Orientational Disorder Research Articles

Orientational Disorder of Alcohol Molecules at Their Solution Surfaces in Low Concentration Range: A Molecular Dynamics Simulation Study.

Molecular dynamics (MD) simulations of short-chain alcohols (methanol, ethanol, and 1-propanol) in solution were carried out to examine the orientational disordering (randomizing) of alcohol molecules at the surface under diluted conditions. Recent vibrational sum frequency generation (VSFG) spectroscopy, combined with photoelectron spectroscopy, has successfully measured the disordering structure at low concentrations. The present MD simulations accurately reproduce this observation for the first time. To ensure reliable results through MD simulations, several widely used force field models for water and alcohol, including polarizable models, were examined. This examination involved a comparison of structural and thermodynamic quantities, such as surface density times orientation and surface excess concentration, which were obtained through surface-specific measurements like VSFG spectroscopy and surface tension measurements. It is found that the width of the density profile for alcohol molecules at the surface, along the surface normal, increases as the concentration decreases in the diluted condition, which is consistent with the results obtained from the previous neutron and X-ray grazing incidence reflection experiments. A molecular mechanism explaining the disordering of alcohol molecules with decreasing concentration is also discussed.

An evaluation of measurement invariance of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition borderline personality disorder criteria across heterosexual, lesbian, gay, and bisexual adults.

There is a robust, yet poorly understood relationship between nonheterosexual orientation and borderline personality disorder (BPD), with lesbian, gay, and bisexual individuals evidencing greater BPD symptoms compared to heterosexual individuals. Recent evidence suggests possible psychometric bias in BPD diagnostic criteria leading to greater endorsement among sexual minority individuals, which hinders researchers' ability to make valid group comparisons. The present study utilized an epidemiological sample of 35,995 men and women to evaluate the extent of differential item functioning (DIF) among BPD criteria across sexual orientation groups using a multiple indicators multiple causes approach. All criteria except affective instability and emptiness indicated DIF for at least one sexual minority focal group, although both demonstrated DIF in sensitivity analyses. DIF was most consistently indicated for suicidality, efforts to avoid abandonment, and impulsivity. Contrary to predictions, DIF was mostly nonuniform with greater item discrimination for sexual minority groups compared to their heterosexual counterparts. Finally, all estimated effect sizes were small, suggesting that DIF was not practically meaningful and unlikely to impact the validity of group comparisons for BPD criteria across heterosexual and nonheterosexual men and women. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Crystal structure and compressibility of magnesium chloride heptahydrate found under high pressure.

The odd hydration number has so far been missing in the water-rich magnesium chloride hydrate series (MgCl2·nH2O). In this study, magnesium chloride heptahydrate, MgCl2·7H2O (or MgCl2·7D2O), which forms at high pressures above 2 GPa and high temperatures above 300 K, has been identified. Its structure has been determined by a combination of in-situ single-crystal X-ray diffraction at 2.5 GPa and 298 K and powder neutron diffraction at 3.1 GPa and 300 K. The single-crystal specimen was grown by mixing alcohols to prevent nucleation of undesired crystalline phases. The results show orientational disorder of water molecules, which was also examined using density functional theory calculations. The disorder involves the reconnection of hydrogen bonds, which differs from those in water ice phases and known disordered salt hydrates. Shrinkage by compression occurs mainly in one direction. In the plane perpendicular to this most compressible direction, oxygen and chlorine atoms are in a hexagonal-like arrangement.

Suppression of a Structural Phase Transition by an Orientational Disorder of Counteranions in an Organic Conductor, β″-β″-(BEDT-TTF)2ClC2H4SO3.

In 2022, we reported that the β″-(BEDT-TTF)2ClC2H4SO3 salt (1) has a phase transition at 210 K on cooling and 260 K on heating, which was suggested as a nondoped-to-doped transition. During the synthesis of 1, a second salt was coproduced, the structure and properties of which are reported here. The new salt β″-β″-(BEDT-TTF)2ClC2H4SO3 (2) has the same composition and is isomorphous to 1L, the low-temperature phase of 1. However, the salt shows no phase transition. 1H, the high-temperature phase of 1, displays rotational disorders of the -SO3- groups. In contrast, the anions in 2 have no rotational disorders but have orientational disorders. Approximately 13% of the anions in 2 have their orientation as opposed to the remaining anions. The geometrically calculated shortest O···O distance is 2.24 Å if neighbor -SO3- groups are able to rotate freely. This is 1.1 Å shorter than the sum of the van der Waals radii, and therefore, this is too close to allow free rotation. Therefore, it is proposed that 2 has no rotational disorder, which leads to no phase transition as is observed in 1.

A national longitudinal study of sexual orientation discordance, sexual identity fluidity, and alcohol and other drug use disorder symptoms

ABSTRACT Background: Many national studies fail to account for discordance between sexual orientation dimensions (e.g. a mismatch between sexual identity and sexual attraction) or sexual identity fluidity (e.g. changes in sexual identity over time). Objective: To examine the longitudinal relationships among sexual identity fluidity/stability, sexual orientation discordance/concordance, and alcohol and other drug use disorder symptoms. Methods: The study used nationally representative longitudinal data from Waves 1–5 (2013–2019) of the Population Assessment of Tobacco and Health (PATH) study of US adolescents and adults (N = 24,591). Results: Substance use disorder symptoms were most prevalent (45.8%) among bisexual-stable females relative to all other sexual identity subgroups. The adjusted odds ratios (AORs) of substance use disorder symptoms were significantly higher among bisexual-stable females vs. heterosexual-stable females in all models (AOR range: 1.94–2.32), while no such associations were found for males. Sexual identity-attraction discordant females had significantly greater AORs (17/20 instances) of substance use disorder symptoms compared to concordant females; this finding was not as consistent for males (6/20 instances). Conclusion: Sexual orientation discordance was significantly associated with substance use disorder symptoms, especially among females discordant in their sexual identity and attraction. Bisexual-stable and discordant females are at highest risk of developing symptomatic substance use; it is vital that they receive screening, no matter where they are in their coming out process. This study highlights pitfalls of relying solely on cross-sectional data using a single sexual orientation dimension to understand the relationship between sexual orientation and substance use disorder.

Critical Role of Framework Flexibility and Disorder in Driving High Ionic Conductivity in LiNbOCl4.

Understanding Li-ion transport is key for the rational design of superionic solid electrolytes with exceptional ionic conductivities. LiNbOCl4 is reported to be one of the most highly conducting materials in the recently realized new class of soft oxyhalide solid electrolytes, exhibiting an ionic conductivity of ∼11 mS·cm-1. Here, we apply X-ray/neutron diffraction and pair distribution function analysis─coupled with density functional theory/ab initio molecular dynamics (AIMD)─to determine a structural model that provides a rationale for the high conductivity that we observe experimentally in this nanocrystalline solid. We show that it arises from unusually high framework flexibility at room temperature. This is due to isolated 1-D [NbOCl4]- anionic chains that exhibit energetically favorable orientational disorder that is─in turn─correlated to multiple, disordered, and equi-energetic Li+ sites in the lattice. As the Li ions sample the 3-D energy landscape with a fast predicted diffusion coefficient of 5.1 × 10-7 cm2/s at room temperature (σicalc = 17.4 mS·cm-1), the inorganic polymer chains can reorient or vice versa. The activation energy barrier for Li migration through the frustrated energy landscape is especially reduced by the elastic nature of the NbO2Cl4 octahedra evident from very widely dispersed Cl-Nb-Cl bond angles in AIMD simulations at 300 K. The phonon spectra are predominantly influenced by Cl vibrations in the low energy range, and there is a strong overlap between the framework (Cl, Nb) and Li partial density of states in the region between 1.2 and 4.0 THz. The framework flexibility is also reflected in a relatively low bulk modulus of 22.7 GPa. Our findings pave the way for the investigation of future "flex-ion" inorganic solids and open up a new direction for the design of high-conductivity, soft solid electrolytes for all-solid-state batteries.

Magnetic Bistability in the Crystaline Fullerene Radical Salt

Comprehensive SummaryCompounds with magnetic bistability is highly attractive for the construction of switches, thermal sensors, information‐storage media and memory devices. Herein, we report a crystalline fullerene radical anion salt [Na(THF)5]C60 (1), obtained by the reduction of C60 with Na in solution, which exhibits magnetic bistability accompanied with one magnetostructural transition, giving low temperature (LT), high temperature (HT) phases and a metastable phase. Fullerene radical anions (C60•‐) in the structure were found arranged into a three‐dimensional close‐packed honeycomb subnetwork with hollow channels occupied by complex cations [Na(THF)5]+ as spacers. The magnetic bistability is attributed to structural transitions as the LT−IT phase transition was associated with the orientational disorder of fullerene anions and the distortion of the complex cations [Na(THF)5]+ in the 3D packing of fullerene anions.

Coupling between cation and anion disorder in β-K2Ca3(CO3)4

Since the development of anionic group theory, the spatial arrangement of anionic groups in optical crystals has been believed to determine their functional, such as nonlinear optical, properties. At the same time, cation substitution, resulting in either the appearance of disordered cation sites in a crystal structure or the emergence of cation-ordered superstructures, has been widely used to control material properties. This work demonstrates the coupling between positional cation disorder and orientational disorder of (CO3)2− anions in the β modification of the recently described K2Ca3(CO3)4 material. In contrast to the α modification [P212121, a = 7.39134 (18), b = 8.8153 (2), c = 16.4803 (4) Å], where the ordered cation sublattice favors the non-centrosymmetric orientationally ordered arrangement of (CO3)2− anionic groups, positional cation disorder in β-K2Ca3(CO3)4 [Pnma, a = 7.5371 (2), b = 16.1777 (5), c = 8.7793 (3) Å] within the cation sublattice of the same topology leads to orientational disorder of (CO3)2− groups and the appearance of an inversion center in the average structure.

On the Structural and Vibrational Properties of Solid Endohedral Metallofullerene Li@C60

The endohedral lithium fulleride, Li+@C60•−, is a potential precursor for new families of molecular superconducting and electronic materials beyond those accessible to date from C60 itself. Solid Li@C60 comprises (Li@C60)2 dimers, isostructural and isoelectronic with the (C59N)2 units found in solid azafullerene. Here, we investigate the structural and vibrational properties of Li@C60 samples synthesized by electrolytic reduction routes. The resulting materials are of high quality, with crystallinity far superior to that of their antecedents isolated by chemical reduction. They permit facile, unambiguous identification of both the reduced state of the fulleride units and the interball C-C bonds responsible for dimerization. However, severe orientational disorder conceals any crystal symmetry lowering due to the presence of dimers. Diffraction reveals the adoption of a hexagonal crystal structure (space group P63/mmc) at both low temperatures and high pressures, typically associated with close-packing of spherical monomer units. Such a situation is reminiscent of the structural behavior of the high-pressure Phase I of solid dihydrogen, H2.

Lost in space(s): Multimodal neuroimaging of disorientation along the Alzheimer's disease continuum.

Orientation is a fundamental cognitive faculty and the bedrock of the neurologic examination. Orientation is defined as the alignment between an individual's internal representation and the external world in the spatial, temporal, and social domains. While spatial disorientation is a recognized hallmark of Alzheimer's disease (AD), little is known about disorientation beyond space in AD. This study aimed to explore disorientation in spatial, temporal, and social domains along the AD continuum. Fifty-one participants along the AD continuum performed an ecological orientation task in the spatial, temporal, and social domains while undergoing functional MRI. Disorientation in AD followed a three-way association between orientation domain, brain region, and disease stage. Specifically, patients with early amnestic mild cognitive impairment exhibited spatio-temporal disorientation and reduced brain activity in temporoparietal regions, while patients with AD dementia showed additional social disorientation and reduced brain activity in frontoparietal regions. Furthermore, patterns of hypoactivation overlapped different subnetworks of the default mode network, patterns of fluorodeoxyglucose hypometabolism, and cortical atrophy characteristic of AD. Our results suggest that AD may encompass a disorder of orientation, characterized by a biphasic process manifesting as early spatio-temporal and late social disorientation. As such, disorientation may offer a unique window into the clinicopathological progression of AD. SIGNIFICANCE STATEMENT: Despite extensive research into Alzheimer's disease (AD), its core cognitive deficit remains a matter of debate. In this study, we investigated whether orientation, defined as the ability to align internal representations with the external world in spatial, temporal, and social domains, constitutes a core cognitive deficit in AD. To do so, we used PET-fMRI imaging to collect behavioral, functional, and metabolic data from 51 participants along the AD continuum. Our findings suggest that AD may constitute a disorder of orientation, characterized by an early spatio-temporal disorientation and followed by late social disorientation, manifesting in task-evoked and neurodegenerative changes. We propose that a profile of disorientation across multiple domains offers a unique window into the progression of AD and as such could greatly benefit disease diagnosis, monitoring, and evaluation of treatment response.

Localization-antilocalization of soundwaves in a disordered phononic crystal with mirror symmetry

Anderson localization in a disordered potential leads to exponential decay of an incoming wave. However, if a 1D disordered potential possesses mirror symmetry, V(-x) = V(x), then the eigenstates are either even or odd functions of x. As such, a wave localized on one side of such a symmetric disordered potential should elicit a corresponding antilocalized peak at the symmetric position on the other side. The distribution of pressure in a symmetric disordered potential is similar to the wave function profile in a symmetrical double-well potential. This similarity opens a way to demonstrate quantum tunneling using acoustic waves. This effect has an important application to secure communications, as the transmitted signal is reduced by disorder to the level of noise, thus excluding the possibility of signal interception, then enhanced by the symmetric part of the potential at the receiver. This is a secure method of information transmission without the need for encryption and decryption. We developed a methodology for identifying the frequency spectrum consisting of narrow doublets that correspond to eigenstates of different parities. A 2 × 30 phononic crystal with orientational disorder was fabricated for experimental observation of antilocalization. [This work is supported by the NSF under EFRI Grant No. 1741677.]

Sidey V.I. ON THE IONIC RADIUS OF THE CYANIDE ION

Sidey V.I. ON THE IONIC RADIUS OF THE CYANIDE ION

Nuclear quantum effects in the acetylene:ammonia plastic co-crystal.

Organic molecular solids can exhibit rich phase diagrams. In addition to structurally unique phases, translational and rotational degrees of freedom can melt at different state points, giving rise to partially disordered solid phases. The structural and dynamic disorder in these materials can have a significant impact on the physical properties of the organic solid, necessitating a thorough understanding of disorder at the atomic scale. When these disordered phases form at low temperatures, especially in crystals with light nuclei, the prediction of material properties can be complicated by the importance of nuclear quantum effects. As an example, we investigate nuclear quantum effects on the structure and dynamics of the orientationally disordered, translationally ordered plastic phase of the acetylene:ammonia (1:1) co-crystal that is expected to exist on the surface of Saturn's moon Titan. Titan's low surface temperature (∼90K) suggests that the quantum mechanical behavior of nuclei may be important in this and other molecular solids in these environments. By using neural network potentials combined with ring polymer molecular dynamics simulations, we show that nuclear quantum effects increase orientational disorder and rotational dynamics within the acetylene:ammonia (1:1) co-crystal by weakening hydrogen bonds. Our results suggest that nuclear quantum effects are important to accurately model molecular solids and their physical properties in low-temperature environments.

Predicting the Resilience of the Elderly in Tehran, Iran, Based on Their Religious Orientation, Mental Toughness, Physical Health, and Sleep Disorders

Background and Aims With the increase in the aged population, the physical and mental health of the elderly have become more important. Since resilience is an important concept in the mental health of the elderly, this study aims to predict the resilience of the elderly in Tehran, Iran, based on their religious orientation, mental toughness, physical health, and sleep disorders. Methods This is a descriptive-correlational study with a cross-sectional design. Participants were 256 elderly people aged >60 years (Mean age: 66.42±4.37 years) selected by a simple random sampling method from those living in Kahrizak Nursing Home in Tehran, Iran. They completed the Connor-Davidson resilience scale, Clough et al.’s mental toughness questionnaire-48 items, physical health questionnaire, and Lynch’s sleep disturbance questionnaire to measure resilience, religious orientation, mental toughness, physical health, and sleep disorders. Finally, the collected data were analyzed using structural equation modeling in AMOS and SPSS software, version 23. Results Religious orientation (t=4.32, r=0.24, P<0.001), mental toughness (t=6.87, r=0.68, P<0.001), physical health (t=5.12, r=0.57, P<0.001) and sleep disorders (t=-5.18, r=-0.52, P<0.001) could significantly predict the resilience of the elderly in Tehran. Conclusion The resilience of the elderly in Tehran has a positive and significant relationship with their religious orientation, mental toughness, physical health, and sleep disorders. These components can predict the resilience of the elderly. Therefore, by controlling these components, the resilience of the elderly can be improved.

Properties of silicon nanoparticles prepared by pulse discharge and ball milling.

In this paper, nano-silicon particles were prepared by pulse discharge and ball milling. Firstly, the bulk silicon material was gasified and melted at high temperature in the process of pulse discharge, and then the micro nanoparticles with small grain sizes, a high degree of disorder in crystal orientation and a certain amorphous structure were obtained by rapid condensation. The particles and internal grains were further refined by ball milling, and finally silicon nanoparticles with a high degree of amorphization, an average particle size of about 80.4 nm and a uniform size distribution were obtained. The results show that the longer the milling time, the smaller the grain size and the higher the proportion of the amorphous phase. The electrochemical performance analysis shows that the first charge specific capacity of Si pulse discharge is 3824 mA h g-1, and the coulombic efficiency is 83.1%. After 100 cycles, the capacity retention rate is 14.2%, while the capacity retention rate of Si-15 h is 41.5%, which greatly improves the cycle life. The preparation method of silicon nanoparticles proposed in this paper is simple and effective, shortens the preparation time, and obtains silicon nanoparticles with a high degree of amorphization, which can provide a new method for the preparation of silicon nanoparticles.

Orientational order/disorder and network flexibility in deuterated methylammonium lead iodide perovskite by neutron total scattering

Methylammonium lead iodide crystallises in three phases. The high-temperature phase is cubic with a high degree of orientational disorder of the molecular ions. The intermediate phase shows progressive alignment of the molecules, but still with disorder.

Clinicopathologic Analyses of Failed Endothelial Keratoplasty (the Clinical Cases)

Purpose: To evaluate the clinicopathologic features of failed endothelial keratoplasty. Methods. In this study 11 patients (11 eyes) with recurrence of bullous keratopathy (BK) were included. Group 1 consisted of 4 patients who underwent repeat Descemet Stripping Automated Endothelial Keratoplasty (DSAEK), group 2 included 7 patients who underwent penetrating keratoplasty (PK) after failed Descemet Membrane Endothelial Keratoplasty (DMEK). Preoperative anterior segment optical coherence tomography (OCT), RTVue-100, Optovue, USA, was performed. Intraoperatively aqueous humour (AqH) samples were collected for multiplex cytokine analysis. During keratoplasty failed grafts/corneal buttons were obtained and then investigated histologically (hematoxylin/eosin staining, primary antibodies to pancytokeratin, vimentin, collagen III). Results. Recurrence of BK in all clinical cases manifests by the increase of inflammatory factors in AqH, corneal edema, neovascularization and remodeling to fibrosis. Glaucoma may induce DMEK/ DSAEK graft failure due to chronic local inflammation. In the clinical cases recurrence of BK was caused by peripheral and central graft detachment, rebubbling, graft upside-down orientation and donor corneal genetic disorders. Conclusions. Chronic local inflammation (including corneal morphological changes) in patients with BK recurrence is an indication for reoperation. The modification of keratoplasty — DMEK/DSAEK/PK — is determined according to slit-lamp and OCT images of the cornea. High-level risk of immune reaction (especially in cases of three and more times repeated keratolasty) is the reason for systemic corticosteroid and, sometimes, cytostatic therapy.

Dimorphism of [Bi2O2(OH)](NO3) - the ordered Pna21 structure at 100 K.

The re-investigation of [Bi2O2(OH)](NO3), dioxidodibismuth(III) hydroxide nitrate, on the basis of single-crystal X-ray diffraction data revealed an apparent structural phase transition of a crystal structure determined previously (space group Cmc21 at 173 K) to a crystal structure with lower symmetry (space group Pna21 at 100 K). The Cmc21 → Pna21 group-subgroup relationship between the two crystal structures is klassengleiche with index 2. In contrast to the crystal structure in Cmc21 with orientational disorder of the nitrate anion, disorder does not occur in the Pna21 structure. Apart from the disorder of the nitrate anion, the general structural set-up in the two crystal structures is very similar: [Bi2O2]2+ layers extend parallel to (001) and alternate with layers of (OH)- anions above and (NO3)- anions below the cationic layer. Whereas the (OH)- anion shows strong bonds to the BiIII cations, the (NO3)- anion weakly binds to the BiIII cations of the cationic layer. A rather weak O-H⋯O hydrogen-bonding inter-action between the (OH)- anion and the (NO3)- anion links adjacent sheets along [001].

STUDI KASUS PADA PASIEN DENGAN GANGGUAN PERSEPSI SENSORI: HALUSINASI PENDENGARAN

Hallucinations are a form of reality orientation disorder which is characterized by a person giving a response or assessment without any stimulus received by the five senses, and is one of the effects of perceptual disorders. The aim of this research is to provide nursing care to patients with auditory sensory perception disorders using dhikr and istighfar therapy. The method used by researchers is qualitative research using case studies with a nursing process approach to one of the patients who experienced sensory perception disorders. Data assessment was carried out by interviewing, observing and looking at the patient's medical records. Data analysis was carried out by data collection and data reduction. The research results showed that the patient was able to control his auditory hallucinations with dhikr and istighfar therapy. Spiritual Therapy with dhikr and istighfar, namely treatment aimed at curing mental illness, for each individual, with inner or spiritual strength, in the form of religious rituals rather than treatment with drugs, with the aim of strengthening a person's faith so that they can develop their potential and religious nature maximally, so it can be concluded that the application of dhikr and istighfar therapy can control the auditory hallucinations experienced by patients.

Slightly Hydrogen-Ordered State of Ice IV Evidenced by In Situ Neutron Diffraction.

Ice IV is a metastable high-pressure phase of ice in which the water molecules exhibit orientational disorder. Although orientational ordering is commonly observed for other ice phases, it has not been reported for ice IV. We conducted in situ powder neutron diffraction experiments for DCl-doped D2O ice IV to investigate its hydrogen ordering. We found abrupt changes in the temperature derivative of unit-cell volume, dV/dT, at ∼120 K, and revealed a slightly ordered structure at low temperatures based on the Rietveld method. The occupancy of the D1 site deviates from 0.5 in particular; it increased when samples were cooled at higher pressures and reached 0.174(14) at 2.38 GPa, 58 K. Our results evidence the presence of a low-symmetry hydrogen-ordered state corresponding to ice IV. It seems, however, difficult to experimentally access the completely ordered phase corresponding to ice IV by slow cooling at high pressure.