Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 83
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Surg Endosc ; 2024 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-39433590

RESUMO

INTRODUCTION: While laparoscopic splenectomy (LS) has been widely used in benign splenic tumor, more concerns have been raised for postoperatively short-term and long-term complications. Laparoscopic partial splenectomy (LPS) is a surgical option, to preserve splenic function, and reduce postoperative complications. The aim of our study was to retrospectively identify the safety and feasibility of LPS compared with LS in patients with splenic benign tumor. MATERIALS AND METHODS: From 2014 to 2024, a total of 165 patients diagnosed with occupational splenic lesions underwent splenectomy, of whom 87 underwent LPS and 78 underwent LS. We compare the perioperative parameters and long term follow up between these two groups. RESULTS: The etiology of splenic space-occupying lesions was nonparasitic splenic cysts, followed by splenic lymphangioma and splenic hemangioma. Of the patients with LPS, 55 underwent conventional surgery with blockage of the splenic arterial branch and resection along the ischemic line (RAIL), and 32 underwent with our modified total splenic blood supply blockade followed by resection alone the tumor edge (RATE). The tumor size, the operative time and estimated blood loss were comparable between the LPS and LS groups. One patient developed abnormal signs during the LPS procedure and was promptly referred for LS. The LPS group had fewer pancreatic leakage, incision infection, and pulmonary infection. As for different vascular types, patients with LS under all branches of the splenic artery had a longer time to resume postoperative feeding. As for the comparison of RAIL and RATE, estimated blood and operative time were significantly reduced in patients receiving RATE. Postoperative complications were the same in patients underwent each surgical procedures. CONCLUSION: LPS is a viable approach for patients with splenic benign tumor. We introduce the tumor artery supply types to indicate the resection region. Our RATE technique has proven to be clinically effective and safety.

2.
Int J Mol Sci ; 25(4)2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38397102

RESUMO

The GRAS (GAI\RGA\SCL) gene family encodes plant-specific transcription factors that play crucial roles in plant growth and development, stress tolerance, and hormone network regulation. Plant dwarfing symptom is mainly regulated by DELLA proteins of the GRAS gene subfamily. In this study, the association between the GRAS gene family and Paulownia witches' broom (PaWB) was investigated. A total of 79 PfGRAS genes were identified using bioinformatics methods and categorized into 11 groups based on amino acid sequences. Tandem duplication and fragment duplication were found to be the main modes of amplification of the PfGRAS gene family. Gene structure analysis showed that more than 72.1% of the PfGRASs had no introns. The genes PfGRAS12/18/58 also contained unique DELLA structural domains; only PfGRAS12, which showed significant response to PaWB phytoplasma infection in stems, showed significant tissue specificity and responded to gibberellin (GA3) in PaWB-infected plants. We found that the internodes were significantly elongated under 100 µmol·L-1 GA3 treatment for 30 days. The subcellular localization analysis indicated that PfGRAS12 is located in the nucleus and cell membrane. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays confirmed that PfGRAS12 interacted with PfJAZ3 in the nucleus. Our results will lay a foundation for further research on the functions of the PfGRAS gene family and for genetic improvement and breeding of PaWB-resistant trees.


Assuntos
Cytisus , Lamiales , Magnoliopsida , Phytoplasma , Magnoliopsida/genética , Doenças das Plantas/genética , Phytoplasma/genética , Melhoramento Vegetal , Lamiales/genética
3.
Int J Mol Sci ; 25(3)2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38339192

RESUMO

Natural products derived from medicinal plants offer convenience and therapeutic potential and have inspired the development of antimicrobial agents. Thus, it is worth exploring the combination of nanotechnology and natural products. In this study, silver nanoparticles (AgNPs) were synthesized from the leaf extract of Ginkgo biloba (Gb), having abundant flavonoid compounds. The reaction conditions and the colloidal stability were assessed using ultraviolet-visible spectroscopy. X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy (FTIR) were used to characterize the AgNPs. AgNPs exhibited a spherical morphology, uniform dispersion, and diameter ranging from ~8 to 9 nm. The FTIR data indicated that phytoconstituents, such as polyphenols, flavonoids, and terpenoids, could potentially serve as reducing and capping agents. The antibacterial activity of the synthesized AgNPs was assessed using broth dilution and agar well diffusion assays. The results demonstrate antibacterial effects against both Gram-positive and Gram-negative strains at low AgNP concentrations. The cytotoxicity of AgNPs was examined in vitro using the CCK-8 method, which showed that low concentrations of AgNPs are noncytotoxic to normal cells and promote cell growth. In conclusion, an environmentally friendly approach for synthesizing AgNPs from Gb leaves yielded antibacterial AgNPs with minimal toxicity, holding promise for future applications in the field of biomedicine.


Assuntos
Nanopartículas Metálicas , Prata , Prata/farmacologia , Prata/química , Ginkgo biloba , Nanopartículas Metálicas/química , Antibacterianos/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
4.
J Environ Manage ; 365: 121512, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38897083

RESUMO

The construction of ecological networks within the context of urbanization is an effective approach to cope with the challenges of urban biodiversity decline, representing a crucial goal in urban planning and development. However, existing studies often overlook the richness and uniqueness within species communities by homogenizing traits of species in the same class. This study proposes a framework for constructing and optimizing ecological networks focused on differential conservation within the same class. By classifying birds into three groups (specialists of water, forest or urban areas) based on their ecological requirements and urbanization tolerance, we constructed an ecological network tailored to their distinct migratory dispersal patterns. We then identified strategic areas including pinch points, barriers, and breakpoints specific to each bird group. Our findings reveal notable variations in suitable habitat distribution among different bird groups in urban environments. Corridor layouts varied according to habitat preferences and migratory dispersal patterns. Despite these differences, urban built-up areas persist as central hubs for the distribution of suitable habitats for 75% of bird species, with peripheral mountain-plain transition areas constituting 63% of crucial dispersal corridors. This emphasizes the critical role of urban built-up areas in maintaining biodiversity and ecological connectivity. Prioritizing connectivity between central urban areas and distant natural spaces is imperative. Our approach innovatively classifies and constructs networks to identify strategic areas with diverse species-specific attributes, providing valuable spatial information for land planning and guiding solutions to enhance target species. While the primary focus is on bird conservation in Beijing, our framework is broadly applicable to global biodiversity management and green planning under urbanization challenges. Overall, this study offers innovative insights for urban planning development and serves as decision support for prioritizing urban actions.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Ecossistema , Urbanização , Conservação dos Recursos Naturais/métodos , Animais , Aves
5.
BMC Ophthalmol ; 23(1): 257, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37286942

RESUMO

BACKGROUND: Ocular trauma is a leading cause of vision loss. Penetrating ocular injury is a major type of open globe injury(OGI), while its epidemiology and clinical characteristics are still uncertain. The aim of this study is to reveal the prevalence and prognostic factors of penetrating ocular injury in the Shandong province. METHODS: A retrospective study of penetrating ocular injury was performed at the Second Hospital of Shandong University, from January 2010 to December 2019. Demographic information, injury causes, ocular trauma types, and initial and final visual acuity(VA) were analyzed. To obtain more precise characteristics of penetrating injury, the eye global was divided into three zones and analyzed. RESULTS: Among 210 OGI, there are 83 penetrating injuries which account for 39.5% of all. In addition, the final VA of 59 penetrating injuries recovered to 0.1 or better, which possesses the highest frequency among OGI. In order to research the relationship between the wound location and the final VA, we took 74 cases of penetrating injuries without retina or optic nerve damage for analysis. Results show that 62 were male and 12 were female. The average age was 36.01 ± 14.15. The most frequent occupation is the worker followed by the peasant. Statistics show that there is an obvious deviation in the Ocular trauma score (OTS) predicting the final VA and the actual final VA in the 45-65 score group (p < 0.05). Results suggest that the commonest penetrating injury zone is zone III (32 cases, 43.8%). Zone III, which is farthest from the center of the visual axis, has the largest improvement of the final VA (p = 0.0001). On the contrary, there is no statistical difference in the visual improvement in zone I and zone I + II that involves the injury of the central visual axis. CONCLUSION: This study describes the epidemiology and clinical characteristics of patients hospitalized for penetrating ocular injury without retina damage in Shandong province. It can be concluded that larger size and closer location to the visual axis of damage are accompanied by worse prognosis improvement. The study provides a better understanding of the disease and enlightenment for the prediction of visual prognosis.


Assuntos
Ferimentos Oculares Penetrantes , Traumatismos Oculares , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Estudos Retrospectivos , Índices de Gravidade do Trauma , Traumatismos Oculares/epidemiologia , Acuidade Visual , Prognóstico , Ferimentos Oculares Penetrantes/diagnóstico , Ferimentos Oculares Penetrantes/epidemiologia
6.
Sensors (Basel) ; 23(3)2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36772132

RESUMO

An atomic magnetometer (AM) was used to non-invasively detect the tiny magnetic field generated by the brain of a single Drosophila. Combined with a visual stimulus system, the AM was used to study the relationship between visual salience and oscillatory activity of the Drosophila brain by analyzing changes in the magnetic field. Oscillatory activity of Drosophila in the 1-20 Hz frequency band was measured with a sensitivity of 20 fT/Hz. The field in the 20-30 Hz band under periodic light stimulation was used to explore the correlation between short-term memory and visual salience. Our method opens a new path to a more flexible method for the investigation of brain activity in Drosophila and other small insects.


Assuntos
Encéfalo , Drosophila , Animais , Encéfalo/fisiologia , Memória de Curto Prazo/fisiologia , Estimulação Luminosa/métodos
7.
Small ; 17(47): e2103778, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34632702

RESUMO

Reducing SF6 (as gas cathode) in Li batteries is a promising concept for the double benefit of mildly converting greenhouse SF6 and providing a high theoretical energy density of 3922 Wh kg-1 . However, the reduction process is hampered by its sluggish kinetics. Here, cobalt phthalocyanine (CoPc) molecules immobilized on porous carbon matrix are, for the first time, introduced to the LiSF6 chemistry to deliver an enhanced energy density. It is revealed that the high redox potential of Co(II)Pc/[Co(I)Pc]- (≈2.85 V) facilitates the formation of Co(I)N4 sites to catalyze the SF6 electrochemical reduction. By using highly porous holey nitrogen-doped carbon nanocages as carbon matrix, the LiSF6 cells deliver a high discharge voltage of 2.82 V at 50 mA gC+CoPc -1 and an unprecedented areal capacity of 25 mAh cm-2 at 0.1 mA cm-2 , much superior to previous results. This work opens up new possibilities for high-efficiency conversion of SF6 in lithium batteries.

8.
Reprod Biol Endocrinol ; 19(1): 126, 2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34404413

RESUMO

In late December 2019, the COVID-19 pandemic caused a great threat to people's lives worldwide. As a special category of the population, pregnant women are vulnerable during emergencies. This study was designed to explore whether or not the COVID-19 pandemic has influenced maternal and infant outcomes. We collected maternal characteristics, laboratory results, condition in the third trimester, maternal outcome, fetal or neonatal outcomes, and characteristics of amniotic fluid, umbilical cord and placenta from pregnant women and fetals or newborns in the first affiliated hospital of Jinan university from 24 January to 31 March 2020 (peak period), chose the same types of data at the hospital during the same period in 2019 and 1 January-23 January 2020 (prior to the outbreak of COVID-19 in 2020) as a control. Our study focused on uncomplicated singleton pregnancies among women not infected by COVID-19. The results demonstrated that there was not an increase in adverse outcomes of pregnant women and newborns during the COVID-19 pandemic; This might be associated with the updated design of major epidemic prevention and control systems in Guangzhou, and the extension of pregnant women's rest time during the third trimester of pregnancy. Nevertheless, the survey showed an increased incidence rate of 25-hydroxyvitamin D and zinc deficiency in newborns during the epidemic, implying that pregnant women should participate in appropriate physical exercise, increase their exposure to outdoor sunlight and improve nutrition intake to ensure healthy newborns during the quarantine period. Our study has provided some guidance for maternal management during the COVID-19 pandemic.


Assuntos
COVID-19/epidemiologia , COVID-19/psicologia , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/psicologia , Resultado da Gravidez/epidemiologia , Resultado da Gravidez/psicologia , Adulto , COVID-19/prevenção & controle , China/epidemiologia , Estudos de Coortes , Feminino , Humanos , Recém-Nascido , Pandemias/prevenção & controle , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , Terceiro Trimestre da Gravidez/psicologia , Estudos Retrospectivos
9.
Int Ophthalmol ; 41(6): 2157-2165, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33772699

RESUMO

PURPOSE: To evaluate whether anti-vascular endothelial growth factor (VEGF) therapy combined with panretinal photocoagulation could reverse diabetic retinopathy (DR). METHOD: Fifty-two patients (72 eyes) with high-risk proliferative DR who were diagnosed and treated from June 2018 to May 2019 were divided into the laser group (16 cases, 32 eyes) and combination group (36 cases, 40 eyes) according to a review of the medical records. RESULTS: Within-group comparison: There were no significant differences in best-corrected visual acuity (BCVA), central foveal thickness (CFT), and microaneurysms in the laser group before and after treatment, but there were statistically significant improvements in the combination group. After the treatment, the BCVA of the patients in the combination group was 0.44 ± 0.17, which was significantly better than 0.70 ± 0.18 before treatment; the CFT after treatment was 266.51 ± 33.28 µm, which was significantly lower than 382.37 ± 54.03 µm at baseline; the MA after treatment was 56.12 ± 23.29, which was significantly lower than 121.44 ± 40.35. There was a statistically significant decrease in hard exudates area in both two groups before and after treatment. Comparison between groups: The difference in BCVA, CFT, MA and between the two groups was statistically significant (all P < 0.05), and the area of retinal neovascularization between the two groups was no significant difference, but decreased more rapidly in the combination group than that in the laser group. CONCLUSION: Using intravitreal injection of anti-VEGF drugs combined with panretinal photocoagulation to treat DR might morphologically and functionally reverse retinal changes caused by diabetes mellitus.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Degeneração Macular , Inibidores da Angiogênese/uso terapêutico , Retinopatia Diabética/complicações , Retinopatia Diabética/diagnóstico , Retinopatia Diabética/tratamento farmacológico , Humanos , Injeções Intravítreas , Fotocoagulação a Laser , Degeneração Macular/tratamento farmacológico , Receptores de Fatores de Crescimento do Endotélio Vascular , Proteínas Recombinantes de Fusão , Estudos Retrospectivos , Resultado do Tratamento , Acuidade Visual
10.
J Cell Mol Med ; 24(7): 4023-4035, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32096914

RESUMO

As a main part of pigmentation disorders, skin depigmentation diseases such as vitiligo and achromic naevus are very common and get more attention now. The pathogenesis of depigmentation includes melanocyte dysfunction and loss, which are possibly caused by heredity, autoimmunity and oxidative stress. Among them, oxidative stress plays a key role; however, few clinical treatments can deal with oxidative stress. As reported, Cistanche deserticola polysaccharide (CDP) is an effective antioxidant; based on that, we evaluated its role in melanocyte and further revealed the mechanisms. In this study, we found that CDP could promote melanogenesis in human epidermal melanocytes (HEMs) and mouse melanoma B16F10 cells, it also induced pigmentation in zebrafish. Furthermore, CDP could activate mitogen-activated protein kinase (MAPK) signal pathway, then up-regulated the expression of microphthalmia-associated transcription factor (MITF) and downstream genes TYR, TRP1, TRP2 and RAB27A. Otherwise, we found that CDP could attenuate H2 O2 -induced cytotoxicity and apoptosis in melanocytes. Further evidence revealed that CDP could enhance NRF2/HO-1 antioxidant pathway and scavenge intracellular ROS. In summary, CDP can promote melanogenesis and prevent melanocytes from oxidative stress injury, suggesting that CDP helps maintain the normal status of melanocytes. Thus, CDP may be a novel drug for the treatment of depigmentation diseases.


Assuntos
Cistanche/química , Heme Oxigenase-1/genética , Melaninas/genética , Proteínas de Membrana/genética , Fator 2 Relacionado a NF-E2/genética , Polissacarídeos/farmacologia , Animais , Humanos , Melaninas/antagonistas & inibidores , Melaninas/biossíntese , Melanócitos/efeitos dos fármacos , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/genética , Melanoma Experimental/patologia , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Pigmentação/efeitos dos fármacos , Pigmentação/genética , Transtornos da Pigmentação/tratamento farmacológico , Transtornos da Pigmentação/genética , Transtornos da Pigmentação/patologia , Polissacarídeos/química , Peixe-Zebra/genética
11.
Sensors (Basel) ; 20(5)2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32110913

RESUMO

For wireless communication networks, cognitive radio (CR) can be used to obtain the available spectrum, and wideband compressed sensing plays a vital role in cognitive radio networks (CRNs). Using compressed sensing (CS), sampling and compression of the spectrum signal can be simultaneously achieved, and the original signal can be accurately recovered from the sampling data under sub-Nyquist rate. Using a set of wideband random filters to measure the channel energy, only the recovery of the channel energy is necessary, rather than that of all the original channel signals. Based on the semi-tensor product, this paper proposes a new model to achieve the energy compression and reconstruction of spectral signals, called semi-tensor product compressed spectrum sensing (STP-CSS), which is a generalization of traditional spectrum sensing. The experimental results show that STP-CSS can flexibly generate a low-dimensional sensing matrix for energy compression and parallel reconstruction of the signal. Compared with the existing methods, STP-CSS is proved to effectively reduce the calculation complexity of sensor nodes. Hence, the proposed model markedly improves the spectrum sensing speed of network nodes and saves storage space and energy consumption.

12.
J Am Chem Soc ; 141(18): 7283-7293, 2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-31021087

RESUMO

Heterogeneous catalysis performs on specific sites of a catalyst surface even if specific sites of many catalysts during catalysis could not be identified readily. Design of a catalyst by managing catalytic sites on an atomic scale is significant for tuning catalytic performance and offering high activity and selectivity at a relatively low temperature. Here, we report a synergy effect of two sets of single-atom sites (Ni1 and Ru1) anchored on the surface of a CeO2 nanorod, Ce0.95Ni0.025Ru0.025O2. The surface of this catalyst, Ce0.95Ni0.025Ru0.025O2, consists of two sets of single-atom sites which are highly active for reforming CH4 using CO2 with a turnover rate of producing 73.6 H2 molecules on each site per second at 560 °C. Selectivity for producing H2 at this temperature is 98.5%. The single-atom sites Ni1 and Ru1 anchored on the CeO2 surface of Ce0.95Ni0.025Ru0.025O2 remain singly dispersed and in a cationic state during catalysis up to 600 °C. The two sets of single-atom sites play a synergistic role, evidenced by lower apparent activation barrier and higher turnover rate for production of H2 and CO on Ce0.95Ni0.025Ru0.025O2 in contrast to Ce0.95Ni0.05O2 with only Ni1 single-atom sites and Ce0.95Ru0.05O2 with only Ru1 single-atom sites. Computational studies suggest a molecular mechanism for the observed synergy effects, which originate at (1) the different roles of Ni1 and Ru1 sites in terms of activations of CH4 to form CO on a Ni1 site and dissociation of CO2 to CO on a Ru1 site, respectively and (2) the sequential role in terms of first forming H atoms through activation of CH4 on a Ni1 site and then coupling of H atoms to form H2 on a Ru1 site. These synergistic effects of the two sets of single-atom sites on the same surface demonstrated a new method for designing a catalyst with high activity and selectivity at a relatively low temperature.

13.
Biochem Biophys Res Commun ; 508(4): 991-996, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30551873

RESUMO

Bladder cancer remains a leading cause of cancer-related death because of its distant metastasis and high recurrence rates. Deregulation of circular RNAs (circRNAs) can act either as tumor suppressors or oncogenes to control cell proliferation, migration, and metastasis. The role of circMTO1 in bladder cancer remain unknown. In this study, we investigated whether circMTO1 could use as a biomarker and therapeutic target for bladder cancer treatment. We first demonstrated that circMTO1 was an important circRNA frequently downregulated in bladder cancer tissue, and lower circMTO1 levels were positively correlated with bladder cancer patients' metastasis and poorer survival. Ectopic expression of circMTO1 in bladder cancer cells inhibited cell's epithelial-to-mesenchymal transition (EMT) and metastasis. In addition, we also revealed that circMTO1 was able to sponge miR-221 and overexpression of circMTO1 negatively regulated the E-cadherin/N-cadherin pathway to inhibit bladder cancer cells' EMT by competing for miR-221. In conclusion, our findings provide comprehensive evidences that circMTO1 is a prognostic biomarker in bladder cancer and suggest that circMTO1 may function as a novel therapeutic target in human bladder cancer.


Assuntos
Transição Epitelial-Mesenquimal/genética , MicroRNAs/metabolismo , RNA/genética , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Animais , Linhagem Celular Tumoral , Regulação para Baixo/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , Pessoa de Meia-Idade , Invasividade Neoplásica , Metástase Neoplásica , Prognóstico , RNA/metabolismo , RNA Circular , Regulação para Cima/genética
14.
Environ Microbiol ; 20(5): 1723-1738, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29528547

RESUMO

The distribution and importance of anaerobic ammonium oxidation (anammox) and nitrite-dependent anaerobic methane oxidation (n-damo) have been identified in aquatic ecosystems; their role in agricultural upland soils however has not yet been well investigated. In this study, we examined spatio-temporal distributions of anammox and n-damo bacteria in soil profiles (300 cm depth) from an agricultural upland. Monitoring nitrogen (N) conversion activity using isotope-tracing techniques over the course of one year showed denitrification (99.0% N-loss in the winter and 85.0% N-loss in the summer) predominated over anammox (1.0% N-loss in the winter and 14.4% N-loss in the summer) and n-damo (0.6% N-loss in the winter) in surface soils (0-20 cm). While below 20 cm depth, N-loss was dominated by anammox (79.4 ± 14.3% in the winter and 65.4 ± 12.5% in the summer) and n-damo was not detected. Phylogenetic analysis showed that Candidatus Brocadia anammoxidans dominated the anammox community in the surface soil and Candidatus Brocadia fulgida dominated below 20 cm depth. Dissimilatory nitrate reduction to ammonium (DNRA), another nitrite reduction process, was found to play a limited role (4.9 ± 3.5%) in the surface soil compared with denitrification; below 80 cm DNRA rates were much higher than rates of anammox and denitrification. Ammonium oxidation was the main source of NO2- above 80 cm (70.9 ± 23.3%), the key influencing factor on anammox rates, and nitrate reduction (100%) was the main NO2- source below 80 cm. Considering the anammox, n-damo and denitrification rates as a whole in the sampled soil profile, denitrification is still the main N-loss process in upland soils.


Assuntos
Bactérias/metabolismo , Nitrogênio/metabolismo , Microbiologia do Solo , Solo/química , Compostos de Amônio/metabolismo , Anaerobiose , Bactérias/classificação , Desnitrificação , Metano/metabolismo , Nitratos , Nitritos/metabolismo , Nitrogênio/química , Oxirredução , Filogenia
15.
Environ Sci Technol ; 52(11): 6226-6236, 2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29750509

RESUMO

Artificial microbial nitrogen (N) cycle hotspots in the plant-bed/ditch system were developed and investigated based on intact core and slurry assays measurement using isotopic tracing technology, quantitative PCR and high-throughput sequencing. By increasing hydraulic retention time and periodically fluctuating water level in heterogeneous riparian zones, hotspots of anammox, nitrification, denitrification, ammonium (NH4+) oxidation, nitrite (NO2-) oxidation, nitrate (NO3-) reduction and DNRA were all stimulated at the interface sediments, with the abundance and activity being about 1-3 orders of magnitude higher than those in nonhotspots. Isotopic pairing experiments revealed that in microbial hotspots, nitrite sources were higher than the sinks, and both NH4+ oxidation (55.8%) and NO3- reduction (44.2%) provided nitrite for anammox, which accounted for 43.0% of N-loss and 44.4% of NH4+ removal in riparian zones but did not involve nitrous oxide (N2O) emission risks. High-throughput analysis identified that bacterial quorum sensing mediated this anammox hotspot with B.fulgida dominating the anammox community, but it was B. anammoxidans and Jettenia sp. that contributed more to anammox activity. In the nonhotspot zones, the NO2- source (NO3- reduction dominated) was lower than the sink, limiting the effects on anammox. The in situ N2O flux measurement showed that the microbial hotspot had a 27.1% reduced N2O emission flux compared with the nonhotspot zones.


Assuntos
Compostos de Amônio , Áreas Alagadas , Desnitrificação , Nitratos , Nitrogênio , Óxido Nitroso , Oxirredução
16.
Int J Mol Sci ; 19(4)2018 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-29561749

RESUMO

Cytoplasmic male sterility (CMS) is universally utilized in cruciferous vegetables. However, the Chinese cabbage hau CMS lines, obtained by interspecific hybridization and multiple backcrosses of the Brassica juncea (B. juncea) CMS line and Chinese cabbage, show obvious leaf etiolation, and the molecular mechanism of etiolation remains elusive. Here, the ultrastructural and phenotypic features of leaves from the Chinese cabbage CMS line 1409A and maintainer line 1409B are analyzed. The results show that chloroplasts of 1409A exhibit abnormal morphology and distribution. Next, RNA-sequencing (RNA-Seq) is used to identify 485 differentially expressed genes (DEGs) between 1409A and 1409B, and 189 up-regulated genes and 296 down-regulated genes are found. Genes that affect chloroplasts development, such as GLK1 and GLK2, and chlorophyll biosynthesis, such as PORB, are included in the down-regulated DEGs. Quantitative real-time PCR (qRT-PCR) analysis validate that the expression levels of these genes are significantly lower in 1409A than in 1409B. Taken together, these results demonstrate that leaf etiolation is markedly affected by chloroplast development and pigment biosynthesis. This study provides an effective foundation for research on the molecular mechanisms of leaf etiolation of the hau CMS line in Chinese cabbage (Brassica rapa L. ssp. pekinensis).


Assuntos
Brassica rapa/genética , Brassica rapa/fisiologia , Estiolamento/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Estudos de Associação Genética , Folhas de Planta/genética , Folhas de Planta/fisiologia , Brassica rapa/anatomia & histologia , Cloroplastos/ultraestrutura , Genes de Plantas , Anotação de Sequência Molecular , Fenótipo , Fotossíntese , Pigmentos Biológicos/metabolismo , Folhas de Planta/ultraestrutura , Transcriptoma/genética
17.
Molecules ; 21(12)2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27916965

RESUMO

Fresh-cut Chinese water chestnuts (CWC) turn yellow after being peeled, reducing their shelf life and commercial value. Metabolomics, the systematic study of the full complement of small molecular metabolites, was useful for clarifying the mechanism of fresh-cut CWC etiolation and developing methods to inhibit yellowing. In this study, metabolic alterations associated with etiolation at different growth stages (0 day, 2 days, 3 days, 4 days, 5 days) from fresh-cut CWC were investigated using LC-MS and analyzed by pattern recognition methods (principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and orthogonal projection to latent structures-discriminant analysis (OPLS-DA)). The metabolic pathways of the etiolation molecules were elucidated. The main metabolic pathway appears to be the conversion of phenylalanine to p-coumaroyl-CoA, followed by conversion to naringenin chalcone, to naringenin, and naringenin then following different pathways. Firstly, it can transform into apigenin and its derivatives; secondly, it can produce eriodictyol and its derivatives; and thirdly it can produce dihydrokaempferol, quercetin, and myricetin. The eriodictyol can be further transformed to luteolin, cyanidin, dihydroquercetin, dihydrotricetin, and others. This is the first reported use of metabolomics to study the metabolic pathways of the etiolation of fresh-cut CWC.


Assuntos
Eleocharis/metabolismo , Estiolamento/fisiologia , Metaboloma/fisiologia , Metabolômica
18.
Phys Chem Chem Phys ; 17(15): 10151-9, 2015 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-25790778

RESUMO

Layered lithium-rich oxides have several serious shortcomings such as fast voltage fading and poor cyclic stability of energy density which greatly hinder their practical applications. Fabrication of a stable framework of layered lithium-rich oxides during charging-discharging is crucial for addressing the above problems. In this work, we show that Ti modification is a promising way to realize this target with bifunctional roles. For example, it is able to substitute Mn in the lattice framework and form a stable surface layer. It therefore leads to an improved retention of energy density of the Ti-modified Li1.2Mn0.54-xTixNi0.13Co0.13O2 (x = 0.04, 0.08, and 0.15) materials during cycling. The evolution of dQ/dV curves show that the layered/spinel phase transformation is suppressed owing to the introduction of strong Ti-O bonds in the framework. In addition, SEM, TEM, and EIS results confirm that a more uniform and stable interface layer is formed on Ti-modified Li1.2Mn0.54-xTixNi0.13Co0.13O2 (x = 0.04, 0.08, and 0.15) materials compared with the Ti-free counterpart. The stable interface layer on the lithium-rich oxides is also beneficial for further reducing side reactions, resulting in stable interface layer resistance. Therefore, the improved cycling performance of the material is due to both contribution of the more stable framework and enhanced electrode/electrolyte interface by Ti modification.

19.
Anal Bioanal Chem ; 406(29): 7523-31, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24871865

RESUMO

A new plasma chemical vapor generation (plasma-CVG) method for Zn was developed by dielectric barrier discharge (DBD). The dissolved Zn ions was readily converted to volatile species by DBD plasma in the presence of hydrogen and then, the generated Zn vapor, Zn(0), was detected by cold vapor atomic fluorescence spectrometry (AFS). It eliminated the use of unstable tetrahydroborate-reducing reagent and high-purity acids. The operating conditions for the DBD plasma-CVG system were optimized for the efficient vapor generation of Zn. In addition, possible interferences from coexisting ions on the plasma-CVG of Zn were also examined. No appreciable matrix interference was found from most of the examined ions at concentration of 1 mg L(-1). However, severe depression of the Zn vapor generation efficiency was observed in the presence of ions at 10 mg L(-1). Under the optimal conditions, the limit of detection (LOD) was calculated to be 0.2 µg L(-1); good repeatability (relative standard deviation (RSD) = 2.6%, n = 11) was obtained for a 20 Zn µg L(-1) standard. The accuracy of the proposed method was validated though analysis of Zn in reference material of simulated natural water sample GSB07-1184-2000 and the determined result was in good agreement with the reference value. The proposed method has also been successfully applied to the determination of Zn in Changjiang River water, Wuhan East Lake water, and Wuhan tap water samples. It provides an alternative green vapor generation method for Zn.

20.
J Agric Food Chem ; 72(43): 23859-23874, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-39432373

RESUMO

A previous study showed that kiwifruit polysaccharide (KFP) has benefits in relieving intestinal inflammation, while the underlying mechanism remains unresolved. The objective of this study was to investigate the regulatory effect of KFP on the gut microbiota metabolism and intestinal barrier of ulcerative colitis (UC) mice induced by dextran sulfate sodium (DSS). KFP significantly improved the UC symptoms including weight loss, shortened colon length, splenomegaly, diarrhea, hematochezia, and colon inflammation of mice. In addition, KFP could alleviate DSS-caused gut microbiota dysbiosis and increase the levels of short-chain fatty acids in the cecal contents of mice. Furthermore, the results of nontargeted and targeted metabolomics analysis combined with antibiotic treatment revealed that KFP could regulate gut microbiota-dependent tryptophan metabolism, activate the aryl hydrocarbon receptor (AhR) in colon cells, and enhance interleukin-22 production and tight junction proteins' (ZO-1, occludin, and claudin3) expression to repair the intestinal barrier in UC mice. Immunofluorescence results showed that KFP significantly upregulated the conjunction of lectin WGA and UEA1 in the UC mouse colon, implying that KFP promoted fucosylation in the colon. These results suggest that KFP alleviates UC primarily via targeting the gut microbiota involved in the AhR pathway and upregulating colon fucosylation.


Assuntos
Actinidia , Colite Ulcerativa , Colo , Microbioma Gastrointestinal , Camundongos Endogâmicos C57BL , Polissacarídeos , Triptofano , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/metabolismo , Colite Ulcerativa/microbiologia , Colite Ulcerativa/induzido quimicamente , Camundongos , Colo/metabolismo , Colo/microbiologia , Colo/efeitos dos fármacos , Polissacarídeos/farmacologia , Polissacarídeos/administração & dosagem , Polissacarídeos/química , Masculino , Triptofano/metabolismo , Humanos , Actinidia/química , Frutas/química , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/metabolismo , Bactérias/genética , Extratos Vegetais/farmacologia , Extratos Vegetais/administração & dosagem , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores de Hidrocarboneto Arílico/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA