bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical investigations on geometrical and electronic structures of silver clusters
Authors: Tsuneda Takao
Published: October 2018

Geometrical structures and ground and excited states of silver clusters are theoretically investigated using long‐range corrected (LC) density functional theory (DFT) calculations. The discrepancy between HOMO‐LUMO gaps and the vertical ionization potential minus vertical electron affinity values, which should be the same values, is explored to reveal the significance of long‐range exchange effects on the electronic states of metal clusters. The difference between HOMO‐LUMO gaps and HOMO‐LUMO excitation energies, which is called “exciton binding energy,” is also tested. As a result, it is found that the long‐range exchange effects are requisite in DFT calculations to quantitatively investigate the ground and excited states of metal clusters. © 2018 Wiley Periodicals, Inc.
Ru‐Sn‐B/TiO2 catalysts for methyl oleate selective hydrogenation. Influence of the preparation method and the chlorine content
Authors: Sánchez María A , Mazzieri Vanina A , Pronier Stéphane , Vicerich María A , Especel Catherine , Epron Florence , Pieck Carlos L
Published: October 2018

BACKGROUND

Fatty alcohols are produced commercially by selective hydrogenation of fatty acid esters using copper‐chromium catalysts. To reduce drastic reaction conditions, ruthenium‐tin (Ru‐Sn) catalysts reduced with sodium borohydride (NaBH4) have been proposed. Chlorine (Cl) negatively affects the selectivity and activity of this catalytic system. To get further information on why Cl influences the selectivity negatively, this study investigated the influence of the preparation method on titania (TiO2)‐supported catalysts, which leads to catalysts with different Cl contents.

RESULTS

The activity and selectivity were greatly affected by the Cl content, which depends on the metal impregnation method (co‐impregnation in excess of solution or co‐impregnation by incipient wetness) and the support pre‐calcination. Chlorine affects the Ru–Sn metal interaction, modifying the activity and selectivity. Catalysts with high Ru–Sn interaction are more selective to oleyl alcohol. Catalysts prepared by the co‐impregnation method exhibit bigger particles than catalysts prepared by the incipient wetness method, with agglomerated Ru3Sn7 cubic phase of 50 nm surrounded by amorphous Ru‐Sn.

CONCLUSION

High interaction between Ru and Sn is preferred because segregated Ru species are not selective for the formation of oleyl alcohol. The electronic state of Ru0 is very important because small variations in the electron density lead to a decrease in the adsorption of hydrogen, or because Ru0‐H species do not have the adequate binding energy to produce the necessary ‘hydride form’. The Ru electronic state is modified by the Cl that surrounds it, decreasing its ability to adsorb hydrogen. © 2018 Society of Chemical Industry
Doppler ultrasonographic and clinical features of middle aortic syndrome
Authors: Yan Lei , Li Hai‐Ying , Ye Xiao‐Jian , Xu Rong‐Quan , Chen Xiao‐Yu
Published: October 2018

Objectives

To discuss Doppler ultrasonographic and clinical features of middle aortic syndrome (MAS).

Materials and methods

Doppler ultrasonographic images and clinical dates of 11 patients with MAS confirmed by angiography were retrospectively analyzed from January 2004 to September 2016.

Results

The median age of 11 patients was 10 years (1‐39 years). Ten patients presented with hypertension, only 2 cases presented with symptomatic intermittent claudication, and 1 case presented with abdominal pain. The ultrasonographic features of 11 patients with MAS included: (a) Gray‐scale image showed significant segmental narrowing of the aorta in 9 cases. (b) Color Doppler demonstrated aliasing in the suspicious narrowed vessels of all cases. (c) On Spectral Doppler image, peak systolic velocity in the location of aorta coarctation was significantly elevated (range, 2.3~4.8 m/s). When infrarenal aorta was involved, a tardus‐parvus waveform was only seen in the distal aorta. When suprarenal or inter‐renal aorta was involved, a tardus‐parvus pattern was seen in the distal aorta as well as renal artery.

Conclusions

Significant segmental narrowing and a tardus‐parvus waveform are the important ultrasonographic features in patients with MAS, the latter may be more reliable. Doppler ultrasound can be used as a simple screening method, especially for children and adolescents suspected of having a vascular cause of refractory hypertension.
Carotid arterial wall stiffness correlates positively with impedance of the umbilical and uterine arteries in women with preeclampsia
Authors: Li Jingyu , Wang Bin , Cai Ailu , Yuan Qian , Ding Hao , Zhao Dan
Published: October 2018

Purpose

This study aimed to determine whether the stiffness of the arterial walls of women with preeclampsia (PE) differs from that of healthy controls and to evaluate its association with fetal and uterine artery Doppler variables and perinatal outcomes in PE.

Methods

We enrolled 30 women with PE and 30 normotensive pregnant women. Carotid artery stiffness and Doppler variables of the uterine, umbilical, and fetal middle cerebral arteries and the ductus venosus were measured in both groups. Measurements of the common carotid artery were performed by the Aloka ultrasonic echo‐tracking technique.

Results

Stiffness of the carotid artery wall of women with PE was significantly higher than that of healthy controls. It was positively correlated with the pulsatility index of the uterine and umbilical arteries and negatively correlated with the cerebroplacental ratio in women with PE. In women with PE, the carotid artery augmentation index showed negative correlations with birth weight and Apgar score.

Conclusions

The stiffness of the carotid arteries of women with PE is increased, and this increase is positively correlated with the impedance of the umbilical and uterine arteries.
“My future is bright…I won't die with the cause of AIDS”: ten‐year patient ART outcomes and experiences in South Africa
Authors: Hendrickson Cheryl J , Pascoe Sophie J S , Huber Amy N , Moolla Aneesa , Maskew Mhairi , Long Lawrence C , Fox Matthew P
Published: October 2018

Introduction

South Africa is moving into a new era of HIV treatment with “treat all” policies where people may be on treatment for most of their lives. We need to understand treatment outcomes and facilitators of long‐term antiretroviral treatment (ART) adherence and retention‐in‐care in the South African context. In one of the first studies to investigate long‐term treatment outcomes in South Africa, we aimed to describe ten‐year patient outcomes at a large public‐sector HIV clinic in Johannesburg and explore patient experiences of the treatment programme over this time in order to ascertain factors that may aid or hinder long‐term adherence and retention.

Methods

We conducted a cohort analysis (n = 6644) and in‐depth interviews (n = 24) among HIV‐positive adults initiating first‐line ART between April 2004 and March 2007. Using clinical records, we ascertained twelve‐month and ten‐year all‐cause mortality and loss to follow‐up (LTF). Cox proportional hazards regression was used to identify baseline predictors of attrition (mortality and LTF (>3 months late for the last scheduled visit)) at twelve months and ten years. Twenty‐four patients were purposively selected and interviewed to explore treatment programme experiences over ten years on ART.

Results

Excluding transfers, 79.5% (95% confidence intervals (CI): 78.5 to 80.5) of the cohort were alive, in care at twelve months dropping to 35.1% (95% CI: 33.7 to 36.4) at ten years. Over 44% of deaths occurred within 12 months. Ten‐year all‐cause mortality increased, while LTF decreased slightly, with age. Year and age at ART initiation, sex, nationality, baseline CD4 count, anaemia, body mass index and initiating regimen were predictors of ten‐year attrition. Among patients interviewed, the pretreatment clinic environment, feelings of gratitude and good fortune, support networks, and self‐efficacy were facilitators of care; side effects, travel and worsening clinical conditions were barriers. Participants were generally optimistic about their futures and were committed to continued care.

Conclusions

This study demonstrates the complexities of long‐term chronic HIV treatment with declining all‐cause mortality and increasing LTF over ten years. Barriers to long‐term retention still present a significant challenge. As more people become eligible for ART in South Africa under “treatment for all,” new healthcare delivery challenges will arise; interventions are needed to ensure long‐term programme successes continue.
Evaluation of intraductal delivery of poly(ethylene glycol)‐doxorubicin conjugate nanocarriers for the treatment of ductal carcinoma in situ (DCIS)‐like lesions in rats
Authors: Gu Zichao , Al‐Zubaydi Firas , Adler Derek , Li Shike , Johnson Steven , Prasad Puja , Holloway Jennifer , Szekely Zoltan , Love Susan , Gao Dayuan , Sinko Patrick J.
Published: October 2018

Ductal carcinoma in situ is the most commonly diagnosed early stage breast cancer. The efficacy of intraductally delivered poly(ethylene glycol)‐doxorubicin (PEG‐DOX) nanocarriers, composed of one or more DOX conjugated to various PEG polymers, was investigated in an orthotopic ductal carcinoma in situ‐like rat model. In vitro cytotoxicity was evaluated against 13762 Mat B III cells using MTT assay. The orthotopic model was developed by inoculating cancer cells into mammary ducts of female Fischer 344 retired breeder rats. The ductal retention and in vivo antitumour efficacy of two of the six nanocarriers (5 kDa PEG‐DOX and 40 kDa PEG‐(DOX)4) were investigated based on in vitro results. Mammary retention of DOX and PEG‐DOX nanocarriers was quantified using in vivo imaging. Histopathologic effects of DOX and PEG‐DOX nanocarriers on mammary ductal structure were also investigated. Cytotoxicities of small linear PEG‐DOX nanocarriers (5 and 10 kDa) were not different from DOX whereas larger PEG‐DOX nanocarriers showed reduced potency. The order of mammary retention was 40 kDa PEG‐(DOX)4 > 5 kDa PEG‐DOX >> DOX, in normal and tumour‐bearing rats. Intraductally administered PEG‐DOX nanocarriers and DOX were effective in reducing tumour incidence and increasing survival rate, with no significant differences found among the three treatment groups. However, nanocarriers administered intravenously at the same doses were not effective, and intraductally administered free DOX caused severe local toxicity. Intraductal administration of PEG‐DOX nanocarriers is effective and less toxic than that of free DOX, as well as IV DOX/PEG‐DOX. Furthermore, PEG‐DOX nanocarriers demonstrate the added benefit of prolonging DOX ductal retention, which would necessitate less frequent dosing.
MRI‐guided treatment in the breast
Authors: Pediconi Federica , Marzocca Flaminia , Cavallo Marincola Beatrice , Napoli Alessandro
Published: October 2018

In the last decades, an increasing interest has developed towards non‐invasive breast lesion treatments, which offer advantages such as the lack of surgery‐related complications, better cosmetic outcomes, and less psychological distress. In addition, these treatments could be an option for patients with poor health who are not candidates for surgery. Non‐surgical ablation can be performed under magnetic resonance (MR) or ultrasound (US) guidance. US is cheaper and easily available, while contrast‐enhanced MR is more accurate, ensuring better safety and efficacy for the patient. Overall results of studies about MRI‐guided tumor ablation reported complete ablation rates ranging between 20% and 100%. High‐intensity focused ultrasound (HIFU or FUS) is the most studied ablative technique and it is already established as a valid technique for ablation of benign and malignant tumors in various organs. Ultrasound‐guided FUS is very useful for young patients who refuse surgery or with multiple nodules; however, MR‐guided FUS is more sensitive and allows a better evaluation of thermal accumulation within the ablated tissue or the adjacent structures. Most MR‐guided FUS studies used a dedicated high‐field MR scanner and complete tumor ablation was reported in 17–90% of cases. Other techniques using thermal tissue destruction are radiofrequency ablation (RFA) and laser interstitial thermal therapy (LITT). Only a few studies assessed the efficacy of these treatments, all were performed with open MR devices. RFA showed complete tumor ablation in 30–96% of patients, while LITT in 10–71%, but all the studies had a small number of patients. Cryoablation obtains tissue ablation by a rapid decrease of temperature, with a complete tumor removal reported in 18–52% of cases with MR guidance. No serious complications were reported with these techniques. Currently, breast conservative surgery replaced radical surgery when possible. Therefore, future research should focus on these treatments to shift towards an even less invasive approach to breast neoplasms.

Level of Evidence: 5

Technical Efficacy: Stage 5

J. Magn. Reson. Imaging 2018;48:1479–1488
Hemodynamic measurements with an abdominal 4D flow MRI sequence with spiral sampling and compressed sensing in patients with chronic liver disease
Authors: Bane Octavia , Peti Steven , Wagner Mathilde , Hectors Stefanie , Dyvorne Hadrien , Markl Michael , Taouli Bachir
Published: October 2018

Background

The test–retest/interobserver repeatability and diagnostic value of 4D flow MRI in liver disease is underreported.

Purpose

To determine the reproducibility/repeatability of flow quantification in abdominal vessels using a spiral 4D flow MRI sequence; to assess the value of 4D flow parameters in diagnosing cirrhosis and degree of portal hypertension.

Study Type

Prospective.

Subjects

Fifty‐two patients with chronic liver disease.

Field Strength/Sequence

1.5T/spiral 4D flow acquired in one breath‐hold.

Assessment

Thirteen abdominal vessels were identified and segmented by two independent observers to measure maximum and time‐averaged through‐plane velocity, net flow, and vessel cross‐section area. Interobserver agreement and test–retest repeatability were evaluated in 15 and 4 cases, respectively. Prediction of the presence and severity of cirrhosis and portal hypertension was assessed using 4D flow parameters.

Statistical Tests

Cohen's kappa coefficient, coefficient of variation (CV), Bland–Altman, Mann–Whitney tests, logistic regression.

Results

For all vessels combined, measurements showed acceptable agreement between observers, with Cohen's kappa = 0.70 (P < 0.001), CV < 21%, Bland–Altman bias <5%, but high limits of agreement ([–75%,75%]). Test–retest repeatability was excellent in large vessels (CV = 1–15%, bias = 1–25%, Bland–Altman limits of agreement [BALA] = [4%,150%]), and poor in small vessels (CV = 7–130%, bias = 10–200%, BALA = [8%,190%]). Average velocity in the right hepatic vein and average area of the splenic vein were higher in cirrhosis (P = 0.027/0.0039). Flow in the middle hepatic vein strongly correlated with Child–Pugh score (ρ = 0.84, P = 0.0238), while flow in the splenic vein (ρ = 0.43, P = 0.032), time‐average (ρ = 0.46, P = 0.02) and peak velocity in the superior mesenteric vein (ρ = 0.45, P = 0.032), and peak velocity in the infrarenal IVC (ρ = 0.39, P = 0.032) positively correlated with an imaging‐based portal hypertension score. Average area of the splenic vein predicted cirrhosis (P = 0.019; area under the curve AUC [95% confidence interval, CI] = 0.87 [0.71,1.00]) and clinically significant portal hypertension (P = 0.042; AUC [95% CI] = 0.78 [0.57–0.99]).

Data Conclusion

Spiral 4D flow allows comprehensive assessment of abdominal vessels in one breath‐hold, with substantial interobserver reproducibility, but variable test–retest repeatability. 4D flow may potentially reflect vascular changes due to cirrhosis and portal hypertension.

Level of Evidence: 2

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2019;49:994–1005.
Multiplex and quantitative PCR targeting SCAR markers for strain‐level detection and quantification of biofertilizers
Authors: Reddypriya Pasupuleti , Soumare Abdoulaye , Balachandar Dananjeyan
Published: October 2018

Biofertilizers are the eco‐friendly bio‐input being used to sustain the agriculture by reducing the chemical inputs and improving the soil health. Quality is the major concern of biofertilizer technology which often leads to poor performance in the field and thereby loses the farmers’ faith. To authenticate the strain as well as its presumed cell load of a commercial product, sequence characterized amplified region (SCAR) markers were developed for three biofertilizer strains viz., Azospirillum brasilense (Sp7), Bacillus megaterium (Pb1) and Azotobacter chroococcum (Ac1). We evaluated the feasibility of multiplex‐PCR and quantitative real‐time PCR for SCAR marker‐based quality assessment of the product as well as the persistence of the strains during crop growth. We showed that multiplex PCR can concurrently discriminate the strains based on the amplicons’ size and detects up to 104 cells per g or per ml of carrier‐based or liquid formulation of biofertilizer, respectively. The detection limit of quantitative PCR targeting SCAR markers is 103 cells per g or ml of biofertilizer. Both the PCR methods detected and quantified them in the maize rhizosphere. Hence SCAR marker‐based quality assessment would be a sensitive tool to monitor the biofertilizer production as well as its persistence in the inoculated crop rhizosphere.
Quorum sensing communication: Bradyrhizobium‐Azospirillum interaction via N‐acyl‐homoserine lactones in the promotion of soybean symbiosis
Authors: dos Santos Lima Fagotti Dáfila , Abrantes Julia Laura Fernandes , Cerezini Paula , Fukami Josiane , Nogueira Marco A. , del Cerro Pablo , Valderrama‐Fernández Rocio , Ollero Francisco J. , Megías Manuel , Hungria Mariangela
Published: October 2018

Quorum‐sensing (QS) mechanisms are important in intra‐ and inter‐specific communication among bacteria. We investigated QS mechanisms in Bradyrhizobium japonicum strain CPAC 15 and Azospirillum brasilense strains Ab‐V5 and Ab‐V6, used in commercial co‐inoculants for the soybean crop in Brazil. A transconjugant of CPAC 15‐QS with partial inactivation of N‐acyl‐homoserine lactones (AHLs) was obtained and several parameters were evaluated; in vitro, CPAC 15 and the transconjugant differed in growth, but not in biofilm formation, and no differences were observed in the symbiotic performance in vivo. The genome of CPAC 15 carries functional luxI and luxR genes and low amounts of three AHL molecules were detected: 3‐OH‐C12‐AHL, 3‐OH‐C14‐AHL, and 3‐oxo‐C14‐AHL. Multiple copies of luxR‐like genes, but not of luxI are present in the genomes of Ab‐V5 and Ab‐V6, and differences in gene expression were observed when the strains were co‐cultured with B. japonicum; we may infer that the luxR‐genes of A. brasilense may perceive the AHL molecules of B. japonicum. Soybean symbiotic performance was improved especially by co‐inoculation with Ab‐V6, which, contrarily to Ab‐V5, did not respond to the AHLs of CPAC 15. We concluded that A. brasilense Ab‐V5, but not Ab‐V6, responded to the QS signals of CPAC 15, and that the synergistic interaction may be credited, at least partially, to the QS interaction. In addition, we confirmed inter‐ and intra‐species QS communication between B. japonicum and A. brasilense and, for Azospirillum, at the strain level, impacting several steps of the symbiosis, from cell growth to plant nodulation and growth.
Fruit nutritional quality under deficit irrigation: the case of table grapes in California
Authors: Centofanti Tiziana , Bañuelos Gary S , Ayars James E
Published: October 2018

BACKGROUND

Sustainable agricultural practices are needed to face current threats to agricultural production in areas where water scarcity, recurrent droughts, and decreased soil quality are endangering productivity and food security. Deficit irrigation (DI) practices consist of reducing irrigation applied at levels below full crop evapotranspiration losses throughout the growing season or at specific phenological stages of the specific crop.

The goal of our study was to evaluate the physiological response of table grapes subjected to DI relative to fruit quality. DI treatments were developed as a percentage of the grower practice (evapotranspiration losses are fully replenished by irrigation) on commercial fields of table grapes in central California. DI practices began in 2011 and were continued throughout 2015. Grape berries were analyzed for mineral elements, berry weight, diameter and firmness, carbon and nitrogen content, pH, soluble solids, and total phenolic compounds.

RESULTS

In this study, DI practices in all treatments did not significantly increase or decrease nutraceutical compounds in grape berry and measured physiological responses to DI were mixed, with significant variation between years.

CONCLUSIONS

This study showed that DI practices could be safely used in dry areas for at least four years without affecting the nutritional quality of grape berry in ‘Crimson seedless’ and ‘Sugraone’. © 2018 Society of Chemical Industry
Impact of Water Mixing and Ice Formation on the Warming of Lake Superior: A Model‐guided Mechanism Study
Authors: Ye Xinyu , Anderson Eric J. , Chu Philip Y. , Huang Chenfu , Xue Pengfei
Published: October 2018

The Laurentian Great Lakes are one of the most prominent hotspots for the study of climate change induced lake warming. Warming trends in large, deep lakes, which are often inferred by the observations of lake surface temperature (LST) in most studies, are strongly linked to the total lake heat content. In this study, we use a 3D hydrodynamic model to examine the nonlinear processes of water mixing and ice formation that cause changes in lake heat content and further variation of LST. With a focus on mechanism study, a series of process‐oriented experiments is carried out to understand the interactions among these processes and their relative importance to the lake heat budget. Using this hydrodynamic model, we estimate the lake heat content by integrating over the entire 3D volume. Our analysis reveals that (1) Heat content trends do not necessarily follow (can even be opposed to) trends in LST. Hence, using LST as a warming indicator can be problematic; (2) vertical mixing in water column may play a more important role in regulating lake warming than traditionally expected. Changes in the water mixing pattern can have a prolonged effect on the thermal structure; (3) Ice albedo feedback, even in cold winters, has little impact on lake thermal structure, and its influence on lake warming may have been overestimated. Our results indicate that climate change will not only affect the air‐lake energy exchange but can also alter lake internal dynamics, therefore, the lake's response to a changing climate may vary with time.
Lidocaine‐induced potentiation of thermal damage in skin and carcinoma cells
Authors: Raff Adam B. , Thomas Carina N. , Chuang Gary S. , Avram Mathew M. , Le Monica H. , Anderson R. Rox , Purschke Martin
Published: October 2018

Objective

Lidocaine acts as a local anesthetic by blocking transmembrane sodium channel permeability, but also induces the synthesis of heat shock proteins and sensitizes cells to hyperthermia. A previous study reported two cases of deep focal skin ulceration at points corresponding to depot local lidocaine injection sites after treatment with non‐ablative fractional resurfacing and it was hypothesized that lidocaine had focally sensitized keratinocytes to the thermal damage of laser treatment. The objective of this study was to investigate whether lidocaine potentiates hyperthermia damage to both normal and cancerous skin cells using an in vitro model.

Methods

Normal skin cell lines (fibroblasts, keratinocytes), skin cancer cell lines (melanoma, basal cell carcinoma), and a mucosal cancer cell line (cervical carcinoma) were exposed to various concentrations of lidocaine (0–0.3%) with or without hyperthermia (37°C, 42°C).

Results

Compared to normal skin cells, we demonstrate that cancer cell lines show significantly increased cell toxicity when a moderate temperature (42°C) and low lidocaine concentrations (0.1–0.2%) are combined. The toxicity directly correlates with a higher percentage of cells in S‐phase (28–57%) in the cancer cell lines compared to normal skin cell lines (13–19%; R‐square 0.6752).

Conclusion

These results suggest that lidocaine potentiates thermal sensitivity of cell cycle active skin cells. The direct correlation between cell toxicity and S‐phase cells could be harnessed to selectively treat skin and mucosal cancer cells while sparing the surrounding normal tissue. Additional research pre‐clinically and clinically using several different heat sources (e.g., lasers, ultrasound, etc.) and lidocaine concentrations is needed to confirm and optimize these results. Lidocaine‐enhanced hyperthermia may provide a non‐invasive, alterative treatment option for highly proliferating, superficial skin, and mucosal lesions such as cancer or warts. Lasers Surg. Med. 51:88–94, 2019. © 2018 Wiley Periodicals, Inc.
Novel stress corrosion testing method for high‐strength steels
Authors: Latypova Renata , Kauppi Timo , Mehtonen Saara , Hänninen Hannu , Porter David , Kömi Jukka
Published: October 2018

This paper presents a novel TFT (tuning fork test) stress corrosion testing method, which was developed for classifying martensitic high‐strength steels. The novel method was developed by applying finite element calculations to optimize a tuning fork geometry to enable accurate stress adjustment with simple inexpensive equipment. Different steels were exposed to cathodic hydrogen charging conditions with various elastic tensile stress levels that were achieved by displacement control. All steels exhibited hydrogen‐induced stress corrosion cracking after exceeding a material‐specific threshold stress level that decreased linearly with increasing hardness.
Effects of volume fraction of Ni‐containing LPSO phase on mechanical and corrosion properties of Mg‐Gd‐Ni alloys
Authors: Han Zhenhua , Zhang Kai , Yang Jun , Wei Ran , Zhang Changjun
Published: October 2018

Mg‐Gd‐Ni alloys with same Gd/Ni mole ratios but different volume fraction of Ni‐containing LPSO phase were prepared. The effects of the volume fraction of Ni‐containing LPSO phase on the mechanical and corrosion properties of Mg‐Gd‐Ni alloys were systematically investigated. It was found that the strength was remarkably enhanced but the plasticity was decreased with the increase of the volume fraction of Ni‐containing LPSO phase. The electro‐potential distribution characteristic shows that the Ni‐containing LPSO phase had a lower electro‐potential than the Mg matrix, which was related to the existence of Ni in LPSO phase. Consequently, Ni‐containing LPSO phase was preferentially eroded during micro‐galvanic corrosion. High volume fraction LPSO phases accelerated the corrosion rate of Mg‐Gd‐Ni alloy. The detailed corrosion mechanisms were discussed in the present study.
Corrosion of welds in biomass power plants
Authors: Montgomery Melanie , Dahl Kristian V. , Hald John
Published: October 2018

In addition to understanding the corrosion of base materials in superheater tubes in biomass power plants, it is also important to understand how welded joints are subjected to corrosion or degradation. In the course of corrosion testing in the boiler, two different filler materials were used to weld together 18%Cr 12%Ni austenitic tubes. The two filler materials compared were a high alloyed Ni‐based filler material (wt% approx. 20% Cr, 12% Fe, 3.6% Nb, Ti, balance Ni) and the CN 18/11 IG filler material (18%Cr, 10%Ni, balance Fe). Austenitic steel test tubes were exposed in two different plants where the different filler materials were utilized and the attack of the welds and tubes adjacent the welds are described. Preferential attack of the tube material immediately adjacent the weld only occurred for the Ni rich weld and the indications are that this is galvanic corrosion. This type of attack decreased with decrease in steam temperature.
Effect of MWCNTs on Wetting and Thermal Properties of an Immiscible Polymer Blend
Authors: Ajitha A. R. , Aswathi M. K. , Reghunadhan Arunima , Mathew Lovley , Terzano Roberto , Thomas Sabu
Published: October 2018

Poly (trimethylene terephthalate)/Polypropylene blend (PTT/PP) is prepared using melt mixing method and 1 wt% multiwalled carbon nanotubes (MWCNTs) are incorporated to study its effect on the thermal and wetting properties. The droplet morphology reveals the immiscibility of the neat polymers in the blend and there is a reduction in the domain size of the dispersed phase with the addition of MWCNTs due to the compatibilization effect of MWCNTs. With the addition of MWCNTs, there is a slight improvement in the melting temperatures of both PTT and PP while an increase in the crystallization temperature and glass transition temperature (Tg) is observed that may be due to the nucleation effect of MWCNTs. On blending with PP, the thermal stability of PTT matrix is increased and with the addition of MWCNTs there is not much improvement in the thermal stability of the polymer components is observed. With the addition of MWCNTs the contact angle of the blend slightly increased, may be attributed to the hydrophobic nature of MWCNTs.
Selective Localization of MWCNT in Poly (Trimethylene Terephthalate)/Poly Ethylene Blends: Theoretical Analysis, Morphology, and Mechanical Properties
Authors: Kunjappan Aswathi M. , Ramachandran Ajitha A. , Padmanabhan Moothetty , Mathew Lovely P. , Thomas Sabu
Published: October 2018

Theoretical analysis is carried out to predict the nature of selective localization of multi‐walled carbon nanotubes (MWCNTs) in poly(trimethylene terephthalate/polyethylene (PTT/PE) blends. In agreement with theoretical data experimental results clearly indicate that MWCNT prefers to get associated with PTT phase than with PE. Molecular interactions responsible for such selective localization of MWCNT to PTT component can be attributed to mutual and collective π–π interactions possible between the aromatic moieties present in PTT and MWCNT. In addition, the reinforcing effect of MWCNT in the PTT/PE system was determined using tensile analysis and the morphological features of blends and blend nanocomposites are studied using scanning electron microscope (SEM). Compared to the PTT/PE blend system MWCNT incorporated blend nanocomposites show better mechanical properties. The elongation at break of the blend system is seen to rise with increasing amount of PE content. Among various blend nanocomposites, we have investigated the nanocomposites with higher PTT content show higher tensile strength and Young's modulus. The blend nanocomposite with 90/10/1 composition shows 12% increment in Young's modulus and as much as 80% increment in tensile strength compared to 90/10 blend system which signifies the role MWCNT plays in the blend system.
Polycardanol and Poly(cardanol‐co‐styrene): Synthesis, Characterization, and Performance as Asphaltene Flocculant
Authors: Maravilha Tatiana S. L. , Spinelli Luciana S.
Published: October 2018

The destabilization of asphaltenes in crude oil mainly happens due to variations in pressure, temperature, and oil composition; causing significant losses. Polymers containing specific groups can be used as asphaltene stabilizers, thus avoiding their precipitation, or as asphaltene flocculants in a particular type of unconventional oil, for example, assisting in further destabilization of the model system to enable removal of suspended fine solids, such as kaolinite. Asphaltene precipitation is usually evaluated by tests with variation in stability of asphaltenes in function of adding a flocculant solvent. In this work, two molecules with different amounts of cardanol and styrene are synthesized and structurally characterized by FTIR and 1H NMR. Their molar mass is also determined by SEC and their thermal stability is measured by TGA. In addition, the efficiency of these synthesized molecules as asphaltene dispersants or flocculants is analyzed. The stability of asphaltenes is monitored by precipitation tests induced by a flocculant agent (n‐heptane), using an ultraviolet–visible (UV–vis) spectrometer. The synthesis results indicated formation of an oligomer instead of a polymer. The asphaltene stability results indicate that the synthesized molecules can act as asphaltene flocculants, decreasing the onset of precipitation to smaller volumes of n‐heptane. Furthermore, the increase in concentration of these synthesized molecules in the model systems containing asphaltenes dispersed in mixtures of toluene and n‐heptane in different concentrations promote greater flocculant action of the asphaltenes.
Hyperthermia System Based on Extrinsically Magnetic Poly (Butylene Succinate)
Authors: Moraes Rafael S. , Saez Vivian , Hernandez José A. R. , de Souza Júnior Fernando G.
Published: October 2018

In this work, an extrinsically magnetic composite based on modified magnetite and poly (butylene succinate) (PBS) is prepared. The magnetic composite is obtained by the emulsion–solvent evaporation method. Several analytical tests confirm the synthesis of the composites. Among them, Nuclear magnetic resonance (NMR) results in comparison with literature confirms the synthesis of PBS. X‐Ray Diffraction (XRD) shows the characteristic peaks of PBS, in its monoclinic structure. The crystallite size (Lc) of magnetic particles inside the composite, is equal to 13 nm. Thermogravimetric analysis (TGA) reveals the presence of 5.3 wt% magnetite in the composite and demonstrates that the inclusion of magnetite does not affect the thermal stability of the polymer. The analysis of Fourier transform infrared attenuated total reflection spectra (FTIR‐ATR) indicates the synthesis of desired products as well as the encapsulation of magnetite in PBS polymer matrix. The composite presents magnetic force, which allows its magnetic guidance to a target area. Besides, the magnetic induction heating test promotes heating within the therapeutic range from 40 to 45 °C, being able, according to literature, to promote the death of several types of cancer's cells. Therefore, the material here presented possesses potential to be deeply researched as a future cancer treatment tool.
Recycled Polyurethane as a Second Phase in Thermoset Blends and Its Effect on Thermal Degradation Kinetics Studies
Authors: Reghunadhan Arunima , Stranskowski Michal , Datta Janusz , Kalarikkal Nandakumar , Thomas Sabu
Published: October 2018

A new approach is introduced in the modification of thermosetting polymer by using different amount of polyurethane of waste origin. The post consumer polyurethane foam coatings are degraded using glycolysis process and the recycled product is further converted into new polyurethane. The blending of recycled polyurethane with epoxy exhibits transparency and produces nanostructures. The effective interaction between two polymers is confirmed with dynamic mechanical analysis at 10 Hz. Selected relaxations are also noticed by the inclusion of the flexible PU chains at low temperature regions. The glass transition temperature shows a shift in value from neat epoxy indicating effective miscibility of the flexible domains. The initial degradation temperatures of the blends are increased by the polyurethane inclusion, which is confirmed by thermogravimetric analysis. The increase is more than 25 °C for the 20 phr inclusion. The thermal degradation kinetics is correlated with different theoretical equations like Cord‐Redfern, Horowitz‐Metzger, and Broido.
Preparation and Properties of Poly(lactic Acid)/Thermoplastic Starch/Reduced Graphene Oxide Composites
Authors: Ferreira Willian H. , Andrade Cristina T.
Published: October 2018

Glucose‐reduced graphene oxide (rGO‐g) is incorporated in thermoplastic starch (TPS)/polylactic acid (PLA) 1:1 immiscible blend by one‐step extrusion. X‐ray diffraction shows increased crystallinity for TPS/PLA/rGO‐g composites and intercalation of rGO‐g lamellae. Differential scanning calorimetry indicated that the rGO‐g filler induced crystal nucleation in the composites. Scanning electron microscopy images obtained for the composites presented improved adhesion between the phases. Thermogravimetric analysis results showed improvement in the maximum degradation rate (Tmax) for TPS and for PLA phases in the composites. Tensile tests revealed increase of rigidity of the composites in relation to the neat blend, reaching 10‐fold increase of the Young's modulus for the composition with rGO‐g incorporated at 5.0% mass content. The presence of rGO‐g intercalated lamellae resulted in a small volume of conductive pathways, which led to conductivity values around σ = 10−8 and 10−7 S cm−1 for the composition with rGO‐g incorporated at 3.0 and 5.0% mass content, respectively.
Comparative Analyses of Poly(ethylene 2,5‐furandicarboxylate) − PEF − and Poly(ethylene terephthalate) − PET − Resins and Production Processes
Authors: Gomes Frederico W. , Lima Rafael C. , Piombini Carolinne R. , Sinfitele Jorge F. , de Souza Fernando G. , Coutinho Paulo L. A. , Pinto José Carlos
Published: October 2018

The increasing interest in environment friendly products and processes has encouraged studies on the production of polymers from renewable sources. In this context, poly(ethylene 2,5‐furandicarboxylate) − PEF − is regarded as a potential alternative for poly(ethylene terephthalate) − PET − resins. However, despite the increasing number of studies on PEF synthesis and characterization, there is still room for comparisons between processes used to produce PEF and PET and between some characteristics of the produced resins. For this reason, in the present work PEF was produced through direct esterification and through transesterification, whilst PET was synthesized through transesterification, to allow comparative analyses of the respective process performances. Results indicate that PEF can be produced at milder and simpler operation conditions, although PEF processing is much more difficult, since PEF is less stable to heat, melts at lower temperatures, is more crystalline and is much more rigid than PET, indicating that appropriate modification of PEF resins is needed for the effective replacement of PET in real industrial applications.
Comparative Characterization of Melt Electrospun Fibers and Films Based on PLA‐PHB Blends: Diffusion, Drug Release, and Structural Features
Authors: Liu Yong , Cao Kuan , Karpova Svetlana , Olkhov Anatoliy , Filatova Anna , Zhulkina Anna , Burkov Andrey , Fomin Sergey V. , Rosa Derval S. , Iordanskii Alexey L.
Published: October 2018

Comparative structural‐dynamic characterization of the biopolyester blends based on poly(3‐hydroxybutyrate) and poly‐L‐lactide (PLA) [PHB/PLA] is performed. The melt electrospun fibers and molded films with the same compositions (1/0, 1/9, 3/7) but obtained by two different fabrication ways are explored by combination of structural and dynamic methods. The structural‐dynamic features such as segmental mobility (by spin‐probe ESR technique), thermophysical transitions (by DSC), and surface morphology (by SEM) are applied to elucidate the distinctive diffusion features as the essential constituent of drug release. The ultrathin electrospun fibers and molded films loaded by dipyridamole (DPD), as a modeling drug, shows the different structural behavior including crystallinity and the diversity in diffusion coefficients and the drug release profiles. To emphasize the special transport phenomena in nano‐sized drug vehicles, the diffusivity modeling is performed and further the drug diffusion coefficients in the ultrathin fibers and the macroscopic films are compared.
Poly(ɛ‐caprolactone)/Functionalized‐Carbon Nanotube Electrospun Nanocomposites: Crystallization and Thermal Properties
Authors: Bicy K. , Geethamma V. G. , Kalarikkal Nandakumar , Rouxel Didier , Thomas Sabu
Published: October 2018

The interest of eco‐friendly polymer nanocomposites is continuously growing because of the increased concern about environmental pollution. Polycaprolactone (PCL) is one of the extensively used bio‐degradable polymers. The advantage of this biopolymer is further enhanced by the addition of nanofillers and developing nanocomposites. Carbon Nanotube (CNT) is one of the best matching nanofillers, the inclusion of CNT in PCL matrix increase the use of PCL in diverse areas. In this work PCL/CNT nanocomposites prepared by the electrospinning technique, in order to avoid CNT agglomeration, acid functionalized CNT (f‐CNT) is used. Morphological properties of the electrospun nanofiber are studied by SEM and the interaction between PCL and f‐CNT is studied by FT‐IR. DSC and optical microscopic studies reveal the influence of f‐CNT's to enhance the crystallinity and reduce the lamellar thickness and spherulite growth of PCL. The H‐bonded interaction between PCL and f‐CNT enhances the physical properties of bio‐degradable PCL and thereby enhances its commercial application.
Study of Controlled Release of PMMA‐g‐PEG Copolymer and Derivatives Incorporated with the Indomethacin Drug
Authors: Azevedo Maria L. S. , Silveira Benila M. , Novack Kátia M. , Barboza Ana P. M. , Neves Bernardo R. A. , dos Santos Viviane M. R.
Published: October 2018

Synthetic polymers are made up of repeated monomeric units, and this gives them a very versatile appearance, making them useful in many areas of science. One is the pharmaceutical, which correlates the properties of the polymer with the active principle, so they can be used as an excipient or in the controlled release system. The PMMA‐g‐PEG4000 has characteristics derived from its precursors, that are pharmacologically active. When we incorporate drugs into this structure, the polymer can act on the controlled release, lessening the toxic character of the drug and producing fewer side effects. In this work, incorporations of the drug indomethacin were made in the PMMA‐g‐PEG copolymer and derivatives (PMMA‐g‐PEG4000 ETIL and PMMA‐g‐PEG4000 ACET). The samples were characterized by infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), thermogravimetric analysis (TGA), and atomic force microscopy (AFM) measurements. For each sample, the controlled release was performed in a total time of 4 h and the efficiency of the modified structures was verified.
Crucial role of reactive oxygen species (ROS) for the proapoptotic effects of indirubin derivative DKP‐073 in melanoma cells
Authors: Zhivkova Veselina , Kiecker Felix , Langer Peter , Eberle Jürgen
Published: October 2018

Melanoma represents a prime example demonstrating the success of targeted therapy in cancer. Nevertheless, it remained a deadly disease until now, and the identification of new, independent strategies as well as the understanding of their molecular mechanisms may help to finally overcome the high mortality. Both indirubins and TNF‐related apoptosis‐inducing ligand (TRAIL) represent promising candidates. Here, the indirubin derivative DKP‐073 is shown to trigger apoptosis in melanoma cells, which is enhanced by the combination with TRAIL and is accompanied by complete loss of cell viability. Addressing the signaling cascade, characteristic molecular steps were identified as caspase‐3 activation, downregulation of XIAP, upregulation of p53 and TRAIL receptor 2, loss of mitochondrial membrane potential, and STAT‐3 dephosphorylation. The decisive step, however, turned out to be the early production of ROS already at 1 h. This was proven by antioxidant pretreatment, which completely abolished apoptosis induction and loss of cell viability as well as abrogated all signaling effects listed above. Thus, ROS appeared as upstream of all proapoptotic signaling. The data indicate a dominant role of ROS in apoptosis regulation, and the new pathway may expose a possible Achilleś heel of melanoma.
Spatio‐temporal precipitation and temperature trend analysis of the Seyhan–Ceyhan River Basins, Turkey
Authors: Gumus Veysel
Published: October 2018

Despite the recent popularity of studying the effects of climate change on critical regions worldwide, there is a paucity of data documenting the results from trend analysis for these regions based on hydro‐climatic variables such as precipitation and temperature. The purpose of this study was to undertake a spatio‐temporal precipitation and temperature trend analysis for the Seyhan and Ceyhan River Basins located in the south of Turkey. The data for the seasonal and annual temperature variations (minimum, maximum and mean) and the total precipitation outputs obtained from the 14 stations in these basins are considered. The non‐parametric Mann–Kendall and the Mann–Kendall rank correlation tests are employed to determine the trend and its year of initiation. The linear slopes of the trends are calculated by using Sen's slope estimation technique and the spatial distributions for the slope of trends are presented. The results show that statistically significant upward trends exist for these basins based on the annual maximum temperature values, and the years of initiation of the trends are determined as mid‐1990 and mid‐2000.
Standards for Nutrition Support: Adult Hospitalized Patients
Authors: Ukleja Andrew , Gilbert Karen , Mogensen Kris M. , Walker Renee , Ward Ceressa T. , Ybarra Joe , Holcombe Beverly ,   Task Force on Standards for Nutrition Support: Adult Hospitalized Patients, the American Society for Parenteral and Enteral Nutrition
Published: October 2018

The American Society for Parenteral and Enteral Nutrition defines standards as benchmarks representing a range of performance of competent care that should be provided to assure safe and efficacious nutrition care in most circumstances. Standards are documents that define the structure needed to provide competent care. These Standards for Nutrition Support for Adult Hospitalized Patients are an update of the 2010 Standards. These practice‐based standards are intended for use by healthcare professionals charged with the care of adult hospitalized patients receiving nutrition support therapy in any hospital with or without a formal nutrition support service or team. These Standards address professional responsibilities as they relate to patient assessment, diagnosis, education, care plan development, implementation, clinical monitoring, evaluation, and professional issues around nutrition support.
Metabolic Support of the Patient on Continuous Renal Replacement Therapy
Authors: Nystrom Erin M. , Nei Andrea M.
Published: October 2018

Continuous renal replacement therapy (CRRT) is the modality of choice in critically ill patients with hemodynamic instability requiring renal replacement therapy. The goal of this review is to discuss an overview of CRRT types, components, and important considerations for nutrition support provision. Evidence basis for guidelines and our recommendations are reviewed. Nutrition support–related implications include the possibility of calorie gain with citrate‐based anticoagulation, calorie loss with glucose‐free replacement fluids and dialysate, and significant amino acid losses in effluent. We challenge nutrition support clinicians to develop a keen understanding of the specific CRRT modalities that are employed in their intensive care units and to be able to determine how the CRRT prescription may impact a patient's nutrition support prescription.