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1.
Neural Regen Res ; 20(2): 548-556, 2025 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38819066

RESUMO

JOURNAL/nrgr/04.03/01300535-202502000-00031/figure1/v/2024-05-28T214302Z/r/image-tiff Transforming growth factor-beta 1 (TGF-ß1) has been extensively studied for its pleiotropic effects on central nervous system diseases. The neuroprotective or neurotoxic effects of TGF-ß1 in specific brain areas may depend on the pathological process and cell types involved. Voltage-gated sodium channels (VGSCs) are essential ion channels for the generation of action potentials in neurons, and are involved in various neuroexcitation-related diseases. However, the effects of TGF-ß1 on the functional properties of VGSCs and firing properties in cortical neurons remain unclear. In this study, we investigated the effects of TGF-ß1 on VGSC function and firing properties in primary cortical neurons from mice. We found that TGF-ß1 increased VGSC current density in a dose- and time-dependent manner, which was attributable to the upregulation of Nav1.3 expression. Increased VGSC current density and Nav1.3 expression were significantly abolished by preincubation with inhibitors of mitogen-activated protein kinase kinase (PD98059), p38 mitogen-activated protein kinase (SB203580), and Jun NH2-terminal kinase 1/2 inhibitor (SP600125). Interestingly, TGF-ß1 significantly increased the firing threshold of action potentials but did not change their firing rate in cortical neurons. These findings suggest that TGF-ß1 can increase Nav1.3 expression through activation of the ERK1/2-JNK-MAPK pathway, which leads to a decrease in the firing threshold of action potentials in cortical neurons under pathological conditions. Thus, this contributes to the occurrence and progression of neuroexcitatory-related diseases of the central nervous system.

2.
J Am Chem Soc ; 146(19): 12883-12888, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38709642

RESUMO

Polyamides represent one class of materials that is important in modern society. Because of the numerous potential applications of polyamides in various fields, there is a high demand for new polyamide structures, which necessitates the development of new polymerization methods. Herein, we report a novel and efficient palladium-catalyzed hydroaminocarbonylative polymerization of dienes and diamines for the synthesis of cycloaliphatic polyamides. The method employs readily available starting materials, proceeds in an atom-economic manner, and creates a series of new functional polyamides in high yields and high molecular weights. In contrast with the traditional polyamides based on adipic acid, the cycloaliphatic polyamides have superior thermal resistance, higher glass-transition temperature, and better solubility in common organic solvents, thus probably featuring the merits of high-performance and good processability.

3.
Angew Chem Int Ed Engl ; 63(26): e202406226, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38618886

RESUMO

In contrast to the kinetically favored outward isomerization-hydrocarbonylation of alkenes, the disfavored inward isomerization-hydrocarbonylation of alkenes remains an important challenge. Herein, we have developed a novel and effective palladium-catalyzed inward isomerization-hydroaminocarbonylation of unactivated alkenes and aniline hydrochlorides for the formation of synthetically valuable α-aryl carboxylic amides in high yields and high site-selectivities. The high efficiency of the reaction is attributed to a relay catalysis strategy, in which the Markovnikov-favored [PdH]-PtBu3 catalyst is responsible for inward isomerization, while the [PdH]-Ruphos catalyst is responsible for hydroaminocarbonylation of the resulting conjugated aryl alkenes. The reaction exhibits highly functional group tolerance and provides a new method for formal carbonylation of remote C(sp3)-H bond.

4.
Org Lett ; 25(45): 8110-8115, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37921830

RESUMO

The current investigation presents an innovative palladium-catalyzed asymmetric carbonylative Heck esterification method. This approach facilitates the efficient synthesis of various chiral γ-ketoacid esters by utilizing o-alkenyliodobenzenes and arylboronic acids as primary substrates. This reaction achieves the creation of three carbon-carbon bonds, two carbon-oxygen bonds, and the establishment of a quaternary carbon center within a single step. The α-chiral γ-ketoacid esters were obtained in yields ranging from good to high yields, displaying enantiomeric excesses (ee's) levels up to 92% under mild reaction conditions.

5.
Int Immunopharmacol ; 124(Pt B): 110943, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37804654

RESUMO

Activation of Toll-like receptor (TLR) 4 plays important roles in the influenzaA virus (IAV) infection. To explore TLR4 inhibitors, 161 traditional Chinese medicines (TCMs) were screened. Further, we screened out Ixeris sonchifolia Hance, and its active compound, Apigetrin (apigenin-7-O-glucoside). Antiviral activity of Apigetrin was determined by plaque assay. We also further investigated the influence of Apigetrin on immune signaling pathways including TLRs, MAPK, NF-κB and autophagy pathways. The in-vitro results showed that the extract and its several ingredients could significantly inhibit IAV replication. Apigetrin significantly improved IAV-induced oxidative stress, inhibited the IAV-induced cytokine storm by suppressing the excessive activation of TLR3/4/7, JNK/p38 MAPK and NF-κB. Apigetrin decreased autophagosome accumulation and promoted degradation of IAV protein. Interestingly, Apigetrin antiviral activity was reversed by using H2O2 and the agonists of TLR4, JNK/p38, NF-κB and autophagy. Most important, the in-vitro effective concentration is higher than the reported plasma concentration. The in-vivo test showed that Apigetrin significantly increased the average survival time, reduced the lung edema and IAV replication. In conclusion, we have found that Ixeris sonchifolia Hance and its several ingredients can inhibit IAV infection, and the mechanisms of action of Apigetrin against IAV is by regulating TLR4 and autophagy signaling pathways.


Assuntos
Vírus da Influenza A , Influenza Humana , Humanos , Influenza Humana/tratamento farmacológico , Vírus da Influenza A/fisiologia , NF-kappa B/metabolismo , Apigenina/uso terapêutico , Receptor 4 Toll-Like/metabolismo , Avaliação Pré-Clínica de Medicamentos , Peróxido de Hidrogênio/farmacologia , Replicação Viral , Antivirais/farmacologia , Antivirais/uso terapêutico , Autofagia
6.
Front Microbiol ; 14: 1165721, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37664129

RESUMO

Introduction: Candida palmioleophila is a rare human pathogenic fungus, which has been poorly characterized at the genome level. In this study, we reported the first fatal case of C. palmioleophila infection in China and investigate the microevolution of C. palmioleophila in the human host environment. Methods: A series of C. palmioleophila stains were collected from the patient at different time points for routine microbial and drug sensitivity testing. The first C. palmioleophila isolate 07202534 was identified by de novo whole genome sequencing. The in vitro and in vivo genetic evolutionary characteristics of C. palmioleophila were discussed based on the analysis of bioinformatics data. Results: The six C. palmioleophila isolates displayed dose-dependent sensitivity to fluconazole. The C. palmioleophila genome contained homologous genes such as CDR1 and MDR1, which were recognized to be related to azole resistance. In addition, amino acid variation was detected at F105L and other important sites of ERG11. In addition, the mean divergence time between C. palmioleophila and Scheffersomyces stipites CBS 6054 was 406.04 million years, indicating that C. palmioleophila originated earlier than its closest relative. In addition, the six strains of C. palmioleophila isolated form the patient had higher homology and fewer mutation sites, which indicated the stability in C. palmioleophila genome. We also found that C. palmioleophila had a wide natural niche and may evolve slowly. Discussion: We believe that this study will contribute to improve our understanding of the genetic evolution, pathogenicity, and drug resistance of C. palmioleophila and will aid in the prevention and control of its spread.

7.
Macromol Rapid Commun ; 44(20): e2300281, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37543181

RESUMO

Intelligent actuating materials have drawn enormous attention because of their potential applications in soft robots, smart sensors, bionics, etc. Aiming to integrate light, thermal, and humidity stimuli deformations and self-healing function into a single polymer, a smart actuating polyurethane material CPPU-50 is designed and successfully synthesized through co-polymerization of azobenzene-containing Azo-C12 , polyethylene glycol 200 (PEG200), and 4,4'-diphenylmethane diisocyanate (MDI) at a ratio of 1:1:2. The obtained polyurethane CPPU-50 exhibits good photoinduced bending, thermal responsive shape memory effect, humidity triggered deflections and self-healing properties. Furthermore, an actuator combining light and thermal stimuli is created and the self-healing CPPU-50 film can withstand the object of 1800 times without tearing. This work can pave a way for further development of long-lived multi-stimuli-responsive actuating devices and intelligent materials.


Assuntos
Poliuretanos , Materiais Inteligentes , Umidade , Biônica , Polietilenoglicóis , Polímeros
8.
Nat Commun ; 14(1): 2572, 2023 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-37142571

RESUMO

Activation and cleavage of carbon-carbon (C-C) bonds is a fundamental transformation in organic chemistry while inert C-C bonds cleavage remains a long-standing challenge. Retro-Diels-Alder (retro-DA) reaction is a well-known and important tool for C-C bonds cleavage but less been explored in methodology by contrast to other strategies. Herein, we report a selective C(alkyl)-C(vinyl) bond cleavage strategy realized through the transient directing group mediated retro-Diels-Alder reaction of a six-membered palladacycle, which is obtained from an in situ generated hydrazone and palladium hydride species. This unprecedented strategy exhibits good tolerances and thus offers new opportunities for late-stage modifications of complex molecules. DFT calculations revealed that an intriguing retro-Pd(IV)-Diels-Alder process is possibly involved in the catalytic cycle, thus bridging both Retro-Diels-Alder reaction and C-C bond cleavage. We anticipate that this strategy should prove instrumental for potential applications to achieve the modification of functional organic skeletons in synthetic chemistry and other fields involving in molecular editing.

9.
Ann Clin Transl Neurol ; 10(7): 1058-1071, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37198730

RESUMO

OBJECTIVE: The aim of this study was to examine the predictive value of the multiplication of neutrophil and monocyte counts (MNM) in peripheral blood, and develop a new predictive model for the prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH). METHODS: This is a retrospective analysis that included 2 separate cohorts of patients undergoing endovascular coiling for aSAH. The training cohort consisted of 687 patients in the First Affiliated Hospital of Shantou University Medical College; the validation cohort consisted of 299 patients from Sun Yat-sen University's Affiliated Jieyang People's Hospital. The training cohort was used to develop 2 models to predict unfavorable prognosis (modified Rankin scale of 3-6 at 3 months): one was based on traditional factors (e.g., age, modified Fisher grade, NIHSS score, and blood glucose), and another model that included traditional factors as well as MNM on admission. RESULTS: In the training cohort, MNM upon admission was independently associated with unfavorable prognosis (odds ratio after adjustment, 1.06; 95% confidence interval [CI], 1.03-1.10). In the validation cohort, the basic model that included only traditional factors had 70.99% sensitivity, 84.36% specificity, and 0.859 (95% CI, 0.817-0.901) area under the receiver operating characteristic curve (AUC). Adding MNM increased model sensitivity (from 70.99% to 76.48%), specificity (from 84.36% to 88.63%), and overall performance (AUC 0.859 [95% CI, 0.817-0.901] to 0.879 [95% CI, 0.841-0.917]). INTERPRETATION: MNM upon admission is associated with unfavorable prognosis in patients undergoing endovascular embolization for aSAH. The nomogram including MNM is a user-friendly tool to help clinicians quickly predict the outcome of patients with aSAH.


Assuntos
Nomogramas , Hemorragia Subaracnóidea , Humanos , Hemorragia Subaracnóidea/diagnóstico , Hemorragia Subaracnóidea/complicações , Estudos Retrospectivos , Prognóstico , Neutrófilos
10.
Nat Commun ; 14(1): 3167, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37258529

RESUMO

Novel strategy for acid chlorides formation that do not use carboxylic acids is particularly attractive in chemical synthesis but remains challenging. Herein, we reported the development of a highly effective Pd-catalyzed hydrochlorocarbonylation of alkenes with CO for the formation of alkyl acid chlorides. Chlorosilane and AcOH were found as a mild HCl source for the reaction. The reaction shows broad substrate scope and produces both branched and linear alkyl acid chlorides in good to high yields upon different ligands and solvents. Cooperating with follow-up acylation reactions, the Pd-catalyzed hydrochlorocarbonylation offers a complementary platform for the synthesis of diverse carbonyl compounds from alkenes. Mechanistic investigations suggested that the reaction proceeded though a palladium hydride pathway, and CO prompted reductive elimination of the acyl-Pd-Cl intermediate.

11.
J Phys Condens Matter ; 35(23)2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-36913735

RESUMO

Bi4Br4is a quasi-one-dimensional van der Waals topological insulator with novel electronic properties. Several efforts have been devoted to the understanding of its bulk form, yet it remains a challenge to explore the transport properties in low-dimensional structures due to the difficulty of device fabrication. Here we report for the first time a gate-tunable transport in exfoliated Bi4Br4nanobelts. Notable two-frequency Shubnikov-de Haas oscillations oscillations are discovered at low temperatures, with the low- and high-frequency parts coming from the three-dimensional bulk state and the two-dimensional surface state, respectively. In addition, ambipolar field effect is realized with a longitudinal resistance peak and a sign reverse in the Hall coefficient. Our successful measurements of quantum oscillations and realization of gate-tunable transport lay a foundation for further investigation of novel topological properties and room-temperature quantum spin Hall states in Bi4Br4.

12.
Biomed Pharmacother ; 160: 114304, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36724638

RESUMO

Ovarian cancer is the second cause of death among gynecological malignancies. In this study, we designed a novel estrogen-targeted PEGylated liposome loaded with oxaliplatin and paclitaxel (ES-SSL-OXA/PTX) which could target estrogen receptor (ER) highly expressed on the surface of SKOV-3 cells to enhance therapeutic efficacy and reduce the side effects for SKOV-3 tumor therapy. ES-SSL-OXA/PTX was prepared by thin film hydration method and exhibited a uniform spherical morphology. Encapsulation efficiency (EE) were determined by HPLC method with the results of 44.10% for OXA and 65.85% for PTX. The mean particle size and polydispersity index (PDI) were 168.46 nm and 0.145, respectively. In vivo and in vitro targeting study confirmed that ES-SSL-OXA/PTX has optimum specific targeting ability. Meanwhile, In vitro and in vivo antitumor results of ES-SSL-OXA/PTX exhibited a superior antiproliferative effect on SKOV-3 cells and a stronger anti-tumor efficacy with the tumor inhibition rate of 85.24%. The pharmacokinetics results of ES-SSL-OXA/PTX showed a prolonged half-life time and a slowed clearance rate. The preliminary safety study of acute toxicity and long-term toxicity demonstrated ES-SSL-OXA/PTX exhibited a reduced toxicity profile. Based on the above results, ES-SSL-OXA/PTX could be a promising novel formulation for the treatment of ovarian cancer in future clinic.


Assuntos
Nanopartículas , Neoplasias Ovarianas , Feminino , Humanos , Paclitaxel , Lipossomos/farmacocinética , Oxaliplatina/uso terapêutico , Linhagem Celular Tumoral , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Sistemas de Liberação de Medicamentos/métodos , Estrogênios/uso terapêutico , Polietilenoglicóis/uso terapêutico
13.
Int Immunopharmacol ; 115: 109706, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36638664

RESUMO

Influenza A viruses (IAV), significant respiratory pathogenic agents, cause seasonal epidemics and global pandemics in intra- and interannual cycles. Despite effective therapies targeting viral proteins, the continuous generation of drug-resistant IAV strains is challenging. Therefore, exploring novel host-specific antiviral treatment strategies is urgently needed. Here, we found that lidocaine, widely used for local anesthesia and sedation, significantly inhibited H1N1(PR8) replication in macrophages. Interestingly, its antiviral effect did not depend on the inhibition of voltage-gated sodium channels (VGSC), the main target of lidocaine for anesthesia. Lidocaine significantly upregulated early IFN-I, interferon α4 (IFNα4) mRNA, and protein levels, but not those of early IFNß in mouse RAW 264.7 cell line and human THP-1 derived macrophages. Knocking out IFNα4 by CRISPR-Cas9 partly reversed lidocaine's inhibition of PR8 replication in macrophages. Mechanistically, lidocaine upregulated IFNα4 by activating TANK-binding kinase 1 (TBK1)-IRF7 and JNK-AP1 signaling pathways. These findings indicate that lidocaine has an incredible antiviral potential by enhancing IFN-I signaling in macrophages. In conclusion, our results indicate the potential auxiliary role of lidocaine for anti-influenza A virus therapy and even for anti-SARS-CoV-2 virus therapy, especially in the absence of a specific medicine.


Assuntos
COVID-19 , Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A , Influenza Humana , Interferon Tipo I , Animais , Humanos , Camundongos , Interferon-alfa , Lidocaína/farmacologia , Antivirais/farmacologia , Transdução de Sinais , Interferon Tipo I/farmacologia , Replicação Viral , Influenza Humana/tratamento farmacológico , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/farmacologia , Fator Regulador 7 de Interferon
14.
Front Immunol ; 13: 974864, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36091068

RESUMO

T lymphocytes are key players in the pathogenesis of autoimmune diabetes. We recruited subjects with T1D (n=81), LADA (n=82), T2D (n=95) and NGT (n=218) and analyzed the percentages of T-lymphocyte subsets, including T helper 1 (Th1), T helper 2 (Th2), T helper 17 (Th17), T cytotoxic 1 (Tc1), regulatory T cells (Tregs), effector T (Teff), naïve T, central memory T (Tcm), and effector memory T (Tem) cells by flow cytometry. LADA patients possessed similar frequencies of IFN-γ+CD4+ T (Th1), IFN-γ+CD8+ T and CD4+ Teff cells compared with T1D patients, but much lower than those of NGT subjects. Like T2D patients, LADA patients had increased frequencies of CD4+ Tem and CD8+ Tem cells with respect to T1D and NGT subjects. In LADA patients, Th2 cells were decreased while CD4+ Tcm cells were increased compared with NGT subjects. Notably, we observed significant negative correlations between the CD4+ Tcm cell frequency and C-peptide in LADA subjects. These data demonstrates that LADA patients possess T-cell subset changes resembling both T1D and T2D and represent the middle of the diabetes spectrum between T1D and T2D. Based on these T-cell subset alterations, we speculate that autoimmunity-induced ß-cell destruction and inflammation-induced insulin resistance might both be involved in the pathogenesis of LADA.


Assuntos
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Intolerância à Glucose , Diabetes Autoimune Latente em Adultos , Adulto , Humanos , Subpopulações de Linfócitos T/patologia , Linfócitos T Reguladores
15.
ACS Nano ; 16(5): 8128-8140, 2022 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-35511070

RESUMO

The near-infrared polarimetric image sensor has a wide range of applications in the military and civilian fields, thus developing into a research hotspot in recent years. Because of their distinguishing 1D structure features, the ordered GaSb nanowire (NW) arrays possess potential applications for near-infrared polarization photodetection. In this work, single-crystalline GaSb NWs are synthesized through a sulfur-catalyzed chemical vapor deposition process. A sulfur-passivation thin layer is formed on the NW surface, which prevents the GaSb NW core from being oxidized. The photodetector based on sulfur-passivation GaSb (S-GaSb) NWs has a lower dark current and higher responsivity than that built with pure GaSb NWs. The photodetector exhibits a large responsivity of 9.39 × 102 A/W and an ultrahigh detectivity of 1.10 × 1011 Jones for 1.55 µm incident light. Furthermore, the dichroic ratio of the device is measured to reach 2.65 for polarized 1.55 µm light. Through a COMSOL simulation, it is elucidated that the origin of the polarized photoresponse is the attenuation of a light electric field inside the NW when the angle of incident polarization light rotates. Moreover, a flexible polarimetric image sensor with 5 × 5 pixels is successfully constructed on the ordered S-GaSb NW arrays, and it exhibits a good imaging ability for incident near-infrared polarization light. These good photoresponse properties and polarized imaging abilities can empower ordered S-GaSb NW arrays with technological potentials in next-generation large-scale near-infrared polarimetric imaging sensors.

16.
Org Lett ; 23(23): 9241-9245, 2021 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-34767367

RESUMO

Rhodium-catalyzed asymmetric desymmetrization Pauson-Khand reaction of C4-alkynyl-tethered cyclohexadienones has been developed as a novel strategy for access to fused 6-5-5 tricycles bearing three consecutive stereogenic centers. An array of chiral tricyclo[6.2.1.04,11]undecenes have been synthesized in high yields and enantioselectivities in a single step under mild conditions. This strategy employs readily accessible internal-olefin-containing 1,6-enynes, providing a potentially powerful tool for constructing chiral polycyclic scaffolds of complex molecules containing cyclopentenones and cyclohexenones.

17.
Nat Commun ; 12(1): 6476, 2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34753933

RESUMO

Polarized light can provide significant information about objects, and can be used as information carrier in communication systems through artificial modulation. However, traditional polarized light detection systems integrate polarizers and various functional circuits in addition to detectors, and are supplemented by complex encoding and decoding algorithms. Although the in-plane anisotropy of low-dimensional materials can be utilized to manufacture polarization-sensitive photodetectors without polarizers, the low anisotropic photocurrent ratio makes it impossible to realize digital output of polarized information. In this study, we propose an integrated polarization-sensitive amplification system by introducing a nanowire polarized photodetector and organic semiconductor transistors, which can boost the polarization sensitivity from 1.24 to 375. Especially, integrated systems are universal in that the systems can increase the anisotropic photocurrent ratio of any low-dimensional material corresponding to the polarized light. Consequently, a simple digital polarized light communication system can be realized based on this integrated system, which achieves certain information disguising and confidentiality effects.

18.
J Food Sci ; 86(10): 4554-4565, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34519054

RESUMO

Combinations of phytochemical(s) and engineered nanoparticles have attracted immense research interest due to their superior antimicrobial effects against contaminations. Herein, a Pickering emulsion is developed with capsulized phytochemicals including borneol and citral (BC-Cap) stabilized by hydrophilic amine-functionalized silica nanoparticles (SiO2 ─NH2 NPs). The droplet sizes of Pickering emulsion were 5.2 ± 1.4 µm under the condition that the concentrations of SiO2 ─NH2 NPs ranged from 0.6 to 1.2 wt.%, and the emulsion showed desirable stability during storage at 40°C for 365 days. In addition, the antibacterial and antibiofilm activities of the Pickering emulsion were investigated. The antibacterial effect of BC-Cap increased by two- to fourfold compared with citral or borneol alone. Treatment of BC/BC-Cap for 4 h eliminated the formation of biofilms generated by Listeria monocytogenes (at 5/1.25 mg/ml; 2 × MIC concentration) and Pseudomonas aeruginosa (at 5/2.5 mg/ml; 2 × MIC concentration). Further mechanistic studies revealed that the antibiofilm effects of BC-Cap were attributed to its ability to increase the porosity and lytic effects on the cell membrane of bacteria. Findings from the current study support the antibacterial and antibiofilm effects of BC-Cap Pickering emulsion as a promising food additive. PRACTICAL APPLICATION: The Pickering emulsion has potential applications as bacteriostatic agent in packaging materials and general surface disinfectant. The combination of borneol and citral is stabilized by hydrophilic amine-functionalized silica nanoparticles (SiO2 ─NH2 NPs). With the synergistic effects of borneol and citral, the Pickering emulsion shows a promising elimination effect against the formation of biofilms produced by Listeria monocytogenes and Pseudomonas aeruginosa.


Assuntos
Monoterpenos Acíclicos , Antibacterianos , Canfanos , Nanopartículas , Monoterpenos Acíclicos/química , Antibacterianos/farmacologia , Canfanos/química , Emulsões/química , Listeria monocytogenes/efeitos dos fármacos , Nanopartículas/química , Tamanho da Partícula , Pseudomonas aeruginosa/efeitos dos fármacos , Dióxido de Silício
19.
J Phys Chem Lett ; 12(32): 7832-7839, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34379422

RESUMO

Thermoelectric materials which enable heat-to-electricity conversion are fundamentally important for heat management in semiconductor devices. Achieving high thermoelectric performance requires blocking the thermal transport and maintaining the high electronic transport, but it is a challenge to satisfy both criteria simultaneously. We propose that tuning the interlayer distance can effectively modulate the electrical and thermal conductivities. We find group IV-VI and V semiconductors with a moderate interlayer distance can exhibit high thermoelectric performance. Taking SnSe as an example, we reveal that in the out-of-plane direction the delocalized pz orbitals combined with the relatively small interlayer distance lead to overlapping of the antibonding state wave functions, which is beneficial for high electronic transport. However, because of the breakdown of the chemical bond, the out-of-plane thermal conductivity is small. This study provides a strategy to enhance electrical conductivity without increasing thermal conductivity and thus sheds light on the design of thermoelectric devices.

20.
Angew Chem Int Ed Engl ; 60(43): 23117-23122, 2021 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-34240535

RESUMO

Asymmetric hydroxycarbonylation is one of the most fundamental yet challenging methods for the synthesis of carboxylic acids. Herein, we reported the development of a palladium-catalyzed highly enantioselective Markovnikov hydroxycarbonylation of vinyl arenes with CO and water. A monodentate phosphoramidite ligand L6 plays vital role in the reaction. The reaction tolerates a range of functional groups, and provides a facile and atom-economical approach to an array of 2-arylpropanoic acids including several commonly used non-steroidal anti-inflammatory drugs. The catalytic system has also enabled an asymmetric Markovnikov hydroalkoxycarbonylation of vinyl arenes with alcohols to afford 2-arylpropanates. Mechanistic investigations suggested that the hydropalladation is irreversible and is the regio- and enantiodetermining step, while hydrolysis/alcoholysis is probably the rate-limiting step.

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