Atomically Precise Nanocluster Assemblies Encapsulating Plasmonic Gold Nanorods

The self‐assembled structures of atomically precise, ligand‐protected noble metal nanoclusters leading to encapsulation of plasmonic gold nanorods (GNRs) is presented. Unlike highly sophisticated DNA nanotechnology, this strategically simple hydrogen bonding‐directed self‐assembly of nanoclusters leads to octahedral nanocrystals encapsulating GNRs. Specifically, the p‐mercaptobenzoic acid (pMBA)‐protected atomically precise silver nanocluster, Na₄[Ag₄₄(pMBA)₃₀], and pMBA‐functionalized GNRs were used. High‐resolution transmission and scanning transmission electron tomographic reconstructions suggest that the geometry of the GNR surface is responsible for directing the assembly of silver nanoclusters via H‐bonding, leading to octahedral symmetry. The use of water‐dispersible gold nanoclusters, Au_≈250(pMBA)_n and Au₁₀₂(pMBA)₄₄, also formed layered shells encapsulating GNRs. Such cluster assemblies on colloidal particles are a new category of precision hybrids with diverse possibilities.     

Retraction Note to: Secondary treated wastewater of latex processing: reusing for irrigation or treatment by membrane filtration

Research on Chemical Intermediates -     

Optimization in a Nonlinear Lanchester-Type Model Involving Supply Units $$^* $$

Journal of Applied and Industrial Mathematics - In this paper, we introduce a nonlinear Lanchester-type model involving supply units. The model describes a battle where the Blue party consisting of...     

Transmission properties of electromagnetic metamaterials: From split-ring resonator to fishnet structure

We experimentally presented the electromagnetic behavior of transformative magnetic metamaterials: from the early invented split-ring resonator to its improvement, the cut-wire pair, for providing a negative magnetic permeability. By adding the continuous wire to cut-wire pair structure, the left-handed (LH) transmission made by doubly negative permittivity and permeability was demonstrated in combined structure. Interestingly, until the width of cut-wire pair increases to be physically merged with the adjacent continuous wire, in other words, to form the so-called fishnet structure, the LH behavior is still observed. This result indicates that in a broad sense, the essence of the electromagnetic response in the fishnet structure is similar to that in a combined structure. Our experimental results show a good agreement with previous theoretical study.     

Natural anti-HIV agents. Part 3: Litseaverticillols A-H, novel sesquiterpenes from Litsea verticillata

Bioassay directed-fractionation led to the identification of litseaverticillols A-H (1-8) from the leaves and twigs of Litsea verticillata Hance. These new sesquiterpenes possess a unique skeleton that was recently designated as ‘litseane’. The structures of these compounds were determined by spectroscopic means including 1D and 2D NMR data. Structural configurations were determined by ROESY experiments. Mosher ester reactions and optical rotation measurements established the sesquiterpenes 1-8 as racemates. Isolates 1-8 inhibited HIV-1 replication in HOG.R5 cells with IC₅₀ values ranging from 2 to 15 μg/ml (8-58 μM) while affecting the growth of HOG.R5 at concentrations 2-3-fold higher. Based on this data, structure-activity relationships can be discerned, suggesting compounds of this class are good candidates for analog production.     

Small subgraphs of random regular graphs

The main aim of this short paper is to answer the following question. Given a fixed graph H, for which values of the degree d does a random d-regular graph on n vertices contain a copy of H with probability close to one?     

Decay mild solutions for two-term time fractional differential equations in Banach spaces

In this paper, we deal with the nonlocal Cauchy problem for a class of two-term time fractional differential equations in Banach spaces. By constructing a suitable measure of noncompactness on the space of solutions, we prove the existence of a compact set containing decay mild solutions to the mentioned problem.     

LIOUVILLE RESULTS FOR STABLE SOLUTIONS OF QUASILINEAR EQUATIONS WITH WEIGHTS

This paper is devoted to the quasilinear equation ■where p 2,Ω is a(bounded or unbounded) domain of R~N,w_1,w_2 are nonnegative continuous functions and f is an increasing function. We establish a Liouville type theorem for nontrivial stable solutions of the equation under some mild assumptions on Ω,w_1, w_2 and f, which extends and unifies several results on this topic.     

Pr(BO2)3 und PrCl(BO2)2: Zwei meta‐Borate des Praseodyms im Vergleich

Pr(BO₂)₃ and PrCl(BO₂)₂: Two Praseodymium meta‐Borates in Comparison Single‐crystalline PrCl(BO₂)₂ can be obtained by the reaction of praseodymium, Pr₆O₁₁ and PrCl₃ with a small excess of B₂O₃ in evacuated silica tubes after seven days at 850 °C. If NaCl is additionally used as flux, single crystals of Pr(BO₂)₃ dominate the main product. Both praseodymium(III) meta‐borates are air and water stable. The crystals of PrCl(BO₂)₂ emerge as long, thin, pale green needles which tend to severe twinning due to their fibrous habit. The crystal structure (triclinic, P1¯; a = 420.56(4), b = 655.42(7), c = 808.34(8) pm, α = 82.361(8), β = 89.173(9), γ = 71.980(7)°, Z = 2) exhibits zigzag chains {[(B1)o^t_1/1O^e_2/2(B2)O^t_1/1O^e_2/2]²⁻} (≡ {[BO₂]⁻}) of corner‐linked [BO₃]³⁻ triangles with syndiotactic orientation of the terminal oxygen atoms which are running parallel to the [100] direction. The Pr³⁺ cations are surrounded by three Cl⁻ and seven O²⁻ anions with the shape of a tetracapped trigonal prism. The green, transparent crystals of Pr(BO₂)₃ (monoclinic, C2/c; a= 984.98(9), b = 809.57(8), c = 641.02(6) pm, β = 126.783(9)°, Z = 4) appear either lath‐shaped or rather spherical. In the crystal structure the B³⁺ cations reside both in trigonal planar as well as in tetrahedral coordination of oxygen atoms. Both types of borate polyhedra ([BO₃]³⁻ and [BO₄]⁵⁻) are linked via corners to form chains of the composition {[(B2)‐O^t_1/1O^e_2/2(B1)O^e_4/2(B2)O^t_1/1O^e_2/2]³⁻} (≡ {[BO₂]⁻}) which run parallel [101]. The coordination sphere of the Pr³⁺ cations consists of ten oxide anions which build up a bicapped square antiprism.     

Bioactive unnatural somatostatin analogues through bioorthogonal iodo- and ethynyl-disulfide intercalators

Iodo- and ethynyl-containing bisalkylating bioconjugation agents 5 and 8 were achieved and allow the introduction of reactive unnatural substituents into proteins and peptides whilst the bioactive 3D structure is retained. Derivatives of the peptide hormone somatostatin bearing a single iodo or ethynyl group were prepared through intercalation into the disulfide bridge. For the first time, the exact reaction mechanism of the intercalation was elucidated by applying 2D NMR experiments and it was shown that, during the reaction, somatostatin diastereomers were formed. Site-directed modification of the ethynyl-modified peptide with a coumarin chromophore was achieved through a [1,3] dipolar Huisgen cycloaddition reaction; this suggests that such a derivative could serve as an attractive platform to prepare artificial somatostatin compound libraries. The biological activity and specificity of a representative modified somatostatin derivative was demonstrated and efficient receptor-mediated cell uptake occurred in a dose-dependent manner into receptor positive cells only. The iodo and ethynyl bioconjugation reagents presented herein could be applied for introducing such substituents into alternative peptides and proteins and, in principle, could facilitate the efficient design of a broad variety of artificial protein and peptide analogues with previously unknown bioactivities.