Lattice Dynamics and Network Dynamics Calculations on Vibrational Modes of Lithium Borate Glasses

1990 ◽  
Vol 210 ◽  
Author(s):  
J. Deppe ◽  
M. Balkanski ◽  
R. F. Wallis ◽  
M. Massot
Keyword(s):  
Lattice Dynamics ◽  
Structural Changes ◽  
Structural Model ◽  
Nearest Neighbor ◽  
Network Dynamics ◽  
Borate Glasses ◽  
Vibrational Modes ◽  
Good Qualitative Agreement ◽  
Covalently Bonded ◽  
The Family

AbstractThe central force nearest neighbor model for glasses is used to discuss the Raman and infrared vibrational data for the family of lithium doped borate glasses B2O3 - xLi2O. The addition of the dopant is shown to cause local structural changes, including the transformation of three-coordinated borons to four-coordinated ones. An extremely simple structural model for the glass gives good qualitative agreement with experiment. The results of lattice dynamics calculations fall within the allowed frequency band limits predicted by network dynamics. The success of this model illustrates the importance of short range order on the vibrational spectra of covalently bonded solids.

Lattice-dynamics and network-dynamics studies of vibrational modes in lithium-doped borate glasses

1990 ◽  
Vol 41 (11) ◽  
pp. 7767-7773 ◽  
Author(s):  
J. Deppe ◽  
M. Balkanski ◽  
R. F. Wallis
Keyword(s):  
Lattice Dynamics ◽  
Network Dynamics ◽  
Borate Glasses ◽  
Vibrational Modes

Structure-Sensitive Vibrations in Zeolites as Studied by Raman Scattering

1987 ◽  
Vol 111 ◽  
Author(s):  
R. G. Buckley ◽  
H. W. Deckman ◽  
J. M. Newsam ◽  
J. A. McHenry ◽  
P. D. Persans ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Lattice Dynamics ◽  
Nearest Neighbor ◽  
Low Frequency ◽  
Force Model ◽  
Vibrational Modes ◽  
Vibrational Assignments ◽  
Structure Sensitive ◽  
Bending Mode ◽  
Bond Bending

AbstractIn this paper we demonstrate the usefulness of a nearest neighbor force model for studying the structural dependence of the lattice dynamics of zeolites. Interpreting Raman scattering in the context of this model confirms earlier empirical vibrational assignments in zeolites and underlines the importance of short range forces in determining the frequencies of certain zeolite vibrational modes. The model describes fully the low frequency bond bending mode of A1 symmetry, although long range forces are shown to be required to model complete zeolite vibrational spectra.

PENENTUAN DAERAH PRIORITAS PELAYANAN AKTA KELAHIRAN DENGAN METODE K-NN DAN K-MEANS

2020 ◽  
Vol 17 (1) ◽  
pp. 319-328
Author(s):  
Ade Muchlis Maulana Anwar ◽  
Prihastuti Harsani ◽  
Aries Maesya
Keyword(s):  
Nearest Neighbor ◽  
Information Gain ◽  
Birth Certificate ◽  
Population Data ◽  
Community Services ◽  
Birth Certificates ◽  
Similar Data ◽  
K Nearest Neighbor ◽  
Civil Registration ◽  
The Family

Population Data is individual data or aggregate data that is structured as a result of Population Registration and Civil Registration activities. Birth Certificate is a Civil Registration Deed as a result of recording the birth event of a baby whose birth is reported to be registered on the Family Card and given a Population Identification Number (NIK) as a basis for obtaining other community services. From the total number of integrated birth certificate reporting for the 2018 Population Administration Information System (SIAK) totaling 570,637 there were 503,946 reported late and only 66,691 were reported publicly. Clustering is a method used to classify data that is similar to others in one group or similar data to other groups. K-Nearest Neighbor is a method for classifying objects based on learning data that is the closest distance to the test data. k-means is a method used to divide a number of objects into groups based on existing categories by looking at the midpoint. In data mining preprocesses, data is cleaned by filling in the blank data with the most dominating data, and selecting attributes using the information gain method. Based on the k-nearest neighbor method to predict delays in reporting and the k-means method to classify priority areas of service with 10,000 birth certificate data on birth certificates in 2019 that have good enough performance to produce predictions with an accuracy of 74.00% and with K = 2 on k-means produces a index davies bouldin of 1,179.

scholarly journals Secondary Structural Model of MALAT1 Becomes Unstructured in Chronic Myeloid Leukemia and Undergoes Structural Rearrangement in Cervical Cancer

2021 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Matthew C. Wang ◽  
Phillip J. McCown ◽  
Grace E. Schiefelbein ◽  
Jessica A. Brown
Keyword(s):  
Cervical Cancer ◽  
Chronic Myeloid Leukemia ◽  
Hela Cells ◽  
Binding Sites ◽  
Myeloid Leukemia ◽  
Structural Changes ◽  
Structural Model ◽  
Dimethyl Sulfate ◽  
K562 Cells ◽  
Cancer Types

Long noncoding RNAs (lncRNAs) influence cellular function through binding events that often depend on the lncRNA secondary structure. One such lncRNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), is upregulated in many cancer types and has a myriad of protein- and miRNA-binding sites. Recently, a secondary structural model of MALAT1 in noncancerous cells was proposed to form 194 hairpins and 13 pseudoknots. That study postulated that, in cancer cells, the MALAT1 structure likely varies, thereby influencing cancer progression. This work analyzes how that structural model is expected to change in K562 cells, which originated from a patient with chronic myeloid leukemia (CML), and in HeLa cells, which originated from a patient with cervical cancer. Dimethyl sulfate-sequencing (DMS-Seq) data from K562 cells and psoralen analysis of RNA interactions and structure (PARIS) data from HeLa cells were compared to the working structural model of MALAT1 in noncancerous cells to identify sites that likely undergo structural alterations. MALAT1 in K562 cells is predicted to become more unstructured, with almost 60% of examined hairpins in noncancerous cells losing at least half of their base pairings. Conversely, MALAT1 in HeLa cells is predicted to largely maintain its structure, undergoing 18 novel structural rearrangements. Moreover, 50 validated miRNA-binding sites are affected by putative secondary structural changes in both cancer types, such as miR-217 in K562 cells and miR-20a in HeLa cells. Structural changes unique to K562 cells and HeLa cells provide new mechanistic leads into how the structure of MALAT1 may mediate cancer in a cell-type specific manner.

LATTICE DYNAMICS OF THE BINARY APERIODIC CHAINS OF ATOMS I: FRACTAL DIMENSION OF PHONON SPECTRA

1995 ◽  
Vol 09 (12) ◽  
pp. 1429-1451 ◽  
Author(s):  
WŁODZIMIERZ SALEJDA
Keyword(s):  
Fractal Dimension ◽  
Lattice Dynamics ◽  
Nearest Neighbor ◽  
Average Distance ◽  
Local Maximum ◽  
Fractal Dimensions ◽  
Dimension Formula ◽  
Phonon Spectra ◽  
Wide Range ◽  
Silver Mean

The microscopic harmonic model of lattice dynamics of the binary chains of atoms is formulated and studied numerically. The dependence of spring constants of the nearest-neighbor (NN) interactions on the average distance between atoms are taken into account. The covering fractal dimensions [Formula: see text] of the Cantor-set-like phonon spec-tra (PS) of generalized Fibonacci and non-Fibonaccian aperiodic chains containing of 16384≤N≤33461 atoms are determined numerically. The dependence of [Formula: see text] on the strength Q of NN interactions and on R=mH/mL, where mH and mL denotes the mass of heavy and light atoms, respectively, are calculated for a wide range of Q and R. In particular we found: (1) The fractal dimension [Formula: see text] of the PS for the so-called goldenmean, silver-mean, bronze-mean, dodecagonal and Severin chain shows a local maximum at increasing magnitude of Q and R>1; (2) At sufficiently large Q we observe power-like diminishing of [Formula: see text] i.e. [Formula: see text], where α=−0.14±0.02 and α=−0.10±0.02 for the above specified chains and so-called octagonal, copper-mean, nickel-mean, Thue-Morse, Rudin-Shapiro chain, respectively.

scholarly journals Involvement of loop 5 lysine residues and the N-terminal β-hairpin of the ribotoxin hirsutellin A on its insecticidal activity

2016 ◽  
Vol 397 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Miriam Olombrada ◽  
Lucía García-Ortega ◽  
Javier Lacadena ◽  
Mercedes Oñaderra ◽  
José G. Gavilanes ◽  
...  
Keyword(s):  
Active Sites ◽  
Structural Changes ◽  
The Other ◽  
Spatial Proximity ◽  
Ribonucleolytic Activity ◽  
The Family ◽  
Lysine Residues ◽  
Hirsutella Thompsonii ◽  
Close Spatial Proximity ◽  
High Degree

Abstract Ribotoxins are cytotoxic members of the family of fungal extracellular ribonucleases best represented by RNase T1. They share a high degree of sequence identity and a common structural fold, including the geometric arrangement of their active sites. However, ribotoxins are larger, with a well-defined N-terminal β-hairpin, and display longer and positively charged unstructured loops. These structural differences account for their cytotoxic properties. Unexpectedly, the discovery of hirsutellin A (HtA), a ribotoxin produced by the invertebrate pathogen Hirsutella thompsonii, showed how it was possible to accommodate these features into a shorter amino acid sequence. Examination of HtA N-terminal β-hairpin reveals differences in terms of length, charge, and spatial distribution. Consequently, four different HtA mutants were prepared and characterized. One of them was the result of deleting this hairpin [Δ(8-15)] while the other three affected single Lys residues in its close spatial proximity (K115E, K118E, and K123E). The results obtained support the general conclusion that HtA active site would show a high degree of plasticity, being able to accommodate electrostatic and structural changes not suitable for the other previously known larger ribotoxins, as the variants described here only presented small differences in terms of ribonucleolytic activity and cytotoxicity against cultured insect cells.

Cerebral autosomo-dominant arteriopathy with subcortical infarctions and leukoencephalopathy

2021 ◽  
Vol 26 (5) ◽  
pp. 30-38
Author(s):  
E. A. Savchuk ◽  
E. P. Golubinskaya ◽  
T. N. Shcherbinina ◽  
G. Yu. Voronin ◽  
E. O. Savchuk ◽  
...  
Keyword(s):  
Clinical Case ◽  
Structural Changes ◽  
Light And Electron Microscopy ◽  
Joint Work ◽  
Genetic Studies ◽  
Small Vessels ◽  
Clinical Case Study ◽  
The Family ◽  
Probable Diagnosis

The article presents an analysis of the literature and a clinical case of a rare disease from the group of diseases of small vessels — cerebral autosomal dominant arteriopathy with subcortical infarction and leukoencephalopathy (CADASIL).It is based on the deposition of osmiophilic granulation material in vessels of small and medium caliber. A mutation in the NOTCH3 gene on chromosome 19p13 leads to significant structural changes in the walls of small arteries due to impaired differentiation and maturation of smooth muscle cells.CADASIL is characterized by four key symptoms: migraines, recurrent ischemic strokes, mental disorders, and cognitive decline. The clinical case study is presented from the standpoint of a multidisciplinary patient-oriented approach of joint work of neurologists and morphologists. On the basis of clinical and laboratory criteria, a probable diagnosis was made. To confirm it, a muscle biopsy was performed (a musculocutaneous flap from the inner surface of the thighs and forearms), in order to conduct light and electron microscopy. The details of the results of the morphological study, which made it possible to verify the patient’s diagnosis, are presented. Differential diagnostic judgments are presented and recommendations for genetic studies in the family, prognosis and treatment of the patient are given.

Ascertaining the nanocluster formation within an ion-irradiated Pt/Ni/C multi-trilayer with X-ray absorption spectroscopy

2012 ◽  
Vol 20 (1) ◽  
pp. 137-144
Author(s):  
Nitya Ramanan ◽  
Sumalay Roy ◽  
Debdutta Lahiri ◽  
Surinder M. Sharma ◽  
B. N. Dev
Keyword(s):  
Absorption Spectroscopy ◽  
Structural Changes ◽  
Nearest Neighbor ◽  
Ion Irradiation ◽  
Physical Adsorption ◽  
X Ray ◽  
Bimetallic Nanoclusters ◽  
Wave Technique ◽  
Wide Scale ◽  
X Ray Absorption

In this work nanoclusters formed in a Pt/Ni/C multi-trilayer by the ion-irradiated method of synthesis are characterized. In particular, an attempt to understand the role of interfaces in the synthesis is made. With this objective, ion-irradiation-induced structural changes in a Pt/Ni/C multi-trilayer using X-ray absorption spectroscopy (at the NiK-edge) in conjunction with the X-ray standing-wave technique are investigated. The XANES analysis identifies chemical binding at pristine Ni/C and Ni/Pt interfaces, in contrast with physical adsorption at the Pt/C interface. The chemical nature of the interfaces determines their relative stability with respect to irradiation and controls the extent of metallic diffusion. The most interesting structural change, upon irradiation, is the disruption of the Pt/C interface and subsequent migration of Pt atoms towards pre-diffused Ni atoms within the C layer, leading to the formation of Ni-centered Ni–Pt bimetallic nanoclusters (with Ni:Pt = 60:40). These clusters are highly disordered beyond their nearest neighbor and find wide-scale applications as, for example, magnetic devicesetc. The implications of these findings on the design goals are discussed.

scholarly journals Tracing the Lineage of Two Traits Associated with the Coat Protein of the Tombusviridae: Silencing Suppression and HR Elicitation in Nicotiana Species

Viruses ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 588 ◽  
Author(s):  
Mustafa Adhab ◽  
Carlos Angel ◽  
Andres Rodriguez ◽  
Mohammad Fereidouni ◽  
Lóránt Király ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Structural Changes ◽  
Coat Proteins ◽  
Silencing Suppressor ◽  
Suppressor Activity ◽  
Nicotiana Species ◽  
Pathogen Effector ◽  
The Family ◽  
Silencing Suppression ◽  
Insight Into

In this paper we have characterized the lineage of two traits associated with the coat proteins (CPs) of the tombusvirids: Silencing suppression and HR elicitation in Nicotiana species. We considered that the tombusvirid CPs might collectively be considered an effector, with the CP of each CP-encoding species comprising a structural variant within the family. Thus, a phylogenetic analysis of the CP could provide insight into the evolution of a pathogen effector. The phylogeny of the CP of tombusvirids indicated that CP representatives of the family could be divided into four clades. In two separate clades the CP triggered a hypersensitive response (HR) in Nicotiana species of section Alatae but did not have silencing suppressor activity. In a third clade the CP had a silencing suppressor activity but did not have the capacity to trigger HR in Nicotiana species. In the fourth clade, the CP did not carry either function. Our analysis illustrates how structural changes that likely occurred in the CP effector of progenitors of the current genera led to either silencing suppressor activity, HR elicitation in select Nicotiana species, or neither trait.

Structural model for a covalently bonded Si45 cluster

1989 ◽  
Vol 163 (4-5) ◽  
pp. 323-327 ◽  
Author(s):  
Efthimios Kaxiras
Keyword(s):  
Structural Model ◽  
Covalently Bonded
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