59 research outputs found

    A Comparison of Sentinel-1 Biased and Unbiased Coherence for Crop Monitoring and Classification

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    Synthetic Aperture Radar (SAR) holds significant potential for applications in crop monitoring and classification. Interferometric SAR (InSAR) coherence proves effective in monitoring crop growth. Currently, the coherence based on the maximum likelihood estimator is biased towards low coherence values. Therefore, the main aim of this work is to access the performance of Sentinel-1 time-series biased coherence and unbiased coherence in crop monitoring and classification. This study was conducted during the 2018 growing season (April-October) in Komoka, an agricultural region in southwestern Ontario, Canada, primarily cultivating three crops: soybean, corn, and winter wheat. To verify the ability of coherence to monitor crops, a linear correlation coefficient between temporal coherence and dual polarimetric radar vegetation index (DpRVI) was fitted. The results revealed a stable correlation between temporal coherence and DpRVI time-series, with the highest correlation observed for soybean (0.7 < R < 0.8), followed by wheat and corn. Notably, unbiased coherence of the VV channel exhibited the highest correlation (R > 0.75). In addition, we applied unbiased coherence to crop classification. The results show that unbiased coherence exhibits very promising classification performance, with the overall accuracy (84.83%) and kappa coefficient (0.76) of VV improved by 8.35% and 0.12, respectively, over biased coherence, and the overall accuracy (73.25%) and kappa coefficient (0.57) of VH improved by 7.56% and 0.14, respectively, over biased coherence, and all crop classification accuracies were also effectively improved. This study demonstrates the feasibility of coherence monitoring of crops and provides new insights in enhancing the higher separability of crops

    A pan-kidney cancer study identifies subtype specific perturbations on pathways with potential drivers in renal cell carcinoma

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    Background: Renal cell carcinoma (RCC) is a complex disease and is comprised of several histological subtypes, the most frequent of which are clear cell renal cell carcinoma (ccRCC), papillary renal cell carcinoma (PRCC) and chromophobe renal cell carcinoma (ChRCC). While lots of studies have been performed to investigate the molecular characterizations of different subtypes of RCC, our knowledge regarding the underlying mechanisms are still incomplete. As molecular alterations are eventually reflected on the pathway level to execute certain biological functions, characterizing the pathway perturbations is crucial for understanding tumorigenesis and development of RCC. Methods: In this study, we investigated the pathway perturbations of various RCC subtype against normal tissue based on differential expressed genes within a certain pathway. We explored the potential upstream regulators of subtype-specific pathways with Ingenuity Pathway Analysis (IPA). We also evaluated the relationships between subtype-specific pathways and clinical outcome with survival analysis. Results: In this study, we carried out a pathway-based analysis to explore the mechanisms of various RCC subtypes with TCGA RNA-seq data. Both commonly altered pathways and subtype-specific pathways were detected. To identify the distinctive characteristics of each subtype, we focused on subtype-specific perturbed pathways. Specifically, we observed that some of the altered pathways were regulated by several recurrent upstream regulators which presenting different expression patterns among distinct RCC subtypes. We also noticed that a large number of perturbed pathways were controlled by the subtype-specific upstream regulators. Moreover, we also evaluated the relationships between perturbed pathways and clinical outcome. Prognostic pathways were identified and their roles in tumor development and progression were inferred. Conclusions: In summary, we evaluated the relationships among pathway perturbations, upstream regulators and clinical outcome for differential subtypes in RCC. We hypothesized that the alterations of common upstream regulators as well as subtype-specific upstream regulators work together to affect the downstream pathway perturbations and drive cancer initialization and prognosis. Our findings not only increase our understanding of the mechanisms of various RCC subtypes, but also provide targets for personalized therapeutic intervention

    Spectroscopic and Structural Probing of Excited-State Molecular Dynamics with Time-Resolved Photoelectron Spectroscopy and Ultrafast Electron Diffraction

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    Pump-probe measurements aim to capture the motion of electrons and nuclei on their natural timescales (femtoseconds to attoseconds) as chemical and physical transformations take place, effectively making molecular movies with short light pulses. However, the quantum dynamics of interest are filtered by the coordinate-dependent matrix elements of the chosen experimental observable. Thus, it is only through a combination of experimental measurements and theoretical calculations that one can gain insight into the internal dynamics. Here, we report on a combination of structural (relativistic ultrafast electron diffraction, or UED) and spectroscopic (time-resolved photoelectron spectroscopy, or TRPES) measurements to follow the coupled electronic and nuclear dynamics involved in the internal conversion and photodissociation of the polyatomic molecule, diiodomethane (CH2I2). While UED directly probes the 3D nuclear dynamics, TRPES only serves as an indirect probe of nuclear dynamics via Franck-Condon factors, but it is sensitive to electronic energies and configurations, via Koopmans\u27 correlations and photoelectron angular distributions. These two measurements are interpreted with trajectory surface hopping calculations, which are capable of simulating the observables for both measurements from the same dynamics calculations. The measurements highlight the nonlocal dynamics captured by different groups of trajectories in the calculations. For the first time, both UED and TRPES are combined with theory capable of calculating the observables in both cases, yielding a direct view of the structural and nonadiabatic dynamics involved

    Calcium orthophosphate-based biocomposites and hybrid biomaterials

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    Trends of mitochondrial changes in AD: a bibliometric study

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    BackgroundAlzheimer’s disease (AD) is a neurodegenerative disease characterized by progressive progress and memory loss, which eventually develops into dementia. It can cause personality disorders and decreased quality of life of patients. Currently, AD patients account for 60–70% of global dementia patients and the incidence rate of AD is increasing annually. AD not only causes pain to patients but also brings a heavy burden to the entire family. Studies have found that there is a connection between mitochondrial dysfunction and other biochemical changes in AD like classical neuropathological hallmarks (β-amyloid and tau protein), inflammation pathways, oxidative stress, and so on. Evidence shows that early treatment targeted directly to mitochondria could extend the lifespan of model mice and decrease the relevant neuropathological markers. Therefore, research on the mitochondrial dysfunction of AD can be of potential significance for clinical treatment. To date, few bibliometric analysis articles related to mitochondrial dysfunction of AD have been published. Bibliometric analysis refers to quantitatively analyzing certain aspects of articles like publishers, authors, and countries by using statistical and mathematical methods. Combined with statistical software, a large number of papers can be converted to visualization figures and tables, which provide vital information such as keyword hotspots and the names of contributing authors. Through the bibliometric analysis method, our study aimed to provide study trends and keyword hotpots for researchers to conduct further relevant research in this field.MethodsWe used the Web of Science core collection database as a literature retrieval tool to obtain data related to mitochondrial changes in Alzheimer’s disease during the last 20 years. The retrieval type was [TS = (Alzheimer’s disease)] ND [TS = (mitochondrion)], ranging from January 1, 2000 to June 30, 2022. VOSviewer v1.6.18, Arcgis 10.8, and HistCite pro 2.1 were used to conduct data visualization analysis. VOSviewer v1.6.18 made relevant network visualization maps of the cooperative relationship between relevant countries, institutions, and authors (co-authorship), the frequency of different keywords appearing together (co-occurrence), and the frequency of different articles cited together (co-cited). Arcgis 10.8 created the world map of publications distribution in this field and Histcite pro 2.1 was used to count the local citation score (LCS) of references. In addition, Journal Citation Reports were used to consult the latest journal import factor and JCI quartile.ResultsAs of June 30, 2022, from the Web of Science core collection, we selected 2,474 original articles in English, excluding the document types of the news items, meeting abstracts, and some articles that had little relevance to our theme. The United States acted as the leader and enjoyed a high reputation in this field. The University of California System was the institution that made the greatest contribution (3.64% with 90 papers). Most articles were published in the Journal of Alzheimer’s Disease (8.21%, with 203 papers). The most frequently co-cited journal in Q1 was the Journal of Biological Chemistry (8,666 citations, TLS: 1039591). Russel H. Swerdlow (55 publications) was the most productive author and PH Reddy was the most co-cited author with 1,264 citations (TLS: 62971). The hotpots of mitochondrial dysfunction in AD were as follows: “oxidative stress,” “amyloid-beta-protein,” “tau,” “apoptosis,” “inflammation,” “autophagy,” “precursor protein,” “endoplasmic-reticulum,” “dynamics” and “mitochondrial unfolded protein response.”ConclusionThis bibliometric analysis research will help readers rapidly identify current hotpots and milestone studies related to directions of interest in AD research

    Mid-term follow-up evaluation of a new arthroscopic Broström procedure for chronic lateral ankle instability

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    Abstract Background Chronic lateral ankle instability (CLAI) usually progresses from a previous lateral ankle sprain that was not treated properly. Several procedures have been introduced to address these patients, including open or arthroscopic techniques, the most common of which is the Broström procedure. Here, we describe a new outside-in arthroscopic Broström procedure and its results for treating patients with CLAI. Methods Thirty-nine patients (16 male and 23 female; mean age, 35 years [range, 16–60 years]) with CLAI were treated arthroscopically after failing non-operative management. All patients were symptomatic with a combination of recurrent ankle sprains, “giving way,” and avoidance of sports and presented with a positive anterior drawer test upon the physical examination. All patients underwent arthroscopic lateral ligament reconstruction using the new technique. Patient characteristics and pre- and postoperative visual analog scale (VAS), American Orthopedic Foot and Ankle Society Ankle-Hindfoot Scale system (AOFAS), and Karlsson scores were recorded. Results The mean AOFAS score increased from 48 (mean 48, range 33–72) preoperatively to 91 (mean 91, range 75–98) at the final follow-up, Karlsson–Peterson and FAAM scores were also significantly improved. Two patients (5.13%) reported superficial peroneal nerve irritation symptoms postoperatively. Three patients (7.69%) complained of mild pain anteroinferior to the lateral ankle. Conclusions The arthroscopic outside-in Broström procedure with a single suture anchor was a safe, effective, and reproducible technique for CLAI. Ankle stability resumed with a high clinical success rate. The main complication was injury to the superficial peroneal nerve, which crossed the area of repair

    Influence of C-rates on Consistency among Batteries in a Set in a Low-temperature Environment

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    The methods of examining and evaluating the consistency among batteries in a set are mostly meant for the batteries in a conventional application environment. Therefore, this article has studied the influence of C-rates on the consistency among batteries in a set in a low-temperature environment, as well as the regular pattern of changes in charging and discharging currents, providing reference data for the correct use of batteries in a low-temperature environment, and establishing a research base for the improvement on the performance of batteries

    Characteristics of the Coal Fines Produced from Low-Rank Coal Reservoirs and Their Wettability and Settleability in the Binchang Area, South Ordos Basin, China

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    By using proximate analysis, X-ray diffraction mineral analysis, scanning electron microscope, contact angle measurement, and settlement simulation experiment, the coal fines produced from the coalbed methane wells of Binchang area were used to study the characteristics including particle size distribution, composition, morphology, wettability, and settleability. The results show that the particle size of coal fines produced from coalbed methane wells are mainly >20 mesh, ranging of 1-400 μm, and the particle size distribution curve is mainly dominated by the main-secondary bimodal type, with the main peak of 30-300 μm. The particle size from large to small is drill cutting coal fines, flowback coal fines, bailing coal fines, and pipeline filter coal fines. In terms of ash content, coal fines are higher than coal seam, and drilling cuttings are higher than bailing coal fines, while the fixed carbon content of the former is lower than that of the latter. The minerals of coal fines are mainly kaolinite, illite, quartz, and other 6 minerals, and the mineral types of drilling coal fines are the most abundant, while the bailing coal fines only contain illite and quartz. The roundness of coal fine particles ranges from excellent to poor in the order of bailing coal fines, pipeline filter coal fines, flowback coal fines, and drilling cuttings. However, the sorting of drilling cuttings is excellent, and the particle edges are straight, neat, and smooth, while the sorting of bailing coal fines is poor, and the particle edges are curved, uneven, and rough. The contact angles of coal fines are 40.25°-69.5°, indicating hydrophilous. The wettability of bailing coal fines is better than that of drilling cuttings. The particle size has a negative correlation with the wettability effect. The more obvious the modification effect of positive wetting agent is, the worse the modification effect of negative wetting agent is. The modification of surfactant has nothing to do with the particle size of the coal fines, but is closely related to organic components and minerals. The larger the coal particle size, the higher the settling rate, and the higher the ash content and the lower the fixed carbon content, the faster the settling rate. With the dividing point 150 mesh, the settling rate of large particles is mainly affected by particle size, while that of small particles is affected by the composition

    The first high-quality chromosome-level genome of Eretmochelys imbricata using HiFi and Hi-C data

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    Abstract Eretmochelys imbricata, a critically endangered sea turtle inhabiting tropical oceans and protected across the world, had an unknown genome sequence until now. In this study, we used HiFi reads and Hi-C technology to assemble a high-quality, chromosome-level genome of E. imbricata. The genome size was 2,138.26 Mb, with contig N50 length of 123.49 Mb and scaffold N50 of 137.21 Mb. Approximately 97.52% of the genome sequence was anchored to 28 chromosomes. A total of 20,206 protein-coding genes were predicted. We also analyzed the evolutionary relationships, gene family expansions, and positive selection of E. imbricata. Our results revealed that E. imbricata diverged from Chelonia mydas 38 million years ago and had enriched olfactory receptors and aging-related genes. Our genome will be useful for studying E. imbricata and its conservation
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