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1.
Int J Mol Sci ; 25(11)2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38892378

ABSTRACT

Dementia, a multifaceted neurological syndrome characterized by cognitive decline, poses significant challenges to daily functioning. The main causes of dementia, including Alzheimer's disease (AD), frontotemporal dementia (FTD), Lewy body dementia (LBD), and vascular dementia (VD), have different symptoms and etiologies. Genetic regulators, specifically non-coding RNAs (ncRNAs) such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are known to play important roles in dementia pathogenesis. MiRNAs, small non-coding RNAs, regulate gene expression by binding to the 3' untranslated regions of target messenger RNAs (mRNAs), while lncRNAs and circRNAs act as molecular sponges for miRNAs, thereby regulating gene expression. The emerging concept of competing endogenous RNA (ceRNA) interactions, involving lncRNAs and circRNAs as competitors for miRNA binding, has gained attention as potential biomarkers and therapeutic targets in dementia-related disorders. This review explores the regulatory roles of ncRNAs, particularly miRNAs, and the intricate dynamics of ceRNA interactions, providing insights into dementia pathogenesis and potential therapeutic avenues.


Subject(s)
Dementia , Gene Expression Regulation , MicroRNAs , RNA, Circular , RNA, Long Noncoding , RNA, Untranslated , Humans , Dementia/genetics , Dementia/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , RNA, Circular/genetics , RNA, Circular/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , RNA, Untranslated/genetics , RNA, Untranslated/metabolism , Animals , Biomarkers , Alzheimer Disease/genetics , Alzheimer Disease/metabolism
2.
Int J Mol Sci ; 25(8)2024 Apr 21.
Article in English | MEDLINE | ID: mdl-38674135

ABSTRACT

Colorectal cancer (CRC) is the third most prevalent cancer to be diagnosed, and it has a substantial mortality rate. Despite numerous studies being conducted on CRC, it remains a significant health concern. The disease-free survival rates notably decrease as CRC progresses, emphasizing the urgency for effective diagnostic and therapeutic approaches. CRC development is caused by environmental factors, which mostly lead to the disruption of signaling pathways. Among these pathways, the Wingless/Integrated (Wnt) signaling pathway, Phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway, Mitogen-Activated Protein Kinase (MAPK) signaling pathway, Transforming Growth Factor-ß (TGF-ß) signaling pathway, and p53 signaling pathway are considered to be important. These signaling pathways are also regulated by non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). They have emerged as crucial regulators of gene expression in CRC by changing their expression levels. The altered expression patterns of these ncRNAs have been implicated in CRC progression and development, suggesting their potential as diagnostic and therapeutic targets. This review provides an overview of the five key signaling pathways and regulation of ncRNAs involved in CRC pathogenesis that are studied to identify promising avenues for diagnosis and treatment strategies.


Subject(s)
Colorectal Neoplasms , Gene Expression Regulation, Neoplastic , RNA, Untranslated , Signal Transduction , Humans , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , RNA, Untranslated/genetics , RNA, Untranslated/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Animals
3.
Small ; 16(9): e1903812, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31515955

ABSTRACT

Microgels, microparticles made of hydrogels, show fast diffusion kinetics and high reconfigurability while maintaining the advantages of hydrogels, being useful for various applications. Here, presented is a new microfluidic strategy for producing polymer-graphene oxide (GO) composite microgels without chemical cues or a temperature swing for gelation. As a main component of microgels, polymers that are able to form hydrogen bonds, such as polyvinyl alcohol (PVA), are used. In the mixture of PVA and GO, GO is tethered by PVA through hydrogen bonding. When the mixture is rapidly concentrated in the core of double-emulsion drops by osmotic-pressure-driven water pumping, PVA-tethered GO sheets form a nematic phase with a planar alignment. In addition, the GO sheets are linked by additional hydrogen bonds, leading to a sol-gel transition. Therefore, the PVA-GO composite remains undissolved when it is directly exposed to water by oil-shell rupture. These composite microgels can be also produced using poly(ethylene oxide) or poly(acrylic acid), instead of PVA. In addition, the microgels can be functionalized by incorporating other polymers in the presence of the hydrogel-forming polymers. It is shown that the multicomponent microgels made from a mixture of polyacrylamide, PVA, and GO show an excellent adsorption capacity for impurities.

4.
Small ; 14(13): e1703934, 2018 03.
Article in English | MEDLINE | ID: mdl-29443449

ABSTRACT

Humidity sensors are essential components in wearable electronics for monitoring of environmental condition and physical state. In this work, a unique humidity sensing layer composed of nitrogen-doped reduced graphene oxide (nRGO) fiber on colorless polyimide film is proposed. Ultralong graphene oxide (GO) fibers are synthesized by solution assembly of large GO sheets assisted by lyotropic liquid crystal behavior. Chemical modification by nitrogen-doping is carried out under thermal annealing in H2 (4%)/N2 (96%) ambient to obtain highly conductive nRGO fiber. Very small (≈2 nm) Pt nanoparticles are tightly anchored on the surface of the nRGO fiber as water dissociation catalysts by an optical sintering process. As a result, nRGO fiber can effectively detect wide humidity levels in the range of 6.1-66.4% relative humidity (RH). Furthermore, a 1.36-fold higher sensitivity (4.51%) at 66.4% RH is achieved using a Pt functionalized nRGO fiber (i.e., Pt-nRGO fiber) compared with the sensitivity (3.53% at 66.4% RH) of pure nRGO fiber. Real-time and portable humidity sensing characteristics are successfully demonstrated toward exhaled breath using Pt-nRGO fiber integrated on a portable sensing module. The Pt-nRGO fiber with high sensitivity and wide range of humidity detection levels offers a new sensing platform for wearable humidity sensors.


Subject(s)
Graphite/chemistry , Nanoparticles/chemistry , Platinum/chemistry , Water/chemistry , Catalysis , Humidity , Nitrogen/chemistry
5.
J Environ Manage ; 205: 192-200, 2018 Jan 01.
Article in English | MEDLINE | ID: mdl-28985598

ABSTRACT

Alginate bead is a promising strontium (Sr) adsorbent in seawater, but highly concentrated Na ions caused over-swelling and damaged the hydrogel bead. To improve the mechanical stability of alginate bead, flexible foam-type zeolite-alginate composite was synthesized and Sr adsorption performance was evaluated in seawater; 1-10% zeolite immobilized alginate foams were prepared by freeze-dry technique. Immobilization of zeolite into alginate foam converted macro-pores to meso-pores which lead to more compact structure. It resulted in less swollen composite in seawater medium and exhibited highly improved mechanical stability compared with alginate bead. Besides, Sr adsorption efficiency and selectivity were enhanced by immobilization of zeolite in alginate foam due to the increase of Sr binding sites (zeolite). In particular, Sr selectivity against Na was highly improved. The 10% zeolite-alginate foam exhibited a higher log Kd of 3.3, while the pure alginate foam exhibited 2.7 in the presence of 0.1 M Na. Finally, in the real seawater, the 10% zeolite-alginate foam exhibited 1.5 times higher Sr adsorption efficiency than the pure alginate foam. This result reveals that zeolite-alginate foam composite is appropriate material for Sr removal in seawater due to its swelling resistance as well as improved Sr adsorption performance in complex media.


Subject(s)
Strontium Radioisotopes , Zeolites , Adsorption , Alginates , Glucuronic Acid , Hexuronic Acids , Seawater , Strontium
6.
Small ; 13(38)2017 10.
Article in English | MEDLINE | ID: mdl-28786553

ABSTRACT

This study demonstrates that small amount of oxygen incorporated into carbon nanotubes (CNTs) during the purification process greatly increases their solubility in chlorosulfonic acid (CSA). Using as-purchased and unpurified CNT powders, the optimal purification process is established to significantly increase the solubility of CNTs in CSA, and spin CNT fibers with high mechanical strength (0.84 N tex-1 ) and electrical conductivity (1.4 MS m-1 ) from the CNT liquid crystal dope with high concentration of CNTs in CSA. The knowledge obtained here may guide development of a way to dissolve extremely long CNTs at high concentration and thereby to enable production of CNT fibers with ultimate properties.

7.
Phys Chem Chem Phys ; 18(15): 10362-6, 2016 Apr 21.
Article in English | MEDLINE | ID: mdl-27025170

ABSTRACT

We demonstrate an efficient technique to align lyotropic chromonic liquid crystals (LCLCs) using secondary sputtering lithography (SSL). Monodomains of LCLCs prepared using SSL maintained their stable alignment for days. A generalization of Berreman's theory was employed to determine the anchoring strength of LCLCs on tessellated surface patterns. The anchoring energy initially increases with the amplitude (A) of the grooves and excellent alignment of LCLCs was observed when the amplitude of the grooves is equal to half its wavelength (λ). We also note that the anchoring energy levels off above qA∼ 3 (where q = 2π/λ), which suggests that increasing qA beyond a certain value does not provide any further advantage for the alignment of LCLCs. This finding provides a useful optimization criterion for the fabrication of the patterned cells to achieve stable monodomain alignment of LCLCs. Our analysis also explains why good alignment of LCLCs has been a difficult task.

8.
Opt Express ; 22(4): 4699-704, 2014 Feb 24.
Article in English | MEDLINE | ID: mdl-24663788

ABSTRACT

We demonstrate large-area, closely-packed optical vortex arrays using self-assembled defects in smectic liquid crystals. Self-assembled smectic liquid crystals in a three-dimensional torus structure are called focal conic domains. Each FCD, having a micro-scale feature size, produces an optical vortex with consistent topological charge of 2. The spiral profile in the interferometry confirms the formation of an optical vortex, which is predicted by Jones matrix calculations.

9.
Phys Chem Chem Phys ; 15(24): 9493-7, 2013 Jun 28.
Article in English | MEDLINE | ID: mdl-23676827

ABSTRACT

We have developed a simple yet versatile method for aligning liquid crystals (LCs) by using magnetic-field oriented single-walled carbon nanotubes (SWNTs) that were modified with magnetic particles. A high degree of homeotropic/planar LC alignment was achieved by SWNTs being exposed to a very low strength magnetic field, combined with strong π-π interactions between the biphenyl group in the LCs and the wall of the SWNTs.

10.
ACS Appl Mater Interfaces ; 15(20): 24681-24692, 2023 May 24.
Article in English | MEDLINE | ID: mdl-37163756

ABSTRACT

Microfiber fabrication via wet-spinning of lyotropic liquid crystals (LCs) with anisotropic nanomaterials has gained increased attention due to the microfibers' excellent physical/chemical properties originating from the unidirectional alignment of anisotropic nanomaterials along the fiber axis with high packing density. For wet-spinning of the microfibers, however, preparing lyotropic LCs by achieving high colloidal stability of anisotropic nanomaterials, even at high concentrations, has been a critically unmet prerequisite, especially for recently emerging nanomaterials. Here, we propose a cationically charged polymeric stabilizer that can efficiently be adsorbed on the surface of boron nitride nanotubes (BNNTs), which provide steric hindrance in combination with Coulombic repulsion leading to high colloidal stability of BNNTs up to 22 wt %. The BNNT LCs prepared from the dispersions with various stabilizers were systematically compared using optical and rheological analysis to optimize the phase behavior and rheological properties for wet-spinning of the BNNT LCs. Systematic optical and mechanical characterizations of the BNNT microfibers with aligned BNNTs along the fiber axis revealed that properties of the microfibers, such as their tensile strength, packing density, and degree of BNNT alignment, were highly dependent on the quality of BNNT LCs directly related to the types of stabilizers.

11.
Chemosphere ; 301: 134518, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35395257

ABSTRACT

Nitrophenols(NPs) are highly toxic compounds that occur in various industrial effluents. Herein, we investigated Cu nanoparticle-loaded cellulose nanofibril (CNF/PEI-Cu) aerogels as a catalyst for degrading 4-nitrophenol (4NP) in the wastewater. Non-noble metal based low-cost catalyst material and easily scalable preparation method make CNF/PEI-Cu aerogel as an appropriate catalyst for practical application in 4NP wastewater treatment. Our strategy to improve the loading amount of homogeneously distributed Cu nanoparticles was to functionalize a CNF aerogel using polyethylene imine (PEI), which can bind Cu2+ ions. Porous CNF aerogels with homogenously distributed 20-40 nm Cu nanoparticles were obtained by adsorbing Cu2+ ions and chemically reducing them to Cu metal. The FTIR, XRD, SEM, XPS and ICP-OES analysis were used to confirm the in-situ formation of Cu nanoparticles. In the presence of the CNF/PEI-Cu aerogels, 4NP was effectively reduced to 4-aminophenol (4AP) without loss of the Cu nanoparticles. The activation energy (Ea) and reaction rate constant (kapp) of the catalytic 4NP reduction reaction by the CNF/PEI2-Cu aerogels were calculated to be Ea = 39.56 kJ mol-1 and kapp = 0.770 min-1, respectively. The Ea is similar or even smaller than the Ea values of the corresponding reactions involving noble-metal catalysts, demonstrating that the CNF/PEI-Cu aerogels developed in the present study have strong potential as practical and economical catalysts.


Subject(s)
Cellulose , Metal Nanoparticles , Cellulose/chemistry , Copper/chemistry , Ions , Metal Nanoparticles/chemistry , Metals , Nitrophenols/chemistry , Porosity
12.
ACS Nano ; 16(6): 9172-9182, 2022 Jun 28.
Article in English | MEDLINE | ID: mdl-35679534

ABSTRACT

Many interesting properties of 2D materials and their assembled structures are strongly dependent on the lateral size and size distribution of 2D materials. Accordingly, effective size separation of polydisperse 2D sheets is critical for desirable applications. Here, we introduce flow field-flow fractionation (FlFFF) for a wide-range size fractionation of graphene oxide (GO) up to 100 µm. Two different separation mechanisms are identified for FlFFF, including normal mode and steric/hyperlayer mode, to size fractionate wide size-distributed GOs while employing a crossflow field for either diffusion or size-controlled migration of GO. Obviously, the 2D GO sheet reveals size separation behavior distinctive from typical spherical particles arising from its innate planar geometry. We also investigate 2D sheet size-dependent mechanical and electrical properties of three different graphene fibers produced from size-fractionated GOs. This FlFFF-based size selection methodology can be used as a generic approach for effective wide-range size separation for 2D materials, including rGO, TMDs, and MXene.

13.
Sci Adv ; 8(16): eabn0939, 2022 Apr 22.
Article in English | MEDLINE | ID: mdl-35452295

ABSTRACT

Theoretical considerations suggest that the strength of carbon nanotube (CNT) fibers be exceptional; however, their mechanical performance values are much lower than the theoretical values. To achieve macroscopic fibers with ultrahigh performance, we developed a method to form multidimensional nanostructures by coalescence of individual nanotubes. The highly aligned wet-spun fibers of single- or double-walled nanotube bundles were graphitized to induce nanotube collapse and multi-inner walled structures. These advanced nanostructures formed a network of interconnected, close-packed graphitic domains. Their near-perfect alignment and high longitudinal crystallinity that increased the shear strength between CNTs while retaining notable flexibility. The resulting fibers have an exceptional combination of high tensile strength (6.57 GPa), modulus (629 GPa), thermal conductivity (482 W/m·K), and electrical conductivity (2.2 MS/m), thereby overcoming the limits associated with conventional synthetic fibers.

14.
Chemosphere ; 285: 131448, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34329132

ABSTRACT

4-Nitrophenol (4-NP) is a hazardous aromatic compound widely used for various industries. Catalytic reduction of 4-NP using metal nanoparticles (NPs) is a highly effective method to treat 4-NP from waste effluent. Even though lots of methods have investigated to prepare efficient metal NPs composites, the nano and/or micro size of composites makes it hard to recover after wastewater treatment, limiting its practical use. Here, we fabricate 3-dimensional polyethylene imine grafted cellulose nanofibril (CNF-PEI) aerogel as a porous support material for platinum (Pt) NPs to practically and effectively treat 4-NP from wastewater. The Pt NPs are formed in-situ mode on cylindrical CNF-PEI aerogel by adsorption reaction with amine groups of PEI and subsequently reduction with NaBH4. Control of PEI grafting density and the initial concentration of Pt ions allows manipulation of the loading mass, size, and distribution of Pt NPs on 3D scaffold of CNF-PEI aerogel. The composite aerogel shows high catalytic activity for conversion of 4-NP. The 4-NP conversion activity is strongly affected by the size of Pt NPs and effective surface area of aerogels. The 2.74 nm size Pt NPs with even distribution in the aerogel show fast reaction kinetics (k = 0.12 min-1). Finally, 4-NP reduction efficiency does not decrease during 5 times reuse cycle of Pt NPs loaded CNF-PEI aerogel. This CNF-PEI aerogel loaded with Pt NPs is recovered easily from wastewater after treatment, so it is reusable and offers high potential as a practical recyclable environmental catalyst.


Subject(s)
Nitrophenols , Wastewater , Catalysis , Cellulose
15.
Chemosphere ; 278: 130288, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33823344

ABSTRACT

Heavy metal contamination in wastewater is a serious problem due to its high toxicity. In this study, three-dimensional porous and flexible polyethylene imine grafted cellulose nanofibril aerogel (PEI@CNF aerogel) is synthesized as a highly efficient biosorbent for continuous treatment of wastewater containing copper (Cu2+). The synthesized PEI@CNF aerogel efficiently separates Cu2+ from wastewater and exhibits outstanding selectivity for Cu2+ in the presence of other metal ions. The amine groups in polyethylene imine (PEI) grafted onto the porous cellulose nanofibrils (CNFs) scaffold form chelates with Cu2+ thereby effectively adsorbing Cu2+. The combination of a flexible CNF scaffold and rigid PEI results in a durable elastic matrix of the aerogel providing excellent wet stability, shape recovery property and recycle ability of PEI@CNF aerogel. Finally, in the column test, the PEI@CNF aerogel treats 88 bed volumes of wastewater containing Cu2+(∼20 mg/L). This result demonstrates that PEI@CNF aerogels are practically viable and highly efficient bio-sorbents for the treatment of wastewater containing Cu2+.


Subject(s)
Nanofibers , Cellulose , Copper , Gels , Wastewater
16.
Carbohydr Polym ; 240: 116348, 2020 Jul 15.
Article in English | MEDLINE | ID: mdl-32475599

ABSTRACT

Recently, graphene oxide(GO) has gained much attention for heavy metal removal due to its high surface area and lots of functional groups on the surface. However, GO itself in powder form is far away from practical adsorbents because it remains dispersed in liquid phase which causes difficulty in the separation from effluent. In this study, GO/carboxymethyl cellulose nanofibril (CMCNF) composite fiber(CF) is developed as an efficient and durable adsorbent. Cross-linked GO/CMCNF CF was continuously produced by employing Fe3+ ion as a coagulant during a typical wet-spinning process. Based on multiple interactions such as ionic bonding and electrostatic interactions between Fe3+ and carboxyl group on CMCNF, the CF exhibits enhanced mechanical property than pure GO fiber. GO/CMCNF-Fe3+ CF showed efficient lead (Pb2+) uptake with successful adsorbent recovery, which indicates durable and cost-competitive fiber type adsorbent for heavy metal ions.


Subject(s)
Carboxymethylcellulose Sodium/chemistry , Graphite/chemistry , Lead/isolation & purification , Nanofibers/chemistry , Adsorption , Lead/chemistry , Particle Size , Surface Properties
17.
Carbohydr Polym ; 228: 115424, 2020 Jan 15.
Article in English | MEDLINE | ID: mdl-31635723

ABSTRACT

Rising demand and elemental rarity requires the recycling of precious metals such as platinum group elements (PGMs). Recently, biosorption has been focused on the capability of recovering precious metals, but in practice, recycling is inefficient or far away from a closed-loop material system. Here we use a polyethylenimine (PEI)-grafted spun-fiber made of cellulose nanofibril (CNF) extracted from a tunicate as a biosorbent for PGMs. Liquid crystallinity (LC) of TCNF suspension appears to contribute the generation of well-developed open porous structure in the fiber. We show the fiber has the selectivity and high capacity of Pt (120.2 mg/g, 86%) and Pd (26.5 mg/g, 74.2%) adsorption under the presence of other metals in simulated automobile waste. The adsorbed Pt and Pd with nano-scale clusters were uniformly distributed on the porous surface, which were directly applied as a catalyst. These results propose an easy approach to recover precious metals and reuse them directly, thereby closing loops of metal recycling.

18.
Carbohydr Polym ; 235: 115984, 2020 May 01.
Article in English | MEDLINE | ID: mdl-32122514

ABSTRACT

In this study, we synthesized a Prussian blue (PB)-embedded macroporous carboxymethyl cellulose nanofibril (CMCNF) membrane for facile cesium (Cs) removal. The PB was formed in situ at Fe3+ sites on a CMCNF framework cross-linked using FeCl3 as a cross-linking agent. Cubic PB particles of size 5-20 nm were observed on the macroporous CMCNF membrane surface. The PB-CMCNF membrane showed 2.5-fold greater Cs adsorption capacity (130 mg/gPB-CMCNF) than commercial PB nanoparticles, even though the PB loading of the PB-CMCNF membrane was less than 100 mg/gPB-CMCNF. The macroporous structure of the CMCNF membrane led to improved diffusion in the solution, thereby increasing the Cs adsorption capacity. The Cs adsorption behavior was systematically investigated in different solution chemistry. Finally, 137Cs removal using a semicontinuous adsorption module was demonstrated in real seawater. The results showed that the PB-CMCNF membrane is a highly effective, practical material for the removal of 137Cs from aqueous environments.

19.
J Am Chem Soc ; 131(41): 15055-60, 2009 Oct 21.
Article in English | MEDLINE | ID: mdl-19764762

ABSTRACT

The discovery of spontaneously induced chirality and enantiomeric separation in liquid crystal and soft crystal systems composed of achiral rod-shaped 4-arylbenzoate esters is described. Negligibly small circular dichroism (CD) signals are produced in the smectic A (SmA) phases of these substances, and the signals were found to increase with increasing smectic order. Since the advent of chirality occurs in freely suspended films, it is not a consequence of surface effects. Both positive and negative CD signals are observed with equal probability at different positions in these films. Vibrational CD spectroscopy and theoretical calculations are used to analyze the conformational changes that are associated with the induced chirality of the rod-shaped molecules. The results show that the phenomenon is caused by the twisting of biphenyl bond associated with the ester moiety in 4-arylbenzoate esters.

20.
J Nanosci Nanotechnol ; 9(12): 6968-73, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19908708

ABSTRACT

We investigate the energy transfer of a highly ordered pi-conjugated liquid crystalline molecule containing two chromophores of biphenyl and pyrene moiety, in which the molecule was prepared by esterification of fluorinated biphenyl compound and 1-pyrenebutanol. DSC, POM and XRD results show that this molecule forms a highly ordered smectic liquid crystalline mesophase, in which the pi-conjugated molecule was strongly packed together over large-areas. We show that the liquid crystalline bi-chromophoric systems with highly ordered structure exhibit the energy hopping and transfer to the chromophore with the energetically lowest S1 state. From the single-molecule spectroscopy of the biphenyl and pyrene chromophore in solution, we show an intramolecular energy transfer from biphenyl to pyrene moieties. In solid thin film, highly ordered structure of the liquid crystal plays a significant role in the formation of the excimer and perfect energy transfer between the chromophores.

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