The BOSCO solar cell – a both sides collecting and contacted structure

The BOSCO solar cell represents a bifacial structure with double‐sided collection. The structure allows the use of standard module interconnection technology and favours the use of material with low to medium diffusion length and low resistivity for maximum benefit towards other structures, such as Al‐BSF and PERC. Within this work, we present first results on different multicrystalline silicon materials yielding a monofacial efficiency of 17.4% on large‐area wafers from block‐cast mc‐Si. This value represents a gain of ～0.7%_abs compared to Al‐BSF cells processed in parallel. The applicability for bifacial operation is demonstrated by a significantly increased quantum efficiency for rear side illumination. These results make the BOSCO solar cell concept a promising candidate to further boost the output of utility‐scale PV plants even when using low‐cost wafers of low to medium diffusion length material.

     

Hodge decomposition and solution formulas for some first-order time-dependent parabolic operators with non-constant coefficients

In this paper, we present a Hodge decomposition for the \(L_p\) -space of some parabolic first-order partial differential operators with non-constant coefficients. This is done over different types of domains in Euclidean space \(\mathbb{R }^n\) and on some conformally flat cylinders and the \(n\) -torus associated with different spinor bundles. Initially, we apply a regularization procedure in order to control the non-removable singularities over the hyperplane \(t=0\) . Using the setting of Clifford algebras combined with a Witt basis, we introduce some specific integral and projection operators. We present an \(L_p\) -decomposition where one of the components is the kernel of the regularized parabolic Dirac operator with non-constant coefficients. After that, we study the behavior of the solutions and the validity of our results when the regularization parameter tends to zero. To round off, we give some analytic solution formulas for the special context of domains on cylinders and \(n\) -tori.     

Predicting the size and properties of dendrimersomes from the lamellar structure of their amphiphilic Janus dendrimers

Dendrimersomes are stable, monodisperse unilamellar vesicles self-assembled in water from amphiphilic Janus dendrimers. Their size, stability, and membrane structure are determined by the chemical structure of Janus dendrimer and the method of self-assembly. Comparative analysis of the periodic arrays in bulk and dendrimersomes assembled by ethanol injection in water of 11 libraries containing 108 Janus dendrimers is reported. Analysis in bulk and in water was performed by differential scanning calorimetry, X-ray diffraction, dynamic light scattering, and cryo-TEM. An inverse proportionality between size, stability, mechanical properties of dendrimersomes, and thickness of their membrane was discovered. This dependence was explained by the tendency of alkyl chains forming the hydrophobic part of the dendrimersome to produce the same local packing density regardless of the branching pattern from the hydrophobic part of the dendrimer. For the same hydrophobic alkyl chain length, the largest, toughest, and most stable dendrimersomes are those with the thinnest membrane that results from the interdigitation of the alkyl groups of the Janus dendrimer. A simplified spherical-shell model of the dendrimersome was used to demonstrate the direct correlation between the concentration of Janus dendrimer in water, c, and the size of self-assembled dendrimersome. This concentration-size dependence demonstrates that the mass of the vesicle membrane is proportional with c. A methodology to predict the size of the dendrimersome based on this correlation was developed. This methodology explains the inverse proportionality between the size of dendrimersome and its membrane thickness, and provides a good agreement between the experimental and predicted size of dendrimersome.     

A LecA Ligand Identified from a Galactoside‐Conjugate Array Inhibits Host Cell Invasion by Pseudomonas aeruginosa

Lectin LecA is a virulence factor of Pseudomonas aeruginosa involved in lung injury, mortality, and cellular invasion. Ligands competing with human glycoconjugates for LecA binding are thus promising candidates to counteract P. aeruginosa infections. We have identified a novel divalent ligand from a focused galactoside(Gal)‐conjugate array which binds to LecA with very high affinity (K_d=82 nM ). Crystal structures of LecA complexed with the ligand together with modeling studies confirmed its ability to chelate two binding sites of LecA. The ligand lowers cellular invasiveness of P. aeruginosa up to 90 % when applied in the range of 0.05–5 μM . Hence, this ligand might lead to the development of drugs against P. aeruginosa infection.     

Generalized Growth Orders for Polymonogenic Functions and Related Inequalities

In this paper we introduce generalized growth orders and growth types in the sense of Shah and Seremeta in the context of polymonogenic functions. They provide a refinement of previously introduced growth orders in the study of the asymptotic growth behavior of functions satisfying higher dimensional Cauchy–Riemann type equations. We prove a number of insight giving inequalities and manage to extend some basic results that were recently proved for the context of the usual first order Cauchy–Riemann system in Clifford analysis.     

Laterally nanostructured adsorbed layers of surfactant/surfmer mixtures before and after polymerisation

The adsorbed layer structure of mixed films of the polymerisable cationic surfactant dodecyldimethyl(ethylmethacrylate)ammonium bromide (MEDDAB) with the cationic and non-ionic surfactants dodecyltrimethylammonium bromide (DTAB) and polyoxyethylene-23-lauryl ether (C12E23) has been investigated by AFM soft-contact imaging before and after solution polymerisation of MEDDAB. MEDDAB alone adsorbs on mica as a planar bilayer, but the adsorbed layer structure can be modified by mixing with DTAB or C12E23 to yield an adsorbed mesh or cylinders. The equilibrium adsorbed film structure after solution polymerisation of the methacrylate group on MEDDAB was found to depend on the solubilising ability of the non-polymerisable surfactant. C12E23 effectively prevented precipitation of polymerised MEDDAB, retaining the unpolymerised adsorbed layer structure, whereas DTAB mixtures became cloudy above 23 mol% MEDDAB. The resultant structure remained similar to the adsorbed rods formed prior to polymerisation, but had a diameter several times larger.     

Tuning the Surface of Nanoparticles: Impact of Poly(2‐ethyl‐2‐oxazoline) on Protein Adsorption in Serum and Cellular Uptake

Due to the adsorption of biomolecules, the control of the biodistribution of nanoparticles is still one of the major challenges of nanomedicine. Poly(2‐ethyl‐2‐oxazoline) (PEtOx) for surface modification of nanoparticles is applied and both protein adsorption and cellular uptake of PEtOxylated nanoparticles versus nanoparticles coated with poly(ethylene glycol) (PEG) and non‐coated positively and negatively charged nanoparticles are compared. Therefore, fluorescent poly(organosiloxane) nanoparticles of 15 nm radius are synthesized, which are used as a scaffold for surface modification in a grafting onto approach. With multi‐angle dynamic light scattering, asymmetrical flow field‐flow fractionation, gel electrophoresis, and liquid chromatography‐mass spectrometry, it is demonstrated that protein adsorption on PEtOxylated nanoparticles is extremely low, similar as on PEGylated nanoparticles. Moreover, quantitative microscopy reveals that PEtOxylation significantly reduces the non‐specific cellular uptake, particularly by macrophage‐like cells. Collectively, studies demonstrate that PEtOx is a very effective alternative to PEG for stealth modification of the surface of nanoparticles.

     

Prediction and Validation of a Druggable Site on Virulence Factor of Drug Resistant Burkholderia cenocepacia**

Burkholderia cenocepacia is an opportunistic Gram-negative bacterium that causes infections in patients suffering from chronic granulomatous diseases and cystic fibrosis. It displays significant morbidity and mortality due to extreme resistance to almost all clinically useful antibiotics. The bacterial lectin BC2L-C expressed in B. cenocepacia is an interesting drug target involved in bacterial adhesion and subsequent deadly infection to the host. We solved the first high resolution crystal structure of the apo form of the lectin N-terminal domain (BC2L-C-nt) and compared it with the ones complexed with carbohydrate ligands. Virtual screening of a small fragment library identified potential hits predicted to bind in the vicinity of the fucose binding site. A series of biophysical techniques and X-ray crystallographic screening were employed to validate the interaction of the hits with the protein domain. The X-ray structure of BC2L-C-nt complexed with one of the identified active fragments confirmed the ability of the site computationally identified to host drug-like fragments. The fragment affinity could be determined by titration microcalorimetry. These structure-based strategies further provide an opportunity to elaborate the fragments into high affinity anti-adhesive glycomimetics, as therapeutic agents against B. cenocepacia.     

Divalent Cations Increase DNA Repair Activities of Bacterial (6‐4) Photolyases

The (6‐4) photolyases of the FeS‐BCP group can be considered as the most ancient type among the large family of cryptochrome and photolyase flavoproteins. In contrast to other photolyases, they contain an Fe‐S cluster of unknown function, a DMRL chromophore, an interdomain loop, which could interact with DNA, and a long C‐terminal extension. We compared DNA repair and photoreduction of two members of the FeS‐BCP family, Agrobacterium fabrum PhrB and Rhodobacter sphaeroides RsCryB, with a eukaryotic (6‐4) photolyase from Ostreococcus, OsCPF, and a member of the class III CPD photolyases, PhrA from A. fabrum. We found that the low DNA repair effectivity of FeS‐BCP proteins is largely stimulated by Mg²⁺ and other divalent cations, whereas no effect of divalent cations was observed in OsCPF and PhrA. The (6‐4) repair activity in the presence of Mg²⁺ is comparable with the repair activities of the other two photolyases. The photoreduction, on the other hand, is negatively affected by Mg²⁺ in PhrB, but stimulated by Mg²⁺ in PhrA. A clear relationship of Mg²⁺ dependency on DNA repair with the evolutionary position conflicts with Mg²⁺ dependency of photoreduction. We discuss the Mg²⁺ effect in the context of structural data and DNA binding.