bluuebunny/crossref_metadata_2025 huggingface dataset:
Pengaruh penerapan praktikum berbasis kearifan lokal terhadap keterampilan literasi sains dan hasil belajar
Authors: Sapitri Riska Dia , Hadisaputra Saprizal , Junaidi Eka
Published: March 2020

Penelitian ini bertujuan untuk mengetahui pengaruh penerapan metode praktikum berbasis kearifan lokal terhadap keterampilan literasi sains dan hasil belajar siswa kelas XI IPA SMAN 3 Sumbawa Besar. Penelitian ini termasuk dalam penelitian eksperimen semu yang menggunakan desain penelitian pre-test posttest control group design. Populasi dalam penelitian ini meliputi seluruh siswa kelas XI IPA SMAN 3 Sumbawa Besar yang berjumlah 130 siswa. Adapun sampel pada penelitian ini yaitu berjumlah 47 siswa. Instrumen yang digunakan berupa angket keterampilam literasi sains dan tes pilihan ganda. Data keterampilan literasi sains (pretest-posttest) dianalisis menggunakan uji N-Gain untuk mengetahui peningkatan keterampilan literasi sains siswa, diperoleh N-Gain kelas eksperimen berkategori sedang 37% dan kelas kontrol berkategori rendah 25%. Hasil uji hipotesis data N-Gain keterampilan literasi sains siswa menggunakan uji-t, diperoleh thitung sebesar 2,55 dan ttabel (probabilitas 5 %) sebesar 1,68, maka thitung >ttabel (2,55 > 1,68). Data hasil belajar (pretest-posttest) dianalisis menggunakan uji N-Gain untuk mengetahui peningkatan hasil siswa, diperoleh N-Gain kelas eksperimen berkategori sedang (31 %) dan kelas kontrol berkategori rendah (24 %). Hasil uji hipotesis data N-Gain hasil belajar siswa menggunakan uji-t, diperoleh thitung sebesar 1,69 dan ttabel (probabilitas 5 %) sebesar 1,68, maka thitung> ttabel (1,69 > 1,68). Berdasrkan hasil uji-t dapat disimpulkan bawah terdapat pengaruh metode praktikum berbasis kearifan lokal terhadap keterampilan literasi sains dan hasil belajar siswa.
Kajian Pelaksanaan Praktikum Ilmu Pengetahuan Alam Sekolah Menengah Pertama Di Kota Mataram
Authors: Hakim Aliefman , Jufri A Wahab , Kosim Kosim , Bachtiar Imam , Bahri Syamsul
Published: March 2020

Penelitian ini bertujuan untuk melakukan pemetaan terhadap aktivitas praktikum IPA di Sekolah Menengah Pertama (SMP) di Kota Mataram diantaranya adalah identifikasi tingkat motivasi guru-guru IPA SMP Negeri di Kota Mataram dalam melakukan kegiatan praktikum IPA, data pelaksanaan praktikum yang telah berlangsung dengan mengobservasi kendala yang ada termasuk kondisi sarana prasarana penunjang praktikum IPA di SMP di Kota Mataram. Penelitian ini merupakan penelitian survey dengan menggunakan metode fishbone diagram (diagram tulang ikan). Pengumpulan data pada survey dijaring menggunakan angket/kuisioner dan wawancara. Jenis kuisioner pada penelitian ini adalah kuisioer tertutup dengan rating scale. populasi penelitian ini berjumlah 24 sekolah negeri. Penentuan sampel dilakukan secara random sehingga diperoleh sampel guru IPA sebanyak 15 sampel. Sampel diberikan tiga jenis angket yaitu angket motivasi praktikum, angket pelaksanaan praktikum, dan angket sarana prasarana penunjang praktikum. Motivasi guru IPA dalam melakukan kegitan praktikum termasuk kategori sedang dengan rata-rata sebesar 64 yang terbagi dalam 13.3% motivasi tinggi dan 86.7% motivasi sedang. Pelaksanaan praktikum IPA tergolong baik yaitu sebesar 80.3%. Adapun ketersediaan saran prasarana penunjang praktikum tergolong sangat baik yaitu sebesar 94.2% tersedia. Akan tetapi, berdasarkan hasil hasil uji regresi linear dengan nilai signifikansi 0.355 lebih besar dari 0.05. Hal ini menunjukkan bahwa motivasi praktium, pelaksanaan praktikum, dan ketersediaan sarana prasarana tidak saling berhubungan.
Pengaruh Penggunaan Media Simulasi Phet (Physics Education Technology) Terhadap Hasil Belajar Fisika
Authors: Saputra Rozi , Susilawati Susilawati , Verawati Ni Nyoman Sri Putu
Published: March 2020

Penelitian ini bertujuan untuk mengetahui pengaruh penggunaan media simulasi PhET (physics education tehnology) terhadap hasil belajar fisika peserta didik SMA Negeri 1 Kediri tahun ajaran 2018/2019. Jenis penelitian ini adalah quasi experiment dengan desain penelitian non-equivalent control group design. Populasi penelitian ini adalah seluruh siswa kelas XI MIA SMAN 1 Kediri dengan jumlah 64 peserta didik, tehnik pengambilan sampel menggunakan cluster random sampling dan diperoleh kelas XI MIA 1 sebagai kelas eksperimen sebanyak 21 orang dan kelas XI MIA 2 sebagai kelas Kontrol sebanyak 20 orang. Kelas eksperimen diberikan perlakuan pembelajaran dengan model pembelajaran langsung menggunakan media simulasi PhET (Physics Education Tehnology) sedangkan kelas kontrol menggunakan pembelajaran konvensional. Uji coba instrument tes hasil belajar telah memenuhi syarat diantaranya, uji validitas, reliabilitas, tingkat kesukaran dan daya beda. Sehingga diperoleh sebanyak 25 soal valid dan 5 soal tidak valid dari 30 soal yang diujikan, kemudian soal tersebut diberikan saat melakukan tes awal dan tes akhir. Setelah didapatkan hasil tes akhir kedua kelas homogen dan terdistribusi normal hipotesis penelitian diujikan dengan uji-t dengan taraf signifikan 5% dan diperoleh hasil thitung sebesar 4,12 danÃÂ  ttabel sebesar 2,02 sehingga dapat dikatakan bahwa nilai thitung lebih besar dari ttabel. Berdasarkan hasil tersebut dapat disimpulkan bahwa terdapat pengaruh penggunaan media simulasi PhET (Physics Education Technology)ÃÂ  terhadap hasil belajar fisika peserta didik.
Pengaruh Dosis Dan Waktu Pemberian Kompos Terhadap Pertumbuhan Kangkung Darat
Authors: Raksun Ahmad , Zulkifli Lalu , Mahrus Mahrus
Published: March 2020

penelitian tentang pengaruh dosis dan waktu pemberian kompos terhadap pertumbuhan kangkung darat telah dilaksankan di Desa Bajur Kecamatan Labuapi kabupaten Lombok Barat. Tujuan penelitian adalah untuk mengetahui: (1) pengaruh dosis kompos terhadap pertumbuhan kangkung darat, (2) pengaruh waktu pemberian kompos terhadap pertumbuhan kangkung darat, (3) pengaruh interaksi antara dosis dan waktu pemberian kompos terhadap pertumbuhan kangkung darat. Dalam penelitian ini digunakan rancangan faktorial yang terdiri atas 2 faktor. Faktor pertama adalah dosisis kompos yang terdiri atas 5 level yaitu: Ko = tampa pemberianÃÂ  kompos (kontrol), K1 = pemberian 0,5 kg kompos/1 m2 lahan pertanian, K2 = pemberian 1,0 kg kompos/1 m2 lahan pertanian, K3 = pemberian 1,5 kg kompos/1 m2 lahan pertanian,, K4 = pemberian 2,0 kg pupuk organik/1 m2 lahan pertanian. Faktor kedua adalah waktu pemberian pupuk kompos yang terdiri atas: W1 = pemberian kompos 10 hari sebelum tanam, W2 = pemberian kompos 20 hari sebelum tanam, W3 = pemberian kompos 30 hari sebelum tanam dan W4 =ÃÂ  Pemberian kompos 40 hari sebelum tanam. Parameter pertumbuhan yang diukur adalah tinggi batang, jumlah daun, panjang helaian daun dan lebar helaian daun. ÃÂ Data penelitian dianalisis dengan analisis sidik ragam. Hasil penelitian menunjukkan bahwa (1) perbedaan dosis kompos berpengaruh nyata terhadap tinggi batang, panjang helaian daun dan lebar helaian daun kangkung darat tetapi tidak berpengaruh nyata terhadap jumlah daun kangkung darat, (2) perbedaan waktu pemberian kompos berpengaruh nyata terhadap tinggi batang, panjang helaian daun, jumlah daun dan lebar helaian daun kangkung darat, (3) interaksi antara dosis dan waktu pemberian kompos berpengaruh nyata terhadap jumlah daun dan panjang helaian daun tetapi tidak berpengaruh nyata terhadapÃÂ  tinggi batang dan lebar helaian daun kangkung darat, (4) dosis optimum kompos yang perlu diberikan pada lahan pertanian Desa Bajur Kecamatan Labuapi agar kangkung darat dapat tumbuh optimal adalh 1,5 kg per 1 m2 lahanÃÂ Kata-kata kunci: Kompos, pertumbuhan kangkung darat
3.4 Micro- and Macro-Vascular Remodeling and Cognitive Function in Hypertension
Authors: Gallo Antonio , Charpentier Etienne , Dietenbeck Thomas , Dufay Antoine , Redheuil Alban , Chupin Marie , Hanon Olivier , Girerd Xavier , Kachenoura Nadjia
Published: March 2020

Background

Cerebral microvascular alterations and hypoperfusion have been associated to cognitive disorder and dementia. We hypothesized that there is a direct link between retinal arteriolar remodelling, as assessed non-invasively using adaptive optics, and cognitive cerebral impairment in hypertensive patients.

Methods

Hypertensive patients over 65 years old with or without mild cognitive impairment were recruited. Each patient had a cognitive evaluation with MMSE; a study of retinal vasculature with adaptative optics RTX1® Camera to measure WT, internal diameter (ID), wall-to-lumen ratio (WLR) and arterio-venous ratio (AVR); an aortic, cerebral and carotid MRI to study cerebral volumes and white matter hyper-intensities (WMH) and carotid/aortic backward/forward flow (BF/FF) and distensibility. Correlations between retinal and cerebral, carotid and aortic remodelling were analysed.

Results

51 treated and controlled hypertensive patients, aged of 74 ± 5 years, 67% males, were able to achieve all exams. Among subjects with higher WLR, a significantly lower MMSE was found (p = 0.04). Eye-Brain: AVR and arteriolar ID coefficient of variation were inversely related to cerebral volumes (r = −0.61, p = 0.01 and r = −0.58, p = 0.02). Eye-Carotid: AVR and arteriolar ID coefficient of variation were directly and indirectly correlated with peak BF/FF, respectively (r = 0.47, p = 0.005; r = −0.39, p = 0.02). Eye-Aorta: WT and AVR were inversely correlated with ascending aorta distensibility (r = −0.48, p = 0.003; r = −0.47, p = 0.007).

Conclusion

In elderly hypertensives, arteriolar retinal remodelling represents a potential marker of early cerebral atrophy, which might be linked to a cerebral microcirculation remodelling. This hypothesis is supported by the association between retinal vascular remodelling and impaired carotid flow and aortic elastic properties.
3.7 Exercise Systolic Blood Pressure Response and Incident Depressive Symptoms — The Maastricht Study
Authors: Zhou Tan Lai , Kroon Abraham , Henry Ronald , Koster Annemarie , Dagnelie Pieter , Bosma Hans , van Greevenbroek Marleen , van der Kallen Carla , Schalkwijk Casper , Wesselius Anke , Reesink Koen , Köhler Sebastian , Schram Miranda , Stehouwer Coen , van Sloten Thomas
Published: March 2020

Background

Exaggerated exercise systolic blood pressure (SBP) is a modifiable risk factor associated with vascular dysfunction. Vascular dysfunction may contribute to the development of late-life depression, but the association between exercise SBP and incident depressive symptoms is unknown. Therefore, we investigated whether an exaggerated exercise SBP is associated with a higher risk of depressive symptoms over time.

Methods

Longitudinal data from the population-based Maastricht Study, with only individuals free of depressive symptoms at baseline included (n = 2,121; 51.3% men; age 59.5 ± 8.5 years). Exercise SBP was measured at baseline with a submaximal exercise cycle test. We calculated a composite score of exercise SBP based on 4 standardized exercise SBP measures: SBP at moderate workload, SBP at peak exercise, SBP change per minute during exercise and SBP 4 minutes after exercise. Clinically relevant depressive symptoms were determined annually at follow-up and defined as a Patient Health Questionnaire score of > = 10.

Results

After a mean follow-up of 3.9 years, 175 participants (8.3%) had incident clinically relevant depressive symptoms. A1 standard deviation higher exercise SBP composite score was associated with a higher incidence of clinically relevant depressive symptoms (hazard ratio: 1.27 [95% confidence interval: 1.04–1.54]). Results were adjusted for age, sex, education level, glucose metabolism status, lifestyle, cardiovascular risk factors, resting SBP and cardiorespiratory fitness.

Conclusion

A higher exercise SBP response is associated with a higher incidence of clinically relevant depressive symptoms.
3.8 The Importance of Micro-and Macrocirculation Indices Implementation for the Amelioration of Cardiovascular Risk Classification
Authors: Areti Triantafyllou , Konstantina Dipla , Nikolaos Koletsos , Eugenia Gkaliagkousi , Antonios Lazaridis , Andreas Zafeiridis , Stella Douma
Published: March 2020

Recently, many promising indices of micro- and macrocirculation have been widely used to promptly detect target organ damage before major cardiovascular events occur. More specifically, nailfold capillaroscopy, fundoscopy, near-infrared spectroscopy, ultrasound, laser speckle contrast analysis and central arterial pressure waveform analysis have been used to reveal capillary rarefaction, retinal vessel alterations, reduced brain and muscle oxygenation, endothelial dysfunction and arterial stiffness respectively. Additionally, the cross-talk between macro- and microvascular alterations has been a topic intensively discussed during the last years. Contrary to what someone might expect, i.e. that different microvascular target organ damage will coexist and occur at the same time in different tissues of the human body, in most studies the different types of microangiopathy seem not to synchronize or follow a specific order of appearance but rather to affect the different tissues randomly. On the other hand, arterial stiffening of the large arteries seems consistently to co-exist and correlate with almost all microvascular lesions. Nevertheless, many questions arise: When do the above lesions coexist? In which individuals? In which diseases? What can they predict when identified in apparently healthy people? In the present paper, the results of the study of the above indices, all applied in the same individuals at the same time, will be presented in a variable spectrum of diseases (naïve hypertensives, diabetics, rheumatologic patients, women with gestational diabetes, obese people, as well as healthy controls) to explore not only the interactions between them but mostly their importance for the amelioration of cardiovascular risk classification.
5.1 The Role of Blood Pressure, Aortic Stiffness, and Haemodynamics in Brain Health in Older People with Type 2 Diabetes Mellitus
Authors: Karayiannis Christopher , Moran Chris , Beare Richard , Sharman James , Phan Thanh , Thrift Amanda , Wang Wei , Srikanth Velandai
Published: March 2020

Aims

Type 2 diabetes (T2D) is associated with dementia, and abnormal blood pressure (BP), aortic stiffness, and haemodynamics. We aimed to study the contribution of such factors to brain structure and cognition, relative to the contribution of metabolic factors in T2D such as insulin resistance and adiposity, in older people with T2D.

Methods

Cross-sectional sample with T2D in the Cognition and Diabetes in Older Tasmanians–Blood Pressure (CDOT-BP) study. Measurements included neuropsychological battery, brain MRI, and Mobil-o-Graph-derived (IEM, Germany) aortic BP and haemodynamics. We studied associations of exposure variables with outcomes using structural equation modelling for cognition, and simple linear regression for brain structure, using standardised coefficients to determine relative contribution of variables to the outcomes in combined regression models.

Results

202 participants (mean age 68.5 years, mean HbA1c = 6.42%). Augmentation index was associated with processing speed (p < 0.05). The contribution of augmentation index to processing speed (standardized β = −0.237) was greater than waist-hip ratio (β = −0.175) and use of oral glucose lowering medications and insulin (β = −0.126), but less than age (β = −0.431). Peripheral systolic BP, pulse wave velocity, and peripheral nocturnal systolic BP dipping were associated with measures of white matter integrity (fractional anisotropy and mean diffusivity, p < 0.05) but not with cortical thickness.

Conclusion

BP, aortic stiffness and altered haemodynamics contribute to early cognitive change and loss of white matter integrity in T2D. The novel association between nocturnal BP dipping and white matter integrity deserves further investigation. Measuring white matter integrity may be useful to detect the effect of these vascular factors on the brain.
5.2 Arterial Stiffness and Periodontitis: A Systematic Review and Meta-Analysis
Authors: Darnaud Christelle , Courtet Alexandre , Schmitt Audrey , Carra Clotilde , Boutouyrie Pierre , Bouchard Philippe
Published: March 2020

Background

Despite a large number of studies linking cardiovascular diseases and periodontitis (Buhlin et al. 2011; Hansen et al. 2016; Pussinen et al. 2003), few studies make it possible to draw accurate conclusions on the link between periodontitis and arterial stiffness. Endothelial cells maintain vascular homeostasis but are affected by inflammatory injuries (Lacolley et al. 2017). Periodontal diseases involve bacteria-induced inflammation of the tissues supporting the teeth (Tomás et al. 2012), inducing endothelial dysfunction. We conducted a systematic review from existing studies for answering the following questions: (1) Do periodontitis patients have impaired arterial stiffness compared to controls? (2) Is periodontal treatment effective to improve pulse wave velocity (PWV) values?

Methods

A systematic review of the literature, focusing on measurements of PWV in periodontitis patients, was conducted by two independent reviewers. The literature search was done until June 2019. Risk of bias was independently assessed. All clinical studies reporting PWV in patients with severe periodontitis were retrieved for full-text evaluation.

Results

Final selection included 16 studies for qualitative analysis and 10 studies for quantitative analysis (meta-regression analysis). The results show that patients with severe periodontitis have increased PWV compared to controls (PWV mean difference 0.81 m/s; 95% CI: 0.56–1.06; p < 0.00001). This concerns both carotid to femoral, brachial ankle and carotid radial PWV. However, we were unable to identify a positive effect of periodontal treatment on PWV value.

Conclusion

This systematic review and meta-analysis support an association between severe periodontitis and PWV.
5.3 Sex Differences in Blood Pressure in Young Adults: Is It All About Body Size?
Authors: Yu Shikai , McDonnell Barry , Maki-Petaja Kaisa , Cockcroft John , Wilkinson Ian , McEniery Carmel
Published: March 2020

Background

In young adults, systolic blood pressure (SBP) and hypertension rates are significantly lower in females than males, although the extent to which this is due to differences in body size (body surface area; BSA) is unclear. Cardiac output (CO), a key haemodynamic determinant of SBP in young adults, is tightly linked with body size, and typically lower in females. Therefore, we hypothesized that in young adults, CO mediates the association between BSA and SBP, and contributes to sex-related differences in SBP in young adults.

Methods

Complete data were available in 3145 healthy young adults (1558 males, 23 ± 6 years). Linear regression analyses were performed, followed by propensity score matching for BSA to investigate sex-related differences.

Results

BSA was significantly associated with SBP (BSA: β male = 0.337; β female = 0.286; p < 0.001 for both). The regression coefficients did not differ statistically (p = 0.8). Addition of CO to the regression models attenuated, but did not remove these associations (β male = 0.279; β female = 0.234, p < 0.001 for both). Matching males and females for BSA resulted in equivalent values of mean pressure between males and females (83 ± 9 vs 84 ± 12 mmHg, p = 0.8). Despite this sex differences in SBP (121 ± 11 vs 114 ± 13 mmHg), CO (7.8 ± 2.0 vs 6.9 ± 1.5 L/min) and peripheral vascular resistance (PVR, 926 ± 325 vs 1026 ± 275 dynes.sec.cm5) still remained (p < 0.001 for all).

Conclusion

CO partially mediates the association between BSA and SBP in healthy young adults. However, sex differences in SBP and its haemodynamic determinants remain after accounting for differences in body size. In particular, for a given level of body size and mean BP, PVR is disproportionately higher, and CO disproportionately lower, in females, which warrants further investigation.
5.5 A Femoral ‘Stealing’ Effect: Presence of Collateral Retrograde Blood Flow Redistribution in the Femoral Bifurcation During Reactive Hyperemia
Authors: Au Jason , Amelard Robert , Yiu Billy , Nahas Hassan , Hughson Richard , Yu Alfred
Published: March 2020

Background & Purpose

The femoral bifurcation houses complex flow recirculation that may be impacted by downstream peripheral resistance; however, conventional ultrasound is unable to quantify multi-directional flow to study these phenomena. The purpose of this study was to examine the multi-directional behavior of blood in the femoral bifurcation during reactive hyperemia (RH) using vector flow imaging.

Methods

Nine healthy adults (25 ± 4 years; 5 men) underwent high-frame-rate ultrasound imaging of their right femoral bifurcation at rest, and during the first cardiac cycle of RH after 5-min of 200 mmHg calf occlusion. Multi-angle Doppler ultrasound was used to qualitatively describe vector blood flow at 750 fps [1]. The bifurcation region was isolated for blood vector dispersion analysis, an index of flow directionality [2].

Results

Blood flow during RH was characterized by near-constant anterograde blood flow to the superficial femoral artery (SFA), adjacent to low/oscillatory flow immediately proximal to the deep femoral artery (DFA) (Figure 1). We observed collateral blood flow redistribution in 3/9 participants, where blood from the DFA appeared to re-enter the SFA during the retrograde flow period. Bifurcation vector dispersion was reduced from baseline (0.53 ± 0.08 vs 0.67 ± 0.09; p < 0.01), but not eliminated, due to preservation of DFA flow reversal.

Conclusion

We demonstrate the presence of distinct, and potentially interacting, blood flow streams within the femoral bifurcation during RH. These observations were made possible by the emerging vector flow imaging technique to study complex hemodynamics in vivo, and suggest novel mechanisms by which blood is distributed to vascular beds, in extreme flow profiles.
5.6 Aortic Pressure Behind Flow Disorganization in Aneurismal Aorta: A Magnetic Resonance Imaging Study
Authors: Bouaou Kevin , Dietenbeck Thomas , Soulat Gilles , Houriez—Gombaud-Saintonge Sophia , Bargiotas Ioannis , De Alain Cesare , Gencer Umit , Giron Alain , Redheuil Alban , Bollache Emilie , Lucor Didier , Mousseaux Elie , Kachenoura Nadjia
Published: March 2020

Purpose

Understanding and prediction of ascending thoracic aortic aneurysms (ATAA) progression are not well established yet and aortic dissection is frequently occurring on normally sized and mildly dilated aortas. Despite known theoretical associations between pressures and blood flow patterns there are no studies focusing on their simultaneous evaluation. Our aim was to propose a comprehensive and quantitative evaluation of pressure-flow-wall interplay from 4D flow MRI in the setting of aortic dilation.

Methods

We studied 12 patients with ATAA (67 ± 14 years, 7 males) and 12 healthy subjects (63 ± 12 years, 8 males) who underwent 4D flow MRI. The segmented velocity fields were used to estimate: 1) local ascending aorta (AA) pressure changes from Navier-Stokes-derived relative pressure maps (AADP, mmHg), 2) AA wall shear stress (AAWSS, Pa) by estimating local velocity derivatives at the aortic borders, 3) aortic flow vorticity using the λ2 method (AAV, s-1).

Results

AA local pressure change (AADP) was significantly associated with both AAV (r = 0.55, p = 0.006) and AAWSS (r = 0.69, p < 0.001) and both associations remained significant after adjustment for diameter, age and BSA (p = 0.007 and p = 0.003 respectively). Such positive associations indicate that local pressure variations affect local blood flow, generating flow current from high to low pressures and subsequently vortices with the underlying stress exerted on the AA wall.

Conclusion

Local variations in aortic pressures, measured using 4D flow MRI, are associated with flow disorganization as quantified by vorticity and with the increase in the stress exerted on the aortic wall, as quantified by wall shear stress.
P1 Biomechanical Properties of the Aortic Dissection Flap in Chronic Aortic Dissection
Authors: Panpho Phakakorn , Davies Hannah , Field Mark , Madine Jillian , Yang Ying , Akhtar Riaz
Published: March 2020

Background

Aortic dissection is a devastating condition, beginning with a tear through from intima to the medial layer, leading to splitting of aortic layers and creating the false and true lumen with a septum (or flap). Little is known about the properties of the dissection flap.

Aim

To determine the time-dependent (creep) biomechanical behaviour and biochemical properties of the dissection flap.

Methods

15 descending thoracic aorta samples were obtained from patients undergoing elective surgery for chronic dissected aneurysms. Creep was measured using a non-destructive ball indentation technique utilising a stainless-steel ball over 5 hours. Images were obtained using a long focal distance objective microscope. Remaining tissues were used to determine elastin and glycosaminoglycan (GAG) levels.

Results

The elastic modulus (tissue stiffness) was 64.68 ± 11 kPa and 55.1 ± 9.5 kPa for the flap and true aortic wall respectively. Over 5 hours, the central deformation of the flap tissue was found to be 0.52 ± 0.07 mm as compared to 0.67 ± 0.07 mm for the true aortic wall (p < 0.05). Elastin levels were 126.8 ± 37.25 mg/mg for the flap and 79.82 ± 19.64 mg/mg for the true aortic wall (p < 0.05). The GAG levels were 4.2 mg/mg ± 0.9 mg/mg for the flap and 3.0 ± 0.5 mg/mg (p < 0.05).

Conclusion

The dissection flap exhibits reduced time-dependent deformation and has higher levels of elastin and GAG relative to the aortic wall. These findings may help develop bespoke surgical treatments based on the unique biomechanical and biochemical properties that have been identified.
P4 Aldosterone-Induced Vascular Dysfunction by Decreasing Nuclear Factor Erythroid 2—Related Factor 2 Activity and Increasing Reactive Oxygen Species Generation
Authors: Rodrigues Daniel , da Costa Tiago Januário , da Costa Rafael Menezes , de Passaglia Rita Cássia Aleixo Tostes
Published: March 2020

Introduction

Chronic increases in aldosterone (Aldo) levels (hyperaldosteronism) increases blood pressure and induces hypertension. In the cardiovascular system, Aldo stimulates reactive oxygen species (ROS) generation. ROS contribute to vascular dysfunction by increasing vascular smooth muscle contractile tone, among other effects. Nuclear factor erythroid 2–related factor 2 (Nrf2), it’s one of the main factors in the adaptive response to oxidative stress.

Hypothesis

Aldo negatively regulates the antioxidant system Nrf2, favoring ROS accumulation and subsequent vascular dysfunction.

Methods

Vascular function was evaluated in mice aortic conductance arteries, by performing concentration-effect curves to phenylephrine (PE) and acetylcholine (ACh). ROS production, determined by lucigenin and AmplexRed chemiluminescence, and Nrf2 activity by a nuclear translocation assay, were determined in endothelial cells (EA.hy926).

Results

Aldo increased PE contractions and decreased the relaxation response to ACh. L-sulforaphane, a Nrf2 activator, prevented Aldo-induced vascular dysfunction. In endothelial cells, Aldo increased ROS generation, i.e. superoxide anion and hydrogen peroxide, in a time-dependent manner. In addition, Aldo increased Nrf2 translocation at 30 min, 1 and 3 hours. However, after 3 hours, Aldo decreased Nrf2 translocation.

Conclusion

These data indicate that Aldo increases ROS in endothelial cells and causes impairment in vascular reactivity, events associated with decreased Nrf2 activity. Financial support: FAPESP (Process Number: 2018/05298-1), CAPES, CNPq. This study was approved by the Ethics Committee on Animal Experimentation of the Ribeirao Preto Medical School (030/2018).
P9 Repeatability and Predictors of a Potentially Blood Pressure-Independent Parameter of Arterial Stiffness
Authors: Butlin Mark , Cox James , Spronck Bart , Tan Isabella , Avolio Alberto
Published: March 2020

Background

Arterial stiffness (e.g., as measured by carotid-femoral pulse wave velocity (cfPWV)) changes acutely with blood pressure (BP). High cfPWV at high BP could be due to structural arterial changes or acute BP effects. Various parameters have been proposed as BP-independent parameters of arterial stiffness. These rely on assumptions to simplify theoretical calculations. This study evaluates a parameter quantifying BP dependency of cfPWV through BP manipulation, avoiding assumptions and mathematical derivations.

Methods

Brachial BP and cfPWV (SphygmoCor XCEL, AtCor Medical, Australia) were assessed in seated and supine position. The postural change invokes a systemic and hydrostatic BP change, thus changing cfPWV. ΔcfPWV/ΔBP was calculated. Repeatability was assessed in 25 participants (28 ± 11 years (mean ± SD), 52% female) across two visits on separate days. Cross-sectional correlation with age, gender, height, weight, seated BP, and supine cfPWV was assessed by stepwise linear regression across 135 participants (49 ± 23 years, 48% female).

Results

Mean ΔcfPWV/ΔBP was 0.061 ± 0.025 m/s/mmHg. Repeatability showed a between-measurement difference of 0.005 ± 0.028 m/s/mmHg (8.2% error on mean). ΔcfPWV/ΔBP was cross-sectionally correlated with seated diastolic BP (standardised β = −0.506, p < 0.001), systolic BP (β = 0.503, p < 0.001), weight (β = −0.220, p = 0.006), and heart rate (β = 0.178, p = 0.039) (model p < 0.05, r2 = 0.264).

Conclusion

ΔcfPWV/ΔBP showed fair repeatability. Notwithstanding accounting for BP, it correlated with typical long-term modifiers of arterial stiffness such as chronic elevated BP and weight. Further studies are required to validate if dividing ΔcfPWV by ΔBP, following acute intervention, creates an acceptable BP-independent arterial stiffness variable before the parameter is investigated for cardiovascular risk prediction to evaluate its clinical utility.
P10 Oscillatory Flow Patterns in Peripheral Conduit Artery are Related to Central Arterial Stiffness in Healthy Subjects
Authors: Badhwar Smriti , Chandran Dinu , Jaryal Ashok , Narang Rajiv , Patel Chetan , Deepak Kishore Kumar
Published: March 2020

Background

Studies in endothelial cell cultures show that oscillating flow pattern leads to endothelial dysfunction [1]. The only factor known to contribute towards oscillatory flows is peripheral arterial conductance [2]. However, contribution of alterations in central arterial properties to oscillatory flows is not established.

Methods

Healthy subjects (n = 28) (Age 51.0 ± 9.4 years) with resting retrograde flow in brachial artery were recruited for the study. Pulsed-wave doppler (M7, MindRay) was used for estimation of blood flow velocity with simultaneous diameter acquisition for shear rate calculation. Oscillatory Shear Index (OSI) was calculated by: Retrograde shear rate/(Anterograde shear rate + Retrograde shear rate). Local and regional central arterial stiffness was estimated using carotid distensibility, compliance and Incremental Elastic Modulus (IEM) (Medical Imaging Applications) and carotid-femoral Pulse Wave Velocity (PWV) using applanation tonometry (SphygmocorÒ) respectively. Peripheral vascular stiffness was assessed by carotid-radial PWV. Forearm vascular resistance was estimated using peripheral mean arterial pressure and mean anterograde flow. Carotid-Intima-Media-Thickness (CIMT) was measured using B-mode ultrasound for subclinical atherosclerotic burden estimation.

Results

Retrograde flow showed a significant positive correlation with IEM, CIMT and Augmentation Index (AI) (r = 0.64, 0.47 and 0.62 respectively) (Figures 1 and 2). A significant negative correlation was seen between retrograde flow and carotid compliance (r = −0.58). OSI correlated positively with IEM (r = 0.56) and AI (r = 0.45).

Conclusion

Results of the current study suggest that oscillatory flow patterns in peripheral conduit artery could originate due to decrease in central arterial compliance possibly because of its impact on the incident pressure wave.
P11 The Role of Smooth Muscle Integrin Alpha V and TGF-Beta Pathways in Vascular Fibrosis
Authors: Raoul Alexandre , Belozertseva Ekaterina , Louis Huguette , Li Zhenlin , Regnault Veronique , Lacolley Patrick
Published: March 2020

It has been demonstrated that arterial stiffness is linked to arterial fibrosis manifested by increased collagen and other extracellular matrix synthesis in smooth muscle cells (SMC). Transmembrane receptors integrins mediating cell-cell and cell-matrix signalling pathways are involved in tissue fibrosis. We study the role of one integrin subunit av in angiotensin II (AngII)-induced SMC proliferation and arterial fibrosis and stiffness using SMC specific knock-out av mouse model (avSMKO) induced in adult mice by injection of tamoxifen. There is no difference in vascular fibrosis in basal conditions between control and mutant mice. However, decreased arterial fibrosis is observed in avSMKO mutant mice after 28-day perfusion of AngII. Analysis of RNA from aorta of control and mutant mice by Affymetrix microarrays indicated an alteration of the TGF-β pathway in AngII-treated mutant mice. In order to examine the mechanism associated to the decreased fibrosis in vascular SMC from avSMKO mice, isolated VSMC from the aorta of control and avSMKO mice were treated with TGF-β1 or AngII. The results indicated that these two treatments increased the expression of collagen, fibronectin and integrin αν at the protein and RNA levels as well as the phosphorylation of ERK and smad2/3 in the control cells. Inactivation of integrin αν partly inhibited all above effects induced by TGF-β1 and AngII. Our study indicates a role of av and TGF-β1 in the arterial fibrogenesis. Therefore, av signaling could be a therapeutic target against arterial fibrosis and stiffness in pathological conditions.
P16 Assessment of Plaque Vulnerability Using a Novel Technique: Multi-spectral Photoacoustic Imaging (CVENT-PAI)
Authors: Imaizumi Yuki , Obeid Hasan , Julia Pierre , Calvet David , Boutouyrie Pierre
Published: March 2020

Background

Identification of intraplaque haemorrhage using magnetic resonance imaging (MRI) is expensive, technically demanding and sometimes uncomfortable. Photoacoustic imaging (PAI) is a new non-invasive technique combining multi-wavelength infrared laser light and ultrasound (US) imaging, able to discriminate blood and other components in the tissues. The measurement by the multi-spectral PAI is likely to be more applicable and therefore could be complementary to MRI.

Objectives

Validate a portable multimodal and multi-wavelength PAI system, for the identification of intraplaque haemorrhage and compare with MRI.

Materials and Methods

Patients underwent carotid MRI, and US. Photoacoustic acquisitions are performed and analysed a posteriori blindly of the status of the subjects and results of MRI/US. All patients gave written informed consent. Histology of plaque will be performed as gold standard.

Results

We included 15 patients (71 ± 5 years old) with carotid stenosis grade of >70% (NASCET). PAI imaging was feasible in all patients. On raw images, only clutter signal can be observed. After adequate post processing, carotid wall with the intima media and plaques were clearly visible with PAI. PAI signal from the lumen can be observed, also strong PAI signals are visible inside the plaque in a reproducible manner. Correspondence between MRI and PAI will be analysed later.

Conclusion

The use of the PAI technique for carotid plaque assessment is feasible, and PAI signal are observed inside the plaque. Further analyses are needed to assess the reflected PAI signal inside the plaque, for haemorrhage detection in the future.
P18 Vascular Aging Index of the Finger Photoplethysmogram: A Validation Study with Vascular Stiffness, Mental Stress, and Day-to-Day Variability
Authors: Tarumi Takashi , Yamabe Takayuki , Sugawara Jun
Published: March 2020

Background

Daily assessment of vascular health may predict cardiovascular incidence. Vascular aging index (VAI) calculated from second derivative of photoplethysmogram (SDPTG) is a simple, non-invasive measure possibly reflecting vascular stiffness. However, the effects of daily life events such as mental stress and day-to-day variability as well as its relation to other indices of vascular stiffness remain unclear.

Purpose

To determine whether VAI measured by finger SDPTG is 1) correlated with peripheral augmentation index (pAI), 2) altered by acute mental stress, and 3) affected by day-to-day variability.

Methods

Simultaneous measurements of finger photoplethysmogram and radial artery tonometry were performed in 68 healthy subjects (age = 22–64 years) of whom 31 subjects were further tested during a 30-second mental arithmetic and 10 subjects underwent day-to-day variability assessment for 5 consecutive days. VAI was calculated from a 20-second segment of photoplethysmogram data [1].

Results

At rest, VAI was positively correlated with pAI (r = 0.62, p < 0.001). During mental arithmetic, VAI increased when compared with the control condition (p = 0.032) whereas pAI did not show significant change. Five day measurements of VAI demonstrated the overall coefficient of variation of 21.1 ± 13.7% across all subjects.

Conclusion

VAI calculated from the finger SDPTG is related to a measure of vascular stiffness and sensitive to mental stress with fair day-to-day variability. These findings suggest that VAI assessment needs to be performed at the quiet resting condition.
P22 Central and Peripheral Contributions to Submaximal Exercise Performance in Older Adults in the SouthAll and Brent REvisited (SABRE) Study
Authors: Jones Siana , Schultz Martin , Tillin Therese , Williams Suzanne , Chaturvedi Nishi , Hughes Alun
Published: March 2020

Background

Functional capacity declines with age leading to disability and increased cost of health and social care. In older adults, factors that influence the ability to sustain sub-maximal exercise (a marker of functional capacity) are not well defined. We aimed to determine the contribution of cardiac function, skeletal muscle oxygen desaturation, extraction and oxidative capacity to sub-maximal exercise performance in a population-based sample of older adults.

Methods

Participants in the SABRE study undertook a 6-minute stepper test (6MST). Sub-maximal exercise performance was assessed as the highest achieved whole-body oxygen uptake (VO2) during the 6MST. Near Infrared Spectroscopy (NIRS) was used to locally assess skeletal muscle oxygen extraction, desaturation and maximum oxidative capacity. Echocardiography was used to measure cardiac function. Analysis was by multiple linear regression adjusted for confounders: age, sex, ethnicity, diabetes and obesity.

Results

395 participants (73.0 ± 6.3 years old, male; n = 229) undertook the 6MST, skeletal muscle desaturation measurements and echocardiography. Skeletal muscle desaturation and cardiac output were independently associated with whole-body VO2 (standardized β: −0.20, p < 0.001 & 0.47, p < 0.001, respectively). Local skeletal muscle oxygen extraction was independently associated with whole-body VO2 (standardized β adjusted for confounders & cardiac output: 0.32, p < 0.001). Maximum oxidative capacity was not associated with VO2 (β (95% CI: 0.02 (−0.01, 0.04), p = 0.152).

Conclusion

Local oxygen extraction and desaturation in skeletal muscle are independent predictors of sub-maximal exercise performance in older adults. These associations persist with adjustment for cardiac output suggesting local capacity to extract oxygen could be a major limiting factor functional capacity in older adults.
P24 Restored Physiological Local Carotid Pulse Wave Velocity After Bariatric Surgery in Obese Subjects
Authors: Giudici Alessandro , Morizzo Carmela , Kozakova Michaela , Losso Lorenzo , Palombo Carlo , Cruickshank Kennedy J. , Khir Ashraf
Published: March 2020

Obesity is a risk factor for cardiovascular events and is associated with increased arterial stiffness [1,2]. However, the effect of drastic changes in Body Mass Index (BMI) on arterial mechanics has not been fully investigated. Our study aimed at evaluating changes in local carotid PWV (cPWV) in obese patients before and 6 months after bariatric surgery. N = 20 obese subjects free of cardiovascular events and diabetes (44 ± 9 years, 5 men, BMI = 48.8 ± 7.5 kg/m2) undergoing bariatric surgery were recruited in the Pisa University Hospital (Italy). Flow and diameter waveforms were acquired by ultrasound scanner (Aloka Alpha10, Hitachi Group, Japan) (1 kHz) at the right common carotid artery at baseline, after a 32.4 ± 7.6 days diet period, and 6.5 ± 2.7 months post-intervention. The lnDU-loop method was used for the estimation of cPWV [3]. Basal cPWV was 6.05 ± 1.21 m/s. The 1-month diet period produced a 2 kg/m2 reduction in BMI, while cPWV decreased by approx. 0.6 m/s. 6–7 months after bariatric surgery, BMI dropped to 35.3 ± 6.5 kg/m2 and cPWV furtherly decreased of approx. 0.9 m/s reaching a mean value of 4.57 ± 1.02 m/s (76% of the basal value) (Figure 1). Bariatric surgery and the consequent intensive weight loss produced a significant decrease of arterial stiffness and restored cPWV to physiological values of age-matched healthy subjects [4]. The fast reversal of increased arterial stiffness suggests a functional mechanism possibly related to a reduced haemodynamic load. Moreover, while having a small effect on the BMI, 1-month diet regulation effectively decreased cPWV by 10%, possibly indicating the short-term positive effects of a healthy lifestyle on haemodynamics.
P36 Leukocyte Telomere Length is Inversely Associated with Wave Reflection in 566 Normotensive and Never-treated Hypertensive Subjects
Authors: Pörsti Ilkka , Honkonen Milja , Vääräniemi Kati , Saijonmaa Outi , Tikkakoski Antti , Koskela Jenni , Eräranta Arttu , Kähönen Mika , Mustonen Jukka , Fyhrquist Frej
Published: March 2020

Background

Telomeres are short segments in chromosome ends, the length of which is reduced during cell life-cycles. We examined the association of leukocyte telomere length and short telomere proportion with hemodynamic variables.

Methods

Altogether 566 subjects (279 women and 287 men) without cardiovascular disease and medications with direct cardiovascular influences were subjected supine recordings for 5 minutes. Haemodynamics were captured using continuous tonometric pulse wave analysis and whole-body impedance cardiography. The analyses were adjusted for age, body mass index (BMI), alcohol use, smoking, plasma chemistry, and estimated glomerular filtration rate (eGFR).

Results

In univariate analyses, leukocyte telomere length correlated with age, BMI, eGFR, aortic blood pressure, augmentation index, pulse wave velocity, and systemic vascular resistance (p < 0.05 for all). Short telomere proportion correlated with age, BMI, eGFR, aortic systolic blood pressure, augmentation index, and pulse wave velocity (p < 0.05 for all). In linear regression analyses of all hemodynamic variables, leukocyte telomere length was only an independent explanatory factor for augmentation index (Beta −0.006, p = 0.032), while short telomere proportion was not an explanatory factor for any of the hemodynamic variables, in contrast to age, BMI and several cardiovascular risk factors.

Conclusion

Augmentation index was predominantly related with chronological aging, but also with leukocyte telomere length, suggesting that this variable of central wave reflection is a moderate marker of vascular biological aging.
P38 Association of Daytime Augmentation Index with Brain-derived Neurotrophic Factor in Untreated Hypertensive Patients
Authors: Nemcsik János , Batta Dóra , Kőrösi Beáta , Nemcsik-Bencze Zsófia , László Andrea , Lénárt Lilla , Fekete Andrea
Published: March 2020

Brain-derived neurotrophic factor (BDNF) is a neurotrophic molecule with impact on microvasculature and also with complex psychosomatic connections. The aim of our study was to evaluate its associations with 24-hour brachial and central hemodynamic parameters and arterial stiffness in untreated patients who were studied because of elevated office blood pressure. Mobil-O-Graph was used to measure the 24-hour brachial and central parameters. Serum BDNF was measured with ELISA, depression and anxiety were evaluated with questionnaires (Beck Depression Inventory and Hamilton Anxiety Scale, respectively). 73 patients were involved into the study. The average serum BDNF level was 28610 ± 7965 pg/ml. SeBDNF was correlated with daytime augmentation index (Aix, r = 0.234, p = 0.046). A borderline correlation was found with 24-hour total peripheral resistance (r = 0.227, p = 0.053). In multiple linear regression model the association between Aix and BDNF remained significant after the adjustment for age, depression and anxiety (B = 0.243, p = 0.034), but was attenuated after further adjustment for total vascular resistance (B = 0.186, p = 0.106). In conclusions, the impact of BDNF on microvasculature can have physiological importance as through the mediation of total vascular resistance it can influence pulse wave reflection.
P41 24 h Arterial Stiffness Measurement on Healthy and COPD Patients
Authors: Böcskei R. M. , Benczúr B. , Bikov A. , Böcskei Cs. , Bohács A. , Husznai R. , Cziráki A.
Published: March 2020

Introduction

Chronic obstructive pulmonary disease (COPD) is currently one of the leading causes of death worldwide. COPD frequently occur together with cardiovascular disease. The coexistence of the two diseases are associated with worse outcomes than either condition alone. ABPM and 24 h arterial stiffness parameters were measured in stabile COPD patients, who were free from any cardiovascular disease and control individuals for the detection of increased cardiovascular risk and for the detection of early atherosclerosis in COPD.

Methods

We measured 23 healthy (54 ± 9.1 years) and 26 COPD (57 ± 9 years) subjects in the study. ABPM and 24 h arterial stiffness parameters were oscillometrically measured with Arteriograph 24.

Results

We have found significant higher day- and night averages in systolic blood pressure (SBPbr) {p = 0.032, p < 0.001} systolic aortic blood pressure (SBPao) {p < 0.001, p < 0.001} aortic pulse wave velocity (PWVao) {p < 0.001, p < 0.001} and aortic augmentation index (Aixao) {p < 0.001, p < 0.001} in COPD patients than controls. In 26% of COPD patients did not reduced the nighttime blood pressure compared to daytime systolic blood pressure.

Conclusion

In this study we found elevated day- and night blood pressure and arterial stiffness parameters in COPD patients. These results are indicating the presence of earlier atherosclerosis and higher cardiovascular risk in patients with COPD than in control individuals.