142 research outputs found

    Learning Deep Intensity Field for Extremely Sparse-View CBCT Reconstruction

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    Sparse-view cone-beam CT (CBCT) reconstruction is an important direction to reduce radiation dose and benefit clinical applications. Previous voxel-based generation methods represent the CT as discrete voxels, resulting in high memory requirements and limited spatial resolution due to the use of 3D decoders. In this paper, we formulate the CT volume as a continuous intensity field and develop a novel DIF-Net to perform high-quality CBCT reconstruction from extremely sparse (fewer than 10) projection views at an ultrafast speed. The intensity field of a CT can be regarded as a continuous function of 3D spatial points. Therefore, the reconstruction can be reformulated as regressing the intensity value of an arbitrary 3D point from given sparse projections. Specifically, for a point, DIF-Net extracts its view-specific features from different 2D projection views. These features are subsequently aggregated by a fusion module for intensity estimation. Notably, thousands of points can be processed in parallel to improve efficiency during training and testing. In practice, we collect a knee CBCT dataset to train and evaluate DIF-Net. Extensive experiments show that our approach can reconstruct CBCT with high image quality and high spatial resolution from extremely sparse views within 1.6 seconds, significantly outperforming state-of-the-art methods. Our code will be available at https://github.com/xmed-lab/DIF-Net.Comment: MICCAI'2

    Online Channels and Store Brands: Strategic Interactions

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    This study examines the strategic interactions between the online channel strategies of a national brand manufacturer and the store brand strategies of a retailer. We develop a game-theoretical model in which a manufacturer makes channel choices, a retailer selects product lines, and both need to take the other’s strategy into consideration. We compare the results with cases where no interactions are involved to explicate how the manufacturer’s online channel choice affects the retailer’s store brand strategy, and vice versa. The results suggest that the retailer executes a more defensive strategy if the threat of the online channel is severe but tends to be cooperative when the threat is less alarming. The manufacturer, however, would rather give up its efficient online channel to act cooperatively when the store brand is introduced. Our findings explain certain stylized facts regarding supply chain coordination

    Interactive bundle pricing strategy for online pharmacies

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    Online retail pharmacies usually price their products differently from traditional drugstores. Based on real-time consumer behaviors, this paper proposes a dynamic bundle pricing strategy to maximize the pharmacy's profit. Given free shipping thresholds and consumer budgets, we propose a mixed-integer nonlinear programming model and a heuristic to sequentially price customized bundles. We further conduct a numerical study using the data from a leading e-pharmacy in China. Our computational results indicate that the proposed model not only improves the e-pharmacy's profit by attracting more customers but noticeably contributes to consumer surplus. Through sensitivity analysis, our model is proved to be robust under various scenarios.</p

    Freight transportation planning in platform service supply chain considering carbon emissions

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    The online-to-offline (O2O) platform is becoming increasingly popular in today's market. This study investigates the decision-making problem of an O2O freight platform facing uncertain demand and carbon emission constraints to achieve sustainable development and establish an environment-friendly image. By receiving customer orders online and then delivering them offline, the platform chooses the optimal dispatching time and pricing level to maximize its profit under a limited carbon cap. We consider a stochastic model with two kinds of demand functions, i.e., additive and multiplicative cases, and solve the optimization problems. By adopting a data set from a leading O2O freight platform in China, we find that the proposed model can effectively increase the revenue of the platform by more than 20 % if the platform increases the price appropriately. The results further show that market parameters such as potential market size and price elasticity have a more significant influence on the price decision than logistics parameters such as the fixed shipping cost and holding cost per unit volume per unit time, while logistics parameters affect the dispatching time decision more significantly than market parameters. With respect to the profit, as the carbon cap increases, the profit of the platform first climbs up to a peak point and then decreases with the further increase of the cap due to rising inventory holding costs. Furthermore, the O2O platform can benefit from a large-scale market and thus might suffer a loss at its start-up stage. Our study contributes to the literature on the O2O platform and the freight transportation planning with the consideration of sustainable development

    Pathological complete response after neoadjuvant immunotherapy combined with chemotherapy in pediatric rectal carcinoma: A case report

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    BackgroundPediatric colorectal carcinoma (PCRC) is a rare non-embryonal tumor with an incidence of 0.1% to 1% of adults. Immune checkpoint inhibitors (ICIs) targeting programmed death-1 (PD-1) have shown significant efficacy in defective mismatch repair/Microsatellite instability-high (dMMR/MSI-H) metastatic CRC (mCRC). Although several studies have reported neoadjuvant immunotherapy (NIT) in MSI-H/dMMR non-mCRC patients, not all patients achieved pathological complete remission (pCR). There are differences between PCRC and adult colorectal carcinoma (CRC), and the role of NIT in PCRC remains to be further defined.Case presentationWe report the case of a 12-year-old child who was admitted to the hospital with abdominal pain and vomiting for more than 3 months. The child’s diagnosis was difficult and complex. He was initially diagnosed with intestinal obstruction, eventually diagnosed with a rare PCRC and identified as locally advanced colorectal cancer (LACRC) with genetic sequencing results showing MSI-H. After a thorough evaluation by clinicians, he received 4 cycles of Camrelizumab (anti-PD-1 antibody) + CapeOx (capecitabine and oxaliplatin) NIT combination chemotherapy. Repeat imaging and all tumor markers were unremarkable, and R0 resection was achieved. Postoperative pathology showed a tumor regression grade (TRG) of 0 grade determined as pCR. Postoperative review has not shown any recurrence or metastasis to date and the prognosis is good.ConclusionPCRC should improve the diagnostic efficiency to prevent misdiagnosis and miss the best time for treatment. NIT and or chemotherapy can be a reasonable and effective treatment option for dMMR/MSI-H locally advanced PCRC. Our report provides some support and evidence for neoadjuvant immunotherapy for locally advanced PCRC, while highlighting the importance of preoperative detection of microsatellite status for locally advanced PCRC

    Effect of Kang Fu Yan capsule on phenol mucilage-induced intrauterine adhesion injury in female rats

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    Purpose: To investigate the effect of Kang fu yan capsule (KFYC) on phenol mucilage-induced intrauterine adhesion (IUA) in a rat model, and the underlying mechanisms. Methods: An IUA model was established by injecting 0.06 mL of 25 % phenol mucilage into the uterus of female Sprague-Dawley rats. The IUA model rats (n=59) were randomly divided into 5 groups: IUA group, fuke qianjin tablet group (FKQJT, 0.22 mg/kg), and 3 KFYC groups given different doses of the drug i.e. 0.13, 0.39and 1.17 mg/kg. A group of 10 healthy female rats served as control. After 19 days treatment, blood samples were collected for determination of IL-2 and IL-10 by ELISA, while uterine tissues were subjected to histological examination using hematoxylin and eosin staining (H&amp;E) and Masson staining. Expressions of Notch1, recombination signal binding protein-JK (RBP-JK), a disintegrin and metalloprotease (ADAM)-12, ADAM-15, matrix metalloprotein-9 (MMP-9), and inhibitor of NF-κB (IĸB) in uterine tissues were determined using RT-qPCR and western blot analysis. Results: Compared to IUA group, histological results showed reduced inflammatory cell infiltration in rat uterine tissue of KFYC group. Moreover, KFYC significantly reversed uterine fibrosis (p &lt; 0.05). Serum concentrations of IL-2 significantly decreased in KFYC groups (p &lt; 0.05 or p &lt; 0.01), and there was significant increases the serum concentrations of IL-10 in KFYC groups (p &lt; 0.05 or &lt; 0.01), when compared to IUA group. The mRNA and protein expressions of Notch1, RBP-JK, ADAM-12, ADAM-15, MMP-9 were also significantly down-regulated (p &lt; 0.05), while protein expression of IĸB was upregulated in KFYC group, when compared to IUA group. Conclusion: KFYC exerts an anti-IUA effect via amelioration of uterine inflammation and fibrosis, probably via a mechanism involving regulation of Notch1/ADAM pathway

    Antiaging effects of dietary supplements and natural products

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    Aging is an inevitable process influenced by genetics, lifestyles, and environments. With the rapid social and economic development in recent decades, the proportion of the elderly has increased rapidly worldwide, and many aging-related diseases have shown an upward trend, including nervous system diseases, cardiovascular diseases, metabolic diseases, and cancer. The rising burden of aging-related diseases has become an urgent global health challenge and requires immediate attention and solutions. Natural products have been used for a long time to treat various human diseases. The primary cellular pathways that mediate the longevity-extending effects of natural products involve nutrient-sensing pathways. Among them, the sirtuin, AMP-activated protein kinase, mammalian target of rapamycin, p53, and insulin/insulin-like growth factor-1 signaling pathways are most widely studied. Several studies have reviewed the effects of individual natural compounds on aging and aging-related diseases along with the underlying mechanisms. Natural products from food sources, such as polyphenols, saponins, alkaloids, and polysaccharides, are classified as antiaging compounds that promote health and prolong life via various mechanisms. In this article, we have reviewed several recently identified natural products with potential antiaging properties and have highlighted their cellular and molecular mechanisms. The discovery and use of dietary supplements and natural products that can prevent and treat multiple aging-related diseases in humans will be beneficial. Thus, this review provides theoretical background for existing dietary supplements and natural products as potential antiaging agents

    Disentangling land model uncertainty via Matrix-based Ensemble Model Inter-comparison Platform (MEMIP)

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    Background Large uncertainty in modeling land carbon (C) uptake heavily impedes the accurate prediction of the global C budget. Identifying the uncertainty sources among models is crucial for model improvement yet has been difficult due to multiple feedbacks within Earth System Models (ESMs). Here we present a Matrix-based Ensemble Model Inter-comparison Platform (MEMIP) under a unified model traceability framework to evaluate multiple soil organic carbon (SOC) models. Using the MEMIP, we analyzed how the vertically resolved soil biogeochemistry structure influences SOC prediction in two soil organic matter (SOM) models. By comparing the model outputs from the C-only and CN modes, the SOC differences contributed by individual processes and N feedback between vegetation and soil were explicitly disentangled. Results Results showed that the multi-layer models with a vertically resolved structure predicted significantly higher SOC than the single layer models over the historical simulation (1900–2000). The SOC difference between the multi-layer models was remarkably higher than between the single-layer models. Traceability analysis indicated that over 80% of the SOC increase in the multi-layer models was contributed by the incorporation of depth-related processes, while SOC differences were similarly contributed by the processes and N feedback between models with the same soil depth representation. Conclusions The output suggested that feedback is a non-negligible contributor to the inter-model difference of SOC prediction, especially between models with similar process representation. Further analysis with TRENDY v7 and more extensive MEMIP outputs illustrated the potential important role of multi-layer structure to enlarge the current ensemble spread and the necessity of more detail model decomposition to fully disentangle inter-model differences. We stressed the importance of analyzing ensemble outputs from the fundamental model structures, and holding a holistic view in understanding the ensemble uncertainty

    Application of carbon nanoparticles combined with refined extracapsular anatomy in endoscopic thyroidectomy

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    ObjectiveTo evaluate the value of refined extracapsular anatomy combined with carbon nanoparticle suspension tracing technology for protecting parathyroid function and the thoroughness of lymph node dissection in the central region during endoscopic thyroid cancer surgery.Patients and methodsRetrospective clinical data analysis was performed on 108 patients who underwent endoscopic thyroid cancer surgery at the First Affiliated Hospital of Wannan Medical College (Yijishan Hospital) from November 2019 to November 2022. Before surgery, thyroid function tests, color Doppler ultrasounds and neck-enhanced CT scans were performed on all patients. Cytopathological diagnosis obtained via ultrasound-guided fine-needle aspiration served as confirmation for the primary diagnosis. It was determined whether to perform a total thyroidectomy or a hemithyroidectomy (HT) together with preventive unilateral (ipsilateral) central neck dissection. Follow-up times were 1 to 34 months.ResultsTransient neuromuscular symptoms were present in 3.70% (4/108) cases, with no permanent neuromuscular symptoms or permanent hypoparathyroidism. Regarding transient hypoparathyroidism, the patients recovered after three months and did not need long-term calcium supplementation. The number of harvested LNs (mean± SD) was 5.54 ± 3.84, with ≤5 in 57.41% (62/108) and &gt;5 in 42.59% (46/108) cases. The number of patients with metastatic LNs was 37.96% (41/108), with ≤2 in 65.85% (27/41) and &gt;2 in 34.15% (14/41) cases.ConclusionsFine extracapsular anatomy combined with carbon nanoparticle suspension tracing is effective in endoscopic thyroid cancer surgery. It can improve the thoroughness of prophylactic central neck dissection and recognition of the parathyroid gland and avoid parathyroid injury and other complications to effectively protect parathyroid function
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