Micro- and Nanostructured Microfluidic Devices for Localized Protein Immobilization and Other Biomedical Applications

A new immobilization method for the localized adsorption of proteins on thermoplastic surfaces is introduced. Artificial three-phase interfaces were realized by surface structuring to control the wetting behavior which lead to a preferred adsorption in these modified areas. Additionally, different fabrication methods were analyzed to determine mass fabrication capabilities. These fabrication methods also allowed the production of fully structured microchannels to tune the fluids behavior within

Micro- and Nanostructured Microfluidic Devices for Localized Protein Immobilization and Other Biomedical Applications

A new immobilization method for the localized adsorption of proteins on thermoplastic surfaces is introduced. Artificial three-phase interfaces were realized by surface structuring to control the wetting behavior which lead to a preferred adsorption in these modified areas. Additionally, different fabrication methods were analyzed to determine mass fabrication capabilities. These fabrication methods also allowed the production of fully structured microchannels to tune the fluids behavior within

Truly unentangled photon pairs without spectral filtering

We demonstrate that an integrated silicon microring resonator is capable of efficiently producing photon pairs that are completely unentangled; such pairs are a key component of heralded single photon sources. A dual-channel interferometric coupling scheme can be used to independently tune the quality factors associated with the pump and signal and idler modes, yielding a biphoton wavefunction with Schmidt number arbitrarily close to unity. This will permit the generation of heralded single photon states with unit purity.Comment: 5 pages, 3 figure

Analysis of vapor barrier experiments to evaluate their effectiveness as a means to mitigate HF concentrations: final report

CER88-89RNM-DEN-SHS-TS-TZT-GW-1.Prepared for Exxon Research and Engineering Company.On behalf of An Industry Cooperative HF Mitigation Program, Vapor Barrier Subcommittee.Includes bibliographical references (pages 153-159).July 1988 (Revised February, 1989).Accidental releases of Hydrogen Fluoride (HF) can result in initially dense, highly reactive and corrosive gas clouds. These clouds will typically contain a mixture of gases, aerosols and droplets which can be transported significant distances before lower hazard levels of HF concentration are reached. Containment fences or vapor barriers have been proposed as a means to hold-up or delay cloud expansion, elevate the plume downwind of the barriers, and enhance cloud dilution. Previous related field and laboratory experiments have been analyzed to estimate the effectiveness of barrier devices. The experiments were examined to determine their relevance to Hydrogen Fluoride spill scenarios. Wind tunnel and field data were compared where possible to validate the laboratory experiments. Barrier influence on peak concentrations, cloud arrival time, peak concentration arrival time, and cloud departure time were determined. These data were used to develop entrainment models to incorporate into integral and depth averaged numerical models. The models were then run to examine barrier performance for a typical Hydrogen Fluoride spill for a wide range of vapor barrier heights, spill sizes, meteorological conditions and release configurations. Finally the results of the data analysis and numerical sensitivity study were interpreted and expressed in a form useful to evaluate the efficacy of vapor barrier mitigation devices

A transient homotypic interaction model for the influenza A virus NS1 protein effector domain

Influenza A virus NS1 protein is a multifunctional virulence factor consisting of an RNA binding domain (RBD), a short linker, an effector domain (ED), and a C-terminal 'tail'. Although poorly understood, NS1 multimerization may autoregulate its actions. While RBD dimerization seems functionally conserved, two possible apo ED dimers have been proposed (helix-helix and strand-strand). Here, we analyze all available RBD, ED, and full-length NS1 structures, including four novel crystal structures obtained using EDs from divergent human and avian viruses, as well as two forms of a monomeric ED mutant. The data reveal the helix-helix interface as the only strictly conserved ED homodimeric contact. Furthermore, a mutant NS1 unable to form the helix-helix dimer is compromised in its ability to bind dsRNA efficiently, implying that ED multimerization influences RBD activity. Our bioinformatical work also suggests that the helix-helix interface is variable and transient, thereby allowing two ED monomers to twist relative to one another and possibly separate. In this regard, we found a mAb that recognizes NS1 via a residue completely buried within the ED helix-helix interface, and which may help highlight potential different conformational populations of NS1 (putatively termed 'helix-closed' and 'helix-open') in virus-infected cells. 'Helix-closed' conformations appear to enhance dsRNA binding, and 'helix-open' conformations allow otherwise inaccessible interactions with host factors. Our data support a new model of NS1 regulation in which the RBD remains dimeric throughout infection, while the ED switches between several quaternary states in order to expand its functional space. Such a concept may be applicable to other small multifunctional proteins

In vivo molecular imaging of chemokine receptor CXCR4 expression in patients with advanced multiple myeloma

CXCR4 is a G-protein-coupled receptor that mediates recruitment of blood cells toward its ligand SDF-1. In cancer, high CXCR4 expression is frequently associated with tumor dissemination and poor prognosis. We evaluated the novel CXCR4 probe [(68)Ga]Pentixafor for in vivo mapping of CXCR4 expression density in mice xenografted with human CXCR4-positive MM cell lines and patients with advanced MM by means of positron emission tomography (PET). [(68)Ga]Pentixafor PET provided images with excellent specificity and contrast. In 10 of 14 patients with advanced MM [(68)Ga]Pentixafor PET/CT scans revealed MM manifestations, whereas only nine of 14 standard [(18)F]fluorodeoxyglucose PET/CT scans were rated visually positive. Assessment of blood counts and standard CD34(+) flow cytometry did not reveal significant blood count changes associated with tracer application. Based on these highly encouraging data on clinical PET imaging of CXCR4 expression in a cohort of MM patients, we conclude that [(68)Ga]Pentixafor PET opens a broad field for clinical investigations on CXCR4 expression and for CXCR4-directed therapeutic approaches in MM and other diseases

Aphid and Plant Volatiles Induce Oviposition in an Aphidophagous Hoverfly

Episyrphus balteatus DeGeer (Diptera, Syrphidae) is an abundant and efficient aphid-specific predator. We tested the electroantennographic (EAG) response of this syrphid fly to the common aphid alarm pheromone, (E)-β-farnesene (EβF), and to several plant volatiles, including terpenoids (mono- and sesquiterpenes) and green leaf volatiles (C6 and C9 alcohols and aldehydes). Monoterpenes evoked significant EAG responses, whereas sesquiterpenes were inactive, except for the aphid alarm pheromone (EβF). The most pronounced antennal responses were elicited by six and nine carbon green leaf alcohols and aldehydes [i.e., (Z)-3-hexenol, (E)-2-hexenol, (E)-2-hexenal, and hexanal]. To investigate the behavioral activity of some of these EAG-active compounds, E. balteatus females were exposed to R-(+)-limonene (monoterpene), (Z)-3-hexenol (green leaf alcohol), and EβF (sesquiterpene, common aphid alarm pheromone). A single E. balteatus gravid female was exposed for 10 min to an aphid-free Vicia faba plant that was co-located with a semiochemical dispenser. Without additional semiochemical, hoverfly females were not attracted to this plant, and no oviposition was observed. The monoterpene R-(+)-limonene did not affect the females’ foraging behavior, whereas (Z)-3-hexenol and EβF increased the time of flight and acceptance of the host plant. Moreover, these two chemicals induced oviposition on aphid-free plants, suggesting that selection of the oviposition site by predatory hoverflies relies on the perception of a volatile blend composed of prey pheromone and typical plant green leaf volatiles

Use of lower quality water in irrigated agriculture and effects on forages with productive potential in Semiarid regions: a review.

In the agricultural sector, using lower quality water sources has increased in irrigation practice. Thus, this review summarizes the consequences of using brackish and/or saline water in irrigated agriculture, highlighting some effects on soil and plants in general. Water quality for irrigation and the salinity tolerance threshold of forage species with productive potential for semiarid regions are also discussed. Between January and June 2022, a systematic search was carried out for studies that evaluated the quality of water for irrigation, the effects of using water with excess salts on the soil and on plants in general, and on forage species with productive potential in semiarid regions. The databases consulted were: ScienceDirect, Scopus, Wiley Online Library, Web of Science, Taylor and Francis, and Scholar Google. A total of 1567 studies were found. Of these, 200 studies were reviewed and 154 were used because they met the review objective. The forage plants reported here have salinity tolerance ranging from low to moderate. The management adopted, as well as the species used, are factors that influence the performance of the crop under stress. Although they are widely cultivated in arid and semiarid regions of the world, few studies still show the salinity threshold of these crops, mainly for forage cactus, sunflower, and pigeon pea species. Therefore, it is essential to carry out more research on this topic in order to provide information that improves the management of production systems in saline environments around the world.Online