bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Eight‐Membered Nitrogen Heterocycles via a Heterogeneous PtI2‐Catalyzed Cascade Cycloaddition Reaction of δ‐Aminoalkynes with Electron‐Deficient Alkynes
Authors: Li Xinhong , Wang Songmeng , Wang Hongkai , Wang Weilin , Liu Lingyan , Chang Weixing , Li Jing 
Published: February 2020

AbstractA novel heterogeneous PtI2‐catalyzed cascade reaction of δ‐aminoalkynes was developed for the synthesis of various eight‐membered nitrogen heterocycles in excellent yields. The reaction proceeds via a hydration of δ‐aminoalkynes and subsequent intramolecular cyclization and intermolecular addition as well as ring‐expansion cascade reaction with another electron‐deficient alkynes. This method has the advantages of simple operation and mild reaction conditions. And the simple PtI2 with no any supports could be readily recycled through simple centrifugation without substantial loss of activity in 1,2‐dichloroethane (DCE). The recyclability of PtI2 may be ascribed to its insolubility in DCE. The reaction constitutes a formal [6+2]‐cycloaddition.magnified image
Phosphoramidates as Transient Precursors of Nitrogen‐Centered Radical Under Visible‐Light Irradiation: Application to the Synthesis of Phthalazine Derivatives
Authors: De Abreu Maxime , Selkti Mohamed , Belmont Philippe , Brachet Etienne 
Published: February 2020

AbstractPhosphoramidates are for the first time presented as efficient N‐Centered Radical (NCR) precursors under visible‐light irradiation. More precisely among this class of phosphorus‐derived compounds, we studied the radical reactivity of phosphonohydrazones, under mild reaction conditions, which allowed the synthesis of a wide and diversified library of the scarcely reported phthalazine scaffold. Mechanistic investigations confirmed the formation of a NCR from these brand‐new phosphonohydrazones (derivatived from phosphoramidates), which were further engaged in an intramolecular 6‐exo‐dig cyclization to provide phthalazines. Compared to other pre‐activated moieties, the phosphoramidate group is self‐immolative, thus enhancing its attractiveness for the C−N bond formation.magnified image
DBSA‐Catalyzed Regioselective Dehydrative Friedel‐Crafts Arylation of CF3‐Containing 3‐Indolyl(2‐thiophenyl)methanols with 2‐Substituted Indoles in Water
Authors: An Di , Miao Xinzhu , Ling Xiangxiang , Chen Xianxiao , Rao Weidong 
Published: February 2020

AbstractA green and efficient regioselective dehydrative Friedel‐Crafts arylation of trifluorinated 3‐indolyl(2‐thiophenyl) methanols with 2‐substituted indoles, catalyzed by DBSA (dodecylbenzenesulfonic acid) in water is described. This simple and atom‐economical protocol features a unique regioselective 1,8‐addition, operational simplicity, mild conditions, excellent functional group compatibility, and environmental benignity.magnified image
Nitrogen effect on zinc biofortification of maize and cowpea in Zimbabwean smallholder farms
Authors: Manzeke Muneta G. , Mtambanengwe Florence , Watts Michael J. , Broadley Martin R. , R. Murray Lark , Mapfumo Paul 
Published: February 2020

AbstractAgronomic biofortification of crops with zinc (Zn) can be enhanced under increased nitrogen (N) supply. Here, the effects of N fertilizer on grain Zn concentration of maize (Zea mays L.) and cowpea (Vigna unguiculata L.) were determined at two contrasting sites in Zimbabwe over two seasons. All treatments received soil and foliar zinc‐sulphate fertilizer. Seven N treatments, with three N rates (0, 45, and 90 kg ha−1 for maize; 0, 15, and 30 kg ha−1 for cowpea), two N forms (mineral and organic), and combinations thereof were used for each crop in a randomized complete block design (n = 4). Maize grain Zn concentrations increased from 27.2 to 39.3 mg kg−1 across sites. At 45 kg N ha−1, mineral N fertilizer increased maize grain Zn concentration more than organic N from cattle manure or a combination of mineral and organic N fertilizers. At 90 kg N ha−1, the three N fertilizer application strategies had similar effects on maize grain Zn concentration. Co‐application of N and Zn fertilizer was more effective at increasing Zn concentration in maize grain than Zn fertilizer alone. Increases in cowpea grain Zn concentration were less consistent, although grain Zn concentration increased from 39.8 to 52.7 mg kg−1 under optimal co‐applications of N and Zn. Future cost/benefit analyses of agronomic biofortification need to include information on benefits of agro‐fortified grain, complex farmer management decisions (including cost and access to both N and Zn fertilizers), as well as understanding of the spatial and site‐specific variation in fertilizer responses.
“Anytime, anyplace, anywhere”—A sample selection model of mobile internet adoption in german agriculture
Authors: Michels Marius , Fecke Wilm , Feil Jan‐Henning , Musshoff Oliver , Lülfs‐Baden Frederike , Krone Saskia 
Published: February 2020

AbstractMobile internet is considered one of the most important developments in information and communication technology due to its considerable effect on both the economy and our daily lives. Furthermore, mobile internet is an essential tool for overcoming the rural–urban digital divide. With respect to agriculture, mobile internet can play a central role in information gathering as well as the implementation of precision and smart farming technologies. Yet, no study has identified the determinants of mobile internet adoption in agriculture. Using a bivariate probit model with a sample selection and a representative data set from 815 German farmers, this study showed that, among other characteristics, the age of the farmer, farm size and location, as well as familiarity with internet risks is associated with mobile internet adoption in agriculture. These results may be of interest to policy makers, who deal with internet infrastructure, and providers of farm equipment that rely on mobile internet connection. [EconLit citations: Q16].
Microfluidic synthesis of ultrasmall Co nanoparticles over reduced graphene oxide and their catalytic properties
Authors: Yang Mei , Luo Lamei , Chen Guangwen 
Published: February 2020

AbstractWe prepared a one‐stage microfluidic‐based method for continuous synthesis of cobalt (Co) nanoparticles over reduced graphene oxide (rGO) to produce Co/rGO composites. These were generated by the coreduction of Co2+ ions and GO with NaBH4 which was confined within discrete aqueous plugs segmented by octane as continuous phase. Owing to the excellent transfer properties from recirculation in these plugs, ultrasmall Co nanoparticles were distributed homogeneously on the GO sheets without using any surfactants. As compared to batch methods, the average size of Co nanoparticles and the relative standard deviation decreased from 4.0 ± 1.42 nm and 35.9% to 2.0 ± 0.45 nm and 22.6%, respectively. The as‐prepared Co/rGO composites exhibited superior activity towards the catalytic reduction of p‐nitrophenol to p‐aminophenol with NaBH4 compared with Co nanoparticles and rGO; this enhanced activity could be attributed to the synergistic effect between Co nanoparticles and rGO.
Hydrodynamic forces on monodisperse assemblies of axisymmetric elongated particles: Orientation and voidage effects
Authors: Sanjeevi Sathish K. P. , Padding Johan T. 
Published: February 2020

AbstractWe investigate the average drag, lift, and torque on static assemblies of capsule‐like particles of aspect ratio 4. The performed simulations are from Stokes flow to high Reynolds numbers (0.1 ≤ Re ≤ 1,000) at different solids volume fraction (0.1 ≤ ɛs ≤ 0.5). Individual particle forces as a function of the incident angle ϕ with respect to the average flow are scattered. However, the average particle force as a function of ϕ is found to be independent of mutual particle orientations for all but the highest volume fractions. On average, a sine‐squared scaling of drag and sine‐cosine scaling of lift holds for static multiparticle systems of elongated particles. For a packed bed, our findings can be utilized to compute the pressure drop with knowledge of the particle‐orientation distribution, and the average particle drag at ϕ = 0° and 90°. We propose closures for average forces to be used in Euler–Lagrange simulations of particles of aspect ratio 4.
Synthesis of Disulfide Surrogate Peptides Incorporating Large‐Span Surrogate Bridges Through a Native‐Chemical‐Ligation‐Assisted Diaminodiacid Strategy
Authors: Qu Qian , Gao Shuai , Wu Fangming , Zhang Meng‐Ge , Li Ying , Zhang Long‐Hua , Bierer Donald , Tian Chang‐Lin , Zheng Ji‐Shen , Liu Lei 
Published: February 2020

AbstractThe use of synthetic bridges as surrogates for disulfide bonds has emerged as a practical strategy to obviate the poor stability of some disulfide‐containing peptides. However, peptides incorporating large‐span synthetic bridges are still beyond the reach of existing methods. Herein, we report a native chemical ligation (NCL)‐assisted diaminodiacid (DADA) strategy that enables the robust generation of disulfide surrogate peptides incorporating surrogate bridges up to 50 amino acids in length. This strategy provides access to some highly desirable but otherwise impossible‐to‐obtain disulfide surrogates of bioactive peptide. The bioactivities and structures of the synthetic disulfide surrogates were verified by voltage clamp assays, NMR, and X‐ray crystallography; and stability studies established that the disulfide replacements effectively overcame the problems of disulfide reduction and scrambling that often plague these pharmacologically important peptides.
Synthesis of Poly(acyclic orthoester)s: Acid‐Sensitive Biomaterials for Enhancing Immune Responses of Protein Vaccine
Authors: Xing Yumeng , Xu Zunkai , Liu Tao , Shi Linqi , Kohane Daniel , Guo Shutao 
Published: February 2020

AbstractWhile poly(acyclic orthoester)s (PAOEs) have many appealing features for drug delivery, their application is significantly hindered by a lack of facile synthetic methods. Reported here is a simple method for synthesizing acyclic diketene acetal monomers from diols and vinyl ether, and their polymerization with a diol to first synthesize PAOEs. The PAOEs rapidly hydrolyze at lysosomal pH. With the help of a cationic lipid, ovalbumin, a model vaccine antigen was efficiently loaded into PAOEs nanoparticles using a double emulsion method. These nanoparticles efficiently delivered ovalbumin into the cytosol of dendritic cells and demonstrated enhanced antigen presentation over poly(lactic‐co‐glycolic acid) (PLGA) nanoparticles. PAOEs are promising vehicles for intracellular delivery of biopharmaceuticals and could increase the utility of poly(orthoesters) in biomedical research.
Water‐Insensitive Synthesis of Poly‐β‐Peptides with Defined Architecture
Authors: Zhou Min , Xiao Ximian , Cong Zihao , Wu Yueming , Zhang Wenjing , Ma Pengcheng , Chen Sheng , Zhang Haodong , Zhang Danfeng , Zhang Donghui , Luan Xiangfeng , Mai Yiyong , Liu Runhui 
Published: February 2020

AbstractBiocompatible and proteolysis‐resistant poly‐β‐peptides have broad applications and are dominantly synthesized via the harsh and water‐sensitive ring‐opening polymerization of β‐lactams in a glovebox or using a Schlenk line, catalyzed by the strong base LiN(SiMe3)2. We have developed a controllable and water‐insensitive ring‐opening polymerization of β‐amino acid N‐thiocarboxyanhydrides (β‐NTAs) that can be operated in open vessels to prepare poly‐β‐peptides in high yields, with diverse functional groups, variable chain length, narrow dispersity and defined architecture. These merits imply wide applications of β‐NTA polymerization and resulting poly‐β‐peptides, which is validated by the finding of a HDP‐mimicking poly‐β‐peptide with potent antimicrobial activities. The living β‐NTA polymerization enables the controllable synthesis of random, block copolymers and easy tuning of both terminal groups of polypeptides, which facilitated the unravelling of the antibacterial mechanism using the fluorophore‐labelled poly‐β‐peptide.
Water‐Soluble Non‐Classical Benzene Mimetics
Authors: Levterov Vadym V. , Panasyuk Yaroslav , Pivnytska Valentyna O. , Mykhailiuk Pavel K. 
Published: February 2020

AbstractA new generation of saturated benzene mimetics, 2‐oxabicyclo[2.1.1]hexanes, was developed. These compounds were designed as analogues of bicyclo[1.1.1]pentane with an improved water solubility. Crystallographic analysis of 2‐oxabicyclo[2.1.1]hexanes revealed that they occupy a novel chemical space, but, at the same time, resemble the motif of meta‐disubstituted benzenes.
Low‐temperature fast curable behavior and properties of bio‐based carbon fiber composites based on resveratrol
Authors: Guo Zongwei , Zhang Mengjie , Zhang Yuansi , Liu Liu , Li Ming , Shang Lei , Ao Yuhui 
Published: February 2020

AbstractEnvironmentally friendly materials are an integral part of sustainable chemistry, and bio‐based polymer composites are an important class of materials. The manufacture of composites is expected to reduce or even eliminate the use of adjuvants, considering the importance of reducing energy consumption and avoiding health and environmental risks. In this study, a phenyl‐containing, polyfunctional, bio‐based epoxy resin (TGER) was synthesized, and carbon fiber‐reinforced, bio‐based epoxy resin composites were fabricated by vacuum‐assisted resin infusion using two aromatic amine curing agents, 4,4′‐diaminodiphenylmethane (DDM) and 3,3′‐diethyl‐4,4′‐diaminodiphenylmethane (DEDDM). Curing reactions and rheological behavior studies showed that TGER had higher curing reactivity toward DDM and DEDDM than to diglycidyl ether of bisphenol A (DGEBA) and possessed good processability. The results indicated that the resveratrol‐based epoxy resin displayed low‐temperature fast curing properties. The evaluation of the mechanical properties of the carbon fiber composites showed that the flexural strengths of CF/TGER/DDM and CF/TGER/DEDDM were 520 and 628 MPa, respectively. The initial decomposition temperature of CF/TGER composites is above 200°C. Furthermore, the carbon fiber–reinforced biopolymers possess excellent heat resistance. Therefore, carbon fiber‐reinforced, resveratrol‐based epoxy resin composites are promising candidates as alternatives to petroleum‐based high‐performance carbon fiber composites.
Heat‐responsive shape memory Eucommia ulmoides gum composites reinforced by zinc dimethacrylate
Authors: Kang Hailan , Xu Mingze , Wang Haoyu , Li Long , Li Jiaxi , Fang Qinghong , Zhang Jichuan 
Published: February 2020

AbstractWith the renewability, functionality, and biocompatibility of Eucommia ulmoides gum (EUG), shape memory polymers fabricated from EUG present the potential application in biomedical devices and sensors. In this study, heat‐responsive shape memory composites were developed and reinforced by zinc dimethacrylate (ZDMA). ZDMA particles were in situ polymerized and uniformly dispersed in the EUG, showing strong interfacial interactions with EUG. The obviously improved tensile strength and storage modulus in the elastic state are attributed to the reinforcement of poly‐ZDMA particles. The switching temperature of EUG/ZDMA composites changed from 50 to 29°C through altering the dicumyl peroxide and ZDMA loading. The EUG/ZDMA composites exhibited high shape fixity of 95% and shape recovery of 90%, which favors theirs biomedical applications.
A Porous and Stable Porphyrin Metal‐Organic Framework as an Efficient Catalyst towards Visible‐Light‐Mediated Aerobic Cross‐Dehydrogenative‐Coupling Reactions
Authors: Liu Jiewei , Zhang Kun , Chen Zhiyao , Wei Zhang‐Wen , Zhang Li 
Published: February 2020

AbstractPorphyrin metal‐organic frameworks (PMOFs) are emerging as heterogeneous photocatalysts owing to the well‐designed frameworks incorporated with powerful light‐harvesting porphyrin chromophores. The porous and stable framework Ir−PCN‐224 (which is also denoted as Ir−PMOF‐1), which has been prepared by the self‐assembly of Ir(TCPP)Cl (TCPP=tetrakis(4‐carboxyphenyl)porphyrin) and ZrCl4, is reported herein to be efficient for the aerobic cross‐dehydrogenative carbon−phosphorus coupling reaction, giving rise to a high turn‐over number (TON) of up to 17200 under visible light irradiation (λ≥420 nm). Electron paramagnetic resonance (EPR) experiments disclose that the active species might be the superoxide radical anion (O2.−). Additionally, the intermediate imine cation has been detected by high‐resolution mass spectrometry (HRMS).
A new approach for affinity‐based purification of horseradish peroxidase
Authors: Almaz Zuleyha , Oztekin Aykut , Abul Nurgul , Gerni Serpil , Erel Deniz , Kocak Seyma Mehtap , Sengül Mehmet Emin , Ozdemir Hasan 
Published: February 2020

AbstractWe have developed efficient procedure for isolation of horseradish peroxidase (HRP) using aminobenzohydrazide‐based affinity chromatography. Sepharose 4B‐bounded aminobenzohydrazides are suitable for long‐term use and large‐scale purification. In this study, 26 aminobenzohydrazide derivatives were synthesized, characterized and defined as new HRP inhibitors. In addition, detailed inhibition effects of these molecules on HRP enzyme were investigated. Affinity matrix was formed by bonding aminobenzohydrazides, which exhibited inhibitory activity to sepharose‐4B‐l‐tyrosine. HRP was isolated from crude homogenate in single step and purification factors were recorded as 1,151‐fold (recovery of 8.5%) with 4‐amino 3‐bromo benzohydrazide and as 166.16‐fold (recovery of 16.67 %) with 3‐amino 4‐chloro benzohydrazide.
Formulation of a pH‐sensitive cancer cell‐targeted gene delivery system based on folate–chitosan conjugated nanoparticles
Authors: Mohammadzadeh Reza , Shahim Parinaz , Akbari Ali 
Published: February 2020

AbstractIn this study, we investigated the design and construct of a chitosan (CA)‐based targeted gene delivery system and evaluated its function. To this end, CA–folic acid/pDNA (CA–FA/pDNA) nanoparticles were prepared in different formulations using the ion gelation method. All the synthesized nanoparticles were characterized using FTIR, TEM, SEM and DLS. Moreover, the effects of molecular weight (MW) of CA, DNA, and CA concentration were inspected on encapsulation efficiency (EE). The results showed that the EE of pDNA was directly proportional with MW of CA and CA concentration but was in an inverse proportion with DNA concentration. In addition, high MW of CA and low MW of CA nanoparticles showed lower and higher pDNA release in all pH ranges, respectively. It is concluded that the N/P ratio increase can cause controlled pDNA release.
Reading and writing for well‐being: A qualitative exploration of the therapeutic experience of older adult participants in a bibliotherapy and creative writing group
Authors: Malyn Brianna O. , Thomas Zoe , Ramsey‐Wade Christine E. 
Published: February 2020

AbstractThis study provides a qualitative exploration of the therapeutic mechanisms occurring within three community‐based reading and writing for well‐being groups attended by older adults, located in a city in England. Whilst it is increasingly accepted that community‐based participatory arts programmes can contribute to health and well‐being (Clift, 2012), research in this area has tended to focus on the visual and performing arts, with less attention given to literary interventions. This study aims to develop a deeper understanding of the therapeutic mechanisms occurring within these groups which facilitate well‐being, with the objectives of (a) enhancing practitioners' ability to effectively implement such interventions and (b) contributing to the development of a strong theoretical base from which such interventions can be meaningfully evaluated. Twelve individual, semi‐structured interviews were conducted for this study and analysed using thematic analysis, following the guidelines of Braun and Clarke (2006). Four overarching themes were developed through the analysis. These are expressed through a relational framework as follows: ‘Relationship to self’, ‘Relationship with others’, ‘Relationship with facilitator’ and ‘An intermediary object’. It is concluded that community‐based bibliotherapy and therapeutic creative writing groups support well‐being in older adults by providing a unique space in which participants feel acknowledged, accepted, challenged and inspired. Future research should focus on the efficacy of the intervention for reducing social isolation and loneliness. Practice implications for traditional group and individual therapies are also discussed.
SCAI publications committee manual of standard operating procedures
Authors: Szerlip Molly , Feldman Dmitriy N. , Aronow Herbert D. , Blankenship James C. , Choi James W. , Elgendy Islam Y. , Elmariah Sammy , Garcia Santiago , Goldstein Bryan H. , Herrmann Howard , Hira Ravi S. , Jaff Michael R. , Kalra Ankur , Kaluski Edo , Kavinsky Clifford J. , Kolansky Daniel M. , Kong David F. , Messenger John C. , Mukherjee Debabrata , Patel Rajan A. G. , Piana Robert , Senerth Emily , Shishehbor Mehdi , Singh Gagan , Singh Vikas , Yadav Pradeep K. , Cox David 
Published: February 2020

AbstractEvidence‐based recommendations for clinical practice are intended to help health care providers and patients make decisions, minimize inappropriate practice variation, promote effective resource use, improve clinical outcomes, and direct future research. The Society for Cardiovascular Angiography and Interventions (SCAI) has been engaged in the creation and dissemination of clinical guidance documents since the 1990s. These documents are a cornerstone of the society's education, advocacy, and quality improvement initiatives. The publications committee is charged with oversight of SCAI's clinical documents program and has created this manual of standard operating procedures to ensure consistency, methodological rigor, and transparency in the development and endorsement of the society's documents. The manual is intended for use by the publications committee, document writing groups, external collaborators, SCAI representatives, peer reviewers, and anyone seeking information about the SCAI documents program.
Langerhans cell histiocytosis: A case report with oral manifestations and the role of pediatric dentists in the diagnosis
Authors: Hammouri Eman Hussein , Sweidan Hala Antoun , AShokaibi Omar , Al Omari Leen 
Published: February 2020

AbstractLangerhans cell histiocytosis (LCH) is a benign disease that behaves malignantly. Early recognition and treatment of oral manifestation of LCH by pediatric dentist and other medical specialties is important to prevent further organ damage.
Huge fetal ovarian cyst
Authors: Wang Liangcheng , Shimizu Emi , Ikeda Taro , Ishiguro Aya , Irie Yuko , Ko Hiroyoshi , Horiuchi Isao , Chikazawa Kenro , Imai Ken , Kuwata Tomoyuki , Takagi Kenjiro 
Published: February 2020

AbstractMost fetal ovarian cysts increase in size during the late stages of pregnancy. Early treatment of a huge neonatal cyst may reduce the risk of gastrointestinal obstruction.
Pembrolizumab‐axitinib‐induced tumor lysis syndrome in a patient with metastatic renal cancer
Authors: Shah Manan , Jain Sanjay , Abe Temidayo , Surapaneni Phani Keerthi , Bhatia Kapil 
Published: February 2020

AbstractTumor lysis syndrome is uncommon in solid tumors but with the use of immunotherapy (checkpoint inhibitors) their incidence is increasing. Physicians need to take adequate precautions while treating patients with immunotherapy. The findings of our case report will help improve our current understanding of tumor lysis syndrome specially in solid tumors and will help in developing multidisciplinary treatment and prophylaxis strategies for this uncommon, but potentially fatal complication.
A case of stercoral colitis with marked elevation of serum carcinoembryonic antigen
Authors: Takehara Kiyoto , Takehara Yuko , Ueyama Satoshi , Kobayashi Tatsunori 
Published: February 2020

AbstractIt should be noted that the serum CEA level can become elevated in severe stercoral colitis. Marked elevation of the serum CEA level in stercoral colitis may suggest the necessity of surgery in patients with stercoral colitis.