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1.
JACS Au ; 4(10): 3921-3930, 2024 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-39483221

RESUMO

Short-wave infrared (SWIR) imaging systems offer remarkable advantages, such as enhanced resolution and contrast, compared to their optical counterparts. However, broader applications demand improvements in performance, notably the elimination of cryogenic temperature requirements and cost reduction in manufacturing processes. In this manuscript, we present a new development in SWIR photodetection, exploiting the potential of metal halide perovskite materials. Our work introduces a cost-effective and easily fabricated SWIR photodetector with an ultrabroad detection range from 900 to 2500 nm, a room-temperature responsivity of 1.57 × 102 A/W, and a specific detectivity of 4.18 × 1010 Jones at 1310 nm. We then performed comprehensive static and time-resolved optical and electrical measurements under ambient conditions, complemented by extensive density functional theory simulations, validating the formation of heterojunctions within the intrinsic n-type and extrinsic p-type perovskite structures. The potential of our perovskite-based SWIR materials extends from photodetectors to photovoltaic cells and introduces a possibility for high SWIR responsivity at room temperature and atmospheric pressure, which promotes its economic efficiency.

2.
ACS Nano ; 18(43): 29724-29735, 2024 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-39401376

RESUMO

Metal-support interaction (MSI) is pivotal and ubiquitously used in the development of next-generation catalysts, offering a pathway to enhance both catalytic activity and stability. However, owing to the lattice mismatch and poor solubility, traditional catalysts often exhibit a metal-on-support heterogeneous structure with limited interfaces and interaction and, consequently, a compromised enhancement of properties. Herein, we report a universal and tunable method for supersaturated doping of transition-metal carbides via strongly nonequilibrium carbothermal shock synthesis, characterized by rapid heating and swift quenching. Our results enable ∼20 at. % Ni2FeCo doping in Mo2C, significantly surpassing the thermodynamic equilibrium limit of <3 at. %. The supersaturation ensures more catalytically active NiFeCo doping and sufficient interaction with Mo2C, resulting in the maximized MSI (Max-MSI) effect. The Max-MSI enables outstanding activity and particularly stability in alkaline oxygen evolution reaction, showing an overpotential of 284 mV at 100 mA cm-2 and stable for 700 h, while individual Ni2FeCo and Mo2C only last less than 70 and 10 h (completely dissolved), respectively. In particular, the SD-Mo2C catalyst also exhibits excellent durability at 100 mA cm-2 for up to 400 h in 7 M KOH. Such a significantly improved stability is attributed to the supersaturated doping that led to each Mo atom strongly binding with adjacent heteroatoms, thus elevating the dissolution potential and corrosion resistance of Mo2C at a high current density. Additionally, the highly dispersed NiFeCo also facilitates the formation of dense oxyhydroxide coating during reconstruction, further protecting the integrated catalysts for durable operation. Furthermore, the synthesis has been successfully scaled up to fabricate large (16 cm2) electrodes and is adaptable to nickel foam substrates, indicating promising industrial applications. Our strategy allows the general and versatile production of various highly doped transition-metal carbides, such as Ni2FeCo-doped TiC, NbC, and W2C, thus unlocking the potential of maximized or adjustable MSI for diverse catalytic applications.

3.
J Chem Phys ; 161(16)2024 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-39469964

RESUMO

The movements of molecules at interfaces and surfaces are restricted by their asymmetric environments, leading to anisotropic orientational motions. In this work, in-plane orientational motions of the -C=O and -CF3 groups of coumarin 153 (C153) at the air/water interface were measured using time-resolved (TR) vibrational sum frequency generation (SFG). The in-plane orientational time constants of the -C=O and -CF3 groups of C153 are found to be 41.5 ± 8.2 and 36.0 ± 4.5 ps. These values are over five-times faster than that of 198 ± 15 ps for the permanent dipole of the whole C153 molecule at the interface, which may indicate that the two groups experience different interfacial friction in the plane. These differences could also be the result of the permanent dipole of C153 being almost five times those of the -C=O and -CF3 groups. The difference in orientational motions reveals the microscopic heterogeneous environment that molecules experience at the interface. While the interfacial dynamics of the two functional groups are similar, our TR-SFG experiments allowed the quantification of the in-plane dynamics of individual functional groups for the first time. Our experimental findings about the interfacial molecular motion have implications for molecular rotations, energy transfer, and charge transfer at material interfaces, photocatalysis interfaces, and biological cell/membrane aqueous interfaces.

4.
J Phys Chem Lett ; : 11087-11096, 2024 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-39471391

RESUMO

MXenes are a family of two-dimensional (2D) materials with broad and varied applications in biology, materials science, photonics, and environmental remediation owing to their layered structure and high surface area-to-volume ratio. MXenes have exhibited significant nonlinear optical characteristics, which have been primarily explored in the context of photonics applications, yet the second-harmonic generation (SHG) behavior of MXenes remains an unexplored aspect of their optical properties. Herein, we demonstrate and quantify large second-order responses of 2D Ti3C2Tx MXenes both in aqueous solutions and on a silicon substrate for the first time. MXene flakes showed strong second-harmonic scattering (SHS) in a dilute suspension with a sensitivity of less than 0.1 µg/mL. Angle-dependent SHS experiments further found that the second-order responses originate from coherent 2D dipole radiation. Through confocal and atomic force microscopies, we found that the intense SHG signal from free-standing MXene flakes increases exponentially with decreasing thickness, while two-photon fluorescence increases linearly with thickness. The second-order susceptibility of the MXenes was determined to be 3.6 pm V-1 with a thickness of 10 nm, almost twice of that for an often-used SHG crystal, beta barium borate. We further explored surface properties of the MXene sheets by investigating the SHS responses upon addition of organic dye molecules to the system. It was found that the adsorption of crystal violet (CV) obeys a Langmuir adsorption model while the addition of malachite green (MG) resulted in almost no change in SHG intensity, even though the adsorption capacities for both CV (61.3 ± 1.7 mg/g) and MG (54.8 ± 2.8 mg/g) are similar. Such a stark difference in adsorption characteristics between cationic organic CV and MG dyes is likely due to their distinct orientational orderings on the MXene surfaces. This work opens many possibilities for the further employment of the family of 2D materials in photonics, optics, and surface catalysis applications.

5.
J Chem Phys ; 161(11)2024 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-39291691

RESUMO

Two-dimensional electronic spectroscopy (2D-ES) has become an important technique for studying energy transfer, electronic coupling, and electronic-vibrational coherence in the past ten years. However, since 2D-ES is not interface specific, the electronic information at surfaces and interfaces could not be demonstrated clearly. Two-dimensional electronic sum-frequency generation (2D-ESFG) is an emerging spectroscopic technique that explores the correlations between different interfacial electronic transitions and is the extension of 2D-ES to surface and interfacial specificity. In this work, we present the detailed development and implementation of phase-cycling 2D-ESFG spectroscopy using an acousto-optic pulse shaper in a pump-probe geometry. With the pulse pair generated by a pulse shaper rather than optical devices based on birefringence or interference, this 2D-ESFG setup enables rapid scanning, phase cycling, and the separation of rephasing and nonrephasing signals. In addition, by collecting data in a rotating frame, we greatly improve experimental efficiency. We demonstrate the method for azo-derivative molecules at the air/water interface. This method could be readily extended to different interfaces and surfaces. The unique phase-cycling 2D-ESFG technique enables one to quantify the energy transfer, charge transfer, electronic coupling, and many other electronic properties and dynamics at surfaces and interfaces with precision and relative ease of use. Our goal in this article is to present the fine details of the fourth-order nonlinear optical technique in a manner that is comprehensive, succinct, and approachable such that other researchers can implement, improve, and adapt it to probe unique and innovative problems to advance the field.

6.
Anal Chem ; 96(33): 13607-13615, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39126390

RESUMO

Droplet interfaces are instrumental in processes of biology, engineering, production, and environmental systems. The chemical and physical properties of heterogeneous interfaces are known to be different from those of their underlying bulk phases, and different again when considering the curved surface of submicron aerosol droplets. The recently developed technique of vibrational sum-frequency scattering (VSFS) spectroscopy from airborne particles has emerged as an interface-specific method for the in situ analysis of this unique system. While the technique has shown promise in debut works, a quantitative analysis of the VSFS system has not yet been performed. Here we provide a comprehensive analysis of a VSFS spectrometer with reference to the well-documented planar analog. We decompose the VSFS signal into coherent and incoherent as well as resonant and nonresonant components as a function of incident pulse delay time. We then quantify and compare resonant and nonresonant VSFS and VSFG experimental data using the same laser and detection systems. Using the air/water interface as a guide, we show that the resonant and nonresonant contributions to the SF responses are comparable for the two systems by extracting second-order susceptibilities and hyperpolarizabilities, and using them to estimate single-particle susceptibilities. A quantitative analysis of the signal detection systems for the scattering and planar geometries is made, and conversion efficiencies for VSFG, VSFS, and other nonlinear scattering experiments are compared. Lastly, the possibility of a low-repetition (1 kHz) VSFS spectrometer is considered, determining that it may be possible with modern laser technology but is inevitably less efficient than a high-repetition (100 kHz) system. Though this multistep analysis we obtain a better understanding of the components of the VSFS signal from aerosol particles, further validate the feasibility of the experiments, and provide insight to those wishing to conduct similar experiments and how they may be improved.

7.
J Am Chem Soc ; 146(30): 20996-21007, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39037260

RESUMO

Conical intersections (CIs) hold significant stake in manipulating and controlling photochemical reaction pathways of molecules at interfaces and surfaces by affecting molecular dynamics therein. Currently, there is no tool for characterizing CIs at interfaces and surfaces. To this end, we have developed phase-cycling interface-specific two-dimensional electronic spectroscopy (i2D-ES) and combined it with advanced computational modeling to explore nonadiabatic CI dynamics of molecules at the air/water interface. Specifically, we integrated the phase locked pump pulse pair with an interface-specific electronic probe to obtain the two-dimensional interface-specific responses. We demonstrate that the nonadiabatic transitions of an interface-active azo dye molecule that occur through the CIs at the interface have different kinetic pathways from those in the bulk water. Upon photoexcitation, two CIs are present: one from an intersection of an optically active S2 state with a dark S1 state and the other from the intersection of the progressed S1 with the ground state S0. We find that the molecular conformations in the ground state are different for interfacial molecules. The interfacial molecules are intimately correlated with the locally populated excited state S2 being farther away from the CI region. This leads to slower nonadiabatic dynamics at the interface than in bulk water. Moreover, we show that the nonadiabatic transition from the S1 dark state to the ground state is significantly longer at the interface than that in the bulk, which is likely due to the orientationally restricted configuration of the excited state at the interface. Our findings suggest that orientational configurations of molecules manipulate reaction pathways at interfaces and surfaces.

8.
Medicine (Baltimore) ; 103(30): e38852, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39058844

RESUMO

RATIONALE: Spinal cord ischemia injury is a serious complication after intra-aortic surgery, with a low incidence but high disability rate. However, patients often do not receive comprehensive treatment in the early stages of the disease. Therefore, active neurological intervention is needed to protect and prevent spinal cord ischemia during and after surgery. In this paper, rehabilitation program and imaging data of 2 cases with spinal cord ischemic injury are presented and discussed regarding causes, prevention and acute treatment with this disease, which could be referred by clinicians. PATIENT CONCERNS: Case report 1: A 69-year-old male patient underwent aortic arch aneurysm and thoracic endovascular aortic repair (coated stent) was performed under general anesthesia. Complete paralysis of both lower limbs, constipation, and urinary retention occurred after surgery and was subsequently referred to our rehabilitation department. Case report 2: A man aged 41 years experienced sudden chest pain with no dizziness or headache. Weakness of both lower limbs gradually appeared over 30 minutes with subsequent loss of consciousness. He was diagnosed with aortic dissection and underwent aortic stent implantation. Inpatient rehabilitation began systematically 3 months after discharge. DIAGNOSES: The 2 patients were diagnosed with paraplegia and spinal cord ischemic injury. INTERVENTIONS: The patients received strength and transfer training, sensory input, health mission, and activities of daily living. OUTCOMES: Patient 1 returned home without assistive devices and patient 2 returned home with wheelchair. LESSONS: Perioperative spinal cord protection is directly related to postoperative quality of life. Once the symptoms of spinal cord ischemic injury occur, cerebrospinal fluid drainage should be performed as soon as possible to increase mean arterial pressure. At the same time, methylprednisolone, ganglioside, anticoagulation, vasodilator drugs, and symptomatic supportive treatments are required. Intercostal artery and subclavian artery are reconstructed if necessary. Symptom stability flags referral to commence rehabilitation. Repetitive functional training is necessary to help patients return to the family and society as soon as possible.


Assuntos
Isquemia do Cordão Espinal , Humanos , Masculino , Idoso , Isquemia do Cordão Espinal/etiologia , Adulto , Complicações Pós-Operatórias/etiologia , Paraplegia/etiologia , Dissecção Aórtica/cirurgia , Aneurisma da Aorta Torácica/cirurgia , Procedimentos Endovasculares/métodos , Procedimentos Endovasculares/efeitos adversos
9.
World J Clin Cases ; 12(17): 3168-3176, 2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38898838

RESUMO

BACKGROUND: High-dose vitamin C treatment (HVCT) can reduce the adverse effect of chemotherapy and enhance the effect of antitumor therapy, which has been considered one of the safest alternative treatments. However, the severity of its adverse effects may have been underestimated. The most serious adverse effect is hemolysis, which may result in acute kidney injury or death. Although glucose-6-phosphate dehydrogenase (G6PD) deficiency is considered to be the main cause, the probability and pathological mechanism are not completely understood, leading to a lack of effective and standardized treatment methods. CASE SUMMARY: Two patients with colorectal cancer developed hemolytic anemia after using 1 g/kg HVCT. In contrast to previous cases, the lowest hemoglobin level in the two cases was < 50 g/L, which was lower than previously reported. This may be because Case 1 had chronic hepatitis B for many years, which caused abnormal liver reserve function, and Case 2 had grade II bone marrow suppression. Both patients improved and were discharged after blood replacement therapy. Our cases had the most severe degree of hemolysis but the best prognosis, suggesting that our treatment may be helpful for rescue of drug-induced hemolysis. This is the first review of the literature on hemolysis caused by HVCT, and we found that all patients with G6PD deficiency developed hemolysis after HVCT. CONCLUSION: G6PD deficiency should be considered as a contraindication to HVCT, and it is not recommended for patients with bone marrow suppression, moderate-to-severe anemia, hematopoietic abnormalities, or abnormal liver and kidney function. Early blood purification and steroid therapy may avoid acute kidney injury or death caused by HVCT-related hemolytic anemia.

10.
Front Physiol ; 15: 1369165, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38751986

RESUMO

A novel regression model, monotonic inner relation-based non-linear partial least squares (MIR-PLS), is proposed to address complex issues like limited observations, multicollinearity, and nonlinearity in Chinese Medicine (CM) dose-effect relationship experimental data. MIR-PLS uses a piecewise mapping function based on monotonic cubic splines to model the non-linear inner relations between input and output score vectors. Additionally, a new weight updating strategy (WUS) is developed by leveraging the properties of monotonic functions. The proposed MIR-PLS method was compared with five well-known PLS variants: standard PLS, quadratic PLS (QPLS), error-based QPLS (EB-QPLS), neural network PLS (NNPLS), and spline PLS (SPL-PLS), using CM dose-effect relationship datasets and near-infrared (NIR) spectroscopy datasets. Experimental results demonstrate that MIR-PLS exhibits general applicability, achieving excellent predictive performances in the presence or absence of significant non-linear relationships. Furthermore, the model is not limited to CM dose-effect relationship research and can be applied to other regression tasks.

11.
Elife ; 122024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38686992

RESUMO

Dissection of neural circuitry underlying behaviors is a central theme in neurobiology. We have previously proposed the concept of chemoconnectome (CCT) to cover the entire chemical transmission between neurons and target cells in an organism and created tools for studying it (CCTomics) by targeting all genes related to the CCT in Drosophila. Here we have created lines targeting the CCT in a conditional manner after modifying GFP RNA interference, Flp-out, and CRISPR/Cas9 technologies. All three strategies have been validated to be highly effective, with the best using chromatin-peptide fused Cas9 variants and scaffold optimized sgRNAs. As a proof of principle, we conducted a comprehensive intersection analysis of CCT genes expression profiles in the clock neurons, uncovering 43 CCT genes present in clock neurons. Specific elimination of each from clock neurons revealed that loss of the neuropeptide CNMa in two posterior dorsal clock neurons (DN1ps) or its receptor (CNMaR) caused advanced morning activity, indicating a suppressive role of CNMa-CNMaR on morning anticipation, opposite to the promoting role of PDF-PDFR on morning anticipation. These results demonstrate the effectiveness of conditional CCTomics and its tools created here and establish an antagonistic relationship between CNMa-CNMaR and PDF-PDFR signaling in regulating morning anticipation.


Assuntos
Sistemas CRISPR-Cas , Neurônios , Animais , Neurônios/metabolismo , Neurônios/fisiologia , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Conectoma
13.
Int J Biol Macromol ; 267(Pt 1): 131273, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38569994

RESUMO

The nanopore-based translocation of a single-stranded RNA (ssRNA) in mixed salt solution has garnered increasing interest for its biological and technological significance. However, it is challenging to comprehensively understand the effects of the mixed ion species on the translocation dynamics due to their cooperation and competition, which can be directly reflected by the ion screening and neutralizing effects, respectively. In this study, Langevin dynamics simulation is employed to investigate the properties of ssRNA conformation and translocation in mixed Na+-Mg2+ ion environments. Simulation results reveal that the ion screening effect dominates the change in the ssRNA conformational size, the ion neutralizing effect controls the capture rate of the ssRNA by the nanopore, and both of them take charge of the different changes in translocation time of the ssRNA under various mixed ion environments. Under high Na+ ion concentration, as Mg2+ concentration increases, the ion neutralizing effect strengthens, weakening the driving force inside the nanopore, leading to longer translocation time. Conversely, at low Na+ concentration, an increase in Mg2+ concentration enhances the ion screening effect, aiding in faster translocation. Furthermore, these simulation results will be explained by quantitative analysis, advancing a deeper understanding of the complicated effects of the mixed Na+-Mg2+ ions.


Assuntos
Magnésio , Conformação de Ácido Nucleico , Sódio , Sódio/química , Sódio/metabolismo , Magnésio/química , Nanoporos , Simulação de Dinâmica Molecular , Íons/química , RNA/química
14.
Genetics ; 227(2)2024 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-38547502

RESUMO

Face recognition is important for both visual and social cognition. While prosopagnosia or face blindness has been known for seven decades and face-specific neurons for half a century, the molecular genetic mechanism is not clear. Here we report results after 17 years of research with classic genetics and modern genomics. From a large family with 18 congenital prosopagnosia (CP) members with obvious difficulties in face recognition in daily life, we uncovered a fully cosegregating private mutation in the MCTP2 gene which encodes a calcium binding transmembrane protein expressed in the brain. After screening through cohorts of 6589, we found more CPs and their families, allowing detection of more CP associated mutations in MCTP2. Face recognition differences were detected between 14 carriers with the frameshift mutation S80fs in MCTP2 and 19 noncarrying volunteers. Six families including one with 10 members showed the S80fs-CP correlation. Functional magnetic resonance imaging found association of impaired recognition of individual faces by MCTP2 mutant CPs with reduced repetition suppression to repeated facial identities in the right fusiform face area. Our results have revealed genetic predisposition of MCTP2 mutations in CP, 76 years after the initial report of prosopagnosia and 47 years after the report of the first CP. This is the first time a gene required for a higher form of visual social cognition was found in humans.


Assuntos
Reconhecimento Facial , Proteínas de Membrana , Prosopagnosia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética , Proteínas de Membrana/genética , Mutação , Linhagem , Prosopagnosia/genética , Prosopagnosia/congênito
15.
Sci Adv ; 10(5): eadj0146, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38306436

RESUMO

Acute pancreatitis (AP) is one of the most common gastrointestinal diseases. Bile acids (BAs) were proposed to be a cause of AP nearly 170 years ago, though the underlying mechanisms remain unclear. Here, we report that two G protein-coupled receptors, GPR39 and GHSR, mediated cellular responses to BAs. Our results revealed GPR39 as an evolutionarily conserved receptor for BAs, particularly 3-O-sulfated lithocholic acids. In cultured cell lines, GPR39 is sufficient for BA-induced Ca2+ elevation. In pancreatic acinar cells, GPR39 mediated BA-induced Ca2+ elevation and necrosis. Furthermore, AP induced by BAs was significantly reduced in GPR39 knockout mice. Our findings provide in vitro and in vivo evidence demonstrating that GPR39 is necessary and sufficient to mediate BA signaling, highlighting its involvement in biliary AP pathogenesis, and suggesting it as a promising therapeutic target for biliary AP.


Assuntos
Pancreatite , Receptores Acoplados a Proteínas G , Animais , Camundongos , Doença Aguda , Ácidos e Sais Biliares , Proteínas de Transporte/metabolismo , Camundongos Knockout , Pancreatite/genética , Pancreatite/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais
16.
Sci Total Environ ; 914: 169986, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38211865

RESUMO

Landfill treatment of municipal solid waste incineration fly ash (MSWI FA) after stabilization is the primary disposal technology. However, only few studies have assessed the stability of MSWI-FA-chelated products in different landfill scenarios. In this study, three commonly used dithiocarbamate (DTC)-based organic chelating agents (CAs) (TS-300, SDD, and PD) were selected to stabilize heavy metals (HMs) in MSWI FA. In addition, the leaching toxicity and environmental risks of the chelated products were assessed in different disposal environments. The results demonstrate that the HM leaching concentrations of the chelated products met the concentration limits of the sanitary landfill standard (GB16889-2008; mixed Landfill Scenario) for the three CAs at a low additive level (0.3 %). However, in the compartmentalized landfill scenario (the leaching agent was acid rain), the leaching of HMs from the chelated products met the standard when TS-300, SDD, and PD were added at 1.5 %, 6.0 %, and 8.0 %, respectively. Additionally, Pb, Zn, and Cd in the chelated products from the 1.5 %-TS-300 and 6.0 %-SDD groups met the leaching limits within the pH ranges 6-12 and 7-12, 6-12 and 7-12, and 8-12 and 8-12, respectively. This was primarily due of TS-300's multiple DTC groups forming stable chain-like macromolecular chelates with Pb. However, although the environmental risks associated with Pb, Zn, and Cd in the initial (0-d) chelated products of the 1.5 %-TS-300 and 6.0 %-SDD groups were minimized to low and negligible levels, there was a significant increase in the leaching of the three HMs after 28 d of storage. Therefore, with appropriate CA addition, although the leaching concentration of HMs in the chelated product may comply with the GB16889-2008 standards, it remains essential to consider its environmental risk, particularly in highly acidic or alkaline environments and during prolonged storage of the product.

17.
Elife ; 122023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38126335

RESUMO

The discovery of a new neurotransmitter, especially one in the central nervous system, is both important and difficult. We have been searching for new neurotransmitters for 12 y. We detected creatine (Cr) in synaptic vesicles (SVs) at a level lower than glutamate and gamma-aminobutyric acid but higher than acetylcholine and 5-hydroxytryptamine. SV Cr was reduced in mice lacking either arginine:glycine amidinotransferase (a Cr synthetase) or SLC6A8, a Cr transporter with mutations among the most common causes of intellectual disability in men. Calcium-dependent release of Cr was detected after stimulation in brain slices. Cr release was reduced in Slc6a8 and Agat mutants. Cr inhibited neocortical pyramidal neurons. SLC6A8 was necessary for Cr uptake into synaptosomes. Cr was found by us to be taken up into SVs in an ATP-dependent manner. Our biochemical, chemical, genetic, and electrophysiological results are consistent with the possibility of Cr as a neurotransmitter, though not yet reaching the level of proof for the now classic transmitters. Our novel approach to discover neurotransmitters is to begin with analysis of contents in SVs before defining their function and physiology.


Assuntos
Creatina , Deficiência Intelectual , Masculino , Humanos , Camundongos , Animais , Creatina/genética , Deficiência Intelectual/genética , Sistema Nervoso Central , Neurotransmissores , Eletrofisiologia
18.
Nat Commun ; 14(1): 7414, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37973849

RESUMO

Supported metal catalysts often suffer from rapid degradation under harsh conditions due to material failure and weak metal-support interaction. Here we propose using reductive hydrogenated borophene to in-situ synthesize Pt/B/C catalysts with small sizes (~2.5 nm), high-density dispersion (up to 80 wt%Pt), and promising stability, originating from forming Pt-B bond which are theoretically ~5× stronger than Pt-C. Based on the Pt/B/C module, a series (~18 kinds) of carbon supported binary, ternary, quaternary, and quinary Pt intermetallic compound nanocatalysts with sub-4 nm size are synthesized. Thanks to the stable intermetallics and strong metal-support interaction, annealing at 1000 °C does not cause those nanoparticles sintering. They also show much improved activity and stability in electrocatalytic oxygen reduction reaction. Therefore, by introducing the boron chemistry, the hydrogenated borophene derived multielement catalysts enable the synergy of small size, high loading, stable anchoring, and flexible compositions, thus demonstrating high versatility toward efficient and durable catalysis.

19.
Light Sci Appl ; 12(1): 230, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37714841

RESUMO

Diffractive liquid-crystal optics is a promising optical element for virtual reality (VR) and mixed reality as it provides an ultrathin formfactor and lightweight for human factors and ergonomics. However, its severe chromatic aberrations impose a big challenge for full-color display applications. In this study, we demonstrate an achromatic diffractive liquid-crystal device to overcome this longstanding chromatic aberration issue. The proposed device consists of three stacked diffractive liquid crystal optical elements with specifically designed spectral response and polarization selectivity. The concept is validated by both simulations and experiments. Our experimental results show a significant improvement in imaging performance with two types of light engines: a laser projector and an organic light-emitting diode display panel. In addition, our simulation results indicate that the lateral color shift is reduced by ~100 times in comparison with conventional broadband diffractive liquid-crystal lens. Potential applications for VR-enabled metaverse, spatial computing, and digital twins that have found widespread applications in smart tourism, smart education, smart healthcare, smart manufacturing, and smart construction are foreseeable.

20.
Elife ; 122023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37440432

RESUMO

Human mutations in the gene encoding the solute carrier (SLC) 6A17 caused intellectual disability (ID). The physiological role of SLC6A17 and pathogenesis of SLC6A17-based-ID were both unclear. Here, we report learning deficits in Slc6a17 knockout and point mutant mice. Biochemistry, proteomic, and electron microscopy (EM) support SLC6A17 protein localization in synaptic vesicles (SVs). Chemical analysis of SVs by liquid chromatography coupled to mass spectrometry (LC-MS) revealed glutamine (Gln) in SVs containing SLC6A17. Virally mediated overexpression of SLC6A17 increased Gln in SVs. Either genetic or virally mediated targeting of Slc6a17 reduced Gln in SVs. One ID mutation caused SLC6A17 mislocalization while the other caused defective Gln transport. Multidisciplinary approaches with seven types of genetically modified mice have shown Gln as an endogenous substrate of SLC6A17, uncovered Gln as a new molecule in SVs, established the necessary and sufficient roles of SLC6A17 in Gln transport into SVs, and suggested SV Gln decrease as the key pathogenetic mechanism in human ID.


Assuntos
Deficiência Intelectual , Vesículas Sinápticas , Animais , Camundongos , Glutamina/metabolismo , Deficiência Intelectual/genética , Deficiência Intelectual/metabolismo , Mutação , Proteômica , Vesículas Sinápticas/metabolismo
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