bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palladium complexes of bidentate pyridine N‐heterocyclic carbenes: Optical resolution, antimicrobial and cytotoxicity studies
Authors: Choo Kar Bee , Mah Wee Li , Lee Sui Mae , Lee Wai Leng , Cheow Yuen Lin 
Published: May 2018

A series of bidentate pyridine‐functionalized palladium N‐heterocyclic carbene (Pd NHC) complexes with various wingtip substituents (R = methyl, phenyl and tert‐butyl) have been synthesized and evaluated for their potential biomedical applications as antimicrobials and antiproliferative drug candidates. The obtained Pd NHC complexes were applied in a standard broth microdilution assay for determination of their antimicrobial activities against thirteen strains of pathogenic microorganisms. In addition to that, cytotoxic activities of the Pd NHC complexes were also evaluated against three human cancer cell lines, namely breast (MCF‐7), colon (HCT116) and oral (H103) cancer cells, using a standard MTT assay. Upon coordination to palladium, the Pd NHC complexes show significant antimicrobial activities with minimum inhibitory concentrations in the micromolar range, and they are cytotoxic to the tested carcinomas with IC50 ranging from 13 to 38 μM. Evidences for influence of both wingtip substituents and optical isomerism on the biological activities of the complexes have been found.
Thermodynamic and structural study of complexation of phenylboronic acid with salicylhydroxamic acid and related ligands
Authors: Martínez‐Aguirre Mayte A. , Flores‐Alamo Marcos , Yatsimirsky Anatoly K. 
Published: May 2018

Stability constants of boronate complexes with a highly efficient bioconjugation ligand salicylhydroxamic acid, its derivatives and some structurally related compounds were determined by potentiometric and spectroscopic titrations at variable pH allowing one to obtain detailed stability – pH profiles and to identify the optimum pH for complexation with each ligand. The N,O‐binding of salicylhydroxamic acid via condensation of boronic acid with phenolic OH and hydroxamic NH groups was established by crystal structure determination of isolated complexes with phenylboronic and 4‐nitrophenylboronic acids. Although this type of binding is impossible for N‐methylated salicylhydroxamic acid it still forms stable boronate complexes supposedly involving unusual 7‐membered –O‐B‐O‐ cycle supported by 1H NMR studies. Hydroxamic acids lacking ortho‐OH group and salicyloyl hydrazide form less stable boronate complexes, which nevertheless possess stabilities similar to those of catechole complexes and may be useful for conjugation applications. In contrast to other ligands, which form tetrahedral anionic complexes, salicylamidoxime forms tetrahedral, but neutral boronate complex with high stability in weakly acid solutions. The highest affinity in neutral and acid solutions surpassing that of salicylhydroxamic acid is observed with 2,6‐dihydroxybenzhydroxamic acid (Kobs = 5.2 × 104 at pH 7.4). Fairly stable mono‐ and bisboronate complexes are formed with 2,5‐dihydroxy‐1,4‐benzdihydroxamic acid, which also possesses intense fluorescence and may serve as a boronic acid sensor with detection limit 4 μM. Results presented in this study provide quantitative basis for rational applications of hydroxamic acid derivatives in bioconjugation and sensing.
Synthesis, Structural, Biological Evaluation, Molecular Docking and DFT Studies of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) Complexes bearing Heterocyclic Thiosemicarbazone ligand
Authors: Konakanchi Ramaiah , Haribabu Jebiti , Prashanth Jyothi , Nishtala Venkata Bharat , Mallela Ramachary , Manchala Saikumar , Gandamalla Durgaiah , Karvembu Ramasamy , Reddy Byru Venkatram , Yellu Narsimha Reddy , Kotha Laxma Reddy 
Published: May 2018

A new ligand, 2‐aminonicotinaldehyde N‐methyl thiosemicarbazone (ANMTSC) and its metal complexes [Co(II) (1); Ni(II) (2); Cu(II) (3); Zn(II) (4); Cd(II) (5) or Hg(II) (6)] were synthesized. The compounds were characterized by analytical methods and various spectroscopic (infrared, magnetic, thermal, 1H, 13C NMR, electronic and ESR) tools. The structure of ANMTSC ligand was confirmed by single crystal X‐ray diffraction study. The spectral data of metal complexes indicate that the ligand acts as mononegative, bidentate coordination through imine nitrogen (N) and thiocarbonyl sulphur (S−) atoms. The proposed geometries for complexes were octahedral (1–2), distorted octahedral (3) and tetrahedral (4–6). Computational details of theoretical calculations (DFT) of complexes have been discussed. The compounds were subjected to antimicrobial, antioxidant, antidiabetic, anticancer, ROS, studies and EGFR targeting molecular docking analysis. Complex 5 has shown excellent antibacterial activity and the complexes 2 and 5 have shown good antifungal activity. The complexes 1 and 4 displayed good antioxidant property with IC50 values of 11.17 ± 1.92 μM and 10.79 ± 1.85 μM, respectively compared to standard. In addition, in vitro anticancer activity of the compounds was investigated against HeLa, MCF‐7, A549, IMR‐32 and HEK 293 cell lines. Among all the compounds, complex 4 was more effective against HeLa (IC50 = 10.28 ± 0.69 μM), MCF‐7 (IC50 = 9.80 ± 0.83 μM), A549 (IC50 = 11.08 ± 0.57 μM) and IMR‐32 (10.41 ± 0.60 μM) exhibited superior anticancer activity [IC50 = 9.80 ± 0.83 (4) and 9.91 ± 0.37 μM (1)] against MCF‐7 compared with other complexes.
Synthesis and biological evaluation of novel 99mTc‐oxo and 99mTc‐tricarbonyl complexes with C3′‐functionalized thymidine dithiocarbamate for tumor imaging
Authors: Duan Xiaojiang , Gan Qianqian , Song Xiaoqing , Fang Si'an , Zhang Xuran , Ruan Qing , Zhang Junbo 
Published: May 2018

A novel C3′‐functionalized thymidine dithiocarbamate derivative (3’DTC‐TdR) was successfully synthesized and labelled using [99mTcO]3+ core and [99mTc(CO)3(H2O)3]+ core with high yields. The structures of the 99mTc complexes were verified by preparation and characterization of the corresponding stable rhenium complexes. Both of the complexes were lipophilic and stable in vitro. Cell internalization experiments indicated that the uptakes of 99mTcO‐3’DTC‐TdR were related to nucleoside transporters. Biodistribution of these complexes in mice bearing tumor showed that they had high tumor uptakes, good tumor/muscle ratios and tumor/blood ratios. Especially for 99mTcO‐3’DTC‐TdR, it exhibited the highest tumor/muscle ratio and tumor/blood ratio at 4 h post‐injection. SPECT/CT imaging studies indicated clear accumulation in tumor, suggesting 99mTcO‐3’DTC‐TdR would be a promising candidate for tumor imaging.
Expanding the chemical space of anti‐HCV NS5A inhibitors by stereochemical exchange and peptidomimetic approaches
Authors: Ramsis Triveena M. , Abdel Karim Shereen E. , Vassilaki Niki , Frakolaki Efseveia , Kamal Ahmed A. M. , Zoidis Grigoris , Ahmed Nermin S. , Abadi Ashraf H. 
Published: May 2018

AbstractHere we report a series of potent anti‐HCV agents bearing a symmetrical benzidine l‐prolinamide backbone with different capping groups including alkyl/aryl carbamates of natural and unnatural valine and leucine amino acids. All compounds were investigated for their inhibitory activity in an HCV replicon assay on genotype 1b. The novel compounds share some chemical and clinical attributes of commercially available NS5A inhibitors. Compounds 5 and 6 with unnatural capping residue and ethyl and isobutyl carbamates showed EC50 values in the picomolar range with a low toxicity profile and selectivity indices of several orders of magnitude. These findings enlarge the chemical space from which NS5A inhibitors may be discovered by adopting unnatural amino acids, amino acids other than valine and carbamates other than methyl as the capping groups.
Complex prospection of medieval underground salt chambers in the village of Wiślica, Poland
Authors: Gołębiowski Tomisław , Pasierb Bernadetta , Porzucek Sławomir , Łój Monika 
Published: May 2018

AbstractIn the period of its great boom, i.e. between the fourteenth and the sixteenth centuries, Wiślica (a village in the southeast part of Poland) was one of the administrative capitals of Poland, an important centre of commerce and trade, as well as one of the most important centres of salt trade in the country. There is a hypothesis that underground chambers previously existed in Wiślica where salt was stored. This paper delineates archaeological, geological, and hydrogeological studies conducted in Wiślica and presents historical background with a particular focus on the salt trade. The main part of the paper consists of the results of geophysical studies carried out in the Solny Square, and the objective of the investigations was verification of the hypothesis of the existence of underground salt chambers. Three geophysical techniques were employed, i.e. ground penetrating radar (GPR), electrical resistivity tomography (ERT), and a micro‐gravimetric method. The GPR method was applied for examination of the near‐surface zone to find the remains of medieval shafts located over the underground chambers facilities. ERT and micro‐gravimetric methods were applied for detection of chambers or their remains located at depths from a few to a dozen or so metres. The results of geophysical surveys were correlated with information from boreholes. ERT and micro‐gravimetric data were correlated, which allowed the determination of three main anomalous regions located several metres under Solny Square. A control borehole was drilled in the central part of the largest geophysical anomaly and samples were collected to establish pH; the borehole data confirmed the existence of a depression in the rock mass filled with Quaternary material with alkaline pH. It is likely that two of three anomalies indicated the locations of remains of medieval underground salt chambers.
Feedback Linearization Control for Systems with Mismatched Uncertainties via Disturbance Observers
Authors: Kayacan Erkan , Fossen Thor I. 
Published: May 2018

AbstractThis paper focuses on a novel feedback linearization control (FLC) law based on a self‐learning disturbance observer (SLDO) to counteract mismatched uncertainties. The FLC based on BNDO (FLC‐BNDO) demonstrates robust control performance only against mismatched time‐invariant uncertainties while the FLC based on SLDO (FLC‐SLDO) demonstrates robust control performance against mismatched time‐invariant and ‐varying uncertainties, and both of them maintain the nominal control performance in the absence of mismatched uncertainties. In the estimation scheme for the SLDO, the BNDO is used to provide a conventional estimation law, which is used as the learning error for the type‐2 neuro‐fuzzy system (T2NFS), and T2NFS learns mismatched uncertainties. Thus, the T2NFS takes the overall control of the estimation signal entirely in a very short time and gives unbiased estimation results for the disturbance. A novel learning algorithm established on sliding mode control theory is derived for an interval type‐2 fuzzy logic system. The stability of the overall system is proven for a second‐order nonlinear system with mismatched uncertainties. The simulation results show that the FLC‐SLDO demonstrates better control performance than the traditional FLC, FLC with an integral action (FLC‐I), and FLC‐BNDO.
Morphological Abnormalities in True Bugs (Heteroptera) near Swiss Nuclear Power Stations
Authors: Körblein Alfred , Hesse‐Honegger Cornelia 
Published: May 2018

After the nuclear accidents of Chernobyl and Fukushima, several studies reported adverse health effects on wildlife animals. Epidemiological studies in humans found significant increases of leukemia rates in young children residing within 5 km from nuclear power plants. This study investigates morphological abnormalities in true bugs (Heteroptera), collected in the environs of three Swiss nuclear power stations (NPS). The objective of the study is to test whether there is an increased frequency of abnormalities in the vicinity of NPS. We found a frequency of abnormalities of 14.1% at distances r < 5 km and a frequency of 6.8% for distances r > 5 km, a rate ratio of 2.1 (P < 0.0001). The corresponding odds ratio was 2.26 (95% CI: 1.59, 3.18). We also conducted logistic regression of abnormality rates on reciprocal distance for each NPS site. The trend was significant for NPS Beznau (regression coefficient β = 1.5 ± 0.3, P < 0.0001) but not significant for NPS Gösgen und NPS Leibstadt with little samples within 5 km. To the best of our knowledge, this study is the first to find adverse health effects on insects near operating nuclear power plants. Due to its ecological design, however, it cannot answer the question whether the effect is caused by radiation from nuclear power plants.
Osmium Tag for Post‐transcriptionally Modified RNA
Authors: Debnath Turja Kanti , Okamoto Akimitsu 
Published: May 2018

Abstract5‐Methylcytidine (m5C) and 5‐methyluridine (m5U) are highly abundant post‐transcriptionally modified nucleotides that are observed in various natural RNAs. Such nucleotides were labeled through a chemical approach, as both underwent oxidation at the C5=C6 double bond, leading to the formation of osmium–bipyridine complexes, which could be identified by mass spectrometry. This osmium tag made it possible to distinguished m5C and m5U from their isomers, 2′‐O‐methylcytidine and 2′‐O‐methyluridine, respectively. Queuosine and 2‐methylthio‐N6‐isopentenyladenosine in tRNA were also tagged through complex formation.
A novel unbalanced translocation between the short arms of chromosomes 6 and 16 in a newborn girl: Clinical features and management
Authors: de Sousa Paula , Kennedy Alasdair , Lalani Heva H. S. 
Published: May 2018

Key Clinical MessageThe reporting of previously undescribed genetic mutations and resulting clinical phenotypes guides management and enables a more accurate prognosis for clinicians treating newborns with similar features. Previous cases of 6p deletions and 16p duplications have been described as separate entities. This patient presents with both and has a unique phenotype.
Protein‐Assisted Formation and Stabilization of Catalytically Active Polyoxometalate Species
Authors: Vandebroek Laurens , De Zitter Elke , Ly Hong Giang Thi , Conić Dragan , Mihaylov Tzvetan , Sap Annelies , Proost Paul , Pierloot Kristine , Van Meervelt Luc , Parac‐Vogt Tatjana N. 
Published: May 2018

AbstractThe effect of the protein environment on the formation and stabilization of an elusive catalytically active polyoxometalate (POM) species, K6[Hf(α2‐P2W17O61)] (1), is reported. In the co‐crystal of hen egg‐white lysozyme (HEWL) with 1, the catalytically active monomeric species is observed, originating from the dimeric 1:2 POM form, while it is intrinsically unstable under physiological pH conditions. The protein‐assisted dissociation of the dimeric POM was rationalized by means of DFT calculations. The dissociation process is unfavorable in bulk water, but becomes favorable in the protein–POM complex due to the low dielectric response at the protein surface. The crystal structure shows that the monomeric form is stabilized by electrostatic and water‐mediated hydrogen bonding interactions with the protein. It interacts at three distinct sites, close to the aspartate‐containing hydrolysis sites, demonstrating high selectivity towards peptide bonds containing this residue.
Synthesis of ZIF‐93/11 Hybrid Nanoparticles via Post‐Synthetic Modification of ZIF‐93 and Their Use for H2/CO2 Separation
Authors: Sánchez‐Laínez Javier , Zornoza Beatriz , Orsi Angelica F. , Łozińska Magdalena M. , Dawson Daniel M. , Ashbrook Sharon E. , Francis Stephen M. , Wright Paul A. , Benoit Virginie , Llewellyn Philip L. , Téllez Carlos , Coronas Joaquín 
Published: May 2018

AbstractThe present work shows the synthesis of nano‐sized hybrid zeolitic imidazolate frameworks (ZIFs) with the rho topology based on a mixture of the linkers benzimidazole (bIm) and 4‐methyl‐5‐imidazolecarboxaldehyde (4‐m‐5‐ica). The hybrid ZIF was obtained by post‐synthetic modification of ZIF‐93 in a bIm solution. The use of different solvents, MeOH and N,N‐dimethylacetamide (DMAc), and reaction times led to differences in the quantity of bIm incorporated to the framework, from 7.4 to 23 % according to solution‐state NMR spectroscopy. XPS analysis showed that the mixture of linkers was also present at the surface of the particles. The inclusion of bIm to the ZIF‐93 nanoparticles improved the thermal stability of the framework and also increased the hydrophobicity according to water adsorption results. N2 and CO2 adsorption experiments revealed that the hybrid material has an intermediate adsorption capacity, between those of ZIF‐93 and ZIF‐11. Finally, ZIF‐93/11 hybrid materials were applied as fillers in polybenzimidazole (PBI) mixed matrix membranes (MMMs). These MMMs were used for H2/CO2 separation (at 180 °C) reaching values of 207 Barrer of H2 and a H2/CO2 selectivity of 7.7 that clearly surpassed the Robeson upper bound (corrected for this temperature).
Access to Functionalized Imidazolidin‐2‐one Derivatives by Iron‐Catalyzed Oxyamination of Alkenes
Authors: Manick Anne‐Doriane , Aubert Sidonie , Yalcouye Boubacar , Prangé Thierry , Berhal Farouk , Prestat Guillaume 
Published: May 2018

AbstractFunctionalized imidazolidin‐2‐one were prepared by using an iron‐catalyzed alkene oxyamination reaction. Hydroxylamine derivatives were used in this atom‐economical process, and the addition of an external oxidant was not required. The conditions developed were shown to be efficient for mono‐, di‐, and trisubstituted double bonds, and a large scope of diamino alcohol precursors were delivered in good yields with good diastereoselectivities. The mechanistic pathway was studied and appears to involve both a fused aziridine and a carbocationic species.
Toward Cleavable Metabolic/pH Sensing “Double Agents” Hyperpolarized by NMR Signal Amplification by Reversible Exchange
Authors: Kidd Bryce E. , Mashni Jamil A. , Limbach Miranda N. , Shi Fan , Chekmenev Eduard Y. , Hou Yuqing , Goodson Boyd M. 
Published: May 2018

AbstractWe show the simultaneous generation of hyperpolarized 13C‐labeled acetate and 15N‐labeled imidazole following spin‐relay of hyperpolarization and hydrolysis of the acetyl moiety on 1–13C‐15N2‐acetylimidazole. Using SABRE‐SHEATH (Signal Amplification by Reversible Exchange in SHield Enables Alignment Transfer to Heteronuclei), transfer of spin order occurs from parahydrogen to acetylimidazole 15N atoms and the acetyl 13C site (≈263‐fold enhancement), giving rise to relatively long hyperpolarization lifetimes at 0.3 T (T1≈52 s and ≈149 s for 13C and 15N, respectively). Immediately following polarization transfer, the 13C‐labeled acetyl group is hydrolytically cleaved to produce hyperpolarized 13C‐acetate/acetic acid (≈140‐fold enhancement) and 15N‐imidazole (≈180‐fold enhancement), the former with a 13C T1 of ≈14 s at 0.3 T. Straightforward synthetic routes, efficient spin‐relay of SABRE hyperpolarization, and facile bond cleavage open a door to the cheap and rapid generation of long‐lived hyperpolarized states within a wide range of molecular targets, including biologically relevant carboxylic acid derivatives, for metabolic and pH imaging.
Impact of lung‐function measures on cardiovascular disease events in older adults with metabolic syndrome and diabetes
Authors: Lee Hwa Mu , Zhao Yanglu , Liu Michael A. , Yanez David , Carnethon Mercedes , Graham Barr R. , Wong Nathan D. 
Published: May 2018

BackgroundIndividuals with metabolic syndrome (MetS) and diabetes (DM) are more likely to have decreased lung function and are at greater risk of cardiovascular disease (CVD).Hypothesis.Lung‐function measures can predict CVD events in older persons with MetS, DM, and neither condition.MethodsWe followed 4114 participants age ≥ 65 years with and without MetS or DM in the Cardiovascular Health Study. Cox regression examined the association of forced vital capacity (FVC) and 1‐second forced expiratory volume (FEV1; percent of predicted values) with incident coronary heart disease and CVD events over 12.9 years.ResultsDM was present in 537 (13.1%) and MetS in 1277 (31.0%) participants. Comparing fourth vs first quartiles for FVC, risk of CVD events was 16% (HR: 0.84, 95% CI: 0.59–1.18), 23% (HR: 0.77, 95% CI: 0.60–0.99), and 30% (HR: 0.70, 95% CI: 0.58–0.84) lower in DM, MetS, and neither disease groups, respectively. For FEV1, CVD risk was lower by 2% (HR: 0.98, 95% CI: 0.70–1.37), 26% (HR: 0.74, 95% CI: 0.59–0.93), and 31% (HR: 0.69, 95% CI: 0.57–0.82) in DM. Findings were strongest for predicting congestive heart failure (CHF) in all disease groups. C‐statistics increased significantly with addition of FEV1 or FVC over risk factors for CVD and CHF among those with neither MetS nor DM.ConclusionsFEV1 and FVC are inversely related to CVD in older adults with and without MetS, but not DM (except for CHF); however, their value in incremental risk prediction beyond standard risk factors is limited mainly to metabolically healthier persons.
Predicted airway obstruction distribution based on dynamical lung ventilation data: A coupled modeling‐machine learning methodology
Authors: Pozin N. , Montesantos S. , Katz I. , Pichelin M. , Vignon‐Clementel I. , Grandmont C. 
Published: May 2018

AbstractIn asthma and chronic obstructive pulmonary disease, some airways of the tracheobronchial tree can be constricted, from moderate narrowing up to closure. Those pathological patterns of obstructions affect the lung ventilation distribution. While some imaging techniques enable visualization and quantification of constrictions in proximal generations, no noninvasive technique exists to provide the airway morphology and obstruction distribution in distal areas. In this work, we propose a method that exploits lung ventilation measures to access positions of airway obstructions (restrictions and closures) in the tree. This identification approach combines a lung ventilation model, in which a 0D tree is strongly coupled to a 3D parenchyma description, along with a machine learning approach. On the basis of synthetic data generated with typical temporal and spatial resolutions as well as reconstruction errors, we obtain very encouraging results of the obstruction distribution, with a detection rate higher than 85%.