Pre-arranged building block approach for the orthogonal synthesis of an unfolded tetrameric organic-inorganic phosphazane macrocycle.

Inorganic macrocycles remain challenging synthetic targets due to the limited number of strategies reported for their syntheses. Among these species, large fully inorganic cyclodiphosphazane macrocycles have been experimentally and theoretically highlighted as promising candidates for supramolecular chemistry. In contrast, their hybrid organic-inorganic counterparts are lagging behind due to the lack of synthetic routes capable of controlling the size and topological arrangement (i.

A facile crush-and-sieve treatment for recycling end-of-life photovoltaics.

The shift towards renewable energy mix has resulted in an exponential growth of the photovoltaic (PV) industry over the past few decades. Parallelly, new recycling technology developments are required to address the incoming volume of waste as they gradually approach their end-of-life (EoL) to realize the concept of a circular economy. Typical recycling processes involve high-temperature burning for separation and release of the PV cells for metal recovery processes.

Inorganic frameworks of low-dimensional perovskites dictate the performance and stability of mixed-dimensional perovskite solar cells.

Mixed-dimensional perovskites containing mixtures of organic cations hold great promise to deliver highly stable and efficient solar cells. However, although a plethora of relatively bulky organic cations have been reported for such purposes, a fundamental understanding of the materials' structure, composition, and phase, along with their correlated effects on the corresponding optoelectronic properties and degradation mechanism remains elusive. Herein, we systematically engineer the structures of bulky organic cations to template low-dimensional perovskites with contrasting inorganic framework dimensionality, connectivity, and coordination deformation.

Upcycling End of Life Solar Panels to Lithium-Ion Batteries Via a Low Temperature Approach.

The massive adoption of renewable energy especially photovoltaic (PVs) panels is expected to create a huge waste stream once they reach end-of-life (EoL). Despite having the highest embodied energy, present photovoltaic recycling neglects the high purity silicon found in the PV cell. Herein, a scalable and low energy process is developed to recover pristine silicon from EoL solar panel through a method which avoids energy-intensive high temperature processes.

Knowledge, Attitudes, and Practices of COVID-19 Vaccination among Adults in Singapore: A Cross-Sectional Study.

Public health measures promoting compliance of COVID-19 vaccination requires understanding of knowledge, attitudes, and practices (KAP). This study explored the KAP and risk factors influencing COVID-19 vaccination, including changes in preventive practices before and after vaccination in a high-income country, Singapore. An online cross-sectional study among Singaporeans and permanent residents aged 21 years and older was conducted from July to August 2021.

The Impact of Frailty, Falls and Cognition on Osteoporosis Management in the Oldest Old.

Data and clinical guidelines on the management of osteoporosis in nonagenarians are lacking. The aim of this study was to assess the characteristics of osteoporosis management and identify any gaps or trends in a cohort of nonagenarians who were newly diagnosed with osteoporosis during an inpatient admission. A retrospective analysis of nonagenarians admitted to the medicine department of a tertiary hospital who were newly diagnosed with osteoporosis based on extracted ICD-10 codes.

Upcycling Silicon Photovoltaic Waste into Thermoelectrics.

Two decades after the rapid expansion of photovoltaics, the number of solar panels reaching end-of-life is increasing. While precious metals such as silver and copper are usually recycled, silicon, which makes up the bulk of a solar cells, goes to landfills. This is due to the defect- and impurity-sensitive nature in most silicon-based technologies, rendering it uneconomical to purify waste silicon.

Healthcare workers as a sentinel surveillance population in the early phase of the COVID-19 pandemic.

Introduction: Healthcare workers (HCWs) are a critical resource in the effort to control the COVID-19 pandemic. They are also a sentinel surveillance population whose clinical status reflects the effectiveness of the hospital's infection prevention measures in the pandemic.

Methods: This was a retrospective cohort study conducted in Singapore General Hospital (SGH), a 1,822-bed tertiary hospital.

Mechanosynthesis of Higher-Order Cocrystals: Tuning Order, Functionality and Size in Cocrystal Design*.

The ability to rationally design and predictably construct crystalline solids has been the hallmark of crystal engineering research. To date, numerous examples of multicomponent crystals comprising organic molecules have been reported. However, the crystal engineering of cocrystals comprising both organic and inorganic chemical units is still poorly understood and mostly unexplored.

N-Bridged Acyclic Trimeric Poly-Cyclodiphosphazanes: Highly Tuneable Cyclodiphosphazane Building Blocks.

We have synthesized a completely new family of acyclic trimeric cyclodiphosphazane compounds comprising NH, N Pr, N Bu and NPh bridging groups. In addition, the first NH-bridged acyclic dimeric cyclophosphazane has been produced. The trimeric species display highly tuneable characteristics so that the distance between the terminal N(H)R moieties can be readily modulated by the steric bulk present in the bridging groups (ranging from ≈6 to ≈10 Å).

Rationale and design of a randomized trial of early intensive blood pressure lowering on cerebral perfusion parameters in thrombolysed acute ischemic stroke patients.

Background And Rationale: Uncertainty persists over the optimal management of blood pressure (BP) in the early phase of acute ischemic stroke (AIS). This study aims to determine the safety and effects of intensive BP lowering on cerebral blood flow (CBF) and functional in AIS patients treated with intravenous thrombolysis.

Methods: In a randomized controlled trial, 54 thrombolysed AIS patients with a systolic BP of 160 to 180 mm Hg will be randomized to early intensive BP lowering (systolic target range 140-160 mm Hg) or guideline-based BP management (systolic range 160-180 mm Hg) during first 72-hours using primarily intravenous labetalol.

Synthesis of Unique Phosphazane Macrocycles via Steric Activation of C-N Bonds.

Herein we describe that oxidation reactions of the dimeric cyclophosphazanes, [{P(μ-NR)}(μ-NR)], R = Bu (1), to produce a series of diagonally dioxidized products P(μ-N Bu)E [E = O (2), S (3), and Se (4)] and tetraoxidized frameworks. The latter display an unexpected C-N bond activation and cleavage to produce a series of novel phosphazane macrocyclic arrangements containing newly formed N-H bonds. Macromolecules P(μ-N Bu)(μ-NH)O (5) and P(μ-N Bu)(μ-NH)E, E = S (6) and Se (7), dicleaved and tricleaved products, respectively, are rare examples of dimeric macrocycles containing NH bridging groups.

Orthogonality in main group compounds: a direct one-step synthesis of air- and moisture-stable cyclophosphazanes by mechanochemistry.

Mechanochemistry has been established to be an environmentally-friendly way of conducting reactions in a solvent-free manner. The development of mechanochemical orthogonal reactions, in which multiple reagents are milled together, can be a powerful strategy to selectively yield the desired product. Such orthogonal syntheses are rare, especially those involving main group frameworks - based on bonds other than carbon - which are yet to be reported.

Mechanochemical Synthesis of Phosphazane-Based Frameworks.

Mechanochemistry is emerging as a powerful solvent-free approach to chemical synthesis, having been applied to metal oxides, pharmaceutical materials, organic compounds and to a lesser extent, coordination complex synthesis. Notably, examples of applications of mechanochemical methodologies in the synthesis of main-group compounds are few and far between. Herein, we demonstrate that ball milling enabled the solvent-free synthesis of a range of phosphazane frameworks with a broad substrate scope, yielding seven new acyclic and macrocyclic species.

Unique Triphenylphosphonium Derivatives for Enhanced Mitochondrial Uptake and Photodynamic Therapy.

In this study, unique methyl-functionalized derivatives (T*PP) of the drug carrier triphenylphosphonium (TPP) that exhibit significant enhancement of the accumulation of both the cation and its conjugated cargo in cell mitochondria are designed. We show that the presence of methyl group(s) at key positions within the phenyl ring results in an increase in the hydrophobicity and solvent accessible surface area of T*PP. In particular, when the para position of the phenyl ring in T*PP is functionalized with a methyl group, the cation is most exposed to the surrounding environment, leading to a large decrease in water entropy and an increase in the level of van der Waals interaction with and partition into a nonpolar solvent.

Dietary Intake among Adolescents in a Middle-Income Country: An Outcome from the Malaysian Health and Adolescents Longitudinal Research Team Study (the MyHeARTs Study).

Optimal nutrition is essential for healthy growth during adolescence. This study aims to investigate the baseline nutritional intake of Malaysian adolescents by gender, body mass index, and places of residence, both urban and rural. A cohort study was conducted consisting of 794 adolescents (aged 13-years) attending 15 public secondary schools from the Central (Kuala Lumpur and Selangor) and Northern (Perak) Regions of Peninsular Malaysia.