bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exosomes in Tumor Immunotherapy: Mediator, Drug Carrier, and Prognostic Biomarker
Authors: Wan Zhuo , Dong Yan , Wei Mengying , Gao Xiaotong , Yang Guodong , Zhang Jian , Liu Li 
Published: July 2020

AbstractExosomes, which are small lipid bilayer vesicles that can be released by multiple cell types, mediate communication between cells by transporting nucleic acids, proteins, and other bioactive molecules. Pioneering studies have revealed that exosomes can exert multiple functions in shaping tumor immune responses in the crosstalk between tumor cells and surrounding immune cells. Emerging studies have also demonstrated the powerful function of engineered exosomes in cancer immunotherapy. Here, the recent progress in this field and focus on exosomes as mediators, drug carriers, and prognostic biomarkers in tumor immunotherapy is summarized. This review not only summarizes the progress of this field, but also provides insights and perspectives on exosome‐based strategies in cancer immunotherapy.
Template‐Directed Growth of Hierarchical MOF Hybrid Arrays for Tactile Sensor
Authors: Zhou Kui , Zhang Chen , Xiong Ziyu , Chen Hong‐Ye , Li Teng , Ding Guanglong , Yang Baidong , Liao Qiufan , Zhou Ye , Han Su‐Ting 
Published: July 2020

AbstractRecently, conductive metal−organic frameworks (MOFs) as the active material have provided broad prospects for electronic device application. The positioning technologies for MOFs enable the fabrication of novel microstructures, which can modulate the morphology of the material and tune the properties for the targeted application. Herein, a template‐method is used to synthesize the hierarchical structure of MOF hybrid array (MHA) on copper mesh (MHA@Mesh) for flexible sensor. Finite element method (FEM) results indicate that the 3D hierarchical MHA@Mesh can mimic the micro/nanoscale structure of human skin, which enables an interlocking contact. MHA@Mesh‐based flexible sensor presents rapid response rate (<1 ms) and high sensitivity (up to 307 kPa−1) which is 20 times higher than that of MHA@Foil‐based sensor (15 kPa−1). The flexible pressure device could be applied to monitor the finger motion and human pulses. Moreover, the music recognition can be performed by integrating the MOFs hardware sensors with machine learning algorithms. Overall, this design concept of 3D hierarchical microarray structures demonstrates potential in the fields of wearable technologies and human–machine interfaces.
One‐Step Preparation of Biocompatible Gold Nanoplates with Controlled Thickness and Adjustable Optical Properties for Plasmon‐Based Applications
Authors: Ye Sunjie , Connell Simon D. , McLaughlan James R. , Roach Lucien , Aslam Zabeada , Chankhunthod Navadecho , Brown Andy P. , Brydson Rik , Bushby Richard J. , Critchley Kevin , Coletta P. Louise , Markham Alexander F. , Evans Stephen D. 
Published: July 2020

AbstractThe ability to synthesize plasmonic nanomaterials with well‐defined structures and tailorable size is crucial for exploring their potential applications. Gold nanoplates (AuNPLs) exhibit appealing structural and optical properties, yet their applications are limited by difficulties in thickness control. Other challenges include a narrow range of tunability in size and surface plasmon resonance, combined with a synthesis conventionally involving cytotoxic cetyltrimethylammonium (CTA) halide surfactant. Here, a one‐step, high‐yield synthesis of single‐crystalline AuNPLs is developed, based on the combined use of two structure‐directing agents, methyl orange and FeBr3, which undergo preferential adsorption onto different crystalline facets of gold. The obtained AuNPLs feature high shape homogeneity that enables mesoscopic self‐assembly, broad‐range tunability of dimensions (controlled thickness from ≈7 to ≈20 nm, accompanied by modulation of the edge length from ≈150 nm to ≈2 µm) and plasmonic properties. These merits, coupled with a preparation free of CTA‐halide surfactants, have facilitated the exploration of various uses, especially in bio‐related areas. For example, they are demonstrated as biocompatible photothermal agents for cell ablation in NIR I and NIR II windows. This work paves the way to the innovative fabrication of anisotropic plasmonic nanomaterials with desired attributes for wide‐ranging practical applications.
Full‐State Synthesis of Electromagnetic Fields using High Efficiency Phase‐Only Metasurfaces
Authors: Wu Jun Wei , Wang Zheng Xing , Fang Zu Qi , Liang Jing Cheng , Fu Xiaojian , Liu Jun Feng , Wu Hao Tian , Bao Di , Miao Long , Zhou Xiao Yang , Cheng Qiang , Cui Tie Jun 
Published: July 2020

AbstractA metasurface is a thin array of subwavelength elements with designable scattering responses, and metasurface holography is a powerful tool for imaging and field control. The existing metasurface holograms are classified into two types: one is based on phase‐only metasurfaces (including the recently presented vectorial metasurface holography), which has high power efficiency but cannot control the phases of generated fields; while the other is based on phase‐amplitude‐modulated metasurfaces, which can control both field amplitudes and phases in the region of interest (ROI) but has very low efficiency. Here, for the first time, it is proposed to synthesize the field amplitudes and phases in ROI simultaneously and independently by using high‐efficiency phase‐only metasurfaces. All points in ROI may have independent values of field amplitudes and phases, and the requirements for X and Y components may be different in achieving spatially varied polarization states. To this end, an efficient design method based on equivalent electromagnetic model and gradient‐based nonlinear optimization is proposed. Full‐wave simulations and experimental results demonstrate that the phase‐only metasurface designed by the method has 10 times higher efficiency than the phase‐amplitude‐modulated metasurface. This work opens a way to realize more complicated and high‐efficiency metasurface holography.
A Thermal Radiation Modulation Platform by Emissivity Engineering with Graded Metal–Insulator Transition
Authors: Tang Kechao , Wang Xi , Dong Kaichen , Li Ying , Li Jiachen , Sun Bo , Zhang Xiang , Dames Chris , Qiu Chengwei , Yao Jie , Wu Junqiao 
Published: July 2020

AbstractThermal radiation from a black body increases with the fourth power of absolute temperature (T4), an effect known as the Stefan–Boltzmann law. Typical materials radiate heat at a portion of this limit, where the portion, called integrated emissivity (εint), is insensitive to temperature (|dεint/dT| ≈ 10−4 °C–1). The resultant radiance bound by the T4 law limits the ability to regulate radiative heat. Here, an unusual material platform is shown in which εint can be engineered to decrease in an arbitrary manner near room temperature (|dεint/dT| ≈ 8 × 10−3 °C–1), enabling unprecedented manipulation of infrared radiation. As an example, εint is programmed to vary with temperature as the inverse of T4, precisely counteracting the T4 dependence; hence, thermal radiance from the surface becomes temperature‐independent, allowing the fabrication of flexible and power‐free infrared camouflage with unique advantage in performance stability. The structure is based on thin films of tungsten‐doped vanadium dioxide where the tungsten fraction is judiciously graded across a thickness less than the skin depth of electromagnetic screening.
Light Management with Natural Materials: From Whiteness to Transparency
Authors: Jacucci Gianni , Schertel Lukas , Zhang Yating , Yang Han , Vignolini Silvia 
Published: July 2020

AbstractThe possibility of structuring material at the nanoscale is essential to control light–matter interactions and therefore fabricate next‐generation paints and coatings. In this context, nature can serve not only as a source of inspiration for the design of such novel optical structures, but also as a primary source of materials. Here, some of the strategies used in nature to optimize light–matter interaction are reviewed and some of the recent progress in the production of optical materials made solely of plant‐derived building blocks is highlighted. In nature, nano‐ to micrometer‐sized structured materials made from biopolymers are at the origin of most of the light‐transport effects. How natural photonic systems manage light scattering and what can be learned from plants and animals to produce photonic materials from biopolymers are discussed. Tuning the light‐scattering properties via structural variations allows a wide range of appearances to be obtained, from whiteness to transparency, using the same renewable and biodegradable building blocks. Here, various transparent and white cellulose‐based materials produced so far are highlighted.
Influence of Depolymerases and Lipases on the Degradation of Polyhydroxyalkanoates Determined in Langmuir Degradation Studies
Authors: Tarazona Natalia A. , Machatschek Rainhard , Lendlein Andreas 
Published: July 2020

AbstractMicrobially produced polyhydroxyalkanoates (PHAs) are polyesters that are degradable by naturally occurring enzymes. Albeit PHAs degrade slowly when implanted in animal models, their disintegration is faster compared to abiotic hydrolysis under simulated physiological environments. Ultrathin Langmuir‐Blodgett (LB) films are used as models for fast in vitro degradation testing, to predict enzymatically catalyzed hydrolysis of PHAs in vivo. The activity of mammalian enzymes secreted by pancreas and liver, potentially involved in biomaterials degradation, along with microbial hydrolases is tested toward LB‐films of two model PHAs, poly(3‐R‐hydroxybutyrate) (PHB) and poly[(3‐R‐hydroxyoctanoate)‐co‐(3‐R‐hydroxyhexanoate)] (PHOHHx). A specific PHA depolymerase from Streptomyces exfoliatus, used as a positive control, is shown to hydrolyze LB‐films of both polymers regardless of their side‐chain‐length and phase morphology. From amorphous PHB and PHOHHx, ≈80% is eroded in few hours, while mass loss for semicrystalline PHB is 25%. Surface potential and interfacial rheology measurements show that material dissolution is consistent with a random‐chain‐scission mechanism. Degradation‐induced crystallization of semicrystalline PHB LB‐films is also observed. Meanwhile, the surface and the mechanical properties of both LB‐films remain intact throughout the experiments with lipases and other microbial hydrolases, suggesting that non‐enzymatic hydrolysis could be the predominant factor for acceleration of PHAs degradation in vivo.
Researchers' ethical concerns regarding habituating wild‐nonhuman primates and perceived ethical duties to their subjects: Results of an online survey
Authors: Green Victoria M. , Gabriel Kara I. 
Published: July 2020

AbstractWhile the process of habituation is essential for researchers to observe primates in their natural habitats, ethical dilemmas may arise from its consequences. We collected data from 286 participants via an online survey to investigate: (a) how primatologists perceive their ethical duties toward their subjects; (b) the extent to which primatologists are concerned about the potential ethical consequences of habituation; and (c) the methods primatologists use to reduce potential harms caused by habituation. Overall, primatologists felt an extremely strong duty to mitigate harms that they may cause (e.g., to not stress individuals during observation, treat injuries, and reunite separated individuals) and expressed very high concern for habituation's potential to increase the vulnerability of their subjects to poaching and disease transfer. Ratings for those items were so high that they could not be included in subsequent exploratory factor analyses that were designed to reveal constructs underlying respondents’ ratings of their ethical duties and concerns. Factor analysis of ratings of ethical duties revealed that primatologists reported a strong duty to mitigate harms caused by other humans and a lower perceived duty to mitigate naturally occurring harmful events. Factor analysis on ethical concern ratings revealed that respondents were concerned about harms during the habituation process, the presence of unhabituated behavior after habituation had been established, and indirect harms of habituation. Concerns for unhabituated behavior and indirect harms were rated slightly higher than concern for harms during the habituation process. To mitigate potential harms, primatologists primarily reported engaging in strategies to reduce stress in their subjects. Our findings reveal a disconnect between primatologists' ratings of their ethical concerns and their reported mitigation practices that may, in part, stem from gaps in knowledge about the true impacts of habituation. We suggest areas of discussion and research in the field necessary to address those gaps.
Die Erzeugung von Tyrosinaseaktivität in einer Catecholoxidase erlaubt die Identifizierung der für die C‐H‐Aktivierung in Typ‐III‐Kupferenzymen verantwortlichen Aminosäurereste
Authors: Kampatsikas Ioannis , Pretzler Matthias , Rompel Annette 
Published: July 2020

AbstractTyrosinasen (TYRs) katalysieren die Hydroxylierung von Phenolen und die Oxidation der resultierenden o‐Diphenole zu o‐Chinonen, während Catecholoxidasen (COs) nur die letztere Aktivität aufweisen. Die Auronsynthase (AUS) reagiert nicht mit klassischen Tyrosinasesubstraten wie Tyramin und l‐Tyrosin, jedoch hydroxyliert sie ihr natürliches Substrat: das Isoliquiritigenin. Der strukturelle Unterschied zwischen TYRs, COs und AUS, der zu ihren unterschiedlichen katalytischen Aktivitäten führt, ist noch immer ein Rätsel. Zu dessen Klärung wurde eine Bibliothek von 39 Mutanten der AUS von Coreopsis grandiflora (CgAUS) erstellt. Aktivitätsstudien an diesen zeigten, dass die Reaktivität der drei konservierten Histidine (HisA2, HisB1 und HisB2) durch ihre benachbarten Reste (HisB1+1, HisB2+1) und den Wasserträgerrest bestimmt wird, womit diese entweder als stärkere Basen reagieren oder/und in einer für das Verschieben von Substratprotonen günstigen Position stabilisiert werden. Diese Studie liefert das Verständnis für die CH‐Aktivierung basierend auf dem Typ‐III‐Kupferzentrum, das in zukünftigen biotechnologischen Prozessen verwendet werden kann.
Identification of Amino Acid Residues Responsible for C−H Activation in Type‐III Copper Enzymes by Generating Tyrosinase Activity in a Catechol Oxidase
Authors: Kampatsikas Ioannis , Pretzler Matthias , Rompel Annette 
Published: July 2020

AbstractTyrosinases (TYRs) catalyze the hydroxylation of phenols and the oxidation of the resulting o‐diphenols to o‐quinones, while catechol oxidases (COs) exhibit only the latter activity. Aurone synthase (AUS) is not able to react with classical tyrosinase substrates, such as tyramine and l‐tyrosine, while it can hydroxylate its natural substrate isoliquiritigenin. The structural difference of TYRs, COs, and AUS at the heart of their divergent catalytic activities is still a puzzle. Therefore, a library of 39 mutants of AUS from Coreopsis grandiflora (CgAUS) was generated and the activity studies showed that the reactivity of the three conserved histidines (HisA2, HisB1, and HisB2) is tuned by their adjacent residues (HisB1+1, HisB2+1, and waterkeeper residue) either to react as stronger bases or / and to stabilize a position permissive for substrate proton shuffling. This provides the understanding for C−H activation based on the type‐III copper center to be used in future biotechnological processes.
Organocatalytic Control over a Fuel‐Driven Transient‐Esterification Network**
Authors: van der Helm Michelle P. , Wang Chang‐Lin , Fan Bowen , Macchione Mariano , Mendes Eduardo , Eelkema Rienk 
Published: July 2020

AbstractSignal transduction in living systems is the conversion of information into a chemical change, and is the principal process by which cells communicate. In nature, these functions are encoded in non‐equilibrium (bio)chemical reaction networks (CRNs) controlled by enzymes. However, man‐made catalytically controlled networks are rare. We incorporated catalysis into an artificial fuel‐driven out‐of‐equilibrium CRN, where the forward (ester formation) and backward (ester hydrolysis) reactions are controlled by varying the ratio of two organocatalysts: pyridine and imidazole. This catalytic regulation enables full control over ester yield and lifetime. This fuel‐driven strategy was expanded to a responsive polymer system, where transient polymer conformation and aggregation are controlled through fuel and catalyst levels. Altogether, we show that organocatalysis can be used to control a man‐made fuel‐driven system and induce a change in a macromolecular superstructure, as in natural non‐equilibrium systems.
Planar Cyclopenten‐4‐yl Cations: Highly Delocalized π Aromatics Stabilized by Hyperconjugation
Authors: Nees Samuel , Kupfer Thomas , Hofmann Alexander , Braunschweig Holger 
Published: July 2020

AbstractTheoretical studies predicted the planar cyclopenten‐4‐yl cation to be a classical carbocation, and the highest‐energy isomer of C5H7+. Hence, its existence has not been verified experimentally so far. We were now able to isolate two stable derivatives of the cyclopenten‐4‐yl cation by reaction of bulky alanes CpRAlBr2 with AlBr3. Elucidation of their (electronic) structures by X‐ray diffraction and quantum chemistry studies revealed planar geometries and strong hyperconjugation interactions primarily from the C−Al σ bonds to the empty p orbital of the cationic sp2 carbon center. A close inspection of the molecular orbitals (MOs) and of the anisotropy of current (induced) density (ACID), as well as the evaluation of various aromaticity descriptors indicated distinct aromaticity for these cyclopenten‐4‐yl derivatives, which strongly contrasts the classical description of this system. Here, strong delocalization of π electrons spanning the whole carbocycle has been verified, thus providing rare examples of π aromaticity involving saturated sp3 carbon atoms.
Monitoring the Crystallization Behavior of Hydrogenated Coconut Oil Using Ultrasonic Phase Velocity
Authors: Mori Daisuke , Matsuura Tsutashi , Masuko Tomosada , Katsuno Nakako , Nishizu Takahisa 
Published: July 2020

AbstractFat crystals are known to affect the stability and applicability of fat‐containing foods, and changes in quality during low‐temperature preservation. Therefore, understanding fat crystallization behavior is important for product development and quality control. Ultrasonic measurement is a nondestructive, noncontact, and highly versatile on‐line measurement method. Herein, we aim to verify the applicability of the ultrasonic characteristics to monitor fat crystallization behavior of hydrogenated coconut oil (HCO) using ultrasonic phase velocity (UPV) at 1.98 MHz under different cooling rates and with different emulsifier additives. The UPV was found to increase with decreasing HCO temperature, and the UPV‐temperature relation had an inflection point at approximately 20–25 °C. The inflection point coincided with the crystallization onset temperature determined by differential scanning calorimetry. The density of HCO was found to increase with decreasing temperature, while the compressibility of HCO decreased with the temperature. From the Laplace equation established between the UPV (c) and the density (ρ), c = (ρβ)−0.5, the increase in the compressibility (β) of UPV indicates a decrease in ρβ. Consequently, since the density increases with cooling, the dominant factor that causes an increase in UPV is a reduction in compressibility. The UPV of the solid phase was highly correlated with the crystallization enthalpy (R2 = 0.99).
Bio‐based hydroxymethylated eugenol modified bismaleimide resin and its high‐temperature composites
Authors: Ning Yi , Li Dian‐sen , Wang Ming‐cun , Chen Yi‐chi , Jiang Lei 
Published: July 2020

AbstractHydroxymethylated eugenol (MEG) and poly (hydroxymethylated eugenol) (PMEG) were synthesized by the condensation reaction of eugenol (EG) with formaldehyde. The different contents of MEG and PMEG were used to modify 4,4′‐bismaleimidediphenylmethane (BMI). The cured MEG‐BMI resins exhibit good thermal stability evidenced by its 5% weight loss temperatures above 407°C and its residue above 39.4% at 800°C under nitrogen. For carbon/MEG‐BMI composites, their glass transition temperatures were around 400°C; their flexural strength and moduli were maintained at a range of 488.87–575.47 MPa and 48.84–60.26 GPa, respectively. With the increasing content of BMI in the resin formulation, the flexural properties decreased; comprehensively the composite with the eugenol/maleimide unit ratio (1:0.3 mol) had the best mechanical and thermal properties, meanwhile its renewable carbon content was as high as 57.80%. As a new candidate of high temperature thermosetting resin, MEG would find promising applications for advanced composites' matrice.
A homogeneous immunoassay for detection of the interaction between two tumor biomarkers of IGF1R‐β and SOCS1
Authors: Kuang Zhenzhan , Deng Hao , Xu Lan , Hu Qianying , Cai Yan , Wang Ruixue , Luo Shuhong , Liu Tiancai , Hao Wenbo 
Published: July 2020

AbstractThe current protein interaction method is time consuming and cumbersome or the instrument is expensive. A new method that is convenient, fast, and high throughput needs to be studied urgently. The purpose of this study was to establish a homogeneous immunoassay to detect the interaction between insulin‐like growth factor‐1 receptor‐β (IGF1R‐β) and suppressor of cytokine signaling 1 (SOCS1). The recombinant vectors IGF1R‐β/pENTER and SOCS1/pENTER were constructed and transfected into 293T cells. Based on homogeneous immunoassay technology, we established a suitable method. The signal intensity in the 293T lysate that overexpressed IGF1R‐β and SOCS1, respectively, was compared with the signal intensity in the simultaneous expression of IGF1R‐β and SOCS1. The interaction between IGF1R‐β and SOCS1 was verified in vitro. The detection system for the interaction between IGF1R‐β and SOCS1 was established. Compared with other methods, homogeneous immunoassay has the advantages of being rapid and sensitive, having higher sensitivity, and easy to operate. The interaction between IGF1R‐β and SOCS1 was tested to verify the feasibility of this method and prove its practicability and sensitivity. This new method can be used as a high‐throughput platform for protein–protein interaction, with the advantages of trace detection, short detective time, and high detective sensitivity.
Firm sustainable investment: Are female directors greener?
Authors: Atif Muhammad , Alam Md. Samsul , Hossain Mohammed 
Published: July 2020

AbstractAre female directors greener than their male counterparts? We investigate this issue by examining the impact of female directors on firm sustainable investment. Using data of S&P 1500 indexed firms in the United States, covering the period 2004–2016, we find a positive relationship between female directors and sustainable investment. Consistent with critical mass theory, we also find that boards with two or more female directors have a pronounced impact on sustainable investment. Moreover, female independent directors have a stronger impact on sustainable investment than female executive directors. Our additional analysis shows higher value for firms with the presence of female directors and sustainable investment. Our findings are robust to alternative variable specification, estimation techniques, and different identification strategies including the two‐stage least squares, generalized method of moments, and propensity score matching. The study provides novel evidence on the role of female directors in promoting sustainable investment and adds a new dimension to the ongoing debate in sustainability literature.