273 research outputs found

    Estimation of Viscoelastic Properties of Cells Using Acoustic Tweezing Cytometry

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135346/1/jum201635122537.pd

    5,8-Dibromo-14,17-difluoro-2,11-dithia­[3.3]paracyclo­phane

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    The title compound, C16H12Br2F2S2 [systematic name: 12,15-dibromo-52,55-difluoro-2,7-dithia-1,5(1,4)-dibenzenaocta­phane], has two approximately parallel benzene rings with a dihedral angle of 1.53 (15)° between them and with a centroid–centroid distance of 3.3066 (18) Å. In the crystal structure, mol­ecules are stacked along the a axis through an inter­molecular π–π inter­action with a centroid–centroid distance of 3.7803 (18) Å. Mol­ecules are also connected by a C—H⋯S inter­action, forming a chain along the b axis

    Spatio-temporal stratified associations between urban human activities and crime patterns: a case study in San Francisco around the COVID-19 stay-at-home mandate

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    Crime changes have been reported as a result of human routine activity shifting due to containment policies, such as stay-at-home (SAH) mandates during the COVID-19 pandemic. However, the way in which the manifestation of crime in both space and time is affected by dynamic human activities has not been explored in depth in empirical studies. Here, we aim to quantitatively measure the spatio-temporal stratified associations between crime patterns and human activities in the context of an unstable period of the ever-changing socio-demographic backcloth. We propose an analytical framework to detect the stratified associations between dynamic human activities and crimes in urban areas. In a case study of San Francisco, United States, we first identify human activity zones (HAZs) based on the similarity of daily footfall signatures on census block groups (CBGs). Then, we examine the spatial associations between crime spatial distributions at the CBG-level and the HAZs using spatial stratified heterogeneity statistical measurements. Thirdly, we use different temporal observation scales around the effective date of the SAH mandate during the COVID-19 pandemic to investigate the dynamic nature of the associations. The results reveal that the spatial patterns of most crime types are statistically significantly associated with that of human activities zones. Property crime exhibits a higher stratified association than violent crime across all temporal scales. Further, the strongest association is obtained with the eight-week time span centred around the SAH order. These findings not only enhance our understanding of the relationships between urban crime and human activities, but also offer insights into that tailored crime intervention strategies need to consider human activity variables

    Ponder: Point Cloud Pre-training via Neural Rendering

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    We propose a novel approach to self-supervised learning of point cloud representations by differentiable neural rendering. Motivated by the fact that informative point cloud features should be able to encode rich geometry and appearance cues and render realistic images, we train a point-cloud encoder within a devised point-based neural renderer by comparing the rendered images with real images on massive RGB-D data. The learned point-cloud encoder can be easily integrated into various downstream tasks, including not only high-level tasks like 3D detection and segmentation, but low-level tasks like 3D reconstruction and image synthesis. Extensive experiments on various tasks demonstrate the superiority of our approach compared to existing pre-training methods.Comment: Project page: https://dihuang.me/ponder

    Sub-cycle Oscillations in Virtual States Brought to Light

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    Understanding and controlling the dynamic evolution of electrons in matter is among the most fundamental goals of attosecond science. While the most exotic behaviors can be found in complex systems, fast electron dynamics can be studied at the fundamental level in atomic systems, using moderately intense (less than or similar to 10(13) W/cm(2)) lasers to control the electronic structure in proof-of-principle experiments. Here, we probe the transient changes in the absorption of an isolated attosecond extreme ultraviolet (XUV) pulse by helium atoms in the presence of a delayed, few-cycle near infrared (NIR) laser pulse, which uncovers absorption structures corresponding to laser-induced virtual intermediate states in the two-color two-photon (XUV+NIR) and three-photon (XUV+NIR+NIR) absorption process. These previously unobserved absorption structures are modulated on half-cycle (similar to 1.3 fs) and quarter-cycle (similar to 0.6 fs) timescales, resulting from quantum optical interference in the laser-driven atom

    Targeting RNA N6-methyladenosine modification—— a novel therapeutic target for HER2- positive gastric cancer

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    Gastric cancer is one of the most common cancers and is considered the 5th most frequent occurring cancer worldwide. It has gained great attention from the clinicians and researchers because of high mortality rate. It is generally treated with chemotherapy, radiotherapy, and surgery. Recently, additional treatment options including immunotherapy and targeted therapy and immunotherapy have been developed. However, poor prognosis, limited survival rate of patients, and drug resistance to treatment remain critical problems. To improve treatment options or to overcome the bottleneck of treatment, identification of diagnostic and prognostic markers, determining the most effective therapeutic options, and uncovering the molecular regulations associated with treatment strategies are required. In this regard n6-methyladenosine (m6A) regulation is considered important. This reversible modification plays a crucial role in progression, development and treatment of HER2-positive gastric cancer. Here, we discuss the role of m6A modification in HER2-positive gastric cancer progression through collecting related studies at present. We further discuss the association of m6A modification with therapeutic efficacy in HER2-positive gastric cancer and list some examples. We conclude that modification of m6A can be a new strategy for improving the prognosis and survival rate of HER2-positive gastric cancer patients
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