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1.
Artigo em Inglês | MEDLINE | ID: mdl-31980830

RESUMO

There are approximately 12 000 new individuals with spinal cord injury (SCI) each year, and close to 200 000 individuals live with a SCI-related disability in the United States. The majority of patients with SCI have bladder dysfunction as a result of their injury, with over 75% unable to void volitionally following their injury. In patients with traumatic SCI, intermittent catheterization is commonly recommended, but a lack of adherence to clean intermittent catheterization (CIC) has been observed, with up to 50% discontinuing CIC within 5 yr of injury. The Finetech Brindley Bladder System (FBBS) is an implantable sacral nerve stimulator for improving bladder function in patients with SCI, avoiding the need for CIC. The FDA-approved implantation (Humanitarian Device Exemption H980008) of the FBBS is combined with a posterior rhizotomy to reduce reflex contraction of the bladder, improving continence. However, the posterior rhizotomy is irreversible and has unwanted effects; therefore, the current FDA-approved implantation is being studied without rhizotomy as part of a clinical trial (Investigational Device Exemption G150201) (ClinicalTrials.gov Identifier: NCT02978638). In this video, we present a case of a 66-yr-old female who presented 40-yr status post-T12 SCI, resulting in complete paraplegia and neurogenic bladder not satisfactorily controlled with CIC. We demonstrate the operative steps to complete the implantation of the device without rhizotomy in the first patient enrolled as part of the clinical trial Electrical Stimulation for Continence After SCI (NCT02978638). Appropriate IRB and patient consent were obtained.

2.
Sci Total Environ ; 706: 135719, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31940728

RESUMO

Understanding the impacts of multiple climatic and edaphic factors on forest diversity, structure and biomass is crucial to predicting how forests will react to global environmental change. Here, we addressed how do forest structural attributes (i.e. top 1% big, top 25% big medium and small trees; in terms of tree height, diameter, and crown), species richness, and aboveground biomass respond to temperature-related and water-related climatic factors as well as to edaphic factors. By assuming disturbance as a constant factor in the study forests, we hypothesize that water-related and temperature-related climatic factors play contrasting roles whereas edaphic factors play an additional role in shaping forest diversity, structure and aboveground biomass in species-poor and structurally-complex forests. We used forest inventory and environmental factors data from 248 forest plots (moist temperate, semi-humid, and semi-arid) across 12 sites in Iran. We developed multiple linear mixed-effect models for each response variable by using multiple climatic and edaphic factors as fixed effects whereas sites as a random effect. Top 1% big, top 25% big, medium, and small trees enhanced with mean annual temperature but declined with water-related climatic (i.e. mean annual precipitation, cloud cover, potential evapotranspiration, and wet day frequency) factors, whereas soil texture (i.e. sand content) and pH were of additional importance. Species richness increased with precipitation and cloud cover but decreased with temperature, potential evapotranspiration, soil fertility and sand content. Aboveground biomass increased along temperature gradient but decreased with potential evapotranspiration, clay and sand contents. Temperature seemed to be the main driver underlying the increase in forest structure (i.e. diameter-related attributes) and biomass whereas precipitation did so for species richness. We argue that the impacts of multiple climatic factors on forest structural attributes, diversity and biomass should be properly evaluated in order to better understand the responses of species-poor forests to climate change.

3.
Front Neurol ; 10: 1167, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31736869

RESUMO

Background: Head computed tomography (CT) scans are widely used in acute head injury for medical triage and surgical decisions, yet there are contradictions on the prognostic value of different head CT classifications. The intra-axial (axial) lesion vs. extra-axial lesion is a well-known systemic classification but has not been applied into clinical practice since there is no evidence-based support for its prognostic value. Hypothesis: Axial injury is related to worse functional independence compared to extra-axial injury at admission to and discharge from acute rehabilitation hospitalization. Design: Observational retrospective study. Settings and participants: Data from 71 participants who were enrolled at an acute rehabilitation hospital in the Northern California Traumatic Brain Injury Model System of Care (NCTBIMS) between 2005 and 2018 were included in the analysis. Main outcome measure and statistical analysis: Results of non-contrast head CT within the first 7 days after injury were analyzed to determine those with axial vs. extra-axial lesions. Functional Independence Measure (FIM) total scores were compared between the axial vs. extra-axial groups at admission and discharge using parametric and non-parametric tests. Results: There were no statistically significant group differences in FIM total scores at rehabilitation admission and discharge between the axial group and extra-axial groups. Conclusion: In this cohort of patients there was no evidence to support the hypothesis that axial injury is related to worse functional independence compared to extra-axial injury at rehabilitation admission and discharge. Utilizing MRI findings or other outcome measures, such as the 10 meter ambulation test or cognitive tests, may provide better sensitivity to potential functional differences.

4.
Sci Total Environ ; 697: 134153, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31479909

RESUMO

Topography, grazing disturbances, and soil textures are the main determining factors of natural herbaceous plant communities. Yet, while interesting efforts have been made to link topography, soil conditions, grazing disturbances, species diversity and aboveground biomass, we still lack a comprehensive understanding of how soil textural properties and grazing disturbances co-vary along topographic gradients, and how they jointly shape vegetation quantity and quality in natural rangelands. In this study, we used abiotic and biotic datasets from 735 quadrats of natural rangelands located in the southern Alborz Province of Iran. We quantified topographic variables (i.e. elevation, slope, and aspect), grazing disturbance intensities, soil textural properties (i.e. gravel, sand, silt, and clay contents) as predictor variables. Vegetation quantity (i.e. aboveground biomass, vegetation coverage, and vegetation density) and quality (i.e. species richness, Shannon's diversity, and species evenness) variables were used as response variables. We used boosted regression trees (BRT) models for assessing the relative contribution and effects of multiple predictors on each response variable. We found that vegetation quantity and quality were jointly explained by topography, grazing disturbances, and soil textural properties. Vegetation quantity increased gradually or showed a hump-backed type pattern whereas vegetation quality decreased with elevation. Intensive grazing decreased vegetation quantity of shrubs and graminoids, which in turn determined the vegetation quantity of whole-community (i.e. all species). Higher vegetation quantity of shrubs was located on sandy soils while high vegetation quality was located on silty soils, whereas forbs and graminoids showed an opposite trend. Although the drivers of rangelands' vegetation quantity and quality are not mutually exclusive, the magnitude, shape and complexity of these relationships are highly dependent on plant growth forms. This study suggests that high grazing at lower elevation should be managed properly in order to conserve graminoids and to enhance their functioning in line with forbs and shrubs species.


Assuntos
Monitoramento Ambiental , Pradaria , Herbivoria , Biodiversidade , Biomassa , Carbono , Ecossistema , Irã (Geográfico) , Desenvolvimento Vegetal , Plantas , Solo
5.
Ecol Indic ; 1072019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31478008

RESUMO

Understanding the effects of plant species diversity and trait composition on aboveground biomass is a central focus of ecology and has important implications for biodiversity conservation. However, the simultaneous direct and indirect effects of soil nutrients, species asynchrony, functional trait diversity, and trait composition for explaining the community temporal stability of aboveground biomass remain underrepresented in natural forests. Here, we hypothesized that species asynchrony relative to soil nutrients, functional trait diversity, and trait composition plays a central role in stabilizing the community temporal stability of natural forests. We tested this hypothesis using a structural equation model based on 10-year continuous monitoring data (i.e., three-time repeated forest inventories) in both second-growth and old-growth temperate forests in northeast China. Our results showed that the community temporal stability of aboveground biomass was driven by a strong direct positive effect of species asynchrony in both second-growth and old-growth temperate forests, whereas functional trait diversity and composition (i.e. community-weighted mean of leaf nitrogen content) were of additional importance in an old-growth forest only. Functional trait diversity decreased community-weighted mean of leaf nitrogen content in an old-growth forest, whereas this relationship was non-significant in a second-growth forest. Soil nutrients had non-significant effects on the community temporal stability of both second-growth and old-growth forests. Species asynchrony was the direct determinant of the community temporal stability of aboveground biomass in temperate forests. The direct effect of species asynchrony increased with forest succession, implying that temporal niche differentiation and facilitation increase over time. This study suggests that managing forests with mixtures of both early and late successional species or shade intolerant and tolerant species, not only species diversity, is important for maintaining forest stability in a changing environment. We argue that the species asynchrony effect is crucial to understand the underlying ecological mechanisms for a diversity-biomass relationship in natural forests.

6.
J Mass Spectrom ; 54(8): 667-675, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31183927

RESUMO

We present a procedure for the determination of the isotopic ratios of silicon and oxygen from the same aliquot of anhydrous silicate material. The sample is placed in a bromine pentafluoride atmosphere as it is heated with a CO2 laser system releasing silicon tetrafluoride and oxygen gasses. The oxygen gas is then purified to remove other reaction by-products through several liquid nitrogen traps before being captured onto a molecular sieve and transferred to an isotope ratio mass spectrometer. The silicon tetrafluoride gas is then purified using a supplementary line by repeatedly freezing to -196°C with liquid nitrogen and then thawing with an ethanol slurry at -110°C through a series of metal and Pyrex traps. The purified gas is then condensed into a Pyrex sample tube before it is transferred to an isotope ratio mass spectrometer for silicon isotope ratio measurements. This system has silicon yields of greater than 90% for pure quartz, olivine, and garnet standards and has a reproducibility of ±0.1‰ (2σ) for pure quartz for both oxygen and silicon isotope measurements. Meteoritic samples were also successfully analyzed to demonstrate this system's ability to measure the isotopic ratio composition of bulk powders with precision. This unique technique allows for the fluorination of planetary material without the need for wet chemistry. Though designed to analyze small aliquots of meteoritic material (1.5 to 3 mg), this approach can also be used to investigate refractory terrestrial samples where traditional fluorination is not suitable.

7.
Glob Chang Biol ; 25(8): 2810-2824, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31120573

RESUMO

Large-diameter, tall-stature, and big-crown trees are the main stand structures of forests, generally contributing a large fraction of aboveground biomass, and hence play an important role in climate change mitigation strategies. Here, we hypothesized that the effects of large-diameter, tall-stature, and big-crown trees overrule the effects of species richness and remaining trees attributes on aboveground biomass in tropical forests (i.e., we term the "big-sized trees hypothesis"). Specifically, we assessed the importance of: (a) the "top 1% big-sized trees effect" relative to species richness; (b) the "99% remaining trees effect" relative to species richness; and (c) the "top 1% big-sized trees effect" relative to the "99% remaining trees effect" and species richness on aboveground biomass. Using environmental factor and forest inventory datasets from 712 tropical forest plots in Hainan Island of southern China, we tested several structural equation models for disentangling the relative effects of big-sized trees, remaining trees attributes, and species richness on aboveground biomass, while considering for the full (indirect effects only) and partial (direct and indirect effects) mediation effects of climatic and soil conditions, as well as interactions between species richness and trees attributes. We found that top 1% big-sized trees attributes strongly increased aboveground biomass (i.e., explained 55%-70% of the accounted variation) compared to species richness (2%-18%) and 99% remaining trees attributes (6%-10%). In addition, species richness increased aboveground biomass indirectly via increasing big-sized trees but via decreasing remaining trees. Hence, we show that the "big-sized trees effect" overrides the effects of remaining trees attributes and species richness on aboveground biomass in tropical forests. This study also indicates that big-sized trees may be more susceptible to atmospheric drought. We argue that the effects of big-sized trees on species richness and aboveground biomass should be tested for better understanding of the ecological mechanisms underlying forest functioning.


Assuntos
Biodiversidade , Árvores , Biomassa , China , Mudança Climática , Clima Tropical
8.
Trop Anim Health Prod ; 51(7): 1927-1933, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30972624

RESUMO

The present study aimed at investigating the percent prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in equines and associated personnel. A total of 150 swabs of equines and 50 nasal swab samples of associated personnel were collected. These samples were processed in mannitol salt broth for enrichment. A total of 175 nasal swab samples changed the broth color from pink to yellow which were detected as samples containing S. aureus. These samples were processed further on specific media, namely mannitol salt agar, Staph-110, and blood agar, for phenotypic and Gram's staining-based confirmation of S. aureus isolates. Out of these 175 S. aureus-positive samples, 150 were of equine and 25 were of human origin. Identification of MRSA isolates in 175 S. aureus-positive samples was carried out by antimicrobial susceptibility testing by disc diffusion method. Results showed the presence of MRSA in 87 samples, out of which 81 samples were collected from equines and six samples from humans. Results of antibiotic testing revealed that percentage positivity of MRSA was higher (54%) in equines as compared with the associated personnel (24%). Most resistant antibiotics against MRSA isolates were oxacillin and methicillin while linezolid was found to be the most sensitive antibiotic against MRSA. In conclusion, our findings indicated prevalence of MRSA in equines and associated personnel evidencing an occupational risk of contracting MRSA from horses.


Assuntos
Antibacterianos/farmacologia , Cavalos/microbiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Ágar , Animais , Estudos Transversais , Meios de Cultura , Humanos , Meticilina , Resistência a Meticilina , Testes de Sensibilidade Microbiana , Prevalência , Zoonoses
9.
Ecology ; 100(5): e02650, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30742311

RESUMO

Forests play a key role in regulating the global carbon cycle, and yet the abiotic and biotic conditions that drive the demographic processes that underpin forest carbon dynamics remain poorly understood in natural ecosystems. To address this knowledge gap, we used repeat forest inventory data from 92,285 trees across four large permanent plots (4-25 ha in size) in temperate mixed forests in northeast China to ask the following questions: (1) How do soil conditions and stand age drive biomass demographic processes? (2) How do vegetation quality (i.e., functional trait diversity and composition) and quantity (i.e., initial biomass stocks) influence biomass demographic processes independently from soil conditions and stand age? (3) What is the relative contribution of growth, recruitment, and mortality to net biomass change? Using structural equation modeling, we showed that all three demographic processes were jointly constrained by multiple abiotic and biotic factors and that mortality was the strongest determinant on net biomass change over time. Growth and mortality, as well as functional trait diversity and the community-weighted mean of specific leaf area (CWMSLA ), declined with stand age. By contrast, high soil phosphorous concentrations were associated with greater functional diversity and faster dynamics (i.e., high growth and mortality rates), but associated with lower CWMSLA and initial biomass stock. More functionally diverse communities also had higher recruitment rates, but did not exhibit faster growth and mortality. Instead, initial biomass stocks and CWMSLA were stronger predictors of biomass growth and mortality, respectively. By integrating the full spectrum of abiotic and biotic drivers of forest biomass dynamics, our study provides critical system-level insights needed to predict the possible consequences of regional changes in forest diversity, composition, structure and function in the context of global change.


Assuntos
Ecossistema , Florestas , Biomassa , Carbono , China , Demografia , Árvores
10.
PLoS One ; 14(2): e0212057, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30811442

RESUMO

Biodiversity conservation, plant growth and spatial distribution of plant species are the central issues in contemporary community ecology. Ephemeral stream may influence soil properties, which in turn may determine biodiversity and function of an ecosystem in alluvial fan of arid desert region. Ephemeral stream is one of the most common natural disturbances, yet the effects of the ephemeral stream on plant communities in terms of species diversity and plant species distribution remain poorly studied. In this study, the information of species distribution, ephemeral stream beds ('washes'), and the characteristics of plant growth, i.e. height, crown area, were interpreted at different heights using the images of low altitude unmanned aerial vehicle (UAV). After that, soil properties such as soil texture (sand, silt and clay), soil water content, pH, soil organic matter, soil electric conductivity, soil bulk density and the percentage of gravel content, and their relationships with UAV data were assessed in order to explore the influences of ephemeral stream on species diversity, plant growth characteristics and species distribution in an alluvial fan of arid desert region. The results showed that deep-rooted plants were only distributed in washes whereas shallow-rooted plants were distributed in both washes and the outside of washes ('non-washes'). Species richness was significantly higher in washes than that in non-washes whereas the opposite pattern was true for abundance. Soil properties, plant height and crown area were higher in washes than that in non-washes. Plant height, crown area and the total number of individual plants increased with increasing wash width and per unit length of stream flow. This study highlights that the coupling factors of ephemeral stream, such as soil erosion, particle transport and sedimentation, can dramatically cause changes in soil properties and total number of individual plants, and hence, can influence species diversity, plant growth characteristics and spatial distribution of plant species in an alluvial fan of arid desert regions.


Assuntos
Biodiversidade , Desenvolvimento Vegetal/fisiologia , Clima Desértico , Monitoramento Ambiental/métodos , Concentração de Íons de Hidrogênio , Modelos Lineares , Rios , Solo/química
11.
Sci Total Environ ; 656: 45-54, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30502734

RESUMO

Most of the previous studies have shown that the relationship between functional diversity and aboveground biomass is unpredictable in natural tropical forests, and hence also contrary to the predictions of niche complementarity effect. However, the direct and indirect effects of functional diversity on aboveground biomass via tree crown complementarity in natural forests remain unclear, and this potential ecological mechanism is yet to be understood across large-scale ecological gradients. Here, we hypothesized that tree crown complementarity would link positive functional diversity and aboveground biomass due to increasing species coexistence through efficient capture and use of available resources in natural tropical forests along large-scale ecological gradients. We quantified individual tree crown variation, functional divergence of tree maximum height, and aboveground biomass using data from 187,748 trees, in addition to the quantifications of climatic water availability and soil fertility across 712 tropical forests plots in Hainan Island of Southern China. We used structural equation modeling to test the tree crown complementarity hypothesis. Aboveground biomass increased directly with increasing functional diversity, individual tree crown variation and climatic water availability. As such, functional diversity enhanced individual tree crown variation, thereby increased aboveground biomass indirectly via individual tree crown variation. Additional positive effects of climatic water availability and soil fertility on aboveground biomass were accounted indirectly via increasing individual tree crown variation and/or functional diversity. This study shows that tree crown complementarity mediates the positive effect of functional diversity on aboveground biomass through light capture and use along large-scale ecological gradients in natural forests. This study also mechanistically shows that tree crown complementarity increases species coexistence through maintenance of functional diversity, which in turn enhances aboveground biomass in natural tropical forests. Hence, managing natural forests with the aim of increasing tree crown complementarity holds promise for enhancing carbon storage while conserving biodiversity in functionally-diverse communities.


Assuntos
Biodiversidade , Biomassa , Florestas , Árvores/fisiologia , China
12.
Sci Total Environ ; 647: 1211-1221, 2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30180329

RESUMO

Climatic water availability is a key spatial driver of species distribution patterns in natural forests. Yet, we do not fully understand the importance of climatic water availability relative to temperature, and climate relative to edaphic factors for multiple biotic attributes across large-scale elevational gradients in natural forests. Here, we modelled multiple abiotic factors (elevation, climate, and edaphic factors) with each of the taxonomic-related (Shannon's species diversity, species richness, species evenness, and Simpson's dominance) and tree size or biomass-related (individual tree size variation, functional dominance and divergence, and aboveground biomass) biotic attributes through boosted regression trees (BRT) models, using biophysical data from 247,691 trees across 907 plots in tropical forests in Hainan Island of Southern China. The tested multiple abiotic factors explained simultaneously 43, 50, 36, 45, 37, 50, 17 and 46%, respectively, of the variations in Shannon's species diversity, species richness, species evenness, Simpson's dominance, individual tree size variation, functional dominance, functional divergence and aboveground biomass. After the large influences of elevation (i.e. 30.43 to 62.83%), climatic water availability accounted for most (i.e. 15.52 to 25.30%) of the variations in all biotic attributes. Beside the increasing trend with elevational gradients, taxonomic diversity increased strongly with climatic water availability whereas tree size or biomass-related biotic attributes showed strong decreasing and increasing trends. Tree size or biomass-related rather than taxonomic-related biotic attributes also decreased apparently with mean annual temperature. Most of the biotic attributes monotonically increased with soil fertility but decreased with soil pH, whereas soil textural properties had mostly negligible influences. This study strongly reveals that future climate change (i.e. a decrease in climatic water availability with an increase in mean annual temperature) is thus likely to have a substantial influence on the biotic attributes in the studied tropical forests across large-scale elevational gradients.

13.
Conf Proc IEEE Eng Med Biol Soc ; 2019: 6387-6390, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31947304

RESUMO

The feasibility of using normalized cumulative difference attenuation (NCDA) map for tracking the spatial and temporal evolution of temperature during microwave hyperthermia experiment on in-vitro phantoms is explored in this study. The NCDA maps were estimated from the beamformed ultrasound radio frequency (RF) data using a regularized log spectral difference (RLSD) technique. The NCDA maps were estimated at different time instants for the entire period of the experiment. The contour maps of the NCDA and the ground truth temperature map, obtained using an infra-red(IR) thermal camera corresponding to the ultrasound imaging plane, showed that NCDA was able to locate the axial and lateral co-ordinates of the hotspot with the error of <; 1.5 mm axially and <; 0.1 mm laterally. The error in the estimated hotspot area was less than 8 %. This preliminary in-vitro study suggests that NCDA maps estimated using RLSD may have potential in evaluating the spatio-temporal evolution of temperature and may help in the development of ultrasound-based image-guided temperature monitoring system for microwave hyperthermia.

14.
Kidney Int Rep ; 3(6): 1328-1335, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30450459

RESUMO

Introduction: Medial arterial calcification is common in chronic kidney disease (CKD) and portends poor clinical outcomes, but its progression relative to the severity of CKD and the role of other risk factors is unknown because of the lack of reliable quantification. Methods: Calcification of breast arteries detected by mammography, which is exclusively medial and correlates with medial calcification in peripheral arteries and with cardiovascular outcomes, was used to measure the progression of medial arterial calcification in women with CKD and end-stage renal disease (ESRD). Measurements showed intra- and interobserver correlations of 0.98, an interstudy variability of 8% to 11%, and a correlation with computed tomographic measurements of 0.92. Results: Progression of calcification was measured in 60 control subjects (estimated glomerular filtration rate (eGFR) ≥ 90 ml/min per 1.73 m2) and 137 subjects with CKD (eGFR < 90 ml/min per 1.73 m2). Progression in control subjects was linear over time and independent of age. The rate of progression was increased in CKD but only at eGFR < 40 ml/min per 1.73 m2 (median, 8.1 vs. 3.9 mm/breast/yr in controls; P = 0.006). Progression accelerated markedly in subjects with ESRD (median, 20 mm/breast/yr; n = 36), but did not differ from controls after kidney transplantation (n = 25). Diabetes significantly augmented progression in subjects with CKD and ESRD but not in controls. Conclusion: Mammography is a convenient and reliable method to measure the progression of medial arterial calcification. Progression does not increase until advanced stages of CKD, accelerates markedly in ESRD, and returns to control rates after kidney transplantation. Diabetes significantly increases progression in CKD and ESRD.

15.
Int J Mol Sci ; 19(4)2018 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-29587367

RESUMO

Cancer is a highly lethal disease that is characterized by aberrant cell proliferation, migration, and adhesion, which are closely related to the dynamic changes of cytoskeletons and cytoskeletal-adhesion. These will further result in cell invasion and metastasis. Plakins are a family of giant cytolinkers that connect cytoskeletal elements with each other and to junctional complexes. With various isoforms composed of different domain structures, mammalian plakins are broadly expressed in numerous tissues. They play critical roles in many cellular processes, including cell proliferation, migration, adhesion, and signaling transduction. As these cellular processes are key steps in cancer development, mammalian plakins have in recent years attracted more and more attention for their potential roles in cancer. Current evidence shows the importance of mammalian plakins in various human cancers and demonstrates mammalian plakins as potential biomarkers for cancer. Here, we introduce the basic characteristics of mammalian plakins, review the recent advances in understanding their biological functions, and highlight their roles in human cancers, based on studies performed by us and others. This will provide researchers with a comprehensive understanding of mammalian plakins, new insights into the development of cancer, and novel targets for cancer diagnosis and therapy.


Assuntos
Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias/metabolismo , Plaquinas/genética , Plaquinas/metabolismo , Animais , Movimento Celular , Proliferação de Células , Citoesqueleto/metabolismo , Humanos , Camundongos , Camundongos Knockout , Invasividade Neoplásica , Metástase Neoplásica , Neoplasias/patologia , Transdução de Sinais
16.
Sci Total Environ ; 630: 422-431, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-29482149

RESUMO

Forests play an important role in regulating the global carbon cycle. Yet, how abiotic (i.e. soil nutrients) and biotic (i.e. tree diversity, stand structure and initial biomass) factors simultaneously contribute to aboveground biomass (coarse woody) productivity, and how the relative importance of these factors changes over succession remain poorly studied. Coarse woody productivity (CWP) was estimated as the annual aboveground biomass gain of stems using 10-year census data in old growth and secondary forests (25-ha and 4.8-ha, respectively) in northeast China. Boosted regression tree (BRT) model was used to evaluate the relative contribution of multiple metrics of tree diversity (taxonomic, functional and phylogenetic diversity and trait composition as well as stand structure attributes), stand initial biomass and soil nutrients on productivity in the studied forests. Our results showed that community-weighted mean of leaf phosphorus content, initial stand biomass and soil nutrients were the three most important individual predictors for CWP in secondary forest. Instead, initial stand biomass, rather than diversity and functional trait composition (vegetation quality) was the most parsimonious predictor of CWP in old growth forest. By comparing the results from secondary and old growth forest, the summed relative contribution of trait composition and soil nutrients on productivity decreased as those of diversity indices and initial biomass increased, suggesting the stronger effect of diversity and vegetation quantity over time. Vegetation quantity, rather than diversity and soil nutrients, is the main driver of forest productivity in temperate mixed forest. Our results imply that diversity effect for productivity in natural forests may not be so important as often suggested, at least not during the later stage of forest succession. This finding suggests that as a change of the importance of different divers of productivity, the environmentally driven filtering decreases and competitively driven niche differentiation increases with forest succession.


Assuntos
Ciclo do Carbono , Monitoramento Ambiental , Florestas , Biodiversidade , Biomassa , China
17.
Int J Mol Sci ; 19(2)2018 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-29370110

RESUMO

Osteoporosis is a progressive skeletal disease characterized by decreased bone mass and degraded bone microstructure, which leads to increased bone fragility and risks of bone fracture. Osteoporosis is generally age related and has become a major disease of the world. Uncovering the molecular mechanisms underlying osteoporosis and developing effective prevention and therapy methods has great significance for human health. Mesenchymal stem cells (MSCs) are multipotent cells capable of differentiating into osteoblasts, adipocytes, or chondrocytes, and have become the favorite source of cell-based therapy. Evidence shows that during osteoporosis, a shift of the cell differentiation of MSCs to adipocytes rather than osteoblasts partly contributes to osteoporosis. Thus, uncovering the molecular mechanisms of the osteoblast or adipocyte differentiation of MSCs will provide more understanding of MSCs and perhaps new methods of osteoporosis treatment. The MSCs have been applied to both preclinical and clinical studies in osteoporosis treatment. Here, we review the recent advances in understanding the molecular mechanisms regulating osteoblast differentiation and adipocyte differentiation of MSCs and highlight the therapeutic application studies of MSCs in osteoporosis treatment. This will provide researchers with new insights into the development and treatment of osteoporosis.


Assuntos
Adipócitos/citologia , Diferenciação Celular , Células-Tronco Mesenquimais/citologia , Osteoblastos/citologia , Osteoporose/terapia , Adipócitos/metabolismo , Animais , Humanos , Transplante de Células-Tronco Mesenquimais/efeitos adversos , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/metabolismo , Osteoblastos/metabolismo , Osteoporose/etiologia
18.
J Environ Manage ; 205: 308-318, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29031134

RESUMO

The positive relationships between biodiversity and aboveground biomass are important for biodiversity conservation and greater ecosystem functioning and services that humans depend on. However, the interaction effects of plant coverage and biodiversity on aboveground biomass across plant growth forms (shrubs, forbs and grasses) in natural rangelands are poorly studied. Here, we hypothesized that, while accounting for environmental factors and disturbance intensities, the positive relationships between plant coverage, biodiversity, and aboveground biomass are ubiquitous across plant growth forms in natural rangelands. We applied structural equation models (SEMs) using data from 735 quadrats across 35 study sites in semi-steppe rangelands in Iran. The combination of plant coverage and species richness rather than Shannon's diversity or species diversity (a latent variable of species richness and evenness) substantially enhance aboveground biomass across plant growth forms. In all selected SEMs, plant coverage had a strong positive direct effect on aboveground biomass (ß = 0.72 for shrubs, 0.84 for forbs and 0.80 for grasses), followed by a positive effect of species richness (ß = 0.26 for shrubs, 0.05 for forbs and 0.09 for grasses), and topographic factors. Disturbance intensity had a negative effect on plant coverage, whereas it had a variable effect on species richness across plant growth forms. Plant coverage had a strong positive total effect on aboveground biomass (ß = 0.84 for shrubs, 0.88 for forbs, and 0.85 for grasses), followed by a positive effect of species richness, and a negative effect of disturbance intensity across plant growth forms. Our results shed light on the management of rangelands that is high plant coverage can significantly improve species richness and aboveground biomass across plant growth forms. We also found that high disturbance intensity due to heavy grazing has a strong negative effect on plant coverage rather than species richness in semi-steppe rangelands. This study suggests that proper grazing systems (e.g. rotational system) based on carrying capacity and stocking rate of a rangeland may be helpful for biodiversity conservation, better grazing of livestock, improvement of plant coverage and enhancement of aboveground biomass.


Assuntos
Biodiversidade , Desenvolvimento Vegetal , Biomassa , Ecossistema , Irã (Geográfico) , Plantas
19.
Sci Total Environ ; 615: 895-905, 2018 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-29017131

RESUMO

Rangelands play an important role in the biodiversity conservation and ecosystem functions. Yet, few studies have assessed the effects of biotic and abiotic factors on aboveground biomass across plant growth forms and at whole-community level in rangelands. Here, we hypothesized that aboveground biomass is driven by both biotic (plant coverage, species richness and evenness) and abiotic factors (soil textural properties and topographic factors) but biotic factors may best predict aboveground biomass, probably due to small spatial scale. To test this hypothesis, we performed multiple linear mixed model by including abiotic and biotic factors as fixed effects while sites aspects and plant community types across sites, and disturbance intensities as random effects, using data from 735 quadrats across 35 sites in semi-steppe rangelands in Iran. The optimal model for shrubs showed that aboveground biomass was positively related to plant coverage, species richness, elevation, sand, silt and clay. Aboveground biomass of forbs and grasses was positively related to plant coverage, species richness, elevation and slope. Whole-community aboveground biomass was positively related to plant coverage, species richness and elevation, but negatively to species evenness and slope. We conclude that higher aboveground biomass is related to high species richness and plant coverage, and located on high elevation and/or slope across plant growth forms while having medium-coarse-textured to fine-textured soils for adaptation of shrubs only. Few dominant species or niche overlap in whole-community may also drive high aboveground biomass, and located on high elevation with gentle slope. Therefore, we found support for both the niche complementarity and selection effects across plant growth forms and at whole-community. In addition, this study shows that plant coverage is the best proxy for aboveground biomass in the studied rangelands.

20.
Cancer Sci ; 108(10): 1953-1958, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28782898

RESUMO

Cancer is a polygenic disease characterized by uncontrolled growth of normal body cells, deregulation of the cell cycle as well as resistance to apoptosis. The spectraplakin protein microtubule actin cross-linking factor 1 (MACF1) plays an essential function in various cellular processes, including cell proliferation, migration, signaling transduction and embryo development. MACF1 is also involved in processes such as metastatic invasion in which cytoskeleton organization is a critical element that contributes to tumor progression in various human cancers. Aberrant expression of MACF1 initiates the tumor cell proliferation, and migration and metastasis in numerous cancers, such as breast cancer, colon cancer, lung cancer and glioblastoma. In this review, we summarized the current knowledge of MACF1 and its critical role in different human cancers. This will be helpful for researchers to investigate the novel functional role of MACF1 in human cancers and as a potential target to enhance the efficacy of therapeutic treatment modalities.


Assuntos
Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Neoplasias/metabolismo , Processamento Alternativo , Movimento Celular , Proliferação de Células , Progressão da Doença , Humanos , Invasividade Neoplásica , Transdução de Sinais
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