Estimated prevalence of frailty and prefrailty in patients undergoing coronary artery or valvular surgeries/procedures: A systematic review and proportional meta-analysis.

Background: The aging population has led to an increasing number of older patients undergoing cardiac surgeries/procedures. Frailty and prefrailty have emerged as important prognostic indicators among these patients. This proportional meta-analysis estimated the prevalence of frailty and prefrailty among patients undergoing cardiac surgery.

Formation of Iodide-Rich Domains During Halide Segregation in Lead-Halide Perovskite Nanocrystals.

Mixed iodide-bromide methylammonium lead perovskite (MAPbIBr) nanocrystals (NCs) hold promise for use in light-emitting applications owing to the size- and composition-tunability of their bandgap. However, the segregation of halides during light exposure causes their band gaps to become unstable and narrow. Here, we use transient absorption spectroscopy to track excited-state dynamics during photoinduced halide segregation.

In Situ Measurement of Evolving Excited-State Dynamics During Deposition and Processing of Organic Films by Single-Shot Transient Absorption.

A significant advantage of organic semiconductors over many of their inorganic counterparts is solution processability. However, solution processing commonly yields heterogeneous films with properties that are highly sensitive to the conditions and parameters of casting and processing. Measuring the key properties of these materials in situ, during film production, can provide new insight into the mechanism of these processing steps and how they lead to the emergence of the final organic film properties.

The prognostic impacts of frailty on clinical and patient-reported outcomes in patients undergoing coronary artery or valvular surgeries/procedures: A systematic review and meta-analysis.

Background: Frailty is emerging as an important prognostic indicator for patients undergoing cardiac surgeries/procedures. We sought to evaluate the prognostic and differential impacts of frailty on patients undergoing coronary artery or valvular surgical procedures of different levels of invasiveness, and to explore the differential predictability of various frailty measurement models.

Methods: Eight databases were searched for prospective cohort studies that have adopted validated measure(s) of frailty and reported clinical, healthcare service utilization, or patient-reported outcomes in patients undergoing coronary artery or valvular surgeries/procedures.

Psychometric Validation of the Chinese Version of the Atrial Fibrillation Knowledge Scale in Chinese Patients With Atrial Fibrillation.

Background: Assessment of patients' knowledge on atrial fibrillation (AF) and its management is important for evaluating their learning needs. However, a validated and comprehensive instrument to be used among Chinese patients is yet to be developed.

Objectives: The aim of this study was to develop and validate the Chinese version of the Atrial Fibrillation Knowledge Scale (AFKS-C) in Chinese patients.

Ligand-engineered bandgap stability in mixed-halide perovskite LEDs.

Lead halide perovskites are promising semiconductors for light-emitting applications because they exhibit bright, bandgap-tunable luminescence with high colour purity. Photoluminescence quantum yields close to unity have been achieved for perovskite nanocrystals across a broad range of emission colours, and light-emitting diodes with external quantum efficiencies exceeding 20 per cent-approaching those of commercial organic light-emitting diodes-have been demonstrated in both the infrared and the green emission channels. However, owing to the formation of lower-bandgap iodide-rich domains, efficient and colour-stable red electroluminescence from mixed-halide perovskites has not yet been realized.

Single-shot transient absorption spectroscopy techniques and design principles.

Single-shot transient absorption (SSTA) spectroscopy is fundamentally identical to transient absorption (TA) spectroscopy but differs in its implementation to enable the measurement of sample response at a range of pump-probe time delays in a single laser shot. As in TA, a pump pulse in SSTA photoexcites a sample, inducing a change in the absorption of a probe pulse. Both commercial and home-built TA instruments typically execute serial measurements at a range of pump-probe time delays to yield transients that report on the dynamics of the photoexcited species, with the sample returning to the same relaxed state between each measurement.

An empowerment-based cognitive behavioural therapy for persons with mild cognitive impairment and insomnia: Protocol for a mixed-method pilot study.

Aim: This study aims to examine the feasibility and effects of an empowerment-based cognitive behavioural therapy for insomnia on sleep, cognitive outcomes, and health-related quality of life in persons with mild cognitive impairment and insomnia.

Study Design: This mixed-methods study comprises a pilot randomized controlled trial and an exploratory qualitative study.

Methods: A total of 60 community-dwelling patients aged ≥50 years with mild cognitive impairment and self-reported sleep complaints will be recruited from the community centres for older people operated by two non-governmental organizations in Hong Kong.

Revealing the evolving mixture of molecular aggregates during organic film formation using simulations of in situ absorbance.

In this work, we introduce a method for modeling the evolving absorbance spectrum of an organic molecule, pseudoisocyanine (PIC), measured during the process of molecular aggregation. Despite being historically considered a J-aggregate, we find that the absorbance spectrum of PIC cannot be adequately modeled using solely J-aggregates either during molecular aggregation or in the final dry film. The collection of absorbance spectra during solution-casting is particularly difficult since a distribution of aggregates with various sizes and structures can coexist.

Evolving Stark Effect During Growth of Perovskite Nanocrystals Measured Using Transient Absorption.

Methylammonium lead triiodide (MAPbI) nanocrystals (NCs) are emerging materials for a range of optoelectronic applications. Photophysical characterization is typically limited to structurally stable NCs owing to the long timescales required for many spectroscopies, preventing the accurate measurement of NCs during growth. This is a particular challenge for non-linear spectroscopies such as transient absorption.

Broadband single-shot transient absorption spectroscopy.

The duration of transient absorption spectroscopy measurements typically limits the types of systems for which the excited state dynamics can be measured. We present a single-shot transient absorption (SSTA) instrument with a spatially encoded 60 ps time delay range and a 100 nm spectral range that is capable of acquiring a transient spectrum in 20 s. We describe methods to spatially overlap the flat-top pump and probe beams at the sample plane, calibrate the spatially encoded time delay, and correct for non-uniform excitation density.

In Situ Measurement of Exciton Dynamics During Thin-Film Formation Using Single-Shot Transient Absorption.

The exciton dynamics of pseudoisocyanine (PIC) is reported during the formation of a thin film dropcast from solution. Tilted pump pulses are used to spatially encode a pump-probe time delay, enabling the collection of a transient in a single shot. We demonstrate that a spatially encoded delay can be used to accurately measure exciton dynamics in thin-film samples, with a signal-to-noise ratio above 20 attained in 2 s.

Single-shot transient absorption spectroscopy with a 45 ps pump-probe time delay range.

We report a single-shot transient absorption apparatus that successfully uses a tilted pump pulse to spatially encode a 45 ps pump-probe time delay. The time delay range is significantly improved over other reported instruments by using a spatial light modulator to flatten the intensity of the excitation field at the sample position. The full time delay range of the instrument is demonstrated by measuring a long-lived dye.

A randomized controlled trial on the psychophysiological effects of physical exercise and Tai-chi in patients with chronic schizophrenia.

The chronic and prevalent natures of schizophrenia result in long-term institutionalization for the patients. Conventional treatment of anti-psychotic medication on management of psychotic symptoms often brings on severe side effects and reduces patients' well-being. Tai-chi is a mind-body exercise that underscores motor coordination and relaxation.

Exciton dynamics reveal aggregates with intermolecular order at hidden interfaces in solution-cast organic semiconducting films.

Large-scale organic electronics manufacturing requires solution processing. For small-molecule organic semiconductors, solution processing results in crystalline domains with high charge mobility, but the interfaces between these domains impede charge transport, degrading device performance. Although understanding these interfaces is essential to improve device performance, their intermolecular and electronic structure is unknown: they are smaller than the diffraction limit, are hidden from surface probe techniques, and their nanoscale heterogeneity is not typically resolved using X-ray methods.

The psychophysiological effects of Tai-chi and exercise in residential schizophrenic patients: a 3-arm randomized controlled trial.

Background: Patients with schizophrenia are characterized by high prevalence rates and chronicity that often leads to long-term institutionalization. Under the traditional medical model, treatment usually emphasizes the management of psychotic symptoms through medication, even though anti-psychotic drugs are associated with severe side effects, which can diminish patients' physical and psychological well-being. Tai-chi, a mind-body exercise rooted in Eastern health philosophy, emphasizes the motor coordination and relaxation.

Electronic coherence lineshapes reveal hidden excitonic correlations in photosynthetic light harvesting.

The effective absorption cross-section of a molecule (acceptor) can be greatly increased by associating it with a cluster of molecules that absorb light and transfer the excitation energy to the acceptor molecule. The basic mechanism of such light harvesting by Förster resonance energy transfer (FRET) is well established, but recent experiments have revealed a new feature whereby excitation is coherently shared among donor and acceptor molecules during FRET. In the present study, two-dimensional electronic spectroscopy was used to examine energy transfer at ambient temperature in a naturally occurring light-harvesting protein (PE545 of the marine cryptophyte alga Rhodomonas sp.

Three-pulse photon-echo peak shift spectroscopy and its application for the study of solvation and nanoscale excitons.

An understanding of chemical reactivity begins with an understanding of the dynamics involved regarding system-bath interactions. Spectroscopic studies of these interactions in condensed-phase multichromophoric systems are intricate and contain much information. Photon-echo spectroscopy has proven to be a useful tool for probing these interactions.

Biexcitonic fine structure of CdSe nanocrystals probed by polarization-dependent two-dimensional photon echo spectroscopy.

The spectroscopy of colloidal CdSe nanocrystals is investigated using two-dimensional photon echo (2DPE) spectroscopy with copolarized and cross-polarized pulse sequences. Clearly resolved excited state absorption features are observed to beat at the frequency of the longitudinal-optical phonon, and the phase of this beating is found to be polarization-dependent. A simulation is performed using the excitonic and biexcitionic fine structure states predicted by theory, and the polarization-dependent beating allows each feature to be assigned to a particular excited state absorption pathway.

Adult day health care for participants with Alzheimer's disease.

The purpose of this study was to explore existing practices and services provided by adult day health care (ADHC) in Massachusetts and to document how providers are addressing the specific needs of participants with Alzheimer's disease and related disorders. Specific focus related to the early, late, and end stages of the disease process, and to early-onset dementia. Both quantitative and qualitative methods were used.

Coherently wired light-harvesting in photosynthetic marine algae at ambient temperature.

Photosynthesis makes use of sunlight to convert carbon dioxide into useful biomass and is vital for life on Earth. Crucial components for the photosynthetic process are antenna proteins, which absorb light and transmit the resultant excitation energy between molecules to a reaction centre. The efficiency of these electronic energy transfers has inspired much work on antenna proteins isolated from photosynthetic organisms to uncover the basic mechanisms at play.

Exciton fine structure and spin relaxation in semiconductor colloidal quantum dots.

Quantum dots (QDs) have discrete quantum states isolated from the environment, making QDs well suited for quantum information processing. In semiconductor QDs, the electron spins can be coherently oriented by photoexcitation using circularly polarized light, creating optical orientation. The optically induced spin orientation could serve as a unit for data storage and processing.

Ideal dipole approximation fails to predict electronic coupling and energy transfer between semiconducting single-wall carbon nanotubes.

The electronic coupling values and approximate energy transfer rates between semiconductor single-wall carbon nanotubes are calculated using two different approximations, the point dipole approximation and the distributed transition monopole approximation, and the results are compared. It is shown that the point dipole approximation fails dramatically at tube separations typically found in nanotube bundles ( approximately 12-16 A) and that the disagreement persists at large tube separations (>100 A, over ten nanotube diameters). When used in Forster resonance energy transfer theory, the coupling between two point transition dipoles is found to overestimate energy transfer rates.