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1.
Microsyst Nanoeng ; 10: 41, 2024.
Article in English | MEDLINE | ID: mdl-38523657

ABSTRACT

The perception of fish locomotion is important for understanding their adaptive behaviors and ethological characteristics. However, the main strategy used for extracting fish attitudes involves the use of a vision-based monitoring system, which is limited in its range of observation and cannot perform tracking for long times. Here, we report the use of a wearable tagging electronic device, referred to as an underwater vest, to capture the surrounding flow field disturbances triggered by swimming or momentary postural changes. All of these goals were achieved by integrating a pair of pseudocapacitive pressure-sensing units and a flexible circuit board. Notably, additional conditions, such as variable hydraulic pressures and minimal changes in fish posture, require high stability and sensitivity of the sensing units. Thus, hybrid hydrogel electrodes were developed through cross-linking MXene with holey-reduced graphene oxide nanosheets and further modification with 1-ethyl-3-methylimidazolium dicyanamide ionic liquids, which increased the interfacial capacitance and long-term interfacial activity of the MXene. Consequently, the sensing unit exhibited ultrahigh sensitivity (Smax~136,207 kPa-1) in an aquatic environment for 60 days and superior high-pressure resolution (10 Pa) within a wide working range of 1 MPa. Ultimately, an underwater vest integrated with such sensing units clearly distinguished and recorded fish locomotion. We believe that the designed device may open avenues in flow field monitoring and ocean current detection and provide new insights into the development of sensitive underwater tagging.

2.
Mov Disord ; 39(3): 486-497, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38197134

ABSTRACT

BACKGROUND: Spinocerebellar ataxia type 4 (SCA4) is an autosomal dominant ataxia with invariable sensory neuropathy originally described in a family with Swedish ancestry residing in Utah more than 25 years ago. Despite tight linkage to the 16q22 region, the molecular diagnosis has since remained elusive. OBJECTIVES: Inspired by pathogenic structural variation implicated in other 16q-ataxias with linkage to the same locus, we revisited the index SCA4 cases from the Utah family using novel technologies to investigate structural variation within the candidate region. METHODS: We adopted a targeted long-read sequencing approach with adaptive sampling on the Oxford Nanopore Technologies (ONT) platform that enables the detection of segregating structural variants within a genomic region without a priori assumptions about any variant features. RESULTS: Using this approach, we found a heterozygous (GGC)n repeat expansion in the last coding exon of the zinc finger homeobox 3 (ZFHX3) gene that segregates with disease, ranging between 48 and 57 GGC repeats in affected probands. This finding was replicated in a separate family with SCA4. Furthermore, the estimation of this GGC repeat size in short-read whole genome sequencing (WGS) data of 21,836 individuals recruited to the 100,000 Genomes Project in the UK and our in-house dataset of 11,258 exomes did not reveal any pathogenic repeats, indicating that the variant is ultrarare. CONCLUSIONS: These findings support the utility of adaptive long-read sequencing as a powerful tool to decipher causative structural variation in unsolved cases of inherited neurological disease. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.


Subject(s)
Cerebellar Ataxia , Spinocerebellar Ataxias , Humans , Pedigree , Spinocerebellar Ataxias/genetics , Cerebellar Ataxia/genetics , Exons , Homeodomain Proteins/genetics
4.
iScience ; 26(9): 107608, 2023 Sep 15.
Article in English | MEDLINE | ID: mdl-37664625

ABSTRACT

An unprecedented efficient protocol is developed for the oxidative cleavage of C≡C bonds in alkynes to produce structure-diverse esters using heterogeneous cobalt nanoparticles as catalyst with molecular oxygen as the oxidant. A diverse set of mono- and multisubstituted aromatic and aliphatic alkynes can be effectively cleaved and converted into the corresponding esters. Characterization analysis and control experiments indicate high surface area and pore volume, as well as nanostructured nitrogen-doped graphene-layer coated cobalt nanoparticles are possibly responsible for excellent catalytic activity. Mechanistic studies reveal that ketones derived from alkynes under oxidative conditions are formed as intermediates, which subsequently are converted to esters through a tandem sequential process. The catalyst can be recycled up to five times without significant loss of activity.

5.
Nat Commun ; 14(1): 2981, 2023 May 24.
Article in English | MEDLINE | ID: mdl-37221164

ABSTRACT

The cleavage and functionalization of C-S bonds have become a rapidly growing field for the design or discovery of new transformations. However, it is usually difficult to achieve in a direct and selective fashion due to the intrinsic inertness and catalyst-poisonous character. Herein, for the first time, we report a novel and efficient protocol that enables direct oxidative cleavage and cyanation of organosulfur compounds by heterogeneous nonprecious-metal Co-N-C catalyst comprising graphene encapsulated Co nanoparticles and Co-Nx sites using oxygen as environmentally benign oxidant and ammonia as nitrogen source. A wide variety of thiols, sulfides, sulfoxides, sulfones, sulfonamides, and sulfonyl chlorides are viable in this reaction, enabling access to diverse nitriles under cyanide-free conditions. Moreover, modifying the reaction conditions also allows for the cleavage and amidation of organosulfur compounds to deliver amides. This protocol features excellent functional group tolerance, facile scalability, cost-effective and recyclable catalyst, and broad substrate scope. Characterization and mechanistic studies reveal that the remarkable effectiveness of the synergistic catalysis of Co nanoparticles and Co-Nx sites is crucial for achieving outstanding catalytic performance.

6.
JACS Au ; 3(2): 476-487, 2023 Feb 27.
Article in English | MEDLINE | ID: mdl-36873692

ABSTRACT

The oxidative cleavage and functionalization of unsaturated C-C bonds are important processes for synthesis of carbonyl compounds from hydrocarbon feedstocks, yet there has been no report of direct amidation of unsaturated hydrocarbons via an oxidative cleavage of unsaturated C-C bonds with molecular oxygen as an environmentally benign oxidant. Herein, for the first time, we describe a manganese oxide-catalyzed auto-tandem catalysis strategy that enables direct synthesis of amides from unsaturated hydrocarbons by coupling oxidative cleavage with amidation. With oxygen as an oxidant and ammonia as a nitrogen source, a wide range of structurally diverse mono- and multisubstituted activated and unactivated alkenes or alkynes can smoothly undergo unsaturated C-C bond cleavage to deliver one- or multiple-carbon shorter amides. Moreover, a slight modification of the reaction conditions also allows for the direct synthesis of sterically hindered nitriles from alkenes or alkynes. This protocol features excellent functional group tolerance, a broad substrate scope, flexible late-stage functionalization, facile scalability, and a cost-effective and recyclable catalyst. Detailed characterizations reveal that the high activity and selectivity of the manganese oxides are attributed to the large specific surface area, abundant oxygen vacancies, better reducibility, and moderate acid sites. Mechanistic studies and density functional theory calculations indicate that the reaction proceeds through divergent pathways depending on the structure of substrates.

7.
Sci Adv ; 8(40): eadd1267, 2022 Oct 07.
Article in English | MEDLINE | ID: mdl-36206338

ABSTRACT

The cleavage and functionalization of recalcitrant carbon─carbon bonds is highly challenging but represents a very powerful tool for value-added transformation of feedstock chemicals. Here, an enzyme-mimic iron single-atom catalyst (SAC) bearing iron (III) nitride (FeN3) motifs was prepared and found to be robust for cleavage and cyanation of carbon-carbon bonds in secondary alcohols and ketones. High nitrile yields are obtained with a wide variety of functional groups. The prepared FeN3-SAC exhibits high enzyme-like activity and is capable of generating a dioxygen-to-superoxide radical at room temperature, while the commonly reported FeN4-SAC bearing FeN4 motifs was inactive. Density functional theory (DFT) calculation reveals that the activation energy of dioxygen activation and the activation energy of the rate-determining step of nitrile formation are lower over FeN3-SAC than FeN4-SAC. In addition, DFT calculation also explains the catalyst's high selectivity for nitriles.

8.
Micromachines (Basel) ; 12(6)2021 Jun 19.
Article in English | MEDLINE | ID: mdl-34205388

ABSTRACT

Magnetic flux vertical modulation method based on piezoelectric resonance can reduce the 1/f noise of tunnel magnetoresistance (TMR) magnetic sensor and significantly improves the low-frequency magnetic field detectivity. However, the amplitude variation of the modulation structure will lead to the instability of the sensor output. In order to improve the amplitude stability of the modulation structure, an amplitude control method based on the amplitude ratio of the first and second harmonic components of the modulated signal was proposed. Compared with the piezoelectric or capacitive feedback method, this method does not require an independent amplitude conversion circuit, and has the advantages of simple structure, high control efficiency and strong anti-interference ability. The experimental results showed that the amplitude and temperature drift of the modulated structure was significantly suppressed, which is of great significance for enhancing the adaptability of the TMR magnetic sensor to the application environments.

9.
Angew Chem Int Ed Engl ; 59(43): 19268-19274, 2020 Oct 19.
Article in English | MEDLINE | ID: mdl-32662588

ABSTRACT

Selective cleavage and functionalization of C-C bonds have important applications in organic synthesis and biomass utilization. However, functionalization of C-C bonds by controlled cleavage remains difficult and challenging because they are inert. Herein, we describe an unprecedented efficient protocol for the breaking of successive C-C bonds in alcohols to form esters with one or multiple carbon atoms less using heterogeneous cobalt nanoparticles as catalyst with dioxygen as the oxidant. A wide range of alcohols including inactive long-chain alkyl aryl alcohols undergo smoothly successive cleavage of adjacent -(C-C)n - bonds to afford the corresponding esters. The catalyst was used for seven times without any decrease in activity. Characterization and control experiments disclose that cobalt nanoparticles are responsible for the successive cleavage of C-C bonds to achieve excellent catalytic activity, while the presence of Co-Nx has just the opposite effect. Preliminary mechanistic studies reveal that a tandem sequence reaction is involved in this process.

10.
Article in English | MEDLINE | ID: mdl-28811824

ABSTRACT

BACKGROUND OF THE STUDY: As a widely used traditional medicine, Galla Chinensis is rich in tannins. However, there are few detailed studies about pharmaceutical preparations of Galla Chinensis tannin extract (GTE). In the present experiments, for better application and to investigate the possibility that Galla Chinensis tannin extract can be used as an antidiarrheal drug, we prepared Galla Chinensis oral solution (GOS). MATERIALS AND METHODS: GOS was prepared with GTE, and its physicochemical and microbiological stability was evaluated. The oral acute toxicity of GOS was calculated by the 50% lethal dose (LD50). The antidiarrheal activity was determined in a castor oil-induced diarrhea model in mice through diarrhea symptoms, fluid accumulation ratio, and percentage of distance moved by charcoal meal. RESULTS: The tannin content of GTE was 47.75%. GOS could endure a high temperature without a significant decrease of tannin content. After storage for six months, the tannin content of GOS was still more than 90%. GOS was determined to be nontoxic. Meanwhile, GOS showed significant antidiarrheal activity in a castor oil-induced diarrhea model in mice (P < 0.01). CONCLUSION: The results suggested that GOS is an effective and stable antidiarrheal drug that can be used to complement other therapies.

11.
Int J Med Sci ; 14(5): 452-461, 2017.
Article in English | MEDLINE | ID: mdl-28539821

ABSTRACT

Objectives: 4E-BP1 is a family member of eIF4E binding proteins (4E-BPs) which act as the suppressors of cap-dependent translation of RNA via competitively associating with cap-bound eIF4E. RNA translation regulation is an important manner to control the cellular responses to a series of stress conditions such as ionizing radiation (IR)-induced DNA damage response and cell cycle controlling. This study aimed to determine the mechanism of 4E-BP1 stabilization and its potential downstream target(s) in the response to IR. Methods: PI3Ks kinase inhibitors were used to determine the signaling control of 4E-BP1 phosphorylation and protein stability. shRNA strategy was employed to silence the expression of 4E-BP1 in HeLa and HepG2 cells, and determine its effect on the irradiation-induced CHK2 phosphorylation. The protein degradation/stability was investigated by western blotting on the condition of blocking novel protein synthesis by cycloheximide (CHX). Results: The phosphorylation of 4E-BP1 at Thr37/46 was significantly increased in both HepG2 and HeLa cells by ionizing radiation. Depression of 4E-BP1 by shRNA strategy resulted in an incomplete G2 arrest at the early stage of 2 hours post-irradiation, as well as a higher accumulation of mitotic cells at 10 and 12 hours post-irradiation as compared to the control cells. Consistently, the CHK2 phosphorylation at Thr68 induced by IR was also attenuated by silencing 4E-BP1 expression. Both PI3K and DNA-PKcs kinase inhibitors significantly decreased the protein level of 4E-BP1, which was associated with the accelerated degradation mediated by ubiquitination-proteasome pathway. Conclusion: PI3K kinase activity is necessary for maintaining 4E-BP1 stability. Our results also suggest 4E-BP1 a novel biological role of regulating cell cycle G2 checkpoint in responding to IR stress in association with controlling CHK2 phosphorylation.


Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Checkpoint Kinase 2/genetics , Phosphatidylinositol 3-Kinases/genetics , Phosphoproteins/genetics , Protein Biosynthesis/genetics , Cell Cycle Proteins , G2 Phase Cell Cycle Checkpoints/radiation effects , Gene Expression Regulation/radiation effects , HeLa Cells , Hep G2 Cells , Humans , Phosphorylation/radiation effects , Protein Biosynthesis/radiation effects , Proto-Oncogene Proteins c-akt/genetics , RNA, Small Interfering/genetics , Radiation, Ionizing , Signal Transduction/genetics , Signal Transduction/radiation effects
12.
Chem Commun (Camb) ; 53(26): 3709-3712, 2017 Mar 28.
Article in English | MEDLINE | ID: mdl-28300244

ABSTRACT

A europium-containing isopolyoxoniobate with the formula (CN3H6)7K3H17{Eu3(H2O)9Nb48O138(H2O)6}·40H2O is synthesized under the protection of citric acid. ESI-MS spectra show that the polyoxoanion structural unit {Eu3(H2O)9[Nb48O138(H2O)6]}27- is intact in aqueous solution. Moreover, its solid-state luminescence displays a red emission with the long lifetime of 258 µs.

13.
Int J Ophthalmol ; 9(1): 58-62, 2016.
Article in English | MEDLINE | ID: mdl-26949611

ABSTRACT

AIM: To compare the agreement of anterior chamber depth (ACD) and central vault measurements obtained by anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) of post surgical high myopic eyes with posterior chamber phakic intraocular lens (Visian ICL; STAAR Surgical) implantation. METHODS: Fifty-two phakic eyes of 28 high myopic patients who underwent implantable Collamer lens (ICL) surgery for the correction of high myopia were studied. The postoperative ACD, the distance between the corneal endothelium and the anterior surface of ICL (cornea-ICL) and the central vault were measured with the AS-OCT system and the UBM system. Intraclass correlation coefficient (ICC) and the Bland-Altman plot were used to evaluate the repeatability and agreement of two devices. RESULTS: The mean ACD, cornea-ICL and central vault in the 52 phakic eyes after ICL surgery was 3.19±0.28 mm, 2.47±0.28 mm, 0.50±0.19 mm by AS-OCT and 3.13±0.25 mm, 2.49±0.25 mm, 0.44±0.19 mm by UBM, respectively. Pairwise comparison of ACD and central vault measurements showed significant differences between AS-OCT and UBM (P<0.05). However, no statistically significant difference was found between these imaging techniques in cornea-ICL (P>0.05). The Pearson correlation coefficient (r) between AS-OCT and UBM measurements for ACD, cornea-ICL and vault was 0.88, 0.80 and 0.89, respectively (P<0.001). The ICC was 0.89-0.94 for the measurements of AS-OCT and UBM. Bland-Altman analysis showed the 95% limits of agreement of ACD, cornea-ICL, central vault measurements between these two devices were -0.20 to 0.32 mm, -0.36 to 0.32 mm and -0.12 to 0.24 mm, respectively. CONCLUSION: Central ACD and vault measurements using AS-OCT demonstrated a slight significantly higher value than using UBM in phakic eyes after ICL surgery. These two devices should not be used interchangeably for measurements of central ACD and vault in patients after phakic intraocular lens implantation.

14.
Neuroreport ; 21(4): 282-6, 2010 Mar 10.
Article in English | MEDLINE | ID: mdl-20145501

ABSTRACT

Ku80 plays a critical role in DNA double strand breaks repair. However, Ku80 is silenced in mature neurocytes. In this study, the mechanism of Ku80 silencing and its role in DNA double strand break repair in retinal neurocytes was investigated. Our data show that Ku80 expression is activated in primary cultured retinal neurocytes after treatment with 5-azacytidine in vitro, whereas methylation of -179 bp in Ku80 promoter induces Ku80 silencing in retinal neurocytes. Ku80 reactivation in retinal neurocytes by 5-azacytidine enhances DNA integrity after treatment with H(2)O(2). Therefore, our data suggest Ku80 might be a target for reactivation to increase retinal neuronal DNA repair.


Subject(s)
Antigens, Nuclear/genetics , Antigens, Nuclear/metabolism , DNA Methylation , DNA Repair , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Retinal Neurons/metabolism , Animals , Antimetabolites, Antineoplastic/pharmacology , Azacitidine/pharmacology , Blotting, Western , Cell Culture Techniques , DNA/drug effects , DNA/genetics , DNA/metabolism , DNA Breaks, Double-Stranded/drug effects , DNA Methylation/drug effects , DNA Methylation/genetics , DNA Repair/drug effects , DNA Repair/genetics , Gene Silencing/drug effects , Hydrogen Peroxide/pharmacology , Ku Autoantigen , Mice , Mice, Inbred BALB C , Oxidants/pharmacology , Promoter Regions, Genetic/drug effects , Promoter Regions, Genetic/genetics , Retinal Neurons/drug effects , Reverse Transcriptase Polymerase Chain Reaction , Up-Regulation/drug effects
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