Modulating the Supramolecular Assembly of α-Cyclodextrin and Anderson-type Polyoxometalate through Covalent Modifications.

A series of unprecedented supramolecular complexes of covalently modified Anderson-type polyoxometalates (POMs) and α-cyclodextrins (α-CDs) have been obtained and characterized in solid state by single-crystal X-ray diffraction, and in aqueous solution using various techniques including H DOSY NMR, 2D NOESY H NMR, isothermal titration calorimetry (ITC), and electrospray ionization time-of-flight mass spectroscopy (ESI-TOF-MS). It has been demonstrated that the supramolecular assembly process could be modulated by different covalent modification modes of the Anderson POMs, giving rise to a new type of POM/α-CD complexes featuring organic-inorganic pseudo-rotaxane structures, which are in good contrast to those of POM/γ-CD complexes of poly-rotaxane structures. Moreover, it is delighted to find that these pseudo-rotaxanes of POM/α-CD complexes exhibit stable chirality in aqueous solution, which has not been accomplished in previously reported POM/CD assemblies.

Force-triggered hypso- and bathochromic bidirectional fluorescence switching beyond 120 nm and its anticounterfeiting applications.

Achieving high-contrast tricolor emissive regulation of a single-component molecule using a single type of external stimulus is highly desirable but challenging. In the present study, we report a symmetric acceptor-donor-acceptor (A-D-A)-type aggregation-induced emission-active luminogen, which displays a sequential high-contrast fluorescence switching just by anisotropic mechanical grinding. Specifically, upon light grinding, an orange-yellow-to-blue hypsochromic mechanofluorochromic response with a distinct color contrast (change in the maximum emission wavelength, Δλ = 122 nm) is noticed, and the slightly ground solid exhibits a blue-to-red high-contrast (Δλ = 185 nm) bathochromic mechanofluorochromic conversion upon vigorous grinding.

Post-anthesis supplementary irrigation improves grain yield and nutritional quality of drip-irrigated rice ( L.).

Introduction: Approximately 50% of irrigation water is saved during drip-irrigation of rice, which has tremendous potential for water-saving agriculture, particularly in areas where water resources are scarce. However, the grain yield and quality of drip-irrigated rice are adversely affected.

Methods: In this study, we investigated the effects of different irrigation strategies on the grain yield and quality of drip-irrigated rice using field experiments.

Dynamic Bond-Directed Synthesis of Stable Mesoporous Metal-Organic Frameworks under Room Temperature.

Stable metal-organic frameworks (MOFs) with mesopores (2-50 nm) are promising platforms for immobilizing nanosized functional compounds, such as metal-oxo clusters, metal-sulfide quantum dots, and coordination complexes. However, these species easily decompose under acidic conditions or high temperatures, hindering their encapsulation in stable MOFs, which are usually synthesized under harsh conditions involving excess acid modulators and high temperatures. Herein, we report a route for the room-temperature and acid-modulator-free synthesis of stable mesoporous MOFs and MOF catalysts with acid-sensitive species encapsulated: (1) we initially construct a MOF template by connecting stable Zr clusters with labile Cu-bipyridyl moieties; (2) Cu-bipyridyl moieties are subsequently exchanged by organic linkers to afford a stable version of Zr-MOFs; (3) acid-sensitive species, including polyoxometalates (POMs), CdSeS/ZnS quantum dots, and Cu-coordination cages, can be encapsulated into the MOFs during step 1.

Full-Color Emissive D-D-A Carbazole Luminophores: Red-to-NIR Mechano-fluorochromism, Aggregation-Induced Near-Infrared Emission, and Application in Photodynamic Therapy.

Invited for the cover of this issue are Zhao Chen at Jiangxi Science and Technology Normal University and Yue Sun at Tiangong University. For this cover picture, yellow ball containing character "D" represents donor, green ball containing character "A" represents acceptor. The image depicts eight donor-donor-acceptor-type carbazole derivatives that display full-color emission, and a luminogen that shows red to near-infrared mechano-fluorochromism and a photodynamic therapy effect.

Full-Color Emissive D-D-A Carbazole Luminophores: Red-to-NIR Mechano-fluorochromism, Aggregation-Induced Near-Infrared Emission, and Application in Photodynamic Therapy.

The preparation of multifunctionalized luminophores with full-color emission based on an identical core skeleton is a significative but challenging research topic. In this work, eight donor-donor-acceptor (D-D-A)-type luminogens based on a central carbazole core bearing a C hydrocarbon chain were designed by using different kinds of donor and acceptor units on the left and right, and synthesized in good yields. These D-D-A carbazole derivatives display deep-blue, sky-blue, cyan, green, yellow-green, yellow, orange and red fluorescence in the solid state, achieving full-color emission covering the whole visible light range under UV light illumination.

Performance enhancement of deep-ultraviolet LEDs by using quaternary AlInGaN polarization-engineered multiple-symmetrical-stair quantum barriers without electron blocking layer.

In this paper, a structure design using quaternary AlInGaN as multiple-symmetrical-stair-shaped quantum barriers without an electron blocking layer is shown. The results show this design mitigates the droop effect to ∼0.1, and the internal quantum efficiency reaches about 93.

Prevalence and surveillance of tuberculosis in Yemen from 2006 to 2018.

Tuberculosis is a major public health issue in Yemen, a country located at the southwestern tip of the Arabian Peninsula, while the situation of tuberculosis had been further exacerbated since the war started in 2015. The objective of this study is to investigate the incidence of tuberculosis in Yemen before the outbreak of COVID-19, from 2006 to 2018. During the 13-year period, 92 482 patients were enrolled in the TB programme records from the 22 governorates.

Highly Emissive Multipurpose Organoplatinum(II) Metallacycles with Contrasting Mechanoresponsive Features.

The development of supramolecular coordination complexes (SCCs) with a bright aggregate state or mechanical-stimuli-responsive luminescence is very significant and challenging. Herein, we report the synthesis of three different supramolecular platinum(II) metallacycles via coordination-driven self-assembly of a diplatinum(II) acceptor and organic donors with a triphenylamine, carbazole, or tetraphenylethylene moiety. The triphenylamine-modified SCC exhibits aggregation-induced emission enhancement (AIEE) but no mechanofluorochromism.

Persistent room-temperature phosphorescence or high-contrast phosphorescent mechanochromism: polymorphism-dependent different emission characteristics from a single gold(I) complex.

Luminophores with persistent room-temperature phosphorescence (p-RTP) or effective phosphorescent mechanochromism features have significant potential applications in the field of optoelectronic materials. Until now, p-RTP and remarkable phosphorescent mechanochromism phenomena have been observed in some luminescent molecules with different molecular structures. However, separately realizing p-RTP and high-contrast phosphorescent mechanochromism in different polymorphs from a single luminophore is still a valuable and challenging topic.

Ligand-Triggered Platinum(II) Metallacycle with Mechanochromic and Vapochromic Responses.

Supramolecular coordination complexes with solid-state stimuli-responsive characteristics are highly desirable but are rarely reported. Herein, we describe two coordination-driven self-assembled monoanthracene or dianthracene-based hexagonal metallacycles by subtle structure modification. Notably, the dianthracene-containing hexagon exhibits tricolor mechanochromic and vapochromic characteristics, while the monoanthracene-containing hexagon does not show obvious changes toward mechanical force.

1,8-Naphthalimide-Based Highly Emissive Luminophors with Various Mechanofluorochromism and Aggregation-Induced Characteristics.

Six 1,8-naphthalimide-based tetraphenylethene derivatives were reported. These highly solid-state emissive compounds showed aggregation-induced emission enhancement or aggregate fluorescence change characteristics. Furthermore, these aggregation-induced green light-emitting or aggregation-induced yellow light-emitting luminophors also exhibited various mechanofluorochromism behaviors involving different fluorescent color changes.

Thiophene-containing tetraphenylethene derivatives with different aggregation-induced emission (AIE) and mechanofluorochromic characteristics.

Four thiophene-containing tetraphenylethene derivatives were successfully synthesized and characterized. All these highly fluorescent compounds showed typical aggregation-induced emission (AIE) characteristics and emitted different fluorescence colors including blue-green, green, yellow and orange in the aggregation state. In addition, these luminogens also exhibited various mechanofluorochromic phenomena.

[Effects of enclosing on soil microbial community diversity and soil stoichiometric characteristics in a degraded alpine meadow].

Enclosing is an effective rehabilitation measure for degraded pastures that mimics natural recovery of vegetation. To examine the interaction between biotic and abiotic in lightly degraded and enclosing grasslands is helpful for a clear understanding of the structure and function of grassland ecosystem. In this study, soil microbial community and soil stoichiometric characteristics in lightly degraded and 10-year enclosing alpine meadows were studied by high-throughput sequencing and Biolog-Eco methods.

An Activity Switch in Human Telomerase Based on RNA Conformation and Shaped by TCAB1.

Ribonucleoprotein enzymes require dynamic conformations of their RNA constituents for regulated catalysis. Human telomerase employs a non-coding RNA (hTR) with a bipartite arrangement of domains-a template-containing core and a distal three-way junction (CR4/5) that stimulates catalysis through unknown means. Here, we show that telomerase activity unexpectedly depends upon the holoenzyme protein TCAB1, which in turn controls conformation of CR4/5.

[Characteristics of soil microbes and enzyme activities in different degraded alpine meadows].

Soil microbial biomass C and N, microbial diversities and enzyme activity in 0-10 cm and 10-20 cm soil layers of different degraded grasslands (non-degradation, ND; light degradation, LD; moderate degradation, MD; sever degradation, SD; and black soil beach, ED) were measured by Biolog and other methods. The results showed that: 1) There were significant diffe-rences between 0-10 cm and 10-20 cm soil layers in soil microbial biomass, diversities and inver-tase activities in all grasslands. 2) The ratio of soil microbial biomass C to N decreased significantly with the grassland degradation.

Adipose-derived mesenchymal stem cells ameliorate hyperglycemia through regulating hepatic glucose metabolism in type 2 diabetic rats.

Infusion of mesenchymal stem cells (MSCs) has been identified in the rapid alleviation in hyperglycemia of diabetic individuals, but the mechanism involved has not been adequately explained by these cells' potential role in modulating system insulin sensitivity and islet regeneration. In this study, we demonstrated adipose-derived mesenchymal stem cells (ASCs) produced significantly lower blood glucose via promoting hepatic glycogen synthesis and inhibiting hepatic glucose production within 24 h after infusion in T2DM rats. In vitro, HepG2 cells treated with palmitate (PA) were used as a model of hepatic glucose metabolism disorder to confirm that ASCs stimulates the phosphorylation of hepatic AMP-activated protein kinase (AMPK) to restores hepatic glucose metabolism in type 2 diabetes.

Multi-OMICs and Genome Editing Perspectives on Liver Cancer Signaling Networks.

The advent of the human genome sequence and the resulting ~20,000 genes provide a crucial framework for a transition from traditional biology to an integrative "OMICs" arena (Lander et al., 2001; Venter et al., 2001; Kitano, 2002).

Water-bath assisted convective assembly of aligned silver nanowire films for transparent electrodes.

Manipulating Ag nanowire (AgNW) assembly to tailor the opto-electrical properties and surface morphology could improve the performance of next-generation transparent conductive electrodes. In this paper, we demonstrated a water-bath assisted convective assembly process at the temporary water/alcohol interface for fabricating hierarchical aligned AgNW electrodes. The convection flow plays an important role during the assembly process.

Enhanced photovoltaic performance of organic/silicon nanowire hybrid solar cells by solution-evacuated method.

A method has been developed to fabricate organic-inorganic hybrid heterojunction solar cells based on n-type silicon nanowire (SiNW) and poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) hybrid structures by evacuating the PEDOT:PSS solution with dip-dropping on the top of SiNWs before spin-coating (solution-evacuating). The coverage and contact interface between PEDOT:PSS and SiNW arrays can be dramatically enhanced by optimizing the solution-evacuated time. The maximum power conversion efficiency (PCE) reaches 9.

Performance enhancement of blue light-emitting diodes without an electron-blocking layer by using special designed p-type doped InGaN barriers.

In this study, the characteristics of the nitride-based blue light-emitting diode (LED) without an electron-blocking layer (EBL) are analyzed numerically. The emission spectra, carrier concentrations in the quantum wells (QWs), energy band diagrams, electrostatic fields, and internal quantum efficiency (IQE) are investigated. The simulation results indicate that the LED without an EBL has a better hole-injection efficiency and smaller electrostatic fields in its active region over the conventional LED with an AlGaN EBL.

[Inheritance analysis of resistant starch content in kernels of wheat].

In this study, three wheat (Triticum aestivum L.) cultivars with high and low levels of resistant starch contents each were selected to obtain 15 F1 combinations from a diallel cross without reciprocals to be used to study the inheritance of resistant starch content. The results of this study are useful to select new wheat cultivar with high level of resistant starch content.

The acoustic attenuation and hydraulic roughness in a large section sewer pipe with periodical obstacles.

The acoustic attenuation, relative sound pressure levels and the equivalent Nikuradse wall roughness under variable flow conditions in a 600 mm concrete sewer pipe are experimentally investigated. The values of the acoustic attenuation are obtained in the case of airborne sound propagation in the dry pipe. A range of values of the equivalent wall roughness is artificially generated by deploying a periodical array of engineering bricks.