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1.
Artículo en Inglés | MEDLINE | ID: mdl-33890784

RESUMEN

It is still a big challenge to effectively suppress dendrite growth, which increases the safety and life of lithium-metal-based high energy/power density batteries. To address such issues, herein we design and fabricate a lithiophilic VN@N-rGO as a multifunctional layer on commercial polypropylene (PP) separator, which is constructed by a thin N-rGO nanosheet-wrapped VN nanosphere with a uniform pore distribution, relatively high lithium ionic conductivity, excellent electrolyte wettability, additional lithium-ion diffusion pathways, high mechanical strength, and reliable thermal stability, which are beneficial to regulate the interfacial lithium ionic flux, resulting in the formation of a stable and homogeneous current density distribution on Li-metal electrodes and hard modified separators that can resist dendrites piercing. Consequently, the growth of Li dendrite is effectively suppressed, and the cycle stability of lithium-metal batteries is significantly improved. In addition, even at a high current density of 10 mA cm-2 and cutoff areal capacity of 5 mAh cm-2, the Li|Li symmetric batteries with VN@N-rGO/PP separators still work very well even over 2500 h, exhibiting ultrahigh cycling stability. This work presents rational design ideas and a facile fabrication strategy of a lithiophilic 3D porous multifunctional interlayer for dendrite-free and ultrastable lithium-metal-based batteries.

2.
Small ; : e2100460, 2021 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-33891797

RESUMEN

The slow redox kinetics during cycling process and the serious shuttle effect caused by the solubility of lithium polysulfides (LiPSs) dramatically hinder the practical application of Li-S batteries. Herein, a facile and scalable spray-drying strategy is presented to construct conductive polar Mo2 C quantum dots-decorated carbon nanotube (CNT) networks (MCN) as an efficient absorbent and electrocatalyst for Li-S batteries. The results reveal that the MCN/S electrode exhibits a high specific capacity of 1303.3 mAh g-1 at 0.2 C, and ultrastable cycling stability with decay of 0.019% per cycle even at 1 C. Theoretical simulation uncovers that Mo2 C exhibits much stronger binding energies for S8 and Li2 Sn . The energy barrier for the conversion between Li2 S4 and Li2 S2 decreases from 1.02 to 0.72 eV when hybriding with Mo2 C. Furthermore, in situ discharge/charge-dependent Raman spectroscopy shows that long-chain Li2 S8 configuration is generated via S8 ring opening near the first plateaus at ≈2.36 V versus Li/Li+ and the S6 2- configuration in CNT/S electrode is maintained below the potential of ≈2.30 V versus Li/Li+ , indicating that the shuttle of soluble LiPSs happens during the whole discharge process. This work provides deep insights into the polar nanoarchitecture design and scalable fabrication for advanced Li-S batteries.

3.
Micromachines (Basel) ; 12(3)2021 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-33800898

RESUMEN

The damage repair of fused silica based on the CO2 laser repair technique has been successfully applied in high-power laser systems in the controllable nuclear fusion field. However, this kind of repairing technique mainly focuses on large-scale laser damage with sizes larger than 200 µm, but ignores the influence of cluster small-scale damage with sizes smaller than 50 µm. In order to inhibit the growth of small-scale damage and further improve the effect of fused silica damage repair, this paper carried out a study on the repair of fused silica damage using the magnetorheological (MR) removing method. The feasibility of fused silica damage repairing was verified, and the evolution law of the number, morphology, and the surface roughness of small-scale damage were all analyzed. The results showed that the MR removing method was non-destructive compared to traditional repairing technologies. It not only effectively improved the whole damage repairing rate to more than 90%, but it also restored the optical properties and surface roughness of the damaged components in the repairing process. Based on the study of the MR removing repair law, a combined repairing process of 4 µm MR removal and 700 nm computer controlled optical surfacing (CCOS) removal is proposed. A typical fused silica element was experimentally repaired to verify the process parameters. The repairing rate of small-scale damage was up to 90.4%, and the surface roughness was restored to the level before repairing. The experimental results validate the effectiveness and feasibility of the combined repairing process. This work provides an effective method for the small-scale damage repairing of fused silica components.

4.
Artículo en Inglés | MEDLINE | ID: mdl-33847040

RESUMEN

Tyrosine nitration of proteins represents one of the most important oxidative post-translational modifications in vivo and is closely related to human physiology, pathology and aging. A major obstacle for its biochemical and physiological studies is the lack of efficient and chemoselective protein tyrosine nitration reagents. Herein, we report a generalizable strategy for light-controlled protein tyrosine nitration by employing biocompatible dinitroimidazole reagents. Upon 390 nm irradiation, dinitroimidazoles efficiently convert tyrosine residues into 3-nitrotyrosine residues in peptides and proteins with fast kinetics and high chemoselectivity under neutral aqueous buffer conditions. We demonstrate that the incorporation of 3-nitrotyrosine residues enhances the thermostability of lasso peptide natural products and endows murine tumor necrosis factor-α with strong immunogenicity to break self-tolerance. Furthermore, the light-controlled time-resolution of this method allows the investigation of the impact of tyrosine nitration on the self-assembly behavior of α-synuclein.

5.
ACS Appl Mater Interfaces ; 13(12): 14004-14014, 2021 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-33728894

RESUMEN

Developing novel activatable photosensitizers with excellent plasma membrane targeting ability is urgently needed for smart photodynamic therapy (PDT). Herein, a tumor acidity-activatable photosensitizer combined with a two-step bioorthogonal pretargeting strategy to anchor photosensitizers on the plasma membrane for effective PDT is developed. Briefly, artificial receptors are first anchored on the cell plasma membrane using cell-labeling agents (Az-NPs) via the enhanced permeability and retention effect to achieve the tumor cell labeling. Then, pH-sensitive nanoparticles (S-NPs) modified with dibenzocyclooctyne (DBCO) and chlorin e6 (Ce6) accumulate in tumor tissue and disassemble upon protonation of their tertiary amines in response to the acidic tumor environment, exposing the contained DBCO and Ce6. The selective, highly specific click reactions between DBCO and azide groups enable Ce6 to be anchored on the tumor cell surface. Upon laser irradiation, the cell membrane is severely damaged by the cytotoxic reactive oxygen species, resulting in remarkable cellular apoptosis. Taken together, the membrane-localized PDT by our bioorthogonal pretargeting strategy to anchor activatable photosensitizers on the plasma membrane provides a simple but effective method for enhancing the therapeutic efficacy of photosensitizers in anticancer therapy.

6.
Artículo en Inglés | MEDLINE | ID: mdl-33729935

RESUMEN

A solidly mounted resonator on flexible Polyimide (PI) substrate with high effective coupling coefficient (Kt2) of 14.06% is reported in this paper. This high Kt2 is resulting from the LiNbO3 (LN) single crystalline film and [SiO2/Mo]3 Bragg reflector. The quality of LN film fabricated by Crystal-ion-slicing (CIS) technique using Benzocyclobutene (BCB) bonding layer was close to the bulk crystalline LN. The interfaces of the Al/LN/Al/[SiO2/Mo]3 Bragg reflector/BCB/PI multilayer are sharp and the thickness of each layer is consistent with its design value. The resonant frequency and the Kt2 keep stable when it is bended at different radii. These results demonstrate a feasible approach to realizing RF filters on flexible polymer substrates, which is an indispensable device for building integrated and multi-functional wireless flexible electronic systems.

7.
J Colloid Interface Sci ; 592: 385-396, 2021 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-33677198

RESUMEN

Rational design and highly efficient dual-functional catalyst are still difficult to develop for electrocatalytic oxygen evolution reaction and degradation of RhB dye pollutant. Herein, we report a highly efficient "bandgap matching and interfacial coupling" strategy to synthesize nano-assembled ultrathin layered MoS2@NiFe2O4 (MS@NiFeO) bifunctional catalyst constructed by the hydrothermal route and subsequently amine-hydrolysis. The OER performance of the prepared MS@NiFeO catalyst delivers a low overpotential of 290 mV at 10 mA/cm2 and Tafel slope is 69.2 mV dec-1 in an alkaline solution. In addition, the nano-assembled ultrathin layered structure of MS@NiFeO showed a highly efficient (96.37%) RhB dye degradation performance than that of MoS2 nanosheets and NiFe2O4 nanostructures. Unique nanostructure of ultrathin layered MS@NiFeO with suitable band matching, interfacial charge transfer, high surface area and more active sites favored for the enhancement of the catalytic activity. This work presents an unpretentious construction and low-cost production strategy to synthesize bifunctional hybrid catalyst for oxygen evolution reaction as well as degradation of organic pollutant with superior efficiency and longer stability.

8.
Aging (Albany NY) ; 13(7): 10659-10671, 2021 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-33770763

RESUMEN

The mechanisms underlying the development of neuropathy associated with diabetes mellitus are not fully understood. Resveratrol, as a nonflavonoid polyphenol, plays a variety of beneficial roles in the treatment of chronic diseases such as Alzheimer's disease, coronary heart disease and obesity. In our study, the role of nuclear erythroid 2-related factor 2 (Nrf2) in resveratrol-mediated protection against streptozotocin-induced diabetic peripheral neuropathy (DPN) was investigated, and the antioxidant effect of resveratrol in diabetic peripheral nerves was studied. The STZ-treated model mice were divided into two groups. The resveratrol group was intragastrically administered 10 ml/kg 10% resveratrol once a day until the 12th week after STZ injection. The vehicle-treated mice were injected with the same volume of DMSO. Analysis of the effects of resveratrol in DPN revealed the following novel findings: (i) the pain and temperature sensitivities of diabetic mice were improved after treatment with resveratrol; (ii) Nrf2 expression was increased in the diabetic peripheral nerves of resveratrol-treated mice, and NF-KB pathway inhibition protected nerves upon resveratrol treatment in peripheral neuropathy; and (iii) resveratrol modulated the anti-inflammatory microenvironment of peripheral nerves by increasing Nrf2 activation and the expression of p-p65, and these changes may have been responsible for the neuroprotective effect of resveratrol in DPN, which was confirmed by Nrf2 knockout in diabetic mice. Overall, this study demonstrates that resveratrol may attenuate the severity of DPN by protecting peripheral nerves from apoptosis by inhibiting the NF-KB pathway and increasing Nrf2 expression.

9.
Bioresour Technol ; 329: 124919, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33676353

RESUMEN

Links between synergy and microbial community characteristics in co-digestion of food waste (FW), cattle manure (CM) and corn straw (CS) were investigated. Mono-digestion of FW and CS were inhibited by organic acids. Co-digestion of FW with CM achieved greater synergistic rates (18.5% and 22.3%) than CM with CS (14.8% and 12.3%). Synergy resulted from coupling effects of improving nutrient balance, dilution of toxic compounds, higher buffering capacity, detoxification based on co-metabolism, which ultimately reflected in microbial community functions. Although co-digestion of FW with CS exhibited lowest synergistic rates (7.9% and 4.9%), detoxification based on co-metabolism of syntrophic communities of Syntrophomonadaceae with hydrogenotrophic methanogens accelerated system recovery. Digester with the greatest synergy (65% FW + 35% CM) maintained dominant growth of hydrogenotrophic methanogens (68.9%), highest methanogenic community diversity and relative abundance of Methanosarcina (14.6%), which sustained more diverse and switchable methanogenic pathways therefore ensured powerful methanogenic functions and vigorous methanogenic capability.


Asunto(s)
Microbiota , Eliminación de Residuos , Anaerobiosis , Animales , Biocombustibles , Reactores Biológicos , Bovinos , Digestión , Alimentos , Estiércol , Metano , Zea mays
10.
J Diabetes Investig ; 2021 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-33650778

RESUMEN

AIMS/INTRODUCTION: Diabetes has been considered as a 'pro-thrombotic state' with enhanced platelet reactivity. Abnormality in platelet aggregation has been found in patients with its most common chronic complication - diabetic peripheral neuropathy (DPN). The purpose of this study was to investigate the potential association of platelet indices with nerve conduction function and the presence of DPN in Chinese patients with type 2 diabetes mellitus. MATERIALS AND METHODS: This study involved a total of 211 inpatients with type 2 diabetes mellitus and 55 healthy individuals for whom nerve conduction studies were carried out. DPN was diagnosed according to the American Diabetes Association recommendation. Clinical data were retrospectively collected. RESULTS: Patients with diabetes in whom neuropathy developed had lower levels of platelet count (PLT) and plateletcrit (PCT) than healthy controls (P < 0.05). Statistically significant associations of low PLT and PCT levels with the reduction of summed amplitude/velocity Z-score, and the prolongation of F-wave minimum latency in nerve conduction studies were found. Furthermore, after multivariate adjustment, logistic regression analysis showed that low levels of PLT (odds ratio 2.268, 95% confidence interval 1.072-4.797; P < 0.05; PLT <226 vs PLT ≥226) and PCT (odds ratio 2.050, 95% confidence interval 1.001-4.201; P < 0.05; PCT <0.222 vs PCT ≥0.222) in type 2 diabetes mellitus patients were risk factors for the presence of DPN. CONCLUSIONS: Lower PLT and PCT levels are closely associated with poorer peripheral nerve conduction functions and the presence of neuropathy in patients with type 2 diabetes mellitus, which suggests that PLT and PCT might be potential biomarkers for showing DPN.

11.
Neurosci Lett ; 750: 135766, 2021 04 17.
Artículo en Inglés | MEDLINE | ID: mdl-33639221

RESUMEN

Ischemic stroke is one of the major diseases that cause mortality and morbidity of human beings, but there is still lack of effective treatment and prevention. We found that 2-(2-Benzofuranyl)-2-Imidazoline (2-BFI) is potently protective against stroke and acute inflammatory immune disease. Moreover, the mammalian target of rapamycin (mTOR) signaling contributes effectively to the modulation of post-stroke neuroinflammatory response. However, whether the protection of 2-BFI against ischemic injury is through mTOR-mediated neuroinflammatory response remains unestablished. Here, we used 2-BFI to treat ischemic rats induced by distal middle cerebral artery occlusion (dMCAO). We found that 2-BFI administration after dMCAO improved the neurological deficits and decreased the infarct volume. 2-BFI reduced phosphorylation of mTOR and p70S6, increased IL-10 and TGF-ß, and decreased IFN-γ levels in ischemic rats. Our results demonstrated that 2-BFI attenuates ischemic injury by inhibiting the activation of mTOR signaling and modulating neuroinflammation after stroke in rats.

13.
Target Oncol ; 16(2): 177-187, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33492568

RESUMEN

BACKGROUND: Abemaciclib, a cyclin-dependent kinase 4 and 6 inhibitor, is approved in combination with endocrine therapy or as monotherapy for hormone receptor-positive and human epidermal growth factor receptor-2-negative (HR+/HER2-) advanced breast cancer outside of China. OBJECTIVE: To evaluate the safety, tolerability, and pharmacokinetic (PK) profile of abemaciclib in Chinese patients with advanced and/or metastatic cancers. PATIENTS AND METHODS: A multicenter, open-label, phase I trial of abemaciclib in Chinese patients with advanced and/or metastatic cancers was conducted. Patients were randomized (1:1) to oral abemaciclib 150 or 200 mg every 12 h on a 28-day cycle. Safety analyses (primary outcome) included all patients receiving at least one dose of abemaciclib. PK and antitumor activity were also assessed. RESULTS: Of the 26 patients randomized, 25 received abemaciclib 150 mg (n = 12) or 200 mg (n = 13). All 25 patients reported ≥ 1 treatment-emergent adverse event (TEAE). The majority of TEAEs were Common Terminology Criteria for Adverse Events (CTCAE) Grade 1 or 2 in severity. The most frequent TEAEs of Grade ≥ 3 were neutropenia (32%) and thrombocytopenia (24%). Four patients (16%) discontinued treatment due to AEs. Abemaciclib exhibited slow absorption and clearance at single dose, with maximum concentrations achieved after around 6 h and an elimination half-life of approximately 24 h. No complete response was observed, two patients (8%) achieved partial response, with one confirmed responder, and the disease control rate was 68% (n = 17). CONCLUSIONS: Abemaciclib was well tolerated and the safety and PK profiles in Chinese patients were comparable to those previously reported in non-Chinese populations. Preliminary antitumor activity was observed. CLINICALTRIALS. GOV IDENTIFIER: NCT02919696.

14.
J Environ Manage ; 279: 111772, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33310238

RESUMEN

This study investigated responses of anaerobic digestion (AD) of food waste (FW) with different inocula to varying organic loads and to pH control under high load in terms of process performance and microbial characteristics. Without pH control, digester inoculated by thickened sludge obtained high methane yield of 547.8 ± 27.8 mL/g VS under organic load of 7.5 g VS/L but was inhibited by volatile fatty acids (VFAs) under higher loads (15 and 30 g VS/L). However, digesters inoculated by anaerobic sludge obtained high methane yields of 575.9 ± 34.2, 569.3 ± 24.8 and 531.9 ± 26.2 mL/g VS under organic loads of 7.5, 15 and 30 g VS/L and VFAs inhibition only appeared under extremely high load of 45 g VS/L. Digesters under VFA inhibition with high load were significantly enhanced by controlling single ecological factor pH at 6.5, 7.0 and 7.5, as indicated by shorter lag phases, higher peak values of methane production rate, greater methane yields and fast VFAs degradation. Maximum methane recovery was obtained with pH control at 7.5 under high load. VFA inhibition was accompanied by the degeneration of ecological functions of Syntrophomonadaceae and unidentified Bacteroidales and the dominant growth of unidentified Clostridiales. Under high load and pH control, high stability was strongly associated with obvious growth of Methanosarcina, which enriched methanogenic pathways thus improved system robustness and tolerance to VFAs. Moreover, pH control stimulated the growth of syntrophic Bacteria Syntrophomonadaceae while maintaining the high activity of hydrogenotrophic methanogens therefore sustained efficient syntrophic communities of Bacteria and methanogens and avoided over accumulation of VFAs. pH control promoted adaptive selection of methanogens, leading to obvious decline of archaeal community diversity. This study provided practical guidance on digester configurations of high-load AD of FW and expanded the understanding of responses to coupling effects of inoculum origins, organic loads and pH control under high load concerning process performance and microbial community dynamics.


Asunto(s)
Reactores Biológicos , Eliminación de Residuos , Anaerobiosis , Alimentos , Concentración de Iones de Hidrógeno , Metano
15.
Front Med (Lausanne) ; 7: 556818, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33304910

RESUMEN

Background: Coronavirus disease (COVID-19) has swept around the globe and led to a worldwide catastrophe. Studies examining the disease progression of patients with non-severe disease on admission are scarce but of profound importance in the early identification of patients at a high risk of deterioration. Objectives: To elucidate the differences in clinical characteristics between patients with progressive and non-progressive COVID-19 and to determine the risk factors for disease progression. Study design: Clinical data of 365 patients with non-severe COVID-19 from 1 January 2020 to 18 March 2020 were retrospectively collected. Patients were stratified into progressive and non-progressive disease groups. Univariate and multivariate logistic regression analyses were performed to determine the independent risk factors for disease progression. Results: Compared with patients with non-progressive disease, those who progressed to severe COVID-19 were older and had significantly decreased lymphocyte and eosinophil counts; increased neutrophil and platelet counts; lower albumin levels; higher levels of lactate dehydrogenase, C-reactive protein (CRP), creatinine, creatinine kinase, and urea nitrogen; and longer prothrombin times. Hypertension, fever, fatigue, anorexia, bacterial coinfection, bilateral patchy shadowing, antibiotic and corticosteroid administration, and oxygen support had a significantly higher incidence among patients with progressive disease. A significantly longer duration of hospital stay was also observed in patients with progressive disease. Bilateral patchy shadowing (OR = 4.82, 95% CI: 1.33-17.50; P = 0.017) and elevated levels of creatinine (OR =6.24, 95% CI: 1.42-27.40; P = 0.015), and CRP (OR = 7.28, 95% CI: 2.56-20.74; P < 0.001) were independent predictors for disease progression. Conclusion: The clinical characteristics of patients with progressive and non-progressive COVID-19 were significantly different. Bilateral patchy shadowing and increased levels of creatinine, and CRP were independent predictors of disease progression.

16.
Artículo en Inglés | MEDLINE | ID: mdl-33258579

RESUMEN

Strategic design and fabrication of a highly efficient and cost-effective bifunctional electrocatalyst is of great significance in water electrolysis in order to produce sustainable hydrogen fuel in a large scale. However, it is still challenging to develop a stable, inexpensive, and efficient bifunctional electrocatalyst that can overcome the sluggish oxygen evolution kinetics in water electrolysis. To address the aforementioned concerns, a metal-organic framework-derived Fe-doped Ni3Fe/NiFe2O4 heterostructural nanoparticle-embedded carbon nanotube (CNT) matrix (Fe(0.2)/Ni-M@C-400-2h) is synthesized via a facile hydrothermal reaction and subsequent carbonization of an earth-abundant Ni/Fe/C precursor. With a novel porous nanoarchitecture fabricated by a Ni3Fe/NiFe2O4 heterostructure on a highly conductive CNT matrix, this catalyst exhibits exceptional bifunctional activity during water electrolysis over the Ni/Fe-based electrocatalysts reported recently. It delivers a low overpotential of 250 mV to achieve a current density of 10 mA/cm2 with a small Tafel slope of 43.4 mV/dec for oxygen evolution reaction. It requires a low overpotential of 128 mV (η10) for hydrogen evolution reaction and displays a low overpotential of 1.62 V (η10) for overall water splitting. This study introduces a facile and straightforward synthesis strategy to develop transition metal-based nanoarchitectures with high performance and durability for overall water-splitting catalysis.

17.
Small ; : e2006881, 2020 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-33373091

RESUMEN

The energy conversion efficiency of water electrolysis is determined by the activity of selected catalysts. Ideal catalysts should possess not only porous architecture for high-density assembly of active sites but also a subtle electronic configuration for the optimized activity at each site. In this context, the development of stable porous hosting materials that allow the incorporation of various metal elements is highly desirable for both experimental optimization and theoretical comparison/prediction. Herein, MOF-derived spongy nanosheet arrays constructed by assembly of carbon encapsulated hetero-metal doped Ni2 P nanoparticles is presented as a superior bifunctional electrocatalyst for water splitting. This hierarchical structure can be stably retained when secondary metal dopants are introduced, providing a flexible platform for electronic modulation. The catalytic origin of activity enhancement via metal (Fe, Cr, and Mn) doping is deciphered through experimental and theoretical investigations. Combining the advantages in both morphological and electronic structures, the optimized catalyst NiMn-P exhibits remarkable activity in both hydrogen and oxygen evolution in the alkaline media, with an ultrasmall cell voltage of 1.49 V (at 10 mA cm-2 ) and high durability for at least 240 h.

18.
Food Chem ; : 128650, 2020 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-33229159

RESUMEN

Zirconium(Ⅳ)-based metal-organic framework (MOF)-UiO-66-NH2 was fabricated to adsorb the imidacloprid and thiamethoxam in fruit samples before analysis using UPLC-MS/MS. The UiO-66-NH2 was confirmed by SEM, FTIR, and XRD. Key experimental parameters were investigated by response surface methodology (RSM). The desirability recovery of imidacloprid was 94.52% under optimum conditions (mount of adsorbent = 52.48 mg, volume of eluent = 5.18 mL, pH = 9, extraction time = 15 min). The desirability recovery of thiamethoxam was 93.57% under optimum conditions (mount of adsorbent = 50.58 mg, volume of eluent = 2.6 mL, pH = 5.65, extraction time = 11.94 min). Under the optimal conditions, the actual recovery of imidacloprid and thiamethoxam was 92.39% and 94.37%, respectively. Besides, the method was applied successfully to detect imidacloprid and thiamethoxam in different fruit samples. The results demonstrated that the UiO-66-NH2 is an excellent adsorbent for the extraction imidacloprid and thiamethoxam from fruit samples.

19.
Mar Pollut Bull ; : 111829, 2020 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-33243441

RESUMEN

Quantifying the occurrence of Antarctic antibiotic-resistant bacteria (ARB) is essential for assessing the level of pollution and assessing the "baseline" or background level of ARB in human uninhabited environments. Animal feces, soil, and sediments were sampled from Fildes Peninsula. The abundance of sulfamethazine- and ciprofloxacin-resistance bacteria and antibotic resistance genes (ARGs) within ARB were investigated. The results showed Ciprofloxacin- and Sulfamethazine-resistant bacteria isolated from samples accounted for the highest abundances of 30 CFU/g and 79.8 CFU/g, respectively. The dominant genus of Sulfamethazine-and quinolone-resistance bacteria was Pseudomonas and Arthrobacter, respectively. 106 ARGs were detected from ARB. Strong positive correlations between mobile genetic elements (MGEs) and ARGs were found, what is relatively novel observation that the mechanism is confirmed to also occur in the Antarctic. This study reveals the compositional characteristics of ARGs of strains in Antarctic, providing support for the source of Antarctic antibiotic resistance and drug resistance mechanisms.

20.
Nat Prod Rep ; 2020 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-33206093

RESUMEN

Covering: 2000 to 2020.trans-Bicyclo[4.4.0]decane/decene (such as trans-decalin and trans-octalin)-containing natural products display a wide range of structural diversity and frequently exhibit potent and selective antibacterial activities. With one of the major factors in combatting antibiotic resistance being the discovery of novel scaffolds, the efficient construction of these natural products is an attractive pursuit in the development of novel antibiotics. This highlight aims to provide a critical analysis on how the presence of dense architectural and stereochemical complexity necessitated special strategies in the synthetic pursuits of these natural trans-bicyclo[4.4.0]decane/decene antibiotics.

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