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1.
Artigo em Inglês | MEDLINE | ID: mdl-31957920

RESUMO

Sichuan mountainous black-bone (SMB) chicken is a small-sized black-feathered chicken breed with low amount of meat, while Dahen (DH) chicken has a larger body size and a faster growth rate. MicroRNAs (miRNAs) are involved in various physiological processes, but their role in chicken muscle growth remains unclear. We aimed to investigate the miRNAs and pathways participating in the muscle growth of chicken. MiRNA profiles of four SMB chickens and four DH chickens were detected by small RNA sequencing. A total of 994 known miRNAs were identified, among which gga-miR-1a-3p, gga-miR-148-3p and gga-miR-133a-3p exhibited the highest enrichment in both breeds of chickens. Thirty-two miRNAs were differently expressed between SMB and DH chickens. The differently expressed miRNAs were mainly associated with fatty acid metabolism, immunity and MAPK activation-related processes. Kyoto encyclopaedia of genes and genomes (KEGG) analysis showed that miRNAs were involved in the immunity-related and MAPK signalling pathways. Moreover, miR-204 was downregulated in DH chicken compared with SMB chicken, and significantly inhibited the expression of MAP3K13, which is involved in the MAPK pathway. It was confirmed through luciferase reporter assays that miR-204 specifically inhibited the activity of MAP3K13. Our results helped demonstrate the potential molecular mechanisms of muscle growth in chickens and provide valuable information for chicken breeding.

2.
Aging Cell ; 19(3): e13097, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31991048

RESUMO

Telomere shortening follows a developmentally regulated process that leads to replicative senescence of dividing cells. However, whether telomere changes are involved in postmitotic cell function and aging remains elusive. In this study, we discovered that the level of the TRF2 protein, a key telomere-capping protein, declines in human skeletal muscle over lifetime. In cultured human myotubes, TRF2 downregulation did not trigger telomere dysfunction, but suppressed expression of the mitochondrial Sirtuin 3 gene (SIRT3) leading to mitochondrial respiration dysfunction and increased levels of reactive oxygen species. Importantly, restoring the Sirt3 level in TRF2-compromised myotubes fully rescued mitochondrial functions. Finally, targeted ablation of the Terf2 gene in mouse skeletal muscle leads to mitochondrial dysfunction and sirt3 downregulation similarly to those of TRF2-compromised human myotubes. Altogether, these results reveal a TRF2-SIRT3 axis controlling muscle mitochondrial function. We propose that this axis connects developmentally regulated telomere changes to muscle redox metabolism.

3.
FASEB J ; 34(1): 525-539, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31914679

RESUMO

Whereas much is known about the genes regulated by ΔNp63α in keratinocytes, how ΔNp63α is regulated is less clear. During studies with the hydroxylase, factor inhibiting hypoxia-inducible factor 1 (FIH-1), we observed increases in epidermal ΔNp63α expression along with proliferative capacity in a conditional FIH-1 transgenic mouse. Conversely, loss of FIH-1 in vivo and in vitro attenuated ΔNp63α expression. To elucidate the FIH-1/p63 relationship, BioID proteomics assays identified FIH-1 binding partners that had the potential to regulate p63 expression. FIH-1 interacts with two previously unknown partners, Plectin1 and signal transducer and activator of transcription 1 (STAT1) leading to the regulation of ΔNp63α expression. Two known interactors of FIH-1, apoptosis-stimulating of P53 protein 2 (ASPP2) and histone deacetylase 1 (HDAC1), were also identified. Knockdown of ASPP2 upregulated ΔNp63α and reversed the decrease in ΔNp63α by FIH-1 depletion. Additionally, FIH-1 regulates growth arrest and DNA damage-45 alpha (GADD45α), a negative regulator of ΔNp63α by interacting with HDAC1. GADD45α knockdown rescued reduction in ΔNp63α by FIH-1 depletion. Collectively, our data reveal that FIH-1 positively regulates ΔNp63α in keratinocytes via variety of signaling partners: (a) Plectin1/STAT1, (b) ASPP2, and (c) HDAC1/GADD45α signaling pathways.

4.
Ultramicroscopy ; 208: 112861, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31670053

RESUMO

The orbital angular momentum (OAM) sorter is a new electron optical device for measuring an electron's OAM. It is based on two phase elements, which are referred to as the "unwrapper" and "corrector" and are placed in Fourier-conjugate planes in an electron microscope. The most convenient implementation of this concept is based on the use of electrostatic phase elements, such as a charged needle as the unwrapper and a set of electrodes with alternating charges as the corrector. Here, we use simulations to assess the role of imperfections in such a device, in comparison to an ideal sorter. We show that the finite length of the needle and the boundary conditions introduce astigmatism, which leads to detrimental cross-talk in the OAM spectrum. We demonstrate that an improved setup comprising three charged needles can be used to compensate for this aberration, allowing measurements with a level of cross-talk in the OAM spectrum that is comparable to the ideal case.

5.
Polymers (Basel) ; 11(12)2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31766705

RESUMO

A new strategy for nanocrystal encapsulation, release and application based on pH-sensitive covalent dynamic hyperbranched polymers is described. The covalent dynamic hyperbranched polymers, with multi-arm hydrophobic chains and a hydrophilic hyperbranched poly(amidoamine) (HPAMAM) core connected with pH-sensitive imine bonds (HPAMAM-DA), could encapsulate CdTe quantum dots (QDs) and Au nanoparticles (NPs). Benefiting from its pH response property, CdTe QDs and Au NPs encapsulated by HPAMAM-DA could be released to aqueous phase after imine hydrolysis. The released CdTe/HPAMAM and Au/HPAMAM nanocomposites exhibited excellent biological imaging behavior and high catalytic activities on p-nitrophenol hydrogenation, respectively.

6.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(4): 1111-1117, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31418365

RESUMO

OBJECTIVE: To investigate the apoptosis-inducing effect of Ginsenoside (Rh2) on human acute T lymphoblastic leukemia Jurkat cells and it mechamism. METHODS: The effects of different concentration of Rh2 (0, 10 , 20, 40 and 80 µg/ml) on the proliferation activity of Jurkat cells were detected by methyl thiazolyl tetrazolium (MTT) method, and the semi-inhibitory concentration (IC50) of Rh2 on Jurkat cells at 48 h was calculated. Microscopy and Hoechst 33258 fluorescence staining were used to observe the apoptosis of Jurkat cells treated with IC50 Rh2 for 48 h. And then, the cell experiment was divided into 4 groups: control, Rh2 (IC50), PI3K inhibitor LY294002 (50 µmol/l) and Rh2 (IC50) + LY294002 (50 µmol/l). After synchronous culture for 48 h, the apoptosis and cycle changes of Jurkat cells were detected by using PI single staining and Annexin V-FITC/PI double staining, respectively. Western blot was used to detect the expression level of apoptosis-related protein BAX, BCL-2, Cleaved-Caspasase 3, cell cycle-related protein Cyclin D1 and PI3K/AKT signaling pathway-related protein AKT and p-AKT. RESULTS: Rh2 (10-80 µg/ml) inhibited the Jurkat cell proliferation in a dose-time dependent manner (r48h = 0.999, P<0.01; r80 µg/ml = 0.991; P>0.05), accompanied by obvious morphological changes of apoptosis cells. Flow cytometry showed that compared with the control group, the cell apoptosis rate in Rh2 or LY294002 group significantly increased, and the cell cycle was mostly blocked in G0/G1 phase. However, the cell apoptosis and cell cycle block in Rh2+LY294002 group were more significant than that in Rh2 and LY294002 group. Western blot showed that compared with the control group, Rh2 significantly promoted the expression of BAX and Cleaved-Caspasase 3, inhibited the expression of BCL-2, Cyclin D1 and p-AKT, furthermore LY294002 significantly promoted this effect. CONCLUSION: Rh2 can induce the apoptosis of Jurkat cells in time-dose dependent manner, moreover, Rh2 also can result in an obvious block of Jurkat cells at G0/G1, that may be closely related to a series of apoptotic signaling cascades mediated by Rh2 inhibiting PI3K/AKT pathway.


Assuntos
Ginsenosídeos , Leucemia-Linfoma Linfoblástico de Células Precursoras , Apoptose , Proliferação de Células , Humanos , Células Jurkat , Fosfatidilinositol 3-Quinases
7.
Invest Ophthalmol Vis Sci ; 60(10): 3570-3583, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31419300

RESUMO

Purpose: Single-cell RNA-sequencing (scRNA-seq) was used to interrogate the relatively rare stem (SC) and early transit amplifying (TA) cell populations in limbal/corneal epithelia from wild-type and autophagy-compromised mice. Methods: We conducted scRNA-seq on ocular anterior segmental tissue from wild-type and beclin 1-deficient (beclin1+/-) mice, using a 10X Gemomics pipeline. Cell populations were distinguished by t-distributed stochastic neighbor embedding. Seurat analysis was conducted to compare gene expression profiles between these two groups of mice. Differential protein expression patterns were validated by immunofluorescence staining and immunoblotting. Results: Unbiased clustering detected 10 distinct populations: three clusters of mesenchymal and seven clusters of epithelial cells, based on their unique molecular signatures. A discrete group of mesenchymal cells expressed genes associated with corneal stromal SCs. We identified three limbal/corneal epithelial cell subpopulations designated as stem/early TA, mature TA, and differentiated corneal epithelial cells. Thioredoxin-interacting protein and PDZ-binding kinase (PBK) were identified as novel regulators of stem/early TA cell quiescence. PBK arrested corneal epithelial cells in G2/M phase of the cell cycle. Beclin1+/- mice displayed a decrease in proliferation-associated (Ki67, Lrig1) and stress-response (H2ax) genes. The most increased gene in beclin1+/- mice was transcription factor ATF3, which negatively regulates limbal epithelial cell proliferation. Conclusions: Establishment of a comprehensive atlas of genes expressed by stromal and epithelial cells from limbus and cornea forms the foundation for unraveling regulatory networks among these distinct tissues. Similarly, scRNA-seq profiling of the anterior segmental epithelia from wild-type and autophagy-deficient mice provides new insights into how autophagy influences proliferation in these tissues.


Assuntos
Autofagia/fisiologia , Epitélio Anterior/citologia , Limbo da Córnea/citologia , Células-Tronco Mesenquimais/citologia , RNA/genética , Transcriptoma/genética , Animais , Proteína Beclina-1/fisiologia , Biomarcadores/metabolismo , Contagem de Células , Ciclo Celular , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Epitélio Anterior/metabolismo , Feminino , Imuno-Histoquímica , Limbo da Córnea/metabolismo , Glicoproteínas de Membrana/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA
8.
Neurosci Biobehav Rev ; 104: 240-254, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31330196

RESUMO

Pattern classification and stratification approaches have increasingly been used in research on Autism Spectrum Disorder (ASD) over the last ten years with the goal of translation towards clinical applicability. Here, we present an extensive scoping literature review on those two approaches. We screened a total of 635 studies, of which 57 pattern classification and 19 stratification studies were included. We observed large variance across pattern classification studies in terms of predictive performance from about 60% to 98% accuracy, which is among other factors likely linked to sampling bias, different validation procedures across studies, the heterogeneity of ASD and differences in data quality. Stratification studies were less prevalent with only two studies reporting replications and just a few showing external validation. While some identified strata based on cognition and intelligence reappear across studies, biology as a stratification marker is clearly underexplored. In summary, mapping biological differences at the level of the individual with ASD is a major challenge for the field now. Conceptualizing those mappings and individual trajectories that lead to the diagnosis of ASD, will become a major challenge in the near future.

9.
Nano Lett ; 19(9): 6363-6369, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31361961

RESUMO

The construction of multiple types of active sites on the surface of a metallic catalyst can markedly enhance its catalytic activity toward specific reactions. Here, we show that heterophase gold nanowires (Au NWs) with multiple types of active surface sites can be synthesized using an etching-assisted process, yielding the highest reported turnover frequency (TOF) for Au catalysts toward the silane oxidation reaction by far. We use synchrotron powder X-ray diffraction (PXRD) and aberration-corrected (scanning) transmission electron microscopy (TEM) to show that the Au NWs contain heterophase structures, planar defects, and surface steps. Moreover, the contribution to the catalytic performance from each type of active sites was clarified. Surface steps on the Au NW catalysts, which were identified using aberration-corrected (scanning) TEM, were shown to play the most important role in enhancing the catalytic performance. By using synchrotron PXRD, it was shown that a small ratio of metastable phases within Au NWs can enhance catalytic activity by a factor of 1.35, providing a further route to improve catalytic activity. Of the three types of surface active sites, surface terminations of planar defects such as twin boundaries (TB) and stacking faults (SF) are less active than metastable phases and surface steps for Au catalysts toward the silane oxidation reaction. Such an etching-assisted synthesis of heterophase Au NWs promises to open new possibilities for catalysis, plasmonic, optics, and electrical applications.

10.
Medicine (Baltimore) ; 98(11): e14732, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30882640

RESUMO

This study aims to explore the principles of clinical classification and individualized treatment of basicranial artery injuries based on its anatomical correlation.The data of 172 patients with various types of basicranial artery injuries were retrospectively analyzed. Among these patients, 128 patients were male and 44 patients were female, and the average age of these patients was 28.3 years old. All patients underwent computed tomography, some patients underwent computed tomography angiography or magnetic resonance angiography, and all the diagnoses were confirmed by digital subtraction angiography (DSA). According to anatomical correlation, the injuries were classified into 5 types: vascular wall injury (type I), intradural injury (type II), epidural injury (type III), sinus injury (type IV), and skull base bone injury (type V). Individualized treatment was adopted based on the different types and characteristics of injuries.The percentages of basicranial artery injuries were as follows: type I, 4.6%; type II, 5.8%; type III, 3.5%; type IV, 77.9%; and type V, 8.1%. All 172 patients underwent DSA to demonstrate the classification. The lesion elimination rate revealed by DSA was 99.4% immediately after the operation, 98.3% at 1 week after the operation, and 98.8% at 3 months after the operation. The follow-up after 6 months revealed that the percentage of patients in whom clinical symptoms or signs completely disappeared was 97.7%, the percentage of patients with limited eye movement or visual impairment was 1.2%, and the percentage of patients with mild limb dysfunction was 0.6%.Basicranial artery injuries can be classified into 5 types. Individualized design of embolization therapy based on different characteristics might be applicable for basicranial artery injuries treatment.


Assuntos
Fístula Carotidocavernosa/diagnóstico por imagem , Traumatismos Craniocerebrais/diagnóstico por imagem , Lesões do Sistema Vascular/diagnóstico por imagem , Adulto , Fístula Carotidocavernosa/etiologia , Angiografia por Tomografia Computadorizada , Traumatismos Craniocerebrais/complicações , Feminino , Humanos , Angiografia por Ressonância Magnética , Masculino , Lesões do Sistema Vascular/classificação
11.
Phys Chem Chem Phys ; 21(11): 6171-6177, 2019 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-30821806

RESUMO

The manipulation of magnetic states in nanoparticle supercrystals promises new pathways to design nanocrystalline magnetic materials and devices. Trench-patterned silicon substrates were used as templates to guide the self-assembly of iron oxide nanoparticles. Grazing incidence small angle X-ray scattering shows that the nanoparticles form a long-range ordered structure along the trench direction while in the direction perpendicular to the trenches, no coherent structure is observable. Electron holography provides evidence of an ordered magnetic state of nanoparticle moments in the remanent state after the application of a saturation magnetic field parallel to the trenches. However, a disordered magnetic state was observed in a perpendicular geometry. Hysteresis loops indicate that the nanoparticle moments form a superferromagnetic state for the geometry parallel to the trenches. Memory effect investigations reveal that the disordered magnetic state corresponds to a collective superspin glass state in the perpendicular geometry, while the superferromagnetic state in the parallel geometry suppresses the superspin glass state.

12.
Sci Rep ; 9(1): 3412, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30833607

RESUMO

Complete mitochondrial genomes contain large and diverse datasets for species delineation. To better understand the divergence of the two morphologically indistinguishable weevil species in Curculionini, we first sequenced and compared their complete mitochondrial genomes. The complete mitochondrial genomes of Curculio chinensis and Curculio sp. were 19,713 bp with an A + T content of 76.61% and 19,216 bp with an A + T content of 76.85%, respectively. All 37 of the typical mitochondrial genes were determined in both species. The 13 protein sequences of the two species shared high homology (about 90%) except for ATP8 (73.08%). The differences in secondary structure of ATP8 were the number of possible proteins and nucleic acid binding sites. There were 22 and 15 mismatched base-pairs in the tRNA secondary structures from C. chinensis and Curculio sp., respectively. Maximum Likelihood and Bayesian analyses indicated that Curculio sp. is a novel species closely related to C. chinensis. The divergence time estimation suggests that Cryptorhynchinae and Curculionini lines diverged in the Cenozoic Period, while C. chinensis and Curculio sp. diverged at 6.7079 (95% CI 5-13) Mya. This study demonstrates the utility of using complete mitochondrial gene sets for phylogenetic analysis and enhances our understanding of the genetic basis for the evolution of the Curculionini.

13.
Am J Transl Res ; 11(2): 520-528, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30899359

RESUMO

Epidermal growth factor receptor (EGFR) is a well-characterized receptor tyrosine kinase that involved in many vital activities in cell development, such as cellular homeostasis, proliferation, division, differentiation and apoptosis. Natural activation of EGFR and the concomitant downstream signaling pathways regulation are substantial to maintain normal cellular functions. In recent studies, EGFR was demonstrated to be a fundamental modulator in the control of skin inflammatory responses. Several dermatologic diseases including psoriasis are related to the anomalous activation of EGFR signaling. It has been proved that the expression and activity of EGFR and its endogenous ligands are overexpressed in the active epidermis lesions of psoriasis. Moreover, the remarkable therapeutic improvement of chronic psoriasis in cancer patients during the treatment of EGFR inhibitors or anti-EGFR monoclonal antibodies are also recorded, suggesting that the EGFR-mediated signaling may conduct a crucial role in the pathophysiology of psoriasis.

14.
Autophagy ; 15(5): 813-826, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30661440

RESUMO

Cutaneous inflammation from UV radiation exposure causes epidermal damage, cellular infiltration, and secretion of pro-inflammatory mediators that exacerbate tissue destruction. Recovery is mediated chiefly by anti-inflammatory M2 macrophages that suppress inflammation and augment epidermal regeneration. Vitamin D enables anti-inflammation to promote tissue repair in response to injury. Since vitamin D enhances cellular macroautophagy/autophagy, we investigated the role of autophagy in vitamin D protection of UV-mediated sunburn and inflammation. Using a UV-mediated acute skin injury mouse model, we demonstrate that a single dose of vitamin D resolves injury with sustained inhibition of inflammatory cytokines associated with enhanced autophagy in myeloid anti-inflammatory M2 macs. Increased MAP1LC3B/LC3 expression corroborated with complete autolysosome formation detected by electron microscopy and correlated with degradation of SQSTM1/p62 in the skin following vitamin D treatment. Specifically, pharmacological inhibition of autophagy increased UV-induced apoptosis, suppressed M2 macs recruitment, and prevented vitamin D downregulation of Tnf and Mmp9 in the skin. Furthermore, selective deletion of autophagy in myeloid cells of atg7 cKO mice abrogated vitamin D-mediated protection and recapitulated UV-induced inflammation. Mechanistically, vitamin D signaling activated M2-autophagy regulators Klf4, Pparg, and Arg1. Lastly, analysis of UV-exposed human skin biopsies detected a similar increase in macrophage autophagy following vitamin D intervention, identifying an essential role for autophagy in vitamin D-mediated protection of skin from UV damage. Abbreviations: ARG1: arginase 1; ATG7 cKO: autophagy related 7 conditional knockout; HPF: high powered field; KLF4: Kruppel like factor 4; MAP1LC3B/LC3: microtubule-associated protein 1 light chain 3 beta; macs: macrophage; 3-MA: 3-methyladenine; MMP9: matrix metallopeptidase 9; NOS2: nitric oxide synthase 2, inducible; PPARG: peroxisome proliferator activated receptor gamma; SQSTM1/p62: sequestosome 1; TNF: tumor necrosis factor; UV: ultraviolet; VD: vitamin D, 25-hydroxy vitamin D3; 1,25-VD: 1, 25-dihydroxy vitamin D3.

15.
Anim Biotechnol ; 30(3): 233-241, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30601081

RESUMO

Objective: The goal of this study was to investigate the mechanisms of muscle growth and development of three chicken breeds. Participants: Eighteen chickens, including three different breeds with different growth speeds (White Broiler, Daheng, and Commercial Layers of Roman), were used. Methods: Total RNA from breast muscle of these chickens was subjected to a gene expression microarray. Differentially expressed genes (DEGs) were screened and functional enrichment analysis was performed using DAVID. Seven DEGs were confirmed by quantitative reverse transcription PCR. Results: Overall, 8,398 DEGs were found among the different lines. The DEGs between each two lines that were unique for a developmental stage were greater than those that were common during all stages. Functional analysis revealed that DEGs across the entire developmental process were primarily involved in positive cell proliferation, growth, cell differentiation, and developmental processes. Genes involved in muscle regulation, muscle construction, and muscle cell differentiation were upregulated in the faster-growing breed compared to the slower-growing breed. DEGs including myosin heavy chain 15 (MYH15), myozenin 2 (MYOZ2), myosin-binding protein C (MYBPC3), insulin-like growth factor 2 (IGF2), apoptosis regulator (BCL-2), AP-1 transcription factor subunit (JUN), and AP-1 transcription factor subunit (FOS) directly regulated muscle growth or were in the center of the protein-protein interaction network. Pathways, including the extracellular matrix (ECM)-receptor interaction, mitogen-activated protein kinase (MAPK) signaling pathway, and focal adhesion, were the most enriched DEGs between lines or within lines under different developmental stages. Conclusions: Genes involved in muscle construction and cell differentiation were differentially expressed among the three breeds.


Assuntos
Galinhas/genética , Transcriptoma , Animais , Cruzamento , Galinhas/crescimento & desenvolvimento , Biologia Computacional , Feminino , Perfilação da Expressão Gênica/veterinária , Desenvolvimento Muscular/genética , Análise de Sequência com Séries de Oligonucleotídeos/veterinária , Músculos Peitorais/crescimento & desenvolvimento
16.
Sci Adv ; 4(9): eaat8355, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30225369

RESUMO

Semiconductors are essential materials that affect our everyday life in the modern world. Two-dimensional semiconductors with high mobility and moderate bandgap are particularly attractive today because of their potential application in fast, low-power, and ultrasmall/thin electronic devices. We investigate the electronic structures of a new layered air-stable oxide semiconductor, Bi2O2Se, with ultrahigh mobility (~2.8 × 105 cm2/V⋅s at 2.0 K) and moderate bandgap (~0.8 eV). Combining angle-resolved photoemission spectroscopy and scanning tunneling microscopy, we mapped out the complete band structures of Bi2O2Se with key parameters (for example, effective mass, Fermi velocity, and bandgap). The unusual spatial uniformity of the bandgap without undesired in-gap states on the sample surface with up to ~50% defects makes Bi2O2Se an ideal semiconductor for future electronic applications. In addition, the structural compatibility between Bi2O2Se and interesting perovskite oxides (for example, cuprate high-transition temperature superconductors and commonly used substrate material SrTiO3) further makes heterostructures between Bi2O2Se and these oxides possible platforms for realizing novel physical phenomena, such as topological superconductivity, Josephson junction field-effect transistor, new superconducting optoelectronics, and novel lasers.

17.
J Ophthalmol ; 2018: 7894647, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30050691

RESUMO

Identification and characterization of the limbal epithelial stem cells (LESCs) has proven to be a major accomplishment in anterior ocular surface biology. These cells have been shown to be a subpopulation of limbal epithelial basal cells, which serve as the progenitor population of the corneal epithelium. LESCs have been demonstrated to play an important role in maintaining corneal epithelium homeostasis. Many ocular surface diseases, including intrinsic (e.g., Sjogren's syndrome) or extrinsic (e.g., alkali or thermal burns) insults, which impair LESCs, can lead to limbal stem cell deficiency (LSCD). LSCD is characterized by an overgrowth of conjunctival-derived epithelial cells, corneal neovascularization, and chronic inflammation, eventually leading to blindness. Treatment of LSCD has been challenging, especially in bilateral total LSCD. Recently, advances in LESC research have led to novel therapeutic approaches for treating LSCD, such as transplantation of the cultured limbal epithelium. These novel therapeutic approaches have demonstrated efficacy for ocular surface reconstruction and restoration of vision in patients with LSCD. However, they all have their own limitations. Here, we describe the current status of LSCD treatment and discuss the advantages and disadvantages of the available therapeutic modalities.

18.
Bioconjug Chem ; 29(7): 2239-2247, 2018 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-29847101

RESUMO

Polymeric prodrugs with precisely controlled drug loading content (DLC) and rapid intracellular destabilization generally require complicated chemistry that hinders large-scale manufacture. For this purpose, we reported in this study a facile construction of reduction-sensitive amphiphilic polyprodrugs with an anticancer drug, 10-hydroxycamptothecin (HCPT), and a hydrophilic poly(ethylene oxide) (PEG) moiety as the alternating building blocks of the multiblock copolymer using Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAc) click coupling between azide-SS-HCPT-SS-azide and alkyne-PEG-alkyne. Adoption of PEGs with two different molecular weights (MWs) of 400 and 1450 Da (PEG400 and PEG1450) afforded two polyprodrugs with different DLCs. Both formulations can self-assemble into spherical micelles with hydrodynamic diameter smaller than 200 nm, and exhibit glutathione (GSH)-triggered degradation for promoted drug release. A further comparison study revealed that the PEG1450-based polyprodrug is a better formulation than the analogue constructed from PEG400 in terms of in vitro drug release behaviors, and cytotoxicity. This work thus provides a facile yet efficient strategy toward polymeric prodrugs with precisely controlled DLC and reduction-triggered degradation for enhanced anticancer drug delivery.


Assuntos
Camptotecina/análogos & derivados , Preparações de Ação Retardada/síntese química , Liberação Controlada de Fármacos , Polímeros/uso terapêutico , Pró-Fármacos/síntese química , Antineoplásicos/administração & dosagem , Camptotecina/administração & dosagem , Reação de Cicloadição/métodos , Preparações de Ação Retardada/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Micelas , Peso Molecular , Polietilenoglicóis/uso terapêutico , Polímeros/química , Pró-Fármacos/química , Tensoativos/química
19.
Ultramicroscopy ; 189: 46-53, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29614394

RESUMO

Nearly eighty years ago, Scherzer showed that rotationally symmetric, charge-free, static electron lenses are limited by an unavoidable, positive spherical aberration. Following a long struggle, a major breakthrough in the spatial resolution of electron microscopes was reached two decades ago by abandoning the first of these conditions, with the successful development of multipole aberration correctors. Here, we use a refractive silicon nitride thin film to tackle the second of Scherzer's constraints and demonstrate an alternative method for correcting spherical aberration in a scanning transmission electron microscope. We reveal features in Si and Cu samples that cannot be resolved in an uncorrected microscope. Our thin film corrector can be implemented as an immediate low cost upgrade to existing electron microscopes without re-engineering of the electron column or complicated operation protocols and can be extended to the correction of additional aberrations.

20.
Chemphyschem ; 19(16): 2025-2036, 2018 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-29539212

RESUMO

A simple device, which is equipped with a non-woven fabric filter medium immobilized with ion-recognizable smart hollow microgels, is developed for facile detection of trace lead(II) ions (Pb2+ ). The ion-recognizable smart microgels are made of poly(N-isopropylacrylamide-co-benzo-18-crown-6-acrylamide) (PNB), in which the 18-crown-6 groups act as the sensors of Pb2+ and the N-isopropylacrylamide groups act as the actuators. The PNB hollow microgels can isothermally change from a shrunk state to a swollen state in response to recognizing Pb2+ in the aqueous environment due to the electrostatic repulsion among the charged 18-crown-6/Pb2+ complex groups and the enhancement of hydrophilicity of the microgels. Due to the hollow structures, the PNB microgels show remarkable isothermal swelling ratio. Thus, the flux of solution pass through the non-woven fabric filter medium decreases significantly because of the remarkable reduction in the space for liquid flowing upon recognizing Pb2+ . The Pb2+ concentration can be detected quantitatively by simply and easily measuring the change of solution flux using the proposed device, which is operated without external power supply or spectroscopic measurements. The strategy proposed in this study provides a promising method for facile detection of trace Pb2+ in aqueous environments.

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