4,269 research outputs found

    Keratin 6a marks mammary bipotential progenitor cells that can give rise to a unique tumor model resembling human normal-like breast cancer.

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    Progenitor cells are considered an important cell of origin of human malignancies. However, there has not been any single gene that can define mammary bipotential progenitor cells, and as such it has not been possible to use genetic methods to introduce oncogenic alterations into these cells in vivo to study tumorigenesis from them. Keratin 6a is expressed in a subset of mammary luminal epithelial cells and body cells of terminal end buds. By generating transgenic mice using the Keratin 6a (K6a) gene promoter to express tumor virus A (tva), which encodes the receptor for avian leukosis virus subgroup A (ALV/A), we provide direct evidence that K6a(+) cells are bipotential progenitor cells, and the first demonstration of a non-basal location for some biopotential progenitor cells. These K6a(+) cells were readily induced to form mammary tumors by intraductal injection of RCAS (an ALV/A-derived vector) carrying the gene encoding the polyoma middle T antigen. Tumors in this K6a-tva line were papillary and resembled the normal breast-like subtype of human breast cancer. This is the first model of this subtype of human tumors and thus may be useful for preclinical testing of targeted therapy for patients with normal-like breast cancer. These observations also provide direct in vivo evidence for the hypothesis that the cell of origin affects mammary tumor phenotypes

    Embracing corruption burstiness: Fast error recovery for ZigBee under wi-Fi interference

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.The ZigBee communication can be easily and severely interfered by Wi-Fi traffic. Error recovery, as an important means for ZigBee to survive Wi-Fi interference, has been extensively studied in recent years. The existing works add upfront redundancy to in-packet blocks for recovering a certain number of random corruptions. Therefore the bursty nature of ZigBee in-packet corruptions under Wi-Fi interference is often considered harmful, since some blocks are full of errors which cannot be recovered and some blocks have no errors but still requiring redundancy. As a result, they often use interleaving to reshape the bursty errors, before applying complex FEC codes to recover the re-shaped random distributed errors. In this paper, we take a different view that burstiness may be helpful. With burstiness, the in-packet corruptions are often consecutive and the requirement for error recovery is reduced as ”recovering any k consecutive errors” instead of ”recovering any random k errors”. This lowered requirement allows us to design far more efficient code than the existing FEC codes. Motivated by this implication, we exploit the corruption burstiness to design a simple yet effective error recovery code using XOR operations (called ZiXOR). ZiXOR uses XOR code and the delay is significantly reduced. More, ZiXOR uses RSSI-hinted approach to detect in packet corruptions without CRC, incurring almost no extra transmission overhead. The testbed evaluation results show that ZiXOR outperforms the state-of-the-art works in terms of the throughput (by 47%) and latency (by 22%)This work was supported by the National Natural Science Foundation of China (No. 61602095 and No. 61472360), the Fundamental Research Funds for the Central Universities (No. ZYGX2016KYQD098 and No. 2016FZA5010), National Key Technology R&D Program (Grant No. 2014BAK15B02), CCFIntel Young Faculty Researcher Program, CCF-Tencent Open Research Fund, China Ministry of Education—China Mobile Joint Project under Grant No. MCM20150401 and the EU FP7 CLIMBER project under Grant Agreement No. PIRSES-GA- 2012-318939. Wei Dong is the corresponding author

    The effect of e-cigarettes on smoking cessation and cigarette smoking initiation: An evidence-based rapid review and meta-analysis.

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    The contribution made by e-cigarettes to smoking cessation continues to be controversial. Reports suggest that teenagers are becoming increasingly addicted to e-cigarettes and that e-cigarette use in adolescents is associated with subsequent cigarette smoking. Systematic searches of eleven databases were conducted (January 2015 to June 2020). Systematic reviews, randomized controlled trials (RCTs) and cohort studies comparing e-cigarettes with placebo e-cigarettes, nicotine replacement therapy (NRT) or no e-cigarette use were included. The two primary outcomes were smoking cessation among smokers and smoking initiation among non-smoking teenagers. The secondary outcome was adverse events. Data were synthesized using risk ratio (RR) or adjusted odds ratio (AOR) with 95% confidence interval (CI). Six systematic reviews, 5 RCTs and 24 cohort studies were identified. For smoking cessation, findings from 4 systematic reviews indicated that e-cigarettes contributed to cessation while one found the opposite. Meta-analysis of 5 RCTs suggested that e-cigarettes were superior to NRT or placebo for smoking cessation (RR=1.55; 95% CI: 1.00-2.40; I =57.6%; low certainty; 5 trials, n=4025). Evidence from 9 cohort studies showed that e-cigarette use was not associated with cessation (AOR=1.16; 95% CI: 0.88-1.54; I =69.0%; n=22220). Subgroup analysis suggested that intensive e-cigarette use may be associated with cessation. In terms of smoking initiation, adolescents who ever used e-cigarettes had a greater risk for smoking initiation than non-users (AOR=2.91; 95% CI: 2.61-3.23; I =61.0%; 15 trials, n=68943), the findings were consistent with one included systematic review. No serious adverse events were reported in the included studies. Low certainty evidence suggests that e-cigarettes appear to be potentially effective for smoking cessation. The use of e-cigarettes in adolescents may be associated with smoking initiation. No serious adverse events were reported. [Abstract copyright: © 2021 Zhang Y.Y. et al.

    Whistle detection and classification for whales based on convolutional neural networks

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    Passive acoustic observation of whales is an increasingly important tool for whale research. Accurately detecting whale sounds and correctly classifying them into corresponding whale species are essential tasks, especially in the case when two species of whales vocalize in the same observed area. Whistles are vital vocalizations of toothed whales, such as killer whales and long-finned pilot whales. In this paper, based on deep convolutional neural networks (CNNs), a novel method is proposed to detect and classify whistles of both killer whales and long-finned pilot whales. Compared with traditional methods, the proposed one can automatically learn the sound characteristics from the training data, without specifying the sound features for classification and detection, and thus shows better adaptability to complex sound signals. First, the denoised sound to be analyzed is sent to the trained detection model to estimate the number and positions of the target whistles. The detected whistles are then sent to the trained classification model, which determines the corresponding whale species. A GUI interface is developed to assist with the detection and classification process. Experimental results show that the proposed method can achieve 97% correct detection rate and 95% correct classification rate on the testing set. In the future, the presented method can be further applied to passive acoustic observation applications for some other whale or dolphin species

    Adding Chinese herbal medicine to probiotics for irritable bowel syndrome-diarrhea: A systematic review and meta-analysis of randomized controlled trials

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    © 2020 Beijing University of Chinese Medicine Objective: This study assessed whether Chinese herbal medicine (CHM) combined with probiotics/synbiotics for irritable bowel syndrome - diarrhea (IBS-D) was more effective and safer than probiotics/synbiotics alone. Methods: Ten databases were searched for randomized control trials (RCTs) of IBS-D as diagnosed by Manning or Rome criteria. Trials comparing probiotics and probiotics with CHM were included. The Cochrane risk of bias (ROB) was evaluated for each trial. RevMan 5.3 was used to conduct a meta-analysis. Results: Twenty-six RCTs were included (25 Chinese, 1 English), involving 2045 participants. Meta-analysis was conducted on two outcomes: overall symptom improvement and relapse. CHM combined with live Bifidobacterium and Lactobacillus preparations reduced relapse rate (RR 0.28, 95%CI 0.15–0.52, 3 trials, n = 205) compared with probiotics alone. The subgroup analysis showed the benefit of CHM prescriptions based on soothing liver and invigorating spleen (1.28, 1.14–1.44, 3, 244), invigorating spleen and resolving dampness (1.20, 1.03–1.41, 2, 128), or warming and invigorating spleen and kidney formulae (1.27, 1.09–1.46, 2, 210) combined with triple Bifidobacterium preparations than the same probiotics alone which improved overall symptoms for IBS-D. There was unclear bias in almost domains of ROB. Most studies had a high risk of bias due to lack of blinding of investigator and participants, and selective reporting. Conclusions: This study showed that CHM combined with probiotics may reduce relapse rate by 72%, and improve overall symptoms of IBS-D (as diagnosed by Rome II and III) compared to probiotics alone. From the limited subgroup analysis, only soothing liver and invigorating spleen formulae, represented by Tongxie Yaofang, added to triple Bifidobacterium preparations may be superior to the single preparations in terms of overall symptoms. However, due to the poor methodological quality and small sample size of the trials, these findings must be interpreted with caution

    Well-posedness for degenerate third order equations with delay and applications to inverse problems

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    [EN] In this paper, we study well-posedness for the following third-order in time equation with delay <disp-formula idoperators defined on a Banach space X with domains D(A) and D(B) such that t)is the state function taking values in X and u(t): (-, 0] X defined as u(t)() = u(t+) for < 0 belongs to an appropriate phase space where F and G are bounded linear operators. Using operator-valued Fourier multiplier techniques we provide optimal conditions for well-posedness of equation (0.1) in periodic Lebesgue-Bochner spaces Lp(T,X), periodic Besov spaces Bp,qs(T,X) and periodic Triebel-Lizorkin spaces Fp,qs(T,X). A novel application to an inverse problem is given.The first, second and third authors have been supported by MEC, grant MTM2016-75963-P. The second author has been supported by AICO/2016/30. The fourth author has been supported by MEC, grant MTM2015-65825-P.Conejero, JA.; Lizama, C.; Murillo-Arcila, M.; Seoane Sepúlveda, JB. (2019). 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    Negative CT Contrast Agents for the Diagnosis of Malignant Osteosarcoma

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    © 2019 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The current positive computed tomography (CT) contrast agents (PCTCAs) including clinical iodides, present high CT density value (CT-DV). However, they are incapable for the accurate diagnosis of some diseases with high CT-DV, such as osteosarcoma. Because bones and PCTCAs around osteosarcoma generate similar X-ray attenuations. Here, an innovative strategy of negative CT contrast agents (NCTCAs) to reduce the CT-DV of osteosarcoma is proposed, contributing to accurate detection of osteosarcoma. Hollow mesoporous silica nanoparticles, loading ammonia borane molecules and further modified by polyethylene glycol, are synthesized as NCTCAs for the diagnosis of osteosarcoma. The nanocomposites can produce H2 in situ at osteosarcoma areas by responding to the acidic microenvironment of osteosarcoma, resulting in nearly 20 times reduction of CT density in osteosarcoma. This helps form large CT density contrast between bones and osteosarcoma, and successfully achieves accurate diagnosis of osteosarcoma. Meanwhile, The NCTCAs strategy greatly expands the scope of CT application, and provides profound implications for the precise clinical diagnosis, treatment, and prognosis of diseases
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