bluuebunny/crossref_metadata_2025_split huggingface dataset:
X‐ray Magnetic Circular Dichroism Spectroscopy Applied to Nitrogenase and Related Models: Experimental Evidence for a Spin‐Coupled Molybdenum(III) Center
Authors: Kowalska Joanna K. , Henthorn Justin T. , Van Stappen Casey , Trncik Christian , Einsle Oliver , Keavney David , DeBeer Serena 
Published: May 2019

AbstractNitrogenase enzymes catalyze the reduction of atmospheric dinitrogen to ammonia utilizing a Mo‐7Fe‐9S‐C active site, the so‐called FeMoco cluster. FeMoco and an analogous small‐molecule (Et4N)[(Tp)MoFe3S4Cl3] cubane have both been proposed to contain unusual spin‐coupled MoIII sites with an S(Mo)=1/2 non‐Hund configuration at the Mo atom. Herein, we present Fe and Mo L3‐edge X‐ray magnetic circular dichroism (XMCD) spectroscopy of the (Et4N)[(Tp)MoFe3S4Cl3] cubane and Fe L2,3‐edge XMCD spectroscopy of the MoFe protein (containing both FeMoco and the 8Fe‐7S P‐cluster active sites). As the P‐clusters of MoFe protein have an S=0 total spin, these are effectively XMCD‐silent at low temperature and high magnetic field, allowing for FeMoco to be selectively probed by Fe L2,3‐edge XMCD within the intact MoFe protein. Further, Mo L3‐edge XMCD spectroscopy of the cubane model has provided experimental support for a local S(Mo)=1/2 configuration, demonstrating the power and selectivity of XMCD.
Acridan‐Grafted Poly(biphenyl germanium) with High Triplet Energy, Low Polarizability, and an External Heavy‐Atom Effect for Highly Efficient Sky‐Blue TADF Electroluminescence
Authors: Hung Miao‐Ken , Tsai Kuen‐Wei , Sharma Sunil , Wu Jun‐Yi , Chen Show‐An 
Published: May 2019

AbstractWe propose the novel σ–π conjugated polymer poly(biphenyl germanium) grafted with two electron‐donating acridan moieties on the Ge atom for use as the host material in a polymer light‐emitting diode (PLED) with the sky‐blue‐emitting thermally activated delayed fluorescence (TADF) material DMAC‐TRZ as the guest. Its high triplet energy (ET) of 2.86 eV is significantly higher than those of conventional π–π conjugated polymers (ET=2.65 eV as the limit) and this guest emitter (ET=2.77 eV). The TADF emitter emits bluer emission than in other host materials owing to the low orientation polarizability of the germanium‐based polymer host. The Ge atom also provides an external heavy‐atom effect, which increases the rate of reverse intersystem crossing in this TADF guest, so that more triplet excitons are harvested for light emission. The sky‐blue TADF electroluminescence with this host/guest pair gave a record‐high external quantum efficiency of 24.1 % at maximum and 22.8 % at 500 cd m−2.
A Single‐Atom Iridium Heterogeneous Catalyst in Oxygen Reduction Reaction
Authors: Xiao Meiling , Zhu Jianbing , Li Gaoran , Li Na , Li Shuang , Cano Zachary Paul , Ma Lu , Cui Peixin , Xu Pan , Jiang Gaopeng , Jin Huile , Wang Shun , Wu Tianpin , Lu Jun , Yu Aiping , Su Dong , Chen Zhongwei 
Published: May 2019

AbstractCombining the advantages of homogeneous and heterogeneous catalysts, single‐atom catalysts (SACs) are bringing new opportunities to revolutionize ORR catalysis in terms of cost, activity and durability. However, the lack of high‐performance SACs as well as the fundamental understanding of their unique catalytic mechanisms call for serious advances in this field. Herein, for the first time, we develop an Ir‐N‐C single‐atom catalyst (Ir‐SAC) which mimics homogeneous iridium porphyrins for high‐efficiency ORR catalysis. In accordance with theoretical predictions, the as‐developed Ir‐SAC exhibits orders of magnitude higher ORR activity than iridium nanoparticles with a record‐high turnover frequency (TOF) of 24.3 e− site−1 s−1 at 0.85 V vs. RHE) and an impressive mass activity of 12.2 A mg−1Ir, which far outperforms the previously reported SACs and commercial Pt/C. Atomic structural characterizations and density functional theory calculations reveal that the high activity of Ir‐SAC is attributed to the moderate adsorption energy of reaction intermediates on the mononuclear iridium ion coordinated with four nitrogen atom sites.
Homoleptic Aryl Complexes of Uranium (IV)
Authors: Wolford Nikki J. , Sergentu Dumitru‐Claudiu , Brennessel William W. , Autschbach Jochen , Neidig Michael L. 
Published: May 2019

AbstractThe synthesis and characterization of sterically unencumbered homoleptic organouranium aryl complexes containing U−C σ‐bonds has been of interest to the chemical community for over 70 years. Reported herein are the first structurally characterized, sterically unencumbered homoleptic uranium (IV) aryl‐ate species of the form [U(Ar)6]2− (Ar=Ph, p‐tolyl, p‐Cl‐Ph). Magnetic circular dichroism (MCD) spectroscopy and computational studies provide insight into electronic structure and bonding interactions in the U−C σ‐bond across this series of complexes. Overall, these studies solve a decades‐long challenge in synthetic uranium chemistry, enabling new insight into electronic structure and bonding in organouranium complexes.
Distribution and habitat characteristics of three sympatric cetacean species in the coastal waters of Matang, Perak, Peninsular Malaysia
Authors: Kuit Sui Hyang , Ponnampalam Louisa Shobhini , Ng Jol Ern , Chong Ving Ching , Then Amy Yee‐Hui 
Published: May 2019

Abstract

Coastal cetaceans in Southeast Asia are poorly studied and are particularly vulnerable to anthropogenic threats, especially in intensive fishing grounds.
To investigate the distribution and habitat characteristics of cetaceans in the productive coastal waters of Matang, Perak, Malaysia, boat‐based line transect surveys were conducted between 2013 and 2016.
The Irrawaddy dolphin (Orcaella brevirostris) was most frequently encountered at 3.87 sightings per 100 km, followed by the Indo‐Pacific finless porpoise (Neophocaena phocaenoides) at 1.72 sightings per 100 km, and the Indo‐Pacific humpback dolphin (Sousa chinensis) at 0.66 sightings per 100 km.
The mean group size was largest for humpback dolphins (8.4 individuals), followed by Irrawaddy dolphins (6.4 individuals), and finless porpoises (2.8 individuals).
Humpback dolphins exhibited a clustered distribution concentrated mainly in shallow estuarine waters (<10 m deep and <5 km from river mouths), whereas Irrawaddy dolphins were more widely distributed in farther coastal waters (<15 m deep and <15 km from river mouths), and finless porpoises were mostly found farthest from the shore in coastal waters (10–25 m deep and >15 km from river mouths).
The spatial distribution of the three cetaceans overlapped minimally, and this is likely to reflect the distribution of preferred prey resources, species interactions, and their differential responses to anthropogenic activities and species dominance.
The results from our study serve as baseline information for future research, conservation, and habitat management of these vulnerable and endangered coastal cetaceans. Conservation actions are recommended for the Matang area.
An Examination of the Development and Localization of Key Immune Cells in Developing Pouch Young of the Red‐Tailed Phascogale (Phascogale calura)
Authors: Borthwick Casey R. , Young Lauren J. , Old Julie M. 
Published: May 2019

ABSTRACTCells expressing the surface markers CD3, CD4, CD79b, IgM, MHC class II, and ModoUG (nonclassical MHC class I) were detected in red‐tailed phascogale tissues using immunohistochemistry, and the appearance and localization of cells observed here was consistent with previous observations in other marsupial species. CD3+ cells were first detected at one day postpartum (dpp) in the thymus, followed by ModoUG+ cells at 5–7 dpp in the thymus and lymph nodes. CD79b+ cells were first detected at 12–14 dpp in bone marrow, spleen, and lymph nodes. IgM+ cells were first detected at 12–14 dpp in thymus, bone marrow, spleen, and lymph nodes. MHC class II+ cells were first detected at 12–14 dpp in thymus, bone marrow, and lymph nodes. CD4+ cells were detected in adult thymus and spleen only. The presence of the mature immune cell populations and their localization to characteristic T and B cell zones in mature lymphoid tissues with normal histological structure indicates that red‐tailed phascogales develop immunocompetence by the end of pouch life. Anat Rec, 302:1985–2002, 2019. © 2019 American Association for Anatomy
Using organic surrogates to manage unit operations for disinfection byproducts’ control
Authors: Rodriguez Angela B. , Duranceau Steven J. 
Published: May 2019

AbstractTotal organic carbon (TOC) and ultraviolet absorbance at 254 nm wavelength (UV254) water quality parameters were used to manage the integrated operations of granular activated carbon (GAC) and spray aeration (SA) treatment systems to optimize disinfection byproduct (DBP) control in a potable water system. Models using treatment process TOC and UV254 parameters that predicted locational running annual average (LRAA) total trihalomethane (TTHM) and haloacetic acid (HAA) concentrations were developed. F‐Tests comparing predicted LRAA DBP levels to actual LRAA DBP levels determined no statistically significant difference. Adherence to the model's GAC and SA operational guidelines extended the life of the carbon beds by 2 months and, in concert with modified carbon purchasing policies, resulted in an estimated $413,000 savings per year. The combined use of the GAC and SA were found to reduce LRAA TTHM and HAA concentrations from 125 to 38.5 μg/L and from 52 to 20.5 μg/L, respectively.
Silicon nanoparticles synthesized using a microwave method and used as a label‐free fluorescent probe for detection of VB12
Authors: Long Yao , Zhang Li , Yu Ying , Lin Bixia , Cao Yujuan , Guo Manli 
Published: May 2019

AbstractA simple and rapid detection strategy for vitamin B12 (VB12) was established based on label‐free silicon quantum dots (SiQDs); the detection mechanism was additionally investigated. SiQDs were synthesized using a one‐step microwave method, and their fluorescence was stronger than that synthesized using the hydrothermal method. SiQDs fluorescence was quenched using VB12 due to the inner filter effect (IFE), which was demonstrated using ultraviolet (UV) absorption spectra, fluorescence lifetime, transmission electron microscopy and zeta potential analysis. Subsequently, quercetin (Que) and doxorubicin (Dox) with absorption peaks that overlapped the excitation or emission peaks of SiQDs respectively were used as control groups to investigate the quenching mechanism. Results showed that quenching efficiency was related to the level of overlap between the adsorption peak of the quencher and the excitation or emission peaks of SiQDs. A greater level of overlap caused a higher quenching efficiency. Therefore, the sensitive quenching of VB12 for SiQDs was due to the synergistic effect of the synchronous overlap between the absorption peak of VB12 with the excitation and emission peaks of SiQDs. Fluorescence quenching efficiency increased linearly in the 0.5 to 16.0 μmol·L−1 VB12 concentration range, and the detection limit was 158 nmol·L−1. In addition, SiQDs were applied to determine VB12 in tablets and human urine samples with satisfactory recoveries ranging from 97.7 to 101.1%.
Novel findings of 18β‐glycyrrhetinic acid on sRAGE secretion through inhibition of transient receptor potential canonical channels in high‐glucose environment
Authors: Li Zih‐Ying , Tung Yu‐Tang , Chen Sheng‐Yi , Yen Gow‐Chin 
Published: May 2019

AbstractEnhancing soluble receptor for advanced glycation endproducts (sRAGE) is considered as a potent strategy for diabetes therapy. sRAGE secretion is regulated by calcium and transient receptor potential canonical (TRPC) channels. However, the role of TRPC channels in diabetes remains unknown. 18β‐Glycyrrhetinic acid (18β‐GA), produced from liquorice, has shown antidiabetic properties. This study was aimed to investigate the effect of 18β‐GA on sRAGE secretion via TRPC channels in high glucose (HG)‐induced THP‐1 cells. HG treatment enhanced TRPC3 and TRPC6 expression and consequently caused reactive oxygen species (ROS) accumulation mediated through p47 nicotinamide‐adenine dinucleotide phosphate oxidase and inducible nitric oxide synthase (iNOS) associated with uncoupling protein 2 (UCP2) decline and lower sRAGE secretion. Interestingly, 18β‐GA showed the dramatic effects similar to Pyr3 or 2‐aminoethyl diphenyl borinate inhibitors and effectively reversed HG‐elicited mechanisms including that blocking TRPC3 and TRPC6 protein expressions, suppressing intracellular [Ca2+] concentration, decreasing expressions of ROS, p47s, and iNOS, but increasing UCP2 level and promoting sRAGE secretion. Therefore, 18β‐GA provides a potential implication to diabetes mellitus and its complications.
Hybrid optimization of preparative chromatography for a ternary monoclonal antibody mixture
Authors: Fischer Vivien , Kucia‐Tran Richard , Lewis William J. , Velayudhan Ajoy 
Published: May 2019

AbstractIn the purification of monoclonal antibodies, ion‐exchange chromatography is typically used among the polishing steps to reduce the amount of product‐related impurities such as aggregates and fragments, whilst simultaneously reducing HCP, residual Protein A and potential toxins and viruses. When the product‐related impurities are difficult to separate from the products, the optimization of these chromatographic steps can be complex and laborious. In this paper, we optimize the polishing chromatography of a monoclonal antibody from a challenging ternary feed mixture by introducing a hybrid approach of the simplex method and a form of local optimization. To maximize the productivity of this preparative bind‐and‐elute cation‐exchange chromatography, wide ranges of the three critical operational parameters—column loading, the initial salt concentration, and gradient slope—had to be considered. The hybrid optimization approach is shown to be extremely effective in dealing with this complex separation that was subject to multiple constraints based on yield, purity, and product breakthrough. Furthermore, it enabled the generation of a large knowledge space that was subsequently used to study the sensitivity of the objective function. Increased design space understanding was gained through the application of Monte Carlo simulations. Hence, this work proposes a powerful hybrid optimization method, applied to an industrially relevant process development challenge. The properties of this approach and the results and insights gained, make it perfectly suited for the rapid development of biotechnological unit operations during early‐stage bioprocess development.
Comparison  of  efficacy, safety, and costs between neoadjuvant hypofractionated radiotherapy and conventionally fractionated radiotherapy for esophageal carcinoma
Authors: Lyu Jiahua , Liu Tao , Li Tao , Li Fang , Wang Qifeng , Wang Jie , Han Yongtao , Wang Junchao , Zhang Jun , Peng Lin , Lang Jinyi 
Published: May 2019

AbstractBackgroundWe compared the efficacy, safety, and costs of hypofractionated radiotherapy (HFRT) and conventional fractionated radiotherapy (CFRT) for the neoadjuvant treatment of esophageal cancer.Materials and MethodsOverall, 110 patients with esophageal cancer treated with neoadjuvant chemoradiotherapy from October 2002 to July 2017 were retrospectively included and divided into a HFRT group (42 patients received 30 Gray [Gy]/10 fractions for 2 weeks) and a CFRT group [68 patients received 40 Gy/20 fractions for 4 weeks]. Concurrent chemotherapy comprised cisplatin combined with either 5‐FU or taxane. Surgery was performed 3‐8 weeks after radiotherapy. We compared the outcomes, adverse events, and costs between the two groups.ResultsPathological downstaging was achieved in 78.6% of the HFRT group and 83.8% of the CFRT group (P = 0.612). Compared with the CFRT group, the HFRT group had similar pathological complete response (pCR) (33.3% vs 35.3%; P = 0.834), median overall survival (OS) (40.8 months vs 44.9 months; P = 0.772) and progression free survival (32.7 months vs 35.4 months; P = 0.785). The perioperative complication rates were also similar between the groups, but the treatment time and costs were significantly reduced in the HFRT group (P < 0.05). Finally, multivariate analysis identified cN0 stage, pathological downstaging and pCR as independent predictors of better OS.ConclusionPreoperative HFRT is effective and safe for esophageal cancer. Moreover, it is similar to CFRT in terms of overall survival and toxicity and is cost effective and less time consuming.
Overexpression of PRDM5 promotes acute myeloid leukemia cell proliferation and migration by activating the JNK pathway
Authors: Zhou Pan , Chen Xing , Li Mengke , Sun Xiaolu , Tan Jiaqi , Wang Xiaomin , Chu Yajing , Zhang Yicheng , Cheng Tao , Zhou Jianfeng , Wang Gaoxiang , Yuan Weiping 
Published: May 2019

AbstractPRDM family proteins are dysregulated in many human diseases, especially hematological malignancies and solid cancers, and share a unique N‐terminal PR domain followed by zinc fingers toward the C terminus. With a high frequency of DNA promoter hypermethylation, PRDM5 is primarily considered as a tumor suppressor in solid tumors. However, little is known about the function of PRDM5 in blood malignancies, especially acute myeloid leukemia (AML). In this study, we showed that high PRDM5 expression levels were independently correlated with poor overall survival in AML patients. PRDM5 overexpression promoted cell proliferation, colony formation, and migration in vitro and enhanced tumorigenesis in an in vivo xenograft model. Furthermore, we found that PRDM5 overexpression promoted cell cycle progression with the decreased level of cell cycle inhibitors such as p16 and p21, and regulated the expression of epithelial‐mesenchymal transition markers ZO‐1 and Vimentin to promote migration. Moreover, we observed that PRDM5 upregulated the Jun N‐terminal kinase (JNK) signaling pathway and downregulated c‐Myc expression. Pharmacological inhibition of JNK by SP600125 partially abrogated PRDM5‐induced cell proliferation and migration. Taken together, our findings demonstrate that PRDM5 functions as an oncogenic driver in AML via JNK pathway, suggesting that PRDM5 is a potential therapeutic target for AML.
Advanced Non‐metallic Catalysts for Electrochemical Nitrogen Reduction under Ambient Conditions
Authors: Zhang Lili , Chen Gao‐Feng , Ding Liang‐Xin , Wang Haihui 
Published: May 2019

AbstractThe electrochemical reduction of nitrogen into ammonia under ambient conditions is a potential strategy for sustainable ammonia production. At present, one of the main research directions in the field of electrochemical nitrogen fixation is to improve the current efficiency and ammonia yield by developing efficient nitrogen reduction catalysts. To optimise the selectivity and catalytic activity of nitrogen reduction catalysts more efficiently, herein, we systematically summarise the progress of research on nitrogen reduction catalysts in recent years and present some general catalyst design strategies. Considering that it is difficult for metal‐based catalysts to balance the competitive reactions of nitrogen activation and hydrogen evolution, we discuss in detail the advantages and application prospects of non‐metallic catalysts in electrochemical nitrogen fixation. Moreover, both the design strategy of surface or interface defects, and how this atomic‐level control of functionalisation helps to promote selectivity and catalytic activity are also discussed by theoretical and experimental electrochemistry. On this basis, we also discussed the future development direction, opportunities and challenges of nitrogen reduction electrocatalysts.
Calixrotanes: Calixarenes Incorporating Spiro‐Linked Cyclopropyl Groups
Authors: Shalev Ori , Biali Silvio E. 
Published: May 2019

AbstractMacrocyclic compounds (calix[4]‐ and calix[6]arene derivatives) with aryl rings interconnected by spirocyclopropyl groups have been synthesized and structurally characterized. The compounds were prepared by the reaction of dichlorocarbene with calixarenes possessing exocyclic double bonds at the bridges, followed by reductive perdechlorination of the spirocyclopropyl groups. In all systems, pairs of geminal rings connected to the quaternary spiro carbon atoms are oriented anti, and the methylene groups of the cyclopropyl rings are located in isoclinal positions. Calix[6]rotane adopts in the crystal and in solution a 1,3,5‐alternate conformation. The presence of the spirocyclopropyl groups increases the rigidity of the macrocyclic ring.
Silver‐Catalyzed Asymmetric Insertion into Phenolic O−H Bonds using Aryl Diazoacetates and Theoretical Mechanistic Studies
Authors: Harada Shingo , Tanikawa Koki , Homma Haruka , Sakai Chigaya , Ito Tsubasa , Nemoto Tetsuhiro 
Published: May 2019

AbstractAn enantioselective insertion reaction of silver carbenes generated from donor–acceptor‐substituted diazo compounds into the O−H bond of phenols was developed. A homobinuclear silver complex with a chiral phosphorous ligand was created in situ from AgNTf2 and (S)‐XylylBINAP (in a 2:1 mole ratio). Detailed mechanistic studies using combined experimental and computational techniques revealed that one silver atom center of the catalyst forms a silver carbene and another one works as a Lewis acid for the nucleophilic addition of a phenol. Two counter‐anions, two water molecules, and two silver atoms cooperatively mediate the subsequent protonation event to lower the activation energy and control enantioselectivity, affording an array of valuable α‐aryl‐α‐aryloxy esters.
The effects of popular diets on type 2 diabetes management
Authors: Chester Brittannie , Babu Jeganathan Ramesh , Greene Michael W. , Geetha Thangiah 
Published: May 2019

SummaryType 2 diabetes can be managed with the use of diabetes self‐management skills. Diet and exercise are essential segments of the lifestyle changes necessary for diabetes management. However, diet recommendations can be complicated in a world full of different diets. This review aims to evaluate the evidence on the effects of three popular diets geared towards diabetes management: low‐carbohydrate and ketogenic diet, vegan diet, and the Mediterranean diet. While all three diets have been shown to assist in improving glycaemic control and weight loss, patient adherence, acceptability, and long‐term manageability play essential roles in the efficacy of each diet.
A new set of DIP‐SNP markers for detection of unbalanced and degraded DNA mixtures
Authors: Liu Jinding , Li Wenyan , Wang Jiaqi , Chen Deqing , Liu Zidong , Shi Jie , Cheng Feng , Li Zeqin , Ren Jianbo , Zhang Gengqian , Yun Keming 
Published: May 2019

AbstractUnbalanced and degraded mixtures (UDM) are frequently encountered during forensic DNA analysis. For example, forensic DNA units regularly encounter DNA mixture signal where the DNA signal from the alleged offender is masked or swamped by high quantities of DNA from the victim. Our previous data presented a new kind of DNA markers that composed of a deletion/insertion polymorphism (DIP) and a SNP and we termed this new kind of microhaplotypes DIP‐SNP (combination of DIP and SNP). Since such markers could be designed short enough for degraded DNA amplification, we hypothesized that DIP‐SNP markers are applicable for typing of UDM. In this study, we developed a new set of DIP‐SNPs with short amplicons which were complement to our prior developed system. The multiplex PCR and SNaPshot assay were established for 20 DIP‐SNPs in a Chinese Han population. The DIP‐SNPs were capable of detecting the minor contributor's allele in home‐made DNA mixture with sensitivities from 1:100 to 1:1000 with a total of 1 –10 ng input DNA. Moreover, this system successfully typed the degraded DNA whether it came from the single source or mixture samples. In Chinese population, the system showed an average informative value of 0.293 and combined informative value of 0.998363862. Our results demonstrated that DIP‐SNPs may serve as a valuable tool in detection of UDM in forensic medicine.