A photon phreak digs the LDEF happening

A year ago at the First Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium, detailed measurements on trunnion sections, as well as results from 'intentional' samples (Co, Ni, In, Ta, and V) and spacecraft parts were reported. For this year's Symposium, some of these findings are re-evaluated in combination with more recent results, to cast a longer perspective on the LDEF experience, and to sketch some promising avenues toward more effective participation in future missions. The LDEF analysis effort has been a superb training exercise, from which lessons learned need to be applied to future missions - right back to the early phases of mission planning

Doing photons with MERLIN 2 at Oroville

A very large n-type high-purity Ge-semiconductor detector has recently been installed in the Lawrence Berkeley Laboratory's underground low-background facility at Oroville. The detector (named MERLIN II) is mounted in a low-activity cryostat and has a rated 'efficiency' of about 115 percent -- nearly 4 times higher than our original MERLIN detector, which was used extensively to measure the minute amounts of radioactivity in samples from the LDEF satellite. We discuss gamma-spectrometric analyses with MERLIN II on some of the same LDEF samples, providing direct evidence for improvement in performance achieved with the larger detector

Immune Response Testing of Electrospun Polymers: An Important Consideration in the Evaluation of Biomaterials

Due primarily to cell sourcing issues, many in the field of tissue engineering have opted to create scaffolds that promote in situ regeneration, using the body as both the bioreactor and the cell source for the remodeling of scaffolds, resulting in the formation of native tissue. This practice raises many concerns, with the body’s immune response to such an implant often being neglected as a potential problem in preliminary design and biocompatibility testing. More importantly, what happens over time in terms of the immune responses as the biodegradable scaffold structures being utilized to promote in situ regeneration begin to degrade, forming structural fragments and degradation products? In summary, immune response evaluations are critical considerations that must be conducted when evaluating bioresorbable scaffolds. In addition, it is essential that these evaluations analyze materials for their potential dose-response and time-course effects on the various components of innate and acquired immunity

The Resilience Factor: What Extension Can Learn from Adolescents Coping with Parental Cancer

Using a developmental systems framework and grounded theory methods, the study reported here describes the psychosocial experiences of late adolescents coping with parental cancer. Results suggest three primary psychosocial developmental influences, including multilevel influences, coping strategies to maintain control, and responses to uncertainty and anticipatory grief. Identity and intimacy were the two most salient psychosocial tasks. The central unifying concept of resilience was the primary psychosocial developmental outcome that resulted from coping with parental cancer during late adolescence. This finding illuminates the need for Extension to expand its focus on positive outcomes that can result from coping with life crises during adolescence

Comorbidity, Pain, Utilization, and Psychosocial Outcomes in Older versus Younger Sickle Cell Adults: The PiSCES Project

Background. Patients with SCD now usually live well into adulthood. Whereas transitions into adulthood are now often studied, little is published about aging beyond the transition period. We therefore studied age-associated SCD differences in utilization, pain, and psychosocial variables. Methods. Subjects were 232 adults in the Pain in Sickle Cell Epidemiology Study (PiSCES). Data included demographics, comorbidity, and psychosocial measures. SCD-related pain and health care utilization were recorded in diaries. We compared 3 age groups: 16–25 (transition), 26–36 (younger adults), and 37–64 (older adults) years. Results. Compared to the 2 adult groups, the transition group reported fewer physical challenges via comorbidities, somatic complaints, and pain frequency, though pain intensity did not differ on crisis or noncrisis pain days. The transition group utilized opioids less often, made fewer ambulatory visits, and had better quality of life, but these differences disappeared after adjusting for pain and comorbidities. However, the transition group reported more use of behavioral coping strategies. Conclusion. We found fewer biological challenges, visits, and better quality of life, in transition-aged versus older adults with SCD, but more behavioral coping. Further study is required to determine whether age-appropriate health care, behavioral, or other interventions could improve age-specific life challenges of patients with SCD

Effect of silver content on the structure and antibacterial activity of silver-doped phosphate-based glasses

Staphylococcus aureus can cause a range of diseases, such as osteomyelitis, as well as colonize implanted medical devices. In most instances the organism forms biofilms that not only are resistant to the body's defense mechanisms but also display decreased susceptibilities to antibiotics. In the present study, we have examined the effect of increasing silver contents in phosphate-based glasses to prevent the formation of S. aureus biofilms. Silver was found to be an effective bactericidal agent against S. aureus biofilms, and the rate of silver ion release (0.42 to 1.22 µg·mm–2·h–1) from phosphate-based glass was found to account for the variation in its bactericidal effect. Analysis of biofilms by confocal microscopy indicated that they consisted of an upper layer of viable bacteria together with a layer (20 µm) of nonviable cells on the glass surface. Our results showed that regardless of the silver contents in these glasses (10, 15, or 20 mol%) the silver exists in its +1 oxidation state, which is known to be a highly effective bactericidal agent compared to that of silver in other oxidation states (+2 or +3). Analysis of the glasses by 31P nuclear magnetic resonance imaging and high-energy X-ray diffraction showed that it is the structural rearrangement of the phosphate network that is responsible for the variation in silver ion release and the associated bactericidal effectiveness. Thus, an understanding of the glass structure is important in interpreting the in vitro data and also has important clinical implications for the potential use of the phosphate-based glasses in orthopedic applications to deliver silver ions to combat S. aureus biofilm infections

Psychometric properties of the Stroke and Aphasia Quality of Life Scale (SAQOL-39) in a generic stroke population

Background: We previously developed the Stroke and Aphasia Quality of Life scale (SAQOL-39) and tested it with people with chronic aphasia. A scale allowing comparisons of quality of life between people with versus without aphasia post-stroke would be of value to clinicians. Objectives: To evaluate the psychometrics of the SAQOL-39 in a generic stroke sample. Should this process result in a generic-stroke version of the scale (SAQOL-39g), a further aim is to compare the latter and the SAQOL-39 as tested in chronic aphasia. Design and subjects: Repeated measures psychometric study, evaluating internal consistency, test—retest reliability, construct validity and responsiveness to change. People admitted to hospital with a first stroke were assessed two weeks, three months and six months post stroke. Measures: SAQOL-39, National Institutes of Health Stroke Scale, Barthel, Frenchay Aphasia Screening Test, General Health Questionnaire-12 and Frenchay Activities Index. Results: Of 126 eligible participants, 96 (76%) participated and 87 (69%) were able to self-report and are presented here. Testing the SAQOL-39 in generic stroke resulted in the SAQOL-39g, which has the same items as the SAQOL-39 but three domains: physical, psychosocial, communication. The SAQOL-39g showed good internal consistency (α = 0.95 overall score, 0.92—0.95 domains), test—retest reliability (interclass correlation (ICC) = 0.96 overall, 0.92—0.98 domains), convergent (r = 0.36—0.70 overall, 0.47—0.78 domains) and discriminant validity (r = 0.26 overall, 0.03—0.40 domains). It differentiated people by stroke severity and visual analogue scale (VAS)-defined quality of life. Moderate changes (d = 0.35—0.49; standardized response mean (SRM) = 0.29—0.53) from two weeks to six months supported responsiveness. Conclusions: The SAQOL-39g demonstrated good reliability, validity and responsiveness to change. It can be used to evaluate quality of life in people with and without aphasia post stroke

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Identification and synthesis of a unique thiocarbazate cathepsin L inhibitor

Library samples containing 2,5-disubstituted oxadiazoles were identified as potent hits in a high throughput screen (HTS) of the NIH Molecular Libraries Small Molecule Repository (MLSMR) directed at discovering inhibitors of cathepsin L. However, when synthesized in pure form, the putative actives were found to be devoid of biological activity. Analyses by LC–MS of original library samples indicated the presence of a number of impurities, in addition to the oxadiazoles. Synthesis and bioassay of the probable impurities led to the identification of a thiocarbazate that likely originated via ring opening of the oxadiazole. Previously unknown, thiocarbazates (-)-11 and (-)-12 were independently synthesized as single enantiomers and found to inhibit cathepsin 20 L in the low nanomolar range