Prior research on object valuation ignores the effect of non-ownership physical possession types such as
renting
and
borrowing
. Evidence from four experiments demonstrates that the valuation (i.e., ...willingness-to-pay) for rented objects is greater than the valuation for non-possessed or borrowed objects. Borrowed objects are not valued any differently than non-possessed objects. Psychological ownership mediates the relationship between valuation and non-ownership physical possession. Additionally, psychological ownership varies for different possession types (ownership, renting, and borrowing) as its contributing routes (control, self-investment, and knowledge) operate differently for each possession type. As further evidence of the psychological ownership based theoretical account, the research shows that rented objects are not valued higher than non-possessed objects if the control or self-investment routes of psychological ownership are suppressed. The moderating influence of product hedonism–utilitarianism and consumers’ tightwad–spendthrift tendency on the valuation of rented and borrowed objects is also examined.
Ambient mass spectrometry (AMS)‐based techniques are performed under ambient conditions in which the ionization and desorption occur in the open environment allowing the direct analysis of molecules ...with minimal or no sample preparation. A selected group of AMS techniques demonstrate imaging capabilities that can provide information about the localization of molecules on complex sample surfaces such as biological tissues. 2D, 3D, and multimodal imaging have unlocked an array of applications to systematically address complex problems in many areas of research such as drug monitoring, natural products, forensics, and cancer diagnostics. In the present review, we summarize recent advances in the field with respect to the implementation of new ambient ionization techniques and current applications in the last 5 years. In more detail, we mainly focus on imaging applications in topics related to animal whole bodies and tissues, single cells, cancer diagnostics and biomarkers, microbial cultures and co‐cultures, plant and natural product metabolomics, and forensic applications. Finally, we discuss new areas of research, future perspectives, and the overall direction that the field may take in the years to come.
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•Laser assisted synthesis of ultrapure carbon nanoparticles in deionized water.•Efficient generation of short chain polyynes with high laser repetition rates.•Optimization of ...viscosity of the colloidal suspension from 0.89 to 12mPa.s.•First time demonstration of laser generated nanoparticles as nano-inks.
High-quality carbon nanoparticles with controlled viscosity and high aqueous stability were prepared by liquid-phase laser ablation of a graphite target in deionized water. The size distribution was found to vary from 5nm to 50nm with mean size of 18nm, in the absence of any reducing chemical reagents. Efficient generation of short chain polyynes was recorded for high laser repetition rates. Homogeneous and stable nanoparticle suspensions with viscosities ranging from 0.89 to 12mPa.s were obtained by suspending the nanoparticles in different solvent mixtures such as glycerol–water and isopropanol–water. Optical properties were investigated by absorption and photoluminescence spectroscopy. Raman spectroscopy confirmed graphitic-like structure of nanoparticles and the surface chemistry was revealed by Fourier-transform infrared spectroscopy demonstrating sufficient electrostatic stabilization to avoid particle coagulation or flocculation. This paper present an exciting alternative method to engineer carbon nanoparticles and their potential use as a ligand-free nano-ink for ink jet printing (jetting) applications.
A picosecond laser ablation approach has been developed for the synthesis of ligand-free AuAg bimetallic NPs where the relative amount of Ag is controlled in situ through a laser shielding effect. ...Various measurements, such as optical spectroscopy, transmission electron microscopy combined with energy dispersive X-ray spectroscopy and inductively coupled plasma optical emission spectrometry, revealed the generation of homogenous 15 nm average size bimetallic NPs with different compositions and tunable localized surface plasmon resonance. Furthermore, ligand-free metallic nanoparticles with respect to chemically synthesized nanoparticles display outstanding properties, i.e. featureless Raman background spectrum, which is a basic requirement in many plasmonic applications such as Surface Enhanced Raman Spectroscopy. Various molecules were chemisorbed on the nanoparticle and SERS investigations were carried out, by varying the laser wavelength. The SERS enhancement factor for AuAg bimetallic NPs shows an enhancement factor of about 5.7 × 10(5) with respect to the flat AuAg surface.
Silicon nanoparticles were prepared by ultrafast laser ablation of a silicon target in deionized water. The nanoparticles were characterized by using optical absorption, Raman spectroscopy, and ...transmission electron microscopy. The mean size is found to vary from 60 to 2.5 nm in the absence of any reducing chemical reagents, decreasing the pulse energy value. High-resolution transmission electron microscopy together with Raman spectroscopy confirms the crystalline structure of the generated silicon nanoparticles. The energy confinement of carriers which is evaluated from optical experiments varies from 90 to 550 meV when the mean nanoparticles size decreases from 60 to 2.5 nm. In particular, the evaluated nanoparticle sizes from optical analysis and the LCAO theoretical model are found in agreement with transmission electron microscopy and Raman measurements for the silicon nanoparticles with a size less than 6 nm. Finally, we present stability studies which show that the smallest nanoparticles aggregate over time.
The COVID-19 pandemic has caused disruption in everyone's lives globally. Optometrists, being primary health care professionals are at a higher risk of infection in their practices during these ...testing times. Optometrists and optical store owners need practically implementable guidelines as lockdown gets lifted in various parts of our country. As these practices gear up to provide eye examination and vision correction to people, they need to take necessary precautions to avoid any cross contaminations. Optometry Council of India guidelines were circulated among optometry and optical associations and among experts in various optometry specialty. A consensus among various bodies were arrived. These guidelines provide recommendation for optical and optometry practices.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Heavy-metal-free semiconductor material like Silicon Nanoparticle (Si-NPs) is attracting scientists because of their diverse applications in biomedical field. In this work, pulsed laser ablation of ...silicon in aqueous solution is employed to generate Si-NPs in one step avoiding use of chemical precursors. Characterization by absorption, electron and photoluminescence analysis proves the generation of luminescent Si-NPs. The productivity rate of Si-NPs is investigated by Inductively Coupled Plasma Spectrometry. Furthermore, Si-NPs quantum yield and confocal microscopy studies corroborate the potential use of these biocompatible Si-NPs for imaging applications.
Depression and anxiety are two common normal responses to a chronic disease such as glaucoma. This study analysed the measurement properties of the depression screening instrument - Patient Health ...Questionnaire-9 (PHQ-9) using Rasch analysis to determine if it can be used as a measure.
In this hospital-based cross-sectional study, the PHQ-9 was administered to primary glaucoma adults attending a glaucoma clinic of a tertiary eye care centre, South India. All patients underwent a comprehensive clinical evaluation. Patient demographics and sub-type of glaucoma were abstracted from the medical record. Rasch analysis was used to investigate the following properties of the PHQ-9: behaviour of the response categories, measurement precision (assessed using person separation reliability, PSR; minimum recommended value 0.80), unidimensionality (assessed using item fit 0.7-1.3 and principal components analysis of residuals), and targeting.
198 patients (mean age ± standard deviation = 59.83±12.34 years; 67% male) were included. The native PHQ-9 did not fit the Rasch model. The response categories showed disordered thresholds which became ordered after category reorganization. Measurement precision was below acceptable limits (0.62) and targeting was sub-optimal (-1.27 logits). Four items misfit that were deleted iteratively following which a set of five items fit the Rasch model. However measurement precision failed to improve and targeting worsened further (-1.62 logits).
The PHQ-9, in its present form, provides suboptimal assessment of depression in patients with glaucoma in India. Therefore, there is a need to develop a new depression instrument for our glaucoma population. A superior strategy would be to use the item bank for depression but this will also need to be validated in glaucoma patients before deciding its utility.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We determined if the Impact of Vision Impairment (IVI) is a valid questionnaire to measure the vision-related quality of life (VRQoL) in keratoconus patients, and investigated if the VRQoL varied ...with disease severity in this sample.
WE RECRUITED 160 CONSECUTIVE BILATERAL KERATOCONUS PATIENTS (MEAN AGE 23.3 YEARS, 63% MALE) FROM AN INDIAN TERTIARY EYE CARE CENTER. PARTICIPANTS UNDERWENT A CLINICAL EXAMINATION AND COMPLETED THE IVI. PARTICIPANTS WERE DIVIDED INTO THREE GROUPS BASED ON THE AVERAGE OF THE STEEP KERATOMETRY (K) READINGS: mild (average Sim K < 45 diopters D), moderate (average Sim K 45-52 D), and severe (average Sim K > 52 D). Rasch analysis was used to validate the IVI and the VRQoL scores thus obtained were compared across the disease groups.
THE MAJORITY (63%) OF PATIENTS HAD SEVERE, WHILE THE REMAINDER (37%) HAD MODERATE KERATOCONUS. RASCH ANALYSIS DEMONSTRATED THE VALIDITY OF THE IVI TO ASSESS VRQOL THROUGH TWO SUBSCALES: vision-specific functioning (VF) and emotional well-being (EWB). There was no significant difference in VF (mean change -0.16, P = 0.55) and EWB scores (mean change -0.32, P = 0.23) between moderate and severe keratoconus groups.
The revised IVI subscales have interval-level measurement properties, which support their suitability to measure VRQoL in this keratoconus sample. Patients with moderate or severe keratoconus had similar, but higher VRQoL scores as assessed by the revised IVI subscales, indicating lack of impact of the disease on their VRQoL. However, this does not exclude the possibility of finding an impact in other populations.
Nanoalloys and nanocomposites are widely studied classes of nanomaterials within the context of biological systems. They are of immense interest because of the possibility of tuning the optical, ...magnetic, electronic and chemical properties through particle composition and internal architecture. In principle these properties can therefore be optimized for application in biological detections such as of DNA sequences, bacteria, viruses, antibodies, antigens, and cancer cells. This article presents an overview of methods currently used for nanoalloy and nanocomposite synthesis and characterisation, focusing on Au-Ag and Fe
x
O
y
@Au structures as primary components in detection platforms for plasmonic and magnetically enabled plasmonic bio-sensing.
Nanoalloys and nanocomposites are widely studied classes of nanomaterials within the context of biological systems. This article presents an overview of methods currently used for nanoalloy and nanocomposite synthesis and characterization, focusing on Au-Ag and FexOy@Au structures as primary components in detection platforms for plasmonic and magnetically enabled plasmonic bio-sensing.
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