U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PubAg

Main content area

You searched for: Publication year rev 7981-2019 Remove constraint Publication year rev: 7981-2019 Subject term X-ray diffraction Remove constraint Subject term: X-ray diffraction Text availability Citation in PubAg Remove constraint Text availability: Citation in PubAg
Start Over

Search

6,131  Search Results

« Previous | 1 - 20 of 6,131 |
Number of results to display per page

Search Results

1. (+)- and (−)-Alternarilactone A: Enantiomers with a Diepoxy-Cage-like Scaffold from an Endophytic Alternaria sp.

Author:
Jian-Wei Tang; Hou-Chao Xu; Wei-Guang Wang; Kun Hu; Yuan-Fei Zhou; Rong Chen; Xiao-Nian Li; Xue Du; Han-Dong Sun; Pema-Tenzin Puno
Source:
Journal of natural products 2019 v.82 no.4 pp. 735-740
ISSN:
1520-6025
Subject:
Alternaria; X-ray diffraction; enantiomers; endophytes; fungi; moieties; nuclear magnetic resonance spectroscopy; probability analysis; quantum mechanics; risk
Abstract:
... The enantiomers (+)- and (−)-alternarilactone A (1), the first examples of dibenzo-α-pyrones bearing a diepoxy-cage-like moiety, were isolated from the endophytic fungus Alternaria sp. hh930. The deficiency in ¹H–¹H COSY and HMBC correlations caused by the highly oxidized caged system of 1 and the deceptive and ambiguous signals such as “W” couplings in NMR data increased the risk of structure mis ...
DOI:
10.1021/acs.jnatprod.8b00571

2. (+/−)-Lucidumone, a COX-2 Inhibitory Caged Fungal Meroterpenoid from Ganoderma lucidum

Author:
Yong-Ming Yan; Hao-Xing Zhang; Huan Liu; Yan Wang; Jing-Bo Wu; Yan-Peng Li; Yong-Xian Cheng
Source:
Organic letters 2019 v.21 no.21 pp. 8523-8527
ISSN:
1523-7052
Subject:
Ganoderma lucidum; X-ray diffraction; amino acids; biochemical pathways; chemical reactions; chemical structure; meroterpenoids
Abstract:
... (±)-Lucidumone (1), an enantiomeric meroterpenoid possessing an unprecedented skeleton comprising a fused 6/5/6/6/5 polycyclic system, was isolated from Ganoderma lucidum and structurally identified. The absolute configuration of (−)-1 was assigned by single-crystal X-ray crystallography. A plausible biosynthetic pathway for 1 is proposed. A chemical biology approach reveals that (−)-1 selectively ...
DOI:
10.1021/acs.orglett.9b02840

3. (±)-Alternamgin, a Pair of Enantiomeric Polyketides, from the Endophytic Fungi Alternaria sp. MG1

Author:
Jun-Chen Wu; Yanan Hou; Qianhe Xu; Xiao-Jie Jin; Yaxiong Chen; Jianguo Fang; Burong Hu; Quan-Xiang Wu
Source:
Organic letters 2019 v.21 no.5 pp. 1551-1554
ISSN:
1523-7052
Subject:
Alternaria; X-ray diffraction; biochemical pathways; chemical reactions; chemical structure; endophytes; fungi; human cell lines; necrosis; polyketides
Abstract:
... A pair of enantiomeric polyketides, (+)- and (−)-alternamgin (1), featuring an unprecedented 6/6/6/6/5/6/6 seven ring backbone, were isolated from the endophytic fungi Alternaria sp. MG1. The relative configuration of 1 was determined using X-ray diffraction, and the absolute configurations of (±)-1 were confirmed by comparing the experimental and calculated ECD data. Plausible biosynthetic pathwa ...
DOI:
10.1021/acs.orglett.9b00475

4. 2D few-layer iron phosphosulfide: a self-buffer heterophase structure induced by irreversible breakage of P–S bonds for high-performance lithium/sodium storage

Author:
Chao-Ying Fan; Xiao-Hua Zhang; Yan-Hong Shi; Hai-Yang Xu; Jing-Ping Zhang; Xing-Long Wu
Source:
Journal of materials chemistry A 2019 v.7 no.4 pp. 1529-1538
ISSN:
2050-7496
Subject:
Fourier transform infrared spectroscopy; X-ray diffraction; anodes; chemical bonding; electrochemistry; energy; graphene; iron; lithium; nanosheets; phosphides; phosphorus; sodium; transmission electron microscopy
Abstract:
... To pursue an anode candidate with a high capacity and favorable potential is urgent for a prospective energy storage system. In this work, an earth-abundant ternary metal phosphosulfide, here FePS₃, which is expected to combine the merits of metal sulfide and phosphorus, is explored for lithium/sodium storage. In order to facilitate charge transfer and relieve volume stress on the electrode, orien ...
DOI:
10.1039/c8ta09057b

5. 2D–3D Mixed Organic–Inorganic Perovskite Layers for Solar Cells with Enhanced Efficiency and Stability Induced by n-Propylammonium Iodide Additives

Author:
Disheng Yao; Chunmei Zhang; Shengli Zhang; Yang Yang; Aijun Du; Eric Waclawik; Xiaochen Yu; Gregory J. Wilson; Hongxia Wang
Source:
ACS applied materials & interfaces 2019 v.11 no.33 pp. 29753-29764
ISSN:
1944-8252
Subject:
X-ray diffraction; X-ray photoelectron spectroscopy; additives; air; cations; contact angle; density functional theory; encapsulation; energy; hydrophobicity; hysteresis; industrial applications; oxygen; relative humidity; solar cells; solar energy; surface water; wettability
Abstract:
... Device instability has become an obstacle for the industrial application of organic–inorganic metal halide perovskite solar cells that has already demonstrated over 23% laboratory power conversion efficiency (PCE). It has been discovered that the sliding of A-site cations in the perovskite compound through and out of the three-dimensional [PbI₆]⁴– crystal frame is one of the main reasons that are ...
DOI:
10.1021/acsami.9b06305

6. 3-Substituted Benzo[e][1,2,4]triazines: Synthesis and Electronic Effects of the C(3) Substituent

Author:
Agnieszka Bodzioch; Dominika Pomikło; Małgorzata Celeda; Anna Pietrzak; Piotr Kaszyński
Source:
Journal of organic chemistry 2019 v.84 no.10 pp. 6377-6394
ISSN:
1520-6904
Subject:
Lewis bases; X-ray diffraction; carboxylic acids; catalytic activity; copper; crystal structure; density functional theory; energy; geometry; hydrolysis; morpholine; nitroanilines; nuclear magnetic resonance spectroscopy; organic chemistry; palladium; triazines; ultraviolet-visible spectroscopy
Abstract:
... A series of 19 structurally diverse C(3)-substituted derivatives of benzo[e][1,2,4]triazine were synthesized from 3-chloro- (1c) and 3-iodobenzo[e][1,2,4]triazine (1d) obtained in three steps from 2-nitroaniline in 37–55% yields. Nucleophilic aromatic substitution and metal-catalyzed (Pd, Cu) reactions led to functional derivatives that include alkyl (C₅H₁₁), (het)aryl (Ph, 2-thienyl, ferrocenyl), ...
DOI:
10.1021/acs.joc.9b00716

7. 3D gel printing of graded TiC-high manganese steel cermet

Author:
Xinyue Zhang; Leichen Guo; Fang Yang; Alex A. Volinsky; Megan Hostetter; Zhimeng Guo
Source:
Journal of materials science 2019 v.54 no.3 pp. 2122-2132
ISSN:
0022-2461
Subject:
X-ray diffraction; gels; hardness; manganese; manufacturing; mechanical properties; microstructure; polymerization; rheological properties; scanning electron microscopy; slurries; steel
Abstract:
... A new solid freeform process, 3D gel printing (3DGP), was proposed for designing and manufacturing graded composites. As an example, TiC-high manganese steel cermet with a gradient distribution of TiC was successfully designed and fabricated by 3DGP. The rheological behavior and polymerization of slurries with different TiC content have been researched. The complex-shaped green bodies were printed ...
DOI:
10.1007/s10853-018-2945-5

8. 3D structure fungi-derived carbon stabilized stearic acid as a composite phase change material for thermal energy storage

Author:
Chuanchang Li; Baoshan Xie; Zhangxing He; Jian Chen; Yi Long
Source:
Renewable energy 2019 v.140 pp. 862-873
ISSN:
0960-1481
Subject:
Fourier transform infrared spectroscopy; Raman spectroscopy; X-ray diffraction; X-ray photoelectron spectroscopy; carbon; carbonization; enthalpy; freezing; melting; moieties; renewable energy sources; stearic acid; surface area; thermal conductivity; thermal energy; thermal stability
Abstract:
... Stearic acid (SA)/fungi-derived carbon (FDC) composite phase change materials (PCM) were fabricated by vacuum impregnation, where three types of FDC (FDC-C, FDC-H, and FDC-K) as carrier were synthesized by diverse synthetic procedures of carbonization. The FDC-K modified by synergistic hydrothermal and KOH-assisted calcination process had a 3D-cellular structure with considerably higher inner surf ...
DOI:
10.1016/j.renene.2019.03.121

9. 5‑Fluorouracil loaded chitosan/polyacrylic acid/Fe3O4 magnetic nanocomposite hydrogel as a potential anticancer drug delivery system

Author:
Mohammad Sadegh Amini-Fazl; Reza Mohammadi; Karim Kheiri
Source:
International journal of biological macromolecules 2019 v.132 pp. 506-513
ISSN:
0141-8130
Subject:
Fourier transform infrared spectroscopy; X-ray diffraction; chitosan; colon; drug delivery systems; drug therapy; fluorouracil; hydrogels; magnetism; nanocomposites; neoplasms; scanning electron microscopy; thermogravimetry
Abstract:
... In most cancer treatments, chemotherapy is currently necessary; hence, more attention was devoted to developing new methods for designing drug delivery systems (DDS) with controlled drug release. For this aim, anticancer 5‑fluorouracil (5-FU) drug was loaded into chitosan/polyacrylic acid/Fe3O4 magnetic nanocomposite hydrogel (CS/PAA/Fe3O4) through immersing in the drug solution. The prepared CS/P ...
DOI:
10.1016/j.ijbiomac.2019.04.005

10. A Ca²⁺ MOF combining highly efficient sorption and capability for voltammetric determination of heavy metal ions in aqueous media

Author:
Anastasia D. Pournara; Antigoni Margariti; Georgios D. Tarlas; Andreas Kourtelaris; Valeri Petkov; Christos Kokkinos; Anastasios Economou; Giannis S. Papaefstathiou; Manolis J. Manos
Source:
Journal of materials chemistry A 2019 v.7 no.25 pp. 15432-15443
ISSN:
2050-7496
Subject:
X-ray diffraction; aqueous solutions; cadmium; calcium; cations; copper; graphene; heavy metals; lead; metal ions; monitoring; nickel; quartz; remediation; sensors (equipment); sorbents; sorption; spectroscopy; wastewater; zinc
Abstract:
... We recently discovered that a Ca²⁺ two-dimensional framework, namely [Ca(H₄L)(DMA)₂]·2DMA (Ca-MOF), was capable of exchanging the Ca²⁺ ions with Cu²⁺ almost quantitatively in a matter of seconds in aqueous solution. Herein, we report that Ca-MOF exhibits the capability of both removal and voltammetric determination of heavy metal ions in aqueous media. Ca-MOF shows one of the highest Pb²⁺ sorption ...
DOI:
10.1039/c9ta03337h

11. A Comparison of Ionic Liquids and Organic Solvents on the Separation of Cellulose-Rich Material from River Red Gum

Author:
Pobitra Halder; Sazal Kundu; Savankumar Patel; Mohammad Ramezani; Rajarathinam Parthasarathy; Kalpit Shah
Source:
BioEnergy research 2019 v.12 no.2 pp. 275-291
ISSN:
1939-1234
Subject:
Eucalyptus camaldulensis; Fourier transform infrared spectroscopy; X-ray diffraction; acetates; biomass; bioprocessing; biorefining; cost effectiveness; crystal structure; ethanol; industry; ionic liquids; lignin; methanol; porosity; scanning electron microscopy; spectral analysis; thermogravimetry
Abstract:
... With the aim of separating cellulose-rich material from river red gum, it was pre-treated with three ionic liquids (ILs), i.e. 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]), 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) and 1-butyl-3-methylimidazolium acetate ([Bmim][OAc]) as well as with two organic solvents, i.e. methanol and ethanol. All ILs and organic solvents were able to remove more ...
DOI:
10.1007/s12155-019-09967-8

12. A Cytotoxic Indole Characterized by Incorporation of a Unique Carbon–Nitrogen Skeleton and Two Pentacyclic Corynanthean Alkaloids Incorporating a Substituted Tetrahydrofuranone Ring from Kopsia arborea

Author:
Soon-Kit Wong; Suet-Pick Wong; Kae-Shin Sim; Siew-Huah Lim; Yun-Yee Low; Toh-Seok Kam
Source:
Journal of natural products 2019 v.82 no.7 pp. 1902-1907
ISSN:
1520-6025
Subject:
X-ray diffraction; alkaloids; bark; biochemical pathways; copper; cytotoxicity; human cell lines; humans; inhibitory concentration 50; monoterpenoids; neoplasm cells; nuclear magnetic resonance spectroscopy; oxygen
Abstract:
... Three new alkaloids were isolated from the bark extract of the Malayan Kopsia arborea, viz., arbophyllidine (1), an unusual pentacyclic, monoterpenoid indole characterized by an absence of oxygen atoms and incorporating a new carbon–nitrogen skeleton, and arbophyllinines A (2) and B (3), two pentacyclic corynanthean alkaloids incorporating a hydroxyethyl-substituted tetrahydrofuranone ring. The st ...
DOI:
10.1021/acs.jnatprod.9b00255

13. A Facile Synthesis of Itaconic Acid Based Biodegradable Co-polyesters: An In-Vitro Anticancer Evaluation and Controlled Drug Delivery System

Author:
Udayakumar Veerabagu; Gowsika Jaikumar; Lu Fushen
Source:
Journal of polymers and the environment 2019 v.27 no.12 pp. 2756-2768
ISSN:
1566-2543
Subject:
Fourier transform infrared spectroscopy; X-ray diffraction; antineoplastic activity; biodegradability; breast neoplasms; carbon; catalysts; citrates; coatings; condensation reactions; crystal structure; differential scanning calorimetry; drug carriers; glass transition temperature; glycols; human cell lines; humans; inhibitory concentration 50; melting point; nuclear magnetic resonance spectroscopy; pH; polyesters; scanning electron microscopes; scanning electron microscopy; spectral analysis; stable isotopes; tamoxifen; titanium; toxicity; wide-angle X-ray scattering
Abstract:
... A series of aliphatic co-polyesters were prepared via one-step polycondensation reaction of itaconic acid, 1,4-cyclohexane dimethanol and diols using titanium tetraisopropoxide (TTIP) as a catalyst. The chemical structure of the repeating units present in the polymer chains were confirmed by FTIR, ¹H and ¹³C NMR spectral data. The glass transition temperature (Tg), melting temperature (Tₘ) and dec ...
DOI:
10.1007/s10924-019-01562-4

14. A Green Process for Starch Oleate Synthesis by Cryptococcus sp. MTCC 5455 Lipase and Its Potential as an Emulsifying Agent

Author:
Aarthy Mayilvahanan; Aparna Ramchary; Ayyadurai Niraikulam; Gowthaman Marichetti Kuppuswami; Kamini Numbi Ramudu
Source:
Stärke = 2019 v.71 no.1-2 pp. e1700325
ISSN:
0038-9056
Subject:
X-ray diffraction; carboxylic ester hydrolases; emulsifiers; emulsions; esterification; food industry; oleic acid; potato starch; scanning electron microscopy; starch; thermal stability; thermogravimetry; yeasts
Abstract:
... Starch oleate is synthesized in an aqueous medium using lipase from the yeast Cryptococcus sp. MTCC 5455. The optimum conditions of esterification are found at 24 h and 30 °C with an oleic acid/starch molar ratio of 1:2 using 500 U of lipase and the degree of substitution was 0.26. Spectral techniques confirm the presence of oleate group in the modified potato starch. Scanning electron microscopic ...
DOI:
10.1002/star.201700325

15. A New Eco-friendly Anticorrosion Strategy for Ferrous Metals: Plasma Electrolytic Aluminating

Author:
Chen Zhao; Wei Zha; Ran Cai; Xueyuan Nie; Jimi Tjong
Source:
ACS sustainable chemistry & engineering 2019 v.7 no.5 pp. 5524-5531
ISSN:
2168-0485
Subject:
X-ray diffraction; X-ray photoelectron spectroscopy; cast iron; ceramics; coatings; corrosion; cost effectiveness; electric potential difference; electrochemistry; electrolytes; hardness; scanning electron microscopy; zinc
Abstract:
... To avoid possible eco-disadvantages of phosphating and zinc plating used for corrosion protection of ferrous metals, this work was to develop an alternative coating technique, called plasma electrolytic aluminating (PEA) process, which can be environmentally friendly in terms of the process itself, and eco-friendly with respect to the coating materials. The PEA process was to form a metal aluminat ...
DOI:
10.1021/acssuschemeng.8b06839

16. A Protonated Quinone Methide Stabilized by a Combination of Partial Aromatization and π-Interaction: Spectroscopic and Crystallographic Analysis

Author:
Muhammad Kazim; Maxime A. Siegler; Thomas Lectka
Source:
Journal of organic chemistry 2019 v.84 no.12 pp. 8284-8288
ISSN:
1520-6904
Subject:
X-ray diffraction; aromatization; moieties; organic chemistry; protonation; quinones; spectroscopy
Abstract:
... We have expanded the repertoire of cation−π interactions to include a carbocation−π system resulting from the protonation of a π-stacked para-quinone methide (p-QM). This unusual carbocation is stabilized by a combination of partial aromatization of the QM moiety and through-space interaction with the π-system of the adjacent aromatic ring. Single crystal X-ray analysis of the protonated form reve ...
DOI:
10.1021/acs.joc.9b00923

17. A Uranium Tri-Rhenium Triple Inverse Sandwich Compound

Author:
Michael A. Boreen; Trevor D. Lohrey; Guodong Rao; R. David Britt; Laurent Maron; John Arnold
Source:
Journal of the American Chemical Society 2019 v.141 no.13 pp. 5144-5148
ISSN:
1520-5126
Subject:
Lewis bases; X-ray diffraction; dioxane; electron paramagnetic resonance spectroscopy; moieties; nuclear magnetic resonance spectroscopy; rhenium; sodium; uranium
Abstract:
... Salt metathesis between the anionic rhenium(I) compound, Na[Re(η⁵-Cp)(BDI)] (BDI = N,N′-bis(2,6-diisopropylphenyl)-3,5-dimethyl-β-diketiminate), and the uranium(III) salt, UI₃(1,4-dioxane)₁.₅, generated the triple inverse sandwich complex, U[(μ-η⁵:η⁵-Cp)Re(BDI)]₃, which was isolated and structurally characterized as the Lewis base adducts, (L)U[(μ-η⁵:η⁵-Cp)Re(BDI)]₃ (1·L, L = THF, 1,4-dioxane, DMA ...
DOI:
10.1021/jacs.9b01331

18. A bimetallic sulfide CuCo2S4 with good synergistic effect was constructed to drive high performance photocatalytic hydrogen evolution

Author:
Lingjiao Li; Jing Xu; JinPing Ma; Zeying Liu; Yanru Li
Source:
Journal of colloid and interface science 2019 v.552 pp. 17-26
ISSN:
0021-9797
Subject:
X-ray diffraction; electron transfer; electrons; hydrogen; hydrogen production; photocatalysis; photocatalysts; photoluminescence; reflectance spectroscopy; semiconductors; sulfides; synergism
Abstract:
... In order to further improve the photocatalytic performance of the semiconductor photocatalyst, a photocatalytic hydrogen production performance was measured using a bimetallic sulfide photocatalyst. On this basis, the hydrogen production performance of the bimetallic sulfide CuCo2S4 (CCS-3) was compared with that of the single metal sulfides Cu31S16 and CoS2. The results showed that the bimetallic ...
DOI:
10.1016/j.jcis.2019.05.036

19. A bio-inspired imidazole-functionalised copper cage complex

Author:
Sarah C. Bete; Christian Würtele; Matthias Otte
Source:
Chemical communications 2019 v.55 no.30 pp. 4427-4430
ISSN:
1364-548X
Subject:
X-ray diffraction; active sites; alcohols; copper; geometry; imidazoles; ligands; oxidants; oxidation; oxygen
Abstract:
... An imidazole-functionalised cage is synthesised that can coordinate to Cu(i). X-ray analysis reveals a T-shaped coordination of copper by the imidazole ligands reminiscent of the coordination geometry found in enzymatic active sites. This cage complex can catalyse the oxidation of benzylic alcohols to benzaldehydes utilizing oxygen as the terminal oxidant. ...
DOI:
10.1039/c9cc00437h

20. A bio-inspired strategy for the synthesis of zinc oxide nanoparticles (ZnO NPs) using the cell extract of cyanobacterium Nostoc sp. EA03: from biological function to toxicity evaluation

Author:
Mojgan Ebadi; Mohammad Reza Zolfaghari; Seyyed Soheil Aghaei; Mohsen Zargar; Morvarid Shafiei; Hossein Shahbani Zahiri; Kambiz Akbari Noghabi
Source:
RSC advances 2019 v.9 no.41 pp. 23508-23525
ISSN:
2046-2069
Subject:
Escherichia coli; Fourier transform infrared spectroscopy; Nostoc; Pseudomonas aeruginosa; Staphylococcus aureus; X-ray diffraction; absorption; amino acid derivatives; bacterial growth; bioactive compounds; biofilm; confocal laser scanning microscopy; cytotoxicity; differential scanning calorimetry; energy-dispersive X-ray analysis; exopolysaccharides; fibroblasts; flow cytometry; lungs; nanoparticles; photosynthetic bacteria; pigments; proteins; scanning electron microscopy; thermogravimetry; toxicity testing; transmission electron microscopy; ultraviolet-visible spectroscopy; viability; zeta potential; zinc oxide
Abstract:
... Cyanobacteria, as one of the largest groups of phototrophic bacteria, have a high potential as an excellent source of fine chemicals and bioactive compounds, including lipid-like compounds, amino acid derivatives, proteins, and pigments. This study aimed to synthesize ZnO nanoparticles using the cell extract of the cyanobacterium Nostoc sp. EA03 (CEN-ZnO NPs) through a rapid and eco-friendly appro ...
DOI:
10.1039/c9ra03962g