148 research outputs found
Near-ultraviolet photon-counting dual-comb spectroscopy
Ultraviolet spectroscopy provides unique insights into the structure of
matter with applications ranging from fundamental tests to photochemistry in
the earth's atmosphere and astronomical observations from space telescopes. At
longer wavelengths, dual-comb spectroscopy with two interfering laser frequency
combs has evolved into a powerful technique that can offer simultaneously a
broad spectral range and very high resolution. Here we demonstrate a
photon-counting approach that can extend the unique advantages of this method
into ultraviolet regions where nonlinear frequency-conversion tends to be very
inefficient. Our spectrometer, based on two frequency combs of slightly
different repetition frequencies, provides broad span, high resolution,
frequency calibration within the accuracy of an atomic clock, and overall
consistency of the spectra. We demonstrate a signal-to-noise ratio at the
quantum limit and optimal use of the measurement time, provided by the
multiplex recording of all spectral data on a single photo-counter. Our initial
experiments are performed in the near-ultraviolet and in the visible spectral
ranges with alkali-atom vapor, with a power per comb line as low as a
femtowatt. This crucial step towards precision broadband spectroscopy at short
wavelengths clears the path to extreme-ultraviolet dual-comb spectroscopy and,
more generally, generates a new realm of applications for diagnostics at photon
level, as encountered e.g., when driving single atoms or molecules
Causal-DFQ: Causality Guided Data-free Network Quantization
Model quantization, which aims to compress deep neural networks and
accelerate inference speed, has greatly facilitated the development of
cumbersome models on mobile and edge devices. There is a common assumption in
quantization methods from prior works that training data is available. In
practice, however, this assumption cannot always be fulfilled due to reasons of
privacy and security, rendering these methods inapplicable in real-life
situations. Thus, data-free network quantization has recently received
significant attention in neural network compression. Causal reasoning provides
an intuitive way to model causal relationships to eliminate data-driven
correlations, making causality an essential component of analyzing data-free
problems. However, causal formulations of data-free quantization are inadequate
in the literature. To bridge this gap, we construct a causal graph to model the
data generation and discrepancy reduction between the pre-trained and quantized
models. Inspired by the causal understanding, we propose the Causality-guided
Data-free Network Quantization method, Causal-DFQ, to eliminate the reliance on
data via approaching an equilibrium of causality-driven intervened
distributions. Specifically, we design a content-style-decoupled generator,
synthesizing images conditioned on the relevant and irrelevant factors; then we
propose a discrepancy reduction loss to align the intervened distributions of
the pre-trained and quantized models. It is worth noting that our work is the
first attempt towards introducing causality to data-free quantization problem.
Extensive experiments demonstrate the efficacy of Causal-DFQ. The code is
available at https://github.com/42Shawn/Causal-DFQ.Comment: Accepted to ICCV202
Advances in Single Nucleotide Polymorphisms of Vitamin D Metabolic Pathway Genes and Respiratory Diseases
Vitamin D is a fat-soluble vitamin. It is an essential vitamin for human body. It has a classical effect on regulating calcium and phosphorus metabolism. Participate in cellular and humoral immune processes by regulating the growth, differentiation and metabolism of immune cells. A large number of studies in recent years have shown that vitamin D deficiency increases the incidence of respiratory diseases. Respiratory diseases mainly include bronchial asthma, chronic obstructive pulmonary disease, tuberculosis, acute upper respiratory tract infection and pneumonia. Vitamin D metabolic pathway genes play a very important regulatory role in the transformation of vitamin D into active vitamin D, including CYP2R1,,CYP27B1, CYP24A1, VDBP, VDR five genes. Genetic polymorphism of genes is the molecular basis of individual differences and disease development. Therefore, this paper summarizes the research on single nucleotide polymorphism of vitamin D metabolic pathway gene and respiratory diseases. In order to provide a new idea for future treatment
Comparison of 18F-FDG and 68Ga-FAPI PET/CT in the diagnosis of lung metastasis in different malignant tumors
Background and purpose: 18F-flurodeoxyglucose (18F-FDG) positron emission tomography and computed tomography (PET/CT) is a common method for the diagnosis of malignant tumors with distant metastases. However the detection of lung metastases, especially small lesions, is still unsatisfactory. 68Ga-labeled fibroblast activation protein inhibitors (68Ga-FAPI) have been used to target fibroblast activating proteins and visualize tumor stroma. The diagnostic value of 68Ga-FAPI PET/CT is higher than that of 18F-FDG in the primary sites and metastases of most cancers, but no comparative study has been seen in lung metastases of malignant tumors. Therefore, this study aimed to investigate the diagnostic value of 18F-FDG and 68Ga-FAPI PET/CT in different malignant lung metastases. Methods: The clinical, pathological and imaging data of 20 patients with lung metastasis who underwent 18F-FDG and 68Ga-FAPI PET/CT examination within one week in Fudan University Shanghai Cancer Center from May 2020 to March 2022 were retrospectively analyzed. Among them, 11 cases were epithelial malignant tumors (carcinoma), and 9 cases were mesophyll malignant tumors (sarcoma). The semi-quantitative metabolic parameters including maximum standard uptake value (SUVmax) and target-to-background ratio (TBR) of 68Ga-FAPI and 18F-FDG were compared by paired t test. The linear correlation between SUVmax and TBR and the short diameter of lung metastasis were analyzed. Results: A total of 81 lung metastases (51 carcinomas and 30 sarcomas) were detected in 20 patients, 72 positive lesions were detected by 18F-FDG and 70 positive lesions by 68Ga-FAPI. Compared with 68Ga-FAPI, 18F-FDG uptake was higher in lung metastases, especially those of carcinoma (P<0.001). The results of linear correlation analysis showed that the semi-quantitative metabolic parameters of the two imaging probes were positively correlated with the short diameter of lung metastases (P<0.001). Conclusion: 68Ga-FAPI has no obvious advantage in the detection of lung metastases from malignant tumors. Especially in the diagnosis of lung metastases from epithelial tissues, the uptake of 18F-FDG tends to be higher
Cytotoxicity Study of Cyclopentapeptide Analogues of Marine Natural Product Galaxamide towards Human Breast Cancer Cells
Herein, we report the cytotoxicity of cyclopentapeptide analogues of marine natural product galaxamide towards breast carcinoma cells and the underlying mechanisms. We examined the effect of the novel galaxamide analogues on cancer cell proliferation by MTT assay and also further examined the most active compound for morphological changes using Hoechst33342 staining technique, induction of apoptosis, cell cycle phases, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) generation using flow cytometry in human breast cancer MCF-7 cells in vitro. Galaxamide and its analogues effectively induced toxicity in human hepatocellular carcinoma HepG2, human breast carcinoma MCF-7, human epitheloid cervix carcinoma HeLa, and human breast carcinoma MB-MDA-231 cell lines. Amongst them, compound 3 exhibited excellent toxicity towards MCF-7 cells. This galaxamide analogue significantly induced apoptosis in a dose-dependent manner in MCF-7 cells involves cell cycle arrest in the G1 phase, a reduction of MMP, and a marked increase in generation of ROS. Particularly, compound 3 of galaxamide analogues might be a potential candidate for the treatment of breast cancer
Cholinergic signal activated renin angiotensin system associated with cardiovascular changes in the ovine fetus
Aim: Cholinergic regulation is important in the control of cardiovascular and endocrine responses. The mechanisms behind cardiovascular responses induced by cholinergic activation are explored by studying hormonal systems, including renin-angiotensin and vasopressin (VP). Results: In chronically prepared fetal sheep, intravenous infusion of the cholinergic agonist carbachol increased fetal systolic, diastolic, and mean arterial pressure accompanied with bradycardia at near-term. Although intravenous administration of carbachol had no effect on plasma VP concentrations, this agonist increased angiotensin I and angiotensin II levels in fetal plasma. Fetal blood values, including sodium, osmolality, nitric oxide, hemoglobin, and hematocrit were unchanged by intravenous carbachol. Conclusion: Cholinergic activation by carbachol controls fetal blood pressure and heart rate in utero. An over-activated fetal renin-angiotensin-system (RAS) is associated with changes in vascular pressure following intravenous administration of carbachol, indicating that the cholinergic stimulation-mediated hormonal mechanism in the fetus might play a critical role in the regulation of cardiovascular homeostasis.Peer Reviewe
The global landscape and research trend of lymphangiogenesis in breast cancer: a bibliometric analysis and visualization
BackgroundBreast cancer persists as a major public health issue on a global scale. Lymphangiogenesis is an indispensable element in the promotion of breast cancer metastasis. Inhibiting the metastasis of breast cancer can be accomplished through targeting lymphangiogenesis. The purpose of this study was to examine research trends, major topics, and development directions of lymphangiogenesis in breast cancer through a bibliometric analysis, which may serve as a reference for future research and clinical practice.MethodsEnglish publications with article type article or review about lymphangiogenesis in breast cancer from inception to September 30, 2023, retrieved from the Web of Science Core Collection Database (WOSCC), and VOSviewer, CiteSpace, and Microsoft Excel were applied for bibliometric study.ResultsIn this paper, a total of 369 articles and reviews were included. The 369 papers were written by 2120 authors from 553 organizations across 42 countries, published in 199 journals, and cited 12458 references from 1801 journals up to September 30, 2023. Moreover, the annual publications had a rising trajectory between 2004 to 2014 but declined from 2015. The US was the leading nation in publications and citations. Meanwhile, academics Mousumi Majumder and Peeyush Lala had the highest cumulative number of publications. Based on the number of publications/citations, Cancer Research was the most influential journal. The most cited paper was “Lymphangiogenesis: Molecular Mechanisms and Future Promise” by Tuomas Tammela, published in the Journal of Cell. Additionally, keywords frequency analysis demonstrated that “lymphangiogenesis,” “breast cancer,” “VEGF-C,” “angiogenesis,” and “metastasis” were the most frequent keywords, and the newly emergent topics could be represented by “tumor microenvironment,” “metastasis,” “stem-cell,” “triple-negative breast cancer,” and “blood vessels.”ConclusionsCurrently, there is a strong research basis for lymphangiogenesis in breast cancer. The core research team was primarily situated in the US. Investigating the mechanism of lymphangiogenesis in breast cancer will always remain a highly discussed topic. In particular, it was essential to emphasize the relationship between lymphangiogenesis and tumor microenvironment, stem cells, triple-negative breast cancer, and metastasis, which could be the frontiers
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