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1.
Sci Rep ; 14(1): 14365, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38906924

RESUMO

A large number of tectonically mixed rock belts and complex tectonic zones are distributed in the southwestern part of China. In these areas, high geostress and tectonic stresses have caused some underground rock layers to be crushed and broken, eventually forming crushed rock zones. Which may undergo creep deformation under long-term loads. The manuscript is based on a typical crushed rock in the southwestern China. Firstly, the factors affecting creep deformation were analysed, and the response law of each influencing factor to rock creep is demonstrated. Then, the theory of uncorroborated measures and hierarchical analysis were used to systematically correlate the factors influencing creep. Thereby, a creep level qualitative evaluating model of crushed rock is established. Finally, this model was used to qualitatively evaluate the creep level of the crushed rock in the study area. It is concluded that the creep level qualitative evaluating of this crushed rock is rated as Class II, which is characterised by a low creep level and small creep deformations (0-10 mm). The research results can provide a reference for the creep analysis of crushed rock and provide a basis for the safe construction of engineering slopes.

2.
Chem Commun (Camb) ; 59(98): 14544-14546, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-37987162

RESUMO

Despite the fact that effective photosensitizers (PSs) can be achieved through rational molecular design, controlling the hierarchical assemblies of individual PSs with distinct function and morphological nanoscopic architectures remains a challenge. Here, very ordered one-dimensional PS polymers and their hollow tubular structures are presented from aqueous assembly of organic PS-based di- or tri-blocked supramolecules. Di-blocked PSs were interdigitated into 1D fibrils, significantly quenching photooxidation. Meanwhile, tri-blocked PSs were tilted with respect to each other to generate hollow tubules, showing remarkable photo-activities as well as photo-stability, which are particularly suited for green chemistry due to their unusual rapid photo-oxidation.

3.
Nat Commun ; 14(1): 2503, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37130853

RESUMO

Photosensitizers (PSs) with nano- or micro-sized pore provide a great promise in the conversion of light energy into chemical fuel due to the excellent promotion for transporting singlet oxygen (1O2) into active sites. Despite such hollow PSs can be achieved by introducing molecular-level PSs into porous skeleton, however, the catalytic efficiency is far away from imagination because of the problems with pore deformation and blocking. Here, very ordered porous PSs with excellent 1O2 generation are presented from cross-linking of hierarchical porous laminates originated by co-assembly of hydrogen donative PSs and functionalized acceptor. The catalytic performance strongly depends on the preformed porous architectures, which is regulated by special recognition of hydrogen binding. As the increasing of hydrogen acceptor quantities, 2D-organized PSs laminates gradually transform into uniformly perforated porous layers with highly dispersed molecular PSs. The premature termination by porous assembly endows superior activity as well as specific selectivity for the photo-oxidative degradation, which contributes to efficient purification in aryl-bromination without any postprocessing.

4.
Chem Asian J ; 17(21): e202200818, 2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36047433

RESUMO

During the past decades, in synthetic organic chemistry, directing-group-assisted C-H functionalization is found to be a key tool for the expedient and site-selective construction of C-C and hybrid bonds. Among C-H functionalization of ferrocene derivatives, the directed group strategy is undoubtedly the most commonly used method. Compared to the other directing groups, ferrocene amides can be synthesized easily and are now recognized as one of the most efficient tools for the selective functionalization of certain positions because its metal centre permits fine, tuneable and reversible coordination. The family of amide directing groups mainly comprises monodentate and bidentate directing groups, which are categorized on the basis of coordination sites. In this review, various C-H bond functionalization reactions of ferrocene using amide directing groups are broadly discussed.


Assuntos
Amidas , Elementos de Transição , Amidas/química , Metalocenos , Catálise , Elementos de Transição/química
5.
Anal Chem ; 94(2): 1397-1405, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34962777

RESUMO

The sensing technologies for monitoring molecular analytes in biological fluids with high frequency and in real time could enable a broad range of applications in personalized healthcare and clinical diagnosis. However, due to the limited dynamic range (less than 81-fold), real-time analysis of biomolecular concentration varying over multiple orders of magnitude is a severe challenge faced by this class of analytical platforms. For the first time, we describe here that temperature-modulated electrochemical aptamer-based sensors with a dynamically adjustable calibration-free detection window could enable continuous, real-time, and accurate response for the several-hundredfold target concentration changes in unprocessed actual samples. Specifically, we could regulate the electrode surface temperature of sensors to obtain the corresponding dynamic range because of the temperature-dependent affinity variations. This temperature modulation method relies on an alternate hot and cold electrode reported by our group, whose surface could actively be heated and cooled without the need for altering ambient temperature, thus likewise applying for the flowing system. We then performed dual-frequency calibration-free measurements at different interface temperatures, thus achieving an extended detection window from 25 to 2500 µM for procaine in undiluted urine, 1-500 µM for adenosine triphosphate, and 5-2000 µM for adenosine in undiluted serum. The resulting sensor architecture could drastically expand the real-time response range accessible to these continuous, reagent-less biosensors.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Temperatura
6.
Vet Med Sci ; 7(5): 1860-1866, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33955692

RESUMO

The purpose of this study was to investigate the effects of Amaranthus hypochondriacus (AH) inclusion in the diets of gestating and lactating sows on the lactational feed intake, nutrient digestibility, and growth performance of suckling piglets. During gestation, 40 multiparous Landrace sows were restrictively fed with either a control diet or a diet including 30% AH. Both diets had similar levels of digestible energy and crude protein, but the 30% AH diet had higher crude fibre levels than the control diet. After breeding, lactating sows were fed ad libitum with one of two isoenergetic and isonitrogenous diets, either a control diet or a diet containing 10% AH. In gestating sows, AH supplementation was found to be associated with decreased digestibility of crude protein and dry matter (p < .001), resulting in lesser backfat depth (p < .001). However, in lactating sows, AH supplementation had little effect on digestibility and milk composition; moreover, it increased the feed intake (p < .001) and decreased backfat loss (p < .001) in sows. On the 21st day of lactation, suckling piglets in AH group showed significantly greater average daily gains (p < .001), and average body weight and litter weight significantly increased compared with sows fed the control diet. In conclusion, AH-supplementation increased lactational feed intake in sows and improved the growth performance of suckling piglets.


Assuntos
Amaranthus , Lactação , Ração Animal/análise , Animais , Suplementos Nutricionais , Ingestão de Alimentos , Nutrientes , Melhoramento Vegetal , Gravidez , Suínos
7.
Anal Chim Acta ; 1164: 338521, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33992217

RESUMO

Conventional UV/Vis absorption spectroscopy is an economical and user-friendly technique for online monitoring, however, by which some electroactive chemicals are hardly determined in the presence of fluctuating background due to the formation of colored chemicals. Here, we propose an electrochemical difference absorption spectroscopy (EDAS) to accurately quantify colorless chemicals based on visible color change via electrolysis with strong variation in the background. EDAS is realized by twin spectroelectrochemical flow cells system, replacing the two cuvette cells of a dual beam spectrophotometer. Each cell consists of a three-electrode system, quartz windows and a thin flow channel. Flowing of analyte from one cell (reference cell) to the other (sample cell) can eliminate the influence of colored interferents even while their concentrations are changing. When different potentials are applied on the sample and reference cells respectively, electrolysis occurs and colored products flowing through quartz windows can absorb the incident light, resulting in difference absorption spectra induced from potential difference. We find that steady-state difference absorbance (ΔA) at characteristic wavelength is linearly changed with sample concentrations. EDAS is firstly verified by Fe(CN)64- at different potentials and flow rates, in good agreements with a simplified theory that describes linear relationship between ΔA and analyte concentration. Then EDAS is used to determine Cu(I) in Cu(I)-Cu(II) mixed solutions and tetramethylbenzidine in its partially oxidized solutions to illustrate the powerful ability to detect colorless chemicals with varied background, implying its promising potential applications in the chemical industry.

8.
Animals (Basel) ; 11(3)2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33652945

RESUMO

This study was conducted to investigate the effects of indole-3-acetate sodium (IAA-Na) inclusion in diets on the egg production performance, egg quality, intestinal tissue morphology, serum hormone levels and biochemical parameters of Danzhou chickens to preliminarily explore the efficacy of IAA-Na as a feed additive. A total of 192 Danzhou chickens (50 weeks old) were randomly assigned to 2 groups of 96. The diets for the treatment group consisted of the basal diets, supplemented with IAA-Na (200 mg/kg). The formal feeding trial lasted for four weeks. The results showed that the feed supplemented with IAA-Na not only increased the laying rate (p < 0.05) and egg yolk ratio (0.05 < p < 0.1), but also significantly reduced the feed:egg ratio (p < 0.05). In addition, the dietary supplementation of IAA-Na significantly increased the serum estradiol levels (p < 0.05) and decreased serum alkaline phosphatase activity (p < 0.05). Compared with the control group, the addition of IAA-Na to the diet had no significant effect on the intestinal tissue morphology or serum antioxidant capacity of Danzhou chickens. This study preliminarily provides evidence that dietary IAA-Na can improve laying performance, indicating that IAA-Na is a potentially effective feed additive for laying hens, but further studies are required before arriving at definite conclusions.

9.
Vet Med Sci ; 7(4): 1347-1358, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33620158

RESUMO

The purpose of this study was to investigate the effects of adding Pennisetum purpureum (P. purpureum, also known as Napier grass or elephant grass) to the diets of late gestation on the antioxidant indexes, immune indexes and faecal microbiota of sows. At the 90 days of gestation, 300 healthy sows were randomly divided into three groups, and they received the basic commercial diet or added 5% P. purpureum and 10% P. purpureum, respectively. The experiment started from 90 days of gestation to parturition. The results showed that the total antioxidant capacity, immunoglobulins and serum equol concentrations of sows on 100 days of gestation and at parturition increased linearly (p < .05) with the increase of the content of P. purpureum in the gestation diet. The 5% P. purpureum increased the relative abundance of Bacteroidetes (p = .027) and Actinobacteria (p < .001) at phylum level, Coriobacteriaceae (p < .001) at family level and Prevotellaceae_UCG_001 (p = .004) at genus level, and decreased the relative abundance of Escherichia_Shigella (p < .001) at genus level. In summary, this study shows that the additive of P. purpureum can increase the concentration of serum equol, improve the antioxidant capacity and immune function of sow in late gestation. In addition, the additive of 5% P. purpureum in the diet might change the composition of intestinal microbiota of sows, particularly the relative abundance of Coriobacteriaceae (p < .001) increased.


Assuntos
Antioxidantes/metabolismo , Suplementos Nutricionais/análise , Fezes/microbiologia , Imunidade Inata , Microbiota , Pennisetum/química , Prenhez/fisiologia , Sus scrofa/imunologia , Ração Animal/análise , Animais , Dieta/veterinária , Feminino , Imunidade Inata/efeitos dos fármacos , Microbiota/efeitos dos fármacos , Gravidez , Prenhez/efeitos dos fármacos
10.
Animals (Basel) ; 9(6)2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31159180

RESUMO

The amino acids and other components of diet provide nourishment for piglet intestinal development and maturation. However, early-weaned piglets struggle with tremendous stress, impairing normal intestinal health and leading to intestinal dysfunction and even death. The high prevalence worldwide of post-weaning diarrhoea syndrome (PWDS) in piglets has led to much interest in understanding the important role of nutrients in the establishment and maintenance of a functional intestinal tract. In particular, the impacts of amino acids on these functions must be considered. Amino acid levels greatly influence intestinal development in weaning piglets. The lack of amino acids can cause marked structural and functional changes in the intestine. Therefore, a comprehensive understanding of the functions of amino acids is necessary to optimize amino acid requirements of the developing intestinal tract to maximize piglet health and growth performance. This review summarizes the role of specific amino acids (arginine, glutamate, threonine, sulphur-containing amino acids (SCAAs), and branched-chain amino acids (BCAAs)) that have been proven to be beneficial for the intestinal health of weaned piglets.

11.
Bioorg Med Chem Lett ; 12(17): 2287-90, 2002 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-12161117

RESUMO

A series of 2-(substituted phenyl)-N-methyl-N-[(1S)-1-(substituted alkyl)-2-(1-(3-pyrrolinyl))ethyl]acetamides were synthesized and evaluated as highly selective kappa-agonists with K(i) values in low nanomolar range. 3-Pyrroline incorporated into the basic amino functionality in combination with 2-(methylthio)ethyl substituent on the carbon adjacent to the amide nitrogen remarkably enhanced the kappa-selectivity. 3,4-Dichlorophenyl derivative 1e was found the most potent and selective analgesic in this series with ED(50) value of 0.023 mg/kg.


Assuntos
Acetamidas/farmacologia , Analgésicos Opioides/síntese química , Receptores Opioides kappa/agonistas , Acetamidas/administração & dosagem , Acetamidas/síntese química , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/farmacologia , Animais , Humanos , Injeções Intraperitoneais , Dor/tratamento farmacológico , Pirróis/química , Ensaio Radioligante , Ratos , Relação Estrutura-Atividade
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