bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gene Overexpression and Biochemical Characterization of the Biotechnologically Relevant Chlorogenic Acid Hydrolase fromAspergillus niger
Authors: Benoit Isabelle , Asther Michèle , Bourne Yves , Navarro David , Canaan Stéphane , Lesage-Meessen Laurence , Herweijer Marga , Coutinho Pedro M. , Asther Marcel , Record Eric 
Published: July 2007

ABSTRACTThe full-length gene that encodes the chlorogenic acid hydrolase fromAspergillus nigerCIRM BRFM 131 was cloned by PCR based on the genome of the strainA. nigerCBS 513.88. The complete gene consists of 1,715 bp and codes for a deduced protein of 512 amino acids with a molecular mass of 55,264 Da and an acidic pI of 4.6. The gene was successfully cloned and overexpressed inA. nigerto yield 1.25 g liter−1, i.e., 330-fold higher than the production of wild-type strainA. nigerCIRM BRFM131. The histidine-tagged recombinant ChlE protein was purified to homogeneity via a single chromatography step, and its main biochemical properties were characterized. The molecular size of the protein checked by mass spectroscopy was 74,553 Da, suggesting the presence of glycosylation. ChlE is assembled in a tetrameric form with several acidic isoforms with pIs of around 4.55 and 5.2. Other characteristics, such as optimal pH and temperature, were found to be similar to those determined for the previously characterized chlorogenic acid hydrolase ofA. nigerCIRM BRFM 131. However, there was a significant temperature stability difference in favor of the recombinant protein. ChlE exhibits a catalytic efficiency of 12.5 × 106M−1s−1toward chlorogenic acid (CGA), and its ability to release caffeic acid from CGA present in agricultural by-products such as apple marc and coffee pulp was clearly demonstrated, confirming the high potential of this enzyme.
Propionibacterium jensenii
Produces the Polyene Pigment Granadaene and Has Hemolytic Properties Similar to Those of
Streptococcus agalactiae
Authors: Vanberg Christin , Lutnaes Bjart Frode , Langsrud Thor , Nes Ingolf F. , Holo Helge 
Published: July 2007

ABSTRACT

The red polyene pigment granadaene was purified and identified from
Propionibacterium jensenii
. Granadaene has previously been identified only in
Streptococcus agalactiae
, where the pigment correlates with the hemolytic activity of the bacterium. A connection between hemolytic activity and the production of the red pigment has also been observed in
P. jensenii
, as nonpigmented strains are nonhemolytic. The pigment and hemolytic activity from
S. agalactiae
can be extracted from the bacterium with a starch extraction solution, and this solution also extracts the pigment and hemolytic activity from
P. jensenii
. A partial purification of the hemolytic activity was achieved, but the requirement for starch to preserve its activity made the purification unsuccessful. Partially purified hemolytic fractions were pigmented, and the color intensity of the fractions coincided with the hemolytic titer. The pigment was produced in a soluble form when associated with starch, and the UV-visual spectrum of the extract gave absorption peaks of 463 nm, 492 nm, and 524 nm. The pigment could also be extracted from the cells by a low-salt buffer, but it was then aggregated. The purification of the pigment from
P. jensenii
was performed, and mass spectrometry and nuclear magnetic resonance analysis revealed that
P. jensenii
indeed produces granadaene as seen in
S. agalactiae
.
“CandidatusBacilloplasma,” a Novel Lineage ofMollicutesAssociated with the Hindgut Wall of the Terrestrial IsopodPorcellio scaber(Crustacea: Isopoda)
Authors: Kostanjšek Rok , Štrus Jasna , Avguštin Gorazd 
Published: July 2007

ABSTRACTPointed, rod-shaped bacteria colonizing the cuticular surface of the hindgut of the terrestrial isopod crustaceanPorcellio scaber(Crustacea: Isopoda) were investigated by comparative 16S rRNA gene sequence analysis and electron microscopy. The results of phylogenetic analysis, and the absence of a cell wall, affiliated these bacteria with the classMollicutes, within which they represent a novel and deeply branched lineage, sharing less than 82.6% sequence similarity to knownMollicutes. The lineage has been positioned as a sister group to the clade comprising theSpiroplasmagroup, theMycoplasma pneumoniaegroup, and theMycoplasma hominisgroup. The specific signature sequence was identified and used as a probe in in situ hybridization, which confirmed that the retrieved sequences originate from the attached rod-shaped bacteria from the hindgut ofP. scaberand made it possible to detect these bacteria in their natural environment. Scanning and transmission electron microscopy revealed a spherically shaped structure at the tapered end of the rod-shaped bacteria, enabling their specific and exclusive attachment to the tip of the cuticular spines on the inner surface of the gut. Specific adaptation to the gut environment, as well as phylogenetic positioning, indicate the long-term association and probable coevolution of the bacteria and the host. Taking into account their pointed, rod-shaped morphology and their phylogenetic position, the name “CandidatusBacilloplasma” has been proposed for this new lineage of bacteria specifically associated with the gut surface ofP. scaber.
Response Regulators SrrA and SskA Are Central Components of a Phosphorelay System Involved in Stress Signal Transduction and Asexual Sporulation in
Aspergillus nidulans
Authors: Vargas-Pérez Itzel , Sánchez Olivia , Kawasaki Laura , Georgellis Dimitris , Aguirre Jesús 
Published: July 2007

ABSTRACT

Among eukaryotes, only slime molds, fungi, and plants contain signal transduction phosphorelay systems. In filamentous fungi, multiple sensor kinases appear to use a single histidine-containing phosphotransfer (HPt) protein to relay signals to two response regulators (RR). In
Aspergillus nidulans
, the RR SskA mediates activation of the mitogen-activated protein kinase SakA in response to osmotic and oxidative stress, whereas the functions of the RR SrrA were unknown. We used a genetic approach to characterize the
srrA
gene as a new member of the
skn7/prr1
family and to analyze the roles of SrrA in the phosphorelay system composed of the RR SskA, the HPt protein YpdA, and the sensor kinase NikA. While mutants lacking the HPt protein YpdA are unviable, mutants lacking SskA (Δ
sskA
), SrrA (Δ
srrA
), or both RR (Δ
srrA
Δ
sskA
) are viable and differentially affected in osmotic and oxidative stress responses. Both RR are involved in osmostress resistance, but Δ
sskA
mutants are more sensitive to this stress, and only SrrA is required for H
2
O
2
resistance and H
2
O
2
-mediated induction of catalase CatB. In contrast, both RR are individually required for fungicide sensitivity and calcofluor resistance and for normal sporulation and conidiospore viability. The Δ
srrA
and Δ
sskA
sporulation defects appear to be related to decreased mRNA levels of the key sporulation gene
brlA
. In contrast, conidiospore viability defects do not correlate with the activity of the spore-specific catalase CatA. Our results support a model in which NikA acts upstream of SrrA and SskA to transmit fungicide signals and to regulate asexual sporulation and conidiospore viability. In contrast, NikA appears dispensable for osmotic and oxidative stress signaling. These results highlight important differences in stress signal transmission among fungi and define a phosphorelay system involved in oxidative and osmotic stress, cell wall maintenance, fungicide sensitivity, asexual reproduction, and spore viability.
The Autotransporter Esterase EstA of
Pseudomonas aeruginosa
Is Required for Rhamnolipid Production, Cell Motility, and Biofilm Formation
Authors: Wilhelm Susanne , Gdynia Aneta , Tielen Petra , Rosenau Frank , Jaeger Karl-Erich 
Published: July 2007

ABSTRACT

Pseudomonas aeruginosa
PAO1 produces the biodetergent rhamnolipid and secretes it into the extracellular environment. The role of rhamnolipids in the life cycle and pathogenicity of
P. aeruginosa
has not been completely understood, but they are known to affect outer membrane composition, cell motility, and biofilm formation. This report is focused on the influence of the outer membrane-bound esterase EstA of
P. aeruginosa
PAO1 on rhamnolipid production. EstA is an autotransporter protein which exposes its catalytically active esterase domain on the cell surface. Here we report that the overexpression of EstA in the wild-type background of
P. aeruginosa
PAO1 results in an increased production of rhamnolipids whereas an
estA
deletion mutant produced only marginal amounts of rhamnolipids. Also the known rhamnolipid-dependent cellular motility and biofilm formation were affected. Although only a dependence of swarming motility on rhamnolipids has been known so far, the other kinds of motility displayed by
P. aeruginosa
PAO1, swimming and twitching, were also affected by an
estA
mutation. In order to demonstrate that EstA enzyme activity is responsible for these effects, inactive variant EstA* was constructed by replacement of the active serine by alanine. None of the mutant phenotypes could be complemented by expression of EstA*, demonstrating that the phenotypes affected by the
estA
mutation depend on the enzymatically active protein.
HLA-A*02 is associated with a reduced risk and HLA-A*01 with an increased risk of developing EBV+ Hodgkin lymphoma
Authors: Niens Marijke , Jarrett Ruth F. , Hepkema Bouke , Nolte Ilja M. , Diepstra Arjan , Platteel Mathieu , Kouprie Niels , Delury Craig P. , Gallagher Alice , Visser Lydia , Poppema Sibrand , te Meerman Gerard J. , van den Berg Anke 
Published: July 2007

AbstractPrevious studies showed that the HLA class I region is associated with Epstein-Barr virus (EBV)–positive Hodgkin lymphoma (HL) and that HLA-A is the most likely candidate gene in this region. This suggests that antigenic presentation of EBV-derived peptides in the context of HLA-A is involved in the pathogenesis of EBV+ HL by precluding efficient immune responses. We genotyped exons 2 and 3, encoding the peptide-binding groove of HLA-A, for 32 single nucleotide polymorphisms in 70 patients with EBV+ HL, 31 patients with EBV− HL, and 59 control participants. HLA-A*01 was significantly overrepresented and HLA-A*02 was significantly underrepresented in patients with EBV+ HL versus controls and patients with EBV− HL. In addition, HLA-A*02 status was determined by immunohistochemistry or HLA-A*02–specific polymerase chain reaction (PCR) on 152 patients with EBV+ HL and 322 patients with EBV− HL. The percentage of HLA-A*02+ patients in the EBV+ HL group (35.5%) was significantly lower than in 6107 general control participants (53.0%) and the EBV− HL group (50.9%). Our results indicate that individuals carrying the HLA-A*02 allele have a reduced risk of developing EBV+ HL, while individuals carrying the HLA-A*01 allele have an increased risk. It is known that HLA-A*02 can present EBV-derived peptides and can evoke an effective immune response, which may explain the protective phenotype.
Hierarchical MFI Zeolite Membranes for Superior Xylene Separation
Authors: Liu Menglei , Ge Yingying , Du Jiahuan , Song Zhifei , Zhang Chun , Zhou Qiaoqiao , Zhang Yuting , Gu Xuehong 
Published: March 2024

AbstractThe separation of p‐xylene from its xylene isomers (o‐xylene, m‐xylene) is a significant concern in the petrochemical industry. MFI zeolite membranes offer great potential for energy‐efficient and high‐selective xylene separation. Synthesizing ultrathin (< 1 µm) MFI zeolite membrane for high‐flux separation is highly desired but remains challenging. Herein, a novel and facile strategy for synthesizing hierarchical MFI zeolite membranes on ceramic hollow fibers from multi‐dimensionally assembled (2D@0D) seed layers is demonstrated. Owing to the rapid growth of 0D MFI seeds and the voids‐preserved growth of stacked 2D MFI seeds, the hierarchical MFI membrane synthesized for 2 h yielded an ultrathin skin layer (≈255 nm thick) and many macro‐voids within the sublayer (void fraction: 14.86%), which facilitated molecular permeation and simultaneously maintained high separation selectivity of zeolitic pores. The membrane exhibited over sevenfold higher p‐xylene permeance (2.81 × 10−7 mol m−2 s−1 Pa−1) and over threefold improved p‐/o‐xylene separation factor (1228) than the conventional MFI membrane.
Ink to Power: An Organic‐based Polymer Electrolyte for Ambient Printing of Flexible Zinc Batteries
Authors: Tao Shiwei , Ramirez Julio , Shewan Heather M. , Lyu Miaoqiang , Gentle Ian , Wang Lianzhou , Knibbe Ruth 
Published: March 2024

AbstractThe rapid evolution of wearable devices, the Internet of Things, and flexible displays has underscored the need for thin, flexible batteries. Screen‐printing has emerged as a mature technique for manufacturing these batteries, particularly those using a zinc chemistry. This study presents a commercially viable polymer electrolyte using a low‐cost organic electrolyte solvent, ethylene glycol. This first‐of‐its‐kind electrolyte formulation overcomes challenges associated with either water‐based or ionic‐liquid‐based solvents. The simple fabrication process allows for printing under ambient conditions and eliminates additional processing steps. Rheological analysis confirms that the developed polymer electrolyte is suitable for screen‐printing. Using this polymer electrolyte, a secondary printed battery with a 4 mAh cm−2 areal capacity is achieved. The study also investigates the mechanical behavior of the printed battery and emphasizes the importance of understanding interfacial stresses and bonding for designing optimal multilayered flexible batteries. This research offers an integrated solution, combining practical printed battery fabrication with battery testing and mechanical characterization, promising advancements in printed batteries and electronics.
Nonlinear Photodetector Based on InSe p–n Homojunction for Improving Spatial Imaging Resolution
Authors: Zhang Yu , Chen Xiaoqing , Zhang Mingwen , Wu Xianghu , Wang Jianguo , Tian Ruijuan , Fang Liang , Zhang Yanyan , Zhao Jianlin , Gan Xuetao 
Published: March 2024

AbstractAn efficient nonlinear photodetector (NLPD) is demonstrated with quadratic response based on a few‐layer InSe p–n homojunction, which is beneficial from the strong second harmonic generation (SHG) process in InSe and effective harvest of photocarriers actuated by the high‐quality homojunction. The NLPD can sense light with photon energy smaller than InSe's electronic bandgap because the SHG process in InSe doubles the frequency of incident light, extending InSe's photodetection wavelength range to 1750 nm. The InSe p–n homojunction, which is electrostatically doped by two split back gates, presents a rectification ratio exceeding 106 with a dark current down to 2 pA and a high normalized responsivity of 0.534 A W−2 for the telecom‐band pulsed light at 1550 nm. The photocurrents of the SHG‐assisted photodetection have a quadratic dependence on the optical powers, making the NLPD highly sensitive to light intensity variation with improved spatial resolution. As examples, the NLPD is employed to precisely determine the localization point of a focused laser beam waist and implement spatial imaging with an improved resolution compared with the linear photodetector. These features highlight the potential of the proposed NLPD in developing advanced optical sensing and imaging systems.
Photoluminescent Characterization of Metal Nanoclusters: Basic Parameters, Methods, and Applications
Authors: Lin Hongbin , Song Xiaorong , Chai Osburg Jin Huang , Yao Qiaofeng , Yang Huanghao , Xie Jianping 
Published: March 2024

AbstractMetal nanoclusters (MNCs) can be synthesized with atomically precise structures and molecule formulae due to the rapid development of nanocluster science in recent decades. The ultrasmall size range (normally < 2 nm) endows MNCs with plenty of molecular‐like properties, among which photoluminescent properties have aroused extensive attention. Tracing the research and development processes of luminescent nanoclusters, various photoluminescent analysis and characterization methods play a significant role in elucidating luminescent mechanism and analyzing luminescent properties. In this review, it is aimed to systematically summarize the normally used photoluminescent characterizations in MNCs including basic parameters and methods, such as excitation/emission wavelength, quantum yield, and lifetime. For each key parameter, first its definition and meaning is introduced and then the relevant characterization methods including measuring principles and the revelation of luminescent properties from the collected data are discussed. Then, it is discussed in details how to explore the luminescent mechanism of MNCs and construct NC‐based applications based on the measured data. By means of these characterization strategies, the luminescent properties of MNCs and NC‐based designs can be explained quantitatively and qualitatively. Hence, this review is expected to provide clear guidance for researchers to characterize luminescent MNCs and better understand the luminescent mechanism from the measured results.
Application of Nanostructured Parylene‐C Films for Improved Optical Characteristics of Organic Light‐Emitting Diodes
Authors: Kim Hyun‐Bin , Baek Seung‐Yo , Boo So‐Young , Sung Baeksang , Kwon Sungmin , Lee Jonghee , Lee Jae‐Hyun 
Published: March 2024

AbstractAnti‐reflection (AR) characteristics on the display surface and light outcoupling efficiency are significant factors for controlling external and internal light in organic light‐emitting diodes (OLEDs), respectively. This paper presents the fabrication of moth‐eye nanostructured parylene‐C films that simultaneously achieve optimized AR characteristics and enhanced OLED performance. AR performance is optimized by varying the nanostructure dimensions, resulting in a nanostructured film with a reflectance of <1%. Furthermore, applying this nanostructured film to OLEDs improved the light outcoupling efficiency by 40% compared with the reference device. Therefore, employing nanostructured parylene‐C films to enhance the optical characteristics of OLEDs is proposed.
Mediation of Interfacial Mo2C Bridging Effect in MoS2@Carbon Colloid Dots Featuring Improved Photovoltaic Performances of Si‐Based Hybrid Solar Cells
Authors: Wei Ta‐Cheng , Chen Shih‐Hsiu , Lin Kuan‐Han , Wu Tsung‐Yen , Hsiao Po‐Hsuan , Chen Chia‐Yun 
Published: March 2024

AbstractAdvances in silicon‐based hybrid solar cells with high photovoltaic performance, low synthetic cost, and sound environmental resistance are emerged as potential candidate for solar conversion. Solution‐processed few‐layer MoS2 sheets are regarded as compelling constitutes that paves ways for tailoring the solar harvesting capability; yet the improvement on charge separation of photoexcited carriers remains demanded, and the lack of environmental stability due to intentionally grabbing electrons from adsorbed moistures constrains the scope of practical assessment. In this work, the employment of MoS2/Mo2C/carbon colloid dots (CCDs) heterostructures within PEDOT:PSS matrix is invoked, where the transfer of photoexcited electrons from MoS2 is mediated with Mo2C electron‐transport channels, which further couple out the creation of positive trions by combining with defect‐bound excitons at CCD surfaces. These features dynamically involve with slow recombination probability and further improve the photovoltaic gain. Thus, the noticeable improvement of conversion efficiency of 16.1% with 1.6 times of efficiency enhancement outperforming the bare conventional hybrid solar cells is accomplished, and further exhibits a sound long‐term stability, which opens new avenues for exploiting the photophysical bound‐carrier transition on advanced photovoltaic applications.
Double‐Sided, Thin‐Film Microelectrode Array with Hemispheric Electrodes for Subretinal Stimulation
Authors: Kim Namju , Hong Yeji , Cha Seongkwang , Kang Yoo Na , Seo Hee Won , Moon Hyunmin , Ahn Jungryul , Intisar Aseer , Kim Minseok S. , Kim Seong‐Woo , Goo Yong Sook , Kim Sohee 
Published: March 2024

AbstractComponents in neural implants, such as the electrode array and stimulator circuit, are often fabricated discretely. This modular fabrication scheme offers flexibility during development but poses difficulties during assembly, as components must be compactly integrated for implantation. It is particularly difficult in cases where the electrode array is required to have a high number of channels, such as in retinal prostheses. This paper presents the development of a parylene C‐based, double‐sided microelectrode array with 294 hemispheric electrodes for subretinal stimulation. The bonding pads on the bottom side of the double‐sided array are connected with electrodes through vias, eliminating the interconnection lines. The array can be integrated with a stimulator circuit through pad‐to‐pad bonding, resulting in a compact implant. The hemispheric electrodes are fabricated using thermally reflowed photoresist infillings, through which the height and width of the hemispheres can be easily controlled. The long‐term stability and biocompatibility of the materials and methods used to fabricate and package the electrodes are demonstrated in in vitro and in vivo environments over months. Finally, subretinal stimulation by the developed electrodes is successfully demonstrated using in vitro retinal patches from mice and monkeys.
Reversing Internal Electric Field Direction at BiVO4/TiO2 Heterostructure Interface by a Thin W‐VO2 Layer: Turning Waste Charge Carriers into Wealth
Authors: Seck Astou , Mirzaei Amir , Shayegan Zahra , Ngom Balla D , Ma Dongling , Chaker Mohamed 
Published: March 2024

AbstractIn heterojunction photocatalysts, the band edge alignment and internal electric field (IEF) direction significantly affect the charge carrier separation, thus the photoconversion efficiency. For example, because of an unfavorable band alignment and compared to BiVO4 alone, BiVO4/TiO2 results in ≈24% reduction in photocurrent density in this study. Herein, a tungsten‐doped VO2 (W‐VO2) thin film is inserted between BiVO4 and TiO2 to modify unfavorable spike‐like conduction band offset and IEF direction in ternary heterojunction. After reversing the IEF direction and engineering the band edges through W‐VO2 insertion, the photocurrent density is enhanced by ≈145% and ≈91% compared to BiVO4/TiO2 and BiVO4, respectively at 1.23 V versus RHE. Besides, under visible light irradiation, the kinetics rate constant for tetracycline removal by BiVO4/W‐VO2/TiO2 photocatalyst is 225% higher than that of BiVO4/TiO2, due to utilizing charge carriers before being recombined, without doping the BiVO4 and TiO2 structures. Lastly, LC‐HR‐MS/MS analysis followed by the Toxicity Estimation Software Tool (T.E.S.T.) reveals the high importance of the band alignment on the detoxification of the solution. The tunability of the VO2 work function with a low bandgap, yet distinctive valence and conduction bands (which distinguished it from metals) opens new avenues for designing high‐performance heterojunction‐based devices.