bluuebunny/crossref_metadata_2025 huggingface dataset:
Bounds for GL3
L-functions in depth aspect
Authors: Sun Qingfeng , Zhao Rui
Published: February 2019

Let f be a Hecke–Maass cusp form for

SL
3

⁢

(
ℤ
)

{\mathrm{SL}_{3}(\mathbb{Z})}

and χ a primitive Dirichlet character of prime power conductor

𝔮
=

p
κ

{\mathfrak{q}=p^{\kappa}}

, with p prime.
We prove the subconvexity bound

L
⁢

(

1
2

,

π
⊗
χ

)

≪

p
,
π
,
ε

𝔮

3
/
4

-

3
/
40

+
ε

L\Big{(}\frac{1}{2},\pi\otimes\chi\Big{)}\ll_{p,\pi,\varepsilon}\mathfrak{q}^{%
3/4-3/40+\varepsilon}

for any

ε
>
0

{\varepsilon>0}

, where the dependence of the implied constant on
p is explicit and polynomial.
2D Seismic Interpretation of the Meyal Area, Northern Potwar Deform Zone, Potwar Basin, Pakistan
Authors: Riaz Muhammad , Nuno Pimentel , Zafar Tehseen , Ghazi Shahid
Published: February 2019

Meyal Field is considered as one of the chief hydrocarbon producing fields in the Potwar Basin, Pakistan. The present research emphasize on the subsurface structures affecting the Mesozoic-Cenozoic successions exclusively foremost reservoir units comprising the Eocene Chor Gali and Sakesar formations. Data from six seismic lines and three wells (aligned with those lines) have been deliberated comprehensively with remarkable and tremendous calibration. Five prominent and imperative reflectors specifically the Permian, Triassic, Jurassic, Paleocene and Eocene successions were interpreted through seismic tactics. Time structure maps were equipped on the basis of two-way travel time (TWT) of the seismic line. Likewise, four isopach maps portrayed the thickness discrepancy of prospective hydrocarbon strata. Structurally, analytical section reveals that the Meyal anticline is a plunging and faulted anticline. The pop-up structure is constrained by back-thrust from the north and fore-thrust from the south, on the dip lines. These maps depicted potential reservoir, demarcate promising site for future hydrocarbon exploration.
Double Robust Efficient Estimators of Longitudinal Treatment Effects: Comparative Performance in Simulations and a Case Study
Authors: Tran Linh , Yiannoutsos Constantin , Wools-Kaloustian Kara , Siika Abraham , van der Laan Mark , Petersen Maya
Published: February 2019

A number of sophisticated estimators of longitudinal effects have been proposed for estimating the intervention-specific mean outcome. However, there is a relative paucity of research comparing these methods directly to one another. In this study, we compare various approaches to estimating a causal effect in a longitudinal treatment setting using both simulated data and data measured from a human immunodeficiency virus cohort. Six distinct estimators are considered: (i) an iterated conditional expectation representation, (ii) an inverse propensity weighted method, (iii) an augmented inverse propensity weighted method, (iv) a double robust iterated conditional expectation estimator, (v) a modified version of the double robust iterated conditional expectation estimator, and (vi) a targeted minimum loss-based estimator. The details of each estimator and its implementation are presented along with nuisance parameter estimation details, which include potentially pooling the observed data across all subjects regardless of treatment history and using data adaptive machine learning algorithms. Simulations are constructed over six time points, with each time point steadily increasing in positivity violations. Estimation is carried out for both the simulations and applied example using each of the six estimators under both stratified and pooled approaches of nuisance parameter estimation. Simulation results show that double robust estimators remained without meaningful bias as long as at least one of the two nuisance parameters were estimated with a correctly specified model. Under full misspecification, the bias of the double robust estimators remained better than that of the inverse propensity estimator under misspecification, but worse than the iterated conditional expectation estimator. Weighted estimators tended to show better performance than the covariate estimators. As positivity violations increased, the mean squared error and bias of all estimators considered became worse, with covariate-based double robust estimators especially susceptible. Applied analyses showed similar estimates at most time points, with the important exception of the inverse propensity estimator which deviated markedly as positivity violations increased. Given its efficiency, ability to respect the parameter space, and observed performance, we recommend the pooled and weighted targeted minimum loss-based estimator.
Nursing Education Challenges from Saudi Nurse Educators’ and Leaders’ Perspectives: A Qualitative Descriptive Study
Authors: Alghamdi Reem , Albloushi Monirah , Alzahrani Ebtesam , Aldawsari Aisha , Alyousef Seham
Published: February 2019

Aim

To explore the challenges in nursing education in Saudi Arabia from nurse educators’ and leaders’ perspectives.

Background

Saudi Arabia considerably lacks Saudi nurses and most nurses in Saudi healthcare facilities are expatriates with diverse academic, cultural, and linguistic backgrounds. The perception regarding nurses’ profession and their low status in Saudi Arabia affect the nursing profession negatively, leading to staff insufficiency. Understanding the difficulties of the nursing profession could help intervene accordingly, in encouraging students to pursue a career in nursing.

Methods

An exploratory qualitative method was used. Three Saudi nursing educators and four leaders were interviewed. They were recruited through purposive sampling. The interviews were transcribed verbatim and data were analyzed using thematic analysis.

Findings

Participants indicated that nursing education in Saudi Arabia is facing multiple challenges requiring serious attention from Saudi leaders. The challenges were divided to four themes and different categories; cultural challenges, educational challenges, organizational challenges (weak nursing authority, lack of acknowledgement for Saudi nurses), and work challenges (poor working environment, language barrier).

Discussion

The challenges that face nursing education in Saudi Arabia were mainly at three levels: management, system, and social. These challenges were the reasons for Saudi nurses to leave the profession.

Conclusion

This study revealed some of the challenges facing nursing education in Saudi Arabia. These challenges are not unique to Saudi Arabia but knowing about these challenges will help nurse educators and leaders to improve nursing programs, enhance students’ clinical experiences, and promote nursing profession in Saudi Arabia.
Cost, profitability and value of laboratory diagnostics: in God we trust, all others bring data
Authors: Lippi Giuseppe , Plebani Mario
Published: February 2019

Although laboratory tests are the most used diagnostic investigations for screening, diagnosing, prognosticating and therapeutic monitoring of most human diseases, laboratory medicine is currently seen as many other economic industries by some policymakers and administrators, and is hence subjected to scale economy and assessed accordingly, despite the incremental clinical value that laboratory tests can generate. According to a genuine economic perspective, the impact of diagnostic testing on a healthcare budget is lower than 2.5%, whilst its profitability is over 100%, a net profit margin over 7-fold larger than whatever other human industry. Even more importantly, the impact of laboratory tests on clinical outcomes is now clear and virtually incontestable, as their use will improve clinical pathways much more than any other diagnostic investigations. The many ongoing attempts to downsize the importance of laboratory medicine as costs centers, or even the concept that public laboratory services can be safely eliminated or outsourced to external private professional organizations, shall hence be challenged. Laboratory medicine not only is vital to patient care and patient flow, and will remain so for many years to come, but is also a valuable economical resource for the healthcare facilities.
Retinol-binding protein 4 better correlates with metabolic syndrome than cystatin C
Authors: Klisic Aleksandra , Kavaric Nebojsa , Soldatovic Ivan , Ninic Ana , Kotur-Stevuljevic Jelena
Published: February 2019

Background

Retinol-binding protein 4 (RBP4) and cystatin C are regarded as novel metabolic risk markers. Therefore, we aimed to examine which one of these biomarkers better correlates with metabolic syndrome (MetS) in a cohort of postmenopausal women.

Methods

A total of 129 postmenopausal women (among which 62 women had MetS) were recruited in this cross-sectional study. MetS was diagnosed according to the International Diabetes Federation criteria.

Results

Cystatin C and RBP4 levels were significantly higher in women with MetS, compared to those without MetS (p=0.011 vs. p<0.001, respectively). A significant difference in the proportion of women with and without MetS across cystatin C and RBP4 quartiles was observed (χ2=5.1, p=0.025, and χ2=11.1, p=0.001, respectively). Logistic regression analysis revealed a borderline significant relationship between cystatin C and MetS (p=0.066), but this significance disappeared after adjustment for age, inflammation level and duration of menopause (p=0.221). On the contrary, a significant relationship between RBP4 and MetS was observed not only without adjustment (p=0.009), but also even after adjustment for age, inflammation level and duration of menopause (p=0.006).

Conclusions

RBP4 better correlates with MetS than cystatin C in postmenopausal women.
Analysis of ticagrelor’s cardio-protective effects on patients with ST-segment elevation acute coronary syndrome accompanied with diabetes
Authors: Li Dong-Tao , Li Shun-Bao , Zheng Jian-Yong , Tang Hai-hong , Qiu Yi-Gang , Xue Ning , Cao Yi
Published: February 2019

Background

To analyze the cardio-protective effects of ticagrelor in patients with acute coronary syndrome with S-T segment elevation.

Methods

The sample was 200 patients who had been diagnosed with acute coronary syndrome accompanied by diabetes Mellitus type II. Only patients having ST segment elevation before the treatment were included. Then, the subjects were further randomly divided into an observation group and a control group. The control group of 100 patients received clopidogrel; the observation group of 100 patients of ticagrelor. The serous creatine kinase CK-MB, functional cardiac indexes of left ventricular end diastolic diameter (LVDD), cardiac troponin I, ventricular ejection fraction, and relevant major adverse cardiovascular events (MACE) were compared between the two groups.

Results

One month after a percutaneous coronary intervention (PCI) the observation group showed better results against angina, stent thrombosis, and all-cause mortality compared with those of the control subjects. Six months after treatment, both groups suffered adverse reactions. The number of patients who suffered adverse reactions in respiratory tract in the observation group was higher than in the control group. The inhibition of platelet aggregation IPA of ticagrelor was found to be significantly higher than clopidogrel, having a significant p value.

Conclusion

Ticagrelor can effectively protect myocardial function for patients with ST-segment elevation acute coronary syndrome accompanied by diabetes and can reduce the incidence of adverse reactions..
The Islamic and Western Cultures and Values of Privacy
Authors: Almutairi Sattam Eid
Published: February 2019

The paper provides valuable accounts of the general concepts underlying privacy law in both cultures, and great detail about the impact of criminal procedure and evidence rules on privacy in reality rather than legal theory. It is, in this sense, a “realist” approach to privacy, particularly but not exclusively in relation to sexual activity. The distinction which the article draws between the frameworks within which privacy is conceived broadly, self-determination and limited government in the USA, protection of one’s persona in Europe, and reputation in Islamic law. However, the paper argues that Western and Islamic traditions share many of the same concepts about the tests to be applied when deciding how far an intrusion on privacy is justified and value many of the same interests in doing so. At the same time, it will highlight those areas where they differ which are not ones of crucial importance when deciding, for example, what are the proper limits on mass surveillance. Indirectly, this shows that even though there may be stark differences between the cultures on some points, there is enough agreement on some aspects of privacy to make comparisons in relation to issues such as mass surveillance.
Nonprofit Practitioners Chat Back: An Exploratory Content Analysis of Participant Responses to the National Council of Nonprofit’s Webinar on the 2017 Tax Cuts and Jobs Act
Authors: Abzug Rikki
Published: February 2019

As the first major overhaul of the United States’ tax code in a generation, the passage of the Tax Cuts and Jobs Act of 2017 has particular significance for the operation of US nonprofit organizations. Provisions of the Tax Act, including raising the ceiling on individual standard deductions, imposing excise taxes on highly compensated nonprofit employees, repealing the individual mandate of the Affordable Care Act, etc., are causing great uncertainty and consternation within organizations of, and bridging, the nonprofit sector. In response to some of the initial confusion, the National Council of Nonprofits offered a webinar, entitled, “Now What: How the New Federal Tax Law Impacts Charitable Nonprofits” on January 11, 2018. A one-hour slide-show with voice-overs was complemented by a running “chat” of nonprofit listeners/participants. This exploratory study undertakes a content analysis of the one-hour nonprofit participant chat that accompanied the webinar in order to take a pulse of the concerns of the practitioners as the potential impact of the law was explicated.
Novel proton exchange membranes based on PVC for microbial fuel cells (MFCs)
Authors: Gaurav Kumar , Singh Ram , Tiwari Brajesh Kumar , Srivastava Richa
Published: February 2019

Proton exchange membranes (PEMs), used as separators, are one of the important components in microbial fuel cells (MFCs). The efficiency of MFC is greatly influenced by PEM. Nafion, which is a commonly used membrane, has several disadvantages in addition to its high cost. The aim of the present work was to develop low-cost PEMs with higher conductivity. In the current work, membranes were prepared using comparatively cheaper material polyvinyl chloride with different concentrations of silica (SiO2), citric acid and phosphotungstic acid (PWA) by the solution casting method. Different membrane properties such as surface morphology, water uptake capacity, ion exchange capacity (IEC), tensile strength, leaching test and potential applications in MFCs were investigated. The results showed that the prepared membrane with 10% silica has the highest water uptake of 55.8%. The IEC of prepared membranes was found to vary from 0.024 to 0.875 meq/g. The membranes showing better IEC were applied to the MFC. The maximum power density obtained was 43.91 m W/cm2 in the case of a membrane with both 5% PWA and 5% silica. The results obtained make this membrane a promising and economically viable new material in MFC applications.
The effects of dietary methionine restriction on the function and metabolic reprogramming in the liver and brain – implications for longevity
Authors: Mladenović Dušan , Radosavljević Tatjana , Hrnčić Dragan , Rasic-Markovic Aleksandra , Stanojlović Olivera
Published: February 2019

Methionine is an essential sulphur-containing amino acid involved in protein synthesis, regulation of protein function and methylation reactions. Dietary methionine restriction (0.12–0.17% methionine in food) extends the life span of various animal species and delays the onset of aging-associated diseases and cancers. In the liver, methionine restriction attenuates steatosis and delays the development of non-alcoholic steatohepatitis due to antioxidative action and metabolic reprogramming. The limited intake of methionine stimulates the fatty acid oxidation in the liver and the export of lipoproteins as well as inhibits de novo lipogenesis. These effects are mediated by various signaling pathways and effector molecules, including sirtuins, growth hormone/insulin-like growth factor-1 axis, sterol regulatory element binding proteins, adenosine monophosphate-dependent kinase and general control nonderepressible 2 pathway. Additionally, methionine restriction stimulates the synthesis of fibroblast growth factor-21 in the liver, which increases the insulin sensitivity of peripheral tissues. In the brain, methionine restriction delays the onset of neurodegenerative diseases and increases the resistance to various forms of stress through antioxidative effects and alterations in lipid composition. This review aimed to summarize the morphological, functional and molecular changes in the liver and brain caused by the methionine restriction, with possible implications in the prolongation of maximal life span.
Iterative and avertive polysemy in Moksha Mordvin
Authors: Kozlov Alexey
Published: February 2019

The paper focuses on a two aspectual morphemes in Moksha Mordvin (<Mordvin<Finno-Ugric). The first of them, the Frequentative, has four phonologically conditioned allomorphs, -ənd-, -n’ə-, -s’ə-, and -kšn’ə-. These affixes used to be separate morphemes in Proto-Finno-Ugric, but ended up as having the same meaning and being complementarily distributed. A remnant of a more archaic stage of language evolution is the Avertive marker, -əkšn’ə-, only different from one of the Frequentative allomorphs by one phoneme, which can hardly be a coincidence. A diachronic hypothesis about how iterative-avertive polyfunctionality could have arisen is suggested.
The effect of Paracetamol exposure on hepatic and renal tissues during statin usage
Authors: Aksun Saliha , Gökcimen Alpaslan , Kahyaoglu Fadime , Demirci Buket
Published: February 2019

Objective

Statins and Paracetamol have widespread use in clinic and both drugs possess similar side effects; therefore, we investigated if drug-interaction occurs when the combination of these two drugs is used during therapy.

Materials and methods

A total of 32 (12–15 months old) grown-up male rats were divided into four groups: Control group, RSV group (10 mg/kg Rosuvastatin/daily), APAP group (50 mg/kg Paracetamol/5 days/weekly), RSV+APAP (10 mg/kg Rosuvastatin/daily+50 mg/kg Paracetamol/5 days/weekly). At the end of 8 weeks of chronic treatment, the blood and tissue samples were taken under the Ketamine and Xylasine anesthesia (50 mg/kg and 5 mg/kg, respectively).

Results

In the liver, sinusoidal dilatations, pyknotic nuclei and hemorrhagic foci are more frequently seen in the group receiving combination therapy; although serum liver functions among groups were not significantly different. Kidney histopathologic alterations in APAP and RSV+APAP groups were found more distinct than in RSV alone group. Inducible nitric oxide synthase activity was highly increased with combination therapy in liver and kidney tissues.

Conclusion

RSV-Paracetamol interaction may occur as an important drug interaction histopathologically even before it is manifested biochemically in the clinic.
An Accelerated Test Method to Evaluate Cementitious Mixtures Subjected to Chemical Sulfate Attack
Authors: Aguayo Federico M. , Drimalas Thano , Folliard Kevin J.
Published: February 2019

External sulfate attack continues to be a major threat to the long-term durability of concrete structures. Soil or water containing sufficient levels of sulfates can penetrate and chemically react with the hydrated cement compounds, leading to volumetric expansion, and in severe cases, softening of the hardened cementitious paste. While ASTM C1012, Standard Test Method for Length Change of Hydraulic-Cement Mortars Exposed to a Sulfate Solution, is the most widely accepted performance test method used to access the sulfate resistance of cementitious binders, the test requires at least six months and often up to twelve months to perform. This article presents a new accelerated method that places mortar bar specimens under high-vacuum while immersed in sulfate solution to accelerate the penetration and diffusion of sulfates in the specimens and therefore, the degradation and measured linear expansion of the specimens. Expansion, mass change, and visual degradation were assessed over time on mortar specimens immersed in a 5 % and 0.89 % sodium sulfate solution (Na2SO4) and subjected to the vacuum saturation procedure. Expansion results are compared with companion mortar bars that followed the ASTM C1012 method without vacuum saturation. When compared with the current ASTM method, the new test method showed a significant acceleration in the rate of expansion with severe visual deterioration observed two to three times quicker. Visual degradation and measured expansion occurred more rapidly for specimens subjected to the accelerated method and immersed in 5 % Na2SO4; however, mixtures subjected to the accelerated method and immersed in 0.89 % Na2SO4 still showed much faster expansion than companion specimens tested according to ASTM C1012 in 5 % Na2SO4.
Use of Electrochemical Techniques in Measuring Corrosion in the Laboratory and Monitoring Corrosion in the Field
Authors: Papavinasam Sankara
Published: February 2019

Most corrosion mechanisms are electrochemical in nature. Therefore, electrochemical techniques are widely used to understand corrosion in many corrosion education institutes and research organizations. Electrochemical techniques are also used in plant monitoring of corrosion mainly because of their ability to produce instantaneous corrosion rates. This paper presents the status of application of electrochemical techniques for measuring corrosion in the laboratory and for monitoring corrosion in the field. The information presented in the paper was collected based on a survey of corrosion professionals from education institutes, from research organizations, and from those working in the field. The salient features of the survey include: a large percentage of professionals are not following any standard procedures in conducting corrosion tests using electrochemical techniques; a fairly large percentage of field personnel are not aware of procedures used to calculate general corrosion rates (this practice prevails because many field-deployable devices have inbuilt general corrosion rate calculators); almost 50 % of these professionals do not evaluate localized corrosion (because localized corrosion may lead to catastrophic failures in the field, 80 % of field operators evaluate the susceptibility of materials to localized corrosion); the involvement of education professionals in field corrosion rate monitoring is very limited (given the safety and security procedures to be followed in the field, the lesser involvement of academic community in the field is understandable; however, the establishment of paths for exposing students in the field will be useful in the long run); and the knowledge transfer cycle is broken at the field operator to educationists step (consequently, field use of electrochemical techniques is not taught during education). The findings of the survey should be considered within the limitations of it. A major limitation of the survey is that it summarized responses of only 55 professionals.
Recent Developments in Standards for Electrochemical Corrosion Testing
Authors: Dean Sheldon W.
Published: February 2019

Electrochemical methods are now widely used in corrosion testing and evaluation. About one-third of all research articles recently published on corrosion science and technology have some electrochemical components in the studies reported. New methods continue to be developed and standardized. The purpose of this paper is to highlight the newer standards and discuss changes made to existing standards developed by ASTM Subcommittee G01.11 on Electrochemical Methods. Among the newer methods discussed are ASTM G192, Standard Test Method for Determining the Crevice Repassivation Potential of Corrosion-Resistant Alloys Using a Potentiodynamic-Galvanostatic-Potentiostatic Technique, and ASTM G217, Standard Guide for Corrosion Monitoring in Laboratories and Plants with Coupled Multielectrode Array Sensor Method. Older standards that have been updated are also discussed, including ASTM G5, Standard Reference Method for Making Potentiodynamic Anodic Polarization Measurements, and ASTM G69, Standard Test Method for Measurement of Corrosion Potentials of Aluminum Alloys. Some outstanding issues with existing standards and suggestions for new standards are provided in the discussion.
Electrode Potential as a Key Indicator of Corrosion Performance
Authors: Dean Sheldon W.
Published: February 2019

The electrode potential of a metal surface in a corrosive environment (e.g., natural water) is a key indicator of the material’s tendency to corrode. This fact has become more important as technologies for measuring the electrode potential have evolved. Electrode potential measurements are essential for assessing the performance of cathodic protection systems. These measurements have also been important in determining whether reinforcing bar in concrete is corroding. In addition, electrode potential measurements are important in the polarization resistance technique of monitoring corrosion rates. They have also been used to evaluate the tendency of alloys to develop pitting and crevice corrosion in chloride-containing environments. ASTM G215, Standard Guide for Electrode Potential Measurement, covers the measurement of electrode potentials, including the care and maintenance of reference electrodes used for measuring electrode potentials. This new standard is discussed along with more details on the errors and problems that can arise with these measurements.
Corrosion Rates of Ductile Iron Pipe in Drilling Fluids: A Comparison of ASTM Electrochemical Standards G59, G102, and G106 to ASTM Weight Loss Standard G162
Authors: Horton Mike
Published: February 2019

One of the most commonly used piping materials for transport of water and wastewater in the United States is ductile iron pipe (DIP). Although this piping normally is installed using open trench cuts, a trenchless installation method that is finding increased popularity for DIP is horizontal directional drilling (HDD). Many HDD installations utilize specialized drilling fluids, commonly called “drilling muds,” which may be composed of bentonite clay, various organic and inorganic additives, polymers, lubricants, wetting agents, or polymers mixed with water (or any combination thereof). To evaluate the corrosion characteristics of these fluids in contact with DIP, a 1-year corrosion study involving more than 200 ductile iron pipe specimens was conducted comparing five commercially available directional drilling fluids. Corrosion tests were conducted using electrochemical test methods described in ASTM G59, Standard Test Method for Conducting Potentiodynamic Polarization Resistance Measurements, ASTM G102, Standard Practice for Calculation of Corrosion Rates and Related Information from Electrochemical Measurements, and ASTM G106, Standard Practice for Verification of Algorithm and Equipment for Electrochemical Impedance Measurements, and these results were compared to 1-year weight loss test results obtained using ASTM G162, Standard Practice for Conducting and Evaluating Laboratory Corrosions Tests in Soils. This paper discusses which electrochemical test method and method of analysis gave results closest to those obtained with ASTM G162 weight loss evaluation.
Electrochemical Sensors for Continuous Measurement of Corrosion and Coating System Performance in Outdoor and Accelerated Atmospheric Tests
Authors: Friedersdorf Fritz J. , Demo Jeff C. , Brown Nathan K. , Kramer Patrick C.
Published: February 2019

Organic coatings are the primary means of protecting structures from atmospheric corrosion in harsh environments. Environmental compliance and a desire for increased performance continue to drive the development of new coatings; however, this process may take many years. Corrosion tests for coatings development, qualification, and selection often provide poor correlation to service performance. Conventional tests and characterization procedures may not assess the most relevant degradation mechanisms of loss of barrier properties, localized corrosion, and galvanic attack. Furthermore, these tests do not yield information on interactions between specific environmental parameters and material degradation or the kinetics of failure. To improve coating evaluations, electrochemical sensors and data acquisition systems have been developed to measure coating performance and corrosion continuously during atmospheric tests. The sensing elements are incorporated in multisensor test panels that can be cleaned, coated, and scribed like conventional coating test panels. The multisensor panels support measurement of coating barrier properties, free corrosion, and galvanic corrosion. The barrier properties and free corrosion are measured using impedance-based methods, and galvanic corrosion is quantified using a zero resistance ammeter. Local measurements of panel surface temperature, air temperature, and relative humidity are used to correlate degradation rates and barrier properties to environmental conditions. The simultaneous environmental measurements also provide records that can be used to ensure the validity of performance comparisons between separate tests and within a single test. A description of the sensors, electrochemical measurements, and methods for coating testing are reported.
Use of Alternating Current Impedance Spectra as a Supplemental Verification of Rebar Passivation in Two Marine Viaducts
Authors: Lee Madeline , Tinnea Ryan
Published: February 2019

Cathodic protection (CP) systems were installed on a viaduct in Ketchikan, Alaska, in 2001. Three CP styles were implemented to meet the changing protection needs in several marine environments over varying elevations. The systems installed included galvanic thermal spray zinc metallizing installed on cast-in-place pile caps and precast deck panels in the upper splash and atmospheric zones; fiberglass-reinforced plastic jackets with embedded galvanic zinc mesh anodes installed on the pile caps and piling in the tidal and lower splash zones; and submerged aluminum anodes protecting the piling in the submerged zone. A 2017 inspection found that the systems were still providing protection to most of the cathodically protected areas. In contrast, areas not originally protected with CP showed severe cracking and delamination exacerbated by corrosion of the reinforcing steel. Depolarization testing of CP systems in concrete is often a lengthy process that can take weeks to months to fully achieve. The extreme tidal changes in Ketchikan provided further challenges as measured corrosion potentials in many areas were influenced by tide level. As a result, passivation verification technique (PVT) testing was utilized to provide additional support to the depolarization data. PVT is an alternating current technique that provides a qualitative analysis of the condition of the reinforcing steel by measuring changes in phase angle over a partial spectrum—100, 10, 1, 0.1, and 0.01 Hz. These PVT and depolarization measurements are used to determine if the reinforcing steel is exhibiting passive or active behavior and whether the reinforcement is corroding or protected.
Experimental Studies on the Effect of Electrode Spacing in Coupled Multielectrode Array Sensors on Corrosion Rate Measurements
Authors: Yang Lietai , Sun Xiaodong
Published: February 2019

The electrodes in a coupled multielectrode array sensor (CMAS) are usually flush-mounted in an insulator, and the spacing between adjacent electrodes is an important parameter. The common belief is that the smaller the spacing is, the better the multielectrode array simulates the behavior of a real one-piece metal. Experiments were conducted to study the effect of spacing in CMAS on the measurements of corrosion rates. The data suggest that the spacing has no significant effect on the measured nonuniform corrosion rate for carbon steel in simulated seawater when the spacing varies from 1 to 8 mm. Preliminary studies also suggest that the CMAS with 16 closely packed electrodes and small spacing (0.05–0.25 mm) may measure a lower than usual nonuniform corrosion rate because of the efficient chemical interaction among all of the electrodes packed within a small area. The efficient chemical interaction may have caused all the electrodes in the small area to be under active corrosion such that there were no effective cathodic electrodes left to support localized corrosion. This was evidenced by the measurement of the open-circuit potentials of individual electrodes soon after decoupling of the electrodes. The data showed that there is a small variation in the open-circuit potentials for the probe with closely packed electrodes (small standard deviation). In contrast, the standard deviations for the probes that have a spacing of 1 or 8 mm were larger. As a sensor, the loss of effective cathode may not represent the situation for industrial equipment where the cathodic sites in faraway locations may always be available when there is localized corrosion.
Status of Pitting Corrosion Prediction in Mixed Solutions Containing Reduced Sulfur Species
Authors: Nguyen Van Anh , Carcea Anatolie G. , Ghaznavi Mahmoudreza , Newman Roger C.
Published: February 2019

Pitting of stainless steels and nickel-base alloys in solutions containing reduced sulfur species has features that are distinct from ordinary chloride-induced pitting. In particular, very severe pitting of molybdenum-free alloys occurs in neutral sodium sulfate solution containing thiosulfate ions for a certain range of sulfate to thiosulfate concentration ratio and a certain range of potential. Such pitting is hard to initiate without mechanical damage of the metal surface in situ; thus, the potentiostatic scratch test is particularly appropriate in this case. For chloride-thiosulfate mixtures, mechanical damage is not mandatory, and the quantification of pitting susceptibility is more complex because pitting can also occur in solutions containing only chloride anions. The signature of catalyzed (thiosulfate-induced) pitting is a large drop in pitting potential compared with the pure chloride case. The chloride-thiosulfate case is also notable in that the favorable ratio of chloride to thiosulfate concentration is very large for nickel-base alloys but much smaller for stainless steels. Reaction-transport modeling has been used to elucidate two particular features of pitting in these systems—the B value in Galvele's pitting potential equation and the enrichment of anions in pits as a function of their charge. It is found that the B value for chloride solutions is around 100 mV, in agreement with experiments, if one assumes that chromium cations exist mainly in the form of chloro-complexes. When thiosulfate is present, it is much more strongly enriched in pits than chloride. For sulfate-based solutions, the B value is around 50 mV, in line with the double charge of sulfate (and thiosulfate). Sulfide, not being an anion in the acidic conditions of a pit, shows different behavior in that deeper pits are less stable than shallow pits because the limiting flux of sulfide to the bottom of the pit decreases.
Progress in Development of Electrochemical Methods in Corrosion Science and Engineering
Authors: Glover Carol F. , Hutchinson Michael J. , Rafla Veronica N. , Bland Leslie G. , Scully John R.
Published: February 2019

The role and impact of four electrochemical techniques in the study of various corrosion applications are discussed; these are scanning vibrating electrode technique, coupled multielectrode array technique, scanning electrochemical microscope, and atomic emission spectroelectrochemistry. A common theme is an ability to monitor corrosion phenomena in situ on a local electrochemical scale with high resolution of electrochemical and, in some cases, chemical reaction rates. In all cases, the techniques presented here are discussed in the context of specific corrosion problems carried out in full immersion conditions. Examples taken from the current literature, and new data, are presented to demonstrate the use and advantages of these techniques, or a combination of these techniques, as powerful tools for industrially important applications. This includes assessment of the galvanic interactions and throwing power of metal-rich primer coatings for active corrosion protection, corrosion/corrosion resistance mechanisms of new metal alloys, the effect of pretreatments on coating integrity, current distributions within a crevice, and pitting corrosion.
In situ growth of deep-sea octocorals after the Deepwater Horizon oil spill
Authors: Girard Fanny , Cruz Rafaelina , Glickman Orli , Harpster Tyler , Fisher Charles R.
Published: February 2019

Although the role of deep-sea corals in supporting biodiversity is well accepted, their ability to recover from anthropogenic impacts is still poorly understood. An important component of recovery is the capacity of corals to grow back after damage. Here we used data collected as part of an image-based long-term monitoring program that started in the aftermath of the Deepwater Horizon oil spill to develop a non-destructive method to measure in situ growth rates of Paramuricea spp. corals and characterize the impact of the spill on growth. About 200 individual coral colonies were imaged every year between 2011 and 2017 at five sites (three that were impacted by the spill and two that were not). Images were then used to test different methods for measuring growth. The most effective method was employed to estimate baseline growth rates, characterize growth patterns, estimate the age of every colony, and determine the effects of impact and coral size on growth. Overall growth rates were variable but low, with average annual growth rates per site ranging from 0.14 to 2.5 cm/year/colony. Based on coral size and growth rates, some colonies are estimated to be over two thousand years old. While coral size did not have an influence on growth, the initial level of total impact in 2011 had a significant positive effect on the proportion of new growth after 2014. However, growth was not sufficient to compensate for branch loss at one of the impacted sites where corals are expected to take an average of 50 years to grow back to their original size. The non-destructive method we developed could be used to estimate the in situ growth rates on any planar octocoral, and would be particularly useful to follow the recovery of corals after impact or assess the effectiveness of Marine Protected Areas.
Hepatoblastoma and Wilms’ tumour in an infant with Beckwith–Wiedemann syndrome and diazoxide resistant congenital hyperinsulinism
Authors: Uppal Saurabh , Blackburn James , Didi Mohammed , Shukla Rajeev , Hayden James , Senniappan Senthil
Published: February 2019

Beckwith–Wiedemann syndrome (BWS) can be associated with embryonal tumours and congenital hyperinsulinism (CHI). We present an infant with BWS who developed congenital hepatoblastoma and Wilms’ tumour during infancy. The infant presented with recurrent hypoglycaemia requiring high intravenous glucose infusion and was biochemically confirmed to have CHI. He was resistant to diazoxide but responded well to octreotide and was switched to Lanreotide at 1 year of age. Genetic analysis for mutations of ABCC8 and KCNJ11 were negative. He had clinical features suggestive of BWS. Methylation-sensitive multiplex ligation-dependent probe amplification revealed hypomethylation at KCNQ1OT1:TSS-DMR and hypermethylation at H19
/IGF2:IG-DMR consistent with mosaic UPD(11p15). Hepatoblastoma was detected on day 4 of life, which was resistant to chemotherapy, requiring surgical resection. He developed Wilms’ tumour at 3 months of age, which also showed poor response to induction chemotherapy with vincristine and actinomycin D. Surgical resection of Wilms’ tumour was followed by post-operative chemotherapy intensified with cycles containing cyclophosphamide, doxorubicin, carboplatin and etoposide, in addition to receiving flank radiotherapy. We report, for the first time, an uncommon association of hepatoblastoma and Wilms’ tumour in BWS in early infancy. Early onset tumours may show resistance to chemotherapy. UPD(11p15) is likely associated with persistent CHI in BWS.

Learning points:

Long-acting somatostatin analogues are effective in managing persistent CHI in BWS.

UPD(11)pat genotype may be a pointer to persistent and severe CHI.

Hepatoblastoma and Wilms’ tumour may have an onset within early infancy and early tumour surveillance is essential.

Tumours associated with earlier onset may be resistant to recognised first-line chemotherapy.
Determining Which Prosthetic to Use During Aortic Valve Replacement in Patients Aged Younger than 70 Years: A Systematic Review of the Literature
Authors: Borger Philip , Charles Eric J , Smith Eric D , Mehaffey J Hunter , Hawkins Robert B , Kron Irving L , Ailawadi Gorav , Teman Nicholas
Published: February 2019

Background: The choice of bioprosthesis versus mechanical prosthesis in patients aged less than 70 years undergoing aortic valve replacement (AVR) remains controversial, with guidelines disparate in their recommendations. The objective of this study was to explore outcomes after AVR for various age ranges based on type of prosthesis.

Methods: A systematic review was undertaken according to the Preferred Reporting Instructions for Systematic Reviews and Meta-Analyses (PRISMA) guidelines by using Medline (PubMed), Cochrane, Web of Science, Embase, and Scopus databases. Rates of long-term survival (primary outcome), reoperation, major bleeding, thromboembolism, stroke, structural valve deterioration, and endocarditis were compared between subjects receiving biologic and mechanical prostheses. Findings were grouped into patients aged <60 years, aged ≤65 years, and finally aged <70 years.

Results: A total of 19 studies met inclusion criteria. Seven evaluated patients aged <60 years, 4 of which found mechanical prosthesis patients to have higher long-term survival, whereas the remaining studies found no difference. Eight additional studies included patients aged 65 years or younger, and 9 studies included patients aged <70 years. The former found no difference in survival between prosthesis groups, whereas the latter favored mechanical prostheses in 3 studies. Bleeding, thromboembolism, and stroke were more prevalent in patients with a mechanical prosthesis, whereas reoperation was more common in those receiving a bioprosthesis.

Conclusions: Published literature does not preclude the use of bioprostheses for AVR in younger patients. As new valves are developed, the use of bioprosthetic aortic valves in younger patients will likely continue to expand. Clinical trials are needed to provide surgeons with more accurate guidelines.
Negative Pressure versus Conventional Sternal Wound Dressing in Coronary Surgery Using Bilateral Internal Mammary Artery Grafts
Authors: Ruggieri Vito Giovanni , Olivier Maud-Emmanuelle , Aludaat Chaudi , Rosato Stefano , Marticho Paul , Saade Yves Assad , Lefebvre Annick , Poncet Anne , Rubin Sylvain , Biancari Fausto
Published: February 2019

Background: Sternal wound infection (SWI) is a major complication occurring often after coronary artery bypass grafting (CABG) using bilateral internal mammary artery (BIMA) grafts. The aim of this study is to assess whether such a risk may be reduced by using incision negative pressure wound therapy (INPWT).
Methods: Data on patients undergoing isolated CABG using BIMA grafts at the Reims University Hospital, France, from 2013 to 2016 without or with INPWT was prospectively collected. 
Results: INPWT was used in 161 patients and conventional sterile wound dressing was used in 266 patients. Propensity score matching resulted in 128 pairs with similar characteristics. SWIs were similarly distributed between the conventional sterile wound dressing (10.9%) and the INPWT cohorts (10.2%) (P = 1.00). Patients treated with INPWT had a lower rate of deep SWI/mediastinitis than patients who had conventional sterile dressing (5.5% versus 10.2%, P = .210), but the difference did not reach statistical significance. Tests for interaction confirmed these findings in different patient subgroups.
Conclusion: The routine use of INPWT may not significantly reduce the risk of SWI in patients undergoing BIMA grafting. In view of previous reports showing a benefit with the use of this method, a large randomized study is justified to assess the efficacy of INPWT in patients undergoing cardiac surgery.
A New Perspective in Comparing Injuries Caused by Short-Duration External and Internal Forces in Saphenous Vein
Authors: Denli Yalvac Emine Seyma , Cumbul Alev , Uslu Unal , Soztutar Erdem , Bilisli Edibe , Balak Naci
Published: February 2019

Background: Great saphenous vein (GSV) graft failure is one of the major reasons for repeat bypass grafting. A comparison of the effects of simultaneous, short-duration, externally squeezing and internally distending forces on the same segment of ex-vivo human GSV has not yet been published, although similar studies have compared the experimental injury of different ex-vivo human veins.
Methods: Approximately 8-cm-long segments of GSV were harvested from each of the 15 patients. For each specimen, one end of the vein piece was occluded at a distance of 1 cm with an external cross-clamp for 5 min and the other end was similarly occluded at a distance of 1 cm by an endoluminal balloon. The middle sections of the veins, which were not occluded by any means, were taken as the control group. Two histologists, who were blinded to the groups, graded the hematoxylin and eosin (H&E) and Weigert-Van Gieson (WVG) stained sections semi-quantitatively and performed the histomorphometric measurements.
Results: The result of the histopathological evaluation of the intima layer showed that the microscopic scoring of lesions in the balloon group was significantly higher than that in the clamp and control groups (5.16 ± 1.32, 3.83 ± 0.75, and 1.00 ± 1.09, respectively, P < .001). In the adventitia layer, this level of scoring increased more in the clamp group than in the balloon and control groups (5.16 ± 1.16, 3.00 ± 0.89, and 0.16 ± 0.40, respectively, P < .001).
Conclusion: Both the endoluminal balloon and external clamp techniques have harmful effects on the vein wall. Studying different kind of forces on different veins cannot provide us with reliable comparisons.