Changes In Cell Parameters Research Articles

Structural Changes in Ytterbium Ferrite YbFe2O4 in the Temperature Range From–150 °C TO 300 °C

Structural changes and thermal expansion of the iron ferrite sample YbFe2O4 of a rhombohedral modification are studied by high-temperature X-ray diffraction and differential thermal analysis. It is demonstrated that no phase transitions are observed in the temperature range from–150 °C to 300 °С. There are only anisotropic changes in unit cell parameters due to changes in Yb–O and Fe–O bond lengths.

High-Temperature Studies of the Thermal Expansion of FeNb2O6

High-temperature X-ray diffraction is used to study structural changes and thermal expansion of the synthesized iron niobate sample FeNb2O6 of the orthorhombic modification. It is demonstrated that no phase transformations are observed in the temperature range 30–1230 °C; there are only anisotropic changes in unit cell parameters. The temperature dependences of the unit cell parameters are approximated by third order polynomials. Tensor coefficients of the thermal expansion are calculated based on the obtained data. The Schneider-Eberhard formalism is used for the quantitative estimation of thermal expansion anisotropy.

Impact of Corticosteroid Administration on Outcomes Following Stereotactic Ablative Radiation Therapy for Non-Small Cell Lung Cancer

Because radiotherapy (RT) induces beneficial antitumoral immune responses, administering corticosteroids (CS) for other medical issues such as COPD, RT-related toxicity attenuation, is a major oncologic concern. This is the only known study evaluating the impact of CS on outcomes of early-stage non-small cell lung cancer (NSCLC) following stereotactic ablative RT (SABR). A prospectively-registered institutional database of SABR for early-stage non-metastatic NSCLC was queried (2005-2015). CS administration (non-inhaled, regardless of dose/agent) was dichotomized based on two definitions: 1) CS receipt within two days of the SABR course, and 2) CS delivery between up to 6 months before SABR and the date of last follow-up or any progressive disease (LFU/PD). Statistics included Kaplan-Meier survival analysis, Cox proportional hazards modeling, and cumlative incidence analysis utilizing death as a competing risk model evaluated with Gray’s test. Of 912 consecutive patients, 87 (10%) received CS based on the ± 2-day definition, and 211 (23%) based on the LFU/PD definition. The most common CS agents were prednisone (62%) and dexamethasone (19%); most common CS indications were COPD (34%) and pneumonitis caused by SABR or other previous treatments (24%). Median follow-up was 45 months. Groups were largely well-balanced. Patients receiving CS appears to have a significant change in blood white cell parameters. Although CS administration associated with worse isolated locoregional recurrence-free survival, distant metastasis-free survival, recurrence-free survival, and overall survival on Kaplan-Meier and Cox multivariate analysis, there were no differences in cumulative incidences of recurrence (local, regional, isolated locoregional, distant, any) when using death as a competing risk model, in both CS delivery definitions (p>0.05 for all). Although further corroboration is required and causation is not implied, these data do not suggest a detriment in outcomes if corticosteroids are administered in proximity with SABR. Individualized judgment in administering CS for these settings is still recommended. These data have implications not only for ongoing cooperative group trials, but also the construction and implementation of immunotherapy-SABR trials.

Grain size effects on irradiated CeO2, ThO2, and UO2

Microcrystalline and nanocrystalline UO2, ThO2, and CeO2 (∼2 μm and∼20 nm particle size, respectively) were irradiated with 946 MeV Au ions at room temperature and characterized by synchrotron X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. All samples show a small increase in unit cell parameter as a function of ion fluence (0.17 ± 0.03% for CeO2 and 0.11 ± 0.03% for ThO2), except microcrystalline UO2, which displays a small contraction of the unit cell (−0.06 ± 0.02%). Raman spectroscopy measurements of microcrystalline UO2 indicate an increase in nonstoichiometry after irradiation. All bulk materials are subject to an increase in heterogeneous microstrain, most notably UO2, implying that the relatively small changes in unit cell parameter are accompanied by substantial local disorder induced by isolated defects. The magnitude of volumetric swelling for all materials is larger in the nanocrystalline form as compared with the microcrystalline form (0.38 ± 0.60% for CeO2, 0.14 ± 0.03% for ThO2, and 0.52 ± 0.13% for UO2). ThO2 shows the smallest difference in swelling between the microcrystalline and nanocrystalline samples (∼0.03%). All nanocrystalline materials exhibit irradiation-induced grain coarsening along with a decrease in heterogeneous microstrain with increasing ion fluence, except nanocrystalline CeO2, which shows no observable change in grain size and a slight increase in heterogeneous microstrain attributed to the accelerated formation of a secondary Ce11O20 phase evidenced in the X-ray diffraction data, present in both nanocrystalline and microcrystalline materials. Surprisingly, nanocrystalline UO2 exhibits a significant degree of swelling indicative of a decrease in oxygen content along with an increase in disorder induced by oxygen loss at grain boundaries during irradiation, based on the analysis of X-ray diffraction and Raman spectroscopy.

Changes in cell parameters and improvement in photocatalytic activity of KNbO3 and NaNbO3 crystals via polarization

A representative ferroelectric tetragonal potassium niobate (TKN) and antiferroelectric orthorhombic sodium niobate (ONN) crystalline powder samples were polarized by using an external electric field. The changes in lattice distortion and crystal symmetry of these samples polarized were revealed. The photocatalytic activities of the samples before and after the polarization were evaluated by photocatalytic decomposition of water and photocatalytic reduction of Ag+. The results imply that the polarization of such kind of perovskite-type niobate samples using the external electric field is one of effective ways to improve the photocatalytic performance, whether ferroelectric TKN or antiferroelectric ONN. The exploration of mechanism suggests that the polarization can change the ferroelectricity of niobate powder crystals. Furthermore, the photocatalytic activity on different exposed facets of these niobate crystals was also evaluated by detecting Ag content on the surfaces of sample via photocatalytic reduction of Ag+. It is found that {001} facet is the highest active facet of TKN, and {101} facet of ONN crystals has the highest photocatalytic activity among the exposed facets. The photocatalytic activity on each exposed facet can be increased to a certain extent by polarization, and the influence of polarization on photocatalytic activity is greater than that of surface energy.

Detection of Cell Morphological Changes of Ischemic Rabbit Liver Tissue Using Bioimpedance Spectroscopy.

Bioimpedance spectroscopy is a promising method for tissue ischemia monitoring; it is used in this research to study ischemia and cell morphology using bioimpedance measurements of rabbit liver tissue. This paper presents the evolution of Cole parameters and cell parameters with time and establishes a relation between cellular morphological changes during cell ischemia with bioimpedance measurements at different frequencies. The general behavior of ischemic liver tissue has been analyzed. Evolution of Cole parameters was extrapolated from BIS measurements, and their behavior was studied with respect to time. Then, cell parameters were estimated from Cole parameters. A detailed analysis of the changes of cell parameters was done in parallel with explanations for these changes depending on the physiological mechanism of ischemia and necrosis bioprocess. These explanations give a confirmation of the established relation between cell morphological changes and the corresponding BIS measurements.

Effect of Mn substitution on superconductivity in iron selenide (Li, Fe)OHFeSe single crystals**Project supported by the National Key Research and Development Program of China (Grant Nos. 2017YFA0303003 and 2016YFA0300300), the National Natural Science Foundation of China (Grant No. 11574370), and the Strategic Priority Research Program and Key Research Program of Frontier Sciences of the Chinese Academy of Sciences (Grant Nos.

We synthesize a series of Mn substituted (Li, Fe)OHFeSe superconductor single crystals via a modified ion-exchange method, with the Mn concentration z (the atomic ratio of Mn:Se) ranging from 0 to 0.07. The distribution homogeneity of the Mn element incorporated into the lattice of (Li, Fe)OHFeSe is checked by combined measurements of high-angle-annular-dark-field (HAADF) imaging and electron energy-loss spectroscopy (EELS). Interestingly, we find that the superconducting transition temperature Tc and unit cell parameter c of the Mn-doped (Li, Fe)OHFeSe samples display similar V-shaped evolutions with the increasing dopant concentration z. We propose that, with increasing doping level, the Mn dopant first occupies the tetrahedral sites in the (Li, Fe)OH layers before starting to substitute the Fe element in the superconducting FeSe layers, which accounts for the V-shaped change in cell parameter c. The observed positive correlation between the Tc and lattice parameter c, regardless of the Mn doping level z, indicates that a larger interlayer separation, or a weaker interlayer coupling, is essential for the high-Tc superconductivity in (Li, Fe)OHFeSe. This agrees with our previous observations on powder, single crystal, and film samples of (Li, Fe)OHFeSe superconductors.

High pressure magnetic, structural, and electronic transitions in multiferroic Ba3NbFe3Si2O14

The magnetic, structural, and electronic properties of multiferroic Ba3NbFe3Si2O14 from the langasite family were investigated by several methods including synchrotron X-ray diffraction (XRD) and synchrotron Mössbauer source (SMS) technique at high hydrostatic pressures (up to 60 GPa) created in diamond anvil cells. A cascade of structural phase transitions at pressures of about 3.5, 17.5, and 41 GPa was revealed by structural XRD, magnetic SMS, and electronic methods, including Raman, Mössbauer, and optical absorption. The transition at 17.5 GPa leads to strong changes in unit cell parameters and a sharp drop in the cell volume by about 7%. This drastically changes the magnetic properties of the crystal, which separates into two magnetic phases. The Néel temperature TN in one of the phases is increased up to 100 K, which is more than three times higher than the TN value of the parent compound (∼27 K). Above 41 GPa, the optical gap decreases to about 0.7 eV, implying a transition from dielectric to a semiconducting state, while the TN value of the magnetic phase decreases from 100 to 58 K. The magnetic transitions are explained by the redistribution of Fe ions between tetrahedral and possibly octahedral (or/and interstitial) sites resulting in enhancement of exchange interactions. The appearance of a low spin state of Fe3+ ions in octahedral sites is also discussed.

Formulas for the Detection β-Thalassemia Carriers Are Affected by Changes in Red Cell Parameters.

Formulas for the Detection β-Thalassemia Carriers Are Affected by Changes in Red Cell Parameters.

Blood Cellular Haematological Changes in Patients with Visceral Leishmaniasis Attending Kimalel SubCounty Hospital, Baringo County

Background: Visceral Leishmaniasis (VL) or Kala-azar is a chronic infectious disease caused by parasites of the Leishmania donovani complex that can cause various hematologic manifestations. Anemia is the most common hematological manifestation but the disease may also be associated with leucopenia, thrombocytopenia, and hemophagocytosis and disseminated intravascular coagulation. VL is characterized by fever, hepatomegaly, and splenomegaly and weight loss. Diagnostic as well as clinical symptomatology is non-specific in VL; the diagnostic mechanisms utilized are both invasive and time consuming. Using hematological blood cell parameter changes as a unique indicator of VL will pave way for fast Turnaround Time (TAT) and management. Objectives: to determine unique blood cellular changes that can be used to aid in early diagnosis of visceral leishmaniasis Study subjects: seventy four participants diagnosed with visceral leishmaniasis Materials and Methods: splenic aspirates stained with Giemsa stain were examined for detecting LD bodies. Complete blood cell count and differential counts, red blood cells examination were done Results: There were no significant unique blood cellular changes that can be used for early diagnosis and detection of VL Conclusions: While cellular changes are noted in VL, they may not be solely significant in the diagnosis of VL

Effect of broccoli sprouts on thyroid function, haematological, biochemical, and immunological parameters in rats with thyroid imbalance

Broccoli sprouts may exert a negative influence on thyroid function as they are a rich source of glucosinolates, in particular glucoraphanin. Under the study in a long-term experiment broccoli sprouts were tested as an element of rats diet, combined with deficient iodine, or sulfadimethoxine ingestion – two models of hypothyroidism. Evaluations were performed for serum TSH and thyroid hormones completed with analyzes of selected haematological, biochemical and immunological (IL-6, IL-10) parameters, as well as cytosolic glutathione peroxidase (GPX1), thioredoxin reductase (TR) in the thyroid, and plasma glutathione peroxidase (GPX3). A thermographic analysis was conducted to provide auxiliary indicators for determining a potential thyroid dysfunction under the specific experimental conditions. The levels of TSH, fT3 and fT4 remained unchanged following broccoli sprouts ingestion, which was even found to have a protective effect against sulfadimethoxine induced thyroid damage. Moreover, TR activity significantly increased in response to sprouts ingestion. In animals with hypothyroidism, broccoli sprouts were found to exert a beneficial influence on the antioxidant balance of the thyroid gland. In comparison to the rats with iodine deficiency, broccoli sprouts addition to the diet was observed to decrease IL-6 level. No significant differences in IL-10 concentration were determined.Neither addition of broccoli sprouts to the diet, nor sulfadimethoxine and iodine deficiency, caused negative changes in red blood cell parameters, glucose and uric acid concentrations, or kidney function. However, such a dietary intervention resulted in reduced WBC and PLT levels, and it may adversely interfere with liver function in rats, most likely due to a higher dietary intake of glucosinolates.

Effect of thrombopoietin receptor agonists on leukocyte and haematopoietic stem and progenitor cells in the peripheral blood of patients with immune thrombocytopenic purpura.

The thrombopoietin receptor agonists (TPO-RAs), romiplostim and eltrombopag, stimulate megakaryopoiesis and thereby increase platelet counts. Both drugs are increasingly used in the treatment of immune thrombocytopenic purpura (ITP). To assess the effect of TPO-RAs on trilineage haematopoiesis, colony-forming cell (CFC) assays were performed on peripheral blood mononuclear cells of 8 healthy donors and 52 ITP patients. Additionally, we revaluated the regular and complete blood counts (CBCs) performed during romiplostim therapy in 45 patients and the CBCs performed in 9 patients during eltrombopag therapy. The clonogenic capacity of PBMCs was significantly increased in patients treated with TPO-RAs compared with healthy donors and untreated patients [BFU-E, 69±47; CFU-GM, 61±48; CFU-GEMM, 16±11; CFU-total, 145±94; P values <0.05)]. Relative leukocytosis was observed in routine blood counts in 12 of 45 (26%) patients treated with romiplostim. The regular CBCs, performed time dependent within the first 5days, revealed a maximum increase of leukocytes on days 2 and 3 following romiplostim administration. There were no significant changes in red blood cell parameters. None of the affected patients did recognise any significant symptom, which may be related to leukocytosis. Similarly, we observed a statistically significant increase of leukocyte count in a small cohort of ITP patients (n=9) in whom CBCs were controlled following treatment initiation (P=0.044). Our results indicate that TPO-RAs may also mobilize haematopoietic stem and progenitor cells (HSPCs) in peripheral blood and the occurrence of such relative leukocytosis may signalize an early symptom of myelofibrosis due to treatment with TPO-RAs.

Cation Disorder In Cu2ZnSnS4Thin Films: Effect On Solar Cell Performances

High (300 °C) and low (160 °C) temperature post deposition annealing treatments are performed on Cu2ZnSnS4 (CZTS) thin film solar cells to modify the order degree of the CZTS absorber and investigate its effect on the device performances. Large and reversible changes of solar cell parameters are observed, with photovoltaic conversion efficiencies varying from about 4% in the case of more ordered materials, up to nearly 8% after the disordering treatment. Both spectrophotometry and photoluminescence reveal that the ordered materials are characterized by a higher bandgap and a lower deep defect density, whereas the absorption tails and the red shift of the luminescence peak compared to the bandgap are found to be independent of the ordering level. Coherently with the bandgap variation, solar cells in the ordered state are characterized by a lower short circuit current density and a higher open circuit voltage. Ordered devices are found to be limited by low fill factor values, often associated with anomalous “S-shaped” light J–V curves revealing a blocking behavior. A mechanism based on the increase of a blocking barrier at the CZTS/MoS2 back interface induced by a change in the valence band offset is proposed to explain the lower performances of the ordered devices.

Aluminium metallisation for interdigitated back-contact silicon heterojunction solar cells

Back-contact silicon heterojunction solar cells with an efficiency of 22% were manufactured, featuring a simple aluminium metallisation directly on the doped amorphous silicon films. Both the open-circuit voltage and the fill factor heavily depend on the parameters of the annealing step after aluminium layer deposition. Using numerical device simulations and in accordance with the literature, we demonstrate that the changes in solar cell parameters with annealing can be explained by the formation of an aluminium silicide layer at temperatures as low as 150 °C, improving the contact resistance and thus enhancing the fill factor. Further annealing at higher temperatures initialises the crystallisation of the amorphous silicon layers, yielding even lower contact resistances, but also introduces more defects, diminishing the open-circuit voltage.

Inorganic Anions Regulate the Phase Transition in Two Organic Cation Salts Containing [(4-Nitroanilinium)(18-crown-6)]+ Supramolecules

Inorganic Anions Regulate the Phase Transition in Two Organic Cation Salts Containing [(4-Nitroanilinium)(18-crown-6)]+ Supramolecules

Chemical and physical characterizations of the n = 1 Ruddlesden–Popper phases: Nd2 − y Sr y Ni1 − x Co x O4 ± δ (y = 1 and 0.1 ≤ x ≤ 0.9)

The structural stability and physical properties of NdSrNi1 − xCoxO4 ± δ (0.1 ≤ x ≤ 0.9) mixed oxides, elaborated by conventional sol–gel process, have been investigated and obtained results show that substitution of nickel by cobalt at x = 0.5 enhances conductivity at room temperature; σ = 17.24 Ω−1 cm−1 coinciding with minimum activation energy (Ea = 0.05 eV). Rietveld refinements of X-ray powder diffraction patterns at room temperature indicate that all compositions crystallize in a tetragonal system with I4/mmm space group and exhibit K2NiF4-type structure. Variations of a and c parameters display various behavior with increasing cobalt content. Changes in cell parameters are discussed in terms of crystal field theory. In addition, transition metal oxidation state is investigated on the basis of the Brown bond valence calculation. The deduced Global Instability Index (GII) value decreases when cobalt substance increases, indicating that the structure becomes more stable once cobalt is introduced. Oxygen stoichiometry of these compounds was determined from thermogravimetric analyses (TGA) followed by reduction in 5% H2 in N2 gas. Conductivity of NdSrNi1 − xCoxO4 ± δ (0.1 ≤ x ≤ 0.9) oxides was measured by an ac four-probe method. Oxygen vacancies are the possible ionic charge carriers. Specimens exhibit a semiconducting behavior in the whole range of temperature. The electrical transport mechanism agrees with an adiabatic small polaron hopping (ASPH) model. [Figure not available: see fulltext.]. © 2017, Springer-Verlag Berlin Heidelberg.

Crystal-chemistry insight into the photocatalytic activity of BiOClxBr1−x nanoplate solid solutions

In this study, a facile alcoholysis method was developed to synthesize BiOCl x Br1−x nanoplates at room temperature and atmospheric pressure. In this route, strong acid or alkaline environment was absolutely avoided to realize the high exposure of {001} crystal facets. The regular changes in XRD peaks and cell parameters as a function of the Br content strongly declared that the obtained BiOCl x Br1−x products belonged to a group of solid solutions. The 2D nanosheets with in-plane wrinkles were clearly observed in TEM images. Interestingly, as the Br content increased, band gaps of BiOCl x Br1−x solid solutions gradually decreased. The photocatalytic degradation of RhB under simulated sunlight irradiation indicated that BiOCl0.5Br0.5 had the best photocatalytic activity. From the viewpoint of crystal chemistry, the photocatalytic activity of BiOCl x Br1−x solid solutions was closely related with the exposure amount of {001} facets, interlayer spacing of (001) plane and energy-level position of valence band.

Temperature Dependence in the Terahertz Spectrum of Nicotinamide: Anharmonicity and Hydrogen-Bonded Network.

We have investigated the terahertz-spectral property of nicotinamide focusing on the temperature dependence in the range of 14-300 K. We observed that almost all peaks in the terahertz spectrum of the nicotinamide crystal showed a remarkable shift with temperature, whereas the lowest-frequency peak at 34.8 cm-1 showed a negligible shift with temperature. By analyzing the terahertz spectrum with the dispersion-corrected density functional theory calculations, we found that the difference in the temperature dependence of the peak shift is well understood in terms of the presence/absence of stretching vibration of the intermolecular hydrogen bond in the mode and the change of cell parameters. The anharmonicity in the dissociation potential energy of very weak intermolecular hydrogen bonding causes the remarkable peak shift with temperature in the terahertz spectrum of nicotinamide. This finding suggests that the assignment and identification of peaks in the terahertz spectrum are systematically enabled by temperature-dependent measurements.

Epitaxy of oligothiophenes on alkali metal hydrogen phthalates: Simulations and experiments.

Three alkali metal hydrogen phthalate salts (denoted as XAP, X = K+, Rb+, and Cs+) are chosen as substrates for the growth of quaterthiophene (4T) and hexathiophene (6T) thin films by organic molecular beam epitaxy to study the influence of gradual changes of surface unit cell parameters on the epitaxialgrowth. The increment of substrate lattice parameters increases the distance between the planes that define the furrows where oligothiophene molecules lie, while keeping unmodified the interactions between the overlayer and the substrate. Atom-atom potential simulations predict the preferential azimuthal orientations of the overlayer, which are compared with those experimentally observed. The agreement between simulations and experiments about contact planes and orientation of the crystalline domains in the films is satisfactory for both 4T/XAP and 6T/XAP. The increasing width of the surface furrows existing on moving from KAP to RbAP and CsAP does not cause any significant variation of the orientation and density of the overlayer domains, demonstrating that the interaction between overlayer and substrate is the key factor guiding organic epitaxialgrowth.

Dynamics of cytochemical parameters of pseudoeosinophils in the blood of guineafow

The cytochemical organization of neutrophils and pseudoeosinophils in different classes of vertebrates is poorly studied. The purpose of this study is to determine the cytochemical status of pseudoeosinophils in the blood of guineafowl. We analyzed the blood of Volga white guineafowl breed, colored blue and gray-speckled guineafowl populations (174, 186, and 208 days) and one-day-old nestlings of these populations. It was found that the changes in cytochemical blood cell parameters during the period of development (days 174–208) were multidirectional: the activity of acid phosphatase and glycogen increased, while the activity of myeloperoxidase and alkaline phosphatase decreased. The activity rates of myeloperoxidase and lysosomal-cationic proteins during this period were stable.