Significant Dip Research Articles

EXERCISE AS MEDICINE; CHRONOTHERAPY IN HYPERTENSION MANAGEMENT

Objective: Adequate blood pressure regulation is a critical target in the management of hypertension and CVD. Circadian rhythms are increasingly recognized for their impacts on health outcomes including vascular function and metabolism. We posited that optimized exercise combined with chronotherapy will lead to meaningful improvements in BP, vascular health, and cardiovascular outcomes by coordinating the timing of interventions with diurnal rhythms. Design and method: Our studies, funded by National Institute of Health (NIH), are focused on ambulatory BP monitoring (ABPM) to capture circadian variations in BP, including nocturnal BP and morning surge. In particular, the project focuses on the efficacy of physical activity to improve nocturnal BP. We are using a 48-hr period of ABPM to reliably access nocturnal BP, which has not been implemented in other exercise studies focusing on ambulatory BP, in addition to measuring sleep with actigraphy. Given nocturnal BP is recognized as a strong indicator of cardiovascular health and outcomes, examining how interventions modify this ambulatory BP outcome is needed to understand the effect of the intervention on health and future risk. Results: Our preliminary data on all non-Hispanic 22 female subjects included 7 African Americans with average age of 68 and average BMI of 30.6. Mean seated BP (all BP values reported in mm of Hg) was 135/73 while awake BP from ABPM was 135/76 and awake central BP (calculated with device using a proprietary algorithm) was 126/78. Mean asleep BP determined from analysis of wrist actigraphy data was 117/61 and mean asleep central BP was 112/64. Mean nocturnal BP (calculated by average of the 4 lowest systolic blood pressure measures during the asleep period, waiting at least 1 hour after going to bed) was 116.7/61.6. Average nocturnal systolic dip was 30.4 and nocturnal diastolic dip was 14.4 with percentage nocturnal dips at 20.3% and 14.2% respectively. Conclusions: In our preliminary results, we found that evening exercise as chronotherapy in hypertensive post-menopausal patients showed significant nocturnal dipping of blood pressure.

An Episode of Occultation Events in Gaia21bcv

A previously unremarkable star near the Canis Major OB1/R1 association underwent an episode of multiple deep brightness minima. Light curves based on archival Gaia, Zwicky Transient Facility (ZTF), and NEOWISE data and additional observations from the Las Cumbres Observatory and UKIRT show that the star was not variable prior to 2019 August 18 (MJD 58700), and on that date started showing brightness dips of up to 3 mag in the Gaia G and ZTF r bandpasses. After MJD 59500, ≈800 days after the onset of these dipping events, the star returned to its previous brightness, and no significant dipping events have been recorded since. Compared to the stable phase, NEOWISE IR photometry in the W1 and W2 bands indicates a generally redder color, and both decreases and increases in brightness at different times during the dipping episode. The spectrum of Gaia21bcv taken after the end of the dipping episode shows several neutral and ionized metal absorption lines, including Li, indicating a spectral type of ≈K5. Variable emission from [O i] was observed. The Hα absorption in Gaia21bcv is too faint and irregular for this spectral type, indicating that the line is partly filled in by variable emission, a signature of weak episodic accretion. Gaia21bcv lies above the zero-age main sequence, but is much fainter than typical R CrB stars. We interpret the light curve of Gaia21bcv as being similar to the occultation events in ϵ Aurigae, i.e., occultation by a disk around a companion object orbiting the primary star.

Local coupled Markov chain model for simulating varied stratigraphy

The coupled Markov chain (CMC) model is widely employed to simulate geological uncertainty based on sparse borehole data, owing to its simplicity, parameter efficiency, and computational effectiveness. However, the existing CMC methods exhibit limitations in accurately predicting the orientation and significant dip angle changes of soil stratigraphy. These limitations stem from their reliance on a globally constant Walther constant, resulting in generated layer boundaries converging to a fixed angle. To address these issues, this study develops a local CMC model to enhance the accuracy of predicting layer sequences and describe the geological uncertainty of complex geological structures using limited borehole and surface data. In the proposed local CMC method, the global geological profile is decomposed into interconnected fragments, guided by reference boreholes. For each CMC fragment, the likelihood of observational scenarios is determined to identify the layer orientation and optimal Walther’s constant corresponding to the local geological profile. By combining the most likely realizations from all CMC fragments, the final geological profile and stratigraphic uncertainty are obtained. Illustrative case studies demonstrate that the proposed approach effectively addresses the limitations of conventional CMC models in accurately simulating significant changes in layer orientation and dip angle variations, given the same conditions of sparse borehole data. The employed localization strategy enables the prediction of geological profiles that encompass special layers such as soil interlayers, anticlines, and synclines, which cannot be well achieved by conventional CMC models. The local CMC model significantly improves the matching accuracy of geological model in situations with limited boreholes. Therefore, it plays a crucial role in the analysis of geological structures under data-scarce conditions.

3D mineral prospectivity modeling in the Sanshandao goldfield, China using the convolutional neural network with attention mechanism

Mineralization distribution is spatially heterogeneous and jointly controlled by multiple ore-controlling factors. Given this ubiquitous feature, we integrated the attention mechanism of the Convolutional Block Attention Module (CBAM), which contains both channel and spatial attention modules, into a convolutional neural network (CNN) to develop a more robust 3D mineral prospectivity modeling (MPM) approach. A network interpretive algorithm (DeepLIFT) was conducted to the CNN deconstruction to evaluate whether the key ore-controlling information is read. The Sanshandao goldfield in China, with significant fault controls on gold mineralization distribution, was selected as a case study to verify the proposed method. In this case, we generated the 5-channel images by projecting five ore-related fault features to feed into CNN. The optimal prospectivity model of CNN + CBAM was subsequently yielded by a gradient-based optimization of stochastic objective functions and an optimized regularization cross-entropy loss function. By decomposing the constructed model and the vanilla CNN model, we observed the CNN + CBAM has lower feature scores of fault distance and larger scores of fault geometry (e.g., dip and undulation) at Xiling, Haiyu, and Xinli than CNN. These segments occur significant fault strike or dip changes that have influenced mineralization spatial continuity, which is well consistent with the expert knowledge of metallogeny in the Sanshandao goldfield. This means that the CBAM has induced the CNN to focus on key ore-controlling features from complex exploration data, which is likely to improve the model’s prediction ability. The prospectivity results of CNN + CBAM and other comparison shallow machine learning methods (e.g., random forest) revealed that the CNN + CBAM model produced more reliable results, as evidenced by (1) being highly consistent with known mineralization, (2) having the highest AUC values and success rate, and (3) accurately predicting deep voxels that have been explored by drill holes. Thus, the proposed CNN + CBAM method, with a remarkable capacity for emphasizing critical ore-associated features, is recommended for application in deep 3D MPM. Six possible mineralization sites in the Sanshandao field were identified based on the CNN + CBAM prospective data, which may aid future gold exploration.

Permeability evolution and production characteristics of inclined coalbed methane reservoirs on the southern margin of the Junggar Basin, Xinjiang, China

The thick and steeply inclined coal seams of the Junggar Basin of Xinjiang, China, are unique with dip angles generally >50° but over the range 0°–85°. Initial and evolving permeability and pressures change drastically around wells down-dip within the steeply inclined reservoir as a result of the depth differential. Hence, the evolution of permeability and fluid pressures during drainage exhibits significant differences from those of flat-lying or even slightly inclined reservoirs. We apply a hydro-mechanical model to evaluate the interaction of two-phase flows of gas and water in the inclined system. The influence of different reservoir inclinations (15°, 30°, 45°, 60°, and 75°) on the evolution of permeability, reservoir pressure, and gas production are explored through finite element modeling of this system. The results show that: 1) Reservoir inclination induces differences in permeability, reservoir pressure, gas content and methane production between the shallower updip reservoir and deeper downdip reservoir. The difference in permeability between the updip and downdip reservoirs is amplified as the dip angle increases and as drainage proceeds in the presence of the varying stress gradient. 2) An apparent asymmetric distribution of reservoir pressures results for wells along dip. The difference in reservoir pressure between the updip and downdip reservoirs intensifies as the inclination increases but lessens with the progress of drainage. The larger the dip angle, the smaller the final reservoir pressure. 3) The pressure reduction in the updip reservoir is larger than that in the downdip reservoir, resulting in the unsynchronized desorption of methane in the updip and downdip reservoirs. Methane within the updip reservoir desorbs preferentially over that in the downdip reservoir. For reservoir dip angles <45° a single peak in methane production rate is apparent but this is supplanted by dual peaks for inclinations >45°. The time gap in gas desorption between the updip and downdip reservoirs results in the “dual-peak” on gas production profile. 4) A larger well spacing along the dip of a more highly inclined reservoir results in more efficient water drainage and gas production. An inverted trapezoidal well pattern is recommended to facilitate the drainage and gas production of reservoirs with significant dip angles.

Postharvest quality evaluation on the hot water-dipped Zingiber officinale rhizomes stored at low-temperature storage

Storing ginger at chilling temperature will reduce its postharvest quality as they are prone to chilling injury (CI). Therefore, a study on hot-water dip treatment in alleviating CI in 'Bentong' ginger rhizome on physical and chemical properties was conducted. Fresh ginger rhizomes were harvested in the 9th month after planting. The fresh and cleaned rhizomes were hot-water treated at 45°C for 0, 5, 10 and 15 mins before being packed in a box and stored at 5°C for 0, 8 and 16 days. There was a significant interaction effect between dipping and storage durations on the physical and chemical properties of the rhizome. Exposed rhizome for 5, 10 and 15 mins was observed to maintain the ho and L* of the rhizome after storage at 5°C. The decreases in h° from yellow to slightly brown also indicated rhizome browning. Rhizome held at 45°C for 5 mins managed to reduce browning as compared to other durations. In addition, dipping for 15 mins resulted in a significant increase in total phenolic content, total flavonoid content and 6-gingerols. While 6-shogaols was maintained at 45°C for 5 mins. Preconditioning by the hot-water treatment could induce chilling tolerance upon storage at chilling temperature.

Fabrication of Cu grating guided-mode resonance filter by electroplating

A polarization wavelength filter was fabricated using two-beam interference and electroplating methods. The device consists of a Cu grating with a pitch of 400 nm on an ITO film. For normal incidence, the transverse magnetic (TM) transmission spectrum had a sharp spectrum at a wavelength of 648 nm and a significant dip at 735 nm. Furthermore, a sharp reflection spectrum in TM-light was obtained at a 685 nm wavelength and incident angle of 40°, and the peak wavelength shifted to a longer wavelength as the incident angle increased. This fabrication method is less complex and inexpensive than conventional methods.

Chromium contamination accentuates changes in the microbiome and heavy metal resistome of a tropical agricultural soil.

The impacts of hexavalent chromium (Cr) contamination on the microbiome, soil physicochemistry, and heavy metal resistome of a tropical agricultural soil were evaluated for 6 weeks in field-moist microcosms consisting of a Cr-inundated agricultural soil (SL9) and an untreated control (SL7). The physicochemistry of the two microcosms revealed a diminution in the total organic matter content and a significant dip in macronutrients phosphorus, potassium, and nitrogen concentration in the SL9 microcosm. Heavy metals analysis revealed the detection of seven heavy metals (Zn, Cu, Fe, Cd, Se, Pb, Cr) in the agricultural soil (SL7), whose concentrations drastically reduced in the SL9 microcosm. Illumina shotgun sequencing of the DNA extracted from the two microcosms showed the preponderance of the phyla, classes, genera, and species of Actinobacteria (33.11%), Actinobacteria_class (38.20%), Candidatus Saccharimonas (11.67%), and Candidatus Saccharimonas aalborgensis (19.70%) in SL7, and Proteobacteria (47.52%), Betaproteobacteria (22.88%), Staphylococcus (16.18%), Staphylococcus aureus (9.76%) in SL9, respectively. Functional annotation of the two metagenomes for heavy metal resistance genes revealed diverse heavy metal resistomes involved in the uptake, transport, efflux, and detoxification of various heavy metals. It also revealed the exclusive detection in SL9 metagenome of resistance genes for chromium (chrB, chrF, chrR, nfsA, yieF), cadmium (czcB/czrB, czcD), and iron (fbpB, yqjH, rcnA, fetB, bfrA, fecE) not annotated in SL7 metagenome. The findings from this study revealed that Cr contamination induces significant shifts in the soil microbiome and heavy metal resistome, alters the soil physicochemistry, and facilitates the loss of prominent members of the microbiome not adapted to Cr stress.

Influence of ground anchors corrosion and uncertainty strength parameters: A case study slope failure in northern Taiwan

A significant fatal scale dip slope failure incident occurred at The Freeway No.3, located in Northern Taiwan, on April 25, 2010. From the post-failure investigations, it is found that the deteriorating anchor systems and uncertainties in strength parameters as the most likely the primary reasons for this slope failure. This study main conducted a numerical modeling work using Universal Distinct Element Code (UDEC), a two-dimensional numerical program based on the distinct element method for discontinuum modeling. First, the numerical modeling was generated to check the original design of this dip slope failure. Then a series of parametric studies were introduced to investigate the influences of the triggering design factors that affected this slope-failure event. The ground anchor failure order in this slope is also assessed by bracketing approach and strength-reduction method using a new term called “Adjusted Factor”. Furthermore, this study will focus on an anchors’ failure order from the perspective of the random field to assess whether the anchors’ failure mechanism considering the random field will match or be closely similar to the anchor failure order in the field.

Abstract 1200: Aurora kinase A is a potential therapeutic target regulated by the MYCN oncogene in human retinoblastoma

Abstract Retinoblastoma (RB) is a pediatric intraocular neoplasm characterized by loss of function mutations in the RB1 gene. RB has a near-perfect prognosis in developed countries, but a significant dip in patient survival is observed in low and middle-income nations, with an overall survival rate of around 40%. Chemotherapy is a primary treatment modality in RB. However, the immediate and long-term side effects of conventional and intra-arterial chemotherapies necessitate the need for additional treatment options. Aurora kinases are serine/threonine kinases that play a pivotal role in mitosis. In recent years, Aurora kinase A (AURKA) has gained prominence as a drug target in various tumors and several small molecule inhibitors of AURKA are currently in clinical development. In this study, we have shown that AURKA is overexpressed in RB patient specimens and cell lines using immunohistochemistry and immunoblotting. Moreover, induced expression of AURKA significantly correlated with optic nerve invasion of the tumor suggesting a role of AURKA in RB progression. Inhibition of AURKA in RB cell lines and patient specimens using small molecule inhibitors or selective silencing with lentivirus-mediated shRNA knockdown led to decreased cell viability, increased apoptosis, cell cycle arrest at G2/M phase and subsequent induction of polyploidy. To further investigate the deleterious effects of AURKA inhibition within the tumor microenvironment, chorio-allantoic membrane (CAM) xenografts with RB cells were performed. The in-ovo data revealed a delay in tumor growth when treated with AURKA inhibitors. MYCN is an essential oncogene in RB progression immediately to RB1 mutations. Notably, an in-silico promoter analysis predicted the presence of MYCN binding sites upstream of the transcription start site of AURKA. Chromatin immunoprecipitation - qPCR (ChIP-qPCR) confirmed the binding of MYCN to the promoter region of AURKA. Besides, immunoblots corroborated that AURKA was downregulated in MYCN knockdown RB cells. Overall, our findings show that elevated AURKA levels in RB could be targeted in-vitro and in-ovo, and its expression is transcriptionally regulated by the MYCN oncogene. These data not only shed light on the role of AURKA in RB tumorigenesis but also unravel its potential as a therapeutic target, in isolation or through MYCN-driven downstream pathways. Acknowledgements: Department of Biotechnology - Innovative Young Biotechnologist Award (DBT-IYBA to MMR), Ministry of Science and Technology, Government of India; Hyderabad Eye Research Foundation (HERF), L V Prasad Eye Institute, Bhubaneswar, India; Indian Council of Medical Research - Senior Research Fellowship (ICMR-SRF to NAB), Ministry of Health and Family Welfare, Government of India. Citation Format: Naheed Arfin Borah, Ruchi Mittal, Devjyoti Tripathy, Swathi Kaliki, Suryasnata Rath, Srinivas Patnaik, Mamatha M. Reddy. Aurora kinase A is a potential therapeutic target regulated by the MYCN oncogene in human retinoblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1200.

High-power supercontinuum lasers with a flat blue spectrum through pump modulation: a numerical study.

We numerically investigate high-power, modulational instability-based supercontinuum sources. Such sources have spectra that reach the infrared material absorption edge and as a result the spectrum has a strong narrow blue peak (dispersive wave group velocity matched to solitons at the infrared loss edge) followed by a significant dip in the neighboring longer-wavelength region. In a wide range of applications one prefers a broader and more flat blue part within a certain minimum and maximum power spectral density. From the perspective of fiber degradation it would be desirable to achieve this at reduced pump peak powers. We show that it is possible to improve the flatness by more than a factor of 3 by modulating the input peak power, although this comes at the expense of slightly higher relative intensity noise. Specifically, we consider a standard 6.6 W, 80 MHz supercontinuum source with a 455 nm blue edge, which uses 7 ps pump pulses. We then modulate its peak power to generate a pump pulse train having two and three different sub-pulses.

Particle shape effect on the structural evolution and force propagation inside the three-dimensional sandpile.

This paper employs the discrete element method to examine the impact of particle shape on the pressure dip phenomenon and structural characterization of the three-dimensional sandpiles. Particular attention has been given to the underlying mechanism in the sandpile, which arises from the interplay of the initial created structure and the induced changes in the subsequent deposition process. Different aspect ratios produced different initial local geometry. The contact vector and strong contact force rotated away from the z-axis when the aspect ratio deviates from 1.0. The flat particles had a better memory of initial structures under the subsequent deposition process, which plays a vital role in force transmission and stress propagation. However, when the aspect ratio approaches 1.0, the stress state behaves as a joint result of maintained and gained contacts. For a certain range of aspect ratios, the newly generated interactions of elongated particles induced the major stress in the horizontal plane, which thus produces a significant pressure dip phenomenon. The results indicated that complex models accounting for contact creation are required to capture the pressure profile.

Coseismic displacement fields and the slip mechanism of the 2021 Mw 6.7 Hovsgol earthquake in Mongolia constrained by Sentinel-1 and ALOS-2 InSAR

ABSTRACT On 11 January 2021, an Mw 6.7 earthquake, which involved a complex rupture mechanism, occurred in Lake Hovsgol, Mongolia. This study measured the earthquake’s 3-D coseismic surface displacement fields using interferometric synthetic aperture radar (InSAR) pairs of three radar look directions: Sentinel-1B from the descending path and Advanced Land Observing Satellite-2 from the ascending and descending paths. The three DInSARs showed that the maximum coseismic surface displacement appeared east of the Northern Hovsgol Fault (NHF), where the displacement components were 18 cm, 5 cm, and 33 cm in the east–west, north–south, and up–down directions, respectively (precision: 1.7 cm, 20.4 cm, and 5.2 cm). However, the 3-D displacements indicated that although the earthquake induced a combination of normal faulting with strike slip motions, the displacements in the north–south direction had very large uncertainty owing to the similar geometry of the InSARs in the descending path. Later, we performed inversions of the DInSAR-measured coseismic surface displacement fields in the line-of-sight direction, which assumes a fault plane’s uniform and distributed slips in analyzing the slip mechanism. We conducted slip distribution estimations on the ruptured fault plane in accordance with the optimal fault geometry and source parameters determined by the uniform slip model. Investigations revealed that, with a correlation of 95.3%, the simulated displacements from the best-fitted distributed slip model were consistent with the observed displacements from DInSARs. Besides, our slip distribution model showed two distinctive slip patches, which include differences in their magnitudes and directions on the fault plane. We also observed ruptured faults experiencing a predominant right-lateral strike slip with a significant dip slip, according to the slip distribution, which caused two distinct slips due to the dramatic bending of the fault strike. Then, by analyzing the Coulomb stress change, our findings proposed that the seismic risk potential of active faults in the Hovsgol Basin increased after the earthquake. Overall, the great potential of multi-track DInSAR observations in the identification of complex slip mechanisms was demonstrated.

Coseismic Rupture Behaviors of the January and March 2022 MW &gt; 5.5 Hala Lake Earthquakes, NE Tibet, Constrained by InSAR Observations

On 23 January and 25 March 2022, two MW &gt; 5.5 Hala Lake earthquakes characterized by right-lateral strike-slip faulting occurred around the Elashan Fault in Northeastern Tibet, marking the two largest events since the 1927 MW 6.2 Hala Lake earthquake. Since no surface rupture related to the two earthquakes has been reported, the seismogenic faults and coseismic rupture behaviors of the two events are still unknown. The occurrence of the two events provides a rare opportunity to gain insight into the seismogenic structure and rupture behavior of the less studied region, further helping us accurately evaluate the regional seismic hazard. Here, we first exploit Interferometric synthetic aperture radar (InSAR) data to obtain the coseismic deformation associated with the two earthquakes and then invert for the fault geometry and detailed coseismic slip of the two events. Coseismic modeling reveals that the January and March 2022 earthquakes ruptured two buried west-dipping moderate-angle and high-angle right-lateral strike-slip faults, respectively. Most of the slip of the January event occurred at depths from 1.7–7.6 km, while the majority of the slip associated with the March event occurred at depths from 2.5–10 km, which may have been restricted by the intersections between the January and March Hala Lake seismogenic faults. By a comprehensive analysis of the coseismic inversions, stress changes, and early postseismic signal, we suggest that the significant fault dip difference (~30°), highlighting a fault segmentation, stops the rupture propagation from one fault segment to another and that fluid migration may encourage the restart of the rupture of the later event, which requires further investigation. Moreover, Coulomb stress modeling shows stress loading on the eastern segment of the Daxueshan–Shule Fault and the northern segment of the Elashan fault, which we should pay more attention to.

Establishing a hyperacute stroke service during the COVID-19 pandemic: our institution’s one year experience

Background and aimsThe corononavirus 2019 (COVID-19) pandemic resulted in modifications in the workflow and redistribution of human resources, causing challenges in setting up of an acute stroke service. We would like to share our preliminary outcome amid this pandemic, to determine if the implementation of COVID-19 standard operating procedures (SOPs) affected the delivery of our hyperacute stroke service.MethodsWe retrospectively analyzed one-year data from our stroke registry that began with the establishment of our hyperacute stroke service at Universiti Putra Malaysia Teaching Hospital from April 2020 until May 2021.ResultsSetting up acute stroke services during the pandemic with constrained manpower and implementation of COVID-19 SOPs, was challenging. There was a significant dip of stroke admission from April to June 2020 due to the Movement Control Order (MCO) implemented by the government to curb the spread of COVID-19. However, the numbers of stroke admission steadily rose approaching 2021, after the implementation of recovery MCO. We managed to treat 75 patients with hyperacute stroke interventions i.e. intravenous thrombolysis (IVT), mechanical thrombectomy (MT) or both. Despite implementing COVID-19 SOPs and using magnetic resonance imaging (MRI) as our first line acute stroke imaging modality, clinical outcomes in our cohort were encouraging; almost 40% of patients who underwent hyperacute stroke treatment had early neurological recovery (ENR), and only 33% of patients had early neurological stability (ENS). In addition, we were able to maintain our door-to-imaging (DTI) and door-to-needle (DTN) time in line with international recommendations.ConclusionsOur data reflects that COVID-19 SOPs did not deter successful delivery of hyperacute stroke services in our center. However, bigger and multi center studies are required to support our findings.

Longevity, Centenarians and Modified Cellular Proteodynamics.

We have shown before that at least one intracellular proteolytic system seems to be at least as abundant in the peripheral blood lymphocytes of centenarians as in the same cells of young individuals (with the cells of the elderly population showing a significant dip compared to both young and centenarian cohorts). Despite scarce published data, in this review, we tried to answer the question how do different types of cells of longevous people-nonagenarians to (semi)supercentenarians-maintain the quality and quantity of their structural and functional proteins? Specifically, we asked if more robust proteodynamics participate in longevity. We hypothesized that at least some factors controlling the maintenance of cellular proteomes in centenarians will remain at the "young" level (just performing better than in the average elderly). In our quest, we considered multiple aspects of cellular protein maintenance (proteodynamics), including the quality of transcribed DNA, its epigenetic changes, fidelity and quantitative features of transcription of both mRNA and noncoding RNAs, the process of translation, posttranslational modifications leading to maturation and functionalization of nascent proteins, and, finally, multiple facets of the process of elimination of misfolded, aggregated, and otherwise dysfunctional proteins (autophagy). We also included the status of mitochondria, especially production of ATP necessary for protein synthesis and maintenance. We found that with the exception of the latter and of chaperone function, practically all of the considered aspects did show better performance in centenarians than in the average elderly, and most of them approached the levels/activities seen in the cells of young individuals.

Eddy Current Loss Reduction in Axial-Flux Motors Using 3D Printing

As more electrification and emission-free transportation trends receive more attention, electrical systems applied in the aircraft and automotive industries are changing from fossil fuel and hydraulic systems to electric AC machine drive systems. Three-dimensional printing technology has been contributing to a new design of machines, because it provides many opportunities without limitation compared to the conventional manufacturing system. Although 3D printing technology opened a door for increasing the efficiency and power density of AC machine drives with low conduction loss, an optimal design process for eddy current loss reduction is required, because eddy current loss is affected by the design structure of the machine. The slit structure at the stator shoe is proposed to reduce eddy current loss. With the three variables, the number of slits, the thickness of slits, and the length of ribs, a parametric analysis was conducted to find an optimal design with eddy current loss reduction without a significant performance dip. The optimal design provides an 18.75% decrease in eddy current loss.

Широкополосное излучение суперлюминесцентных диодов на основе многослойных структур с квантовыми яма-точками InGaAs/GaAs

We have studied superluminescent diodes with simplified design and active region based on 5 or 7 layers of InGaAs/GaAs quantum well-dots (QWDs). Emission peaks of the individual QWD layers are shifted with respect to each other by 15-35 nm to provide as wide as possible emission line in a superluminescent mode with central wavelength of about 1 µm without significant spectral dips. For superluminescent diodes with the active region based on 5 and 7 QWD layers, the maximal value of full width at half maximum of emission spectrum was 92 and 103 nm respectively.

PS-BPR02-6: NOT FOR THE FAINT OF HEART: A CASE REPORT OF BRADYCARDIA INDUCED HYPERTENSION

Background: Bradycardia is an underreported and often overlooked contributor to resistant hypertension. We present a case of refractory hypertension and bradycardia with atrial fibrillation and marked improvement in BP control following pacemaker implantation. Case Presentation: A 66-year-old asymptomatic Chinese male with a past history of hypertension with unilateral adrenalectomy (no hyperaldosteronism), remote myocardial infarction, treated obstructive sleep apnea, and type 2 diabetes presented with gradually increasing blood pressure (BP) and decreasing heart rate (HR). From 2019 to 2020, his 24-hour ambulatory BP average increased from 140/49 mmHg to 188/66 mmHg with a decrease in HR from 55 to 43 bpm; there was no significant nocturnal dipping. Home and office BPs were similar. Daily medications included candesartan 64 mg, amlodipine 20 mg, chlorthalidone 50 mg, spironolactone 50 mg, doxazosin 8 mg, hydralazine 300 mg, nitropatch 0.8 mg/hour, and kayexalate for persistent hyperkalemia. Medication adherence was confirmed by a pharmacy database review. Secondary hypertension workup was negative for Cushing's Disease, pheochromocytoma, and renal artery stenosis. Plasma aldosterone was undetectable and plasma renin activity was 1.95 (normal 0.10–1.10ng/L/s) while taking the above medications. Serial 24-hour Holter monitors captured sinus bradycardia without pauses. Echocardiogram revealed concentric left ventricular (LV) hypertrophy, left atrial enlargement, and LV ejection fraction of 55%. Subsequent 2-week Holter monitoring revealed atrial fibrillation with average HR of 44 bpm and multiple prolonged ventricular pauses (longest 5.1 seconds). Following pacemaker insertion, BP normalized to an average of 130/80 mmHg with only 3 agents. Conclusion: There is a paucity of literature on severe bradycardia resulting in resistant hypertension; the English language PubMed database documents 3 reported cases. Severe bradycardia may impair cerebral and renal blood flow, increase LV filling pressures through prolonged diastole causing greater ventricular stretch and increased force of contraction, and may alter arterial stiffness. This case demonstrates a rare but important phenomenon of refractory hypertension and bradycardia with marked improvement in BP control following pacemaker insertion. It is important that physicians are aware of this potential phenomenon when evaluating patients with resistant hypertension and bradycardia.

PS-C12-12: EFFECT OF CHRONOTHERAPY ON BLOOD PRESSURE VARIABILITY IN HYPERTENSIVE AND CHRONIC KIDNEY DISEASE ADULT PATIENTS IN NIGERIA

Background: Blood pressure is synchronized predictably with the circadian activity-rest cycle. Few available studies have shown that chronotherapy may improve blood pressure variability (BPV) among hypertensive and chronic kidney disease patients. Empirical evidence is lacking among Nigerians. Objective: This study ascertained the effect of chronotherapy (taken as the use of antihypertensive medications at bedtime) on BPV of adult patients aged 18 years and above diagnosed with hypertension (control) and chronic kidney disease (CKD) using ambulatory blood pressure monitoring over three months follow up. Design and method: We conducted a retrospective analysis of data of respondents included in the Ibadan Ambulatory Blood Pressure Registry (IABPR) at the University College Hospital, Ibadan, Nigeria. Sociodemographic characteristics, lifestyle habits, and anthropometric measurements were obtained. Paired t-test was used to test the differences in the mean BP parameters before and after the study at p 0.05. Results: There were 52 respondents, 24 hypertensive controls (mean age 58.6 ± 11.3years) and 28 CKD patients (mean age 45.2 ± 11.1years). The hypertensive controls had significantly reduced mean systolic, diastolic, and arterial BP at the end of the study. Similarly, the wake-up and sleep periods mean systolic, diastolic, and arterial BP decreased significantly among the hypertensive controls. However, the CKD patients showed no significant BP variability with chronotherapy at the end of the study. Both the hypertensive controls and CKD patients experienced no significant BP dipping during the study period. Conclusion: Hypertensive patients in our study experienced a significant reduction in their BP parameters with chronotherapy, while CKD patients showed no significant changes in their BP. Further studies are needed in Nigeria to determine the beneficial effects of chronotherapy in this population.