The spatial-temporal distribution of hepatitis B virus infection in China,2006-2018.

Objectives: Hepatitis B is a liver disease caused by Hepatitis B virus (HBV) infection and is highly prevalent in China. To better understand the epidemiological characteristics of hepatitis B in China and develop effective disease control strategies, we employed temporal and spatial statistical methods.

Methods: We obtained HBV incidence data from the Public Health Science Data Center of the Chinese Center for Disease Control and Prevention for the years 2006 to 2018.

Atomically precise photothermal nanomachines.

Interfacing molecular machines to inorganic nanoparticles can, in principle, lead to hybrid nanomachines with extended functions. Here we demonstrate a ligand engineering approach to develop atomically precise hybrid nanomachines by interfacing gold nanoclusters with tetraphenylethylene molecular rotors. When gold nanoclusters are irradiated with near-infrared light, the rotation of surface-decorated tetraphenylethylene moieties actively dissipates the absorbed energy to sustain the photothermal nanomachine with an intact structure and steady efficiency.

[Rapid determination of 16 polycyclic aromatic hydrocarbons in atmospheric fine particles by molecularly imprinted column-high performance liquid chromatography].

Objective: A high performance liquid chromatographic method based on the purification of polycyclic aromatic hydrocarbon molecularly imprinted columns was developed, this method was used for the rapid quantitative determination of 16 polycyclic aromatic hydrocarbons(PAHs) in fine particulate matter(PM_(2.5)).

Methods: The polycyclic aromatic hydrocarbons of the sample were extracted with acetonitrile ultrasonically, purified by molecular imprinting column(MIP-PAHs), and tested after being concentrated by nitrogen blowing.

CuH: a peculiar chiral nanocluster with an exposed Cu atom and 13 surface hydrides.

Reported herein is a racemate of a chiral nanocluster [CuH(SP(OiPr))], which has a tetrahedral Cu core embedded in a peculiar Cu shell. The CuH framework conforms to idealized symmetry. The positions of the hydrides were determined by a combinatorial use of H NMR and SC-XRD, revealing four different coordination modes: face-capping μ-H, butterfly μ'-H, tetrahedral μ-H, and square-pyramidal μ-H.

N-Heterocyclic Carbene-Stabilized Gold Nanoclusters with Organometallic Motifs for Promoting Catalysis.

The complexity of heterogeneous metal catalysts makes it challenging to gain insights into their catalytic mechanisms. Thus, there exists a huge gap between heterogeneous catalysis and organometallic catalysis. With the success in the preparation of highly robust atomically precise metal nanocluster catalysts (i.

Simple and Selective Synthesis of Copper-Containing Metal Nanoclusters Using (PPh ) CuBH as Reducing Agent.

A simple and selective synthetic protocol, using (PPh ) CuBH as reducing agent, for Cu-containing mixed metal nanoclusters (NCs) is reported. Representative NCs include alkynyl-protected [Ag Cu (PhCC) (PPh ) Cl H ] (1), thiolate-capped [AuCu (SR) (PPh ) ] (R = 4-flurothiophenol) (2), and phosphine-stabilized [Au Cu (PPh ) Cl ] (3), which are fully characterized by single-crystal X-ray diffraction analysis, electrospray ionization mass, nuclear magnetic resonance ( H, H, C, and P NMR), and optical measurements, respectively. This work demonstrates the advantages of using (PPh ) CuBH as a reducing agent in the synthesis of Cu-containing heterometallic NCs in terms of versatility as well as high yield and high purity of the products.

Ti-Oxo Clusters with Peripheral Alkyl Groups as Cathode Interlayers for Efficient Organic Solar Cells.

Three independent Ti-oxo clusters (TOCs) that contain 6, 8, and 12 Ti atoms in the cores and alkyl groups on the surface were developed as cathode interlayers in bulk-heterojunction organic solar cells (OSCs). These TOCs have precise chemical structures with a single crystal, excellent solubility in methanol, and well-aligned work function. Smooth films can be facilely obtained by spin-casting their solution on top of the active layer.

Tertiary Chiral Nanostructures from C-H⋅⋅⋅F Directed Assembly of Chiroptical Superatoms.

We report the synthesis and structure of tertiary chiral nanostructures with 100 % optical purity. A novel synthetic strategy, using chiral reducing agent, R and S-BINAPCuBH (BINAP is 2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl), is developed to access to atomically precise, intrinsically chiral [Au Ag Cu (R- or S-BINAP) (SCH Ph) ]SbF nanoclusters in one-pot synthesis. The clusters represent the first tri-metallic superatoms with inherent chirality and fair stability.

Dissection of bicapped octahedral copper hydride cluster to form two chiral tetrahedral copper hydride cluster series exhibiting auto deracemization and photoluminescence.

Three series of copper hydride clusters [CuHL] (1), [CuHXL] where X = Cl (2a), Br (2b), I (2c), N (2d) and SCN (2e), and [CuHXL] where X = Br (3b) and I (3c) (L = 2-(diphenylphosphino)pyridine, dppy) were synthesized and characterized by single-crystal X-Ray crystallography and standard spectroscopic techniques. The metal core of 1, Cu, can be described as a bicapped octahedron, while those of 2 and 3 series adopt tetrahedral structures. The hydride positions were deduced from difference electron density maps and corroborated by NMR and DFT calculations.

Analysis of methylparaben in cosmetics based on a chemiluminescence H O -NaIO -CNQDs system.

In this article, a simple, effective chemiluminescence (CL) method for the detection of methylparaben (MP) in cosmetic samples was developed based on an IO -H O -carbon nitrogen quantum dots (CNQDs) system without a separation process. The results indicated that the redox reaction between periodate and hydrogen peroxide released hydroxide radicals and superoxide radical anions in the presence of bicarbonate. These two radicals were responsible for the formation of excited luminophor CNQD* with a maximum wavelength at 480 nm.

Highly Robust but Surface-Active: An N-Heterocyclic Carbene-Stabilized Au Nanocluster.

Surface organic ligands play a critical role in stabilizing atomically precise metal nanoclusters in solutions. However, it is still challenging to prepare highly robust ligated metal nanoclusters that are surface-active for liquid-phase catalysis without any pre-treatment. Now, an N-heterocyclic carbene-stabilized Au nanocluster with high thermal and air stabilities is presented as a homogenous catalyst for cycloisomerization of alkynyl amines to indoles.

An All-Alkynyl Protected 74-Nuclei Silver(I)-Copper(I)-Oxo Nanocluster: Oxo-Induced Hierarchical Bimetal Aggregation and Anisotropic Surface Ligand Orientation.

The hardness of oxo ions (O ) means that coinage-metal (Cu, Ag, Au) clusters supported by oxo ions (O ) are rare. Herein, a novel μ -oxo supported all-alkynyl-protected silver(I)-copper(I) nanocluster [Ag Cu O (PhC≡C) ] (NC-1, avg. x=37.

Microporous Cyclic Titanium-Oxo Clusters with Labile Surface Ligands.

By using ethylene glycol and monocarboxylic acid as surface ligands, a series of cyclic Ti-oxo clusters (CTOC) with permanent microporosity are successfully synthesized. With a cyclic {Ti O } backbone made of eight connected Ti tetrahedral cages that are arranged in a zigzag fashion, the clusters have a "donut" shape with an inner diameter of 8.3 Å, outer diameter of 26.

Insights into Magnetic Interactions in a Monodisperse Gd Fe Metal Cluster.

The largest Ln-Fe metal cluster [Gd Fe (μ -OH) (μ -OH) (μ -O) (TEOA) (CH COO) (H O) ]⋅(CH COO) (CH CN) ⋅(H O) (1) and the core-shell monodisperse metal cluster of 1 a@SiO (1 a=[Gd Fe (μ -OH) (μ -OH) (μ -O) (TEOA) (CH COO) (H O) ] ) were prepared. Experimental and theoretical studies on the magnetic properties of 1 and 1 a@SiO reveal that encapsulation of one cluster into one silica nanosphere not only effectively decreases intermolecular magnetic interactions but also significantly increases the zero-field splitting effect of the outer layer Fe ions.

Atomically Precise Bimetallic AuCu Nanocluster with an Icosidodecahedral Cu Shell and an Alkynyl-Cu Interface.

Bimetallic nanoclusters AuCu with chemical composition of [AuCu(C≡CR)(PhP)Cl](NO) (where RC≡C is from 3-ethynylthiophene (HCS-3-C≡CH) or ethynylbenzene (PhC≡CH)) has been synthesized. Single X-ray structural analysis reveals that AuCu has a multishelled core structure of Au@Au@Cu@Au, comprising a centered icosahedral Au (Au@Au) surrounded by an icosidodecahedral Cu shell and an outmost shell of a chairlike hexagonal Au. The alkynyl carbon is bound to the hollow sites on the AuCu nanocluster surface, which is a novel interfacial binding mode in alkynyl-protected alloy nanoclusters.

Efficient capillary electrophoresis separation and determination of free amino acids in beer samples.

Simultaneous detection of various o-phthalaldehyde (OPA)-labeled amino acids (AAs) in food samples was reported based on CE separation. Ionic liquid was used for the first time for CE analysis of AAs with in-capillary derivatization. Several other additives, including SDS, α/β-CD, and ACN, as well as key parameters for CE separation (buffer pH value, separation voltage), were also investigated.