Quantification of hydroxyl radical concentration using two chemical probes was assessed through the Fenton reaction. The probes were 1,2-benzopyrone (coumarin) for fluorescence and ...5,5-dimethyl-1-pyrroline-N-oxide (DMPO) for electron spin resonance (ESR). The corresponding hydroxylated species, namely 7-hydroxycoumarin (7HC) and 2-hydroxy-5,5-dimethyl-1-pyrroline-N-oxide (DMPO-OH adduct), were monitored by fluorescence and ESR-spin trapping techniques, respectively. The experiments were designed according to the theoretical conditions determined for stable fluorescence and EPR signals. The results demonstrate that: the optimal chemical probe : H
O
ratio predicted by a simplified quasi-steady-state model was in good agreement with the optimal chemical probe : H
O
ratio observed experimentally for H
O
: Fe
= 10, and the proper adjustment of the chemical probe : H
O
ratio at a given concentration of the Fenton's reagent improves the detected amount of hydroxyl radicals. Finally, using DMPO required a higher concentration compared to coumarin to yield the same amount of ˙OH detected but resulted in a more reliable probe for detecting ˙OH under the consideration of this study.
A
bstract
The higher-order quantum electrodynamics (QED) effect for vacuum pair production has been searched without success since 1954. In this paper, we show that the combined world-wide data of ...lepton pair vacuum production is about 20% smaller than the latest lowest order QED calculation with a 5.2 sigma-level of significance and is consistent with the corresponding higher-order QED result. We claim the discovery of higher-order effect for the QED pair production, which settles the dust of previous debates for several decades. The verification of higher-order QED effect is a fundamental scientific problem, which is an important milestone towards the nonperturbative and nonlinear regime of QED vacuum.
Objective
Social frailty is related to adverse health-related outcomes. However, the measurement thereof is controversial and research into the relationship between social frailty and physical ...functioning remains limited. This study aimed to determine social frailty status via developing a simple self-reported screening tool, termed the HALFT scale, and to examine the association between social frailty and physical functioning, cognition, depression, and mortality among community-dwelling older adults.
Design
Prospective cohort study.
Setting
Community.
Participants
1697 community-dwelling adults aged ≥60 years from Beijing Longitudinal Study of Aging were included.
Measurements
The HALFT scale was developed based on 5 items: unhelpful to others, limited social participation, loneliness, financial difficulty, and not having anyone to talk to. Socioeconomic and demographic data were collected, and physical functioning, frailty index, cognition, and depression were assessed.
Results
The prevalence of social frailty was 7.7% (weighted, 4.5%). Participants with physical frailty, low levels of physical activity, and poor physical functioning had a higher prevalence of social frailty. Social frailty was associated with dementia, subjective memory decline, depression, cognitive impairment, and having experienced a recent significant life event. After adjusting for age and sex, the 8-year mortality hazard ratios were 2.5-4.3 and 1.6-2.3, respectively, for those with social frailty or pre-social frailty. Each component of the HALFT scale predicted 8-year mortality.
Conclusion
Social frailty is associated with physical functioning, cognition, and depression, and predicts mortality. The HALFT scale could be a useful screening tool for determining social frailty in older adults. Interventions aimed at preventing or delaying social frailty are warranted.
Plastic packaging for food and non-food applications is non-biodegradable, and also uses up valuable and scarce non-renewable resources like petroleum. With the current focus on exploring ...alternatives to petroleum and emphasis on reduced environmental impact, research is increasingly being directed at development of biodegradable food packaging from biopolymer-based materials. The proposed paper will present a review of recent developments in biopolymer-based food packaging materials including natural biopolymers (such as starches and proteins), synthetic biopolymers (such as poly lactic acid), biopolymer blends, and nanocomposites based on natural and synthetic biopolymers. The paper will discuss the various techniques that have been used for developing cost-effective biodegradable packaging materials with optimum mechanical strength and oxygen and moisture barrier properties. This is a timely review as there has been a recent renewed interest in research studies, both in the industry and academia, towards development of a new generation of biopolymer-based food packaging materials with possible applications in other areas.
Nanoparticle (NP) assemblies are of considerable interest for both fundamental research and applications, since they provide direct bridges between nanometer‐scale objects and the macroscale world. ...Unlike two‐dimensional or three‐dimensional NP assemblies, which have been extensively studied and reviewed, reports on one‐dimensional (1D) NP assemblies are rather rare, even though these assemblies are likely to play critical roles in the improvement of the efficiencies of various electronic, optoelectronic, magnetic, and other devices based on single NPs or their composites. Additionally, 1D assemblies of NPs, i.e., chains, can significantly help in the understanding of a number of biological processes and fundamental quantum mechanics of nanometer‐scale systems. The difficulties are very evident when one wants to realize anisotropic 1D assemblies from presumably isotropic, zero‐dimensional NPs. In this context, the authors present a systemic review of current research on 1D NP assemblies. Their preparation methods are classified and novel characteristics of NP chains, such as collective properties and directional transfer of photons, electrons, spins, etc., are elucidated. Current problems underlying the fundamental research and practical applications of 1D NP assemblies are also addressed.
The current research status of one‐dimensional (1D) assemblies of nanoparticles (NPs; see Figure) is reviewed. Their preparation methods are classified and novel characteristics of NP chains, such as collective properties and directional transfer of photons, electrons, spins, etc., are elucidated. Current problems underlying the fundamental research and practical applications of 1D NP assemblies are also addressed.
The objectives of this study were to propose a clinical prognostic scoring system applicable for intrahepatic cholangiocarcinoma (ICC) and to evaluate the prognostic validity of the American Joint ...Committee on Cancer (AJCC) 7th edition staging system.
Retrospective univariate and multivariate survival analyses were conducted for 344 patients with ICC who underwent hepatectomy. A simple clinical prognostic scoring system (Fudan score) was developed based on the independent predictors. The prognostic validity was assessed in 74 patients with unresected tumors and compared with the AJCC 6th and 7th edition systems.
In the training set, serum alkaline phosphatase level, carbohydrate antigen 19-9 level, tumor boundary type, tumor size, and number of intrahepatic tumors were independent predictive factors of survival in ICC and were incorporated into the Fudan score. Three hundred forty-four patients were categorized into four subsets with 5-year overall survival rates of 48.6%, 25.6%, 10.3%, and 0.0% for low-, intermediate-, high-, and extremely high-risk groups, respectively. The discriminative ability of the Fudan score was better than that of the AJCC staging system and well applied in the unresected patient set.
A Fudan score based on clinical factors may provide a relatively accurate prognostic prediction for ICC patients regardless of resection status.
Recently, significant enhancements of e+e− pair production at very low transverse momentum (pT<0.15 GeV/c) were observed by the STAR collaboration in peripheral hadronic A+A collisions. This excesses ...can not be described by the QGP thermal radiation and ρ in-medium broadening calculations. This is a sign of coherent photon–photon interactions, which were conventionally studied only in ultra-peripheral collisions. In this article, we present calculations of lepton pair (e+e− and μ+μ−) production from coherent photon–photon interactions in hadronic A+A collisions at RHIC and LHC energies within the STAR and ALICE acceptance.
OBJECTIVE: Compared with thoracotomy, video-assisted thoracoscopic surgery (VATS) has the advantage of post-operative recovery for patients undergoing surgery. However, studies comparing the efficacy ...of VATS with conventional traditional thoracotomy for treating patients with
pulmonary TB (PTB) are inconsistent.METHODS: Five electronic databases were used to search studies on VATS and conventional thoracotomy for PTB up to 15 March 2022. Standardised mean differences (SMDs) and odds ratios (ORs) were calculated for comparison.RESULTS: A total
of 14 were included. Compared with traditional thoracotomy, patients with drug-resistant TB treated using VATS had shorter operative time, less intra-operative bleeding, faster post-operative recovery and fewer post-operative complications (operation time: SMD -0.87, 95% CI -1.29
to -0.45; blood loss: SMD -1.31, 95% CI -1.71 to -0.92; duration of hospital stay: SMD -1.68, 95% CI -2.46 to -0.90; catheterisation time: SMD -1.56, 95% CI -2.39 to -0.73; post-operative complication: OR 0.40, 95% CI 0.27 to 0.60).CONCLUSION:
Compared with conventional thoracotomy, VATS for patients with multidrug-resistant PTB undergoing lobectomy and wedge resection has the advantages of minor bleeding, shorter operative time, shorter hospital stay and post-operative pleural cavity drainage duration, and fewer post-operative
complications, which can accelerate the post-operative recovery of patients.
Context. The Gaia mission has released the second data set (Gaia DR2), which contains parallaxes and proper motions for a large number of massive, young stars. Aims. We investigate the spiral ...structure in the solar neighborhood revealed by Gaia DR2 and compare it with that depicted by VLBI maser parallaxes. Methods. We examined three samples with different constraints on parallax uncertainty and distance errors and stellar spectral types: (1) all OB stars with parallax errors of less than 10%; (2) only O-type stars with 0.1 mas errors imposed and with parallax distance errors of less than 0.2 kpc; and (3) only O-type stars with 0.05 mas errors imposed and with parallax distance errors of less than 0.3 kpc. Results. In spite of the significant distance uncertainties for stars in DR2 beyond 1.4 kpc, the spiral structure in the solar neighborhood demonstrated by Gaia agrees well with that illustrated by VLBI maser results. The O-type stars available from DR2 extend the spiral arm models determined from VLBI maser parallaxes into the fourth Galactic quadrant, and suggest the existence of a new spur between the Local and Sagittarius arms.
The design of advanced, nanostructured materials at the molecular level is of tremendous interest for the scientific and engineering communities because of the broad application of these materials in ...the biomedical field. Among the available techniques, the layer‐by‐layer assembly method introduced by Decher and co‐workers in 1992 has attracted extensive attention because it possesses extraordinary advantages for biomedical applications: ease of preparation, versatility, capability of incorporating high loadings of different types of biomolecules in the films, fine control over the materials' structure, and robustness of the products under ambient and physiological conditions. In this context, a systematic review of current research on biomedical applications of layer‐by‐layer assembly is presented. The structure and bioactivity of biomolecules in thin films fabricated by layer‐by‐layer assembly are introduced. The applications of layer‐by‐layer assembly in biomimetics, biosensors, drug delivery, protein and cell adhesion, mediation of cellular functions, and implantable materials are addressed. Future developments in the field of biomedical applications of layer‐by‐layer assembly are also discussed.
Layer‐by‐layer assembly is becoming more and more important in the biomedical field. This Review surveys current research and discusses prospects for the varied potential biomedical applications of nanostructures fabricated by this method. The image shows the lateral structure of artificial nacre, an organic–inorganic composite, prepared using the layer‐by‐layer technique.
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