bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Belt-Rib Concept: A Structronic Approach to Variable Camber
Authors: Campanile L. F. , Sachau D. 
Published: August 2002

The belt-rib concept for lifting surfaces with variable camber evolved at DLR recently as one of the most promising solutions for the adaptive wing. With the belt-rib idea the adaptive wing issue is approached in a new way: instead of a “mechatronic” solution with hinges or linear bearings a “structronic” solution is chosen, where distributed flexibility allows the desired shape changes. The resulting system is not only easier to maintain due to the absence of wear, but also is structurally more reliable and substantially lighter. The new concept evolves from the classical wing structure. The classical rib, which is in charge of the wing section’s stiffness, is replaced by a “belt rib,” which allows camber changes within given limits while leaving the remaining in-plane stiffness properties of the section widely unchanged. The evolution of the belt-rib concept was accompanied by experimental tests on different prototypes. After a first development stage, in which mainly the system’s shape adaptability and the overall stiffness properties were investigated, further steps followed, focused on manufacturing, weight optimization and strength aspects. Recent developments dealt with the construction of a model with solid-state hinges, realized as hybrid glass fiber-carbon-fiber reinforced composite structure. The model is actuated mechanically by cables, which can be replaced by multifunctional actuators—like shape memory wires—in the future. The paper opens with an introduction about shape control of aerospace structures and variable camber in particular, in which the major advantages of a “structronic” approach with respect to classical solutions are discussed. Then the fundamentals of the belt-rib concept are sketched, with some significant results of the feasibility proof phase, followed by the description of the last developments. The conclusion summarizes the potential of a structronic approach to shape control with an outline of possible future work.
A Simple Failure Analysis of the Composite Transmission Tower
Authors: Yeh Hsien-Yang , Yeh Hsien-Liang 
Published: August 2002

The failure analysis of the composite transmission tower made of new and better material, E-Glass with vinylester, is presented in this paper. The conventional fastener method to join the cross members to the leg members was in place of a slip joint that was developed by Goldsworthy Engineering. The lamina of the leg member and the cross bracing were tested and compared with several other failure criteria, including the Tsai-Wu Theory, the Tsai-Hill Theory, the Hoffman Theory, the Fischer Criterion, the Cowin Criterion, the Yeh-Stratton Criterion, and the Quadric Surfaces Criterion. Besides, the full-scale tower tests were performed at Electrical and Power Research Institute. From the results of the simple failure analysis of the composite transmission tower with those failure criteria, it shows that building a transmission tower from a composite material, E-Glass and vinylester, is feasible.
Using Polymer Characterization Techniques to Predict LDPE Resin Suitability for Extruded Foam Applications
Authors: Auger Jim , Nguyen Lan 
Published: August 2002

All LDPE resins are not created equal. It is well known that autoclave LDPEs are considered to be the products of choice for extrusion coating applications. On the other hand, LDPE resins produced using tubular reactors have a different structure that makes them more suitable for extruded foam applications. More specifically, within the choices of tubular LDPE resins for extruded foam applications, some are easier to process and produce better quality foam products than others. What makes one resin better than another? This paper discusses the general chemical and rheological differences between autoclave and tubular LDPE resins then focuses in more detail on those differences for a variety of tubular LDPE products used in the extruded foam market.
A Hybrid Non-Contact Ultrasonic System for Sensing Bond Quality in Tow-Placed Thermoplastic Composites
Authors: Di Scalea Francesco Lanza , Green Robert E. 
Published: August 2002

A novel non-contact nondestructive evaluation system is proposed for sensing bond quality in tow-placed graphite/PEEK thermoplastic composites. The inspection tool consists of a hybrid ultrasonic system which employs laser generation of narrow-band surface waves with fiberoptic light delivery, and signal detection by air-coupled transduction. The fiberoptic link enhances flexibility and remoteness of the laser source from the test piece. The system output is not influenced by the poor light reflectivity of the test graphite/PEEK material. Signal narrow-banding by light spatial modulation enhances the measurement sensitivity and avoids detrimental material ablation while allowing control of the surface wave penetration depth. The theory of the laser generation of narrow-band surface waves is reviewed and the generation efficiency as a function of the wave propagation direction in the composite is discussed. The inspection capabilities of the proposed system are demonstrated by successful detection of a series of subsurface defects in a tow-placed unidirectional AS-4/APC-2 cylinder provided by Boeing Commercial Aircraft. The defects examined include regions of poor consolidation, inter-laminar linear porosity (voids elongated along the fibers with 1.5% volume fraction), and delamination or interlaminar weakness. The ultrasonic inspection unit is non-contact, flexible, light-weight and allows for high inspection rates. These characteristics, coupled with a large signal-to-noise ratio of the measurements, show promises for the use of the proposed sensor in on-line control of the thermoplastic tow-placement process with in situ consolidation.
Transient Interaction of Buildings with HVAC Systems— Updating the State of the Art
Authors: Lstiburek Joseph W. , Pressnail Kim , Timusk John 
Published: August 2002

This paper reviews work that has led to the development of a number of multi-zonal airflow models (network models). At present, the network analysis and perturbation methods cannot be used to solve the interstitial flow, pressure and resistance regimes. Network analysis and perturbation may suggest that such flows exist, but the complexity and workmanship dependence of the interstitial flow, pressure and resistance regime requires direct measurement. In other words, at present, the boundary conditions of the interstitial regime can be defined analytically using traditional methods, but the pressures and flows within the interstitial spaces cannot be predicted with certainty using analytical means. Difficulties in obtaining the detailed information on mechanical systems and the leakage areas of building assemblies make the traditional approach of measuring airflows and constructing models using leakage areas impractical for diagnostic purposes. Additionally, a pressure difference across an assembly alone, where interstitial pressures are not considered, is not enough to describe performance of the building envelope. The interstitial air pressures are usually small and until recently have been beyond measurement. Research on building envelope durability and indoor air quality has shown the significance of these small, but persisting interstitial air pressure fields. To enhance the capability of network models, a relational model was developed. This approach permits the measured building air pressure field to be used with the network analysis. Furthermore, the response of the analytical model is calibrated by comparing the effect of a specific perturbation on both the building air pressure field and the analytical model. This paper is written in two parts, the first reviewing issues in prediction of airflow in the buildings and building envelope, the second analyzing the actual data of measured pressure response of buildings.
Hygrothermal Effects on Painted and Unpainted Glass/Epoxy Composites—Part B: Degradation Studies
Authors: Pavan Raja M.V. , Saravanan V. , Dinesh A. R. , Rao Y. J. , Srihari Shylaja , Revathi A. 
Published: August 2002

Studies were conducted on the degradation of ILSS and compression strength properties of glass/epoxy composite specimens painted and unpainted that were subjected to immersion in a water bath maintained at 323 K. It is found that both ILSS and compressive strength of the composite degraded more in the case of unpainted specimens (coded L0) compared to the painted ones ( L1 or L2). Further, the specimens with a thicker paint coat ( L2) degraded less than those with a thinner paint coat ( L1).
Pharmacokinetics of betamethasone in twin and singleton pregnancy
Authors: Ballabh Praveen , Lo E. S. , Kumari J. , Cooper T. B. , Zervoudakis I. , Auld P. A. M. , Krauss A. N. 
Published: August 2002

ObjectiveThe aims of the study were to compare the pharmacokinetics of betamethasone in singleton pregnancy with the pharmacokinetics in twin pregnancy and to assess the adrenal suppression produced by betamethasone.Study DesignWe measured serial betamethasone and cortisol levels in 30 singleton and 21 twin pregnancies after the first dose of betamethasone and calculated the pharmacokinetic parameters for betamethasone including volume of distribution, half‐life, and clearance. We also measured cord and maternal blood levels of betamethasone at the birth of infants of 13 singleton and 9 twin pregnancies.ResultsThe half‐life of betamethasone in mothers with twin pregnancies was significantly shorter than that in mothers with singleton pregnancies (7.2 ± 2.4 versus 9.0 ± 2.7 hours; P < .017). Clearance of betamethasone in the twin pregnancies appeared greater than in singleton pregnancies (8.4 ± 6.4 versus 5.7 ± 3.1 L/h; P = .06) but did not reach statistical significance. Volume of distribution was similar in the two groups. Because the time between the last dose of betamethasone and birth varied widely (range, 2–158 hours), mothers with a longer interval after treatment tended to have a higher cord–to–maternal betamethasone ratio than did mothers with a shorter interval in both twin and singleton pregnancies. This finding indicated delayed fetal clearance, but the correlation was weak (R2 = 0.29 for twins and 0.08 for singletons).ConclusionThe shorter half‐life of betamethasone in twin pregnancy than in singleton pregnancy may cause the level of betamethasone to be subtherapeutic for lung maturation in twin pregnancy.Clinical Pharmacology & Therapeutics (2002) 71, 39–45; doi: 10.1067/mcp.2002.120250
Ferrous/Ferric Ions Crosslinked Type II Collagen Multifunctional Hydrogel for Advanced Osteoarthritis Treatment
Authors: Wang Lili , Chen Xian , Wang Shenghong , Ma Jianrui , Yang Xiaxia , Chen Hongli , Xiao Jianxi 
Published: January 2024

AbstractOsteoarthritis (OA) is a highly prevalent and intricate degenerative joint disease affecting an estimated 500 million individuals worldwide. Collagen‐based hydrogels have sparked immense interest in cartilage tissue engineering, but substantial challenges persist in developing biocompatible and robust crosslinking strategies, as well as improving their effectiveness against the multifaceted nature of OA. Herein, a novel discovery wherein the simple incorporation of ferrous/ferric ions enables efficient dynamic crosslinking of type II collagen, leading to the development of injectable, self‐healing hydrogels with 3D interconnected porous nanostructures, is unveiled. The ferrous/ferric ions crosslinked type II collagen hydrogels demonstrate exceptional physical properties, such as significantly enhanced mechanical strength, minimal swelling ratios, and remarkable resistance to degradation, while also exhibiting extraordinary biocompatibility and bioactivity, effectively promoting cell proliferation, adhesion, and chondrogenic differentiation. Additionally, the hydrogels reveal potent anti‐inflammatory effects by upregulating anti‐inflammatory cytokines while downregulating pro‐inflammatory cytokines. In a rat model of cartilage defects, these hydrogels exhibit impressive efficacy, substantially accelerating cartilage tissue regeneration through enhanced collagen deposition and increased proteoglycan secretion. The innovative discovery of the multifunctional role of ferrous/ferric ions in endowing type II collagen hydrogels with a myriad of beneficial properties presents exciting prospects for developing advanced biomaterials with potential applications in OA.
Phenotypic Screening of Prospective Analgesics Among FDA‐Approved Compounds using an iPSC‐Based Model of Acute and Chronic Inflammatory Nociception
Authors: Black Bryan James , Ghazal Rasha El , Lojek Neal , Williams Victoria , Rajput Jai Singh , Lawson Jennifer M. 
Published: January 2024

AbstractClassical target‐based drug screening is low‐throughput, largely subjective, and costly. Phenotypic screening based on in vitro models is increasingly being used to identify candidate compounds that modulate complex cell/tissue functions. Chronic inflammatory nociception, and subsequent chronic pain conditions, affect peripheral sensory neuron activity (e.g., firing of action potentials) through myriad pathways, and remain unaddressed in regard to effective, non‐addictive management/treatment options. Here, a chronic inflammatory nociception model is demonstrated based on induced pluripotent stem cell (iPSC) sensory neurons and glia, co‐cultured on microelectrode arrays (MEAs). iPSC sensory co‐cultures exhibit coordinated spontaneous extracellular action potential (EAP) firing, reaching a stable baseline after ≈27 days in vitro (DIV). Spontaneous and evoked EAP metrics are significantly modulated by 24‐h incubation with tumor necrosis factor‐alpha (TNF‐α), representing an inflammatory phenotype. Compared with positive controls (lidocaine), this model is identified as an “excellent” stand‐alone assay based on a modified Z’ assay quality metric. This model is then used to screen 15 cherry‐picked, off‐label, Food and Drug Administration (FDA)‐approved compounds; 10 of 15 are identified as “hits”. Both hits and “misses” are discussed in turn. In total, this data suggests that iPSC sensory co‐cultures on MEAs may represent a moderate‐to‐high‐throughput assay for drug discovery targeting inflammatory nociception.
Copper‐Catalyzed Asymmetric Synthesis of Silicon‐Stereogenic Benzoxasiloles
Authors: Gan Wan‐Er , Wu Yong‐Shun , Wu Bin , Fang Chun‐Yuan , Cao Jian , Xu Zheng , Xu Li‐Wen 
Published: January 2024

AbstractA Cu‐catalyzed asymmetric synthesis of silicon‐stereogenic benzoxasiloles has been realized via intramolecular Si−O coupling of [2‐(hydroxymethyl)phenyl]silanes. Cu(I)/difluorphos is found to be an efficient catalytic system for enantioselective Si−C bond cleavage and Si−O bond formation. In addition, kinetic resolution of racemic substituted [2‐(hydroxymethyl)phenyl]silanes using Cu(I)/ PyrOx (pyridine‐oxazoline ligands) as the catalytic system is developed to afford carbon‐ and silicon‐stereogenic benzoxasiloles. Ring‐opening reactions of chiral benzoxasiloles with organolithiums and Grignard reagents yield various enantioenriched functionalized tetraorganosilanes.
Predicting the apolipoprotein E ε4 allele carrier status based on gray matter volumes and cognitive function
Authors: Kim Hyug‐Gi , Tian Yunan , Jung Sue Min , Park Soonchan , Rhee Hak Young , Ryu Chang‐Woo , Jahng Geon‐Ho 
Published: January 2024

AbstractBackgroundApolipoprotein E (ApoE) ε4 carriers have a higher risk of developing Alzheimer's disease (AD) and show brain atrophy and cognitive decline even before diagnosis.ObjectiveTo predict ApoE ε4 status using gray matter volume (GMV) obtained from magnetic resonance imaging images and demographic data with machine learning (ML) methods.MethodsWe recruited 74 participants (25 probable AD, 24 amnestic mild cognitive impairment, and 25 cognitively normal older people) with known ApoE genotype (22 ApoE ε4 carriers and 52 noncarriers) and scanned them with three‐dimensional (3D) T1‐weighted (T1W) and 3D double inversion recovery (DIR) sequences. We extracted GMV from regions of interest related to AD pathology and used them as features along with age and mini–mental state examination (MMSE) scores to train different ML models. We performed both receiver operating characteristic curve analysis and the prediction analysis of the ApoE ε4 carrier with different ML models.ResultsThe best model of ML analyses was a cubic support vector machine (SVM3) that used age, the MMSE score, and DIR GMVs at the amygdala, hippocampus, and precuneus as features (AUC = .88). This model outperformed models using T1W GMV or demographic data alone.ConclusionOur results suggest that brain atrophy with DIR GMV and cognitive decline with aging can be useful biomarkers for predicting ApoE ε4 status and identifying individuals at risk of AD progression.
Recurrence‐free survival dynamics following adjuvant chemotherapy for resected colorectal cancer: A systematic review of randomized controlled trials
Authors: Vail Emma , Choubey Ankur P. , Alexander H. Richard , August David A. , Berry Abril , Boland Patrick M. , Eskander Mariam F. , Grandhi Miral S. , Haliani Brittany , In Haejin , Kennedy Timothy J. , Langan Russell C. , Maggi Jason C. , Pitt Henry A. , Ganesan Shridar , Ecker Brett L. 
Published: January 2024

AbstractBackgroundSeveral cytotoxic chemotherapies have demonstrated efficacy in improving recurrence‐free survival (RFS) following resection of Stage II–IV colorectal cancer (CRC). However, the temporal dynamics of response to such adjuvant therapy have not been systematically quantified.MethodsThe Cochrane Central Register of Trials, Medline (PubMed) and Web of Science were queried from database inception to February 23, 2023 for Phase III randomized controlled trials (RCTs) where there was a significant difference in RFS between adjuvant chemotherapy and surgery only arms. Summary data were extracted from published Kaplan–Meier curves using DigitizeIT. Absolute differences in RFS event rates were compared at matched intervals using multiple paired t‐tests.ResultsThe initial search yielded 1469 manuscripts. After screening, 18 RCTs were eligible (14 Stage II/III; 4 Stage IV), inclusive of 16,682 patients. In the absence of adjuvant chemotherapy, the greatest rate of recurrence was observed in the first year (mean RFS event rate; 0–0.5 years: 0.22 ± 0.21; 0.5–1 years: 0.20 ± 0.09). Adjuvant chemotherapy was associated with significant decreases in the RFS event rates for the intervals 0–0.5 years (0.09 ± 0.09 vs. 0.22 ± 0.21, p < 0.001) and 0.5–1 years (0.14 ± 0.11 vs. 0.20 ± 0.09, p = 0.001) after randomization, but not at later intervals (1–5 years). In Stage IV trials, RFS event rates significantly differed for the interval 0–0.5 years (p = 0.012), corresponding with adjuvant treatment durations of 6 months. In Stage II/III trials, which included therapies of 6–24 months duration, there were marked differences in the RFS event rates between surgery and chemotherapy arms for the intervals 0–0.5 years (p < 0.001) and 0.5–1 years (p < 0.001) with smaller differences in the RFS event rates for the intervals 1–2 years (p = 0.012) and 2–3 years (p = 0.010).ConclusionsIn a systematic review of positive RCTs comparing adjuvant chemotherapy to surgery alone for Stage II–IV CRC, observed RFS improvements were driven by early divergences that occurred primarily during active cytotoxic chemotherapy. Late recurrence dynamics were not influenced by adjuvant therapy use. Such observations may have implications for the use of chemotherapy for micrometastatic clones detectable by cell‐free DNA‐based methodologies.
Outcomes with and without postmastectomy radiotherapy for pT3N0‐1M0 breast cancer: An institutional experience
Authors: Rao Xinxin , Wang Xuanyi , Jin Kairui , Yang Yilan , Zhao Xu , Pan Zhe , Lv Weiluo , Zhang Zhen , Zhang Li , Yu Xiaoli , Guo Xiaomao 
Published: January 2024

AbstractAimThe objective of this study is to comprehensively evaluate the therapeutic efficacy of postmastectomy radiotherapy (PMRT) in treating patients with pT3N0‐1M0 breast cancer within the context of modern therapeutic strategies.MethodsClinical data from patients with pT3N0‐1M0 breast cancer who underwent mastectomy from January 2005 to December 2018 at our institution were retrospectively analyzed.ResultsThe study involved a total of 222 participants, with 112 individuals undergoing PMRT and 110 individuals not receiving it. The median follow‐up duration was 77 months (range: 6–171 months). The entire cohort demonstrated 5‐year disease‐free survival (DFS) and overall survival (OS) rates of 85.1% and 91.0%, respectively, along with a locoregional recurrence (LRR) rate as low as 7.2%. The PMRT group showed significantly better 5‐year DFS (90.2% vs. 80.0%, p = 0.02) and OS (95.5% vs. 86.4%, p = 0.012) rates, as well as a lower LRR rate (4.5% vs. 10.0%, p = 0.122), compared to the group without PMRT. Cox regression analysis confirmed the independent prognostic significance of PMRT for both DFS (p = 0.040) and OS (p = 0.047). Following propensity score matching (PSM), the analysis included 100 matched patients, revealing an improved prognosis for those who received PMRT (DFS: p = 0.067; OS: p = 0.043).ConclusionsOur study reveals favorable prognoses for pT3N0‐1M0 breast cancer patients treated within contemporary therapeutic approaches. The pivotal role of PMRT in this context is evident. However, due to the retrospective design of our study and the relatively limited sample size, further investigation is imperative to validate and enhance these initial findings.
Synthesis and Modular Reactivity of Low Valent Al/Zn Heterobimetallics Supported by Common Monodentate Amides
Authors: Dankert Fabian , Hevia Eva 
Published: January 2024

AbstractRecent advances on low valent main group metal chemistry have shown the excellent potential of heterobimetallic complexes derived from Al(I) to promote cooperative small molecule activation processes. A signature feature of these complexes is the use of bulky chelating ligands which act as spectators providing kinetic stabilization to their highly reactive Al−M bonds. Here we report the synthesis of novel Al/Zn bimetallics prepared by the selective formal insertion of AlCp* into the Zn−N bond of the utility zinc amides ZnR2 (R=HMDS, hexamethyldisilazide; or TMP, 2,2,6,6‐tetramethylpiperidide). By systematically assessing the reactivity of the new [(R)(Cp*)AlZn(R)] bimetallics towards carbodiimides, structural and mechanistic insights have been gained on their ability to undergo insertion in their Zn−Al bond. Disclosing a ligand effect, when R=TMP, an isomerization process can be induced giving [(TMP)2AlZn(Cp*)] which displays a special reactivity towards carbodiimides and carbon dioxide involving both its Al−N bonds, leaving its Al−Zn bond untouched.
Technical language analysis of online explanatory videos concerning redox chemistry
Authors: Lohrmann Friederike , Peetz Michael , Belova Nadja 
Published: January 2024

AbstractIm Vermittlungsprozess chemischer Fachinhalte ist ein reflektierter Gebrauch der chemischen Fachsprache unumgänglich. Diesem Anspruch müssen auch Online‐Erklärvideos als beliebtes Lernmedium deutscher Schüler:innen gerecht werden. Diese Studie untersucht die fachsprachliche Qualität von Online‐Erklärvideos mit dem übergeordneten Ziel herauszufinden, inwiefern sich Unterschiede zwischen verschiedenen Erklärvideoproduzent:innen feststellen lassen. Allgemein lässt sich festhalten, dass die fachsprachliche Qualität aktueller Online‐Erklärvideos unzureichend ist. Verschiedene Kriterien, die unter Berücksichtigung fachdidaktischer Forschungsergebnisse als lernhinderlich beschrieben werden, kommen in den instruktionalen Erklärungen der Videos vor. Darüber hinaus gehen die Videos der Lehrer:innen und Organisationen als didaktische Expert:innen gleichermaßen mit fachlichen Fehlkonzepten und fachsprachlichen Unstimmigkeiten einher, wie auch die von Privatpersonen und Fachwissenschaftler:innen.