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1.
Waste Manag ; 103: 305-313, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31923839

RESUMO

In this paper, three sets of laboratory tests were conducted on high-food-waste-content (HFWC-), no-food-waste-content (NFWC-) and decomposed (D-) MSWs to characterize their compression behaviors. The immediate compression ratios C'c were 0.30, 0.23 and 0.18 for HFWC-MSW, NFWC-MSW and D-MSW respectively, and tended to increase with the increasing food waste content of MSW. The release of intra-particle water contained in food waste contributed over 23.6-29.2% to immediate compression for HFWC-MSW. The mechanical creep ratios C'sc were 0.02, 0.015 and 0.01 for HFWC-MSW, NFWC-MSW and D-MSW respectively. A prediction model for C'sc was proposed which incorporated the effects of moisture content, dry unit weight and organic waste content. The bio-compression ratios C'sbI, C'sbII and C'sbIII in response to degradation stage I, II and III were 0.12, 0.10 and 0.02 for HFWC-MSW, and were 0.01, 0.15 and 0.01 for NFWC-MSW. Bio-compression is dominant in stage I and II and mechanical creep is the major contributor in stage III for HFWC-MSW, but to NFWC-MSW, mechanical creep is dominant in stage I and III, and bio-compression takes the main position in stage II. The bio-compression tended to increase linearly with leachate draining rate for HFWC-MSW, and the release of intra-particle water contributed 61.9-65.6% to bio-compression. A new model was proposed that can well capture the highly non-linear behavior of bio-compression for both HFWC-MSW and NFWC-MSW. Based on the above findings, the settlement behavior of HFWC-MSW and NFWC-MSW landfills was compared, and suggestions for technique-efficient and cost-effective design of a NFWC-MSW landfill were discussed.

2.
Environ Pollut ; : 113676, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31818614

RESUMO

CH4 oxidation in landfill cover soils plays a significant role in mitigating CH4 release to the atmosphere. Oxygen availability and the presence of co-contaminants are potentially important factors affecting CH4 oxidation rate and the fate of CH4-derived carbon. In this study, microbial populations that oxidize CH4 and the subsequent conversion of CH4-derived carbon into CO2, soil organic C and biomass C were investigated in landfill cover soils at two O2 tensions, i.e., O2 concentrations of 21% ("sufficient") and 2.5% ("limited") with and without toluene. CH4-derived carbon was primarily converted into CO2 and soil organic C in the landfill cover soils, accounting for more than 80% of CH4 oxidized. Under the O2-sufficient condition, 52.9%-59.6% of CH4-derived carbon was converted into CO2 (CECO2-C), and 29.1%-39.3% was converted into soil organic C (CEorganic-C). A higher CEorganic-C and lower CECO2-C occurred in the O2-limited environment, relative to the O2-sufficient condition. With the addition of toluene, the carbon conversion efficiency of CH4 into biomass C and organic C increased slightly, especially in the O2-limited environment. A more complex microbial network was involved in CH4 assimilation in the O2-limited environment than under the O2-sufficient condition. DNA-based stable isotope probing of the community with 13CH4 revealed that Methylocaldum and Methylosarcina had a higher relative growth rate than other type I methanotrophs in the landfill cover soils, especially at the low O2 concentration, while Methylosinus was more abundant in the treatment with both the high O2 concentration and toluene. These results indicated that O2-limited environments could prompt more CH4-derived carbon to be deposited into soils in the form of biomass C and organic C, thereby enhancing the contribution of CH4-derived carbon to soil community biomass and functionality of landfill cover soils (i.e. reduction of CO2 emission).

3.
Waste Manag ; 103: 159-168, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31887688

RESUMO

Vertical wells are conventionally used to lower leachate levels or pressures in municipal solid waste (MSW) landfills. However, they are not always efficient or even effective, and in some circumstances retro-fitted horizontal wells represent a potential alternative. However, horizontal wells can be difficult to install and there is a lack of data on their performance. This paper describes the trial construction and operation of three horizontal wells in a landfill at Tianziling, China. The trial was used to develop an improved well installation technique, and to demonstrate the viability of the approach in a typical Chinese landfill. Three wells, between 50 m and 56 m in length, were successfully installed using an improved casing-protected directional drilling method. Average leachate flow rates of two wells were 10.66 m3/day and 3.93 m3/day, respectively. After 74 days of drainage, the maximum leachate level drawdown around the highest flow well was 2.7 m and its distance of influence was up to 50 m. Building on the experience gained at Tianziling, a wellfield comprising twelve horizontal wells having a total length of 1000 m was installed at Xingfeng landfill. After 157 days of drainage, a total volume of ~24,000 m3 leachate had been discharged and the leachate level had been lowered to near the elevation of the horizontal wells. This paper indicates the effectiveness of horizontal wells in reducing leachate level in landfills containing MSW typical of that generated in China, and gives data on installation and performance that may be useful for the design and operation of such an approach.

4.
Waste Manag Res ; : 734242X19893007, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856695

RESUMO

A newly developed static chamber method with a laser methane detector and a biogas analyser was proposed to measure the landfill gas emissions and methane (CH4) oxidation rates in landfill covers. The method relied on a laser methane detector for measuring CH4 concentration, avoiding gas samplings during test and hence the potential interference of gas compositions inside the chamber. All the measurements could be obtained on site. The method was applied to determine the landfill gas emissions and CH4 oxidation rates in a full-scale loess gravel capillary barrier cover constructed in landfill. Both laboratory calibration and in-situ tests demonstrated that fast (i.e. <20 min) and accurate measurements could be obtained by the proposed method. The method is capable of capturing the significant spatial and temporal variations of the landfill gas emissions and CH4 oxidation rates in landfill site.

5.
Nanotechnology ; 31(9): 095401, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31711047

RESUMO

Despite many recent attempts to restrict it, the dissolution and diffusion of polysulfides, leading to inferior cycling performance, is still the main bottleneck hindering commercialization of the Li-S battery. Herein, a new strategy of using lithium polyacrylate (LiPAA) to clad multiwalled carbon nanotube/sulfur (MWNT/S) composites as the interface layer for an MWNT/S/LiPAA cathode was proposed, not only to suppress polysulfide migration through physical encapsulation and chemical adsorption, but also to facilitate Li+ diffusion during the charge/discharge process. Attributed to these functions of LiPAA, MWNT/S/LiPAA exhibited a rate capability and cycling performance superior to those of MWNT/S and MWNT/S/PAA. Moreover, thanks to the introduction of LiPAA, the MWNT/S/LiPAA was endowed with robust mechanical properties, making it suitable for a flexible cathode in a flexible Li-S battery with stable output under deformation. This work could open up a promising way to suppress polysulfide migration for high-performance flexible Li-S batteries.

6.
Nanotechnology ; 31(9): 095404, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31726430

RESUMO

Although secondary batteries are common in many fields, new electrode materials with a reasonable structure are desired for high battery performance. Herein, Sb/N-doped graphene nanosheets (NGNS-Q) were constructed with the help of 7,7,8,8-tetracyanoquinodimethane anions (TCNQ·-). TCNQ·- were used to anchor Sb3+ into the graphene layer by electrostatic interaction, which improves the distribution of Sb nanoparticles. Meanwhile, TCNQ·- act as a N source to form N-doped graphene, enhancing the electron conductivity of the composite. Benefiting from the stable structure and good conductivity, the Sb/NGNS-Q composite achieved good electrochemical battery performance for Li/Na ion batteries (LIBs/SIBs). At a current density of 0.1 A g-1, Sb/NGNS-Q exhibited a capacity of 615 mAh g-1 after cycling 200 times and 240 mAh g-1 after 100 cycles for LIBs and SIBs, respectively.

7.
Neuropsychologia ; 135: 107236, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31654648

RESUMO

The oblique effect (OE) describes the visuospatial advantage for identifying stimuli oriented horizontally or vertically rather than diagonally; little is known about brain aging and the OE. We investigated this relationship using the Judgment of Line Orientation (JLO) in 107 older adults (∼age = 67.8 ± 6.6; 51% female) together with neuropsychological tests of executive functioning (EF), attention/information processing (AIP), and neuroimaging. Only JLO lines falling between 36-54° or 126-144° were considered oblique. To quantify the oblique effect, we calculated z-scores for oblique errors (zOblique = #oblique errors/#oblique lines), and similarly, horizontal + vertical line errors (zHV), and a composite measure of oblique relative to HV errors (zOE). Composite z-scores of EF and AIP reflected domains associated with JLO performance. Graph theory analysis integrated T1-derived volumetry and diffusion MRI-derived white matter tractography into connectivity matrices analyzed for select network properties. Participants produced more zOblique than zHV errors (p < 0.001). Age was not associated with zOE adjusting for sex, education, and MMSE. Similarly adjusted linear regression models revealed that lower EF was associated with a larger oblique effect (p < 0.001). Modular analyses of neural connectivity revealed a differential patterns of network affiliation that varied by high versus low group status determined via median split of zOblique and zHV errors, separately. Older adults exhibit the oblique effect and it is associated with specific cognitive processes and regional brain networks that may facilitate future investigations of visuospatial preference in aging.

8.
Waste Manag ; 91: 128-138, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31203934

RESUMO

Gaseous emissions from municipal solid waste (MSW) disposal plants pose serious odor pollution and health risks. In this study, the emission of volatile organic compounds and carbon disulfide was compared in the main processing units of three disposal methods, i.e., landfilling, eco-mechanical biological treatment (EMBT) and anaerobic fermentation in a MSW disposal plant. Among the detected volatile compounds (VCs), the top ten odor compounds were methanethiol, dimethyl sulfide, dimethyl disulfide, carbon disulfide, styrene, m-xylene, 4-ethyltoluene, ethylbenzene, 2-hexyl ketone and n-hexane in the MSW disposal plant. Sulfur compounds were the main source of odor at the majority of sampling sites, and aromatic compounds were the dominant odor substrates at the tipping unit and sorting system of EMBT, while 2-hexanone was the major odor substrate at the tipping unit (AT) and sorting system (AS) of anaerobic fermentation and the landfill working surface. At AS and AT, the lifetime cancer risk values for 1,2-dichloroethane and trichloroethylene exceeded the carcinogenic risk value (>1.0E-04), and the hazard index values of naphthalene, trichloroethylene and acrolein all exceeded the acceptable level (>1). Therefore, special attention should be paid to VC emissions from MSW disposal facilities, and protection measures should be adopted for on-site workers to minimize health risks.


Assuntos
Poluentes Atmosféricos , Eliminação de Resíduos , Humanos , Odorantes , Resíduos Sólidos , Instalações de Eliminação de Resíduos
9.
Environ Sci Pollut Res Int ; 26(20): 20325-20343, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31093916

RESUMO

In this study, integrate electrical resistivity tomography (ERT) tests were carried out in a large-scale (5.0 × 4.0 × 7.5 m) MSW landfill cell to investigate the possibility of detecting perched leachate mounds, leachate level, and gas accumulation zones at wet landfills. The resistivity of both bulk waste and waste components at different moisture states were measured and the three-phase volumetric relationships of the waste pile were analyzed to better interpret the ERT test results in the large-scale cell. The following observations were given: (1) The relationship between resistivity and volumetric moisture content (VMC) of waste sample can be reasonably fitted by Archie's law. The resistivity of waste components at a saturated state was all lower than 21 Ω m. (2) A significant amount of void gas was entrapped in the underwater waste, being 30.4-34.8% of the whole waste pile in volume. (3) Low-resistivity zones (< 5.0 Ω m) were observed in the waste pile being fully drained under a gravity condition, which was believed to be related to a perched leachate. (4) The average VMC values of the waste layer below and above the leachate level were in the ranges of 46.5-53.1% and 28.1-41.3%, respectively. (5) Irregular variations of high-resistivity zones (> 40 Ω m) observed in the underwater waste were associated with the accumulation and dissipation of gas pressure. It was found that the "gas-breaking value" in the gas accumulation zone was up to 10.5 kPa greater than the pore liquid pressure in the stable methanogenesis stage. These findings shone a light on the possibility of using the ERT method as an efficient tool for mapping the gas/leachate distribution and improving operations at wet landfills.


Assuntos
Gases/análise , Tomografia/métodos , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise , Eletricidade , Eliminação de Resíduos/métodos
10.
Neuroimage ; 196: 152-160, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30980900

RESUMO

Cardiovascular disease risk factors (CVD-RFs) are associated with decreased gray and white matter integrity and cognitive impairment in older adults. Less is known regarding the interplay between CVD-RFs, brain structural connectome integrity, and cognition. We examined whether CVD-RFs were associated with measures of tract-based structural connectivity in 94 non-demented/non-depressed older adults and if alterations in connectivity mediated associations between CVD-RFs and cognition. Participants (age = 68.2 years; 52.1% female; 46.8% Black) underwent CVD-RF assessment, MRI, and cognitive evaluation. Framingham 10-year stroke risk (FSRP-10) quantified CVD-RFs. Graph theory analysis integrated T1-derived gray matter regions of interest (ROIs; 23 a-priori ROIs associated with CVD-RFs and dementia), and diffusion MRI-derived white matter tractography into connectivity matrices analyzed for local efficiency and nodal strength. A principal component analysis resulted in three rotated factor scores reflecting executive function (EF; FAS, Trail Making Test (TMT) B-A, Letter-Number Sequencing, Matrix Reasoning); attention/information processing (AIP; TMT-A, TMT-Motor, Digit Symbol); and memory (CVLT-II Trials 1-5 Total, Delayed Free Recall, Recognition Discriminability). Linear regressions between FSRP-10 and connectome ROIs adjusting for word reading, intracranial volume, and white matter hyperintensities revealed negative associations with nodal strength in eight ROIs (p-values<.05) and negative associations with efficiency in two ROIs, and a positive association in one ROI (p-values<.05). There was mediation of bilateral hippocampal strength on FSRP-10 and AIP, and left rostral middle frontal gyrus strength on FSRP-10 and AIP and EF. Stroke risk plays differential roles in connectivity and cognition, suggesting the importance of multi-modal neuroimaging biomarkers in understanding age-related CVD-RF burden and brain-behavior.


Assuntos
Encéfalo/patologia , Doenças Cardiovasculares/complicações , Cognição , Substância Cinzenta/patologia , Substância Branca/patologia , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Doenças Cardiovasculares/patologia , Doenças Cardiovasculares/psicologia , Conectoma/métodos , Feminino , Substância Cinzenta/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Substância Branca/diagnóstico por imagem
11.
Am J Clin Nutr ; 109(2): 361-368, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30698630

RESUMO

Background: Accumulating evidence suggests that higher Mediterranean diet (MedDiet) adherence is associated with higher global cognitive performance and brain structural integrity as well as decreased risk of Alzheimer disease (AD) and vascular dementia (VaD). Objectives: We directly examined cross-sectional associations between the MedDiet and cognitive and neuroimaging phenotypes associated with AD and VaD (separately) in a cohort of nondemented, nondepressed older adults. Methods: Community-dwelling older adults (n = 82; aged ∼68.8 y; 50% female, 50% minority) underwent dietary (Block Food Frequency Questionnaire 2005) and neuropsychological assessments and neuroimaging. MedDiet scores were quantified with the use of published criteria, and participants were divided into High and Low (median split) adherence groups. We focused our neuropsychological investigation on cognitive phenotypes primarily associated with AD [i.e., learning and memory (L&M)] and VaD (i.e., information processing and executive functioning). AD neuroimaging phenotypes consisted of hippocampal and dentate gyrus volumes quantified using T1-weighted images and the FreeSurfer 6.0 segmentation pipeline (http://surfer.nmr.mgh.harvard.edu). The VaD neuroimaging phenotype consisted of total white matter hyperintensity (WMH) volumes quantified using combined T1-weighted and T2-fluid-attenuated inversion recovery images. Neuroimaging metrics were adjusted for total intracranial volume. Separate multivariable linear regression models controlling for age, sex, education, body mass index, and caloric intake examined the associations between MedDiet groups (High compared with Low) and cognitive and neuroimaging outcomes. Results: When compared with the Low MedDiet group, the High MedDiet group was associated with better L&M performance and larger dentate gyri. MedDiet adherence was not associated with information processing, executive functioning, or WMH. Conclusion: Results highlight the association between increasing MedDiet adherence and specific cognitive and neuroimaging phenotypes that, when altered, are associated with AD.


Assuntos
Encéfalo , Transtornos Cognitivos , Cognição , Demência , Dieta Mediterrânea , Processos Mentais , Fenótipo , Idoso , Doença de Alzheimer/patologia , Doença de Alzheimer/prevenção & controle , Encéfalo/patologia , Transtornos Cognitivos/patologia , Transtornos Cognitivos/prevenção & controle , Estudos de Coortes , Estudos Transversais , Demência/patologia , Demência/prevenção & controle , Ingestão de Energia , Função Executiva , Feminino , Humanos , Modelos Lineares , Masculino , Memória , Neuroimagem/métodos , Testes Neuropsicológicos
12.
Artigo em Inglês | MEDLINE | ID: mdl-31892441

RESUMO

OBJECTIVE: We sought to determine whether the aspects of white matter connectivity implicated in major depression also relate to mild depressive symptoms in family dementia caregivers (dCGs). METHODS: Forty-one dCGs (average age=69 years, standard deviation=6.4) underwent a 7 Tesla 64-direction (12-minute) diffusion-weighted imaging sequence. We compared the fractional anisotropy (FA) of 11 white matter features between dCGs with (n=20) and without (n=21) depressive symptoms (Patient Health Questionnaire-9 scores ≥5). RESULTS: Caregivers reporting depression symptoms had lower FA in tracts connecting to the posterior cingulate cortex (Cohen's d = -0.9) and connecting dorsolateral prefrontal with rostral cingulate regions (Cohen's d = -1.2). CONCLUSIONS: Posterior cingulate and dorsolateral prefrontal-to-rostral cingulate white matter, implicated in prior studies of major depression, appear relevant to mild depression in dCGs.

14.
Netw Neurosci ; 2(3): 344-361, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30294703

RESUMO

We introduce NeuroCave, a novel immersive visualization system that facilitates the visual inspection of structural and functional connectome datasets. The representation of the human connectome as a graph enables neuroscientists to apply network-theoretic approaches in order to explore its complex characteristics. With NeuroCave, brain researchers can interact with the connectome-either in a standard desktop environment or while wearing portable virtual reality headsets (such as Oculus Rift, Samsung Gear, or Google Daydream VR platforms)-in any coordinate system or topological space, as well as cluster brain regions into different modules on-demand. Furthermore, a default side-by-side layout enables simultaneous, synchronized manipulation in 3D, utilizing modern GPU hardware architecture, and facilitates comparison tasks across different subjects or diagnostic groups or longitudinally within the same subject. Visual clutter is mitigated using a state-of-the-art edge bundling technique and through an interactive layout strategy, while modular structure is optimally positioned in 3D exploiting mathematical properties of platonic solids. NeuroCave provides new functionality to support a range of analysis tasks not available in other visualization software platforms.

15.
Front Psychiatry ; 9: 365, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30150944

RESUMO

Connectomics is a framework that models brain structure and function interconnectivity as a network, rather than narrowly focusing on select regions-of-interest. MRI-derived connectomes can be structural, usually based on diffusion-weighted MR imaging, or functional, usually formed by examining fMRI blood-oxygen-level-dependent (BOLD) signal correlations. Recently, we developed a novel method for assessing the hierarchical modularity of functional brain networks-the probability associated community estimation (PACE). PACE uniquely permits a dual formulation, thus yielding equivalent connectome modular structure regardless of whether positive or negative edges are considered. This method was rigorously validated using the 1,000 functional connectomes project data set (F1000, RRID:SCR_005361) (1) and the Human Connectome Project (HCP, RRID:SCR_006942) (2, 3) and we reported novel sex differences in resting-state connectivity not previously reported. (4) This study further examines sex differences in regard to hierarchical modularity as a function of age and clinical correlates, with findings supporting a basal configuration framework as a more nuanced and dynamic way of conceptualizing the resting-state connectome that is modulated by both age and sex. Our results showed that differences in connectivity between men and women in the 22-25 age range were not significantly different. However, these same non-significant differences attained significance in both the 26-30 age group (p = 0.003) and the 31-35 age group (p < 0.001). At the most global level, areas of diverging sex difference include parts of the prefrontal cortex and the temporal lobe, amygdala, hippocampus, inferior parietal lobule, posterior cingulate, and precuneus. Further, we identified statistically different self-reported summary scores of inattention, hyperactivity, and anxiety problems between men and women. These self-reports additionally divergently interact with age and the basal configuration between sexes.

16.
J Agric Food Chem ; 66(34): 8976-8982, 2018 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-30095908

RESUMO

Five new resorcylic acid lactones (RALs) hispidulactones A-E (1, 4, 5, 8, and 9), a new natural product (2), and four known ones (3, 6, 7, and 10) with different ring systems were isolated from the desert plant Chaetosphaeronema hispidulum. [corrected]. The new compounds were characterized by NMR data, CD spectra, and X-ray experiment. The new natural product (2) displayed strongly biological effects on the seedlings growth of Arabidopsis thaliana, Digitaria sanguinalis, and Echinochloa crusgalli with a dose-dependent relationship. Compounds 1, 2, and 6 were also tested cytotoxic activities against three cancer cell lines HCT116, Hela, and MCF7 and only did the new natural product (2) display biological activities with IC50 values at 54.86 ± 1.52, 4. 90 ± 0.02, and 20.04 ± 4.00 µM, respectively, whereas the IC50 values of the positive control cis-platinum were 11.36 ± 0.42, 3.54 ± 0.12, and 14.32 ± 1.01 µM, respectively.


Assuntos
Ascomicetos/química , Endófitos/química , Lactonas/química , Lactonas/farmacologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/microbiologia , Sobrevivência Celular/efeitos dos fármacos , Digitaria/crescimento & desenvolvimento , Digitaria/microbiologia , Echinochloa/crescimento & desenvolvimento , Echinochloa/microbiologia , Células HCT116 , Células HeLa , Humanos , Lactonas/isolamento & purificação , Estrutura Molecular
17.
J Alzheimers Dis ; 64(1): 149-169, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29865049

RESUMO

T1-weighted MRI has been extensively used to extract imaging biomarkers and build classification models for differentiating Alzheimer's disease (AD) patients from healthy controls, but only recently have brain connectome networks derived from diffusion-weighted MRI been used to model AD progression and various stages of disease such as mild cognitive impairment (MCI). MCI, as a possible prodromal stage of AD, has gained intense interest recently, since it may be used to assess risk factors for AD. Little work has been done to combine information from both white matter and gray matter, and it is unknown how much classification power the diffusion-weighted MRI-derived structural connectome could provide beyond information available from T1-weighted MRI. In this paper, we focused on investigating whether diffusion-weighted MRI-derived structural connectome can improve differentiating healthy controls subjects from those with MCI. Specifically, we proposed a novel feature-ranking method to build classification models using the most highly ranked feature variables to classify MCI with healthy controls. We verified our method on two independent cohorts including the second stage of Alzheimer's Disease Neuroimaging Initiative (ADNI2) database and the National Alzheimer's Coordinating Center (NACC) database. Our results indicated that 1) diffusion-weighted MRI-derived structural connectome can complement T1-weighted MRI in the classification task; 2) the feature-rank method is effective because of the identified consistent T1-weighted MRI and network feature variables on ADNI2 and NACC. Furthermore, by comparing the top-ranked feature variables from ADNI2, NACC, and combined dataset, we concluded that cross-validation using independent cohorts is necessary and highly recommended.


Assuntos
Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Conectoma , Imagem de Difusão por Ressonância Magnética/métodos , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade
18.
Bioresour Technol ; 248(Pt A): 122-133, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28634127

RESUMO

Bio-stability is a key feature for the utilization and final disposal of biowaste-derived residues, such as aerobic compost or vermicompost of food waste, bio-dried waste, anaerobic digestate or landfilled waste. The present paper reviews conventional methods and advanced techniques used for the assessment of bio-stability. The conventional methods are reclassified into two categories. Advanced techniques, including spectroscopic (fluorescent, ultraviolet-visible, infrared, Raman, nuclear magnetic resonance), thermogravimetric and thermochemolysis analysis, are emphasized for their application in bio-stability assessment in recent years. Their principles, pros and cons are critically discussed. These advanced techniques are found to be convenient in sample preparation and to supply diversified information. However, the viability of these techniques as potential indicators for bio-stability assessment ultimately lies in the establishment of the relationship of advanced ones with the conventional methods, especially with the methods based on biotic response. Furthermore, some misuses in data explanation should be noted.


Assuntos
Eliminação de Resíduos , Termogravimetria
19.
Hum Brain Mapp ; 39(1): 232-248, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28990258

RESUMO

Occurring in at least 1 in 3,000 live births, chromosome 22q11.2 deletion syndrome (22q11DS) produces a complex phenotype that includes a constellation of medical complications such as congenital cardiac defects, immune deficiency, velopharyngeal dysfunction, and characteristic facial dysmorphic features. There is also an increased incidence of psychiatric diagnosis, especially intellectual disability and ADHD in childhood, lifelong anxiety, and a strikingly high rate of schizophrenia spectrum disorders, which occur in around 30% of adults with 22q11DS. Using innovative computational connectomics, we studied how 22q11DS affects high-level network signatures of hierarchical modularity and its intrinsic geometry in 55 children with confirmed 22q11DS and 27 Typically Developing (TD) children. Results identified 3 subgroups within our 22q11DS sample using a K-means clustering approach based on several midline structural measures-of-interests. Each subgroup exhibited distinct patterns of connectome abnormalities. Subtype 1, containing individuals with generally healthy-looking brains, exhibited no significant differences in either modularity or intrinsic geometry when compared with TD. By contrast, the more anomalous 22q11DS Subtypes 2 and 3 brains revealed significant modular differences in the right hemisphere, while Subtype 3 (the most anomalous anatomy) further exhibited significantly abnormal connectome intrinsic geometry in the form of left-right temporal disintegration. Taken together, our findings supported an overall picture of (a) anterior-posteriorly differential interlobar frontotemporal/frontoparietal dysconnectivity in Subtypes 2 and 3 and (b) differential intralobar dysconnectivity in Subtype 3. Our ongoing studies are focusing on whether these subtypes and their connnectome signatures might be valid biomarkers for predicting the degree of psychosis-proneness risk found in 22q11DS. Hum Brain Mapp 39:232-248, 2018. © 2017 Wiley Periodicals, Inc.


Assuntos
Encéfalo/fisiopatologia , Conectoma , Síndrome de DiGeorge/fisiopatologia , Adolescente , Encéfalo/diagnóstico por imagem , Encéfalo/crescimento & desenvolvimento , Criança , Análise por Conglomerados , Conectoma/métodos , Síndrome de DiGeorge/diagnóstico por imagem , Feminino , Lateralidade Funcional , Humanos , Estudos Longitudinais , Masculino , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia
20.
ACS Appl Mater Interfaces ; 9(45): 39371-39379, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-28937731

RESUMO

A novel two-dimensional porous sandwich-like Si/carbon nanosheet is designed and successfully fabricated as an anode for superior lithium storage, where a porous Si nanofilm grows on the two sides of reduced graphene oxide (rGO) and is then coated with a carbon layer (denoted as C/Si-rGO-Si/C). The coexistence of micropores and mesopores in C/Si-rGO-Si/C nanosheets offers a rapid Li+ diffusion rate, and the porous Si provides a short pathway for electric transportation. Meanwhile, the coated carbon layer not only can promote to form a stable SEI layer, but also can improve the electric conductivity of nanoscale Si coupled with rGO. Thus, the unique nanostructures offer the resultant C/Si-rGO-Si/C electrode with high reversible capacity (1187 mA h g-1 after 200 cycles at 0.2 A g-1), excellent cycle stability (894 mA h g-1 after 1000 cycles at 1 A g-1), and high rate capability (694 mA h g-1 at 5 A g-1, 447 mA h g-1 at 10 A g-1).

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