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1.
BMC Plant Biol ; 24(1): 599, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38918732

RESUMEN

BACKGROUND: Cowpea wilt is a harmful disease caused by Fusarium oxysporum, leading to substantial losses in cowpea production. Melatonin reportedly regulates plant immunity to pathogens; however the specific regulatory mechanism underlying the protective effect of melatonin pretreated of cowpea against Fusarium oxysporum remains known. Accordingly, the study sought to evaluate changes in the physiological and biochemical indices of cowpea following melatonin treated to facilitate Fusarium oxysporum resistance and elucidate the associated molecular mechanism using a weighted gene coexpression network. RESULTS: Treatment with 100 µM melatonin was effective in increasing cowpea resistance to Fusarium oxysporum. Glutathione peroxidase (GSH-PX), catalase (CAT), and salicylic acid (SA) levels were significantly upregulated, and hydrogen peroxide (H2O2) levels were significantly downregulated in melatonin treated samples in roots. Weighted gene coexpression network analysis of melatonin- and Fusarium oxysporum-treated samples identified six expression modules comprising 2266 genes; the number of genes per module ranged from 9 to 895. In particular, 17 redox genes and 32 transcription factors within the blue module formed a complex interconnected expression network. KEGG analysis revealed that the associated pathways were enriched in secondary metabolism, peroxisomes, phenylalanine metabolism, flavonoids, and flavonol biosynthesis. More specifically, genes involved in lignin synthesis, catalase, superoxide dismutase, and peroxidase were upregulated. Additionally, exogenous melatonin induced activation of transcription factors, such as WRKY and MYB. CONCLUSIONS: The study elucidated changes in the expression of genes associated with the response of cowpea to Fusarium oxysporum under melatonin treated. Specifically, multiple defence mechanisms were initiated to improve cowpea resistance to Fusarium oxysporum.


Asunto(s)
Resistencia a la Enfermedad , Fusarium , Redes Reguladoras de Genes , Melatonina , Enfermedades de las Plantas , Vigna , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Melatonina/farmacología , Melatonina/metabolismo , Resistencia a la Enfermedad/genética , Resistencia a la Enfermedad/efectos de los fármacos , Fusarium/fisiología , Vigna/genética , Vigna/microbiología , Vigna/efectos de los fármacos , Vigna/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Ácido Salicílico/metabolismo
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 321: 124699, 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38909559

RESUMEN

The identification and quantification of melatonin (MT) are crucial for early diagnosis of disorders associated with circadian rhythm disruption. Herein, novel blue-emissive carbon dots (BCDs) were synthesized through an improved hydrothermal treatment using serine and malic acid as reductant and carbon source. The excellent optical properties of the as-obtained BCDs were used for ratiometric sensing by strategically constructing a MT sensing system integrating BCDs with C3N4 nanosheets loaded with platinum/ruthenium nanoparticles (PtRu/CN). In this system, H2O2 activated the peroxidase-like activity of PtRu/CN to generate •OH and 1O2 for oxidizing the colorless o-phenylenediamine (OPD) into yellow 2,3-diaminophenazine (DAP) with fluorescence emission at 565 nm. Concurrently, the fluorescence emission of BCDs at 439 nm was quenched by the generated DAP via the static quenching and inner filter effect (IFE) process. However, MT rapidly scavenged the generated free radicals to reverse the ratio fluorescence signal. The developed BCDs/PtRu/CN/OPD/H2O2 sensing platform enabled quantitative analysis of MT at concentrations ranging from 0.06 to 600 µmol/L with a low detection limit of 23.56 nmol/L. Moreover, smartphone-based RGB sensing of MT was successfully developed for rapid visualization and portable processing. More broadly, novel insights into the preparation of carbon dots with sensitive fluorescence sensing properties were presented, promising for future considerations.

3.
J Hazard Mater ; 476: 134909, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38905979

RESUMEN

Developing highly-efficient electrocatalysts for the nitrate reduction reaction (NITRR) is a persistent challenge. Here, we present the successful synthesis of 14 amorphous/low crystallinity metal nanofilms on three-dimensional carbon fibers (M-NFs/CP), including Al, Ti, Mn, Fe, Co, Ni, Cu, Zn, Ag, In, Sn, Pb, Au, or Bi, using rapid thermal evaporation. Among these samples, our study identifies the amorphous Co nanofilm with fine agglomerated Co clusters as the optimal electrocatalyst for NITRR in a neutral medium. The resulting Co-NFs/CP exhibits a remarkable Faradaic efficiency (FENH3) of 91.15 % at - 0.9 V vs RHE, surpassing commercial Co foil (39 %) and Co powder (20 %), despite sharing the same metal composition. Furthermore, during the electrochemical NITRR, the key intermediates on the surface of the Co-NFs/CP catalyst were detected by in situ Fourier-transform infrared (FTIR) spectroscopy, and the possible reaction ways were probed by Density functional theory (DFT) calculations. Theoretical calculations illustrate that the abundant low-coordinate Co atoms of Co-NFs/CP could enhances the adsorption of *NO3 intermediates compared to crystalline Co. Additionally, the amorphous Co structure lowers the energy barrier for the rate-determining step (*NH2→*NH3). This work opens a new avenue for the controllable synthesis of amorphous/low crystallinity metal nano-catalysts for various electrocatalysis reaction applications.

4.
Chem Soc Rev ; 53(10): 5149-5189, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38566609

RESUMEN

The electrochemical reduction of CO2 into value-added chemicals has been explored as a promising solution to realize carbon neutrality and inhibit global warming. This involves utilizing the electrochemical CO2 reduction reaction (CO2RR) to produce a variety of single-carbon (C1) and multi-carbon (C2+) products. Additionally, the electrolyte solution in the CO2RR system can be enriched with nitrogen sources (such as NO3-, NO2-, N2, or NO) to enable the synthesis of organonitrogen compounds via C-N coupling reactions. However, the electrochemical conversion of CO2 into valuable chemicals still faces challenges in terms of low product yield, poor faradaic efficiency (FE), and unclear understanding of the reaction mechanism. This review summarizes the promising strategies aimed at achieving selective production of diverse carbon-containing products, including CO, formate, hydrocarbons, alcohols, and organonitrogen compounds. These approaches involve the rational design of electrocatalysts and the construction of coupled electrocatalytic reaction systems. Moreover, this review presents the underlying reaction mechanisms, identifies the existing challenges, and highlights the prospects of the electrosynthesis processes. The aim is to offer valuable insights and guidance for future research on the electrocatalytic conversion of CO2 into carbon-containing products of enhanced value-added potential.

5.
Shock ; 61(3): 387-394, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-37878488

RESUMEN

ABSTRACT: Background: Sepsis is caused by the invasion of the bloodstream by microorganisms from local sites of infection, leading to high mortality. This study aimed to compare the predictive ability of the biomarkers presepsin, procalcitonin (PCT), and C-reactive protein for bacteraemia. Methods: In this retrospective, multicentre study, a dataset of patients with sepsis who were prospectively enrolled between November 2017 and June 2021 was analyzed. The performances of the biomarkers for predicting positive blood cultures and infection with specific pathogens were assessed by the areas under the receiver operating characteristic curves (AUCs). The independent effects of the pathogen and foci of infection on presepsin and PCT levels were assessed by linear logistic regression models. Results: A total of 577 patients with 170 positive blood cultures (29.5%) were enrolled. The AUC achieved using PCT levels (0.856) was significantly higher than that achieved using presepsin (0.786, P = 0.0200) and C-reactive protein (0.550, P < 0.0001) levels in predicting bacteraemia. The combined analysis of PCT and presepsin levels led to a significantly higher AUC than the analysis of PCT levels alone for predicting blood culture positivity (0.877 vs. 0.856, P = 0.0344) and gram-negative bacteraemia (0.900 vs. 0.875, P = 0.0216). In a linear regression model, the elevated concentrations of presepsin and PCT were both independently related to Escherichia coli , Klebsiella species, Pseudomonas species, and Streptococcus species infections and Sequential Organ Failure Assessment score. Presepsin levels were also associated with Acinetobacter species and abdominal infection, and PCT levels were positively associated with other Enterobacteriaceae and negatively associated with respiratory infection. Combined analysis of presepsin and PCT levels provided a high sensitivity and specificity in identifying E. coli or Klebsiella species infection. Conclusions: Presepsin and PCT were promising markers for predicting bacteraemia and common pathogens at the time of sepsis onset with a synergistic effect.


Asunto(s)
Sepsis , Humanos , Bacteriemia/diagnóstico , Biomarcadores/sangre , Cultivo de Sangre , Proteína C-Reactiva , Calcitonina , Escherichia coli , Receptores de Lipopolisacáridos , Fragmentos de Péptidos , Polipéptido alfa Relacionado con Calcitonina , Estudios Prospectivos , Estudios Retrospectivos , Sepsis/diagnóstico
6.
Anal Methods ; 15(37): 4842-4850, 2023 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-37702073

RESUMEN

Nowadays, the presence of highly toxic and persistent residues of pesticides in water and food around the world is becoming a serious problem, and so their rapid and sensitive detection is critical to human health. In this work, a 3D composite nanoparticle of porous PDA (polydopamine) microspheres and Au NPs (PPDA@Au NPs) was proposed as a SERS substrate to detect pesticides. Porous PDA as a substrate was first synthesized with F127 (Pluronic F127), dopamine hydrochloride, and 1,3,5-TMB (1,3,5-trimethylbenzene) under weakly alkaline conditions by a one-step method. Then, HAuCl4 was in situ reduced in the pores of PPDA spheres and grew sequentially for effecting the reducibility of PPDA. As a result, uniform 3D PPDA@Au NPs with "hot spots" were successfully synthesized as SERS substrates, which could effectively avoid the agglomeration of gold nanoparticles to greatly improve the sensitivity and uniformity of the SERS platform. At the same time, methyl parathion, 4-chlorophenol, and 2,4-D as representatives of pesticides were detected with the proposed PPDA@Au NP-based SERS platform, with detection limits lower than 7.26, 7.52, and 11 ng mL-1, separately. The current work presents a simple preparation method to prepare sensitive and uniform SERS platform PPDA@Au NPs, which have potential for applications in actual pesticide and drug testing.


Asunto(s)
Nanopartículas del Metal , Plaguicidas , Humanos , Plaguicidas/análisis , Verduras , Oro/química , Porosidad , Nanopartículas del Metal/química , Espectrometría Raman
7.
Shock ; 60(1): 42-50, 2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-37267265

RESUMEN

ABSTRACT: Background: Pulmonary sepsis and abdominal sepsis have pathophysiologically distinct phenotypes. This study aimed to compare their clinical characteristics and predictors of mortality. Methods: In this multicenter retrospective trial, 1,359 adult patients who fulfilled the Sepsis-3 criteria were enrolled and classified into the pulmonary sepsis or abdominal sepsis groups. Plasma presepsin was measured, and the scores of Acute Physiology and Chronic Health Evaluation (APACHE) II, Mortality in Emergency Department Sepsis (MEDS), and Simplified Acute Physiology Score (SAPS) II were calculated at enrollment. Data on 28-day mortality were collected for all patients. Results: Compared with patients with abdominal sepsis (n = 464), patients with pulmonary sepsis (n = 895) had higher 28-day mortality rate, illness severity scores, incidence of shock and acute kidney injury, and hospitalization costs. Lactate level and APACHE II and MEDS scores were independently associated with 28-day mortality in both sepsis types. Independent predictors of 28-day mortality included Pa o2 /F io2 ratio (hazard ratio [HR], 0.998; P < 0.001) and acute kidney injury (HR, 1.312; P = 0.039) in pulmonary sepsis, and SAPS II (HR, 1.037; P = 0.017) in abdominal sepsis. A model that combined APACHE II score, lactate, and MEDS score or SAPS II score had the best area under the receiver operating characteristic curve in predicting mortality in patients with pulmonary sepsis or abdominal sepsis, respectively. Interaction term analysis confirmed the association between 28-day mortality and lactate, APACHE II score, MEDS score, SAPS II score, and shock according to the sepsis subgroups. The mortality of patients with pulmonary sepsis was higher than that of patients with abdominal sepsis among patients without shock (32.9% vs. 8.8%; P < 0.001) but not among patients with shock (63.7 vs. 48.4%; P = 0.118). Conclusions: Patients with pulmonary sepsis had higher 28-day mortality than patients with abdominal sepsis. The study identified sepsis subgroup-specific mortality predictors. Shock had a larger effect on mortality in patients with abdominal sepsis than in those with pulmonary sepsis.


Asunto(s)
Lesión Renal Aguda , Infecciones Intraabdominales , Sepsis , Adulto , Humanos , Estudios Retrospectivos , Pronóstico , Curva ROC , Ácido Láctico , Fragmentos de Péptidos , Receptores de Lipopolisacáridos
8.
JCI Insight ; 8(9)2023 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-36976637

RESUMEN

Several preclinical studies have demonstrated that certain cytotoxic drugs enhance metastasis, but the importance of host responses triggered by chemotherapy in regulating cancer metastasis has not been fully explored. Here, we showed that multidose gemcitabine (GEM) treatment promoted breast cancer lung metastasis in a transgenic spontaneous breast cancer model. GEM treatment significantly increased accumulation of CCR2+ macrophages and monocytes in the lungs of tumor-bearing as well as tumor-free mice. These changes were largely caused by chemotherapy-induced reactive myelopoiesis biased toward monocyte development. Mechanistically, enhanced production of mitochondrial ROS was observed in GEM-treated BM Lin-Sca1+c-Kit+ cells and monocytes. Treatment with the mitochondria targeted antioxidant abrogated GEM-induced hyperdifferentiation of BM progenitors. In addition, GEM treatment induced upregulation of host cell-derived CCL2, and knockout of CCR2 signaling abrogated the pro-metastatic host response induced by chemotherapy. Furthermore, chemotherapy treatment resulted in the upregulation of coagulation factor X (FX) in lung interstitial macrophages. Targeting activated FX (FXa) using FXa inhibitor or F10 gene knockdown reduced the pro-metastatic effect of chemotherapy. Together, these studies suggest a potentially novel mechanism for chemotherapy-induced metastasis via the host response-induced accumulation of monocytes/macrophages and interplay between coagulation and inflammation in the lungs.


Asunto(s)
Factor X , Neoplasias Pulmonares , Ratones , Animales , Mielopoyesis , Macrófagos/patología , Monocitos/patología , Neoplasias Pulmonares/patología , Gemcitabina
9.
Phys Chem Chem Phys ; 25(13): 9273-9281, 2023 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-36919713

RESUMEN

In many of the existing refractive index (RI) sensing works, only the shape and size of plasmonic structures are usually taken into account, while the parameters of spacer layers are ignored. In this publication, we explored the long-range surface plasmon resonance (LRSPR) and Fabry-Pérot resonance coupling effects of our proposed gold nanoring cavity array/spacer layer/Au mirror/glass substrate. Both the RI sensitivity and full width at half-maximum (FWHM) values were superior than those of conventional surface plasmon resonance substrates. We discussed the tunability of the RI sensitivity through changing the RI and thickness of the spacer layer. Then, under the optimized parameter conditions of the spacer layer, the geometry parameters (including size, gap and periodicity) of gold nanoring cavity arrays were tuned to optimize the best RI sensitivity. Finally, we broke the structural symmetry of a nanoring cavity to introduce Fano resonances into our system, and a high RI sensitivity and figure-of-merit (FOM) of 695 nm per RIU (refractive index unit) and 96.5, respectively, were achieved when the breaking angle θ was 30°. This study opens up many possibilities for boosting the FOM of RI sensing by taking into account the hybridization effects of localized surface plasmon resonance, LRSPR, and Fabry-Pérot and Fano resonances.

10.
ACS Nano ; 17(4): 3209-3224, 2023 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-36786415

RESUMEN

The electrochemical coreduction of carbon dioxide (CO2) and nitrogenous species (such as NO3-, NO2-, N2, and NO) for urea synthesis under ambient conditions provides a promising solution to realize carbon/nitrogen neutrality and mitigate environmental pollution. Although an increasing number of studies have made some breakthroughs in electrochemical urea synthesis, the unsatisfactory Faradaic efficiency, low urea yield rate, and ambiguous C-N coupling reaction mechanisms remain the major obstacles to its large-scale applications. In this review, we present the recent progress on electrochemical urea synthesis based on CO2 and nitrogenous species in aqueous solutions under ambient conditions, providing useful guidance and discussion on the rational design of metal nanocatalyst, the understanding of the C-N coupling reaction mechanism, and existing challenges and prospects for electrochemical urea synthesis. We hope that this review can stimulate more insights and inspiration toward the development of electrocatalytic urea synthesis technology.

11.
Lab Chip ; 23(2): 388-399, 2023 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-36621932

RESUMEN

The identification of biomacromolecules by using surface-enhanced Raman scattering (SERS) remains a challenge because of the near-field effect of traditional substrates. Long-range surface plasmon resonance (LRSPR) is a special type of surface optical phenomenon that provides higher electromagnetic field enhancement and longer penetration depth than conventional surface plasmon resonance. To break the limit of SERS detection distance and obtain a SERS substrate with increased enhancement ability, a bowtie nanoaperture array was sandwiched between two symmetric dielectric environments. Then, an Au mirror was inserted to form a metal-insulator-metal configuration. Finite-difference time-domain simulations revealed that numerous hybrid modes can be provided by this novel configuration (denoted as long-range SERS [LR-SERS] substrate). In particular, the LRSPR mode can be excited and reach the maximum value through the regulation of the polarizations of the incident light and the geometrical parameters of the LR-SERS substrate. The optimized LR-SERS substrate was then applied to detect SARS-CoV-2 spike (S) and nucleocapsid (N) proteins. This substrate displayed ultralow detection limits of ∼9.2 and ∼11.3 pg mL-1 for the S and N proteins, respectively. Moreover, with the help of principal component analysis and receiver operating characteristic methods, our fabricated sensors exhibited excellent selectivity and hold great potential for the diagnosis of SARS-CoV-2 proteins in real samples.


Asunto(s)
COVID-19 , Nanopartículas del Metal , Humanos , Espectrometría Raman/métodos , SARS-CoV-2 , Nanopartículas del Metal/química , Oro/química , COVID-19/diagnóstico
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 289: 122134, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36512966

RESUMEN

In this work, a simple and sensitive SERS-based miRNA biosensor was constructed based on porous MOFs nanoparticles and efficient subject-object recognition ability. MOFs as a container can package lots of signal probe neutral red (NR) for the advantages of three dimensional structure and porosity. The partially complementary duplex DNA can as a "lock" to lock up the hole for obtaining a weak Raman signal. In the present of miRNA, miRNA just like a "key" to open the duplex structure with the results of releasing NR. At this time, the released NR can be captured by SERS substrate AuNS@CB[7] for the subject-object recognition ability to produce a strong Raman signal which was positive correlation to target miRNA. By this way, the proposed SERS biosensor can achieve sensitively and selectively detect miRNA with a detection limit of 0.562 fM. This MOF-based SERS biosensor also be hopeful application for clinical diagnostics.


Asunto(s)
Técnicas Biosensibles , Nanopartículas del Metal , MicroARNs , Nanopartículas , Porosidad , Espectrometría Raman/métodos , Técnicas Biosensibles/métodos , Oro/química , Límite de Detección , Nanopartículas del Metal/química
13.
Front Immunol ; 13: 943783, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36119040

RESUMEN

Basic research for prevention and treatment of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues worldwide. In particular, multiple newly reported cases of autoimmune-related diseases after COVID-19 require further research on coronavirus-related immune injury. However, owing to the strong infectivity of SARS-CoV-2 and the high mortality rate, it is difficult to perform relevant research in humans. Here, we reviewed animal models, specifically mice with coronavirus-related immune disorders and immune damage, considering aspects of coronavirus replacement, viral modification, spike protein, and gene fragments. The evaluation of mouse models of coronavirus-related immune injury may help establish a standardised animal model that could be employed in various areas of research, such as disease occurrence and development processes, vaccine effectiveness assessment, and treatments for coronavirus-related immune disorders. COVID-19 is a complex disease and animal models cannot comprehensively summarise the disease process. The application of genetic technology may change this status.


Asunto(s)
COVID-19 , Glicoproteína de la Espiga del Coronavirus , Animales , Modelos Animales de Enfermedad , Humanos , Ratones , SARS-CoV-2
14.
Anal Chim Acta ; 1228: 340340, 2022 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-36127003

RESUMEN

In this work, a simple and sensitive SERS biosensor was proposed for ultrasensitive detecting miRNA 122 based on ZnO nanoparticle amplification strategy and the full utilization of DNA chain. Firstly, ZnO@S1/S2 and CoFe2O4@S3 complexes can flock together with the assistance of target miRNA. Accompanied with the incremental amount of miRNA, the quantity of ZnO@S1/S2 would increase. Therefore, a significant amplification capability can be obtained by converting ZnO complexes into Zn2+ with the assistance of HCl. In this case, the DNA chain S2 can be obtained by the ZnO dissolving. In addition, through a clever design, the obtained Zn2+ can be further utilized to induce DNA enzyme cycle amplification to cleave S5 into DNA chain which was similar with DNA S2. This step greatly avoided the waste of DNA chains and improved the utilization efficiency of DNA chains. The S2 and abundant S2 analogues can complement with S4 on the Raman sensing interface to imbed lots of Raman probe DOX for obtaining strong Raman signal. By this way, with the increased number of miRNA, the S2 and abundant S2 analogues would increase, so the amount of DOX would increase to produce strong Raman signal to quantitatively detect target miRNA. As a result, this SERS biosensor based on Zn+ amplification and high utilization efficiency of DNA chain can obtain a low detection limit of 6.82 aM and wide linear range from 10 aM to 10 pM, which shown great potential in the clinical application and medical diagnosis.


Asunto(s)
Técnicas Biosensibles , Nanopartículas del Metal , MicroARNs , Óxido de Zinc , ADN/genética , Límite de Detección , MicroARNs/genética , Zinc
15.
Food Chem ; 390: 133164, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35551030

RESUMEN

Thiram (TRM), one dithiocarbamate fungicide, is hazardous due to its ever-growing threat to our production and living. In order to detecting TRM more sensitively, a subtle surface-enhanced Raman scattering (SERS) substrate was reported to achieve TRM detection based on oil-water biphasic self-assembly interface of multi-interstitial Au@Ag@Au NPs crosslinking with 4,4' -Diamino-p-Terphenyl (DATP). This Au@Ag@Au@DATP array shows a noteworthy enhanced Raman signal and stability by controlling the inter-particle spacing of Au@Ag@Au NPs, which overcomes problems of traditional randomly self-assembly methods without cross linker. The Au@Ag@Au@DATP array attained the limit of detection (LOD) of 7.56 × 10-3 ppb for TRM. In addition, this work gives a new approach for controlling gap of SERS hot spot, which have distinct potential in rapid assessment and identification of pesticides on foods.


Asunto(s)
Nanopartículas del Metal , Tiram , Oro , Plata , Espectrometría Raman/métodos
16.
Langmuir ; 38(20): 6454-6463, 2022 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-35549353

RESUMEN

Plasmonic sensors are promising for ultrasensitive chemical and biological analysis. Gold nanoplates (Au NPLs) show unique geometrical structures with high ratios of surface to bulk atoms, which display fascinating plasmonic properties but require optimization. This study presented a systematic investigation of the influence of different parameters (shape, aspect ratio, and resonance mode) on localized surface plasmon resonance properties, refractive index (RI, n) sensitivities, and surface-enhanced Raman scattering (SERS) enhancement ability of different types of Au NPLs through finite-difference time-domain (FDTD) simulations. As a proof of concept, triangular, circular, and hexagonal Au NPLs with varying aspect ratios were fabricated via a three-step seed-mediated growth method by the experiment. Both FDTD-simulated and measured experimental results confirm that the RI sensitivities increase with the aspect ratio. Furthermore, choosing a lower order resonance mode of Au NPLs benefits higher RI sensitivities. The SERS enhancement abilities of Au NPLs also predicted to be highly dependent on the shape and aspect ratio. The triangular Au NPLs showed the highest SERS enhancement ability, while it drastically decreased for circular Au NPLs after the rounding process. The SERS enhancement ability gradually became more intense as the hexagonal Au NPLs overgrown on circular Au NPLs with increasing volumes of HAuCl4 solution. The results are expected to help develop effective biosensors.


Asunto(s)
Oro , Nanopartículas del Metal , Refractometría , Oro/química , Nanopartículas del Metal/química , Refractometría/instrumentación , Espectrometría Raman/métodos , Resonancia por Plasmón de Superficie/métodos
17.
Front Plant Sci ; 13: 821683, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35145539

RESUMEN

As a rate-limiting enzyme for chlorophyll biosynthesis, Mg-chelatase is a promising target for improving photosynthetic efficiency. It consists of CHLH, CHLD, and CHLI subunits. In pea (Pisum sativum L.), two putative CHLI genes (PsCHLI1 and PsCHLI2) were revealed recently by the whole genome sequencing, but their molecular features are not fully characterized. In this study, PsCHLI1 and PsCHLI2 cDNAs were identified by PCR-based cloning and sequencing. Phylogenetic analysis showed that PsCHLIs were derived from an ancient duplication in legumes. Both PsCHLIs were more highly expressed in leaves than in other organs and downregulated by abscisic acid and heat treatments, while PsCHLI1 was more highly expressed than PsCHLI2. PsCHLI1 and PsCHLI2 encode 422- and 417-amino acid proteins, respectively, which shared 82% amino acid identity and were located in chloroplasts. Plants with a silenced PsCHLI1 closely resembled PsCHLI1 and PsCHLI2 double-silenced plants, as both exhibited yellow leaves with barely detectable Mg-chelatase activity and chlorophyll content. Furthermore, plants with a silenced PsCHLI2 showed no obvious phenotype. In addition, the N-terminal fragment of PsCHLI1 (PsCHLI1N, Val63-Cys191) and the middle fragment of PsCHLI1 (PsCHLI1M, Gly192-Ser336) mediated the formation of homodimers and the interaction with CHLD, respectively, while active PsCHLI1 was only achieved by combining PsCHLI1N, PsCHLI1M, and the C-terminal fragment of PsCHLI1 (Ser337-Ser422). Taken together, PsCHLI1 is the key CHLI subunit, and its peptide fragments are essential for maintaining Mg-chelatase activity, which can be used to improve photosynthetic efficiency by manipulating Mg-chelatase in pea.

18.
World J Emerg Med ; 13(1): 32-37, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35003414

RESUMEN

BACKGROUND: To investigate effects of Maxingloushi decoction on lung inflammation and programmed death markers (programmed death-1 [PD-1], programmed death-ligand 1 [PD-L1]) in the lung tissue, peripheral blood, and bronchoalveolar lavage fluid (BLF) in a mouse model of chronic obstructive pulmonary disease (COPD). METHODS: Thirty-six mature male BALB/C mice were randomly divided into normal group (group A, n=6), COPD model group (group B, n=10), Maxingloushi decoction + COPD group (group C, n=10), and PD-1 inhibitor + COPD group (group D, n=10). The COPD model was established by smoke inhalation combined with lipopolysaccharide (LPS). Levels of PD-1 and PD-L1 in plasma and BLF were measured by enzyme-linked immunosorbent assay (ELISA). Histopathological techniques were used to semi-quantitatively analyze the immuno-fluorescence optical density (IOD) value of the lung tissue. RESULTS: In plasma and BLF, the expression of PD-1 in the group B was higher than that in the group A, and the expression of PD-L1 was lower than that in the group A. The expression of PD-1 and PD-L1 in the lung tissue was normalized in the group C in comparison with the group B (P<0.05) and the group D (P<0.05), and inflammatory cell infiltration in the lung tissue was also improved. CONCLUSIONS: These findings reveal that COPD causes an immune imbalance in the peripheral blood and lung tissue, and that both Maxingloushi decoction and PD-1 inhibitor treatment can mitigate lung inflammation in COPD by reducing PD-1 expression and increasing PD-L1 expression. The treatment effect of Maxingloushi decoction may be superior to that of PD-1 inhibitor.

19.
Shock ; 57(1): 63-71, 2022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-34618727

RESUMEN

INTRODUCTION: Long-term use of antibiotics for septic patients leads to bacterial resistance, increased mortality, and hospital stay. In this study, we investigated an emerging biomarker presepsin-guided strategy, which can be used to evaluate the shortening of antibiotic treatment in patients with sepsis without risking a worse outcome. METHODS: In this multicenter prospective cohort trial, patients were assigned to the presepsin or control groups. In the presepsin group, antibiotics were ceased based on predefined cut-off ranges of presepsin concentrations. The control group stopped antibiotics according to international guidelines. The primary endpoints were the number of days without antibiotics within 28 days and mortality at 28 and 90 days. Secondary endpoints were the percentage of patients with a recurrent infection, length of stay in ICU and hospital, hospitalization costs, days of first episode of antibiotic treatment, percentage of antibiotic administration and multidrug-resistant bacteria, and SOFA score. RESULTS: Overall, 656 out of an initial 708 patients were eligible and assigned to the presepsin group (n = 327) or the control group (n = 329). Patients in the presepsin group had significantly more days without antibiotics than those in the control group (14.54 days [SD 9.01] vs. 11.01 days [SD 7.73]; P < 0.001). Mortality in the presepsin group showed no difference to that in the control group at days 28 (17.7% vs. 18.2%; P = 0.868) and 90 (19.9% vs. 19.5%; P = 0.891). Patients in the presepsin group had a significantly shorter mean length of stay in the hospital and lower hospitalization costs than control subjects. There were no differences in the rate of recurrent infection and multidrug-resistant bacteria and the SOFA score tendency between the two groups. CONCLUSIONS: Presepsin guidance has potential to shorten the duration of antibiotic treatment in patients with sepsis without risking worse outcomes of death, recurrent infection, and aggravation of organ failure. TRIAL REGISTRATION: ChiCTR, ChiCTR1900024391. Registered 9 July 2019-Retrospectively registered, http://www.chictr.org.cn.


Asunto(s)
Antibacterianos/administración & dosificación , Receptores de Lipopolisacáridos/sangre , Fragmentos de Péptidos/sangre , Sepsis/tratamiento farmacológico , Anciano , Biomarcadores/sangre , Estudios de Cohortes , Esquema de Medicación , Femenino , Costos de Hospital , Humanos , Tiempo de Internación , Masculino , Sepsis/sangre , Sepsis/mortalidad
20.
J Genet ; 1002021.
Artículo en Inglés | MEDLINE | ID: mdl-34470920

RESUMEN

Histone acetylation is an important posttranslational modification associated with gene activation. In Arabidopsis, histone acetyltransferase 1 (HAC1) can promote flowering by regulating the transcription of FLOWERING LOCUS C (FLC), a major floral repressor. The size of the full-length cDNA and genomic DNA sequences of the histone acetyltransferase 1 gene (BrcuHAC1) in Chinese flowering cabbage (Brassica rapa syn. campestris ssp. chinensis var. utilis) were 5846 bp and 7376 bp, with an open reading frame (ORF) coding for a peptide with 1689 amino acids. The expression levels of BrcuHAC1 in different tissues and different developmental stages were as follows: flower>leaf>stem>root, and completed bolting and flowering stage>5th true leaf-stage>4th true leaf-stage>3rd true leaf-stage>2nd true leaf-stage>1st true leaf-stage. Silencing of BrcuHAC1 resulted in slow growth, and delayed bolting and flowering time in Chinese flowering cabbage. Molecular analysis showed that the mRNA level of FLC was increased, indicating that the delayed flowering phenomenon was mediated by FLC in the silenced group. In contrast, the expression levels of the autonomous-pathway genes were not significantly affected in the silenced group. In addition, the histone modification of FLC chromatin was also not affected in the silenced group. FLC is not the direct target gene of BrcuHAC1. However, BrcuHAC1 may affect the bolting and flowering time of Chinese flowering cabbage through the epigenetic modification of upstream factors of FLC.


Asunto(s)
Brassica/crecimiento & desarrollo , Brassica/genética , Flores/crecimiento & desarrollo , Flores/genética , Histona Acetiltransferasas/genética , Histona Acetiltransferasas/metabolismo , Acetilación , Clonación Molecular , Epigénesis Genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Proteínas de Dominio MADS/genética , Proteínas de Dominio MADS/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
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