bluuebunny/crossref_metadata_2025 huggingface dataset:
Water quality assessment at selected sites in Perak and Kinta River
Authors: Wakif S A M , Sabtu N , Abustan I
Published: September 2020

This paper describes the water quality study which was carried out at five (5) sampling sites along Sg. Perak and Sg. Kinta respectively. The objective of the study was to examine the chemical, physical and biological characteristics of the river and to determine the level and classification at each site based on the Water Quality Index (WQI) and National Water Quality Standards (NWQS). Water samples from the river were subjected to in-situ and laboratory water quality analyses and focused on six (6) important parameters based on WQI which are Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), Ammoniacal Nitrogen (NH3-N), and pH. All testing procedures used in this study adhered to the American Public Health Association (APHA) testing procedures. Based on the results obtained, the quality of water for four (4) sampling stations along Sg. Perak can be concluded as CLASS III with only one station concluded as CLASS IV according to the National Water Quality Standards (NWQS). For Sg. Kinta, four sampling stations were classified as CLASS III whereas only one station falls into CLASS II. It is important to determine the WQI at different areas of along the river in order to predict (possible) points of pollution for monitoring purposes.
Assessment of the Effect of High Tide and Low Tide Condition on Stream Flow Velocity at Sungai Rompin’s Mouth
Authors: Akhtar M N , Anees M T , Bakar E A
Published: September 2020

The variation in stream flow velocities depends on the riverbed slopes. In upstream areas, where slope is steep, the magnitude of velocity is high, whereas in downstream areas, where slope is gentle, the magnitude of velocity is slow. The focus of this study is in the downstream area, where variations in the magnitude of velocities are due to high tide and low tide situations. Due to sea level rise, flooding occurs with high tides in several coastal regions which causes road closures due to submerged in water and public inconveniences. Velocities in high tide conditions need to be examine for safety and health risk of people. Therefore, the main objective of this study to assess the variation in velocity values of stream flow at both high tide and low tide condition near river mouth. One dimensional Hydrological Engineering Centre-River Analysis System (HEC RAS) simulation was conducted 9.4 km along reach of Sungai Rompin. A total of 188 river cross sections were used at an interval of 50 m. Other river geometries such as river central line, riverbanks and flow paths were constructed in RAS mapper of HEC RAS. The unsteady flow was run in both high tide and low tide conditions. The outputs of the simulation were compared and analysed. The results revealed that the stream flow velocities reduced up to 60% in high tide condition when compared to the low tide condition near the river mouth.
Breath sound analysis of sleep apnea syndrome using cluster model
Authors: Shirasuna M
Published: September 2020

Sleep apnea syndrome (SAS) is a contemporary disease, with few subjective symptoms. For this reason, many people with SAS have not received a medical examination. In this paper, the possibility of a person with a high probability of having SAS in the near future (Pre-SAS) is determined from only the sound of the subject’s breathing during sleep. The sound is extracted and the breathing pattern and its tendency analysed using the cluster method. Compared to the conventional SAS process for diagnosis in medical institutions, the method proposed in this paper is very simple and easy.
Developing the Regression Relationships for the Critical Period of the Reservoir Systems at Sungai Bekok and Sungai Kesang Catchments in Malaysia
Authors: Oskoui I S , Abdullah R
Published: September 2020

The knowledge of critical period (CR) for determining the behavior type of reservoir systems is very beneficial in the planning process for distinguishing the period of the required streamflow data in the simulation procedure. Generally, for within-year systems (CR < twelve months) utilizing the critical twelve months of the flow data record is required, whereas for the carryover systems (CR > twelve months) employing the annual streamflow data will suffice. Currently, there is no relationship in the literature that can be used for predicting the behavior type of reservoir systems employing reliability and vulnerability performance indices in Sungai Bekok and Sungai Kesang catchments. Hence, the objective of this study is to develop a novel equation involving performance indices for estimating the critical period of the aforementioned reservoir systems. The reservoirs were analyzed employing a Monte Carlo technique by improved sequent peak algorithm. Afterward, new regression equations for the critical period were developed based on simulation results and then verified by comparing the equations’ outcomes with simulation results. Finally, it was found that the performance of the new equations is excellent in reproducing the critical period.
Exfoliation of charcoal by electrochemical method to synthesize few layers graphene sheets
Authors: Yap K L , Liu W W
Published: September 2020

Graphene is a new 2D carbon nanomaterial that has unique properties for several applications. However, the synthesis of large quantity of graphene is a key challenge for researchers. Previous conventional methods such as Chemical Vapour Deposition (CVD) and epitaxial growth resulted in low production rate and high cost. The research on the electrochemical exfoliation by using charcoal as an electrode is still remains unknown as most researchers employed graphite to produce graphene. The electrochemical exfoliation of charcoal and graphite rod is easy to operate and less time-consuming in the synthesis of few layers graphene sheets. An electrochemical cell consists of charcoal/graphite (as anode) and copper foil (as cathode) which immersed in several types of electrolytes was developed. The surfaces of exfoliated graphene sheets were observed as wrinkle, flaky and layered structures. Fourier transform infrared spectroscopy (FTIR) showed the presence of oxygen functional groups in the exfoliated graphene sheets while the characteristic peak of GO showed up at 2θ = 9-10° was not seen clearly in all XRD spectrums. The results proved that high amount of exfoliated graphene sheets was formed but less amount of graphene oxide (GO) was produced in the electrochemical exfoliation process.
Study on fluttering characteristics of articulated flat plate flag
Authors: Yamagishi Masaki , Shida Hiroki
Published: September 2020

For wind/water power generation, we have been trying to harness flow-induced vibration, and we used a flag as the oscillating body. The flag was made of flat plates joined by articulations. To achieve a suitable design in engineering, it is important to clarify the fluttering characteristics of this articulated flat plate. The fluttering characteristics were therefore investigated experimentally in a wind tunnel. In the experiment, several rectangular plates were tested in several conditions of stream-wise length, span-wise length, thickness, and density. To investigate the fluttering characteristics, the fluttering frequency in a uniform flow velocity was focused on. The fluttering mode was observed simultaneously. It was found that an articulated flat plate flutters in a uniform flow and has a steady fluttering mode. The fluttering frequency increases with increasing uniform flow velocity for all conditions. The frequency was higher when the streamwise-length was short, thickness was thin, and density was small. It was found that there were two modes of fluttering: node-less mode and one-node mode. Furthermore, the dimensional analysis was performed, and the results show that the non-dimensional number consisting of the Strouhal number, Reynolds number, and mass ratio became constant.
Vibration Control and Smart Integrated Transportation Strategy of Crane Systems
Authors: Terashima Kazuhiko , Tho Ho Duc
Published: September 2020

This paper presents number of vibration control schemes and smart integrated transportation strategies for crane systems. First, robust control problem of payload’s skew rotation in crane systems is discussed. A robust integral sliding mode controller is proposed to realize skew transportation without residual vibration. Robust stability conditions with respect to parametric uncertainties of the closed-loop system are imposed on control gains. Second, transportation of bulk material using an overhead crane system is considered, in which the transferred material can be dropped/discharged while in the air. This paper introduces a new concept, named tossing control methodology, to enhance transportation productivity. A specific type of tossing controller is established, which relies on the phenomenon of linear resonance. It will be shown that the resonance-based tossing control is able to break the time limitation of the minimum-time vibration suppression control. Simulation and experimental results are provided to verify the effectiveness of the proposed control systems. Finally, a diffusion-based obstacle-avoidance path planning method for crane systems is outlined to realize a fully autonomous crane in future.
Cubic Spline-Based Genetic Algorithm Optimization for Millimeter and Microwave Integrated Circuits
Authors: Mansor N H , Abdul-Rahman R
Published: September 2020

A clamped cubic spline profile taper of an air-filled substrate integrated waveguide (SIW) transition was optimized to search for the optimal design of taper in this paper. The optimization technique involved a combination of the multi-objective genetic algorithm (MOGA) and full-wave analysis of the waveguide. The data from the return and transmission losses provides a basis for the optimization of the transition tapers design. The simulation results show the efficacy of our proposed strategy, where the optimal taper geometry yields an improvement of the return loss while maintaining its original transmission loss at Ka-band (26–40 GHz) frequencies.
Application of electromagnetic induction for impact load measurement
Authors: Adachi T , Ishii Y
Published: September 2020

In this paper, a small impact testing machine was developed as an application of the method for measuring impact load based on electromagnetic induction phenomena. The experimental results were shown to determine the effectiveness of the method. The electromotive forces generated in two coils near a specimen were measured when a small impactor containing a neodymium magnet, having a mass of 0.36 g, was dropped freely onto a 1.2-mm-thick glass plate. The histories of the impact load and the relation between the impact load and specimen deflection were evaluated from the measured electromotive forces because the electromotive force per impactor velocity is dependent on only the position of the impactor. The method and developed machine with the measurement system were determined to be effective by considering the experimental impact test results for the glass plates.
Test Condition Optimization for Testing of Hip Protectors
Authors: Yahaya S. A. , D’raj J. , Ripin Z. M. , Ridzwan M. I. Z.
Published: September 2020

Determining the efficacy of hip protectors designed to reduce the menace of the alarming rise in hip fracture due to fall among the elderly population is particularly challenging. Hip protector evaluation has been done using different soft tissue surrogate and at different energy level to determine the effectiveness of various hip protectors. However, some hip protectors that had been ranked effective in mechanical testing systems proof otherwise when deployed for clinical trials, this may be due to lack of optimization of the testing condition, most notably in testing when the soft tissue surrogate attenuates impacts that may be unduly attributed to the effectiveness of the hip protector. In this study, the performance of a surrogate soft tissue, fabricated from polyethylene, was evaluated at different energy levels (3.68 J – 37.9 J) to ascertain the optimal position for evaluating the efficacy of a hip protector to simulate a representative condition of an actual fall to the sideways by a person. A drop-weight impact testing machine was used to evaluate the impact force response of an employed femoral geometry with and without the soft tissue at various residual impact energy. The result showed that the soft tissue might be responsible for up to about 95.17 % of peak impact force attenuation if not adequately modelled. Therefore various conditions were examined to get representative sideways impact condition where the soft tissue employed do not attenuate beyond 11 - 28 % of the peak impact force. This finding demonstrates that the impact condition is as critical as all other parameters in determining the performance of a hip protector.
Reliability analysis on the reservoir dam spillway structure using fluid-structure interaction
Authors: Zawawi Mohd Hafiz , Ng F C , Azman Aqil , Tung L H , Abustan Ismail , Mohd Remy Rozainy Z , Abas Aizat
Published: September 2020

This paper presents a combined reliability and flow analysis on the spillway of reservoir dam using the numerical fluid-structure interaction (FSI) approach. The spillway is an important structure to the operation of reservoir dam, as it regulates the water flow from upstream to downstream. Therefore, a rapid discharge of water from the reservoir along the spillway will causes possibly flooding at downstream and incurs high structural stress. Using the ANSYS software, the two-way FSI problem of a dam spillway is numerically simulated. Such FSI numerical study able to simultaneously simulate and obtain both the parameters on fluid flow and structural deformation. The current study shows that the downstream has the highest flow velocity; while the highest deformation of 10.7 mm being observed in the connection bridge section. As the general stress level of the overall spillway structure (max. 30.75 MPa) is less than the yield stress of corresponding materials, the spillway will not exhibit any structural failure upon the current discharge mode.
Effect of the oil spill on the soil friction angle
Authors: Ramli Harris , Saat Hafizul , Azmi Mastura , Ahmad Fauziah
Published: September 2020

There are many factors governs the soil stability, and strength is one of the most important aspects. In the event of soil contamination by oil spills, the soil characteristic and its physical properties will change due to the intrusion of oil in the subsurface. This changes mainly related to the viscous properties of the oil in comparable to natural groundwater. As the soil friction angle is one of the main components of the soil shear strength, the viscosity of the oil will affect the soil friction angle. In this study, three types of typical sand were used to mix with water and oil, and the soil friction angle is determined using direct shear test on these samples under dried condition, 50% of soil saturation and at optimum moisture content. The three sand is classified as Sandy clay, Silt clay with sand and Silt with sand. It is found all samples followed soil compaction principal when the sample mixed with water or oil, except for Sandy clay soil. For sandy clay, as the soil friction angle supposed to increase when reaching the optimum moisture content (φ = 38.7°), the soil friction angle is continued to reduce (φ = 34.2°). This may due to less than 60% coarse grain of the grain size distribution in sandy clay. As coarse grain is the main factor for the grain angularity function that provides the interlocking between particles.
Mechanical behaviour of Steel fibre reinforced concrete beams: a review
Authors: Fares Amin Al-Khwaja Aysar , Keong Choong Kok , Geem-Eng Tan
Published: September 2020

Concrete is one of the most widely utilized material in the world. It is mainly used in construction due to its capability to be formed to any required shape. This because of the good workability of the fresh concrete. However, concrete is still a brittle material that makes it tends to fail under tension. Thus, a material with high tensile strength needs to be included in the mixture such as steel rebars and steel fibres (SF). This review paper summarizes previous studies that investigated the effect of SFs addition on the mechanical properties of reinforced concrete (RC) beams. Researchers in all previous studies agreed that the addition of fibres in RC beams can noticeably improve the mechanical properties, serviceability, and durability of RC beams. Generally, the effect of SFs on the RC beams was dependent on various factors such as aspect ratios, volume percentages, and type of SFs. It was confirmed that the optimum SFs content ranged from 0.75 to 1.5 V.%, depending on the strength of concrete. However, more studies are required to further understand the effect of fibres on the properties of concrete in beams with different cross-sectional shapes.
Effect of hydrogen embrittlement towards thermal and mechanical behavior of NiTi shape memory alloy
Authors: Ng C W , Mahmud A S , Razali M F , Ahmad M N
Published: September 2020

NiTi arch wires are susceptible to hydrogen embrittlement upon contact with dental brackets in oral cavity during orthodontic treatment. This study investigated the effect of hydrogen absorption and diffusion over time towards the thermal and mechanical properties of NiTi shape memory wire. The hydrogen absorption process was carried out via electrolytic charging at constant current density for 16 hours in 1.0 weight percent (wt.%) sodium sulphate solution. The hydrogen charged wires were aged at room temperature in air for different durations to allow further inward diffusion of the hydrogen into the specimens. The results show that after hydrogen charging, the latent heat of forward and reverse martensitic phase transformation of the NiTi wire changed from 19.96 to 11.98 J/g, and 19.21 to 13.42 J/g, respectively. Further suppression and disappearance of thermal transformation peaks were observed as the charged specimen aged for 7 days. The transformation stress level on tensile deformation increased by almost 90 MPa after hydrogen charging, and exhibited non-flat stress plateau after further aging.
Evaporation rate of molten copper in argon and nitrogen gas flow and characteristics of condensed particles
Authors: Yokoyama S , Nakano K , Sasano J
Published: September 2020

Copper has been levitation-melted in room temperature Ar and N2 gas flows to investigate the evaporation rate and characteristics of condensed particles. The evaporation measured experimentally increased with the increases of the temperature of the levitated Cu, and the gas flow rate. The site, the concentration and temperature at the vapor condensation in the gas film around the levitated Cu was analysed using the temperature distribution and the critical supersaturation concentration of Cu vapor. There was a linear relationship between the calculated and the experimentally obtained evaporation rates. The calculated evaporation rate was larger than the experimentally measured rate. The condensed particles were metallic Cu. When the temperature at the vapor condensation site was lower than the melting point of Cu, the vapor condensed as a solid phase, and the solid particles did not grow with collision-coalescence of the particles. Therefore, the size of them was not influenced by the temperature of levitated Cu and the gas flow rate. When the temperature at the condensation site was higher than the melting point, the size of them was increased by the distance which was the difference in the position at the melting point and the vapor condensation.
Effect of Modulation of the Astrocytic Glutamate Transporters’ Expression on Cocaine-Induced Reinstatement in Male P Rats Exposed to Ethanol
Authors: Hammad Alaa M , Alasmari Fawaz , Sari Youssef
Published: September 2020

Aim

Reinforcing properties of ethanol and cocaine are mediated in part through the glutamatergic system. Extracellular glutamate concentration is strictly maintained through several glutamate transporters, such as glutamate transporter 1 (GLT-1), cystine/glutamate transporter (xCT) and glutamate aspartate transporter (GLAST). Previous findings revealed that cocaine and ethanol exposure downregulated GLT-1 and xCT, and that β-lactam antibiotics restored their expression.

Methods

In this study, we investigated the effect of ampicillin/sulbactam (AMP/SUL) (200 mg/kg, i.p.), a β-lactam antibiotic, on cocaine-induced reinstatement and locomotor activity in male alcohol preferring (P) rats using free choice ethanol (15 and 30%, v/v) and water. We also investigated the effect of co-exposure to ethanol and cocaine (20 mg/kg, i.p.) on GLT-1, xCT and GLAST expression in the nucleus accumbens (NAc) core, NAc shell and dorsomedial prefrontal cortex (dmPFC).

Results

Cocaine exposure decreased ethanol intake and preference. Cocaine and ethanol co-exposure acquired place preference and increased locomotor activity compared to ethanol-exposed rats. GLT-1 and xCT expression were downregulated after cocaine and ethanol co-exposure in the NAc core and shell, but not in dmPFC. AMP/SUL attenuated reinstatement to cocaine as well attenuated the decrease in locomotor activity and ethanol intake and preference. These effects were associated with upregulation of GLT-1 and xCT expression in the NAc core/shell and dmPFC. GLAST expression was not affected after ethanol and cocaine co-exposure or AMP/SUL treatment.

Conclusion

Our findings demonstrate that astrocytic glutamate transporters within the mesocorticolimbic area are critical targets in modulating cocaine-seeking behavior while being consuming ethanol.
By Whose Authority? Sexual Ethics, Postmodernism, and Orthodox Christianity
Authors: Ford Mary S
Published: September 2020

The traditional Christian teaching is that engaging in sexual activity, whether heterosexual or homosexual, outside the marriage of one man and one woman is sinful (as distinct from having thoughts about illicit sexual desire, which need not be sinful as long as they are not meditated and/or acted upon—in the same way that the Church teaches about any “logismoi”). In direct contrast, there are those in the Church who quite recently have begun to insist that the traditional teachings concerning sexual sin need to be changed. In particular, the effort is being made to have the Church accept homosexual behavior as not sinful or problematic in any way—at least not for committed homosexuals, as comparable to committed heterosexuals in a marriage. As we all know, this relatively recent view has been promoted heavily in the media and popular culture, and even by our national government. As we make our observations, we will particularly focus on traditional Orthodox Christianity as the fullness of the truth and, thus, the source of the true alternative to this “new” outlook that is gripping much of popular Western culture today.
Financial subordination and uneven financialization in 21st century Africa
Authors: Kvangraven Ingrid Harvold , Koddenbrock Kai , Sylla Ndongo Samba
Published: September 2020

The financialization debate has not paid enough attention to the African continent. The continent’s populations and governments have found creative ways of dealing with the capitalist world market and political power relations since decolonization in the late 1950s. However, several forms of structural dependence and subordination persist. We ask in this article how the global process of financialization has unfolded across the continent and what it means for relations of dependence. We understand financialization as the global expansion of financial practices, and, in particular, the financial sector, that followed the end of the Bretton Woods era. We consider to what extent it has occurred at all in the four case study countries of Mauritius, Nigeria, Zambia, and South Africa. The empirical analysis of aggregate country data shows that financialization is, at best, an uneven and patchy process on the continent, not a general structural shift in the way capital accumulation is organized. Rather, where financialization occurred, it appears to have diversified the relations of dependence that states, corporations, and populations have found themselves in.
Treatment of Coronavirus Disease 2019 Patients With Prolonged Postsymptomatic Viral Shedding With Leflunomide: A Single-center Randomized Controlled Clinical Trial
Authors: Wang Mengmei , Zhao Yang , Hu Weihua , Zhao Dong , Zhang Yunting , Wang Tao , Zheng Zhishui , Li Xiaochen , Zeng Shaolin , Liu Zhenlian , Lu Li , Wan Zhihui , Hu Ke
Published: September 2020

Background

We aimed to evaluate the efficacy and safety of leflunomide, an approved dihydroorotate dehydrogenase inhibitor, to treat coronavirus disease 2019 (COVID-19) patients with prolonged postsymptomatic viral shedding.

Methods

We conducted a prospective, randomized controlled, open-label trial involving hospitalized adult COVID-19 patients with prolonged polymerase chain reaction (PCR) positivity. Patients were randomly assigned to receive either leflunomide (50 mg every 12 hours, 3 consecutive times, orally; then 20 mg once daily for 8 days), in addition to nebulized interferon alpha 2a (IFN-α-2a, 3 million IU each time, twice daily for 10 days), or nebulized IFN-α-2a alone for 10 days. The primary endpoint was the duration of viral shedding.

Results

A total of 50 COVID-19 patients with prolonged PCR positivity were randomized into 2 groups: 26 were assigned to the leflunomide plus IFN-α-2a group, and 24 were assigned to the interferon-alone group. Treatment with leflunomide was not associated with a difference from the interferon-alone group in the duration of viral shedding (hazard ratio for negative reverse-transcription PCR, 0.70 [95% confidence interval, .391–1.256]; P = .186). In addition, the patients given leflunomide did not have a substantially shorter length of hospital stay than patients treated with interferon alone, with median durations of 29.0 (interquartile range [IQR], 19.3–47.3) days and 33.0 (IQR, 29.3–42.8) days, respectively (P = .170). Two leflunomide recipients were unable to complete the full 10-day course of administration due to adverse events.

Conclusions

In COVID-19 patients with prolonged PCR positivity, no benefit in terms of the duration of viral shedding was observed with the combined treatment of leflunomide and IFN-α-2a beyond IFN-α-2a alone.
A Theory of Professional Identity in Journalism: Connecting Discursive Institutionalism, Socialization, and Psychological Resilience Theory
Authors: Raemy Patric
Published: September 2020

Studies about journalists’ professional identity have so far been scarce. However, understanding the constitution and formation processes of professional identity helps to explore journalists’ and journalism’s identity, performance, and adaption to challenges. The study enhances theories about journalistic roles, professional identity, and adaptation processes in journalism, based on a synthesis of literature from different fields as well as qualitative interviews with 20 journalists from print and online Swiss newspapers. This research proposes a model that explains: (a) the constitution of professional identity in journalism as an additive, relational, and hierarchical concept; and (b) the process of formation at three distinct level of analysis. The idea is that different theories address adaptation processes on distinctive analytical fields: discursive institutionalism captures the relationship between journalists’ and journalism’s identity (macro); socialization theory focuses on the adaption process into a social community (meso); and resilience theory explains individuals’ adaptation in face of challenges (micro).
Comparative differences in the atherosclerotic disease burden between the epicardial coronary arteries: quantitative plaque analysis on coronary computed tomography angiography
Authors: Bax A Maxim , van Rosendael Alexander R , Ma Xiaoyue , van den Hoogen Inge J , Gianni Umberto , Tantawy Sara W , Hollenberg Emma J , Andreini Daniele , Al-Mallah Mouaz H , Budoff Matthew J , Cademartiri Filippo , Chinnaiyan Kavitha , Choi Jung Hyun , Conte Edoardo , Marques Hugo , de Araújo Gonçalves Pedro , Gottlieb Ilan , Hadamitzky Martin , Leipsic Jonathon A , Maffei Erica , Pontone Gianluca , Shin Sanghoon , Kim Yong-Jin , Lee Byoung Kwon , Chun Eun Ju , Sung Ji Min , Lee Sang-Eun , Virmani Renu , Samady Habib , Stone Peter H , Berman Daniel S , Min James K , Narula Jagat , Lin Fay Y , Chang Hyuk-Jae , Shaw Leslee J ,   for the PARADIGM Investigators
Published: September 2020

Aims

Anatomic series commonly report the extent and severity of coronary artery disease (CAD), regardless of location. The aim of this study was to evaluate differences in atherosclerotic plaque burden and composition across the major epicardial coronary arteries.

Methods and results

A total of 1271 patients (age 60 ± 9 years; 57% men) with suspected CAD prospectively underwent coronary computed tomography angiography (CCTA). Atherosclerotic plaque volume was quantified with categorization by composition (necrotic core, fibrofatty, fibrous, and calcified) based on Hounsfield Unit density. Per-vessel measures were compared using generalized estimating equation models. On CCTA, total plaque volume was lowest in the LCx (10.0 ± 29.4 mm3), followed by the RCA (32.8 ± 82.7 mm3; P < 0.001), and LAD (58.6 ± 83.3 mm3; P < 0.001), even when correcting for vessel length or volume. The prevalence of ≥2 high-risk plaque features, such as positive remodelling or spotty calcification, occurred less in the LCx (3.8%) when compared with the LAD (21.4%) or RCA (10.9%, P < 0.001). In the LCx, the most stenotic lesion was categorized as largely calcified more often than in the RCA and LAD (55.3% vs. 39.4% vs. 32.7%; P < 0.001). Median diameter stenosis was also lowest in the LCx (16.2%) and highest in the LAD (21.3%; P < 0.001) and located more distal along the LCx when compared with the RCA and LAD (P < 0.001).

Conclusion

Atherosclerotic plaque, irrespective of vessel volume, varied across the epicardial coronary arteries; with a significantly lower burden and different compositions in the LCx when compared with the LAD and RCA. These volumetric and compositional findings support a diverse milieu for atherosclerotic plaque development and may contribute to a varied acute coronary risk between the major epicardial coronary arteries.
Pulmonary valve endocarditis in adults with congenital heart disease: the role of echocardiography in a case series
Authors: Fusco Flavia , Scognamiglio Giancarlo , Correra Anna , Merola Assunta , Colonna Diego , Palma Michela , Romeo Emanuele , Sarubbi Berardo
Published: September 2020

Background

Pulmonary valve (PV) endocarditis is a frequent complication during follow-up in patients with repaired right ventricular outflow tract (RVOT) obstruction and poses relevant diagnostic and treatment challenges. We aimed to describe in details the possible different clinical presentations of this rare condition and to highlight the role of both transthoracic and transoesophageal echocardiography which, in experienced hands, may provide comprehensive useful information for the clinicians.

Case summary

We below describe the clinical presentation and the echo findings of three cases of pulmonary valve endocarditis complicating disease course after different repair modalities of congenital right ventricular outflow tract obstruction.

Discussion

The present case series outlines the diagnostic challenges of this increasingly frequent complication during follow-up of patients with congenital RVOT dysfunction after both surgical and percutaneous repair. Despite the diffusion of multimodality imaging, echocardiography with PV-dedicated views play a pivotal role in diagnosing such condition and guiding clinical management. Furthermore, this case series highlight that the suspicion of infective endocarditis should be raised whenever a sudden increase in transvalvular gradient is found during follow-up.
Mechanisms, features, and significance of diastolic mitral regurgitation: a case series
Authors: Li Quan , Liu Yu , Zuo Wuxu , Chen Haiyan , Zhao Weipeng , Dong Lili , Pan Cuizhen , Shu Xianhong
Published: September 2020

Background

Diastolic mitral regurgitation (DMR) is a type of functional mitral regurgitation. Its occurrence in the diastolic phase of cardiac cycle renders DMR an easily ignored entity. Confusing it with systolic mitral regurgitation occasionally happens. The reversal of left atrioventricular pressure gradient during diastole and the incomplete closure of mitral valve are the essential conditions for DMR. Diastolic mitral regurgitation develops under various situations, where the mechanisms of diastolic reversal of left atrioventricular pressure gradient differ.

Case summary

Patient 1 was a 50-year-old man diagnosed with 2:1 second-degree atrioventricular block (AVB). Patient 2 was a 70-year-old man diagnosed with first-degree AVB. Patient 3 was a 66-year-old man diagnosed with atrial fibrillation with long intermission and occasional atrial flutter with unequal conduction. Patient 4 was a 54-year-old woman diagnosed with dilated cardiomyopathy with complete left bundle branch block. Patient 5 was a 36-year-old man diagnosed with severe acute aortic regurgitation secondary to subacute bacterial endocarditis.

Discussion

Although the degree of DMR is relatively mild, its appearance generally prompts further clinical considerations. The appreciation of DMR has an incremental value for diagnosing and evaluating the underlying cardiovascular disease.
Recurrent seizures in a young woman: when video-EEG diagnoses a cardiac cause: a case report
Authors: Chaumont Corentin , Bourilhon Julie , Chastan Nathalie , Mirolo Adrian , Eltchaninoff Hélène , Anselme Frédéric
Published: September 2020

Background

While transient loss of consciousness is a frequent presenting symptom, differential diagnosis between syncope and epilepsy can be challenging. Misdiagnosis of epilepsy leads to important psychosocial consequences and eliminates the opportunity to treat patient’s true condition.

Case summary

A 39-year-old woman presenting with recurrent seizures since her childhood was referred to neurological consultation. Electroencephalograms (EEGs) and magnetic resonance imaging previously performed were normal. A sleep-deprived video-EEG was performed and highlighted after 12 h of sleep deprivation a progressive dropping of the heart rate followed by a complete heart block without ventricular escape rhythm and asystole for about 30 s. Her EEG recording later showed diffuse slow waves traducing a global cerebral dysfunction and suffering. The diagnosis of vaso-vagal syncope with predominant cardioinhibitory response was made and a dual-chamber pacemaker with rate-drop response algorithm was implanted. After a 2 years of follow-up, the patient remained free of syncope.

Discussion

Patients presenting with loss of consciousness and convulsion are often diagnosed with epilepsy despite normal EEGs. In patients presenting with recurrent seizures with unclear diagnosis of epilepsy or in a situation of drug-resistant epilepsy, syncope diagnosis should always be considered and a risk stratification is necessary. The benefit of pacemaker implantation in patients with recurrent vaso-vagal syncope is still very controversial. Only patients presenting with spontaneous asystole should be considered for pacemaker implantation in case of recurrent vaso-vagal syncope.
Case report of asymptomatic very late presentation of ALCAPA syndrome: review of the literature since pathophysiology until treatment
Authors: Cambronero-Cortinas Esther , Moratalla-Haro Pedro , González-García Ana Elvira , Oliver-Ruiz José María
Published: September 2020

Background

Anomalous origin of the left coronary artery (LCA) from the pulmonary artery (ALCAPA) is an unusual congenital heart defect which affects approximately 1 in 300 000 live births and accounts for 0.5% of all congenital heart disease. Without surgical intervention, most patients die in infancy (nearly 90%).

Case summary

We present a rare case of an asymptomatic 67-year-old female. Transthoracic echocardiography demonstrated a dilated right coronary artery (RCA) and multiple collaterals. ALCAPA was confirmed by multidetector computed tomography. The left main artery was seen originating from the pulmonary artery and well-developed collaterals were visualized between the RCA and LCA. No areas of myocardial infarction were identified on cardiac magnetic resonance. Stress studies showed no inducible ischaemia.

Discussion

Our clinical case of an ALCAPA patient who survived and remained asymptomatic to their late 60’s, highlights the importance of well-collateralized and pressurized coronary system to maintain adequate myocardial perfusion. Physicians should be aware of this congenital anomaly as appropriate early diagnosis is crucial to prevent irreversible myocardial damage, acute ischaemia, and arrhythmias, and can improve patient outcomes. Surgical treatment is suggested irrespective of symptomatology or the presence of inducible myocardial ischaemia.
MitraClip-related infective endocarditis in a frail, elderly patient: a case report
Authors: Leow Kevin , Isreb Courtney , Brown Martin
Published: September 2020

Background

The incidence of infective endocarditis (IE) following a MitraClip is rare with 17 reported cases in the literature. The reported mortality rate is high, at 41%, despite both medical and surgical therapies. To date, this is the first documented case of IE following a MitraClip procedure in Australia.

Case summary

An 88-year-old male presented with a 1-week history of confusion and dyspnoea. Clinical examination was significant for a temperature of 37.7°C, a pansystolic murmur and bilateral pitting oedema to mid-shin, but no peripheral stigmata of IE. His history included a MitraClip procedure 11 weeks prior for severe mitral regurgitation. Initial blood cultures grew enterococcus faecalis. A transthoracic echocardiogram did not identify vegetations on the MitraClip. Subsequent transoesophageal echocardiogram (TOE) identified a 4 mm × 2 mm echodensity on the posterior mitral valve leaflet suggestive of IE. He was deemed not suitable for surgical intervention due to poor cognitive reserve and his medical comorbidities, so he commenced intravenous (IV) Ampicillin and Ceftriaxone which was later changed to Benzylpenicillin. Repeat TOE 2 weeks later showed the vegetation to have increased to ∼1 cm in length, so his treatment was reverted to Ampicillin. A further TOE 4 weeks later showed reduction in size to 5 mm × 2 mm. After 6 weeks of IV antibiotics, the patient was discharged on lifelong oral antibiotics.

Discussion

Infective endocarditis following MitraClip procedure is rare. This disease has a high mortality rate despite optimal medical and surgical therapy. Increased awareness amongst clinicians is important given an increasing volume of MitraClip procedures.
Global, regional, and national burden of ischaemic heart disease and its attributable risk factors, 1990–2017: results from the Global Burden of Disease Study 2017
Authors: Dai Haijiang , Much Arsalan Abu , Maor Elad , Asher Elad , Younis Arwa , Xu Yawen , Lu Yao , Liu Xinyao , Shu Jingxian , Bragazzi Nicola Luigi
Published: September 2020

Aims

The aim of this study was to estimate the burden and risk factors for ischaemic heart disease (IHD) in 195 countries and territories from 1990 to 2017.

Methods and results

Data from the Global Burden of Disease Study 2017 were used. Prevalence, incidence, deaths, years lived with disability (YLDs), and years of life lost (YLLs) were metrics used to measure IHD burden. Population attributable fraction was used to estimate the proportion of IHD deaths attributable to potentially modifiable risk factors. Globally, in 2017, 126.5 million [95% uncertainty interval (UI) 118.6 to 134.7] people lived with IHD and 10.6 million (95% UI 9.6 to 11.8) new IHD cases occurred, resulting in 8.9 million (95% UI 8.8 to 9.1) deaths, 5.3 million (95% UI 3.7 to 7.2) YLDs, and 165.0 million (95% UI 162.2 to 168.6) YLLs. Between 1990 and 2017, despite the decrease in age-standardized rates, the global numbers of these burden metrics of IHD have significantly increased. The burden of IHD in 2017 and its temporal trends from 1990 to 2017 varied widely by geographic location. Among all potentially modifiable risk factors, age-standardized IHD deaths worldwide were primarily attributable to dietary risks, high systolic blood pressure, high LDL cholesterol, high fasting plasma glucose, tobacco use, and high body mass index in 2017.

Conclusion

Our results suggested that IHD remains a major public health challenge worldwide. More effective and targeted strategies aimed at implementing cost-effective interventions and addressing modifiable risk factors are urgently needed, particularly in geographies with high or increasing burden.
The International Criminal Tribunal for Rwanda and Post-Genocide Justice 25 Years On
Authors: Labuda Patryk I
Published: September 2020

2019 marked the 25th anniversary of the Rwandan genocide and of the establishment of the International Criminal Tribunal for Rwanda (ICTR). After prosecuting 73 people, including high-ranking politicians and military leaders, the Rwanda Tribunal closed its doors in 2015. Together with its sister tribunal, the International Criminal Tribunal for the former Yugoslavia, the ICTR is considered one of the first-generation ad hoc tribunals mandated to bring justice to countries emerging from conflict. This review essay examines four books to take stock of the scholarly debate on the ICTR’s performance. After analysing the Tribunal’s achievements and shortcomings, it explains that scholarly assessments of the ICTR rely on two different analytical lenses – a national and/or international perspective – to make claims about the roles of international criminal tribunals. The essay then discusses the ICTR’s interactions with other post-genocide justice mechanisms in Rwanda and the compatibility of concurrent judicial responses to mass violence. In conclusion, it suggests that evolving interpretations of the ICTR’s performance reflect prevailing ideas about the goals and limitations of international criminal tribunals.
Relevance of obstructive sleep apnea and smoking: Obstructive sleep apnea and smoking
Authors: Esen Ayse Didem , Akpinar Meltem
Published: September 2020

Background

The data concerning the association of smoking and obstructive sleep apnea (OSA) are limited. The effects of cigarette smoking on OSA still remain obscure.

Objectives

To reveal the impact of smoking on obstructive sleep apnea.

Methods

About 384 patients with the diagnosis of OSA through full night polysomnographic (PSG) examination were included to the study. The demographic data (age, sex and BMI), complaints and medical history, status of smoking as non-smokers and smokers, smoking frequency (cigarettes/day), polysomnograhic data comprising apnea hypopnea index (AHI), non-REM sleep AHI (NREM AHI), REM sleep AHI (REM AHI), minimum oxygen saturation (min SaO2) were recorded for all the subjects. Non-smokers and smokers were compared in terms of severity of OSA.

Results

The study population consisted of 384 subjects, 253 males and 131 females. Smoking frequency was not found correlated with OSA severity. Among smokers, males had higher severe OSA rate (P = 0.002, P < 0.05). In subjects with BMI < 30, severe OSA rate was higher in smokers (34.44% versus 21%) (P = 0.027, P < 0.05).

Conclusions

Our study detected higher rate of severe OSA in male smokers and smokers with BMI < 30. PSG data did not yield statistically significant difference in non-smokers and smokers. OSA severity was not found correlated with smoking frequency. Along with the study results, the impact of smoking on OSA is still controversial. Prospective studies with larger sample size may be contributive to further evaluation of the association of OSA with smoking.
Tailored Exercise and Home Hazard Reduction Program for Fall Prevention in Older People With Cognitive Impairment: The i-FOCIS Randomized Controlled Trial
Authors: Taylor Morag E , Wesson Jacqueline , Sherrington Catherine , Hill Keith D , Kurrle Susan , Lord Stephen R , Brodaty Henry , Howard Kirsten , O’Rourke Sandra D , Clemson Lindy , Payne Narelle , Toson Barbara , Webster Lyndell , Savage Roslyn , Zelma Genevieve , Koch Cecelia , John Beatrice , Lockwood Keri , Close Jacqueline C T
Published: September 2020

Background

The evidence to support effective fall prevention strategies in older people with cognitive impairment (CI) is limited. The aim of this randomized controlled trial (RCT) was to determine the efficacy of a fall prevention intervention in older people with CI.

Method

RCT involving 309 community-dwelling older people with CI. The intervention group (n = 153) received an individually prescribed home hazard reduction and home-based exercise program during the 12-month study period. The control group (n = 156) received usual care. The primary outcome was rate of falls. Secondary outcomes included faller/multiple faller status, physical function, and quality of life.

Results

Participants’ average age was 82 years (95% CI 82–83) and 49% were female. There was no significant difference in the rate of falls (incidence rate ratio [IRR] 1.05; 95% confidence interval [95% CI] 0.73–1.51). A sensitivity analysis, controlling for baseline differences and capping the number of falls at 12 (4 participants), revealed a nonsignificant reduction in fall rate in the intervention group (IRR 0.78; 95% CI 0.57–1.07). Analyses of secondary outcomes indicated the intervention significantly reduced the number of multiple fallers by 26% (RR 0.74; 95% CI 0.54–0.99) when adjusting for baseline differences. There was a differential impact on falls in relation to physical function (interaction term p-value = .023) with a significant reduction in fall rate in intervention group participants with better baseline physical function (IRR 0.60; 95% CI 0.37–0.98). There were no significant between-group differences for other secondary outcomes.

Conclusions

This intervention did not significantly reduce the fall rate in community-dwelling older people with CI. The intervention did reduce the fall rate in participants with better baseline physical function.

Clinical Trials Registration Number

Australian and New Zealand Trials Registry ACTRN12614000603617.
The significance of symptoms before and after surgery for anomalous aortic origin of coronary arteries in adolescents and adults
Authors: Meijer Fleur M M , Egorova Anastasia D , Jongbloed Monique R M , Koppel Claire , Habib Gracia , Hazekamp Mark G , Vliegen Hubert W , Kies Philippine
Published: September 2020

OBJECTIVES

The aim of this study is to describe the significance of symptoms preoperatively and at medium-term follow-up in adolescent and adult patients who underwent surgery of anomalous aortic origin of a coronary artery (AAOCA).

METHODS

Consecutive patients who underwent surgery for AAOCA in our tertiary referral centre between 2001 and 2018 were included. Clinical characteristics and symptoms were evaluated and medium-term outcomes were recorded. Symptoms were classified according to the ‘2019 ESC guidelines on chronic coronary syndromes’.

RESULTS

A total of 53 (55% male) patients with mean age of 44 at time of surgery underwent surgical repair of AAOCA. Data on symptoms and events ˃3 months after surgery were available in 34 patients with a median follow-up of 3 years (interquartile range 1.0–5.3). Preoperatively, only 35% patients had typical anginal complaints. After surgical correction of AAOCA, 59% of the patients were free of symptoms, compared to 6% preoperatively (P < 0.001). A total of 3 (9%) patients needed a reoperation/reintervention related to the operated AAOCA. All 3 patients presented postoperatively with novel typical anginal complaints.

CONCLUSIONS

Adolescent and adult patients with AAOCA present with varying symptoms. Only 35% have typical anginal complaints. Surgical correction of AAOCA reduces the symptoms in the vast majority of patients. One should be aware of potential lesions of the operated coronary artery in patients presenting with typical anginal complaints postoperatively.