bluuebunny/crossref_metadata_2025_split huggingface dataset:
Symmetric, Unsymmetrical, and Asymmetric [7]‐, [10]‐, and [13]Helicenes
Authors: Pedersen Stephan K. , Eriksen Kristina , Pittelkow Michael 
Published: October 2019

AbstractFully aromatic helicenes with more than one pitch‐length are illustrious synthetic targets with potential applications in advanced optical devices and nano‐electronics. The task of extending the length of fully conjugated helicenes past one pitch length is challenging. Now, the synthesis of a series of azaoxa[7]‐, [10]‐, and [13]helicenes is described. The synthesis is based on iterative oxidative furan formation between 3,6‐dihydroxycarbazoles and/or 2‐naphthols. The flexibility of the presented method allows the convenient and scalable synthesis of symmetric, unsymmetrical, and asymmetric homo‐chiral structures. The [13]helicenes can be synthetically functionalized both at the termini and the periphery. The full range of helicenes were characterized using NMR and optical spectroscopy (UV/Vis, fluorescence, and CD) along with single‐crystal X‐ray crystallography. The enantiomers of the [13]helicenes are the longest optically pure helicenes isolated to date.
Anisotropically Electrochemical–Mechanical Evolution in Solid‐State Batteries and Interfacial Tailored Strategy
Authors: Sun Nan , Liu Qingsong , Cao Yi , Lou Shuaifeng , Ge Mingyuan , Xiao Xianghui , Lee Wah‐Keat , Gao Yunzhi , Yin Geping , Wang Jiajun , Sun Xueliang 
Published: October 2019

AbstractAll‐solid‐state batteries have attracted attention owing to the potential high energy density and safety; however, little success has been made on practical applications of solid‐state batteries, which is largely attributed to the solid–solid interface issues. A fundamental elucidation of electrode–electrolyte interface behaviors is of crucial significance but has proven difficult. The interfacial resistance and capacity fading issues in a solid‐state battery were probed, revealing a heterogeneous phase transition evolution at solid–solid interfaces. The strain‐induced interfacial change and the contact loss, as well as a dense metallic surface phase, deteriorate the electrochemical reaction in solid‐state batteries. Furthermore, the in situ growth of electrolytes on secondary particles is proposed to fabricate robust solid–solid interface. Our study enlightens new insights into the mechanism behind solid–solid interfacial reaction for optimizing advanced solid‐state batteries.
Total Synthesis of (−)‐Perezoperezone through an Intermolecular [5+2] Homodimerization of Hydroxy p‐Quinone
Authors: Long Yang , Ding Yiming , Wu Hai , Qu Chunlei , Liang Hong , Zhang Min , Zhao Xiaoli , Long Xianwen , Wang Shu , Puno Pema‐Tenzin , Deng Jun 
Published: October 2019

AbstractThe first copper‐catalyzed intermolecular [5+2] homodimerization of hydroxy p‐quinone is presented, furnishing bicyclo[3.2.1]octadienone core structures in typically good yields and excellent diastereoselectivities. Applying this synthetic approach enables a concise nine‐step total synthesis of (−)‐perezoperezone from commercially available 3,5‐dimethoxytoluene.
Significant Upregulation of Alzheimer's β‐Amyloid Levels in a Living System Induced by Extracellular Elastin Polypeptides
Authors: Ma Chao , Su Juanjuan , Sun Yao , Feng Yang , Shen Nolan , Li Bo , Liang Yingxia , Yang Xintong , Wu Hui , Zhang Hongjie , Herrmann Andreas , Tanzi Rudolph E. , Liu Kai , Zhang Can 
Published: October 2019

AbstractAlzheimer's disease (AD) is a neurodegenerative disorder and the primary cause of age‐related dementia. The etiology of AD is complex and has not been completely elucidated. Herein, we report that treatment with elastin‐like polypeptides (ELPs), a component of the brain extracellular matrix (ECM), significantly increased the levels of AD‐related amyloid‐β peptides (Aβ) both in vitro and in vivo. Regarding the molecular mechanism(s), the upregulation of Aβ levels was related to increased proteolytic processing of the amyloid precursor protein. Furthermore, nesting tests demonstrated that the ELP‐treated animals showed significant neurobehavioral deficits with cognitive impairment. These results suggest that the elastin is associated with AD‐related pathological and behavioral changes. This finding presents a new aspect for Alzheimer's amyloidosis event and provides a great promise in developing ELP‐based model systems to better understand the pathogenesis of AD.
Synthesis and kinetics studies of N′‐(2‐(3,5‐disubstituted‐4H‐1,2,4‐triazol‐4‐yl)acetyl)‐6/7/8‐substituted‐2‐oxo‐2H‐chromen‐3‐carbohydrazide derivatives as potent antidiabetic agents
Authors: Menteşe Emre , Baltaş Nimet , Bekircan Olcay 
Published: October 2019

AbstractA novel series of N′‐(2‐(3,5‐disubstituted‐4H‐1,2,4‐triazol‐4‐yl)acetyl)‐6/7/8‐substituted‐2‐oxo‐2H‐chromen‐3‐carbohydrazides were synthesized and studied for their α‐glucosidase inhibition activity. Most of the synthesized compounds exhibited potential α‐glucosidase inhibition activity with IC50 values ranging from 0.96 ± 0.02 to 32.86 ± 0.73 µg/ml. Among them, compounds 3e and 4e, having a methoxy group on the coumarin ring, proved to be the most potent ones, showing an enzyme inhibition activity with IC50 = 0.96 ± 0.02 and 1.44 ± 0.06 µg/ml, respectively. The kinetic study through Lineweaver–Burk plots revealed that the inhibition mechanism of the most active compounds 3d, 3e, 4d, and 4e, on the α‐glucosidase activity, was found to be in the competitive mode.
The Usefulness of Saturated Salt Solution Embalming Method for Oral Surgical Skills Training: A New Cadaveric Training Model for Bone Harvesting
Authors: Watanabe Masato , Yoneyama Yuya , Hamada Hayato , Kohno Michihide , Hasegawa On , Takahashi Hidetoshi , Kawase‐Koga Yoko , Matsuo Akira , Chikazu Daichi , Kawata Shinichi , Itoh Masahiro 
Published: October 2019

The purpose of this study was to assess the usefulness of saturated salt solution‐embalmed cadavers for oral surgical skills training related to bone graft harvesting. Two half‐day surgical skills training workshops were held at the Tokyo Medical University utilizing eight cadavers embalmed with the saturated salt solution. A total of 22 participants including oral surgeons, residents, and dentists attended the workshop. Surgical training consisted of six procedures related to intraoral and extraoral bone harvesting. The participants were surveyed to assess self‐confidence levels for each surgical procedure before and after completion of each workshop. The Wilcoxon signed‐rank test was used to compare the differences between each median score before and after the workshop. There were statistically significant increases in the self‐assessed confidence scores in bone harvesting procedures for the zygomatic bone (P = 0.003), maxillary tuberosity (P = 0.002), and other sites (P < 0.001). The anatomical features of saturated salt solution‐embalmed cadavers were also examined. The textures of the oral mucosa and skin were similar to those of living individuals. The structure of bone tissues was well‐preserved and the hardness was realistic. Consequently, all procedures were performed with sufficient realism. The saturated salt solution method has a relatively low cost of preparation and storage, and almost no odor. The authors suggest that saturated salt solution‐embalmed cadavers could provide a new model for oral surgical skills training in bone harvesting.
Novel therapeutic targets in salivary duct carcinoma uncovered by comprehensive molecular profiling
Authors: Gargano Stacey M. , Senarathne Wijendra , Feldman Rebecca , Florento Elena , Stafford Phillip , Swensen Jeffrey , Vranic Semir , Gatalica Zoran 
Published: October 2019

AbstractSalivary duct carcinoma (SDC) is a rare, aggressive salivary gland malignancy, which often presents at an advanced stage. A proportion of SDC are characterized by HER2 amplification and/or overexpression of androgen receptor (AR), which could be targeted in a subset of patients, but the presence of AR splice variant‐7 (AR‐V7) in some SDC cases could result in resistance to anti‐androgen therapy. We evaluated a cohort of 28 cases of SDC for potentially targetable biomarkers and pathways using immunohistochemistry (IHC) and next‐generation sequencing (DNA and RNA) assays. Pathogenic genetic aberrations were found in all but 1 case and affected TP53 (n = 19), HRAS (n = 7), PIK3CA, ERBB2 (HER2), and NF1 (n = 5 each); KMT2C (MLL3) and PTEN (n = 3 each); BRAF (p.V600E), KDM5C and NOTCH1 (n = 2 each). Androgen receptor was expressed in all cases and 13 of 27 harbored the AR‐V7 splice variant (including a case without any other detectable genetic alteration). HER2 IHC was expressed in 11 of 28 cases. The majority of SDC cases had no biomarkers predictive of immunotherapy response: 5 cases exhibited low (1%‐8%) programmed death ligand 1 (PD‐L1) expression in tumor cells, 2 cases exhibited elevated TMB, and no samples exhibited microsatellite instability. Notably, the pre‐treatment biopsies from 2 patients with metastatic disease, who demonstrated clinical responses to anti‐androgen therapy, showed AR expression and no AR splice variants. We conclude that comprehensive molecular profiling of SDCs can guide the selection of patients for targeted therapies involving AR, HER2, PD‐L1, mitogen‐activated protein kinase, and PIK3CA pathways.
Investigation of a New Type I Baeyer–Villiger Monooxygenase from Amycolatopsis thermoflava Revealed High Thermodynamic but Limited Kinetic Stability
Authors: Mansouri Hamid R. , Mihovilovic Marko D. , Rudroff Florian 
Published: October 2019

AbstractBaeyer–Villiger monooxygenases (BVMOs) are remarkable biocatalysts, but, due to their low stability, their application in industry is hampered. Thus, there is a high demand to expand on the diversity and increase the stability of this class of enzyme. Starting from a known thermostable BVMO sequence from Thermocrispum municipale (TmCHMO), a novel BVMO from Amycolaptosis thermoflava (BVMOFlava), which was successfully expressed in Escherichia coli BL21(DE3), was identified. The activity and stability of the purified enzyme was investigated and the substrate profile for structurally different cyclohexanones and cyclobutanones was assigned. The enzyme showed a lower activity than that of cyclohexanone monooxygenase (CHMOAcineto) from Acinetobacter sp., as the prototype BVMO, but indicated higher kinetic stability by showing a twofold longer half‐life at 30 °C. The thermodynamic stability, as represented by the melting temperature, resulted in a Tm value of 53.1 °C for BVMOFlava, which was comparable to the Tm of TmCHMO (ΔTm=1 °C) and significantly higher than the Tm value for CHMOAcineto ((ΔTm=14.6 °C)). A strong deviation between the thermodynamic and kinetic stabilities of BVMOFlava was observed; this might have a major impact on future enzyme discovery for BVMOs and their synthetic applications.
It hurts to swallow! Pseudoachalasia resulting from attempted transcatheter occlusion of a giant congenital coronary artery fistula
Authors: Le Jonathan , Deano Roderick C. , Raval Amish N. 
Published: October 2019

AbstractCongenital coronary artery fistula (CAF) is a rare anomaly that can cause heart failure and myocardial ischemia. In recent decades, transcatheter approaches to occlude CAF have emerged as minimally invasive alternatives to surgical ligation. Reported complications with transcatheter CAF occlusion include device embolization and dissection. We report the first case of attempted transcatheter occlusion of a giant CAF that resulted in severe pseudoachalasia.
Sugar Puckering Drives G‐Quadruplex Refolding: Implications for V‐Shaped Loops
Authors: Haase Linn , Dickerhoff Jonathan , Weisz Klaus 
Published: October 2019

AbstractA DNA G‐quadruplex adopting a (3+1) hybrid structure was modified in two adjacent syn positions of the antiparallel strand with anti‐favoring 2′‐deoxy‐2′‐fluoro‐riboguanosine (FrG) analogues. The two substitutions promoted a structural rearrangement to a topology with the 5′‐terminal G residue located in the central tetrad and the two modified residues linked by a V‐shaped zero‐nucleotide loop. Strikingly, whereas a sugar pucker in the preferred north domain is found for both modified nucleotides, the FrG analogue preceding the V‐loop is forced to adopt the unfavored syn conformation in the new quadruplex fold. Apparently, a preferred C3′‐endo sugar pucker within the V‐loop architecture outweighs the propensity of the FrG analogue to adopt an anti glycosidic conformation. Refolding into a V‐loop topology is likewise observed for a sequence modified at corresponding positions with two riboguanosine substitutions. In contrast, 2′‐F‐arabinoguanosine analogues with their favored south‐east sugar conformation do not support formation of the V‐loop topology. Examination of known G‐quadruplexes with a V‐shaped loop highlights the critical role of the sugar conformation for this distinct structural motif.
Peralkynylated Tetraazaacene Derivatives
Authors: Reiss Hilmar , Rominger Frank , Freudenberg Jan , Bunz Uwe H. F. 
Published: October 2019

AbstractThe synthesis of a decaethynylated tetraazapentacene is described. It was obtained by a combination of condensation reactions giving the two pyrazine rings and subsequent consecutive Stille‐type couplings. This is the first example of any higher (hetero)acene that is peralkynylated. The presence of the four nitrogen atoms removes the peri interaction of the substituted alkyne groups, giving this rock‐stable and highly twisted heteroacene.
A Highly Stabilized Phosphonium Ylide that Forms Supramolecular Dimers in Solution and the Solid State
Authors: Kim Min Ji , Luo Stella M. , Greenlee Andrew J. , Young Victor G. , Cao Dennis D. 
Published: October 2019

AbstractThis work describes the unexpected formation of an unusual phosphonium ylide when attempting the synthesis of bisphosphonium pyromellitic diimides. Spectroscopic and crystallographic characterization reveals that a combination of π–π and CH⋅⋅⋅O interactions leads to supramolecular homodimerization of the ylide both in solution and in the solid‐state. Only strong acids are able to protonate the ylide, which is otherwise inert to Wittig and alkylation reactivity. Taken together, these observations indicate that this compound is one of the most highly stabilized phosphonium ylides discovered to date.
Saturated N‐Heterocyclic Carbene Based Thiele's Hydrocarbon with a Tetrafluorophenylene Linker
Authors: Kundu Gargi , De Sriman , Tothadi Srinu , Das Abhishek , Koley Debasis , Sen Sakya S. 
Published: October 2019

AbstractThe synthesis of a SIPr [1,3‐bis(2,6‐diisopropylphenyl)‐imidazolin‐2‐ylidene] derived Kekulé diradicaloid with a tetrafluorophenylene spacer (3) has been described. Two synthetic routes have been reported to access 3. The cleavage of C−F bond of C6F6 by SIPr in the presence of BF3 led to double C−F activated compound with two tetrafluoro borate counter anions (2), which upon reduction by lithium metal afforded 3. Alternatively, 3 can be directly accessed in one step by reacting SIPr with C6F6 in presence of Mg metal. Compounds 2 and 3 were well characterized spectroscopically and by single‐crystal X‐ray diffraction studies. Experimental and computational studies support the cumulenic closed‐shell singlet state of 3 with a singlet‐triplet energy gap (ΔES–T) of 23.7 kcal mol−1.
Theoretical Investigation of Cyano‐Chalcogen Dimers and Their Importance in Molecular Recognition
Authors: Previtali Viola , Sánchez‐Sanz Goar , Trujillo Cristina 
Published: October 2019

AbstractIn this manuscript the different noncovalent interactions established between (HYCN)2dimers (Y=S, Se and Te) have been studied at the MP2 and CCSD(T) level of theory. Several homodimers have been taken into account, highlighting the capacity of these compounds to act both as electron donor and acceptor. The main properties studied were geometries, binding energy (Eb), and molecular electrostatic potential (MEP). Given the wide application of chalcogen bonds, and more specifically of cyano‐chalcogen moieties in molecular recognition, natural bond orbital (NBO), “atoms‐in‐molecules” (AIM), and electron density shift (EDS) analysis were also used to analyse the different noncovalent interactions upon complexation. The presence of hydrogen, chalcogen and dipole‐dipole interactions was confirmed and their implications on molecular recognition were analysed.
Deoxyguanosine is a TLR7 agonist
Authors: Davenne Tamara , Bridgeman Anne , Rigby Rachel E. , Rehwinkel Jan 
Published: October 2019

AbstractToll‐like receptor 7 (TLR7) is an innate immune sensor for single‐strand RNA (ssRNA). Recent structural analysis revealed that TLR7 has an additional binding site for nucleosides such as guanosine, and is activated when both guanosine and ssRNA bind. The nucleoside binding site also accommodates imidazoquinoline derivatives such as R848, which activate TLR7 in the absence of ssRNA. Here, we report that deoxyguanosine (dG) triggered cytokine production in murine bone marrow derived macrophages and plasmacytoid dendritic cells, as well as in human peripheral blood mononuclear cells, including type I interferons and pro‐inflammatory factors such as TNF and IL‐6. This signalling activity of dG was dependent on TLR7 and its adaptor MyD88 and did not require amplification via the type I interferon receptor. dG‐triggered cytokine production required endosomal maturation but did not depend on the concurrent provision of RNA. We conclude that dG induces an inflammatory response through TLR7 and propose that dG is an RNA‐independent TLR7 agonist.
In situ Electrochemical Synthesis of a Composite Film Containing Nickel Hexacyanoferrate and Bentonite Clay for the Sensitive Determination of Acetaminophen and Dopamine
Authors: Yadav Mamta , Singh Preeti , Ganesan Vellaichamy , Gupta Rupali , Sonkar Piyush Kumar , Yadav Dharmendra Kumar 
Published: October 2019

AbstractA composite film of nickel hexacyanoferrate (NiHCF) and bentonite (Bt) clay (abbreviated as NiHCF−Bt) is synthesized by an in situ electrochemical method. For this synthesis, nickel ions are immobilized on Bt clay by an ion‐exchange process, equilibrating Bt clay with nickel nitrate. On a glassy carbon electrode (GCE), the nickel ion‐exchanged Bt clay (Ni2+−Bt) is coated to get the modified electrode which is represented as GCE/Ni2+−Bt. The NiHCF−Bt composite film is prepared on the GCE surface using the GCE/Ni2+−Bt and scanning the electrode potentials between −0.10 to 1.00 V continuously in an aqueous solution containing potassium hexacyanoferrate and potassium chloride. This NiHCF−Bt modified GCE (GCE/NiHCF−Bt) exhibits redox peaks due to the oxidation and reduction of the central metal ion, Fe2+. The electro‐generated Fe3+ present in the GCE/NiHCF−Bt, electrocatalytically oxidizes a range of drugs like acetaminophen (AC), dopamine (DA), and tyrosine (TY) at decreased overpotentials with high current. This property is advantageously used for the precise quantification of AC, DA, and TY. Sensitivity, limit of detection, and linear calibration range for the determination of AC are found to be 0.20 μA μM−1 cm−2, 1.5 μM, and 25.0–1000.0 μM, respectively. Further, the amount of AC present in pharmaceutical products is satisfactorily quantified which demonstrated the use of the NiHCF−Bt composite film in electroanalysis.
Activated hepatic stellate cells promote angiogenesis in hepatocellular carcinoma by secreting angiopoietin‐1
Authors: Lin Nan , Meng Lili , Lin Jizong , Chen Shuxian , Zhang Peng , Chen Qilong , Lin Yang 
Published: October 2019

AbstractAngiogenesis is the central pathological process in hepatocellular carcinoma (HCC), and its progression is affected by tumor cells and the microenvironment. Activated hepatic stellate cells (aHSCs) are the most significant stromal cells involved in HCC. This study was aimed to explore the effects and mechanisms of aHSCs on angiogenesis in HCC. We isolated primary hepatoma cells, aHSCs, and hepatic vascular endothelial cells from human HCC samples. Then, we performed a novel in vitro assay and in vivo experiment in a nude mouse HCC model to investigate the functions of aHSCs on angiogenesis in HCC. Our results demonstrated that aHSCs are the primary sources of angiopoietin‐1 (Ang‐1) in human HCC in vitro, and aHSCs could promote hepatic vascular endothelial cell (HVEC) growth by secreting Ang‐1. Furthermore, aHSCs could induce HVEC microtubule formation, and this ability was reduced when Ang‐1 expression was silenced in aHSCs. In addition, CD34 expression in a nude mouse HCC model was downregulated when Ang‐1 messenger RNA was silenced in aHSCs. Our data also indicated that HSC Ang‐1 expression could be inhibited by overexpressing Raf kinase inhibitor protein. Therefore, we suggest that aHSCs promote angiogenesis through secreting Ang‐1, potentially providing an interesting target for antiangiogenic therapies for HCC.
Long noncoding RNA LINC00319 regulates ROMO1 expression and promotes bladder cancer progression via miR‐4492/ROMO1 axis
Authors: Yang Yu , Zhang Fangyi , Huang Hang , Xie Zhiyue , Huang Weiping , Xie Hui , Wang Feng 
Published: October 2019

AbstractGrowing reports indicate that long noncoding RNA (lncRNA) are involved in the regulation of various biological processes of cancer cells. LINC00319 is an ill investigated lncRNA and has been shown to regulate lung cancer, nasopharyngeal carcinoma and ovarian cancer. Nevertheless, its roles in bladder cancer (BCa) remain unclear. In our research, LINC00319 was shown to be an upregulated lncRNA in BCa tissues. LINC00319 expression is negatively correlated with the patient's prognosis. Silencing of LINC00319 suppressed BCa proliferation and invasiveness. In addition, the data indicated LINC00319 was a sponge for miR‐4492 and miR‐4492 suppressed ROMO1 expression in BCa. Furthermore, our results illustrated miR‐4492/ROMO1 axis regulates proliferation, migration, and invasion and LINC00319 exerts oncogenic roles through modulating miR‐4492/ROMO1 axis. In sum, this study suggested that LINC00319 acts as oncogenic roles in BCa progression.
Complicated trafficking behaviors involved in paradoxical regulation of sortilin in lipid metabolism
Authors: Sun Sha , Yang Jing , Xie Wei , Peng Tianhong , Lv Yuncheng 
Published: October 2019

AbstractThis review aims to summarize and discuss the most recent advances in our understanding of the underlying mechanisms of the paradoxical effects of sortilin on lipid metabolism. The vacuolar protein sorting 10 protein (Vps10p) domain in the sortilin protein is responsible for substrate binding. Its cytoplasmic tail interacts with adaptor molecules, and modifications can determine whether sortilin trafficking occurs via the anterograde or retrograde pathway. The complicated trafficking behaviors likely contribute to the paradoxical roles of sortilin in lipid metabolism. The anterograde pathway of sortilin trafficking in hepatocytes, enterocytes, and peripheral cells likely causes an increase in plasma lipid levels, while the retrograde pathway leads to the opposite effect. Hepatocyte sortilin functions via the anterograde or retrograde pathway in a complicated and paradoxical manner to regulate apoB‐containing lipoprotein metabolism. Clarifying the regulatory mechanisms underlying the trafficking behaviors of sortilin is necessary and may lead to artificial sortilin intervention as a potential therapeutic strategy for lipid disorder diseases. Conclusively, the paradoxical regulation of sortilin in lipid metabolism is likely due to its complicated trafficking behaviors.