bluuebunny/crossref_metadata_2025 huggingface dataset:
Verification of Probabilistic Fracture Mechanics Analysis Code Through Benchmark Analyses
Authors: Li Yinsheng , Uno Shumpei , Masaki Koichi , Katsuyama Jinya , Dickson Terry , Kirk Mark
Published: October 2018

A probabilistic fracture mechanics (PFM) analysis code PASCAL has been developed by Japan Atomic Energy Agency based on Japanese methods and data to evaluate failure probabilities and failure frequencies of Japanese reactor pressure vessels (RPVs) considering pressurized thermal shock (PTS) events and neutron irradiation embrittlement. To verify PASCAL, we have been performing benchmark analyses by using a PFM code FAVOR which has been developed in the United States and utilized in nuclear regulation. Based on two-year activities, the applicability of PASCAL in failure probability and failure frequency evaluation of Japanese RPVs was confirmed with great confidence. The analysis conditions, approaches and results are given in this paper.
Perspectives on Safety Margin Associated With Internal Repair of Buried Class 2 and 3 Safety Related Piping Using Carbon Fiber Reinforced Polymer Composites
Authors: Uddin M. F. , Krishnaswamy P. , Basavaraju C. , Manoly K. A.
Published: October 2018

Carbon fiber reinforced polymer (CFRP) composites have been used for decades in various industries such as aerospace, oil and gas, and transportation mainly due to their high strength-to-weight-ratio and excellent corrosion resistance. However, the use of CFRP in nuclear industry applications has been very limited. Recently, a new ASME Boiler and Pressure Vessel (BPV) Code Case N-871 has been proposed for internal repair of buried Class 2 and 3 nuclear safety related piping using CFRP for Service Levels A, B, C and D at temperatures not exceeding 200F. This is a first-of-a-kind CFRP application for nuclear safety related piping.

It is known that CFRP materials are subject to property degradation due to environmental exposure as well as creep behavior under sustained loading. These factors should be considered when designing the CFRP repair for any nuclear safety related piping application to ensure an adequate safety margin is maintained. In the proposed Code Case, there are provisions for using two different design (analysis method) methods — Allowable Stress Design (ASD) and Load and Resistance Factor Design (LRFD) methods. The LRFD method has been widely used in civil engineering applications but has never been used in ASME Section III Code for nuclear piping applications. This paper presents a comparison of these two methods from a safety margin point of view. As CFRP is a new material for ASME BPV Code for nuclear safety related applications, several areas have been identified in the design concepts to ensure an adequate safety margin for Service Levels A, B, C and D. An effort is also made to provide guidelines on the required safety margin for CFRP repair of safety related piping. Finally, Code Case N-871 is reviewed to evaluate the minimum safety margin available for both ASD and LRFD methods.
A General Comparison of the Design Margins and Design Rules for ASME Section VIII, Divisions 1 and 2
Authors: Barkley Nathan
Published: October 2018

Beginning with the 2017 Edition of the ASME Boiler and Pressure Vessel Code, vessels designed according to the rules of Section VIII, Division 2 shall be designated as either Class 1 or Class 2. One of the key differences between Class 1 and Class 2 is the applicable Design Margin of 3.0 and 2.4 against the Ultimate Tensile Strength of the material, respectively. Vessels designed in accordance to Section VIII, Division 1 have a Design Margin of 3.5 against the Ultimate Tensile Strength of the material. Code Case 2695 allows the vessel designer to utilize the design rules of Section VIII, Division 2 for a Section VIII, Division 1 vessel while maintaining the tensile strength Design Margin of 3.5. However, Design Margins against the Ultimate Tensile Strength of the material are not the only applicable margins that must be considered.

This paper reviews the procedure for deriving the allowable stresses of materials under tensile loading based on the required Design Margins for each Division and Class with some historical background provided. Discussion and comparisons of some of the relevant differences between the design rules of Section VIII, Division 1 and 2 and how the differing Design Margins affect the component design is presented. Carbon Steel with joint efficiencies of 1.0 are used for simplicity.
Hybrid Welding: Investigation of the Induced Residual Stresses
Authors: Gallee Sébastien , Robin Vincent , Gommez Florence , Jourden Erwan , Lacroix Rémi
Published: October 2018

The present paper deals with the hybrid laser/MIG welding process, which allows to join high thickness steel sheets. The laser heat source added to the MIG torch improves the process productivity while respecting quality standard.

The multi-pass welding simulation of a plate is presented in this paper and numerical results are compared to experimental measurements (temperature and stresses).
Prediction of Residual Stresses in a Multipass Pipe Weld by a Novel 3D Finite Element Approach
Authors: Huang Hui , Chen Jian , Carlson Blair , Wang Hui-Ping , Crooker Paul , Frederick Gregory , Feng Zhili
Published: October 2018

Due to enormous computation cost, current residual stress simulation of multipass girth welds are mostly performed using two-dimensional (2D) axisymmetric models. The 2D model can only provide limited estimation on the residual stresses by assuming its axisymmetric distribution. In this study, a highly efficient thermal-mechanical finite element code for three dimensional (3D) model has been developed based on high performance Graphics Processing Unit (GPU) computers. Our code is further accelerated by considering the unique physics associated with welding processes that are characterized by steep temperature gradient and a moving arc heat source. It is capable of modeling large-scale welding problems that cannot be easily handled by the existing commercial simulation tools. To demonstrate the accuracy and efficiency, our code was compared with a commercial software by simulating a 3D multi-pass girth weld model with over 1 million elements. Our code achieved comparable solution accuracy with respect to the commercial one but with over 100 times saving on computational cost. Moreover, the three-dimensional analysis demonstrated more realistic stress distribution that is not axisymmetric in hoop direction.
Creep Deformation Analyses for Grade 91 Steels Considering Heat-to-Heat Variation
Authors: Shigeyama Haruhisa , Takahashi Yukio , Siefert John , Parker Jonathan
Published: October 2018

In order to evaluate creep life of heat-resistant materials used in power plants, it is important to estimate variation of stress distribution caused by creep deformation appropriately. For achieving this, creep strain equations which can express the creep deformation behavior with good accuracy are indispensable. Additionally, a lot of heat-resistant steels show large heat-to-heat variations in creep properties. Therefore, it is also important to take into account of the heat-to-heat variations in the creep analyses.

In this study, existing creep strain equations for Grade 91 steel were applied to six heats with a variety of creep strength and creep deformation behavior. Furthermore, some modification was made in order to obtain better agreement with test data in primary creep stage. It was found that reasonable agreements were obtained between the measured creep deformation behavior and predictions obtained by these equations only by changing creep rupture property depending on the particular heats. This suggests that reasonable prediction for creep deformation can be made even for the materials lacking the information of creep deformation as long as their rupture properties are known.
Strain Capacity Investigation on Grade X70 High Strain Line Pipe With Girth Weld
Authors: Tajika Hisakazu , Sakimoto Takahiro , Handa Tsunehisa , Igi Satoshi , Ikeda Rinsei , Kondo Joe
Published: October 2018

Recently high grade pipeline project have been planned in hostile environment like landslide in mountain area, liquefaction in reclaimed land or the frost heave in Polar Regions. Geohazards bring large scale ground deformation and effect on the varied pipeline to cause large deformation. Therefore, strain capacity is important for the pipeline and strain based design is also needed to keep gas transportation project in safe. High grade steel pipe for linepipe tends to have higher yield to tensile (Y/T) ratio and it has been investigated that the lower Y/T ratio of the material improves strain capacity in buckling and tensile limit state. In onshore pipeline project, pipe usually transported in 12 or 18m each and jointed in the field. Girth weld (GW) is indispensable so strength matching of girth weld towards pipe body is important.

In this study strain capacity of Grade X70 high strain pipe with size of 36” OD and 23mm WT was investigated with two types of experiments. One was a pipe bending test with whole pipe. The length of the specimen was approximately 8m and GW was made in the middle of joint length. A fixed internal pressure was applied during the bending test. Actual pipe situation in work was simulated and both circumferential and longitudinal stress occurred in this test.

The other test was curved wide plate (CWP) test. In both tests, test pipes were cut and welded using GTAW in the first two layers and GMAW for the subsequent passes. Welding wire of TG-S62 and MG-S58P were used for GTAW and GMAW respectively to achieve over-matching girth weld considering the pipe body strength. Elliptical EDM notch was installed in the GW HAZ as simulated weld defect.

In pipe bending test, buckling occurred at the intrados at 300 mm apart from the GW. 2D average compressive strain at buckling was 3.59% and this high compressive strain was considered to derive from the high strain capacity of this pipes. After the buckling, deformation concentrated to the buckling wrinkle. Test pipe broke at 35.5 degrees of pipe end rotation and the location was in base metal at the extrados opposite to the buckling wrinkle. The HAZ notch opened and CTOD was 1.44 mm and the global strain in 2D length average strain was 7.8%.

In CWP test, tensile strain simply got large and pipe finally broke at global strain of 9.6% and CTOD of 15 mm. The break location was the HAZ notch. There was a significant difference in CTOD growth in HAZ between two test types. Conditions and factors that effect to these differences are argued in this paper.
Defect Localization for Pressure Vessel Based on Circumferential Guided Waves: An Experimental Study
Authors: Zhai Shuangmiao , Chen Chaofeng , Hu Gangyi , Zhou Shaoping
Published: October 2018

Pressure vessels are normally employed under extreme environments with high temperature and high pressure. Inevitably, the defects like crack and corrosion that easily occur in the equipment and can significantly influence the normal operation. Guided wave-based method is a cost-effective means to measure the utility of pressure vessel. In this paper, finite element (FE) simulation is used to explore the propagation characteristics of circumferential guided waves in pressure vessel. Based on the propagation characteristics, the experiments with different configurations of piezoelectric transducers (PETs), which contain a sparse array and a dense array, have been conducted on pressure vessel respectively. Different imaging methods, including discrete ellipse imaging algorithm and probability damage imaging algorithm have been applied to locate the defect based on the configurations above. Furthermore, a multi-channel ultrasonic guided wave detection system has been set up for pressure vessel inspection. The experimental results show that the sparse array with the discrete ellipse imaging algorithm can locate the defect effectively. The imaging results based on probability damage imaging algorithm show that the dense array presents the better localization result.
Modelling of Dilution Effects on Microstructure and Residual Stress in a Multi-Pass Weldment
Authors: Sun Yongle , Hamelin C. J. , Smith M. C. , Vasileiou A. N. , Flint T. F. , Francis J. A.
Published: October 2018

Three-pass gas tungsten arc welding in a 20-mm thick SA508 steel plate is modelled using a sequentially coupled thermal-metallurgical-mechanical model. The dilution for each pass is estimated as the proportion of base material in the weld metal, based on an analysis of the cross-sectional area of each fusion zone. The thermal solution of the weld model is validated using thermocouple measurement data and cross-weld macrographs. The predicted microstructure is qualitatively compared with that observed in cross-weld optical micrographs. The measured hardness distribution is used to quantitatively validate the post-weld ferritic phase distribution (e.g. the ferrite, bainite and martensite fractions), based on a hardness-microstructure correlation. The predicted residual stresses are compared with those measured by neutron diffraction. The results show that dilution significantly influences the metallurgical and mechanical properties of weld metal (either as-deposited or reheated), and its consideration notably improves microstructure and residual stress predictions for a multi-pass steel weldment. For the weldment considered, an increase in dilution promotes the formation of martensite, enhances the hardness and leads to lower tensile stresses (or higher compressive stresses) in the weld metal. Such behaviour arises due to the higher hardenability of the base material, coupled with delayed austenite decomposition on cooling.
Fluid Structure Coupling Simulation on Flow-Induced Vibration in Tee Junction Pipes
Authors: Ishigami Takahiro , Nishiguchi Masato , Maekawa Munenori , Izuchi Hisao
Published: October 2018

Flow-Induced Vibration (FIV) caused by turbulent flow inside a pipe could lead to fatigue failure through shell mode vibration. Our previous study investigated the excitation source of the FIV for tee junctions experimentally to understand the FIV mechanism and to obtain Power Spectral Density (PSD) profiles of pressure fluctuations. Unsteady Computational Fluid Dynamics (CFD) simulations with a Large Eddy Simulation (LES) model were also performed to understand the turbulent structure for the tee junctions. As a result, the experiment shows the PSD profiles of pressure fluctuations have a dominant frequency component around Strouhal number 0.16, and the simulation results were well matched with the results of the experiment. The simulated flow field showed that the relatively large vortex shed from the branch pipe impinged periodically on the bottom of the main pipe with a frequency of Strouhal number 0.16, and the large vortex was dissipated downstream. These vortex behaviors would be the main mechanism generating the FIV excitation source. This study reports the simulation results of the vibration response by the fluid-structure coupling simulation with a one-way coupling method, which uses the unsteady pressure fluctuations obtained by CFD simulations. The simulated vibration response shows good agreement with the experiment.
Evaluation of Fatigue Design Curves for a Double-Side Welded Connection Used in Offshore Applications
Authors: Correia José A. F. O. , Correia Miguel , Holm Mads , Ekeborg Julle , Lesiuk Grzegorz , Castro José M. , de Jesus Abílio M. P. , Calçada Rui
Published: October 2018

One of the major concerns in offshore structures are the welded connections where fatigue failures are highly relevant. In many cases of offshore welded connections, the fatigue cracks initiated may grow from the weld to the base material, but also from the root of the weld.

In this study, the evaluation of design S-N curves for a double-side welded connection made of S355J2 steel used in offshore applications is proposed. The characteristic fatigue curve of the double-side welded connection is obtained using statistical analyses based either in the ASTM E739 standard as well as the probabilistic fatigue model proposed by Castillo & Fernández-Canteli. This study concludes with a comparison between the experimental fatigue curves obtained and the design S-N curves proposed in design codes for offshore structures. Existing code recommendations are very conservative when comparing the design S-N curves with the proposed new characteristic S-N curves. For the joint under investigation the hot spot and nominal stress approaches yield very similar S-N results.
High Pressure Composite Vessel With Integrated Optical Fiber Sensors: Monitoring of Manufacturing Process and Operation
Authors: Gąsior Paweł , Rybczyński Radosław , Kaleta Jerzy , Villalonga Stephane , Nony Fabien , Magnier Christophe
Published: October 2018

The main purpose of the work was development of high-pressure composite vessel for hydrogen storage (type IV, CFRC) with an integrated Structural Health Monitoring (SHM) system, based on optical fiber sensors. It has been assumed that this NDE system should provide for continuous and reliable monitoring of the structure during its long operation and enable estimation of degradation degree of the composite vessel load-carrying layer, and by that determination of its safe operation period. Showing suitability of the system for control of the vessels manufacturing technology and fulfilling the requirements of vessel certification standards has been also considered essential. It has been expected, that reaching the work goals required application of measurement methods based at fibre optic sensors with particular consideration for the Fibre Bragg Gratings (FBG). These transducers allowed for integration with the monitored object and were embedded in the composite material structure without influencing its mechanical properties. The research object were prototype vessels for Hydrogen storage in automotive applications, with nominal working pressures up to 700 bars. FBG sensors were integrated with COPV during manufacturing process (winding by robot). It allowed for controlling of each manufacturing steps (winding each layer, curing, hydraulic test) and further use during vessel normal operation. Additional investigations were dedicated to evaluation of SHM strategy, which allows for detection of damages in the vessel structure from manufacturing process through the whole lifespan. The proposed SHM solution was validated during pressure cycle test, which were performed according to the current regulations (EC 406/2010).
ASME ANDE-1: A Completely New Approach to Personnel Qualification
Authors: Zavadil Tomáš , Turnbow Michael L.
Published: October 2018

ASME (American Society of Mechanical Engineers) Nondestructive Examination (NDE) and Quality Control (QC) Central Qualification and Certification Program (ANDE-1 Standard) is a new independent qualification system for NDT and QC personnel. It is the first to come with a requirement of performance-based experience of Nondestructive Testing (NDT) personnel on the basis of practical demonstration to perform all required activities rather than length of experience. It also adds unflawed samples to the test sets in order to simulate real situation in industrial practice, where decisions about the acceptance is necessary. This article analyzes the ANDE-1 Standard and compares it with other relevant qualification standards used in the European Union (EU).
Green's function extraction by crosscorrelation and multidimensional deconvolution for outdoor sound propagation
Authors: Denis Max F. , Collier Sandra L. , Noble John M. , Kirkpatrick Alberts W. C. , Ligon David A. , Sim Leng K. , James Deryck , Reiff Christian G.
Published: October 2018

In this work, the Green's function is estimated from outdoor measurements of controlled-sources. Crosscorrelation and multidimensional deconvolution have successfully been employed for Green's function retrieval. Crosscorrelation assumes a lossless medium and equipartitioned wavefield; when these assumptions are not satisfied it may result in a Green's function smeared with the source point-spread function. Multidimensional deconvolution removes the point-spread function from the retrieved Green's function. Both methods are employed to estimate the Green's function between two array stations for a single and multiple controlled-sources. The results demonstrate that the source-to-center radius has a negligible effect on the retrieved Green's function, if the source-to-center radius is larger than the distance between the two array stations.
Transistor in a tube: A route to three-dimensional bioelectronics
Authors: Pitsalidis C. , Ferro M. P. , Iandolo D. , Tzounis L. , Inal S. , Owens R. M.
Published: October 2018

We report development of the first biomimetic transistor in a tube for continuous monitoring of 3D cell cultures.
Unique ion rectification in hypersaline environment: A high-performance and sustainable power generator system
Authors: Zhu Xuanbo , Hao Junran , Bao Bin , Zhou Yahong , Zhang Haibo , Pang Jinhui , Jiang Zhenhua , Jiang Lei
Published: October 2018

Ion-selective Janus membranes with one-way ionic transport in hypersaline solution approach efficient osmotic energy conversion.
Poly(amide-imide) materials for transparent and flexible displays
Authors: Kim Sun Dal , Lee Byungyong , Byun Taejoon , Chung Im Sik , Park Jongmin , Shin Isaac , Ahn Nam Young , Seo Myungeun , Lee Yunho , Kim Yeonjoon , Kim Woo Youn , Kwon Hyukyun , Moon Hanul , Yoo Seunghyup , Kim Sang Youl
Published: October 2018

Transparent polymers that can match the optical and thermal expansion properties of glass were synthesized for flexible devices.
Type 3 cytokines IL-17A and IL-22 drive TGF-β–dependent liver fibrosis
Authors: Fabre Thomas , Molina Manuel Flores , Soucy Geneviève , Goulet Jean-Philippe , Willems Bernard , Villeneuve Jean-Pierre , Bilodeau Marc , Shoukry Naglaa H.
Published: October 2018

Type 3 immune response defined by increased IL-22 production drives fibrosis during chronic liver injury via enhanced TGF-β signaling.
Outcomes by MIC Values for Patients Treated with Isavuconazole or Voriconazole for Invasive Aspergillosis in the Phase 3 SECURE and VITAL Trials
Authors: Andes David R. , Ghannoum Mahmoud A. , Mukherjee Pranab K. , Kovanda Laura L. , Lu Qiaoyang , Jones Mark E. , Santerre Henriksen Anne , Lademacher Christopher , Hope William W.
Published: October 2018

This pooled analysis evaluated the relationship of isavuconazole and voriconazole MICs of
Aspergillus
pathogens at baseline with all-cause mortality and clinical outcomes following treatment with either drug in the SECURE and VITAL trials. Isavuconazole and voriconazole may have had reduced efficacy against pathogens with drug MICs of ≥16 µg/ml, but there was no relationship with clinical outcomes in cases where the MIC was <16 µg/ml for either drug.
Can Herbivore-Induced Volatiles Protect Plants by Increasing the Herbivores’ Susceptibility to Natural Pathogens?
Authors: Gasmi Laila , Martínez-Solís María , Frattini Ada , Ye Meng , Collado María Carmen , Turlings Ted C. J. , Erb Matthias , Herrero Salvador
Published: October 2018

Multitrophic interactions involving insect pests, their natural enemies, microorganisms, and plant hosts are increasingly being recognized as relevant factors in pest management. In response to herbivory attacks, plants activate a wide range of defenses that aim to mitigate the damage. Attacked plants release herbivore-induced plant volatiles (HIPVs), which can act as priming signals for other plants and attract natural enemies of herbivores, and which may have a direct negative impact on herbivore survival. In the present work, we show that exposure of the insects to the induced volatiles could increase the insects’ susceptibility to the entomopathogens naturally occurring in the plant environment. These findings suggest a novel role for plant volatiles by influencing insect interactions with natural pathogens, probably mediated by alterations in the insect microbiota composition. In addition, this work provides evidence for selectable plant traits (production of secondary metabolites) that can have an influence on the ecology of the pests and could be relevant in the improvement of pest management strategies using natural entomopathogens.
Histologically confirmed case of complete atrioventricular block due to hepatocellular carcinoma
Authors: Nishiwaki Takuro , Yamamoto Norihiko , Hirokawa Yoshihumi , Takei Yoshiyuki
Published: October 2018

A 72-year-old man, who had been diagnosed as having hepatocellular carcinoma (HCC) with multiple extrahepatic metastasis, complained a general fatigue which appeared 2 weeks before admission. Because bradycardia was detected on physical examination, ECG was performed which revealed the complete atrioventricular (AV) block. We stopped Ca-blocker and β-blocker, but the bradycardia persisted. He was admitted to our hospital for an emergent pacemaker implantation. On admission, he complained dyspnoea. After the surgery, he died due to deterioration of heart failure. The autopsy revealed cardiac metastasis of HCC on AV node, so it was suspected that cardiac metastasis caused the AV block. We thought that the cause of his death was the exacerbation of heart failure associated with bradycardia. It was likely that complete AV block as a very rare complication caused by cardiac metastasis of HCC influenced the prognosis of this patient.
Coronary artery vasospasm in a patient withChurg-Strauss syndrome
Authors: Trivedi Siddharth J , Tanous David , Suan Dan
Published: October 2018

Patients with Churg-Strauss syndrome often suffer from unusual cardiac manifestations and sudden cardiac death. This differs from patients with other autoimmune disorders, who typically present with premature ischaemic heart disease. We report the case of a 56-year-old man with recurrent coronary vasospasm, including an inferoposterior ST-elevation myocardial infarction, complicated by bradycardic arrest. There was only minor coronary artery disease on coronary angiography. An elevated eosinophil count was noted. His medical history included allergic rhinitis with polyposis, adult-onset asthma and biopsy-proven eosinophilic oesophagitis. Review of his sinus biopsies demonstrated blood vessels with marked accumulation of eosinophils in extravascular areas. The patient, therefore, met the American College of Rheumatology criteria for Churg-Strauss syndrome. The patient was commenced on immunosuppression, with the return of the eosinophil count to within normal limits, and remains free of cardiovascular events over 24 months.
Giant vesicle calculi leading to spontaneous bladder rupture and acute renal failure: an unusual presentation
Authors: Sharma Deepanshu , Garg Gaurav , Pandey Siddharth , Goel Apul
Published: October 2018

Spontaneous rupture of the urinary bladder is extremely rare. We report a case of a 70-year-old man with spontaneous bladder rupture secondary to neglected giant vesicle calculi who presented as acute renal failure. The patient was stabilised with per-urethral catheterisation and extravesical drain placement. About 700 mL pus mixed with urine was drained through the per-urethral catheter and approximately 2000 mL of pus was drained through the extravesical drain. Cystolithotomy showed two large calculi which were removed.
Acute aortic dissection: a missed diagnosis
Authors: Wong Hiu Fung , Bevis Paul
Published: October 2018

A 60-year-old man with a history of indigestion and untreated hypertension presented with sudden-onset central chest pain which radiated to his back. Acute coronary syndrome was initially suspected but excluded in the emergency department before the patient was discharged. The pain subsequently abated to mild intermittent episodes and was misdiagnosed as indigestion. A week later the patient developed new shortness of breath and ‘flu-like’ symptoms with a positive d-dimer test. CT angiography revealed a Stanford type B aortic dissection which was causing hypoperfusion of the right kidney, resulting in an acute kidney injury. Due to uncontrolled hypertension despite rigorous antihypertensive medication and his failing renal function, the patient underwent endovascular repair and made a good recovery postoperatively.
Solitary fibrous tumour of caecum wall: an unlikely cause of low gastrointestinal haemorrhage
Authors: Santos Mariana Nogueira , Tavares Amelia Brandao , Viveiros Fernando Arruda , Baldaia Helena
Published: October 2018

Solitary fibrous tumour (SFT), previously denominated as haemangiopericytoma, is a rare, spindle cell neoplasm that was first described in the thoracic pleura. It is now known that this tumour may develop from almost any anatomic location. We report a case of SFT, in a 65-year-old man, which was located in the muscularis propria layer of the caecum with involvement of the serosa and the ileocecal appendix, location never described in the literature, and with an uncommon clinical presentation of hematochezia. A radical right hemicolectomy was performed, and the patient was asymptomatic without evidence of metastasis or relapse after 6 months of follow-up.
Why has adolescent smoking declined dramatically? Trend analysis using repeat cross-sectional data from New Zealand 2002–2015
Authors: Ball Jude , Sim Dalice , Edwards Richard
Published: October 2018

Objectives

Adolescent smoking has declined in New Zealand and in many other countries since the late 1990s, yet the reasons for the decline are not well understood. We investigated the extent to which established risk factors for adolescent smoking (parental, sibling and peer smoking, and exposure to smoking in the home) explained the downward trend.

Design

Trend analysis of repeat cross-sectional data from an annual nationally representative survey.

Setting

New Zealand.

Participants

Secondary school students aged 14–15 (n=398 221).

Outcome measure

Regular (at least monthly) smoking.

Methods

For each risk factor (parental smoking, best friend smoking, older sibling smoking and past week exposure to smoking in the home) we plotted prevalence of exposure, 2002–2015. Next, using multivariable logistic regression, we modelled the trend in regular smoking (expressed as an OR for year) adjusting for age, sex, ethnicity and socioeconomic position. The risk factors were added to the model—individually and collectively—to test whether they attenuated the OR for year.

Results

Exposure to all risk factors except ‘past week exposure to smoking in the home’ decreased between 2002 and 2015. We observed a strong downward trend in regular smoking among adolescents (OR=0.88 per year, 95% CI 0.88 to 0.88, p<0.001). ‘Best friend smoking’ was the only risk factor that significantly attenuated the trend. However, due to circularity, this factor provides an unsatisfactory explanation for population level smoking decline.

Conclusions

The established risk factors that we explored do not appear to have contributed to the remarkable decline in adolescent smoking in New Zealand between 2003 and 2015. Further research is needed to assess the possible contribution of factors outside our model, such as changes in the policy context, the social meaning of smoking and broader social and economic conditions.
Determination of venlafaxine and its active metabolite O-desmethylvenlafaxine in human plasma by HPLC fluorescence
Authors: Shen Shujuan , Zhang Chen , Mao Yemeng
Published: October 2018

Background

Therapeutic drug monitoring guides clinical individualised medication by measuring plasma concentration, which could improve the curative effect, avoid drug overdose and reduce the incidence of adverse reactions. At present, there are few reports on the clinical detection of venlafaxine and its active metabolite O-desmethylvenlafaxine. In this paper, the detection method of venlafaxine and O-desmethylvenlafaxine in blood plasma was established, which provides an effective and convenient means for guiding clinical application of medication.

Aim

To establish a method for determination of venlafaxine and its active metabolite O-desmethylvenlafaxine in human plasma by high-performance liquid chromatography with fluorescence detection.

Methods

Chromatographic separation was achieved on an Agilent Eclipse XDB-C18 Column (4.6 × 150 mm, 5 µm) with water containing sodium dihydrogen phosphate (0.05 mol/L) and acetonitrile (72:28) as the mobile phases. The following parameters were employed: flow rate 0.5 mL/min, column temperature 30°C, fluorescence excitation wavelength 276 nm and emission wavelength 598 nm.

Results

The method showed good linearity in the concentration range 10–1000 ng/mL. The regression equation for venlafaxine was R=0.0054C+0.0264, r2=0.99991. The regression equation for O-desmethylvenlafaxine was R=0.0034C+0.0272, r2=0.99969. The intraday and interday precisions (relative SD) were less than 10%, and the quantitative limit was 10 ng/mL.

Conclusion

We established a sensitive, specific and simple method for the detection of venlafaxine and O-desmethylvenlafaxine. This method fully meets the needs of clinical trials of venlafaxine and the requirements of relevant guidelines. It provided a reference for the clinical detection of venlafaxine and O-desmethylvenlafaxine plasma concentrations and pharmacokinetic study.
A case of clozapine-induced skin picking behaviour
Authors: Reddy Balaswamy , Das Soumitra , Guruprasad Srinivas
Published: October 2018

There is some evidence consistently linking the occurrence of de novo obsessive-compulsive disorder (OCD) with clozapine. This skin-picking disorder is also known as impulsive-compulsive disorder-unspecified which with an increasing convergence with OCD has been placed in the current Diagnostic and statistical manual of mental disorders-fifth edition by American Psychiatric Association (DSM-5), in the category of the obsessive-compulsive and related disorders. To the best of our knowledge, there is no literature relating antipsychotics like clozapine with the occurrence of skin-picking behaviour. In this article, we present a case in whom skin-picking behaviour emerged during the upward dose titration of clozapine and was successfully treated with escitalopram.
Olanzapine-induced leucopaenia and thrombocytopaenia in an elderly patient: a case report and review of the evidence
Authors: Malik Yogender Kumar , Sahoo Swapnajeet , Avasthi Ajit
Published: October 2018

Haematological adverse effects of antipsychotics are rare but life threatening. Existing literature is limited to case reports, which are mostly reported on second generation antipsychotics (clozapine, olanzapine, risperidone, quetiapine). Elderly individuals are at risk of developing side effects with any psychotropics. Olanzapine is commonly used for the management of psychotic symptoms as well as for the management of behavioural and psychological problems with dementia in the elderly. In this case report, we report thrombocytopaenia and leucopaenia in an elderly individual with schizophrenia which developed after initiation of olanzapine and reverted back after stoppage of the drug. This case report highlights that the elderly are susceptible to develop haematological side effects with olanzapine and hence monitoring may be essential.
Viral vectors as a novel tool for clinical and neuropsychiatric research applications
Authors: Wang Yao , Hu Zhiwei , Ju Peijun , Yin Shan , Wang Fujie , Pan Oudong , Chen Jinghong
Published: October 2018

Background

A viral vector is a genetically modified vector produced by genetic engineering. As pathogenic genes in the virus are completely or largely eliminated, it is safe to be widely used in multidisciplinary research fields for expressing genes, such as neuroscience, metabolism, oncology and so on. Neuroscience and psychiatry are the most closely related disciplines in either basic research or clinical research, but the application of viral vectors in neuropsychiatry has not received much attention or not been widely accepted.

Objective

This article will focus on the application of viral vectors in basic and clinical neuropsychiatric research.

Methods

By using viral vectors, scientists can perform neurological labelling, gene expression regulation and physiological manipulation for investigating phenomenon from molecular mechanisms to behaviours. At the same time, to treat mental or neurological disorders, viral vectors can be designed for gene therapy, which alter gene expression levels or repair mutated genes in the brains of patients.

Perspective

Viral vectors play an important role in basic research and clinical applications. To further understand brain function and prevent mental and neurological diseases, we hypothesize that viral vectors could be used along with various advanced technologies, such as sequencing and high-throughput expression analysis in the neuroscience research field.
Prevalence and risk factors of acquired long QT syndrome in hospitalized patients with chronic kidney disease
Authors: Liu Peng , Han Dan , Sun Xuanzi , Tan Hui , Wang Zhigang , Liu Chao , Zhang Yali , Li Bailin , Sun Chaofeng , Shi Rui , Li Guoliang
Published: October 2018

Patients with chronic kidney disease (CKD) have a high risk of fatal arrhythmias. The extended severe corrected QT (QTc) interval is a hallmark of ventricular arrhythmias and sudden cardiac death. The objective of this study was to evaluate the prevalence of acquired long QT syndrome (aLQTS) in hospitalized patients with CKD and search for potential risk factors to improve clinical risk stratification in patients with CKD. Information about patients with CKD was retrospectively collected in our hospital between January 2013 and June 2017. The prevalence of aLQTS in different stages of CKD was evaluated. The common risk factors for QTc prolongation in patients with CKD were compiled, and multivariable logistic regression analysis was used to evaluate how each factor was related to aLQTS in CKD. A total of 804 patients with CKD (299 females, 37.2%) participated in our study. The prevalence of aLQTS among all 804 patients was 56.97%, and the prevalence of QTc prolongation (>500 ms) was 10.07%. Among the elderly, impaired kidney function, hemodialysis, low serum potassium and low left ventricular ejection fraction (LVEF) were associated with QTc prolongation in patients with CKD. The prevalence of aLQTS is much higher and increases with the decline of kidney function in hospitalized patients with CKD, which is related to older age, impaired kidney function, hemodialysis, serum potassium and low LVEF.
Brain mechanisms underlying apathy
Authors: Le Heron Campbell , Holroyd Clay B , Salamone John , Husain Masud
Published: October 2018

The past few decades have seen growing interest in the neuropsychiatric syndrome of apathy, conceptualised as a loss of motivation manifesting as a reduction of goal-directed behaviour. Apathy occurs frequently, and with substantial impact on quality of life, in a broad range of neurological and psychiatric conditions. Apathy is also consistently associated with neuroimaging changes in specific medial frontal cortex and subcortical structures, suggesting that disruption of a common systems-level mechanism may underlie its development, irrespective of the condition that causes it. In parallel with this growing recognition of the clinical importance of apathy, significant advances have been made in understanding normal motivated behaviour in humans and animals. These developments have occurred at several different conceptual levels, from work linking neural structures and neuromodulatory systems to specific aspects of motivated behaviour, to higher order computational models that aim to unite these findings within frameworks for normal goal-directed behaviour. In this review we develop a conceptual framework for understanding pathological apathy based on this current understanding of normal motivated behaviour. We first introduce prominent theories of motivated behaviour—which often involves sequences of actions towards a goal that needs to be maintained across time. Next, we outline the behavioural effects of disrupting these processes in animal models, highlighting the specific effects of these manipulations on different components of motivated behaviour. Finally, we relate these findings to clinical apathy, demonstrating the homologies between this basic neuroscience work and emerging behavioural and physiological evidence from patient studies of this syndrome.
Organoids as hybrids: ethical implications for the exchange of human tissues
Authors: Boers Sarah N , van Delden Johannes J M , Bredenoord Annelien L
Published: October 2018

Recent developments in biotechnology allow for the generation of increasingly complex products out of human tissues, for example, human stem cell lines, synthetic embryo-like structures and organoids. These developments are coupled with growing commercial interests. Although commercialisation can spark the scientific and clinical promises, profit-making out of human tissues is ethically contentious and known to raise public concern. The traditional bioethical frames of gift versus market are inapt to capture the resulting practical and ethical complexities. Therefore, we propose an alternative approach to identify, evaluate and deal with the ethical challenges that are raised by the increasing commercialisation of the exchange of sophisticated human tissue products. We use organoid technology, a cutting-edge stem cell technology that enables the cultivation of ‘mini-organs’ in a dish, as an example. First, we examine the moral value of organoids and recognise them as hybrids that relate to persons and their bodies as well as to technologies and markets in ambiguous ways. Second, we show that commercialisation of organoids is legitimised by a detachment of the instrumental and commercial value of organoids from their associations with persons and their bodies. This detachment is enacted in steps of disentanglement, among which consent and commodification. Third, we contend that far-reaching disentanglement is ethically challenging: (1) Societal interests could be put under pressure, because the rationale for commercialising organoid technology, that is, to stimulate biomedical innovation for the good of society, may not be fulfilled; (2) The interests of donors are made subordinate to those of third parties and the relational moral value of organoids may be insufficiently recognised. Fourth, we propose a ‘consent for governance’ model that contributes to responsible innovation and clinical translation in this exciting field.
Mapping the potential of community first responders to increase cardiac arrest survival
Authors: Barry Tomás , González Ainhoa , Conroy Niall , Watters Paddy , Masterson Siobhán , Rigby Jan , Bury Gerard
Published: October 2018

Objective

Resuscitation from out-of-hospital cardiac arrest (OHCA) is largely determined by the availability of cardiopulmonary resuscitation (CPR) and defibrillation within 5–10 min of collapse. The potential contribution of organised groups of volunteers to delivery of CPR and defibrillation in their communities has been little studied. Ireland has extensive networks of such volunteers; this study develops and tests a model to examine the potential impact at national level of these networks on early delivery of care.

Methods

A geographical information systems study considering all statutory ambulance resource locations and all centre point locations for community first responder (CFR) schemes that operate in Ireland were undertaken. ESRI ArcGIS Desktop 10.4 was used to map CFR and ambulance base locations. ArcGIS Online proximity analysis function was used to model 5–10 min drive time response areas under sample peak and off-peak conditions. Response areas were linked to Irish population census data so as to establish the proportion of the population that have the potential to receive a timely cardiac arrest emergency response.

Results

This study found that CFRs are present in many communities throughout Ireland and have the potential to reach a million additional citizens before the ambulance service and within a timeframe where CPR and defibrillation are likely to be effective treatments.

Conclusion

CFRs have significant potential to contribute to survival following OHCA in Ireland. Further research that examines the processes, experiences and outcomes of CFR involvement in OHCA resuscitation should be a scientific priority.
Comparative analysis of swallowtail transcriptomes suggests molecular determinants for speciation and adaptation
Authors: Cong Qian , Grishin Nick V.
Published: October 2018

Genetic determinants of speciation in closely related species are poorly understood. We sequenced and analyzed transcriptomes of swallowtail butterflies Heraclides cresphontes (northeastern species) and Heraclides rumiko (southwestern species), a pair of mostly allopatric sister species whose distribution ranges overlap narrowly in central Texas. We found that the two swallowtails confidently differ (FST > 0.5 for both species) in about 5% of genes, similarly to the divergence in another pair of swallowtail species Pterourus glaucus (southern species) and Pterourus canadensis (northern species). The same genes tend to diverge in both species pairs, suggesting similar speciation paths in Heraclides and Pterourus. The most significant differences for both species pairs were found in the circadian clock genes that were conserved within each species and diverged strongly between species (P-value < 0.01 and FST > 0.7). This divergence implied that adaptations to different climates and photoperiod at different latitudes or differences in mating behavior, including mating time and copulation duration, may be possible factors in ecological or behavioral-based speciation. Finally, we suggest several nuclear DNA regions that consistently and prominently differ between the sister swallowtail species as nuclear barcodes for swallowtail identification, with the best barcode being an exon from the protein TIMELESS.
DNA barcode data reveal biogeographic trends in Arctic non-biting midges
Authors: Ekrem Torbjørn , Stur Elisabeth , Orton Matthew G. , Adamowicz Sarah J.
Published: October 2018

Chironomid flies (non-biting midges) are among the most abundant and diverse animals in Arctic regions, but detailed analyses of species distributions and biogeographical patterns are hampered by challenging taxonomy and reliance on morphology for species-level identification. Here we take advantage of available DNA barcode data of Arctic Chironomidae in BOLD to analyse similarities in species distributions across a northern Nearctic – West Palearctic gradient. Using more than 260 000 barcodes representing 4666 BINs (Barcode Index Numbers) and 826 named species (some with interim names) from a combination of public and novel data, we show that the Greenland chironomid fauna shows affinities to both the Nearctic and the West Palearctic regions. While raw taxon counts indicate a strong Greenland – North American affinity, comparisons using Chao’s dissimilarity metric support a slightly higher similarity between Greenland and West Palearctic chironomid communities. Results were relatively consistent across different definitions of species taxonomic units, including morphologically determined species, BINs, and superBINs based on a ∼4.5% threshold. While most taxa found in Greenland are shared with at least one other region, reflecting circum-Arctic dispersal, our results also reveal that Greenland harbours a small endemic biodiversity. Our exploratory study showcases how DNA barcoding efforts using standardized gene regions contribute to an understanding of broad-scale patterns in biogeography by enabling joint analysis of public DNA sequence data derived from diverse prior studies.