2,152 research outputs found
Au-SN Flip-Chip Solder Bump for Microelectronic and Optoelectronic Applications
As an alternative to the time-consuming solder pre-forms and pastes currently
used, a co-electroplating method of eutectic Au-Sn alloy was used in this
study. Using a co-electroplating process, it was possible to plate the Au-Sn
solder directly onto a wafer at or near the eutectic composition from a single
solution. Two distinct phases, Au5Sn and AuSn, were deposited at a composition
of 30at.%Sn. The Au-Sn flip-chip joints were formed at 300 and 400 degrees
without using any flux. In the case where the samples were reflowed at 300
degrees, only an (Au,Ni)3Sn2 IMC layer formed at the interface between the
Au-Sn solder and Ni UBM. On the other hand, two IMC layers, (Au,Ni)3Sn2 and
(Au,Ni)3Sn, were found at the interfaces of the samples reflowed at 400
degrees. As the reflow time increased, the thickness of the (Au,Ni)3Sn2 and
(Au,Ni)3Sn IMC layers formed at the interface increased and the eutectic
lamellae in the bulk solder coarsened.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Elevated intracellular cAMP exacerbates vulnerability to oxidative stress in optic nerve head astrocytes.
Glaucoma is characterized by a progressive loss of retinal ganglion cells and their axons, but the underlying biological basis for the accompanying neurodegeneration is not known. Accumulating evidence indicates that structural and functional abnormalities of astrocytes within the optic nerve head (ONH) have a role. However, whether the activation of cyclic adenosine 3',5'-monophosphate (cAMP) signaling pathway is associated with astrocyte dysfunction in the ONH remains unknown. We report here that the cAMP/protein kinase A (PKA) pathway is critical to ONH astrocyte dysfunction, leading to caspase-3 activation and cell death via the AKT/Bim/Bax signaling pathway. Furthermore, elevated intracellular cAMP exacerbates vulnerability to oxidative stress in ONH astrocytes, and this may contribute to axonal damage in glaucomatous neurodegeneration. Inhibition of intracellular cAMP/PKA signaling activation protects ONH astrocytes by increasing AKT phosphorylation against oxidative stress. These results strongly indicate that activation of cAMP/PKA pathway has an important role in astrocyte dysfunction, and suggest that modulating cAMP/PKA pathway has therapeutic potential for glaucomatous ONH degeneration
Interactive media server with media synchronized raid storage system
We propose an efficient placement algorithm and per-disk prefetching method to effectively support interactive operations in the media server. Our placement policy is incorporated with an encoder having a special bitcount control scheme that repeatedly tunes quantization parameters to adjust the bitcounts of video frames. This encoder can generate coded frames whose sizes are synchronized with the RAID stripe size, so that when various fast-forward levels are accessed we can reduce the seek and rotational latency and enhance the disk throughput of each disk in the RAID system. In the experimental results, the proposed placement policy and bitrate control scheme can significantly improve the average service time, which can enlarge the capacity of the interactive media server
On Monotonic Aggregation for Open-domain QA
Question answering (QA) is a critical task for speech-based retrieval from
knowledge sources, by sifting only the answers without requiring to read
supporting documents. Specifically, open-domain QA aims to answer user
questions on unrestricted knowledge sources. Ideally, adding a source should
not decrease the accuracy, but we find this property (denoted as
"monotonicity") does not hold for current state-of-the-art methods. We identify
the cause, and based on that we propose Judge-Specialist framework. Our
framework consists of (1) specialist retrievers/readers to cover individual
sources, and (2) judge, a dedicated language model to select the final answer.
Our experiments show that our framework not only ensures monotonicity, but also
outperforms state-of-the-art multi-source QA methods on Natural Questions.
Additionally, we show that our models robustly preserve the monotonicity
against noise from speech recognition. We publicly release our code and
setting.Comment: INTERSPEECH 2023 Camera Read
CSF Otorrhea Resulting from Osteoradionecrosis of the Temporal Bone in a Patient with Recurrent Meningioma
Osteoradionecrosis of the temporal bone is a very rare but potentially lethal complication of radiotherapy for head and neck or skull base tumors. Only two cases of osteoradionecrosis of the temporal bone complicating cerebrospinal fluid (CSF) otorrhea have been reported in the literature. This report describes a case of CSF otorrhea and osteoradionecrosis of the temporal bone in a patient with meningioma who was treated with tympanomastoid surgery and autologous fat obliteration in the mastoid
Integrative Literature Review on the Antecedents of Informal Learning in the Workplace: A Conceptual Framework for Future Research
Despite the explosion of interest in informal learning in the workplace, few attempts have been made to synthesize the current literature. This article provides an integrative and analytical review of prior empirical studies, particularly focusing on what factors have been identified as antecedents of informal learning in organizations and how informal learning has been conceptualized and measured. It then suggests future avenues for theory building, research, and practice. The authors propose a conceptual framework for understanding informal learning activities using three dimensions: learning competence, intentionality, and developmental relatedness. Implications for human resource development research and practice are also discussed
Regulatory gaps between LNG carriers and LNG fuelled ships
Given a number of marine vessels treating the liquefied natural gas either as cargo or fuel, this paper examined the regulatory gaps of two different international Codes – the InternationalCodeof the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk and the International Code of Safety for Ships Using Gases or Other Low-flashpoint Fuels – from the regulatory standpoint. Results of the gap analysis have identified and discussed the key areas encountered with regulatory discrepancies or ambiguities that might interrupt the proper design, construction and operation of LNG carrier and LNG fuelled ship. A systematic investigation and harmonisation process across the Codes was proposed to mitigate the potential issues that may arise from the discordant regulations. Also, the International Maritime Organization was suggested to take proactive action to improve such dissonances while a general insight into the importance of filling those gaps was provided for rule-makers and stakeholders
The Rhizome Mixture of Anemarrhena asphodeloides
We investigated the effect of DWac on the gut microbiota composition in mice with 2,3,6-trinitrobenzenesulfonic acid- (TNBS-) induced colitis. Treatment with DWac restored TNBS-disturbed gut microbiota composition and attenuated TNBS-induced colitis. Moreover, we examined the effect of DWac in mice with mesalazine-resistant colitis (MRC). Intrarectal injection of TNBS in MRC mice caused severe colitis, as well as colon shortening, edema, and increased myeloperoxidase activity. Treatment with mesalazine (30 mg/kg) did not attenuate TNBS-induced colitis in MRC mice, whereas treatment with DWac (30 mg/kg) significantly attenuated TNBS-induced colitis. Moreover, treatment with the mixture of mesalazine (15 mg/kg) and DWac (15 mg/kg) additively attenuated colitis in MRC mice. Treatment with DWac and its mixture with mesalazine inhibited TNBS-induced activation of NF-κB and expression of M1 macrophage markers but increased TNBS-suppressed expression of M2 macrophage markers. Furthermore, these inhibited TNBS-induced T-bet, RORγt, TNF-α, and IL-17 expression but increased TNBS-suppressed Foxp3 and IL-10 expression. However, Th2 cell differentiation and GATA3 and IL-5 expression were not affected. These findings suggest that DWac can ameliorate MRC by increasing the polarization of M2 macrophage and correcting the disturbance of gut microbiota and Th1/Th17/Treg, as well as additively attenuating MRC along with mesalazine
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