113 research outputs found

    Ocean-related global change alters lipid biomarker production in common marine phytoplankton

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    Lipids, in their function as trophic markers in food webs and organic matter source indicators in the water column and sediments, provide a tool for reconstructing the complexity of global change effects on aquatic ecosystems. It remains unclear how ongoing changes in multiple environmental drivers affect the production of key lipid biomarkers in marine phytoplankton. Here, we tested the responses of sterols, alkenones and fatty acids (FAs) in the diatom Phaeodactylum tricornutum, the cryptophyte Rhodomonas sp. and the haptophyte Emiliania huxleyi under a full-factorial combination of three temperatures (12, 18 and 24 ∘C), three N : P supply ratios (molar ratios 10 : 1, 24 : 1 and 63 : 1) and two pCO2 levels (560 and 2400 µatm) in semicontinuous culturing experiments. Overall, N and P deficiency had a stronger effect on per-cell contents of sterols, alkenones and FAs than warming and enhanced pCO2. Specifically, P deficiency caused an overall increase in biomarker production in most cases, while N deficiency, warming and high pCO2 caused nonsystematic changes. Under future ocean scenarios, we predict an overall decrease in carbon-normalized contents of sterols and polyunsaturated fatty acids (PUFAs) in E. huxleyi and P. tricornutum and a decrease in sterols but an increase in PUFAs in Rhodomonas sp. Variable contents of lipid biomarkers indicate a diverse carbon allocation between marine phytoplankton species in response to changing environments. Thus, it is necessary to consider the changes in key lipids and their consequences for food-web dynamics and biogeochemical cycles, when predicting the influence of global change on marine ecosystems

    Clinical analysis of decision implementation by a multidisciplinary team in cervical cancer cases in Ganzhou, China

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    ObjectiveIn this study, we evaluated the role of a multidisciplinary team (MDT) in clinical practice for cervical cancer by analyzing the development of a single-case multidisciplinary consultation for cervical cancer.MethodsPatients in MDT consultations for cervical cancer were retrospectively analyzed for clinical information, decision content of MDT discussion, implementation, and follow-up results.ResultsOf the 392 patients who met the inclusion criteria, 359 had a first episode, of which 284 were stage IA-IIA2 (79.11%) and 75 were stage IIB-IVB (20.89%). Of these 392, 33 had a recurrence (8.42%). A total of 416 cases were analyzed, and neoadjuvant chemotherapy with surgery was recommended in 43 cases, of which 40 cases were implemented, and 36 of the 40 achieved the expected outcome. Surgical treatment was recommended in 241 cases, of which 226 underwent surgery, and 215 of them achieved the expected outcome. Radiotherapy was recommended in 31 cases, of which 26 cases underwent it, and 22 of them achieved the expected efficacy. Concurrent chemoradiotherapy was recommended in 57 cases, of which 49 underwent it, and 39 of them achieved the expected efficacy. Other treatments were recommended in 44 cases, of which 23 cases were implemented, and 10 of them achieved the expected efficacy, with statistically significant differences compared with cases without implementation (P <0.05). MDT decisions were correlated with age; the younger the patients, the higher the implementation efficiency (P <0.05). The difference between MDT expectation in all implementation and partial implementation and age was statistically significant (P <0.05). No significant difference was found between age and MDT expectation in all not fully implemented decisions (P >0.05). Some decisions were not fully implemented due to economic status and fear of certain treatments of the patient.ConclusionThe MDT plays an important role in clinical practice such as clinical staging, treatment plan, and the complete treatment management of patients with cervical cancer, which can significantly improve the near-term treatment effect, whereas its effect on a long-term prognosis needs further clinical observation and active exploration

    The first rare case of Candida palmioleophila infection reported in China and its genomic evolution in a human host environment

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    IntroductionCandida palmioleophila is a rare human pathogenic fungus, which has been poorly characterized at the genome level. In this study, we reported the first fatal case of C. palmioleophila infection in China and investigate the microevolution of C. palmioleophila in the human host environment.MethodsA series of C. palmioleophila stains were collected from the patient at different time points for routine microbial and drug sensitivity testing. The first C. palmioleophila isolate 07202534 was identified by de novo whole genome sequencing. The in vitro and in vivo genetic evolutionary characteristics of C. palmioleophila were discussed based on the analysis of bioinformatics data.ResultsThe six C. palmioleophila isolates displayed dose-dependent sensitivity to fluconazole. The C. palmioleophila genome contained homologous genes such as CDR1 and MDR1, which were recognized to be related to azole resistance. In addition, amino acid variation was detected at F105L and other important sites of ERG11. In addition, the mean divergence time between C. palmioleophila and Scheffersomyces stipites CBS 6054 was 406.04 million years, indicating that C. palmioleophila originated earlier than its closest relative. In addition, the six strains of C. palmioleophila isolated form the patient had higher homology and fewer mutation sites, which indicated the stability in C. palmioleophila genome. We also found that C. palmioleophila had a wide natural niche and may evolve slowly.DiscussionWe believe that this study will contribute to improve our understanding of the genetic evolution, pathogenicity, and drug resistance of C. palmioleophila and will aid in the prevention and control of its spread

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    A Distributed Control Strategy for Frequency Regulation in Smart Grids Based on the Consensus Protocol

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    This paper considers the problem of distributed frequency regulation based on the consensus control protocol in smart grids. In this problem, each system component is coordinated to collectively provide active power for the provision of ancillary frequency regulation service. Firstly, an approximate model is proposed for the frequency dynamic process. A distributed control algorithm is investigated, while each agent exchanges information with neighboring agents and performs behaviors based on communication interactions. The objective of each agent is to converge to a common state considering different dynamic load characteristics, and distributed frequency control strategy is developed to enable the agents to provide active power support. Then, the distributed proportional integral controllers with the state feedback are designed considering the consensus protocol with topology . The theory of distributed consensus protocol isfurther developed to prove the stability of the proposed control algorithm. Whenproperly controlled, the controllers can provide grid support services in a distributed manner that turn out the grid balanced globally. Finally, simulations of the proposed distributed control algorithm are tested to validate the availability of the proposed approach and the performance in the electrical networks

    Acoustic Vector Sensor Multi-Source Detection Based on Multimodal Fusion

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    The direction of arrival (DOA) and number of sound sources is usually estimated by short-time Fourier transform and the conjugate cross-spectrum. However, the ability of a single AVS to distinguish between multiple sources will decrease as the number of sources increases. To solve this problem, this paper presents a multimodal fusion method based on a single acoustic vector sensor (AVS). First, the output of the AVS is decomposed into multiple modes by intrinsic time-scale decomposition (ITD). The number of sources in each mode decreases after decomposition. Then, the DOAs and source number in each mode are estimated by density peak clustering (DPC). Finally, the density-based spatial clustering of applications with the noise (DBSCAN) algorithm is employed to obtain the final source counting results from the DOAs of all modes. Experiments showed that the multimodal fusion method could significantly improve the ability of a single AVS to distinguish multiple sources when compared to methods without multimodal fusion

    Nondestructive inspection of through silicon via depth using scanning acoustic microscopy

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    In this paper, an innovative application of an existing nondestructive inspection, i.e, time-of-flight mode of scanning acoustic microscopy (SAM), was proposed for the measurement of through silicon via (TSV) depth. A feasibility study was performed on a dummy wafer with various sizes of TSVs to evaluate this method. From the image reconstruction of B-scan SAM, the depth of TSVs can be clearly identified. In addition, cross-section inspections were performed to verify this nondestructive inspection method. It was found that, for TSV sizes larger than φ30 μm, the depth measured by the ultrasonic scanning method could be very close to the results of cross-section inspection (less than 5% error). The current results are considered very encouraging and the proposed nondestructive inspection method should have very good potential for the high throughput and low cost in-line measurement of TSV depth during the TSV forming process

    Acoustic Vector Sensor Multi-Source Detection Based on Multimodal Fusion

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    The direction of arrival (DOA) and number of sound sources is usually estimated by short-time Fourier transform and the conjugate cross-spectrum. However, the ability of a single AVS to distinguish between multiple sources will decrease as the number of sources increases. To solve this problem, this paper presents a multimodal fusion method based on a single acoustic vector sensor (AVS). First, the output of the AVS is decomposed into multiple modes by intrinsic time-scale decomposition (ITD). The number of sources in each mode decreases after decomposition. Then, the DOAs and source number in each mode are estimated by density peak clustering (DPC). Finally, the density-based spatial clustering of applications with the noise (DBSCAN) algorithm is employed to obtain the final source counting results from the DOAs of all modes. Experiments showed that the multimodal fusion method could significantly improve the ability of a single AVS to distinguish multiple sources when compared to methods without multimodal fusion

    A hybrid denoising method for gyroscopes based on multiple screening

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    To reduce the random error of microelectromechanical system (MEMS) gyroscope, a hybrid method combining improved empirical mode decomposition (EMD) and least squares algorithm (LS) is proposed. Firstly, based on the multiple screening mechanism, intrinsic mode functions (IMFs) from the first decomposition are divided into noise IMFs, strong noise mixed IMFs, weak noise mixed IMFs and signal IMFs. Secondly, according to their characteristics, they are processed again. IMFs from the second decomposition are divided into noise IMFs and signal IMFs. Finally, useful signal is gathered to obtain the final denoising signal. Compared with some other denoising methods proposed in recent years, the experimental results show that the proposed method has obvious advantages in suppressing random error, greatly improving the signal quality and improving the accuracy of inertial navigation
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