296 research outputs found
Advancements in Development of Chemical-Looping Combustion: A Review
Chemical-looping combustion (CLC) is a novel combustion technology with inherent separation of greenhouse CO2. Extensive research has been performed on CLC in the last decade with respect to oxygen carrier development, reaction kinetics, reactor design, system efficiencies, and prototype testing. Transition metal oxides, such as Ni, Fe, Cu, and Mn oxides, were reported as reactive species in the oxygen carrier particles. Ni-based oxygen carriers exhibited the best reactivity and stability during multiredox cycles. The performance of the oxygen carriers can be improved by changing preparation method or by making mixedoxides. The CLC has been demonstrated successfully in continuously operated prototype reactors based on interconnected fluidized-bed system in the size range of 0.3–50 kW. High fuel conversion rates and almost 100% CO2 capture efficiencies were obtained. The CLC system with two interconnected fluidized-bed reactors was considered the most suitable reactor design. Development of oxygen carriers with excellent reactivity and stability is still one of the challenges for CLC in the near future. Experiences of building and operating the large-scale CLC systems are needed before this technology is used commercially. Chemical-looping reforming (CLR) and chemical-looping hydrogen (CLH) are novel chemical-looping techniques to produce synthesis gas and hydrogen deserving more attention and research
Shortcuts to adiabaticity in Fermi gases
Shortcuts to adiabaticity (STA) provide an alternative to adiabatic protocols
to guide the dynamics of the system of interest without the requirement of slow
driving. We report the controlled speedup via STA of the nonadiabatic dynamics
of a Fermi gas, both in the non-interacting and strongly coupled, unitary
regimes. Friction-free superadiabatic expansion strokes, with no residual
excitations in the final state, are demonstrated in the unitary regime by
engineering the modulation of the frequencies and aspect ratio of the harmonic
trap. STA are also analyzed and implemented in the high-temperature regime,
where the shear viscosity plays a pivotal role and the Fermi gas is described
by viscous hydrodynamics.Comment: 12 pp, 6 figure
Study on the effects of granularity of paprika on physicochemical properties and volatile flavor compounds of chili oil
Objective: This study aimed to investigate the effects of granularity of paprika on the physical and chemical properties and volatile flavor compounds of chili oil. Methods: Chili oil samples(KLD2-KLD5)were prepared from mechanically crushed paprika with different granularity (35, 30, 26, 20 mesh), and the content of capsaicinoids, chromatic aberration value, and peroxide value of oil samples were determined by high performance liquid chromatography(HPLC), colorimeter and other methods. The types and contents of volatile flavor compounds were detected and analyzed by gas chromatography-ion mobility spectrometry (GC-IMS) combined with principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and heat map cluster analysis. In addition, a comparative analysis was performed with the traditional hand-milled chili oil sample (KLD1). Results: In the KLD2-KLD5 chili oil samples prepared with mechanically crushed paprika, the concentration of capsaicin, dihydrocapsaicin and capsaicinoids, scoville heat units (SHU) and pungency degree decreased with the increase of the granularity of paprika. The peroxide value increases with the increase of the granularity, and the brightness L* increased first and then decreased with the decrease of the granularity, and there was a significant difference(P<0.05) had been observed. A total of 58 volatile organic compounds (VOCs) were identified by GC-IMS, mainly including: alcohols, aldehydes, ketones, carboxylic acids, esters, heterocyclics and thioethers, with 10, 18, 12, 4, 7, 5 and 2 types respectively. GC-IMS fingerprints combined with the relative percentage of VOCs showed that the types of VOCs in KLD2-KLD5 samples were the same, but the contents were different. The types and content of VOCs in KLD1 were quite different from those in KLD2-KLD5. Fourteen key differential markers of 5 chili oils were screened by PLS-DA. The results of principal component analysis, nearest neighbor analysis, and heat map clustering analysis of VOCs in five kinds of chili oil samples were consistent with the results of GC-IMS fingerprints. These samples could be accurately distinguished and the flavor of KLD1 was the most unique. Conclusion: The granularity of paprika had a significant impact on the dissolution rate of capsaicin and dihydrocapsaicin in chili oil, peroxide value, and brightness L* (P<0.05), but has no effect on the types of volatile flavor compounds in chili oil. However, the content of volatile flavor compounds in each sample had a certain difference
Real-world TRAE association between niraparib and platinum-based chemotherapy
BackgroundPre-clinical studies showed the anti-tumor mechanisms of PARP inhibitors (PARPi) and platinum have some crossover and overlap in the DNA damage repair pathway, patients who respond to platinum-based chemotherapy are also more likely to be sensitive to PARPi. This real-world study mainly aimed to evaluate whether TRAE (treatment-related adverse event) between platinum based chemotherapy (PBC) and niraparib are also associated.MethodsPatients received niraparib as maintenance treatment or salvage therapy for advanced ovarian cancer at the First Affiliated Hospital of Gannan Medical University from January 2020 to August 2023 were included. Survival data of niraparib treatment and adverse events occurred during the last platinum-based chemotherapy cycle before starting niraparib treatment and during niraparib treatment are documented. Fisher’s exact test were used for correlation analysis.Results1. 40 patients treated with niraparib were included in the analysis, including 31 patients treated with niraparib for 1st-line maintenance therapy, 6 patients for PSR (platinum-sensitive recurrence) maintenance therapy, and 3 patients for salvage therapy. The overall median follow-up time was 15.0 months (ranged from 2.2 months to 32.1 months). 2. Overall grade≥3 TRAE (40% vs 70%, p=0.012) including anemia (20% vs 45%, p=0.041) and neutrophil count decreased (17.5% vs 57.5%, p<0.001) was significantly lower during niraparib treatment compared to during chemotherapy. 3. Any grade TRAE (75% vs 100%, p=0.002) including white blood cell count decreased (47.5% vs 87.5%, p<0.001), red blood cell count decreased (57.5% vs 92.5%, p<0.001), anemia (55% vs 87.5%, p<0.001) and neutrophil count decreased (35% vs 85%, p<0.001) were also significantly lower in niraparib treatment group compared with chemotherapy group. No new safety signals were identified.Conclusion1. In this real-world practice, we observed that patients with advanced ovarian cancer who experienced any grade and grade ≥3 TRAE during chemotherapy were well tolerated when treated with niraparib, particularly the incidence of any grade and grade ≥3 anemia, and neutrophil count decreased during niraparib treatment were significantly lower compared with that during chemotherapy. 2. For patients with ovarian cancer who have experienced grade ≥3 hematological adverse reactions during prior platinum-based chemotherapy, greater attention should be paid to the monitoring and management of hematological adverse reactions during subsequent treatment with niraparib
Molecular analysis of the diversity of vaginal microbiota associated with bacterial vaginosis
<p>Abstract</p> <p>Background</p> <p>Bacterial vaginosis (BV) is an ecological disorder of the vaginal microbiota that affects millions of women annually, and is associated with numerous adverse health outcomes including pre-term birth and the acquisition of sexually transmitted infections. However, little is known about the overall structure and composition of vaginal microbial communities; most of the earlier studies focused on predominant vaginal bacteria in the process of BV. In the present study, the diversity and richness of vaginal microbiota in 50 BV positive and 50 healthy women from China were investigated using culture-independent PCR-denaturing gradient gel electrophoresis (DGGE) and barcoded 454 pyrosequencing methods, and validated by quantitative PCR.</p> <p>Results</p> <p>Our data demonstrated that there was a profound shift in the absolute and relative abundances of bacterial species present in the vagina when comparing populations associated with healthy and diseased conditions. In spite of significant interpersonal variations, the diversity of vaginal microbiota in the two groups could be clearly divided into two clusters. A total of 246,359 high quality pyrosequencing reads was obtained for evaluating bacterial diversity and 24,298 unique sequences represented all phylotypes. The most predominant phyla of bacteria identified in the vagina belonged to <it>Firmicutes</it>, <it>Bacteroidetes</it>, <it>Actinobacteria </it>and <it>Fusobacteria</it>. The higher number of phylotypes in BV positive women over healthy is consistent with the results of previous studies and a large number of low-abundance taxa which were missed in previous studies were revealed. Although no single bacterium could be identified as a specific marker for healthy over diseased conditions, three phyla - <it>Bacteroidetes</it>, <it>Actinobacteria </it>and <it>Fusobacteria</it>, and eight genera including <it>Gardnerella</it>, <it>Atopobium</it>, <it>Megasphaera</it>, <it>Eggerthella</it>, <it>Aerococcus</it>, <it>Leptotrichia</it>/<it>Sneathia</it>, <it>Prevotella </it>and <it>Papillibacter </it>were strongly associated with BV (<it>p </it>< 0.05). These genera are potentially excellent markers and could be used as targets for clinical BV diagnosis by molecular approaches.</p> <p>Conclusions</p> <p>The data presented here have clearly profiled the overall structure of vaginal communities and clearly demonstrated that BV is associated with a dramatic increase in the taxonomic richness and diversity of vaginal microbiota. The study also provides the most comprehensive picture of the vaginal community structure and the bacterial ecosystem, and significantly contributes to the current understanding of the etiology of BV.</p
The Design and Joint Positioning Method of an ultra-wideband Through-wall Radar System for Distributed Wireless Networking
Through-wall radar systems with single transmitter and receiver have the advantages of portability, simplicity, and independent operation; however, they cannot accomplish two-dimensional (2D) localization and tracking of targets. This paper proposes distributed wireless networking for through-wall radar systems based on a portable single transmitter and single receiver radar. Moreover, a target joint positioning method is proposed in this study, which can balance system portability, low cost, and target 2D information estimation. First, a complementary Gray code transmission waveform is utilized to overcome the issue of mutual interference when multiple radars operate simultaneously in the same frequency band, and each radar node communicates with the processing center via wireless modules, forming a distributed wireless networking radar system. In addition, a data synchronization method combines the behavioral cognition theory and template matching, which identifies identical motion states in data obtained from different radars, realizing slow-time synchronization among distributed radars and thereby eliminating the strict hardware requirements of conventional synchronization methods. Finally, a joint localization method based on Levenberg-Marquardt is proposed, which can simultaneously estimate the positions of radar nodes and targets without requiring prior radar position information. Simulation and field experiments are performed, and the results reveal that the distributed wireless networking radar system developed in this study can obtain 2D target positions and track moving targets in real time. The estimation accuracy of the radar’s own position is less than 0.06 m, and the positioning accuracy of moving human targets is less than 0.62 m
A novel transcription factor-based signature to predict prognosis and therapeutic response of hepatocellular carcinoma
Background: Hepatocellular carcinoma (HCC) is one of the most common aggressive malignancies with increasing incidence worldwide. The oncogenic roles of transcription factors (TFs) were increasingly recognized in various cancers. This study aimed to develop a predicting signature based on TFs for the prognosis and treatment of HCC.Methods: Differentially expressed TFs were screened from data in the TCGA-LIHC and ICGC-LIRI-JP cohorts. Univariate and multivariate Cox regression analyses were applied to establish a TF-based prognostic signature. The receiver operating characteristic (ROC) curve was used to assess the predictive efficacy of the signature. Subsequently, correlations of the risk model with clinical features and treatment response in HCC were also analyzed. The TF target genes underwent Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, followed by protein-protein-interaction (PPI) analysis.Results: A total of 25 differentially expressed TFs were screened, 16 of which were related to the prognosis of HCC in the TCGA-LIHC cohort. A 2-TF risk signature, comprising high mobility group AT-hook protein 1 (HMGA1) and MAF BZIP transcription factor G (MAFG), was constructed and validated to negatively related to the overall survival (OS) of HCC. The ROC curve showed good predictive efficiencies of the risk score regarding 1-year, 2-year and 3-year OS (mostly AUC >0.60). Additionally, the risk score independently predicted OS for HCC patients both in the training cohort of TCGA-LIHC dataset (HR = 2.498, p = 0.007) and in the testing cohort of ICGC-LIRI-JP dataset (HR = 5.411, p < 0.001). The risk score was also positively correlated to progressive characteristics regarding tumor grade, TNM stage and tumor invasion. Patients with a high-risk score were more resistant to transarterial chemoembolization (TACE) treatment and agents of lapatinib and erlotinib, but sensitive to chemotherapeutics. Further enrichment and PPI analyses demonstrated that the 2-TF signature distinguished tumors into 2 clusters with proliferative and metabolic features, with the hub genes belonging to the former cluster.Conclusion: Our study identified a 2-TF prognostic signature that indicated tumor heterogeneity with different clinical features and treatment preference, which help optimal therapeutic strategy and improved survival for HCC patients
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