bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimization and Partial Characterization of Biosurfactants Produced by Bacillus Species and Their Potential for Ex-Situ Enhanced Oil Recovery
Authors: Al-Sulaimani H.. , Al-Wahaibi Y.. , Al-Bahry S.. , Elshafie A.. , Al-Bemani A.. , Joshi S.. , Zargari S.. 
Published: June 2011

Summary
This study aims to test the potential of microbial enhanced oil recovery (MEOR) as an effective alternative in Omani oil fields. In this study, biosurfactants produced by Bacillus licheniformis and Bacillus subtilis strains isolated from oil-contaminated soils from different parts of the Sultanate of Oman were investigated. Eight different minimal production media using different sugars as carbon sources were tested on three of the strains to select the medium that maximized the production of biosurfactants which were indicated by the interfacial tension (IFT) reduction. All isolates were tested on their potential media to screen for the best biosurfactant producer among the available strains. It was found that Bacillus subtilis Strain W19 gave the maximum IFT reduction (46.6 mN/m to 3.28 mN/m) in 16 hours of incubation when grown in a minimal medium containing glucose. The yield of the biosurfactant produced by B. subtilis W19 was 2.5g/L. Critical micelle concentration (CMC) was measured to be 0.4 g/L. The biosurfactant was partially characterized by FT-IR analysis, in which the peaks obtained imply the presence of aliphatic hydrocarbons as well as a peptide-like moiety in the biosurfactant.
The cell-free biosurfactant broth produced from Strain W19 was found to be stable over a pH range from 6 to 10 and was most effective at 7. It also showed no loss in surface activity when subjected to various temperatures (60, 80, and 120°C). The biosurfactant also retained almost 60% of its activity even in a high-saline environment up to 20% NaCl (w/v).
Further studies were conducted to test the interaction of biosurfactant produced by B. subtilis W19 with porous media in coreflooding experiments as a tertiary-recovery stage. The results showed high potential of using this bacterium during ex-situ MEOR applications in which a total of 23% of residual oil was produced after biosurfactant and concentrated-biosurfactant injection.
Optimization of Production Performance With ICVs by Using Temperature-Data Feedback in Horizontal Wells
Authors: Li Zhuoyi , Zhu Ding 
Published: June 2011

SummaryHorizontal wells with intelligent completions have been used widely in many field cases. With inflow-control valves (ICVs), production can be optimized either on individual wells or at large reservoir scale. A critical step in this procedure is to understand the inflow profiles along horizontal wellbores. To develop control and optimization strategies, permanent monitoring systems such as pressure gauges and temperature sensors have been deployed with downhole control valves to provide temperature or pressure data in real time, and to translate downhole-flow conditions from these data.The relationships between temperature and inflow distribution have been developed before in intelligent-well models, and these models are very useful in locating water or gas entries and obtaining better production performances. In this work, we present a new idea—using temperature feedback to directly regulate flow-control valves to achieve an approximately uniform flow distribution. Instead of detecting water or gas flow with different thermal properties of fluids, we aim to regulate flow distribution through temperature behavior to achieve optimal flow conditions. Early-time temperature and pressure data are used to estimate permeability and initial flow profiles along the well; then, developed models are applied to generate a desired temperature profile that yields an evenly distributed flow rate along the wellbore. ICVs are operated on the basis of the guidance from the initial temperature data, and the temperature is monitored as it approaches the desired temperature profile. Through this procedure, we will produce a well at an optimal condition by choking down the flow rate at higher-permeability locations along the well. This can increase oil-flow rate and delay early water breakthrough.This paper explains the details of the procedure. Two examples are used to illustrate the application of the method; one is for a waterdrive reservoir, and the other is a water-injection case. The results show significant improvement in well performance in both examples.
Extension of Das and Butler Semianalytical Flow Model
Authors: Knorr Kelvin D. , Imran Muhammad 
Published: June 2011

Summary
In this work, the Das and Butler flow model was extended to account for the effect of differential pressure across a laterally and vertically spaced horizontal injection- and production-well pair for solvent vapour extraction (SVX) processes. The extended model provides a more-rigorous dispersion-coefficient correlation using interstitial pore velocity and mean particle size. This was used to history match oil-production data from 3D-scaled physical model experiments and to determine the effective dispersion coefficient of the solvent in heavy oil. The SVX experiments were performed with two model sizes and three different permeabilities spanning than two orders of magnitude. Laterally spaced horizontal wells were used to inject an 86:14 mol% mixture of butane and methane, respectively, as a dense vapour. The average dispersion coefficient of solvent (butane) was found to decrease with injected cumulative solvent and increase with reduction in permeability, and both of these relationships could be approximated with an inverse power function.
La modernité gandhienne de l'Intifada arabe
Authors: Ravenel Bernard 
Published: June 2011

La révolution dans le monde arabe a pris la forme d’une lutte populaire non-violente qui a triomphé d’abord en Tunisie, puis en Egypte. Mais pour mieux comprendre ce phénomène historique, on ne peut ignorer le précédent que représente la résistance non-violente en Palestine comme ce fut le cas avec la première Intifada de 1987 à 1993 avant que cette forme de résistance soit relancée à partir de 2005. Cette innovation politique oblige à repenser le rapport entre révolution et violence et à considérer le choix de la non-violence comme une nécessité politique et historique.
Insécurités alimentaires : les risques géopolitiques se précisent en Méditerranée
Authors: Abis Sébastien 
Published: June 2011

Les pays arabes de la Méditerranée subissent plusieurs chocs simultanément : politique, économique, climatique et alimentaire. Tout est lié dans cette région du Monde qui semble connaitre les débuts d’une transition majeure de son histoire. Parmi les nombreux enjeux à relever, celui consistant à gérer les insécurités alimentaires s’amplifie. Bien qu’il ne soit pas nouveau, le problème prend une tonalité de plus en plus géostratégique dans une zone où notamment les ressources en eau et en sols se font rares. Le développement agricole est contrarié, tout comme l’accès à l’alimentation se complexifie. Il faut regarder attentivement cette fragilité alimentaire qui s’accroît parmi les risques majeurs auxquels la région devra faire face. Au même moment, c’est également la dérive des territoires, entre des villes littorales globalisées et des zones rurales enclavées, qui s’affiche comme l’une des failles majeures traversant ces pays et ces sociétés
Entre littérature, science et politique : les œuvres alchimiques de Thomas Norton et George Ripley
Authors: Mairey Aude 
Published: June 2011

Résumé Les œuvres alchimiques de Thomas Norton (The Ordinal of Alchemy) et George Ripley (The Compound of Alchemy) constituent deux des plus importants témoignages de la popularité de l’alchimie dans l’Angleterre de la seconde moitié du xv e siècle, mais elles n’ont généralement été étudiées que sous l’angle de leur pseudo- scientificité. Or, leurs auteurs abordent, particulièrement dans leurs prologues, des questions cruciales sur les notions de littérature, de langue et de connaissance, mais aussi sur leur rapport au pouvoir et au prince. Cela est d’autant plus notable qu’ils souhaitent transmettre une discipline à la croisée des sciences et des arts, marquée par la culture du secret. De fait, ces textes invitent à repenser tout autant les frontières établies entre cultures savantes et non savantes que celles entre les genres littéraires médiévaux. Ils participent pleinement à la constitution d’une culture laïque possédant une forte identité anglaise et marquée par des enjeux politiques essentiels – la transformation du prince aux fins de bon gouvernement – dans le contexte d’une société politique troublée par la guerre civile.
Le livre français en Italie à la fin du xixe siècle : problématiques et méthodes
Authors: Muller Raphaël 
Published: June 2011

Résumé Entre 1880 et 1920, le livre français est présent en Italie sous différentes formes : en version originale, comme en traduction. Dans un pays dont les élites sont très majoritairement francophones, où la culture française est une référence constante, dans un pays aussi qui a récemment achevé son unité territoriale et s’est engagé dans un processus d’unification culturelle qui passe par un élargissement du lectorat, le livre est un vecteur majeur de la présence culturelle française. Cette présence peut être mesurée précisément grâce aux séries bibliographiques nationales mises en place à partir de 1885 pour recenser les ouvrages publiés en Italie et les ouvrages étrangers acquis par les bibliothèques italiennes. Dans un marché éditorial en pleine expansion, caractérisé par l’émergence de maisons de dimension nationale, la traduction de livres français, et tout particulièrement de romans populaires issus des feuilletons de la presse parisienne, est particulièrement active et constitue le vecteur majeur de la conquête de nouveaux publics, nés des progrès de l’alphabétisation. Largement présent dans les fonds, dans les bibliothèques publiques de la Péninsule, le livre en français est un support majeur de la diffusion des savoirs académiques, en particulier en matière de médecine, d’histoire ou de critique littéraire, alors que les ouvrages de philosophie ou de philologie étaient plus fréquemment importés d’Allemagne.
Surgical Outcomes of 23- and 20-Gauge Vitrectomies for Rhegmatogenous Retinal Detachment Associated With Posterior Vitreous Detachment
Authors: Hikichi Taiichi , Kosaka Shoko , Takami Kimitaka , Ariga Hiroko , Ohtsuka Hideo , Higuchi Makoto , Matsushita Takuro , Matsushita Reiko 
Published: June 2011

BACKGROUND AND OBJECTIVE:
To compare the outcomes of 23- and 20-gauge vitrectomies 1 year after primary repair of rhegmatogenous retinal detachments (RRDs) associated with a posterior vitreous detachment (PVD).

PATIENTS AND METHODS:
One hundred seventy-five consecutive eyes were reviewed that had undergone 23- or 20-gauge vitrectomy for RRDs associated with PVD.

RESULTS:

Retinal reattachment during the year after the first vitrectomy occurred in 88 (91%) of 97 eyes in the 23-gauge group and 70 (90%) of 78 eyes in the 20-gauge group. All eyes in both groups achieved anatomic success after another procedure. The surgical time in the 23-gauge group was significantly (
P
= .03) shorter than in the 20-gauge group. No significant difference was found between the preoperative and postoperative visual acuities in both groups.

CONCLUSION:
Twenty-three–gauge vitrectomy can obtain anatomic and visual acuity results similar to those obtained with 20-gauge vitrectomy after primary repair of RRDs and may be a surgical option for treating the disorder.
Simulations of the NK Cell Immune Synapse Reveal that Activation Thresholds Can Be Established by Inhibitory Receptors Acting Locally
Authors: Kaplan Asya , Kotzer Shulamit , Almeida Catarina R. , Kohen Refael , Halpert Gilad , Salmon-Divon Mali , Köhler Karsten , Höglund Petter , Davis Daniel M. , Mehr Ramit 
Published: June 2011

Abstract
NK cell activation is regulated by a balance between activating and inhibitory signals. To address the question of how these signals are spatially integrated, we created a computer simulation of activating and inhibitory NK cell immunological synapse (NKIS) assembly, implementing either a “quantity-based” inhibition model or a “distance-based” inhibition model. The simulations mimicked the observed molecule distributions in inhibitory and activating NKIS and yielded several new insights. First, the total signal is highly influenced by activating complex dissociation rates but not by adhesion and inhibitory complex dissociation rates. Second, concerted motion of receptors in clusters significantly accelerates NKIS maturation. Third, when the potential of a cis interaction between Ly49 receptors and MHC class I on murine NK cells was added to the model, the integrated signal as a function of receptor and ligand numbers was only slightly increased, at least up to the level of 50% cis-bound Ly49 receptors reached in the model. Fourth, and perhaps most importantly, the integrated signal behavior obtained when using the distance-based inhibition signal model was closer to the experimentally observed behavior, with an inhibition radius of the order 3–10 molecules. Microscopy to visualize Vav activation in NK cells on micropatterned surfaces of activating and inhibitory strips revealed that Vav is only locally activated where activating receptors are ligated within a single NK cell contact. Taken together, these data are consistent with a model in which inhibitory receptors act locally; that is, that every bound inhibitory receptor acts on activating receptors within a certain radius around it.
A Self-Reactive TCR Drives the Development of Foxp3+ Regulatory T Cells That Prevent Autoimmune Disease
Authors: Killebrew Justin R. , Perdue Nikole , Kwan Alan , Thornton Angela M. , Shevach Ethan M. , Campbell Daniel J. 
Published: June 2011

AbstractAlthough Foxp3+ regulatory T cells (Tregs) are thought to express autoreactive TCRs, it is not clear how individual TCRs influence Treg development, phenotype, and function in vivo. We have generated TCR transgenic mice (termed SFZ70 mice) using Tcra and Tcrb genes cloned from an autoreactive CD4+ T cell isolated from a Treg-deficient scurfy mouse. The SFZ70 TCR recognizes a cutaneous autoantigen and drives development of both conventional CD4+ Foxp3− T cells (Tconv) and Foxp3+ Tregs. SFZ70 Tregs display an activated phenotype evidenced by robust proliferation and expression of skin-homing molecules such as CD103 and P-selectin ligand. Analysis of Foxp3-deficient SFZ70 mice demonstrates that Tregs inhibit Tconv cell expression of tissue-homing receptors and their production of proinflammatory cytokines. In addition, Treg suppression of SFZ70 Tconv cells can be overcome by nonspecific activation of APCs. These results provide new insights into the differentiation and function of tissue-specific Tregs in vivo and provide a tractable system for analyzing the molecular requirements of Treg-mediated tolerance toward a cutaneous autoantigen.
Social Rank, Female Competition for Food, and Behavioral Time‐Budgets in the Golden Snub‐Nosed Monkey Rhinopithecus roxellana Multi‐Level Society
Authors: He Shujun , Yang Yi , Hu Zhengfeng , Wu Fan , Wang Chengliang , Tian Wenyong , Bai Rui‐Feng , Qi Gao , Xie Yule , Li Baoguo , Guo Songtao , Dunn Derek W. 
Published: February 2025

ABSTRACTCompetition within primate groups often translates to a social hierarchy, with high‐rank individuals gaining privileged access to resources, especially food. Golden snub‐nosed monkeys Rhinopithecus roxellana live in a multi‐level society, with multiple one‐male units (OMUs), each containing a single adult male and several females, forming a breeding‐band. High‐rank males have increased access to high‐value foods and spend less time feeding and more time being groomed by females, potentially enhancing social cohesion within their OMUs. The adults of each OMU mainly feed and socialize together, with food competition predominantly acting at the OMU level. We thus predicted that adult females by association attain the rank and feeding privileges of their OMU leader males, and make similar time‐budget trade‐offs. By food‐provisioning a wild breeding‐band during winter and spring, when natural foods are abundant or limited, respectively, we found that females of high‐rank OMUs ate more provisioned foods at higher rates, especially during winter when provisioned foods had increased value. In winter, females of low‐rank OMUs fed for longer on natural foods and females of high‐rank OMUs longer on provisioned foods. Females of high‐rank OMUs spent longer being groomed by other OMU members, especially during winter. Our results are consistent with females attaining the feeding privileges of their OMU leader male, enhanced during winter due to increased value of provisioned foods, high thermal demands, and reduced natural food availability. Importantly, the feeding privileges attained by females of high rank OMUs were less pronounced than those previously found for leader males, possibly due to higher tolerance between females of different OMUs. We suggest that behavioral time‐budget effects of food competition in female R. roxellana enhance cohesion in high‐rank OMUs, contributing to OMU integrity and, hence, the social structure of this multi‐level society.
Hydrogen Bonding‐Induced Inversion and Amplification of Circularly Polarized Luminescence (CPL) in Supramolecular Assemblies of Axially Chiral Luminogens
Authors: Ghorai Sandipan , Show Soumyadip , Das Anindita 
Published: February 2025

AbstractHerein, we report the self‐assembly and chiroptical properties of two axially chiral π‐conjugated luminogens, R‐NMI and S‐NMI, each equipped with two pyridyl moieties for hydrogen (H)‐bonding with chiral diacids. The two enantiomers display aggregation‐induced emission enhancement (AIEE) and increased CD and CPL signals in the self‐assembled state with a high glum value of 1.5 (±0.06)×10−2 in 1:9 dioxane:methylcyclohexane. Crystallographic analysis confirmed mirror‐image helical structures for R‐NMI and S‐NMI involving both intra‐ and intermolecular π‐π stacking, leading to elongated hexagonal platelets. Supramolecular co‐assembly of R‐NMI with D‐ and L‐tartaric acids (D‐TA and L‐TA) could remarkably modulate and invert the chiroptical properties of R‐NMI, which is unachievable with control chiral monoacids. The co‐assembled structures were driven by pyridine‐carboxylic acid H‐bonding as revealed from the crystal structure analysis, which was also supported by computational studies. Strikingly, R‐NMI+D‐TA leads to an exceptionally high fourfold amplification in the glum value [5.4 (±0.04)×10−2] with an inverted sign, which additionally demonstrates intriguing temperature‐dependent switching. In contrast, R‐NMI+L‐TA results in a threefold reduction in the glum value [0.54 (±0.015)×10−3], also with an inverted sign compared to R‐NMI alone, establishing a clear strategy for chiral discrimination between the two enantiomers of TA.
“Self‐Catalysis” Acceleration of Carrier Transport in One‐Dimensional Covalent Organic Frameworks with Mortise‐Tenon Stacking
Authors: Zhang Zhe , Liu Yuxin , Qi Yuhang , Yu Zhuochen , Chen Xiao‐bo , Li Chunguang , Shi Zhan , Feng Shouhua 
Published: February 2025

AbstractCovalent Organic Frameworks (COFs) are promising in the field of photonic energy conversion. However, most efforts have been concentrated on the design of ligand geometric structures and chemical bonding relationships, while understanding the impact of stacking methods on photonic energy conversion remains a significant challenge. In this work, four COFs (1D‐COF, 1D‐MeCOF, 1D‐tBuCOF and 2D‐COF) with the same main‐chain structure but different stacking methods are designed and synthesized, using photocatalytic hydrogen evolution as a model reaction. Mortise‐tenon stacked 1D‐MeCOF exhibits far superior photocatalytic hydrogen evolution performance to other stacking methods, and it maintains high efficiency and stability in natural seawater systems. Extensive characterization demonstrates that such a unique mortise‐tenon stacking structure of 1D‐MeCOF inhibits interchain slippage, enhances π‐stacking, and maximizing light absorption capabilities. Furthermore, unidirectional carrier transport characteristics of one‐dimensional structure can generate a strong photo‐induced self‐built electric field, which acts as “self‐catalysis” to accelerate carrier transport. This work provides an effective design strategy and mechanistic insights on the stacking engineering of photonic energy conversion materials.
Mapping the Catalytic Cycle of Ru‐Catalyzed Ammonia Oxidation
Authors: Yuan Bowei , Tripodi Guilherme L. , Derks M.T.G.M. , Pereverzev Aleksandr Y. , Zhou Shaodong , Roithová Jana 
Published: February 2025

AbstractThis study presents a mechanism of ammonia oxidation catalyzed by [RuII(NH3)][PF6]2 (Ru=Ru(tpy)(dmabpy)) complexes. All intermediates, including the elusive [RuIII(NH2)]2+ and [RuIV(NH)]2+, were detected, with several intermediates characterized spectroscopically. The catalytic cycle follows multiple reaction pathways branching at the key intermediates [RuIII(NH2)]2+ and [RuII(N2H4)]2+. The competition between the pathways is influenced by ammonia concentration and the local proton concentration generated during electrooxidation at the anode. In the N−N bond‐forming steps, dimerization of [RuIII(NH2)]2+ and nucleophilic attack of [RuIV(NH)]2+ by ammonia compete, while in the subsequent [RuII(N2H4)]2+ oxidation, direct oxidation competes with proton‐catalyzed disproportionation. These findings provide molecular‐level insights into the catalytic cycle and offer guidance for developing more efficient ruthenium‐based ammonia oxidation catalysts.
An Organic Crystalline Ternary Pseudo‐Heterojunction with Contrasting Luminescent and Mechanical Properties Prepared by Thermotropic Phase Transition
Authors: Qi Jianqun , Lan Linfeng , Zhang Hongyu 
Published: February 2025

AbstractAdvancements in crystal engineering have enabled the precise tuning of the physical properties of organic crystals, thereby enhancing their potential in advanced optoelectronics. Here, we design an organic compound which crystallizes into distinct polymorphs with contrasting luminescent and mechanical behaviors. Controlled growth conditions yield flexible (Cry‐O: orange fluorescence) and brittle (Cry‐Y: yellow fluorescence) crystals which exhibit unique fluorescence shifts and reversible spectral changes between room and low temperatures, alongside unidirectional phase transitions upon thermal stimulation. The optical and mechanical differences between the polymorphs O and Y stem from their distinct molecular packing arrangements and intermolecular interactions. Notably, Cry‐O undergoes sequential phase transitions upon heating to 98 and 132 °C, enabling the creation of a ternary “pseudo‐heterojunction” structure, facilitating the integration of multiple functional phases into a single material. These findings not only enhance the understanding of structure–property relationships of organic materials but also demonstrate the potential of polymorphism‐driven property tuning for optoelectronic devices, thermal management systems, and optical sensors.