bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cooperative Ligands in Dissolution of Gold
Authors: Heliövaara Eeva , Liljeqvist Henri , Muuronen Mikko , Eronen Aleksi , Moslova Karina , Repo Timo 
Published: April 2021

AbstractDevelopment of new, environmentally benign dissolution methods for metallic gold is driven by needs in the circular economy. Gold is widely used in consumer electronics, but sustainable and selective dissolution methods for Au are scarce. Herein, we describe a quantitative dissolution of gold in organic solution under mild conditions by using hydrogen peroxide as an oxidant. In the dissolution reaction, two thiol ligands, pyridine‐4‐thiol and 2‐mercaptobenzimidazole, work in a cooperative manner. The mechanistic investigations suggest that two pyridine‐4‐thiol molecules form a complex with Au0 that can be oxidized, whereas the role of inexpensive 2‐mercaptobenzimidazole is to stabilize the formed AuI species through a ligand exchange process. Under optimized conditions, the reaction proceeds vigorously and gold dissolves quantitatively in two hours. The demonstrated ligand‐exchange mechanism with two thiols allows to drastically reduce the thiol consumption and may lead to even more effective gold dissolution methods in the future.
Conjugated Polymers with Aggregation‐Induced Emission Characteristics for Fluorescence Imaging and Photodynamic Therapy
Authors: Wang Lirong , Hu Rong , Qin Anjun , Tang Ben Zhong 
Published: April 2021

AbstractAccurate diagnosis and treatment have been extensively developed in the field of biomedicine, which put forward higher requirements for the development of biomedical materials with high efficiency and selectivity. Among them, conjugated polymers featuring aggregation‐induced emission (AIE) characteristics (AIE conjugated polymers) have stood out in recent years owing to their unique properties, such as intense solid emission, high light‐harvesting ability, efficient energy transfer, and high 1O2 generation ability, which empower them with effective biomedical functions in fluorescence imaging (FLI), photodynamic therapy (PDT), FLI‐guided PDT, two‐photon excited photodynamic therapy (2PE‐PDT), etc. In this review, we highlight recent progress in AIE conjugated polymers and their applications in anticancer and antibacterial areas based on FLI and PDT, and summarize the mechanism of color‐tuned fluorescence emission and efficient 1O2 generation ability. The challenges and perspectives for the future development of AIE conjugated polymers are also discussed.
CogramDroid–An approach towards malware detection in Android using opcode ngrams
Authors: Bhat Parnika , Dutta Kamlesh 
Published: April 2021

AbstractThe recent increase in Android's popularity has resulted in a swamp of attacks faced by the platform. Several researchers have come out with various static malware detection tools using opcodes as features since opcodes provide the details of intrinsic patterns of application raw data. This article presents a new malware detection approach CogramDroid based on opcode ngrams. The approach classifies the applications based on the relative frequency patterns of the opcode ngrams using the concept of word cooccurrence of natural language processing. The objective of the article is to develop a malware detection approach with high accuracy and time efficiency. The article also presents an analysis of the number of opcodes required for effective malware detection. In this study, an accuracy rate of 96.22% and an F1‐score of 96.69% is achieved using seven core opcodes and three grams.
The effects of green supply chain management capability on the internalisation of environmental management systems and organisation performance
Authors: Daddi Tiberio , Heras‐Saizarbitoria Iñaki , Marrucci Luca , Rizzi Francesco , Testa Francesco 
Published: April 2021

AbstractThe capability to manage the supply chain is a key issue in general management as well as green management. The topic has been widely discussed in the literature, however only few studies focused on how this capability could influence the effectiveness of certified Environmental Management Systems. To bridge this gap, we administered a survey with more than 400 EU EMAS‐registered companies in order to investigate the relation between green supply chain management capability and some key organisational performance such as environmental management system internalisation, environmental reputation, eco‐innovation and market competitiveness. The results show a positive influence of green supply chain management capability on performance through the mediating role of the internalisation of environmental management system and directly on market competitiveness. The study opens the floor on further academic debates on green supply chain management capability in environmental management systems and it identifies possible managerial and policy implications.
Cross‐Talk‐Suppressing Electrolyte Additive Enabling High Voltage Performance of Ni‐Rich Layered Oxides in Li‐Ion Batteries
Authors: Pham Hieu Quang , Nguyen Minh Tri , Tarik Mohamed , El Kazzi Mario , Trabesinger Sigita 
Published: April 2021

AbstractControl of electrode‐electrolyte interfacial reactivity at high‐voltage is a key to successfully obtain high‐energy‐density lithium‐ion batteries. In this study, 2‐aminoethyldiphenyl borate (AEDB) is investigated as a multifunctional electrolyte additive in stabilizing surface and bulk of both Ni‐rich LiNi0.85Co0.1Mn0.05O2 (NCM851005) and graphite electrodes in a cell operated with elevated upper cutoff voltage of 4.4 V vs. Li+/Li. The presence of AEDB in a full‐cell inhibits structural degradation of both cathode and anode materials, suppressing crack formation, and reduces metal dissolution at the cathode and metal deposition at the anode. As a consequence, the interfacial resistance is significantly reduced. Moreover, this is a case where “the whole is greater than the sum of the parts”: the effect of AEDB in half‐cells is rather modest, whereas in full‐cells its addition results in tremendous performance improvement. The graphite‖NCM851005 full‐cell in the presence of AEDB has a capacity retention of 88 % after 100 cycles, even when the upper cutoff voltage is set to 4.35 V, corresponding to 4.4 V vs Li+/Li, whereas with standard electrolyte under the same conditions it is only 21 %. The study shows a simple and easy approach to using Ni‐rich cathodes in an extended voltage window and demonstrates the importance of full‐cell testing for electrolyte additive selection.
Tunnel FET‐based ultra‐lightweight reconfigurable TRNG and PUF design for resource‐constrained internet of things
Authors: Japa Aditya , Majumder Manoj Kumar , Sahoo Subhendu K. , Vaddi Ramesh 
Published: April 2021

SummaryConventional complementary metal oxide semiconductor (CMOS)‐based dedicated true random number generator (TRNG) and physically unclonable function (PUF) designs have exhibited higher energy consumption and large area overhead with technology scaling. In contrast, this paper for the first time presents emerging tunnel field‐effect transistor (TFET)‐based ultra‐lightweight reconfigurable TRNG and PUF design. A unique methodology is proposed that considers p‐i‐n forward current characteristics to generate random keys for PUF and TRNG designs. Leveraging the p‐i‐n forward current of TFET, a ring oscillator (RO) is designed that exhibits variation in the operating frequency and acts as the main source of entropy for both PUF and TRNG. The TRNG in the proposed design is robust and passed all the National Institute of Standards and Technology (NIST) tests. Considering the variation in p‐i‐n forward current, the uniqueness of PUF is calculated as 47.5% and 46% at a supply voltage of 0.5 and 0.45 V, respectively. Moreover, PUF achieves high reliability of 82% and 88.7% with supply voltage and temperature variations, respectively. The proposed design is proved to be compact with relatively lower gate count and shows low energy consumption of 4.8 pJ/bit at 0.5‐V supply voltage. With these performance metrics, the proposed design is highly suitable for resource‐constrained internet of things (IoT).
Aspects of unmanned aerial vehicles path planning: Overview and applications
Authors: Khan Muhammad Toaha Raza , Muhammad Saad Malik , Ru Yang , Seo Junho , Kim Dongkyun 
Published: April 2021

SummaryAiming to the applications from security surveillance, military operational capabilities to the content and package delivery, unmanned aerial vehicles (UAVs) has a successfully created his space in the available technologies. The compact sized powerful flying robots are wirelessly controlled and are capable to complete tasks with and without direct human intervention. UAVs however still face serious challenges that limit the dream of complete autonomous unmanned flying machines. The key challenges include path planning and obstacle avoidance of these unmanned flying robots that are unavoidable while performing the application‐specific functionalities both in indoor and outdoor environments. In this manuscript with a survey, we investigate the state‐of‐the‐art UAV path planning algorithms and obstacle avoidance techniques. We have also summarized and compared the schemes in tabular form. In addition, current and future research directions and challenges are also discussed, showing the prospective research directions.
Histopathological comparison of aspiration and biopsy needles in endoscopic ultrasound‐guided tissue acquisition in patients with subepithelial lesions
Authors: Watanabe Masafumi , Okuwaki Kosuke , Kida Mitsuhiro , Tadehara Masayoshi , Adachi Kai , Masutani Hironori , Tamaki Akihiro , Imaizumi Hiroshi , Iwai Tomohisa , Yamauchi Hiroshi , Kaneko Toru , Hasegawa Rikiya , Kurosu Takahiro , Koizumi Wasaburo 
Published: April 2021

AbstractBackgroundInformation on whether a fine‐needle biopsy (FNB) needle can improve histopathological specimen quality or the amount of core tissue collected in the diagnosis of subepithelial lesions (SELs) remains insufficient. In this study, we aimed to compare the procedure outcomes and adequacy of histopathological specimens of fine‐needle aspiration (FNA) and FNB needles in endoscopic ultrasound‐guided tissue acquisition (EUS‐TA) using sample isolation processing by stereomicroscopy (SIPS) in patients with SELs.MethodsWe performed a retrospective comparison of SEL cases registered in two previously conducted prospective studies. Of 61 cases, we identified 56 cases of SELs that involved the muscularis propria layer. Of these, 27 patients who underwent EUS‐TA using a 22‐gauge FNA needle between July 2016 and December 2017, and 29 patients who underwent the procedure using a 22‐gauge FNB needle between March 2018 and January 2019 were included in the FNA and FNB group, respectively.ResultsPatient background characteristics did not differ between the groups. The technical success rate was 100% in both groups. The median adequacy score was significantly higher in the FNB group than in the FNA group (P < .01). The histological diagnosis showed no significant difference in the accuracy rate between the groups.ConclusionsIn EUS‐TA using the SIPS procedure to target SELs derived from the muscularis propria layer, FNB needles collect more core tissues and significantly improve histopathological specimen quality compared with FNA needles. When combined with SIPS, a high tissue diagnosis rate may be obtained regardless of the type of puncture needle used.
A questionnaire survey on radiation protection among 282 medical staff from 26 endoscopy‐fluoroscopy departments in Japan
Authors: Hayashi Shiro , Takenaka Mamoru , Kogure Hirofumi , Yakushijin Takayuki , Maruyama Hirotsugu , Hori Yasuki , Yoshio Toshiyuki , Ikezawa Kenji , Takagi Tadayuki , Asai Satoshi , Matsunaga Kazuhiro , Matsumoto Kengo , Tsumura Hidetaka , Yamaguchi Shinjiro , Sumiyoshi Tetsuya , Nagaike Koji , Tamaru Yuzuru , Hara Kazuo , Fujisawa Toshio , Oda Ichiro , Ohnita Ken , Kato Motohiko , Nebiki Hiroko , Mikami Tatsuya , Nishihara Akihiro , Egawa Satoshi , Minami Ryuki , Hosono Makoto , Nishida Tsutomu 
Published: April 2021

AbstractBackground and aimsIt is essential for endoscopists, technologists, and nurses to understand radiation protection. However, protective equipment usage is still low, and there is little awareness of radiation protection in practice.MethodsWe conducted a questionnaire survey on radiation protection from January to February 2020. The participants were medical staff, including medical doctors, nurses, and radiological and endoscopy technician in endoscopy‐fluoroscopy departments. The questionnaire included 14 multiple‐choice questions divided among three parts: background, equipment, and knowledge.ResultsWe surveyed a total of 282 subjects from 26 institutions. There were 168 medical doctors (60%), 90 nurses (32%), and 24 technologists (9%). Although almost all staff members (99%) always wore a lead apron, only a few wore a thyroid collar (32%) and lead glasses (21%). The rate of wearing a radiation dosimeter was insufficient (69%), especially among doctors (52%). A few subjects knew the radiation exposure dose of each procedure (15%), and slightly over half had attended lectures on radiation protection (64%) and knew about the three principles of radiation protection (59%). Protection adherence did not differ by years of experience, knowledge of fluoroscopy, awareness of radiation exposure doses, or attendance at basic lectures on radiation protection. However, medical doctors who were aware of the radiation exposure dose of each procedure were significantly more likely to wear dosimeters than those who were not (p = 0.0008).ConclusionMedical staff in endoscopy departments in Japan do not have enough radiation protection equipment or education.
Vitamin D insufficiency is associated with metabolic syndrome independent of insulin resistance and obesity in young adults ‐ The Berlin Aging Study II
Authors: Buchmann Nikolaus , Eckstein Nils , Spira Dominik , Demuth Ilja , Steinhagen‐Thiessen Elisabeth , Norman Kristina 
Published: April 2021

AbstractPurposeAge‐related changes affect vitamin D absorption and metabolism. Low 25‐hydroxyvitamin D concentrations have been reported as risk factor for the development of metabolic syndrome (MetS). However, recent evaluations suggest this association might be explained by obesity or insulin resistance (IR) in subjects with MetS. Our aim was to analyze associations between vitamin D insufficiency and MetS in a young cohort without diabetes and two senior cohorts with and without diabetes.MethodsFour hundred sixteen young and 1357 older BASE‐II participants were analyzed. Type 2 diabetes (T2D) was defined according to European Society of Cardiology (ESC) guidelines, MetS as suggested by International Diabetes Federation/American Heart Association/National Heart, Lung and Blood Institute (IDF/AHA/NHLBI 2009). Vitamin D insufficiency was defined as 25‐hydroxyvitamin D concentrations <50 nmol/L. Among other confounders, BMI and IR were taken into account.ResultsMetS was prevalent in 7.7% of the young and in 35.6% of the older BASE‐II participants and T2D occurred in 12.7% of the older participants. In young subjects without diabetes, vitamin D insufficiency was associated with an independent 3.2‐fold increased odds of having MetS (OR: 3.2 CI: 1.0–8.7; p = 0.042). However, in the older participants, this association was lost once BMI was taken into account among those with diabetes, and once IR was taken into account among those without diabetes.ConclusionIndependent associations between vitamin D insufficiency and MetS were only found among young subjects without diabetes. In the older adults, BMI annihilated these associations among subjects without diabetes as did HOMA‐IR among subjects with diabetes.
Two‐Photon Absorption Properties in “Push‐Pull” Ruthenium Nitrosyl Complexes with various Fluorenylterpyridine‐Based Ligands
Authors: Bukhanko Valerii , León‐Rojas Andrés Felipe , Lacroix Pascal G. , Tassé Marine , Ramos‐Ortiz Gabriel , Barba‐Barba Rodrigo M. , Farfán Norberto , Santillan Rosa , Malfant Isabelle 
Published: April 2021

AbstractUsing the compound [RuII(FT)(bipy)(NO)](PF6)3 (FT is the electron‐rich 4’‐(2‐fluorenyl)‐2,2’:6’,2’’‐terpyridine ligand and bipy is 2–2’bipyridine) as a reference, two new compounds are presented in which carbon‐carbon double and triple bonds are inserted between the fluorenyl substituent and the terpyridine to provide an extended conjugation path. The electronic properties of the three complexes are compared experimentally by UV‐visible spectroscopy and computationally by means of the density functional theory. All of them exhibit a capability for NO release under irradiation on their low‐energy transition located in the 400–500 nm range, with a quantum yield around 0.01. Their two‐photon absorption (TPA) cross sections are investigated by the Z‐scan technique at λ=800 nm. While the reference compound exhibits a cross‐section equal to 108 GM, the introduction of double and triple bonds leads to increased cross‐sections equal to 131 GM and 150 GM, respectively. These values are discussed in reference to the two‐level model in use for “push‐pull” dipolar TPA chromophores.
Selective Bromination of β‐Positions of Porphyrin by Self‐Catalytic Behaviour of VOTPP: Facile Synthesis, Electrochemical Redox Properties and Catalytic Application
Authors: Maurya Mannar R. , Prakash Ved , Avecilla Fernando , Sankar Muniappan 
Published: April 2021

AbstractOxidovanadium(IV) complex of β‐octabromo‐meso‐tetraphenylporphyrin, {[VIVO(TPPBr8)], 2} was synthesized by self‐catalytic oxidative bromination of meso‐tetraphenylporphyrinatooxidovanadium(IV) {[VIVO(TPP), 1} in excellent yield under mild conditions at 25 °C and its structure was confirmed by single crystal X‐ray study. UV‐Vis and 1H NMR spectra further confirmed that the meso‐phenyl rings are not brominated and thus emphasizes on the selectivity as well as synthetic importance of this catalytic method. In the presence of substrates e. g. phenol derivatives, 1 biomimics the vanadium bromoperoxidase (VBPO) enzyme and catalyses the oxidative bromination of substrates in water at 25 °C. Remarkably, 2 also catalyses the oxidative bromination of phenol derivatives under similar reaction conditions with very high turnover frequency (TOF) values (ca. 29 s−1) along with its recyclability. It was found that 2 showed superior catalytic performance as compared to 1 because of its electron deficient nature due to electron withdrawing bromo substituents and robust saddle shaped nonplanar structure (further supported by DFT studies).
Conjugated Bis‐Guanidines (CBGs) as β‐Diketimine Analogues: Synthesis, Characterization of CBGs/Their Lithium Salts and CBG Li Catalyzed Addition of B−H and TMSCN to Carbonyls
Authors: Peddarao Thota , Baishya Ashim , Sarkar Nabin , Acharya Rudresh , Nembenna Sharanappa 
Published: April 2021

AbstractHerein, we report a range of conjugated bis‐guanidines (CBGs) L [L={(ArHN)(ArHN)C=N−C=(NAr)(NHAr)}; Ar=2, 6‐Me2 ‐ C6H3, (1), 2, 4, 6‐Me3−C6H2, (2), 2, 6‐Et2−C6H3, (3), 2, 6‐iPr2−C6H3, (4)]. These compounds can be easily accessed by the reaction between N,N′‐diaryl carbodiimide, and aq. ammonia in acetonitrile. Deprotonation of 1 with n‐BuLi in a 1 : 1 ratio in THF resulted in the formation of four coordinate lithium complex, [1Li ⋅ (THF)2] (5), while at the same reaction conditions, ligands 3 and 4 gave three coordinate lithium complexes, [3Li⋅THF] (6) and [4Li⋅THF] (7), respectively. However, both compounds 1 and 4 upon deprotonation with n‐BuLi in diethyl ether allowed [1Li⋅Et2O] (8) and [4Li⋅Et2O] (9), respectively, while compounds 1 and 3 in toluene afforded un‐solvated lithium complexes [1Li] (10) and [3Li] (11), respectively. Significantly, a reaction between compound 4 and n‐BuLi in a 1 : 1 ratio in toluene yielded sandwich lithium complex [4Li] (12). All new CBGs 1–4 and lithium salts of CBG, 5, 8, and 12 were characterized by single‐crystal X‐ray structural analysis. The compounds 5–12 were characterized by multinuclear magnetic resonance spectroscopy. Moreover, we have investigated the catalytic application of lithium salts of CBGs for the addition of B−H and TMSCN to carbonyls.
Synthesis and Characterization of Poly‐NHC‐Derived Silver(I) Assemblies and Their Transformation into Poly‐Imidazolium Macrocycles
Authors: Gutiérrez‐Blanco Ana , Dobbe Christian , Hepp Alexander , Daniliuc Constantin G. , Poyatos Macarena , Hahn F. Ekkehardt , Peris Eduardo 
Published: April 2021

AbstractThree metallosupramolecular assemblies composed of two bis‐NHCs and two silver atoms, [4](PF6)2, two tetra‐NHCs and four silver atoms, [7](PF6)4, and two tri‐NHCs and three silver atoms [8](BF4)3, have been prepared. Assemblies [4](PF6)2 and [7](PF6)4 feature NHC ligands decorated with terminal olefin groups. Irradiation of [4](PF6)2 yielded complex [5](PF6)2 with two terminal cyclobutane rings linking the two bis‐NHC ligands. Liberation of the macrocyclic tetrakisimidazolium salt H4‐6(PF6)4 was achieved by reaction of [5](PF6)2 with NH4Cl/NH4PF6. No [2+2] cycloaddition was observed upon irradiation of [7](PF6)4, apparently due to an unfavorable orientation of the olefin groups. Irradiation of complex [8](BF4)3 with three internal pairs of olefin groups leads to [9](BF4)3 as a mixture of two isomers that differ on the relative orientation of the internal cyclobutane rings. Reaction of [9](BF4)3 with NH4Cl/NH4BF4 yields an isomer mixture of the novel cage‐line hexakisimidazolium salt H6‐10(BF4)6.
A Conformer‐Dependent, Quantitative Quadrant Model
Authors: Zahrt Andrew F. , Rinehart N. Ian , Denmark Scott E. 
Published: April 2021

AbstractThis study reports the development and application of a conformer‐dependent quantitative quadrant descriptor for generating models that relate catalyst performance to catalyst structure in enantioselective transformations. The generality of these descriptors is demonstrated by using them for three different reactions: (1) copper‐catalyzed, enantioselective cyclopropanation of alkenes, (2) rhodium‐catalyzed enantioselective hydrogenation ofα‐substitutedN‐acyl‐enamides, and (3) enantioselective addition of thiols toN‐acyl imines. This work will provide researchers an interpretable steric descriptor that merges the heuristic value of quadrant models with a quantitative tool that can be used to create statistically meaningful correlations between the steric occupancy of catalyst quadrants and stereoselectivity. The low dimensionality of this descriptor, its ability to capture conformational effects and stereostructure, and its direct relationship to intuitive structural properties make it particularly well‐suited for creating Quantitative Structure‐Selectivity Relationships (QSSR) with smaller datasets of asymmetric reactions.