bluuebunny/crossref_metadata_2025_split huggingface dataset:
Can earthworms biosynthesize highly luminescent quantum dots?
Authors: Talaeeshoar Farzane , Delavari H. Hamid , Poursalehi Reza 
Published: April 2018

AbstractBand gap tunable cadmium selenide (CdSe) quantum dots (QDs) were synthesized within earthworms that emit in the middle of the visible spectrum. We demonstrated that this luminescence emission is a combination of the earthworm's protein and QD luminescence, such that the contribution of QDs in the luminescence was negligible. Eisenia fetida earthworms were used for QD biosynthesis and were exposed to different concentrations of CdCl2 and Na2SeO3 in standard soil for an adequate exposure time. The size of the CdSe QDs based on the effective mass model was in agreement with the size measured from the transmission electron microscopy analysis, with an average diameter of 7 nm. Ultraviolet–visible and photoluminescence analyses confirmed the synthesis of CdSe QDs with unique absorption and luminescence at 430 nm and 605 nm, respectively.
Effect of annealing temperature and dopant concentration on the thermoluminescence sensitivity in LiF:Mg,Cu,Ag material
Authors: Yahyaabadi Akram , Torkzadeh Falamarz , Rezaei Ochbelagh Dariush , Hosseini Pooya Seyed Mahdi 
Published: April 2018

AbstractLiF:Mg,Cu,Ag is a new dosimetry material that is similar to LiF:Mg,Cu,P in terms of dosimetric properties. The effect of the annealing temperature in the range of 200 to 350°C on the thermoluminescence (TL) sensitivity and the glow curve structure of this material at different concentrations of silver (Ag) was investigated. It has been demonstrated that the optimum values of the annealing temperature and the Ag concentration are 240°C and 0.1 mol% for better sensitivity, respectively. The TL intensity decreases at annealing temperatures lower than 240°C or higher than 240°C, reaching a minimum at 300°C and then again increases for various Ag concentrations. It was observed that the glow curve structure altered and the area under the low temperature peak as well as the area under the main dosimetric peak decreased with increasing annealing temperature. The position of the main dosimetric peak moved in the direction of higher temperatures, but at 320 and 350°C annealing temperatures, it shifted to lower temperatures. It was also observed that the TL sensitivity could partially be recovered by a combined annealing procedure.
An impurity characterization based approach for the rapid development of integrated downstream purification processes
Authors: Timmick Steven M. , Vecchiarello Nicholas , Goodwine Chaz , Crowell Laura E. , Love Kerry R. , Love J. Christopher , Cramer Steven M. 
Published: April 2018

AbstractIn this study, we describe a new approach for the characterization of process‐related impurities along with an in silico tool to generate orthogonal, integrated downstream purification processes for biological products. A one‐time characterization of process‐related impurities from product expression in Pichia pastoris was first carried out using linear salt and pH gradients on a library of multimodal, salt‐tolerant, and hydrophobic charge induction chromatographic resins. The Reversed‐phase ultra‐performance liquid chromatography (UPLC) analysis of the fractions from these gradients was then used to generate large data sets of impurity profiles. A retention database of the biological product was also generated using the same linear salt and pH gradients on these resins, without fraction collection. The resulting two data sets were then analyzed using an in silico tool, which incorporated integrated manufacturing constraints to generate and rank potential three‐step purification sequences based on their predicted purification performance as well as whole‐process “orthogonality” for impurity removal. Highly ranked sequences were further examined to identify templates for process development. The efficacy of this approach was successfully demonstrated for the rapid development of robust integrated processes for human growth hormone and granulocyte‐colony stimulating factor.
Quantification of metronidazole in healthy subjects' feces using an LC–MS/MS method
Authors: Vanol Pravin G. , Sanyal Mallika , Shah Priyanka A. , Shrivastav Pranav S. 
Published: April 2018

AbstractA highly selective and sensitive liquid chromatography–tandem mass spectrometry (LC MS/MS) method was developed for the quantification of metronidazole (MTZ) in human feces. The analyte was recovered from feces after liquid–liquid extraction with ethyl acetate and separated on Waters Symmetry® C18 (100 × 4.6 mm, 5μm) column using 0.1% formic acid in water and acetonitrile (40:60, v/v) as the mobile phase. A stable‐deuterated internal standard metronidazole‐d4 (MTZ‐d4) was used in the study. Mass analysis was performed on a triple quadrupole mass spectrometer in the positive electrospray ionization mode. A linear response function of MTZ was established in the concentration range of 0.50–250 ng/g, based on dry mass. The mean extraction recovery of MTZ (97.28%) and MTZ‐d4 (96.76%) from spiked feces samples was consistent at higher as well as lower concentrations. Post‐column infusion analysis showed no ion‐suppression/enhancement effects and the mean IS‐normalized matrix factor ranged from 0.986 to 1.013. Spiked feces samples stored at −20 and − 70°C for long‐term stability were stable for at least 3 months, while extracted samples (dry and wet extracts) were stable up to 24 h. The method was applied to determine MTZ in feces of 12 healthy Indian subjects.
Synthesis and Characterization of Pyridine Compounds for Amperometric Measurements of Leukocyte Esterase
Authors: Hanson Douglas , Menard Travis , Blazek Teresa , McHardy Stanton , Gorski Waldemar 
Published: April 2018

AbstractWe introduce a new class of substrates (compounds I–III) for leukocyte esterase (LE) that react with LE yielding anodic current in direct proportion to LE activity. The kinetic constants Km and kcat for the enzymatic reactions were determined by amperometry at a glassy carbon electrode. The binding affinity of I–III for LE was two orders of magnitude better than that of existing optical LE substrates. The specificity constant kcat/Km was equal to 2.7, 3.8, and 5.8×105 m−1 s−1 for compounds containing the pyridine (I), methoxypyridine (II), and (methoxycarbonyl)pyridine (III), respectively, thus showing an increase in catalytic efficiency in this order. Compound III had the lowest octanol/water partition coefficient (log p=0.33) along with the highest topological surface area (tPSA=222 Å2) and the best aqueous solubility (4.0 mg mL−1). The average enzymatic activity of LE released from a single leukocyte was equal to 4.5 nU when measured with compound III.
Organic Polysulfides Based on −S−S−S− Structure as Additives or Cosolvents for High Performance Lithium‐Sulfur Batteries
Authors: Gu Sui , Jin Jun , Zhuo Shangjun , Qian Rong , Wen Zhaoyin 
Published: April 2018

AbstractLithium‐sulfur (Li−S) batteries are presently attracting immense research interest on the global level due to their excellent specific capacity and energy density. However, the practical development of Li−S batteries has so far been hindered by a series of obstacles. To enhance the sulfur utilization rate and facilitate capacity performance of Li−S batteries, a new organosulfide, dimethyl trisulfide (DMTS, CH3S3CH3), as electrolyte additive or cosolvent was employed. Boosted capacities were demonstrated with appropriate amount of DMTS. Li−S batteries with 5 % and 10 % DMTS delivered discharge capacities of 1207(1st)/1009(100th) and 1648(1st)/1133(100th) mAh g−1, respectively. Such high capacities are particularly attractive for Li−S batteries towards high energy density devices. The methyl‐terminated polysulfides (DMTS and reaction products of DMTS/S8) were supposed to contribute the extra capacity.
Efficient In Situ Utilization of Caustic for Sequential Recovery and Separation of Sn, Fe, and Cu in Microbial Fuel Cells
Authors: Huang Liping , Lin Zheqian , Quan Xie , Zhao Qingliang , Yang Wulin , Logan Bruce E. 
Published: April 2018

AbstractA novel strategy to sequentially recover and separate Sn(II), Fe(II) and Cu(II) from a synthetic wastewater from printed circuit board (PrCB) manufacturing in a single microbial fuel cell (MFCSn)‐MFCFe‐MFCCu process was achieved, where in‐situ produced caustic was primarily utilized for Sn precipitation (MFCSn) and then secondly used for Fe deposition (MFCFe) and anaerobic Cu(II) reduction in the final MFCCu. An external resistance of 1000 Ω in the MFCSn and MFCFe, and a 10 Ω resistor in the MFCCu achieved predominant recovery of Sn (MFCSn: 80.8±0.8 %), Fe (MFCFe: 59.1±0.8 %), and Cu (MFCCu: 68.2±1.8 %) in the three MFCs, with separation factors of 32.1±1.6 for Sn (MFCSn) and 7.5±1.8 for Fe (MFCFe), and complete recovery of Cu (MFCCu, 42‐mesh cathodes). The metal concentrations in the final effluent were below national discharge limits (Sn, 2.0 mg/L; Fe, 5.0 mg/L; Cu, 0.2 mg/L). The metal recoveries ranged from 2.6 (Sn, MFCSn)–12.0 (Cu, MFCCu), and the separation factors were 8.4 (Sn, MFCSn)–∞ (Cu, MFCCu) times those of the open circuit controls. Cathodes with 120‐mesh size of stainless steel mesh produced lower metal recoveries [33.7 % (Sn, MFCSn) and 27.0 % (Fe, MFCFe) decrease] and separation factors than MFCs with 42‐mesh cathodes. This study provides a viable approach for efficiently recovering and separating Sn, Fe and Cu from stripping solutions produced in PrCB manufacturing, with simultaneous power production.
Tetrachlorinated Polycyclic Aromatic Dicarboximides: New Electron‐Poor π‐Scaffolds and NIR Emitters by Palladium‐Catalyzed Annulation Reaction
Authors: Mahl Magnus , Shoyama Kazutaka , Rühe Jessica , Grande Vincenzo , Würthner Frank 
Published: April 2018

AbstractHerein we report a palladium‐catalyzed annulation reaction consisting of a Suzuki–Miyaura cross‐coupling and a C−H arylation cascade for the synthesis of tetrachlorinated polycyclic aromatic dicarboximides (PADIs). This convergent synthetic route afforded a broad series of hitherto unknown electron‐deficient PADIs under optimized reaction conditions by coupling of a dibromo‐tetrachloro‐perylene dicarboximide with different polycyclic aromatic hydrocarbon (PAH) boronic acid pinacol esters in up to 89 % yields. The new PADI compounds show broad absorption in the visible range and some of them emit in the near‐infrared (NIR) region. Cyclic and square wave voltammetric studies revealed that these tetrachlorinated PADIs are more electron‐deficient than a non‐chlorinated reference compound and they possess lower lying frontier orbitals. Thus, the newly synthesized electron‐poor PADIs are potential n‐type semiconductors. Moreover, these chlorinated PADIs are interesting building blocks for the construction of large π‐extended arrays by metal‐mediated coupling reactions.
Selective Activation of N,N′‐Diacyl Rhodamine Pro‐fluorophores Paired with Releasing Enzyme, Porcine Liver Esterase (PLE)
Authors: Abney Kristopher K. , Ramos‐Hunter Susan J. , Romaine Ian M. , Goodwin J. Shawn , Sulikowski Gary A. , Weaver C. David 
Published: April 2018

AbstractThis study reports the synthesis and testing of a family of rhodamine pro‐fluorophores and an enzyme capable of converting pro‐fluorophores to Rhodamine 110. We prepared a library of simple N,N′‐diacyl rhodamines and investigated porcine liver esterase (PLE) as an enzyme to activate rhodamine‐based pro‐fluorophores. A PLE‐expressing cell line generated an increase in fluorescence rapidly upon pro‐fluorophore addition demonstrating the rhodamine pro‐fluorophores are readily taken up and fluorescent upon PLE‐mediated release. Rhodamine pro‐fluorophore amides trifluoroacetamide (TFAm) and proponamide (PAm) appeared to be the best substrates using a cell‐based assay using PLE expressing HEK293. Our pro‐fluorophore series showed diffusion into live cells and resisted endogenous hydrolysis. The use of our engineered cell line containing the exogenous enzyme PLE demonstrated the rigorousness of amide masking when compared to cells not containing PLE. This simple and selective pro‐fluorophore rhodamine pair with PLE offers the potential to be used in vitro and in vivo fluorescence based assays.
The Design of Water Oxidation Electrocatalysts from Nanoscale Metal–Organic Frameworks
Authors: Shao Qi , Yang Jian , Huang Xiaoqing 
Published: April 2018

AbstractMetal–organic frameworks (MOFs), as the shining stars in field of materials science, have become an important class of highly efficient catalysts for electrochemical oxygen evolution reaction (OER). Although tremendous progresses have been achieved by exploring two MOF‐based groups: the MOF‐derived electrocatalysts and the direct MOF electrocatalysts in recently years, it appears that both activity and stability of these two kinds of MOF‐based electrocatalysts have big rooms for improvement. In order to overcome these issues, a comprehensive summary of the advanced designs of catalysts is timely urgent. Here, the advanced engineering strategies including structural, carbon‐based, metal‐based and substrate‐engineered strategies of MOF‐derived catalysts have been introduced. In addition, the detailed explorations of the nanostructured direct MOF catalysts for OER are also reviewed. Finally, short comments and perspectives about the future development of the MOF‐based OER electrocatalysts are provided.
Metal‐Free Deoxygenation and Reductive Disilylation of Nitroarenes by Organosilicon Reducing Reagents
Authors: Bhattacharjee Argha , Hosoya Hiromu , Ikeda Hideaki , Nishi Kohei , Tsurugi Hayato , Mashima Kazushi 
Published: April 2018

AbstractA metal‐free deoxygenation and reductive disilylation of nitroarenes was achieved using N,N′‐bis(trimethylsilyl)‐4,4′‐bipyridinylidene (1) under mild and neutral reaction conditions, and a broad functional group tolerance was possible in this reaction. Mono‐deoxygenation, giving a synthetically valuable N,O‐bis(trimethylsilyl)phenylhydroxylamine (7 a) as a readily available and safe phenylnitrene source from nitrobenzene, and double‐deoxygenation, giving N,N‐bis(trimethylsilyl)anilines 8, were easily controlled by varying the amounts of 1 and reaction temperature as well as adding dibenzothiophene (DBTP). Reaction of 2‐arylnitrobenzenes with 1 resulted in the formation of the corresponding carbazoles 14 via in situ‐generated phenylnitrene species derived by thermolysis of N,O‐bis(trimethylsilyl)phenylhydroxylamines 7, followed by their subsequent intramolecular C−H insertion. In addition, the intramolecular N−N coupling reaction proceeded in the reduction of 2,2′‐dinitrobiphenyl derivatives by 1, giving the corresponding benzo[c]cinnolines.
Designing Anticancer Peptides by Constructive Machine Learning
Authors: Grisoni Francesca , Neuhaus Claudia S. , Gabernet Gisela , Müller Alex T. , Hiss Jan A. , Schneider Gisbert 
Published: April 2018

AbstractConstructive (generative) machine learning enables the automated generation of novel chemical structures without the need for explicit molecular design rules. This study presents the experimental application of such a deep machine learning model to design membranolytic anticancer peptides (ACPs) de novo. A recurrent neural network with long short‐term memory cells was trained on α‐helical cationic amphipathic peptide sequences and then fine‐tuned with 26 known ACPs by transfer learning. This optimized model was used to generate unique and novel amino acid sequences. Twelve of the peptides were synthesized and tested for their activity on MCF7 human breast adenocarcinoma cells and selectivity against human erythrocytes. Ten of these peptides were active against cancer cells. Six of the active peptides killed MCF7 cancer cells without affecting human erythrocytes with at least threefold selectivity. These results advocate constructive machine learning for the automated design of peptides with desired biological activities.
Potentially inappropriate medication use in older patients with breast and colorectal cancer
Authors: Karuturi Meghan S. , Holmes Holly M. , Lei Xiudong , Johnson Michael , Barcenas Carlos H. , Cantor Scott B. , Gallick Gary E. , Bast Robert C. , Giordano Sharon H. 
Published: April 2018

BACKGROUNDThe objective of this study was to determine patient characteristics associated with potentially inappropriate medication (PIM) use and its impact on outcomes for patients with breast or colorectal cancer receiving adjuvant chemotherapy.METHODSThe Surveillance, Epidemiology, and End Results database, linked to Medicare claims, was used. The cohort included patients who were 66 years old or older and were diagnosed with stage II or III breast or colorectal cancer between July 1, 2007, and December 31, 2009. The Drugs to Avoid in the Elderly (DAE) list and the Beers criteria were used to identify PIM use. Univariate/multivariate logistic regression determined the association of baseline PIMs with covariates. Event‐free survival (EFS) was defined as the time from chemotherapy initiation to the first emergency room (ER) visit, hospitalization, death, or a composite until 3 months after chemotherapy. Cox proportional hazards modeling determined the association of PIMs with EFS.RESULTSThe analysis included 1595 patients with breast cancer and 1528 patients with colorectal cancer. The baseline PIM frequencies were 22.2% (according to the DAE list) and 27.6% (according to the Beers criteria) in the breast cohort and 15.5% (according to the DAE list) and 24.8% (according to the Beers criteria) in the colorectal cohort. Among patients with breast cancer, 37.5% had at least 1 adverse outcome; associations included the use of ≥5 medications, an advanced stage, higher comorbidity, and prior ER visits/hospitalizations. Baseline PIM use according to the DAE list was associated with an increased risk of death in patients with breast cancer. Among patients with colorectal cancer, 45% had at least 1 adverse outcome, and associations included the use of ≥5 medications, older age, female sex, and higher comorbidity. A time‐to‐event analysis revealed no association between baseline PIM use and most outcomes.CONCLUSIONSThese findings require further prospective confirmation, but they support a correlation between polypharmacy and adverse outcomes for cancer patients and call into question the association with PIMs. Cancer 2018;124:3000‐7. © 2018 American Cancer Society.
Long‐lived 15N Hyperpolarization and Rapid Relaxation as a Potential Basis for Repeated First Pass Perfusion Imaging – Marked Effects of Deuteration and Temperature
Authors: Harris Talia , Gamliel Ayelet , Uppala Sivaranjan , Nardi‐Schreiber Atara , Sosna Jacob , Gomori J. Moshe , Katz‐Brull Rachel 
Published: April 2018

AbstractDeuteration of the exchangeable hydrogens of [15N2]urea was found to prolong the T1 of the 15N sites to more than 3 min at physiological temperatures. This significant increase in the lifetime of the hyperpolarized state of [15N2]urea, compared to [13C]urea – a pre‐clinically proven perfusion agent, makes [15N2]urea a promising perfusion agent. The molecular parameters that may lead to this profound effect were assessed by investigating small molecules with different molecular structures containing 15N sites bound to labile protons and determining the hyperpolarized 15N T1 in H2O and D2O. Dissolution in D2O led to marked prolongation for all of the selected sites. In whole human blood, the T1 of [15N2]urea was shortened. We present a general strategy for exploiting the markedly longer T1 outside the body and the quick decay in blood for performing multiple hyperpolarized perfusion measurements with a single hyperpolarized dose. Improved storage of the generated [15N2]urea polarization prior to the contact with the blood is demonstrated using higher temperatures due to further T1 prolongation.
Randomized clinical trial pilot study of prolonged exposure versus present centred affect regulation therapy for PTSD and anger problems with male military combat veterans
Authors: Ford Julian D. , Grasso Damion J. , Greene Carolyn A. , Slivinsky Michelle , DeViva Jason C. 
Published: April 2018

A randomized controlled trial pilot study (www.ClinicalTrials.org; NCT01228539) with N = 31 U.S. male military recent combat veterans with PTSD and severe anger problems was conducted comparing 10‐session individual therapy versions of Trauma Affect Regulation: Guide for Education and Therapy (TARGET) versus prolonged exposure (PE). TARGET had fewer drop‐outs than PE (i.e., 29% vs. 64%). At post‐test, improvements were found for both interventions in increased emotion regulation and hope, and reduced PTSD symptoms, hostility, experiential avoidance, and mental health problems. At a four‐month follow‐up, comparable proportions (approximately 40%) of recipients in each therapy maintained clinically significant gains. Self‐rated expectancy of therapeutic outcome and working alliance was comparable for both PE and TARGET early in therapy, at mid‐treatment, and at the end of treatment. While preliminary, these results suggest that TARGET may be a viable therapeutic option for male military veterans with PTSD and anger problems.
Growth and Characterization of α and β Polymorphs of l‐Glutamic Acid and its Anticancer and Antibacterial Application
Authors: Aarthi Jayaraj , Dhanasekaran Palanisamy , Senthil T. Subramaniyam , Ganesan N. Muthukrishnan 
Published: April 2018

AbstractIn this work, l‐glutamic acid polymorphs of metastable α and stable β crystals are grown by slow evaporation method. The selective additive l‐phenylalanine is added at different concentrations into the l‐glutamic acid aqueous solution and the effect of the additive on l‐glutamic acid polymorphs is reviewed. It is creating that at a level of 0.04 g/100 ml concentration, the additive contributes to the crystallization of l‐glutamic acid in α‐form. Powder X‐ray diffraction study of grown α and β crystals belongs to the orthorhombic crystal structure. The UV‐Vis spectral analysis of both α and β crystals have a high transparency range in the complete visible region. Functional groups present in the crystals are identified by FTIR spectroscopic analysis. DSC study reveals that both polymorphs is stable and does not show any phase transformation until their melting. Antibacterial activity study is carried out against human pathogens. DPPH radical scavenging study, exhibit good antioxidant activity and calculated the IC50 value of α (217.43 µg ml−1) and β (233.57 µg ml−1) polymorphs, this value comparable with standard Vitamin C (201.72 µg ml−1). The anticancer activity study identify the both polymorphs inhibit the cancer cell line and calculate the IC50 value of α (165.21µg ml−1) and β (145.49 µg ml−1) polymorphs.