70 research outputs found

    Controlling Stray Electric Fields on an Atom Chip for Rydberg Experiments

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    Experiments handling Rydberg atoms near surfaces must necessarily deal with the high sensitivity of Rydberg atoms to (stray) electric fields that typically emanate from adsorbates on the surface. We demonstrate a method to modify and reduce the stray electric field by changing the adsorbates distribution. We use one of the Rydberg excitation lasers to locally affect the adsorbed dipole distribution. By adjusting the averaged exposure time we change the strength (with the minimal value less than 0.2 V/cm0.2\,\textrm{V/cm} at 78 μm78\,\mu\textrm{m} from the chip) and even the sign of the perpendicular field component. This technique is a useful tool for experiments handling Ryberg atoms near surfaces, including atom chips

    TRAIL Coated Genetically Engineered Immunotherapeutic Nano-Ghosts Vesicles Target Human Melanoma-Avoiding the Need for High Effective Therapeutic Concentration of TRAIL

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    Cancer cell therapy using cytotoxic T lymphocytes (CTL) or mesenchymal stem cells (MSC) possesses hurdles due to the cells, susceptibility to host induced changes. Here, versatile inanimate broadly applicable nanovesicles, termed immunotherapeutic-nano-ghosts (iNGs), are armed with inherent surface-associated targeting and therapeutic capabilities in which the promise and benefits of MSC therapy and T cell immunotherapy are combined into one powerful off-the-shelf approach for treating malignant diseases. To mimic the cytotoxic or immunosuppressive functions of T cells, iNG are produced from MSC that were genetically engineered (GE) or metabolically manipulated to express additional membrane-bound proteins, endowing the NGs derived therefrom with additional surface-associated functions such as tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). iNGs from GE-MSCs (GE-iNGs) show superior TRAIL retention and induce apoptosis in different cancer cell lines in vitro. In vivo studies on a human melanoma model demonstrate that a systemic, three-day frequency, administration of GE-iNGs result in tumor inhibition comparable to a six orders of magnitude higher concentration of soluble TRAIL. The iNGs are therefore a promising nanovesicle platform that can affect tumors in a non-immunogenic manner while avoiding the need for a highly effective therapeutic concentration

    Trapping cold atoms using surface-grown carbon nanotubes

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    We present a feasibility study for loading cold atomic clouds into magnetic traps created by single-wall carbon nanotubes grown directly onto dielectric surfaces. We show that atoms may be captured for experimentally sustainable nanotube currents, generating trapped clouds whose densities and lifetimes are sufficient to enable detection by simple imaging methods. This opens the way for a novel type of conductor to be used in atomchips, enabling atom trapping at sub-micron distances, with implications for both fundamental studies and for technological applications

    University-level practical activities in bioinformatics benefit voluntary groups of pupils in the last 2 years of school

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    This work was supported in part by the Science and Technology Facilities Council under grant ST/M000435/1 to Daniel Barker.Background Bioinformatics—the use of computers in biology—is of major and increasing importance to biological sciences and medicine. We conducted a preliminary investigation of the value of bringing practical, university-level bioinformatics education to the school level. We conducted voluntary activities for pupils at two schools in Scotland (years S5 and S6; pupils aged 15–17). We used material originally developed for an optional final-year undergraduate module and now incorporated into 4273π, a resource for teaching and learning bioinformatics on the low-cost Raspberry Pi computer. Results Pupils’ feedback forms suggested our activities were beneficial. During the course of the activity, they provide strong evidence of increase in the following: pupils’ perception of the value of computers within biology; their knowledge of the Linux operating system and the Raspberry Pi; their willingness to use computers rather than phones or tablets; their ability to program a computer and their ability to analyse DNA sequences with a computer. We found no strong evidence of negative effects. Conclusions Our preliminary study supports the feasibility of bringing university-level, practical bioinformatics activities to school pupils.Publisher PDFPeer reviewe

    Continuous delivery of endogenous inhibitors from poly(lactic-co-glycolic acid) polymeric microspheres inhibits glioma tumor growth

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    There is an urgent need for modalities that can localize and prolong the administration of the antitumor agents, particularly antiangiogenic, to achieve long-term tumor inhibition. However, one of the major obstacles is designing a device in which the biological activity of sensitive endogenous inhibitors is retained. We have designed a biodegradable polymeric device, which provides a unique and practical means of localizing and continuously delivering hemopexin (PEX) or platelet factor 4 fragment (PF-4/CTF) at the tumor site while maintaining their biological activity. The potential and efficacy of this system is shown in vitro and in vivo in a human glioma mouse model

    Continuous delivery of endogenous inhibitors from poly (lactic-co-glycolic acid) polymeric microspheres inhibits glioma tumor growth

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    Purpose: There is an urgent need for modalities that can localize and prolong the administration of the antitumor agents, particularly antiangiogenic, to achieve long-term tumor inhibition. However, one of the major obstacles is designing a device in which the biological activity of sensitive endogenous inhibitors is retained. We have designed a biodegradable polymeric device, which provides a unique and practical means of localizing and continuously delivering hemopexin (PEX) or platelet factor 4 fragment (PF-4/CTF) at the tumor site while maintaining their biological activity. The potential and efficacy of this system is shown in vitro and in vivo in a human glioma mouse model. Experimental Design: Polymeric microspheres made of poly(lactic-co-glycolic acid) (PLGA) were loaded with very low amounts of PEX and PF-4/CTF. The release profiles of these factors from PLGA and their biological activity were confirmed in vitro using proliferation assays done on endothelial and tumor cells. Tumor inhibition using this system was studied in nude mice bearing a human s.c. glioma. Results: PEX and PF-4/CTF released in vitro from PLGA microspheres were biologically active and significantly inhibited the proliferation of human umbilical vein endothelial cells, bovine capillary endothelial cells, and U87-MG cells. A single local s.c. injection of PLGA microspheres loaded with low amounts of PEX or PF-4/CTF resulted in an 88% and 95% reduction in glioma tumor volume 30 days post-treatment. Immunohistochemical analysis of the treated tumors showed a marked decrease in tumor vessel density compared with untreated tumors. Conclusion: Our findings show that polymeric microspheres are a very promising approach to locally and efficiently deliver endogenous inhibitors to the tumor site leading to a significant inhibition of the tumor
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