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Precisely controlling the selectivity of nanocatalysts has always been a hot topic in heterogeneous catalysis but remains difficult owing to their complex and inhomogeneous catalytic sites. Herein, an effective strategy to regulate the chemoselectivity of Pd nanocatalysts for selective hydrogenation reactions by inserting single-atom Zn into Pd nanoparticles is reported. Taking advantage of the tannic acid coating-confinement strategy, small-sized Pd nanoparticles with inserted single-atom Zn are obtained on the O-doped carbon-coated alumina. Compared with the pure Pd nanocatalyst, the Pd nanocatalyst with single-atom Zn insertion exhibits prominent selectivity for the hydrogenation of p-iodonitrobenzene to afford the hydrodeiodination product instead of nitro hydrogenation ones. Further computational studies reveal that the single-atom Zn on Pd nanoparticles strengthens the adsorption of the nitro group to avoid its reduction and increases the d-band center of Pd atoms to facilitate the reduction of the iodo group, which leads to enhanced selectivity. This work provides new guidelines to tune the selectivity of nanocatalysts with guest single-atom sites.
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Strawflower (Helichrysum bracteatum, Asteraceae) , an annual or biennial herb, is one of the most popular flowers in the world because of the colorful flowers and the long flowering period. However, the ornamental plants belonging to Asteraceae are susceptible to numerous viruses such as cucumber mosaic virus (CMV) (Cucumovirus, Bromoviridae) , potato virus Y (Potyvirus, Potyviridae), tomato mosaic virus (ToMV) (Tobamovirus, Virgaviridae), tobacco mosaic virus (TMV) (Tobamovirus, Virgaviridae), chrysanthemum virus B (CVB) (Carlavirus, Betaflexiviridae), tomato aspermy virus (TAV) (Cucumovirus, Bromoviridae), tomato spotted wilt virus (TSWV) (Orthotospovirus tomatomaculae, Tospoviridae), and impatiens necrotic spot virus (INSV) (Orthotospovirus impatiensnecromaculae, Orthotospovirus) resulting in severe yield loss (Verma et al. 2003; Raj et al. 2007; Kondo et al. 2011; Liu et al. 2014; Marys et al. 2014; Min et al. 2020; Gautam et al. 2021; Read et al. 2022; Supakitthanakorn et al. 2022). Among these viruses, the TSWV, a thrips-transmitted negative-stranded RNA virus, is well known to cause viral disease in several plant species while is less reported in Helichrysum, especially in China. In April 2021, viral attack symptoms were detected on the leaves of H. bracteatum during our routine checks in the greenhouse located at Shunyi District, Beijing, China, such as wilting, shrinking, chlorotic blotches, chlorotic ring spots. To investigate the virus infecting H. bracteatum, in total of 25 symptomatic and 5 asymptomatic leaves were sampled and tested by the effective double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) using antisera against CMV, PVY/PVX, ToMV, TMV, CVB, TAV, TSWV, INSV, separately (Agdia, USA). Only the TSWV showed positive in symptomatic samples, and asymptomatic samples were all negative, which implied TSWV infection. To further confirm the virus type of TSWV isolated from H. bracteatum samples, the genomic RNA of the virus was isolated using reverse transcription and polymerase chain reaction (RT-PCR), and then was cloned, sequenced and analyzed. Total RNA of five symptomatic leaves (ELISA-positive) were extracted using the FastPure Plant Total RNA Isolation Kit (Vazyme, China), and then were reverse transcribed by HiScript II Reverse Transcriptase (Vazyme, China). Each genome segments were amplified using Phanta Max Super-Fidelity DNA Polymerase (Vazyme, China) with TSWV-specific primers newly designed and listed in Table S1. The PCR setup was as follow: 95°C for 30 s, followed by 35 cycles at 95°C for 30 s, 55°C for 30 s, and 72°C for 1.5 min, with a final extension at 72°C for 10 min. All PCR products were cloned into the TA/Blunt-Zero vector (Vazyme, China) and sequenced (GENEWIZ, Inc.). We assembled and then analyzed the evolutionary relationship of three genomic fragments, that is, TSWV-BJFC-Hb S (2923 bp), M (4785 bp) and L (8971 bp) using the BLAST tools. The results showed high similarity with TSWV-henan isolated from pepper in China (99.6% to TSWV-S (MT799179.1), 99.8 % to TSWV-M (MT799178.1) and 99.8 % TSWV-L (MT799177.1)). These sequences have been submitted to the GenBank (OM982910, OM982911 and OM937131). Taking all of these evidences together, the viral disease observed in H. bracteatum was closely associated with TSWV. TSWV is currently widespread in China, infecting Nasturtium, Chrysanthemum and cowpea (Xiao et al. 2015; Hu et al. 2018; Yu et al. 2021). Epidemics of TSWV have also been reported in several other countries such as Korea, North Carolina, Turkey and India (Renukadevi et al. 2015; Koehler et al. 2016; Kwak et al. 2021; Erilmez, S. 2022). This is the first report of TSWV infection on H. bracteatum in China. Due to the fast spread and serious economic losses of TSWV, the rapid detection may be the essential way to prevent this viral disease among crops (Macharia et al. 2014).
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A Gram-positive, smooth, sub-transparent, faint yellow,0.5-0.7 µm diameter, rod shaped aerobic or facultative aerobic strain P40-2Twas isolated from livestock farms in Northeast China. Strain P40-2T grew at 25-40 °C (optimum 30-38 °C), and in 0-4% (w/v) NaCl (optimum 0%) in LB medium. Based on 16S rRNA gene sequence analysis, strain P40-2T belongs to the class Cellulomonas and is most closely related to C. denverensis strain W6929, C. pakistanensis strain NCCP-11and C. hominis strain CE40.DNA-DNA hybridization rate of strain P40-2T was 29%, and the ANI with C.denverensisstrainW6929 was 85.33%. The genome is 3437431 bp long with a G + C content of 71.99%. Of the 3177 predicted genes, 3119 were protein-coding genes and 58 were RNA encoding genes. The chemotaxonomic data: menaquinone was MK-9(H4), anteiso-C15:â0, C16:0 and anteiso-C17:â0 were the major cellular fatty acids, and the main cell-wall amino acids were ornithine,alanine, glycine and glutamate. The cell wall peptidogly can sugars included glucose, rhamnose, galactose and mannose. The polar lipid present were DPG, PG, PE, and PIM. On the basis of DNA-DNA relatedness, phylogenetic position, complete genome sequence and physiological characteristics, strain P40-2T can be differentiated from other species of the genus Cellulomonas with validly published names and thus represents a novel species, for which the name Cellulomonas taurus is proposed. The type strain is Cellulomonas taurus P40-2T (= CGMCC No.1.17732T).The acute toxicity test in mice showed that LD50 of strain P40-2T was rather high with 1.5 × 1011 CFU/mouse, which indicated low pathogenicity. Drug susceptibility showed that strainP40-2T was resistant to most antibiotics and only sensitive to six antibiotics. Strain P40-2T contained a variety of hydrolytic enzymes including the ability to hydrolyze cellulose, ß-glucan, chitin, xylan, and casein. Microbial flocculant MBF-P40 for sewage was prepared with strain P40-2T, after strain P40-2T was confirmed that had good flocculation effect. MBF-P40 was used to prepare flocculation rate of 99.40%. MBF-P40 treatmented sewage from eight different sources. Flocculation rate for pig farm wastewater was 96.07%, COD removal rate is 71.05%, ammonia nitrogen removal rate is 18.22%. The result shows that MBF-P40 has a good flocculation effect, and good prospect of development and application for wastewater treatment.
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Cellulomonas , Purificação da Água , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Cellulomonas/genética , DNA Bacteriano/genética , Ácidos Graxos/análise , Hidrolases , Gado , Camundongos , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Suínos , Vitamina K 2RESUMO
Circadian rhythm of stomatal aperture is mainly regulated by light/darkness. Blue and red light induce stomatal opening through different mechanisms that are mediated by special receptors. ROP2, a member of Rho GTPase family in Arabidopsis (Arabidopsisthaliana), has been found to negatively regulate light-induced stomatal opening. However, the upstream guanine nucleotide exchange factor (GEF) RopGEFs have not been revealed, and it is unclear which photoreceptor is required for the action of RopGEFs-ROPs. Here, we showed that RopGEF2 acted as a negative regulator in phytochrome B (phyB)-mediated red light-induced stomatal opening. Meanwhile, ROP7, another member of ROP family, acting redundantly with ROP2, was regulated by RopGEF2 in this process. RopGEF2 interacted with ROP7 and ROP2 and enhanced their intrinsic nucleotide exchange rates. Furthermore, the direct interactions between phyB and RopGEF2 were detected in vitro and in plants, and phyB enhanced the GEF activity of RopGEF2 toward both ROP7 and ROP2 under light. In addition, RopGEF4 functioned redundantly with RopGEF2 in red light-induced stomatal opening by activating both ROP7 and ROP2, and RopGEF2/RopGEF4 acted genetically downstream of phyB; however, the GEF activity of RopGEF4 was not directly enhanced by phyB. These results revealed that red light-activated phyB enhances the GEF activities of RopGEF2 and RopGEF4 directly or indirectly, and then activate both ROP7 and ROP2 in guard cells. The negative mechanism triggered by phyB prevents the excessive stomatal opening under red light.
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Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Fitocromo B/metabolismo , Estômatos de Plantas/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Ligação ao GTP/genética , Regulação da Expressão Gênica de Plantas , Fatores de Troca do Nucleotídeo Guanina/genética , Luz , Redes e Vias Metabólicas , Proteínas Monoméricas de Ligação ao GTP/genética , Mutação , Fitocromo B/genética , Plantas Geneticamente Modificadas , Transporte ProteicoRESUMO
BACKGROUND: In engineered strains of Escherichia coli, bioconversion efficiency is determined by not only metabolic flux but also the turnover efficiency of relevant pathways. Methyl-D-erythritol 4-phosphate (MEP)-dependent carotenoid biosynthesis in E. coli requires efficient turnover of precursors and balanced flux among precursors, cofactors, and cellular energy. However, the imbalanced supply of glyceraldehyde 3-phosphate (G3P) and pyruvate precursors remains the major metabolic bottleneck. To address this problem, we manipulated various genetic targets related to the Entner-Doudoroff (ED)/pentose phosphate (PP) pathways. Systematic target modification was conducted to improve G3P and pyruvate use and rebalance the precursor and redox fluxes. RESULTS: Carotenoid production was improved to different degrees by modifying various targets in the Embden-Meyerhof-Parnas (EMP) and ED pathways, which directed metabolic flux from the EMP pathway towards the ED pathway. The improvements in yield were much greater when the MEP pathway was enhanced. The coordinated modification of ED and MEP pathway targets using gene expression enhancement and protein coupling strategies in the pgi deletion background further improved carotenoid synthesis. The fine-tuning of flux at the branch point between the ED and PP pathways was important for carotenoid biosynthesis. Deletion of pfkAB instead of pgi reduced the carotenoid yield. This suggested that anaplerotic flux of G3P and pyruvate might be necessary for carotenoid biosynthesis. Improved carotenoid yields were accompanied by increased biomass and decreased acetate overflow. Therefore, efficient use of G3P and pyruvate precursors resulted in a balance among carotenoid biosynthesis, cell growth, and by-product metabolism. CONCLUSIONS: An efficient and balanced MEP-dependent carotenoid bioconversion strategy involving both the ED and PP pathways was implemented by the coordinated modification of diverse central metabolic pathway targets. In this strategy, enhancement of the ED pathway for efficient G3P and pyruvate turnover was crucial for carotenoid production. The anaplerotic role of the PP pathway was important to supply precursors for the ED pathway. A balanced metabolic flux distribution among precursor supply, NADPH generation, and by-product pathways was established.
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Carotenoides/biossíntese , Eritritol/metabolismo , Escherichia coli/metabolismo , Via de Pentose Fosfato , Reatores Biológicos , Eritritol/análogos & derivados , Eritritol/química , Escherichia coli/genética , Gliceraldeído 3-Fosfato/metabolismo , Engenharia Metabólica , Redes e Vias Metabólicas , Ácido Pirúvico/metabolismoRESUMO
OBJECTIVE: To explore the impact of extracellular acidic environment on the expression and activity of P-glycoprotein (P-gp) and on the P-gp-mediated cytotoxicity of daunomycin in cancer cells by using microfluidic chip technology. METHODS: The A549 cells cultured on a microfluidic chip were divided into experiment group and control group. The experiment group was exposed to an acidic cell culture medium (pH 6.6), while the control group was treated with a neutral cell culture medium (pH 7.4). The expression of P-gp was detected by cell immunofluorescense analysis and the activity of P-gp was evaluated by Rhodamine 123 efflux experiment. Meanwhile, the cytotoxicity of daunomycin was analyzed by cell live/dead fluorescence staining method. RESULTS: Microfluidic chip designed in this study could provide a suitable microenvironment for the growth of A549 cells and the A549 cells reached the confluence of 90% after inoculation for 72 h. Treatment of the acidic cell culture media on A549 cells did not make a significant difference on the expression level of P-gp. However, the activity of P-gp was significantly enhancement and peaked at 6 h after treatment with acidic cell culture media. Meanwhile, the cytotoxicity of daunomycin reduced significantly after treatment with acidic cell culture medium for 6 h,and a reversal effect was obtained when synergy with verapamil. CONCLUSIONS: Microfluidic chip technology can shorten the analysis time and reduce the reagent consumption. It can be used as a new technology platform for understanding the mechanisms of multi-drug resistance and for screening highly efficient multi-drug resistance reversal agents.
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Espaço Extracelular , Microfluídica , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Meios de Cultura , Daunorrubicina , Humanos , Concentração de Íons de HidrogênioRESUMO
AIM: To quantify changes in radial peripapillary capillary vessel density (ppVD) and the peripapillary retinal nerve fiber layer (pRNFL) in children with type 1 diabetes without clinical diabetic retinopathy by optical coherence tomography angiography (OCTA), providing a basis for early retinopathy in children with type 1 diabetes. METHODS: This was a retrospective study. A total of 30 patients (3-14y) with type 1 diabetes without clinical diabetic retinopathy (NDR group) were included. A total of 30 age-matched healthy subjects were included as the normal control group (CON group). The HbA1c level in the last 3mo was measured once in the NDR group. The pRNFL thickness and ppVD were automatically measured, and the mean pRNFL and ppVD were calculated in the nasal, inferior, temporal, and superior quadrants. The changes in ppVD and pRNFL in the two groups were analyzed. RESULTS: Compared with CON group, the nasal and superior ppVDs decreased in the NDR group (all P<0.01). The thickness of the nasal pRNFL decreased significantly (P<0.01), while the inferior, temporal and superior pRNFLs slightly decreased but not significant in the NDR group (all P>0.05). Person and Spearman correlation analysis of ppVD and pRNFL thickness in each quadrant of the NDR group showed a positive correlation between nasal and superior (all P<0.01), while inferior and temporal had no significant correlation (all P>0.05). There was no significant correlation between the HbA1c level and ppVD and pRNFL in any quadrant (all P>0.05). There was no significant correlation between the course of diabetes mellitus and ppVD and pRNFL in any quadrant (all P>0.05). CONCLUSION: ppVD and pRNFL decrease in eyes of children with type 1 diabetes before clinically detectable retinopathy and OCTA is helpful for early monitoringï¼.
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OBJECTIVE: To investigate the preparation process of total coumarins from Laportea bulbifera. METHODS: The optimum condition for the extraction of total coumarins was studied using the orthogonal test, and the extracts was purled with different kinds of macroporous resins. The content of total coumarins was detected by ultraviolet spectrophotometry. RESULTS: The optimum extraction process was as follows: three-time circumfluence with 4 times volume of 75% ethanol for 1.5 h each time. HPD300 macroporous resin was the optimum one for the separation and purification of total coumarins. The extraction condition was loading 30 mL of 0.4 g/mL the crude drug, flowing at 2BV/h, then edulcorating with 4 times volume of distilled water and eluting with the same volume of 75% ethanol. The yield rate was more than 52%. CONCLUSION: This method is suitable for the preparation of total coumarins in Laportea bulbifera, and the process is stable and repeatable.
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Cumarínicos/isolamento & purificação , Resinas Sintéticas/química , Tecnologia Farmacêutica/métodos , Urticaceae/química , Adsorção , Cumarínicos/análise , Etanol/química , Raízes de Plantas/química , Espectrofotometria Ultravioleta , Fatores de TempoRESUMO
To investigate the distribution characteristics of the cyanobacteria community and the driving factors in impounded lakes and reservoirs in Shandong on the east route of the South-to-North Water Diversion Project, monthly samples of phytoplankton and the aquatic environment from Nansi Lake, Dongping Lake, Datun Reservoir, Donghu Reservoir, and Shuangwangcheng Reservoir were collected from May to November during 2010 to 2019. A total of 44 planktonic cyanobacteria taxa were identified with 23 filamentous cyanobacteria taxa. Pseudanabaena limnetica, Cylindrospermopsis raciborskii, Microcystis aeruginosa, and Microcystis wesenbergii were the dominant harmful cyanobacteria species, with a high detection frequency and abundance in all lakes and reservoirs. By analyzing the distribution characteristics of the cyanobacteria community in impounded lakes and reservoirs, we found that filamentous cyanobacteria had growth advantages in the water with large hydraulic disturbances, which should be the key points of cyanobacteria prevention and control in the future. Pearson correlation analysis and generalized linear fitting curve results showed that total nitrogen, total phosphorus, water temperature, and water depth played a key role in affecting the growth of P. limnetica, C. raciborskii, M. aeruginosa, and M. wesenbergii. The nitrogen and phosphorus nutrients could promote the growth of harmful cyanobacteria. Due to the good temperature adaptability, P. limnetica could still become the dominant species in early summer and late autumn, and C. raciborskii, M. aeruginosa, and M. wesenbergii had growth advantages when the water temperature was higher than 25â. In addition, shallow water was more conducive to the growth of C. raciborskii. It was suggested that based on strengthening of the control of nitrogen and phosphorus nutrient input in lakes and reservoirs, the key monitoring of P. limnetica in lakes should be conducted in early summer and late autumn, and the growth of C. raciborskii in shallow water areas should be paid close attention in the high temperature period to ensure the safety of water quality.
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Cianobactérias , Lagos , Lagos/microbiologia , Monitoramento Ambiental , Fitoplâncton , Fósforo/análise , Nitrogênio/análiseRESUMO
RATIONALE: Gefitinib is a potent and selective orally active growth factor receptor (EGFR)-tyrosine kinase inhibitor that is commonly used to treat advanced non-small cell lung cancer patients with activating EGFR mutations. Hearing impairment with gefitinib was sparsely reported. In this report, we describe a case of sensorineural deafness associated with the administration of gefitinib, with a Naranjo score of 7. PATIENT CONCERNS: An 81-year-old female was diagnosed with lung adenocarcinoma with bone metastasis and an EGFR-activating mutation. The patient was prescribed gefitinib tablets at a daily dose of 250 mg for lung adenocarcinoma treatment. However, the patient experienced moderate to severe bilateral sensorineural deafness, primarily in her right ear, after taking gefitinib. Following the cessation of gefitinib administration, the patient exhibited partial restoration of auditory function. Upon resuming the medication, she experienced a worsening of deafness. DIAGNOSES: The otoscopic audiogram and hearing test indicated moderate to severe bilateral sensorineural deafness. INTERVENTIONS: The otolaryngologist recommended bilateral hearing aids to enhance hearing function. OUTCOMES: Throughout our follow-up period, the patient did not receive a hearing aid implant. LESSONS: This article first reported the ototoxicity caused by gefitinib. While rare, our report highlights that gefitinib-induced sensorineural deafness is possible and its mechanisms are still unclear. This adverse reaction should be monitored closely during clinical application of gefitinib to improve patient outcomes.
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Adenocarcinoma de Pulmão , Carcinoma Pulmonar de Células não Pequenas , Surdez , Perda Auditiva Neurossensorial , Neoplasias Pulmonares , Humanos , Feminino , Idoso de 80 Anos ou mais , Gefitinibe/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/patologia , Perda Auditiva Neurossensorial/induzido quimicamente , Receptores ErbB/metabolismo , MutaçãoRESUMO
The eicosanoid signaling pathway mediates insect immune reactions to a wide range of stimuli. This pathway begins with the biosynthesis of arachidonic acid (AA) from the hydrolysis of phospholipids catalyzed by phospholipase A2 (PLA2 ). We report here that the PLA2 inhibitor, dexamethasone (DEX), impaired the innate immune response including nodulation, encapsulation, and melanization in Ostrinia furnacalis larvae, while AA partially reversed these effects of DEX. We cloned a full-length complementary DNA encoding a PLA2 , designated as OfsPLA2 , from O. furnacalis. The open reading frame of OfsPLA2 encodes a 195-amino acid residue protein with a 22-residue signal peptide. Sequence alignment analyses indicated that O. furnacalis PLA2 might be a Group III secretory PLA2 . The highest transcript levels of OfsPLA2 were detected in the fat body, and its transcript levels increased dramatically after infection with Escherichia coli, Micrococcus luteus, or Beauveria bassiana. Recombinant OfsPLA2 significantly induced prophenoloxidase (PPO) activation in larval hemolymph in the presence of Ca2+ and encapsulation of agarose beads. Injection of recombinant OfsPLA2 into larvae resulted in increased transcript levels of attacin, defencin, and moricin-3 genes. Our results demonstrate the involvement of the eicosanoid signaling pathway in the innate immune response of O. furnacalis larvae and provide new information about the roles of O. furnacalis secretory PLA2 in activating PPO and antimicrobial peptide production.
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Beauveria , Mariposas , Fosfolipases A2/metabolismo , Animais , Imunidade Inata , Proteínas de Insetos/metabolismo , Mariposas/enzimologia , Mariposas/imunologia , Zea maysRESUMO
In order to explore the feasibility of soil leaching and the remediation of agricultural land polluted by medium (heavy) cadmium (Cd), the soil column was used to simulate in-situ leaching, and the citric acid (CA)+ferric chloride (FeCl3) composite leaching agent was selected. Under the optimal concentration combination and the addition amount of the composite leaching agent, the distribution characteristics of Cd in the plow-layer soil and below were investigated. The influence of the leaching process on soil health and the regulation effect of biochar were also investigated. The results showed that:â 0.1 mol·L-1 CA and 0.01 mol·L-1 FeCl3 were the best concentration combinations; under this concentration combination, when the eluent reached 9 pore volume, the content of Cd in the 20 cm soil column was lower than the risk screening value of 0.4 mg·kg-1 (GB 15618-2018) in the corresponding pH value of the tested soil after leaching. â¡ Under the optimal leaching conditions, the longitudinal distribution of Cd in the 60 cm soil column showed that the content of total Cd increased with the increase in soil depth after leaching, and the leachate of the soil column contained a certain amount of Cd, indicating that the leaching process promoted the downward migration of Cd. The content of available Cd in the soil after composite leaching also increased with the increase in soil depth, which was partly due to the change in exchangeable and carbonate-bound Cd in different soil layers. ⢠A portion of the soil health indexes and enzyme activities decreased after CA+FeCl3 composite leaching. The addition of biochar can improve the health status of the soil after leaching; the soil health indexes and enzyme activities were restored significantly, and the risk of Cd reactivation also decreased after the addition of biochar. The results showed that part of Cd in the soil can be leached below the plow layer by CA+FeCl3 composite leaching; however, the leaching process may have a certain impact on soil health, and biochar has a significant effect on the recovery of soil after leaching.
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Poluentes do Solo , Solo , Agricultura , Cádmio/análise , Carvão Vegetal , Ácido Cítrico , Poluentes do Solo/análiseRESUMO
The formation of heterojunction structures can effectively prevent the recombination of photogenerated electron-hole pairs in semiconductors and result in the enhancement of photoelectric properties. Using TiO2 nanotubes (prepared using the hydrothermal-impregnation method) as carriers, CdS-TiO2NTs were fabricated as a photoelectrochemical (PEC) sensor, which can be used under visible light and can exhibit good PEC performance due to the existence of the heterojunction structure. The experimental results show that the prepared CdS-TiO2NTs electrode had a linear response to 2-16 mM glutathione (GSH). The sensor's sensitivity and detection limit (LOD) were 102.9 µA·mM-1 cm-2 and 27.7 µM, respectively. Moreover, the biosensor had good stability, indicating the potential application of this kind of heterojunction PEC biosensor.
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Class II lanthipeptide synthetases (LanMs) are relatively promiscuous to core peptide variations. Previous studies have shown that different LanMs catalyze identical reactions on the same core sequence fused to their respective cognate leaders. We characterized a new LanM enzyme from Microcystis aeruginosa NIES-88, MalM, and demonstrated that MalM and ProcM exhibited disparate dehydration and cyclization patterns on identical core peptides. Our study provided new insights into the regioselectivity of LanMs and showcased an appropriate strategy for lanthipeptide structural diversity engineering.
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Ligases , Microcystis , Ciclização , Ligases/química , Microcystis/metabolismo , Peptídeos/química , Especificidade por SubstratoRESUMO
Thioamitides are apoptosis-inducing ribosomally synthesized and post-translationally modified peptides (RiPPs) with substantial post-translational modifications (PTMs), whose biosynthetic details remain elusive. We reconstituted their key PTMs through in vitro enzymatic reactions and gene coexpressions in E. coli and rigorously demonstrated the order of those modifications. Notably, thioamitide biosynthesis involves N- to C-terminal thioamidations and employs both leader-dependent and leader-independent reactions followed by leader removal by successive degradation. Our study provides a comprehensive overview of thioamitide biosynthesis and lays the foundation for thioamitide engineering in E. coli.
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Escherichia coliRESUMO
Organoids have certain cellular composition and physiological features in common with real organs, making them promising models of organ formation, function, and diseases. However, Matrigel, the commonly used animal-derived matrices in which they are developed, has limitations in mechanical adjustability and providing complex physicochemical signals. Here, the incorporation of Ti3 C2 Tx MXene nanomaterial into Matrigel regulates the properties of Matrigel and exhibits satisfactory biocompatibility. The Ti3 C2 Tx MXene Matrigel composites (MXene-Matrigel) regulate the development of Cochlear Organoids (Cochlea-Orgs), particularly in promoting the formation and maturation of organoid hair cells. Additionally, regenerated hair cells in MXene-Matrigel are functional and exhibit better electrophysiological properties compared to hair cells in Matrigel. MXene-Matrigel potentiates the amycin (mTOR) signaling pathway to promote hair cell differentiation, and mTOR signaling inhibition restrains hair cell differentiation. Moreover, MXene-Matrigel facilitates innervation establishment between regenerated hair cells and spiral ganglion neurons (SGNs) growing from the Cochlea modiolus in a co-culture system, as well as promotes synapse formation efficiency. The approach overcomes some limitations of the Matrigel-dependent culture system and greatly accelerates the application of nanomaterials in organoid development and research on therapies for hearing loss.
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Hidrogéis , Organoides , Animais , Titânio , Cóclea/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismoRESUMO
Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by inflammation of pancreatic islets and destruction of ß cells. Up to now, there is still no cure for this devastating disease and alternative approach should be developed. To explore a novel gene therapy strategy combining immunotherapy and ß cell regeneration, we constructed a non-viral plasmid encoding proinsulin (PI) and pancreatic regenerating (Reg) III protein (pReg/PI). Therapeutic potentials of this plasmid for T1DM were investigated. Intramuscular delivery of pReg/PI resulted in a significant reduction in hyperglycemia and diabetes incidence, with an increased insulin contents in the serum of T1DM mice model induced by STZ. Treatment with pReg/PI also restored the balance of Th1/Th2 cytokines and expanded CD4(+)CD25(+)Foxp3(+) T regulatory cells, which may attribute to the establishment of self-immune tolerance. Additionally, in comparison to the mice treated with empty vector pBudCE4.1 (pBud), attenuated insulitis and apoptosis achieved by inhibiting activation of NF-κB in the pancreas of pReg/PI treated mice were observed. In summary, these results indicate that intramuscular delivery of pReg/PI distinctly ameliorated STZ-induced T1DM by reconstructing the immunological self-tolerance and promoting the regeneration of ß cells, which might be served as a promising candidate for the gene therapy of T1DM.
Assuntos
DNA/administração & dosagem , DNA/uso terapêutico , Diabetes Mellitus Tipo 1/terapia , Terapia Genética , Proinsulina/genética , Proteínas/genética , Animais , Células COS , Chlorocebus aethiops , DNA/genética , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/patologia , Expressão Gênica , Hiperglicemia/terapia , Injeções Intramusculares , Insulina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pâncreas/metabolismo , Pâncreas/patologia , Plasmídeos/administração & dosagem , Plasmídeos/genética , Plasmídeos/uso terapêutico , Proinsulina/uso terapêutico , Proteínas/uso terapêutico , Estreptozocina , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologiaRESUMO
OBJECTIVE: To investigate the expression of low molecular mass polypeptide-2 (LMP2) and protein phosphatase 1A (PPM1A) in gestational trophoblastic disease and elucidate their predictive value in malignant transformation of hydatidiform mole. METHODS: The expressions of LMP2 and PPM1A protein in 196 complete hydatidiform moles (in which 28 cases with malignant transformation), 7 invasive moles, 5 choriocarcinomas and 20 normal chorionic villus were detected with the method of EnVision immunohistochemistry. Their clinicopathologic data were retrospectively analyzed. RESULTS: LMP2 and PPM1A protein expressed in cytotrophocytes, syncytiotrophoblast and extravillous trophoblast. The level of LMP2 expression in deteriorative hydatidiform mole was significantly higher than that in non-deteriorative hydatidiform mole or normal chorionic villus (6.79±2.38, 5.26±2.63 and 3.10±1.65, all P<0.01), while there were no difference compared with gestational trophoblastic neoplasms (6.42±2.68, P=0.113). The level of PPM1A expression was highest in normal chorionic villus, and decreased gradually in hydatidiform mole (non-deteriorative and deteriorative) and gestational trophoblastic neoplasms (6.30±2.98, 4.93±2.50, 4.43±2.04 and 3.33±2.06, all P<0.01); the level of PPM1A expression in deteriorative hydatidiform mole was significantly lower than that in non-deteriorative hydatidiform mole (P=0.001). The expression of LMP2 protein was correlated to theca lutein ovarian cyst, the expression of PPM1A protein was related with uterine size (P<0.05). While, there was no correlation between the expressions of the two proteins (P>0.05). CONCLUSIONS: High expression of LMP2 and low expression of PPM1A might play an important role in the motility and invasiveness of trophoblast cells and malignant transformation of hydatidiform mole. Testing the expression of LMP2 and PPM1A in hydatidiform mole tissues of initial uterine evacuation might be have some reference significance in judging outcomes of hydatidiform mole.
Assuntos
Cisteína Endopeptidases/metabolismo , Doença Trofoblástica Gestacional/metabolismo , Mola Hidatiforme/patologia , Fosfoproteínas Fosfatases/metabolismo , Neoplasias Uterinas/metabolismo , Adolescente , Adulto , Estudos de Casos e Controles , Vilosidades Coriônicas/metabolismo , Feminino , Doença Trofoblástica Gestacional/patologia , Humanos , Mola Hidatiforme/metabolismo , Imuno-Histoquímica , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Gravidez , Proteína Fosfatase 2C , Estudos Retrospectivos , Trofoblastos/metabolismo , Neoplasias Uterinas/patologia , Adulto JovemRESUMO
Laryngeal and hypopharyngeal carcinomas are common malignant tumors of the head and neck, and the incidence of both is increasing. Laryngopharyngeal reflux refers to the retrograde flow of gastric contents into the larynx, oropharynx, and/or nasopharynx. It remains controversial whether laryngopharyngeal reflux is a risk factor for laryngeal and hypopharyngeal cancers. The refluxing substances mainly include hydrochloric acid, pepsin, and occasionally bile acids and bile salts, as well as bacteria that colonize the gastrointestinal tract. Loss of epithelium in the mucous membrane of the larynx and hypopharynx is thought to be caused by pepsin. Here, we review the relationships between laryngopharyngeal reflux and both laryngeal and hypopharyngeal carcinomas, as well as the significance of pepsin, methods of clinical detection, and the mechanism of carcinogenesis.
RESUMO
BACKGROUND: Aspirin is the first-line medication for prevention and treatment of coronary heart disease (CHD). However, long-term use of aspirin resulting in gastrointestinal mucosal injury and bleeding limits the regularity of medication. Xuesaitong is a marketed Chinese medicine contained main active component in Panax notoginseng saponins (PNS), which can significantly inhibit platelet aggregation in patients with CHD. Our previous studies have already showed that PNS could reduce the gastrointestinal mucosal injury caused by aspirin in preclinical study. However, there is a need for further clinical studies to evaluate synergy and attenuation effect of the combination. METHODS: This trial is a prospectively planned, open-labeled, parallel-grouped, single-centered clinical trial. A total of eligible 480 participants will be randomly allocated into three groups: aspirin group, Xuesaitong group, and drug combination group at a ratio of 1 : 1 : 1. The primary outcome is the change of platelet aggregation rate and calprotectin activity. Secondary outcomes include PAC-1, P-selectin, P2Y12, I-FABP activity, and fecal occult blood. Discussion. The results of the study are expected to provide evidence of high methodological and reporting quality on the synergy function of Xuesaitong and aspirin upon the antiplatelet and anti-gastrointestinal injury effect for CHD. It also provides an experimental basis for clinical rational drug combination therapy. Trial Registration. This trial was registered in the Chinese Clinical Trail Registry, ChiCTR2000036311, on 22 August 2020, http://www.chictr.org.cn/edit.aspx?pid=58798&htm=4.