Orientational Disorder Research Articles

Structure and Dynamics in Mg2+-Stabilized γ-Na3PO4.

In parallel with advances in the synthesis of solid-state ionic conductors, there is a need to understand the underlying mechanisms behind their improved ionic conductivities. This can be achieved by obtaining an atomic level picture of the interplay between the structure of materials and the resultant ionic diffusion processes. To this end, the structure and dynamics of Mg2+-stabilized rotor phase material γ-Na3PO4, characterized by neutron scattering, are detailed in this work. The Mg2+-stabilized rotor phase is found to be thermally stable from 4 to 650 K. However, signatures of orientational disorder of the phosphate anions are also evident in the average structure. Long-range Na+ self-diffusion was probed by quasi-elastic neutron scattering and subsequently modeled via a jump diffusion matrix with consideration of the phosphate anion rotations. The resultant diffusion model points directly to coupled anion-cation dynamics. Our approach highlights the importance of considering the whole system when developing an atomic level picture of structure and dynamics, which is critical in the rational design and optimization of energy materials.

High-temperature γ ↔ β′ ↔ α phase transitions in Ca2B2O5: Thermal expansion and crystal structure of α-phase

A sequence of reversible phase transitions γ ↔ β′ (at 511°С) ↔ α (at 587°С) was found in Ca2B2O5 by high-temperature X-ray powder diffraction, DSC and in the high-temperature Raman spectroscopy. The crystal structure of high-temperature modification, α-Ca2B2O5, was refined by the Rietveld method at 600°С. It is isostructural to the α-Sr2B2O5 and shows the orientational disorder of isolated B2O5 pyroborate groups. Thermal expansion is strongly anisotropic (α11 = 25, α22 = 7, α33 = 2 × 10−6 °C−1 at 400 °C) and dictated by preferential orientations of BO3 triangles in the structure.

Diagnostic assessments leading to the acceptance of incapacity or limited legal capacity and their relationship with the parameters of forensic psychiatric examination and expert assessment

The terms "capability" and "incapability" are the most common and most important in forensic psychiatric practice in civil proceedings. Capability is acquired by presumption, and incapability is subject to proof. In the study of incapability there is no single standard that would guarantee the unification of forensic psychiatric practice in the field of capability. The ambiguities in the incapability criteria lead to unsatisfactory reliability in the preparation of forensic psychiatric evaluation by various experts. The purpose of this publication is to analyze the diagnostic assessments leading to the acceptance of incapability or limited capability and their relationship with the parameters of forensic psychiatric examination and expert assessment. The subject of the study are a total of 327 persons, certified in civil cases by experts with subsequent court decisions by the District Court - Varna, for a period of 5 years. To determine the criterion of "incapability" in psychiatric diagnoses, the most common are the following symptoms and syndromes: thinking disorders, hallucinations or delusions of reality, affective disorders with a predominance of diseased emotions, disorders of personality orientation and situations, attention disorders and memory, severe disorders of the self, quantitative and qualitative disorders of consciousness, lack of insight, negative symptoms, paratymia and parabulia.

Features of prognostic function in patients with ischemic stroke of frontal localization in the early recovery period

The article presents the results of the research of the features of the anticipation and prognostic function in patients with ischemic stroke of frontal localization in the early recovery period.Material and methods. The total sample group was represented by 60 patients who had suffered an ischemic stroke of frontal or parietal localization. The average age of the research subjects was 53.00 ± 5.44 years. The study was conducted with the use of functional neuropsychological tests (by A.R. Luria, L.S. Tsvetkova), methods of predictive function research (time estimation test, spatial anticipation test, Maze test, London Tower test, “incomplete images” test), as well as statistical methods of quantitative and qualitative data processing.Results. In patients with prefrontal localization of ischemic stroke a specific impairment of prognostic function and a non-specific decrease in anticipation were revealed. It is due to disorders of mental activity purposefulness and preliminary orientation in the conditions of the task. When the lesion was localized in the premotor areas, a less significant decrease in the rate and accuracy of the prognostic function due to the inertia of the mental processes was revealed. In the localization of ischemic stroke in the associative parietal cortex, a specific decrease in the rate and accuracy of sensorimotor, perceptual, and temporal anticipation was revealed, as well as a non-specific decrease in the rate of planning, while maintaining its accuracy of implementation.Conclusion. In terms of practical significance, taking into account the features of prognostic function that have arisen in a particular form of brain damage can serve as a basis for restoring other gnostic or motor impaired functions, increasing the effectiveness of correctional and rehabilitation measures.

Structural and Electronic Properties of Small Perovskite Nanoparticles of the Form ABX3 (A = MA, DEA, FA, GA, B = Pb, Sn, X = Cl, Br, I)

Using a combination of first principles and semiempirical calculation, we explore the structural, electronic, and optical properties of a wide range of perovskite (ABX3) nanoparticle of different size and composition. The variations of the BX3 backbone structure considered include all possible combinations of the cations B=Pb,Sn and the anions X=Cl,Br,I, while the interstitial cation A is either methylamonium (MA), or formamidinium (FA), or guanidine amine (GA), or dimethylamine (DEA). Our results indicate that the orientational disorder of the A moieties may affect the structural and electronic properties of the NPs while the optical properties exhibit a clear dependence on the NPs’ size and the types of B cations and X anions, but they are quite insensitive to the type of A cation.

Collagen fiber orientation disorder from H&E images is prognostic for early stage breast cancer: clinical trial validation

Collagen fiber organization has been found to be implicated in breast cancer prognosis. In this study, we evaluated whether computerized features of Collagen Fiber Orientation Disorder in Tumor-associated Stroma (CFOD-TS) on Hematoxylin & Eosin (H&E) slide images were prognostic of Disease Free Survival (DFS) in early stage Estrogen Receptor Positive (ER+) Invasive Breast Cancers (IBC). A Cox regression model named MCFOD-TS, was constructed using cohort St (N = 78) to predict DFS based on CFOD-TS features. The prognostic performance of MCFOD-TS was validated on cohort Sv (N = 219), a prospective clinical trial dataset (ECOG 2197). MCFOD-TS was prognostic of DFS in both St and Sv, independent of clinicopathological variables. Additionally, the molecular pathways regarding cell cycle regulation were identified as being significantly associated with MCFOD-TS derived risk scores. Our results also found that collagen fiber organization was more ordered in patients with short DFS. Our study provided a H&E image-based pipeline to derive a potential prognostic biomarker for early stage ER+ IBC without the need of special collagen staining or advanced microscopy techniques.

Evaluation of the predictive validity of the Hessisch Oldendorf Risk of Falling Scale (HOSS)

Objective: This study aims to further validate the Hessisch Oldendorf Risk of Falling Scale (HOSS) for neurological rehabilitation patients. Design: The overall scale performance and fall rate was calculated in a retrospective data analysis. Setting: The study was performed in a subacute care facility during inpatient neurological rehabilitation. Subjects: The study population (n = 512) included neurological and neurosurgical patients with heterogeneous levels of disability. Main measures: The HOSS total score and the suspected risk of falling were compared with the number of falls. Characteristics of fallers and non-fallers were compared using non-parametric group comparisons. Overall scale performance was assessed by calculating the area under the receiver operating characteristic curve of the HOSS as well as by calculating the sensitivity and specificity. Results: A total of 82 (16%) patients experienced at least one fall. Fallers were characterized by an older age, a longer length of stay, a more severe impairment in the activities of daily living upon admission, a hemiparesis, an orientation disorder, a need of a walking aid device and an urinary incontinence. The number of falls was associated with the HOSS total score. Sixty-four fallers and two hundred seventy-four non-fallers were correctly categorized leading to a sensitivity of 78.0% and a specificity of 63.7%. The area under the receiver operating characteristic curve of the HOSS was 0.778 ± 0.25 (CI = 0.729–0.828, P < 0.001). Conclusion: The scale performance of the HOSS showed a good sensitivity and an adequate specificity to identify neurological patients who are at high risk of falling during inpatient rehabilitation.

2/1 and 1/1 cubic approximants in the ternary R-Cd-Mg (R = Y, Er) systems

The atomic structures of three cubic approximants (cAPs), Y12.7Cd61.8Mg25.5 [2/1 cAP with space group Pa 3, a = 25.0654 (1) Å] and Er12.5Cd72.0Mg15.5 [2/1 cAP with Pa 3, a = 24.9658 (1) Å], and Y14.5Cd66.1Mg19.4 [1/1 cAP with Im 3, a = 15.4577 (1) Å], were investigated using X-ray structure analysis. The two 2/1 cAPs were found to be isostructural to the binary 2/1 cAP, YbCd5.8, which is composed of two building units, namely Tsai-type rhombic triacontahedron (RTH) cluster and double-Friauf polyhedron (DFP). The 1/1 cAP, in contrast, was found to be isostructural to the binary 1/1 cAP, YbCd6, which is composed solely of the RTH cluster. The refined structure models of the three cAPs exhibit substitutional disorders due to the Mg content that enters into Cd sites of the parent binary cAPs. In addition, in the 2/1 cAPs, the Y3(Er3) site on the third icosahedron shell of the RTH cluster and two positions inside DFP, Y5(Er5) sites, are partially mixed with Mg. Moreover, characteristic positional disorders owing to orientational disorder in the first shell of the RTH cluster is observed in all the three cAPs. A close relationship between the occupational disorder of the Y3(Er3) and Y5(Er5) sites in 2/1 cAPs and the elemental distribution in their first coordination shells is revealed.

The role of the envelope protein in the stability of a coronavirus model membrane against an ethanolic disinfectant.

Ethanol is highly effective against various enveloped viruses and can disable the virus by disintegrating the protective envelope surrounding it. The interactions between the coronavirus envelope (E) protein and its membrane environment play key roles in the stability and function of the viral envelope. By using molecular dynamics simulation, we explore the underlying mechanism of ethanol-induced disruption of a model coronavirus membrane and, in detail, interactions of the E-protein and lipids. We model the membrane bilayer as N-palmitoyl-sphingomyelin and 1-palmitoyl-2-oleoylphosphatidylcholine lipids and the coronavirus E-protein. The study reveals that ethanol causes an increase in the lateral area of the bilayer along with thinning of the bilayer membrane and orientational disordering of lipid tails. Ethanol resides at the head-tail region of the membrane and enhances bilayer permeability. We found an envelope-protein-mediated increase in the ordering of lipid tails. Our simulations also provide important insights into the orientation of the envelope protein in a model membrane environment. At ∼25 mol. % of ethanol in the surrounding ethanol-water phase, we observe disintegration of the lipid bilayer and dislocation of the E-protein from the membrane environment.

Influence of molecular architecture, hydrogen bonding, chemical moieties and flexible chain for smectic polymorphism in (4)EoBD(3)AmBA:nOBAs

A novel series of calamitic, complementary hydrogen-bonded (HB), meta-extended Schiff base core containing liquid crystalline (LC) complexes with ethoxy chain at one end and varied flexible chain at other end, viz., (4)EoBD(3)AmBA:nOBAs for n = 3–12 is reported. 1H, 13C NMR and FTIR spectroscopy confirm complex formation. LC phases, phase transition temperatures (T C) and enthalpy are characterized by polarizing optical microscopy and differential scanning calorimetry(DSC). SmA, SmC, SmBcryst,SmF, SmI, SmE, SmG and SmH phases are exhibited. Clearing and melting temperatures exhibit odd–even effect. Schiff base bridged by oxygen atom promoted of smectic phase occurrence. Complementary HB-induced and -enhanced tilted smectic phase range. Large LC phase variants, i.e., tetra, penta and hexa are observed. Hexa LC phase variant for n = 6 and 12. Unlike in p-n-alkoxy benzoic acids (nOBAs), Nematic phase is quenched. Quasi two-dimensional LC SmF and SmI phases identified. Lower (for n = 3,5), intermediate (for n = 6,7) and higher (n = 9) homologues exhibit 3D SmBcryst phase. Monotropic LC phase occurrence is also noticed. Apart from other LC phase transitions, SmA–SmC transition is mostly found to be second order or very weakly first order nature. Phase diagram by DSC infers existence of multi-critical points in the vicinity of SmF and SmI phase structures with psuedo hexagonal packing. Influence of meta-extended core, complementary HB and flexibility component are discussed for LC phase abundance. Role of orientational disorder induced by flexible component discussed. In comparison with LC phase occurrence in (4)MeoBD(3)AmBA:nOBAs, shielded inductomeric effect is argued for large thermal range of tilted smectic phases. Integrated and differential heat energies are estimated in successive heating and cooling scans to investigate optimized realization of LC phases. Results are discussed in the wake of contemporary reports in other LCs.

Lowering the Activation Barriers for Lithium-Ion Conductivity through Orientational Disorder in the Cyanide Argyrodite Li6PS5CN

Lowering the Activation Barriers for Lithium-Ion Conductivity through Orientational Disorder in the Cyanide Argyrodite Li₆PS₅CN

Structure and nature of ice XIX

Ice is a material of fundamental importance for a wide range of scientific disciplines including physics, chemistry, and biology, as well as space and materials science. A well-known feature of its phase diagram is that high-temperature phases of ice with orientational disorder of the hydrogen-bonded water molecules undergo phase transitions to their ordered counterparts upon cooling. Here, we present an example where this trend is broken. Instead, hydrochloric-acid-doped ice VI undergoes an alternative type of phase transition upon cooling at high pressure as the orientationally disordered ice remains disordered but undergoes structural distortions. As seen with in-situ neutron diffraction, the resulting phase of ice, ice XIX, forms through a Pbcn-type distortion which includes the tilting and squishing of hexameric clusters. This type of phase transition may provide an explanation for previously observed ferroelectric signatures in dielectric spectroscopy of ice VI and could be relevant for other icy materials.

Understanding disorder and linker deficiency in porphyrinic zirconium-based metal\u2013organic frameworks by resolving the Zr8O6 cluster conundrum in PCN-221

Porphyrin-based metal–organic frameworks (MOFs), exemplified by MOF-525, PCN-221, and PCN-224, are promising systems for catalysis, optoelectronics, and solar energy conversion. However, subtle differences between synthetic protocols for these three MOFs give rise to vast discrepancies in purported product outcomes and description of framework topologies. Here, based on a comprehensive synthetic and structural analysis spanning local and long-range length scales, we show that PCN-221 consists of Zr6O4(OH)4 clusters in four distinct orientations within the unit cell, rather than Zr8O6 clusters as originally published, and linker vacancies at levels of around 50%, which may form in a locally correlated manner. We propose disordered PCN-224 (dPCN-224) as a unified model to understand PCN-221, MOF-525, and PCN-224 by varying the degree of orientational cluster disorder, linker conformation and vacancies, and cluster–linker binding. Our work thus introduces a new perspective on network topology and disorder in Zr-MOFs and pinpoints the structural variables that direct their functional properties.

Ultrastructural mitral valve abnormalities in infective endocarditis

Aim. Using an original method based on backscattered scanning electron microscopy, to study the structural features of the mitral valve leaflets in infective endocarditis.Material and methods. We examined 9 mitral valves extracted during surgical interventions due to structural malfunction in patients with infective endocarditis (IE). The samples were fixed in buffered paraformaldehyde with osmium tetraoxide postfixation. After dehydration by increasing alcohol concentration and acetone, the samples were placed in epoxy resin. After the resin has polymerized, the samples were ground and then polished to the desired depth. To increase the electronic contrast, the samples were treated with a uranyl acetate alcohol solution during dehydration and with Reynolds' lead citrate after polishing the epoxy blocks. The samples were visualized by backscattered scanning electron microscopy at an accelerating 15-kV voltage.Results. Structural leaflet injuries caused by IE were most pronounced in the central part and the base. Necrotic areas were extensive electron-dense formations located in the central leaflet layers, or displaced towards the ventricular surface. The electron-dense material in the necrotic area was poorly structured and contained individual cells and bacteria. Bacteria were also present outside the necrotic area. Necrotic areas were surrounded by a layer of a modified extracellular matrix, usually covered with a fibrin layer. Among the extracellular matrix fibers, the macrophages, smooth myocytes and fibroblasts was noted. The fibrin layer, in addition to these cells, contained a large number of blood vessels and was often covered with endothelium.Conclusion. Infection of the mitral valve leaflets causes a simultaneous inflammatory response and regeneration activation. Without adequate regulatory factors, the processes of inflammation and connective tissue creation lead to structural and functional leaflet failure. Specific causes may be overgrowth of necrotic and inflammatory areas, edema and fiber orientation disorder, as well as leaflet rupture.

Detecting rotational disorder in heme proteins: A comparison between resonance Raman spectroscopy, nuclear magnetic resonance, and circular dichroism

AbstractIn heme proteins, the canonical and reversed conformations result from the rotation of the heme group by 180° about the α,γ‐meso axis in the protein pocket. The coexistence of the two different heme orientations has been observed both in proteins reconstituted with hemin and in some native proteins. The reversal of the heme orientation can also change certain functional properties of heme proteins. Complementing the results from other experimental techniques, like circular dichroism and nuclear magnetic resonance, resonance Raman spectroscopy provides detailed information on the structure of the reversed heme. This allows one to elucidate the effects of the heme rotation on the vibrational spectra of the peripheral substituents, especially the vinyl groups. Furthermore, the combination of resonance Raman spectroscopy on single crystals and solution samples of heme proteins is proposed to be a sensitive tool to detect heme orientational disorder, even in the absence of structural data.

A Psychological Portrait of a Teenager in the Posttraumatic Confusional State

The Russian statistics demonstrate that in Russia, brain injuries are increasing every year what is particularly tragic if to speak about children. After traumatic brain injury (TBI), the process of consciousness restoration develops in stages. In Russian science, stages of mental recovery in adults are described by the neuropsychiatric group of researchers from Burdenko Institute of Neurosurgery. The authors have introduced the term amnestic confusion to designate the stage at which there is a possibility to have the verbal contact with amnestic defects and disorders of orientation in time and space. In foreign literature, this stage is defined as post-traumatic state of confused consciousness (PTCS). In children (adolescents), the state of confused consciousness after traumatic brain injury is met in about 80%. The aim of the study was to make a detailed description and phenomenological analysis of some psychological characteristics of the confused state in adolescents after brain injury what will add to the overall picture of medical and neuropsychological examinations. 62 teenagers in the confused consciousness state after TBI were taken into the study. The authors present their observations and analysis of such psychological phenomena as behavioral and emotional characteristics, social intelligence, gender and age identification.

Anisotropy in fifth-order exciton-exciton-interaction two-dimensional spectroscopy.

Exciton-exciton-interaction two-dimensional (EEI2D) spectroscopy is a fifth-order variant of 2D electronic spectroscopy. It can be used to probe biexciton dynamics in molecular systems and to observe exciton diffusion in extended systems such as polymers or light-harvesting complexes. The exciton transport strongly depends on the geometrical and energetic landscape and its perturbations. These can be of both local character, such as molecular orientation and energetic disorder, and long-range character, such as polymer kinks and structural domains. In the present theoretical work, we investigate the anisotropy in EEI2D spectroscopy. We introduce a general approach for how to calculate the anisotropy by using the response-function formalism in an efficient way. In numerical simulations, using a Frenkel exciton model with Redfield-theory dynamics, we demonstrate how the measurement of anisotropy in EEI2D spectroscopy can be used to identify various geometrical effects on exciton transport in dimers and polymers. Investigating a molecular heterodimer as an example, we demonstrate the utility of anisotropy in EEI2D spectroscopy for disentangling dynamic localization and annihilation. We further calculate the annihilation in extended systems such as conjugated polymers. In a polymer, a change in the anisotropy provides a unique signature for exciton transport between differently oriented sections. We analyze three types of geometry variations in polymers: a kink, varying geometric and energetic disorder, and different geometric domains. Our findings underline that employing anisotropy in EEI2D spectroscopy provides a way to distinguish between different geometries and can be used to obtain a better understanding of long-range exciton transport.

Reversible colossal barocaloric effects near room temperature in 1-X-adamantane (X=Cl, Br) plastic crystals

Plastic crystals undergo phase transitions with unusually large volume and entropy changes related to strong molecular orientational disordering. These features have led to a resurgent interest in these materials because recently they have shown great potential in solid-state cooling applications driven by pressure. Here we demonstrate that two plastic crystals derived from adamantane -1-Br-adamantane and 1-Cl-adamantane- undergo colossal reversible barocaloric effects under moderate pressure changes in a wide temperature span near room temperature thanks to a relatively small hysteresis and very high sensitivity of the transition temperature to pressure. In particular, 1-Cl-adamantane displays an optimal operational temperature range covering from ~40 K below and up to room temperature, and under a pressure change of 1 kbar this compound outperforms any other barocaloric material known so far. Our work gives strong support to plastic crystals as best candidates for barocaloric cooling. We also provide insight into the physical origin of the entropy changes through the analysis of the disorder on the involved phases.

Infectious keratoconjunctivitis in red deer (Cervus elaphus) in Poland - A case report

Infectious keratoconjunctivitis (IKC) has not been observed in European deer (Cervus elaphus). Our case concerned two red deer bulls in a natural environment, which had orientation disorders and/or circle movement. A detailed post-mortem examination of one of the bulls revealed extensive conjunctivitis in both eyes, clouding and ulceration of the cornea. There were no lesions in the other organs, particularly in the central nervous system (CNS). The histopathological examination of the eyeballs showed corneal epithelium erosions and vascularisation and an inflammatory infiltration of the stroma. Descemet’s membrane was found to be disrupted and the corneal stroma was fused with the iris. The remaining structure of the eye did not show any lesions. Furthermore, the polymerase chain reaction analysis for OvHV-1, BHV-1, BHV-5, CapHV-1, CcHV-1, and EHV-1 showed negative results. In the agar culture, only single bacteria were present. There were no Thelazia spp. worms in the conjunctival sac, but numerous Lipoptena cervi flies were present on the skin in the eye region and on the corneal surface. The findings of our case study and those reported in the literature suggest that IKC is a polyetiological disease, where the composition of the pathogenic agents may differ from case to case. The present study suggests that the mechanical irritation of L. cervi parasites could be a contributing factor to the corneal damage, infection and chronic inflammation resulting in a loss of vision in red deer.

What We Know About the Genetic Determinants of Human Homosexuality? A Short Review Communication

“Homosexualism”, “sexual orientation disorder”, “egodistonic homosexuality”, “unspecified sexual disorder”, “sexual maturity disorder” and “sexual relationship disorder”. Since 1948, these have been, throughout the history of the Diagnostic and Statistical Manual of Mental Disorders (DCM) and the International Statistical Classification of Diseases and Related Health Problems (ICD), the terms used by the scientific community to categorize the homoaffective spectrum until in 2017, in the face of strong social and academic demand, their complete disengagement from any terminology that categorizes them as physical and/or mental illness. On the other hand, some areas of science have contributed substantially to a better understanding of this subject, such as genetics and epigenetics. Today, although the scientific community still offers some points of resistance, especially in more conservative countries, it is a consensus that since the implementation of the genome project there has been a considerable methodological expansion that has opened new possibilities of studies that have allowed this advance.