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2. |
- Joseph, Christine G., et al.
(author)
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Exomic analysis of myxoid liposarcomas, synovial sarcomas, and osteosarcomas
- 2014
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In: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257. ; 53:1, s. 15-24
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Journal article (peer-reviewed)abstract
- Bone and soft tissue sarcomas are a group of histologically heterogeneous and relatively uncommon tumors. To explore their genetic origins, we sequenced the exomes of 13 osteosarcomas, eight myxoid liposarcomas (MLPS), and seven synovial sarcomas (SYN). These tumors had few genetic alterations (median of 10.8). Nevertheless, clear examples of driver gene mutations were observed, including canonical mutations in TP53, PIK3CA, SETD2, AKT1, and subclonal mutation in FBXW7. Of particular interest were mutations in H3F3A, encoding the variant histone H3.3. Mutations in this gene have only been previously observed in gliomas. Loss of heterozygosity of exomic regions was extensive in osteosarcomas but rare in SYN and MLPS. These results provide intriguing nucleotide-level information on these relatively uncommon neoplasms and highlight pathways that help explain their pathogenesis. (c) 2013 Wiley Periodicals, Inc.
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3. |
- Killela, Patrick J., et al.
(author)
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TERT promoter mutations occur frequently in gliomas and a subset of tumors derived from cells with low rates of self-renewal
- 2013
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In: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 110:15, s. 6021-6026
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Journal article (peer-reviewed)abstract
- Malignant cells, like all actively growing cells, must maintain their telomeres, but genetic mechanisms responsible for telomere maintenance in tumors have only recently been discovered. In particular, mutations of the telomere binding proteins alpha thalassemia/mental retardation syndrome X-linked (ATRX) or death-domain associated protein (DAXX) have been shown to underlie a telomere maintenance mechanism not involving telomerase (alternative lengthening of telomeres), and point mutations in the promoter of the telomerase reverse transcriptase (TERT) gene increase telomerase expression and have been shown to occur in melanomas and a small number of other tumors. To further define the tumor types in which this latter mechanism plays a role, we surveyed 1,230 tumors of 60 different types. We found that tumors could be divided into types with low (<15%) and high (>= 15%) frequencies of TERT promoter mutations. The nine TERT-high tumor types almost always originated in tissues with relatively low rates of self renewal, including melanomas, liposarcomas, hepatocellular carcinomas, urothelial carcinomas, squamous cell carcinomas of the tongue, medulloblastomas, and subtypes of gliomas (including 83% of primary glioblastoma, the most common brain tumor type). TERT and ATRX mutations were mutually exclusive, suggesting that these two genetic mechanisms confer equivalent selective growth advantages. In addition to their implications for understanding the relationship between telomeres and tumorigenesis, TERT mutations provide a biomarker that may be useful for the early detection of urinary tract and liver tumors and aid in the classification and prognostication of brain tumors.
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4. |
- Kumar, Varun, et al.
(author)
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Highly time-resolved chemical speciation and source apportionment of organic aerosol components in Delhi, India, using extractive electrospray ionization mass spectrometry
- 2022
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In: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 22:11, s. 7739-7761
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Journal article (peer-reviewed)abstract
- In recent years, the Indian capital city of Delhi has been impacted by very high levels of air pollution, especially during winter. Comprehensive knowledge of the composition and sources of the organic aerosol (OA), which constitutes a substantial fraction of total particulate mass (PM) in Delhi, is central to formulating effective public health policies. Previous source apportionment studies in Delhi identified key sources of primary OA (POA) and showed that secondary OA (SOA) played a major role but were unable to resolve specific SOA sources. We address the latter through the first field deployment of an extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF) in Delhi, together with a high-resolution aerosol mass spectrometer (AMS). Measurements were conducted during the winter of 2018/19, and positive matrix factorization (PMF) was used separately on AMS and EESI-TOF datasets to apportion the sources of OA. AMS PMF analysis yielded three primary and two secondary factors which were attributed to hydrocarbon-like OA (HOA), biomass burning OA (BBOA-1 and BBOA-2), more oxidized oxygenated OA (MO-OOA), and less oxidized oxygenated OA (LO-OOA). On average, 40 % of the total OA mass was apportioned to the secondary factors. The SOA contribution to total OA mass varied greatly between the daytime (76.8 %, 10:00–16:00 local time (LT)) and nighttime (31.0 %, 21:00–04:00 LT). The higher chemical resolution of EESI-TOF data allowed identification of individual SOA sources. The EESI-TOF PMF analysis in total yielded six factors, two of which were primary factors (primary biomass burning and cooking-related OA). The remaining four factors were predominantly of secondary origin: aromatic SOA, biogenic SOA, aged biomass burning SOA, and mixed urban SOA. Due to the uncertainties in the EESI-TOF ion sensitivities, mass concentrations of EESI-TOF SOA-dominated factors were related to the total AMS SOA (i.e. MO-OOA + LO-OOA) by multiple linear regression (MLR). Aromatic SOA was the major SOA component during the daytime, with a 55.2 % contribution to total SOA mass (42.4 % contribution to total OA). Its contribution to total SOA, however, decreased to 25.4 % (7.9 % of total OA) during the nighttime. This factor was attributed to the oxidation of light aromatic compounds emitted mostly from traffic. Biogenic SOA accounted for 18.4 % of total SOA mass (14.2 % of total OA) during the daytime and 36.1 % of total SOA mass (11.2 % of total OA) during the nighttime. Aged biomass burning and mixed urban SOA accounted for 15.2 % and 11.0 % of total SOA mass (11.7 % and 8.5 % of total OA mass), respectively, during the daytime and 15.4 % and 22.9 % of total SOA mass (4.8 % and 7.1 % of total OA mass), respectively, during the nighttime. A simple dilution–partitioning model was applied on all EESI-TOF factors to estimate the fraction of observed daytime concentrations resulting from local photochemical production (SOA) or emissions (POA). Aromatic SOA, aged biomass burning, and mixed urban SOA were all found to be dominated by local photochemical production, likely from the oxidation of locally emitted volatile organic compounds (VOCs). In contrast, biogenic SOA was related to the oxidation of diffuse regional emissions of isoprene and monoterpenes. The findings of this study show that in Delhi, the nighttime high concentrations are caused by POA emissions led by traffic and biomass burning and the daytime OA is dominated by SOA, with aromatic SOA accounting for the largest fraction. Because aromatic SOA is possibly more toxic than biogenic SOA and primary OA, its dominance during the daytime suggests an increased OA toxicity and health-related consequences for the general public.
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5. |
- Svensson, Charlotte, et al.
(author)
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REST mediates androgen receptor actions on gene repression and predicts early recurrence of prostate cancer.
- 2014
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In: Nucleic Acids Research. - : Oxford University Press (OUP). - 1362-4962 .- 0305-1048. ; 42:2, s. 999-1015
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Journal article (peer-reviewed)abstract
- The androgen receptor (AR) is a key regulator of prostate tumorgenesis through actions that are not fully understood. We identified the repressor element (RE)-1 silencing transcription factor (REST) as a mediator of AR actions on gene repression. Chromatin immunoprecipitation showed that AR binds chromatin regions containing well-characterized cis-elements known to mediate REST transcriptional repression, while cell imaging studies confirmed that REST and AR closely co-localize in vivo. Androgen-induced gene repression also involves modulation of REST protein turnover through actions on the ubiquitin ligase β-TRCP. Androgen deprivation or AR blockage with inhibitor MDV3100 (Enzalutamide) leads to neuroendocrine (NE) differentiation, a phenomenon that is mimicked by REST inactivation. Gene expression profiling revealed that REST not only acts to repress neuronal genes but also genes involved in cell cycle progression, including Aurora Kinase A, that has previously been implicated in the growth of NE-like castration-resistant tumors. The analysis of prostate cancer tissue microarrays revealed that tumors with reduced expression of REST have higher probability of early recurrence, independently of their Gleason score. The demonstration that REST modulates AR actions in prostate epithelia and that REST expression is negatively correlated with disease recurrence after prostatectomy, invite a deeper characterization of its role in prostate carcinogenesis.
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6. |
- Tong, Chuan, et al.
(author)
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Annual CO2 and CH4 fluxes in coastal earthen ponds with Litopenaeus vannamei in southeastern China
- 2021
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In: Aquaculture. - : ELSEVIER. - 0044-8486 .- 1873-5622. ; 545
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Journal article (peer-reviewed)abstract
- Small-scale aquaculture operation is being increasing practised around the world, particularly in the developing countries, but the greenhouse gas (GHG) dynamics and fluxes from small aquaculture ponds are still poorly assessed. In this study, the dissolved concentrations and fluxes of CO2 and CH4 were determined in three coastal earthen shrimp ponds over one whole year, covering both the farming and non-farming periods, in the Min River Estuary, southeastern China. Both ebullitive and diffusive CH4 fluxes were measured, which were rarely done in previous studies. The average concentrations of dissolved CO2 and CH4 in water column in the farming period varied between 18.1 +/- 0.1 and 79.6 +/- 1.1 mu mol L-1, and 1.3 +/- 0.1 and 55.9 +/- 3.2 mu mol L-1, respectively. When averaged across the whole year, the mean CO2 and CH4 fluxes from the ponds were - 18.4 +/- 7.4 and 22.6 +/- 6.9 mg m- 2 h-1, respectively, suggesting that the shrimp ponds acted as a CO2 sink and a CH4 source. Based on the sustained-flux global warming potential (SGWP) and sustained-flux global cooling potential (SGCP) models, the annual warming potential was estimated to be 7.1 x 103 g CO2-eq m- 2 yr- 1, with approximately 90% of this arising from the farming period. Ebullition was the dominant emission pathway for CH4, accounting for over 90% of the total CH4 emission during the farming period. This full-year study improves our understanding of carbon cycling in coastal aquaculture ponds and provides a scientific basis for updating the GHG inventories.
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7. |
- Wang, Cheng-Xiang, et al.
(author)
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On the Road to 6G: Visions, Requirements, Key Technologies, and Testbeds
- 2023
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In: IEEE Communications Surveys and Tutorials. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1553-877X. ; 25:2, s. 905-974
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Journal article (peer-reviewed)abstract
- Fifth generation (5G) mobile communication systems have entered the stage of commercial deployment, providing users with new services, improved user experiences as well as a host of novel opportunities to various industries. However, 5G still faces many challenges. To address these challenges, international industrial, academic, and standards organizations have commenced research on sixth generation (6G) wireless communication systems. A series of white papers and survey papers have been published, which aim to define 6G in terms of requirements, application scenarios, key technologies, etc. Although ITU-R has been working on the 6G vision and it is expected to reach a consensus on what 6G will be by mid-2023, the related global discussions are still wide open and the existing literature has identified numerous open issues. This paper first provides a comprehensive portrayal of the 6G vision, technical requirements, and application scenarios, covering the current common understanding of 6G. Then, a critical appraisal of the 6G network architecture and key technologies is presented. Furthermore, existing testbeds and advanced 6G verification platforms are detailed for the first time. In addition, future research directions and open challenges are identified to stimulate the on-going global debate. Finally, lessons learned to date concerning 6G networks are discussed.
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8. |
- Yang, Ping, et al.
(author)
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Dynamics of dissolved nutrients in the aquaculture shrimp ponds of the Min River estuary, China: Concentrations, fluxes and environmental loads
- 2017
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In: Science of the Total Environment. - : ELSEVIER SCIENCE BV. - 0048-9697 .- 1879-1026. ; 603, s. 256-267
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Journal article (peer-reviewed)abstract
- Dissolved inorganic nutrients (NO2--N, NO3--N, NH4+-N, and PO43--P) play a critical role in the effective management ofwater quality and prevention of fish and shrimp diseases in aquaculture systems. In this study, dissolved inorganic nutrient concentrations in the water column and sediment porewater, and the fluxes across the sediment-water interface (SWI) were investigated in three intensive shrimp ponds with zero water exchange to examine nutrient cycling during the different growth stages of shrimps. Distinct changes in the dissolved inorganic nutrient concentrations in both the water column and sediment porewater were observed among the three growth stages. Average NO2--N, NO3--N, NH4+-N, and PO43--P concentrations in the sediment porewater were 3.53, 2.81, 29.68, and 6.44 times higher, respectively, than those in the water column over the study period, indicating that the pond sediment acted as a net source of nutrients to the water column. This was further supported by the net release of nutrients from the sediments to the water column observed during the incubation experiment. Nutrient fluxes were dominated by NH4+-N, while NOx--N (NO2--N and NO3--N) and PO43--P fluxes remained low. The high rates of NH4+-N release from the sediment highlight the need of taking into account the biogeochemical role of sediments in mitigating the problem of water quality degradation in coastal shrimp ponds. Based on a total water surface area of mariculture ponds and a total mariculture production of 2.57 x 10(6) ha and 2.30 x 10(9) kg, respectively, we estimated conservatively that approximately 4.77 x 10(4) tons of total nitrogen and 3.75 x 10(3) tons of total phosphorus are being discharged annually from the mariculture ponds into the adjacent coastal zones across China. Results demonstrated the importance of aquaculture pond effluent as amajor contributor ofwater pollution in the coastal areas of China, and called for actions to properly treat these effluents in alleviating the eutrophication problem in the Chinese coastal zones. (C) 2017 Elsevier B.V. All rights reserved.
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9. |
- Yang, Ping, et al.
(author)
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Large increase in diffusive greenhouse gas fluxes from subtropical shallow aquaculture ponds during the passage of typhoons
- 2020
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In: Journal of Hydrology. - : ELSEVIER. - 0022-1694 .- 1879-2707. ; 583
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Journal article (peer-reviewed)abstract
- Tropical cyclones are extreme perturbations that can affect the biogeochemical cycles in tropical and temperate coastal ecosystems. Yet, whether typhoon events would affect the magnitude of greenhouse gas (GHG) emissions from shallow aquaculture ponds in the subtropical coastal regions is still poorly understood. In this study, we estimated and compared the diffusive fluxes of CO2, CH4, and N2O in the mariculture ponds at a subtropical estuary in southeast China before, during, and after the passage of three typhoons. Our results indicate that the average diffusive CO2, CH4, and N2O fluxes during typhoon passage were one to two orders of magnitude higher than those observed during both the pre-typhoon and post-typhoon periods. We estimated conservatively that the estuarine aquaculture ponds emitted GHGs at a rate of about 3145 mg CO2-eq m(-2) h(-1) into the atmosphere during the passage of typhoons, which was substantially higher than the average emission rates of 30.8 and 35.2 mg CO2-eq m(-2) h(-1) observed during the pre- and post-typhoon periods, respectively. Our findings demonstrated that the typhoon passage period can be a hot moment of GHG emissions from aquaculture ponds in the subtropical estuaries, and highlight the importance of capturing short-term disturbance events such as typhoons to accurately assess the annual GHG balance and hence the climatic impacts on these shallow water ecosystems.
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10. |
- You, Xiaohu, et al.
(author)
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Towards 6G wireless communication networks: vision, enabling technologies, and new paradigm shifts
- 2021
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In: Science China Information Sciences. - : Science Press. - 1674-733X .- 1869-1919. ; 64:1
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Research review (peer-reviewed)abstract
- The fifth generation (5G) wireless communication networks are being deployed worldwide from 2020 and more capabilities are in the process of being standardized, such as mass connectivity, ultra-reliability, and guaranteed low latency. However, 5G will not meet all requirements of the future in 2030 and beyond, and sixth generation (6G) wireless communication networks are expected to provide global coverage, enhanced spectral/energy/cost efficiency, better intelligence level and security, etc. To meet these requirements, 6G networks will rely on new enabling technologies, i.e., air interface and transmission technologies and novel network architecture, such as waveform design, multiple access, channel coding schemes, multi-antenna technologies, network slicing, cell-free architecture, and cloud/fog/edge computing. Our vision on 6G is that it will have four new paradigm shifts. First, to satisfy the requirement of global coverage, 6G will not be limited to terrestrial communication networks, which will need to be complemented with non-terrestrial networks such as satellite and unmanned aerial vehicle (UAV) communication networks, thus achieving a space-air-ground-sea integrated communication network. Second, all spectra will be fully explored to further increase data rates and connection density, including the sub-6 GHz, millimeter wave (mmWave), terahertz (THz), and optical frequency bands. Third, facing the big datasets generated by the use of extremely heterogeneous networks, diverse communication scenarios, large numbers of antennas, wide bandwidths, and new service requirements, 6G networks will enable a new range of smart applications with the aid of artificial intelligence (AI) and big data technologies. Fourth, network security will have to be strengthened when developing 6G networks. This article provides a comprehensive survey of recent advances and future trends in these four aspects. Clearly, 6G with additional technical requirements beyond those of 5G will enable faster and further communications to the extent that the boundary between physical and cyber worlds disappears.
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