Topological sound

Recently, we witnessed a tremendous effort to conquer the realm of acoustics as a possible playground to test with topologically protected sound wave propagation. In this article, we review the latest efforts to explore with sound waves topological states of quantum matter in two- and three-dimensional systems where we discuss how spin and valley degrees of freedom appear as highly novel ingredients to tailor the flow of sound in the form of one-way edge modes and defect-immune protected acoustic waves. Both from a theoretical stand point and based on contemporary experimental verifications, we summarize the latest advancements of the flourishing research frontier on topological sound.X.J.Z. and L.M.H. are supported by the National Natural Science Foundation of China (Grant No. 11625418 and No. 51732006). M.X. is supported by the U. S. National Science Foundation (Grant No. CBET-1641069). Y.C. acknowledges the support from the National Natural Science Foundation of China (NSFC) (Grant Nos. 11834008,11874215, 11674172, and 11574148) and from the National Basic Research Program of China (Grant No. 2017YFA0303702). J.C. acknowledges the support from the European Research Council (ERC) through the Starting Grant No. 714577 PHONOMETA and from the MINECO through a Ramón y Cajal grant (Grant No. RYC-2015-17156

tert-Butyl 6-amino-3,4-dihydro-2H-1,4-benzoxazine-4-carboxyl­ate

The title mol­ecule, C13H18N2O3, contains a benzene ring fused to an oxazine ring and one tert-but­oxy­carbonyl group bound to the N atom of the oxazine ring. A weak intra­molecular C—H⋯O inter­action occurs. In the crystal, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds stack the mol­ecules down the b axis. Weak C—H⋯N contacts connect the stacks, generating a three-dimensional network

Disruption of Smad4 impairs TGF-β/Smad3 and Smad7 transcriptional regulation during renal inflammation and fibrosis in vivo and in vitro

The mechanism by which TGF-β regulates renal inflammation and fibrosis is largely unclear; however, it is well accepted that its biological effects are mediated through Smad2 and Smad3 phosphorylation. Following activation, these Smads form heteromeric complex with Smad4 and translocate into the nucleus to bind and regulate the expression of target genes. Here we studied the roles of Smad4 to regulate TGF-β signaling in a mouse model of unilateral ureteral obstruction using conditional Smad4 knockout mice and in isolated Smad4 mutant macrophages and fibroblasts. Disruption of Smad4 significantly enhanced renal inflammation as evidenced by a greater CD45+ leukocyte and F4/80+ macrophage infiltration and upregulation of IL-1β, TNF-α, MCP-1, and ICAM-1 in the obstructed kidney and in IL-1β-stimulated macrophages. In contrast, deletion of Smad4 inhibited renal fibrosis and TGF-β1-induced collagen I expression by fibroblasts. Further studies showed that the loss of Smad4 repressed Smad7 transcription, leading to a loss of functional protein. This, in turn, inhibited IκBα expression but enhanced NF-κB activation, thereby promoting renal inflammation. Interestingly, deletion of Smad4 influenced Smad3-mediated promoter activities and the binding of Smad3 to the COL1A2 promoter, but not Smad3 phosphorylation and nuclear translocation, thereby inhibiting the fibrotic response. Thus, Smad4 may be a key regulator for the diverse roles of TGF-β1 in inflammation and fibrogenesis by interacting with Smad7 and Smad3 to influence their transcriptional activities in renal inflammation and fibrosis

The effects of Solidago canadensis water extracts on maize seedling growth in association with the biomass allocation pattern

Background Solidago canadensis L. is an aggressive exotic plant species in China that has potential allelopathic effects on competing plant species. Effects of hormesis are frequently observed in studies of allelopathy; however, the mechanisms of such effects need to be elucidated. Allelopathic compounds may affect the growth of recipient plants via alteration of biomass allocation patterns or photosynthetic capacity. The aim of this study was to determine how water extracts from S. canadensis affected the shoot and root growth of recipient plants and whether the underlying mechanism was related to the biomass allocation pattern or photosynthetic gas exchange capacity. Methods The water extracts from S. canadensis shoots at 12 different concentrations in the range of 0–0.25 g/ml were applied thrice in 9 days to maize seedlings cultivated in silica sand. The growth (shoot height, leaf length and area and root length) and biomass accumulation and allocation (specific leaf area (SLA), leaf area ratio (LAR) and leaf mass ratio (LMR)) were compared among maize seedlings exposed to different treatment concentrations. Gas exchange (photosynthetic light response curve) was measured and compared among maize seedlings exposed to three concentrations of water extract (0, 0.0125 and 0.2 g/ml) before and after the first application, and seedling growth was measured after the third and final application. Results The growth of seedlings (shoot height, leaf length and area and root length) was promoted at concentrations below 0.125 g/ml and inhibited at concentrations above this level (P 0.05). The water extract treatments did not significantly affect the photosynthetic capacity (P > 0.05), but the dark respiration rate was higher in the low-dose treatment than that in the high-dose treatment. Shoot height was positively correlated with the biomass allocation indicators SLA and LAR (P 0.05). Conclusions The results suggested that the effects of the water extracts from S. canadensis were highly dependent on the concentration, with the growth of maize seedlings promoted at low concentrations of water extracts. The effects of the water extracts on the growth of maize seedlings were mainly due to the effects on the LAR, the allocation to leaf area growth, whereas the effects of the water extracts on leaf gas exchange capacity cannot explain variation of seedling growth. Thus, the stimulation of plant growth was very likely due to increased biomass allocation towards the shoot

Optimiranje podloge za uzgoj i sastava aminokiselina u miceliju gljive Pleurotus cornucopiae SD-01 obogaćenog kromom

Chromium(III) is an essential trace element for humans and animals. Pleutorus cornucopiae SD-01 is a nutritional and functional mushroom containing many kinds of bioactive ingredients. The aims of this work are to optimize the conditions of P. cornucopiae SD-01 cultivation with Cr enrichment in submerged culture by determining the dry cell mass, Cr content in mycelia and the rate of Cr enrichment, and to analyze the amino acid composition of Cr-enriched mycelia. The optimal medium contained (in g/L): potato 200, sucrose 25, yeast extract 4, KH2PO4 1 and MgSO4·7H2O 1. The optimum parameters of liquid culture were temperature 25 °C, cultivation time 6 days, the volume of the medium 100 mL, rotation speed 160 rpm and initial pH=6.5. Under the optimized conditions, the values of the dry cell mass, Cr content in mycelia and the rate of Cr enrichment were (6.63±0.35) g/L, (3670±211) μg/g and (12.15±1.01) % respectively, which were by (23.23±1.22), (18.19±1.06) and (45.68±2.67) % respectively, higher than those in the control. Chromium(III) in Cr-enriched mycelia was mainly combined with protein and polysaccharide. The contents of total amino acids and essential amino acids in Cr-enriched mycelia were increased by (31.25±0.58) and (44.26±0.76) %, respectively.Trovalentni je krom esencijalni element u tragovima, potreban za rast ljudi i životinja. Pleurotus cornucopiae SD-01 hranjiva je gljiva funkcionalnih svojstava, koja sadrži mnoge bioaktivne komponente. Svrha je ovoga rada bila optimirati uvjete uzgoja P. cornucopiae SD-01 u podlozi obogaćenoj kromom, i to određivanjem suhe stanične mase, udjela kroma u miceliju i stupnja obogaćivanja micelija, te analizirati aminokiselinski sastav micelija obogaćenog kromom. Optimalni sastav podloge bio je (u g/L): krumpir 200, saharoza 25, kvaščev ekstrakt 4, KH2PO4 1 i MgSO4·7H2O 1. Utvrđeni su optimalni parametri rasta: temperatura 25 °C, vrijeme uzgoja 6 dana, volumen podloge 100 mL, brzina rotacije 160 rpm i početni pH=6,5. U tim su uvjetima dobivene sljedeće vrijednosti: suha stanična masa od (6,63±0,35) g/L, veća za (23,23±1,22) %; udio kroma u miceliju od (3670±211) mg/g, veći za (18,19±1,06) % i stupanj obogaćivanja micelija kromom od (12,15±1,01) %, što je za (45,68±2,67) % više nego u kontrolnom uzorku. Utvrđeno je da se trovalentni krom u miceliju uglavnom veže za proteine i ugljikohidrate. Ukupni se udio aminokiselina u takvom obogaćenom miceliju povećao za (31,25±0,58) %, a udio esencijalnih aminokiselina za (44,26±0,76) %

Moir\'{e} Flat Bands of Twisted Few-layer Graphite

We report that the twisted few layer graphite (tFL-graphite) is a new family of moir\'{e} heterostructures (MHSs), which has richer and highly tunable moir\'{e} flat band structures entirely distinct from all the known MHSs. A tFL-graphite is composed of two few-layer graphite (Bernal stacked multilayer graphene), which are stacked on each other with a small twisted angle. The moir\'{e} band structure of the tFL-graphite strongly depends on the layer number of its composed two van der Waals layers. Near the magic angle, a tFL-graphite always has two nearly flat bands coexisting with a few pairs of narrowed dispersive (parabolic or linear) bands at the Fermi level, thus, enhances the DOS at $E_F$. This coexistence property may also enhance the possible superconductivity as been demonstrated in other multiband superconductivity systems. Therefore, we expect strong multiband correlation effects in tFL-graphite. Meanwhile, a proper perpendicular electric field can induce several isolated nearly flat bands with nonzero valley Chern number in some simple tFL-graphites, indicating that tFL-graphite is also a novel topological flat band system.Comment: Submitted version,supplementary materials are adde

Colloid chemistry approach to understand the storage stability of fermented carrot juice

Probiotic-fermented carrot juice (PFCJ) is a functional food, for which colloidal stability during storage is essential. The water-soluble polysaccharides (WSPs) it contains provide this stability as colloidal stabilizers; they are pectinic, mainly containing galacturonic acid, galactose and arabinose as monosaccharide units. The particle-size distribution, ζ potential, centrifugal sediment ratio, soluble solids content, total acid and structural features of these WSPs were evaluated as functions of storage time. The PFCJ displayed pseudoplastic fluid behavior. Molecular weight and solid morphology of WSPs did not change significantly with storage, although the molecular weights of WSPs showed a slight decrease. The storage stability is ascribed to its WSPs acting as electrosteric stabilizers (which are very robust colloidal stabilizers) by adsorbing onto the insoluble plant cell wall polysaccharides which comprise the dispersed phase in the suspension. Viscosity and particle size remained relatively stable when stored at 4 °C and 25 °C, while centrifugal sediment ratio, soluble solids content and total acid all increased significantly; these can also be explained in terms of the structure of the WSPs. This can provide guidance to choosing ingredients which improve storage stability and other properties of importance to consumers by using the precepts of electrosteric colloidal stabilization: e.g. the presence of water-soluble polysaccharides with long hydrophilic moieties