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1.
Nano Lett ; 21(22): 9619-9624, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34748355

RESUMO

Layered sodium manganese-based oxides are appealing cathode candidates due to their high capacity and cost-effectiveness, yet performance degradation related with unwanted structural evolution still remains a disturbing disadvantage. Herein, atomic resolution STEM (scanning transmission electron microscopy) images of Na-extracted Na2/3NixCo1/3-xMn2/3O2 (x = 0, 1/6, 1/3) are collected and analyzed, to decipher the effect of cobalt and nickel substitution on the structural integrity of layered manganese-based oxides. Cobalt substitution is demonstrated to alleviate the lattice stress and retain the layered structure after sodium removal, and only a local P2-to-O2 phase transition could be identified. By contrast, various types of defects and phase transformation, including rarely reported P2-to-O3, are discovered in the Ni-substituted oxides. The generation of spinel and rock-salt phases is the critical evidence of cation mixing that leads to unrecoverable capacity loss. The interplay of different transition metals is complex, and compositional optimization is encouraged to minimize the effect of the concomitant phase transition.

2.
Nat Commun ; 12(1): 6806, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34815417

RESUMO

Single-atom catalysts (SACs) have been applied in many fields due to their superior catalytic performance. Because of the unique properties of the single-atom-site, using the single atoms as catalysts to synthesize SACs is promising. In this work, we have successfully achieved Co1 SAC using Pt1 atoms as catalysts. More importantly, this synthesis strategy can be extended to achieve Fe and Ni SACs as well. X-ray absorption spectroscopy (XAS) results demonstrate that the achieved Fe, Co, and Ni SACs are in a M1-pyrrolic N4 (M= Fe, Co, and Ni) structure. Density functional theory (DFT) studies show that the Co(Cp)2 dissociation is enhanced by Pt1 atoms, thus leading to the formation of Co1 atoms instead of nanoparticles. These SACs are also evaluated under hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), and the nature of active sites under HER are unveiled by the operando XAS studies. These new findings extend the application fields of SACs to catalytic fabrication methodology, which is promising for the rational design of advanced SACs.

3.
Org Biomol Chem ; 2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34751696

RESUMO

Triptycene derivatives, a type of specific aromatic compound, have been attracting much attention in many research areas. Over the past several years, triptycene and its derivatives have been described to be useful and efficient building blocks for the design and synthesis of novel supramolecular acceptors, porous materials and luminescent materials with specific structures and properties. In this review, recent researches on triptycene derivatives in supramolecular and materials chemistry are summarized. Especially, the construction of a new type of macrocyclic arenes and organic cages with triptycene and its derivatives as building blocks are focused on, and their applications in molecular recognition, self-assembly and gas selective sorption are highlighted. Moreover, the applications of triptycene and its derivatives in porous organic materials and thermally activated delayed fluorescence (TADF) materials are also discussed.

4.
Adv Mater ; : e2102562, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34643001

RESUMO

Optoelectronic science and 2D nanomaterial technologies are currently at the forefront of multidisciplinary research and have numerous applications in electronics and photonics. The unique energy and optically induced interfacial electron transfer in these nanomaterials, enabled by their relative band alignment characteristics, can provide important therapeutic modalities for healthcare. Given that nano-heterostructures can facilitate photoinduced electron-hole separation and enhance generation of reactive oxygen species (ROS), 2D nano-heterostructure-based photosensitizers can provide a major advancement in photodynamic therapy (PDT), to overcome the current limitations in hypoxic tumor microenvironments. Herein, a bismuthene/bismuth oxide (Bi/BiOx)-based lateral nano-heterostructure synthesized using a regioselective oxidation process is introduced, which, upon irradiation at 660 nm, effectively generates 1 O2 under normoxia but produces cytotoxic •OH and H2 under hypoxia, which synergistically enhances PDT. Furthermore, this Bi/BiOx nano-heterostructure is biocompatible and biodegradable, and, with the surface molecular engineering used here, it improves tumor tissue penetration and increases cellular uptake during in vitro and in vivo experiments, yielding excellent oxygen-independent tumor ablation with 660 nm irradiation, when compared with traditional PDT agents.

5.
Dis Markers ; 2021: 4029470, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34671434

RESUMO

The pathogenesis of benign prostatic hyperplasia (BPH) is extremely complicated which involving the multiple signaling pathways. The deficiency of vitamin D is an important risk factor for BPH, and exogenous vitamin D is effective for the treatment of BPH. In this study, we provided in vitro mechanical evidence of vitamin D as a treatment for BPH using BPH-1, WPMY-1, and PBMC cells. We found that 25-hydroxyvitamin D (25-OH D) level is decreased in BPH and closely correlated with age, prostate volume, maximum flow, international prostate symptom score, and prostate-specific antigen of the BPH patients. We further revealed that 25-OH D ameliorated TGF-ß1 induces epithelial-mesenchymal transition (EMT) of BPH-1 cells and proliferation of WPMY-1 cells via blocking TGF-ß signaling. Moreover, 25-OH D was able to block NF-κB signaling in PBMCs of BPH patients and STAT3 signaling in BPH cells to relieve inflammation. 25-OH D also protects BPH cells from inflammatory cytokines selected by PBMCs. Finally, we uncovered that 25-OH D alleviated prostate cell oxidative stress by triggering Nrf2 signaling. In conclusion, our data verified that 25-OH D regulated multiple singling pathways to restrain prostate cell EMT, proliferation, inflammation, and oxidative stress. Our study provides in vitro mechanical evidence to support clinical use of vitamin D as a treatment for BPH.

6.
Adv Sci (Weinh) ; : e2102178, 2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34713629

RESUMO

Multiferroic materials with flexibility are expected to make great contributions to flexible electronic applications, such as sensors, memories, and wearable devices. In this work, super-flexible freestanding BiMnO3 membranes with simultaneous ferroelectricity and ferromagnetism are synthesized using water-soluble Sr3 Al2 O6 as the sacrificial buffer layer. The super-flexibility of BiMnO3 membranes is demonstrated by undergoing an ≈180° folding during an in situ bending test, which is consistent with the results of first-principles calculations. The piezoelectric signal under a bending radius of ≈500 µm confirms the stable existence of electric polarization in freestanding BiMnO3 membranes. Moreover, the stable ferromagnetism of freestanding BiMnO3 membranes is demonstrated after 100 times bending cycles with a bending radius of ≈2 mm. 5.1% uniaxial tensile strain is achieved in freestanding BiMnO3 membranes, and the piezoresponse force microscopy (PFM) phase retention behaviors confirm that the ferroelectricity of membranes can survive stably up to the strain of 1.7%. These super-flexible membranes with stable ferroelectricity and ferromagnetism pave ways to the realizations of multifunctional flexible electronics.

7.
Nano Lett ; 21(22): 9675-9683, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34668713

RESUMO

Developing advanced electrode materials with enhanced charge-transfer kinetics is the key to realizing fast energy storage technologies. Commonly used modification strategies, such as nanoengineering and carbon coating, are mainly focused on electron transfer and bulk Li+ diffusion. Nonetheless, the desolvation behavior, which is considered as the rate-limiting process for charge-storage, is rarely studied. Herein, we designed a nitridation layer on the surface of Wadsley-Roth phase FeNb11O29 (FNO-x@N) to act as a desolvation promoter. Theoretical calculations demonstrate that the adsorption and desolvation of solvated Li+ is efficiently improved at FNO-x@N/electrolyte interphase, leading to the reduced desolvation energy barrier. Moreover, the nitridation layer can also help to prevent solvent cointercalation during Li+ insertion, leading to advantageous shrinkage of block area and reduced volume change of lattice cell during cycling. Consequently, FNO-x@N exhibits a high-rate capacity of 129.7 mAh g-1 with negligible capacity decay for 10 000 cycles.

9.
Adv Mater ; 33(43): e2102666, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34499778

RESUMO

Potassium-based solid electrolyte interphases (SEIs) have a much smaller damage threshold than their lithium counterpart; thus, they are significantly more beam sensitive. Here, an ultralow-dose cryogenic transmission electron microscopy (cryo-TEM) technique (≈8 e Å-2 s-1  × 10 s), which enables the atomic-scale chemical imaging of the electron-beam-sensitive potassium metal and SEI in its native state, is adapted. The potassium-based SEI consists of large brackets of diverse inorganic phases (≈hundreds of nanometers) interspersed with amorphous phases, which are different from the tiny nanocrystalline inorganic phases (≈a few nanometers) formed in a lithium-based SEI. Organic phosphate-based electrolyte solvents induce the formation of a thin and stable SEI layer for enhanced cycling performance, while the carbonate ester-based electrolytes result in large quantities of metastable KHCO3 , and K4 CO4 products in the SEI, depleting the potassium reserves in the battery. The findings provide deep insights and guidance in the selection of optimum electrolytes that should be used for potassium batteries.

10.
BMC Neurol ; 21(1): 359, 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34530757

RESUMO

BACKGROUND: Reports have proven that shorter door-to-needle time (DTN time) indicates better outcomes in AIS patients received intravenous thrombolysis. Efforts have been made by hospitals and centers to minimize DTN time in many ways including introducing a stroke nurse. However, there are few studies to discuss the specific effect of stroke nurse on patients' prognosis. This study aimed to compare consecutive AIS patients before and after the intervention to analyze the effect of stroke nurse on clinical outcome of AIS patients. METHODS: In this retrospective study, we observed 1003 patients from November 2016 to December 2020 dividing in two groups, collected and analyzed AIS patients' medical history, clinical assessment information, important timelines, 90 mRS score, etc. Comparative analysis and mediation analysis were also used in this study. RESULTS: A total of 418 patients was included in this study, and 199 patients were enrolled in the stroke nurse group and 219 was in the preintervention group. Baseline characteristics of patients showed no significant difference except there seems more patients with previous ischemic stroke history in the group of stroke nurse. (p = 0.008). The median DTN time significantly decreased in the stroke nurse group (25 min versus 36 min, p < 0.001) and multivariate logistic regression analysis showed the 90-day mRS clinical outcome significantly improved in the stroke nurse group (p = 0.001). Mediation analysis indicated the reduction of DTN time plays a partial role on the 90 days mRS score and the stroke nurse has some direct effect on the improvement of clinical outcome (p = 0.006). CONCLUSIONS: The introduction of stroke nurse is beneficial to clinical outcome of AIS patients and can be use of reference in other hospitals or centers.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Isquemia Encefálica/complicações , Isquemia Encefálica/tratamento farmacológico , Fibrinolíticos/uso terapêutico , Humanos , Estudos Retrospectivos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica , Tempo para o Tratamento , Ativador de Plasminogênio Tecidual/uso terapêutico , Resultado do Tratamento
11.
Adv Mater ; : e2106353, 2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34569108

RESUMO

The sodium (potassium)-metal anodes combine low-cost, high theoretical capacity, and high energy density, demonstrating promising application in sodium (potassium)-metal batteries. However, the dendrites' growth on the surface of Na (K) has impeded their practical application. Herein, density functional theory (DFT) results predict Na2 Te/K2 Te is beneficial for Na+ /K+ transport and can effectively suppress the formation of the dendrites because of low Na+ /K+ migration energy barrier and ultrahigh Na+ /K+ diffusion coefficient of 3.7 × 10-10 cm2 s-1 /1.6 × 10-10 cm2 s-1 (300 K), respectively. Then a Na2 Te protection layer is prepared by directly painting the nanosized Te powder onto the sodium-metal surface. The Na@Na2 Te anode can last for 700 h in low-cost carbonate electrolytes (1 mA cm-2 , 1 mAh cm-2 ), and the corresponding Na3 V2 (PO4 )3 //Na@Na2 Te full cell exhibits high energy density of 223 Wh kg-1 at an unprecedented power density of 29687 W kg-1 as well as an ultrahigh capacity retention of 93% after 3000 cycles at 20 C. Besides, the K@K2 Te-based potassium-metal full battery also demonstrates high power density of 20 577 W kg-1 with energy density of 154 Wh kg-1 . This work opens up a new and promising avenue to stabilize sodium (potassium)-metal anodes with simple and low-cost interfacial layers.

12.
J Am Chem Soc ; 143(34): 13605-13615, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34465098

RESUMO

Single-atom catalysts (SACs) with 100% active sites have excellent prospects for application in the oxygen evolution reaction (OER). However, further enhancement of the catalytic activity for OER is quite challenging, particularly for the development of stable SACs with overpotentials <180 mV. Here, we report an iridium single atom on Ni2P catalyst (IrSA-Ni2P) with a record low overpotential of 149 mV at a current density of 10 mA·cm-2 in 1.0 M KOH. The IrSA-Ni2P catalyst delivers a current density up to ∼28-fold higher than that of the widely used IrO2 at 1.53 V vs RHE. Both the experimental results and computational simulations indicate that Ir single atoms preferentially occupy Ni sites on the top surface. The reconstructed Ir-O-P/Ni-O-P bonding environment plays a vital role for optimal adsorption and desorption of the OER intermediate species, which leads to marked enhancement of the OER activity. Additionally, the dynamic "top-down" evolution of the specific structure of the Ni@Ir particles is responsible for the robust single-atom structure and, thus, the stability property. This IrSA-Ni2P catalyst offers novel prospects for simplifying decoration strategies and further enhancing OER performance.

13.
Nat Commun ; 12(1): 5235, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475400

RESUMO

Single-atom catalysts have been widely investigated for several electrocatalytic reactions except electrochemical alcohol oxidation. Herein, we synthesize atomically dispersed platinum on ruthenium oxide (Pt1/RuO2) using a simple impregnation-adsorption method. We find that Pt1/RuO2 has good electrocatalytic activity towards methanol oxidation in an alkaline media with a mass activity that is 15.3-times higher than that of commercial Pt/C (6766 vs. 441 mA mg‒1Pt). In contrast, single atom Pt on carbon black is inert. Further, the mass activity of Pt1/RuO2 is superior to that of most Pt-based catalysts previously developed. Moreover, Pt1/RuO2 has a high tolerance towards CO poisoning, resulting in excellent catalytic stability. Ab initio simulations and experiments reveal that the presence of Pt‒O3f (3-fold coordinatively bonded O)‒Rucus (coordinatively unsaturated Ru) bonds with the undercoordinated bridging O in Pt1/RuO2 favors the electrochemical dehydrogenation of methanol with lower energy barriers and onset potential than those encountered for Pt‒C and Pt‒Ru.

14.
ACS Appl Mater Interfaces ; 13(34): 41315-41322, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34410105

RESUMO

Integrating characteristics of materials through constructing artificial superlattices (SLs) has raised extensive attention in multifunctional materials. Here, we report the synthesis of BiFeO3/BiMnO3 SLs with considerable ferroelectric polarizations and tunable magnetic moments. The polarization of BiFeO3/BiMnO3 SLs presents a decent value of 12 µC/cm2, even as the dimensionality of BiFeO3 layers per period is reduced to about five-unit cells when keeping the BiMnO3 layers same. Moreover, it is found that the tunable magnetic moments of SLs are linked intimately to the dimensionality of BiFeO3 layers. Our simulations demonstrate that the superexchange interaction of Fe-O-Mn tends to be antiferromagnetic (AFM) with a lower magnetic domain formation energy rather than ferromagnetic (FM). Therefore, as the dimensionality of BiFeO3 per period is reduced, the AFM superexchange interaction between BiFeO3 and BiMnO3 in the SLs becomes weak, promoting a robust magnetization. This interlayer modulation effect in SLs presents an alluring way to accurately control the multiple order parameters in a multiferroic oxide system.

15.
J Pers Med ; 11(6)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199840

RESUMO

Genetic polymorphisms are defined as the presence of two or more different alleles in the same locus, with a frequency higher than 1% in the population. Since the discovery of long non-coding RNAs (lncRNAs), which refer to a non-coding RNA with a length of more than 200 nucleotides, their biological roles have been increasingly revealed in recent years. They regulate many cellular processes, from pluripotency to cancer. Interestingly, abnormal expression or dysfunction of lncRNAs is closely related to the occurrence of human diseases, including cancer and degenerative neurological diseases. Particularly, their polymorphisms have been found to be associated with altered drug response and/or drug toxicity in cancer treatment. However, molecular mechanisms are not yet fully elucidated, which are expected to be discovered by detailed studies of RNA-protein, RNA-DNA, and RNA-lipid interactions. In conclusion, lncRNAs polymorphisms may become biomarkers for predicting the response to chemotherapy in cancer patients. Here we review and discuss how gene polymorphisms of lncRNAs affect cancer chemotherapeutic response. This knowledge may pave the way to personalized oncology treatments.

16.
Front Cell Dev Biol ; 9: 615928, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249898

RESUMO

The role of high-fat diet (HFD) induced gut microbiota alteration and Ghrelin as well as their correlation in benign prostatic hyperplasia (BPH) were explored in our study. The gut microbiota was analyzed by 16s rRNA sequencing. Ghrelin levels in serum, along with Ghrelin and Ghrelin receptor in prostate tissue of mice and patients with BPH were measured. The effect of Ghrelin on cell proliferation, apoptosis, and induction of BPH in mice was explored. Our results indicated that BPH mice have the highest ratio of Firmicutes and Bacteroidetes induced by HFD, as well as Ghrelin level in serum and prostate tissue was significantly increased compared with control. Elevated Ghrelin content in the serum and prostate tissue of BPH patients was also observed. Ghrelin promotes cell proliferation while inhibiting cell apoptosis of prostate cells. The effect of Ghrelin on enlargement of the prostate was found almost equivalent to that of testosterone propionate (TP) which may be attenuated by Ghrelin receptor antagonist YIL-781. Ghrelin could up-regulate Jak2/pJak2/Stat3/pStat3 expression in vitro and in vivo. Our results suggested that Gut microbiota may associate with Ghrelin which plays an important role in activation of Jak2/Stat3 in BPH development. Gut microbiota and Ghrelin might be pathogenic factors for BPH and could be used as a target for mediation.

17.
Adv Mater ; 33(33): e2101425, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34235791

RESUMO

Hydrogen (H2 ) production from direct seawater electrolysis is an economically appealing yet fundamentally and technically challenging approach to harvest clean energy. The current seawater electrolysis technology is significantly hindered by the poor stability and low selectivity of the oxygen evolution reaction (OER) due to the competition with chlorine evolution reaction in practical application. Herein, iron and phosphor dual-doped nickel selenide nanoporous films (Fe,P-NiSe2 NFs) are rationally designed as bifunctional catalysts for high-efficiency direct seawater electrolysis. The doping of Fe cation increases the selectivity and Faraday efficiency (FE) of the OER. While the doping of P anions improves the electronic conductivity and prevents the dissolution of selenide by forming a passivation layer containing P-O species. The Fe-dopant is identified as the primary active site for the hydrogen evolution reaction, and meanwhile, stimulates the adjacent Ni atoms as active centers for the OER. The experimental analyses and theoretical calculations provide an insightful understanding of the roles of dual-dopants in boosting seawater electrolysis. As a result, a current density of 0.8 A cm-2 is archived at 1.8 V with high OER selectivity and long-term stability for over 200 h, which surpasses the benchmarking platinum-group-metals-free electrolyzers.

18.
Angew Chem Int Ed Engl ; 60(38): 20960-20969, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34258863

RESUMO

Most P2-type layered oxides exhibit a large volume change when they are charged into high voltage, and it further leads to bad structural stability. In fact, high voltage is not the reason which causes the irreversible phase transition. There are two internal factors which affect structural evolution: the amount and distribution of Na ions retained in the lattice. Hereon, a series of layered oxides Na2/3 Mnx Nix-1/3 Co4/3-2x O2 (1/3≤x≤2/3) were synthesized. It is observed that different components have different structural evolutions during the charge/discharge processes, and further researches find that the distribution of Na ions in layers is the main factor. By controlling the distribution of Na ions, the phase transition process can be well controlled. As the referential component, P2-Na2/3 Mn1/2 Ni1/6 Co1/3 O2 cathode with uniform distribution of Na ions is cycled at the voltage window of 1.5-4.5 V, which exhibits a volume change as low as 1.9 %. Such a low strain is beneficial for cycling stability. The current work provides a new and effective route to regulate the structural evolution of the promising P2-type layered cathode for sodium ion batteries.

19.
Neuroimage ; 241: 118430, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34314848

RESUMO

PURPOSE: Heating of gradient coils and passive shim components is a common cause of instability in the B0 field, especially when gradient intensive sequences are used. The aim of the study was to set a benchmark for typical drift encountered during MR spectroscopy (MRS) to assess the need for real-time field-frequency locking on MRI scanners by comparing field drift data from a large number of sites. METHOD: A standardized protocol was developed for 80 participating sites using 99 3T MR scanners from 3 major vendors. Phantom water signals were acquired before and after an EPI sequence. The protocol consisted of: minimal preparatory imaging; a short pre-fMRI PRESS; a ten-minute fMRI acquisition; and a long post-fMRI PRESS acquisition. Both pre- and post-fMRI PRESS were non-water suppressed. Real-time frequency stabilization/adjustment was switched off when appropriate. Sixty scanners repeated the protocol for a second dataset. In addition, a three-hour post-fMRI MRS acquisition was performed at one site to observe change of gradient temperature and drift rate. Spectral analysis was performed using MATLAB. Frequency drift in pre-fMRI PRESS data were compared with the first 5:20 minutes and the full 30:00 minutes of data after fMRI. Median (interquartile range) drifts were measured and showed in violin plot. Paired t-tests were performed to compare frequency drift pre- and post-fMRI. A simulated in vivo spectrum was generated using FID-A to visualize the effect of the observed frequency drifts. The simulated spectrum was convolved with the frequency trace for the most extreme cases. Impacts of frequency drifts on NAA and GABA were also simulated as a function of linear drift. Data from the repeated protocol were compared with the corresponding first dataset using Pearson's and intraclass correlation coefficients (ICC). RESULTS: Of the data collected from 99 scanners, 4 were excluded due to various reasons. Thus, data from 95 scanners were ultimately analyzed. For the first 5:20 min (64 transients), median (interquartile range) drift was 0.44 (1.29) Hz before fMRI and 0.83 (1.29) Hz after. This increased to 3.15 (4.02) Hz for the full 30 min (360 transients) run. Average drift rates were 0.29 Hz/min before fMRI and 0.43 Hz/min after. Paired t-tests indicated that drift increased after fMRI, as expected (p < 0.05). Simulated spectra convolved with the frequency drift showed that the intensity of the NAA singlet was reduced by up to 26%, 44 % and 18% for GE, Philips and Siemens scanners after fMRI, respectively. ICCs indicated good agreement between datasets acquired on separate days. The single site long acquisition showed drift rate was reduced to 0.03 Hz/min approximately three hours after fMRI. DISCUSSION: This study analyzed frequency drift data from 95 3T MRI scanners. Median levels of drift were relatively low (5-min average under 1 Hz), but the most extreme cases suffered from higher levels of drift. The extent of drift varied across scanners which both linear and nonlinear drifts were observed.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Análise de Dados , Bases de Dados Factuais/normas , Imageamento por Ressonância Magnética/normas , Espectroscopia de Ressonância Magnética/normas , Humanos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos
20.
Biomater Sci ; 9(9): 3410-3424, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33949388

RESUMO

There is an urgent need to develop novel antibiotic agents that can combat emerging drug resistance. Herein, we report the design and investigation of a class of short dimeric antimicrobial lipo-α/sulfono-γ-AA hybrid peptides. Some of these peptides exhibit potent and broad-spectrum antimicrobial activity toward both clinically related Gram-positive and Gram-negative bacteria. The TEM study suggests that these hybrid peptides can compromise bacterial membranes and lead to bacterial death. Membrane depolarization and fluorescence microscopy studies also indicate that the mechanism of action is analogous to host-defense peptides (HDPs). Furthermore, the lead compound shows the ability to effectively inhibit biofilms formed from MRSA and E. coli. Further development of the short dimeric lipo-α/sulfono-γ-AA hybrid peptides may lead to a new generation of antimicrobial biomaterials to combat drug resistance.


Assuntos
Antibacterianos , Bactérias Gram-Negativas , Antibacterianos/farmacologia , Escherichia coli , Bactérias Gram-Positivas , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade
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