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1.
Aging Cell ; : e13510, 2021 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-34719871

RESUMO

Citrate is an essential substrate for energy metabolism that plays critical roles in regulating cell growth and survival. However, the action of citrate in regulating metabolism, cognition, and aging at the organismal level remains poorly understood. Here, we report that dietary supplementation with citrate significantly reduces energy status and extends lifespan in Drosophila melanogaster. Our genetic studies in fruit flies implicate a molecular mechanism associated with AMP-activated protein kinase (AMPK), target of rapamycin (TOR), and ketogenesis. Mice fed a high-fat diet that supplemented with citrate or the ketone body ß-hydroxybutyrate (ßOHB) also display improved metabolic health and memory. These results suggest that dietary citrate supplementation may prove to be a useful intervention in the future treatment of age-related dysfunction.

2.
Artigo em Inglês | MEDLINE | ID: mdl-34802759

RESUMO

Rechargeable aqueous zinc-ion batteries (RAZIBs) have received increasing attention due to cost-effectiveness and inherent safety. A wide variety of advanced cathode materials have been revealed with promising performance in RAZIBs. However, these materials usually require sophisticated procedures at high temperatures, which greatly limit further practical application. Herein, a chimie douce approach is adopted to prepare vanadium oxides from V2O5 suspension with the addition of various transition metal cations (Mn2+, Zn2+, Ag+, and Fe3+) by simple liquid-solid mixing under ambient conditions. For the cases of Mn2+ and Zn2+, the dissolution-recrystallization process takes place leading to layered Mn0.31V3O7·1.40H2O (MnVO) and Zn0.32V3O7·1.52H2O (ZnVO). The use of Ag+ forms tunneled Ag0.33V2O5 (AgVO), and the present of Fe3+ stays mainly unreacted V2O5. The underlying reaction chemistries are proposed, for which the pH values of precursor solutions are found to be a key factor. Among the prepared materials, layered vanadium oxides exhibit promising battery performance. Particularly, MnVO delivers 340 and 217 mAh g-1 at 1 and 8 A g-1, respectively. A specific capacity of 164 mAh g-1 can be retained after 500 cycles at 1 A g-1. By contrast, AgVO and FeVO demonstrate inferior performance with retaining only 89 and 20 mAh g-1 after 500 cycles.

3.
Food Funct ; 12(20): 9658-9668, 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34664597

RESUMO

The major cause of death in colorectal cancer (CRC) patients is metastasis. Moreover, lots of studies have emphasized that the epithelial-mesenchymal transition (EMT) is a pivotal step in metastasis. Both transforming growth factor beta (TGF-ß) and dysregulation of microRNAs (miRNAs) can induce or regulate EMT, promoting the loss of intercellular adhesion and increased motility of cancer cells. Therefore, it is necessary to prevent or inhibit the metastasis of colorectal cancer. Relatively little is known about the anti-metastatic effect of oxyresveratrol (OXY), a natural derivative of resveratrol (RES), compared to RES. Accordingly, RES was used as the positive control to investigate the effects of OXY on colon cancer cell migration. The results showed that OXY could significantly inhibit cell migration (67.17% ± 0.04, 64.89% ± 0.04) compared to RES (84.6% ± 0.07, 76.34% ± 0.08) in HCT116 cells and TGF-ß-induced HT-29 cells, respectively, via Snail/E-cadherin expression. In addition, OXY improved EMT-related miRNA expression through, for example, lowering the levels of miR-3687 and miR-301a-3p while upregulating miR-3612 in TGF-ß-induced HT-29 cells. In conclusion, OXY inhibits human colon cancer cell migration by regulating EMT and miRNAs. Based on these findings, it can be stated that OXY promotes anti-metastatic properties in CRC.

4.
Sci Rep ; 11(1): 20242, 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34642351

RESUMO

Dravet syndrome (DS) is an uncommon epilepsy syndrome that may negatively affect the patients and their caregivers. However, reliable and valid measures of its impact on caregivers and the characteristics of patients with DS in Taiwan are lacking. This study aimed to describe the characteristics of patients with DS and concerns of their caregivers and establish a baseline frequency of disease characteristics using a cross-sectional survey in Taiwan. We assessed the caregivers of patients with DS using an online anonymous questionnaire. The seizure frequency decreased with age, although lacking statistical significance. Vaccines show no influence on the condition of patients with DS. Our findings revealed the highest impact on the domains affecting the caregivers' daily life, including additional household tasks, symptom observation, further medical plan, and financial issues. Caregivers also expressed concerns regarding the lack of independence/constant care, seizure control, speech/communication, and impacts on siblings because of long-term care of the patients in parents' absence. Our findings highlight the significant effects of caring for a child with DS on the lives of their caregivers in Taiwan; these findings will help raise awareness regarding the needs of these families. Furthermore, we discussed the possible pathophysiological mechanisms of associated comorbidities.

7.
Orphanet J Rare Dis ; 16(1): 348, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34353347

RESUMO

BACKGROUND: Studies suggest that enzyme-replacement therapy (ERT) is crucial to the survival of patients with infantile-onset Pompe disease (IOPD). Hearing impairment (HI) is one of the clinical sequelae observed in long-term survivors. However, the benefits of early ERT for hearing outcomes have not yet been reported. This study aimed to investigate the impact of early ERT on IOPD patients. METHODS: This retrospective longitudinal study recruited IOPD patients who were referred by newborn screening for confirmatory diagnosis based on our rapid diagnostic criteria and received early ERT treatment between January 1, 2010, and January 31, 2018. The hearing test battery included a tympanogram, otoacoustic emission, auditory brainstem evoked response (ABR), pure-tone audiometry or conditioned play audiometry. RESULTS: Nineteen patients with IOPD were identified, 6 of whom had hearing impairment (HI); 1 had conductive HI, 2 had sensorineural HI (one had bilateral mild HI and one had mild HI in a single ear) and 1 had moderate mixed-type HI. Two patients failed the newborn screening test and had mild HI in the ABR. The mean age of the initial time to ERT was 11.05 ± 4.31 days, and the HI rate was 31.6% (6/19). CONCLUSION: Our study is the largest cohort to show the characteristic hearing outcomes of IOPD patients after ERT. Early ERT within 2 weeks after birth may contribute to better hearing outcomes. Clinicians should be vigilant in testing for the hearing issues associated with IOPD and should intervene early if any HI is detected.


Assuntos
Doença de Depósito de Glicogênio Tipo II , Terapia de Reposição de Enzimas , Doença de Depósito de Glicogênio Tipo II/tratamento farmacológico , Audição , Testes Auditivos , Humanos , Recém-Nascido , Estudos Longitudinais , Estudos Retrospectivos , alfa-Glucosidases/uso terapêutico
8.
Clin Transl Immunology ; 10(6): e1299, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34141434

RESUMO

FIRES (febrile infection-related epilepsy syndrome) is a protracted neuroinflammatory condition of obscure cause. It mainly afflicts school-age children and often leads to permanent neurological sequelae. Most treatments to date have been of limited efficacy, while ketogenic diet and anti-interleukin-1 therapy appear beneficial for some patients. Research into this clinical entity is hampered by its rarity and complexity. Nonetheless, accumulating evidence derived from basic investigations and clinical observations converges to implicate the autoinflammatory nature of this syndrome. A closer analysis of current literature suggests that microglia and the NLRP3 inflammasome might be the pivotal cellular and molecular players in FIRES pathogenesis, respectively. Through evidence synthesis, herein we formulate the working hypothesis of overactivation of microglial NLRP3 inflammasome/interleukin-1 axis as the driving event in FIRES by creating a proinflammatory and proconvulsive milieu. The reverberation between neuroinflammation and seizure forms a vicious cycle. The unique properties of microglia might also contribute to unopposed IL-1 signalling and incessant sterile neuroinflammation in this context. The potential therapeutic relevance of the proposed conceptual framework is discussed.

9.
J Agric Food Chem ; 69(16): 4745-4754, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33848157

RESUMO

The overweight and obese population has skyrocketed, resulting in a high incidence of metabolic disorders. Agardhiella subulata (AS) contains a variety of beneficial components, such as sulfur-containing polysaccharides (dietary fiber) and astaxanthin, which is considered to have anti-obesity potential. In this study, we investigated the effects and possible mechanisms of dietary AS on high-fat diet (HFD)-induced obesity in mice. AS supplementation significantly reduced HFD-induced weight gain (19%) and the visceral adiposity index (4.1%). In addition, the level of total cholesterol, triglyceride, and low-density lipoprotein was significantly decreased; adiponectin was significantly increased in serum and fecal triglyceride excretion was significantly higher in mice fed AS compared with mice on an HFD. Preadipocyte factor 1 and Sry-box transcription factor 9 that were significantly higher than the levels found for the HFD group lead to reduced adipogenesis. Moreover, accompanying the lipolysis and fatty acid ß-oxidation that occur in the AS group, the concentration of non-esterified fatty acids was lowered to 0.4 ± 0.1 mEq/L. In addition, peroxisome proliferator-activated receptor γ and phosphorylation acetyl-CoA carboxylase increased 1.5- and 1-fold, thus increasing the expression of adiponectin and the activation of AMPK and ultimately resulting in lower blood glucose levels. The results of this study suggest that AS supplementation increases lipid excretion and improves energy metabolism to prevent obesity in mice fed a HFD.


Assuntos
Fármacos Antiobesidade , Dieta Hiperlipídica , Adipogenia , Animais , Fármacos Antiobesidade/farmacologia , Dieta Hiperlipídica/efeitos adversos , Fígado , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/etiologia , Obesidade/genética
10.
Diagnostics (Basel) ; 11(3)2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33809853

RESUMO

Acute necrotizing encephalopathy is a devastating clinico-radiological syndrome characterized by fulminant neurological deterioration after an antecedent febrile illness, as well as the imaging hallmark of bilateral thalamic involvement. Herein, we describe a 4-year-old boy with typical clinical and neuroimaging features of acute necrotizing encephalopathy. The bithalamic swelling led to a block of cerebrospinal fluid circulation at the foramen of Monro, thereby causing the mild dilatation of lateral ventricles. The periventricular areas could, therefore, have been potentially affected by the acute necrotizing encephalopathy per se and/or transependymal edema secondary to obstructive hydrocephalus. The information from diffusion imaging allows for differentiation between these two pathophysiological processes.

11.
Materials (Basel) ; 14(2)2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33430051

RESUMO

A concrete-filled steel tube (CFT) combines the advantages of concrete and steel in construction and structural applications. However, research on the time-dependent deformation of the CFT under long-term sustained loading are still limited, particularly for stress transfer between the steel tube and concrete due to creep. This study investigated the creep behavior of CFT over a long period of 400 days. The creep and shrinkage strain of CFT was significantly lower than those of concrete that was not confined within a steel tube. The vertical strains of the steel tube and concrete core were almost identical, and it was shown that they were well bonded and acted as a composite. The vertical stress of steel increased by 32.7%, whereas the vertical stress of concrete decreased by 15.8% at 375 days. The stress transfer is notable and cannot be neglected in CFT design. Moreover, the results of creep and shrinkage were compared to prediction values of the B4 model and B4-TW model to verify their validity.

12.
J Gerontol A Biol Sci Med Sci ; 76(1): 50-56, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32808644

RESUMO

Reduced expression of the Indy (I'm Not Dead Yet) gene extends life span in Caenorhabditis elegans and Drosophila melanogaster and improves the metabolic heath of Mus musculus through inducing a physiological status akin to dietary restriction (DR). Although the function of Indy in aging and hepatic metabolism has been extensively studied, its role in the mouse nervous system remains unclear. Here, we explore the effect of mammalian Indy (mIndy, SLC13A5) gene deletion on murine cognitive function. Similar to what is seen in DR animals, systemic deletion of the mIndy gene (mIndy knockout [KO]) significantly improves memory performance and motor coordination of mice. Both DR and mIndy KO mice act normally in other behavioral tasks, including emotional, social, and food-seeking behaviors. Moreover, we find that tissue-specific deletion of mIndy in the nervous system is sufficient to improve memory performance, while liver-specific deletion has no effect on memory, and results in tests of motor coordination show no changes in either mutant. Mice with systemic or nervous system deletion of mIndy also exhibit increased hippocampal neurogenesis and dendritic spine formation in dentate granule cells; these changes are well-documented contributors to enhanced memory performance. Together, our studies demonstrate a critical role for brain-derived mIndy expression in the regulation of memory function in animals.


Assuntos
Restrição Calórica , Cognição , Transportadores de Ácidos Dicarboxílicos/genética , Deleção de Genes , Memória , Sistema Nervoso , Simportadores/genética , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL
13.
Children (Basel) ; 7(10)2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33076220

RESUMO

Cognitive impairment is increasingly recognized as an important clinical issue in pediatric multiple sclerosis (MS). However, variations regarding its assessment and remediation are noted in clinical arena. This scoping review aims to collate available evidence concerning cognitive assessment tool and cognitive rehabilitation for pediatric MS. We performed a systematic search of electronic databases (MEDLINE, PubMed, CINAHL Plus, and Web of Science) from inception to February 2020. Reference lists of included articles and trial registers were also searched. We included original studies published in English that addressed cognitive assessment tools or cognitive rehabilitation for pediatric-onset MS. Fourteen studies fulfilled our inclusion criteria. Among them, 11 studies evaluated the psychometric aspects of various cognitive assessment tools in the context of pediatric MS, and different neuro-cognitive domains were emphasized across studies. There were only three pilot studies reporting cognitive rehabilitation for pediatric-onset MS, all of which used home-based computerized programs targeting working memory and attention, respectively. Overall, more systematic research on cognitive assessment tools and rehabilitation for pediatric MS is needed to inform evidence-based practice. Computer-assisted cognitive assessment and rehabilitation appear feasible and deserve further studies.

15.
Mult Scler Relat Disord ; 45: 102425, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32799120

RESUMO

BACKGROUND: The epidemiology of multiple sclerosis (MS) and neuromyelitis optica (NMO) remains to be clarified or updated in many parts of Asia. This study aims to investigate the epidemiology and comorbidities of MS and NMO during 2001-2015 in Taiwan. METHODS: We conducted a retrospective nationwide population-based study using data from Taiwan's National Health Insurance Research Database. Cases of MS and NMO aged 20 years or above during 2001-2015 were enrolled. The incidence, prevalence, demographic features, and comorbidities were investigated. RESULTS: We identified 4627 MS and 861 NMO incident cases aged 20 or above during 2003-2015. The incidence of MS was relatively stationary, while that of NMO apparently rose steeply during the study period. The age-standardized incidence rate of MS and NMO in 2015 were 1.34 and 0.61 per 100,000 person-years, respectively. The age-standardized prevalence rate of MS and NMO in 2015 were 6.69 and 1.47 per 100,000 persons, respectively. The female preponderance was evident for both MS and NMO. Except for diabetes mellitus, the most common autoimmune comorbidities for MS and NMO were Sjogren syndrome and systemic sclerosis, and Sjogren syndrome and systemic lupus erythematosus, respectively. CONCLUSIONS: Taiwan has transitioned from low- to medium-risk zone during 2001-2015 in terms of MS prevalence, although its incidence remained stationary. The apparent upsurge of NMO over the period probably reflects increased awareness of this clinical entity. Comorbid autoimmune disorders were relatively common, and overlapping but differential autoimmune comorbidity profiles were noted for MS and NMO.


Assuntos
Esclerose Múltipla , Neuromielite Óptica , Adulto , Idoso de 80 Anos ou mais , Comorbidade , Feminino , Humanos , Esclerose Múltipla/epidemiologia , Neuromielite Óptica/epidemiologia , Estudos Retrospectivos , Taiwan/epidemiologia , Adulto Jovem
16.
Mult Scler Relat Disord ; 44: 102379, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32650124

RESUMO

BACKGROUND: The long-term outcome of optic neuritis (ON) is heterogeneous, and it appears to vary among different populations. Identification of determinants of natural history of ON would be helpful in therapeutic planning and prognostication, while relevant investigations in Asian patients were less reported. This study aims to clarify whether comorbidities and treatment in ON patients are associated with differential risks of subsequent development of multiple sclerosis (MS) or neuromyelitis optica (NMO) in Taiwan. METHODS: We conducted the nationwide population-based cohort study using data from Taiwan's National Health Insurance Research Database. Incident ON cases during 2003~2014 were followed until the end of 2015. Pediatric and adult sub-cohorts were examined separately. The associations between immune-related comorbidities or treatment and outcomes were analyzed using Cox proportional hazards models. RESULTS: A total of 11,923 adult and 1365 pediatric ON patients were enrolled. The rates of subsequent development of MS were 2.7% for adult and 3.1% for pediatric ON with median follow-up duration of 6.3 and 7.3 years respectively, while 1.2% of pediatric and adult ON evolved to NMO. Comorbid systemic lupus erythematosus was associated with increased risks of subsequent development of MS in adult (adjusted hazard ratio [aHR], 2.80; 95% CI, 1.04-7.49) and pediatric ON patients (aHR, 21.65; 95% CI, 1.29-363.4). Adult ON patients were at increased risks of NMO if comorbid with myasthenia gravis (aHR, 9.13; 95% CI, 1.20-69.45) or Sjogren's syndrome (aHR, 4.71; 95% CI, 1.74-12.76). CONCLUSION: ON could be the sentinel event linking several peripheral autoimmune comorbidities to distinct forms of central nervous system demyelination.


Assuntos
Esclerose Múltipla , Neuromielite Óptica , Neurite Óptica , Adulto , Criança , Estudos de Coortes , Humanos , Esclerose Múltipla/epidemiologia , Neuromielite Óptica/epidemiologia , Neurite Óptica/epidemiologia , Taiwan/epidemiologia
17.
J Agric Food Chem ; 68(46): 12788-12799, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-32064876

RESUMO

Supplementation with natural compounds found in fruits and vegetables has long been associated with a reduced risk of several types of cancer. Pterostilbene is a natural stilbenoid and a dimethylated analogue of resveratrol which is found primarily in blueberries. Pterostilbene exhibits a range of pharmacological properties, particularly anti-inflammatory and anticancer effects. Due to two methoxy groups in its skeleton, pterostilbene is more lipophilic than resveratrol and thus possesses higher intestinal permeability and cellular uptake and enhanced stability. Moreover, pterostilbene exhibits less toxicity and fewer adverse effects, providing it with superior potential in cancer chemoprevention and chemotherapy applications. Numerous research studies have demonstrated that pterostilbene possesses detoxification activities, mediating the anti-inflammation response, regulating the cell cycle, augmenting apoptosis, enhancing autophagy, and inhibiting tumor angiogenesis, invasion, and metastasis by modulating signal transduction pathways which block multiple stages of carcinogenesis. In this review, we illustrate that pterostilbene is a natural compound having bioavailability. The extensive metabolism of pterostilbene will be discussed. We also summarize recent research on pterostilbene's anti-inflammatory and anticancer properties in the multistage carcinogenesis process and related molecular mechanism and conclude that it should contribute to improved cancer management.


Assuntos
Anti-Inflamatórios/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Extratos Vegetais/farmacologia , Estilbenos/farmacologia , Animais , Anti-Inflamatórios/química , Antineoplásicos Fitogênicos/química , Disponibilidade Biológica , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Extratos Vegetais/química , Estilbenos/química
18.
J Neurol ; 267(4): 925-932, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31781928

RESUMO

BACKGROUND AND OBJECTIVE: The epidemiology of pediatric acquired demyelinating disorders remains to be clarified in many parts of Asia. We carry out this study to depict the epidemiology of pediatric multiple sclerosis (MS), neuromyelitis optica (NMO), and optic neuritis (ON) in Taiwan. METHODS: We conducted a retrospective nationwide population-based study using data from Taiwan's National Health Insurance Research Database. Prevalent cases of pediatric MS and NMO during 2001-2015, and incident cases of pediatric MS, NMO, and ON during 2003-2015 were identified. The demographic features and comorbidities were investigated. RESULTS: We identified 403 MS, 42 NMO, and 1496 ON incident cases under the age of 20 during 2003-2015. The majority of pediatric MS (86.1%) and NMO (90.5%) patients were 10 years old or above. The incidence of MS and ON was relatively steady, while that of NMO increased prominently later during the study period. The average incidence of pediatric MS and NMO during 2011-2015 was 0.52 and 0.11 per 100,000 person-years, respectively. The female preponderance was evident for pediatric MS and NMO, and less so for pediatric ON. The most common autoimmune comorbidities for pediatric MS were thyrotoxicosis (1.0%) and systemic lupus erythematosus (0.7%). CONCLUSION: The epidemiology of pediatric MS was largely stationary in Taiwan during 2001-2015, while the prevalence of pediatric NMO rose steeply during this period, probably reflecting better recognition of this clinical entity. Autoimmune comorbidities were uncommon for pediatric MS and NMO in Taiwan.


Assuntos
Lúpus Eritematoso Sistêmico/epidemiologia , Esclerose Múltipla/epidemiologia , Neurite Óptica/epidemiologia , Tireotoxicose/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Comorbidade , Bases de Dados Factuais , Feminino , Humanos , Incidência , Lactente , Masculino , Programas Nacionais de Saúde/estatística & dados numéricos , Neuromielite Óptica/epidemiologia , Prevalência , Estudos Retrospectivos , Fatores Sexuais , Taiwan/epidemiologia , Adulto Jovem
19.
Pediatrics ; 144(5)2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31662417

RESUMO

Schilder disease, also termed diffuse myelinoclastic sclerosis, is characterized by a large demyelinating lesion involving 1 or both sides of the centrum semiovale of the cerebral hemispheres. It often presents with tumorlike features and poses a diagnostic challenge. Schilder disease can be monophasic or relapsing, and disease-modifying therapy for the latter scenario is largely empirical. Here, we report a 14-year-old girl with relapsing Schilder disease within 1 year after disease onset. She has been followed-up for nearly 10 years and remains in sustained remission ever since interferon-ß therapy was prescribed after the second attack. In this case study, it is suggested that interferon-ß may induce long-term remission in relapsing Schilder disease and is therefore worth considering in this regard.


Assuntos
Encéfalo/diagnóstico por imagem , Esclerose Cerebral Difusa de Schilder/tratamento farmacológico , Fatores Imunológicos/uso terapêutico , Interferon beta-1a/uso terapêutico , Adolescente , Corticosteroides/uso terapêutico , Esclerose Cerebral Difusa de Schilder/diagnóstico por imagem , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Metilprednisolona/uso terapêutico , Neuroimagem , Fármacos Neuroprotetores/uso terapêutico , Indução de Remissão , Tomografia Computadorizada por Raios X
20.
Ying Yong Sheng Tai Xue Bao ; 30(3): 832-840, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30912375

RESUMO

Extracellular enzyme activitie (EEAs) are a sensitive indicator of microbial function and soil organic matter decomposition in response to climate warming. Up to now, most studies of climate warming and their effects on EEAs have been restricted on the relatively carbon rich topsoil (the upper 20 cm of the soil), whereas little is known about EEAs in subsoil (below 30 cm depth). This study focused on the responses of EEAs to soil warming in a subtropical forest at depths of 0-10 cm, 10-20 cm, 20-40 cm and 40-60 cm. The examined extracellular enzymes included ß-glucosidase (BG), cellobiohydrolase (CBH), phenoloxidase (PHO) and peroxidase (PEO), all being involved in the C-cycle. The results showed that, 1) warming significantly increased all EEAs (18%-69%) at the depth of 0-10 cm and 10-20 cm. Below the depth of 20 cm, warming did no affect or suppressed EEAs (13%-31%), except increasing PHO (10%) at 20-40 cm. 2) Results from the redundancy analysis showed that the EEAs were mainly driven by ammonium nitrogen (NH4+-N) and soil moisture (M) in organic carbon rich topsoil. Warming enhanced nutrient competition between soil microorganisms and plants. Thus, it increased EEAs to meet NH4+-N demands of microorganisms. In subsoil with relatively low substrate availability, the EEAs were dominated by dissolved organic matter and microbial biomass (MBC). Warming increased dissolved organic matter and thus provided more substrates for microorganisms, which relieved the dependence of microbes on EEAs. Consequently, warming diminished EEAs in subsoils. Our results suggested that EEAs at the four depths showed different responses to warming. In addition, environmental factors accounting for the variances in EEAs under soil warming condition were different at topsoil and subsoil. Paying more attention to microbes at different soil depths has important implications to precisely predict ecosystem C cycling in response to global warming.


Assuntos
Cunninghamia , Microbiologia do Solo , Carbono , Nitrogênio , Solo
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