Thermal Performance Testing of Order Dependancy of Aerogels Multilayered Insulation

Robust multilayer insulation systems have long been a goal of many research projects. Such insulation systems must provide some degree of structural support and also mechanical integrity during loss of vacuum scenarios while continuing to provide insulative value to the vessel. Aerogel composite blankets can be the best insulation materials in ambient pressure environments; in high vacuum, the thermal performance of aerogel improves by about one order of magnitude. Standard multilayer insulation (MU) is typically 50% worse at ambient pressure and at soft vacuum, but as much as two or three orders of magnitude better at high vacuum. Different combinations of aerogel and multilayer insulation systems have been tested at Cryogenics Test Laboratory of NASA Kennedy Space Center. Analysis performed at Oak Ridge National Laboratory showed an importance to the relative location of the MU and aerogel blankets. Apparent thermal conductivity testing under cryogenic-vacuum conditions was performed to verify the analytical conclusion. Tests results are shown to be in agreement with the analysis which indicated that the best performance is obtained with aerogel layers located in the middle of the blanket insulation system

New Active Optical Technique Developed for Measuring Low-Earth-Orbit Atomic Oxygen Erosion of Polymers

Polymers such as polyimide Kapton (DuPont) and Teflon FEP (DuPont, fluorinated ethylene propylene) are commonly used spacecraft materials because of desirable properties such as flexibility, low density, and in the case of FEP, a low solar absorptance and high thermal emittance. Polymers on the exterior of spacecraft in the low-Earth-orbit (LEO) environment are exposed to energetic atomic oxygen. Atomic oxygen reaction with polymers causes erosion, which is a threat to spacecraft performance and durability. It is, therefore, important to understand the atomic oxygen erosion yield E (the volume loss per incident oxygen atom) of polymers being considered in spacecraft design. The most common technique for determining E is a passive technique based on mass-loss measurements of samples exposed to LEO atomic oxygen during a space flight experiment. There are certain disadvantages to this technique. First, because it is passive, data are not obtained until after the flight is completed. Also, obtaining the preflight and postflight mass measurements is complicated by the fact that many polymers absorb water and, therefore, the mass change due to water absorption can affect the E data. This is particularly true for experiments that receive low atomic oxygen exposures or for samples that have a very low E. An active atomic oxygen erosion technique based on optical measurements has been developed that has certain advantages over the mass-loss technique. This in situ technique can simultaneously provide the erosion yield data on orbit and the atomic oxygen exposure fluence, which is needed for erosion yield determination. In the optical technique, either sunlight or artificial light can be used to measure the erosion of semitransparent or opaque polymers as a result of atomic oxygen attack. The technique is simple and adaptable to a rather wide range of polymers, providing that they have a sufficiently high optical absorption coefficient. If one covers a photodiode with a uniformly thick sheet of semitransparent polymer such as Kapton H polyimide, then as atomic oxygen erodes the polymer, the short-circuit current from the photodiode will increase in an exponential manner with fluence. This nonlinear response with fluence results in a lack of sensitivity for measuring low atomic oxygen fluences. However, if one uses a variable-thickness polymer or carbon sample, which is configured as shown in the preceding figure, then a linear response can be achieved for opaque materials using a parabolic well for a circular geometry detector or a V-shaped well for a rectangular-geometry detector. Variable-thickness samples can be fabricated using many thin polymer layers. For semitransparent polymers such as Kapton H polyimide, there is an initial short-circuit current that is greater than zero. This current has a slightly nonlinear dependence on atomic oxygen fluence in comparison to opaque materials such as black Kapton as shown in the graph. For this graph figure, the total thickness of Kapton H was assumed to be 0.03 cm. The photodiode short-circuit current shown in the graph was generated on the basis of preliminary measurements-a total reflectance rho of 0.0424 and an optical absorption coefficient a of 146.5 cm(sup -1). In addition to obtaining on-orbit data, the advantage of this active erosion and erosion yield measurement technique is its simplicity and reliance upon well-characterized fluence witness materials as well as a nearly linear photodiode short-circuit current dependence upon atomic oxygen fluence. The optical technique is useful for measuring either atomic oxygen fluence or erosion, depending on the information desired. To measure the atomic oxygen erosion yield of a test material, one would need to have two photodiode sensors, one for the test material and one that uses a known erosion yield material (such as Kapton) to measure the atomic oxygen fluence

Electrocatalytic Assisted Performance Enhancement for the Na-S Battery in Nitrogen-Doped Carbon Nanospheres Loaded with Fe.

Room temperature sodium-sulfur batteries have been considered to be potential candidates for future energy storage devices because of their low cost, abundance, and high performance. The sluggish sulfur reaction and the "shuttle effect" are among the main problems that hinder the commercial utilization of room temperature sodium-sulfur batteries. In this study, the performance of a hybrid that was based on nitrogen (N)-doped carbon nanospheres loaded with a meagre amount of Fe ions (0.14 at.%) was investigated in the sodium-sulfur battery. The Fe ions accelerated the conversion of polysulfides and provided a stronger interaction with soluble polysulfides. The Fe-carbon nanospheres hybrid delivered a reversible capacity of 359 mAh·g-1 at a current density of 0.1 A·g-1 and retained a capacity of 180 mAh·g-1 at 1 A·g-1, after 200 cycles. These results, combined with the excellent rate performance, suggest that Fe ions, even at low loading, are able to improve the electrocatalytic effect of carbon nanostructures significantly. In addition to Na-S batteries, the new hybrid is anticipated to be a strong candidate for other energy storage and conversion applications such as other metal-sulfur batteries and metal-air batteries

4-(1H-Tetra­zol-5-yl)benzoic acid monohydrate

The asymmetric unit of the title compound, C8H6N4O2·H2O, consists of one 4-(1H-tetra­zol-5-yl)benzoic acid mol­ecule and one water mol­ecule. Hydrogen-bonding and π–π stacking (centroid–centroid distance between tetra­zole and benzene rings = 3.78 Å) inter­actions link the mol­ecules into a three-dimensional network

Experience of long-term use of anti-IgE therapy in a patient with chronic spontaneous urticarial

Chronic spontaneous urticaria is an urgent health problem. Recurrent urticarial rashes, angioedema and severe itching reduce the quality of life of patients. The ineffectiveness of standard therapy requires the search for new modern methods of treating this disease. Taking into account the current data on the pathogenesis, the third line of therapy for chronic spontaneous urticaria is the addition of anti-IgE therapy (omalizumab) to antihistamines of the 2nd generation. The presented clinical case is devoted to the experience of long-term use of omalizumab in a patient with chronic spontaneous urticaria. Having a disease duration of about a year, the patient was thoroughly examined, all concomitant diseases were identified and compensated, parasitic invasion was treated, but this did not lead to a regression of symptoms. Antihistamines of the 2nd generation in standard and increased doses (up to 4 times) did not control the disease, systemic glucocorticosteroids stopped the symptoms for a short time, and therefore, in  the future, the  patient began to use them independently and uncontrollably. Almost daily use of  corticosteroids for 6 months caused the development of complications in the form of weight gain and Cushing’s syndrome. Omalizumab completely stopped all the symptoms during the first day, no side effects were detected. The clinical effect lasted from 3 to 4 weeks. Thus, omalizumab therapy allowed the patient to almost completely get rid of the symptoms of CSC, which significantly improved the quality of life and made it possible to cancel systemic glucocorticosteroids. The peculiarity of the presented case is the duration of the use of omalizumab (more than 2 years) with the inability to cancel due to the return of urticarial rashes and itching

An open-label multi-center phase 1 safety study of BXQ-350 in children and young adults with relapsed solid tumors, including recurrent malignant brain tumors

BACKGROUND: BXQ-350 is a novel anti-neoplastic agent composed of saposin C (SapC) and phospholipid dioleoylphosphatidyl-serine sodium (DOPS) that selectively binds tumor cell phosphatidylserine (PS), inducing apoptosis. BXQ-350 has demonstrated preclinical antitumor effects in high-grade gliomas (HGG) and clinical activity in adult patients with recurrent HGG. METHODS: A phase 1 study was conducted in pediatric patients with relapsed/refractory solid tumors, including recurrent brain tumors. Primary objectives were to characterize safety and determine maximum tolerated dose (MTD) and preliminary antitumor activity. Sequential dose cohorts were assessed up to 3.2 mg/kg using an accelerated titration design. Each cycle was 28 days; dosing occurred on days 1-5, 8, 10, 12, 15, and 22 of cycle 1, and day 1 of subsequent cycles, until disease progression or toxicity. RESULTS: Nine patients, median age 10 years (range: 4-23), were enrolled. Seven patients (78%) had central nervous system (CNS) and two (22%) had non-CNS tumors. Eight patients completed cycle 1. No dose limiting toxicity (DLT) or BXQ-350-related serious adverse events (SAEs) were observed. Six patients experienced at least one adverse event (AE) considered possibly BXQ-350-related, most were grade ≤2. One patient with diffuse intrinsic pontine glioma experienced stable disease for 5 cycles. The study was terminated after part 1 to focus development on the frontline setting. CONCLUSION: No DLTs or BXQ-350-related SAEs were reported, and the maximal planned dose of 3.2 mg/kg IV was tolerable. Limited safety and efficacy data support continued BXQ-350 development in pediatric HGG; however, early discontinuations for progression suggest novel therapies be assessed at earlier disease stages

Experience with the triple fixed combination in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is one of the most important problems of modern medicine associated with a high mortality rate, high costs of treatment and relief of exacerbations of COPD. The main objectives of COPD treatment are symptom control, reduce the frequency of exacerbations and hospitalizations, and reduced risk of exacerbation in the future. The recommendations of the GOLD initiative propose a treatment approach based on the assessment of exacerbation rates external respiratory function indicators (spirometric classification of GOLD), the severity of symptoms assessed on the CAT test and mMRC. When choosing therapy, the physician must first of all take into account the effectiveness, safety of the drug, adherence to treatment in order to achieve the therapeutic goals of treating patients with COPD. The change in therapeutic approaches in COPD treatment is associated with the accumulation of knowledge in physiology, clinical pharmacology, and the isolation of new clinical phenotypes of COPD. Currently, the main classes of drugs for the treatment of COPD are long-acting beta-agonists (LABA), longacting anticholinergics (LAMA), and inhaled glucocorticosteroids (ICS). The evolution of therapeutic approaches in COPD treatment has led to the creation of new fixed inhalation combinations of the main groups of drugs for COPD treatment. The therapeutic strategies recommended by GOLD and the Russian Federal Guidelines determine the long-term goals of COPD treatment – the impact on the risk of exacerbations in the future. The presented clinical observation of a patient with severe COPD demonstrates the effectiveness of a triple fixed combination vilanterol/umeclidinium/fluticasone furoate 55/22/92 μg as a basic therapy. The  chosen treatment strategy not only reduces the  severity of  the  symptoms of  the  disease, but also reduces the  risk of exacerbations in the future