Investigation of the influence of active dopant and co-dopant on the luminescent properties of the phosphor based on calcium aluminate

In the present study the luminescent properties of calcium aluminate activated by Eu3+ and Dy3+ions are investigated. The phosphor on the basis of calcium aluminate was obtained via citric-nitrate sol gel method using a microwave radiation. It was determined by X-ray diffraction method and by electron microprobe analysis that rare earth elements (REE) ions incorporate into lattice of calcium aluminate and don't form own phases. Luminescent properties of calcium aluminate activated by REE ions were studied by spectrofluorimeter. Luminescent spectrum of Ca0,95Eu0,05Al2O4 contains five bands groups of emission between 580-710 nm which correspond to 5D0 - 7Fj transitions of Eu3+(λ=254 nm). Present maxima lie in the red area of the spectrum and determine the obtainment of red glow phosphor. Excitation spectrum of Ca0,95Dy0,05Al2O4 contains two bands with maxima at 240 and 380 nm. Exciting the sample by the far ultraviolet (240 nm), two bands with maxima at 420 and 490 nm conditioning a blue glow of phosphor under overlapping of violet (4G11/2 - 6H15/2 transition of Dy3+) and blue-green (4F9/2 - 6H15/2 transition of Dy3+) radiations, respectively, were observed. Exciting the sample by the near ultraviolet (380 nm), one intense band at 420 nm and bright violet glowing were observed. Emission spectrum of the phosphor obtaining by co-activation of calcium aluminate by two test REE ions is identical to the emission spectrum of calcium aluminate activated by Dy3+ ions. Transitions of Eu3+ in this case are not observed. Nevertheless, the increase of band intensity conditioning more bright violet glowing was observed

Polycaprolactone-Based 3D-Printed Scaffolds as Potential Implant Materials for Tendon-Defect Repair

Chronic tendon ruptures are common disorders in orthopedics. The conventional surgical methods used to treat them often require the support of implants. Due to the non-availability of suitable materials, 3D-printed polycaprolactone (PCL) scaffolds were designed from two different starting materials as suitable candidates for tendon-implant applications. For the characterization, mechanical testing was performed. To increase their biocompatibility, the PCL-scaffolds were plasma-treated and coated with fibronectin and collagen I. Cytocompatibility testing was performed using L929 mouse fibroblasts and human-bone-marrow-derived mesenchymal stem cells. The mechanical testing showed that the design adaptions enhanced the mechanical stability. Cell attachment was increased in the plasma-treated specimens compared to the control specimens, although not significantly, in the viability tests. Coating with fibronectin significantly increased the cellular viability compared to the untreated controls. Collagen I treatment showed an increasing trend. The desired cell alignment and spread between the pores of the construct was most prominent on the collagen-I-coated specimens. In conclusion, 3D-printed scaffolds are possible candidates for the development of tendon implants. Enhanced cytocompatibility was achieved through surface modifications. Although adaptions in mechanical strength still require alterations in order to be applied to human-tendon ruptures, we are optimistic that a suitable implant can be designed

Combined Prospective Seroconversion and PCR Data of Selected Cohorts Indicate a High Rate of Subclinical SARS-CoV-2 Infections—an Open Observational Study in Lower Saxony, Germany

Despite lockdown measures, intense symptom-based PCR, and antigen testing, the SARS-CoV-2 pandemic spread further. In this open observational study conducted in Lower Saxony, Germany, voluntary SARS-CoV-2 PCR tests were performed from April 2020 until June 2021, supported by serum antibody testing to prove whether PCR testing in subjects with none or few symptoms of COVID-19 is a suitable tool to manage the pandemic. In different mobile stations, 4,817 subjects from three different working fields participated in the PCR testing. Serum antibody screening using the SARS-CoV-2 ViraChip IgG (Viramed, Germany) and the Elecsys Anti-SARS-CoV-2 assay (Roche, Germany) was performed alongside virus neutralization testing. Subjects were questioned regarding comorbidities and COVID-19 symptoms. Fifty-one subjects with acute SARS-CoV-2 infection were detected of which 31 subjects did not show any symptoms possibly characteristic for COVID-19. An additional 37 subjects reported a previous SARS-CoV-2 infection (total prevalence 1.82%). Seroconversion was discovered in 58 subjects with known SARS-CoV-2 infection and in 58 subjects that never had a positive PCR test. The latter had a significantly lower Charlson Comorbidity Index, and one third of them were asymptomatic. In 50% of all seroconverted subjects, neutralizing serum antibodies (NAbs) were detectable in parallel to N/S1 (n = 16) or N/S1/S2 antigen specific antibodies (n = 40) against SARS-CoV-2. NAb titers decreased within 100 days after PCR-confirmed SARS-CoV-2 acute infection by at least 2.5-fold. A relatively high rate of subclinical SARS-CoV-2 infections may contribute to the spread of SARS-CoV-2, suggesting that in addition to other intervention strategies, systematic screening of asymptomatic persons by PCR testing may significantly enable better pandemic control

Mobile SARS‑CoV‑2 screening facilities for rapid deployment and university-based diagnostic laboratory

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has created a public crisis. Many medical and public institutions and businesses went into isolation in response to the pandemic. Because SARS-CoV-2 can spread irrespective of a patient's course of disease, these institutions’ continued operation or reopening based on the assessment and control of virus spread can be supported by targeted population screening. For this purpose, virus testing in the form of polymerase chain reaction (PCR) analysis and antibody detection in blood can be central. Mobile SARS-CoV-2 screening facilities with a built-in biosafety level (BSL)-2 laboratory were set up to allow the testing offer to be brought close to the subject group's workplace. University staff members, their expertise, and already available equipment were used to implement and operate the screening facilities and a certified diagnostic laboratory. This operation also included specimen collection, transport, PCR and antibody analysis, and informing subjects as well as public health departments. Screening facilities were established at different locations such as educational institutions, nursing homes, and companies providing critical supply chains for health care. Less than 4 weeks after the first imposed lockdown in Germany, a first mobile testing station was established featuring a build-in laboratory with two similar stations commencing operation until June 2020. During the 15-month project period, approximately 33,000 PCR tests and close to 7000 antibody detection tests were collected and analyzed. The presented approach describes the required procedures that enabled the screening facilities and laboratories to collect and process several hundred specimens each day under difficult conditions. This report can assist others in establishing similar setups for pandemic scenarios

German Geographical Research on North America : A Bibliography with Comments and Annotations

The 27th International Geographical Congress in Washington, D.C., 1992 is the first geographical congress to take place in the United States for 40 years. This event and the 40th anniversaiy of the readmittance of Germany into the IGU offer a welconte opportunity of providing the international scientific Community with a survey of the research on North America by German and German speaking geographers in the form of a commentated bibliography

Genetical, clinical and functional analysis of a large international cohort of patients with autosomal recessive congenital ichthyosis due to mutations in NIPAL4

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When Feedback Interventions Backfire: Why Higher Performance Feedback May Result in Lower Self-Perceived Competence and Satisfaction with Performance

In relative performance evaluation systems, appraisers may choose to adopt stricter or laxer evaluation criteria. When laxer (vs. stricter) criteria are used, higher absolute performance evaluations become easier (vs. harder) to achieve. Thus, each appraisee's absolute performance feedback and the mean of the distribution of absolute performance feedback are shifted upward (vs. downward). Yet, relative performance remains constant. When evaluation outcomes depend solely on relative performance, can the adoption of laxer (vs. stricter) criteria-leading to higher absolute performance feedback but no change in relative performance-influence appraisees' satisfaction with performance? Despite the ubiquity of such systems in organizations, research has not addressed this question. This article points to an important gap between practitioners' beliefs and research findings. We show that while most appraisers believe that higher absolute performance feedback will automatically result in more satisfaction with performance, the opposite may also happen. Specifically, we find that appraisees with a stronger (vs. weaker) chronic or contextual need to engage in social comparison are more satisfied with lower (vs. higher) absolute performance feedback. Overall, we demonstrate why and how feedback interventions in relative performance evaluation systems may backfire, and suggest a set of practical guidelines for maximizing appraisees' satisfaction with performance in such systems

Glioneuronal tumor with ATRX alteration, kinase fusion and anaplastic features (GTAKA): a molecularly distinct brain tumor type with recurrent NTRK gene fusions

Glioneuronal tumors are a heterogenous group of CNS neoplasms that can be challenging to accurately diagnose. Molecular methods are highly useful in classifying these tumors-distinguishing precise classes from their histological mimics and identifying previously unrecognized types of tumors. Using an unsupervised visualization approach of DNA methylation data, we identified a novel group of tumors (n = 20) that formed a cluster separate from all established CNS tumor types. Molecular analyses revealed ATRX alterations (in 16/16 cases by DNA sequencing and/or immunohistochemistry) as well as potentially targetable gene fusions involving receptor tyrosine-kinases (RTK; mostly NTRK1-3) in all of these tumors (16/16; 100%). In addition, copy number profiling showed homozygous deletions of CDKN2A/B in 55% of cases. Histological and immunohistochemical investigations revealed glioneuronal tumors with isomorphic, round and often condensed nuclei, perinuclear clearing, high mitotic activity and microvascular proliferation. Tumors were mainly located supratentorially (84%) and occurred in patients with a median age of 19 years. Survival data were limited (n = 18) but point towards a more aggressive biology as compared to other glioneuronal tumors (median progression-free survival 12.5 months). Given their molecular characteristics in addition to anaplastic features, we suggest the term glioneuronal tumor with ATRX alteration, kinase fusion and anaplastic features (GTAKA) to describe these tumors. In summary, our findings highlight a novel type of glioneuronal tumor driven by different RTK fusions accompanied by recurrent alterations in ATRX and homozygous deletions of CDKN2A/B. Targeted approaches such as NTRK inhibition might represent a therapeutic option for patients suffering from these tumors