56 research outputs found
Seeing What You Miss: Vision-Language Pre-training with Semantic Completion Learning
Cross-modal alignment is essential for vision-language pre-training (VLP)
models to learn the correct corresponding information across different
modalities. For this purpose, inspired by the success of masked language
modeling (MLM) tasks in the NLP pre-training area, numerous masked modeling
tasks have been proposed for VLP to further promote cross-modal interactions.
The core idea of previous masked modeling tasks is to focus on reconstructing
the masked tokens based on visible context for learning local-to-local
alignment. However, most of them pay little attention to the global semantic
features generated for the masked data, resulting in the limited cross-modal
alignment ability of global representations. Therefore, in this paper, we
propose a novel Semantic Completion Learning (SCL) task, complementary to
existing masked modeling tasks, to facilitate global-to-local alignment.
Specifically, the SCL task complements the missing semantics of masked data by
capturing the corresponding information from the other modality, promoting
learning more representative global features which have a great impact on the
performance of downstream tasks. Moreover, we present a flexible vision
encoder, which enables our model to perform image-text and video-text
multimodal tasks simultaneously. Experimental results show that our proposed
method obtains state-of-the-art performance on various vision-language
benchmarks, such as visual question answering, image-text retrieval, and
video-text retrieval
Blood-coated sensor for high-throughput ptychographic cytometry on a Blu-ray disc
Blu-ray drive is an engineering masterpiece that integrates disc rotation,
pickup head translation, and three lasers in a compact and portable format.
Here we integrate a blood-coated image sensor with a modified Blu-ray drive for
high-throughput cytometric analysis of various bio-specimens. In this device,
samples are mounted on the rotating Blu-ray disc and illuminated by the
built-in lasers from the pickup head. The resulting coherent diffraction
patterns are then recorded by the blood-coated image sensor. The rich spatial
features of the blood-cell monolayer help down-modulate the object information
for sensor detection, thus forming a high-resolution computational bio-lens
with a theoretically unlimited field of view. With the acquired data, we
develop a lensless coherent diffraction imaging modality termed rotational
ptychography for image reconstruction. We show that our device can resolve the
435 nm linewidth on the resolution target and has a field of view only limited
by the size of the Blu-ray disc. To demonstrate its applications, we perform
high-throughput urinalysis by locating disease-related calcium oxalate crystals
over the entire microscope slide. We also quantify different types of cells on
a blood smear with an acquisition speed of ~10,000 cells per second. For in
vitro experiment, we monitor live bacterial cultures over the entire Petri dish
with single-cell resolution. Using biological cells as a computational lens
could enable new intriguing imaging devices for point-of-care diagnostics.
Modifying a Blu-ray drive with the blood-coated sensor further allows the
spread of high-throughput optical microscopy from well-equipped laboratories to
citizen scientists worldwide
GSK-3β regulates tumor growth and angiogenesis in human glioma cells.
BACKGROUND: Glioma accounts for the majority of primary malignant brain tumors in adults.
METHODS: Glioma specimens and normal brain tissues were analyzed for the expression levels of GSK-3β and p-GSK-3β (Ser9) by tissue microarray analysis (TMA) and Western blotting. Glioma cells over-expressing GSK-3β were used to analyze biological functions both in vitro and in vivo.
RESULTS: The levels of p-GSK-3β (Ser9), but not total GSK-3β, are significantly up-regulated in glioma tissues compared to normal tissues, and are significantly correlated with the glioma grades. Ectopic expression of GSK-3β decreased the phosphorylation levels of mTOR and p70S6K1; and inhibited β-catenin, HIF-1α and VEGF expression. Forced expression of GSK-3β in glioma cells significantly inhibited both tumor growth and angiogenesis in vivo.
CONCLUSIONS: These results reveal that GSK-3β regulates mTOR/p70S6K1 signaling pathway and inhibits glioma progression in vivo; its inactivation via p-GSK-3β (Ser9) is associated with glioma development, which is new mechanism that may be helpful in developing GSK-3β-based treatment of glioma in the future
Lensless polarimetric coded ptychography (pol-CP) for high-resolution, high-throughput birefringence imaging on a chip
Polarimetric imaging provides valuable insights into the polarization state
of light interacting with a sample. It can infer crucial birefringence
properties of bio-specimens without using any labels, thereby facilitating the
diagnosis of diseases such as cancer and osteoarthritis. In this study, we
introduce a novel polarimetric coded ptychography (pol-CP) approach that
enables high-resolution, high-throughput birefringence imaging on a chip. Our
platform deviates from traditional lens-based polarization systems by employing
an integrated polarimetric coded sensor for lensless diffraction data
acquisition. Utilizing Jones calculus, we quantitatively determine the
birefringence retardance and orientation information of bio-specimens from four
recovered intensity images. Our portable pol-CP prototype can resolve the
435-nm linewidth on the resolution target and the imaging field of view for a
single acquisition is limited only by the detector size of 41 mm^2. The
prototype allows for the acquisition of gigapixel birefringence images with a
180-mm^2 field of view in ~3.5 minutes, achieving an imaging throughput
comparable to that of a conventional whole slide scanner. To demonstrate its
biomedical applications, we perform high-throughput imaging of malaria-infected
blood smears, locating parasites using birefringence contrast. We also generate
birefringence maps of label-free thyroid smears to identify thyroid follicles.
Notably, the recovered birefringence maps emphasize the same regions as
autofluorescence images, indicating the potential for rapid on-site evaluation
of label-free biopsies. The reported approach offers a portable, turnkey
solution for high-resolution, high-throughput polarimetric analysis without
using lenses, with potential applications in disease diagnosis, sample
screening, and label-free chemical imaging
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