bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fracture Toughness and Critical Crack Sizes for the Space Shuttle Solid Rocket Motor D6AC Steel Case
Authors: Newman JC , Bland JD , Berry RF 
Published: March 2009

Fracture toughness and critical crack size tests were conducted on a variety of fracture specimens that were machined from actual Space Shuttle solid rocket motor (SRM) D6AC steel cylindrical case segments. Plane-strain fracture toughness tests were conducted at four temperatures ranging from −30‡C to 55‡C. Average values ranged from a low of 87.6 MPa-m1/2 at −30 ‡C to a high of 120.3 MPa-m1/2 at room temperature. Fracture tests were also conducted on seven different crack configurations that simulate details in the SRM field and factory joint locations. These configurations included: surface and through cracks, corner and through cracks at an open hole, and through and corner cracks at a pin-loaded hole. Elastic stress-intensity factors at failure, KIe, were found to be constant within ± 10% for the range of crack and specimen sizes tested. The fatigue pre-cracking stress levels were found to have a strong influence on KIe. An effective elastic fracture toughness, accounting for crack-closure effects, was found to be nearly constant for a wide range of fatigue pre-cracking stress-intensity factor levels.
Fatigue tests were also conducted on simulated SRM case-segment joint leak-check port specimens to determine crack initiation locations, fatigue-crack growth and critical crack sizes. Eddy-current probes, identical to those used in actual hardware, were used to monitor crack growth. Specimens were cycled at either proof-test load or flight-load levels at various temperatures until failure. Critical crack sizes obtained were greater than 25 mm in length and required more than 2,700 cycles to grow from a damage-tolerant crack size (1 mm) to failure.
Common Murre Abundance, Phenology, and Productivity on the Barren Islands, Alaska: The Exxon Valdez Oil Spill and Long-Term Environmental Change
Authors: Boersma PD , Parrish JK , Kettle AB 
Published: March 2009

The Exxon Valdez oil spill in 1989 caused substantial seabird mortality. By 1 August, more than 30 000 seabird carcasses (74% murres) were recovered, and it was initially estimated that between 100 000 and 300 000 seabirds were killed. The Barren Islands, in particular East Amatuli Island, support the largest seabird colonies within the path of the spill. With respect to murres nesting on the Barren Islands, claims were made that the population suffered at least a 50% loss and that the remaining population underwent a change in breeding phenology, a breakdown in breeding synchrony, and a widespread failure to fledge chicks in the years following the spill. As a result of these effects, it was projected that the population would take 20–70 years to recover.
Principally because of the paucity of prespill data on the Barren Islands murre population size and reproductive success, it is impossible to quantify any effect of the spill on these populations. Available prespill data (1976–1978) on the East Amatuli murre population size ranges from 19 000 to 61 000 birds. These data are not systematic, replicated counts but rather are estimates indicating a broad range within which the true attendance figure probably resided. Our postspill attendance counts range from 31 041 to 37 128 (1990–1992). Comparisons between matched historical and 1990s photographs showed nearly identical attendance patterns, although there were significantly more murres in the 1990s photographs. Postspill attendance data from multiply censused areas suggest a recovery may have been taking place because of greater than expected annual increases (+25% from 1990 to 1991).
Prespill data on reproductive activity of the murres nesting in the Barren Islands were collected from a single 5 × 5-m plot located in a dense, flat section of the East Amatuli Light Rock colony. Comparisons with similarly collected postspill data suggest that phenology, egg production, and chick production are extremely variable among years, athough chicks were fledged in all years. Egg and chick production were highest in 1977 and 1991 and lowest in 1992.
On the basis of these analyses, we conclude that, although murres rafting near the Barren Islands undoubtedly suffered substantial mortality as a result of the Exxon Valdez oil spill, there is no justification for claims of either a dramatic reduction in colony attendance or substantial failure of the remaining birds to settle and reproduce, in the years following the spill. In spite of continued perturbations to the system from both natural and human-induced sources, East Amatuli Island continues to support a large, reproductively active colony of murres.
Elektromechanischer Energiewandler auf Basis eines piezokeramischen BiegebalkensElectromechanical Energy Harvester Based on a Piezoceramic Bending Cantilever
Authors: Albach Thorsten , Sutor A. , Lerch Reinhard 
Published: March 2009

Zusammenfassung
Es wird ein elektromechanischer Energiewandler vorgestellt, der auf dem piezoelektrischen Wandlungsprinzip in Form eines Biegebalkens beruht. Er wandelt Umgebungs-Vibrationen in elektrische Energie. Ausgehend vom bekannten Aufbau mit konstantem Balkenquerschnitt wird der Energieertrag durch Modifikation des Balkenprofiles erhöht. Im Hinblick auf eine praktische Realisierbarkeit wird die analytisch gefundene optimale Geometrie durch ein lineares Profil approximiert. Die Ergebnisse werden mittels einer Finite-Elemente-Simulation verifiziert. Am Beispiel einer Vakuumpumpe als Schwingungserreger wird die Funktionsfähigkeit des Wandlers demonstriert. Es kann eine Leistung von 15mW und eine Leistungsdichte von 670W/m3 bei ohmscher Beschaltung erreicht werden. Eine selbstversorgende Elektronik wandelt die gewonnene Wechselspannung auf ein stabiles -3V-Potenzial.
A Novel Machine Learning Algorithm for Creating Risk-Adjusted Payment Formulas
Authors: Andriola Corinne , Ellis Randall P. , Siracuse Jeffrey J. , Hoagland Alex , Kuo Tzu-Chun , Hsu Heather E. , Walkey Allan , Lasser Karen E. , Ash Arlene S. 
Published: April 2024

ImportanceModels predicting health care spending and other outcomes from administrative records are widely used to manage and pay for health care, despite well-documented deficiencies. New methods are needed that can incorporate more than 70 000 diagnoses without creating undesirable coding incentives.ObjectiveTo develop a machine learning (ML) algorithm, building on Diagnostic Item (DXI) categories and Diagnostic Cost Group (DCG) methods, that automates development of clinically credible and transparent predictive models for policymakers and clinicians.Design, Setting, and ParticipantsDXIs were organized into disease hierarchies and assigned an Appropriateness to Include (ATI) score to reflect vagueness and gameability concerns. A novel automated DCG algorithm iteratively assigned DXIs in 1 or more disease hierarchies to DCGs, identifying sets of DXIs with the largest regression coefficient as dominant; presence of a previously identified dominating DXI removed lower-ranked ones before the next iteration. The Merative MarketScan Commercial Claims and Encounters Database for commercial health insurance enrollees 64 years and younger was used. Data from January 2016 through December 2018 were randomly split 90% to 10% for model development and validation, respectively. Deidentified claims and enrollment data were delivered by Merative the following November in each calendar year and analyzed from November 2020 to January 2024.Main Outcome and MeasuresConcurrent top-coded total health care cost. Model performance was assessed using validation sample weighted least-squares regression, mean absolute errors, and mean errors for rare and common diagnoses.ResultsThis study included 35 245 586 commercial health insurance enrollees 64 years and younger (65 901 460 person-years) and relied on 19 clinicians who provided reviews in the base model. The algorithm implemented 218 clinician-specified hierarchies compared with the US Department of Health and Human Services (HHS) hierarchical condition category (HCC) model’s 64 hierarchies. The base model that dropped vague and gameable DXIs reduced the number of parameters by 80% (1624 of 3150), achieved an R2 of 0.535, and kept mean predicted spending within 12% ($3843 of $31 313) of actual spending for the 3% of people with rare diseases. In contrast, the HHS HCC model had an R2 of 0.428 and underpaid this group by 33% ($10 354 of $31 313).Conclusions and RelevanceIn this study, by automating DXI clustering within clinically specified hierarchies, this algorithm built clinically interpretable risk models in large datasets while addressing diagnostic vagueness and gameability concerns.
CD44 and RHAMM Are Microenvironmental Sensors with Dual Metastasis Promoter and Suppressor Functions
Authors: Tolg Cornelia , Hill Kathleen Allen , Turley Eva Ann 
Published: April 2024

AbstractThe progression of primary tumors to metastases remains a significant roadblock to the treatment of most cancers. Emerging evidence has identified genes that specifically affect metastasis and are potential therapeutic targets for managing tumor progression. However, these genes can have dual tumor promoter and suppressor functions that are contextual in manifestation, and that complicate their development as targeted therapies. CD44 and RHAMM/HMMR are examples of multifunctional proteins that can either promote or suppress metastases, as demonstrated in experimental models. These two proteins can be viewed as microenvironmental sensors and this minireview addresses the known mechanistic underpinnings that may determine their metastasis suppressor versus promoter functions. Leveraging this mechanistic knowledge for CD44, RHAMM, and other multifunctional proteins is predicted to improve the precision of therapeutic targeting to achieve more effective management of metastasis.
Constructing High‐Content Sb Atomic Clusters and Robust Sb─O─C Bond in Sb/C Composites for Ultrahigh Rate and Long‐Term Sodium Storage
Authors: Xu Anding , Huang Mianying , Liu Chenxi , Li Teng , Li Xue , Wu Songping , Xu Zhiguang , Yan Yurong 
Published: April 2024

AbstractConstructing Sb atomic clusters with obvious size effect in Sb/C composites has great potential for boosting electrochemical reactivity toward ultrahigh rate and long‐term sodium storage. However, how to balance the contradiction between ultra‐small size of Sb atomic clusters and high loading in a specific Sb/C composite is an unprecedented challenge. Here, a facile in situ vaporization‐reduction strategy is presented for preparing Sb atomic clusters@N, S co‐doped carbon networks (Sb ACs@NSC). Featuring the high content of Sb atomic clusters (45.30 wt%, ICP) with superior electrochemical activity, robust Sb─O─C bond and N, S co‐doped conductive carbon matrix, the Sb ACs@NSC electrode possessed ultrafast electrochemical kinetics and impressive long‐term cycling stability for providing unprecedented rate capability of 245.7 mAh g−1 at ultrahigh rate of 80 A g−1 and maintaining highlighted capacity of 306.7 mAh g−1 after 1000 cycles under 10 A g−1, outperforming all reported Sb‐based materials for SIBs. The DFT calculations further revealed that the Sb─O─C bond and N, S co‐doped carbon matrix are beneficial for stable adsorption capabilities and fast electrochemical kinetics of Na+. The designing compromised dense Sb atomic clusters and powerful interface bond will light on developing advanced atomic materials for energy storage and conversion.
Scalable Sol–Gel Permeation Assembly of Phase Change Layered Film Toward Thermal Management and Light‐Thermal Driving Applications
Authors: Han Gaojie , Cheng Hongli , Cheng Yajie , Zhou Bing , Liu Chuntai , Feng Yuezhan 
Published: April 2024

AbstractPhase change materials (PCMs) are pivotal in thermal energy management and conversion applications owing to their exceptional thermal energy storage and release characteristics. However, persistent challenges such as poor thermal conductivity and leakage issues have impeded their widespread adoption. While existing approaches mitigate these challenges by constructing and incorporating 3D thermal conductive networks, they are constrained by discontinuous preparation methods and mold size limitations. Herein, a scalable sol–gel permeation assembly strategy is proposed to prepare phase change layered film by in situ filling polyethylene glycol (PEG) in aramid nanofibers (ANF)/graphene nanoplates (GNP) network. Befitting from the laminated network encapsulation effect of ANF and GNP, the phase change film demonstrates leak‐free and stable phase transition behavior, even after undergoing 500 heating/cooling cycles. Moreover, the resulting PEG/ANF/GNP layered film exhibits an impressive in‐plane thermal conductivity of 23.7 W mK−1 at GNP loading of 28.1 vol.%, rendering it suitable for thermal management applications in electronic devices. The phase change layered film possesses exceptional photo‐thermal conversion properties, maintaining temperatures exceeding 90 °C under a light power density of 200 mW cm−2. Capitalizing on the thermally induced flexibility of the phase transition film and its temperature‐dependent stiffness, its utility extended to developing a light‐thermal driving gripper.
Topological States Decorated by Twig Boundary in Plasma Photonic Crystals
Authors: Li Jianfei , Yao Jingfeng , Wang Ying , Zhou Zhongxiang , Lan Zhihao , Yuan Chengxun 
Published: April 2024

AbstractThe twig edge states in graphene‐like structures are viewed as the fourth states complementary to their zigzag, bearded, and armchair counterparts. In this work, a rod‐in‐plasma system in a honeycomb lattice with twig edge truncation under external magnetic fields and lattice scaling is studied and it is shown that twig edge states can exist in different phases of the system, such as quantum Hall (QH) phase, quantum spin Hall (QSH) phase, and insulating phase. The twig edge states in the negative permittivity background exhibit robust one‐way transmission properties immune to backscattering and thus provide a novel avenue for solving the plasma communication blackout problem. Moreover, it is demonstrated that corner and edge states can exist within the shrunken structure by modulating the on‐site potential of the twig edges. Especially, helical edge states with the unique feature of pseudospin‐momentum locking that can be excited by chiral sources are demonstrated at the twig edges. These results show that the twig edges and interface engineering can bring new opportunities for more flexible manipulation of electromagnetic waves.
Thermoregulated CPL‐Active Flexible Polymer/Perovskite Hybrid Materials with High Luminescence Dissymmetry Factor
Authors: Cao Rui , Zhou Xinning , Dai Haitao , Wang Yong , Xiao Yin 
Published: April 2024

AbstractCPL‐active flexible materials with high luminescence dissymmetry factor (glum) and luminescent quantum yield are indispensable for 3D displays, wearable devices and so on. Perovskite has drawn much attention due to its fascinating photoelectric properties as well as its abundant applications. However, the existing strategies are inefficient in acquiring perovskite NCs with high glum. In this work, thermoregulated CPL‐active flexible polymer/perovskite hybrid materials with high glum by the creation of chiral photonic bandgap in polymer film with cholesteric domains using toluene as the dielectric media is reported. Based on selective CPL reflection, a satisfied CPL with a maximum glum of 0.6 is achieved. Importantly, the chiral photonic bandgap center of the polymer film can be easily tuned by thermal annealing at different temperatures to adapt various perovskite NCs with full‐spectral emission. The handedness of CPL of hybrid materials can be regulated with and without dielectric media. The presence of the flexible polymer makes hybrid materials a candidate to achieve patterned display applications. Additionally, the polymer/perovskite hybrid materials show excellent stability thanks to the encapsulation effect from polymers. This work provides a facile and general approach to induce adjustable CPL in the whole visible spectrum with high glum and photoluminescence quantum yield (PLQY).
Ligand Detachment—New Insight into the Mechanochromic Luminescence Mechanism of Copper Iodide Complexes with Thermally Activated Delayed Fluorescence
Authors: Li Haibo , Yang Jing , Wang Qianqian , Tong Hua , Zhu Jialin , Liu Wei , Ouyang Gangfeng 
Published: April 2024

AbstractMechanochromic luminescence materials have recently attracted increasing interest due to its promising applications, but the intensive inquiry of the mechanochromic luminescence mechanism is still insufficient. Herein, an in‐depth study of mechanochromic luminescent copper iodide complexes exhibiting ligand detachment and structural transformation is reported. The yellowish–green emissive CuI(dmpz) (dmpz = 2,6‐dimethylpyrazine) is ground into orange–red emissive CuI(dmpz)0.5 and the detailed structural transformation process is revealed by the thorough analysis of the crystalline structure before and after grinding. More importantly, new insight into the mechanochromic luminescence mechanism is proposed, that is, under the external force of grinding, the dmpz ligand detachment triggers the structural transformation from 1D chain to 2D network, which leads to the reduction of band gap energy and contraction of Cu─Cu bonds, together resulting in the red shift of luminescence ultimately. Moreover, the two complexes are also found to have thermochromic luminescence properties, attributing to their thermally activated delayed fluorescence process. The anti‐counterfeiting application of CuI(dmpz) is tentatively explored, demonstrating the favorable application prospect of CuI(dmpz). This study provides new insights involved in the mechanochromic luminescence mechanism of copper iodide complexes, and may provide a new understanding for rational molecular design and structural regulation of intelligent responsive luminescence.
Embedding Bifurcations into Pneumatic Artificial Muscle
Authors: Akashi Nozomi , Kuniyoshi Yasuo , Jo Taketomo , Nishida Mitsuhiro , Sakurai Ryo , Wakao Yasumichi , Nakajima Kohei 
Published: April 2024

AbstractHarnessing complex body dynamics has long been a challenge in robotics, particularly when dealing with soft dynamics, which exhibit high complexity in interacting with the environment. Recent studies indicate that these dynamics can be used as a computational resource, exemplified by the McKibben pneumatic artificial muscle, a common soft actuator. This study demonstrates that bifurcations, including periodic and chaotic dynamics, can be embedded into the pneumatic artificial muscle, with the entire bifurcation structure using the framework of physical reservoir computing. These results suggest that dynamics not present in training data can be embedded through bifurcation embedment, implying the capability to incorporate various qualitatively different patterns into pneumatic artificial muscle without the need to design and learn all required patterns explicitly. Thus, this study introduces a novel approach to simplify robotic devices and control training by reducing reliance on external pattern generators and the amount and types of training data needed for control.
Drugtamer‐PROTAC Conjugation Strategy for Targeted PROTAC Delivery and Synergistic Antitumor Therapy
Authors: He Shipeng , Fang Yuxin , Zhu Yaojin , Ma Ziyang , Dong Guoqiang , Sheng Chunquan 
Published: April 2024

AbstractProteolysis‐targeting chimeras (PROTACs) have emerged as a promising strategy for targeted protein degradation and drug discovery. To overcome the inherent limitations of conventional PROTACs, an innovative drugtamer‐PROTAC conjugation approach is developed to enhance tumor targeting and antitumor potency. Specifically, a smart prodrug is designed by conjugating “drugtamer” to a nicotinamide phosphoribosyltransferase (NAMPT) PROTAC using a tumor microenvironment responsible linker. The “drugtamer” consists of fluorouridine nucleotide and DNA‐like oligomer. Compared to NAMPT PROTAC and the combination of PROTAC + fluorouracil, the designed prodrug AS‐2F‐NP demonstrates superior tumor targeting, efficient cellular uptake, improved in vivo potency and reduced side effects. This study provides a promising strategy for the precise delivery of PROTAC and synergistic antitumor agents.
Single‐Molecule Electrical Profiling of Peptides and Proteins
Authors: Ju Hongyu , Cheng Li , Li Mengmeng , Mei Kunrong , He Suhang , Jia Chuancheng , Guo Xuefeng 
Published: April 2024

AbstractIn recent decades, there has been a significant increase in the application of single‐molecule electrical analysis platforms in studying proteins and peptides. These advanced analysis methods have the potential for deep investigation of enzymatic working mechanisms and accurate monitoring of dynamic changes in protein configurations, which are often challenging to achieve in ensemble measurements. In this work, the prominent research progress in peptide and protein‐related studies are surveyed using electronic devices with single‐molecule/single‐event sensitivity, including single‐molecule junctions, single‐molecule field‐effect transistors, and nanopores. In particular, the successful commercial application of nanopores in DNA sequencing has made it one of the most promising techniques in protein sequencing at the single‐molecule level. From single peptides to protein complexes, the correlation between their electrical characteristics, structures, and biological functions is gradually being established. This enables to distinguish different molecular configurations of these biomacromolecules through real‐time electrical monitoring of their life activities, significantly improving the understanding of the mechanisms underlying various life processes.
Photocatalytic Enantioselective Radical Cascade Multicomponent Minisci Reaction of β‐Carbolines Using Diazo Compounds as Radical Precursors
Authors: Gu Yi‐Jie , Luo Mu‐Peng , Yuan Hua , Liu Guo‐Kai , Wang Shou‐Guo 
Published: April 2024

AbstractHere, a photocatalytic asymmetric multicomponent cascade Minisci reaction of β‐carbolines with enamides and diazo compounds is reported, enabling an effective enantioselective radical C─H functionalization of β‐carbolines with high yields and enantioselectivity (up to 83% yield and 95% ee). This enantioselective multicomponent Minisci protocol exhibits step economy, high chemo‐/enantio‐selective control, and good functional group tolerance, allowing access to a variety of valuable chiral β‐carbolines. Notably, diazo compounds are suitable radical precursors in enantioselective cascade radical reactions. Moreover, the efficiency and practicality of this approach are demonstrated by the asymmetric synthesis of bioactive compounds and natural products.