Structural study of fluoro-tetraphenylporphyrins relating to large variability in solubilities of the para-F-TPP, ortho-F-TPP and meta-F-TPP

We present the X-ray structures of the crystals of the ortho-, meta-, and para-F-tetraphenylporphyrins crystallized from different solvents to shed light on the differential solubility of these three isomers. The meta-F-TPP is 4300 times more soluble than the para-F-TPP isomer in chloroform. It is shown that the packing of the porphyrins in the crystal is not a key issue in this solubility difference. However, we discovered a large difference in the temperature factors of the phenyls and Fs in the various isomers and this gives us insight into the solubility differences.

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Theoretical insight into the disordered structure of (Z)-2-[(E)-(4-methoxybenzylidene)hydrazinylidene]-1,2-diphenylethanone: the role of noncovalent interactions

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229618009762 ◽

2018 ◽

Vol 74 (9) ◽

pp. 1058-1067

Author(s):

Xue-Jie Tan ◽

Di Wang ◽

Xu-Gang Lei ◽

Jun-Peng Chen

Keyword(s):

Room Temperature ◽

Noncovalent Interactions ◽

Poor Quality ◽

X Ray ◽

Disordered Structure ◽

Theoretical Insight ◽

Insight Into ◽

Shed Light

A global glide disorder has been discovered during an X-ray investigation of the crystal structure of (Z)-2-[(E)-(4-methoxybenzylidene)hydrazinylidene]-1,2-diphenylethanone (MHDE, C22H18N2O2) at room temperature. In another crystal, however, such disorder disappears (still at room temperature). Even though the disorder may be partly due to the poor quality of the harvested crystal, the structure can shed light on the nature of disorder. With the help of quantum chemical calculations, it is found that the global disorder seems to be connected with the need for stabilization of the somewhat rigid but mobile and unstable molecular structure. The most relevant feature driving the packing of the disordered structure concerns the slight perturbations (such as glide) of two or more disorder components (fractional occupancies) distributed throughout the crystal.

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An unprecedented insight into the catalytic mechanism of copper nitrite reductase from atomic-resolution and damage-free structures

Science Advances ◽

10.1126/sciadv.abd8523 ◽

2021 ◽

Vol 7 (1) ◽

pp. eabd8523

Author(s):

Samuel L. Rose ◽

Svetlana V. Antonyuk ◽

Daisuke Sasaki ◽

Keitaro Yamashita ◽

Kunio Hirata ◽

...

Keyword(s):

Bound States ◽

Catalytic Mechanism ◽

Catalytic Efficiency ◽

Atomic Resolution ◽

Reaction Intermediates ◽

X Ray ◽

Nitrite Reductases ◽

Radiation Induced ◽

Insight Into ◽

Shed Light

Copper-containing nitrite reductases (CuNiRs), encoded by nirK gene, are found in all kingdoms of life with only 5% of CuNiR denitrifiers having two or more copies of nirK. Recently, we have identified two copies of nirK genes in several α-proteobacteria of the order Rhizobiales including Bradyrhizobium sp. ORS 375, encoding a four-domain heme-CuNiR and the usual two-domain CuNiR (Br2DNiR). Compared with two of the best-studied two-domain CuNiRs represented by the blue (AxNiR) and green (AcNiR) subclasses, Br2DNiR, a blue CuNiR, shows a substantially lower catalytic efficiency despite a sequence identity of ~70%. Advanced synchrotron radiation and x-ray free-electron laser are used to obtain the most accurate (atomic resolution with unrestrained SHELX refinement) and damage-free (free from radiation-induced chemistry) structures, in as-isolated, substrate-bound, and product-bound states. This combination has shed light on the protonation states of essential catalytic residues, additional reaction intermediates, and how catalytic efficiency is modulated.

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Quantitative Analysis Of X-Ray Images From Geological Materials

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010013482x ◽

1990 ◽

Vol 48 (2) ◽

pp. 244-245

Author(s):

J. M. Paque ◽

R. Browning ◽

P. L. King ◽

P. Pianetta

Keyword(s):

Quantitative Analysis ◽

Bulk Composition ◽

Principal Component ◽

Analytical Description ◽

Bulk Sample ◽

Geological Samples ◽

X Ray ◽

Software And Hardware ◽

And Storage ◽

Insight Into

Geological samples typically contain many minerals (phases) with multiple element compositions. A complete analytical description should give the number of phases present, the volume occupied by each phase in the bulk sample, the average and range of composition of each phase, and the bulk composition of the sample. A practical approach to providing such a complete description is from quantitative analysis of multi-elemental x-ray images.With the advances in recent years in the speed and storage capabilities of laboratory computers, large quantities of data can be efficiently manipulated. Commercial software and hardware presently available allow simultaneous collection of multiple x-ray images from a sample (up to 16 for the Kevex Delta system). Thus, high resolution x-ray images of the majority of the detectable elements in a sample can be collected. The use of statistical techniques, including principal component analysis (PCA), can provide insight into mineral phase composition and the distribution of minerals within a sample.

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Sentence-Based Experience Logging in New Hearing Aid Users

American Journal of Audiology ◽

10.1044/2020_aja-19-00077 ◽

2020 ◽

Vol 29 (3S) ◽

pp. 631-637

Author(s):

Katja Lund ◽

Rodrigo Ordoñez ◽

Jens Bo Nielsen ◽

Dorte Hammershøi

Keyword(s):

Hearing Aid ◽

Patient Experiences ◽

Online Tool ◽

Rehabilitation Process ◽

Hearing Rehabilitation ◽

Clinical Observations ◽

Hearing Aid Use ◽

Wide Range ◽

Insight Into ◽

Shed Light

Purpose The aim of this study was to develop a tool to gain insight into the daily experiences of new hearing aid users and to shed light on aspects of aided performance that may not be unveiled through standard questionnaires. Method The tool is developed based on clinical observations, patient experiences, expert involvement, and existing validated hearing rehabilitation questionnaires. Results An online tool for collecting data related to hearing aid use was developed. The tool is based on 453 prefabricated sentences representing experiences within 13 categories related to hearing aid use. Conclusions The tool has the potential to reflect a wide range of individual experiences with hearing aid use, including auditory and nonauditory aspects. These experiences may hold important knowledge for both the patient and the professional in the hearing rehabilitation process.

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A STRUCTURAL STUDY OF THE SMECTIC MESOPHASES OF TWO BIPHENYL COMPOUNDS AND AN X-RAY INVESTIGATION OF THE MISCIBILITY CRITERION

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1975106 ◽

1975 ◽

Vol 36 (C1) ◽

pp. C1-45-C1-48 ◽

Cited By ~ 4

Author(s):

J. E. LYDON ◽

C. J. COAKLEY

Keyword(s):

Structural Study ◽

X Ray

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Copper–oxygen Dynamics in Tyrosinase

10.26434/chemrxiv.9255251 ◽

2019 ◽

Author(s):

Nobutaka Fujieda ◽

Sachiko Yanagisawa ◽

Minoru Kubo ◽

Genji Kurisu ◽

Shinobu Itoh

Keyword(s):

Catalytic Mechanism ◽

Substrate Binding ◽

Active Form ◽

Copper Ion ◽

Atomic Resolution ◽

Oxygen Species ◽

X Ray ◽

Oxygen Dynamics ◽

Insight Into ◽

Copper Centre

To unveil the activation of dioxygen on the copper centre (Cu2O2core) of tyrosinase, we performed X-ray crystallograpy with active-form tyrosinase at near atomic resolution. This study provided a novel insight into the catalytic mechanism of the tyrosinase, including the rearrangement of copper-oxygen species as well as the intramolecular migration of copper ion induced by substrate-binding.

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Aleksey Peshkov as an editor of Samarskaya Gazeta

Voprosy literatury ◽

10.31425/0042-8795-2020-4-128-138 ◽

2020 ◽

pp. 128-138

Author(s):

A. S. Bik-Bulatov

Keyword(s):

Local History ◽

Organizational Skills ◽

First Time ◽

New Evidence ◽

Insight Into ◽

Shed Light

The article uses little known letters of M. Gorky, many of which were published for the first time in 1997, as well as findings of Samara-based experts in local history to shed light on the writer’s work as editor-in-chief of the Samarskaya Gazeta newspaper in 1895. The researcher introduces hitherto unstudied reminiscences of the journalist D. Linyov (Dalin) about this period, which reference a letter by Gorky, now lost. The paper details a newly discovered episode of Gorky’s professional biography as a journalist: it concerns his campaign against a Samara ‘she-wolf,’ the madam of a local brothel A. Neucheva. Linyov’s reminiscences turn out to be an important and interesting source, offering an insight into the daily grind of the young editor Gorky, providing new evidence of his excellent organizational skills, and describing his moral and social stance. The author presents his work in the context of a recently initiated broader discussion about the need to map out all Russian periodicals for the period until 1917, as well as all research devoted to individual publications.

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