Shuttle-launch triangular space station

A triangular space station deployable in orbit is described. The framework is comprized of three trusses, formed of a pair of generally planar faces consistine of foldable struts. The struts expand and lock into rigid structural engagement forming a repetition of equilater triangles and nonfolding diagonal struts interconnecting the two faces. The struts are joined together by node fittings. The framework can be packaged into a size and configuration transportable by a space shuttle. When deployed, the framework provides a large work/construction area and ample planar surface area for solar panels and thermal radiators. A plurity of modules are secured to the framework and then joined by tunnels to make an interconnected modular display. Thruster units for the space station orientation and altitude maintenance are provided

NADPH oxidase, NOX1, mediates vascular injury in ischemic retinopathy

<b>Aims:</b> Ischemic retinal diseases such as retinopathy of prematurity are major causes of blindness due to damage to the retinal microvasculature. Despite this clinical situation, retinopathy of prematurity is mechanistically poorly understood. Therefore, effective preventative therapies are not available. However, hypoxic-induced increases in reactive oxygen species (ROS) have been suggested to be involved with NADPH oxidases (NOX), the only known dedicated enzymatic source of ROS. Our major aim was to determine the contribution of NOX isoforms (1, 2, and 4) to a rodent model of retinopathy of prematurity. <b>Results:</b> Using a genetic approach, we determined that only mice with a deletion of NOX1, but not NOX2 or NOX4, were protected from retinal neovascularization and vaso-obliteration, adhesion of leukocytes, microglial accumulation, and the increased generation of proangiogenic and proinflammatory factors and ROS. We complemented these studies by showing that the specific NOX inhibitor, GKT137831, reduced vasculopathy and ROS levels in retina. The source of NOX isoforms was evaluated in retinal vascular cells and neuro-glial elements. Microglia, the immune cells of the retina, expressed NOX1, 2, and 4 and responded to hypoxia with increased ROS formation, which was reduced by GKT137831. <b>Innovation:</b> Our studies are the first to identify the NOX1 isoform as having an important role in the pathogenesis of retinopathy of prematurity. <b>Conclusions:</b> Our findings suggest that strategies targeting NOX1 have the potential to be effective treatments for a range of ischemic retinopathie

Retinal dysfunction in diabetic Ren-2 rats is ameliorated by treatment with valsartan but not atenolol

PURPOSE. To determine whether diabetes leads to retinal neuronal dysfunction in hypertensive transgenic (mRen-2)27 rats (Ren-2), and whether the effect can be prevented by treatment of hypertension with either the angiotensin-1 receptor blocker (AT1-RB) valsartan or the ␤1-adrenergic receptor antagonist atenolol. METHODS. Six-week-old Ren-2 rats were made diabetic (streptozotocin 55 mg/kg; n ϭ 34) or remained nondiabetic (0.1 M citrate buffer; n ϭ 43) and studied for 20 weeks. A subset of animals received valsartan (4 mg/kg per day) or atenolol (30 mg/kg per day) by gavage. Sprague-Dawley (SD) rats served as normotensive controls for blood pressure (BP). We evaluated retinal function in all groups with a paired-flash electroretinogram over high light intensities (0.5-2.0 log cd-s ⅐ m Ϫ2 ), to isolate rod and cone responses. RESULTS. A reduction in amplitude of all electroretinogram components (PIII, PII, OPs, cone PII) was found in nondiabetic Ren-2 compared with nondiabetic SD rats. A further reduction was observed in diabetic Ren-2 rats. Treatment of both nondiabetic and diabetic Ren-2 rats with valsartan or atenolol reduced BP to within normal limits. This reduction produced some improvement in function in treated nondiabetic Ren-2 rats. However, in treated diabetic Ren-2 rats, retinal dysfunction was ameliorated by valsartan but not by atenolol, with a significant improvement (P Ͻ 0.05) observed in all components of the electroretinogram, with the exception of the OPs. CONCLUSIONS. These findings suggest that hypertension induces retinal dysfunction that is exacerbated with diabetes and ameliorated by treatment with an AT1-RB, and not just by normalizing BP. These data provide further evidence for the importance of the renin-angiotensin system in development of diabetic complications. (Invest Ophthalmol Vis Sci. 2007;48: 927-934

Advanced cryo-tomography workflow developments - correlative microscopy, milling automation and cryo-lift-out

Cryo-electron tomography (cryo-ET) is a groundbreaking technology for 3D visualisation and analysis of biomolecules in the context of cellular structures. It allows structural investigations of single proteins as well as their spatial arrangements within the cell. Cryo-tomograms provide a snapshot of the complex, heterogeneous and transient subcellular environment. Due to the excellent structure preservation in amorphous ice, it is possible to study interactions and spatial relationships of proteins in their native state without interference caused by chemical fixatives or contrasting agents. With the introduction of focused ion beam (FIB) technology, the preparation of cellular samples for electron tomography has become much easier and faster. The latest generation of integrated FIB and scanning electron microscopy (SEM) instruments (dual beam microscopes), specifically designed for cryo-applications, provides advances in automation, imaging and the preparation of high-pressure frozen bulk samples using cryo-lift-out technology. In addition, correlative cryo-fluorescence microscopy provides cellular targeting information through integrated software and hardware interfaces. The rapid advances, based on the combination of correlative cryo-microscopy, cryo-FIB and cryo-ET, have already led to a wealth of new insights into cellular processes and provided new 3D image data of the cell. Here we introduce our recent developments within the cryo-tomography workflow, and we discuss the challenges that lie ahead. Lay Description This article describes our recent developments for the cryo-electron tomography (cryo-ET) workflow. Cryo-ET offers superior structural preservation and provides 3D snapshots of the interior of vitrified cells at molecular resolution. Before a cellular sample can be imaged by cryo-ET, it must be made accessible for transmission electron microscopy. This is achieved by preparing a 200-300 nm thin cryo-lamella from the cellular sample using a cryo-focused ion beam (cryo-FIB) microscope. Cryo-correlative light and electron microscopy (cryo-CLEM) is used within the workflow to guide the cryo-lamella preparation to the cellular areas of interest. We cover a basic introduction of the cryo-ET workflow and show new developments for cryo-CLEM, which facilitate the connection between the cryo-light microscope and the cryo-FIB. Next, we present our progress in cryo-FIB software automation to streamline cryo-lamella preparation. In the final section we demonstrate how the cryo-FIB can be used for 3D imaging and how bulk-frozen cellular samples (obtained by high-pressure freezing) can be processed using the newly developed cryo-lift-out technology

Nasal Epithelial Cells of Donor Origin after Allogeneic Hematopoietic Cell Transplantation are Generated at a Faster Rate in the First 3 Months Compared with Later Posttransplantation

Detection of donor-type epithelial cells (ECs) after allogeneic hematopoietic cell transplantation (allo-HCT) using XY chromosome fluorescein in situ hybridization (FISH) has suggested that hematopoietic stem cells carry a degree of developmental plasticity. This is controversial, given artifacts of XY-based detection and the possibility of hematopoietic–nonhematopoietic cell fusion. Moreover, the kinetics of donor-type ECs (quantity at different time points after transplant) is unknown. Here, we document unequivocally the existence of donor-type ECs using a method obviating the artifacts of XY-FISH and study their kinetics. Nasal scrapings and blood specimens were collected from 60 allo-HCT survivors between 7 days and 22 years posttransplantation. DNA extracted from laser-captured nasal ECs (ie, CK+CD45− cells) and blood leukocytes was polymerase chain reaction–amplified for a panel of 16 short tandem repeat markers. The median percentage of donor-type ECs (among nasal ECs) was 0% on day 7 posttransplantation, 2.8% at 3 months posttransplantation, and 8.5% at 12-22 years posttransplantation. Cell fusion was ruled out by FISH analysis for two autosomes. We conclude that donor-type nasal ECs exist after HCT, and that their percentage rises rapidly in the first 3 months posttransplantation and more slowly thereafter

Candesartan Attenuates Diabetic Retinal Vascular Pathology by Restoring Glyoxalase-I Function

This is an uncopyedited electronic version of an article accepted for publication in Diabetes. The American Diabetes Association, publisher of Diabetes, is not responsible for any errors or omissions in this version of the manuscript or any version derived from it by third parties. The definitive publisher-authenticated version will be available in a future issue of Diabetes in print and online a

Perylene Diimide as a Precise Graphene-like Superoxide Dismutase Mimetic

Here we show that the active portion of a graphitic nanoparticle can be mimicked by a perylene diimide (PDI) to explain the otherwise elusive biological and electrocatalytic activity of the nanoparticle construct. Development of molecular analogues that mimic the antioxidant properties of oxidized graphenes, in this case the poly(ethylene glycolated) hydrophilic carbon clusters (PEG–HCCs), will afford important insights into the highly efficient activity of PEG–HCCs and their graphitic analogues. PEGylated perylene diimides (PEGn–PDI) serve as well-defined molecular analogues of PEG–HCCs and oxidized graphenes in general, and their antioxidant and superoxide dismutase-like (SOD-like) properties were studied. PEGn–PDIs have two reversible reduction peaks, which are more positive than the oxidation peak of superoxide (O2•–). This is similar to the reduction peak of the HCCs. Thus, as with PEG–HCCs, PEGn–PDIs are also strong single-electron oxidants of O2•–. Furthermore, reduced PEGn–PDI, PEGn–PDI•–, in the presence of protons, was shown to reduce O2•– to H2O2 to complete the catalytic cycle in this SOD analogue. The kinetics of the conversion of O2•– to O2 and H2O2 by PEG8–PDI was measured using freeze-trap EPR experiments to provide a turnover number of 133 s–1; the similarity in kinetics further supports that PEG8–PDI is a true SOD mimetic. Finally, PDIs can be used as catalysts in the electrochemical oxygen reduction reaction in water, which proceeds by a two-electron process with the production of H2O2, mimicking graphene oxide nanoparticles that are otherwise difficult to study spectroscopically

Heavy-lift vehicle-launched Space Station method and apparatus

Methods and apparatus are provided for a single heavylift launch to place a complete, operational space station on-orbit. A payload including the space station takes the place of a Shuttle Orbiter using the launch vehicle of the Shuttle Orbiter. The payload includes a forward shroud, a core module, a propulsion module, and a transition module between the core module and the propulsion module. The essential subsystems are pre-integrated and verified on Earth. The core module provides means for attaching international modules with minimum impact to the overall design. The space station includes six control moment gyros for selectably operating in either LVLH (local-vertical local-horizontal) or SI (solar inertial) flight modes

Determination of ππ\pi\pi scattering lengths from measurement of π+π−\pi^+\pi^- atom lifetime

The DIRAC experiment at CERN has achieved a sizeable production of $\pi^+\pi^-$ atoms and has significantly improved the precision on its lifetime determination. From a sample of 21227 atomic pairs, a 4% measurement of the S-wave $\pi\pi$ scattering length difference $|a_0-a_2| = (.0.2533^{+0.0080}_{-0.0078}|_\mathrm{stat}.{}^{+0.0078}_{-0.0073}|_\mathrm{syst})M_{\pi^+}^{-1}$ has been attained, providing an important test of Chiral Perturbation Theory.Comment: 6 pages, 6 figure