bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient Solar Energy Harvesting and Storage through a Robust Photocatalyst Driving Reversible Redox Reactions
Authors: Zhou Yangen , Zhang Shun , Ding Yu , Zhang Leyuan , Zhang Changkun , Zhang Xiaohong , Zhao Yu , Yu Guihua
Published: June 2018

Simultaneous solar energy conversion and storage is receiving increasing interest for better utilization of the abundant yet intermittently available sunlight. Photoelectrodes driving nonspontaneous reversible redox reactions in solar‐powered redox cells (SPRCs), which can deliver energy via the corresponding reverse reactions, present a cost‐effective and promising approach for direct solar energy harvesting and storage. However, the lack of photoelectrodes having both high conversion efficiency and high durability becomes a bottleneck that hampers practical applications of SPRCs. Here, it is shown that a WO3‐decorated BiVO4 photoanode, without the need of extra electrocatalysts, can enable a single‐photocatalyst‐driven SPRC with a solar‐to‐output energy conversion efficiency as high as 1.25%. This SPRC presents stable performance over 20 solar energy storage/delivery cycles. The high efficiency and stability are attributed to the rapid redox reactions, the well‐matched energy level, and the efficient light harvesting and charge separation of the prepared BiVO4. This demonstrated device system represents a potential alternative toward the development of low‐cost, durable, and easy‐to‐implement solar energy technologies.
A Theoretical and Experimental View on the Temperature Dependence of the Electronic Conduction through a Schottky Barrier in a Resistively Switching SrTiO3‐Based Memory Cell
Authors: Funck Carsten , Marchewka Astrid , Bäumer Christoph , Schmidt Peter C. , Müller Phillip , Dittmann Regina , Martin Manfred , Waser Rainer , Menzel Stephan
Published: June 2018

Metal–semiconductor Schottky interfaces are of high interest in many fields of semiconductor physics. One type of electronic devices based on Schottky contacts are resistive switching cells. The mostly applied analytical models are insufficient to describe all Schottky contact systems, which further impedes finding the correct conduction mechanism and may lead to physical misunderstandings. In this work, the electron transport properties of the resistively switching SrTiO3/Pt interface model system are investigated using a combination of experimental and theoretical methods. Temperature‐dependent I–V curves are measured and analyzed using an analytical approach, an atomistic approach based on density functional theory and the nonequilibrium Green's function formalism, and a continuum modeling approach. The findings suggest two different conduction mechanisms. Instead of a current transport over the barrier, as in the case of Schottky emission theory, the simulations show that tunneling through the Schottky barrier dominates. In the low voltage range, only thermally excited electrons can tunnel into the conduction band. For higher voltages, the SrTiO3 conduction band and the Fermi level at the injecting Pt‐electrode are aligned, allowing also electrons at the Fermi‐edge to tunnel. Consequently, the temperature dependence changes, leading to a crossing of the I–V curves at different temperatures.
Directed Graphene‐Based Nanoplatforms for Hyperthermia: Overcoming Multiple Drug Resistance
Authors: Tu Zhaoxu , Qiao Haishi , Yan Yuting , Guday Guy , Chen Wei , Adeli Mohsen , Haag Rainer
Published: June 2018

Multidrug resistance (MDR), which leads tumors resistance to traditional anticancer drugs, can cause the failure of chemotherapy treatments. Herein, we present a new way to overcome this problem using smart multifunctional graphene‐based drug delivery systems which can target subcellular organelles and show synergistic hyperthermia and chemotherapy. Mitochondria‐targeting ligands are conjugated onto the doxorubicin‐loaded, polyglycerol‐covered nanographene sheets to actively accumulate them inside the mitochondria after charge‐mediated cellular internalization. Upon near‐infrared (NIR) irradiation, adenosine triphosphate (ATP) synthesis and mitochondrial function were inhibited and doxorubicin released into the cellular interior. The hyperthermia‐accelerated drug release led to a highly selective anticancer efficiency, confirmed by in vitro and in vivo experiments.
A 3D Organically Synthesized Porous Carbon Material for Lithium‐Ion Batteries
Authors: Zhao Ziqiang , Das Saikat , Xing Guolong , Fayon Pierre , Heasman Patrick , Jay Michael , Bailey Steven , Lambert Colin , Yamada Hiroki , Wakihara Toru , Trewin Abbie , Ben Teng , Qiu Shilun , Valtchev Valentin
Published: June 2018

We report the first organically synthesized sp–sp3 hybridized porous carbon, OSPC‐1. This new carbon shows electron conductivity, high porosity, the highest uptake of lithium ions of any carbon material to‐date, and the ability to inhibit dangerous lithium dendrite formation. The new carbon exhibits exceptional potential as anode material for lithium‐ion batteries (LIBs) with high capacity, excellent rate capability, long cycle life, and potential for improved safety performance.
Comparing Neutral (Monometallic) and Anionic (Bimetallic) Aluminum Complexes in Hydroboration Catalysis: Influences of Lithium Cooperation and Ligand Set
Authors: Pollard Victoria A. , Fuentes M. Ángeles , Kennedy Alan R. , McLellan Ross , Mulvey Robert E.
Published: June 2018

Bimetallic lithium aluminates and neutral aluminum counterparts are compared as catalysts in hydroboration reactions with aldehydes, ketones, imines and alkynes. Possessing Li–Al cooperativity, ate catalysts are found to be generally superior. Catalytic activity is also influenced by the ligand set, alkyl and/or amido. Devoid of an Al−H bond, iBu2Al(TMP) operates as a masked hydride reducing benzophenone through a β‐Η transfer process. This catalyst library therefore provides an entry point into the future design of Al catalysts targeting substrate specific transformations.
Isonitrile Formation by a Non‐Heme Iron(II)‐Dependent Oxidase/Decarboxylase
Authors: Harris Nicholas C. , Born David A. , Cai Wenlong , Huang Yaobing , Martin Joelle , Khalaf Ryan , Drennan Catherine L. , Zhang Wenjun
Published: June 2018

The electron‐rich isonitrile is an important functionality in bioactive natural products, but its biosynthesis has been restricted to the IsnA family of isonitrile synthases. We herein provide the first structural and biochemical evidence of an alternative mechanism for isonitrile formation. ScoE, a putative non‐heme iron(II)‐dependent enzyme from Streptomyces coeruleorubidus, was shown to catalyze the conversion of (R)‐3‐((carboxymethyl)amino)butanoic acid to (R)‐3‐isocyanobutanoic acid through an oxidative decarboxylation mechanism. This work further provides a revised scheme for the biosynthesis of a unique class of isonitrile lipopeptides, of which several members are critical for the virulence of pathogenic mycobacteria.
An Intrinsically Self‐Healing NiCo||Zn Rechargeable Battery with a Self‐Healable Ferric‐Ion‐Crosslinking Sodium Polyacrylate Hydrogel Electrolyte
Authors: Huang Yan , Liu Jie , Wang Jiaqi , Hu Mengmeng , Mo Funian , Liang Guojin , Zhi Chunyi
Published: June 2018

Self‐healing solid‐state aqueous rechargeable NiCo||Zn batteries are inherently safe and have a high energy density and mechanical robustness. However, the self‐healability of solid‐state batteries has only been realized by a few studies in which electron/ion‐inactive self‐healable substrates are utilized. This arises from the lack of self‐healable electrolytes. Now an intrinsically self‐healing battery has been designed that utilizes a new electrolyte that is intrinsically self‐healable. Sodium polyacrylate hydrogel chains are crosslinked by ferric ions to promote dynamic reconstruction of an integral network. These non‐covalent crosslinkers can form ionic bonds to reconnect damaged surfaces when the hydrogel is cut off, providing an ultimate solution to the intrinsic self‐healability problem of batteries. As a result, this NiCo||Zn battery with this hydrogel electrolyte can be autonomically self‐healed with over 87 % of capacity retained after 4 cycles of breaking/healing.
The effect of fluorosilicone modifiers on the carbon nanotube networks in epoxy matrix
Authors: Shashkeev Konstantin A. , Kondrashov Stanislav V. , Popkov Oleg V. , Solovianchik Lyudmila V. , Lobanov Maxim V. , Nagornaya Valeria S. , Soldatov Mikhail A. , Shevchenko Vitaly G. , Gulyaev Artem I. , Makarova Viktoria V. , Yurkov Gleb Yu.
Published: June 2018

Structure and properties of polymer compositions based on carbon nanotubes (CNTs) filled epoxy matrix containing fluorosilicone copolymers as additives is discussed. Electrical conductivity and dielectric (microwave) permittivity of the composites can be varied by approximately one order of magnitude without changing the CNT concentration, by careful selection of the additive type and concentration. The mutual solubility of the modifiers and epoxy is a key factor determining both rheological properties of the uncured compositions and electrical properties of cured CNT‐nanocomposites. CNT‐nanocomposites modified with amino‐functional (i.e., epoxy crosslinkable) copolymers demonstrate improved electrical conductivity values at increased additive concentration, connected with the formation of specific segregated microstructure. Fluorosilicone additives added in a specific amount also allow for a decrease of the viscosity of uncured epoxy CNT‐nanocomposites, improving their processability. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46539.
Fire retardancy of polypropylene composites reinforced with rice husks: From oxygen index measurements and cone calorimetry to large‐scale single‐burning‐item tests
Authors: Schirp Arne , Barrio Aitor
Published: June 2018

Rice husks containing 12 wt % inorganic silica were incorporated together with halogen‐free fire retardants in a polypropylene matrix and extruded into facade profiles. An increase in the amount of rice husks resulted in an increase in the oxygen index. The cone calorimetry measurements showed that all of the fire retardants tested significantly reduced the peak heat‐release rate (pHRR) and maximum average rate of heat emission (MARHE) of the formulations and moderately reduced total heat release. The best results in terms of MARHE were achieved for the formulation including 24% melamine‐coated ammonium polyphosphate. pHRR and MARHE were reduced with increasing amount of rice husks. Single‐burning‐item (SBI) tests were performed for the extruded profiles based on rice husks and, for comparison, wood flour. In the best case, a B‐s2, d0 classification was obtained. The results obtained from cone calorimetry and SBI tests were in agreement. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 46654.
Synthesis and characterization of a novel stimuli‐responsive magnetite nanohydrogel based on poly(ethylene glycol) and poly(N‐isopropylacrylamide) as drug carrier
Authors: Mozaffari Zahra , Hatamzadeh Maryam , Massoumi Bakhshali , Jaymand Mehdi
Published: June 2018

A novel stimuli‐responsive magnetite nanohydrogel (MNHG), namely [poly(ethylene glycol)‐block‐poly(N‐isopropylacrylamide‐co‐maleic anhydride)2]‐graft‐poly(ethylene glycol)/Fe3O4 [PEG‐b‐(PNIPAAm‐co‐PMA)2]‐g‐PEG/Fe3O4, was successfully developed. For this purpose, NIPAAm and MA monomers were block copolymerized onto PEG‐based macroinitiator through atom transfer radical polymerization technique to produce PEG‐b‐(PNIPAAm‐co‐PMA)2. The synthesized Y‐shaped terpolymer was crosslinked through the esterification of maleic anhydride units using PEG chains to afford a hydrogel. Afterward, magnetite nanoparticles were incorporated into the synthesized hydrogel through the physical interactions. The chemical structures of all synthesized samples were characterized using Fourier transform infrared and proton nuclear magnetic resonance spectroscopies. Morphology, thermal stability, size, and magnetic properties of the synthesized MNHG were investigated. In addition, the doxorubicin hydrochloride loading and encapsulation efficiencies as well as stimuli‐responsive drug release ability of the synthesized MNHG were also evaluated. The drug‐loaded MNHG at physiological condition exhibited negligible drug release values. In contrast, at acidic (pH 5.3) condition and a little bit higher temperature (41 °C) the developed MNHG showed higher drug release values, which qualified it for cancer chemotherapy due to especial physiology of cancerous tissue in comparison with the surrounding normal tissue. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46657.
A method based on the time–temperature superposition principle to predict pressurization time in compression molding
Authors: Zhang Tao , Zhao Yueqing , Zhang Boming
Published: June 2018

The quality of epoxy composites reinforced by glass fibers and manufactured by compression molding is affected by the pressurization time. Traditional methods, including differential scanning calorimetry and dynamic thermomechanical analysis, cannot be reliably used to predict pressurization time in the scenario of continuous production and inconstant circumstances seen in industry. In this paper, the rheological behaviors of epoxy under constant temperature were investigated and analyzed to verify if the time–temperature superposition (TTS) principle, which defines the relation between time and temperature in the deformation and relaxation response of a viscoelastic material, could be suitably applied to describe them. The results show that the TTS principle could indeed be used to predict resin viscosity by the horizontal shift factor. A new method based on the TTS principle and written into a program to forecast pressurization time in compression molding is proposed. The uniform surface color and the qualified thickness of the composite components using the program indicate that the program works well and that this method is feasible for predicting pressurization time during compression molding. The results of tensile and short‐beam shear strength tests show that pressurization time affects the mechanical properties of the final product. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45308.
Binary phase solid‐state photopolymerization behavior of acrylate cryogels under different light sources
Authors: Ali Safdar , Shehzad Farooq Khurum , Maitlo Inamullah , Valiev Sultan , Muhyodin Ghulam , Nie Jun
Published: June 2018

Two types of cryogels were obtained using 2‐hydroxyethyl acrylate (HEA) and 2‐hydroxyethyl methacrylate (HEMA) by homogeneous mixing with poly(ethylene glycol) diacrylate (PEGDA) as crosslinker at subzero temperature followed by photopolymerization with two different light initiation sources (high‐pressure Hg arc lamp and UV‐LED).The solution was frozen unidirectionally at −60 °C before polymerization and finally photopolymerized at the same temperature. The cryogels were characterized using photo‐DSC, UV–vis and Fourier transform infrared spectroscopy, and scanning electron microscopy techniques. The cryogels cured with an LED light showed a higher polymerization rate and better morphological characteristics than ones cured with a high‐pressure Hg arc. The water intake ratio of HEA/PEGDA was higher than HEMA/PEGDA for both curing sources. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46686.
Use of fluorescein isothiocyanate isomer I to study the mechanism of intestinal absorption of fucoidan sulfate in vivo and in vitro
Authors: Zhang E , Chu Fulong , Xu Lixu , Liang Hao , Song Shuliang , Ji Aiguo
Published: June 2018

A new method to label fucoidan sulfate was established with tyramine and fluorescein isothiocyanate isomer I (FITC). Fluorescence spectrophotometry and high performance liquid chromatography verified the successful labelling of fucoidan by FITC. The results of the single‐pass intestinal perfusion indicated that the jejunum and ileum are the main absorption sites, and there was carrier saturation. In addition, fucoidan sulfate at 1 mg/ml had no inhibitory effect on Caco‐2 cell proliferation. Studies on the transmembrane transport mechanism showed that fucoidan can be absorbed because the apparent permeability coefficient of the drugs (Papp) A → B was 3.78 + 0.03 ×10−6 and that of B → A was 1.42 + 0.19 ×10−6. The peak absorption of fucoidan occurred at 120 min after administration; moreover, the higher the concentration used, the worse the absorption was, suggesting the saturation of transport carriers. The absorption was temperature dependent: the absorption at 37°C was much better than that at 4°C. Further, the absorption of fucoidan sulfate might rely on clathrin endocytosis as chlorpromazine (10 μg/ml) significantly inhibited it.
Combination of Aryl Diselenides/Hydrogen Peroxide and Carbon‐Nanotube/Rhodium Nanohybrids for Naphthol Oxidation: An Efficient Route towards Trypanocidal Quinones
Authors: de Carvalho Renato L. , Jardim Guilherme A. M. , Santos Augusto C. C. , Araujo Maria H. , Oliveira Willian X. C. , Bombaça Ana Cristina S. , Menna‐Barreto Rubem F. S. , Gopi Elumalai , Gravel Edmond , Doris Eric , da Silva Júnior Eufrânio N.
Published: June 2018

This work reports a combination of aryl diselenides/hydrogen peroxide and carbon‐nanotube (CNT)/rhodium nanohybrids (RhCNT) for naphthol oxidation towards the synthesis of 1,4‐naphthoquinones and evaluation of their relevant trypanocidal activity. Under a combination of (PhSe)2/H2O2 in the presence of O2 in iPrOH/hexane, several benzenoid (A‐ring)‐substituted quinones were prepared in moderate to high yields. We also studied the contribution of RhCNT as co‐catalyst in this process and, in some cases, yields were improved. This method provides an efficient and versatile alternative for preparing A‐ring‐modified naphthoquinonoid compounds with relevant biological profile.
Is immune checkpoint inhibition part of standard therapy for stage III non‐small cell lung cancer?
Authors: Patel Jyoti D. , Chmura Steven J.
Published: June 2018

Decades of clinical trials investigating radiation dose modification and systemic therapy intensification have failed to improve outcomes in patients with unresectable stage III NSCLC. Treatment with durvalumab after chemoradiation improves progression free survival three‐fold compared to placebo with minimal increases in toxicity and represents a new standard of care for these patients.
Quality of life in patients with proton‐treated pediatric medulloblastoma: Results of a prospective assessment with 5‐year follow‐up
Authors: Kamran Sophia C. , Goldberg Saveli I. , Kuhlthau Karen A. , Lawell Miranda P. , Weyman Elizabeth A. , Gallotto Sara L. , Hess Clayton B. , Huang Mary S. , Friedmann Alison M. , Abrams Annah N. , MacDonald Shannon M. , Pulsifer Margaret B. , Tarbell Nancy J. , Ebb David H. , Yock Torunn I.
Published: June 2018

BACKGROUND

To the authors' knowledge, health‐related quality of life (HRQOL) outcomes are not well described in patients with medulloblastoma. The use of proton radiotherapy (RT) may translate into an improved HRQOL. In the current study, the authors report long‐term HRQOL in patients with proton‐treated pediatric medulloblastoma.

METHODS

The current study was a prospective cohort HRQOL study of patients with medulloblastoma who were treated with proton RT and enrolled between August 5, 2002, and October 8, 2015. Both child report and parent‐proxy report Pediatric Quality of Life Inventory (PedsQL) surveys were collected at baseline during RT and annually thereafter (score range on surveys of 0‐100, with higher scores indicating better HRQOL). Patients were dichotomized by clinical/treatment variables and subgroups were compared. Mixed‐model analysis was performed to determine the longitudinal trajectory of PedsQL scores. The Student t test was used to compare long‐term HRQOL measures with published means from a healthy child population.

RESULTS

Survey data were evaluable for 116 patients with a median follow‐up of 5 years (range, 1‐10.6 years); the median age at the time of diagnosis was 7.6 years (range, 2.1‐18.1 years). At baseline, children reported a total core score (TCS) of 65.9, which increased by 1.8 points annually (P<.001); parents reported a TCS of 59.1, which increased by 2.0 points annually. Posterior fossa syndrome adversely affected baseline scores, but these scores significantly improved with time. At the time of last follow‐up, children reported a TCS of 76.3, which was 3.3 points lower than that of healthy children (P = .09); parents reported a TCS of 69, which was 11.9 points lower than that of parents of healthy children (P<.001). Increased follow‐up time from diagnosis correlated with improved HRQOL scores.

CONCLUSIONS

HRQOL scores appear to increase over time after treatment in children treated with proton RT for medulloblastoma but remain lower compared with those of parent‐proxy reports as well as published means from a healthy normative sample of children. Additional follow‐up may translate into continued improvements in HRQOL. Cancer 2018. © 2018 American Cancer Society.
Investigation of raphe function in the bicuspid aortic valve and its influence on clinical criteria—A patient‐specific finite element study
Authors: Dallard Jérémy , Labrosse Michel R. , Sohmer Benjamin , Beller Carsten J. , Boodhwani Munir
Published: June 2018

The aortic valve is normally composed of 3 cusps. In one common lesion, 2 cusps are fused together. The conjoined area of the fused cusps is termed raphe. Occurring in 1% to 2% of the population, the bicuspid aortic valve (BAV) is the most common congenital cardiac malformation. The majority of BAV patients eventually require surgery. There is a lack in the literature regarding modeling of the raphe (geometry and material properties), its role and its influence on BAV function. The present study aims to propose improvements on these aspects. Three patient‐specific finite element models of BAVs were created based on 3D trans‐esophageal echocardiography measurements, and assuming age‐dependent material properties. The raphe was initially given the same material properties as its underlying cusps. Two levels of validation were performed; one based on the anatomical validation of the pressurized geometry in diastole (involving 7 anatomical measures), as simulated starting from the unpressurized geometry, and the other based on a functional assessment using clinical measurements in both systole and diastole (involving 16 functional measures). The pathology was successfully reproduced in the FE models of all 3 patients. To further investigate the role of the raphe, 2 additional scenarios were considered; (1) the raphe was considered as almost rigid, (2) the raphe was totally removed. The results confirmed the interpretation of the raphe as added stiffness in the fused cusp's rotation with respect to the aortic wall, as well as added support for stress distribution from the fused cusps to the aortic wall.
Electrochemical Oxidation of 5‐Hydroxymethylfurfural to 2,5‐Furandicarboxylic Acid (FDCA) in Acidic Media Enabling Spontaneous FDCA Separation
Authors: Kubota Stephen R. , Choi Kyoung‐Shin
Published: June 2018

2,5‐Furandicarboxylic acid (FDCA) has become an increasingly desirable platform chemical to replace terephthalic acid in the production of a variety of polymeric materials, including polyethylene terephthalate. FDCA can be produced by the oxidation of 5‐hydroxymethylfurfural (HMF), which can be derived from cellulosic biomass. Oxidation of HMF to FDCA is typically performed under basic conditions. Separation of FDCA is most easily accomplished by lowering the pH until FDCA is insoluble and filtering it from solution. In a large‐scale process, this would lead to a high operating cost to purchase the required acid and base and to dispose of the resulting salt waste. In this study, electrochemical oxidation of HMF was carried out in acidic media by using a manganese oxide (MnOx) anode to remove the need to vary the pH to separate FDCA. The MnOx anode afforded a FDCA yield of 53.8 % in a pH 1 H2SO4 solution, in which FDCA precipitation occurred spontaneously from the same reaction solution without altering the pH or other aspects of the solution composition. Electrochemical oxidation in acidic media offers a new pathway to convert HMF into maleic acid, which is another desirable biomass‐derived platform molecule. The performance of the MnOx anode was investigated in comparison with that of a Pt anode to identify unique electrocatalytic properties of the MnOx anode for HMF oxidation.
Iron(III) Complexes with Cross‐Bridged Cyclams: Synthesis and Use in Alcohol and Water Oxidation Catalysis
Authors: Annunziata Alfonso , Esposito Roberto , Gatto Giordano , Cucciolito Maria Elena , Tuzi Angela , Macchioni Alceo , Ruffo Francesco
Published: June 2018

A class of iron(III) complexes containing diversely substituted cross‐bridged cyclams (1‐R,R′: 1‐Me,Me, 1‐Me,Et, 1‐Et,Et, 1‐Me,Bn, 1‐Bn,Bn) has been prepared and characterized. (1‐R,R′) complexes catalyze the oxidation of alcohols to ketones in green conditions, by using tert‐butylhydroperoxide as the oxidant in aqueous solutions. They also exhibit catalytic activity in water oxidation (WO) to molecular oxygen driven by NaIO4, and the results were found to be dependent on the steric hindrance of the R‐substituents. Best compromise in terms of accessibility and protection of the metal center was obtained with 1‐Me,Et (TOF = 1.4 min–1 and TON = 111).
Aminodecalone Scaffolds – Enantioselective Synthesis, Indole and Quinoline Annulation
Authors: Schäfer Benjamin , Schmidtmann Marc , Christoffers Jens
Published: June 2018

Optically active benzo[b]carbazole and benzo[b]acridine derivatives were prepared by Fischer indole or Friedländer quinoline annulation from 2‐oxodecalone‐4a‐carboxylates with a quaternary stereocenter. As an additional point for diversification, the target compounds carry a nitro function, which was transformed to an amide or lactam after reduction. The scaffold itself was accessed by asymmetric, copper catalyzed Michael reaction of a β‐oxoester with methyl vinyl ketone utilizing l‐valine diethyl amide as chiral auxiliary. Two enantiopure, epimeric compounds were obtained with 99 % ee and 92 % ee, which were separated and in parallel sequences submitted to intramolecular aldol reaction and catalytic hydrogenation furnishing the 2‐oxodecalone scaffolds. As a precursor for the primary amino group, the scaffolds contained a nitro function at their 6‐positions, which was reduced at the end of the synthetic sequence. The relative and absolute configurations of all three stereocenters were established by X‐ray crystallography.
SOX2‐mediated upregulation of CD24 promotes adaptive resistance toward targeted therapy in melanoma
Authors: Hüser Laura , Sachindra Sachindra , Granados Karol , Federico Aniello , Larribère Lionel , Novak Daniel , Umansky Viktor , Altevogt Peter , Utikal Jochen
Published: June 2018

Melanoma is often characterized by a constitutively active RAS‐RAF‐MEK‐ERK pathway. For targeted therapy, BRAF inhibitors are available that are powerful in the beginning but resistance occurs rather fast. A better understanding of the mechanisms of resistance is urgently needed to increase the success of the treatment. Here, we observed that SOX2 and CD24 are upregulated upon BRAF inhibitor treatment. A similar upregulation was seen in targeted therapy‐resistant, melanoma‐derived induced pluripotent cancer cells (iPCCs). SOX2 and CD24 are known to promote an undifferentiated and cancer stem cell‐like phenotype associated with resistance. We, therefore, elucidated the role of SOX2 and CD24 in targeted therapy resistance in more detail. We found that the upregulation of SOX2 and CD24 required activation of STAT3 and that SOX2 induced the expression of CD24 by binding to its promoter. We find that the overexpression of SOX2 or CD24 significantly increases the resistance toward BRAF inhibitors, while SOX2 knock‐down rendered cells more sensitivity toward treatment. The overexpression of CD24 or SOX2 induced Src and STAT3 activity. Importantly, by either CD24 knock‐down or Src/STAT3 inhibition in resistant SOX2‐overexpressing cells, the sensitivity toward BRAF inhibitors was re‐established. Hence, we suggest a novel mechanism of adaptive resistance whereby BRAF inhibition is circumvented via the activation of STAT3, SOX2 and CD24. Thus, to prevent adaptive resistance, it might be beneficial to combine Src/STAT3 inhibitors together with MAPK pathway inhibitors.
Metric Advocates Support “Total Immersion” Concept
Authors: Reese Willard , Cathcart George
Published: June 2018

Advocates of metric conversion are convinced that the only way to accomplish the switch is by “total immersion,” using metric units exclusively. This idea was proposed and tested at a workshop with forty participants. An experiment was conducted to see how many remembered their heights and weights in metric units. The result was that, when forced to think metric, people will remember metric.
Cross Connections—Legal or Lethal?
Authors: Markwood Ira M.
Published: June 2018

The hazards of cross connections are discussed, as well as methods of preventing contamination from occurring. Positive air gaps, vacuum breakers, a diaphragm‐operated valve, and backflow prevention devices are covered.
Venturi Tubes — Another Look At A Basic Principle
Authors: Price Benton C.
Published: June 2018

A Venturi tube is a construction in a pipeline that is used to measure flow rates. Various formulas for measuring flow are given. The basic principles of operation are explained.
Reducing Meter Leaks Cuts Claims For Water Damage
Authors: Maz Albert C.
Published: June 2018

Many houses still have meters with mechanical drive couplings utilizing the stuffing box as a means of driving the register gears to indicate the amount of water used. The problem with this type of meter is that the stuffing box sometimes leaks, causing damage to floors and walls. To avoid damage claims from such leaks, the Elizabethtown Water Company in New Jersey started using PTFE packing, cut from rods and drilled to specification to stop the leaks. They have not had a failure since 1968 and have installed the packing in over 81,000 meters.
Butterfly Valves In A Distribution System
Authors: Poland Donald L.
Published: June 2018

This article was a paper presented at the AWWA Indiana Section meeting, February 1976. The application and use of butterfly valves is discussed as well as experiences with them at the Fort Wayne Water Utility, their advantages, maintenance, and specifications.
Lab Holds Key To Water Quality Law
Authors: Fargue Aubrey La
Published: June 2018

With the implementation of the Safe Drinking Water Act, water quality laboratories will be required to undertake more monitoring and analyses of water. In order to keep costs down while maintaining efficiency, several pieces of equipment which have multiple uses can be purchased. Equipment discussed includes the jar machine, the pH meter, turbidity meters, colorimeters, atomic absorption units, and the gas chromatograph.
Save Energy: Use This Method to Check Pumping Efficiency
Authors: Gros William F. H.
Published: June 2018

In order for a centrifugal pump to operate at its maximum capacity several factors need to be considered such as the pump head itself, friction losses, installation of new pumps and the use of power motors to help increase pump capacity.
Dual Media Filtration in Montana
Authors: Skinner Jim
Published: June 2018

The Great Falls Montana Water Plant experienced problems with its filters, which were found to be air bound and clogged by mud balls. In order to remedy the situation, several dual sand and anthracite coal filters were installed. The results were longer filter runs and a savings in washwater.
Diverting Raw Water Prevents Quality Deterioration In Aspen
Authors: Markalunas James J.
Published: June 2018

The city of Aspen, Colorado has taken steps to prevent deterioration of its raw water quality. During the spring melt and summer rains, Castle Creek becomes highly turbid and high in iron content. To prevent this water from entering the city's intake and raw water reservoir, a system was devised to turn off the raw water diversion and restore the raw water pipeline to service after the situation has been cleared up. System operation and the advantages of the system are discussed.
Motorized Equipment Increases Efficiency For Smaller Systems
Authors: Ramey Jesse C.
Published: June 2018

The use of trucks, excavators, and cranes for distribution system construction, operation, maintenance and repair can be economical to small water systems.
Classification, Collection And Concentration Of Sludge
Authors: Doe Peter W.
Published: June 2018

Among the different types of sludge discussed are iron/manganese sludge, lime softening sludge, alum sludge, polymer sludge, and ferric chloride sludge. Also presented are methods of sludge collection and concentration.
Check Pump Efficiency
Authors: Gros Wm. F.H.
Published: June 2018

Procedures for testing pump efficiency and an example of necessary computation are provided in this article.
Selection and Application of Dry‐Chemical Feeders
Authors: Stearns David M.
Published: June 2018

This article is a review of the more common parameters which should be considered when selecting a dry‐chemical feeding system. Things to consider in the process requirements are the chemicals, maximum feed rate, rangeability, hydraulics, physical limitations, alternate chemicals and standby. When selecting a specific feeder, the functions of starting and stopping, feed‐rate control and supervisory controls need to be looked at. Chemical handling characteristics such as bulk density and particle size, flowability, solubility, and materials and construction, house keeping and safety and chemical conditioning are also very important to the selection of the feeding system.
Efficient, Low Cost DPD Chlorine Test
Authors: Engelhardt Terry
Published: June 2018

The water utility in Longmont, Colorado has set up their own small laboratory to perform DPD chlorine tests and they prepare their own solutions, saving them the expense of using prepackaged reagents.
Water Towers and Ice Build Up
Authors: Leary Charles J
Published: June 2018

This article presents information on the types of damage which can occur to water tanks from the formation of ice on tank interiors and exteriors. Also discussed are methods for thawing the ice and a suggested method to avoid extensive ice build up.
Maintaining Your Commercial/Industrial Meters Doesn't Cost—It Pays
Authors: Edgar J T
Published: June 2018

Proper maintenance of meters will assure a long life and accurate meter readings will insure the correct amount of revenue for utilities. There are several ways that repairs to meters may be accomplished. One is to remove them completely and return them to the factory for service, or the utility could purchase the necessary tools and train personnel to take care of the meters. Contracts with outside firms specializing in meter repair and maintenance may be negotiated. Once meters are repaired, it is important to implement a schedule of periodic testing.
Lateral Connections to Pressurized Water Mains (Wet Tapping) Part I
Authors: Morrow Darrel , Breheny Michael J. , Seevers F.R. Dick
Published: June 2018

Wet tapping is tapping a service line into a main that is flowing full under pressure. Methods of wet tapping and precautions which need to be observed are presented.
How to Establish a Preventive Maintenance Program
Authors: Martin William J. , Jacobs Albert L.
Published: June 2018

Step‐by‐step guidelines for the implementation of a preventive maintenance program are given. Hiring of supervisors and operators prior to facility start‐up and the need for a straightforward and flexible program are covered.
Failure to Inspect and Routinely Maintain Rapid‐Sand Filters Results in Extra Labor and Expense for Blissfield, Michigan
Authors: Benzie Richard E. , Van Norman Paul
Published: June 2018

This article describes the deterioration and rehabilitation of rapid sand filters in Blissfield, Michigan. Bonded sand and gravel caused by calcium carbonate carryover into the filters and gravel mounding caused by poor distribution of the backwash water resulting from plugged underdrains created critical operational inefficiencies in the village's water treatment plant. Routine inspection and maintenance could have prevented this occurrence.
From Old Pump House to “Marble Palace”
Authors: Pearson William S.
Published: June 2018

This article describes the renovation of a pump house in Hampstead, Maryland. The refurbished station, which houses chemical storage tanks, metering feed pumps and tubing, and well piping to the distribution system, also contains a control system of automatically regulated pumps.
Destratification and Thermal Inversion (Reservoir Turnover)
Authors: Beer Charles R.
Published: June 2018

Bodies of water such as reservoirs and lakes stratify into upper layers called circulation zones, middle layers called thermoclines, and lower layers called stagnation zones. Turnover of these layers can cause unpleasant taste and odor in the water during the spring and the fall. To avoid the sudden water quality changes that occur with turnover, a water body may be destratified artificially by adding air or oxygen to the stagnation zone, or by pumping water from the stagnation zone to the circulation zone to keep the layers mixed and destroy the thermocline.
Tips on Proper Care of Your Filters
Authors: Curry Michael
Published: June 2018

Some common problems associated with sand filters and various suggestions for keeping filters operating properly are discussed. Among the problems which can occur are loss of head, algae, backwashing, mudballs, air binding and loss of sand.
Preventive Maintenance of Controls
Authors: Shubert W.M.
Published: June 2018

Preventive maintenance is stressed as a way to save money and energy. Covered in this article are the maintenance of motor control centers, variable speed drivers, and instrumentation.
Leak Detection: Two Methods That Work—Part I
Authors: Cole G. Brewster
Published: June 2018

This article points out why interest in leak detection has risen dramatically in the past few years, and notes that the approaches to the problem cluster around listening methods and a combination of flow measurements and listening referred to as the “water audit” method. The listening method, equipment, and procedure are covered.
Cleaning, Recoating Water Storage Tanks
Authors: Miller Al
Published: June 2018

This article presents a procedures plan developed from questions asked about cleaning and painting an average size (100,000‐gal) elevated storage tank exceeding AWWA standards and about coating the interior of the tank with a two‐coat, high‐build epoxy system (AWWA interior system No.1).
Brush Up on Flow Rate Calculations
Authors: Rieman John
Published: June 2018

This portion of “Math for Operators” covers flow rate calculations. Definitions of velocity and flow rate are given, and the relationship between them is described. The continuity equation is covered as well.
Monitor Power Rates Through Electric Meters
Authors: Kramer Chris
Published: June 2018

Operators can use electric meters for maintaining a close watch on energy use. This author suggests that operators obtain rate schedules and previous electric bills, record and interpret meter readings daily, and use capacitors.
Gimmicks and Gadgets
Authors: Goodwin Lee
Published: June 2018

Several slogans advising fuel conservation were designed and printed on self‐adhesive paper in various bright, day‐glow colors. Each month, a different reminder sticks to the dashboard of trucks used by city employees in Vancouver, Washington.
Gimmicks and Gadgets
Authors: Sherman Stan
Published: June 2018

In North Platte, Nebraska, the Water Department sent out a letter which provided customers with many suggestions for preventing freezing in meters, interior piping running along exterior walls in unheated crawl spaces, and outside service lines.
Rural water associations—one resource for the “little guy”
Authors: Johnson Rob
Published: June 2018

The National Rural Water Association and local versions of the national association aid small water systems in many ways. Assistance is provided in the areas of operation and maintenance, management and financing, and water quality. Troubleshooting services are available for problems with water loss, chlorinators, pumps, control valves, water rates, and water treatment.
Chlorination—a proven means of disinfecting mains
Authors: Stevens Robert L. , Dice Jack C.
Published: June 2018

The first part of a two‐part series on chlorine disinfection, this article describes chlorine gas, calcium hypochlorite, and sodium hypochlorite, and also covers crew training, safety procedures, and methods of application including the continuous flow technique.
Action Now seminars haul operators… out of the pits!
Authors: Motzner Ron
Published: June 2018

The Action Now program has helped many small systems operators with problems concerning meter maintenance, fire hydrant inspection and maintenance, operator certification, chlorination, water tank inspection, valve maintenance, and safety. The success of the program in states comprising the Rocky Mountain Section of AWWA is described.
Chlorination—pills for pipe and techniques for tanks
Authors: Stevens Robert L. , Dice Jack C.
Published: June 2018

This article covers the use of chlorine tablets and the disinfection of clear‐water storage facilities. The basic references for these subjects are AWWA standards C601‐81, Disinfecting Water Mains, and D10580, Disinfection of Water Storage Facilities.
A perspective on leak detection
Authors: Laverty Gordon L.
Published: June 2018

This two‐part article is one of several papers chosen from over 30 papers presented at the first Distribution System Symposium (Feb. 24–27. 1980) in Los Angeles. OpFlow presents this and subsequent articles as examples of the high quality of material presented at the DSS.

Part I (Dec. 1980 OpFlow) discussed six major aspects of planning a leak detection program. Part II, presented here, discusses organizing and conducting a leak detection program.
Iron bacteria problems in wells
Authors: Smith Stuart
Published: June 2018

Two major forms of iron bacteria are Gallionella and the Actinomycete group members. These bacteria aid processes which cause slime on well pipes and in water systems, and may result in sudden iron staining, reduced well yield, unpleasant taste and odor, and corrosion. Methods of preventing iron bacterial contamination include use of chlorine disinfectants, circulatory tanks, hypochlorites, quaternary ammonium compounds, acetic acid, and heat.
Development and rehabilitation of water wells
Authors: McNichol Richard F.
Published: June 2018

A water well is a hydraulic structure that can become either an efficient tool or a highly inefficient, poorly constructed problem. Efficient water wells depend on construction and development techniques to improve permeability around the well. Good results have been obtained through surging, the high pressure jetting technique, and over‐pumping and air‐development methods.
Fire pluqs don't operate undercover
Authors: Huls Roy L.
Published: June 2018

An effective indication of an unusable hydrant is a brightly colored cover made of a plastic‐impregnated nylon with a heavily webbed reinforcing tape.
Portable training box saves time
Authors: Kelly James
Published: June 2018

A City of Phoenix Water Service investigator designed and built a portable training aid for instructing new employees in replacement of meters and meter valves under pressure. The box can be constructed to simulate different types of sealed meter installations.
Industrial Hygiene Prevents “Chemi‐Kill” Injuries
Authors: Holler Albert C.
Published: June 2018

Industrial hygiene should be an important concern to all water utility and treatment plant workers. This article defines acute and chronic exposure and threshold‐limit value, and gives examples of and methods of preventing inhalation, skin contact, and eye contact. Chemicals discussed include activated carbon, algicides, corrosion inhibitors, iron salts, hydrogen peroxide, sodium hydroxide (caustic soda), sulfuric acid, chlorine, and sodium chlorite.
Pumps—Mechanical ‘Hearts’ of the Water Industry
Authors: Gierer Bill
Published: June 2018

Centrifugal, vertical‐turbine, piston, and metering pumps are covered in this article. Theories of operation, preventive maintenance, and troubleshooting are discussed.
Filtration the ‘Gritty’ Process of Removing Impurities
Authors: Hart D.H.
Published: June 2018

This is part one of a two‐part article which covers water filtration processes in general. Definitions of filter media, adsorption, influent water, and floc are given, followed by a discussion of various types of filters.
SMP Insurance Policy Protects Water Utilities
Authors: Nelson Jerry
Published: June 2018

A special multi‐peril (SMP) insurance policy provides a water utility with comprehensive coverage in a wide variety of situations. The SMP package may offer crime protection coverage through fidelity bond, broad form money and securities, and depositors' forgery insurance. Miscellaneous SMP insurance commonly covers signs, water storage tanks, contractor and radio equipment, accounts receivable, and valuable papers. Other separate insurance programs discussed include workers' compensation, earthquake, flood, Directors and Officers, umbrella, and automobile insurance. The first part of this two‐part article appeared in the May 1982 issue of Opflow.
Backwashing—Flushing the Impurities Out of Filters
Authors: Hart D.H.
Published: June 2018

In this second part of “Filtration ‐ the ‘Gritty’ Process of Removing Impurities,” the term “head loss” is defined, measurements of head loss are discussed, back‐ washing and surface washing techniques are described, and filtration and backwashing rates are calculated. The first part of the article appeared in the June 1982 issue of OpFlow.
Drain Valve Controls Meters in Seasonal Homes
Authors: Ciesla Andrew R.
Published: June 2018

One‐time installation of a brass drain valve in the meters of seasonal (summer) homes eliminates yearly service calls and allows winterization without removing meters. Installation procedures are provided here.
Chlorine—‘Special Agent’ for Disinfecting Water
Authors: Leidholdt Ralph
Published: June 2018

Chlorination is considered the most economical, efficient, and easily‐applied method of disinfecting water. This article discusses three forms of chlorine used to disinfect water, chlorine (liquid or gas), calcium hypochlorite, and sodium hypochlorite. Chlorine residual is also defined. Three sample dosage calculation problems accompany the article.
These Deposits Take a Lot of Elbow Grease'
Authors: Smith Gary R.
Published: June 2018

This article describes the problem of copper oxide deposits which occurred in that portion of a municipal water supply where the water was of medium hardness and not softened during water treatment procedures. Customers complained of blue‐green deposits on plumbing fixtures, lavatories, bathtubs, and shower stalls. The copper oxide deposits were found both in new homes utilizing a water‐softening unit and in new homes without softening units. To solve the problem, the water utility recommended that customers who had installed water‐softening units either remove the units or bypass them for three to six months to allow a protective scale coating to build up in the newly installed pipes.
Calibration Procedures for Chemical Feed Systems
Authors: Tesar Mike
Published: June 2018

This article presents general procedures for calibrating several types of liquid‐ and dry‐chemical feeders, such as large‐volume metering pumps for liquid alum, small‐volume metering pumps for sodium hexametaphosphate, and dry‐chemical feed systems for such chemicals as activated carbon, fluoride, and lime. Pump calibrations can be used to determine the pump setting needed to deliver a required chemical feed rate.