bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stereoselective Synthesis of Tropanes via a 6π‐Electrocyclic Ring‐Opening/ Huisgen [3+2]‐Cycloaddition Cascade of Monocyclopropanated Heterocycles
Authors: Sonnleitner Carina M. , Park Saerom , Eckl Robert , Ertl Thomas , Reiser Oliver 
Published: July 2020

AbstractThe synthesis of tropanes via a microwave‐assisted, stereoselective 6π‐electrocyclic ring‐opening/ Huisgen [3+2]‐cycloaddition cascade of cyclopropanated pyrrole and furan derivatives with electron‐deficient dipolarophiles is demonstrated. Starting from furans or pyrroles, 8‐aza‐ and 8‐oxabicyclo[3.2.1]octanes are accessible in two steps in dia‐ and enantioselective pure form, being versatile building blocks for the synthesis of pharmaceutically relevant targets, especially for new cocaine analogues bearing various substituents at the C‐6/C‐7 positions of the tropane ring system. Moreover, the 2‐azabicyclo[2.2.2]octane core (isoquinuclidines), being prominently represented in many natural and pharmaceutical products, is accessible via this approach.
Heterogeneous Electrofreezing of Super‐Cooled Water on Surfaces of Pyroelectric Crystals is Triggered by Trigonal Planar Ions
Authors: Curland Sofia , Allolio Christoph , Javitt Leah , Dishon Ben‐Ami Shiri , Weissbuch Isabelle , Ehre David , Harries Daniel , Lahav Meir , Lubomirsky Igor 
Published: July 2020

AbstractElectrofreezing experiments of super‐cooled water (SCW) with different ions, performed directly on the charged hemihedral faces of pyroelectric LiTaO3 and AgI crystals, in the presence and in the absence of pyroelectric charge are reported. It is demonstrated that bicarbonate (HCO3−) ions elevate the icing temperature near the positively charged faces. In contrast, the hydronium (H3O+) slightly reduces the icing temperature. Molecular dynamics simulations suggest that the hydrated trigonal planar HCO3− ions self‐assemble with water molecules near the surface of the AgI crystal as clusters of slightly different configuration from those of the ice‐like hexagons. These clusters, however, have a tendency to serve as embryonic nuclei for ice crystallization. Consequently, we predicted and experimentally confirmed that the trigonal planar ions of NO3− and guanidinium (Gdm+), at appropriate concentrations, elevate the icing temperature near the positive and negative charged surfaces, respectively. On the other hand, the Cl− and SO42− ions of different configurations reduce the icing temperature.
Discovery of 2,4‐diaminopyrimidine derivatives targeting p21‐activated kinase 4: Biological evaluation and docking studies
Authors: Qin Qiaohua , Wu Tianxiao , Yin Wenbo , Sun Yixiang , Zhang Xiangyu , Wang Ruifeng , Guo Jing , Zhao Dongmei , Cheng Maosheng 
Published: July 2020

AbstractIn this study, novel 2,4‐diaminopyrimidine derivatives targeting p21‐activated kinase 4 (PAK4) were discovered and evaluated for their biological activity against PAK4. Among the derivatives studied, promising compounds A2, B6, and B8 displayed the highest inhibitory activities against PAK4 (IC50 = 18.4, 5.9, and 20.4 nM, respectively). From the cellular assay, compound B6 exhibited the highest potency with an IC50 value of 2.533 μM against A549 cells. Some compounds were selected for computational ADME (absorption, distribution, metabolism, and elimination) properties and molecular docking studies against PAK4. The detailed structure–activity relationship based on the biochemical activities and molecular docking studies were explored. According to the docking studies, compound B6 had the lowest docking score (docking energy: −7.593 kcal/mol). The molecular docking simulation indicated the binding mode between compound B6 and PAK4. All these results suggest compound B6 as a useful candidate for the development of a PAK4 inhibitor.
Exosome–transmitted microRNA‐133b inhibited bladder cancer proliferation by upregulating dual‐specificity protein phosphatase 1
Authors: Cai Xiaoxiao , Qu Lili , Yang Jian , Xu Junwen , Sun Li , Wei Xiaowei , Qu Xiaojun , Bai Tingting , Guo Zhirui , Zhu Yefei 
Published: July 2020

AbstractBladder Cancer (BC) is the ninth most common tumor in the world and one of the most common malignant tumors of the urinary system. Some studies reported that miR‐133b expression is reduced in BC, but whether it plays a role in the development of BC and its mechanism is unclear. microRNAs can be packaged into exosomes to mediate communication between tumor cells, affecting their proliferation and apoptosis. The objective of this study was to investigate the effect of exosomal miR‐133b on BC proliferation and its molecular mechanism. Firstly, the expression of miR‐133b was evaluated in BC and adjacent normal tissues, as well as in serum exosomes of BC patients and healthy controls. Then the delivery and internalization of exosomes in cells was observed through fluorescence localization. Cell viability and apoptosis were assessed in BC cells transfected with mimics and incubated with exosomes. The role of exosomal miR‐133b was also analyzed in nude mice transplant tumors. Furthermore, the target gene of miR‐133b was predicted through bioinformatics. The level of miR‐133b was significantly decreased in BC tissues and in exosomes from serum of patients, which was correlated with poor overall survival in TCGA. Exosomal miR‐133b could be obtained using BC cells after transfection with miR‐133b mimics. The miR‐133b expression increased after incubation with exosomal miR‐133b, which lead to the inhibition of viability and increase of apoptosis in BC cells. Exosomal miR‐133b could suppress tumor growth in vivo. In addition, we found that exosomal miR‐133b may play a role in suppressing BC proliferation by upregulating dual‐specificity protein phosphatase 1 (DUSP1). These findings may offer promise for new therapeutic directions of BC.
Diagnostic performance of various liquid biopsy methods in detecting colorectal cancer: A meta‐analysis
Authors: Zhu Yuzhou , Yang Tinghan , Wu Qingbin , Yang Xuyang , Hao Jianqi , Deng Xiangbing , Yang Shuo , Gu Chaoyang , Wang Ziqiang 
Published: July 2020

AbstractLiquid biopsy is a promising method in detecting colorectal cancer (CRC). However, previous meta‐analyses only focused on the diagnostic performance of cell‐free DNA (cfDNA). Therefore, we firstly evaluated the overall performance of all liquid biopsy methods. The pooled sensitivities, specificities, diagnostic odds ratios, and area under curve (AUC) of summary receiver operating characteristic curve for all liquid biopsy methods, exosomes, circulating tumor cells (CTCs), and cfDNA were calculated, respectively. A total of 62 articles involving 18 739 individuals were included. Fifty‐one articles were about cfDNA, five articles were about CTCs, and six articles were about exosomes. The overall performance of all liquid biopsy methods had a pooled sensitivity, specificity, and AUC of 0.77 (95% confidence interval [CI] 0.76‐0.78), 0.89 (95% CI 0.88‐0.90), and 0.9004, respectively. The sensitivities were 0.82 (95% CI 0.79‐0.85), 0.76 (95% CI 0.72‐0.80), and 0.76 (95% CI 0.75‐0.77) for CTCs, exosomes, and cfDNA, respectively. The specificities were 0.97 (95% CI95% CI 0.95‐0.99), 0.92 (95% CI 0.89‐0.94), and 0.88 (95% CI 0.87‐0.89) for CTCs, exosomes, and cfDNA, respectively. The AUC were 0.9772, 0.9037, and 0.8963 for CTCs, exosomes, and cfDNA, respectively. The overall performance of all liquid biopsy methods had great diagnostic value in detecting CRC, regardless of subtypes. Among all liquid biopsy methods, CTCs showed the best diagnostic performance.
Birth month and risk of skin tumors—Follow up of six million Caucasians born from 1950 to 2014 in Sweden
Authors: Ljung Rickard , Talbäck Mats , Khanolkar Amal R. , Feychting Maria 
Published: July 2020

AbstractBackgroundSome studies hypothesize that birth month—as a proxy of exposure to ultraviolet radiation in early infancy—is associated with increased risk of skin tumors.MethodsWe studied a national cohort of all 5 874 607 individuals born in Sweden to parents of Swedish or Nordic origin as a proxy for Caucasian origin, 1950 to 2014. The cohort was followed for incident skin tumors, including squamous cell carcinomas and melanomas but not basal cell carcinomas, through 2015 from birth up to age 65 for the oldest cohort. Cox regression estimated the association between month of birth and risk of skin tumors in models adjusted for sex, calendar period, and education. Crude observed to expected ratios were also calculated.ResultsThere were 33 914 cases of skin tumors, of these, 3025 were squamous cell cancer, 16 968 malignant melanoma and 8493 melanoma in situ/other and 5 428 squamous cell in situ/other in 192 840 593 person‐years of follow‐up. Observed to expected ratios by month of birth showed no association between month of birth and risk of skin tumors, and the same result was seen when Cox regression analysis was used. Subgroup analyses by sex, educational level, calendar period, or age at follow‐up similarly showed no association.ConclusionThis large register‐based cohort study showed no evidence of a higher risk of skin tumors in those born during the spring. Thus, this study lends no support to the hypothesis that birth during spring is a major risk factor for later skin tumors.
What issues bring primary school children to counselling? A service evaluation of presenting issues across 291 schools working with Place2Be
Authors: Toth Katalin , Samad Lamiya , Golden Sarah , Johnston Patrick , Hayes Rachel , Ford Tamsin 
Published: July 2020

AbstractBackgroundPoor mental health reduces children's ability to function at school, which in turn may undermine their mental health. The provision of school‐based counselling aims to help schools to support their pupil's mental health. Most work on the types of difficulties brought to school counsellors has focused on secondary school pupils (aged 11 years or over), and to our knowledge, this is the first study of presenting issues in younger children.MethodData were systematically collected using a list of 21 potential presenting issues during assessment and formulation of 8,893 children referred for counselling in 291 UK primary schools over 3 years. We explored the number, severity and types of presenting issues recorded by counsellors in the whole sample by gender.ResultsThe children assessed by counsellors had higher levels of known correlates for poor mental health than their peers in the same schools. Most children had multiple presenting issues, while 55% of children had at least one severe presenting issue. The commonest presenting issues were generalised anxiety, low self‐esteem, family tensions and mood swings. Girls were more likely to present with all types of anxiety and family tensions, while attentional problems and mood swings were commoner among boys.ConclusionsChildren referred for counselling in primary schools often present with multiple difficulties, which are often severe. This indicates the need for systematic and detailed assessment, adequate training and supervision and good links with external agencies.
Chemical Composition, Antioxidant Potential and Enzymes Inhibitory Properties of Globe Artichoke By‐Products
Authors: Rejeb Ines Ben , Dhen Nahla , Gargouri Mohamed , Boulila Abdennacer 
Published: July 2020

AbstractIn this study, chemical composition and in vitro biological activities of artichoke by‐products (leaves, floral stems and bracts) issued from two Tunisian varieties were evaluated. Analysis was performed by means of high‐performance liquid chromatography with diode array detection coupled to electrospray ionization mass spectrometric (LC/DAD/ESI‐MS). Total phenolic (TPC) and flavonoid (TFC) contents as well as the antioxidant activity conducted by three complementary methods, DPPH, ABTS and FRAP tests, were performed for each sample. Enzyme inhibitory effects against acetylcholinesterase, butyrylcholinesterase and α‐amylase were also studied. Results showed that TPC and TFC varied according to variety as well as the plant part. Bracts presented the highest TPC values (10–15 mg GAE/g DW), while leaves were distinguished by the highest TFC values (52–58 mg EQ/g DW). In vitro assays showed that Violet d'Hyères bracts and Blanc d'Oran leaves present the most antioxidant activities (30.040 and 20.428 mgET/gDW, respectively, by the DPPH method). Leaves demonstrated the highest acetylcholinesterase and butyrylcholinesterase inhibitory effects. Moreover, all organs displayed a noticeable inhibition towards α‐amylase. LC/DAD/MS analysis revealed that artichoke by‐products are a potential source of biopharmaceuticals such as luteolin derivatives from leaves and mono/dicaffeoylquinic acids in the other parts. This research demonstrates that globe artichoke by‐products, unexploited in our country, are a promising source of natural health promoting compounds with potential applications in the food and pharmaceutical industries.
Radiolytic Cyclization Products of Phloridzin as Potent Anti‐Glycation Agents
Authors: Jeong Gyeong Han , Kim Tae Hoon 
Published: July 2020

AbstractThe current research examined for radiolytic structure modification and improved bioefficacy of phloridzin by γ‐ray, subsequent to a 50 kGy irradiation dose. Structures of the unusual degraded products phlorocyclin, isophlorocyclin, and radiophlorisin were determined spectroscopically, by detailed nuclear magnetic resonance (NMR) and mass spectrometry (MS). Additionally, absolute configuration of the novel cyclized phlorocyclin and isophlorocyclin were proposed by circular dichroism (CD) spectrum analysis. Among the compounds tested, phlorocyclin and isophlorocyclin exhibit potent antidiabetic complication capacities toward advanced glycation end products (AGEs) formation inhibition assay, with IC50 values of 9.1±0.5 and 13.8±0.7 μM, respectively. Furthermore, the predominantly formed products phlorocyclin and isophlorocyclin exerted significantly enhanced DPPH radical scavenging activity compared to the parent phloridzin. These results indicate that γ‐ray mediated cyclization of phloridzin exerts a positive influence on the bioactivity.
Perfluorocarbons in Chemical Biology
Authors: Miller Margeaux A. , Sletten Ellen M. 
Published: July 2020

AbstractPerfluorocarbons, saturated carbon chains in which all the hydrogen atoms are replaced with fluorine, form a separate phase from both organic and aqueous solutions. Though perfluorinated compounds are not found in living systems, they can be used to modify biomolecules to confer orthogonal behavior within natural systems, such as improved stability, engineered assembly, and cell‐permeability. Perfluorinated groups also provide handles for purification, mass spectrometry, and 19F NMR studies in complex environments. Herein, we describe how the unique properties of perfluorocarbons have been employed to understand and manipulate biological systems.
Decoupling Oxygen and Chlorine Evolution Reactions in Seawater using Iridium‐based Electrocatalysts
Authors: Ko Jesse S. , Johnson James K. , Johnson Phillip I. , Xia Zhiyong 
Published: July 2020

AbstractA series of iridium (Ir) organometallic‐based electrocatalysts fused onto high surface‐area activated carbon using pyrolysis were prepared for the oxygen evolution reaction (OER) in seawater electrolysis. These catalysts had a low loading of Ir (<6 wt%), while also inducing atom coordination to the Ir center. The morphology and chemical composition of these electrocatalysts were analyzed by scanning electron microscopy, energy dispersive spectroscopy, and X‐ray photoelectron spectroscopy, which all showed a uniform dispersion of Ir and heteroatom‐doped moieties. To assess electrocatalytic activity, we used an artificial electrolyte comprising 0.1 M HClO4+3.5 wt% NaCl, and found that these catalysts delivered a low overpotential of 243 mV, a low Tafel slope (92 mV dec−1), and a high exchange current density (1.4 mA cm−2). By using a headspace chlorine gas (Cl2) detector in situ, we discovered that a Cl2 content of 27 ppm was present. When tested in synthetic seawater, the overpotential exhibited a two‐fold increase, yet Cl2 was undetected, thus indicating favorable OER kinetics. This significant finding exemplifies the need for in situ Cl2 detection for seawater splitting research, since further insight can be derived to help guide the design of novel electrocatalysts.
High Ethylene‐Yield Oxidative Dehydrogenation of Ethane Using Sulfur Vapor as a “Soft” Oxidant
Authors: Liu Shanfu , Arinaga Allison M. , Lohr Tracy L. , Marks Tobin J. 
Published: July 2020

AbstractEthylene remains one of the most valuable chemical feedstocks. Currently the industrial conversion of ethane to ethylene is achieved largely by steam cracking. The catalytic, highly exothermic oxidative dehydrogenation (ODH) of ethane with O2 is a challenging alternative that has been extensively studied on the laboratory scale. Here we investigate the possibility of using disulfur (S2) vapor as a thermodynamically “soft” oxidant for catalytically converting ethane to ethylene (“SODH”). Investigating a series of four catalysts we report a maximum ethylene yield of 76 % over an earth‐abundant FeSx‐based catalyst (maximum 90.2 % C2H4 selectivity at 820 °C). Yield and selectivity are stable for 50 hours on stream. The SODH rate law is 1st order in ethane and
order in S2, supporting a proposed Mars van Krevelen‐like mechanism at temperatures <700 °C. Furthermore, conversion and selectivity become insensitive to catalyst identity at temperatures >860 °C, suggesting the intrusion of radical pathways.
Positron Emission Particle Tracking for Liquid‐Solid Mixing in Stirred Tanks
Authors: Windows-Yule Christopher R. K. , Hart-Villamil Roberto , Ridout Thomas , Kokalova Tzany , Nogueira-Filho Jose C. 
Published: July 2020

AbstractMixing in stirred tanks is vital to a wide range of industrial processes, typically requiring solids to be fully suspended and evenly distributed. The quality of suspension and mixing is typically measured visually. Such measurements are thus subject to human interpretation and can only feasibly be conducted in transparent systems – an uncommon condition in industrial systems. Visual measurements of homogeneity must also infer full 3D distributions of particles solely from the observation of a limited section thereof. This work details methods by which a system's homogeneity and state of suspension may be measured and quantified with no human interpretation, which can extract information from opaque systems and consider full 3D data acquired throughout the interior of a given system.
NanoMetrix: An app for chemometric analysis from near infrared spectra
Authors: Baumann Luiza , Librelotto Marcia , Pappis Cristiane , Helfer Gilson A. , Santos Roberta O. , dos Santos Ronaldo B. , da Costa Adilson Ben 
Published: July 2020

AbstractNear‐infrared spectroscopy (NIR) associated with chemometric methods has been widely used in the determination of various compounds, as it is a fast, nondestructive, and analytical method with minimal sample preparation and universal application. In addition, the trend of miniaturization has allowed the development of new portable equipment, increasing the possibilities of point‐of‐use analysis at low cost. In this context, the objective of this study was to develop a portable analytical methodology using a low‐cost DLP NIRscan Nano spectrophotometer (Texas Instruments®) connected to a smartphone for data storage. For this, an app called NanoMetrix was developed, created natively for Android from Android Studio IDE, according to a software design standard known as Model‐View‐ViewModel (MVVM). To demonstrate the applicability of the method, 36 samples of plant tissue were analyzed to determine total nitrogen content. The calibration models were compared to those obtained with the SOLO+MIA software (Eigenvector Research, Inc.), 8.6.1. The results presented root mean square error of calibration (RMSEC) 1.90 and 1.82 g kg−1, root mean square error of prediction (RMSEP) 2.00 and 1.97 g kg−1, and R2pred 0.973 and 0.975, for the NanoMetrix application and the SOLO+MIA software, respectively. Therefore, the results indicate that the NanoMetrix integrated with the portable spectrophotometer, besides the acquisition of spectra, allows the processing of data in the field and reducing the time for the analysis and obtaining the results. Also, the chemometric associated with the NIR spectroscopy is a viable alternative to replace, or complement, the methods used for nitrogen determination.
Carnoquinolines Target Copper Dyshomeostasis, Aberrant Protein–Protein Interactions, and Oxidative Stress
Authors: Bellia Francesco , Grasso Giuseppa Ida , Ahmed Ikhlas Mohamed Mohamud , Oliveri Valentina , Vecchio Graziella 
Published: July 2020

AbstractMetal dysregulation, oxidative stress, protein modification, and aggregation are factors strictly interrelated and associated with neurodegenerative pathologies. As such, all of these aspects represent valid targets to counteract neurodegeneration and, therefore, the development of metal‐binding compounds with other properties to combat multifactorial disorders is definitely on the rise. Herein, the synthesis and in‐depth analysis of the first hybrids of carnosine and 8‐hydroxyquinoline, carnoquinolines (CarHQs), which combine the properties of the dipeptide with those of 8‐hydroxyquinoline, are reported. CarHQs and their copper complexes were characterized through several techniques, such as ESI‐MS and NMR, UV/Vis, and circular dichroism spectroscopy. CarHQs can modulate self‐ and copper‐induced amyloid‐β aggregation. These hybrids combine the antioxidant activity of their parent compounds. Therefore, they can simultaneously scavenge free radicals and reactive carbonyl species, thanks to the phenolic group and imidazole ring. These results indicate that CarHQs are promising multifunctional candidates for neurodegenerative disorders and they are worthy of further studies.
Gold‐Speckled SPION@SiO2 Nanoparticles Decorated with Thiocarbohydrates for ASGPR1 Targeting: Towards HCC Dual Mode Imaging Potential Applications
Authors: Siciliano Giulia , Corricelli Michela , Iacobazzi Rosa Maria , Canepa Fabio , Comegna Daniela , Fanizza Elisabetta , Del Gatto Annarita , Saviano Michele , Laquintana Valentino , Comparelli Roberto , Mascolo Giuseppe , Murgolo Sapia , Striccoli Marinella , Agostiano Angela , Denora Nunzio , Zaccaro Laura , Curri M. Lucia , Depalo Nicoletta 
Published: July 2020

AbstractEfforts are made to perform an early and accurate detection of hepatocellular carcinoma (HCC) by simultaneous exploiting multiple clinically non‐invasive imaging modalities. Original nanostructures derived from the combination of different inorganic domains can be used as efficient contrast agents in multimodal imaging. Superparamagnetic iron oxide nanoparticles (SPIONs) and Au nanoparticles (NPs) possess well‐established contrasting features in magnetic resonance imaging (MRI) and X‐ray computed tomography (CT), respectively. HCC can be targeted by using specific carbohydrates able to recognize asialoglycoprotein receptor 1 (ASGPR1) overexpressed in hepatocytes. Here, two different thiocarbohydrate ligands were purposely designed and alternatively conjugated to the surface of Au‐speckled silica‐coated SPIONs NPs, to achieve two original nanostructures that could be potentially used for dual mode targeted imaging of HCC. The results indicated that the two thiocarbohydrate decorated nanostructures possess convenient plasmonic/superparamagnetic properties, well‐controlled size and morphology and good selectivity for targeting ASGPR1 receptor.