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"Zhang, Guo-Jun"
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سرقة فاكهة الجينسنغ
في بداية العالم عم الظلام الكون في الفترة التي سميت بـ «الفوضى الأزلية». وبعد مرور 5400 عام، طارت المواد الخفيفة إلى السماء وتحولت إلى الشمس والقمر والنجوم والأجرام الفلكية، وبعد 5400 عام أخرى تجمدت المواد الثقيلة وكونت المياه والنار والجبال والصخور والتربة، وبمرور 5400 عام أخرى وجدت الحياة على الأرض وانقسم العالم إلى أربع قارات الشرقية والغربية والجنوبية والشمالية، وفي القارة الشرقية كان هناك جبل يسمى جبل الأزهار والثمار على قمته صخرة خالدة، تعرضت الصخرة لضوء الشمس والقمر فاكتسبت قدرات خارقة، إلى أن انفجرت وجلبت الفوضى للعالم. وبعد أكثر من 500 كلف راهب من القارة الجنوبية بإحضار الكتب المقدسة من القارة عام الغربية للقضاء على الكوارث والآلام في العالم، ولم تنجح رحلته إلا بعد أن مر بعقبات بلغ عددها 81 عقبة. وترتبط هذه الأسطورة ارتباطا وثيقا بشخصية «القرد» الذي تجرأ وأعلن تمرده على السماء والأرض.
Book
High-entropy pyrochlores with low thermal conductivity for thermal barrier coating materials
High-entropy pyrochlore-type structures based on rare-earth zirconates are successfully produced by conventional solid-state reaction method. Six rare-earth oxides (La
2
O
3
, Nd
2
O
3
, Sm
2
O
3
, Eu
2
O
3
, Gd
2
O
3
, and Y
2
O
3
) and ZrO
2
are used as the raw powders. Five out of the six rare-earth oxides with equimolar ratio and ZrO
2
are mixed and sintered at different temperatures for investigating the reaction process. The results demonstrate that the high-entropy pyrochlores (5RE
1/5
)
2
Zr
2
O
7
have been formed after heated at 1000°C. The (5RE
1/5
)
2
Zr
2
O
7
are highly sintering resistant and possess excellent thermal stability. The thermal conductivities of the (5RE
1/5
)
2
Zr
2
O
7
high-entropy ceramics are below 1 W·m
–1
·K
–1
in the temperature range of 300–1200°C. The (5RE
1/5
)
2
Zr
2
O
7
can be potential thermal barrier coating materials.
Journal Article
Advances in ultra-high temperature ceramics, composites, and coatings
Ultra-high temperature ceramics (UHTCs) are generally referred to the carbides, nitrides, and borides of the transition metals, with the Group IVB compounds (Zr & Hf) and TaC as the main focus. The UHTCs are endowed with ultra-high melting points, excellent mechanical properties, and ablation resistance at elevated temperatures. These unique combinations of properties make them promising materials for extremely environmental structural applications in rocket and hypersonic vehicles, particularly nozzles, leading edges, and engine components, etc. In addition to bulk UHTCs, UHTC coatings and fiber reinforced UHTC composites are extensively developed and applied to avoid the intrinsic brittleness and poor thermal shock resistance of bulk ceramics. Recently, highentropy UHTCs are developed rapidly and attract a lot of attention as an emerging direction for ultra-high temperature materials. This review presents the state of the art of processing approaches, microstructure design and properties of UHTCs from bulk materials to composites and coatings, as well as the future directions.
Journal Article
A high entropy silicide by reactive spark plasma sintering
A high-entropy silicide (HES), (Ti
0.2
Zr
0.2
Nb
0.2
Mo
0.2
W
0.2
)Si
2
with close-packed hexagonal structure is successfully manufactured through reactive spark plasma sintering at 1300 °C for 15 min. The elements in this HES are uniformly distributed in the specimen based on the energy dispersive spectrometer analysis except a small amount of zirconium that is combined with oxygen as impurity particles. The Young’s modulus, Poisson’s ratio, and Vickers hardness of the obtained (Ti
0.2
Zr
0.2
Nb
0.2
Mo
0.2
W
0.2
)Si
2
are also measured.
Journal Article
Molecular and functional imaging in cancer-targeted therapy: current applications and future directions
Targeted anticancer drugs block cancer cell growth by interfering with specific signaling pathways vital to carcinogenesis and tumor growth rather than harming all rapidly dividing cells as in cytotoxic chemotherapy. The Response Evaluation Criteria in Solid Tumor (RECIST) system has been used to assess tumor response to therapy via changes in the size of target lesions as measured by calipers, conventional anatomically based imaging modalities such as computed tomography (CT), and magnetic resonance imaging (MRI), and other imaging methods. However, RECIST is sometimes inaccurate in assessing the efficacy of targeted therapy drugs because of the poor correlation between tumor size and treatment-induced tumor necrosis or shrinkage. This approach might also result in delayed identification of response when the therapy does confer a reduction in tumor size. Innovative molecular imaging techniques have rapidly gained importance in the dawning era of targeted therapy as they can visualize, characterize, and quantify biological processes at the cellular, subcellular, or even molecular level rather than at the anatomical level. This review summarizes different targeted cell signaling pathways, various molecular imaging techniques, and developed probes. Moreover, the application of molecular imaging for evaluating treatment response and related clinical outcome is also systematically outlined. In the future, more attention should be paid to promoting the clinical translation of molecular imaging in evaluating the sensitivity to targeted therapy with biocompatible probes. In particular, multimodal imaging technologies incorporating advanced artificial intelligence should be developed to comprehensively and accurately assess cancer-targeted therapy, in addition to RECIST-based methods.
Journal Article
Mechanical properties of hot-pressed high-entropy diboride-based ceramics
High-entropy ceramics attract more and more attention in recent years. However, mechanical properties especially strength and fracture toughness for high-entropy ceramics and their composites have not been comprehensively reported. In this work, high-entropy (Ti
0.2
Zr
0.2
Hf
0.2
Nb
0.2
Ta
0.2
)B
2
(HEB) monolithic and its composite containing 20 vol% SiC (HEB–20SiC) are prepared by hot pressing. The addition of SiC not only accelerates the densification process but also refines the microstructure of HEB, resulting in improved mechanical properties. The obtained dense HEB and HEB–20SiC ceramics hot pressed at 1800 ℃ exhibit four-point flexural strength of 339±17 MPa and 447±45 MPa, and fracture toughness of 3.81±0.40 MPa·m
1/2
and 4.85±0.33 MPa·m
1/2
measured by single-edge notched beam (SENB) technique. Crack deflection and branching by SiC particles is considered to be the main toughening mechanisms for the HEB–20SiC composite. The hardness
Hv
0.2
of the sintered HEB and HEB–20SiC ceramics is 23.7±0.7 GPa and 24.8±1.2 GPa, respectively. With the increase of indentation load, the hardness of the sintered ceramics decreases rapidly until the load reaches about 49 N, due to the indentation size effect. Based on the current experimental investigation it can be seen that the room temperature bending strength and fracture toughness of the high-entropy diboride ceramics are within ranges commonly observed in structure ceramics.
Journal Article
Sol-gel derived porous ultra-high temperature ceramics
Ultra-high temperature ceramics (UHTCs) are considered as a family of nonmetallic and inorganic materials that have melting point over 3000 °C. Chemically, nearly all UHTCs are borides, carbides, and nitrides of early transition metals (e.g., Zr, Hf, Nb, Ta). Within the last two decades, except for the great achievements in the densification, microstructure tailoring, and mechanical property improvements of UHTCs, many methods have been established for the preparation of porous UHTCs, aiming to develop high-temperature resistant, sintering resistant, and lightweight materials that will withstand temperatures as high as 2000 °C for long periods of time. Amongst the synthesis methods for porous UHTCs, sol-gel methods enable the preparation of porous UHTCs with pore sizes from 1 to 500 urn and porosity within the range of 60%-95% at relatively low temperature. In this article, we review the currently available sol-gel methods for the preparation of porous UHTCs. Templating, foaming, and solvent evaporation methods are described and compared in terms of processing-microstructure relations. The properties and high temperature resistance of sol-gel derived porous UHTCs are discussed. Finally, directions to future investigations on the processing and applications of porous UHTCs are proposed.
Journal Article
Interleukin-33 in Malignancies: Friends or Foes?
The human Interleukin-33 (IL-33), a member of the IL-1 family, is the cytokine as a cell endogenous alarmin, released by damaged or necrotic barrier cells (endothelial and epithelial cells). The signal transduction of IL-33 relies on recognition and interaction with specific receptor ST2, mainly expressed in immune cells. In both innate and adoptive immunity, IL-33 regulates the homeostasis in response to stress from within/out the microenvironment. Various, even negative biofunctions of IL-33 pathways have now been widely verified in pathogenesis among immunological mechanisms, like Th2-related immune-stimuli, inflammation/infection-induced tissue protectors. A larger versatility in studies of IL-33 on malignancies now focuses on: (1) promoting myeloid-derived suppressor cells (MDSC), (2) intervention toward CD8
T, Natural Killer (NK) cell infiltration, group 2 innate lymphoid cells (ILC2) proliferation, dendritic cells (DC) activation, and (3) inhibiting tumor growth and/or further metastasis as an immunoadjuvant. Although IL-33 functioned pro-tumorigenically in various cancers, for some cancer types the findings so far are controversial. This review begins from a summarized introduction of IL-33, to its remarkable implications and molecular transduction pathway in malignant neoplasms, ends with latest inspiration for IL-33 in treatment.
Journal Article
Implementation and benchmarking of a novel analytical framework to clinically evaluate tumor-specific fluorescent tracers
During the last decade, the emerging field of molecular fluorescence imaging has led to the development of tumor-specific fluorescent tracers and an increase in early-phase clinical trials without having consensus on a standard methodology for evaluating an optical tracer. By combining multiple complementary state-of-the-art clinical optical imaging techniques, we propose a novel analytical framework for the clinical translation and evaluation of tumor-targeted fluorescent tracers for molecular fluorescence imaging which can be used for a range of tumor types and with different optical tracers. Here we report the implementation of this analytical framework and demonstrate the tumor-specific targeting of escalating doses of the near-infrared fluorescent tracer bevacizumab-800CW on a macroscopic and microscopic level. We subsequently demonstrate an 88% increase in the intraoperative detection rate of tumor-involved margins in primary breast cancer patients, indicating the clinical feasibility and support of future studies to evaluate the definitive clinical impact of fluorescence-guided surgery.
Fluorescent tracers are being tested in clinical trials to improve detection of tumor margins, but procedures are not standardised. Here, the authors develop an analytical framework that is compatible with the workflow in the operating theatre, and show that it leads to an 88% increase in intraoperative detection of tumor margins in patients with breast cancer.
Journal Article
Nuclear Integrants of Organellar DNA Contribute to Genome Structure and Evolution in Plants
The transfer of genetic material from the mitochondria and plastid to the nucleus gives rise to nuclear integrants of mitochondrial DNA (NUMTs) and nuclear integrants of plastid DNA (NUPTs). This frequently occurring DNA transfer is ongoing and has important evolutionary implications. In this review, based on previous studies and the analysis of NUMT/NUPT insertions of more than 200 sequenced plant genomes, we analyzed and summarized the general features of NUMTs/NUPTs and highlighted the genetic consequence of organellar DNA insertions. The statistics of organellar DNA integrants among various plant genomes revealed that organellar DNA-derived sequence content is positively correlated with the nuclear genome size. After integration, the nuclear organellar DNA could undergo different fates, including elimination, mutation, rearrangement, fragmentation, and proliferation. The integrated organellar DNAs play important roles in increasing genetic diversity, promoting gene and genome evolution, and are involved in sex chromosome evolution in dioecious plants. The integrating mechanisms, involving non-homologous end joining at double-strand breaks were also discussed.
Journal Article