bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in bacterial community structure associated with coastal copper enrichment
Authors: Morán Ana C , Hengst Martha B , de la Iglesia Rodrigo , Andrade Santiago , Correa Juan A , González Bernardo 
Published: June 2008

Abstract
Marine bacterial communities isolated from the water column, sediment, the rock surface, and the green seaweed Ulva compressa were studied in an intertidal ecosystem. The study area included a coastal zone chronically affected by copper mine waste disposals. Bacterial community composition was analyzed by terminal restriction fragment length polymorphism (T-RFLP) of 16S rRNA genes, and multivariate analyses of T-RFLP data sets were used for comparisons. Results showed that diversity and richness indexes were not able to detect differences among compartments. However, comparisons within the same compartment clearly showed that copper enrichment was associated with changes in the composition of the bacterial communities and revealed that the magnitude of the effect depends on the compartment being considered. In this context, communities from sediments appeared as the most affected by copper enrichment. The present study also demonstrated that intertidal bacterial communities were dominated by Gammaproteobacteria, Firmicutes, and Actinobacteria and the changes in these communities were mainly due to changes in their relative abundances.
Formation of Composite Endothelial Cell–Mesenchymal Stem Cell Islets
Authors: Johansson Ulrika , Rasmusson Ida , Niclou Simone P. , Forslund Naomi , Gustavsson Linda , Nilsson Bo , Korsgren Olle , Magnusson Peetra U. 
Published: June 2008

OBJECTIVE—Mesenchymal stem cells (MSCs) contribute to endothelial cell (EC) migration by producing proteases, thereby paving the way into the tissues for ECs. MSCs were added to our previously described composite EC islets as a potential means to improve their capacity for islet angiogenesis.
RESEARCH DESIGN AND METHODS—Human islets were coated with primary human bone marrow–derived MSCs and dermal microvascular ECs. The capacity of ECs, with or without MSCs, to adhere to and grow into human islets was analyzed. The survival and functionality of these composite islets were evaluated in a dynamic perifusion assay, and their capacity for angiogenesis in vitro was assessed in a three-dimensional fibrin gel assay.
RESULTS—ECs proliferated after culture in MSC-conditioned medium, and MSCs improved the EC coverage threefold compared with EC islets alone. Islet survival in vitro and the functionality of the composite islets after culture were equal to those of control islets. The EC-MSC islets showed a twofold increase in total sprout formation compared with EC islets, and vascular sprouts emanating from the EC-MSC–islet surface showed migration of ECs into the islets and also into the surrounding matrix, either alone or in concert with MSCs.
CONCLUSIONS—EC proliferation, sprout formation, and ingrowth of ECs into the islets were enhanced by MSCs. The use of composite EC-MSC islets may have beneficial effects on revascularization and immune regulation. The technique presented allows for pretreatment of donor islets with recipient-derived ECs and MSCs as a means of improving islet engraftment.
Switching-On Survival and Repair Response Programs in Islet Transplants by Bone Marrow–Derived Vasculogenic Cells
Authors: Miller Robyn , Cirulli Vincenzo , Diaferia Giuseppe R. , Ninniri Stefania , Hardiman Gary , Torbett Bruce E. , Benezra Robert , Crisa Laura 
Published: June 2008

OBJECTIVE—Vascular progenitors of bone marrow origin participate to neovascularization at sites of wound healing and transplantation. We hypothesized that the biological purpose of this bone marrow–derived vascular component is to contribute angiogenic and survival functions distinct from those provided by the local tissue-derived vasculature.
RESEARCH DESIGN AND METHODS AND RESULTS—To address this hypothesis, we investigated the functional impact of bone marrow–derived vascular cells on pancreatic islets engraftment using bone marrow–reconstituted Id1+/−Id3−/− mice, a model of bone marrow–derived vasculogenesis. We show that, in this model, bone marrow–derived vasculogenic cells primarily contribute to the formation of new blood vessels within islet transplants. In contrast, graft revascularization in a wild-type background occurs by tissue-derived blood vessels only. Using these distinct transplant models in which bone marrow–and tissue-derived vasculature are virtually mutually exclusive, we demonstrate that bone marrow–derived vasculogenic cells exhibit enhanced angiogenic functions and support prompt activation of islets survival pathways, which significantly impact on islets engraftment and function. Moreover, gene profiling of vascular and inflammatory cells of the grafts demonstrate that neovascularization by bone marrow–derived cells is accompanied by the activation of a genetic program uniquely tuned to downregulate harmful inflammatory responses and to promote tissue repair.
CONCLUSIONS—These studies uncover the biological significance of bone marrow–derived vasculogenic cells in the response to injury during transplantation. Enhancing the contribution of bone marrow–derived vasculogenic cells to transplantation sites may help to overcome both limited angiogenic responses of the adult tissue-derived vasculature and untoward effects of inflammation on transplant engraftment.
Gpr40 Is Expressed in Enteroendocrine Cells and Mediates Free Fatty Acid Stimulation of Incretin Secretion
Authors: Edfalk Sara , Steneberg Pär , Edlund Helena 
Published: June 2008

OBJECTIVE—The G-protein–coupled receptor Gpr40 is expressed in β-cells where it contributes to free fatty acid (FFA) enhancement of glucose-stimulated insulin secretion (1–4). However, other sites of Gpr40 expression, including the intestine, have been suggested. The transcription factor IPF1/PDX1 was recently shown to bind to an enhancer element within the 5′-flanking region of Gpr40 (5), implying that IPF1/PDX1 might regulate Gpr40 expression. Here, we addressed whether 1) Gpr40 is expressed in the intestine and 2) Ipf1/Pdx1 function is required for Gpr40 expression.
RESEARCH DESIGN AND METHODS—In the present study, Gpr40 expression was monitored by X-gal staining using Gpr40 reporter mice and by in situ hybridization. Ipf1/Pdx1-null and β-cell specific mutants were used to investigate whether Ipf1/Pdx1 controls Gpr40 expression. Plasma insulin, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and glucose levels in response to acute oral fat diet were determined in Gpr40 mutant and control mice.
RESULTS—Here, we show that Gpr40 is expressed in endocrine cells of the gastrointestinal tract, including cells expressing the incretin hormones GLP-1 and GIP, and that Gpr40 mediates FFA-stimulated incretin secretion. We also show that Ipf1/Pdx1 is required for expression of Gpr40 in β-cells and endocrine cells of the anterior gastrointestinal tract.
CONCLUSIONS—Together, our data provide evidence that Gpr40 modulates FFA-stimulated insulin secretion from β-cells not only directly but also indirectly via regulation of incretin secretion. Moreover, our data suggest a conserved role for Ipf1/Pdx1 and Gpr40 in FFA-mediated secretion of hormones that regulate glucose and overall energy homeostasis.
Pyruvate Dehydrogenase Kinase 4
Authors: Cadoudal Thomas , Distel Emilie , Durant Sylvie , Fouque Françoise , Blouin Jean-Marc , Collinet Martine , Bortoli Sylvie , Forest Claude , Benelli Chantal 
Published: June 2008

OBJECTIVE—Pyruvate dehydrogenase complex (PDC) serves as the metabolic switch between glucose and fatty acid utilization. PDC activity is inhibited by PDC kinase (PDK). PDC shares the same substrate, i.e., pyruvate, as glyceroneogenesis, a pathway controlling fatty acid release from white adipose tissue (WAT). Thiazolidinediones activate glyceroneogenesis. We studied the regulation by rosiglitazone of PDK2 and PDK4 isoforms and tested the hypothesis that glyceroneogenesis could be controlled by PDK.
RESEARCH DESIGN AND METHODS—Rosiglitazone was administered to Zucker fa/fa rats, and then PDK4 and PDK2 mRNAs were examined in subcutaneous, periepididymal, and retroperitoneal WAT, liver, and muscle by real-time RT-PCR. Cultured WAT explants from humans and rats and 3T3-F442A adipocytes were rosiglitazone-treated before analyses of PDK2 and PDK4 mRNA and protein. Small interfering RNA (siRNA) was transfected by electroporation. Glyceroneogenesis was determined using [1-14C]pyruvate incorporation into lipids.
RESULTS—Rosiglitazone increased PDK4 mRNA in all WAT depots but not in liver and muscle. PDK2 transcript was not affected. This isoform selectivity was also found in ex vivo–treated explants. In 3T3-F442A adipocytes, Pdk4 expression was strongly and selectively induced by rosiglitazone in a direct and transcriptional manner, with a concentration required for half-maximal effect at 1 nmol/l. The use of dichloroacetic acid or leelamine, two PDK inhibitors, or a specific PDK4 siRNA demonstrated that PDK4 participated in glyceroneogenesis, therefore altering nonesterified fatty acid release in both basal and rosiglitazone-activated conditions.
CONCLUSIONS—These data show that PDK4 upregulation in adipocytes participates in the hypolipidemic effect of thiazolidinediones through modulation of glyceroneogenesis.
The Equations of the Rolling Resistance of a Tire Rolling on a Drum
Authors: Hublau V. , Barillier A. 
Published: June 2008

Abstract
This article attempts to write a mechanical justification of the ISO 18164 norm from a mathematical point of view. There are only minor differences between the final equations and the ones used in the norm. Indeed, this work is a formal derivation of what is already known.
The main point of this article is a proper writing of the first law of thermodynamics.
The main difference between physical equations and the ones used in the ISO 18164 standard is that the norm neglects the variations of the bearing friction of the tire and of the drum between the skim test and the loaded one. The order of magnitude of the bearing friction term is approximately 0.1 kg∕t at 80 km∕h.
Ugi products containing boronate esters
Authors: Appoh Francis , Manning Marcy , Gullon Teri , Hansen Margaret , Bevans Emily , Hogan Krista , Turner Courtney , Vogels Christopher , Decken Andreas , Westcott Stephen 
Published: June 2008

Abstract
The Ugi reaction with formylphenylboronic acid derivatives as the carbonyl component proceeds to give the corresponding boron-containing dipeptide derivatives (Ugi products) in good yields.
Molecular machines operated by light
Authors: Credi Alberto , Venturi Margherita 
Published: June 2008

Abstract
The bottom-up construction and operation of machines and motors of molecular size is a topic of great interest in nanoscience, and a fascinating challenge of nanotechnology. Researchers in this field are stimulated and inspired by the outstanding progress of molecular biology that has begun to reveal the secrets of the natural nanomachines which constitute the material base of life. Like their macroscopic counterparts, nanoscale machines need energy to operate. Most molecular motors of the biological world are fueled by chemical reactions, but research in the last fifteen years has demonstrated that light energy can be used to power nanomachines by exploiting photochemical processes in appropriately designed artificial systems. As a matter of fact, light excitation exhibits several advantages with regard to the operation of the machine, and can also be used to monitor its state through spectroscopic methods. In this review we will illustrate the design principles at the basis of photochemically driven molecular machines, and we will describe a few examples based on rotaxane-type structures investigated in our laboratories.
Generalized linear Schrödinger equations and their Darboux transformations
Authors: Schulze-Halberg Axel 
Published: June 2008

Abstract
We construct explicit Darboux transformations of arbitrary order for a class of generalized, linear Schrödinger equations. Our construction contains the well-known Darboux transformations for Schrödinger equations with position-dependent mass, Schrödinger equations coupled to a vector potential and Schrödinger equations for weighted energy.
Synergistic Interface Platforms: Designing Superhydrophilic Conductive Nanoparticle‐Decorated Nanofibrous Membranes
Authors: Keirouz Antonios , Jungwirth Ute , Graf Arthur , Leese Hannah S. 
Published: April 2024

AbstractIn today's technological landscape, advancing methods for producing conductive membranes that simplify and streamline the development of advanced interface materials is crucial. This study introduces a versatile and innovative method for fabricating superhydrophilic, conductive nanofibrous membranes based on the in situ synthesis of polypyrrole nanoparticles on poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) electrospun fibers. The composite membranes morphologically exhibit a particle‐decorated nanofibrous configuration, with polypyrrole nanoparticles distributed along the individual fibers' surface. The nanoparticle‐nanofiber configuration shows distinctive properties; electrochemically, the electrospun mats demonstrate excellent inherent electrical conductivity, good cyclic and high electrochemical stability, and low resistance. Furthermore, the amphiphilic and superhydrophilic behavior, achieved through nanotopography, porosity and interactions between the intrinsically conductive polymer and the PVDF‐HFP fibers, enables efficient uptake of polar and nonpolar analytes. The membranes also demonstrate good in vitro cell viability of both murine and human fibroblasts. Given its efficient interaction with liquids and omnidirectional 360‐degree conductivity, this material emerges as an excellent candidate for use as a biocompatible, multifunctional interface layer. The produced nanoparticle‐nanofibrous membrane materials offer a promising platform for interface applications, featuring enhanced spatiotemporal configurations and wide‐ranging applicability.
Polylactic acid/epoxidized linseed oil/polypropylene grafted maleic anhydride: A promising combination of toughness and rigidity
Authors: Cordeiro Elisangela , Gabino Alessandra A. P. , Henriques Ruan R. , Soares Bluma G. 
Published: April 2024

AbstractIncreasing toughness of brittle polymer without losing modulus of elasticity and tensile strength is highly important for enlarging the range of applications. In this study, polylactic acid (PLA) modified with epoxidized linseed oil (ELO) and polypropylene‐grafted maleic anhydride (PPgMA) with a good balance of toughness and rigidity was successfully prepared by melt mixing procedure. The addition of PPgMA/ELO with appropriate proportions (3:1, 5:1, and 5:5 wt%) resulted in PLA modified samples with significant ductility improvement (around 2200% of elongation at break and 1800% of tensile toughness compared to the neat PLA) with low decrease in Young modulus and tensile strength. This feature was attributed to improved interfacial interactions and the formation of crosslinked structures at the interface that also increased viscosity of the melting system and cold crystallization temperature of PLA. The scanning electron microscopy revealed the presence of small domains of modified systems. The effectiveness of reactive compatibilization among the components was also suggested by Fourier transform infrared (FTIR) spectroscopy and thermal degradation analysis. The combination of toughness, modulus of elasticity and good thermal properties make this low‐cost and scalable eco‐friendly material a promising candidate for use as biodegradable plastic in several fields including medical applications and packaging.
Exploring the substrate spectrum of phylogenetically distinct bacterial polyesterases
Authors: Makryniotis Konstantinos , Nikolaivits Efstratios , Taxeidis George , Nikodinovic‐Runic Jasmina , Topakas Evangelos 
Published: April 2024

AbstractThe rapid escalation of plastic waste accumulation presents a significant threat of the modern world, demanding an immediate solution. Over the last years, utilization of the enzymatic machinery of various microorganisms has emerged as an environmentally friendly asset in tackling this pressing global challenge. Thus, various hydrolases have been demonstrated to effectively degrade polyesters. Plastic waste streams often consist of a variety of different polyesters, as impurities, mainly due to wrong disposal practices, rendering recycling process challenging. The elucidation of the selective degradation of polyesters by hydrolases could offer a proper solution to this problem, enhancing the recyclability performance. Towards this, our study focused on the investigation of four bacterial polyesterases, including DaPUase, IsPETase, PfPHOase, and Se1JFR, a novel PETase‐like lipase. The enzymes, which were biochemically characterized and structurally analyzed, demonstrated degradation ability of synthetic plastics. While a consistent pattern of polyesters’ degradation was observed across all enzymes, Se1JFR stood out in the degradation of PBS, PLA, and polyether PU. Additionally, it exhibited comparable results to IsPETase, a benchmark mesophilic PETase, in the degradation of PCL and semi‐crystalline PET. Our results point out the wide substrate spectrum of bacterial hydrolases and underscore the significant potential of PETase‐like enzymes in polyesters degradation.
Political power differential and forced CEO turnover: Evidence from Chinese non‐state‐owned enterprises
Authors: Zhang Xingyi , Wang Qingfeng , Liu Weimin 
Published: April 2024

AbstractIn China, the prevalence of strong political connections among a significant number of boards of directors and CEOs highlights the importance of cultivating such relationships. This is particularly relevant when considering the Chinese political system where officers holding higher political ranks wield dominant, or even absolute, power in decision‐making. Our findings reveal that the political power differential (PPD) between a board of directors and its CEO plays a pivotal role in mitigating CEO entrenchment associated with political power. Specifically, when directors possess more political power than their CEOs, they can effectively fulfil their disciplinary role, leading to the dismissal of underperforming CEOs. Our study substantiates a significantly positive relationship between PPD and the probability of a forced CEO turnover, as well as the sensitivity of CEO turnover to performance. Notably, as PPD increases by one standard deviation from its mean level, we observe an approximate 30% increase in CEO turnover‐performance sensitivity. These findings confirm a higher likelihood of replacing underperforming CEOs in firms with a politically powerful board. Our results also highlight that a higher proportion of either independent or female directors alone does not guarantee effective monitoring. The key lies in ensuring that these directors possess stronger political power than the CEO.
Targeted therapies for HPV‐associated cervical cancer: Harnessing the potential of exosome‐based chipsets in combating leukemia and HPV‐mediated cervical cancer
Authors: Maitra Swastika , Mukerjee Nobendu , Alharbi Hanan M. , Ghosh Arabinda , Alexiou Athanasios , Thorat Nanasaheb D. 
Published: April 2024

AbstractExosomes play a crucial role in intercellular communication and have emerged as significant vehicles for transporting disease‐specific biomarkers. This feature provides profound insights into the progression of diseases and the responses of patients to treatments. For example, in leukemia, exosomes convey critical information through the carriage of specific proteins and nucleic acids. In the case of human papillomavirus (HPV)‐mediated cervical cancer, exosomes are particularly useful for noninvasive detection as they transport high‐risk HPV DNA and specific biomolecules, which can be indicators of the disease. Despite their vast potential, there are several challenges associated with the use of exosomes in medical diagnostics. These include their inherent heterogeneity, the need for enhanced sensitivity in detection methods, the establishment of standardization protocols, and the requirement for cost‐effective scalability in their application. Addressing these challenges is crucial for the effective implementation of exosome‐based diagnostics. Future research and development are geared towards overcoming these obstacles. Efforts are concentrated on refining the processes of biomarker discovery, establishing comprehensive regulatory frameworks, developing convenient point‐of‐care devices, exploring methods for multimodal detection, and conducting extensive clinical trials. The ultimate goal of these efforts is to inaugurate a new era of precision diagnostics within healthcare. This would significantly improve patient outcomes and reduce the burden of diseases such as leukemia and HPV‐mediated cervical cancer. The integration of exosomes with cutting‐edge technology holds the promise of significantly reinforcing the foundations of healthcare, leading to enhanced diagnostic accuracy, better disease monitoring, and more personalized therapeutic approaches.
Poly(ionic liquid)s‐Based Thermal‐Responsive Microgel for Use as SERS Substrates with “ON–OFF” Switchable Effect
Authors: Chen Yaxian , Wang Huiting , Wan Yu , Li Shun , Zhang Ling , Xing Zhiqiang , Zhang, Qian , Xia Lixin 
Published: April 2024

AbstractA temperature‐responsive surface‐enhanced Raman scattering (SERS) substrate with “ON–OFF” switching based on poly(ionic liquid)s (PILs) block copolymer microgels have been designed and synthesized. The PIL units act as a joint component to anchor the gold nanoparticles (AuNPs) and analytes onto poly(N‐isopropylacrylamide) (PNIPAm). This anchor allows the analytes to be fixed at the formed hot spots under temperature stimulus. Owing to the regulation of the PNIPAm segment, the SERS substrates exhibit excellent thermally responsive SERS activity with a reversible “ON–OFF” effect. Additionally, because of the anion exchange of PILs, microgels can introduce new analytes, which offers more flexibility for the system. The substrate shows excellent reversibility, controllability, and flexibility of SERS activity, which is expected to have a broad application in the field of practical SERS sensors.