Frailty trajectories and determinants in Chinese older adults: A longitudinal study.

Objectives: This study aimed to enrich the research on frailty trajectories by using FRAIL scale and frailty index (FI), and analyze the determinants of the different trajectories in older Chinese.

Methods: 2268 older adults from the Chinese Longitudinal Healthy Longevity Survey were included. The FRAIL scale was constructed from 5 items and FI was constructed from 39 deficits.

Mortality prediction and influencing factors for intensive care unit patients with acute tubular necrosis: random survival forest and cox regression analysis.

Patients with acute tubular necrosis (ATN) not only have severe renal failure, but also have many comorbidities, which can be life-threatening and require timely treatment. Identifying the influencing factors of ATN and taking appropriate interventions can effectively shorten the duration of the disease to reduce mortality and improve patient prognosis. Mortality prediction models were constructed by using the random survival forest (RSF) algorithm and the Cox regression.

Occurrence and Exposure Assessment of Nickel in Zhejiang Province, China.

Nickel (Ni) is a silver-white metal with high antioxidative properties, often existing in a bivalent form in the environment. Despite being the fifth most abundant metal on Earth, anthropogenic activities, including industrial processes, have elevated Ni levels in environmental media. This study investigated Ni contamination in various food groups in Zhejiang Province, China, mainly focusing on Ni levels in beans, vegetables, aquatic foods, meat products, cereal products, and fruits.

Quadratic convergence of monotone iterates for semilinear elliptic obstacle problems.

In this paper, we consider the numerical solution for the discretization of semilinear elliptic complementarity problems. A monotone algorithm is established based on the upper and lower solutions of the problem. It is proved that iterates, generated by the algorithm, are a pair of upper and lower solution iterates and converge monotonically from above and below, respectively, to the solution of the problem.

A novel strategy to assemble achiral ligands to chiral helical polyrotaxane structures.

Using the achiral N,N'-bis(2-pyridylmethyl)-1,6-hexanediamine ligand bearing two end pyridyl groups as the source of conformational chirality, a novel type of TMeQ[6]-based helical polyrotaxane was prepared and characterized by X-ray crystallography and (1)H NMR spectroscopy. The chirality of the polyrotaxane was generated from twisting of the hexylidene of the N,N'-bis(2-pyridylmethyl)-1,6-hexanediamine "string" when bound within the hydrophobic cavity of TMeQ[6]. Two opposite chiral helical polyrotaxanes crystallize as a racemic compound.

2,2'-(Heptane-1,7-di-yl)dibenz-imidazo-lium chloride nitrate monohydrate.

In the title compound, C(21)H(26)N(4) (2+)·Cl(-)·NO(3) (-)·H(2)O, the organic cations, anions and water mol-ecules are linked through N-H⋯Cl, N-H⋯O, N-H⋯N and O-H⋯Cl hydrogen bonds, forming a three-dimensional framework, assisted by C-H⋯π inter-actions.

Structure of supramolecular assemblies formed by alpha,delta-tetramethylcucurbit[6]uril and 4-nitrophenol.

A host-guest assembly, [(C(40)H(44)N(24)O(12)).(C(6)H(5)NO(3))(8).13(H(2)O)] (1), based on a partial substituted cucurbituril, alpha,delta-tetramethylcucurbit[6]uril (TMeQ[6]), and 4-nitrophenol was synthesized and structurally characterized by single-crystal X-ray diffraction.

4-[3-(4-Nitro-phen-oxy)prop-oxy]aniline.

The mol-ecules of the title compound, C(15)H(16)N(2)O(4), are linked via N-H⋯O hydrogen bonds, forming undulating one-dimensional chains. Adjacent chains are linked by weak C-H⋯π inter-actions, forming a three-dimensional network.