104 research outputs found

    A Wideband MIMO Channel Model for Aerial Intelligent Reflecting Surface-Assisted Wireless Communications

    Full text link
    Compared to traditional intelligent reflecting surfaces(IRS), aerial IRS (AIRS) has unique advantages, such as more flexible deployment and wider service coverage. However, modeling AIRS in the channel presents new challenges due to their mobility. In this paper, a three-dimensional (3D) wideband channel model for AIRS and IRS joint-assisted multiple-input multiple-output (MIMO) communication system is proposed, where considering the rotational degrees of freedom in three directions and the motion angles of AIRS in space. Based on the proposed model, the channel impulse response (CIR), correlation function, and channel capacity are derived, and several feasible joint phase shifts schemes for AIRS and IRS units are proposed. Simulation results show that the proposed model can capture the channel characteristics accurately, and the proposed phase shifts methods can effectively improve the channel statistical characteristics and increase the system capacity. Additionally, we observe that in certain scenarios, the paths involving the IRS and the line-of-sight (LoS) paths exhibit similar characteristics. These findings provide valuable insights for the future development of intelligent communication systems.Comment: 6 pages, 7 figure

    Structural reconstruction of the catalytic center of LiPDF through multiple scattering calculation with MXAN

    Get PDF
    Abstract Peptide deformylase (PDF, EC 3.5.1.27) is essential for the normal growth of eubacterium but not for mammalians. Recently, PDF has been studied as a target for new antibiotics. In this paper, X-ray absorption spectroscopy was employed to determine the local structure around the zinc ion of PDF from Leptospira Interrogans in dry powder, because it is very difficult to obtain the crystallized sample of Li PDF. We performed X-ray absorption near edge structure (XANES) calculation and reconstructed successfully the local geometry of the active center, and the results from calculations show that a water molecule (Wat1) has moved towards the zinc ion and lies in the distance range to coordinate with the zinc ion weakly. In addition, the sensitivity of theoretical spectra to the different ligand bodies was evaluated in terms of goodness-of-fit

    Case report: BCR-ABL-positive acute lymphoblastic leukemia with bone destruction: a treatment dilemma

    Get PDF
    Although bone destruction and hypercalcemia without acute peripheral blast BCR-ABL-positive acute lymphoblastic leukemia (ALL) have been reported in children, they are rare in adults. Herein, we describe a case of BCR-ABL positive ALL with a triploid karyotype, WT1, and CDKN2A mutations with hypercalcemia and bone destruction as the first manifestations. Complete remission (CR) was achieved by induction chemotherapy. BCR-ABL turned negative after treatment with dasatinib. However, computed tomography and whole-body bone scan showed extensive bone destruction. Additionally, bone biopsy showed leukemic infiltration. After treatment with dasatinib and VMCP, leukemia recurred with positive BCR-ABL. The T315I mutation occurred. The patient was surgically diagnosed with calculous cholecystitis and achieved CR2 by postoperative orebatinib and VP regimens. Later, the patient died due to a severe pulmonary infection. BCR-ABL-positive ALL with bone destruction is rare and difficult to control using tyrosine kinase inhibitor chemotherapy alone. Therefore, further exploration of more effective treatments is needed

    Evidence of elevation-dependent warming from the Chinese Tian Shan

    Get PDF
    The phenomenon in which the warming rate of air temperature is amplified with elevation is termed elevation-dependent warming (EDW). It has been clarified that EDW can accelerate the retreat of glaciers and melting of snow, which can have significant impacts on the regional ecological environment. Owing to the lack of high-density ground observations in high mountains, there is widespread controversy regarding the existence of EDW. Current evidence is mainly derived from typical high-mountain regions such as the Swiss Alps, the Colorado Rocky Mountains, the tropical Andes and the Tibetan Plateau–Himalayas. Rare evidence in other mountain ranges has been reported, especially in arid regions. In this study, EDW features (regional warming amplification and altitude warming amplification) in the Chinese Tian Shan (CTM) were detected using a unique high-resolution (1 km, 6-hourly) air temperature dataset (CTMD) from 1979 to 2016. The results showed that there were significant EDW signals at different altitudes on different timescales. The CTM showed significant regional warming amplification in spring, especially in March, and the warming trends were greater than those of continental China with respect to three temperatures (minimum temperature, mean temperature and maximum temperature). The significance values of EDW above different altitude thresholds are distinct for three temperatures in 12 months. The warming rate of the minimum temperature in winter showed a significant elevation dependence (p<0.01), especially above 3000 m. The greatest altitudinal gradient in the warming rate of the maximum temperature was found above 4000 m in April. For the mean temperature, the warming rates in June and August showed prominent altitude warming amplification but with different significance above 4500 m. Within the CTM, the Tolm Mountains, the eastern part of the Borokoonu Mountains, the Bogda Mountains and the Balikun Mountains are representative regions that showed significant altitude warming amplification on different timescales. This new evidence could partly explain the accelerated melting of snow in the CTM, although the mechanisms remain to be explored

    Transcriptome and coexpression network analysis reveals properties and candidate genes associated with grape (Vitis vinifera L.) heat tolerance

    Get PDF
    Temperature is one of the most important environmental factors affecting grape season growth and geographical distribution. With global warming and the increasing occurrence of extreme high-temperature weather, the impact of high temperatures on grape production has intensified. Therefore, identifying the molecular regulatory networks and key genes involved in grape heat tolerance is crucial for improving the resistance of grapes and promoting sustainable development in grape production. In this study, we observed the phenotypes and cellular structures of four grape varieties, namely, Thompson Seedless (TS), Brilliant Seedless (BS), Jumeigui (JMG), and Shine Muscat (SM), in the naturally high-temperature environment of Turpan. Heat tolerance evaluations were conducted. RNA-seq was performed on 36 samples of the four varieties under three temperature conditions (28°C, 35°C, and 42°C). Through differential expression analysis revealed the fewest differentially expressed genes (DEGs) between the heat-tolerant materials BS and JMG, and the DEGs common to 1890 were identified among the four varieties. The number of differentially expressed genes within the materials was similar, with a total of 3767 common DEGs identified among the four varieties. KEGG enrichment analysis revealed that fatty acid metabolism, starch and sucrose metabolism, plant hormone signal transduction, the MAPK signaling pathway, and plant-pathogen interactions were enriched in both between different temperatures of the same material, and between different materials of the same temperature. We also conducted statistical and expression pattern analyses of differentially expressed transcription factors. Based on Weighted correlation network analysis (WGCNA), four specific modules highly correlated with grape heat tolerance were identified by constructing coexpression networks. By calculating the connectivity of genes within the modules and expression analysis, six candidate genes (VIT_04s0044g01430, VIT_17s0000g09190, VIT_01s0011g01350, VIT_01s0011g03330, VIT_04s0008g05610, and VIT_16s0022g00540) related to heat tolerance were discovered. These findings provide a theoretical foundation for further understanding the molecular mechanisms of grape heat tolerance and offer new gene resources for studying heat tolerance in grapes

    Differentiation of Soil Conditions over Low Relief Areas Using Feedback Dynamic Patterns

    Get PDF
    In many areas, such as plains and gently undulating terrain, easy-to-measure soil-forming factors such as landform and vegetation do not co-vary with soil conditions across space to the level that they can be effectively used in digital soil mapping. A challenging problem is how to develop a new environmental variable that co-varies with soil spatial variation under these situations. This study examined the idea that change patterns (dynamic feedback patterns) of the land surface, such as those captured daily by remote sensing images during a short period (6-7 d) after a major rain event, can be used to differentiate soil types. To examine this idea, we selected two study areas with different climates: one in northeastern China and the other in northwestern China. Images from the Moderate Resolution Imaging Spectroradiometer (MODIS) were used to capture land surface feedback. To measure feedback dynamics, we used spectral information divergence (SID). Results of an independent-samples t-test showed that there was a significant difference in SID values between pixel pairs of the same soil subgroup and those of different subgroups. This indicated that areas with different soil types (subgroup level) exhibited significantly different dynamic feedback patterns, and areas within the same soil type have similar dynamic feedback patterns. It was also found that the more similar the soil types, the more similar the feedback patterns. These findings could lead to the development of a new environmental covariate that could be used to improve the accuracy of soil snapping in low-relief areas

    Differentiation of Soil Conditions over Low Relief Areas Using Feedback Dynamic Patterns

    Full text link
    In many areas, such as plains and gently undulating terrain, easy-to-measure soil-firming factors such as landform and vegetation do not co-vary with soil conditions across space to the level that they can be effectively used in digital soil mapping. A challenging problem is how to develop a new environmental variable that co-varies with soil spatial variation under these situations. This study examined the idea that change patterns (dynamic feedback patterns) of the land surface, such as those captured daily by remote sensing images during a short period (6-7 d) after a major rain event, can be used to differentiate soil types. To examine this idea, we selected two study areas with different climates: one in northeastern China and the other in northwestern China. Images from the Moderate Resolution Imaging Spectroradiometer (MODIS) were used to capture land surface feedback, To measure feedback dynamics, we used spectral information divergence (SID). Results of an independent-samples t-test showed that there was a significant difference in SID values between pixel pairs of the same soil subgroup and those of different subgroups. This indicated that areas with different soil types (subgroup level) exhibited significantly different dynamic feedback patterns, and areas within the same soil type have similar dynamic feedback patterns. It was also found that the more similar the soil types, the more similar the feedback patterns. These findings could lead to the development of a new environmental covariate that could be used to improve the accuracy of soil mapping in low-relief areas. © Soil Science Society of America, 5585 Guilford Rd., Madison WI 53711 USA All rights reserved

    Palliative care for patients with glioma: A recent scientometric analysis of the Web of Science in 2022

    Get PDF
    BackgroundPatients with glioma present with complex palliative care needs throughout their disease trajectory. A scientometric analysis is effective and widely used to summarize the most influential studies within a certain field. We present the first scientometric analysis of palliative care for patients with glioma.MethodsBased on a Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) principle, we conducted a generalized search for articles on palliative care for glioma in the Web of Science database and evaluated the top 100 most frequently cited articles among 2,542 articles.ResultsThe number of citations for the top 100 cited articles on palliative care for glioma ranged from 10 to 223. We have a narrative conclusion, as follows: most of these articles were published in oncology-specific journals (n = 53) and palliative-specific journals (n = 22). The United States, Australia, and the Netherlands were the top three countries contributing most of the articles (n = 59). Most of the research methods were quantitative analyses, qualitative analyses, and systematic reviews and meta-analyses (n = 70). In quantitative studies, 66 scales were used, and the top three scales used included the following: the Distress Thermometer, Functional Assessment of Cancer Therapy-Brain Index (FACT-Br), and Karnofsky Performance Scale (KPS). The articles were classified into six major categories based on research subjects, including patients (n = 44), caregivers (n = 16), patients and caregivers (n = 20), literature (n = 19), and healthcare providers (n = 1). Articles were classified into seven major categories based on research themes: quality of life (n = 11); end-of-life symptoms and care (n = 16); palliative and supportive care needs (n = 35); advance care planning and decision making (n = 4); psychological, social, and spiritual needs (n = 12); hospice utilization and referral (n = 3); and others (n = 19). The studies of the primary topic are correlated with the number of citations.ConclusionsThe results of the analysis indicated that patients diagnosed with glioma present a high variety of palliative care needs, including physical, psychological, social, and spiritual needs. The caregiver’s burden and needs are important as well. The proportion of quantitative analyses, qualitative analyses, and systematic reviews and meta-analyses is relatively high, but the number of randomized controlled trials (RCTs) was low. End-of-life care and supportive care needs appeared frequently. Thus, palliative care is an urgent need to be addressed in glioma management. The appropriate scales should be selected for patients with glioma and meet their palliative needs

    Characterization of Membrane Permeability and Polymer-Stabilized Model Membranes

    No full text
    The permeability of lipid bilayer membranes to glucose and carboxyfluorescein has been studied in model membranes. Using an enzyme assay, the permeability of glucose was monitored spectrometrically with both large and giant unilamellar vesicles (LUVs and GUVs). The permeability of carboxyfluorescein was studied by entrapping the dye and monitoring its leakage over time from a single GUV. Permeability study using GUVs may provide new information that cannot be obtained from LUVs.The stability of lipid membranes was enhanced by incorporating polymer scaffold. LUVs were prepared with hydrophobic monomers partitioned and then polymerized inside the hydrophobic interior of the lipid bilayers. The sizes of the formed polymers were characterized using gel permeation chromatography and mass spectrometry. This study suggests that large molecular weight polymers were formed inside the lipid bilayers and that the stability of the membranes is related to the size of the polymers

    Effect of PBAT on Property of PLA/PHB Film Used for Fruits and Vegetables

    No full text
    A blend of poly(lactic acid) (PLA) (70% by weight) and poly(3-hydroxybutyrate) (PHB) (30% by weight) with a solubilizing agent (PBAT) at four different concentrations (5%, 10%, 15% and 20% by weight per 100 parts of the blends) were investigated by FTIR, SEM, mechanical testing, water vapor permeability test and biodegradation studies. SEM showed that PBAT can improve the compatibility between PLA and PHB. The film show a great Oxygen transmission rate and Water vapor permeability property when the content of PBAT is 10%
    • …
    corecore