Pressure-induced Superconductivity and Structure Phase Transition in SnAs-based Zintl Compound SrSn2As2

Layered SnAs-based Zintl compounds exhibit a distinctive electronic structure, igniting extensive research efforts in areas of superconductivity, topological insulators and quantum magnetism. In this paper, we systematically investigate the crystal structures and electronic properties of the Zintl compound SrSn2As2 under high-pressure. At approximately 20.8 GPa, pressure-induced superconductivity is observed in SrSn2As2 with a characteristic dome-like evolution of Tc. Theoretical calculations together with high pressure synchrotron X-ray diffraction and Raman spectroscopy have identified that SrSn2As2 undergoes a structural transformation from a trigonal to a monoclinic structure. Beyond 28.3 GPa, the superconducting transition temperature is suppressed due to a reduction of the density of state at the Fermi level. The discovery of pressure-induced superconductivity, accompanied by structural transitions in SrSn2As2, greatly expands the physical properties of layered SnAs-based compounds and provides a new ground states upon compression.Comment: 15 pages, 6 figures. arXiv admin note: text overlap with arXiv:2307.1562

Pressure-induced Superconductivity in Zintl Topological Insulator SrIn2As2

The Zintl compound AIn2X2 (A = Ca, Sr, and X = P, As), as a theoretically predicted new non-magnetic topological insulator, requires experiments to understand their electronic structure and topological characteristics. In this paper, we systematically investigate the crystal structures and electronic properties of the Zintl compound SrIn2As2 under both ambient and high-pressure conditions. Based on systematic angle-resolved photoemission spectroscopy (ARPES) measurements, we observed the topological surface states on its (001) surface as predicted by calculations, indicating that SrIn2As2 is a strong topological insulator. Interestingly, application of pressure effectively tuned the crystal structure and electronic properties of SrIn2As2. Superconductivity is observed in SrIn2As2 for pressure where the temperature dependence of the resistivity changes from a semiconducting-like behavior to that of a metal. The observation of nontrivial topological states and pressure-induced superconductivity in SrIn2As2 provides crucial insights into the relationship between topology and superconductivity, as well as stimulates further studies of superconductivity in topological materials.Comment: 15 pages,5 figure

Design, synthesis and biological evaluation of a novel colchicine-magnolol hybrid for inhibiting the growth of Lewis lung carcinoma in Vitro and in Vivo

Colchicine is a bioactive alkaloid originally from Colchicum autumnale and possesses excellent antiproliferative activity. However, colchicine-associated severe toxicity, gastrointestinal side effects in particular, limits its further therapeutic use. In the current study, we thus designed and synthesized a novel hybrid (CMH) by splicing colchicine and magnolol, a multifunctional polyphenol showing favorable gastrointestinal protection. The antitumor activity of CMH in Lewis lung carcinoma (LLC) was then evaluated in vitro and in vivo. Biologically, CMH inhibited the growth of LLC cells with an IC50 of 0.26 μM, 100 times more potently than cisplatin (26.05 μM) did. Meanwhile, the cytotoxicity of CMH was 10-fold lower than that of colchicine in normal human lung cells (BEAS-2B). In C57BL/6 mice xenograft model, CMH (0.5 mg/kg) worked as efficacious as colchicine (0.5 mg/kg) to inhibit tumor growth and 2 times more potently than cisplatin (1 mg/kg). In terms of mortality, 7 out of 10 mice died in colchicine group (0.75 mg/kg), while no death was observed in groups receiving CMH or cisplatin at 0.75 mg/kg. Mechanistic studies using Western blot revealed that CMH dose-dependently suppressed the protein expression of phosphorylated ERK. Molecular docking analysis further indicated that CMH was well fitted in the colchicine binding site of tubulin and formed several hydrogen bonds with tubulin protein. These results enable our novel hybrid CMH as a potential antineoplastic agent with lower toxicity, and provide perquisites for further investigation to confirm the therapeutic potentiality of this novel hybrid

Nanomedicine in cancer therapy

Abstract Cancer remains a highly lethal disease in the world. Currently, either conventional cancer therapies or modern immunotherapies are non-tumor-targeted therapeutic approaches that cannot accurately distinguish malignant cells from healthy ones, giving rise to multiple undesired side effects. Recent advances in nanotechnology, accompanied by our growing understanding of cancer biology and nano-bio interactions, have led to the development of a series of nanocarriers, which aim to improve the therapeutic efficacy while reducing off-target toxicity of the encapsulated anticancer agents through tumor tissue-, cell-, or organelle-specific targeting. However, the vast majority of nanocarriers do not possess hierarchical targeting capability, and their therapeutic indices are often compromised by either poor tumor accumulation, inefficient cellular internalization, or inaccurate subcellular localization. This Review outlines current and prospective strategies in the design of tumor tissue-, cell-, and organelle-targeted cancer nanomedicines, and highlights the latest progress in hierarchical targeting technologies that can dynamically integrate these three different stages of static tumor targeting to maximize therapeutic outcomes. Finally, we briefly discuss the current challenges and future opportunities for the clinical translation of cancer nanomedicines

Image_4_Glycerol-3-Phosphate Shuttle Is Involved in Development and Virulence in the Rice Blast Fungus Pyricularia oryzae.pdf

<p>The glycerol-3-phosphate (G-3-P) shuttle is an important pathway for delivery of cytosolic reducing equivalents into mitochondrial oxidative phosphorylation, and plays essential physiological roles in yeast, plants, and animals. However, its role has been unclear in filamentous and pathogenic fungi. Here, we characterize the function of the G-3-P shuttle in Pyricularia oryzae by genetic and molecular analyses. In P. oryzae, a glycerol-3-phosphate dehydrogenase 1 (PoGpd1) is involved in NO production, conidiation, and utilization of several carbon sources (pyruvate, sodium acetate, glutamate, and glutamine). A glycerol-3-phosphate dehydrogenase 2 (PoGpd2) is essential for glycerol utilization and fungal development. Deletion of PoGPD2 led to delayed aerial hyphal formation, accelerated aerial hyphal collapse, and reduced conidiation on complete medium (CM) under a light–dark cycle. Aerial mycelial surface hydrophobicity to water and Tween 20 was decreased in ΔPogpd2. Melanin synthesis genes required for cell wall construction and two transcription factor genes (COS1 and CONx2) required for conidiation and/or aerial hyphal differentiation were down-regulated in the aerial mycelia of ΔPogpd2 and ΔPogpd1. Culturing under continuous dark could complement the defects of aerial hyphal differentiation of ΔPogpd2 observed in a light–dark cycle. Two light-sensitive protein genes (PoSIR2 encoding an NAD⁺-dependent deacetylase and TRX2 encoding a thioredoxin 2) were up-regulated in ΔPogpd2 cultured on CM medium in a light–dark cycle. ΔPogpd2 showed an increased intracellular NAD⁺/NADH ratio and total NAD content, and alteration of intracellular ATP production. Culturing on minimal medium also could restore aerial hyphal differentiation of ΔPogpd2, which is deficient on CM medium in a light–dark cycle. Two glutamate synthesis genes, GDH1 and PoGLT1, which synthesize glutamate coupled with oxidation of NADH to NAD⁺, were significantly up-regulated in ΔPogpd2 in a light–dark cycle. Moreover, deletion of PoGpd1 or PoGpd2 led to reduced virulence of conidia or hyphae on rice. The glycerol-3-phosphate shuttle is involved in cellular redox, fungal development, and virulence in P. oryzae.</p

Glycerol-3-Phosphate Shuttle Is Involved in Development and Virulence in the Rice Blast Fungus Pyricularia oryzae

The glycerol-3-phosphate (G-3-P) shuttle is an important pathway for delivery of cytosolic reducing equivalents into mitochondrial oxidative phosphorylation, and plays essential physiological roles in yeast, plants, and animals. However, its role has been unclear in filamentous and pathogenic fungi. Here, we characterize the function of the G-3-P shuttle in Pyricularia oryzae by genetic and molecular analyses. In P. oryzae, a glycerol-3-phosphate dehydrogenase 1 (PoGpd1) is involved in NO production, conidiation, and utilization of several carbon sources (pyruvate, sodium acetate, glutamate, and glutamine). A glycerol-3-phosphate dehydrogenase 2 (PoGpd2) is essential for glycerol utilization and fungal development. Deletion of PoGPD2 led to delayed aerial hyphal formation, accelerated aerial hyphal collapse, and reduced conidiation on complete medium (CM) under a light–dark cycle. Aerial mycelial surface hydrophobicity to water and Tween 20 was decreased in ΔPogpd2. Melanin synthesis genes required for cell wall construction and two transcription factor genes (COS1 and CONx2) required for conidiation and/or aerial hyphal differentiation were down-regulated in the aerial mycelia of ΔPogpd2 and ΔPogpd1. Culturing under continuous dark could complement the defects of aerial hyphal differentiation of ΔPogpd2 observed in a light–dark cycle. Two light-sensitive protein genes (PoSIR2 encoding an NAD+-dependent deacetylase and TRX2 encoding a thioredoxin 2) were up-regulated in ΔPogpd2 cultured on CM medium in a light–dark cycle. ΔPogpd2 showed an increased intracellular NAD+/NADH ratio and total NAD content, and alteration of intracellular ATP production. Culturing on minimal medium also could restore aerial hyphal differentiation of ΔPogpd2, which is deficient on CM medium in a light–dark cycle. Two glutamate synthesis genes, GDH1 and PoGLT1, which synthesize glutamate coupled with oxidation of NADH to NAD+, were significantly up-regulated in ΔPogpd2 in a light–dark cycle. Moreover, deletion of PoGpd1 or PoGpd2 led to reduced virulence of conidia or hyphae on rice. The glycerol-3-phosphate shuttle is involved in cellular redox, fungal development, and virulence in P. oryzae

The Impact of Virtual Water on Sustainable Development in Gansu Province

The concept of virtual water, as a new approach for addressing water shortage and safety issues, can be applied to support sustainable development in water-scarce regions. Using the input-output method, the direct and the complete water use coefficients of industries categorized as primary, secondary, or tertiary, and the spatial flow patterns of the inter-provincial trade in the Gansu province region of China, were explored. The results show that in 2007, 2010, and 2012 the direct and complete water use coefficients of the primary industries were the greatest among the three industry categories, with direct water use coefficients of 1545.58, 882.28, and 762.16, respectively, and complete water use coefficients of 1692.22, 1005.38, and 873.44, respectively; whereas, the direct and complete water use coefficient values of the tertiary industry category were the lowest, with direct water use coefficients of 16.65, 7.74, and 66.89 for 2007, 2010, and 2012, respectively, and complete water use coefficients of 65.46, 66.89, and 72.81 for 2007, 2010, and 2012, respectively. In addition, study results suggest that the volume of virtual water supplied to Gasnu province&rsquo;s local industries has decreased annually, while virtual water exports from the province have increased annually, with the primary industry accounting for 95% of virtual water output. Overall, the virtual water of Gansu province in 2010 showed a net output trend, with a total output of 0.506 billion m3, while in 2007 and 2012 it showed a net input trend with a total input of 0.104 and 1.235 billion m3, respectively. Beijing, Shanghai, Guangdong, Ningxia and other water-scarce areas were the main input, or import source for Gansu&rsquo;s virtual water; during the years studied, these provinces imported more than 50 million m3 individually. Based on these results, it is clear that under the current structure, virtual water is mainly exported to the well-developed coastal areas and their adjacent provinces or other water-abundant regions. Therefore, Gansu province should (1) adjust the industrial structure and develop water-saving and high-tech industries; (2) adjust the current trade pattern to reduce virtual water output while increasing its input to achieve balanced economic development and water resource security

Small earthquakes in NE Kansas and their possible causes

During the past few years the geophysics group at Kansas State University (KSU) has installed and operated two transportable seismic arrays and a permanent seismic station in Kansas. One of the purposes of the experiments is to detect small earthquakes in the area, and another is to study the velocity and anisotropic structure of the crust and the mantle, aiming at finding a possible explanation for the occurrence of intraplate earthquakes in this area, which has experienced a few MMI 7 earthquakes since 1867. The first transportable experiment was conducted between June, 2000 and February, 2001. Eight broadband seismic stations were deployed along a 450-km-long, EW profile between Palco and Atchison, Kansas. The second transportable experiment took place between April and October, 2001, during which eight short-period stations were deployed along the periphery of an approximate circle with a radius of about 20 km, centered at Manhattan, KS. The permanent station is located on the KSU Konza Prairie Biological Research Station. So far it is the second permanent broadband seismic station in Kansas. While the data sets are still being analyzed, we have identified tens of small earthquakes, most of which have occurred in NE Kansas. In addition, by stacking P-to-S converted seismic waves from the the base of the crust, we have found that the crust beneath the Midcontinent rift (MCR) and the areas within about 120 km on each side of the rift axis is thickened by up to 12 km relative to the adjacent areas. The thickening was likely the result of the lateral compression during the closure of the MCR about 1.1 billion years ago. Based on previous data and our new crustal thickness measurement, we hypothesize that the long-lasting uplift of the Nemaha Ridge is the result of the uplift of the Moho toward isostatic balance. Such an uplift is possibly the ultimate cause of earthquakes in NE Kansas