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1.
Photochem Photobiol ; 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39080821

RESUMO

In recent years, studies have shown that low-dose supplemental infrared (IR) irradiation exhibits systemic anti-inflammatory effects. The gut microbiota is increasingly recognized as a potential mediator of these effects due to its role in regulating host metabolism and inflammatory responses. To investigate the role of gut microbiota diversity and metabolite changes in the mechanism of light-emitting diodes (LED) infrared's anti-inflammatory action, we conducted IR irradiation on mice. Serum inflammatory cytokines were measured using ELISA, and fecal samples were subjected to metagenomic, untargeted, and targeted metabolomic analyses. Our results demonstrated a significant increase in the anti-inflammatory cytokine IL-10 in the IR group, accompanied by a declining trend in pro-inflammatory cytokines. Gut microbiome analysis revealed distinct alterations in composition and functional genes between the groups, including the enrichment of beneficial bacteria like various species of Parabacteroides and Akkermansia muciniphila in the IR group. Notably, the IR group exhibited enrichment in carbohydrate metabolism pathways and a reduction in DNA damage and repair pathways. Furthermore, targeted metabolomic analysis highlighted a notable increase in short-chain fatty acids (SCFAs), including butyric acid and isobutyric acid, which positively correlated with the abundance of several beneficial bacteria. These findings suggest a potential interplay between gut microbiota-derived SCFAs and the anti-inflammatory response. In conclusion, our study provides comprehensive insights into the changes in gut microbiota species and functions associated with IR irradiation. Moreover, we emphasize the significance of altered SCFAs levels in the IR group, which may contribute to the observed anti-inflammatory effects. Our findings contribute valuable evidence supporting the role of low-dose infrared light irradiation as an anti-inflammatory therapy.

2.
J Adv Res ; 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38609049

RESUMO

INTRODUCTION: Helicobacter pylori (H. pylori) infection has been associated with gastric carcinogenesis. However, the precise involvement of LRP8, the low-density lipoprotein receptor-related protein 8, in H. pylori pathogenesis and gastric cancer (GC) remains poorly understood. OBJECTIVES: To investigate the potential role of LRP8 in H. pylori infection and gastric carcinogenesis. METHODS: Three-dimensional human-derived gastric organoids (hGO) and gastric cancer organoids (hGCO) were synthesized from the tissues obtained from human donors. In this work, multi-omics combined with in vivo and in vitro studies were conducted to investigate the potential involvement of LRP8 in H. pylori-induced GC. RESULTS: We found that H. pylori infection significantly upregulated the expression of LRP8 in human GC tissues, cells, organoids, and mouse gastric mucous. In particular, LRP8 exhibited a distinct enrichment in cancer stem cells (CSC). Functionally, silencing of LRP8 affected the formation and proliferation of tumor spheroids, while increased expression of LRP8 was associated with increased proliferation and stemness of GC cells and organoids. Mechanistically, LRP8 promotes the binding of E-cadherin to ß-catenin, thereby promoting nuclear translocation and transcriptional activity of ß-catenin. Furthermore, LRP8 interacts with the cytotoxin-associated gene A (CagA) to form the CagA/LRP8/ß-catenin complex. This complex further amplifies H. pylori-induced ß-catenin nuclear translocation, leading to increased transcription of inflammatory factors and CSC markers. Clinical analysis demonstrated that abnormal overexpression of LRP8 is correlated with a poor prognosis and resistance to 5-Fluorouracil in patients with GC. CONCLUSION: Our findings provide valuable information on the molecular intricacies of H. pylori-induced gastric carcinogenesis, offering potential therapeutic targets and prognostic markers for GC.

3.
Life Sci Space Res (Amst) ; 38: 29-38, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37481305

RESUMO

Understanding the structural and antibiotic resistance changes of microbial communities in space environments is critical for identifying potential pathogens that may pose health risks to astronauts and for preventing and controlling microbial contamination. The research to date on microbes under simulated space factors has primarily been carried out on single bacterial species under the individual effects of microgravity or low-dose radiation. However, microgravity (MG) and low-dose ionizing radiation (LDIR) coexist in the actual spacecraft environment, and microorganisms coexist as communities in the spacecraft environment. Thus, the microbial response to the real changes present during space habitation has not been adequately explored. To address this knowledge gap, we compared the dynamics of community composition and antibiotic resistance of synthetic bacterial communities under simulated microgravit, low-dose ionizing radiation, and the conditions combined, as it occurs in spacecraft. To ensure representative bacteria were selected, we co-cultured of 12 bacterial strains isolated from spacecraft cleanrooms. We found that the weakened competition between communities increased the possibility of species coexistence, community diversity, and homogeneity. The number of Bacilli increased significantly, while different species under the combined conditions showed various changes in abundance compared to those under the individual conditions. The resistance of the synthetic community to penicillins increased significantly under low doses of ionizing radiation but did not change significantly under simulated microgravity or the combined conditions. The results of functional predictions revealed that antibiotic biosynthesis and resistance increased dramatically in the community under space environmental stress, which confirmed the results of the drug sensitivity assays. Our results show that combined space environmental factors exert different effects on the microbial community structure and antibiotic resistance, which provides new insights into our understanding of the mechanisms of evolution of microorganisms in spacecraft, and is relevant to effective microbial pollution prevention and control strategies.


Assuntos
Astronave , Ausência de Peso , Bactérias , Resistência Microbiana a Medicamentos , Radiação Ionizante
4.
Mol Cell Probes ; 66: 101863, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36252912

RESUMO

Papillary thyroid cancer (PTC) is a common malignancy. MicroRNAs (miRNAs) may act as oncogenes or tumor suppressor genes. However, the role of miR-451a in PTC is not fully understood. Hence, the objective of the study was to research the effect and mechanism of miR-451a in PTC. Differentially expressed miRNAs between GSE113629 and GSE103996 databases were assessed by Venn diagram. miR-451a and its downstream target genes were assessed by RT-PCR and Western blot. The proliferation, invasion, and apoptosis were determined by CCK-8, EdU, transwell, and flow cytometry assays. Dual-luciferase reporter assay were used to evaluated the target of miR-451a. Xenografted tumors was used to explore the function of miR-451a in vivo. Pathological changes and related protein expression were measured by HE staining and immunohistochemistry. MiR-451a was downregulated in PTC tissues and blood, and low expression of miR-451a was related to short overall survival, serious lymph node metastasis and high TNM grade in PTC patients. Moreover, increase of miR-451a restrained the proliferation and invasion and accelerated the apoptosis. Furthermore, miR-451a repressed VEGF signaling pathway. Importantly, miR-451a was demonstrated to target DCBLD2 and AKT1. Overexpression of DCBLD2 and AKT1 could restore the effect of miR-451a on PTC cells. In addition, miR-451a reduced the growth of xenografted tumors in vivo. The data suggested that miR-451a attenuated the proliferation, invasion and promoted apoptosis in PTC cells via inhibiting DCBLD2 and AKT1.


Assuntos
Carcinoma Papilar , MicroRNAs , Neoplasias da Glândula Tireoide , Humanos , Apoptose/genética , Carcinoma Papilar/genética , Carcinoma Papilar/metabolismo , Carcinoma Papilar/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica/genética , Proteínas de Membrana/genética , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Câncer Papilífero da Tireoide/genética , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo
6.
Biomaterials ; 279: 121178, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34656857

RESUMO

Although synthesized nanotherapeutics (NTs) are attractive for the oral treatment of colon diseases, their clinical translations are constrained by the unsatisfactory therapeutic outcomes, potential adverse effects, and high cost of mass production. Here, we report the development of tea leaf-derived natural NTs with desirable particle sizes (140.0 nm) and negative surface charge (-14.6 mV). These natural exosome-like NTs were found to contain large amounts of lipids, some functional proteins, and many bioactive small molecules. Specifically, galactose groups on the surface of NTs could mediate their specific internalization by macrophages via galactose receptor-mediated endocytosis. Moreover, these NTs were able to reduce the production of reactive oxygen species, inhibit the expression of pro-inflammatory cytokines, and increase the amount of anti-inflammatory IL-10 secreted by macrophages. Orally administered NTs could efficiently inhibit the inflammatory bowel responses, restore disrupted colonic barriers and enhance the diversity and overall abundance of gut microbiota, thereby preventing or alleviating inflammatory bowel disease and colitis-associated colon cancer. The present study brings new insights to the facile application of a versatile and robust natural nanoplatform for the prevention and treatment of colon diseases.


Assuntos
Colite , Doenças Inflamatórias Intestinais , Animais , Colite/tratamento farmacológico , Colite/prevenção & controle , Colo , Citocinas , Modelos Animais de Doenças , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/prevenção & controle , Folhas de Planta , Chá
7.
Cancer Sci ; 112(9): 3569-3584, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34251747

RESUMO

The abundance and type of immune cells in the tumor microenvironment (TME) significantly influence immunotherapy and tumor progression. However, the role of immune cells in the TME of gastric cancer (GC) is poorly understood. We studied the correlations, proportion, and infiltration of immune and stromal cells in GC tumors. Data analyses showed a significant association of infiltration levels of specific immune cells with the pathological characteristics and clinical outcomes of GC. Furthermore, based on the difference in infiltration levels of immune and stromal cells, GC patients were divided into two categories, those with "immunologically hot" (hot) tumors and those with "immunologically cold" (cold) tumors. The assay for transposase-accessible chromatin using sequencing and RNA sequencing analyses revealed that the hot and cold tumors had altered epigenomic and transcriptional profiles. Claudin-3 (CLDN3) was found to have high expression in the cold tumors and negatively correlated with CD8+ T cells in GC. Overexpression of CLDN3 in GC cells inhibited the expression of MHC-I and CXCL9. Finally, the differentially expressed genes between hot and cold tumors were utilized to generate a prognostic model, which predicted the overall survival of GC as well as patients with immunotherapy. Overall, we undertook a comprehensive analysis of the immune cell infiltration pattern in GC and provided an accurate model for predicting the prognosis of GC patients.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Claudina-3/metabolismo , Linfócitos do Interstício Tumoral/imunologia , Transdução de Sinais/genética , Neoplasias Gástricas/imunologia , Neoplasias Gástricas/metabolismo , Microambiente Tumoral/imunologia , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Quimiocina CXCL9/metabolismo , Claudina-3/genética , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Humanos , Prognóstico , RNA-Seq , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Transcriptoma , Transfecção
8.
Oncol Res ; 29(2): 87-103, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-37305397

RESUMO

The activation of some oncogenes promote cancer cell proliferation and growth, facilitate cancer progression and metastasis by induce DNA replication stress, even genome instability. Activation of the cyclic GMP-AMP synthase (cGAS) mediates classical DNA sensing, is involved in genome instability, and is linked to various tumor development or therapy. However, the function of cGAS in gastric cancer remains elusive. In this study, the TCGA database and retrospective immunohistochemical analyses revealed substantially high cGAS expression in gastric cancer tissues and cell lines. By employing cGAS high-expression gastric cancer cell lines, including AGS and MKN45, ectopic silencing of cGAS caused a significant reduction in the proliferation of the cells, tumor growth, and mass in xenograft mice. Mechanistically, database analysis predicted a possible involvement of cGAS in the DNA damage response (DDR), further data through cells revealed protein interactions of the cGAS and MRE11-RAD50-NBN (MRN) complex, which activated cell cycle checkpoints, even increased genome instability in gastric cancer cells, thereby contributing to gastric cancer progression and sensitivity to treatment with DNA damaging agents. Furthermore, the upregulation of cGAS significantly exacerbated the prognosis of gastric cancer patients while improving radiotherapeutic outcomes. Therefore, we concluded that cGAS is involved in gastric cancer progression by fueling genome instability, implying that intervening in the cGAS pathway could be a practicable therapeutic approach for gastric cancer.


Assuntos
Neoplasias Gástricas , Humanos , Animais , Camundongos , Neoplasias Gástricas/genética , Estudos Retrospectivos , Transdução de Sinais , Proliferação de Células/genética , Dano ao DNA
9.
Photosynth Res ; 144(1): 23-34, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32090305

RESUMO

The growth of plants under high carbon dioxide (CO2) concentrations (≥ 1000 ppm) is explored for the climate change and the bioregenerative life support system (BLSS) environment of long-duration space missions. Wheat (Triticum aestivum L.) is a grass cultivated for cereal grain-a global staple food including astronauts. Light and CO2 are both indispensable conditions for wheat seedlings. This study provides insights on the physiology, antioxidant capacity and photosynthetic characteristics of wheat seedlings under a range of photosynthetic photon flux densities in a closed system simulating BLSS with high CO2 concentration. We found that the Fv/Fm, Fv/F0, chlorophyll content, intrinsic water use efficiencies (WUEi), membrane stability index (MSI), and malondialdehyde (MDA) of wheat seedlings grown under an intermediate light intensity of 600 µmol m-2 s-1 environment were all largest. Interestingly, the high light intensity of 1200 mol m-2 s-1 treatment group exhibits the highest net photosynthetic rate but the lowest MDA content. The stomatal conductance and F0 of high light intensity of 1000 µmol m-2 s-1 treatment group were both significantly higher than that of other groups. Our study provides basic knowledge on the wheat growth in different environments, especially in a closed ecosystem with artificial lights.


Assuntos
Dióxido de Carbono/metabolismo , Luz , Fotossíntese/fisiologia , Plântula/metabolismo , Plântula/efeitos da radiação , Triticum/metabolismo , Triticum/efeitos da radiação , Antioxidantes/metabolismo , Ecossistema
10.
Nat Commun ; 11(1): 567, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992692

RESUMO

Since the discovery of metal nanoparticles (NPs) in the 1960s, unknown toxicity, cost and the ethical hurdles of research in humans have hindered the translation of these NPs to clinical use. In this work, we demonstrate that Pt NPs with protein coronas are generated in vivo in human blood when a patient is treated with cisplatin. These self-assembled Pt NPs form rapidly, accumulate in tumors, and remain in the body for an extended period of time. Additionally, the Pt NPs are safe for use in humans and can act as anti-cancer agents to inhibit chemotherapy-resistant tumor growth by consuming intracellular glutathione and activating apoptosis. The tumor inhibitory activity is greatly amplified when the Pt NPs are loaded in vitro with the chemotherapeutic drug, daunorubicin, and the formulation is effective even in daunorubicin-resistant models. These in vivo-generated metal NPs represent a biocompatible drug delivery platform for chemotherapy resistant tumor treatment.


Assuntos
Antineoplásicos/sangue , Antineoplásicos/farmacologia , Nanopartículas Metálicas/química , Platina/sangue , Platina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Cisplatino/farmacologia , Daunorrubicina/farmacologia , Sistemas de Liberação de Medicamentos , Tolerância a Medicamentos , Feminino , Glutationa/metabolismo , Células Hep G2 , Humanos , Células K562 , Glomérulos Renais/efeitos dos fármacos , Glomérulos Renais/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Nus , Tamanho da Partícula , Coroa de Proteína , Fatores de Tempo , Ensaios Antitumorais Modelo de Xenoenxerto , Peixe-Zebra
11.
Clin Chim Acta ; 489: 183-188, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29104036

RESUMO

BACKGROUND: Asprosin has been identified as a novel hormone enriched in white adipose tissue and is pathologically increased in insulin-resistant mice and humans. However, information regarding the role of asprosin in type 2 diabetes mellitus (T2DM) remains unavailable. Via conducting a hospital-based study, we purposed to ascertain the potential relationship between circulating asprosin concentrations and T2DM. METHODS: The study recruited 84 adults with T2DM and 86 controls with normal glucose tolerance. They matched in age, body mass index (BMI), and sex. Serum asprosin concentrations were measured via ELISA method. RESULTS: Compared to the controls, serum asprosin concentrations were significantly increased in the T2DM adults (P<0.001). As asprosin concentrations increased across its tertiles, the percentage of T2DM increased (39.28, 37.50, and 70.68%; P value for trend <0.001). Multivariate logistic regression models demonstrated that compared with the 1st tertile of asprosin, the odds ratio of T2DM was 3.278(95% CI 1.053-10.200, P=0.040) for the 3rd tertile after adjustment for potential confounders. Area under ROC curve of asprosin (sex and age adjusted) for predicting the presence of T2DM was 0.707[95% CI 0.628-0.786]. Finally, multiple stepwise regression analysis indicated that fasting glucose and triglyceride were independently associated with serum asprosin in T2DM. CONCLUSIONS: Asprosin concentrations are increased in adults with T2DM. The results suggest that asprosin might serve as a risk factor associated with the pathogenesis of T2DM, but not an ideal biomarker for predicting T2DM.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Jejum/sangue , Proteínas dos Microfilamentos/sangue , Fragmentos de Peptídeos/sangue , Hormônios Peptídicos/sangue , Triglicerídeos/sangue , Adulto , Feminino , Fibrilina-1 , Humanos , Masculino , Pessoa de Meia-Idade
12.
Cytokine ; 110: 52-57, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29704818

RESUMO

AIMS: C1q/TNF-related protein 9 (CTRP9) is an adipokine mainly secreted by white adipose tissue and plays protective roles in energy metabolism. However, information regarding the role of CTRP9 in nonalcoholic fatty liver disease (NAFLD) is scarce. Here we aimed to ascertain the clinical relevance between circulating CTRP9 levels and NAFLD through a cross-sectional study. METHODS: The study enrolled 82 NAFLD adults and 79 sex- and age-matched non-NAFLD controls. Serum CTRP9 was measured via ELISA method. Metabolic parameters were also determined. RESULTS: Although serum CTRP9 level seems to be higher in NAFLD adults, there was no significant difference among the ultrasonographic degrees of NAFLD (P = 0.275). Further, after adjustment for BMI in the multinomial logistic regression model, no significant odds ratio difference was observed for NAFLD among the CTRP9 tertiles. Moreover, binary logistic regression models demonstrated that, body mass index (BMI) and alanine aminotransferase (ALT) but not CTRP9 were independent factors related to NAFLD. Besides, serum CTRP9 was positively correlated with BMI, waist circumference, Fasting insulin, HbA1c, and HOMA-IR in all subjects. BMI was the independent factor associated with serum CTRP9. CONCLUSIONS: Serum CTRP9 is not independently related to NAFLD. The association between serum CTRP9 and NAFLD might be due to the influence of obesity.


Assuntos
Adiponectina/sangue , Complemento C1q/metabolismo , Glicoproteínas/sangue , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Adipocinas/metabolismo , Adiponectina/metabolismo , Alanina Transaminase/metabolismo , Glicemia/metabolismo , Índice de Massa Corporal , Estudos Transversais , Jejum/sangue , Feminino , Humanos , Insulina/metabolismo , Resistência à Insulina/fisiologia , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade/metabolismo , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose Tumoral , Circunferência da Cintura/fisiologia
13.
J Theor Biol ; 427: 10-16, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28551365

RESUMO

There is much uncertainty about the risks of seed germination after repeated or protracted environmental low-dose ionizing radiation exposure. The purpose of this study is to explore the influence mechanism of low-dose ionizing radiation on wheat seed germination using a model linking physiological characteristics and developmental-dynamics simulation. A low-dose ionizing radiation environment simulator was built to investigate wheat (Triticum aestivum L.) seeds germination process and then a kinetic model expressing the relationship between wheat seed germination dynamics and low-dose ionizing radiation intensity variations was developed by experimental data, plant physiology, relevant hypotheses and system dynamics, and sufficiently validated and accredited by computer simulation. Germination percentages were showing no differences in response to different dose rates. However, root and shoot lengths were reduced significantly. Plasma governing equations were set up and the finite element analysis demonstrated H2O, CO2, O2 as well as the seed physiological responses to the low-dose ionizing radiation. The kinetic model was highly valid, and simultaneously the related influence mechanism of low-dose ionizing radiation on wheat seed germination proposed in the modeling process was also adequately verified. Collectively these data demonstrate that low-dose ionizing radiation has an important effect on absorbing water, consuming O2 and releasing CO2, which means the risk for embryo and endosperm development was higher.


Assuntos
Germinação/efeitos da radiação , Sementes/fisiologia , Triticum/crescimento & desenvolvimento , Relação Dose-Resposta à Radiação , Triticum/efeitos da radiação , Incerteza
14.
J Environ Radioact ; 151 Pt 1: 185-192, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26479196

RESUMO

It remains a mystery why the growth rate of bacteria is higher in low-dose ionizing radiation (LDIR) environment than that in normal environment. In this study, a hypothesis composed of environmental selection and competitive exclusion was firstly proposed from observed phenomena, experimental data and microbial ecology. Then a LDIR environment simulator (LDIRES) was built to cultivate a model organism of bacteria, Escherichia coli (E. coli) DH5α, the accurate response of bacterial population to ionizing radiation intensity variation was measured experimentally, and then the precise relative dosage of ionizing radiation E. coli DH5α population received was calculated by finite element analysis based on drift-diffusion equations of plasma. Finally, a highly valid mathematical model expressing the relationship between E. coli DH5α population and LDIR intensity was developed by system dynamics based on hypotheses, experimental data and microbial ecology. Both experiment and simulation results clearly showed that the E. coli DH5α individuals with greater specific growth rate and lower substrate consumption coefficient would adapt and survive in LDIR environment and those without such adaptability were finally eliminated under the combined effects of ionizing radiation selection and competitive exclusion.


Assuntos
Escherichia coli/efeitos da radiação , Radiação Ionizante , Evolução Biológica , Relação Dose-Resposta à Radiação , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Análise de Elementos Finitos , Modelos Teóricos , Gases em Plasma/química , Simulação de Ambiente Espacial
15.
Photosynth Res ; 126(2-3): 351-62, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25869633

RESUMO

Although terrestrial CO2 concentrations [CO2] are not expected to reach 1000 µmol mol(-1) (or ppm) for many decades, CO2 levels in closed systems such as growth chambers and greenhouses can easily exceed this concentration. CO2 levels in life support systems (LSS) in space can exceed 10,000 ppm (1 %). In order to understand how photosynthesis in C4 plants may respond to elevated CO2, it is necessary to determine if leaves of closed artificial ecosystem grown plants have a fully developed C4 photosynthetic apparatus, and whether or not photosynthesis in these leaves is more responsive to elevated [CO2] than leaves of C3 plants. To address this issue, we evaluated the response of gas exchange, water use efficiency, and photosynthetic efficiency of PSII by soybean (Glycine max (L.) Merr., 'Heihe35') of a typical C3 plant and maize (Zea mays L., 'Susheng') of C4 plant under four CO2 concentrations (500, 1000, 3000, and 5000 ppm), which were grown under controlled environmental conditions of Lunar Palace 1. The results showed that photosynthetic pigment by the C3 plants of soybean was more sensitive to elevated [CO2] below 3000 ppm than the C4 plants of maize. Elevated [CO2] to 1000 ppm induced a higher initial photosynthetic rate, while super-elevated [CO2] appeared to negate such initial growth promotion for C3 plants. The C4 plant had the highest ETR, φPSII, and qP under 500-3000 ppm [CO2], but then decreased substantially at 5000 ppm [CO2] for both species. Therefore, photosynthetic down-regulation and a decrease in photosynthetic electron transport occurred by both species in response to super-elevated [CO2] at 3000 and 5000 ppm. Accordingly, plants can be selected for and adapt to the efficient use of elevated CO2 concentration in LSS.


Assuntos
Dióxido de Carbono/farmacologia , Glycine max/fisiologia , Complexo de Proteína do Fotossistema II/metabolismo , Zea mays/fisiologia , Clorofila/metabolismo , Produtos Agrícolas , Regulação para Baixo , Ecossistema , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Transpiração Vegetal/fisiologia , Água/fisiologia
16.
J Hazard Mater ; 192(2): 658-66, 2011 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-21665363

RESUMO

Biofiltration of ethylene provides an environmentally friendly and economically beneficial option relative to physical/chemical removal, where selection of appropriate bed material is crucial. Here the vermicompost with indigenous microorganisms as bed material was evaluated for ethylene removal through batch test and biofilter experiment. Temporal and spatial dynamics of bacterial community in the vermicompost-biofilter under different ethylene loads were characterized by culture and denaturing gradient gel electrophoresis (DGGE) methods. The results showed that ethylene was effectively degraded by the vermicompost under conditions of 25-50% moisture content and 25-35°C temperature. The vermicompost-biofilter achieved nearly 100% ethylene removal up to an inlet load of 11mg m(-3)h(-1). Local nitrogen lack of the vermicompost in the biofilter was observed over operation time, but the change of pH was slight. DGGE analysis demonstrated that the bacterial abundance and community structure of vermicompost-biofilter varied with the height of biofilter under different ethylene loads. Pseudomonads and Actinobacteria were predominant in the biofilter throughout the whole experiment.


Assuntos
Bactérias/isolamento & purificação , Etilenos/isolamento & purificação , Solo , Bactérias/classificação , Bactérias/metabolismo , Eletroforese em Gel de Poliacrilamida , Filtração
17.
Bioresour Technol ; 102(2): 576-84, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20732808

RESUMO

To establish an economical and environmentally friendly technology for ethylene removal from horticultural facilities and industrial point sources, a bench-scale natural zeolite biofiltration system was developed in this study. The system was evaluated for its performance in removing ethylene from an artificially contaminated air stream and characterized for its bacterial diversity under varied ethylene concentrations, and in different spatial stages of the filter. The biofilter enabled to approximately 100% remove ethylene at loading rates of 0.26-3.76 g m(-3) h(-1) when operated with inoculum containing enriched ethylene-degrading bacteria. The bacterial diversity and abundance varied with the height of the biofilter. Moreover, the occurrence and predominance of specific bacterial species varied with the concentrations of ethylene introduced into the biofilter, as observed by PCR-DGGE methods. Phylogenetic analysis indicated that the biofilter system supported a diverse community of ethylene-degrading bacteria, with high similarity to species in the classes Betaproteobacteria, Gammaproteobacteria, Bacilli, and Actinobacteria.


Assuntos
Bactérias/crescimento & desenvolvimento , Biodiversidade , Etilenos/isolamento & purificação , Filtração/instrumentação , Filtração/métodos , Zeolitas/química , Bactérias/genética , Biodegradação Ambiental , Dióxido de Carbono/análise , Filogenia , RNA Ribossômico 16S/genética , Fatores de Tempo
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