We present a systematic investigation of molecule-metal interactions for transition-metal phthalocyanines (TMPc, with TM = Fe, Co, Ni, Cu) adsorbed on Ag(100). Scanning tunneling spectroscopy and ...density functional theory provide insight into the charge transfer and hybridization mechanisms of TMPc as a function of increasing occupancy of the 3d metal states. We show that all four TMPc receive approximately one electron from the substrate. Charge transfer occurs from the substrate to the molecules, inducing a charge reorganization in FePc and CoPc, while adding one electron to ligand pi orbitals in NiPc and CuPc. This has opposite consequences on the molecular magnetic moment: In FePc and CoPc the interaction with the substrate tends to reduce the TM spin, whereas, in NiPc and CuPc, an additional spin is induced on the aromatic Pc ligand, leaving the TM spin unperturbed. In CuPc, the presence of both TM and ligand spins leads to a triplet ground state arising from intramolecular exchange coupling between d and pi electrons. In FePc and CoPc the magnetic moment of C and N atoms is antiparallel to that of the TM. The different character and symmetry of the frontier orbitals in the TMPc series leads to varying degrees of hybridization and correlation effects, ranging from the mixed-valence (FePc, CoPc) to the Kondo regime (NiPc, CuPc). Coherent coupling between Kondo and inelastic excitations induces finite-bias Kondo resonances involving vibrational transitions in both NiPc and CuPc and triplet-singlet transitions in CuPc.
Superelastic conducting fibers with improved properties and functionalities are needed for diverse applications. Here we report the fabrication of highly stretchable (up to 1320%) sheath-core ...conducting fibers created by wrapping carbon nanotube sheets oriented in the fiber direction on stretched rubber fiber cores. The resulting structure exhibited distinct short- and long-period sheath buckling that occurred reversibly out of phase in the axial and belt directions, enabling a resistance change of less than 5% for a 1000% stretch. By including other rubber and carbon nanotube sheath layers, we demonstrated strain sensors generating an 860% capacitance change and electrically powered torsional muscles operating reversibly by a coupled tension-to-torsion actuation mechanism. Using theory, we quantitatively explain the complementary effects of an increase in muscle length and a large positive Poisson's ratio on torsional actuation and electronic properties.
Background and purpose
Chitinase 3‐like 1 (CHI3L1) and neurofilament light chain (NF‐L) are promising biomarkers of disability in multiple sclerosis (MS). However, their role in cognitive dysfunction ...remains elusive. Here, we aimed to correlate cerebrospinal fluid (CSF) levels of CHI3L1 and NF‐L with cognitive status in MS.
Methods
Fifty one recently diagnosed patients were cognitively evaluated and CSF was collected. Levels of CHI3L1 and NF‐L were determined by ELISA. Spearman's partial correlation coefficient was performed.
Results
After adjusting cognitive scores by age, anxiety and EDSS, association was detected between CHI3L1 levels and Trail Making Test A (rs = 0.348; p = 0.016) and between NF‐L levels and Word List Generation (rs = −0.324; p = 0.025).
Conclusion
High levels of CSF CHI3L1 and NF‐L are associated with cognitive impairment in the early phases of MS.
In the field of beam physics, two frontier topics have taken center stage due to their potential to enable new approaches to discovery in a wide swath of science. These areas are: advanced, high ...gradient acceleration techniques, and x-ray free electron lasers (XFELs). Further, there is intense interest in the marriage of these two fields, with the goal of producing a very compact XFEL. In this context, recent advances in high gradient radio-frequency cryogenic copper structure research have opened the door to the use of surface electric fields between 250 and 500 MV m−1. Such an approach is foreseen to enable a new generation of photoinjectors with six-dimensional beam brightness beyond the current state-of-the-art by well over an order of magnitude. This advance is an essential ingredient enabling an ultra-compact XFEL (UC-XFEL). In addition, one may accelerate these bright beams to GeV scale in less than 10 m. Such an injector, when combined with inverse free electron laser-based bunching techniques can produce multi-kA beams with unprecedented beam quality, quantified by 50 nm-rad normalized emittances. The emittance, we note, is the effective area in transverse phase space (x, p x /m e c) or (y, p y /m e c) occupied by the beam distribution, and it is relevant to achievable beam sizes as well as setting a limit on FEL wavelength. These beams, when injected into innovative, short-period (1-10 mm) undulators uniquely enable UC-XFELs having footprints consistent with university-scale laboratories. We describe the architecture and predicted performance of this novel light source, which promises photon production per pulse of a few percent of existing XFEL sources. We review implementation issues including collective beam effects, compact x-ray optics systems, and other relevant technical challenges. To illustrate the potential of such a light source to fundamentally change the current paradigm of XFELs with their limited access, we examine possible applications in biology, chemistry, materials, atomic physics, industry, and medicine-including the imaging of virus particles-which may profit from this new model of performing XFEL science.
•In the age of big data, Intelligence is recognized as an emerging discipline.•Intelligence has a strong impact on the innovation performance of an organization.•Intelligence activities are oriented ...to both tactical and strategic decision-making.•Intelligence aims to improve the competitiveness of enterprises and economic sectors.•Intelligence is an ethical and legal practice, as opposed to industrial espionage.
The critical factors in the big data era are collection, analysis, and dissemination of information to improve an organization’s competitive position and enhance its products and services. In this scenario, it is imperative that organizations use Intelligence, which is understood as a process of gathering, analyzing, interpreting, and disseminating high-value data and information at the right time for use in the decision-making process. Earlier, the concept of Intelligence was associated with the military and national security sector; however, in present times, and as organizations evolve, Intelligence has been defined in several ways for the purposes of different applications. Given that the purpose of Intelligence is to obtain real value from data, information, and the dynamism of the organizations, the study of this discipline provides an opportunity to analyze the core trends related to data collection and processing, information management, decision-making process, and organizational capabilities. Therefore, the present study makes a conceptual analysis of the existing definitions of intelligence in the literature by quantifying the main bibliometric performance indicators, identifying the main authors and research areas, and evaluating the development of the field using SciMAT as a bibliometric analysis software.
To evaluate the antibacterial and free-radical scavenging (FRS) activities of propolis collected from three different areas of Sonoran Desert in northwestern Mexico Pueblo de Alamos (PAP), Ures (UP) ...and Caborca (CP). The antibacterial and FRS activities of Sonoran propolis were determined by the broth microdilution method and the DPPH (1,1-diphenyl-2-picrylhydracyl) assay, respectively. Propolis samples had antibacterial activity against only Gram-positive bacteria. The UP sample showed the highest antibacterial activity against Staphylococcus aureus minimal inhibitory concentration (MIC) 100 μg ml⁻¹ in a concentration-dependent manner (UP > CP > PAP). Caffeic acid phenethyl ester (CAPE), a UP propolis constituent, had very high growth-inhibitory activity towards Gram-positive bacteria, particularly against S. aureus (MIC 0·1 mmol l⁻¹). To our knowledge, this is the first study showing a strong antibacterial activity of CAPE against S. aureus. Additionally, propolis CP exhibited high FRS activity (86% ± 0·3 at 100 μg ml⁻¹) comparable with those of the reference antioxidants vitamin C (87·4% ± 1·7 at 70 μmol l⁻¹) and BHT (66·07% ± 0·76 at 140 μmol l⁻¹). The propolis compounds CAPE and rutin showed high FRS activity (90·4% ± 0·2 and 88·5% ± 0·8 at 70 μmol l⁻¹, respectively). Sonoran propolis UP and CAPE had strong antibacterial activity against S. aureus. In addition, propolis CP showed potent FRS activity comparable with those of vitamin C and BHT. The strong antibacterial and antioxidant properties of Sonoran propolis and some of its constituents support further studies on the clinical applications of this natural bee product against S. aureus and several oxidative damage-related diseases.
Exposure to particulate air pollution is a major environmental risk factor for cardiovascular mortality and morbidity, on a global scale. Both acute and chronic cardiovascular impacts have so far ...been attributed to particulate-mediated oxidative stress in the lung and/or via ‘secondary’ pathways, including endothelial dysfunction, and inflammation. However, increasing evidence indicates the translocation of inhaled nanoparticles to major organs via the circulation. It is essential to identify the composition and intracellular targets of such particles, since these are likely to determine their toxicity and consequent health impacts. Of potential major concern is the abundant presence of iron-rich air pollution nanoparticles, emitted from a range of industry and traffic-related sources. Bioreactive iron can catalyse formation of damaging reactive oxygen species, leading to oxidative stress and cell damage or death.
Here, we identify for the first time, in situ, that exogenous nanoparticles (~15–40 nm diameter) within myocardial mitochondria of young, highly-exposed subjects are dominantly iron-rich, and co-associated with other reactive metals including aluminium and titanium. These rounded, electrodense nanoparticles (up to ~ 10 x more abundant than in lower-pollution controls) are located within abnormal myocardial mitochondria (e.g. deformed cristae; ruptured membranes). Measurements of an oxidative stress marker, PrPC and an endoplasmic reticulum stress marker, GRP78, identify significant ventricular up-regulation in the highly-exposed vs lower-pollution controls. In shape/size/composition, the within-mitochondrial particles are indistinguishable from the iron-rich, combustion- and friction-derived nanoparticles prolific in roadside/urban environments, emitted from traffic/industrial sources. Incursion of myocardial mitochondria by inhaled iron-rich air pollution nanoparticles thus appears associated with mitochondrial dysfunction, and excess formation of reactive oxygen species through the iron-catalyzed Fenton reaction. Ventricular oxidative stress, as indicated by PrPC and GRP78 up-regulation, is evident even in children/young adults with minimal risk factors and no co-morbidities. These new findings indicate that myocardial iron overload resulting from inhalation of airborne, metal-rich nanoparticles is a plausible and modifiable environmental risk factor for cardiac oxidative stress and cardiovascular disease, on an international scale.
•Air pollution nanoparticles inside human myocardial mitochondria are iron-rich.•The within-mitochondrial particles match iron-rich particles from traffic/industrial sources.•Myocardial iron-rich air pollution nanoparticles abundant even in young children.•Ventricular upregulation of oxidative and ER stress markers in exposed subjects.•Inhalation of iron-rich air pollution a risk factor for cardiovascular disease.
The presence of hypertension among the population with human immunodeficiency virus (HIV) has become a new threat to the health and well-being of people living with this disease, in particular, among ...those who received antiretroviral therapy. The estimated prevalence of high blood pressure in HIV-infected patients is significantly higher than the rate observed in HIV-uninfected subjects. The approach to the HIV-positive patient requires the assessment of individual cardiovascular risk and its consideration when designing the individualized target. On the other hand, the numerous pharmacological interactions of antiretroviral (ARV) drugs are essential elements to take into account. Serum levels of any kind of antihypertensive drugs may be influenced by the coadministration of protease inhibitors, non-nucleoside reverse transcriptase inhibitor, or other antiretroviral. Similarly, plasma concentrations of antiretroviral drugs can be increased by the concomitant use of calcium channel blockers or diuretics. In this regard, the treatment of high blood pressure in HIV patients should be preferentially based on ACE inhibitors or thiazide/thiazide-like diuretics or their combination.
Vacuum and nitrogen as sweep gas were used simultaneously (combination mode) to generate the driving force in a microporous polypropylene membrane contactor for the recovery of dissolved methane from ...water. Experiments were carried out under different liquid flow-rates (5.0–28.0 L h−1), N2 flow-rates (0.5–1.5 L h−1) and vacuum pressures (0–480 mbar). The maximum removal efficiency of methane was >90% at moderate values of gas-to-liquid ratios (G/L) and vacuum of 0.2 and ≤ 200 mbar, respectively. Removal efficiencies obtained in combination mode were usually higher than when using vacuum or sweep gas, separately. To achieve a methane content >35% in the recovered gas, G/L values lower than 0.03 are necessary, with removal efficiency up to 55%. Even at these soft conditions, gas phase mass transfer resistance was demonstrated as being negligible, so the limiting resistance was in the liquid phase. G/L ratios increased until values of 0.3, with a vacuum of 200 mbar, maximised the energy output (>250 kJ m−3 of treated water), in the case of recovered methane mixed with biogas produced in an anaerobic reactor. The results show that combination mode could be used to improve the performance of methane degassing in membrane contactors.
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•Best performance in combination mode rather than vacuum or sweep gas separately.•Methane recovery >90% achieved under moderate vacuum and sweep gas flow-rate.•Gas CH4 content >35%, needed for microturbines, achievable at soft G/L and vacuum.•Liquid phase conditions dominate the overall mass transfer resistance.•Positive energy balance from recovered methane is achieved in combination mode.
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