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1.
Nature ; 618(7965): 484-488, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37198492

RESUMEN

Spider pulsars are millisecond pulsars in short-period (≲12-h) orbits with low-mass (~0.01-0.4 M⊙) companion stars. The pulsars ablate plasma from the companion star, causing time delays and eclipses of the radio emission from the pulsar. The magnetic field of the companion has been proposed to strongly influence both the evolution of the binary system1 and the eclipse properties of the pulsar emission2. Changes in the rotation measure (RM) have been seen in a spider system, implying that there is an increase in the magnetic field near the eclipse3. Here we report a diverse range of evidence for a highly magnetized environment in the spider system PSR B1744 - 24A4, located in the globular cluster Terzan 5. We observe semi-regular profile changes to the circular polarization, V, when the pulsar emission passes close to the companion. This suggests that there is Faraday conversion where the radio wave tracks a reversal in the parallel magnetic field and constrains the companion magnetic field, B (> 10 G). We also see irregular, fast changes in the RM at random orbital phases, implying that the magnetic strength of the stellar wind, B, is greater than 10 mG. There are similarities between the unusual polarization behaviour of PSR B1744 - 24A and some repeating fast radio bursts (FRBs)5-7. Together with the possible binary-produced long-term periodicity of two active repeating FRBs8,9, and the discovery of a nearby FRB in a globular cluster10, where pulsar binaries are common, these similarities suggest that a proportion of FRBs have binary companions.

2.
Anal Chem ; 96(21): 8586-8593, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38728058

RESUMEN

Nowadays, signal enhancement is imperative to increase sensitivity of advanced ECL devices for expediting their promising applications in clinic. In this work, photodynamic-assisted electrochemiluminescence (PDECL) device was constructed for precision diagnosis of Parkinson, where an advanced emitter was prepared by electrostatically linking 2,6-dimethyl-8-(3-carboxyphenyl)4,4'-difluoroboradiazene (BET) with 1-butyl-3-methylimidazole tetrafluoroborate ([BMIm][BF4]). Specifically, protoporphyrin IX (PPIX) can trigger the photodynamic reaction under light irradiation with a wavelength of 450 nm to generate lots of singlet oxygen (1O2), showing a 2.43-fold magnification in the ECL responses. Then, the aptamer (Apt) was assembled on the functional BET-[BMIm] for constructing a "signal off" ECL biosensor. Later on, the PPIX was embedded into the G-quadruplex (G4) of the Apt to magnify the ECL signals for bioanalysis of α-synuclein (α-syn) under light excitation. In the optimized surroundings, the resulting PDECL sensor has a broad linear range of 100.0 aM ∼ 10.0 fM and a low limit of detection (LOD) of 63 aM, coupled by differentiating Parkinson patients from normal individuals according to the receiver operating characteristic (ROC) curve analysis of actual blood samples. Such research holds great promise for synthesis of other advanced luminophores, combined with achieving an early clinical diagnosis.


Asunto(s)
Compuestos de Boro , Técnicas Electroquímicas , Mediciones Luminiscentes , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/diagnóstico , Enfermedad de Parkinson/sangre , Compuestos de Boro/química , Técnicas Biosensibles/métodos , alfa-Sinucleína/análisis , alfa-Sinucleína/sangre , Protoporfirinas/química , Aptámeros de Nucleótidos/química , Límite de Detección
3.
Small ; : e2402397, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38634268

RESUMEN

Optimizing the local electronic structure of electrocatalysts can effectively lower the energy barrier of electrochemical reactions, thus enhancing the electrocatalytic activity. However, the intrinsic contribution of the electronic effect is still experimentally unclear. In this work, the electron injection-incomplete discharge approach to achieve the electron accumulation (EA) degree on the nickel-iron layered double hydroxide (NiFe LDH) is proposed, to reveal the intrinsic contribution of EA toward oxygen evolution reaction (OER). Such NiFe LDH with EA effect results in only 262 mV overpotential to reach 50 mA cm-2, which is 51 mV-lower compared with pristine NiFe LDH (313 mV), and reduced Tafel slope of 54.8 mV dec-1 than NiFe LDH (107.5 mV dec-1). Spectroscopy characterizations combined with theoretical calculations confirm that the EA near concomitant Vo can induce a narrower energy gap and lower thermodynamic barrier to enhance OER performance. This study clarifies the mechanism of the EA effect on OER activity, providing a direct electronic structure modulation guideline for effective electrocatalyst design.

4.
Opt Express ; 32(9): 15827-15839, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38859223

RESUMEN

To advance the development of a compact and highly integrated fiber Bragg grating (FBG) interrogation system, to the best of our knowledge, this paper is the first to present the design and fabrication of a monolithic integration chip based on silicon-on-insulator (SOI), which is specifically intended for application in fiber grating sensing interrogation systems. By considering the impact of coupling structure dimensions on coupling efficiency as well as the effect of the photodetector (PD) parameters on the optical absorption efficiency of the device, we refine the structure of the monolithic integrated chip for arrayed waveguide grating (AWG) and PD. The test results reveal that the coupling loss between AWG and PD is -2.4 dB. The monolithic integrated interrogation chip achieves an interrogation accuracy of approximately 6.79 pm within a dynamic range of 1.56 nm, accompanied by a wavelength resolution of 1 pm. This exceptional performance highlights the potential of the monolithic integrated chip to enhance the integration of AWG-based fiber grating interrogation systems.

5.
Opt Lett ; 49(3): 454-457, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38300029

RESUMEN

Compact fiber Bragg grating (FBG) interrogator is a widely investigated topic in the field of fiber optic sensing. Here we report a dense spectral arrayed waveguide grating (AWG) chip designed for FBG interrogation. By integrating a multimode interference (MMI) coupler with the AWG, bilateral input phase-differential optical signals were achieved at the input port of the AWG. This chip effectively doubles the output channel count without altering the device footprint, while concurrently reducing the channel spacing without modifying the bandwidth and spectral slope of the output spectrum. We further optimized the method for selecting interrogation channels. The results demonstrate that the dynamic range of the interrogation reaches 13.5 nm with an absolute wavelength resolution of 4 pm and an absolute accuracy better than 20 pm.

6.
BMC Cancer ; 24(1): 23, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38166768

RESUMEN

AIM: Pathologists are currently supposed to be aware of both domestic and international guidelines for breast cancer diagnosis, but it is unclear how successfully these guidelines have been integrated into routine clinical practice in China. Thus, this national proficiency testing (PT) scheme for breast pathology was set up to conduct a baseline assessment of the diagnostic capability of pathologists in China. METHODS: This national PT plan is designed and implemented according to the "Conformity assessment-General requirements for proficiency testing" (GB/T27043-2012/ISO/IEC 17043:2010). Five cases of breast cancer with six key items, including histologic type, grade, ER, PR, HER2, and Ki67, were selected for testing among 96 participants. The final PT results were published on the website of the National Quality Control Center for Cancer ( http://117.133.40.88:3927/cn/col22/362 ). RESULTS: Our study demonstrated that the median PT score was 89.5 (54-100). Two institutions with scores < 67 were deemed unacceptable. The accuracy of histologic type, ER, PR, HER2, and Ki67 was satisfactory (all > 86%). However, the histologic grade showed low accuracy (74.0%). The unacceptable results mainly included incorrect evaluation of histologic grade (36.7%), inaccurate evaluation of ER/PR/HER2/Ki67 (28.2%), incorrect identification of C-AD as IBC-NST (15.7%), inappropriate use of 1+/2+/3+ rather than staining percentage for ER/PR (6.1%), misclassification of ER/PR < 1% weak expression as positive staining (1.4%), and no evaluation of histologic grade in ILC, MC, and IMC (5.8%). CONCLUSIONS: our nationwide PT program exhibited a satisfactory baseline assessment of the diagnostic capability of pathologists in China. More importantly, we identify some areas for further improvement.


Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/patología , Antígeno Ki-67/metabolismo , Receptor ErbB-2/metabolismo , Inmunohistoquímica , Receptores de Estrógenos/metabolismo , Ensayos de Aptitud de Laboratorios , Receptores de Progesterona/metabolismo , Biomarcadores de Tumor/metabolismo
7.
Amino Acids ; 56(1): 11, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38319413

RESUMEN

The organic anion-transporting polypeptide 1B3 and P-glycoprotein (P-gp) provide efficient directional transport (OATP1B3-P-gp) from the blood to the bile that serves as a key determinant of hepatic disposition of the drug. Unfortunately, there is still a lack of effective means to evaluate the disposal ability mediated by transporters. The present study was designed to identify a suitable endogenous biomarker for the assessment of OATP1B3-P-gp function in the liver. We established stably transfected HEK293T-OATP1B3 and HEK293T-P-gp cell lines. Results showed that azelaic acid (AzA) was an endogenous substrate for OATP1B3 and P-gp using serum pharmacology combined with metabolomics. There is a good correlation between the serum concentration of AzA and probe drugs of rOATP1B3 and rP-gp when rats were treated with their inhibitors. Importantly, after 5-fluorouracil-induced rat liver injury, the relative mRNA level and expression of rOATP1B3 and rP-gp were markedly down-regulated in the liver, and the serum concentration of AzA was significantly increased. These observations suggest that AzA is an endogenous substrate of both OATP1B3 and P-gp, and may serve as a potential endogenous biomarker for the assessment of the function of OATP1B3-P-gp for the prediction of changes in the pharmacokinetics of drugs transported by OATP1B3-P-gp in liver disease states.


Asunto(s)
Ácidos Dicarboxílicos , Hígado , Metabolómica , Animales , Humanos , Ratas , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP , Biomarcadores , Células HEK293 , Miembro 1B3 de la Familia de los Transportadores de Solutos de Aniones Orgánicos
8.
Analyst ; 149(2): 426-434, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38099364

RESUMEN

Nowadays, organic emitters suffer from insufficient electrochemiluminescence (ECL) efficiency in aqueous solutions, and their practical applications are severely restricted in the bio-sensing field. In this work, palladium nanospheres-embedded metal-organic frameworks (Pd@MOFs) were exploited to enhance the ECL efficiency of 2,6-dimethyl-8-(3-carboxyphenyl)4,4'-difluoroboradiazene (BET) prepared by a one-pot method in aqueous environment. First, the Pd@MOFs were generated via in situ reduction of Pd nanospheres anchored onto the MOFs, and fabricated by orderly coordination of palladium chloride (PdCl2) with 1,2,4,5-benzenetetramine (BTA) tetrahydrochloride. Then, the influence of protons on the ECL response of BET was studied in detail to obtain stronger ECL emission using potassium persulfate (K2S2O8) as co-reactant in aqueous environment. As a result, a 1.47-fold ECL efficiency enlargement of BET/K2S2O8 was harvested at the Pd@MOFs/GCE, where Ru(bpy)32+ behaved as a standard. Based on the fact that the ECL signals of the BET-covered Pd@MOFs modified glassy carbon electrode (simplified as BET/Pd@MOFs/GCE) can be quenched by Cu2+, the as-built ECL sensor showed a wide linear range (1.0-100.0 pM) and a limit of detection (LOD) as low as 0.12 pM. Hence, such research offers huge potential to promote the development of organic emitters in ECL biosensors and environmental monitoring.

9.
Phys Chem Chem Phys ; 26(6): 5569-5578, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38284264

RESUMEN

The g-ZnO/Si9C15 heterojunction is designed, and its stability, electronic properties and photo-electro catalytic properties, and the impact of biaxial strain on the electronic and photocatalytic properties are investigated. The g-ZnO/Si9C15 heterojunction has a staggered (type-II) band structure (band gap is 1.770 eV), following the S-scheme mechanism. A high electron mobility of 5.113 × 103 cm2 V-1 s-1 and hole mobility of 3.324 × 104 cm2 V-1 s-1 are obtained in the zigzag and armchair directions, respectively. Suitable oxidation and reduction potentials are obtained such that photocatalytic water decomposition can occur at pH = 0-14, and the corrected solar to hydrogen (STH) efficiency is up to 35.4%. The absorption of visible light is enhanced, and the power conversion efficiency (PCE) is 15.1%. The electro-catalytic hydrogen evolution reaction (HER) is more likely to occur at the Si9C15 interface with a low over-voltage of 0.190 V. Under biaxial strain, due to the controllable band structure, the corrected STH efficiency and PCE increase to 42.7% and 16.7%, respectively. The heterojunction shows potential value in the field of high-efficiency solar devices and catalytic materials for water splitting.

10.
Phytochem Anal ; 35(2): 254-270, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37758241

RESUMEN

INTRODUCTION: Ginkgo biloba extract (GBE) is an effective substance from traditional Chinese medicine (TCM) G. biloba for treating ischaemic stroke (IS). However, its active ingredients and mechanism of action remain unclear. OBJECTIVES: This study aimed to reveal the potential active component group and possible anti-IS mechanism of GBE. MATERIALS AND METHODS: The network pharmacology method was used to reveal the possible anti-IS mechanism of these active ingredients in GBE. An ultra-high-performance liquid chromatography triple quadrupole electrospray tandem mass spectrometry (UPLC-MS/MS) method was established for the simultaneous detection of the active ingredients of GBE. RESULTS: The active components of GBE anti-IS were screened by literature integration. Network pharmacology results showed that the anti-IS effect of GBE is achieved through key active components such as protocatechuic acid, bilobalide, ginkgolide A, and so on. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the possible anti-IS mechanism of GBE is regulating the PI3K-Akt signalling pathway and other signal pathways closely related to inflammatory response and apoptosis regulation combined with AKT1, MAPK, TNF, ALB, CASP3, and other protein targets. Nineteen main constituents in seven batches of GBE were successfully analysed using the established UPLC-MS/MS method, and the results showed that the content of protocatechuic acid, gallic acid, ginkgolide A, and so forth was relatively high, which was consistent with network pharmacology results, indicating that these ingredients may be the key active anti-IS ingredients of GBE. CONCLUSION: This study revealed the key active components and the anti-IS mechanism of GBE. It also provided a simple and sensitive method for the quality control of related preparations.


Asunto(s)
Isquemia Encefálica , Extracto de Ginkgo , Ginkgólidos , Hidroxibenzoatos , Lactonas , Accidente Cerebrovascular , Espectrometría de Masas en Tándem/métodos , Ginkgo biloba/química , Cromatografía Liquida , Cromatografía Líquida con Espectrometría de Masas , Farmacología en Red , Fosfatidilinositol 3-Quinasas , Extractos Vegetales/farmacología , Extractos Vegetales/química
11.
Sensors (Basel) ; 24(3)2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38339478

RESUMEN

The gas sensitivity of the W defect in WS2 (VW/WS2) to five toxic gases-HCHO, CH4, CH3HO, CH3OH, and CH3CH3-has been examined in this article. These five gases were adsorbed on the VW/WS2 surface, and the band, density of state (DOS), charge density difference (CDD), work function (W), current-voltage (I-V) characteristic, and sensitivity of adsorption systems were determined. Interestingly, for HCHO-VW/WS2, the energy level contribution of HCHO is closer to the Fermi level, the charge transfer (B) is the largest (0.104 e), the increase in W is more obvious than other adsorption systems, the slope of the I-V characteristic changes more obviously, and the calculated sensitivity is the highest. To sum up, VW/WS2 is more sensitive to HCHO. In conclusion, VW/WS2 has a great deal of promise for producing HCHO chemical sensors due to its high sensitivity and selectivity for HCHO, which can aid in the precise and efficient detection of toxic gases.

12.
Angew Chem Int Ed Engl ; 63(2): e202314266, 2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-37940614

RESUMEN

Co-based metal-organic frameworks (MOFs) as electrocatalysts for two-electron oxygen reduction reaction (2e- ORR) are highly promising for H2 O2 production, but suffer from the intrinsic activity-selectivity trade-off. Herein, we report a ZnCo bimetal-triazole framework (ZnCo-MTF) as high-efficiency 2e- ORR electrocatalysts. The experimental and theoretical results demonstrate that the coordination between 1,2,3-triazole and Co increases the antibonding-orbital occupancy on the Co-N bond, promoting the activation of Co center. Besides, the adjacent Zn-Co sites on 1,2,3-triazole enable an asymmetric "side-on" adsorption mode of O2 , favoring the reduction of O2 molecules and desorption of OOH* intermediate. By virtue of the unique ligand effect, the ZnCo-MTF exhibits a 2e- ORR selectivity of ≈100 %, onset potential of 0.614 V and H2 O2 production rate of 5.55 mol gcat -1 h-1 , superior to the state-of-the-art zeolite imidazole frameworks. Our work paves the way for the design of 2e- ORR electrocatalysts with desirable coordination and electronic structure.

13.
J Lipid Res ; 64(12): 100465, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37890669

RESUMEN

Accurate intracellular cholesterol traffic plays crucial roles. Niemann Pick type C (NPC) proteins NPC1 and NPC2, are two lysosomal cholesterol transporters that mediate the cholesterol exit from lysosomes. However, other proteins involved in this process remain poorly defined. Here, we find that the previously unannotated protein TMEM241 is required for cholesterol egressing from lysosomes through amphotericin B-based genome-wide CRISPR-Cas9 KO screening. Ablation of TMEM241 caused impaired sorting of NPC2, a protein utilizes the mannose-6-phosphate (M6P) modification for lysosomal targeting, resulting in cholesterol accumulation in the lysosomes. TMEM241 is a member of solute transporters 35 nucleotide sugar transporters family and localizes on the cis-Golgi network. Our data indicate that TMEM241 transports UDP-N-acetylglucosamine (UDP-GlcNAc) into Golgi lumen and UDP-GlcNAc is used for the M6P modification of proteins including NPC2. Furthermore, Tmem241-deficient mice display cholesterol accumulation in pulmonary cells and behave pulmonary injury and hypokinesia. Taken together, we demonstrate that TMEM241 is a Golgi-localized UDP-GlcNAc transporter and loss of TMEM241 causes cholesterol accumulation in lysosomes because of the impaired M6P-dependent lysosomal targeting of NPC2.


Asunto(s)
Colesterol , Proteínas de Transporte Vesicular , Animales , Ratones , Proteínas de Transporte Vesicular/metabolismo , Colesterol/metabolismo , Uridina Difosfato/metabolismo , Lisosomas/metabolismo
14.
Anal Chem ; 95(50): 18572-18578, 2023 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-38064592

RESUMEN

Electrochemiluminescence (ECL) has attracted significant interest in the analysis of cancer cells, where the ruthenium(II)-based emitter demonstrates urgency and feasibility to improve the ECL efficiency. In this work, the self-enhanced ECL luminophore was prepared by covalent anchoring of Pd nanoclusters on aminated metal organic frameworks (Pd NCs@MOFs), followed by linkage with bis(2,2'-bipyridine)-5-amino-1,10-phenanthroline ruthenium(II) (RuP). The resultant luminophore showed 214-fold self-magnification in the ECL efficiency over RuP alone, combined by promoting the interfacial photoelectron transfer. The enhanced mechanism through ion annihilation was critically proved by controlled experiments and density functional theory (DFT) calculations. Based on the above, a "signal off" ECL biosensor was built by assembly of tyrosine kinase 7 (PTK-7) aptamer (Apt) on the established sensing platform for analysis of human lung cancer cells (A549). The built sensor showed a lower detection limit of 8 cells mL-1, achieving the single-cell detection. This work reported a self-enhanced strategy for synthesis of advanced ECL emitters, combined by exploring the ECL biosensing devices in the single-cell analysis of cancers.


Asunto(s)
Técnicas Biosensibles , Neoplasias Pulmonares , Nanopartículas del Metal , Estructuras Metalorgánicas , Rutenio , Humanos , Mediciones Luminiscentes , Técnicas Electroquímicas , Límite de Detección
15.
Anal Chem ; 95(10): 4735-4743, 2023 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-36852949

RESUMEN

Nowadays, electrochemiluminescence (ECL) efficiency of an organic emitter is closely related with its potential applications in food safety and environmental monitoring fields. In this work, 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine (TATB) was self-assembled to form hydrogen bond organic frameworks (HOFs), which worked as ideal reactors to generate highly active oxygen-containing radicals, followed by linking with isoluminol (ILu) via amide bond (termed ILu-HOFs). After covalent assembly with aminated indium-tin oxide electrode (labeled NH2-ITO), the ECL efficiency of the ILu-HOFs NH2-ITO showed about a 23.4-time increase over that of ILu itself in the presence of H2O2. Meanwhile, the enhanced ECL mechanism was mainly studied by electron paramagnetic resonance, theoretical calculation, and electrochemistry. On the above foundation, an aptamer "sandwich" ECL biosensor was constructed for detecting isocarbophos (ICP) via in situ elimination of H2O2 with catalase-linked palladium nanocubes (CAT-Pd NCs). The as-built sensor showed a broad linear range (1 pM to 100 nM) and a low limit of detection (LOD) down to 0.4 pM, coupled with efficient assays of ICP in lake water and cucumber juice samples. This strategy provides an effective way for the synthesis of advanced ECL emitter, coupled by showing promising applications in environmental and food analysis.


Asunto(s)
Técnicas Biosensibles , Peróxido de Hidrógeno , Enlace de Hidrógeno , Mediciones Luminiscentes , Límite de Detección , Electrodos , Técnicas Electroquímicas
16.
J Med Virol ; 95(1): e28137, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36089815

RESUMEN

To model the spread of monkeypox (MPX) in a metropolitan area for assessing the risk of possible outbreaks, and identifying essential public health measures to contain the virus spread. The animal reservoir is the key element in the modeling of zoonotic disease. Using a One Health approach, we model the spread of the MPX virus in humans considering potential animal hosts such as rodents (e.g., rats, mice, squirrels, chipmunks, etc.) and emphasize their role and transmission of the virus in a high-risk group, including gay and bisexual men-who-have-sex-with-men (gbMSM). From model and sensitivity analysis, we identify key public health factors and present scenarios under different transmission assumptions. We find that the MPX virus may spill over from gbMSM high-risk groups to broader populations if the efficiency of transmission increases in the higher-risk group. However, the risk of outbreak can be greatly reduced if at least 65% of symptomatic cases can be isolated and their contacts traced and quarantined. In addition, infections in an animal reservoir will exacerbate MPX transmission risk in the human population. Regions or communities with a higher proportion of gbMSM individuals need greater public health attention. Tracing and quarantine (or "effective quarantine" by postexposure vaccination) of contacts with MPX cases in high-risk groups would have a significant effect on controlling the spreading. Also, monitoring for animal infections would be prudent.


Asunto(s)
Mpox , Minorías Sexuales y de Género , Masculino , Humanos , Animales , Ratones , Ratas , Mpox/epidemiología , Mpox/prevención & control , Homosexualidad Masculina , Monkeypox virus , Zoonosis/epidemiología , Zoonosis/prevención & control , Sciuridae
17.
J Asian Nat Prod Res ; 25(1): 1-10, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35023415

RESUMEN

Five new compounds, named gingerol A (1a and 1b), gingerol B (2), diphenylheptane glycoside A (3) and diphenylheptane glycoside B (4), were isolated from the acetone extract of Zingiberis Rhizoma Recens. The structures of new compounds were elucidated on the basis of spectroscopic methods including UV, IR, 1D NMR, 2D NMR and HR-ESI-MS. Compounds 2-4 could significantly decrease the apoptosis rate and increase the survival rate of human normal lung epithelial cells (BEAS-2B) at the concentration of 10 µM.


Asunto(s)
Catecoles , Extractos Vegetales , Humanos , Glicósidos
18.
Molecules ; 28(23)2023 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-38067632

RESUMEN

Although membrane separation technology has been widely used in the treatment of oily wastewater, the complexity and high cost of the membrane preparation, as well as its poor stability, limit its further development. In this study, via the vacuum-assisted suction filtration method, polydopamine (PDA)-coated TiO2 nanoparticles were tightly attached and embedded on both sides of laboratory filter paper (FP). The resultant FP possessed the typical wettability of high hydrophilicity in the air with the water contact angle (WCA) of 28°, superoleophilicity with the oil contact angle (OCA) close to 0°, underwater superoleophobicity with the underwater OCA greater than 150°, and superhydrophobicity under the water with the underoil WCA over 150° for five kinds of organic solvents (carbon tetrachloride, toluene, n-hexane, n-octane, and iso-octane). The separation efficiency of immiscible oil/water, oil-in-water, and water-in-oil emulsions using the modified FP is higher than 99%. After 17 cycles of emulsion separation, a high separation efficiency of 99% was still maintained for the FP, along with good chemical and mechanical stability. In addition, successful separation and purification were also realized for the oil-in-water emulsion that contained the methylene blue (MB) dye, along with the complete degradation of MB in an aqueous solution under UV irradiation.

19.
J Am Chem Soc ; 144(5): 2171-2178, 2022 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-34995077

RESUMEN

The coordinated configuration of atomic platinum (Pt) has always been identified as an active site with high intrinsic activity for hydrogen evolution reaction (HER). Herein, we purposely synthesize single vacancies in a carbon matrix (defective graphene) that can trap atomic Pt to form the Pt-C3 configuration, which gives exceptionally high reactivity for HER in both acidic and alkaline solutions. The intrinsic activity of Pt-C3 site is valued with a turnover frequency (TOF) of 26.41 s-1 and mass activity of 26.05 A g-1 at 100 mV, respectively, which are both nearly 18 times higher than those of commercial 20 wt % Pt/C. It is revealed that the optimal coordination Pt-C3 has a stronger electron-capture ability and lower Gibbs free energy difference (ΔG), resulting in promoting the reduction of adsorbed H+ and the acceleration of H2 desorption, thus exhibiting the extraordinary HER activity. This work provides a new insight on the unique coordinated configuration of dispersive atomic Pt in defective C matrix for superior HER performance.

20.
Anal Chem ; 94(8): 3708-3717, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-35172575

RESUMEN

Nowadays, aggregation quenching of most organic photosensitizers in aqueous media seriously restricts analytical and biomedical applications of photoelectrochemical (PEC) sensors. In this work, an aggregation-enhanced PEC photosensitizer was prepared by electrostatically bonding protoporphyrin IX (PPIX) with an ionic liquid of 1-butyl-3-methylimidazole tetrafluoroborate ([BMIm][BF4]), termed as PPIX-[BMIm] for clarity. The resultant PPIX-[BMIm] showed weak photocurrent in pure dimethyl sulfoxide (DMSO, good solvent), while the PEC signals displayed a 44.1-fold enhancement in a water (poor solvent)/DMSO binary solvent with a water fraction (fw) of 90%. Such PEC-enhanced mechanism was critically studied by electrochemistry and density functional theory (DFT) calculation in some detail. Afterward, a label-free PEC cytosensor was built for ultrasensitive bioassay of acute lymphoblastic leukemia (molt-4) cells by electrodepositing Au nanoparticles (Au NPs) on the PPIX-[BMIm] aggregates and sequential assembly of protein tyrosine kinase (PTK) aptamer DNA (aptDNA). The resultant cytosensor showed a wide linear range (300 to 3 × 105 cells mL-1) with a limit of detection (LOD) as low as 63 cells mL-1. The aggregation-enhanced PEC performance offers a valuable and practical pathway for synthesis of advanced organic photosensitizer to explore its PEC applications in early diagnosis of tumors.


Asunto(s)
Técnicas Biosensibles , Líquidos Iónicos , Nanopartículas del Metal , Técnicas Electroquímicas , Oro , Fármacos Fotosensibilizantes , Protoporfirinas , Electricidad Estática
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