bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship between hearing loss in older adults and depression over 12 years: Findings from the Three‐City prospective cohort study
Authors: Cosh Suzanne , Carriere Isabelle , Daien Vincent , Amieva Helene , Tzourio Christophe , Delcourt Cecile , Helmer Catherine ,   the Sense‐Cog Consortium
Published: September 2018

Objective

The present study aims to examine the longitudinal relationship between hearing loss (HL) with depression in older adults over 12 years of follow‐up.

Method

Eight thousand three hundred forty‐four French community‐dwelling adults aged 65 and above participated in the Three‐City prospective population‐based study. Baseline relationships between self‐reported mild and severe HL with depression—assessed by both the Mini International Neuropsychiatric Interview and by the Centre for Epidemiology Studies Depression scale—were explored using logistic regression analyses. Logistic mixed models assessed whether baseline HL was associated with incident depression diagnosis or symptom onset over 12 years in those who were depression‐free at baseline.

Results

At baseline, mild and severe HL were associated with depression symptoms as assessed by the CESD (OR = 1.29, 95% CIs 1.14‐1.47; OR = 1.51, 95% CIs 1.22‐1.87; respectively), although only mild HL was significantly related to major depression diagnosis (OR = 1.51, 95% CIs 1.07‐2.12). Over 12 years, mild and severe HL were associated with incident depression as assessed by the CESD in those without depression at baseline (OR = 1.36, 95% CIs 1.15‐1.61; OR = 1.69, 95% CIs 1.15‐2.30; respectively), but was not associated with a major depression diagnosis.

Conclusions

Both mild and severe thresholds of HL are associated with depression symptoms over time, but not with incident diagnosis of major depression. Improved and ongoing detection of subthreshold depression amongst older adults with HL may improve quality of life for this population.
Factors affecting withdrawal and donation attrition in the brains for dementia research cohort
Authors: Costello Helen , Hayes Gillian M. , Francis Paul T.
Published: September 2018

Objectives

To measure two forms of attrition in a cohort of volunteer brain donors: Withdrawal during life and non‐donation at death. To test whether cognitive impairment independently predicts attrition.

Method

Attrition rates were calculated for all registered participants and for all brain donors who had completed a baseline and follow‐up assessment of cognition, health, and lifestyle. Attrition reasons were described, and attrition rates were compared by gender, age group, and cognitive status. Multivariate logistic regression was used to identify the factors which independently predicted during life and at death.

Results

A total of 3276 brain donors registered and 2307 (70.4%) remained in the cohort. Attrition rate overall was 5.9% for withdrawal and 13.8% for donation. Family disagreement and the brain bank not being informed of participant death were the most common reasons for withdrawal and donation attrition. Withdrawal was associated with having cognitive impairment (OR 2.0 95% CI 1.1‐3.5), increased age (OR 3.1 95% CI 1.4‐6.9), and lower education (OR 1.8 95% CI 1.2‐2.8). Participants exhibiting cognitive decline between assessments were more likely to withdraw (OR 4.9 95% CI 1.7‐13.6). Participants living alone were almost twice as likely to die without donating (OR 1.9 95% CI 1.1‐3.3).

Conclusions

Attrition rates were relatively low, and consistent with other studies cognitive impairment, increased age, and less education predicted study withdrawal. Deaths of participants living alone were less likely to result in donation. Tailored, regular retention practices aimed at resolving family disagreement regarding donation decisions are required.
Functionalization at C(1) of the Dihydroazulene/Vinylheptafulvene Photo‐/Thermoswitch – Establishing Structure−Property Relationship
Authors: Andersen Dianna , Drøhse Kilde Martin , Kadziola Anders , Cacciarini Martina , Brøndsted Nielsen Mogens
Published: September 2018

The optical and switching properties of the dihydroazulene/vinylheptafulvene (DHA/VHF) photo‐/thermoswitch can be finely tuned by substituent groups at specific positions. While the kinetics of the thermal ring closure of VHF into DHA have previously been shown to follow systematic trends in regard to the electron‐withdrawing/donating character of substituents at DHA positions C(2), C(3), and C(7) (Hammett correlations), no such correlation has so far been established for a selection of compounds with different substituents at C(1). Functionalization at this position is at the same time known to have the strongest impact on the VHF‐to‐DHA conversion rate. Here we show that introduction of a benzothiazole ring at C(1) of DHA (corresponding to the vinyl position of VHF) with various electron‐withdrawing/donating groups provides VHFs whose rates of ring closure follow a Hammett correlation – the more electron‐withdrawing substituent on the benzothiazole, the faster ring closure reaction.
The need for planning training among public health officers in Cape Verde
Authors: Ferrinho Paulo , da Luz Lima Mendonça Maria , Delgado António Pedro
Published: September 2018

Cape Verde is a small island developing state (SIDS). The health sector is guided by strategic and programmatic documents of the Ministry of Health.

The objective of this paper is to understand the planning capacity and experience of its Public Health Officers.

A questionnaire was applied to 27 Cape Verdean public health officers in order to collect data on participation in health sector planning: 17 were returned and analyzed.

This study identifies a youthful, medically trained, but poorly differentiated, public health cadre, without the technical competences to plan the changes needed for the health sector. Planning initiatives were preceded by short technical planning training initiatives, but these did not consolidate a planning culture or contribute to a sustainable capacity to respond to the planning needs of the country. The respondents seemed at a loss to specify planning tools and techniques used in the planning exercises in which they partook. SIDS are considered vulnerable to political interference in the implementation of policy processes but that did not seem to be the case in Cape Verde. Planning was perceived as values driven, strengthening the perception that the values that drive the finality of planning are important determinants of the final plan.
Is Taiwan's National Health Insurance a perfect system? Problems related to health care utilization of the aboriginal population in rural townships
Authors: Lee Yi‐Ting , Lee Yen‐Han , Kaplan Warren A.
Published: September 2018

National Health Insurance (NHI) was implemented in Taiwan in 1995, and has significantly increased coverage to 99% of the population. The implementation of NHI has had large impacts on health disparities. Despite that, the NHI faces multiple challenges, including the condition of “coverage without access” among the Taiwanese aboriginal population, mostly residing in mountainous townships and experiencing lower socioeconomic status, decreased health outcomes, and limited access to adequate high‐quality health care services. This paper summarizes the persistent health gap and the differences in health care utilization and health outcomes between the aboriginal population in rural townships and urban populations in Taiwan. Mountainous townships face challenges including lack of access to high‐quality health care services and limited medical resources. Further policy recommendations and current progress are highlighted and discussed.
Physical Activity Modulates the Overexpression of the Inflammatory miR‐146a‐5p in Obese Patients
Authors: Russo Angelo , Bartolini Desireé , Mensà Emanuela , Torquato Pierangelo , Albertini Maria Cristina , Olivieri Fabiola , Testa Roberto , Rossi Sara , Piroddi Marta , Cruciani Gabriele , De Feo Pierpaolo , Galli Francesco
Published: September 2018

Abstracts

Specific microRNAs (miRs), including the “angio‐miR‐126” and the “inflamma‐miR‐146a‐5p,” have been proposed as biomarkers and even therapeutic targets of obesity‐associated metabolic diseases. Physical activity, a key measure of prevention for obesity and its complications, is reported to influence the expression of these miRs. In this study, we investigate whether a physical activity program proven to improve metabolic parameters in obese patients can correct the circulating levels of these miRs. Plasma miR‐126 and miR‐146a‐5p were measured in a cohort of obese patients (n = 31, 16F + 15M) before and after the 3‐month physical activity program of the CURIAMO trial (registration number for clinical trials: ACTRN12611000255987) and in 37 lean controls (24F + 13M). miR‐146a‐5p, but not miR‐126, was significantly increased in obese patients as compared with lean controls and decreased in approximately two‐thirds of the participants post‐intervention with a response that positively correlated with pre‐intervention levels of this miR. Waist circumference, the inflammatory cytokine IL‐8 and lipid parameters, principally total cholesterol, showed the strongest correlation with both the baseline levels and post‐intervention correction of miR‐146a‐5p. Post‐hoc analysis of experimental data supports the use of miR‐146a‐5p as a biomarker and predictor of the clinical response to physical activity in obese patients. Furthermore, miR‐146a‐5p expression was confirmed to increase together with that of the inflammatory genes TLR4, NF‐κB, IL‐6, and TNF‐α in LPS‐stimulated human mononuclear leukocytes. In conclusion, the inflamma‐miR‐146a‐5p can serve as a personalized predictor of clinical outcome in obese patients entering physical activity weight‐reduction programs. © 2018 IUBMB Life, 70(10):1012–1022, 2018
Estimating within‐cluster spillover effects using a cluster randomization with application to knowledge diffusion in rural India
Authors: Alik‐Lagrange Arthur , Ravallion Martin
Published: September 2018

Spillover effects within randomized clusters pose a challenge for identifying impacts of an individualized treatment. The paper proposes a solution. Longitudinal and intra‐household observations are combined in estimating the direct knowledge gain from watching an info‐movie in rural India, while randomized village assignment identifies knowledge sharing. Simulations on synthetic data and econometric tests provide support for the estimation method. We find evidence of information sharing, but far less so for disadvantaged groups, such as illiterate and lower‐caste individuals; these groups rely more on actually seeing the movie. Our results are consistent with sizeable biases in ordinary least squares, matching or instrumental variable impact estimators that ignore within‐cluster spillovers.
TeamSTEPPS®: An evidence‐based approach to reduce clinical errors threatening safety in outpatient settings: An integrative review
Authors: Parker Antay L. , Forsythe Lydia L. , Kohlmorgen Ingrid K.
Published: September 2018

Objective

The objective of this integrative review of literature was to investigate and evaluate feasibility and potential for success of TeamSTEPPS® implementation, the influence of TeamSTEPPS for Office‐Based Care on the clinical error rate in a private outpatient clinic, and influence of TeamSTEPPS for Office‐Based Care on patient satisfaction.

Background

Patient safety remains a top priority for all health care providers in all clinical settings. Despite multiple varied efforts, clinical errors directly attributed to communication are consistently at the top of the list of root causes, although improvement strategies such as Team Strategies and Tools to Enhance Performance and Patient Safety (TeamSTEPPS) have been implemented, there is insufficient data reported measuring the influence of this intervention on patient safety, clinical errors related to communication, and patient satisfaction.

Search Strategy

A systematic search of the electronic databases MEDLINE Complete, CINAHL Complete, Embase, and Science Direct was conducted to seek literature that reported the effectiveness of the TeamSTEPPS tool to reduce clinical errors, improve communication, and increase patient satisfaction. Nineteen studies met inclusion criteria. Levels of evidence for each study was determined using the 2009 American Association of Critical Care Nursing (AACN) levels.

Conclusions

The present review is consistent with marked improvement in communication, decrease in clinical error rates, and improvement in patient satisfaction. There is a significant need for evaluation of the impact of this validated toolkit from the Agency for Healthcare Research and Quality to maintain a sustainable health care environment for all stakeholders. As a result of this integrative review, a quality improvement project related to both the primary and secondary end points is in progress.
Granzyme B induced by Rv0140 antigen discriminates latently infected from active tuberculosis individuals
Authors: Ouni Rym , Gharsalli Houda , Dirix Violette , Braiek Amani , Sendi Nadia , Jarraya Afifa , Douik El Gharbi Leila , Barbouche Mohamed-Ridha , Benabdessalem Chaouki
Published: September 2018

Nearly two billion people are latently infected with Mtb (LTBI). Detection of LTBI with high risk to develop active tuberculosis (aTB) is considered the cornerstone to control the disease. The current challenge is to identify markers that better classify LTBI versus aTB. It has been previously shown that Rv0140, a reactivation-associated antigen of Mtb, induces significantly higher IFN-γ production in LTBI individuals as compared to aTB patients. Herein, we show that Rv0140 induces high granzyme B level by PBMCs derived from LTBI (n = 34) as compared to aTB (n = 18). Receiving operator characteristic (ROC) curves were used to evaluate the capacity of Rv0140 to discriminate between LTBI and aTB by measuring IFN-γ and granzyme B secretion. Our results show that, in response to Rv0140, granzyme B seems to allow better discrimination of LTBI from aTB with areas under the curve (AUC) of 0.88 (95% CI 0.79–0.98) as compared to IFN-γ with AUC of 0.85 (95% CI 0.74–0.96) even though CI overlap. Intracellular staining (ICS) experiments and the use of anti-MHC I antibody showed that granzyme B is mainly produced by CD8+ T cells in response to Rv0140. Thus, we propose granzyme B as a host marker to help identify LTBI individuals.

Rv0140-induced Granzyme B biomarker discriminates TB infection status
Effects of Gadodiamide and Gadoteric Acid on Rat Kidneys: A Comparative Study
Authors: Celiker Fatma Beyazal , Tumkaya Levent , Mercantepe Tolga , Beyazal Mehmet , Turan Arzu , Beyazal Polat Hatice , Suzan Zehra Topal , Inecikli Mehmet Fatih , Akyildiz Kerimali , Yilmaz Adnan
Published: September 2018

Background

Gadolinium‐based contrast agents are complex chelates to provide contrast in NRI. However, recent studies have highlighted the deposition of free Gd+3 ion in various tissues.

Purpose

To evaluate the histopathological and immunohistochemical changes on rat kidney tissue following both macrocyclic (gadoteric acid) and linear (gadodiamide) agents under the hypothesis that gadolinium‐based contrast agents (GBCA) lead to toxic, free Gd+3 accumulation in tissues.

Study Type

The local Animal Care Committee approved the prospective animal study.

Animal Model

Thirty‐two healthy Sprague–Dawley male rats were administered 2 mmol/kg gadodiamide and gadoteric acid for the first 4 days for 5 weeks. Group 1 received no drug (control, n = 8) and Group 2 (n = 8) was administered 0.1 ml/kg saline. Group 3 was administered 0.1 mmol/kg gadodiamide and Group 4 (n = 8) was administered 2 mmol/kg gadoteric acid.

Assessment

Biochemical, histopathological, and immunohistochemical changes in testis kidney tissue were evaluated at the end of 10 weeks.

Statistical Tests

Differences between groups were analyzed using the nonparametric Kruskal–Wallis test followed by one‐way analysis of variance and the Tamhane test, also followed by Turkey's HSD test.

Results

Gadolinium increased serum urea, Ca+2, and Caspase‐3 positive tubular cell number. Larger Bowman capsules shrank proximal and distal tubules were revealed in the gadodiamide and gadoteric acid groups compared to the control group (P < 0.05). Histopathologic examination showed significantly more interstitial fibrosis, amyloid deposits, and vasocongestion in the gadodiamide group than the gadoteric acid and control groups, while the gadoteric acid group demonstrated significantly more leukocytic infiltration with atrophied proximal and distal tubules than the gadodiamide and control groups (P < 0.05).

Data Conclusion

GBCA administration causes significant histopathologic changes in kidney tissue. This study advocates additional investigation to assess the in vivo safety of GBCAs.

Level of Evidence: 1

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2019;49:382–389.
Defects in ribosome function delay the initiation of chromosome replication in Escherichia coli
Authors: Zhang Shujun , Wunier Wunier , Yao Yuan , Morigen Morigen
Published: September 2018

The Sra protein is a component of the 30S ribosomal subunit while RimJ is a ribosome‐associated protein that plays a role in the maturation of the 30S ribosomal subunit. Here we found that Δsra and ΔrimJ cells showed a delayed initiation of DNA replication, prolonged doubling time, decreased cell size, and decreased amounts of total protein and DnaA per cell compared with these observed for wild‐type cells. A temperature sensitivity test demonstrated that absence of the Sra or RimJ protein did not change the temperature sensitivity of the dnaA46, dnaB252, or dnaC2 mutants. Moreover, ectopic expression of Sra reversed the mutant phenotype while cells carrying the pACYC177‐rimJ plasmid did not reverse the rimJ mutant phenotype. The results indicate that deletion of sra or rimJ cause defects in ribosomal function and affect the translation process, leading to a decrease in synthesis of proteins including DnaA. Therefore, we conclude that Sra‐ and RimJ‐mediated ribosomal function is required for precise timing of initiation of chromosome replication.
Wheat nutrition and growth as affected by humic acid‐phosphate interaction
Authors: Rosa Sara Dantas , Silva Carlos Alberto , Maluf Henrique José Guimarães Moreira
Published: September 2018

Low‐grade phosphate rock correctly combined with humic acid (HA) has the capacity of single superphosphate (SS) in supplying P to growing wheat (Triticum aestivum L.). The aim of this study was to evaluate wheat dry matter, macro‐ and micronutrients accumulated in wheat shoot, and the P availability in a Typic Hapludox (Oxisol) under the following humic acid carbon (C‐HA) concentrations: 0, 5, 10, 50, and 100 mg kg−1, which were combined with two P sources, Araxá phosphate rock (APR) and SS. The experiment was carried out under greenhouse conditions. Firstly, soil samples were incubated with combinations of C‐HA concentrations and P sources for 15 d; after that, wheat was grown in the pots for 43 d. Shoot dry matter (SDM), root dry matter (RDM), total dry matter (TDM), macro‐ and micronutrient uptake, and soil resin‐P were determined. Addition of C‐HA increased RDM growth in soils treated with APR and SS, and improved SDM growth under APR. Accumulation of P, S, Cu, Fe, Mn, and Zn increased in wheat shoots grown in soils treated with APR combined with C‐HA concentrations. The addition of 50 mg kg−1 of C‐HA and APR increased RDM and macro‐ and micronutrient uptake and promoted greater production of SDM in comparison to biomass produced in soil not treated with HA. After wheat cultivation, resin‐P contents in soil with APR decreased over C‐HA concentrations, which is evidence of adequate supply of P to wheat by APR. The right combination of HA and APR leads to wheat growth and nutrient uptake equivalent to those found for SS.
Contrasting yield responses to phosphorus applications on mineral and organic soils from extensively managed grasslands: Implications for P management in high ecological status catchments
Authors: González Jiménez José L. , Healy Mark G. , Roberts William M. , Daly Karen
Published: September 2018

Phosphorus (P) loss from grassland production is one of the main causes affecting high status water bodies in Europe. Soils with a high content in organic matter (OM), even if extensively managed, are particularly vulnerable to P losses due to their poor P sorption capacities, and can affect the water quality of high status catchments if the dynamics of applied P in these soils is not well understood. The aim of this study was to assess dry matter yield, herbage P content, and P use efficiency in six soils deficient in P and ranging in OM content from 8.7% to 76.4% in a pot experiment under increasing P applications using the Mitscherlich equation. Of the six soils investigated, there was a better response in dry matter yield and greater P use efficiency in the soils with greater OM content than the mineral soils. The Mitscherlich model described grass response precisely in organic soils due to the higher plant availability of applied P as a consequence of the poor P sorption capacities of these soils. Despite the higher availability of applied P for plants in organic soils, the P requirements to meet the threshold herbage P content for dietary P supply to ruminants were still very high, which may pose a risk of P loss to the environment if P fertiliser is applied based on recommendations obtained from plant analysis. These results indicate that P fertilisation of organic soils in sensitive catchments poses a potentially high risk of P transfer to water bodies.
Nipple‐sparing mastectomy and breast reconstruction with a deep inferior epigastric perforator flap using thoracodorsal recipient vessels and a low lateral incision
Authors: Ho Olivia A. , Lin Yi‐Ling , Pappalardo Marco , Cheng Ming‐Huei
Published: September 2018

Background: Nipple‐sparing mastectomy poses challenges in providing esthetically‐pleasing immediate autologous breast reconstruction. This study was to investigate the outcomes of nipple‐sparing mastectomy with breast reconstruction using free abdominal flaps between two different recipient sites.

Methods: Between 2010 and 2016, 79 patients who underwent nipple‐sparing mastectomy with autologous breast reconstruction using thoracodorsal (TD) vessels in 30 cases or internal mammary (IM) vessels in 49 cases were investigated. Demographics, intraoperative findings, complications, and quality of life using Breast‐Q questionnaire were compared between two groups.

Results: All flap survived. There was no statistical difference in age, BMI, ischemia time, and flap‐used percentage. The TD artery had a statistically smaller diameter 1.8 ± 0.4 mm than the IM artery 2.7 ± 0.43 mm (p = 0.02). At a mean follow‐up of 44.4 ± 35.2 months, there was no statistical difference in total complication rates between TD and IM groups (23.3% and 36.7%, respectively, p > 0.05). The “psychosocial well‐being” of Breast‐Q in TD group 83.9 ± 14.6 was statistically greater than IM group 72.8 ± 17.6 (p = 0.04).

Conclusions: Nipple‐sparing mastectomy with immediate breast reconstruction using TD vessels with a low lateral scar is a safe procedure that provides an inconspicuous scar with better cosmesis and minimal complication rate.
Pancreaticoduodenectomy and metastasectomy for metastatic pancreatic neuroendocrine tumors
Authors: Chawla Akhil , Williams Richelle T. , Sich Nicholas , Clancy Thomas , Wang Jiping , Ashley Stanley , Pezzi Christopher , Swanson Richard
Published: September 2018

Background and Objectives

Various treatment options exist for patients with metastatic pancreatic neuroendocrine tumors (PNETs). Surgical resection with pancreaticoduodenectomy (PD) typically reserved for patients with limited disease. Definitive data are lacking to support either the resection of primary PNET in the metastatic setting or for surgical debulking of metastatic lesions.

Methods

We conducted an analysis of the National Cancer Database (NCDB) using the pancreatic cancer Participant User File. Thirty‐ and 90‐day mortality rates and survival rates were determined for patients undergoing PD for primary tumor resection and compared with patients who had no surgery or metastasectomy. The Kaplan‐Meier method was used to compare survival time. Cox regression models were used to assess factors independently associated with overall survival time.

Results

Resection of the primary tumor or metastatic disease each significantly improved overall survival time compared with no resection. Adding metastasectomy to PD resulted in an incremental increase in overall survival time. Both PD and metastasectomy are independently associated with overall survival time.

Conclusions

Our report highlights the potential for survival time benefit in appropriately selected patients who undergo PD in the setting of metastatic PNET.
Determination of pesticides residues in vegetable and fruit samples by solid‐phase microextraction with a covalent organic framework as the fiber coating coupled with gas chromatography and electron capture detection
Authors: Wang Mengting , Zhou Xin , Zang Xiaohuan , Pang Yachao , Chang Qingyun , Wang Chun , Wang Zhi
Published: September 2018

In this study, a covalent organic framework designated as TpPaNO2 was synthesized by a mechanochemical grinding method and then coated on stainless steel wire by a sol‐gel technique to prepare a solid‐phase microextraction fiber. The TpPaNO2 fiber based solid‐phase microextraction coupled with gas chromatography‐electron capture detection was applied to determine the residues of 11 pesticides (trlfuralln, dicofol, α‐endosulfan, 1‐chloro‐4‐[2,2‐dichloro‐1‐(4‐chlorophenyl)ethenyl]benzene, nitrofen, β‐endosulfan, 1‐chloro‐4‐[2,2‐dichloro‐1‐(4‐chlorophenyl)ethyl]benzene, 1,1,1‐trichloro‐2,2‐bis(4‐chlorophenyl)ethane, bifenthrin, permethrin and fenvalerate) in vegetable and fruit samples. The effects of extraction time, extraction temperature, sample pH, stirring rate and desorption temperature on the extraction efficiency were investigated. Under the optimized conditions, the limits of detection for the eleven pesticides were in the range of 0.04–0.25 μg/kg. The recoveries of the eleven pesticides in the vegetable and fruit samples were 81.5–111% with the relative standard deviations less than 11.2%.
Selective and sensitive determination of tetracyclines by HPLC with chemiluminescence detection based on a cerium(IV)‐methoxylated cypridina luciferin analogue system
Authors: Li Jie , Zeng Wangsheng , Lai Xiaojing , Wang Xu , Xu Xin , Cai Hongping , Wei Lijun , Cheng Xiang lei
Published: September 2018

A novel approach for the simultaneous and selective analysis of chlortetracycline, doxycycline, 4‐epichlortetracycline, oxytetracycline, metacycline, and tetracycline by high‐performance liquid chromatography coupled with sensitive post‐column chemiluminescence reaction was set up. Six tetracyclines were separated through a simple and effective isocratic procedure using a mixture of acetonitrile and 3.5 mM methanesulfonic acid. After that, intensive chemiluminescence signals were produced by the reaction between cerium(IV) and methoxylated cypridina luciferin analogues system in the presence of tetracyclines. Under the appropriate experimental conditions, the developed method was evaluated by testing of linearity, limits of detection, precision, and accuracy. The limit of detection was from 2 to 10 nM and relative standard deviation of intraday precision was below 9%. The developed high‐performance liquid chromatography with chemiluminescence method has been performed for the with trace analysis of tetracycline antibiotic residues in milk samples with satisfactory results.
Effects of chloride concentration on CO2 corrosion of novel 3Cr2Al steel in simulated oil and gas well environments
Authors: Tan Chengtong , Xu Xiuqing , Xu Lining , Yin Chengxian , Qiao Lijie
Published: September 2018

The corrosion behavior of novel 3Cr2Al steel in simulated oil and gas well environments was investigated using scanning electron microscopy, electron diffraction spectroscopy, potentiodynamic polarization, and potentiostatic polarization. The results revealed that the corrosion rate of 3Cr2Al steel increased as the Cl− concentration increased. The thickness of the corrosion product film decreased as the Cl− concentration increased. The increase in Cl− concentration caused a decrease in pH value, subsequently causing an increase in the solubility of Cr(OH)3 and Al(OH)3 and hindering the deposition of corrosion product, eventually yielding a thinner corrosion film.
Synthesis of Nitroxide End‐Labeled Polymers by Capturing Polystyrene Radicals with Spin Traps
Authors: Heiler Katherine E. , Pan Ching W. , Heiler Alexander J. , Wu Jessica P. , Tillman Eric S.
Published: September 2018

Atom transfer radical polymerization is used to synthesize brominated polystyrene, and the alkyl halide chain end is transformed into a nitroxide radical by the addition of excess nitrosobenzene to a redox active reaction mixture. The nitroxide group at the chain is verified using gel permeation chromatography, UV–vis, and electron paramagnetic resonance spectroscopy, showing the addition of the nitroso group does not result in a doubling of molecular weight, with the resulting polymer possessing new absorptions in the 300–400 nm range and an unpaired electron. The nature of the radical trap plays a role in halting the reaction at the end‐capped nitroxide polymer, rather than undergoing dimerization via atom transfer radical coupling‐type pathways. The polymeric nitroxide radical can be used to trap a second polymer radical in a subsequent reaction, simply by reacting with a second bromine‐capped polymer and adjusting the redox activity of the solution.
Nanostructured Membranes from Soft and Hard Nanoparticles Prepared via RAFT‐mediated PISA
Authors: Rubio Adrien , Desnos Gregoire , Semsarilar Mona
Published: September 2018

Reversible addition‐fragmentation chain transfer (RAFT) dispersion polymerization of benzyl methacrylate (BzMA) is used to prepare a series of near mono‐dispersed poly(2‐(dimethylamino)ethyl methacrylate)‐poly(benzyl methacrylate) (PDMA‐PBzMA) diblock copolymer nanoparticles in an ethanol–water binary mixture via polymerization‐induced self‐assembly. A relatively long PDMA (DP = 88) chain transfer agent is targeted to ensure that only spherical morphologies are obtained. High (>99%) BzMA monomer conversions can be achieved within 24 h when targeting degrees of polymerization (DP) of up to 1000. The resulting particles are analyzed using dynamic light scattering and transmission electron microscopy (TEM). Particles with PBzMA DPs of 500 and 1000 are used as templates for deposition of silica particles. TEM images confirm that tetramethyl orthosilicate precursor is successfully converted into silica sols that are deposited on the surface of the spherical polymer nanoparticles. Thin film membranes are then prepared from these silicified spherical particles (hard spheres) as well as the initial spherical particles devoid of silica coating (soft spheres). These membranes are fully characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), and water filtration test.
Cross Conjugated Organometallic Polymers Exhibiting Ultrafast Excitation Energy Channeling: Drastic Effect of the Connectivity
Authors: Lei Hu , Juvenal Frank , Karsenti Paul‐Ludovic , Fortin Daniel , Harvey Pierre D.
Published: September 2018

A polymer composed of 2,6‐diethynylanthraquinone diimine (AQI) and trans‐bis(tributylphosphine)platinum(II), [Pt], flanked by one tetraphenylpalladium(II)porphyrin (TPPPd) and one para‐nitrobenzene (C6H4NO2) is prepared (P1: M
n = 57000, M
w = 124500, Đ = 2.18, DP = 52.5) and is studied by time‐resolved emission spectroscopy and fs transient absorption spectroscopy (fs‐TAS). A model polymer (AQI(C6H4NO2)2‐[Pt])
n
is used for comparison (P2: M
n = 88200, M
w = 188700, Đ = 2.14, DP = 111). Taking advantage of the dynamics of the excited states of [Pt] and TPPPd and those obtained for P1 and P2, it is shown that the excitation energy absorbed by the central polymer chain, (AQI‐[Pt])
n
, channels this energy very efficiently, to the pendent TPPPd with a rate of energy transfer, k
ET(S1), larger than 2.3 × 1010 s−1 for an energy transfer 1(AQI‐[Pt])* → TPPPd for P1 at 298 K based on the decrease of the fluorescence lifetime of the (AQI‐[Pt])
n
chain in P1 compared to P2. This rate is more accurately estimated by fs‐TAS and is found to be 1.8 × 1011 s−1. This rate is ultrafast and is due to a large contribution of the Dexter mechanism across the imine bridge (CN).
Cavitation‐Induced Stress Whitening in Semi‐Crystalline Polymers
Authors: Lu Ying , Men Yongfeng
Published: September 2018

Cavitation‐induced stress whitening in semi‐crystalline polymers during stretching significantly influences the physical properties of the materials. This review summarizes studies focusing on two different cavitation processes triggered at small and large strain regimes. The corresponding mechanisms of these two cavitation processes are discussed. For cavitation activated at small strain, there are two basic but distinctly different models with the initiation of cavities either in the amorphous phase or in the crystalline skeleton. For the cavitation triggered at a large strain regime, there are also two different arguments being either due to the defects located in the ends of micro‐fibrils or as a consequence of the fragmentation of load‐bearing inter‐fibril/micro‐fibril tie chains in highly oriented amorphous networks. A unified understanding of the cavitation processes during stretching semi‐crystalline polymers based on interpenetrated network model is proposed. Finally, this review outlooks future research topics for better understanding the cavitation mechanism to meet the industrial need.
Reversible Chemo‐Topographic Control of Adhesion in Polydopamine Nanomembranes
Authors: Chiang Po‐Ju , Tang Guannan , Kwon Ik Soo , Eristoff Sophia , Bettinger Christopher J.
Published: September 2018

The use of polydopamine nanomembranes as a conformal coating with reversible adhesion is demonstrated. Here, two approaches to achieve reversible adhesion in polydopamine nanomembranes are reported: 1) controlling the surface chemistry using pH and 2) altering the texture through mechanical strain. pH‐dependent reversible adhesion in an aqueous environment can achieve differential pull‐off force of ≈0 and 1.93 ± 0.39 mN. Strain‐dependent adhesion in dry environments can produce between 0.26 ± 0.04 and 1.48 ± 0.06 mN, a range of 5.7 times difference. A theoretical framework based on elliptical Johnson–Kendall–Roberts theory to describe the relation between adhesion and the sinusoidal microtexture geometry is proposed. This model is in good agreement with experimentally determined values for interfacial adhesion in dry environments.
MicroRNA‐451a acts as tumor suppressor in cutaneous basal cell carcinoma
Authors: Sun Hui , Jiang Pingdong
Published: September 2018

Background

Basal cell carcinoma (BCC) is the most common type of skin cancer. The underlying mechanism leading to BCC formation is not fully uncovered. The aim of this study was to characterize miRNA‐451a as a novel tumor suppressor in cutaneous BCC.

Methods

We first evaluated miRNA‐451a level in human BCC clinical tissues and inducible BCC mouse model. Then we studied the impact of overexpressing or inhibiting miR‐451a in cell proliferation, colony formation potential, and cell cycle pattern. Next, we employed luciferase reporter assay and western blotting to evaluate TBX1 as a downstream target of miRNA‐451a. Lastly, we confirmed TBX1 expressional change in BCC tissues by qPCR.

Results

miRNA‐451a was significantly reduced in human BCC tissues. The downregulation of miRNA‐451a was also confirmed in BCC mouse model. Overexpressing miRNA‐451a in tumor cells markedly suppressed cell growth through G1 cell cycle arrest. However, inhibiting miRNA‐451a in primary cells promoted cell growth and colony formation capacity. TBX1 (602054) was predicted as a downstream target of miRNA‐451a and this was confirmed by luciferase assay and protein expression. Finally, TBX1 level was shown upregulated in BCC tissues as inversely to miR451a.

Conclusion

Our studies revealed that miRNA‐451a/TBX1 axis played a pivotal role in BCC tumorigenesis.
Taurine: A Regulator of Cellular Redox Homeostasis and Skeletal Muscle Function
Authors: Seidel Ulrike , Huebbe Patricia , Rimbach Gerald
Published: September 2018

Taurine is a nonproteinogenic ß‐aminosulfonic acid. Important dietary sources of taurine are fish and seafood. Taurine interacts with ion channels, stabilizes membranes, and regulates the cell volume. These actions confirm its high concentrations in excitable tissues like retina, neurons, and muscles. Retinal degeneration, cardiomyopathy, as well as skeletal muscle malfunction are evident in taurine‐deficient phenotypes. There is evidence that taurine counteracts lipid peroxidation and increases cellular antioxidant defense in response to inflammation. In activated neutrophils, taurine reacts with hypochloric acid to form taurine chloramine, which triggers the Kelch‐like ECH‐associated protein 1–nuclear factor E2‐related factor 1 (Keap1–Nrf2) pathway. Consequently, Nrf2 target genes, such as heme oxygenase‐1 and catalase, are induced. Furthermore, taurine may prevent an overload of reactive oxygen species (ROS) directly by an inhibition of ROS generation within the respiratory chain. Taurine affects mitochondrial bioenergetics and taurine‐deficient mice exhibit an impaired exercise performance. Moreover, some studies demonstrate that taurine enhances the glycogen repletion in the postexercise recovery phase. In the case of taurine deficiency, many studies observed a phenotype known in muscle senescence and skeletal muscle disorders. Overall, taurine plays an important role in cellular redox homeostasis and skeletal muscle function.
Design of robust nonfragile H∞ controller for uncertain nonlinear polynomial systems
Authors: Rezgui Marwa , Ayadi Hela Belkhiria , Benhadj Braiek Naceur
Published: September 2018

This paper is concerned with the robust H∞ nonfragile controller design for a particular class of nonlinear systems, namely, the perturbed polynomial systems, which are subject to unstructured bounded uncertainties in both the system model and the control law. Combining the Lyapunov stability theory, properties of linear matrix inequality, and Kronecker product properties, a sufficient condition of robust H∞ nonfragile control design is proposed. More specifically, we propose a robust H∞ controller of nonlinear polynomial systems with additive unstructured uncertainties and variation in the control law itself that guarantee the stability and the attenuation of external perturbations. Two examples are provided to illustrate the effectiveness of the proposed approach.
Surface modification of polyamide 12 angioplasty balloons by photochemical reaction with an aromatic azide
Authors: D'Onofrio Simone , Bignotti Fabio
Published: September 2018

Polyamide 12 (PA12) is used in a variety of applications when low moisture absorption, good dimensional stability, and toughness are required. Polyamide 12 is one of the polymers most frequently employed to fabricate angioplasty balloon catheters; however, its high hydrophobicity and chemical inertness require the application of coatings to make its surface more hydrophilic and biocompatible. In this work, an alternative method, based on the photochemical reaction of PA12 with a hydrophilic aromatic azide, was developed. Static and dynamic contact angle measurements evidenced that the surface modification process was able to improve PA12 wettability and that the effects were retained even after 12 months from surface treatment. Polyamide 12 modification resulted in an increase of its surface free energy, as evaluated by the van Oss, Good, and Chaudhury method. X‐ray photoelectron spectroscopy confirmed the presence of the aromatic azide on PA12 surface. Finally, compliance tests showed that the modification process did not reduce the mechanical performance of balloons.
Identification of Changing Ribosome Protein Compositions using Mass Spectrometry
Authors: Samir Parimal , Browne Christopher M. , Rahul  , Sun Ming , Shen Bingxin , Li Wen , Frank Joachim , Link Andrew J.
Published: September 2018

The regulatory role of the ribosome in gene expression has come into sharper focus. It has been proposed that ribosomes are dynamic complexes capable of changing their protein composition in response to environmental stimuli. MS is applied to identify quantitative changes in the protein composition of S. cerevisiae 80S ribosomes in response to different environmental stimuli. Using quantitative MS, it is found that the paralog yeast ribosomal proteins RPL8A (eL8A) and RPL8B (eL8B) change their relative proportions in the 80S ribosome when yeast is switched from growth in glucose to glycerol. By using yeast genetics and polysome profiling, it is shown that yeast ribosomes containing either RPL8A or RPL8B are not functionally interchangeable. The quantitative proteomic data support the hypothesis that ribosomes are dynamic complexes that alter their composition and functional activity in response to changes in growth or environmental conditions.
Hotelling's T2 control charts with fixed and variable sample sizes for monitoring short production runs
Authors: Chong Nger Ling , Khoo Michael B. C. , Haq Abdul , Castagliola Philippe
Published: September 2018

Short production runs are common in enterprises that require a high degree of flexibility and variety in manufacturing processes. To date, past research on short production runs has little focus on the multivariate control charts. In view of this, fixed sample size (FSS) and variable sample size (VSS) Hotelling's T2 charts are designed to monitor the process mean when the production horizon is finite. Optimal parameters to minimize the out‐of‐control (1) truncated average run length (TARL) and (2) expected TARL (ETARL) are provided such that the in‐control TARL is equal to the number of inspections (say I). The numerical study considers the run length performances of the FSS and VSS T2 short‐run charts for both known and unknown shift sizes. The VSS T2 short‐run chart performs well in swiftly detecting various mean shifts in comparison with the FSS T2 short‐run chart. Additionally, the VSS T2 short‐run chart is superior to the FSS T2 short‐run chart, in terms of the truncated standard deviation of the run length, expected truncated standard deviation of the run length, probability that the chart signals an alarm within the I inspections, ie, P(I) and expected P(I). A case study on the impurity profile of a crystalline drug substance illustrates the implementation of the VSS T2 short‐run chart.
Defects in interferon pathways as potential biomarkers of sensitivity to oncolytic viruses
Authors: Matveeva Olga V. , Chumakov Peter M.
Published: September 2018

Increased sensitivity of cancer cells to viruses is a prerequisite for the success of oncolytic virotherapy. One of the major causes of such a phenotype is the disruption of innate antiviral defenses associated with dysfunction of type 1 interferons (IFNs) that permits unlimited replication of viruses in cancer cells. Defects in IFN pathways help cancer progression by providing additional advantages to tumor cells. However, while these defects promote the survival and accelerated proliferation of malignant cells, they facilitate viral replication and thus enhance the efficiency of viral oncolysis. This review describes a broad spectrum of defects in genes that participate in IFN induction and IFN response pathways. Expression levels and/or functional activities of these genes are frequently low or absent in cancer cells, making them sensitive to virus infection. Therefore, certain specific defects in IFN signaling cascades might serve as potential biomarkers to help in identifying individual cancer patients who are likely to benefit from oncolytic virotherapy.
Nonparametric methods for fault diagnosis in dynamic systems
Authors: Zhirabok Alexey , Shumsky Alexey , Scherbatyuk Alexander
Published: September 2018

The problem of fault diagnosis in engineering systems with uncertainties described by nonlinear discrete‐time models is studied within the scope of analytical redundancy concept. Solution of the problem assumes the checking redundancy relations existing among system inputs and outputs measured over a finite time window. The nonparametric method is used to construct redundancy relations involving transformation of the initial system model into canonical form with special properties. The obtained results are illustrated by the general electric servoactuator of manipulation robots.
pth moment exponential input‐to‐state stability of nonlinear discrete‐time impulsive stochastic delay systems
Authors: Wu Xuan , Zhang Yu
Published: September 2018

This paper investigates the pth moment exponential input‐to‐state stability (ISS) of nonlinear discrete‐time impulsive stochastic delay systems. By employing Lyapunov functionals, some pth moment exponential ISS criteria are provided. The obtained results show that a discrete‐time stochastic delay system can become pth moment exponential input‐to‐state stable by impulsive controls even if it may be not input‐to‐state stable itself. On the other hand, the original system without impulses can retain its ISS property with appropriate destabilizing impulses. As an application, the theoretical results are used to test the ISS for a class of recurrent neural networks under stochastic perturbations. Finally, a numerical example is presented to illustrate the effectiveness of the results.
Data/pilot combination strategies for Compass B1C signal acquisition
Authors: Wang Yiwei , Li Wengang , Qian Tianrong , Huang Chen
Published: September 2018

The new Compass B1C signal, with a power ratio of the data channel to the pilot channel of 1:3, adopts BOC(1,1) in its data channel; a new modulation, namely, a quadrature multiplexed binary offset carrier (QMBOC) in its pilot channel modulates the narrowband BOC(1,1) and the wideband BOC(6,1) components in phase quadrature with each other. To fully exploit the B1C signal and to improve the acquisition sensitivity in a degraded signal or an indoor environment, this paper proposes to combine the data and the pilot channels for B1C signal acquisition. The noncoherent, coherent, and differential coherent strategies are considered for application in the B1C signal. Considering the power inequality between the data and the pilot channels, the maximum signal‐to‐noise ratio combination (MRC) is utilized in these strategies to obtain an optimal combination. This paper also proposes to simplify the differential coherent strategy to obtain a better anti‐noise performance under stable conditions. The computer simulation results are given to verify the theoretical expressions, and some discussions with respect to the proposed strategies are provided.
Towards improved satellite telecommand link availability
Authors: Noels Nele , Aguilar Sánchez Ignacio
Published: September 2018

Compliant with the Consultative Committee for Space Data Systems (CCSDS) set of protocols, we explore enhancing the availability service for space links. In particular, we consider specific improved defences against jamming attacks affecting symbol synchronization. More robust adaptive closed‐loop symbol synchronizers are designated with a view to the planned update of the CCSDS standard for the telecommand synchronization and channel coding sublayer of the data link layer. It is shown that adaptive schemes exploiting instantaneous jammer state information are recommended to counter destructive attacks that may harm the availability.