bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of molecular interactions on the viscoelastic and plastic behaviour of plasticized poly(vinyl chloride)
Authors: Dubault A , Bokobza L , Gandin E , Halary JL 
Published: June 2003

AbstractThe mechanical behaviour of plasticized poly(vinyl chloride) in the glassy state was revisited in order to provide some understanding of the properties observed on the molecular scale. Nine samples were investigated, consisting either of pure poly(vinyl chloride) or of plasticized formulations including different amounts of di‐octyl phthalate or benzyl butyl phthalate in the range 5–20 wt%. Presence of the additives resulted in the depression of the glass transition temperature,Tg, and the main mechanical relaxation temperature,Tα, as determined by differential scanning calorimetry and dynamic mechanical analysis, respectively. These expected results were related to the plasticizing character of the additives on the long‐range cooperative polymer motions. In addition, a marked reduction of the secondary mechanical relaxation β was observed for additive concentrations equal to or larger than 10 wt%. This antiplasticizing effect was interpreted as the hindrance of main‐chain local polymer motions, due to poly(vinyl chloride)–additive interactions. Occurrence of such interactions was confirmed by mid‐ and near‐infrared measurements. The plastic behaviour of the materials in the glassy state was also examined. Particular attention was paid to the strain‐softening amplitude (difference between yield stress and plastic flow stress), to the percentage of non‐elastic deformation and to the mechanical energy to yield. All these quantities are strongly affected by the chain‐mobility characteristics. Copyright © 2003 Society of Chemical Industry
Hydroxyapatite as a filler for biosynthetic PHB homopolymer and P(HB–HV) copolymers
Authors: Bergmann Antje , Owen Anthony 
Published: June 2003

AbstractThis paper deals with some of the fundamental problems encountered when using a semicrystalline polymer as the matrix phase for a particulate‐filled composite. As our model system we adopted poly‐(R)‐3‐hydroxybutyrate, PHB, and two copolymers of (R)‐3‐hydroxybutyrate and (R)‐3‐hydroxyvalerate, P(HB–HV), for the matrix phase, and the mineral calcium hydroxyapatite as a particulate filler. The structure and properties of compression‐moulded films of various compositions were investigated by polarized light microscopy, wide‐angle X‐ray scattering and mechanical testing. It was found that the degree of crystallinity of the matrix was lower in filled samples, and that the spherulitic crystallization of the matrix appeared to cause the filler particles to form agglomerates, which would not be as effective a reinforcement as finely dispersed primary filler particles. The tensile strength, strain‐to‐break and tensile modulus of samples of different compositions were analysed using well‐known theories for composite behaviour. Copyright © 2003 Society of Chemical Industry
Photo‐induced birefringence phenomenon of a double azo polymer
Authors: Wang Jian , Zhang LingZhi , Niu Yongping , Liang Zhaoxi , Chen Yonglie , Huang Yaping , Wang Hui , Lin Weizhu 
Published: June 2003

AbstractPoly(glycidyl methacrylate) grafted with double azo bond 4[4′‐(phenylazo)phenylazo]phenol was synthesized and characterized. Photo‐induced birefringence phenomenon of this polymer was studied by static absorption and dynamic pump‐probe techniques, and was compared with that of another polymer Poly{(methyl methacrylate)‐co‐4‐[(3‐methacryloyloxy)} [P(MMA‐co‐MAZ)] containing mono azobenzene chromophore. The results showed that former polymer carrying two azo bonds, with a larger birefringence ratio, had a relatively faster optical switching response than the latter polymer under the same pump beam power. Copyright © 2003 Society of Chemical Industry
Magnetic and conducting Fe3O4–polypyrrole nanoparticles with core‐shell structure
Authors: Deng Jianguo , Peng Yuxing , He Chuanlan , Long Xingping , Li Pei , Chan Albert S C 
Published: June 2003

AbstractMagnetic and conducting Fe3O4–polypyrrole nanoparticles with core‐shell structure were prepared in the presence of Fe3O4 magnetic fluid in aqueous solution containing sodium dodecylbenzenesulfonate (NaDS) as a surfactant and dopant. Both the conductivity and magnetization of the composites depend strongly on the Fe3O4 content and the doping degree. With increase of Fe3O4 content in the composite, the conductivity at room temperature decreases, but the saturated magnetization and coercive force increase. Transmission electron microscopy (TEM) images of Fe3O4 and Fe3O4–polypyrrole particles show almost spherical particles with diameters ranging from 20 to 30 and 30 to 40 nm, respectively. The thermal stability of Fe3O4–polypyrrole composites is higher than that of pure polypyrrole. Studies of IR, UV–visible and X‐ray photoelectron spectroscopy (XPS) spectra suggest that the increased thermal stability may be due to interactions between Fe3O4 particles and polypyrrole backbone. Copyright © 2003 Society of Chemical Industry
Role of hydrogen bonding in the oxidation potential of enols
Authors: Lal Mukul , Langels Anja , Deiseroth Hans‐Jörg , Schlirf Jens , Schmittel Michael 
Published: June 2003

AbstractThree stable β,β‐dimesityl enols with heteroaromatic rings in the α‐position were synthesized to study the effect of OH···N hydrogen bonding on the oxidation potentials of enols. In contrast to its solid‐state structure, enol E1 exists predominantly as intramolecularly hydrogen‐bonded species in solution. For enol E2 an intermolecular hydrogen bond and for E3 a partial proton transfer were established based on NMR, dilution experiments, solvent dependence and UV–visible spectroscopic studies. Cyclic voltammetric investigations revealed that OH···N hydrogen bonding may shift the oxidation potentials of enols by up to 510 mV cathodically. Copyright © 2003 John Wiley & Sons, Ltd.
Residual thermal birefringence in freely quenched plates of amorphous polymers: Simulation and experiment
Authors: Shyu G. D. , Isayev A. I. , Li C. T. 
Published: June 2003

AbstractFree quenching experiments were performed on thin plates of polystyrene (PS) and polycarbonate (PC). The thermal birefringence distribution along the thickness direction of the plates was measured. The birefringence data were compared with the results of a numerical simulation based on the linear viscoelastic and photoviscoelastic constitutive equations for the mechanical and optical properties, respectively, and the first‐order rate equation for volume relaxation. The effects of the initial temperature, quenching temperature, and quenching media on the development of residual thermal stresses and birefringence were evaluated. At higher initial temperatures (>105 °C), the thermal birefringence in quenched PS plates was negative at the center and positive at the surface, whereas at lower temperatures (close to the glass‐transition temperature), the birefringence became positive at the core and negative at the surface or positive through the entire cross section of the plate. The birefringence in freely quenching PC plates was positive at the center and negative at the surface at any initial temperature. These observations were in fair agreement with predicted data. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1850–1867, 2003
Intersecting branes and 7‐manifolds with G2 holonomy
Authors: Behrndt K. 
Published: June 2003

AbstractIn this talk I discuss intersecting brane configurations coming from explicit metrics with G2 holonomy. An example of a 7‐manifold which representing a \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$\mathbb R^3$\end{document} bundle over a self‐dual Einstein space is described and the potential appearing after compactification over the 6‐d twistor space is derived.
Local intersecting brane worlds
Authors: Uranga A.M. 
Published: June 2003

AbstractWe describe the construction of configurations of D6‐branes wrapped on compact 3‐cycles intersecting at points in non‐compact Calabi‐Yau threefolds. Such constructions provide local models of intersecting brane worlds, and describe sectors of four‐dimensional gauge theories with chiral fermions. We present several classes of non‐compact manifolds with compact 3‐cycles intersecting at points, and several explicit examples of these constructions, some of which have Standard Model like gauge group and three quark‐lepton generations. In some cases, mirror symmetry relates the models to other constructions used in phenomenological D‐brane model building, like D‐branes at singularities.
Screening for Speech and Language Delay and Disorders in Children 5 Years or Younger
Authors: Feltner Cynthia , Wallace Ina F. , Nowell Sallie W. , Orr Colin J. , Raffa Brittany , Middleton Jennifer Cook , Vaughan Jessica , Baker Claire , Chou Roger , Kahwati Leila 
Published: January 2024

ImportanceChildren with speech and language difficulties are at risk for learning and behavioral problems.ObjectiveTo review the evidence on screening for speech and language delay or disorders in children 5 years or younger to inform the US Preventive Services Task Force.Data SourcesPubMed/MEDLINE, Cochrane Library, PsycInfo, ERIC, Linguistic and Language Behavior Abstracts (ProQuest), and trial registries through January 17, 2023; surveillance through November 24, 2023.Study SelectionEnglish-language studies of screening test accuracy, trials or cohort studies comparing screening vs no screening; randomized clinical trials (RCTs) of interventions.Data Extraction and SynthesisDual review of abstracts, full-text articles, study quality, and data extraction; results were narratively summarized.Main Outcomes and MeasuresScreening test accuracy, speech and language outcomes, school performance, function, quality of life, and harms.ResultsThirty-eight studies in 41 articles were included (N = 9006). No study evaluated the direct benefits of screening vs no screening. Twenty-one studies (n = 7489) assessed the accuracy of 23 different screening tools that varied with regard to whether they were designed to be completed by parents vs trained examiners, and to screen for global (any) language problems vs specific skills (eg, expressive language). Three studies assessing parent-reported tools for expressive language skills found consistently high sensitivity (range, 88%-93%) and specificity (range, 88%-85%). The accuracy of other screening tools varied widely. Seventeen RCTs (n = 1517) evaluated interventions for speech and language delay or disorders, although none enrolled children identified by routine screening in primary care. Two RCTs evaluating relatively intensive parental group training interventions (11 sessions) found benefit for different measures of expressive language skills, and 1 evaluating a less intensive intervention (6 sessions) found no difference between groups for any outcome. Two RCTs (n = 76) evaluating the Lidcombe Program of Early Stuttering Intervention delivered by speech-language pathologists featuring parent training found a 2.3% to 3.0% lower proportion of syllables stuttered at 9 months compared with the control group when delivered in clinic and via telehealth, respectively. Evidence on other interventions was limited. No RCTs reported on the harms of interventions.Conclusions and RelevanceNo studies directly assessed the benefits and harms of screening. Some parent-reported screening tools for expressive language skills had reasonable accuracy for detecting expressive language delay. Group parent training programs for speech delay that provided at least 11 parental training sessions improved expressive language skills, and a stuttering intervention delivered by speech-language pathologists reduced stuttering frequency.
Intra‐ and inter‐fractional variations of tumors with fiducial markers measured using respiratory‐correlated computed tomography images for respiratory gated lung stereotactic body radiation therapy
Authors: Manabe Yuki , Shiinoki Takehiro , Fujimoto Koya , Ueda Kazushi , Karita Masako , Ono Taiki , Kajima Miki , Tanaka Hidekazu 
Published: January 2024

AbstractPurposeThis study evaluated the intra‐ and inter‐fractional variation of tumors with fiducial markers (FMs), relative to the tumor‐FM distance, to establish how close an FM should be inserted for respiratory‐gated stereotactic body radiation therapy (RG‐SBRT).MethodsForty‐five lung tumors treated with RG‐SBRT were enrolled. End‐expiratory computed tomography (CT) (CTplan) and four‐dimensional‐CT (4D‐CT) scans were obtained for planning. End‐expiratory CT (CTfr) scanning was performed before each fraction. The FMs were divided into two groups based on the median tumor‐FM distance in the CTplan (Dp). For the intra‐fractional variation, the correlations between the corresponding tumor and FM intra‐fractional motions, defined as the centroid coordinates of those in each 0–90% phase, with the 50% phase of 4D‐CT as the origin, were calculated in the left‐right, anterior‐posterior, and superior‐inferior directions. Furthermore, the maximum difference in the tumor‐FM distance in each phase of 4D‐CT scan, based on those in the 50% phase of 4D‐CT scan (Dmax), was obtained. Inter‐fractional variation was defined as the maximum distance between the tumors in CTplan and CTfr, when the CT scans were fused based on each FM or vertebra.ResultsThe median Dp was 26.1 mm. While FM intra‐fractional motions were significantly and strongly correlated with the tumor intra‐fractional motions in only anterior‐posterior and superior‐inferior directions for the Dp > 26 mm group, they were significantly and strongly correlated in all directions for the Dp ≤ 26 mm group. In all directions, Dmax values of the Dp ≤ 26 mm group were lower than those of the Dp > 26 mm group. The inter‐fractional variations based on the Dp ≤ 26 mm were smaller than those on the Dp > 26 mm and on the vertebra in all directions.ConclusionsRegarding intra‐ and inter‐fractional variation, FMs for Dp ≤ 26 mm can increase the accuracy for RG‐SBRT.
Materials Design Innovations in Optimizing Cellular Behavior on Melt Electrowritten (MEW) Scaffolds
Authors: Devlin Brenna L. , Allenby Mark C. , Ren Jiongyu , Pickering Edmund , Klein Travis J. , Paxton Naomi C. , Woodruff Maria A. 
Published: January 2024

AbstractThe field of melt electrowriting (MEW) has seen significant progress, bringing innovative advancements to the fabrication of biomaterial scaffolds, and creating new possibilities for applications in tissue engineering and beyond. Multidisciplinary collaboration across materials science, computational modeling, AI, bioprinting, microfluidics, and dynamic culture systems offers promising new opportunities to gain deeper insights into complex biological systems. As the focus shifts towards personalized medicine and reduced reliance on animal models, the multidisciplinary approach becomes indispensable. This review provides a concise overview of current strategies and innovations in controlling and optimizing cellular responses to MEW scaffolds, highlighting the potential of scaffold material, MEW architecture, and computational modeling tools to accelerate the development of efficient biomimetic systems. Innovations in material science and the incorporation of biologics into MEW scaffolds have shown great potential in adding biomimetic complexity to engineered biological systems. These techniques pave the way for exciting possibilities for tissue modeling and regeneration, personalized drug screening, and cell therapies.
Biochemotaxis‐Oriented Engineering Bacteria Expressing GLP‐1 Enhance Diabetes Therapy by Regulating the Balance of Immune
Authors: Wang Yifei , Shi Yupeng , Peng Xueyuan , Li Tongtong , Liang Chenglin , Wang Wenhao , Zhou Mengyang , Yang Jiali , Cheng Jingliang , Zhang Zhenzhong , Hou Lin 
Published: January 2024

AbstractGlucagon like peptide‐1 (GLP‐1) is an effective hypoglycemic drug that can repair the pancreas β cells and promote insulin secretion. However, GLP‐1 has poor stability and lacks of target ability, which makes it difficult to reach the site of action to exert its efficacy. Here, GLP‐1‐expressing plasmids are introduced into the Escherichia coli Nissle 1917 (EcN) and a lipid membrane is formed through simple self‐assembly on its surface, resulting in an oral delivery system (LEG) capable of resisting the harsh environment of the gastrointestinal tract. The system utilizes the chemotactic properties of probiotics to achieve efficient enrichment at the pancreatic site, and protects islet β cells from destruction by regulating the balance of immune cells. More interestingly, LEG not only continuously produces GLP‐1 to restore pancreatic islet β cell function and secrete insulin to control blood sugar levels, but also regulates the intestinal flora and increases the richness and diversity of probiotics. In mice diabetes models, oral administration of LEG only once every other day has good biosafety and compliance, and achieves long‐term control of blood glucose. Therefore, this strategy not only provides an oral delivery platform for pancreatic targeting, but also opens up new avenues for reversing diabetes.
Fluorescent Nanocarbons: From Synthesis and Structure to Cancer Imaging and Therapy
Authors: Ghasemlou Mehran , PN Navya , Alexander Katia , Zavabeti Ali , Sherrell Peter C. , Ivanova Elena P. , Adhikari Benu , Naebe Minoo , Bhargava Suresh K. 
Published: January 2024

AbstractNanocarbons are emerging at the forefront of nanoscience, with diverse carbon nanoforms emerging over the past two decades. Early cancer diagnosis and therapy, driven by advanced chemistry techniques, play a pivotal role in mitigating mortality rates associated with cancer. Nanocarbons, with an attractive combination of well‐defined architectures, biocompatibility, and nanoscale dimension, offer an incredibly versatile platform for cancer imaging and therapy. This paper aims to review the underlying principles regarding the controllable synthesis, fluorescence origins, cellular toxicity, and surface functionalization routes of several classes of nanocarbons: carbon nanodots, nanodiamonds, carbon nanoonions, and carbon nanohorns. This review also highlights recent breakthroughs regarding the green synthesis of different nanocarbons from renewable sources. It also presents a comprehensive and unified overview of the latest cancer‐related applications of nanocarbons and how they can be designed to interface with biological systems and work as cancer diagnostics and therapeutic tools. The commercial status for large‐scale manufacturing of nanocarbons is also presented. Finally, it proposes future research opportunities aimed at engendering modifiable and high‐performance nanocarbons for emerging applications across medical industries. This work is envisioned as a cornerstone to guide interdisciplinary teams in crafting fluorescent nanocarbons with tailored attributes that can revolutionize cancer diagnostics and therapy.
Flexible Manipulated Interference Lithography Incorporating Modulated Optical Fourier Transform System
Authors: Ye Yan , Qian Sen , Ye Hong , Lu Chang , Xu Fengchuan , Wang Fei , Cai Yangjian , Wang Qinhua , Chen Linsen , Xu Yishen 
Published: January 2024

AbstractSpatial‐variant micro/nano‐structures are widely utilized in metasurfaces to modulate optical wave‐fronts into arbitrary shapes, performing as a new generation of flat optics. To flexibly fabricate micro/nano‐structures in real time, an optical Fourier transform system modulated by a diaphragm and a binary optical element (BOE) is proposed. Theoretical analysis shows that light field at image plane is a multiple result of twice Fourier transform of diaphragm and BOE's transmission field, with its amplitude and phase distribution independently manipulated by diaphragm and BOE. Inversely, diaphragm and BOE can be designed to get customized interference fields, where four fields with different vectors are generated for instance. Utilizing these four fields for time division multiplexing exposure, fringes inside circle/ring shapes with variant orientations are produced in photoresist film. Furthermore, multiple spatial variant fields can be obtained simultaneously while more symmetric distributed apertures acted as diaphragm, which shows great potential for the fabrication of segmented or interleaved spatial‐variant micro/nano‐structures in addition.
N‐Heterocyclic Carbene Organocatalyzed [3+3] Annulation for the Enantioselective Synthesis of Benzopyranothiazinones
Authors: Mroczyńska Karina , Rafiński Zbigniew 
Published: January 2024

AbstractThe design, inspired by the core‐structure of oxicam has allowed the enantioselective synthesis of benzopyranothiazinone motifs employing N‐heterocyclic carbene (NHC) catalysis. The NHC‐mediated transformation involves the reaction of α,β‐unsaturated aldehydes with suitable substituted benzothiazinone derivatives. This process encompasses the initial formation of α,β‐unsaturated acylazoliums from ynals and concurrent generation of enolates from benzothiazinone. The culmination of these reactions results in an efficient annulation, yielding the desired products with reasonable yields and high stereoselectivities. This study underscores the potential of NHC catalysis in the streamlined synthesis of complex heterocyclic structures.
Magnesium‐Catalyzed Asymmetric Thia‐Michael Addition to α,β‐Unsaturated Ketones
Authors: Jaszczewska‐Adamczak Joanna A. , Baczewska Paulina , Bujok Robert , Mlynarski Jacek 
Published: January 2024

AbstractWe demonstrate the application of chiral magnesium complexes in an asymmetric carbon‐sulfur bond‐forming reaction. Enantioselective and cost‐effective methodology under mild condition for the thia‐Michael addition, utilizing an in situ generated chiral dinuclear magnesium‐ProPhenol complex, has been developed. The versatility of this protocol is demonstrated with a broad range of thiol nucleophiles and a wide selection of enones. Enantioenriched β‐ketosulfides are obtained in good to excellent yields and moderate to excellent enantioselectivity. The presented catalytic system exhibits excellent tolerance for structurally different substrates while maintaining high enantioselectivity. This observation aligns with proposed mechanism, wherein the sulfur atom coordinates to the catalyst in close proximity to the reaction center.
YTHDF2 Is a Therapeutic Target for HCC by Suppressing Immune Evasion and Angiogenesis Through ETV5/PD‐L1/VEGFA Axis
Authors: Wen Jingyuan , Xue Lin , Wei Yi , Liang Junnan , Jia Wenlong , Yong Tuying , Chu Liang , Li Han , Han Shenqi , Liao Jingyu , Chen Zeyu , Liu Yiyang , Liu Qiumeng , Ding Zeyang , Liang Huifang , Gan Lu , Chen Xiaoping , Huang Zhao , Zhang Bixiang 
Published: January 2024

AbstractN6‐methyladenosine (m6A) modification orchestrates cancer formation and progression by affecting the tumor microenvironment (TME). For hepatocellular carcinoma (HCC), immune evasion and angiogenesis are characteristic features of its TME. The role of YTH N6‐methyladenosine RNA binding protein 2 (YTHDF2), as an m6A reader, in regulating HCC TME are not fully understood. Herein, it is discovered that trimethylated histone H3 lysine 4 and H3 lysine 27 acetylation modification in the promoter region of YTHDF2 enhanced its expression in HCC, and upregulated YTHDF2 in HCC predicted a worse prognosis. Animal experiments demonstrated that Ythdf2 depletion inhibited spontaneous HCC formation, while its overexpression promoted xenografted HCC progression. Mechanistically, YTHDF2 recognized the m6A modification in the 5′‐untranslational region of ETS variant transcription factor 5 (ETV5) mRNA and recruited eukaryotic translation initiation factor 3 subunit B to facilitate its translation. Elevated ETV5 expression induced the transcription of programmed death ligand‐1 and vascular endothelial growth factor A, thereby promoting HCC immune evasion and angiogenesis. Targeting YTHDF2 via small interference RNA‐containing aptamer/liposomes successfully both inhibited HCC immune evasion and angiogenesis. Together, this findings reveal the potential application of YTHDF2 in HCC prognosis and targeted treatment.