Self-Assembled Fluorescent Block Copolymer Micelles with Responsive Emission

Responsive fluorescent materials offer a high potential for sensing and (bio‐)imaging applications. To investigate new concepts for such materials and to broaden their applicability, the previously reported non‐fluorescent zinc(II) complex [Zn(L)] that shows coordination‐induced turn‐on emission was encapsulated into a family of non‐fluorescent polystyrene‐block‐poly(4‐vinylpyridine) (PS‐b‐P4VP) diblock copolymer micelles leading to brightly emissive materials. Coordination‐induced turn‐on emission upon incorporation and ligation of the [Zn(L)] in the P4VP core outperform parent [Zn(L)] in pyridine solution with respect to lifetimes, quantum yields, and temperature resistance. The quantum yield can be easily tuned by tailoring the selectivity of the employed solvent or solvent mixture and, thus, the tendency of the PS‐b‐P4VP diblock copolymers to self‐assemble into micelles. A medium‐dependent off–on sensor upon micelle formation could be established by suppression of non‐micelle‐borne emission background pertinent to chloroform through controlled acidification indicating an additional pH‐dependent process

Development of human antibody fragments using antibody phage display for the detection and diagnosis of Venezuelan equine encephalitis virus (VEEV)

<p>Abstract</p> <p>Background</p> <p>Venezuelan equine encephalitis virus (VEEV) belongs to the Alphavirus group. Several species of this family are also pathogenic to humans and are recognized as potential agents of biological warfare and terrorism. The objective of this work was the generation of recombinant antibodies for the detection of VEEV after a potential bioterrorism assault or an natural outbreak of VEEV.</p> <p>Results</p> <p>In this work, human anti-VEEV single chain Fragments variable (scFv) were isolated for the first time from a human naïve antibody gene library using optimized selection processes. In total eleven different scFvs were identified and their immunological specificity was assessed. The specific detection of the VEEV strains TC83, H12/93 and 230 by the selected antibody fragments was proved. Active as well as formalin inactivated virus particles were recognized by the selected antibody fragments which could be also used for Western blot analysis of VEEV proteins and immunohistochemistry of VEEV infected cells. The anti-VEEV scFv phage clones did not show any cross-reactivity with Alphavirus species of the Western equine encephalitis virus (WEEV) and Eastern equine encephalitis virus (EEEV) antigenic complex, nor did they react with Chikungunya virus (CHIKV), if they were used as detection reagent.</p> <p>Conclusion</p> <p>For the first time, this study describes the selection of antibodies against a human pathogenic virus from a human naïve scFv antibody gene library using complete, active virus particles as antigen. The broad and sensitive applicability of scFv-presenting phage for the immunological detection and diagnosis of Alphavirus species was demonstrated. The selected antibody fragments will improve the fast identification of VEEV in case of a biological warfare or terroristic attack or a natural outbreak.</p

Courtship with two spoons—Anatomy and presumed function of the bizarre antennae of Cardiocondyla zoserka ant males

Mating in ants often occurs on the wing during nuptial flights or on the ground when scattered female sexuals attract males by pheromones. In both scenarios, there is little opportunity for males to engage in prolonged aggressive competition or elaborate courtship displays. Male morphology is therefore adapted to locating female sexuals and mating, and it lacks specific weapons or other traits associated with courtship. In contrast, sexuals of the ant genus Cardiocondyla typically mate in their natal nests. As a consequence, in many species winged males have been replaced by wingless fighter or territorial males, which kill or expel rival males with their strong mandibles and show complex mating behavior. However, no wingless males are known from Cardiocondyla zoserka from West Africa, and instead, winged males have evolved a bizarre secondary sexual trait: uniquely shaped antennae with spoon-like tips that show heavily sculptured ventral surfaces with numerous invaginations. We here report on the courtship behavior of C. zoserka males and describe antennal glands with class 3 gland cells, which presumably secrete a close range sex pheromone. Antennal glands have not yet been found in males of other ant species, including a close relative of C. zoserka, suggesting that in ants with intranidal mating sexual selection can rapidly lead to highly divergent adaptations and the evolution of novel structures

Magnetic NiFe₂O₄ Nanoparticles Prepared via Non-Aqueous Microwave-Assisted Synthesis for Application in Electrocatalytic Water Oxidation

Phase‐pure spinel‐type magnetic nickel ferrite (NiFe(2)O(4)) nanocrystals in the size range of 4 to 11 nm were successfully synthesized by a fast and energy‐saving microwave‐assisted approach. Size and accessible surface areas can be tuned precisely by the reaction parameters. Our results highlight the correlation between size, degree of inversion, and magnetic characteristics of NiFe(2)O(4) nanoparticles, which enables fine‐tuning of these parameters for a particular application without changing the elemental composition. Moreover, the application potential of the synthesized powders for the electrocatalytic oxygen evolution reaction in alkaline media was demonstrated, showing that a low degree of inversion is beneficial for the overall performance. The most active sample reaches an overpotential of 380 mV for water oxidation at 10 mA cm(−2) and 38.8 mA cm(−2) at 1.7 V vs. RHE, combined with a low Tafel slope of 63 mV dec(−1)

A large scale hearing loss screen reveals an extensive unexplored genetic landscape for auditory dysfunction

The developmental and physiological complexity of the auditory system is likely reflected in the underlying set of genes involved in auditory function. In humans, over 150 non-syndromic loci have been identified, and there are more than 400 human genetic syndromes with a hearing loss component. Over 100 non-syndromic hearing loss genes have been identified in mouse and human, but we remain ignorant of the full extent of the genetic landscape involved in auditory dysfunction. As part of the International Mouse Phenotyping Consortium, we undertook a hearing loss screen in a cohort of 3006 mouse knockout strains. In total, we identify 67 candidate hearing loss genes. We detect known hearing loss genes, but the vast majority, 52, of the candidate genes were novel. Our analysis reveals a large and unexplored genetic landscape involved with auditory function

Isolation and Characterisation of a Human-Like Antibody Fragment (scFv) That Inactivates VEEV In Vitro and In Vivo

Venezuelan equine encephalitis virus (VEEV) belongs to the Alphavirus genus and several species of this family are pathogenic to humans. The viruses are classified as potential agents of biological warfare and terrorism and sensitive detection as well as effective prophylaxis and antiviral therapies are required