Inversion of exciton level splitting in quantum dots

The demonstration of degeneracy of exciton spin states is an important step toward the production of entangled photon pairs from the biexciton cascade. We measure the fine structure of exciton and biexciton states for a large number of single InAs quantum dots in a GaAs matrix; the energetic splitting of the horizontally and vertically polarized components of the exciton doublet is shown to decrease as the exciton confinement decreases, crucially passing through zero and changing sign. Thermal annealing is shown to reduce the exciton confinement, thereby increasing the number of dots with splitting close to zero

Recommendations for a core outcome set for measuring standing balance in adult populations: a consensus-based approach

Standing balance is imperative for mobility and avoiding falls. Use of an excessive number of standing balance measures has limited the synthesis of balance intervention data and hampered consistent clinical practice.To develop recommendations for a core outcome set (COS) of standing balance measures for research and practice among adults.A combination of scoping reviews, literature appraisal, anonymous voting and face-to-face meetings with fourteen invited experts from a range of disciplines with international recognition in balance measurement and falls prevention. Consensus was sought over three rounds using pre-established criteria.The scoping review identified 56 existing standing balance measures validated in adult populations with evidence of use in the past five years, and these were considered for inclusion in the COS.Fifteen measures were excluded after the first round of scoring and a further 36 after round two. Five measures were considered in round three. Two measures reached consensus for recommendation, and the expert panel recommended that at a minimum, either the Berg Balance Scale or Mini Balance Evaluation Systems Test be used when measuring standing balance in adult populations.Inclusion of two measures in the COS may increase the feasibility of potential uptake, but poses challenges for data synthesis. Adoption of the standing balance COS does not constitute a comprehensive balance assessment for any population, and users should include additional validated measures as appropriate.The absence of a gold standard for measuring standing balance has contributed to the proliferation of outcome measures. These recommendations represent an important first step towards greater standardization in the assessment and measurement of this critical skill and will inform clinical research and practice internationally

Exploring the Caffeine-Induced Teratogenicity on Neurodevelopment Using Early Chick Embryo

Caffeine consumption is worldwide. It has been part of our diet for many centuries; indwelled in our foods, drinks, and medicines. It is often perceived as a “legal drug”, and though it is known to have detrimental effects on our health, more specifically, disrupt the normal fetal development following excessive maternal intake, much ambiguity still surrounds the precise mechanisms and consequences of caffeine-induced toxicity. Here, we employed early chick embryos as a developmental model to assess the effects of caffeine on the development of the fetal nervous system. We found that administration of caffeine led to defective neural tube closures and expression of several abnormal morphological phenotypes, which included thickening of the cephalic mesenchymal tissues and scattering of somites. Immunocytochemistry of caffeine-treated embryos using neural crest cell markers also demonstrated uncharacteristic features; HNK1 labeled migratory crest cells exhibited an incontinuous dorsal-ventral migration trajectory, though Pax7 positive cells of the caffeine-treated groups were comparatively similar to the control. Furthermore, the number of neurons expressing neurofilament and the degree of neuronal branching were both significantly reduced following caffeine administration. The extent of these effects was dose-dependent. In conclusion, caffeine exposure can result in malformations of the neural tube and induce other teratogenic effects on neurodevelopment, although the exact mechanism of these effects requires further investigation

Murine Gammaherpesvirus-68 Inhibits Antigen Presentation by Dendritic Cells

Dendritic cells (DCs) play a central role in initiating adaptive immunity. Murine gammaherpesvirus-68 (MHV-68), like many persistent viruses, infects DCs during normal host colonization. It therefore provides a means to understanding what host and viral genes contribute to this aspect of pathogenesis. The infected DC phenotype is likely to depend on whether viral gene expression is lytic or latent and whether antigen presentation is maintained. For MHV-68, neither parameter has been well defined. Here we show that MHV-68 infects immature but not mature bone marrow-derived DCs. Infection was predominantly latent and these DCs showed no obvious defect in antigen presentation. Lytically infected DCs were very different. These down-regulated CD86 and MHC class I expression and presented a viral epitope poorly to CD8+ T cells. Antigen presentation improved markedly when the MHV-68 K3 gene was disrupted, indicating that K3 fulfils an important function in infected DCs. MHV-68 infects only a small fraction of the DCs present in lymphoid tissue, so K3 expression is unlikely to compromise significantly global CD8+ T cell priming. Instead it probably helps to maintain lytic gene expression in DCs once CD8+ T cell priming has occurred

A feasibility study of X-ray phase-contrast mammographic tomography at the Imaging and Medical beamline of the Australian Synchrotron

Results are presented of a recent experiment at the Imaging and Medical beamline of the Australian Synchrotron intended to contribute to the implementation of low-dose high-sensitivity three-dimensional mammographic phase-contrast imaging, initially at synchrotrons and subsequently in hospitals and medical imaging clinics. The effect of such imaging parameters as X-ray energy, source size, detector resolution, sample-to-detector distance, scanning and data processing strategies in the case of propagation-based phase-contrast computed tomography (CT) have been tested, quantified, evaluated and optimized using a plastic phantom simulating relevant breast-tissue characteristics. Analysis of the data collected using a Hamamatsu CMOS Flat Panel Sensor, with a pixel size of 100 μm, revealed the presence of propagation-based phase contrast and demonstrated significant improvement of the quality of phase-contrast CT imaging compared with conventional (absorption-based) CT, at medically acceptable radiation doses

Borrelia valaisiana resist complement-mediated killing independently of the recruitment of immune regulators and inactivation of complement components

Spirochetes belonging to the Borrelia (B.) burgdorferi sensu lato complex differ in their resistance to complement-mediated killing, particularly in regard to human serum. In the present study, we elucidate the serum and complement susceptibility of B. valaisiana, a genospecies with the potential to cause Lyme disease in Europe as well as in Asia. Among the investigated isolates, growth of ZWU3 Ny3 was not affected while growth of VS116 and Bv9 was strongly inhibited in the presence of 50% human serum. Analyzing complement activation, complement components C3, C4 and C6 were deposited on the surface of isolates VS116 and Bv9, and similarly the membrane attack complex was formed on their surface. In contrast, no surface-deposited components and no aberrations in cell morphology were detected for serum-resistant ZWU3 Ny3. While further investigating the protective role of bound complement regulators in mediating complement resistance, we discovered that none of the B. valaisiana isolates analyzed bound complement regulators Factor H, Factor H-like protein 1, C4b binding protein or C1 esterase inhibitor. In addition, B. valaisiana also lacked intrinsic proteolytic activity to degrade complement components C3, C3b, C4, C4b, and C5. Taken together, these findings suggest that certain B. valaisiana isolates differ in their capability to resist complement-mediating killing by human serum. The molecular mechanism utilized by B. valaisiana to inhibit bacteriolysis appears not to involve binding of the key host complement regulators of the alternative, classical, and lectin pathways as already known for serum-resistant Lyme disease or relapsing fever borreliae

Clinical and radiographic outcomes of the treatment of adolescent idiopathic scoliosis with segmental pedicle screws and combined local autograft and allograft bone for spinal fusion: a retrospective case series

<p>Abstract</p> <p>Background</p> <p>High morbidity has been reported with iliac crest bone graft harvesting; however, donor bone is typically necessary for posterior spinal fusion. Autograft bone combined with allograft may reduce the morbidity associated with iliac crest bone harvesting and improve the fusion rate. Our aim in this study was to determine the presence of complications, pseudarthrosis, non-union, and infection using combined <it>in situ </it>local autograft bone and freeze-dried cancellous allograft bone in patients undergoing posterior spinal fusion for the treatment of adolescent idiopathic scoliosis.</p> <p>Methods</p> <p>A combination of <it>in situ </it>local autograft bone and freeze-dried cancellous allograft blocks were used in 50 consecutive patients with adolescent idiopathic scoliosis treated by posterior fusion and Moss Miami pedicle screw instrumentation. Results were assessed clinically and radiographically and quality of life and functional outcome was evaluated by administration of a Chinese version of the SRS-22 survey.</p> <p>Results</p> <p>There were 41 female and 9 male patients included for analysis with an average age of 14.7 years (range, 12-17). All patients had a minimum follow-up of 18 months (range, 18 to 40 months). The average preoperative Cobb angle was 49.8° (range, 40° to 86°). The average number of levels fused was 9.8 (range, 6-15). Patients had a minimum postoperative follow-up of 18 months. At final follow-up, the average Cobb angle correction was 77.8% (range, 43.4 to 92.5%). There was no obvious loss in the correction, and the average loss of correction was 1.1° (range, 0° to 4°). There was no pseudarthrosis and no major complications.</p> <p>Conclusions</p> <p><it>In situ </it>autograft bone combined with allograft bone may be a promising method enhances spinal fusion in AIS treated with pedicle screw placement. By eliminating the need for iliac crest bone harvesting, significant morbidity may be avoided.</p

El Niño Modulations Over The Past Seven Centuries (Letter to the editor)

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Mathematical model of a telomerase transcriptional regulatory network developed by cell-based screening: analysis of inhibitor effects and telomerase expression mechanisms

Cancer cells depend on transcription of telomerase reverse transcriptase (TERT). Many transcription factors affect TERT, though regulation occurs in context of a broader network. Network effects on telomerase regulation have not been investigated, though deeper understanding of TERT transcription requires a systems view. However, control over individual interactions in complex networks is not easily achievable. Mathematical modelling provides an attractive approach for analysis of complex systems and some models may prove useful in systems pharmacology approaches to drug discovery. In this report, we used transfection screening to test interactions among 14 TERT regulatory transcription factors and their respective promoters in ovarian cancer cells. The results were used to generate a network model of TERT transcription and to implement a dynamic Boolean model whose steady states were analysed. Modelled effects of signal transduction inhibitors successfully predicted TERT repression by Src-family inhibitor SU6656 and lack of repression by ERK inhibitor FR180204, results confirmed by RT-QPCR analysis of endogenous TERT expression in treated cells. Modelled effects of GSK3 inhibitor 6-bromoindirubin-3′-oxime (BIO) predicted unstable TERT repression dependent on noise and expression of JUN, corresponding with observations from a previous study. MYC expression is critical in TERT activation in the model, consistent with its well known function in endogenous TERT regulation. Loss of MYC caused complete TERT suppression in our model, substantially rescued only by co-suppression of AR. Interestingly expression was easily rescued under modelled Ets-factor gain of function, as occurs in TERT promoter mutation. RNAi targeting AR, JUN, MXD1, SP3, or TP53, showed that AR suppression does rescue endogenous TERT expression following MYC knockdown in these cells and SP3 or TP53 siRNA also cause partial recovery. The model therefore successfully predicted several aspects of TERT regulation including previously unknown mechanisms. An extrapolation suggests that a dominant stimulatory system may programme TERT for transcriptional stability

Influence of arthritis and non-arthritis related factors on areal bone mineral density (BMDa) in women with longstanding inflammatory polyarthritis: a primary care based inception cohort

<p>Abstract</p> <p>Background</p> <p>The aim of this analysis was to determine the relative influence of disease and non-disease factors on areal bone mineral density (BMD_a) in a primary care based cohort of women with inflammatory polyarthritis.</p> <p>Methods</p> <p>Women aged 16 years and over with recent onset inflammatory polyarthritis were recruited to the Norfolk Arthritis Register (NOAR) between 1990 and 1993. Subjects were examined at both baseline and follow up for the presence of tender, swollen and deformed joints. At the 10^thanniversary visit, a sub-sample of women were invited to complete a bone health questionnaire and attend for BMD_a(Hologic, QDR 4000). Linear regression was used to examine the association between BMD_awith both (i) arthritis-related factors assessed at baseline and the 10^thanniversary visit and (ii) standard risk factors for osteoporosis. Adjustments were made for age.</p> <p>Results</p> <p>108 women, mean age 58.0 years were studied. Older age, decreasing weight and BMI at follow up were all associated with lower BMD_aat both the spine and femoral neck. None of the lifestyle factors were linked. Indices of joint damage including 10^thanniversary deformed joint count and erosive joint count were the arthritis-related variables linked with a reduction in BMD_aat the femoral neck. By contrast, disease activity as determined by the number of tender and or swollen joints assessed both at baseline and follow up was not linked with BMD_aat either site.</p> <p>Conclusion</p> <p>Cumulative disease damage was the strongest predictor of reduced femoral bone density. Other disease and lifestyle factors have only a modest influence.</p