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1.
Talanta ; 206: 120200, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514845

RESUMO

Highly-sensitive and contamination-free droplet digital PCR (ddPCR) is an enabling technology and widely needed for accurate quantification of nucleic acid in clinical applications. In this paper, a novel droplet reader was developed by combining a "quasi" confocal laser-induced fluorescence (LIF) cytometry with a delicate microfluidic chip design. The droplets with a size of 90 µm was illuminated at an out-of-focus position by two aligned laser beams to generate maximum fluorescent signal. Additionally, the lateral offset position of the microfluidic chip should be precisely tuned so that the bandwidth of the FAM and VIC channels were configured at the matching sizes. Then, PMT gain voltages and pneumatic pressures were optimized for better droplet detection efficiencies. An aerosol adsorption experiment was performed to demonstrate that there was no aerosol contamination, and detected copy numbers of both mutants and wild types scaled linearly with the expected input copy numbers (r2>0.998) with a LoB of 0.0 copies and LoD of 3.0 copies. The results demonstrated that this droplet reader with the delicate chip is a convenient, highly-sensitive and contamination-free to detect fluorescence signals inside droplets after ddPCR, which is highly promising for broad applications of ddPCR in clinical diagnosis.

2.
Meat Sci ; 159: 107919, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31472934

RESUMO

The effects of edible chitosan (CTS) coatings (0, 1, 2, and 3%) on Harbin red sausage storage stability at room temperature compared to vacuum packaging are discussed. The pH, moisture and L* of sausages decreased gradually, while the a*, TBARS, total aerobic bacteria (TAB) and lactic acid bacteria (LAB) increased significantly (P < 0.05) with the prolongation of storage time. In the same storage time, the storage stability was improved with the increase in the concentration of edible CTS coating, but there was no significant difference between 2% and 3% (P > 0.05). Although vacuum packaging can effectively maintain colour, moisture and reduce lipid oxidation, 2% CTS is outstanding in sustaining storage stability (pH and water distribution) and inhibition of microbial growth (TAB and LAB). In addition, no significant difference was observed between CTS coating and vacuum packaging on aroma and flavour (P > 0.05). In conclusion, CTS coating as edible packaging material can be used in meat products preservation.

3.
J Affect Disord ; 260: 334-341, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31521871

RESUMO

BACKGROUND: To investigate mental and physical health comorbidity with chronic back or neck pain in the Chinese population, and assess the level of disability associated with chronic back or neck pain. METHODS: Data were derived from a large-scale and nationally representative community survey of adult respondents on mental health disorders in China (n = 28,140). Chronic back or neck pain, other chronic pain conditions and chronic physical conditions were assessed by self-report. Mental disorders were assessed by the Composite International Diagnostic Interview (CIDI). Role disability during the past 30 days was assessed with the World Health Organization Disability Assessment Schedule (WHO-DAS-II). RESULTS: The 12-month prevalence of chronic back or neck pain was 10.8%. Most of respondents with chronic back or neck pain (71.2%) reported at least one other comorbid condition, including other chronic pain conditions (53.4%), chronic physical conditions (37.9%), and mental disorders (23.9%). It was found by logistic regression that mood disorders (OR = 3.7, 95%CI:2.8-4.8) showed stronger association with chronic back or neck pain than anxiety disorders and substance disorders. Most common chronic pains and physical conditions were significantly associated with chronic back or neck pain. Chronic back or neck pain was associated with role disability after controlling for demographics and for comorbidities. Physical and mental comorbidities explained 0.7% of the association between chronic back or neck pain and role disability. CONCLUSIONS: Chronic back or neck pain and physical-mental comorbidity is very common in China and chronic back or neck pain may increase the likelihood of other physical and mental diseases. This presents a great challenge for both clinical treatment and public health education. We believe that further study needs to be conducted to improve the diagnostic and management skills for comorbidity conditions.

4.
J Nanosci Nanotechnol ; 20(2): 1232-1237, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383123

RESUMO

CO atmosphere plasma and first H2 then CO plasma were attempted to substitute the traditional "calcination-reduction-carburization" processes for the preparation of metallic cobalt phase with hcp structure. CoRu/SiO2 catalyst precursor was prepared via incipient wetness impregnation. Characterization and catalytic results showed that CO could be decomposed in glow discharge plasma field, a large fraction of carbon species was deposited as elementary substance on the catalyst surface, while some of the carbon reacted with cobalt and formed cobalt carbide, which could transform into Co0 with hcp structure after reduction. The hcp structured cobalt containing catalysts showed higher initial Fischer-Tropsch synthesis activity than both calcined and air plasma treated samples.

5.
Sensors (Basel) ; 19(21)2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31671560

RESUMO

This work presents a cost-effective shadow mask printing approach to fabricate flexible sensors. The liquid-state sensing material can be directly brushed on a flexible substrate through a shadow mask. The ink leakage issue which often occurs in printed electronics is addressed with a custom taping scheme. A simple thermal compression bonding approach is also proposed to package the functional area of the sensor. To verify the feasibility and robustness of the proposed fabrication approach, a prototyped strain gauge displacement sensor is fabricated using carbon ink as the sensing material and a flexible polyimide (PI) film as the substrate. Once the substrate is deformed, cracks in the solidified ink layer can cause an increased resistance in the conductive path, thus achieving function of stable displacement/strain sensing. As a demonstration for displacement sensing application, this sensor is evaluated by studying its real-time resistance response under both static and dynamic mechanical loading. The fabricated sensor shows a comparable performance (with a gauge factor of ~17.6) to those fabricated using costly lithography or inkjet printing schemes, while with a significantly lower production cost.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31670938

RESUMO

With the minimization and higher power of electronic devices, materials with effective heat dissipation and high electrical insulation have attracted relentless interest. Especially, highly thermally conductive, highly electrically insulating but low filler content of polymer-based composites are desirable. Herein, a facile and eco-friendly cotton candy-templated method (CTM) to construct three-dimensional heat transport pathways inside epoxy resin is reported. The fabricated Al2O3/epoxy composites with enhanced heat transport capability feature a 15-fold increase in thermal conductivity at a filler content of 36.2 vol% compared to pristine epoxy. Moreover, the remarkable thermal conductive property has excellent stability over a wide range of temperature before and after heating and cooling cycles. Meanwhile, the CTM composite still retain highly electrical insulation. The cotton candy-templated method proposed in this work is a new avenue for the preparation of three-dimensional heat transport pathways within polymer-based composites for microelectronic packaging and electrical engineering systems.

7.
Phys Rev Lett ; 123(11): 116104, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31573246

RESUMO

Bound states in the continuum in periodic photonic systems like photonic crystal slabs are proved to be accompanied by vortex polarization singularities on the photonic bands in the momentum space. The winding structures of polarization states not only widen the field of topological physics but also show great potential that such systems could be applied in polarization manipulating. In this Letter, we report the phenomenon that by in-plane inversion (C_{2}) symmetry breaking, pairs of circularly polarized states could spawn from the eliminated bound states in the continuum. Along with the appearance of the circularly polarized states as the two poles of the Poincaré sphere together with linearly polarized states covering the equator, full coverage on the Poincaré sphere could be realized. As an application, ellipticity modulation of linear polarization is demonstrated in the visible frequency range. This phenomenon provides a new degree of freedom in modulating polarization. The C points could also find applications in light-matter interactions. Further studying and manipulating the reported polarization singularities may lead to novel phenomena and physics in radiation modulating and topological photonics.

8.
Antivir Ther ; 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31566576

RESUMO

BACKGROUND: Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) infections are highly endemic in Sub-Saharan Africa and Nigeria while HBV/HIV co-infection is not uncommon. Antiretroviral (ART)-treatment for HIV can affect HBV whereby antiviral resistance mutations in the HBV-genome can be selected. Here, we determined the prevalence of resistance mutations among ART-experienced and ART-naïve HIV/HBV co-infected patients in Southwestern Nigeria. METHODS: Eighty-one serum samples from HBV/HIV co-infected patients who were either ART-naïve or received lamivudine (3TC)-containing ART-therapy and HBV mono-infected patients were analysed. HBsAg was detected using ELISA. HBV-positive samples were confirmed by PCR amplification of the surface and polymerase regions. Mutations conferring drug resistance to HBV were analysed by direct sequencing. Phylogenetic analysis was performed to identify the HBV genotype. RESULTS: Of the 81 HBsAg-positive samples, 27 had detectable HBV DNA by real time PCR with mean viral loads of 6.77log IU/ml. Phylogenetic analyses showed a predominance of HBV genotype E. A high prevalence (22.2%; 6/27) of HBV resistance mutations among ART-experienced HBV/HIV-co-infected patients was detected. However, a relatively high selection rate of resistance mutations in drug naïve HIV/HBV co-infected (3.7%; 1/27) and in HBV-mono-infected patients potential drug resistance mutations (7.4%; 2/27) were also observed. HBV polymerase amino acid substitutions found included rtV173L, rtL180M, rtM204V, rtK212R, rtS213T, rtV214A, rtL229V and rtP237A/S. CONCLUSIONS: Drug resistant mutations were detected frequently in ART-experienced HIV/HBV patients. Well-coordinated antiviral therapy for HIV patients co-infected with HBV should include proper HBV diagnosis and resistance testing to minimise the emergence and spread of antiviral drug resistance.

9.
ACS Nano ; 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31589407

RESUMO

Silicon (Si), a promising candidate for next-generation lithium-ion battery anodes, is still hindered by its volume change issue for (de)lithiation, thus resulting in tremendous capacity fading. Designing carbon-modified Si materials with a void-preserving structure (Si@void@C) can effectively solve this issue. The preparation of Si@void@C, however, usually depended on template-based routes or chemical vapor deposition, which involve toxic reagents, tedious operation processes, and harsh conditions. Here, a facile templateless approach for preparing Si@void@C materials is reported through controlling the growth kinetics of resin, without the use of toxic hydrofluoric acid or harsh conditions. This approach allows great flexibility in tuning the crucial parameters of Si@void@C, such as the carbon shell thickness, the reserved void size, and the number of Si cores coated by a carbon shell. The optimized Si@void@C delivers a large specific capacity (1993.2 mAh g-1 at 0.1 A g-1), excellent rate performance (799.4 mAh g-1 at 10.0 A g-1), and long cycle life (73.5% capacity retention after 1000 cycles at 2.0 A g-1). In addition, a full cell fabricated with a Si@void@C anode and commercial LiFePO4 cathode also displays an impressive cycling performance.

10.
Gynecol Endocrinol ; : 1-5, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31595804

RESUMO

The aim of this study was to evaluate the effect of virus infection on estradiol (E2) production in human ovarian granulosa cells. Polyriboinosinic polyribocytidylic acid [Poly (I: C)], a synthetic analog of viral double stranded RNA that can be recognized by Toll like receptor 3 (TLR3), was used to imitate virus infection. Granulosa cells (GCs) obtained from patients undergoing in vitro fertilization and embryo transfer (IVF-ET) were cultured in vitro and treated with Poly (I: C), FSH, or both. Concentration of E2 was assayed by electrochemiluminescence. The mRNA and protein expression of TLR3 and aromatase were determined by real-time quantitative PCR (qPCR) and Western blot, respectively. The results showed that expression of TLR3 mRNA was significantly increased after Poly (I: C) stimulation. Poly (I: C) decreased E2 synthesis in FSH-treated GCs. Poly (I: C) inhibited the expression of aromatase in FSH-treated GCs. This study demonstrated that Poly (I: C) inhibits the synthesis of estradiol by granulosa cells under the stimulation of FSH, which might contribute to disturbance of follicular development and ovulation.

11.
J Biosci Bioeng ; 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31587942

RESUMO

The corrosive issues are comprehensively caused in oilfield rejection system, in which sulfide is one of (bio-)chemical factors leading to high corrosive rate and blocking problem. Generally, aerobic treatment is a well-established and cost-effective unit for sulfide removal before oilfield wastewater reinjection. However, the residual dissolved oxygen (DO), which causes chemical, biological and electrochemical corrosion to water injection pipeline equipment, is still high after multi-stage filtration of DO removal. Here, a novel system to achieve quick and efficient DO removal through a three-electrode (cathode-anode-cathode)-upflow bioelectrochemical reactor (RCAC) was constructed before wastewater reinjection. Bioelectrodes were well established by utilizing organic matters of oilfield wastewater and conducted extracellular electron transport to achieve a steady DO removal from ∼5 mg/L to 0.01 mg/L (HRT 6 h), the DO removal efficiency reached approximately 100%, and the downside biocathode made the largest contribution for DO removal. In the treated wastewater, the corrosion rate of stainless steel N80 ultimately declined over 30 days testing. As a result of DO removal and ammonia conversion to nitrate by bioelectrodes, the corrosive microorganisms were substantially changed. Especially, sulfate-reducing bacteria (SRB) on the surface of N80 immersed in treated wastewater were decreased in abundance; while nitrate-reducing bacteria (NRB) enriched more, which can compete with SRB to prevent biological corrosion.

12.
Adv Mater ; : e1902890, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31588637

RESUMO

Domain wall nanoelectronics is a rapidly evolving field, which explores the diverse electronic properties of the ferroelectric domain walls for application in low-dimensional electronic systems. One of the most prominent features of the ferroelectric domain walls is their electrical conductivity. Here, using a combination of scanning probe and scanning transmission electron microscopy, the mechanism of the tunable conducting behavior of the domain walls in the sub-micrometer thick films of the technologically important ferroelectric LiNbO3 is explored. It is found that the electric bias generates stable domains with strongly inclined domain boundaries with the inclination angle reaching 20° with respect to the polar axis. The head-to-head domain boundaries exhibit high conductance, which can be modulated by application of the sub-coercive voltage. Electron microscopy visualization of the electrically written domains and piezoresponse force microscopy imaging of the very same domains reveals that the gradual and reversible transition between the conducting and insulating states of the domain walls results from the electrically induced wall bending near the sample surface. The observed modulation of the wall conductance is corroborated by the phase-field modeling. The results open a possibility for exploiting the conducting domain walls as the electrically controllable functional elements in the multilevel logic nanoelectronics devices.

14.
Int J Biol Macromol ; 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31622702

RESUMO

Flavonoids in tea plant are the important bioactive compounds for both human health and taste quality. Multidrug and Toxic compound Extrusion (MATE) proteins could improve flavonoid accumulations by transporting and sequestering the flavonoid in vacuoles. We identified 41 putative MATE genes in tea plants. The similar intron-exon structures of tea MATEs clustered within the same gene clade. The correlation analysis of tea flavonoid and transcriptome data showed that TEA006173 might be involve in the tea flavonoid accumulation. The RT-PCR results confirmed that TEA006173 showed high expression in the young leaf tissues. Tertiary structure prediction has shown that TEA006173 contained the 12 helices with three active pockets, comprising 13 critical residues. The present study provided the structural variations and expression patterns of tea MATEs and it would be helpful for taste and nutrient quality improvement in tea plant.

15.
Artigo em Inglês | MEDLINE | ID: mdl-31621099

RESUMO

OBJECTIVES: To explore the factors associated with utilization of oral health services among Chinese adults and older adults according to the Andersen Behavior Model. METHODS: Data from the 4th National Oral Health Survey (2015-2016) in China were used. A total of 7206 people (3669 adults aged 35-44 years and 3537 older adults aged 65-74 years) were included in our analysis. Oral health service utilization in the past 12 months was the outcome variable. Explanatory variables were selected according to the Andersen Behavior Model. Descriptive statistics and bivariate associations (chi-square tests) were analysed, followed by hierarchical Poisson regression models, which were conducted to determine the factors associated with oral health service utilization. RESULTS: In total, 21.4% (95% CI: 19.4%-23.7%) of adults (35-44 years old) and 20.7% (95% CI: 18.6%-22.9%) of older adults (65-74 years old) utilized oral health services in the past 12 months. Nearly 80% of adults (78.7%, 95% CI: 74.0%-82.7%) and more than 90% of older adults (93.7%, 95% CI: 91.0%-95.6%) visited a dentist for treatment. Adults aged 35-44 years old who were female (IRR: 1.15, 95% CI: 1.00-1.33, P = .047), had good oral health knowledge and attitudes (IRR: 1.30, 95% CI: 1.06-1.59, P = .011), perceived their oral health status as fair (IRR:1.51, 95% CI:1.24-1.85, P < .001) or poor/very poor (IRR:2.52, 95% CI:2.01-3.18, P < .001) and had a decayed, missing and filled teeth (DMFT) index >0 (IRR: 1.52, 95% CI: 1.11-2.09, P = .009) were more likely to report dental visits in the past 12 months. Older adults who utilized oral health services tended to be female (IRR: 1.32, 95% CI: 1.09-1.59, P = .004); to be covered by Urban Resident Basic Medical Insurance (URBMI) (IRR: 1.56, 95% CI: 1.18-2.05, P = .002), Urban Employee Basic Medical Insurance (UEBMI) (IRR: 1.69, 95% CI: 1.32-2.16, P < .001) or government medical insurance (GMI) (IRR: 1.03, 95% CI:1.01-2.16, P = .044); to have a high education level (IRR: 1.37, 95% CI: 1.08-1.74, P = .010); to have an income level in the 2nd tertile (IRR: 1.44, 95% CI: 1.13-1.84, P = .003) or 3rd tertile (IRR:1.52, 95% CI:1.18-1.95, P = .001); and to perceive their oral health status as poor or very poor (IRR: 1.53, 95% CI: 1.21-1.95, P = .001). CONCLUSIONS: Sex and self-perceived oral health status were associated with oral health utilization among Chinese population. Additionally, for older adults, education level, household income and insurance coverage were determinants of dental service use. These findings can aid in creating more targeted policies to increase the use of dental services by Chinese adults.

16.
Drug Des Devel Ther ; 13: 3529-3538, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31631977

RESUMO

Objective: Chondrocyte apoptosis has also been strongly correlated with the severity of cartilage damage and matrix depletion in an osteoarthritis (OA) joint. Therefore, pharmacological inhibitors of apoptosis may provide a novel treatment option for patients with OA. Aucubin, a natural compound isolated from Eucommia ulmoides, has been proved to possess antioxidative and anti-apoptotic properties. However, anti-osteoarthritis effect of aucubin in animal model and anti-apoptotic response of aucubin in OA chondrocytes remain unclear. This study aimed to determine whether aucubin could slow progression of OA in a mouse model and inhibit the IL-1ß-induced chondrocyte apoptosis. Methods: OA severity and articular cartilage degradation were evaluated by Safranin-O staining, Hematoxylin-eosin (H&E) staining, and Osteoarthritis Research Society International (OARSI) standards. Chondrocyte viability was observed by Cell Counting Kit-8 (CCK8) and live/dead cells assay; the apoptotic rate of chondrocytes was evaluated by flow cytometry (FCM) with Annexin V-FITC/PI kit. Mediators of apoptosis were tested by Western blot of Bax, caspase-3, caspase-9, and Bcl-2 expression. The intracellular levels of Reactive oxygen species (ROS) were assessed by the probe of 2,7-Dichlorofluorescin diacetate (DCFH-DA). Results: The articular cartilage in the limb with destabilization of the medial meniscus (DMM) exhibited early OA-like manifestations characterized by proteoglycan loss, cartilage fibrillation, and erosion, with lower OARSI score. Oral administration of aucubin remarkably attenuated the loss of proteoglycan and the articular cartilage erosion and decreased the OARSI scores underwent DMM surgery. Aucubin treatment significantly reverses IL-1ß-induced cytotoxicity and attenuated the IL-1ß-induced chondrocyte apoptosis. In addition, aucubin can significantly inhibit mediators of apoptosis in rat primary chondrocytes. Furthermore, aucubin remarkably attenuated the IL-1ß-induced intracellular ROS production. Conclusion: Our findings suggest that aucubin has a protective effect on articular cartilage and slowing progression of OA in a mouse model. This protective effect may result from inhibiting chondrocyte apoptosis and excessive ROS production.

17.
Acta Pharmacol Sin ; 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31645661

RESUMO

Extracellular matrix (ECM) deposition following reactive oxygen species (ROS) overproduction has a key role in diabetic nephropathy (DN), thus, antioxidant therapy is considered as a promising strategy for treating DN. Here, we investigated the therapeutic effects of AB38b, a novel synthetic α, ß-unsaturated ketone compound, on the oxidative stress (OS) and ECM accumulation in type 2 diabetes mice, and tried to clarify the mechanisms underlying the effects in high glucose (HG, 30 mM)-treated mouse glomerular mesangial cells (GMCs). Type 2 diabetes model was established in mice with high-fat diet feeding combined with streptozocin intraperitoneal administration. The diabetic mice were then treated with AB38b (10, 20, 40 mg· kg-1· d-1, ig) or a positive control drug resveratrol (40 mg· kg-1· d-1, ig) for 8 weeks. We showed that administration of AB38b or resveratrol prevented the increases in malondialdehyde level, lactate dehydrogenase release, and laminin and type IV collagen deposition in the diabetic kidney. Simultaneously, AB38b or resveratrol markedly lowered the level of Keap1, accompanied by evident activation of Nrf2 signaling in the diabetic kidney. The underlying mechanisms of antioxidant effect of AB38b were explored in HG-treated mouse GMCs. AB38b (2.5-10 µM) or resveratrol (10 µM) significantly alleviated OS and ECM accumulation in HG-treated GMCs. Furthermore, AB38b or resveratrol treatment effectively activated Nrf2 signaling by inhibiting Keap1 expression without affecting the interaction between Keap1 and Nrf2. Besides, AB38b treatment effectively suppressed the ubiquitination of Nrf2. Taken together, this study demonstrates that AB38b ameliorates experimental DN through antioxidation and modulation of Keap1/Nrf2 signaling pathway.

18.
Nature ; 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578525

RESUMO

Transcription and pre-mRNA splicing are key steps in the control of gene expression and mutations in genes regulating each of these processes are common in leukaemia1,2. Despite the frequent overlap of mutations affecting epigenetic regulation and splicing in leukaemia, how these processes influence one another to promote leukaemogenesis is not understood and, to our knowledge, there is no functional evidence that mutations in RNA splicing factors initiate leukaemia. Here, through analyses of transcriptomes from 982 patients with acute myeloid leukaemia, we identified frequent overlap of mutations in IDH2 and SRSF2 that together promote leukaemogenesis through coordinated effects on the epigenome and RNA splicing. Whereas mutations in either IDH2 or SRSF2 imparted distinct splicing changes, co-expression of mutant IDH2 altered the splicing effects of mutant SRSF2 and resulted in more profound splicing changes than either mutation alone. Consistent with this, co-expression of mutant IDH2 and SRSF2 resulted in lethal myelodysplasia with proliferative features in vivo and enhanced self-renewal in a manner not observed with either mutation alone. IDH2 and SRSF2 double-mutant cells exhibited aberrant splicing and reduced expression of INTS3, a member of the integrator complex3, concordant with increased stalling of RNA polymerase II (RNAPII). Aberrant INTS3 splicing contributed to leukaemogenesis in concert with mutant IDH2 and was dependent on mutant SRSF2 binding to cis elements in INTS3 mRNA and increased DNA methylation of INTS3. These data identify a pathogenic crosstalk between altered epigenetic state and splicing in a subset of leukaemias, provide functional evidence that mutations in splicing factors drive myeloid malignancy development, and identify spliceosomal changes as a mediator of IDH2-mutant leukaemogenesis.

19.
J R Soc Interface ; 16(159): 20190366, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31575346

RESUMO

Insect colour is extremely diverse and produced by a large number of pigmentary and nanostructural mechanisms. Considerable research has been dedicated to these optical mechanisms, with most of it focused on chromatic colours, such as blues and greens, and less on achromatic colours like white and gold. Moreover, studies on the evolution of these colours are less common and largely limited to inferences from extant organisms, in part because of the limited amount and types of available fossil material. Here, we directly compare nanostructure and colour of extant and amber-preserved (approx. 15 and 99 Myr old, respectively) gold-coloured representatives of micromoths (Lepidoptera: Micropterigidae) and springtails (Collembola: Tomoceridae). Using electron microscopy, microspectrophotometry and finite domain time difference optical modelling, we show that golden coloration in the extant micromoth is produced by nanometre-scale crossribs that function as zero-order diffraction gratings and in the springtail by a diffraction grating without crossribs. Surprisingly, nanostructure and thus predicted colour of the amber-preserved specimens were nearly identical to those of their extant counterparts. Removal of amber enabled direct colour measurement of the fossil micromoth and further revealed that its colour matched both that of the extant specimen and the predicted colour, providing further support for our optical models. Our data thus clearly show an early origin and striking conservation of scale nanostructures and golden coloration, suggesting strong selection pressure either on the colour itself or on the mechanisms that produce the colour. Furthermore, we show the thus-far untapped potential for the use of amber-preserved specimens in studies on the evolution of organismal coloration.

20.
Biomed Pharmacother ; 120: 109498, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31634780

RESUMO

BACKGROUND: A high glucose level is usually considered to be the factor that induces tissue and cell dysfunction and damage, commonly known as "glucose toxicity". OBJECTIVE: This study aimed to explore the effects and the potential molecular mechanisms of high glucose on myoblast differentiation and insulin sensitivity. MATERIALS AND METHODS: C2C12 cells were cultured in differentiation medium containing 25, 40, or 60 mM glucose for 1, 3, or 5 days. E-MHC positive area and GLUT4 fluorescence were evaluated through Immunofluorescence. The expression of Myf5, MyoD, myogenin were measured by performing western blot and qRT-PCR. The protein expression of GLUT4 on cell membrane and glucose uptake in C2C12 myotubes were measured through western blot and 2-NBDG assay. AKT activator SC79 and inhibitor MK2206 was utilized to reveal the important role of AKT signaling in myogenesis and insulin sensitivity inhibited by high glucose. RESULTS: 60 mM glucose inhibits myogenesis by decreasing the expression of MyoD and myogenin, and induces insulin resistance by reducing both basal and insulin-stimulated GLUT4 expressions and glucose uptakes. The influences of high glucose on myogenesis and IR was related to decreased AKT activation. SC79 rescued the inhibition of high glucose on myogenesis and attenuated IR. MK2206 inhibits the myogenic differentiation and induces IR. CONCLUSION: The present study reveals that high glucose inhibited myogenisis accompanied by inducing IR, through AKT signaling inhibition, which may help to further research for resisting degenerative muscular diseases caused by glucose metabolism disorders.

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