142 research outputs found
Design of a Low-Voltage Distribution Transformer Based on Inductive Filtering
Adopting the connection group structure of Dd0yn11, this paper designs a novel low-voltage (LV) distribution transformer (DT) based on inductive filtering (IF), and verifies the proposed transformer through a comprehensive innovation experiment. Firstly, the functional relationship between valve-side harmonic current and grid-side current was derived according to the winding model, and the filtering features were obtained to compute the impedance between the valve- and grid-side windings. Next, the design calculation was carried out by the engineering magnetic circuit (EMC) method. After that, a three-dimensional (3D) model was established for the proposed transformer on ANSYS Maxwell. The simulation results show that the proposed transformer meets the design requirements on the relevant parameters, and eliminates the harmonic pollution in the grid. Finally, the proposed transformer was proved correct and effective through experiments, and found to stimulate studentsꞌ interest in learning and innovation
AdaFuse: Adaptive Medical Image Fusion Based on Spatial-Frequential Cross Attention
Multi-modal medical image fusion is essential for the precise clinical
diagnosis and surgical navigation since it can merge the complementary
information in multi-modalities into a single image. The quality of the fused
image depends on the extracted single modality features as well as the fusion
rules for multi-modal information. Existing deep learning-based fusion methods
can fully exploit the semantic features of each modality, they cannot
distinguish the effective low and high frequency information of each modality
and fuse them adaptively. To address this issue, we propose AdaFuse, in which
multimodal image information is fused adaptively through frequency-guided
attention mechanism based on Fourier transform. Specifically, we propose the
cross-attention fusion (CAF) block, which adaptively fuses features of two
modalities in the spatial and frequency domains by exchanging key and query
values, and then calculates the cross-attention scores between the spatial and
frequency features to further guide the spatial-frequential information fusion.
The CAF block enhances the high-frequency features of the different modalities
so that the details in the fused images can be retained. Moreover, we design a
novel loss function composed of structure loss and content loss to preserve
both low and high frequency information. Extensive comparison experiments on
several datasets demonstrate that the proposed method outperforms
state-of-the-art methods in terms of both visual quality and quantitative
metrics. The ablation experiments also validate the effectiveness of the
proposed loss and fusion strategy
An experimental study on defrosting performance for an air source heat pump unit with a horizontally installed multi-circuit outdoor coil
When frost forms and accumulates over the outdoor coil’s surface in an air source heat
pump (ASHP) unit, system operating performance will be dramatically deteriorated.
Reverse cycle defrosting is the most widely used standard defrosting method. A previous
related study reported that downwards flowing of melted frost due to gravity over a
vertical multi-circuit outdoor coil would decrease the reverse cycle defrosting
performance. If the outdoor coil can be changed to horizontally installed, the flow path of
melted frost over coil surface can be shortened, and the flow directions of refrigerant and
melted frost changed from opposite to orthogonal. Consequently, a better defrosting
performance is expected. In this paper, therefore, an experimental study on defrosting
performance for an ASHP unit with a horizontally installed multi-circuit outdoor coil was
conducted. Experimental results show that, when a vertical outdoor coil was changed to
horizontally installed, the defrosting efficiency increased 9.8%, however, with the same
defrosting duration at 186 s. Furthermore, when the outdoor air fan was reversed to
blowing the melted frost during defrosting, the total mass of the retained water collected
decreased 222 g. However, the defrosting efficiency was not increased, but decreased 6.6%
because of the heat transfer enhanced between hot coil and cold ambient air.The Hong Kong Polytechnic University, and the Guangdong University of Technology.http://www.elsevier.com/locate/apenergy2017-03-31hb2016Electrical, Electronic and Computer Engineerin
Identification of compounds with anti-human cytomegalovirus activity that inhibit production of IE2 proteins
Using a high throughput screening methodology we surveyed a collection of largely uncharacterized validated or suspected kinase inhibitors for anti-human cytomegalovirus (HCMV) activity. From this screen we identified three structurally related 5-aminopyrazine compounds (XMD7-1, -2 and -27) that inhibited HCMV replication in virus yield reduction assays at low micromolar concentrations. Kinase selectivity assays indicated that each compound was a kinase inhibitor capable of inhibiting a range of cellular protein kinases. Western blotting and RNA sequencing demonstrated that treatment of infected cells with XMD7 compounds resulted in a defect in the production of the major HCMV transcriptional transactivator IE2 proteins (IE2-86, IE2-60 and IE2-40) and an overall reduction in transcription from the viral genome. However, production of certain viral proteins was not compromised by treatment with XMD7 compounds.
Thus, these novel anti-HCMV compounds likely inhibited transcription from the viral genome and suppressed production of a subset of viral proteins by inhibiting IE2 protein production
Brain penetrant LRRK2 inhibitor
This is the author accepted manuscript. The final version is available from ACS via the DOI in this record. Activating mutations in leucine-rich repeat kinase 2 (LRRK2) are present in a subset of Parkinson's disease (PD) patients and may represent an attractive therapeutic target. Here, we report that a 2-anilino-4-methylamino-5- chloropyrimidine, HG-10-102-01 (4), is a potent and selective inhibitor of wild-type LRRK2 and the G2019S mutant. Compound 4 substantially inhibits Ser910 and Ser935 phosphorylation of both wild-type LRRK2 and G2019S mutant at a concentration of 0.1-0.3 μM in cells and is the first compound reported to be capable of inhibiting Ser910 and Ser935 phosphorylation in mouse brain following intraperitoneal delivery of doses as low as 50 mg/kg. © 2012 American Chemical Society.NIHMedical Research CouncilMichael J Fox foundation for Parkinson’s disease researchPharmaceutical companies supporting the DSTT (AstraZeneca, Boehringer-Ingelheim, GlaxoSmithKline, Merck KgaA and Pfizer
PO-099 Targeting the mitogen activated protein kinase ERK5 in human melanoma
Introduction Melanoma is the most aggressive skin cancer with a poor prognosis in advanced stages. Available treatments for melanoma are unsatisfactory, because rapidly lead to an acquired resistance in the majority of cases. Therefore, there is urgent need to identify novel possible targets involved in melanoma growth. ERK5/BMK1 is a member of the Mitogen-Activated Protein Kinases (MAPK) family and regulates cell functions critical for tumour development. Indeed, several studies reported a direct involvement of ERK5 in several types of cancer including prostate and breast cancer and hepatocellular carcinoma. However, no data have been reported about a possible role of ERK5 in melanoma. Material and methods Cell lines and patient-derived primary melanoma cells (wild type B-RAF: SSM2c and M26c; BRAFV600E: A375, SK-Mel-5, SK-Mel-28, 501-Mel, expressing; NRASQ61R: SK-Mel-2; MeWo) have been used for in vitro and in vivo experiments. HEK293T cells were used for protein overexpression. ERK5 inhibition was achieved using ERK5 and MEK5 inhibitors or lentiviral vectors encoding shRNA specific for ERK5. BRAF inhibition was achieved using Vemurafenib, a BRAFV600E inhibitor. Results and discussions In silico data analysis indicated that components of the ERK5 pathway are upregulated in up to 47% melanoma patients. Accordingly, we found that ERK5 is consistently expressed and active in commercial and patients derived melanoma cell lines. On that basis, we investigated the role of ERK5 in melanoma cell growth. In vitro , pharmacological or genetic inhibition of ERK5 decreased the number of viable cells in several melanoma cell lines. Moreover, xenografts performed using LV-shERK5-transduced A375 or SSM2c cells showed a reduced tumour growth when compared to those transduced with control LV-shC. We also found that oncogenic BRAF positively regulates expression, phosphorylation and nuclear localization of exogenous and endogenous ERK5. Accordingly, combined pharmacological inhibition of BRAFV600E and MEK5 is required to decrease nuclear ERK5, that is critical for the regulation of cell proliferation. Furthermore, the combination of MEK5 or ERK5 inhibitors with vemurafenib is more effective than single treatments in reducing 2D colony formation and growth of BRAFV600E melanoma cells and xenografts. Conclusion Our results identify ERK5 as a critical regulator of melanoma growth in vitro and in vivo , and point toward the possibility of targeting ERK5, alone or in combination with BRAF-MEK1/2 inhibitors, for the treatment of melanoma
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Discovery of 3,5-Diamino-1,2,4-triazole Ureas as Potent Anaplastic Lymphoma Kinase Inhibitors
A series of novel 3,5-diamino-1,2,4-triazole benzyl ureas was identified as having potent anaplastic lymphoma kinase (ALK) inhibition exemplified by 15a, 20a, and 23a, which exhibited antiproliferative IC50 values of 70, 40, and 20 nM in Tel-ALK transformed Ba/F3 cells, respectively. Moreover, 15a and 23a potently inhibited the growth and survival of NPM-ALK positive anaplastic large cell lymphoma cell (SU-DHL-1) and neuroblastoma cell lines (KELLY, SH-SY5Y) containing the F1174L ALK mutation. These compounds provide novel leads for the development of small-molecule ALK inhibitors for cancer therapy
Clinical Study Age-Associated Reduction of Asymmetry in Human Central Auditory Function: A 1H-Magnetic Resonance Spectroscopy Study
The aim of this study was to investigate the effects of age on hemispheric asymmetry in the auditory cortex after pure tone stimulation. Ten young and 8 older healthy volunteers took part in this study. Two-dimensional multivoxel 1H-magnetic resonance spectroscopy scans were performed before and after stimulation. The ratios of N-acetylaspartate (NAA), glutamate/glutamine (Glx), and -amino butyric acid (GABA) to creatine (Cr) were determined and compared between the two groups. The distribution of metabolites between the left and right auditory cortex was also determined. Before stimulation, left and right side NAA/Cr and right side GABA/Cr were significantly lower, whereas right side Glx/Cr was significantly higher in the older group compared with the young group. After stimulation, left and right side NAA/Cr and GABA/Cr were significantly lower, whereas left side Glx/Cr was significantly higher in the older group compared with the young group. There was obvious asymmetry in right side Glx/Cr and left side GABA/Cr after stimulation in young group, but not in older group. In summary, there is marked hemispheric asymmetry in auditory cortical metabolites following pure tone stimulation in young, but not older adults. This reduced asymmetry in older adults may at least in part underlie the speech perception difficulties/presbycusis experienced by aging adults
Close-loop dynamic nanohybrids on collagen-ark with in situ gelling transformation capability for biomimetic stage-specific diabetic wound healing
Here, an oxidation/acid dual-responsive nanohybrids/ark system was produced. The microfluidics-produced nanohybrids endow the system with an orchestrated cascade from wound detection, reactive oxygen species scavenging, drug release to hydrogel formation. The drug release behavior imitates the dynamic wound healing process, thus rendering an enhanced bio-mimetic regeneration.Peer reviewe
Deep-ultraviolet photonics for the disinfection of SARS-CoV-2 and its variants (Delta and Omicron) in the cryogenic environment
Deep-ultraviolet (DUV) disinfection technology provides an expeditious and efficient way to suppress the transmission of coronavirus disease 2019 (COVID-19). However, the influences of viral variants (Delta and Omicron) and low temperatures on the DUV virucidal efficacy are still unknown. Here, we developed a reliable and uniform planar light source comprised of 275-nm light-emitting diodes (LEDs) to investigate the effects of these two unknown factors and delineated the principle behind different disinfection performances. We found the lethal effect of DUV at the same radiation dose was reduced by the cryogenic environment, and a negative-U large-relaxation model was used to explain the difference in view of the photoelectronic nature. The chances were higher in the cryogenic environment for the capture of excited electrons within active genetic molecules back to the initial photo-ionised positions. Additionally, the variant of Omicron required a significantly higher DUV dose to achieve the same virucidal efficacy, and this was thanks to the genetic and proteinic characteristics of the Omicron. The findings in this study are important for human society using DUV disinfection in cold conditions (e.g., the food cold chain logistics and the open air in winter), and the relevant DUV disinfection suggestion against COVID-19 is provided
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