7,138 research outputs found
Molecular Imaging in Tracking Tumor Stem-Like Cells
Cancer remains a major public health problem in many countries. It was found to contain a subset of cancer stem cells (CSCs) that are capable of proliferation and self-renewal, and differentiation into various types of cancer cells. CSCs often display characteristics of chemotherapy resistance and radiotherapy resistance. Numerous putative biomarkers of CSCs are currently identified including CD133, CD44, CD24, ALDH (aldehyde dehydrogenase), and ABCG2. Interestingly, no single marker is exclusively expressed by CSCs. Thus, the various combinations of different biomarkers will be possible to identify CSCs, and considerable work is being done to recognize new ones. In order to demonstrate the mechanisms of resistance and response to therapy and predict the outcome as well as prognosis, the ways to track and identify CSCs will be extremely important. The technologies of molecular imaging will reveal mechanisms of cancer progression and provide visual targets for novel therapeutics. Limited studies were investigated on the detection of various types of CSCs by molecular imaging. Although the tracking of circulating CSCs is still hampered by technological challenges, personalized diagnosis and therapies of cancers are expected to be established based on increased understanding of molecular imaging of cancer stem-like cells biomarkers
A Flexible Electronic Helical Guide Controller
AbstractIn this paper, an Electronic Helical Guide Controller (EHGC) is proposed, for helical gear shaping processes. In most traditional gear shaper machines, the cutter's reciprocating movement is driven by a crank-connecting rod mechanism. Therefore, this study adopts this kind of gear shaper as the machine platform to establish an accurate mathematical model. The control algorithm is embedded in the interpolation module of the CNC system using electronic gearbox techniques to realize special multi-axis linkage control requirements. The crankshaft's angular position is measured and the rotational speed is calculated in each control cycle. The actual position and velocity of the cutter along the Z-axis can be calculated using the geometric relations of the crank-connecting mechanism, and motion in the other axes can be controlled by the electronic gearbox. A special G code with parameters (G83) is also designed and the EHGC control through NC programming is realized in an improvised gear shaping CNC machine. The proposed EHGC is low cost and easy to implement in practice since it does not need a linear grating ruler and a probe on the Z-axis. Furthermore, EHGC allows the flexibility to change a part's helix angle to compensate for distortions caused by heat treatment. Simulations and experiments are performed to verify the effectiveness of the proposed EHGC
Vertex Sparsifiers for Hyperedge Connectivity
Recently, Chalermsook et al. [SODA'21(arXiv:2007.07862)] introduces a notion
of vertex sparsifiers for -edge connectivity, which has found applications
in parameterized algorithms for network design and also led to exciting dynamic
algorithms for -edge st-connectivity [Jin and Sun
FOCS'21(arXiv:2004.07650)]. We study a natural extension called vertex
sparsifiers for -hyperedge connectivity and construct a sparsifier whose
size matches the state-of-the-art for normal graphs. More specifically, we show
that, given a hypergraph with vertices and hyperedges with
terminal vertices and a parameter , there exists a hypergraph
containing only hyperedges that preserves all minimum cuts (up to
value ) between all subset of terminals. This matches the best bound of
edges for normal graphs by [Liu'20(arXiv:2011.15101)]. Moreover,
can be constructed in almost-linear time where is the rank of and
is the total size of , or in time if we slightly relax
the size to hyperedges.Comment: submitted to ESA 202
ResFormer: Scaling ViTs with Multi-Resolution Training
Vision Transformers (ViTs) have achieved overwhelming success, yet they
suffer from vulnerable resolution scalability, i.e., the performance drops
drastically when presented with input resolutions that are unseen during
training. We introduce, ResFormer, a framework that is built upon the seminal
idea of multi-resolution training for improved performance on a wide spectrum
of, mostly unseen, testing resolutions. In particular, ResFormer operates on
replicated images of different resolutions and enforces a scale consistency
loss to engage interactive information across different scales. More
importantly, to alternate among varying resolutions effectively, especially
novel ones in testing, we propose a global-local positional embedding strategy
that changes smoothly conditioned on input sizes. We conduct extensive
experiments for image classification on ImageNet. The results provide strong
quantitative evidence that ResFormer has promising scaling abilities towards a
wide range of resolutions. For instance, ResFormer-B-MR achieves a Top-1
accuracy of 75.86% and 81.72% when evaluated on relatively low and high
resolutions respectively (i.e., 96 and 640), which are 48% and 7.49% better
than DeiT-B. We also demonstrate, moreover, ResFormer is flexible and can be
easily extended to semantic segmentation, object detection and video action
recognition. Code is available at https://github.com/ruitian12/resformer.Comment: CVPR 202
Palatine tonsillar metastasis of lung adenocarcinoma: An unusual immunohistochemical phenotype and a potential diagnostic pitfall
Metastasis rarely occurs to the palatine tonsils. Herein, we present an exceedingly rare case of palatine tonsillar metastasis from poorly differentiated lung adenocarcinoma with anaplastic lymphoma kinase (ALK) mutation in a 51-year-old woman. The patient manifested clinically as pharyngalgia without obvious respiratory symptoms, with swelling tonsil histomorphologically resembling lymphoma and partially expressing the markers of epithelial and squamous cell carcinoma (CK5/6, P63, and P40). Due to the non-specific immunohistochemical expression, it is easily misdiagnosed as a primary poorly differentiated squamous cell carcinoma of the tonsil. This case highlights the importance of a comprehensive assessment of suspicious tonsillar lesions, that may be a sign of a primary malignancy elsewhere in the body
Real time detection and characterisation of bioaerosol emissions from wastewater treatment plants
Bioaerosol emissions from wastewater treatment plants may pose adverse health impact on workers and nearby communities. To detect and characterise bioaerosol emissions from wastewater treatment plant (WWTP), a novel real-time bioaerosol sensor, Spectral Intensity Bioaerosol Sensor (SIBS) was employed at a WWTP and a background site. The SIBS records a range of data (size, shape, and fluorescence emission across 16 wavelength bands from 298 to 735 nm for two excitation wavelengths (285 nm and 370 nm)) on single particles in real time. Additionally, excitation-emission matrix (EEM) of wastewater samples obtained by a spectrofluorometer was compared with SIBS spectra from WWTP. The results showed that the average number concentrations of total particles (NT) and fluorescence particles (NF) were both higher at the WWTP (NT = 2.01 cm−3, NF = 1.13 cm−3) than the background site (NT = 1.79 cm−3, NF = 1.01 cm−3). The temporal variation of NF and NT was highly variable at the WWTP and the concentration peaks were consistent with on-site activities. Moreover, the time-resolved number-size distribution of fluorescent particles revealed the predominance of fine scale particles (<1 μm) and the time-series channel by channel number concentrations demonstrated the temporal variability of dominant bio-fluorophores. Furthermore, the overall and size-segregated fluorescence spectra at two sites were multimodal. In particular, the fluorescence intensity increases with increasing particle size in WWTP spectra, which is not present in the background spectra. In addition, the highly resolved SIBS fluorescence spectra were broadly similar to EEM of wastewater. These findings confirmed that the spectrally resolved fluorescence detected by SIBS is capable of providing reliable bio-fluorophores information of bioaerosol emissions generated from wastewater, thus holding the potential for better characterisation of bioaerosols in real time
- …