits in two rice genotypes with contrasting resistance to drought. The results showed that K deficiency reduced canopy transpiration rate by decreasing stomatal conductance, which led to higher canopy temperatures, resulting in limited water deficit tolerance in rice. In addition, K deficiency led to further substantial reductions in leaf relative water content and water potential under water deficit, which increased the imbalance in leaf water relations under water deficit. Notably, K deficiency limited leaf gas exchange by reducing leaf hydraulic conductance, but decreased the intrinsic water use efficiency under water deficit, especially for the drought-resistant cultivar. Further analysis of the underlying process of leaf hydraulic resistance revealed that the key limiting factor of leaf hydraulic conductance under K deficiency was the outside-xylem hydraulic conductance rather than the xylem hydraulic conductance. Overall, our results provide a comprehensive perspective for assessing leaf water relations under K deficiency, water deficit, and their combined stresses, which will be useful for optimal rice fertilization strategies.


Asunto(s)
Sequías , Oryza , Hojas de la Planta , Transpiración de Plantas , Potasio , Agua , Oryza/fisiología , Oryza/genética , Oryza/metabolismo , Hojas de la Planta/fisiología , Hojas de la Planta/metabolismo , Agua/metabolismo , Transpiración de Plantas/fisiología , Potasio/metabolismo , Fotosíntesis/fisiología , Estomas de Plantas/fisiología , Xilema/fisiología , Xilema/metabolismo
5.
Molecules ; 29(10)2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38792066

RESUMEN

The objective of this study is to develop a remediation technology for composited heavy metal-contaminated soil. Biochars (BC300, BC400, and BC500) derived from corn were combined with potassium dihydrogen phosphate (KH2PO4) to immobilize and remove heavy metal ions, including mercury (Hg2+), cadmium (Cd2+), and lead (Pb2+). The adsorption kinetics of metal ions in aqueous solutions with different concentrations was tested, and the fitting effects of the two models were compared. The findings demonstrate that the joint application of biochar and KH2PO4 could markedly enhance the immobilization efficacy of Pb2+, whereas the utilization of KH2PO4 on its own exhibited a more pronounced immobilization impact on Cd2+. Furthermore, the present study underscores the shortcomings of various remediation techniques that must be taken into account when addressing heavy metal-contaminated soils. It also emphasizes the value of comprehensive remediation techniques that integrate multiple remediation agents. This study offers a novel approach and methodology for addressing the intricate and evolving challenges posed by heavy metal contamination in soil. Its practical value and potential for application are significant.


Asunto(s)
Cadmio , Carbón Orgánico , Plomo , Mercurio , Fosfatos , Compuestos de Potasio , Contaminantes del Suelo , Carbón Orgánico/química , Contaminantes del Suelo/química , Cadmio/química , Plomo/química , Adsorción , Mercurio/química , Fosfatos/química , Compuestos de Potasio/química , Restauración y Remediación Ambiental/métodos , Medición de Riesgo , Suelo/química , Metales Pesados/química , Cinética
6.
Polymers (Basel) ; 16(8)2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38675001

RESUMEN

Polypeptoids with well-designed structures have the ability to self-assemble into nanomaterials, which have wide potential applications. In this study, a series of diblock copolypeptoids were synthesized via ring-opening polymerization followed by click chemistry and exhibited both temperature and pH stimulation responsiveness. Under specific temperature and pH conditions, the responsive blocks in the copolypeptoids became hydrophobic and aggregated to form micelles. The self-assembly process was monitored using the UV-Vis and DLS methods, which suggested the reversible transition of free molecules to micelles and bigger aggregates upon instituting temperature and pH changes. By altering the length and proportion of each block, the copolypeptoids displayed varying self-assembly characteristics, and the transition temperature could be tuned. With good biocompatibility, stability, and no cytotoxicity, the polypeptoids reported in this study are expected to be applied as bionanomaterials in fields including drug delivery, tissue engineering, and intelligent biosensing.

7.
Polymers (Basel) ; 16(7)2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38611248

RESUMEN

The development of nontoxic and efficient antifreeze agents for organ cryopreservation is crucial. However, the research remains highly challenging. In this study, we designed and synthesized a series of peptoid oligomers using the solid-phase submonomer synthesis method by mimicking the amphiphilic structures of antifreeze proteins (AFPs). The obtained peptoid oligomers showed excellent antifreeze properties, reducing the ice crystal growth rate and inhibiting ice recrystallization. The effects of the hydrophobicity and sequence of the peptoid side chains were also studied to reveal the structure-property relationship. The prepared peptoid oligomers were detected as non-cytotoxic and considered to be useful in the biological field. We hope that the peptoid oligomers presented in this study can provide effective strategies for the design of biological cryoprotectants for organ preservation in the future.

8.
Molecules ; 29(5)2024 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-38474511

RESUMEN

This study investigates the synergistic effect and mechanism of gelling materials with blast furnace slag (BFS), steel slag (SS) and desulphurization gypsum (DG) as the main components on the hardening of heavy metal ions by lead and zinc tailings. It is found that lead and zinc tailing (LZT) is mainly composed of dolomite and quartz and contain small amounts of calcium, aluminum, iron, magnesium and other elements as well as heavy metals such as lead and zinc. By the mechanical activation method, it is found that the lead and zinc tailings powder has the largest specific surface area and the highest activity index when the ball milling time is 2 h. At a hardening timepoint of 28 d, the calcite crystals in the samples are intertwined with the amorphous C-S-H gel (C-S-H gels are mainly composed of 3CaO∙SiO2 and 2CaO∙SiO2), which enhances the structural strength of the samples. The chemical reaction analysis confirmed that the formation of calcite is a major driver for the hydration reaction of the steel slag-desulphurization gypsum (SSSDG) system. Overall, the slag, steel slag and desulphurization gypsum solid waste-based gelling materials have synergistic effects in hardening heavy metals by limiting the leaching of metal ions, adsorbing metal ions and hardening heavy metals, and facilitating the hydration process through the formation of compound salt precipitates.

9.
Neural Netw ; 172: 106134, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38245924

RESUMEN

Natural data typically exhibits a long-tailed distribution, presenting great challenges for recognition tasks. Due to the extreme scarcity of training instances, tail classes often show inferior performance. In this paper, we investigate the problem within the trendy visual-language (VL) framework and find that the performance bottleneck mainly arises from the recognition confusion between tail classes and their highly correlated head classes. Building upon this observation, unlike previous research primarily emphasizing class frequency in addressing long-tailed issues, we take a novel perspective by incorporating a crucial additional factor namely class correlation. Specifically, we model the representation learning procedure for each sample as two parts, i.e., a special part that learns the unique properties of its own class and a common part that learns shared characteristics among classes. By analysis, we discover that the learning process of common representation is easily biased toward head classes. Because of the bias, the network may lean towards the biased common representation as classification criteria, rather than prioritizing the crucial information encapsulated within the specific representation, ultimately leading to recognition confusion. To solve the problem, based on the VL framework, we introduce the rectification contrastive term (ReCT) to rectify the representation bias, according to semantic hints and training status. Extensive experiments on three widely-used long-tailed datasets demonstrate the effectiveness of ReCT. On iNaturalist2018, it achieves an overall accuracy of 75.4%, surpassing the baseline by 3.6 points in a ResNet-50 visual backbone.


Asunto(s)
Lenguaje , Semántica , Sesgo , Aprendizaje , Reconocimiento en Psicología
10.
Small Methods ; : e2301225, 2024 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-38279586

RESUMEN

Aluminum-oxygen batteries (AOBs) own the benefits of high energy density (8.14 kWh kg-1 ), low cost, and high safety. However, the design of a cathode with high surface area, structure integrity, and good catalytic performance is still challenging for rechargeable AOBs. Herein, the fabrication of a robust self-supporting cathode using 3D graphene aerogel (3DGA) for rechargeable AOBs is demonstrated. Electroanalysis showed that the 3DGA presented good catalytic activity in both oxygen reduction and evolution reactions, which allowed the AOB to operate for >90 cycles with low overpotentials at a current density of 0.2 mA cm-2 , and a high Coulombic efficiency of ca. 99% using ionic liquid as electrolyte. In comparison, the cell with the carbon paper cathode can only cycle for 50 rounds. The excellent cyclic performance can be attributed to the porous structure, large surface area, good electric conductivity, and catalytic activity of the 3DGA, which is prospective to be applied for other metal-air batteries, fuel cells, and supercapacitors.

11.
ACS Omega ; 9(1): 1375-1388, 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38222615

RESUMEN

The structural fracture of the coal seam with its low permeability is the dominant reason for the "difficult gas out" of the broken soft coal seam. The brittleness of the roof and floor rock stratum of the broken soft coal seam has a significant effect on the fracture extension pressure of the surrounding rock after casing perforation and hydraulic fracturing of the horizontal well for coalbed methane (CBM). In this paper, 15 rock samples were scientifically collected from the roof and floor of the main mining coal seam of the Early Permian coal-bearing series in the Xinxie-1 well of the Huainan Coalfield in Anhui Province, China. On the basis of mineral composition analysis of these samples, the influence of mineral composition on the mechanics properties of the rock at the roof and floor of the coal seam was investigated. The correlation analysis and gray correlation analysis were adopted to construct an evaluation method for the brittleness of the rock at the roof and floor of the coal seam based on the mineral content. The results indicated that the most significant compositions of the minerals in the rock at the roof and floor of the broken soft coal seam were quartz and clay minerals. The most significant types of rock cementation are quartz agglomeration and rhodochrosite cementation. Pore destruction as a result of cementation was much greater than that of compaction. In comparison to clay minerals, the variation in the content of brittle minerals such as quartz, plagioclase, and siderite in the rock showed more sensitivity to the mechanics properties of the rock. The more sensitive minerals for compressive strength (CS), shear strength (SS), modulus of elasticity (E), softening coefficient (K), and Poisson's ratio (µ) are quartz, those for tensile strength (TS) are plagioclase and siderite, and those for Poisson's ratio are clay minerals. Based on the established mineral content weighting analysis method, it was calculated that the brittleness index (BI) of the rocks at the roof of the 13-1, 11-2, 9-2, and 4-2 coal seams was larger, which was advantageous for the formation of longer fracturing crack networks. This is theoretical guidance for the optimization of horizontal well fracturing design in the deep coal beds of the Huainan Coalfield.

12.
Plant J ; 117(2): 483-497, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37901950

RESUMEN

Plants grown under low magnesium (Mg) soils are highly susceptible to encountering light intensities that exceed the capacity of photosynthesis (A), leading to a depression of photosynthetic efficiency and eventually to photooxidation (i.e., leaf chlorosis). Yet, it remains unclear which processes play a key role in limiting the photosynthetic energy utilization of Mg-deficient leaves, and whether the plasticity of A in acclimation to irradiance could have cross-talk with Mg, hence accelerating or mitigating the photodamage. We investigated the light acclimation responses of rapeseed (Brassica napus) grown under low- and adequate-Mg conditions. Magnesium deficiency considerably decreased rapeseed growth and leaf A, to a greater extent under high than under low light, which is associated with higher level of superoxide anion radical and more severe leaf chlorosis. This difference was mainly attributable to a greater depression in dark reaction under high light, with a higher Rubisco fallover and a more limited mesophyll conductance to CO2 (gm ). Plants grown under high irradiance enhanced the content and activity of Rubisco and gm to optimally utilize more light energy absorbed. However, Mg deficiency could not fulfill the need to activate the higher level of Rubisco and Rubisco activase in leaves of high-light-grown plants, leading to lower Rubisco activation and carboxylation rate. Additionally, Mg-deficient leaves under high light invested more carbon per leaf area to construct a compact leaf structure with smaller intercellular airspaces, lower surface area of chloroplast exposed to intercellular airspaces, and CO2 diffusion conductance through cytosol. These caused a more severe decrease in within-leaf CO2 diffusion rate and substrate availability. Taken together, plant plasticity helps to improve photosynthetic energy utilization under high light but aggravates the photooxidative damage once the Mg nutrition becomes insufficient.


Asunto(s)
Anemia Hipocrómica , Brassica napus , Brassica napus/metabolismo , Ribulosa-Bifosfato Carboxilasa/metabolismo , Magnesio , Dióxido de Carbono , Fotosíntesis/fisiología , Hojas de la Planta/metabolismo
13.
Artículo en Inglés | MEDLINE | ID: mdl-38069560

RESUMEN

In this study, wheat straw-derived biochar was prepared by setting a temperature of 400 °C under an oxygen-limited environment using the technique of "programmed temperature increase control". The results showed that the biochar had a strong adsorption capacity for Hg2+, Cd2+ and Pb2+ ions, and the adsorption pattern was Hg2+>Cd2+>Pb2+. There was a competitive adsorption effect during the coexistence of the ions. The results of the soil remediation tests showed that the effects of biochar on soil physicochemical properties and heavy metal distribution was generally greater than those of KH2PO4 in single or combined contaminated soil. The adsorption effect of heavy metal ions in soil was the best in the case of mixed additions. The results can provide a scientific basis for the treatment of heavy metal contaminated soil with wheat straw biochar in the future.


Asunto(s)
Mercurio , Metales Pesados , Contaminantes del Suelo , Cadmio/análisis , Plomo , Suelo/química , Contaminantes del Suelo/análisis , Metales Pesados/análisis , Carbón Orgánico/química , Triticum
14.
Toxics ; 11(12)2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-38133404

RESUMEN

In the present study, the developmental toxicity and endocrine-disrupting effects of fenpropathrin on Gobiocypris rarus during the early life stage were studied using a semi-static water exposure method. The results showed that the LOEC (lowest observed effect concentration) of fenpropathrin on the incubation of rare minnow embryos was above 2.5 µg·L-1. The LOEC and NOEC (no observed effect concentration) of fenpropathrin on the developmental malformations and death indicators were 2.0 and 1.5 µg·L-1, respectively. After exposure to 1.5 µg·L-1 of fenpropathrin for 31 days, the expressions of androgen receptor genes (AR) and sex hormone-synthesis-related genes (CYP17 and CYP19a) were significantly decreased and the expressions of thyroid hormone receptor genes (TRß) and aryl hydrocarbon receptor genes (AhR1a and AhR2) were significantly increased in juvenile Gobiocypris rarus. The expression levels of the androgen receptor gene (AR), estrogen receptor gene (ER1), and the sex hormone-synthesis-related genes (HMGR, CYP17, and CYP19a) were significantly decreased, while the estrogen receptor gene (ER2a), thyroid hormone receptor gene (TRß), and aromatic hydrocarbon receptor genes (AhR1a and AhR2) were upregulated in juvenile Gobiocypris rarus under exposure to 2.0 µg·L-1 of fenpropathrin. Relatively low concentrations of fenpropathrin can affect the expression of sex hormone receptor genes, genes related to sex hormone synthesis, thyroid hormone receptor genes, and aromatic hydrocarbon receptor genes, thus interfering with the reproductive system, thyroid system, and metabolic level in Gobiocypris rarus. Therefore, more attention should be paid to the endocrine-disrupting effect caused by the pyrethroid insecticides in the water environment. Furthermore, studies on the internal mechanism of the endocrine-disrupting effect of pyrethroid insecticides on fish is needed in the future.

15.
Chemosphere ; 344: 140390, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37820877

RESUMEN

Crop residues perform an essential role in the material cycling and energy exchange processes and are commonly used as an organic soil amendment and potassium (K) substitute to enhance field productivity in rice-upland rotation systems. Elucidating the effects of continuous K fertilization combined with straw return on the fate of soil K is of great significance to the scientific application of K fertilization and the sustainable development of the ecological environment. A short-(5 years) and a long-term (38 years) field experiments at the Wuxue (WX) and Wangcheng (WC) sites respectively were conducted to study the effects of continuous K fertilization combined with straw return on soil potassium (K) fertility and loss. Results showed that K fertilization and straw return improved soil K supply capacity significantly. K fertilization (NPK) and straw return (NPK + ST) at WX and WC sites significantly increased soil exchangeable K content (KE) by 27.7%-102.1% and 36.6%-100.0%, respectively, compared with that of the treatment without K (NP). K release kinetics showed that most K+ was released in soil of the NPK+ST treatment, indicating a stronger soil K+ supplying capacity. Long-term K deficit resulted in the conversion of illite to interlayer minerals and kaolinite, which were not detected at the short-term experiment site. Integrated K fertilizer and straw return reduced soil bulk density (BD) and degree of anisotropy (DA), increased fractal dimension (FD) and optimized soil pore structure distribution. Nonetheless, continuous sufficient K input raised the amount of total K loss through runoff and leaching. Compared with that of NP treatment, the total K loss of NPK and NPK + ST treatments were increased by 160.3% and 227.5%, respectively. This strategy contributed to the conversion of bio-waste into resources, sustainable soil K management and scientific K fertilizer application for agricultural production.


Asunto(s)
Oryza , Suelo , Suelo/química , Potasio/química , Fertilizantes , Agricultura/métodos , Fertilización , Nitrógeno
16.
Plant Physiol Biochem ; 201: 107912, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37523826

RESUMEN

Under potassium (K) deficiency photosynthetic carboxylation capacities are limited, affecting the photosynthetic rate of plants. However, it is not clear how ionic K within plants regulates carboxylation capacities. Therefore, the photosynthetic rate (A), ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) characteristics, and cytoplasmic pH of Brassica napus leaves with different K levels were measured to evaluate the effects of K on the carboxylation capacity by regulating subcellular pH. The results showed that biochemical limitation dominates the decrease of A. There was a close positive correlation between A and the Rubisco maximum carboxylation rate (Vcmax), which was closer than that between A and the maximum electron transport rate. The thresholds of leaf K concentrations causing decreased A, Vcmax, and Rubisco initial activity were consistent and close to 1.0% in the hydroponic experiments and 1.2% in the field experiments. K deficiency resulted in decreased Rubisco activity, which reduced carboxylation capacity. Moreover, the Rubisco initial activities in vitro with sufficient K supply or under K deficiency all were significantly reduced when the pH was decreased. The cytoplasmic pH was kept neutral at 7.5 under sufficient K supply, and decreased as the leaf K concentration declined below the threshold. Acidified cytoplasmic environment caused by K deficiency could not maintain the pH balance of the chloroplasts, leading to decreased Rubisco initial activity and photosynthetic capacity.


Asunto(s)
Brassica napus , Deficiencia de Potasio , Ribulosa-Bifosfato Carboxilasa/metabolismo , Brassica napus/metabolismo , Fotosíntesis/fisiología , Plantas/metabolismo , Hojas de la Planta/metabolismo , Concentración de Iones de Hidrógeno , Dióxido de Carbono
17.
Foods ; 12(11)2023 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-37297417

RESUMEN

This study aimed to investigate the nutritional properties of yak milk in various areas of Gannan. The milk composition analyzer, automatic amino acid analyzer, and flavor analyzer were used to detect the conventional nutrients, amino acids, and volatile flavor substances of 249 yak milks in Meiren grassland, Xiahe grassland, and Maqu grassland (hereinafter referred to as Meiren yak, Xiahe yak, and Maqu yak) in the Gannan area. The results showed that the fat content of Meiren yak milk was significantly higher than that of Maqu yak and Xiahe yak (p < 0.05). The protein content of Meiren yak milk was significantly higher than that of Xiahe yak (p < 0.05), but not significantly different from that of Maqu yak (p > 0.05). The casein content in the milk of Maqu yak was significantly higher than that of Meiren yak and Xiahe yak (p < 0.05). There was no significant difference in the lactose content of yak milk in the three regions (p > 0.05). The content of glutamic acid in the milk of Meiren yak, Xiahe yak, and Maqu yak was noticeably high, which was 1.03 g/100 g, 1.07 g/100 g, and 1.10 g/100 g, respectively. The total amino acid (TAA) content was 4.78 g/100 g, 4.87 g/100 g, and 5.0 g/100 g, respectively. The ratios of essential amino acids (EAA) and total amino acids (TAA) in the milk of Meiren yak, Xiahe yak, and Maqu yak were 42.26%, 41.27%, and 41.39%, respectively, and the ratios of essential amino acids (EAA) and nonessential amino acids (NEAA) were 73.19%, 70.28%, and 70.61%, respectively. In the yak milk samples collected from three different regions, a total of 34 volatile flavor compounds were detected, including 10 aldehydes, five esters, six ketones, four alcohols, two acids, and seven others. The main flavor substances qualitatively obtained from Meiren yak milk were ethyl acetate, n-valeraldehyde, acetic acid, heptanal, and n-hexanal. Xiahe yak milk mainly contains ethyl acetate, isoamyl alcohol, n-valeraldehyde, heptanal, and ethyl butyrate. Maqu yak milk mainly contains ethyl acetate, n-valeraldehyde, isoamyl alcohol, heptanal, ethyl butyrate, and n-hexanal. Principal component analysis showed that the flavor difference between Xiahe yak and Maqu yak was small, while the flavor difference between Xiahe yak, Maqu yak, and Meiren yak was large. The findings of this research can serve as a foundation for the future advancement and application of yak milk.

18.
Chem Commun (Camb) ; 59(46): 7028-7031, 2023 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-37128894

RESUMEN

Ice crystals can cause great damage. The utilization of antifreeze agents is an efficient method to prevent or reduce ice crystal formation and growth. Synthetic antifreeze agents are toxic and have low efficiency, and natural antifreeze proteins suffer from high cost and low stability. Here, we have designed and synthesized a series of peptoid oligomers by mimicking the antifreeze protein structure, and the structure-property relationship was also studied. The reported peptoids here have excellent antifreeze properties and are nontoxic to cells. These novel peptoid materials have great potential to replace current commonly used antifreeze agents, such as dimethyl sulfoxide, and become a new generation of antifreeze agents applied in cryopreservation.


Asunto(s)
Hielo , Peptoides , Biomimética , Peptoides/farmacología , Crioprotectores/química , Criopreservación/métodos , Proteínas Anticongelantes/química
19.
J Oncol ; 2023: 3876342, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37153834

RESUMEN

Gastric cancer (GC) is the third most lethal and fifth most common cancer in the world. In a variety of cancers, the hexokinase domain component 1 (HKDC1) is carcinogenic. This study was to investigate into how HKDC1 contributes to the development and progression of GC. Three different datasets (GSE103236, GSE13861, and GSE55696) were extracted from the Gene Expression Omnibus (GEO) database and then analyzed using the sva package. The R software was used to identify 411 differentially expressed genes (DEGs) in the pooled dataset. We discovered 326 glycolysis-related genes (glyGenes) in the cancer genome atlas-stomach adenocarcinoma (TCGA-STAD) cohort using gene set enrichment analysis set (GSEA). HKDC1 is one of the most prevalent glyGenes in GC tumor tissues and cells, as seen in the Venn diagram. According to the results of the Cell Count Kit-8 assay, the proliferation of AGS and MKN-45 cells decreased when HKDC1 was knocked down. Lack of HKDC1 in cells enhanced oxygen consumption and decreased glycolytic protein expression while suppressing glucose absorption, lactate production, ATP level, and extracellular acidification ratio. As an oncogene in gastric cancer development, HKDC1 influences cell proliferation and glycolysis.

20.
IEEE J Biomed Health Inform ; 27(5): 2399-2410, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37028301

RESUMEN

Recently, there has been significant progress in medical image segmentation utilizing deep learning techniques. However, these achievements largely rely on the supposition that the source and target domain data are identically distributed, and the direct application of related methods without addressing the distribution shift results in dramatic degradation in realistic clinical environments. Current approaches concerning the distribution shift either require the target domain data in advance for adaptation, or focus only on the distribution shift across domains while ignoring the intra-domain data variation. This paper proposes a domain-aware dual attention network for the generalized medical image segmentation task on unseen target domains. To alleviate the severe distribution shift between the source and target domains, an Extrinsic Attention (EA) module is designed to learn image features with knowledge originating from multi-source domains. Moreover, an Intrinsic Attention (IA) module is also proposed to handle the intra-domain variation by individually modeling the pixel-region relations derived from an image. The EA and IA modules complement each other well in terms of modeling the extrinsic and intrinsic domain relationships, respectively. To validate the model effectiveness, comprehensive experiments are conducted on various benchmark datasets, including the prostate segmentation in magnetic resonance imaging (MRI) scans and the optic cup/disc segmentation in fundus images. The experimental results demonstrate that our proposed model effectively generalizes to unseen domains and exceeds the existing advanced approaches.


Asunto(s)
Benchmarking , Disco Óptico , Masculino , Humanos , Fondo de Ojo , Conocimiento , Pelvis , Procesamiento de Imagen Asistido por Computador
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...