266 research outputs found

    A novel method of restoration path optimization for the AC-DC bulk power grid after a major blackout

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    The restoration control of the modern alternating current-direct current (AC-DC) hybrid power grid after a major blackout is difficult and complex. Taking into account the interaction between the line-commutated converter high-voltage direct current (LCC-HVDC) and the AC power grid, this paper proposes a novel optimization method of restoration path to reconfigure the skeleton network for the blackout power grid. Based on the system strength, the supporting capability of the AC power grid for the LCC-HVDC is first analysed from the aspects of start-up and operation of LCC-HVDCs. Subsequently, the quantitative relationship between the restoration path and the restoration characteristic of LCC-HVDC is derived in detail based on the system strength indices of the short-circuit capacity and the frequency regulation capability. Then, an optimization model of restoration path considering non-tree paths is formulated and a feasible optimization algorithm is proposed to achieve the optimal path restoration scheme. A modified IEEE 39-bus system and a partial power grid of Southwest China are simulated to show that the proposed method is suitable for the restoration of AC-DC power grids and can improve restoration efficiency. This research can be an important guidance for operators to rapidly restore the AC-DC power grid.Comment: Accepted by IET Generation, Transmission & Distributio

    Advancing Medical Imaging with Language Models: A Journey from N-grams to ChatGPT

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    In this paper, we aimed to provide a review and tutorial for researchers in the field of medical imaging using language models to improve their tasks at hand. We began by providing an overview of the history and concepts of language models, with a special focus on large language models. We then reviewed the current literature on how language models are being used to improve medical imaging, emphasizing different applications such as image captioning, report generation, report classification, finding extraction, visual question answering, interpretable diagnosis, and more for various modalities and organs. The ChatGPT was specially highlighted for researchers to explore more potential applications. We covered the potential benefits of accurate and efficient language models for medical imaging analysis, including improving clinical workflow efficiency, reducing diagnostic errors, and assisting healthcare professionals in providing timely and accurate diagnoses. Overall, our goal was to bridge the gap between language models and medical imaging and inspire new ideas and innovations in this exciting area of research. We hope that this review paper will serve as a useful resource for researchers in this field and encourage further exploration of the possibilities of language models in medical imaging

    Methanol extract of Aruncus dioicus exerts antidiabetic effect via PCSK9/LDLR pathway

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    Purpose: To investigate the antidiabetic effect of methanol extract of Aruncus dioicus, and the underlying mechanism(s). Methods: Twenty-four adult female albino mice were randomly assigned to four groups of six mice each: normal control group, diabetic control group and two treatment groups. With the exception of normal control group, the diabetic control and treatment groups consisted of leptin receptor-deficient (db/db) type 2 diabetic mice. The diabetic control group was not treated, while the treatment groups received 200 or 400 mg/kg extract/day orally for 4 weeks. The effect of the extract on fasting blood glucose (FBG), proprotein convertase subtilisin/kexin type 9 (PCSK9), glycogen and lipid profiles were determined. The expressions of PCSK9, low-density lipoprotein receptor (LDL-R) and glucokinase (GCK) were determined in liver tissues using western blotting and real-time quantitative polymerase chain reaction (qRT-PCR). Results: Fasting blood glucose (FBG) was significantly and dose-dependently reduced in the treatment groups, relative to diabetic control group at different time-points (p < 0.05). Total cholesterol (TC), triacylglycerol (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were significantly higher in the diabetic control group than in normal control group (p < 0.05). However, treatment with methanol extract of A. dioicus significantly and dose-dependently reversed the changes in the levels of these parameters (p < 0.05). The expressions of LDLR and GCK were significantly down-regulated in diabetic control group, when compared with normal control group, but their expressions were significantly dose-dependently upregulated in the treatment groups (p < 0.05). Treatment with the extract significantly and dose-dependently down-regulated PCSK9 expression (p < 0.05). Liver injury characterized by large distended lipid droplets and fat accumulation was seen in diabetic mice, but treatment with methanol extract of A. dioicus significantly reversed the histopathological changes induced by DM. Conclusion: These results indicate that the antidiabetic effect of methanol extract of A. dioicus is exerted via a mechanism involving PCSK9/LDLR pathway

    Chemokine CXCL12 and its receptor CXCR4 expression are associated with perineural invasion of prostate cancer

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    <p>Abstract</p> <p>Objective</p> <p>To identify the roles of CXCL12 and CXCR4 and the associated mechanism involved in perineural invasion of prostate cancer.</p> <p>Methods</p> <p>The distribution and expression of CXCL12, CXCR4, MMP-2 and MMP-9 in human prostate cancer and in tumor cells invading nerve tissue were studied with immunohistochemical staining. The effects of exogenous CXCL12 and CXCR4 antagonist AMD3100 on PC3 prostate cancer cells invasiveness were assessed in vitro and in vivo.</p> <p>Results</p> <p>The expression of CXCL12, CXCR4, MMP-2, and MMP-9 in human prostate cancer were higher than those in hyperplastic prostate tissues (<it>P </it>< 0.05). In vitro CXCL12 could stimulate the PC3 cells invasiveness (<it>P </it>< 0.05) while AMD3100 could inhibit invasiveness. In vivo, the number of nerves around the tumor tissue in the group treated with CXCL12 was significantly higher than that found in the control group (<it>P </it>< 0.05). Both the control group and the CXCL12-treated group had more nerves number near the tumor tissue than it found in the AMD3100-treated group. The positive cell number of CXCL12, CXCR4, MMP-2, MMP-9, and NGF expression ranked from highest to lowest, were the CXCL12-treated, the control, and the AMD3100-treated group(<it>P </it>< 0.05).</p> <p>Conclusion</p> <p>CXCL12 and its receptor CXCR4 along with MMP-2 and MMP-9 are related with prostate cancer perineural invasion.</p

    Identifying the orbital angular momentum of light based on atomic ensembles

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    We propose a scheme to distinguish the orbital angular momentum state of the Laguerre-Gaussian (LG) beam based on the electromagnetically induced transparency modulated by a microwave field in atomic ensembles. We show that the transverse phase variation of a probe beam with the LG mode can be mapped into the spatial intensity distribution due to the change of atomic coherence caused by the microwave. The proposal may provide a useful tool for studying higher-dimensional quantum information based on atomic ensembles.Comment: 4 pages, 4 figure

    Development of CCUS Technology in the Context of Carbon Neutrality and Assessment of the Potential for Offshore Storage in Guangdong Province

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    [Introduction] Carbon capture, utilization and storage (CCUS) is one of the key technologies for achieving carbon neutrality. The coastal area of Guangdong Province is a potential area for offshore CO2 storage projects in China. Understanding the development status of CCUS technology in the context of carbon neutrality and analyzing the offshore CO2 storage potential in the coastal area of Guangdong Province are conducive to provide the basis for large-scale CCUS projects, especially the offshore storage projects in the future in China. [Method] The technical routes and development trends of all aspects of CCUS were summarized. The offshore geological storage potential of CO2 in the Pearl River Mouth Basin and the Beibu Gulf Basin off the coast of Guangdong Province was discussed. The problems of offshore CO2 storage in China were summarized, and relevant suggestions were put forward. [Result] In recent years, China has made significant progress in CCUS technology, but some key technologies in transportation and storage has been still at the R&D demonstration stage. The Pearl River Mouth Basin and the Beibu Gulf Basin have enormous geological storage potential of CO2 and an excellent matching relationship with large CO2 emission sources in the coastal area of Guangdong Province, making it an ideal locations for offshore CO2 storage projects. However, offshore CO2 storage still faces problems such as immature technology, high storage costs, uncertain environmental impacts, and inadequate policy and regulation frameworks in China. It is necessary to focus on technological development, promoting cluster projects, and improving policies and relevant regulations to advance the development of offshore CO2 storage. [Conclusion] In the future, China should strengthen research, development and promotion of CCUS, especially the offshore storage technology, to promote the progress of carbon neutrality

    In vivo total or partial hepatectomy followed by ex vivo liver resection and autotransplantation for malignant tumors: a single center experience

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    BackgroundEx vivo liver resection and autotransplantation (ELRAT) may provide an opportunity for R0 resection of conventionally unresectable hepatobiliary cancers and hepatic metastases. To date, few studies of the surgery for malignant tumors have been conducted and there are no known reports of in vivo partial hepatectomy followed by ELRAT (IPH-ELRAT) for malignant tumors.MethodsBetween December 2021 and November 2022, ten patients with malignant hepatobiliary primary cancers or hepatic metastases underwent ELRAT at our institution. We shared the surgical skills and postoperative prognoses of these patients were assessed.ResultsThe types of tumors were biliary tract cancer (BTC, n=8), hepatic metastasis of colonic carcinoma (n=1), and hepatic metastasis of small-bowel stromal tumor (n=1). Five patients underwent in vivo total hepatectomy followed by ex vivo liver resection and autotransplantation (ITH-ELRAT), The other five received in vivo partial hepatectomy followed by ex vivo liver resection and autotransplantation (IPH-ELRAT). Four patients underwent inferior vena cava replacement using artificial blood vessels. The survival rate of all ten patients one month after surgery was 100%. Nine patients (90%) are currently alive, with a median follow-up of 8.5 months (range 6–16.5 months). To date, seven of the nine surviving patients have had no cancer recurrence, including six with BTC.ConclusionsWe report the world first five cases that received IPH-ELRAT for malignancies. We also demonstrated relatively favorable outcomes in patients who underwent ELRAT. ELRAT may be a recommendable surgical option for selected patients with conventionally unresectable hepatobiliary malignant tumors
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