Anionic carbosilane dendrons decorated with sulfonate functions and one thiol moiety at the focal point have been used to synthesize water‐soluble gold nanoparticles (AuNPs) through the direct ...reaction of dendrons, gold precursor, and reducing agent in water, and also through a place‐exchange reaction. These nanoparticles have been characterized by NMR spectroscopy, TEM, thermogravimetric analysis, X‐ray photoelectron spectroscopy (XPS), UV/Vis spectroscopy, elemental analysis, and zeta‐potential measurements. The interacting ability of the anionic sulfonate functions was investigated by EPR spectroscopy with copper(II) as a probe. Different structures and conformations of the AuNPs modulate the availability of sulfonate and thiol groups for complexation by copper(II). Toxicity assays of AuNPs showed that those produced through direct reaction were less toxic than those obtained by ligand exchange. Inhibition of HIV‐1 infection was higher in the case of dendronized AuNPs than in dendrons.
Capturing gold: Water‐soluble gold nanoparticles (AuNPs) have been isolated with pendant anionic sulfonate carbosilane dendrons. The antiviral properties of dendronized AuNPs are higher than that of the free dendrons (see figure).
Controlling graphene conductivity is crucial for its potential applications. With this focus, this paper shows the effect of the non-covalent bonding of a pyrimidine derivative (HIS) on the ...electronic properties of graphene (G). Several G-HIS hybrids are prepared through mild treatments keeping unaltered the structures of both G and HIS. The attachment of HIS to G occurs by π–π stacking of the HIS-aromatic residue with the G surface. This partially blocks the p z electrons of G, giving rise to the splitting of both the valence and conduction bands. Moreover, the width of the splitting is directly related to the HIS content. This fact allows the fine-tuning of the band gap of G-HIS hybrids. Furthermore, HIS keeps its metal-complexing ability in the G-HIS hybrids. Taking advantage of this, a G-HIS–Cu(0) composite was prepared by H2 plasma reduction of a precursor of the G-HIS–Cu(II) type. G-HIS−Cu(0) contains Cu(0) clusters stabilized on the G surface due to interactions with the COO– functions of HIS. In an analogous hybrid, G-HIS–Au(0), the Au(0) NPs are also stabilized by COO– functions. This material, consisting of the coupling of Au(0) NPs and G-HIS, photocatalyzed water reduction under visible light radiation producing 12.5 μmol·g–1·h–1of hydrogen.
A modified seeded growth process has been used for the controlled synthesis of quasispherical, CTAB-stabilized gold nanoparticles from 12 up to 180 nm with narrow size distributions. The UV−visible ...spectra of the aqueous colloids show distinct bands corresponding to dipole and quadrupole plasmon modes, for diameters above 100 nm, in close agreement with predictions based on Mie theory. The assignment of the modes is demonstrated by calculation of near field enhancement maps based on the boundary element method. Apart from other applications, since absorption is drastically reduced above 600 nm, while scattering is largely increased, these particles open new possibilities for construction of highly efficient photonic structures.
Treatment of acute pain in older patients is a common challenge faced in emergency departments (EDs). Despite many studies that have investigated chronic analgesic use in the elderly, data on ...patterns of acute use, especially in EDs, of analgesics according to patient characteristics is scarce.
To investigate sex- and age-related patterns of analgesic use in the Spanish EDs and determine differences in age-related patterns according to patient sex.
A secondary analysis of the Emergency Department and Elderly Needs (EDEN) multipurpose cohort.
Fifty-two Spanish EDs (17% of Spanish EDs covering 25% of Spanish population).
All patients' ≥65 years attending ED during 1 week (April 1-7, 2019). Patient characteristics recorded included age, sex, chronic treatment with non-steroidal anti-inflammatory drugs (NSAIDs) and opiates, comorbidity, dependence, dementia, depression, ability to walk and previous falls. Analgesics used in the ED were categorized in three groups: non-NSAID non-opioids (mainly paracetamol and metamizole, PM), NSAIDs, and opiates.
Frequency of analgesic use was quantified, and the relationship between sex and age and analgesic use (in general and for each analgesic group) was assessed by unadjusted and adjusted logistic regression and restricted cubic spline models. Interaction between sex and age was explored.
We included 24 573 patients, and 6678 (27.2%) received analgesics in the ED: 5551 (22.6%) PM, 1661 (6.8%) NSAIDs and 937 (3.8%) opiates (1312 received combinations). Analgesics were more frequently used in women (adjusted OR = 1.076, 95%CI = 1.014-1.142), as well as with NSAID (1.205, 1.083-1.341). Analgesic use increased with age, increasing PM and decreasing NSAIDs use. Opiate use remained quite constant across age and sex. Interaction of sex with age was present for the use of analgesics in general ( P = 0.006), for PM ( P < 0.001) and for opiates ( P = 0.033), with higher use of all these analgesics in women.
Use of analgesics in older individuals in EDs is mildly augmented in women and increases with age, with PM use increasing and NSAIDs decreasing with age. Conversely, opiate use is quite constant according to sex and age. Age-related patterns differ according to sex, with age-related curves of women showing higher probabilities than those of men to receive any analgesic, PM or opiates.
More than half of the human genome is made of transposable elements whose ongoing mobilization is a driving force in genetic diversity; however, little is known about how the host regulates their ...activity. Here, we show that the Microprocessor (Drosha-DGCR8), which is required for microRNA biogenesis, also recognizes and binds RNAs derived from human long interspersed element 1 (LINE-1), Alu and SVA retrotransposons. Expression analyses demonstrate that cells lacking a functional Microprocessor accumulate LINE-1 mRNA and encoded proteins. Furthermore, we show that structured regions of the LINE-1 mRNA can be cleaved in vitro by Drosha. Additionally, we used a cell culture-based assay to show that the Microprocessor negatively regulates LINE-1 and Alu retrotransposition in vivo. Altogether, these data reveal a new role for the Microprocessor as a post-transcriptional repressor of mammalian retrotransposons and a defender of human genome integrity.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Purpose
Obstructive sleep apnoea (OSA) and cardiac conduction disorders are pathologies with a rising prevalence due to increased life expectancy. Upper airway patency is affected by environmental ...factors that may be associated with seasonal periods. The ability to record the degree of nocturnal apnoea on a daily basis may provide a more accurate picture of seasonal variability.
Methods
This study used an observational, cross-sectional design recruiting consecutive patients with Sorin/Livanova/Microport® pacemakers. The study assessed the seasonal influence on the daily degree of nocturnal apnoea over a minimum period of 180 days. The respiratory events were recorded using a pacemaker-integrated detection algorithm based on transthoracic impedance variation. A generalised linear repeated measure mixed model was used to study the seasonal effect.
Results
A sample of 101 subjects with a mean of 227 valid nights was compiled. Summer was associated with higher RDI (respiratory disturbance index) values and winter with lower values. The mean daily RDI ratio in summer was 1.099 times higher than in winter.
Conclusions
Slight seasonal influences on the degree of nocturnal apnoea were detected through the daily observation of an unselected sample of pacemaker wearers. The degree of apnoea is higher in warmer months and lower in colder months.
This paper reports a new method to obtain ultra-small Pd and Pt nanoparticles (0.5-1 nm) supported on multi-walled carbon nanotubes (MWCNTs). Even at high loadings of both metals (22.3 and 31.5% ...(wt/wt) of Pd
2+
and Pt
2+
, respectively), very narrow and unimodal particle size distributions are achieved. The complexing capabilities of polyethyleneimine covalently attached to the surface of the tubes are optimal for the retention of Pd
2+
and Pt
2+
from solution. We have addressed the reduction of the retained ions by two approaches: a classical treatment with NaBH
4
in aqueous solution, and a novel method using hydrogen cold plasma to preserve the structural features of the material. Cold plasma produced degrees of reduction similar or even larger than NaBH
4
, supporting the advantage of hydrogen cold plasma as reducing agent as it is a simple, clean and fast (15 minutes) procedure. XPS analysis of the reduced materials show an increase in the electron density near the Fermi level. Pt/MWCNT materials have been tested as anode for methanol electrooxidation, showing a catalytic profile typical of that observed for platinum nanoparticles. The stability after 1000 cycles of the plasma-reduced materials is much larger than these reported for Pt/carbon materials, indicating the stability of the ultra-small nanoparticles.
This paper reports a new method to obtain ultra-small Pd and Pt nanoparticles (0.5-1 nm) supported on multi-walled carbon nanotubes (MWCNTs).
DNA molecules containing a 1D silver array may be applied for nanotechnology applications, but first their conducting and photoluminescence behavior must be enhanced. Here we have synthesized and ...characterized three new helical compounds based on stacked silver-mediated cytosine base pairs Ag(mC)
X (mC = N1-methylcytosine; X = NO
(
), BF
(
) and ClO
(
)), that contain uninterrupted polymeric Ag
chains that run through the center of the helixes, comparable to related silver-DNA structures. The exposure of nanostructures of Ag(mC)
BF
(
) to cold hydrogen plasma stimulates the reduction of the prearranged Ag
polymeric chains to metallic silver along the material. This solvent-free reduction strategy leads to the compound Ag
(mC)
X@Ag
(
) that contains uniformly well-distributed silver metallic nanostructures that are responsible for the new conducting and photoluminescence properties of the material. The presence of silver nanostructures alongside compound
has been evaluated by means of X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, and X-ray powder diffraction (XRPD). The conducting and photoactive properties of
were studied by electrostatic force microscopy (EFM) and conducting-AFM (c-AFM), and photoluminescence microscopy (PL), respectively. The results demonstrate that the presence of well-organized metallic silver nanoentities on the material is responsible for the novel conductivity and photoactive properties of the material. This methodology can be employed for the generation of multifunctional silver-DNA related materials with tailored properties.
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