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1.
Protein Expr Purif ; 221: 106507, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38777308

RESUMEN

Recombinant human interleukin-2 (rhIL-2) represents one of the most difficult-to-produce cytokines in E. coli due to its extreme hydrophobicity and high tendency to formation of inclusion bodies. Refolding of rhIL-2 inclusion bodies always represents cumbersome downstream processes and low production efficiency. Herein, we disclosed a fusion strategy for efficiently soluble expression and facile production of rhIL-2 in E. coli Origami B (DE3) host. A two-tandem SUMO fusion partner (His-2SUMO) with a unique SUMO protease cleavage site at C-terminus was devised to fuse with the N-terminus of rhIL-2 and the fusion protein (His-2SUMO-rhIL-2) was almost completely expressed in a soluble from. The fusion partner could be efficiently removed by Ulp1 cleavage and the rhIL-2 was simply produced by a two-step Ni-NTA affinity chromatography with a considerable purity and whole recovery. The eventually obtained rhIL-2 was well-characterized and the results showed that the purified rhIL-2 exhibits a compact and ordered structure. Although the finally obtained rhIL-2 exists in a soluble aggregates form and the aggregation probably has been occurred during expression stage, the soluble rhIL-2 aggregates remain exhibit comparable bioactivity with the commercially available rhIL-2 drug formulation.


Asunto(s)
Escherichia coli , Interleucina-2 , Proteínas Recombinantes de Fusión , Solubilidad , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Interleucina-2/genética , Interleucina-2/biosíntesis , Interleucina-2/química , Interleucina-2/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/aislamiento & purificación , Expresión Génica , Cromatografía de Afinidad , Clonación Molecular , Proteínas Recombinantes/genética , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificación , Cuerpos de Inclusión/química , Cuerpos de Inclusión/genética , Cuerpos de Inclusión/metabolismo
2.
J Environ Manage ; 359: 120993, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38688131

RESUMEN

The fertilization regimes of combining manure with synthetic fertilizer are benefits for crop yields and soil fertility in cropping systems as compared to sole synthetic fertilization, but the responses of nitrous oxide (N2O) emissions to these practices are inconsistent in the literatures. We hypothesized that it is caused by different proportions of nitrogen (N) applied as manure and various soil properties. Here, we conducted a microcosm experiment, and measured the N2O emissions from control (no N) and five manure substitution treatments (supplied 100 mg N kg-1 using the combination of urea with manure) with a range of proportions of N applied as manure (0, 25%, 50%, 75%, and 100%) in three different soil types (fluvo-aquic soil, black soil, and latosol) under aerobic condition. The stimulated effect on N2O emissions was more pronounced after manure application in an alkaline soil with high nitrification rate, due to relatively rapid soil DOC depletion and N mineralization of manure. N2O emissions from partial substitution of urea with manure were significantly higher than manure-only addition under high soil pH due to abundant labile C from manure. However, there was no difference between manure substitution treatments under acid soils. Nitrification inhibitor substantially decreased N2O emissions with increasing soil pH, but it was less effective in mitigating N2O emissions with larger proportion of manure. This is likely due to the slow nitrification under low soil pH, and denitrification derived N2O increased with increasing manure application rate. Collectively, our study shows that the application of manure substitution to alkaline soils requires careful consideration, which might have rapid nitrification potential and hence trigger significant N2O emissions. The knowledge gained in this work will help the decision-makers in optimizing a sound N fertilization regime interacted with soil properties for sustainable crop production and N2O mitigation.


Asunto(s)
Fertilizantes , Estiércol , Óxido Nitroso , Suelo , Suelo/química , Óxido Nitroso/análisis , Fertilizantes/análisis , Nitrógeno , Nitrificación , Concentración de Iones de Hidrógeno
3.
Cell Rep Med ; 5(5): 101530, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38688275

RESUMEN

Chimeric antigen receptor (CAR) T cell therapy is hindered in solid tumor treatment due to the immunosuppressive tumor microenvironment and suboptimal T cell persistence. Current strategies do not address nutrient competition in the microenvironment. Hence, we present a metabolic refueling approach using inosine as an alternative fuel. CAR T cells were engineered to express membrane-bound CD26 and cytoplasmic adenosine deaminase 1 (ADA1), converting adenosine to inosine. Autocrine secretion of ADA1 upon CD3/CD26 stimulation activates CAR T cells, improving migration and resistance to transforming growth factor ß1 suppression. Fusion of ADA1 with anti-CD3 scFv further boosts inosine production and minimizes tumor cell feeding. In mouse models of hepatocellular carcinoma and non-small cell lung cancer, metabolically refueled CAR T cells exhibit superior tumor reduction compared to unmodified CAR T cells. Overall, our study highlights the potential of selective inosine refueling to enhance CAR T therapy efficacy against solid tumors.


Asunto(s)
Adenosina Desaminasa , Dipeptidil Peptidasa 4 , Inmunoterapia Adoptiva , Receptores Quiméricos de Antígenos , Animales , Adenosina Desaminasa/metabolismo , Humanos , Receptores Quiméricos de Antígenos/inmunología , Receptores Quiméricos de Antígenos/metabolismo , Ratones , Inmunoterapia Adoptiva/métodos , Dipeptidil Peptidasa 4/metabolismo , Dipeptidil Peptidasa 4/inmunología , Línea Celular Tumoral , Linfocitos T/inmunología , Linfocitos T/metabolismo , Inosina , Microambiente Tumoral/inmunología , Ensayos Antitumor por Modelo de Xenoinjerto , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Carcinoma de Pulmón de Células no Pequeñas/terapia , Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/patología , Carcinoma Hepatocelular/inmunología , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/patología
4.
Plants (Basel) ; 13(7)2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38611451

RESUMEN

Investigating intraspecific trait variability is crucial for understanding plant adaptation to various environments, yet research on lithophytic mosses in extreme environments remains scarce. This study focuses on Indusiella thianschanica Broth. Hal., a unique lithophytic moss species in the extreme environments of the Tibetan Plateau, aiming to uncover its adaptation and response mechanisms to environmental changes. Specimens were collected from 26 sites across elevations ranging from 3642 m to 5528 m, and the relationships between 23 morphological traits and 15 environmental factors were analyzed. Results indicated that coefficients of variation (CV) ranged from 5.91% to 36.11%, with gametophyte height (GH) and basal cell transverse wall thickness (STW) showing the highest and lowest variations, respectively. Temperature, elevation, and potential evapo-transpiration (PET) emerged as primary environmental drivers. Leaf traits, especially those of the leaf sheath, exhibited a more pronounced response to the environment. The traits exhibited apparent covariation in response to environmental challenges and indicated flexible adaptive strategies. This study revealed the adaptation and response patterns of different morphological traits of I. thianschanica to environmental changes on the Tibetan Plateau, emphasizing the significant effect of temperature on trait variation. Our findings deepen the understanding of the ecology and adaptive strategies of lithophytic mosses.

5.
Plants (Basel) ; 13(6)2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38592873

RESUMEN

The genus Pogonatum stands out as the most diverse within the family Polytrichaceae, encompassing over 50 species. Pogonatum tahitense has been recorded across various Pacific regions, including Hawaii in the United States and Tahiti in French Polynesia, as well as in Asia, such as in Taiwan in China, Java in Indonesia, and Sabah in Malaysia. In the current study, a specimen collected in Tibet, China, is described, confirming its taxonomic classification as P. tahitense through a comprehensive analysis integrating morphological evidence and molecular study based on sequences from the plastid (rbcL, rps4, trnL-F), mitochondrial (nad5), and nuclear (ITS2) regions. This documentation represents the first record of the species within mainland China. A time-calibrated, molecular-based phylogenetic analysis was conducted, employing various approaches for ancestral range inference. The findings suggest that P. tahitense originated during the Pleistocene epoch, approximately 1.8 mya, in Tibet, China.

6.
Acta Biochim Biophys Sin (Shanghai) ; 56(3): 405-413, 2024 03 25.
Artículo en Inglés | MEDLINE | ID: mdl-38425245

RESUMEN

RNA terminal phosphorylase B (RTCB) has been shown to play a significant role in multiple physiological processes. However, the specific role of RTCB in the mouse colon remains unclear. In this study, we employ a conditional knockout mouse model to investigate the effects of RTCB depletion on the colon and the potential molecular mechanisms. We assess the efficiency and phenotype of Rtcb knockout using PCR, western blot analysis, histological staining, and immunohistochemistry. Compared with the control mice, the Rtcb-knockout mice exhibit compromised colonic barrier integrity and prominent inflammatory cell infiltration. In the colonic tissues of Rtcb-knockout mice, the protein levels of TNF-α, IL-8, and p-p65 are increased, whereas the levels of IKKß and IκBα are decreased. Moreover, the level of GSK3ß is increased, whereas the levels of Wnt3a, ß-catenin, and LGR5 are decreased. Collectively, our findings unveil a close association between RTCB and colonic tissue homeostasis and demonstrate that RTCB deficiency can lead to dysregulation of both the NF-κB and Wnt/ß-catenin signaling pathways in colonic cells.


Asunto(s)
Colitis , FN-kappa B , Animales , Ratones , beta Catenina/genética , beta Catenina/metabolismo , Colitis/genética , Ratones Noqueados , FN-kappa B/metabolismo , Vía de Señalización Wnt
7.
J Environ Manage ; 355: 120504, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38447513

RESUMEN

Ammonia-oxidation process directly contribute to soil nitrous oxide (N2O) emissions in agricultural soils. However, taxonomy of the key nitrifiers (within ammonia oxidising bacteria (AOB), archaea (AOA) and complete ammonia oxidisers (comammox Nitrospira)) responsible for substantial N2O emissions in agricultural soils is unknown, as is their regulation by soil biotic and abiotic factors. In this study, cumulative N2O emissions, nitrification rates, abundance and community structure of nitrifiers were investigated in 16 agricultural soils from major crop production regions of China using microcosm experiments with amended nitrogen (N) supplemented or not with a nitrification inhibitor (nitrapyrin). Key nitrifier groups involved in N2O emissions were identified by comparative analyses of the different treatments, combining sequencing and random forest analyses. Soil cumulative N2O emissions significantly increased with soil pH in all agricultural soils. However, they decreased with soil organic carbon (SOC) in alkaline soils. Nitrapyrin significantly inhibited soil cumulative N2O emissions and AOB growth, with a significant inhibition of the AOB Nitrosospira cluster 3a.2 (D11) abundance. One Nitrosospira multiformis-like OTU phylotype (OTU34), which was classified within the AOB Nitrosospira cluster 3a.2 (D11), had the greatest importance on cumulative N2O emissions and its growth significantly depended on soil pH and SOC contents, with higher growth at high pH and low SOC conditions. Collectively, our results demonstrate that alkaline soils with low SOC contents have high N2O emissions, which were mainly driven by AOB Nitrosospira cluster 3a.2 (D11). Nitrapyrin can efficiently reduce nitrification-related N2O emissions by inhibiting the activity of AOB Nitrosospira cluster 3a.2 (D11). This study advances our understanding of key nitrifiers responsible for high N2O emissions in agricultural soils and their controlling factors, and provides vital knowledge for N2O emission mitigation in agricultural ecosystems.


Asunto(s)
Ecosistema , Suelo , Suelo/química , Amoníaco/química , Carbono , Oxidación-Reducción , Archaea , Nitrificación , Microbiología del Suelo
8.
Environ Sci Technol ; 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38329046

RESUMEN

Labile carbon (C) continuously delivered from the rhizosphere profoundly affects terrestrial nitrogen (N) cycling. However, nitrous oxide (N2O) and dinitrogen (N2) production in agricultural soils in the presence of continuous root C exudation with applied N remains poorly understood. We conducted an incubation experiment using artificial roots to continuously deliver small-dose labile C combined with 15N tracers to investigate N2O and N2 emissions in agricultural soils with pH and organic C (SOC) gradients. A significantly negative exponential relationship existed between N2O and N2 emissions under continuous C exudation. Increasing soil pH significantly promoted N2 emissions while reducing N2O emissions. Higher SOC further promoted N2 emissions in alkaline soils. Native soil-N (versus fertilizer-N) was the main source of N2O (average 67%) and N2 (average 80%) emissions across all tested soils. Our study revealed the overlooked high N2 emissions, mainly derived from native soil-N and strengthened by increasing soil pH, under relatively real-world conditions with continuous root C exudation. This highlights the important role of N2O and N2 production from native soil-N in terrestrial N cycling when there is a continuous C supply (e.g., plant-root exudate) and helps mitigate emissions and constrain global budgets of the two concerned nitrogenous gases.

9.
Front Cell Dev Biol ; 12: 1310442, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38404689

RESUMEN

Myeloid-derived suppressor cells (MDSCs) are key immunosuppressive cells in the tumor microenvironment (TME) that play critical roles in promoting tumor growth and metastasis. Tumor-associated platelets (TAPs) help cancer cells evade the immune system and promote metastasis. In this paper, we describe the interaction between MDSCs and TAPs, including their generation, secretion, activation, and recruitment, as well as the effects of MDSCs and platelets on the generation and changes in the immune, metabolic, and angiogenic breast cancer (BC) microenvironments. In addition, we summarize preclinical and clinical studies, traditional Chinese medicine (TCM) therapeutic approaches, and new technologies related to targeting and preventing MDSCs from interacting with TAPs to modulate the BC TME, discuss the potential mechanisms, and provide perspectives for future development. The therapeutic strategies discussed in this review may have implications in promoting the normalization of the BC TME, reducing primary tumor growth and distant lung metastasis, and improving the efficiency of anti-tumor therapy, thereby improving the overall survival (OS) and progression-free survival (PFS) of patients. However, despite the significant advances in understanding these mechanisms and therapeutic strategies, the complexity and heterogeneity of MDSCs and side effects of antiplatelet agents remain challenging. This requires further investigation in future prospective cohort studies.

10.
Environ Res ; 241: 117617, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-37967706

RESUMEN

Digestate is considered as an option for recycling resources and a part of the substitution for chemical fertilizers to reduce environmental impacts. However, its application may lead to significant nitrous oxide (N2O) emissions because of its high concentration of ammonium and degradable carbon. The research objectives are to evaluate how N2O emissions respond to digestate as compared to urea application and whether this depends on soil properties and moisture. Either digestate or urea (100 mg N kg-1) was applied with and without a nitrification inhibitor of 3,4-dimethylpyrazole phosphate (DMPP) to three soil types (fluvo-aquic soil, black soil, and latosol) under three different soil moisture conditions (45, 65, and 85% water-filled pore space (WFPS)) through microcosm incubations. Results showed that digestate- and urea-induced N2O emissions increased exponentially with soil moisture in the three studied soils, and the magnitude of the increase was much greater in the alkaline fluvo-aquic soil, coinciding with high net nitrification rate and transient nitrite accumulation. Compared with urea-amended soils, digestate led to significantly higher peaks in N2O and carbon dioxide (CO2) emissions, which might be due to stimulated rapid oxygen consumption and mineralized N supply. Digestate-induced N2O emissions were all more than one time higher than those induced by urea at the three moisture levels in the three studied soils, except at 85% WFPS in the fluvo-aquic soil. DMPP was more effective at mitigating N2O emissions (inhibitory efficacy: 73%-99%) in wetter digestate-fertilized soils. Overall, our study shows the contrasting effect of digestate to urea on N2O emissions under different soil properties and moisture levels. This is of particular value for determining the optimum of applying digestate under varying soil moisture conditions to minimize stimulated N2O emissions in specific soil properties.


Asunto(s)
Suelo , Urea , Suelo/química , Urea/química , Urea/farmacología , Yoduro de Dimetilfenilpiperazina/farmacología , Óxido Nitroso , Nitrificación , Fertilizantes , Agricultura
11.
J Biomol Struct Dyn ; : 1-20, 2023 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-37771185

RESUMEN

Traditional Chinese medicine is an important part of complementary alternative medicine. Jiedu Qingjin formula (JDQJF) is an effective national invention patent for the treatment of non-small cell lung cancer (NSCLC). We investigated the molecular biological mechanisms based on network pharmacology, molecular docking, and molecular dynamics simulations. Compounds of JDQJF were screened through the TCMSP, ETCM, and literature. Targets were searched by DrugBank and predicted by SwissTargetPrediction. GEO database was applied for screening differentially expressed genes between cancerous tissues and healthy tissues of NSCLC. Subsequently, the protein-protein interaction between JDQJF and NSCLC were obtained by Cytoscape. Visual analyses were carried out to extract candidate genes, then subjected to Metascape for enrichment analyses. Finally, molecular docking was performed by AutoDock, and the best complexes were subjected to molecular dynamics simulation and binding energy calculations by MMPBSA. A total of 273 compounds, 390 targets, 3146 GO terms, and 174 KEGG pathways were obtained. Five potential compounds (quercetin, adenosine, apigenin, heptadecanoic acid, and luteolin) were notably modulated by key targets AKT1, MAPK3, and RAF1. Enrichment results included cell cycle process, growth transduction factor, immune response-activating transduction, and involved PI3K/AKT, MAPK, NF-κB and VEGF pathway. RAF1-quercetin showed the highest binding affinity (-9.1 kcal/mol), revealed stable interactions during the simulation, and the highest estimated relative binding energy of the RAF1-Heptadecanoic was -184.277 kcal/mol. This study suggested that EMT-related, inflammation-related, immune-related, and angiogenesis-related pathways may be associated with JDQJF, and involved in the advancement of NSCLC, which points out the research direction for subsequent utility mechanism validation.Communicated by Ramaswamy H. Sarma.

12.
Environ Microbiol ; 25(11): 2636-2640, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37544653

RESUMEN

Nitrification, a key step in soil nitrogen cycling, is a biologically mediated process crucial to the ecological environment. However, how nitrifiers drive nitrification under different soil properties and climatic factors at large spatial scales is poorly understood. Here, using metagenomic sequencing and network-based approaches, we identified key nitrifying species of upland agricultural soils in northern China, which spans a wide range of climates and geographic distances. We found that potential nitrification rates (PNRs) varied in different soils and were positively correlated with soil pH (5.42-8.46) and mean annual temperature (MAT) and negatively correlated with the C/N ratio. Network analysis revealed that one module (module 3) was significantly correlated with PNR. In this module, 16 dominant nodes were associated with AOB Nitrosomonas and most nodes were significantly correlated with environmental factors, suggesting that abiotic conditions are important for determining the assembly of these key nitrifiers. Our study advanced the understanding of the key nitrifying populations and their environmental drivers in upland agricultural soil across different soil and climate types.


Asunto(s)
Nitrificación , Suelo , Suelo/química , Archaea , Oxidación-Reducción , Microbiología del Suelo , Amoníaco , Nitrógeno/química
13.
Sci Total Environ ; 902: 166451, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37611720

RESUMEN

The long-lived greenhouse gas nitrous oxide (N2O) and short-lived reactive nitrogen (Nr) gases such as ammonia (NH3), nitrous acid (HONO), and nitrogen oxides (NOx) are produced and emitted from fertilized soils and play a critical role for climate warming and air quality. However, only few studies have quantified the production and emission potentials for long- and short-lived gaseous nitrogen (N) species simultaneously in agricultural soils. To link the gaseous N species to intermediate N compounds [ammonium (NH4+), hydroxylamine (NH2OH), and nitrite (NO2-)] and estimate their temperature change potential, ex-situ dry-out experiments were conducted with three Chinese agricultural soils. We found that HONO and NOx (NO + NO2) emissions mainly depend on NO2-, while NH3 and N2O emissions are stimulated by NH4+ and NH2OH, respectively. Addition of 3,4-dimethylpyrazole phosphate (DMPP) and acetylene significantly reduced HONO and NOx emissions, while NH3 emissions were significantly enhanced in an alkaline Fluvo-aquic soil. These results suggested that ammonia-oxidizing bacteria (AOB) and complete ammonia-oxidizing bacteria (comammox Nitrospira) dominate HONO and NOx emissions in the alkaline Fluvo-aquic soil, while ammonia-oxidizing archaea (AOA) are dominant in the acidic Mollisol. DMPP effectively mitigated the warming effect in the Fluvo-aquic soil and the Ultisol. In conclusion, our findings highlight NO2- significantly stimulates HONO and NOx emissions from dryland agricultural soils, dominated by nitrification. In addition, subtle differences of soil NH3, N2O, HONO, and NOx emissions indicated different N turnover processes, and should be considered in biogeochemical and atmospheric chemistry models.

14.
Methods Mol Biol ; 2700: 221-228, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37603184

RESUMEN

Toll-like receptors (TLRs) recognize altered gut microbiota triggering an immune response. These responses play a critical role in the pathogenesis and treatment of inflammatory bowel disease (IBD). IBD is characterized by inflammation of the intestinal tracts as in Crohn's disease and ulcerative colitis. However, one challenge in determining the role of a specific TLR in IBD and its underlying mechanism is disparity. Variance in age, gender, race, and ethnicity shows a dramatic difference in the disease incidence, severity, and response to treatment. Delineating the role of TLRs in IBD relies on both a knockout mouse and a disease model. Here, we describe a detailed protocol on how to use nearly identical genetic backgrounds of TLR wild-type and knockout littermate mice in a dextran sodium sulfate (DSS)-induced colitis model.


Asunto(s)
Colitis Ulcerosa , Colitis , Enfermedad de Crohn , Enfermedades Inflamatorias del Intestino , Animales , Ratones , Enfermedades Inflamatorias del Intestino/genética , Receptores Toll-Like/genética , Ratones Noqueados
15.
Healthcare (Basel) ; 11(14)2023 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-37510458

RESUMEN

BACKGROUND: Alzheimer's disease's (AD) prevalence is projected to increase as the population ages and current treatments are minimally effective. Transcranial photobiomodulation (t-PBM) with near-infrared (NIR) light penetrates into the cerebral cortex, stimulates the mitochondrial respiratory chain, and increases cerebral blood flow. Preliminary data suggests t-PBM may be efficacious in improving cognition in people with early AD and amnestic mild cognitive impairment (aMCI). METHODS: In this randomized, double-blind, placebo-controlled study with aMCI and early AD participants, we will test the efficacy, safety, and impact on cognition of 24 sessions of t-PBM delivered over 8 weeks. Brain mechanisms of t-PBM in this population will be explored by testing whether the baseline tau burden (measured with 18F-MK6240), or changes in mitochondrial function over 8 weeks (assessed with 31P-MRSI), moderates the changes observed in cognitive functions after t-PBM therapy. We will also use changes in the fMRI Blood-Oxygenation-Level-Dependent (BOLD) signal after a single treatment to demonstrate t-PBM-dependent increases in prefrontal cortex blood flow. CONCLUSION: This study will test whether t-PBM, a low-cost, accessible, and user-friendly intervention, has the potential to improve cognition and function in an aMCI and early AD population.

16.
Sci Total Environ ; 895: 165192, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37385503

RESUMEN

The timing and magnitude of greenhouse gas (GHG) production depend strongly on soil oxygen (O2) availability, and the soil pore geometry characteristics largely regulate O2 and moisture conditions relating to GHG biochemical processes. However, the interactions between O2 dynamics and the concentration and flux of GHGs during the soil moisture transitions under various soil pore conditions have not yet been clarified. In this study, a soil-column experiment was conducted under wetting-drying phases using three pore-structure treatments, FINE, MEDIUM, and COARSE, with 0 %, 30 %, and 50 % coarse quartz sand applied to soil, respectively. The concentrations of soil gases (O2, nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4)) were monitored at a depth of 15 cm hourly, and their surface fluxes were measured daily. Soil porosity, pore size distribution, and pore connectivity were quantified using X-ray computed microtomography. The soil O2 concentrations were found to decline sharply as soil moisture increased to the water holding capacities of 0.46, 0.41, and 0.32 cm cm-3 in the FINE, MEDIUM, and COARSE, respectively. The dynamic patterns of the O2 concentrations varied across the soil pore structures, decreasing to anaerobic in FINE (<0.01 %) and MEDIUM (0.02 %), and to hypoxic (4.42 %) in COARSE. Correspondingly, the soil N2O concentration was the highest in FINE (101 µL L-1) and the lowest in COARSE (10 µL L-1), whereas the highest surface N2O flux was observed in MEDIUM (131 µg N m-2 h-1). As soil CO2 concentrations declined, CO2 fluxes increased from FINE to MEDIUM to COARSE. Most pores of FINE, MEDIUM, and COARSE were 15-80 µm, 85-100 µm, and 105-125 µm, respectively, in terms of diameter. The X-ray CT visible (>15 µm) porosity in FINE, MEDIUM and COARSE were 0.09, 0.17, and 0.28 mm3 mm-3, respectively. The corresponding Euler-Poincaré numbers were 180,280, 76,705, and -10,604, respectively, indicating higher connectivity in COARSE than in MEDIUM or FINE. In soil dominated by small air-filled porosity which limits gas diffusion and result in low soil O2 concentration, N2O concentration was increased and CO2 flux was inhibited as the moisture content increased. The turning point in the sharp decrease in O2 concentration was found to correspond with a moisture content, and a pore diameter of 95-110 µm was associated with the critical turning point between holding water and O2 depletion in soil. These findings suggest that O2-regulated biochemical processes are key to the production and flux of GHGs, which in turn are dependent on the soil pore structure and a coupling relationship between N2O and CO2. Improved understanding of the intense effect of soil physical properties provided an empirical foundation for the future development of mechanistic prediction models for how pore-space scale processes with high temporal (hourly) resolution up to GHGs fluxes at larger spatial and temporal scales.

17.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 35(4): 404-408, 2023 Apr.
Artículo en Chino | MEDLINE | ID: mdl-37308197

RESUMEN

OBJECTIVE: To compare the ability of the step-by-step approach and the lab-score method in early identification of non-bacterial infection in febrile infants with less than 90 days old. METHODS: A prospective study was conducted. The febrile infants with less than 90 days old hospitalized in the department of pediatrics of Xuzhou Central Hospital from August 2019 to November 2021 were enrolled. The basic data of the infants were recorded. The infants with high risk or low risk of bacterial infection was evaluated by the step-by-step approach and the lab-score method, respectively. The step-by-step approach was based on clinical manifestations, age, blood neutrophil absolute value or C-reactive protein (CRP), urine white blood cells, blood venous blood procalcitonin (PCT) or interleukin-6 (IL-6) to gradually assess the high risk or low risk of bacterial infection in infants with fever. The lab-score method was based on the levels of laboratory indicators such as blood PCT, CRP and urine white blood cells, which were assigned different scores to evaluate the high risk or low risk of bacterial infection in febrile infants according to the total score. Using clinical bacterial culture results as the "gold standard", the negative predictive value (NPV), positive predictive value (PPV), negative likelihood ratio, positive likelihood ratio, sensitivity, specificity, and accuracy of the two methods were calculated. The consistency of the two evaluation methods was tested by Kappa. RESULTS: A total of 246 patients were enrolled in the analysis, and ultimately confirmed by bacterial culture as non-bacterial infections in 173 cases (70.3%), bacterial infection in 72 cases (29.3%), and unclear in 1 case (0.4%). There were 105 cases with low risk evaluated by the step-by-step approach, and 98 cases (93.3%) were ultimately confirmed as non-bacterial infection; 181 cases with low risk evaluated by the lab-score method, and 140 cases (77.4%) were ultimately confirmed as non-bacterial infection. The consistency of the two evaluation methods was poor (Kappa value = 0.253, P < 0.001). The ability of the step-by-step approach in early identification of non-bacterial infection in febrile infants with less than 90 days old was superior to the lab-score method (NPV: 0.933 vs. 0.773, negative likelihood ratio: 5.835 vs. 1.421), but the sensitivity of the former was lower than that of the latter (0.566 vs. 0.809). The ability of the step-by-step approach in early identification of bacterial infection in febrile infants with less than 90 days old was similar to the lab-score method (PPV: 0.464 vs. 0.484, positive likelihood ratio: 0.481 vs. 0.443), but the specificity of the former was higher than that of the latter (0.903 vs. 0.431). The overall accuracy of the step-by-step approach and the lab-score method was similar (66.5% vs. 69.8%). CONCLUSIONS: The ability of the step-by-step approach in early identification of non-bacterial infections in febrile infants with less than 90 days old is superior to the lab-score method.


Asunto(s)
Infecciones Bacterianas , Humanos , Lactante , Niño , Estudios Prospectivos , Proteína C-Reactiva , Hospitales , Interleucina-6 , Polipéptido alfa Relacionado con Calcitonina
18.
Glob Chang Biol ; 29(17): 4910-4923, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37183810

RESUMEN

Arable soil continues to be the dominant anthropogenic source of nitrous oxide (N2 O) emissions owing to application of nitrogen (N) fertilizers and manures across the world. Using laboratory and in situ studies to elucidate the key factors controlling soil N2 O emissions remains challenging due to the potential importance of multiple complex processes. We examined soil surface N2 O fluxes in an arable soil, combined with in situ high-frequency measurements of soil matrix oxygen (O2 ) and N2 O concentrations, in situ 15 N labeling, and N2 O 15 N site preference (SP). The in situ O2 concentration and further microcosm visualized spatiotemporal distribution of O2 both suggested that O2 dynamics were the proximal determining factor to matrix N2 O concentration and fluxes due to quick O2 depletion after N fertilization. Further SP analysis and in situ 15 N labeling experiment revealed that the main source for N2 O emissions was bacterial denitrification during the hot-wet summer with lower soil O2 concentration, while nitrification or fungal denitrification contributed about 50.0% to total emissions during the cold-dry winter with higher soil O2 concentration. The robust positive correlation between O2 concentration and SP values underpinned that the O2 dynamics were the key factor to differentiate the composite processes of N2 O production in in situ structured soil. Our findings deciphered the complexity of N2 O production processes in real field conditions, and suggest that O2 dynamics rather than stimulation of functional gene abundances play a key role in controlling soil N2 O production processes in undisturbed structure soils. Our results help to develop targeted N2 O mitigation measures and to improve process models for constraining global N2 O budget.


Asunto(s)
Agricultura , Suelo , Suelo/química , Nitrificación , Bacterias , Nitrógeno , Óxido Nitroso/química , Oxígeno
19.
Front Pharmacol ; 14: 1090500, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37089959

RESUMEN

Epidermal growth factor receptor (EGFR) mutations are the most common oncogenic driver in non-small cell lung cancer (NSCLC). Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are widely used in the treatment of lung cancer, especially in the first-line treatment of advanced NSCLC, and EGFR-TKIs monotherapy has achieved better efficacy and tolerability compared with standard chemotherapy. However, acquired resistance to EGFR-TKIs and associated adverse events pose a significant obstacle to targeted lung cancer therapy. Therefore, there is an urgent need to seek effective interventions to overcome these limitations. Natural medicines have shown potential therapeutic advantages in reversing acquired resistance to EGFR-TKIs and reducing adverse events, bringing new options and directions for EGFR-TKIs combination therapy. In this paper, we systematically demonstrated the resistance mechanism of EGFR-TKIs, the clinical strategy of each generation of EGFR-TKIs in the synergistic treatment of NSCLC, the treatment-related adverse events of EGFR-TKIs, and the potential role of traditional Chinese medicine in overcoming the resistance and adverse reactions of EGFR-TKIs. Herbs and active compounds have the potential to act synergistically through multiple pathways and multiple mechanisms of overall regulation, combined with targeted therapy, and are expected to be an innovative model for NSCLC treatment.

20.
ACS Appl Mater Interfaces ; 15(14): 17470-17484, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-36995264

RESUMEN

Immunotherapy has revolutionized the landscape in clinical tumor therapy, although the response rates in "cold" tumors are relatively low owing to the complex tumor microenvironment (TME). Cyclic guanosine monophosphate-adenosine monophosphate synthase/stimulator of interferon genes (cGAS/STING) pathway-inducing agents can reprogram the TME; however, their applications remain underutilized. Herein, we engineered a facile manganese-based metal-organic framework (Mn-MOF) encapsulating polyphyllin I (PPI) and coated it with red blood cell (RBC) membranes (RBC@Mn-MOF/PPI) that enhanced the cGAS/STING-mediated antitumor immunity. RBC@Mn-MOF/PPI was engineered by camouflaging it with a biomimetic RBC membrane for prolonged blood circulation and immune escape, which was also extended with TME-sensitive properties for triggering the release of PPI and Mn2+ to remodel the suppressive TME and augment antitumor immune responses. Furthermore, RBC@Mn-MOF/PPI helped transform cold tumors into "hot" ones by activating immune cells, as evidenced via dendritic cell maturation, cytotoxic T lymphocyte infiltration, and natural killer cell recruitment, thereby targeting primary and abscopal tumors and lung metastatic nodules. Therefore, our engineered nanosystem represents a novel strategy to transform immunologically "cold" tumors into "hot" ones by activating the cGAS/STING pathway, thereby addressing the major challenges associated with immunotherapy.


Asunto(s)
Estructuras Metalorgánicas , Neoplasias , Humanos , Biomimética , Inmunoterapia , Neoplasias/terapia , Diferenciación Celular , Microambiente Tumoral
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