bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of polyethylene pipe on wax deposition under different temperature and flow rate conditions
Authors: Zhang Yu , Huang Qiyu , Liu Yamei , Liu Yiran , Li Rongbin , Wang Yijie , Zhang Xun 
Published: May 2022

AbstractWax deposition is an important but troublesome boulder in petroleum industry that has always plagued pipeline engineering operators. In this study, wax deposition in the polyethylene pipes has different behaviors comparing wax deposition in stainless steel pipes such as smaller weight of wax deposits and lower wax content. After wax deposition experiments, some important parameters, including diffusivity and temperature gradient, were measured and calculated to explore the differences between two material pipes. Moreover, those factors can make a significant impact on radial mass flux. A series of results in polyethylene pipes suggests that higher diffusivity enhances diffusion flux of wax in the radial direction. But it was found that radial concentration gradient accounted for a larger proportion. These factors are the relationship of competition and cooperation and the combination of them results in different performances of wax deposition between polyethylene and stainless steel pipes.
A Stimuli‐Responsive Small‐Molecule Metal‐Carrying Prochelator: A Novel Prodrug Design Strategy for Metal Complexes
Authors: Huang Zeqian , Luo Yong , Zhang Tao , Ding Yaqing , Chen Meixu , Chen Jie , Liu Qiuxing , Huang Yanjuan , Zhao Chunshun 
Published: May 2022

AbstractSelective activation of prodrugs is an important approach to reduce the side effects of disease treatment. We report a prodrug design concept for metal complexes, termed “metal‐carrying prochelator”, which can co‐carry a metal ion and chelator within a single small‐molecule compound and remain inert until it undergoes a specifically triggered intramolecular chelation to synthesize a bioactive metal complex in situ for targeted therapy. As a proof‐of‐concept, we designed a H2O2‐responsive small‐molecule prochelator, DPBD, based on the strong chelator diethyldithiocarbamate (DTC) and copper. DPBD can carry Cu2+ (DPBD‐Cu) and respond to elevated H2O2 levels in tumor cells by releasing DTC, which rapidly chelates Cu2+ from DPBD‐Cu affording a DTC–copper complex with high cytotoxicity, realizing potent antitumor efficacy with low systemic toxicity. Thus, with its unique intramolecularly triggered activation mechanism, this concept based on a small‐molecule metal‐carrying prochelator can help in the prodrug design of metal complexes.
Constructing Organic Electroluminescent Material with Very High Color Purity and Efficiency Based on Polycyclization of the Multiple Resonance Parent Core
Authors: Xu Yincai , Wang Qingyang , Wei Jinbei , Peng Xiaomei , Xue Jianan , Wang Zhiheng , Su Shi‐Jian , Wang Yue 
Published: May 2022

AbstractMultiple resonance thermally activated delayed fluorescence (MR‐TADF) compounds have set off an upsurge of research because of their tremendous application prospects in the field of wide color gamut display. Herein, we propose a novel MR‐TADF molecular construction paradigm based on polycyclization of the multiple resonance parent core, and construct a representative multiple resonance polycyclic aromatic hydrocarbon (MR‐PAH) based on the para‐alignment of boron and nitrogen atoms into a six‐membered ring (p‐BNR). Through the retrosynthesis analysis, a concise synthesis strategy with wide applicability has been proposed, encompassing programmed sequential boron esterification, Suzuki coupling and Scholl oxidative coupling. The target model molecule BN‐TP shows green fluorescence with an emission peak at 523 nm and a narrow full‐width at half‐maximum (FWHM) of 34 nm. The organic light‐emitting diode (OLED) employing BN‐TP as an emitter exhibits ultrapure green emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.26, 0.70), and achieves a maximum external quantum efficiency (EQE) of 35.1 %.
Carbon dioxide embolism during posterior retroperitoneal adrenalectomy
Authors: Alexeev M. , Fedorov E. , Kuleshov O. , Rebrova D. , Efremov S. 
Published: May 2022

SummaryWe report a case of massive carbon dioxide embolism associated with injury to the inferior vena cava, during posterior retroperitoneoscopic adrenalectomy. The presenting clinical features were tachycardia, rapid oxygen desaturation and severe respiratory acidosis, without evidence of bleeding. The patient was resuscitated by increasing the fraction of inspired oxygen, administering intravenous fluid and converting to an open procedure to suture the vein. This case demonstrates that gas embolism due to vessel injury during posterior retroperitoneal adrenalectomy may arise without evidence of bleeding, severe hypotension or an abrupt increase in end‐tidal carbon dioxide. Using a high carbon dioxide insufflation pressure in the retroperitoneal space enhances visualisation of the surgical field by decreasing small‐calibre vessel bleeding. However, it can contribute to, and delay recognition of, carbon dioxide embolism. Knowledge of the clinical features of carbon dioxide embolism, careful monitoring and vigilance for intra‐operative surgical challenges can assist with the detection of this rare but potentially fatal complication.
Excellent antioxidizing, thermally insulating and flame resistance silica‐polybenzoxazine aerogels for aircraft ablative materials
Authors: Xiao Yunyun , Liu Saihui , Hu Yangbiao , Zhang Sizhao , Li Zhenquan , Li Liangjun , Feng Jian 
Published: May 2022

AbstractHigh‐performance thermal protective composites with lightweight, micro‐ ablation and high‐efficient thermal insulation are urgently required for thermal protection systems in advanced hypersonic speed vehicles. However, the practical applications of thermal protective composites have long been hampered by the main issues such as low mass residual rate and poor long‐term antioxidation of the matrix in high‐temperature aerobic environments. Here, we report a novel silica‐polybenz oxazine (SiO2‐PBO) aerogels with interpenetrated networks, possessing the ability to antioxidation, thermal insulation, and flame‐retardant properties. The resulting SiO2‐PBO aerogels exhibit low density (0.25 g/cm3), low thermal conductivity (0.035 W/(m·K)), and superior peak heat release rate value (15.3 W/g). Moreover, the mass residual rate is up to 70.46 wt% in the N2 atmosphere and remains 57.83 wt% despite existing in the air atmosphere and experiencing the highest temperature of 800°C. Briefly, SiO2‐PBO aerogels as‐prepared could be a potential matrix for a new gene ration of high‐performance thermal protective composites in the future.
Tuning the ionic conductivity of flexible polyvinyl alcohol/sodium bromide polymer electrolyte films by incorporating silver nanoparticles for energy storage device applications
Authors: Cyriac Vipin , Molakalu Padre Shilpa , Ismayil  , Sangam Chandrashekar Gurumurthy , Chavan Chetan , Fakeerappa Bhajantri Rajashekhar , Murari Mudiyaru Subrahmanya 
Published: May 2022

AbstractIn this present work, we have synthesized silver nanoparticles (AgNPs) using the chemical reduction method and systematically studied the effect of AgNPs of different loading into polyvinyl alcohol/sodium bromide (PVA/NaBr) polymer electrolytes. X‐ray diffraction and Fourier transform infrared spectroscopy confirmed the variation in the crystallinity and complexation with AgNPs loading, respectively. AgNPs are uniformly distributed in the polymer matrix as depicted in FESEM. According to transport property studies, it is observed that carrier concentration has a strong influence on ionic conductivity. Additionally, I‐t studies showed that most charge carriers are ions and not electrons. The sample PVA/NaBr with AgNPs, prepared from 6 mM AgNO3 solution (PNAg6) with ionic conductivity 1.22 × 10−4 S cm−1 (one order increase with respect to undoped sample) and highest electrochemical stability window (ESW) of 2.86 V, can be chosen as a suitable candidate for energy storage device applications.
Bacteria in cancer therapy: A new generation of weapons
Authors: Fan Jun Ying , Huang Yuan , Li Yi , Muluh Tobias Achu , Fu Shao Zhi , Wu Jing Bo 
Published: May 2022

AbstractTumors are presently a major threat to human life and health. Malignant tumors are conventionally treated through radiotherapy and chemotherapy. However, traditional therapies yield unsatisfactory results due to high toxicity to the normal cells, inability to treat deep tumor tissues, and the possibility of inducing drug resistance in the tumor cells. This has caused immunotherapy to emerge as an effective and alternate treatment strategy. To overcome the limitations of the conventional treatments as well as to avert the risk of various drug resistance and cytotoxicity, bacterial anti‐tumor immunotherapy has raised the interest of researchers. This therapeutic strategy employs bacteria to specifically target and colonize the tumor tissues with preferential accumulation and proliferation. Such bacterial accumulation initiates a series of anti‐tumor immune responses, effectively eliminating the tumor cells. This immunotherapy can use the bacteria alone or concomitantly with the other methods. For example, the bacteria can deliver the anti‐cancer effect mediators by regulating the expression of the bacterial genes or by synthesizing the bioengineered bacterial complexes. This review will discuss the mechanism of utilizing bacteria in treating tumors, especially in terms of immune mechanisms. This could help in better integrating the bacterial method with other treatment options, thereby, providing a more effective, reliable, and unique treatment therapy for tumors.
A Low‐Potential and Stable Bis‐Dimethylamino‐Substituted Anthraquinone for pH‐Neutral Aqueous Redox Flow Batteries
Authors: Xia Lixing , Zhang Yujing , Wang Fuzhi , Chu Fengming , Yang Yun , Li Hui , Tan Zhan'ao 
Published: May 2022

AbstractQuinone‐based aqueous redox flow batteries (RFBs) have drawn much attention due to their high safety, two‐electron involvement, rapid reaction kinetics, property tunability, and potentially low cost. RFBs operating in neutral solution feature a wide electrochemical window of around 2.5 V, which provides much more space for the design of redox‐active materials (RAMs) to realize a high voltage. However, it is still challenging to achieve low potential in the neutral condition for quinone‐based RAMs, owing to inherently pH‐dependent behaviors and deep LUMO (the lowest unoccupied molecular orbital) energy level. Herein, we report three low‐potential quinone‐based RAMs (1,4‐BDPAQCl2, 1,5‐BDPAQCl2, and 1,8‐BDPAQCl2) by bis‐dimethylamino substitution. The half‐wave potential of the quinones in 0.5 M KCl is approximately −0.55 to −0.57 V versus a normal hydrogen electrode. The low potential is ascribed to the introduced functional groups with two effects. First, the intramolecular hydrogen bonds formed between C=O and H−N can weaken the association between protons and dianion Q2−, resulting in a favorable distribution of products. Second, the functional groups can effectively increase the LUMO over 0.22 eV, compared with anthraquinone. Paired with Fe(glycine)2Cl2, the theoretical open‐circuit voltage of full RFBs is achieved at 1.27–1.29 V. We test full batteries using these quinones as negative RAMs at a lower concentration (0.1 M). The results show that 1,8‐BDPAQCl2 displays stability during 300 charge‐discharge cycles. In contrast, the other two quinones exhibit poor cycling stability due to side reactions. We further execute a higher concentration (0.4 M) for 1,8‐BDPAQCl2. The cycling stability of the quinone−iron RFBs is outstanding, with 0.048 % capacity decay per cycle and 0.88 % capacity decay per day. Our finding offers a feasible strategy to design low‐potential quinone molecules for the neutral RFBs.
Mapping Catalyst–Solvent Interplay in Competing Carboamination/Cyclopropanation Reactions
Authors: Wodrich Matthew D. , Chang Miyeon , Gallarati Simone , Woźniak Łukasz , Cramer Nicolai , Corminboeuf Clemence 
Published: May 2022

AbstractGroup 9 metals, in particular RhIII complexes with cyclopentadienyl ligands, are competent C−H activation catalysts. Recently, a Cp*RhIII‐catalyzed reaction of alkenes with N‐enoxyphthalimides showed divergent outcome based on the solvent, with carboamination favored in methanol and cyclopropanation in 2,2,2‐trifluoroethanol (TFE). Here, we create selectivity and activity maps capable of unravelling the catalyst‐solvent interplay on the outcome of these competing reactions by analyzing 42 cyclopentadienyl metal catalysts, CpXMIII (M=Co, Rh, Ir). These maps not only can be used to rationalize previously reported experimental results, but also capably predict the behavior of untested catalyst/solvent combinations as well as aid in identifying experimental protocols that simultaneously optimize both catalytic activity and selectivity (solutions in the Pareto front). In this regard, we demonstrate how and why the experimentally employed Cp*RhIII catalyst represents an ideal choice to invoke a solvent‐induced change in reactivity. Additionally, the maps reveal the degree to which even perceived minor changes in the solvent (e. g., replacing methanol with ethanol) influence the ratio of carboamination and cyclopropanation products. Overall, the selectivity and activity maps presented here provide a generalizable tool to create global pictures of anticipated reaction outcome that can be used to develop new experimental protocols spanning metal, ligand, and solvent space.
Brain size and behavioral specialization in the jataí stingless bee (Tetragonisca angustula)
Authors: Valadares Lohan , Vieira Bruno Gusmão , Santos do Nascimento Fabio , Sandoz Jean‐Christophe 
Published: May 2022

AbstractSocial insects are instructive models for understanding the association between investment in brain size and behavioral variability because they show a relatively simple nervous system associated with a large set of complex behaviors. In the jataí stingless bee (Tetragonisca angustula), division of labor relies both on age and body size differences among workers. When young, both minors and soldiers engage in intranidal tasks and move to extranidal tasks as they age. Minors switch to foraging activities, while soldiers take over defensive roles. Nest defense performed by soldiers includes two different tasks: (1) hovering around the nest entrance for the detection and interception of heterospecific bees (a task relying mostly on vision) and (2) standing at the nest entrance tube for inspection of returning foragers and discrimination against conspecific non‐nestmates based on olfactory cues. Here, using different‐sized individuals (minors and soldiers) as well as same‐sized individuals (hovering and standing soldiers) performing distinct tasks, we investigated the effects of both morphological and behavioral variability on brain size. We found a negative allometric growth between brain size and body size across jataí workers, meaning that minors had relatively larger brains than soldiers. Between soldier types, we found that hovering soldiers had larger brain compartments related to visual processing (the optic lobes) and learning (the mushroom bodies). Brain size differences between jataí soldiers thus correspond to behavioral specialization in defense (i.e., vision for hovering soldiers) and illustrate a functional neuroplasticity underpinning division of labor.
A1D–0D–3Dcoupled model for simulating blood flow and transport processes in breast tissue
Authors: Fritz Marvin , Köppl Tobias , Oden John Tinsley , Wagner Andreas , Wohlmuth Barbara , Wu Chengyue 
Published: May 2022

AbstractIn this work, we present mixed dimensional models for simulating blood flow and transport processes in breast tissue and the vascular tree supplying it. These processes are considered, to start from the aortic inlet to the capillaries and tissue of the breast. Large variations in biophysical properties and flow conditions exist in this system necessitating the use of different flow models for different geometries and flow regimes. In total, we consider four different model types. First, a system of 1D nonlinear hyperbolic partial differential equations (PDEs) is considered to simulate blood flow in larger arteries with highly elastic vessel walls. Second, we assign 1D linearized hyperbolic PDEs to model the smaller arteries with stiffer vessel walls. The third model type consists of ODE systems (0D models). It is used to model the arterioles and peripheral circulation. Finally, homogenized 3D porous media models are considered to simulate flow and transport in capillaries and tissue within the breast volume. Sink terms are used to account for the influence of the venous and lymphatic systems. Combining the four model types, we obtain two different 1D–0D–3D coupled models for simulating blood flow and transport processes: The first model results in a fully coupled 1D–0D–3D model covering the complete path from the aorta to the breast combining a generic arterial network with a patient specific breast network and geometry. The second model is a reduced one based on the separation of the generic and patient specific parts. The information from a calibrated fully coupled model is used as inflow condition for the patient specific sub‐model allowing a significant computational cost reduction. Several numerical experiments are conducted to calibrate the generic model parameters and to demonstrate realistic flow simulations compared to existing data on blood flow in the human breast and vascular system. Moreover, we use two different breast vasculature and tissue data sets to illustrate the robustness of our reduced sub‐model approach.
DNA‐Directed Seeded Synthesis of Gold Nanoparticles without Changing DNA Sequence
Authors: Lu Chang , Zandieh Mohamad , Zheng Jinkai , Liu Juewen 
Published: May 2022

AbstractDNA has been used for directing the growth of noble metal nanoparticles into different morphologies. Most previous studies focused on the effect of DNA sequence, while the effect of DNA adsorption was not thoroughly explored. In this work, we controlled the seeded growth of AuNPs by using the same DNA sequence but under different initial adsorption conditions: room temperature and heating. DNA adsorbed by heating induced more anisotropic nanoparticle growth, and the most effect was observed with 100 nM C30 DNA, where nanoflowers were obtained for the heated sample. By measuring DNA adsorption and desorption, heating did not increase DNA adsorption density but increased the adsorption affinity. The percentage of adsorbed DNA before the growth was only about 10%, regardless of heating, while after the growth, the associated DNA reached 75% or more, indicating that the free DNA also influenced the growth. This study offers fundamental insights into the effect of DNA adsorption on seeded AuNP growth, providing a method to tune the morphology of nanoparticles without changing DNA sequence.
A DFT Study on the Activity Origin of Fe−N−C Sites for Oxygen Reduction Reaction
Authors: Zhang Shishi , Qin Yanyang , Ding Shujiang , Su Yaqiong 
Published: May 2022

AbstractIron‐nitrogen‐carbon materials have been known as the most promising non‐noble metal catalyst for proton‐exchange membrane fuel cells (PEMFCs), but the genuine active sites for oxygen reduction reaction (ORR) are still arguable. Herein, by the thorough density functional theory investigations, we unravel that the planar Fe2N6 site exhibits excellent ORR catalytic activity over both FeN3 and FeN4 sites, and the potential‐determining step is determined to be the *OH hydrogenation step with an overpotential of 0.415 V. The ORR activity of Fe2N6 site originates from the low spin magnetic moment (1.11 μB), which leads to high antibonding states and low d‐band center of the Fe center, further leads to weak binding strength of *OH species. The density of FeN4 sites only has little influence on the ORR activity owing to the similar interaction between active site and intermediates in ORR. Our research sheds light on the activity origin of iron‐nitrogen‐carbon materials for ORR.
Metal Triflates as Catalysts in Organic Synthesis: Determination of Their Lewis Acidity by Mass Spectrometry
Authors: Massi Lionel , Gal Jean‐François , Duñach Elisabet 
Published: May 2022

AbstractMetal triflates have shown a large variety of possibilities as catalysts in organic reactions. Some selected examples of their catalytic activity, in particular in C−O and C−C bond formation are presented. A better understanding of the mode of interaction between these Lewis acids and organic functional groups as ligands should allow for an easier choice of a tailored metal cation for a given reaction. Electrospray ionization mass spectrometry enables the characterization and the quantification of the donor/acceptor interactions involved in the catalytic processes. Both gas‐phase and solution‐phase interactions between various metal triflates and organic functionalities were studied. Based on an original probabilistic model, ligand displacement experiments lead us to establish quantitative affinity scales of ligands toward the metal centers. The main structural effects governing the ranking are identified and discussed.
Marine toxin (+)‐chaetocin‐induced apoptosis of lung large cell carcinoma cell lines through cell cycle arrest via CDKN1A expression and replicative stress
Authors: Qian Mengjia , Cao Xin 
Published: May 2022

AbstractLung large cell carcinoma is a common type of lung cancer with poor prognosis. Although targeted drugs have achieved enormous success in treating non‐small‐cell lung carcinoma (NSCLC), new chemotherapy is needed since the emerged drug resistance always hinders curative effects. The fungal toxin (+)‐chaetocin demonstrated strong antineoplastic activities against the tested lung large cell carcinoma cell lines H460 and H661 at submicromolar concentrations. Further research demonstrated that (+)‐chaetocin effectively induced H460 apoptosis at 10–30 nM concentrations, while cell death occurred at 60 nM concentrations due to DNA duplication errors. Cell cycle and transcriptional analyses proved that cell cycle arrest via CDKN1A expression and the comprehensive replicative stress of (+)‐chaetocin are key factors in the (+)‐chaetocin working mechanisms.