Implications of phosphor coating on the thermal characteristics of phosphor-converted white LEDs

The phosphor layer in phosphor-converted white Light Emitting Diodes (pcLEDs) affects their optical and thermal performances. This paper reports the effects of phosphor thickness and particle concentration on the optical efficiency and temperature rise on conformal phosphor-coated LED package. It is observed that a thicker phosphor layer and a higher phosphor particle concentration will increase the amount of backscattering and back reflection of light from the phosphor layer. These light extraction losses not only reduce the optical efficiency of the light output but also cause heat accumulation in the phosphor layer, leading to higher LED junction temperature. At 2700 K correlated colour temperature (CCT), the temperature rise is observed to increase by as much as 2.6 times as compared to its blue emitting LED package. However, the self-heating effect can be reduced through its die-bonding configuration. Structure function-based thermal evaluation shows heat accumulation in the phosphor layer and that flip-chip bonding can dissipate the heat generated in the GaN LED and phosphor layer effectively. Evidence in this study demonstrates that optical efficiency and thermal resistance of pcLEDs are dependent on the CCT ratings

Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely

Discovery of widespread transcription initiation at microsatellites predictable by sequence-based deep neural network

Using the Cap Analysis of Gene Expression (CAGE) technology, the FANTOM5 consortium provided one of the most comprehensive maps of transcription start sites (TSSs) in several species. Strikingly, ~72% of them could not be assigned to a specific gene and initiate at unconventional regions, outside promoters or enhancers. Here, we probe these unassigned TSSs and show that, in all species studied, a significant fraction of CAGE peaks initiate at microsatellites, also called short tandem repeats (STRs). To confirm this transcription, we develop Cap Trap RNA-seq, a technology which combines cap trapping and long read MinION sequencing. We train sequence-based deep learning models able to predict CAGE signal at STRs with high accuracy. These models unveil the importance of STR surrounding sequences not only to distinguish STR classes, but also to predict the level of transcription initiation. Importantly, genetic variants linked to human diseases are preferentially found at STRs with high transcription initiation level, supporting the biological and clinical relevance of transcription initiation at STRs. Together, our results extend the repertoire of non-coding transcription associated with DNA tandem repeats and complexify STR polymorphism

Study of large-grained n-type polycrystalline silicon thin films made by the solid phase crystallization method

10.1109/PVSC.2013.6744219Conference Record of the IEEE Photovoltaic Specialists Conference586-588CRCN

Integration of β-FeSi2 with poly-Si on glass for thin-film photovoltaic applications

10.1039/c3ra41156gRSC Advances3217733-773