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2.
J Hazard Mater ; 470: 134261, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38608589

RESUMEN

Nitrate reduction reaction (NO3RR) is deemed a promising pathway for both ammonia synthesis and water purification. Developing a high-efficiency catalyst with excellent NH3 selectivity and catalytic stability is desirable but remains challenging. In this work, a dendritic copper oxide catalyst (Cu-B2) has been developed to efficiently catalyze NO3RR for ammonia production, the Cu-B2 exhibits excellent catalytic performance, achieving an NH3 Faradaic efficiency as high as 94 % and an NH3 yield of 16.9 mg h-1 cm-2 with a current density of 192.3 mA cm-2 at - 0.6 V (vs. RHE, reversible hydrogen electrode). During NO3RR testing, the Cu-B2 catalysts are reduced in situ to form highly active Cu0/Cu+ sites, while retaining its dendritic morphology. Compared with other catalysts, the Cu-O bond in Cu-B2 catalyst has weaker polarity, resulting in Cu0/Cu+ sites in lower oxidation states. In situ attenuated total reflection surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) studies reveal the Cu-B2 catalyst exhibits a potential-independent capability for *NO3- adsorption and high conversion efficiency of NO2- intermediate into ammonia, DFT calculations reveal that Cu-B2 exhibts higher NO3- adsorption energy and lower NO3- adsorption energy barrier than Cu-B1, thus endowing it with a remarkably improved catalytic activity and durability.

3.
J Environ Manage ; 357: 120691, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38554452

RESUMEN

Regions affected by heavy metal contamination frequently encounter phosphorus (P) deficiency. Numerous studies highlight crucial role of P in facilitating cadmium (Cd) accumulation in woody plants. However, the regulatory mechanism by which P affects Cd accumulation in roots remains ambiguous. This study aims to investigate the effects of phosphorus (P) deficiency on Cd accumulation, Cd subcellular distribution, and cell wall components in the roots of Salix caprea under Cd stress. The results revealed that under P deficiency conditions, there was a 35.4% elevation in Cd content in roots, coupled with a 60.1% reduction in Cd content in shoots, compared to the P sufficiency conditions. Under deficient P conditions, the predominant response of roots to Cd exposure was the increased sequestration of Cd in root cell walls. The sequestration of Cd in root cell walls increased from 37.1% under sufficient P conditions to 66.7% under P deficiency, with pectin identified as the primary Cd binding site under both P conditions. Among cell wall components, P deficiency led to a significant 31.7% increase in Cd content within pectin compared to P sufficiency conditions, but did not change the pectin content. Notably, P deficiency significantly increased pectin methylesterase (PME) activity by regulating the expression of PME and PMEI genes, leading to a 10.4% reduction in the degree of pectin methylesterification. This may elucidate the absence of significant changes in pectin content under P deficiency conditions and the concurrent increase in Cd accumulation in pectin. Fourier transform infrared spectroscopy (FTIR) results indicated an increase in carboxyl groups in the root cell walls under P deficiency compared to sufficient P treatment. The results provide deep insights into the mechanisms of higher Cd accumulation in root mediated by P deficiency.


Asunto(s)
Pectinas , Salix , Pectinas/química , Pectinas/metabolismo , Pectinas/farmacología , Cadmio/metabolismo , Salix/metabolismo , Raíces de Plantas/química , Pared Celular/metabolismo , Fósforo/análisis
4.
ACS Appl Mater Interfaces ; 16(11): 13611-13621, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38456377

RESUMEN

Cellulose foams are considered an effective alternative to plastic foam, because of their advantages of low density, high porosity, low thermal conductivity, and renewable nature. However, they still suffer from complex processing, poor mechanical properties, and flammability. As an agricultural waste, bagasse is rich in cellulose, which has attracted much attention. Inspired by the fact that borate ions can effectively enhance the strength of plant tissue by their cross-linking with polysaccharides, the present work designs and fabricates a series of multifunctional bagasse foams with robust strength and improved thermal insulation and flame retardancy via a unique borax-induced self-assembly and atmospheric pressure drying route using bagasse as a raw material, borate as a cross-linking agent, and chitosan as an additive. As a result, the optimized foam exhibits a high porosity (93.5%), a high hydrophobic water contact angle (150.4°), a low thermal conductivity (63.4 mW/(m·K) at 25 °C), and an outstanding flame retardancy. The present study provides a novel and inspiring idea for large-scale production of cellulose foams through an environmentally friendly and cost-effective approach.

5.
Nat Commun ; 15(1): 2740, 2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38548733

RESUMEN

Photoreceptor proteins utilise chromophores to sense light and trigger a biological response. The discovery that adenosylcobalamin (or coenzyme B12) can act as a light-sensing chromophore heralded a new field of B12-photobiology. Although microbial genome analysis indicates that photoactive B12-binding domains form part of more complex protein architectures, regulating a range of molecular-cellular functions in response to light, experimental evidence is lacking. Here we identify and characterise a sub-family of multi-centre photoreceptors, termed photocobilins, that use B12 and biliverdin (BV) to sense light across the visible spectrum. Crystal structures reveal close juxtaposition of the B12 and BV chromophores, an arrangement that facilitates optical coupling. Light-triggered conversion of the B12 affects quaternary structure, in turn leading to light-activation of associated enzyme domains. The apparent widespread nature of photocobilins implies involvement in light regulation of a wider array of biochemical processes, and thus expands the scope for B12 photobiology. Their characterisation provides inspiration for the design of broad-spectrum optogenetic tools and next generation bio-photocatalysts.


Asunto(s)
Pigmentos Biliares , Fotorreceptores Microbianos , Fotoquímica , Biliverdina , Proteínas Bacterianas/metabolismo , Fotorreceptores Microbianos/química , Luz
6.
FEBS J ; 291(7): 1404-1421, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38060334

RESUMEN

The photoenzyme protochlorophyllide oxidoreductase (POR) is an important enzyme for understanding biological H-transfer mechanisms. It uses light to catalyse the reduction of protochlorophyllide to chlorophyllide, a key step in chlorophyll biosynthesis. Although a wealth of spectroscopic data have provided crucial mechanistic insight, a structural rationale for POR photocatalysis has proved challenging and remains hotly debated. Recent structural models of the ternary enzyme-substrate complex, derived from crystal and electron microscopy data, show differences in the orientation of the protochlorophyllide substrate and the architecture of the POR active site, with significant implications for the catalytic mechanism. Here, we use a combination of computational and experimental approaches to investigate the compatibility of each structural model with the hypothesised reaction mechanisms and propose an alternative structural model for the cyanobacterial POR ternary complex. We show that a strictly conserved tyrosine, previously proposed to act as the proton donor in POR photocatalysis, is unlikely to be involved in this step of the reaction but is crucial for Pchlide binding. Instead, an active site cysteine is important for both hydride and proton transfer reactions in POR and is proposed to act as the proton donor, either directly or through a water-mediated network. Moreover, a conserved glutamine is important for Pchlide binding and ensuring efficient photochemistry by tuning its electronic properties, likely by interacting with the central Mg atom of the substrate. This optimal 'binding pose' for the POR ternary enzyme-substrate complex illustrates how light energy can be harnessed to facilitate enzyme catalysis by this unique enzyme.


Asunto(s)
Cianobacterias , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Protoclorofilida/química , Luz , Protones , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/metabolismo , Fotoquímica
7.
Biochem Pharmacol ; 219: 115960, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38049008

RESUMEN

Prostate cancer is the most common malignant tumor among men worldwide. Currently, the main treatments are radical prostatectomy, radiotherapy, chemotherapy, and endocrine therapy. However, most of them are poorly effective and induce side effects. Polo-like kinase 1 (PLK1) regulates cell cycle and mitosis. Its inhibitor BI2536 promotes the therapeutic effect of nilotinib in chronic myeloid leukemia, enhances the sensitivity of neural tube cell tumors to radiation therapy and PLK1 silencing enhances the sensitivity of squamous cell carcinoma to cisplatin. Therefore, the aim of this study was to evaluate the effect of the PLK1 inhibitor L-shaped ortho-quinone analog TE6 on prostate cancer. In vitro on prostate cancer cells showed that TE6 inhibited PLK1 protein expression and consequently cell proliferation by blocking the cell cycle at G2 phase. In vivo on a subcutaneous tumor model in nude mice confirmed that TE6 effectively inhibited tumor growth in nude mice, inhibited PLK1 expression and regulated the expression of cell cycle proteins such as p21, p53, CDK1, Cdc25C, and cyclinB1. Thus, PLK1 was identified as the target protein of TE6, these results reveal the critical role of PLK1 in the growth and survival of prostate cancer and point out the ability of TE6 on targeting PLK1, being a potential drug for prostate cancer therapy.


Asunto(s)
Fase G2 , Quinasa Tipo Polo 1 , Neoplasias de la Próstata , Quinonas , Quinasa Tipo Polo 1/antagonistas & inhibidores , Quinonas/química , Quinonas/farmacología , Neoplasias de la Próstata/tratamiento farmacológico , Fase G2/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Xenoinjertos , Humanos , Animales , Ratones , Masculino , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Línea Celular Tumoral , Estructura Molecular
8.
Plant Biotechnol J ; 22(1): 216-232, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37792967

RESUMEN

Lipid biosynthesis and transport are essential for plant male reproduction. Compared with Arabidopsis and rice, relatively fewer maize lipid metabolic genic male-sterility (GMS) genes have been identified, and the sporopollenin metabolon in maize anther remains unknown. Here, we identified two maize GMS genes, ZmTKPR1-1 and ZmTKPR1-2, by CRISPR/Cas9 mutagenesis of 14 lipid metabolic genes with anther stage-specific expression patterns. Among them, tkpr1-1/-2 double mutants displayed complete male sterility with delayed tapetum degradation and abortive pollen. ZmTKPR1-1 and ZmTKPR1-2 encode tetraketide α-pyrone reductases and have catalytic activities in reducing tetraketide α-pyrone produced by ZmPKSB (polyketide synthase B). Several conserved catalytic sites (S128/130, Y164/166 and K168/170 in ZmTKPR1-1/-2) are essential for their enzymatic activities. Both ZmTKPR1-1 and ZmTKPR1-2 are directly activated by ZmMYB84, and their encoded proteins are localized in both the endoplasmic reticulum and nuclei. Based on protein structure prediction, molecular docking, site-directed mutagenesis and biochemical assays, the sporopollenin biosynthetic metabolon ZmPKSB-ZmTKPR1-1/-2 was identified to control pollen exine formation in maize anther. Although ZmTKPR1-1/-2 and ZmPKSB formed a protein complex, their mutants showed different, even opposite, defective phenotypes of anther cuticle and pollen exine. Our findings discover new maize GMS genes that can contribute to male-sterility line-assisted maize breeding and also provide new insights into the metabolon-regulated sporopollenin biosynthesis in maize anther.


Asunto(s)
Arabidopsis , Infertilidad , Zea mays/genética , Zea mays/metabolismo , Edición Génica , Sistemas CRISPR-Cas/genética , Simulación del Acoplamiento Molecular , Pironas/metabolismo , Fitomejoramiento , Arabidopsis/genética , Lípidos , Polen/genética , Polen/metabolismo , Infertilidad/genética , Infertilidad/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
9.
CNS Neurosci Ther ; 30(4): e14547, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38105496

RESUMEN

AIMS: Subsyndromal depression (SSD) is common in mild cognitive impairment (MCI). However, the neural mechanisms underlying MCI with SSD (MCID) are unclear. The default mode network (DMN) is associated with cognitive processes and depressive symptoms. Therefore, we aimed to explore the topological organization of the DMN in patients with MCID. METHODS: Forty-two MCID patients, 34 MCI patients without SSD (MCIND), and 36 matched healthy controls (HCs) were enrolled. The resting-state functional connectivity of the DMN of the participants was analyzed using a graph theoretical approach. Correlation analyses of network topological metrics, depressive symptoms, and cognitive function were conducted. Moreover, support vector machine (SVM) models were constructed based on topological metrics to distinguish MCID from MCIND. Finally, we used 10 repeats of 5-fold cross-validation for performance verification. RESULTS: We found that the global efficiency and nodal efficiency of the left anterior medial prefrontal cortex (aMPFC) of the MCID group were significantly lower than the MCIND group. Moreover, small-worldness and global efficiency were negatively correlated with depressive symptoms in MCID, and the nodal efficiency of the left lateral temporal cortex and left aMPFC was positively correlated with cognitive function in MCID. In cross-validation, the SVM model had an accuracy of 0.83 [95% CI 0.79-0.87], a sensitivity of 0.88 [95% CI 0.86-0.90], a specificity of 0.75 [95% CI 0.72-0.78] and an area under the curve of 0.88 [95% CI 0.85-0.91]. CONCLUSIONS: The coexistence of MCI and SSD was associated with the greatest disrupted topological organization of the DMN. The network topological metrics could identify MCID and serve as biomarkers of different clinical phenotypic presentations of MCI.


Asunto(s)
Encéfalo , Disfunción Cognitiva , Humanos , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Red en Modo Predeterminado , Depresión/diagnóstico por imagen , Imagen por Resonancia Magnética
10.
ACS Eng Au ; 3(6): 461-476, 2023 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-38144680

RESUMEN

Two-dimensional (2D) nanomaterial-MoS2 (molybdenum disulfide) has gained interest among researchers, owing to its exceptional mechanical, biological, and physiochemical properties. This paper reports on the removal of organic dyes and an emerging contaminant, Ciprofloxacin, by a 2D MoS2 nanoflower as an adsorbent. The material was prepared by a green hydrothermal technique, and its high Brunauer-Emmett-Teller-specific area of 185.541m2/g contributed to the removal of 96% rhodamine-B dye and 85% Ciprofloxacin. Various characterizations, such as X-ray diffraction, scanning electron microscopy linked with energy-dispersive spectroscopy, and transmission electron microscopy, revealed the nanoflower structure with good crystallinity. The feasibility and efficacy of 2D MoS2 nanoflower as a promising adsorbent candidate for the removal of emerging pollutants was confirmed in-depth in batch investigations, such as the effects of adsorption time, MoS2 dosages, solution pH, and temperature. The adsorption mechanism was further investigated based on thermodynamic calculations, adsorption kinetics, and isotherm modeling. The results confirmed the exothermic nature of the enthalpy-driven adsorption as well as the fast kinetics and physisorption-controlled adsorption process. The recyclability potential of 2D MoS2 exceeds four regeneration recycles. MoS2 nanoflower has been shown to be an effective organic pollutant removal adsorbent in water treatment.

11.
Int Wound J ; 21(3): e14500, 2023 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-37990074

RESUMEN

Increased intraocular pressure (IOP) is a risk factor for glaucoma. One treatment option is trabeculectomy. Antimetabolic agents are used in the operation to decrease the post-operative scarring of the wound. The two most common medicines are Mitomycin C (MMC) and 5-Fluorouracil (5-FU). The aim of this research is to assess the effect of MMC on post-operation wound healing in comparison with 5-FU in addition to trabeculectomy. Well, we went through four common databases. Our language was limited to English during the study. The last time we looked at the e-databases was August 2023. Case control studies were performed where MMC resulted in better wound healing than 5-FU. Researchers selected a total of 1023 trials and eventually selected six trials for data analysis. Four hundred and ninety one cases of glaucoma were treated with trabeculectomy. Among them, 246 were given MMC and 245 were given 5-FU during operation. Six trials showed that there was no statistical difference between MMC and 5-FU in the incidence of post-operative wound leak in glaucoma patients who received trabeculectomy (OR, 1.21; 95% CI, 0.63-2.30 p = 0.57); Five trials demonstrated that MMC was associated with a reduced risk of post-operative corneal damage compared to 5-FU injection (OR, 0.18; 95% CI, 0.06-0.56 p = 0.003); In both trials, the incidence of post-operative bleeding was not significantly different from that of 5-FU injected in the MMC group (OR, 0.33; 95% CI, 0.05-2.16 p = 0.25). Our results indicate that MMC is superior to 5-FU in the reduction of post-operative corneal injury. Additional comparisons between MMC and 5-FU are required in order to increase the reliability and effectiveness of these findings.

12.
Front Immunol ; 14: 1220646, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37965330

RESUMEN

Background: Whether keratoconus (KC) is an inflammatory disease is currently debated. Hence, we aimed to investigate the immune-related features of KC based on single-cell RNA sequencing (scRNA-seq) and bulk RNA sequencing (bulk RNA-seq) data. Methods: scRNA-seq data were obtained from the Genome Sequence Archive (GSA), bulk RNA-seq data were obtained from the Gene Expression Omnibus (GEO), and immune-associated genes(IAGs) were obtained from the ImmPort database. Cell clusters of KC were annotated, and different cell clusters were then selected. The IAG score of each cell was calculated using the AUCell package. Three bulk RNA-seq datasets were merged and used to identify the differentially expressed genes (DEGs), biological functions, and immune characteristics. Weighted gene coexpression network analysis (WGCNA) was used to select the IAG score-related hub genes. Based on scRNA-seq and bulk RNA-seq analyses, three machine learning algorithms, including random forest (RF), support vector machine (SVM), and least absolute shrinkage and selection operator (LASSO) regression analysis, were used to identify potential prognostic markers for KC. A predictive nomogram was developed based on prognostic markers. Results: Six cell clusters were identified in KC, and decreased corneal stromal cell-5 (CSC-5) and increased CSC-6 were found in KC. CSC and immune cell clusters had the highest IAG scores. The bulk RNA-seq analysis identified 1362 DEGs (553 upregulated and 809 downregulated) in KC. We found different immune cell populations and differentially expressed cytokines in KC. More than three key IAG score-related modules and 367 genes were identified. By integrating the scRNA-seq and bulk RNA-seq analyses, 250 IAGs were selected and then incorporated into three machine learning models, and 10 IAGs (CEP112, FYN, IFITM1, IGFBP5, LPIN2, MAP1B, RNASE1, RUNX3, SMIM10, and SRGN) were identified as potential prognostic genes that were significantly associated with cytokine and matrix metalloproteinase(MMP)1-14 expression. Finally, a predictive nomogram was constructed and validated. Conclusion: Taken together, our results identified CSCs and immune cell clusters that may play a key role during KC progression by regulating immunological features and maintaining cell stability.


Asunto(s)
Queratocono , Humanos , Queratocono/diagnóstico , Queratocono/genética , Análisis de Secuencia de ARN , RNA-Seq , Biomarcadores , Citocinas , ARN
13.
Plants (Basel) ; 12(19)2023 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-37836251

RESUMEN

Anthocyanins are among the flavonoids that serve as the principal pigments affecting the color of plants. During leaf growth, the leaf color of 'Zhonghuahongye' gradually changes from copper-brown to yellow-green. At present, the mechanism of color change at different stages has not yet been discovered. To find this, we compared the color phenotype, metabolome, and transcriptome of the three leaf stages. The results showed that the anthocyanin content of leaves decreased by 62.5% and the chlorophyll content increased by 204.35%, 69.23%, 155.56% and 60%, respectively. Differential metabolites and genes were enriched in the pathway related to the synthesis of 'Zhonghuahongye' flavonoids and anthocyanins and to the biosynthesis of secondary metabolites. Furthermore, 273 flavonoid metabolites were detected, with a total of eight classes. DFR, FLS and ANS downstream of anthocyanin synthesis may be the key structural genes in reducing anthocyanin synthesis and accumulation in the green leaf of 'Zhonghuahongye'. The results of multi-omics analysis showed that the formation of color was primarily affected by anthocyanin regulation and its related synthesis-affected genes. This study preliminarily analyzed the green regression gene and metabolic changes in 'Zhonghuahongye' red leaves and constitutes a reference for the molecular breeding of 'Zhonghuahongye' red leaves.

14.
Materials (Basel) ; 16(17)2023 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-37687588

RESUMEN

Graphite flakes are commonly used to fabricate carbon-based refractories owing to their superior properties, including better corrosion resistance and thermal shock resistance (TSR); unfortunately, their insufficient water-wettability has remarkably hindered their application in castables. Aiming to enhance their water-wettability, a facile and low-cost technique for fabricating carbides coated in graphite was proposed in this work. Firstly, SiC-TiC coated graphite (SiC-TiC@C) powders were prepared via modified molten salt shielding synthesis in an air atmosphere using graphite flake, Si and Ti powders as raw materials and NaCl-KCl as the molten salt shielding medium. Water-wettability and oxidation resistance of SiC-TiC@C powders were significantly improved. Compared to the Al2O3-MgO castables with graphite flakes, the water demand of the castables with SiC-TiC@C was noticeably decreased from 6.85% to 4.89%, thereby decreasing the apparent porosity of the castables with 5% SiC-TiC@C (from 20.3% to 13%), enhancing the cold strength, hot strength and oxidation resistance of the castables. Such enhancements are ascribed to continuous and crack-free SiC-TiC coatings on graphite surfaces ensuring that the castables have outstanding properties.

15.
ACS Omega ; 8(32): 29674-29684, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37599955

RESUMEN

Graphene oxide (GO) is a conventional yet vital precursor for the synthesis of porous graphene (PG). Several strong oxidizing agents such as potassium permanganate and perchlorates are typically used for oxidization of graphite. However, they expose toxic reactants/products that harm the environment. Therefore, a greener approach is desperately needed to oxidize and exfoliate graphite. This study reports for the first time on successful oxidation of graphite by ferrate(VI) compounds via an encapsulation approach. By further reducing GO prepared from this near green route with vitamin C, PG anticipated by many highly important and expanding areas such as water treatment could be readily achieved. X-ray diffraction (XRD), Fourier transform infrared (FTIR) and UV-vis spectroscopy, and scanning electronic microscopy (SEM) along with energy-dispersive spectroscopy confirmed the high yield of GO from the oxidation of graphite. Raman spectroscopy, XRD, and TEM confirmed the formation of high-quality few-layered PG from the reduction of as-prepared GO. The above results demonstrated the practicality of using encapsulated ferrate(VI) compounds to realize green oxidation of graphite and resolve the paradox about the oxidation capability of ferrate(VI). To further illustrate its potential for the removal of emerging and crucial contaminants from water, as-prepared PG was further examined against the contaminants of methyl orange (MeO) dye and ibuprofen (IBU). Taken together, the results revealed that more than 90% removal efficiency could be achieved at a high PG dosage against MeO and IBU. This ground-breaking greener approach opens the door to risk-free, extensive graphene environmental applications.

16.
Nat Commun ; 14(1): 5082, 2023 08 21.
Artículo en Inglés | MEDLINE | ID: mdl-37604813

RESUMEN

CarH is a coenzyme B12-dependent photoreceptor involved in regulating carotenoid biosynthesis. How light-triggered cleavage of the B12 Co-C bond culminates in CarH tetramer dissociation to initiate transcription remains unclear. Here, a series of crystal structures of the CarH B12-binding domain after illumination suggest formation of unforeseen intermediate states prior to tetramer dissociation. Unexpectedly, in the absence of oxygen, Co-C bond cleavage is followed by reorientation of the corrin ring and a switch from a lower to upper histidine-Co ligation, corresponding to a pentacoordinate state. Under aerobic conditions, rapid flash-cooling of crystals prior to deterioration upon illumination confirm a similar B12-ligand switch occurs. Removal of the upper His-ligating residue prevents monomer formation upon illumination. Combined with detailed solution spectroscopy and computational studies, these data demonstrate the CarH photoresponse integrates B12 photo- and redox-chemistry to drive large-scale conformational changes through stepwise Co-ligation changes.


Asunto(s)
Frío , Histidina , Ligandos , Oxidación-Reducción , Iluminación
17.
Zhen Ci Yan Jiu ; 48(6): 592-9, 2023 Jun 25.
Artículo en Chino | MEDLINE | ID: mdl-37385791

RESUMEN

OBJECTIVE: To observe the effect of acupuncture at "Houxi"(SI3) and "Huantiao"(GB30) on high mobility group box 1(HMGB1) protein and mRNA in spinal nerve trunk(SNT) of rats with lumbar disc herniation(LDH), so as to explore the mechanisms of acupuncture at this paired points on the treatment for LDH. METHODS: SD rats were randomly divided into sham operation, model, conventional acupuncture(CA) and paired points(PP) groups (with 8 rats in each group). The LDH model was established by injection of autologous suspension made from rats' own nucleus pulsus into the epidural space. Rats in the CA group received acupuncture treatment at bilateral "Weizhong"(BL40), "Dachangshu"(BL25) and "Shenshu"(BL23), while rats in the PP group received acupuncture at bilateral SI3 and GB30, 30 min each time, once daily for 14 consecutive days. The thermal pain threshold of bilateral hind feet of rats was detected by thermal pain stimulator. The contents of serum IL-1ß, IL-6 and IL-8 of rats were detected by ELISA. Western blot and immunofluorescence were used to detect the expression of HMGB1 protein in the lumbar(L)5 SNT of rats. The relative expression of HMGB1 mRNA in L5 SNT was determined by qPCR. HE staining was used to observe the morphological changes of L5 SNT. RESULTS: Compared with the sham operation group, the thermal pain threshold of bilateral hind feet in the model group was decreased (P<0.05); compared with the model group, the thermal pain threshold of bilateral hind feet in the CA group and the PP group were increased (P<0.05). The expressions of HMGB1 protein and mRNA in L5 SNT, and the contents of serum IL-1ß, IL-6 and IL-8 of rats in the model group were significantly increased(P<0.000 1, P<0.001) in contrast to the sham operation group. The expressions of HMGB1 protein and mRNA in L5 SNT, and the levels of serum IL-1ß, IL-6 and IL-8 were significantly decreased (P<0.01, P<0.000 1, P<0.001, P<0.05) in the CA and PP group, in comparison with those of the model group. Compared with the CA group, the above indexes of rats in the PP group recovered more significantly (P<0.05,P<0.001, P<0.01,P<0.000 1). The histomorphological results showed scattered and various-sized nerve fibers, vacuolation, a large number of disintegrating myelin sheath and lysed Schwann cells in the model group. Myelin sheaths regeneration, regularly-arranged nerve fibers were seen in the CA group and the PP group, with more obvious histopathological recovery observed in the PP group than the CA group. CONCLUSION: Acupuncture intervention inhibites the expressions of HMGB1 protein and mRNA in rats with LDH, and further reduces the production of IL-1ß, IL-6 and IL-8, which is beneficial to inflammatory response inhibition and pain alleviation. The therapeutic effect of the PP group is more obvious than that of the CA group.


Asunto(s)
Terapia por Acupuntura , Proteína HMGB1 , Desplazamiento del Disco Intervertebral , Animales , Ratas , Ratas Sprague-Dawley , Proteína HMGB1/genética , Desplazamiento del Disco Intervertebral/genética , Desplazamiento del Disco Intervertebral/terapia , Interleucina-6/genética , Interleucina-8 , Dolor , Nervios Espinales
18.
Phys Chem Chem Phys ; 25(18): 12629-12640, 2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37128961

RESUMEN

The surface exchange coefficient (k) of porous mixed ionic-electronic conductors (MIECs) determines the device-level electrochemical performance of solid oxide cells. However, a great difference is reported for k values, which are measured using presently available technologies of electrical conductivity relaxation (ECR), electrochemical impedance spectroscopy (EIS), and oxygen isotope exchange (OIE). In terms of this issue, this perspective paper estimates the possible physiochemical processes for the oxygen reduction reaction (ORR) in porous MIECs by comparing the oxygen supply/consumption fluxes through calculation. Then, the potential problems associated with ECR, EIS, and OIE for application in porous materials are discussed regarding theory, assumptions, sample requirements, and data processing. Finally, gas diffusion effects are revealed by comparing the simulated and measured ECR profiles, which show that the ORR process can be significantly delayed by gas diffusion. This perspective aims to recommend a reasonable method to characterize the true ORR kinetics of porous electrodes and quantify the effect of gas diffusion.

19.
ACS Omega ; 8(12): 11544-11555, 2023 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-37008084

RESUMEN

The lack of systematic geological work is an essential reason why underground coal gasification (UCG) has not been industrialized for a long time. Building a scientific index system and favorable area evaluation technology for the UCG site selection is the key to breaking through the geological bottleneck. Aiming at the problems of the single index weight determination method, intense subjectivity, and poor reliability of current evaluation models, we put forward an evaluation modeling methodology for the UCG site selection using the combination weighting method with the game theory. The factors of coal resource conditions associated with the potential risk of UCG are systematically analyzed. From the six dimensions of the geological structure, hydrogeology, seam occurrence, coal properties, reserves, and roof lithology, 23 key factors were selected as evaluation indexes to construct a hierarchical model composed of the target layer, category index layer, and index layer. The influence of each index on UCG and its reasonable value range were systematically analyzed. The evaluation index system for UCG site selection was formed. The improved analytic hierarchy process (AHP) was adopted to sequence indices and determine their subjective weight. And the variability, conflict, and information amount of the index data were analyzed by the CRiteria Importance Through Intercriteria Correlation (CRITIC) method to calculate the objective weight. Then, the subjective and objective weights were combined through game theory. On this basis, fuzzy theory was employed to calculate the membership of indices and construct the fuzzy comprehensive judgment matrix. The evaluation model of the UCG site selection was applied to the suitability evaluation of resource conditions of UCG pilot projects at Zhongliangshan (ZLS), Huating (HT), and Shanjiaoshu (SJS) mines in China. The result shows that the resource conditions of HT are the best, followed by ZLS and, finally, SJS, which are consistent with the actual running effects of the three UCG pilot projects. It indicates that the evaluation model can provide a scientific theoretical basis and reliable technical support for the UCG site selection.

20.
Materials (Basel) ; 16(8)2023 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-37109977

RESUMEN

In this paper, the effect of a sodium tripolyphosphate (STPP) addition on the dispersion and hydration of pure calcium aluminate cement (PCAC) was investigated, and the corresponding mechanism of effect was studied. The effects of STPP on the dispersion, rheology, and hydration processes of PCAC and its adsorption capacity on the surface of cement particles were analysed by measuring the 𝜁-potential on the surface of cement particles, the changes in the concentrations of elemental P and Ca2+ ions in a solution at different STPP additions. The experimental results show that STPP easily complexes with Ca2+ ions to produce the complex [CaP3O10]3- adsorbed on the surface of cement particles, which changes the potential on the surface of cement particles and increases the electrostatic repulsive force between cement particles, thus improving the dispersion and rheology of cement. At the same time, the contact area between cement particles and water is reduced, which hinders the hydration process and makes the time of hydration process longer. A comprehensive analysis shows that the best effect of STPP on pure calcium aluminate cements is achieved when the addition of STPP is 0.2%. This study can provide a reference for the addition of water-reducing agents in refractory castables as well as improving the quality of refractory materials.

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