bluuebunny/crossref_metadata_2025_split huggingface dataset:
BUILDING PEOPLE’S RESILIENCE: SUPPORT MECHANISMS AND POST-RETIREMENT WELL-BEING OF RETIREES IN LAGOS STATE
Authors: ODUNAIKE Bolawale Abayomi , AZEEZ Rasheed Olawale 
Published: June 2024

This study examined the support mechanisms that are available to enhance the post-retirement well-being of Lagos State Civil Service retirees. Using the descriptive survey research design and the purposive/snowball sampling technique, 671 retirees were selected as respondents for this study. Collected and collated data were analyzed using descriptive statistical techniques such as tables, frequencies, and bar charts. Four research questions were stated and findings from research question one revealed that the challenges faced by Lagos State Civil Service retirees encompass financial insecurity, health deterioration, loss of routine, emotional adjustment, lack of purpose, and social isolation. Equally, research question two found that most retirees rely strongly on pensions for financial security. Research question three brought to the fore that 98.4% of the respondents observed that the existing support mechanisms during the transition to retirement are not adequate at all, and research question four indicated that retirees want assistance in financial planning, improved healthcare, lifelong learning opportunities, a centralized information portal, active feedback mechanisms, and housing assistance. Based on these findings, this study concludes that the current support mechanisms are grossly inadequate underscores a critical gap between provided services and the actual needs of the retired populace. Thus, the study recommends amongst others that the Lagos State Civil Service should implement a multi-faceted approach that addresses the diverse needs (i.e., financial education, healthcare accessibility, mental health and social reintegration services, lifelong learning, and volunteer programmes and centralized information portal) of its retirees.
Fused Benzo[b]fluorenols: Palladium‐Catalyzed Intramolecular Dehydroaromatization and Carbonyl Reduction
Authors: Zhao Quansheng , Hu Qiong , Wen Lei , Wu Min , Hu Yimin 
Published: July 2012

AbstractBenzo[b]fluorenols were prepared by a new palladium‐catalyzed one‐pot reaction of en‐one‐ynes with 3‐bromoprop‐1‐yne through intramolecular dehydroaromatization and carbonyl reduction.
Oxidative Methane Upgrading
Authors: Hammond Ceri , Conrad Sabrina , Hermans Ive 
Published: July 2012

AbstractThe economically viable oxidative upgrading of methane presents one of the most difficult but rewarding challenges within catalysis research. Its potential to revolutionalise the chemical value chain, coupled with the associated supremely challenging scientific aspects, has ensured this topic’s high popularity over the preceeding decades. Herein, we report a non‐exhaustive account of the current developments within the field of oxidative methane upgrading and summarise the pertaining challenges that have yet to be solved.
ZipA Is Required for FtsZ-Dependent Preseptal Peptidoglycan Synthesis prior to Invagination during Cell Division
Authors: Potluri Lakshmi-Prasad , Kannan Suresh , Young Kevin D. 
Published: July 2012

ABSTRACT

Rod-shaped bacteria grow by a repetitive cycle of elongation followed by division, and the mechanisms responsible for these two processes have been studied for decades. However, little is known about what happens during the transition between the two activities. At least one event occurs after elongation ends and before division commences, that being the insertion of new cell wall peptidoglycan into a narrowly circumscribed ribbon around midcell where septation is destined to take place. This insertion does not depend on the presence of the septation-specific protein PBP3 and is therefore known as
P
BP3-
i
ndependent
p
eptidoglycan
s
ynthesis (PIPS). Here we report that only FtsZ and ZipA are required to generate PIPS in wild-type
Escherichia coli
. PIPS does not require the participation of other members of the divisome, the MreB-directed cell wall elongation complex, alternate peptidoglycan synthases, the major peptidoglycan amidases, or any of the low-molecular-weight penicillin binding proteins. ZipA-directed PIPS may represent an intermediate stage that connects cell wall elongation to septal invagination and may be the reason ZipA is essential in the gammaproteobacteria.
Haematogenous abdominal wall metastasis of differentiated, alpha-fetoprotein-negative hepatocellular carcinoma after previous antiandrogen therapy within a site of lipoma manifestation since childhood
Authors: Zachau L , Zeckey C , Schlue J , Sander J , Meyer-Heithuis C , Winkler M , Klempnauer J , Schrem H 
Published: July 2012

Abstract

Background
Cases with subcutaneous metastasis of differentiated hepatocellular carcinoma to the abdominal wall without prior seeding as a consequence of local interventions with a negative or normal alpha-fetoprotein level in the serum are extremely rare.

Case report
This is the first report of a case with AFP-negative, differentiated hepatocellular carcinoma metastasis to the abdominal wall within a pre-existing subcutaneous lipoma since childhood after antiandrogen therapy with leuprorelin and buserelin acetate for prostate cancer without seeding.

Methods
Clinical features including histology, immunohistochemistry, clinical course and surgical approach are presented.

Results
Histological examination revealed a hepatocellular carcinoma with a trabecular and pseudoglandular growth pattern with moderately atypical hepatocytes with multifocal bile formation within a lipoma. The postoperative course of abdominal wall reconstruction with a monocryl-prolene mesh and a local flap after potentially curative resection was uncomplicated.

Discussion and conclusion
It may be that previous antiandrogen treatment for prostate carcinoma contributed to the fact that our patient developed alpha-fetoprotein-negative and androgen receptor-negative subcutaneous abdominal wall metastasis within a pre-existing lipoma since childhood.
Profile of native cellulosomal proteins of Clostridium cellulovorans adapted to various carbon sources
Authors: Morisaka Hironobu , Matsui Kazuma , Tatsukami Yohei , Kuroda Kouichi , Miyake Hideo , Tamaru Yutaka , Ueda Mitsuyoshi 
Published: July 2012

Abstract
We performed a focused proteome analysis of cellulosomal proteins predicted by a genome analysis of Clostridium cellulovorans [Tamaru, Y., et al.. 2010. J. Bacteriol. 192:901–902]. Our system employed a long monolithic column (300 cm), which provides better performance and higher resolution than conventional systems. Twenty-three cellulosomal proteins were, without purification, identified by direct analysis of the culture medium. Proteome analysis of the C. cellulovorans cellulosome after culture in various carbon sources demonstrated the production of carbon source-adapted cellulosome components.
Exclusive 1,2‐Aryl Shift in Platinum(II) Chloride‐Catalyzed Cyclization of 1‐(Indol‐2‐yl)‐2,3‐allenols
Authors: Kong Wangqing , Qiu Youai , Zhang Xue , Fu Chunling , Ma Shengming 
Published: July 2012

AbstractAn efficient cyclization of 1‐(indole‐2‐yl)‐2,3‐allenols in the presence of platinum(II) chloride leading to polysubstituted carbazoles via 1,2‐methyl or an exclusive 1,2‐aryl migration of the metal‐carbene intermediate was observed. The reaction proceeds via the intermediacy of a metal carbene intermediate, which induces the carbon‐carbon bond cleavage via 1,2‐migration to afford the products.
A Three‐Enzyme System Involving an Ene‐Reductase for Generating Valuable Chiral Building Blocks
Authors: Mangan David , Miskelly Iain , Moody Thomas S. 
Published: July 2012

AbstractThe use of ene‐reductase (ERED) enzymes for the asymmetric reduction of olefins offers a green, renewable alternative to metal‐catalysed asymmetric reduction. We report herein the first example of an ERED‐catalysed enantiospecific reduction carried out at large scale using a carbonyl reductase (CRED) enzyme in the cofactor recycle. This reaction has been paired with a hydrolase‐mediated regioselective ester hydrolysis to generate a valuable chiral building block using a straightforward one‐pot process.
Regio‐ and Stereoselective Hydroxylation of Optically Active α‐Ionone Enantiomers by Engineered Cytochrome P450 BM3 Mutants
Authors: Venkataraman Harini , Beer Stephanie B. A. de , Geerke Daan P. , Vermeulen Nico P. E. , Commandeur Jan N. M. 
Published: July 2012

AbstractThe selective hydroxylation of an unactivated CH bond is a crucial step in the synthesis of fine chemicals such as hydroxylated terpenoids. In the present study, the ability of 40 cytochrome P450 BM3 mutants to perform the regio‐ and stereoselective hydroxylation of α‐ionone has been investigated. Based on their activity and selectivity to produce 3‐hydroxy‐α‐ionone from racemic α‐ionone, 6 BM3 mutants were selected. Out of these, 3 mutants (M01 A82W, M11 A82W and M11 V87I) showed high selectivity for trans‐3‐hydroxy‐α‐ionone formation while 3 other mutants (M11 L437N, M11 L437S and M11 L437T) formed almost equal amounts of both cis‐3‐hydroxy‐ and trans‐3‐hydroxy‐α‐ionone. Incubation with individual enantiomers showed that M11 L437N, M11 L437S and M11 L437T exhibited opposite stereoselectivity producing (3S,6S)‐hydroxy‐α‐ionone with the (6S)‐enantiomer and (3S,6R)‐hydroxy‐α‐ionone with the (6R)‐enantiomer. Thus for the first time, BM3 mutants that can selectively produce diastereomers of 3‐hydroxy‐α‐ionone (>90% de), with high turnover numbers and minimal secondary metabolism, have been identified. Docking studies have been performed to rationalize the basis of the experimentally observed selectivity. In conclusion, engineered P450 BM3s are promising biocatalysts for regio‐ and stereoselective production of hydroxylated α‐ionones for industrial applications.
Nitrile Reductase from Geobacillus kaustophilus: A Potential Catalyst for a New Nitrile Biotransformation Reaction
Authors: Wilding Birgit , Winkler Margit , Petschacher Barbara , Kratzer Regina , Glieder Anton , Klempier Norbert 
Published: July 2012

AbstractThe cloning, expression and characterization of a nitrile reductase (NRed) from the thermophile Geobacillus kaustophilus is reported. The enzyme shows a 12‐fold increase in activity in response to a temperature change from 25 °C to 65 °C. The substrate scope regarding its biocatalytic applicability was investigated by testing a range of common nitriles. The narrow substrate range observed for the wild‐type enzyme prompted the rational design of GkNRed active site mutants based on a previously published homology model from Bacillus subtilis. The activities of the mutants and the wild‐type enzyme were investigated in their structure‐function relationship regarding the natural substrate 7‐cyano‐7‐deazaguanine (preQ0) as well as a range of synthesized preQ0‐like substrate structures. A distinct dependence of the wild‐type enzyme activity on specific structural modifications of the natural substrate was observed. Two non‐natural nitriles derived from preQ0 could be reduced to their corresponding amino compounds.
Tetraflic Acid (1,1,2,2‐Tetrafluoroethanesulfonic Acid, HC2F4SO3H) and Gallium Tetraflate as Effective Catalysts in Organic Synthesis
Authors: Prakash G. K. Surya , Mathew Thomas , Panja Chiradeep , Kulkarni Aditya , Olah George A. , Harmer Mark A. 
Published: July 2012

AbstractTetraflic acid offers ample acidity for various organic reactions that require high acidity. Its gallium(III) salt is an efficient catalyst under mild condtions for synthetic transformations such as the ketonic Strecker reaction for the synthesis of fluorinated α‐amino nitriles and condensation–cyclzation reactions using suitable fluoro ketones and 1,2‐disubstituted benzenes for the direct preparation of 5‐membered or 6‐membered fluorinated heterocycles.
Modular Bifunctional Chiral Thioureas as Versatile Organocatalysts for Highly Enantioselective Aza‐Henry Reaction and Michael Addition
Authors: Li Hua , Zhang Xu , Shi Xin , Ji Nan , He Wei , Zhang Shengyong , Zhang Bangle 
Published: July 2012

AbstractA series of new modular bifunctional chiral thiourea organocatalysts were synthesized from natural Cinchona alkaloids and amino acids, and their performance in the aza‐Henry reaction of nitroalkanes to imines, the Michael addition of acetylacetone to nitroolefins and the Michael addition of acetone to nitroolefins was investigated. Under the mild conditions, the important building blocks β‐nitro amines and γ‐nitro carbonyl compounds could be obtained in good yields (up to 95%) with excellent enantioselectivities (up to 99% ee) and diastereoselectivity (up to 17:1).
Rhodium‐Catalyzed Asymmetric 1,4‐Additions, in Water at Room Temperature, with In‐Flask Catalyst Recycling
Authors: Lipshutz Bruce H. , Isley Nicholas A. , Moser Ralph , Ghorai Subir , Leuser Helena , Taft Benjamin R. 
Published: July 2012

AbstractUsing the newly introduced designer surfactant polyethylene glycol ubiquinol sebacate (PQS), as the platform for micellar catalysis, non‐racemic BINAP has been covalently attached and rhodium(I) inserted to form PQS‐BINAP‐Rh. This species, the first example of a non‐racemically‐ligated transition metal catalyst‐tethered amphiphile, can be utilized for Rh‐catalyzed asymmetric conjugate addition reactions of arylboronic acids to acyclic and cyclic enones. These are performed in water at room temperature, while the catalyst can be recycled without its removal from water in the reaction vessel.
Oxy Effects on the Platinum‐Catalyzed Carbo‐ and Oxacyclizations of 2‐Oxiranyl‐1‐(1‐oxyalk‐2‐ynyl)benzenes
Authors: Chaudhuri Rupsha , Pawar Samir Kundlik , Pati Kamalkishore , Liu Rai‐Shung 
Published: July 2012

AbstractWe report new platinum‐catalyzed protocols for the synthesis of carbocycles and oxacycles from 2‐oxiranyl‐1‐(1‐oxyalk‐2‐ynyl)benzenes. For 1,2,2‐trisubstituted epoxides bearing an acyloxy group, their platinum‐catalyzed cyclizations proceed through an initial 1,3‐acyloxy shift, followed by an intramolecular attack of an allenyl acetate at the carbonyl group, ultimately giving	2‐naphthyl ketones through a selective 1,2‐alkyl shift. 1,1‐Disubstituted epoxides bearing a siloxy group undergo an oxacyclization to give bicyclic ketals with high diastereoselectivity.
First Metal‐ and Base‐Free Selective Oxidative Coupling of Thiols in Neat Ionic Liquids: NMR Probed “Ambiphilic” Character of Neutral [hmim]Br towards Atom‐Efficient Synthesis of Disulfides
Authors: Kumar Rajesh , Sharma Nandini , Sharma Upendra K. , Shard Amit , Sinha Arun K. 
Published: July 2012

AbstractThe selective oxidative coupling of thiols has been studied in several imidazolium‐based ionic liquids in the absence of any base/metal catalysts. Disulfides were obtained from the corresponding thiols in good to excellent yields in 1‐hexyl‐3‐methylimidazolium bromide ([hmim]Br). Furthermore, a 1H NMR‐based mechanistic study of the SS bond formation demonstrated the cooperative role of halide anion and imidazolium cation of [hmim]Br as an “ambiphile” – a character found to be imperative for the efficient syntheses of disulfides. The developed methodology is simple, selective and green that utilises molecular oxygen as an oxidant and produces water as the only by‐product.
Highly Active Multidentate Alkyne Metathesis Catalysts: Ligand‐Activity Relationship and Their Applications in Efficient Synthesis of Porphyrin‐Based Aryleneethynylene Polymers
Authors: Jyothish Kuthanapillil , Wang Qi , Zhang Wei 
Published: July 2012

AbstractA series of tris(arylmethyl)ammonium‐coordinated molybdenum(VI) propylidyne catalysts was synthesized. Such N‐quarternized multidentate catalysts showed high robustness, strong resistance to small alkyne polymerization and significantly enhanced catalytic activity compared to their corresponding tris(arylmethyl)amine‐based analogues. The high activity of these new catalysts also enabled the efficient synthesis of ethynylene‐bridged porphyrin‐based arylene ethynylene polymers via alkyne metathesis, which represents a highly efficient, defect‐free, viable approach for the synthesis of this class of intriguing polymers.
Asymmetric Hydrogenation of N‐Arylimines Catalyzed by the Xyl‐Skewphos/DPEN‐Ruthenium(II) Complex
Authors: Arai Noriyoshi , Utsumi Noriyuki , Matsumoto Yuki , Murata Kunihiko , Tsutsumi Kunihiko , Ohkuma Takeshi 
Published: July 2012

AbstractThe new catalyst system of RuBr2[(S,S)‐xyl‐skewphos][(S,S)‐dpen] and potassium tert‐butoxide shows high reactivity and enantioselectivity in the hydrogenation of N‐arylimines [Xyl‐Skewphos=2,4‐bis(di‐3,5‐xylylphosphino)pentane, DPEN=1,2‐diphenylethylenediamine]. A range of imines derived from aromatic and heteroaromatic ketones as well as some ferrocenyl and vinylic imines are hydrogenated with a turnover number as high as 18,000 under 10–50 atm of hydrogen to afford the amine products in up to 99% enantiomeric excess. The reaction is applied to the synthesis of a chiral N‐arylamine, which is the synthetic intermediate of a biologically active compound. The mode of enantioselection is interpreted by using transition‐state models based on the X‐ray structure of the Xyl‐Skewphos/DPEN‐RuBr2 complex.
Catalytic Asymmetric Synthesis of 3‐Substituted Proline Derivatives by Using Phase‐Transfer‐Catalyzed Conjugate Addition
Authors: Liu Yan , Usui Asuka , Shirakawa Seiji , Maruoka Keiji 
Published: July 2012

AbstractThe catalytic enantio‐ and diastereoselective synthesis of trans‐3‐substituted proline derivatives has been accomplished by chiral phase‐transfer‐catalyzed asymmetric conjugate addition of N‐(diphenylmethylene)glycine ester to α,β‐unsaturated aldehydes. Various 3‐substituted prolines that contain aromatic, heteroaromatic, and alkyl groups were synthesized efficiently with good to high enantioselectivity. This synthetic method can be applied to the efficient enantioselective synthesis of core structures of L‐pyrrolysine and telaprevir, which are important biologically active compounds. The practicability of the method was demonstrated by a gram‐scale synthesis of a core structure of telaprevir.
Dioxygen Reactivity of Biomimetic Iron–Catecholate and Iron–o‐Aminophenolate Complexes of a Tris(2‐pyridylthio)methanido Ligand: Aromatic CC Bond Cleavage of Catecholate versus o‐Iminobenzosemiquinonate Radical Formation
Authors: Halder Partha , Paria Sayantan , Paine Tapan Kanti 
Published: July 2012

AbstractAn iron(III)–catecholate complex [L1FeIII(DBC)] (2) and an iron(II)–o‐aminophenolate complex [L1FeII(HAP)] (3; where L1=tris(2‐pyridylthio)methanido anion, DBC=dianionic 3,5‐di‐tert‐butylcatecholate, and HAP=monoanionic 4,6‐di‐tert‐butyl‐2‐aminophenolate) have been synthesised from an iron(II)–acetonitrile complex [L1FeII(CH3CN)2](ClO4) (1). Complex 2 reacts with dioxygen to oxidatively cleave the aromatic CC bond of DBC giving rise to selective extradiol cleavage products. Controlled chemical or electrochemical oxidation of 2, on the other hand, forms an iron(III)–semiquinone radical complex [L1FeIII(SQ)](PF6) (2ox‐PF6; SQ=3,5‐di‐tert‐butylsemiquinonate). The iron(II)–o‐aminophenolate complex (3) reacts with dioxygen to afford an iron(III)–o‐iminosemiquinonato radical complex [L1FeIII(ISQ)](ClO4) (3ox‐ClO4; ISQ=4,6‐di‐tert‐butyl‐o‐iminobenzosemiquinonato radical) via an iron(III)–o‐amidophenolate intermediate species. Structural characterisations of 1, 2, 2ox and 3ox reveal the presence of a strong ironcarbon bonding interaction in all the complexes. The bond parameters of 2ox and 3ox clearly establish the radical nature of catecholate‐ and o‐aminophenolate‐derived ligand, respectively. The effect of ironcarbon bonding interaction on the dioxygen reactivity of biomimetic iron–catecholate and iron–o‐aminophenolate complexes is discussed.
A Luminescent and Sublimable DyIII‐Based Single‐Molecule Magnet
Authors: Yi Xiaohui , Bernot Kevin , Pointillart Fabrice , Poneti Giordano , Calvez Guillaume , Daiguebonne Carole , Guillou Olivier , Sessoli Roberta 
Published: July 2012

AbstractThe reaction of [Ln(hfac)3]⋅2 H2O and pyridine‐N‐oxide (PyNO) leads to isostructural dimers of the formula [Ln(hfac)3(PyNO)]2 (Ln=Eu, Gd, Tb, Dy). The Dy derivative shows a remarkable single‐molecule magnet behavior with complex hysteresis at 1.4 K. The dynamics of the magnetization features are two relaxation regimes: a thermally activated one at high temperature (τ0=(5.62±0.4)×10−11 s and Δ=(167±1) K) and a quantum tunneling regime at low temperature with a tunneling frequency of 0.42 Hz. The analysis of the Gd derivative evidences intradimer antiferromagnetic interactions (J=(−0.034±0.001) cm−1). Moreover, the Eu, Tb, and Dy derivatives are luminescent with quantum yield of 51, 53, and 0.1 %, respectively. The thermal investigation of [Dy(hfac)3(PyNO)]2 shows that the dimers can be sublimated intact, suggesting their possible exploit as active materials for surface‐confined nanostructures to be investigated by fluorimetry methods.
Anion Sensing in Aqueous Media by Photo‐active Transition‐Metal Bipyridyl Rotaxanes
Authors: Hancock Laura M. , Marchi Enrico , Ceroni Paola , Beer Paul D. 
Published: July 2012

AbstractA chloride anion templation methodology is utilized in the construction of novel transition‐metal rhenium(I) and ruthenium(II) bipyridyl appended [2]rotaxanes. 1H NMR spectroscopic titrations reveal the ability of the rotaxanes to selectively bind chloride over the more basic oxoanions, with the ruthenium(II) bipyridyl appended rotaxane strongly binding chloride in 30 % water. Photophysical investigations demonstrate the ability of the rotaxanes to sense anions in aqueous media, with chloride being selectively complexed, in general agreement with NMR spectroscopy determined anion binding data.
TMBB-DB: a transmembrane β-barrel proteome database
Authors: Freeman Thomas C. , Wimley William C. 
Published: July 2012

Abstract
Motivation: We previously reported the development of a highly accurate statistical algorithm for identifying β-barrel outer membrane proteins or transmembrane β-barrels (TMBBs), from genomic sequence data of Gram-negative bacteria (Freeman,T.C. and Wimley,W.C. (2010) Bioinformatics, 26, 1965–1974). We have now applied this identification algorithm to all available Gram-negative bacterial genomes (over 600 chromosomes) and have constructed a publicly available, searchable, up-to-date, database of all proteins in these genomes.
Results: For each protein in the database, there is information on (i) β-barrel membrane protein probability for identification of β-barrels, (ii) β-strand and β-hairpin propensity for structure and topology prediction, (iii) signal sequence score because most TMBBs are secreted through the inner membrane translocon and, thus, have a signal sequence, and (iv) transmembrane α-helix predictions, for reducing false positive predictions. This information is sufficient for the accurate identification of most β-barrel membrane proteins in these genomes. In the database there are nearly 50 000 predicted TMBBs (out of 1.9 million total putative proteins). Of those, more than 15 000 are ‘hypothetical’ or ‘putative’ proteins, not previously identified as TMBBs. This wealth of genomic information is not available anywhere else.
Availability: The TMBB genomic database is available at http://beta-barrel.tulane.edu/.
Contact: wwimley@tulane.edu