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The reaction in water of Cu(OH)2 with 2,2′-bipyridine (bipy) and (NH4)2HPO4 in a 4 : 4 : 2 molar ratio under an inert atmosphere leads to the formation of a tetranuclear copper(ii) complex of formula {[(H2O)2Cu4(bipy)4(μ4–PO4)2(μ2–OH)]·0.5HPO4·15.5H2O}, 1, with butterfly topology. The structure of the tetranuclear core in 1 consists of four crystallographically unique copper(ii) ions in approximate square-pyramidal geometry with each coordinated to a bipy ligand and interacting through two μ4–O,O′,O″-phosphate bridges. Additional bridging between Cu(3) and Cu(4) is provided by a hydroxide ligand, whereas two water molecules cap the Cu(1) and Cu(2) square pyramids to yield a N2O3 chromophore at each copper atom. Adjacent tetranuclear units align in anti-parallel fashion where proximate metal-bound water molecules interact with each other through both intra- and inter-molecular H-bonding to link two such clusters. These pairs then further associate through π⋯π interactions between bipy ligands to form a 2D sheet with neighbouring sheets separated by H-bonded lattice water molecules, which form a 2D H-bonded network. Variable-temperature magnetic susceptibility measurements performed upon 1 reveal net intramolecular ferromagnetic coupling between the copper(ii) ions and this is supported and rationalized by a DFT study. [ABSTRACT FROM AUTHOR]

Hyphydrus ovatus beetles inhabit lakes, ponds and slow running streams. In central Europe the larvae develop at water temperatures of >10°C from May to July. All three instars live on or close to plants. The first instar prefers the upper areas of plants. Its prey are insect larvae and small stages of planktonic crustaceans. The second instar chooses deeper areas and catches larger prey, whereas the third instar prefers the root zone and feeds mainly on tubificids and chironomids that are caught in the detritus of the bottom layer. The elongated nasale of Hyphydrus ovatus is equipped with different sensilla. Despite the rather different shape of their outer parts, their ultrastructure indicates that they all have a mechanoreceptive function. Chaetiform sensilla are especially numerous and are especially long near the tip. Plate-like mechanosensilla are positioned in a half circle at the ventral edge of the rostral tip. The assumed function of these sensilla is the location of prey. As in other Hydroporinae, the axis connecting the dorsal and ventral points of articulation of the mandibles is sloped laterally. Thereby, the closing mandibles move upwards and press the prey against the underside of the nasale, which – like the upper jaw in vertebrates – serves as the counterpart of the mandibles. On its ventral side, the nasale is equipped with various cuticular teeth that serve to hold the prey when it is pressed against them by the mandibles. [ABSTRACT FROM AUTHOR]

In the present paper we study higher order embeddings in the context of cyclic coverings. Analyzing the positivity of the line bundle downstairs and its relationship with the branch divisor, we provide criteria for its pull-back to define an embedding of given order. We show that the obtained criteria are sharp. Finally, we apply them to various -- sometimes seemingly unrelated--problems in algebraic geometry. [ABSTRACT FROM AUTHOR]

Electromagnetic plane waves, solutions to Maxwell’s equations, are said to be ‘transverse’ in vacuum. Namely, the waves’ oscillatory electric and magnetic fields are confined within a plane transverse to the waves’ propagation direction. Under tight-focusing conditions however, the field can exhibit longitudinal electric or magnetic components, transverse spin angular momentum, or non-trivial topologies such as Möbius strips. Here, we show that when a suitably spatially structured beam is tightly focused, a three-dimensional polarization topology in the form of a ribbon with two full twists appears in the focal volume. We study experimentally the stability and dynamics of the observed polarization ribbon by exploring its topological structure for various radii upon focusing and for different propagation planes. [ABSTRACT FROM AUTHOR]

Background. Although third-generation cephalosporins, such as ceftriaxone (CTRX), and pneumococcal fluoroquinolones, such as moxifloxacin (MXF), are currently recommended first-line antibiotics for empirical treatment of inpatients with community-acquired pneumonia, CTRX and MXF have never undergone a head-to-head comparison. We therefore compared the efficacy, safety, and speed and quality of defervescence of sequential intravenous or oral MXF and high-dose CTRX with or without erythromycin (CTRX ± ERY) for patients with community-acquired pneumonia requiring parenteral therapy. Methods. In this prospective, multicenter, randomized, controlled, nonblinded study, 397 patients were randomly assigned to receive either MXF (400 mg once daily intravenously, possibly followed by oral tablets) or CTRX (2 g intravenously once daily) with or without ERY (1 g intravenously every 6-8 h) for 7-14 days. Results. Among 317 patients evaluable for efficacy and safety, 138 (85.7%) of 161 MXF-treated patients and 135 (86.5%) of 156 CTRX ± ERY-treated patients (59 [37.8%] of whom received CTRX and ERY) achieved continued clinical resolution. Defervescence and relief of symptoms, such as chest pain, occurred significantly earlier in the MXF-treated group than in the CTRX ± ERY-treated group. Both regimens were generally well tolerated. Conclusions. For adult patients hospitalized with community-acquired pneumonia, sequential MXF therapy was clinically equivalent to high-dose CTRX ± ERY therapy but led to a faster clinical improvement. [ABSTRACT FROM AUTHOR]

Structured light refers to the generation and application of custom light fields. As the tools and technology to create and detect structured light have evolved, steadily the applications have begun to emerge. This roadmap touches on the key fields within structured light from the perspective of experts in those areas, providing insight into the current state and the challenges their respective fields face. Collectively the roadmap outlines the venerable nature of structured light research and the exciting prospects for the future that are yet to be realized. [ABSTRACT FROM AUTHOR]