bluuebunny/crossref_metadata_2025_split huggingface dataset:
Repressor Mutant Forms of the
Azospirillum brasilense
NtrC Protein
Authors: Huergo Luciano F. , Assumpção Marcelo C. , Souza Emanuel M. , Steffens M. Berenice R. , Yates M. Geoffrey , Chubatsu Leda S. , Pedrosa Fábio O. 
Published: October 2004

ABSTRACT

The
Azospirillum brasilense
mutant strains FP8 and FP9, after treatment with nitrosoguanidine, showed a null Nif phenotype and were unable to use nitrate as their sole nitrogen source. Sequencing of the
ntrC
genes revealed single nucleotide mutations in the NtrC nucleotide-binding site. The phenotypes of these strains are discussed in relation to their genotypes.
A Single Amino Acid Substitution Converts γ-Glutamyltranspeptidase to a Class IV Cephalosporin Acylase (Glutaryl-7-Aminocephalosporanic Acid Acylase)
Authors: Suzuki Hideyuki , Miwa Chinatsu , Ishihara Sayaka , Kumagai Hidehiko 
Published: October 2004

ABSTRACT

The aspartyl residue at position 433 of γ-glutamyltranspeptidase of
Escherichia coli
K-12 was replaced by an asparaginyl residue. This substitution enabled γ-glutamyltranspeptidase to deacylate glutaryl-7-aminocephalosporanic acid, producing 7-aminocephalosporanic acid, which is a starting material for the synthesis of semisynthetic cephalosporins.
Stabilization of Oil-Water Emulsions by Hydrophobic Bacteria
Authors: Dorobantu Loredana S. , Yeung Anthony K. C. , Foght Julia M. , Gray Murray R. 
Published: October 2004

ABSTRACT
Formation of oil-water emulsions during bacterial growth on hydrocarbons is often attributed to biosurfactants. Here we report the ability of certain intact bacterial cells to stabilize oil-in-water and water-in-oil emulsions without changing the interfacial tension, by inhibition of droplet coalescence as observed in emulsion stabilization by solid particles like silica.
Cloning and Expression of
clt
Genes Encoding Milk-Clotting Proteases from
Myxococcus xanthus
422
Authors: Poza M. , Prieto-Alcedo M. , Sieiro C. , Villa T. G. 
Published: October 2004

ABSTRACT

The screening of a gene library of the milk-clotting strain
Myxococcus xanthus
422 constructed in
Escherichia coli
allowed the description of eight positive clones containing 26 open reading frames. Only three of them (
cltA
,
cltB
, and
cltC
) encoded proteins that exhibited intracellular milk-clotting ability in
E. coli
,
Saccharomyces cerevisiae
, and
Pichia pastoris
expression systems.
Isolation of Lightning-Competent Soil Bacteria
Authors: Cérémonie Hélène , Buret François , Simonet Pascal , Vogel Timothy M. 
Published: October 2004

ABSTRACT

Artificial transformation is typically performed in the laboratory by using either a chemical (CaCl
2
) or an electrical (electroporation) method. However, laboratory-scale lightning has been shown recently to electrotransform
Escherichia coli
strain DH10B in soil. In this paper, we report on the isolation of two “lightning-competent” soil bacteria after direct electroporation of the Nycodenz bacterial ring extracted from prairie soil in the presence of the pBHCRec plasmid (Tc
r
, Sp
r
, Sm
r
). The electrotransformability of the isolated bacteria was measured both in vitro (by electroporation cuvette) and in situ (by lightning in soil microcosm) and then compared to those of
E. coli
DH10B and
Pseudomonas fluorescens
C7R12. The electrotransformation frequencies measured reached 10
−3
to 10
−4
by electroporation and 10
−4
to 10
−5
by simulated lightning, while no transformation was observed in the absence of electrical current. Two of the isolated lightning-competent soil bacteria were identified as
Pseudomonas
sp. strains.
Polarity Measurement for Ionic Liquids Containing Dissociable Protons
Authors: Ogihara Wataru , Aoyama Takahiro , Ohno Hiroyuki 
Published: October 2004

Abstract
Polarity of a series of ionic liquids (ILs) prepared by neutralization of N-alkylimidazoles and acids was measured with solvatochromic dye, Nile Red. Polarity of the N-alkylimidazolium salt-type ILs was in the comparable range to that of N,N′-dialkylimidazolium salt-type ILs. In the range, higher polarity was found when stronger acid (small pKa value in water) was used. This is the first report on the polarity of ILs containing dissociable protons.
Synthesis of Alkyl-substituted, Strapped Porphyrin to Prepare Stable Alkyl-chain-assisted Self-assembled Monolayers of Porphyrin Conjugates
Authors: Ikeda Taichi , Asakawa Masumi , Miyake Koji , Shimizu Toshimi 
Published: October 2004

Abstract
An alkyl-substituted, strapped porphyrin was synthesized aiming at the preparation of stable alkyl-chain-assisted self-assembled monolayers (SAMs) of porphyrin conjugates. We confirmed that the synthesized strapped porphyrin could form stable SAMs by scanning tunneling microscopy (STM). This approach will lead to the functionalization of alkyl-chain-assisted SAMs by introducing a variety of functional groups in the strapped moiety.
Photochemical Generation of Halo(silyl)silylene: Spectroscopic Observation and Reactivity
Authors: Tanaka Takashi , Ichinohe Masaaki , Sekiguchi Akira 
Published: October 2004

Abstract
Dihalobis(tri-tert-butylsilyl)silanes (t-Bu3Si)2SiX2 (1a: X = Cl, 1b: X = Br) underwent photochemically α-elimination to produce halo(tri-tert-butylsilyl)silylenes, which were successively trapped by carbon tetrachloride, triethylsilane, and 3-hexyne. The halo(tri-tert-butylsily)silylenes were observed by UV–vis spectroscopy in a 3-methylpentane matrix at 77 K.
A Novel Tetra Nuclear Ruthenium Complex Containing Deltoid Core Topology, [Ru4(μ3-O)2]8+, Incorporating Simultaneous O,O- and γ-C Bonded Bridging Acetylacetone Units
Authors: Shono Junpei , Nimura Yukie , Hashimoto Takeshi , Shimizu Kunio 
Published: October 2004

Abstract
The reflux of mononuclear ruthenium precursor [RuII(acac)2(CH3CN)2] (acac = acetylacetonate) in 2-methyl-2-propanol formed the novel diamagnetic β-diketonato ruthenium tetranuclear complex [Ru(μ-acac)2(μ3-O)2Ru3(acac)6] (1), in which was contained the deltoid core, [Ru4(μ3-O)2]8+, consisting of four ruthenium and two oxygen atoms. The complex 1 has been characterized on the basis of elemental analysis, 1H NMR, structural and cyclic voltammetric analyses. The molecular structure of 1 showed that each ruthenium ion was bridged by two oxygen atoms and two ruthenium ions link to γ-carbon on acetylacetonate coordinated to another ruthenium. The cyclic voltammogram of 1 showed two reversible one-electron oxidation peaks and an one-electron reduction peak corresponding to the redox of [Ru4(μ3-O)2]8+ core.
Product-catalyzed Mannich-type Reaction between Trimethylsilyl Enolates and N-Tosylaldimines
Authors: Takahashi Eiki , Fujisawa Hidehiko , Mukaiyama Teruaki 
Published: October 2004

Abstract
Mannich-type reaction between trimethylsilyl enolates and N-tosylaldimines in the presence of a catalytic amount of the alkoxide anion proceeded smoothly to afford the corresponding Mannich-adducts in good to high yields. This result indicated that the initially-formed N-anion of Mannich-adduct behaved as an effective Lewis base in performing the product-catalyzed Mannich-type reaction.
Quick Execution of [2+2] Type Photochemical Cycloaddition Reaction by Continuous Flow System Using a Glass-made Microreactor
Authors: Fukuyama Takahide , Hino Yoshiko , Kamata Naoya , Ryu Ilhyong 
Published: October 2004

Abstract
A photochemical [2+2] cycloaddition reaction was executed in a microflow system using glass-made microchannels having 1000-μm width and 500-μm depth. The reaction of cyclohexenones with vinyl acetates in a microflow system under irradiation (300 W, Hg lamp) gave [2+2] cycloaddition products in good yield with a residence time of 2 h, which is a remarkably shortened reaction time compared with a batch system using the same light source.
Isolation of a Cyclic Intermediate in the Reaction of a Phosphorus Ylide with Elemental Sulfur: Synthesis, Structure, and Reactivity of a 1,2σ5-Thiaphosphirane
Authors: Sase Shohei , Kano Naokazu , Kawashima Takayuki 
Published: October 2004

Abstract
The reaction of a phosphorus ylide with elemental sulfur gave a pentacoordinate thiaphosphirane, which was characterized by X-ray crystallographic analysis, and it was allowed to react with elemental sulfur resulting in a thiophosphinate.
Thermo-sensitive Luminescence Based on the Back Energy Transfer in Terbium(III) Complexes
Authors: Katagiri Shinya , Hasegawa Yasuchika , Wada Yuji , Yanagida Shozo 
Published: October 2004

Abstract
The emission intensities of Tb(hexafluoroacetylacetonato)3(H2O)2 [Tb(HFA)3(H2O)2] and Tb(HFA)3(triphenylphosphine oxide)2 [Tb(HFA)3(TPPO)2] in acetone-d6 dramatically decreased with increasing temperature in contrast to no change observed for Tb(NO3)3. The high thermal sensitivity is attributed to the back energy transfer from Tb(III) ion to triplet state of HFA having the energy barrier.
AFM Observation of Growing Poly Isobutyl Methacrylate (PiBMA) Particles
Authors: Yamamoto Tetsuya , Inoue Michihiro , Kanda Yoichi , Higashitani Ko 
Published: October 2004

Abstract
The growth process of poly(isobutyl methacrylate) (PiBMA) particle prepared in soap-free polymerization using V-50 as an initiator was observed by atomic force microscopy (AFM) to clarify the growth mechanism. As a result, it was found that PiBMA particles were capable of growing by the adhesion of smaller particles, which generated freshly during the particle growth period, to their surfaces.
Recurring homozygous ACTN2 variant (p.Arg506Gly) causes a recessive myopathy
Authors: Donkervoort Sandra , Mohassel Payam , O'Leary Melanie , Bonner Devon E. , Hartley Taila , Acquaye Nicole , Brull Astrid , Mozaffar Tahseen , Saporta Mario A. , Dyment David A. , Sampson Jacinda B. , Pajusalu Sander , Austin‐Tse Christina , Hurth Kyle , Cohen Julie S. , McWalter Kirsty , Warman‐Chardon Jodi , Crunk Amy , Foley A. Reghan ,   Undiagnosed Diseases Network, Mammen Andrew L. , Wheeler Matthew T. , O'Donnell‐Luria Anne , Bönnemann Carsten G. 
Published: February 2024

AbstractObjectiveACTN2, encoding alpha‐actinin‐2, is essential for cardiac and skeletal muscle sarcomeric function. ACTN2 variants are a known cause of cardiomyopathy without skeletal muscle involvement. Recently, specific dominant monoallelic variants were reported as a rare cause of core myopathy of variable clinical onset, although the pathomechanism remains to be elucidated. The possibility of a recessively inherited ACTN2‐myopathy has also been proposed in a single series.MethodsWe provide clinical, imaging, and histological characterization of a series of patients with a novel biallelic ACTN2 variant.ResultsWe report seven patients from five families with a recurring biallelic variant in ACTN2: c.1516A>G (p.Arg506Gly), all manifesting with a consistent phenotype of asymmetric, progressive, proximal, and distal lower extremity predominant muscle weakness. None of the patients have cardiomyopathy or respiratory insufficiency. Notably, all patients report Palestinian ethnicity, suggesting a possible founder ACTN2 variant, which was confirmed through haplotype analysis in two families. Muscle biopsies reveal an underlying myopathic process with disruption of the intermyofibrillar architecture, Type I fiber predominance and atrophy. MRI of the lower extremities demonstrate a distinct pattern of asymmetric muscle involvement with selective involvement of the hamstrings and adductors in the thigh, and anterior tibial group and soleus in the lower leg. Using an in vitro splicing assay, we show that c.1516A>G ACTN2 does not impair normal splicing.InterpretationThis series further establishes ACTN2 as a muscle disease gene, now also including variants with a recessive inheritance mode, and expands the clinical spectrum of actinopathies to adult‐onset progressive muscle disease.
Asymptomatic spinal lesions in patients with AQP4‐IgG‐positive NMOSD: A real‐world cohort study
Authors: Cao Shugang , Zhu Yunfei , Wu Xiaosan , Du Jing , Xu Si , Cui Ping , Li Qi , Xia Mingwu , Xue Qun , Tian Yanghua 
Published: February 2024

AbstractObjectiveThis study aims to explore the frequency and influencing factors of asymptomatic spinal lesions (ASLs) and their impact on subsequent relapses in patients with AQP4‐IgG‐positive NMOSD (AQP4‐NMOSD) in a real‐world setting.MethodsWe retrospectively reviewed clinical information and spinal MRI data from AQP4‐NMOSD patients who had at least one spinal cord MRI during their follow‐ups. Kaplan–Meier curves and Cox proportional hazards models were employed to ascertain potential predictors of remission ASLs and to investigate factors associated with subsequent relapses.ResultsIn this study, we included 129 patients with AQP4‐NMOSD and reviewed 173 spinal MRIs during attacks and 89 spinal MRIs during remission. Among these, 6 ASLs (3.5%) were identified during acute attacks, while 8 ASLs (9%) were found during remission. Remission ASLs were linked to the use of immunosuppressive agents, particularly conventional ones, whereas no patients using rituximab developed ASLs (p = 0.005). Kaplan–Meier curve analysis indicated that patients with ASLs had a significantly higher relapse risk (HR = 4.658, 95% CI: 1.519–14.285, p = 0.007) compared to those without. Additionally, the use of mycophenolate mofetil (HR = 0.027, 95% CI: 0.003–0.260, p = 0.002) and rituximab (HR = 0.035, 95% CI: 0.006–0.203, p < 0.001) significantly reduced the relapse risk. However, after accounting for other factors, the presence of ASLs did not exhibit a significant impact on subsequent relapses (HR = 2.297, 95% CI: 0.652–8.085, p = 0.195).InterpretationASLs may be observed in patients with AQP4‐NMOSD. The presence of ASLs may signify an underlying inflammatory activity due to insufficient immunotherapy. The administration of immunosuppressive agents plays a key role in the presence of remission ASLs and the likelihood of subsequent relapses.
Stable 2,5‐Dihydroxy‐1,4‐benzoquinone Based Organic Cathode Enabled by Coordination Polymer Formation and Binder Optimization
Authors: Gao Xiguang , Wang Yonglin , Menezes Luke T. , Huang Zhe , Kleinke Holger , Li Yuning 
Published: February 2024

AbstractOrganic electrode materials are gaining increased attention in energy storage applications, but often encounter challenges such as low capacity and poor cycling stability. This paper explores the utilization of a 1‐D coordination polymer, copper(II)‐2,5‐dihydroxy‐1,4‐benzoquinone (Cu‐DHBQ), as a cathode material for Li‐ion batteries for the first time. Cu‐DHBQ is air‐stable, devoid of coordinated water molecules, and possesses a high theoretical capacity of 266 mAh g−1. With an optimal sodium alginate (SA) binder content of 25 wt%, the Cu‐DHBQ cathode demonstrates a notable initial capacity of 214 mAh g−1 and outstanding cycling stability, retaining 210 mAh g−1 (98% capacity retention) after 200 cycles at a current rate of 100 mA g−1. A comprehensive investigation into the capacity fading mechanisms, the bonding capability of the SA binder, and the interactions between Cu‐DHBQ and SA is conducted using scanning electron microscope (SEM), peel tests, and Fourier transform infrared spectroscopy (FTIR), respectively. Additionally, the electrochemical reaction mechanisms of Cu‐DHBQ are examined using ex situ X‐ray photoelectron spectroscopy (XPS) and FTIR. These findings offer valuable insights into understanding the electrochemical properties of coordination polymers and metal‐organic frameworks based on DHBQ, shedding light on their potential as materials for battery electrodes.
Chiral Sulfonyl Binaphthalene‐Based Thermally Activated Delayed Fluorescence Materials for Circularly Polarized Electroluminescence
Authors: Tong Jingjing , Wang Peng , Liao Xiang‐Ji , Wang Yi , Zheng You‐Xuan , Pan Yi 
Published: February 2024

AbstractChiral emitters capable of producing circularly polarized luminescence (CPL) with high dissymmetry factors (g) are crucial for circularly polarized organic light‐emitting diodes (CP‐OLEDs) and 3D display. Herein, sulfonyl binaphthalene is incorporated as both electron acceptor and chiral source into three pairs of thermally activated delayed fluorescence (TADF) enantiomers, (R/S)‐BPSTCZ, (R/S)‐BPSDMAC, and (R/S)‐BPSPXZ, for the first time, combining tert‐butylcarbazole, 9,9‐dimethyl‐9,10‐dihydro‐acridine and phenoxazine electron donors, respectively. These TADF compounds exhibit tunable emissions spanning from deep blue to green, accompanied by high photoluminescence quantum yields. Due to the large distorted angles caused by two sulfonyl units, all enantiomers exhibit pronounced CPL with |gPL| factors of up to 6.0 × 10−3 in doped films. The corresponding CP‐OLEDs display good performances with external quantum efficiencies of up to 28.5% and notable |gEL| factors of up to 8.8 × 10−3, surpassing most CP‐OLEDs based on chiral TADF materials.
Well‐Dispersed MOF‐5 on The Polyvinylpyrrolidone‐Coated Random Lamellas of Clinoptilolites for Adsorptive Separation Performance of CO2, CH4, and N2
Authors: Zhou Jiawei , Liu Ming , Bai Shiyang , Sun Jihong , Wei Jia , Wang Ju 
Published: February 2024

AbstractThe MOF‐5@clinoptilolite (MOF@CP) composites are successfully synthesized using polyvinylpyrrolidone (PVP) for adsorption separation of CO2/CH4, CO2/N2, and CH4/N2. The effects of the PVP amounts on the dispersity of MOF‐5 on CP random lamellas of the MOF@CPs are evaluated via various characterizations. Meanwhile, their single‐component gas adsorption isotherms, breakthrough experiments, and cycling test are measured. The results elucidate that the used PVP amount has a significant influence on the particle size and the uniformity of MOF‐5 dispersed on CP random lamellas. The MOF‐5‐loaded amount in MOF@CP is estimated to be up to 42.52 wt.%. Especially, the surface fractal evolutions indicated the surfaces of MOF@CP became from rough to smooth with the increase of PVP. The CO2/CH4, CO2/N2, and CH4/N2 selectivity factors of MOF@CP are higher than that of CP, displaying a better separation performance. Their cycling test revealed that MOF@CPs could be used repetitively, highlighting efficiency for CO2 and CH4 separation. Meanwhile, the MOF‐5@CP stability under moisture is preliminarily investigated, showing higher moisture resistance stability than MOF‐5. Additionally, the grand canonical Monte Carlo simulations demonstrated the adsorption separation mechanism of the prepared MOF@CPs.
A NRF2 Regulated and the Immunosuppressive Microenvironment Reversed Nanoplatform for Cholangiocarcinoma Photodynamic‐Gas Therapy
Authors: Wang Weimin , Gao Yang , Xu Jianjun , Zou Tianhao , Yang Bin , Hu Shaobo , Cheng Xiang , Xia Yun , Zheng Qichang 
Published: February 2024

AbstractPhotodynamic therapy (PDT) is a minimally invasive and controllable local cancer treatment for cholangiocarcinoma (CCA). However, the efficacy of PDT is hindered by intratumoral hypoxia and the presence of an antioxidant microenvironment. To address these limitations, combining PDT with gas therapy may be a promising strategy to enhance tumor oxygenation. Moreover, the augmentation of oxidative damage induced by PDT and gas therapy can be achieved by inhibiting NRF2, a core regulatory molecule involved in the antioxidant response. In this study, an integrated nanotherapeutic platform called CMArg@Lip, incorporating PDT and gas therapies using ROS‐responsive liposomes encapsulating the photosensitizer Ce6, the NO gas‐generating agent L‐arginine, and the NRF2 inhibitor ML385, is successfully developed. The utilization of CMArg@Lip effectively deals with challenges posed by tumor hypoxia and antioxidant microenvironment, resulting in elevated levels of oxidative damage and subsequent induction of ferroptosis in CCA. Additionally, these findings suggest that CMArg@Lip exhibits notable immunomodulatory effects, including the promotion of immunogenic cell death and facilitation of dendritic cell maturation. Furthermore, it contributes to the anti‐tumor function of cytotoxic T lymphocytes through the downregulation of PD‐L1 expression in tumor cells and the activation of the STING signaling pathway in myeloid‐derived suppressor cells, thereby reprogramming the immunosuppressive microenvironment via various mechanisms.
Stroke Related Brain–Heart Crosstalk: Pathophysiology, Clinical Implications, and Underlying Mechanisms
Authors: Fan Xuehui , Cao Jianyang , Li Mingxia , Zhang Dechou , El‐Battrawy Ibrahim , Chen Guiquan , Zhou Xiaobo , Yang Guoqiang , Akin Ibrahim 
Published: February 2024

AbstractThe emergence of acute ischemic stroke (AIS) induced cardiovascular dysfunctions as a bidirectional interaction has gained paramount importance in understanding the intricate relationship between the brain and heart. Post AIS, the ensuing cardiovascular dysfunctions encompass a spectrum of complications, including heart attack, congestive heart failure, systolic or diastolic dysfunction, arrhythmias, electrocardiographic anomalies, hemodynamic instability, cardiac arrest, among others, all of which are correlated with adverse outcomes and mortality. Mounting evidence underscores the intimate crosstalk between the heart and the brain, facilitated by intricate physiological and neurohumoral complex networks. The primary pathophysiological mechanisms contributing to these severe cardiac complications involve the hypothalamic‐pituitary‐adrenal (HPA) axis, sympathetic and parasympathetic hyperactivity, immune and inflammatory responses, and gut dysbiosis, collectively shaping the stroke‐related brain–heart axis. Ongoing research endeavors are concentrated on devising strategies to prevent AIS‐induced cardiovascular dysfunctions. Notably, labetalol, nicardipine, and nitroprusside are recommended for hypertension control, while β‐blockers are employed to avert chronic remodeling and address arrhythmias. However, despite these therapeutic interventions, therapeutic targets remain elusive, necessitating further investigations into this complex challenge. This review aims to delineate the state‐of‐the‐art pathophysiological mechanisms in AIS through preclinical and clinical research, unraveling their intricate interplay within the brain–heart axis, and offering pragmatic suggestions for managing AIS‐induced cardiovascular dysfunctions.
Symmetry‐Breaking Triplet Excited State Enhances Red Afterglow Enabling Ubiquitous Afterglow Readout
Authors: Sk Bahadur , Hirata Shuzo 
Published: February 2024

AbstractMolecular vibrations are often factors that deactivate luminescence. However, if there are molecular motion elements that enhance luminescence, it may be possible to utilize molecular movement as a design guideline to enhance luminescence. Here, the authors report a large contribution of symmetry‐breaking molecular motion that enhances red persistent room‐temperature phosphorescence (RTP) in donor‐π‐donor conjugated chromophores. The deuterated form of the donor‐π‐donor chromophore exhibits efficient red persistent RTP with a yield of 21% and a lifetime of 1.6 s. A dynamic calculation of the phosphorescence rate constant (kp) indicates that the symmetry‐breaking movement has a crucial role in selectively facilitating kp without increasing nonradiative transition from the lowest triplet excited state. Molecules exhibiting efficient red persistent RTP enable long‐wavelength excitation, indicating the suitability of observing afterglow readout in a bright indoor environment with a white‐light‐emitting diode flashlight, greatly expanding the range of anti‐counterfeiting applications that use afterglow.