162 research outputs found

    Head and Neck Tumor Segmentation from [18F]F-FDG PET/CT Images Based on 3D Diffusion Model

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    Head and neck (H&N) cancers are among the most prevalent types of cancer worldwide, and [18F]F-FDG PET/CT is widely used for H&N cancer management. Recently, the diffusion model has demonstrated remarkable performance in various image-generation tasks. In this work, we proposed a 3D diffusion model to accurately perform H&N tumor segmentation from 3D PET and CT volumes. The 3D diffusion model was developed considering the 3D nature of PET and CT images acquired. During the reverse process, the model utilized a 3D UNet structure and took the concatenation of PET, CT, and Gaussian noise volumes as the network input to generate the tumor mask. Experiments based on the HECKTOR challenge dataset were conducted to evaluate the effectiveness of the proposed diffusion model. Several state-of-the-art techniques based on U-Net and Transformer structures were adopted as the reference methods. Benefits of employing both PET and CT as the network input as well as further extending the diffusion model from 2D to 3D were investigated based on various quantitative metrics and the uncertainty maps generated. Results showed that the proposed 3D diffusion model could generate more accurate segmentation results compared with other methods. Compared to the diffusion model in 2D format, the proposed 3D model yielded superior results. Our experiments also highlighted the advantage of utilizing dual-modality PET and CT data over only single-modality data for H&N tumor segmentation.Comment: 28 pages, 5 figure

    Target-oriented Domain Adaptation for Infrared Image Super-Resolution

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    Recent efforts have explored leveraging visible light images to enrich texture details in infrared (IR) super-resolution. However, this direct adaptation approach often becomes a double-edged sword, as it improves texture at the cost of introducing noise and blurring artifacts. To address these challenges, we propose the Target-oriented Domain Adaptation SRGAN (DASRGAN), an innovative framework specifically engineered for robust IR super-resolution model adaptation. DASRGAN operates on the synergy of two key components: 1) Texture-Oriented Adaptation (TOA) to refine texture details meticulously, and 2) Noise-Oriented Adaptation (NOA), dedicated to minimizing noise transfer. Specifically, TOA uniquely integrates a specialized discriminator, incorporating a prior extraction branch, and employs a Sobel-guided adversarial loss to align texture distributions effectively. Concurrently, NOA utilizes a noise adversarial loss to distinctly separate the generative and Gaussian noise pattern distributions during adversarial training. Our extensive experiments confirm DASRGAN's superiority. Comparative analyses against leading methods across multiple benchmarks and upsampling factors reveal that DASRGAN sets new state-of-the-art performance standards. Code are available at \url{https://github.com/yongsongH/DASRGAN}.Comment: 11 pages, 9 figure

    Two-stream convolutional neural network for non-destructive subsurface defect detection via similarity comparison of lock-in thermography signals

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    Active infrared thermography is a safe, fast, and low-cost solution for subsurface defects inspection, providing quality control in many industrial production tasks. In this paper, we explore deep learning-based approaches to analyze lock-in thermography image sequences for non-destructive testing and evaluation (NDT&amp;E) of subsurface defects. Different from most existing Convolutional Neural Network (CNN) models that directly classify individual regions/pixels as defective and non-defective ones, we present a novel two-stream CNN architecture to extract/compare features in a pair of 1D thermal signal sequences for accurate classification/differentiation of defective and non-defective regions. In this manner, we can significantly increase the size of the training data by pairing two individually captured 1D thermal signals, thereby greatly easing the requirement for collecting a large number of thermal sequences of specimens with defects to train deep CNN models. Moreover, we experimentally investigate a number of network alternatives, identifying the optimal fusion scheme/stage for differentiating the thermal behaviors of defective and non-defective regions. Experimental results demonstrate that our proposed method, directly learning how to construct feature representations from a large number of real-captured thermal signal pairs, outperforms the well-established lock-in thermography data processing techniques on specimens made of different materials and at various excitation frequencies.</p

    Characterization of the ompL1 gene of pathogenic Leptospira species in China and cross-immunogenicity of the OmpL1 protein

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    <p>Abstract</p> <p>Background</p> <p>The usefulness of available vaccine and serological tests for leptospirosis is limited by the low cross-reactivity of antigens from numerous serovars of pathogenic <it>Leptospira </it>spp. Identification of genus-specific protein antigens (GP-Ag) of <it>Leptospira </it>would be important for development of universal vaccines and serodiagnostic methods. OmpL1, a transmembrane porin of pathogenic leptospires, was identified as a possible GP-Ag, but its sequence diversity and immune cross-reactivity among different serovars of pathogenic leptospires remains largely unknown.</p> <p>Results</p> <p>PCR analysis demonstrated that the <it>ompL1 </it>gene existed in all 15 official Chinese standard strains as well as 163 clinical strains of pathogenic leptospires isolated in China. In the standard strains, the <it>ompL1 </it>gene could be divided into three groups (<it>ompL1/1</it>, <it>ompL1/2 </it>and <it>ompL1/3</it>) according to their sequence identities. Immune electron microscopy demonstrated that all products of the different gene types of <it>ompL1 </it>are located on the surface of leptospires. The microscopic agglutination test revealed extensive yet distinct cross-immunoagglutination among the antisera against recombinant OmpL1 (rOmpL1) and leptospiral strains belonging to different <it>ompL1 </it>gene types. These cross-immunoreactions were further verified by ELISAs using the OmpL1 proteins as the coated antigens in serum samples from 385 leptospirosis patients. All the antisera against rOmpL1 proteins could inhibit <it>L. interrogans </it>strain Lai from adhering to J774A.1 cells. Furthermore, immunization of guinea pigs with each of the rOmpL1 proteins could cause cross-immunoprotection against lethal challenge with leptospires from different <it>ompL1 </it>gene types.</p> <p>Conclusion</p> <p>Three types of the <it>ompL1 </it>gene are present in pathogenic leptospires in China. OmpL1 is an immunoprotective GP-Ag which should be considered in the design of new universal vaccines and serodiagnostic methods against leptospirosis.</p

    Ex vivo mono-ring technique simplifies culotte stenting for treatment of true bifurcation lesions: Insights from bench testing and clinical application

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    Background: Despite various culotte-based stenting techniques available clinically, the optimal one remains undetermined. The study aimed to test whether ex vivo mono-ring culotte stenting (MRC) was technically feasible and superior to mini culotte stenting (MCS) in treatment of coronary bifurcation lesions.Methods: Mono-ring culotte stenting was characterized by ex vivo wiring of the most proximal cell of the side branch (SB) stent to ensure a mono-ring result of the culotte stenting. Comparison of MRC vs. MCS in treatment of true bifurcation lesions was performed in vitro (n = 15 for each group) and in clinical case-controlled study with propensity matching at a ratio of 1:2 (n = 21 for MRC group; n = 42 for MCS group).Results: Compared to MCS, MRC had lower incidence of stent under-expansion band (0% vs. 53.3%, p = 0.002) and less residual ostial area stenosis of SB (9.2 ± 9.0% vs. 20.0 ± 14.8%, p = 0.023), as assessed in vitro by micro-computed tomography. In a case-controlled study, no adverse cardiac events were observed in the MRC group. The procedural success was similar between MRC and MCS (100% vs. 95.2%, p = 0.548), but MRC had less residual ostial stenosis of the SB (8.7% ± 11.0% vs. 16.8% ± 11.2%, p = 0.008), lower procedural(33.3 ± 9.5 min vs. 46.7 ± 15.6 min, p = 0.001) and fluoroscopic (19.7 ± 4.9 min vs. 26.2 ± 7.1 min, p &lt; 0.001) time, and less contrast use (114.3 ± 28.9 mL vs. 156.5 ± 56.4 mL, p = 0.002).Conclusions: Mono-ring culotte stenting as compared to MCS is associated with better bifurcation stent morphology,less procedural complexity and residual ostial SB stenosis

    Использование индексного подхода для оценки надежности показателей паритета покупательной способности валют в Китае

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    The introduction of representative products in International Comparison Program makes the purchasing power parities (PPPs) a computable concept. The representative extent of the product list for the participating countries has important impacts on the reliability of PPPs and the global results. However, the measurement of representativeness and its induced biases in the estimated PPPs has not been carried out to our knowledge. Therefore, the paper designs a new index approach - Intra-National Assessment (INA), to assess the reliability of PPPs via representativeness. The approach considers the regional disparity and urban-rural differences from the lowest level of the product specifications to the GDP level. This bottom-up approach is applied to empirically assess the reliability of China’s PPPs in 2011 ICP. From the reliability degree perspective, the China’s PPP at GDP level is reliable, but the variation at main category is relatively larger. The PPP reliability of the lower levels function differently. The reliability of food and its subcategories are more reliable than any other categories because of detailed survey data sources. The reliability results of durable consumer goods, transport and communications, housing, machinery and equipment, and construction vary considerably. Further problems about the INA approach are discussed. Reliability implications in this study would be helpful for measuring the real size of China and the world economy.По мнению авторов, реализация требований репрезентативности при отборе товаров (услуг) - представителей в Программе международных сопоставлений (ПМС) является условием расчетов паритета покупательной способности валют (ППС). Репрезентативность включаемых в список товаров (услуг) - представителей (в участвующих в сопоставлениях странах) оказывает большое влияние на надежность оценок ППС и на глобальные результаты. Однако насколько нам известно, оценка репрезентативности товаров и ее влияние на искажения при исчислении ППС не проводилась. В данной работе предложен новый индексный подход - внутринациональная оценка надежности ППС на основе определения репрезентативности отбираемых товаров (услуг) - представителей. При таком подходе рассматриваются различия между регионами, а также между городской и сельской местностями, начиная с самого низкого уровня агрегирования до уровня ВВП. Подход «снизу-вверх» применяется для эмпирической оценки надежности ППС для Китая в ПМС 2011. Можно утверждать, что оценки ППС для Китая надежны на уровне ВВП, однако по мнению авторов, имеет место дифференциация в степени надежности применительно к отдельным составляющим конечного продукта. Оценки надежности ППС на более низких уровнях агрегирования различаются. Надежность оценок для категории «продукты питания» и ее подкатегорий обеспечивается наличием подробных данных. Оценки надежности показателей для категорий «товары длительного пользования», «транспорт и связь», «жилищные услуги», «машины и оборудование», «строительство» существенно различаются. Обсуждаются вопросы дальнейшего развития подхода на основе применения внутринациональной оценки. Результаты, полученные в данной работе, будут полезными для измерения реального размера как экономики Китая в частности, так и мировой экономики в целом

    Transfer-free, lithography-free and fast growth of patterned CVD graphene directly on insulators by using sacrificial metal catalyst

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    Chemical vapor deposited graphene suffers from two problems: transfer from metal catalysts to insulators, and photoresist induced degradation during patterning. Both result in macroscopic and microscopic damages such as holes, tears, doping, and contamination, translated into property and yield dropping. We attempt to solve the problems simultaneously. A nickel thin film is evaporated on SiO2 as a sacrificial catalyst, on which surface graphene is grown. A polymer (PMMA) support is spin-coated on the graphene. During the Ni wet etching process, the etchant can permeate the polymer, making the etching efficient. The PMMA/graphene layer is fixed on the substrate by controlling the surface morphology of Ni film during the graphene growth. After etching, the graphene naturally adheres to the insulating substrate. By using this method, transfer-free, lithography-free and fast growth of graphene realized. The whole experiment has good repeatability and controllability. Compared with graphene transfer between substrates, here, no mechanical manipulation is required, leading to minimal damage. Due to the presence of Ni, the graphene quality is intrinsically better than catalyst-free growth. The Ni thickness and growth temperature are controlled to limit the number of layers of graphene. The technology can be extended to grow other two-dimensional materials with other catalysts

    Discovery of Digenic Mutation, KCNH2 c.1898A >C and JUP c.916dupA, in a Chinese Family with Long QT Syndrome via Whole-Exome Sequencing

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    Long QT syndrome (LQTS), which is caused by an ion channel–related gene mutation, is a malignant heart disease with a clinical course of a high incidence of ventricular fibrillation and sudden cardiac death in the young. Mutations in KCNH2 (which encodes potassium voltage-gated channel subfamily H member 2) are responsible for LQTS in many patients. Here we report the novel mutation c.1898A>C in KCNH2 in a Chinese family with LQTS through whole-exome sequencing. The c.916dupA mutation in JUP (which encodes junction plakoglobin) is also discovered. Mutations in JUP were found to be associated with arrhythmogenic right ventricular cardiomyopathy. The double mutation in the proband may help explain his severe clinical manifestations, such as sudden cardiac death at an early age. Sequencing for the proband’s family members revealed that the KCNH2 mutation descends from his paternal line, while the mutation in JUP came from his maternal line. The data provided in this study may help expand the spectrum of LQTS-related KCNH2 mutations and add support to the genetic diagnosis and counseling of families affected by malignant arrhythmias

    Periodontal therapy for primary or secondary prevention of cardiovascular disease in people with periodontitis

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    Background There may be an association between periodontitis and cardiovascular disease (CVD); however, the evidence so far has been uncertain about whether periodontal therapy can help prevent CVD in people diagnosed with chronic periodontitis. This is the second update of a review originally published in 2014, and first updated in 2017. Although there is a new multidimensional staging and grading system for periodontitis, we have retained the label 'chronic periodontitis' in this version of the review since available studies are based on the previous classification system. Objectives To investigate the effects of periodontal therapy for primary or secondary prevention of CVD in people with chronic periodontitis. Search methods Cochrane Oral Health's Information Specialist searched the Cochrane Oral Health's Trials Register, CENTRAL, MEDLINE, Embase, and CINAHL, two trials registries, and the grey literature to September 2019. We placed no restrictions on the language or date of publication. We also searched the Chinese BioMedical Literature Database, the China National Knowledge Infrastructure, the VIP database, and Sciencepaper Online to August 2019. Selection criteria We included randomised controlled trials (RCTs) that compared active periodontal therapy to no periodontal treatment or a different periodontal treatment. We included studies of participants with a diagnosis of chronic periodontitis, either with CVD (secondary prevention studies) or without CVD (primary prevention studies). Data collection and analysis Two review authors carried out the study identification, data extraction, and 'Risk of bias' assessment independently and in duplicate. They resolved any discrepancies by discussion, or with a third review author. We adopted a formal pilot‐tested data extraction form, and used the Cochrane tool to assess the risk of bias in the studies. We used GRADE criteria to assess the certainty of the evidence. Main results We included two RCTs in the review. One study focused on the primary prevention of CVD, and the other addressed secondary prevention. We evaluated both as being at high risk of bias. Our primary outcomes of interest were death (all‐cause and CVD‐related) and all cardiovascular events, measured at one‐year follow‐up or longer. For primary prevention of CVD in participants with periodontitis and metabolic syndrome, one study (165 participants) provided very low‐certainty evidence. There was only one death in the study; we were unable to determine whether scaling and root planning plus amoxicillin and metronidazole could reduce incidence of all‐cause death (Peto odds ratio (OR) 7.48, 95% confidence interval (CI) 0.15 to 376.98), or all CVD‐related death (Peto OR 7.48, 95% CI 0.15 to 376.98). We could not exclude the possibility that scaling and root planning plus amoxicillin and metronidazole could increase cardiovascular events (Peto OR 7.77, 95% CI 1.07 to 56.1) compared with supragingival scaling measured at 12‐month follow‐up. For secondary prevention of CVD, one pilot study randomised 303 participants to receive scaling and root planning plus oral hygiene instruction (periodontal treatment) or oral hygiene instruction plus a copy of radiographs and recommendation to follow‐up with a dentist (community care). As cardiovascular events had been measured for different time periods of between 6 and 25 months, and only 37 participants were available with at least one‐year follow‐up, we did not consider the data to be sufficiently robust for inclusion in this review. The study did not evaluate all‐cause death and all CVD‐related death. We are unable to draw any conclusions about the effects of periodontal therapy on secondary prevention of CVD. Authors' conclusions For primary prevention of cardiovascular disease (CVD) in people diagnosed with periodontitis and metabolic syndrome, very low‐certainty evidence was inconclusive about the effects of scaling and root planning plus antibiotics compared to supragingival scaling. There is no reliable evidence available regarding secondary prevention of CVD in people diagnosed with chronic periodontitis and CVD. Further trials are needed to reach conclusions about whether treatment for periodontal disease can help prevent occurrence or recurrence of CVD
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