Singular disruptive events like solar eclipses affect the measured values of meteorological variables at the earth's surface. To quantify such an impact, it is necessary to estimate what value the ...parameter would have taken had the event not occurred. We design and compare several methods to perform such an estimate based on longer observational timeseries from individual meteorological surface stations. Our methods are based on regularised regressions (including a Bayesian variant) and provide both a point an associated error estimate of the disruptive event's impact. With their help, we study the effect of the total solar eclipse of July 2nd, 2019, in the Coquimbo Region of Chile, on near-surface air temperatures and winds. The observational data used have been collected by the meteorological surface station network of the Centro de Estudios Avanzados en Zonas Áridas (CEAZA). Most stations inside the eclipse's umbra registered a temperature drop of 1-2 Formula: see textC, while the most extreme estimated temperature drop surpassed 6 Formula: see textC. The presence of an 'eclipse cyclone' can neither be proven nor refuted. Application of the regression methods to other comparable problems like volcanic eruptions, forest fires, or simply gap filling of observational data, are conceivable.
Recent research evidences the strong modulatory role of controlled submicron and nanoscale topographies on stem cells fate. To harness these physical surface cues for clinical applications, ...fabrication of nano- and submicron patterns on clinically relevant biomaterials is greatly needed. In this study, an electron beam lithography method for direct patterning (i.e., no use of masters/imprinting steps) of titanium in the submicron range was developed. The process required the use of an etch mask consisting of a double layer of SiO2 and Al, and the positive AR P-6200.04 electron beam resist. An optimum electron beam dose of 288 μC/cm2 was established for writing the desired patterns. The transfer of the patterns into the titanium substrates was achieved by three different steps: inductively coupled plasma etching of the mask in BCl3/Cl2 followed by reactive ion etching of titanium in SF6/CHF3/O2 and a final wet etch of mask residue. Highly ordered arrays of titanium pits with submicron diameters were produced with high reproducibility. This method provides great versatility in pattern design, direct transfer into titanium and increased control of titanium pattern features at submicron to nanoscale enabling clinically relevant and systematic studies on pattern-induced cellular responses.
Display omitted
•Submicron pits were generated directly in titanium by electron beam lithography.•The process required a hard mask consisting of Al and SiO2 layers.•The optimum exposure dose was established.•Such patterns can control cells response at the titanium implant – bone interface.
Les réactions cutanées aux médicaments ou aux infections peuvent être parfois très sévères.
Nous rapportons le cas d'un adolescent en mauvais état général qui s'est présenté avec un état fébrile, une ...importante pustulose diffuse et une détresse respiratoire. Les examens complémentaires ont mis en évidence une infection aiguë à
Chlamydia pneumoniae et une biopsie de peau a posé le diagnostic de pustulose exanthématique aiguë généralisée.
La pustulose exanthématique aiguë généralisée est une affection caractérisée par l'apparition de pustules non folliculaires stériles sur tout le corps associée à des signes systémiques. La plupart des cas sont des réactions médicamenteuses, mais ils peuvent être secondaires à des infections virales ou bactériennes. Nous décrivons le premier cas en relation avec une infection aiguë à
C. pneumoniae.
Skin reactions to drugs or infections can be very important.
A 14-year-old boy developed fever, a diffuse pustular rash and a respiratory distress. Chest X-rays and serology were consistent with an acute
Chlamydia pneumoniae infection. A skin biopsy revealed an acute generalized exanthematous pustulosis.
Acute generalized exanthematous pustulosis (AGEP) is a disease manifested by a diffuse eruption of follicular sterile pustules. Most of the cases are drug induced, but they may be secondary to viral or bacterial infections. We report the first case of AGEP in a child with an acute
C. pneumoniae infection.
Nanocrystalline diamond/amorphous carbon (NCD/a-C) nanocomposite films have been deposited by microwave plasma chemical vapour deposition (MWCVD) from CH
4/N
2 mixtures. The films have been ...thoroughly characterized by a variety of methods with respect to their composition, morphology, structure and bonding environment. Thereafter, the bioproperties of these films have been investigated. Tests with osteoblast-like cells and pneumocytes proved that the NCD/a-C films are not cytotoxic. In addition, exposure of the films to a simulated body fluid revealed that they are bioinert. Further experiments addressed the question whether biomolecules such as RNA or proteins bind unspecifically on the surfaces of NCD/a-C films. By means of atomic force microscopy (AFM) and scanning force spectroscopy measurements it was established that, in contrast to control experiments with mica and glass, no interaction between the nanocrystalline diamond and either RNA or protein molecules took place. The results of these experiments concerning the biologically relevant properties of NCD/a-C films are discussed in view of possible future applications, e.g. as a material for the immobilization of biomolecules and their characterization by AFM measurements and related techniques.
Nanocrystalline diamond/amorphous carbon (NCD/a-C) composite films have been prepared by microwave plasma chemical vapor deposition (MWCVD) from methane/nitrogen mixtures and investigated with ...respect of their bioproperties. By means of atomic force microscopy (AFM) it was shown that RNA molecules can be attached to the NCD/a-C surface, which has been treated in hydrogen plasma and biochemically modified prior to the attachment. Further experiments addressed the influence of the morphology of the films on the viability and proliferation of endothelial cells. The results from scanning electron microscopy (SEM) and fluorescent microscopy revealed that homogeneous and uniform NCD/a-C films did not affect the cell shape and cytoskeleton, in contrast to films composed of individual nodules.
The hammerhead ribozyme undergoes a well-defined two-stage conformational folding process, induced by the binding of magnesium ions. In this study, we have used isothermal titration calorimetry to ...analyze the thermodynamics of magnesium binding and magnesium ion-induced folding of the ribozyme. Binding to the natural sequence ribozyme is strongly exothermic and can be analyzed in terms of sequential interaction at two sites with association constants K A = 480 and 2840 M-1. Sequence variants of the hammerhead RNA give very different isothermal titration curves. An A14G variant that cannot undergo ion-induced folding exhibits endothermic binding. By contrast, a deoxyribose G5 variant that can undergo only the first of the two folding transitions gives a complex titration curve. However, despite these differences the ITC data for all three species can be analyzed in terms of the sequential binding of magnesium ions at two sites. While the binding affinities are all in the region of 103 M-1, corresponding to free energies of ΔG° = −3.5 to −4 kcal mol-1, the enthalpic and entropic contributions show much greater variation. The ITC experiments are in good agreement with earlier conformational studies of the folding of the ion-induced folding of the hammerhead ribozyme.
The hammerhead ribozyme is the smallest naturally occurring RNA endonuclease. It is found in subviral plant pathogens and transcripts of satellite DNA from a limited number of organisms. We have ...performed a database search for novel examples of this catalytic RNA, taking into consideration the recently defined structural requirements for an efficient cleavage under physiological magnesium ion concentrations. In this search, we find, apart from the known examples, several hundreds of motifs in organisms of all kingdoms of life. In a first set of experiments, we analysed hammerhead ribozymes from Arabidopsis thaliana. We found that these sequences are tissue-specifically expressed and that they undergo self-cleavage in planta. Furthermore, their activity under physiological magnesium ion concentrations depends on functional loop-loop interactions, as shown by the lack of activity of appropriate mutants.
The relationship between blood CD8+ T lymphocyte subsets, as defined by CD28 and CD38 expression, and plasma viraemia and CD4+ T cells in HIV‐1 infection was investigated. In a cross‐sectional study ...of 46 patients with either no or stable anti‐retroviral treatment, there was a strong negative correlation between the percentage of CD8+CD28− and the percentage of CD4+ T cells (r = − 0.75, P < 0.0001), and a positive correlation between absolute numbers of CD8+CD28+ and CD4+ T cells (r = 0.56, P < 0.0001). In contrast, the expression of CD38 by CD8+ T lymphocytes correlated primarily with plasma viraemia (e.g. the percentage of CD38+ in CD8bright cells, r = 0.76, P < 0.0001). In the 6 months following triple therapy initiation in 32 subjects, there was a close correlation between changes (Δ) in CD8+CD28+ or CD8+CD28− and in CD4+ T cells (e.g. Δ% CD8+CD28+versusΔ% CD4+, r = 0.37, P = 0.0002; Δ% CD8+CD28−versusΔ% CD4+, r = − 0.66, P < 0.0001). A marked decline of the number of CD8+ T cells expressing CD38 was also observed. These results suggest the existence of a T cell homeostasis mechanism operating in blood with CD4+ and CD8+CD28+ cells on the one hand, and with CD8+CD28− cells on the other. In addition, the percentage of CD38+ cells in CD8+ cells, generally considered an independent prognostic factor, could merely reflect plasma viral load.
We report a Mycobacterium haemophilum outbreak after permanent make-up of the eyebrows performed by the same freelance artist. Twelve patients presented an eyebrow lesion and cervical lymphadenitis. ...All were treated with antibiotics. Surgery was required in 10 cases. M. haemophilum DNA was identified in the make-up ink.
Abstract
The target asymmetry
T
, recoil asymmetry
P
, and beam-target double polarization observable
H
were determined in exclusive
$$\pi ^0$$
π
0
and
$$\eta $$
η
photoproduction off quasi-free ...protons and, for the first time, off quasi-free neutrons. The experiment was performed at the electron stretcher accelerator ELSA in Bonn, Germany, with the Crystal Barrel/TAPS detector setup, using a linearly polarized photon beam and a transversely polarized deuterated butanol target. Effects from the Fermi motion of the nucleons within deuterium were removed by a full kinematic reconstruction of the final state invariant mass. A comparison of the data obtained on the proton and on the neutron provides new insight into the isospin structure of the electromagnetic excitation of the nucleon. Earlier measurements of polarization observables in the
$$\gamma p \rightarrow \pi ^0 p$$
γ
p
→
π
0
p
and
$$\gamma p \rightarrow \eta p$$
γ
p
→
η
p
reactions are confirmed. The data obtained on the neutron are of particular relevance for clarifying the origin of the narrow structure in the
$$\eta n$$
η
n
system at
$$W = 1.68\ \textrm{GeV}$$
W
=
1.68
GeV
. A comparison with recent partial wave analyses favors the interpretation of this structure as arising from interference of the
$$S_{11}(1535)$$
S
11
(
1535
)
and
$$S_{11}(1650)$$
S
11
(
1650
)
resonances within the
$$S_{11}$$
S
11
-partial wave.
PDF
