bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hemodynamic and plasma atrial natriuretic peptide responses to acute digitalis therapy in patients with normal and impaired left ventricular function
Authors: Miller Wayne L. , Bailey Kent R. , Weston Susan A. , Burnett John C. , Rodeheffer Richard J. 
Published: October 2002

AbstractBackground:Digitalis has a long history in the treatment of heart failure but its effects on cardiac hemodynamics and neurohormonal modulation are not well characterized.Aims:The purpose of this study was to evaluate the relationship between atrial natriuretic peptide (ANP) and the hemodynamic responses to acute digitalis administration in patients with normal and impaired left ventricular function (LVD).Methods and Results:Thirty patients were enrolled in the study, 20 with LVD (LVEF‐22±8%) and 10 control subjects (LVEF‐77±10%). Hemodynamics and plasma ANP concentrations were measured supine and with leg elevation before and after digitalis. In patients with normal ventricular function, the hemodynamic stress of leg elevation in the pre‐digitalis state resulted in significant (P<0.05) increases in PAWP and MPAP. Digitalis administration in the supine position produced reductions in heart rate, PAWP, MPAP and CI; SVR was increased. In LVD patients leg elevation further increased PAWP, RAP and MPAP. Digitalis in the supine position, however, reduced RAP, MPAP and PAWP and increased CI. These improved hemodynamics were preserved during the stress of leg elevation. Leg elevation following digitalis resulted in increased ANP concentrations despite decreased cardiac filling pressures.Conclusions:Acute digitalis administration results in hemodynamic improvement in LVD patients which may in part result from digitalis stimulated release of myocardial ANP under conditions of hemodynamic stress.
Normokinesia adjacent to left ventricular aneurysm: a differential risk for sudden cardiac death
Authors: Hassapoyannes Constantine A. , McLaurin Brent T. , Hornung Carlton A. , Chavda Kiran , Giurgiutiu Dan‐Victor 
Published: October 2002

AbstractBackground:Following myocardial infarction, the ejection fraction (EF) is an indiscriminate predictor of both non‐sudden cardiac death (NSCD) and sudden cardiac death (SCD). However, development of a left ventricular aneurysm (LVA) confers independent risk only for SCD. Thus, we tested the hypothesis that mechanical factors, other than the global left ventricular performance, are causally related to SCD in the presence of LVA.Methods:A secondary analysis was conducted from a longitudinal, prospective, long‐term follow‐up cohort study of 66 patients with LVA (diastolic eccentricity and systolic dyskinesia) diagnosed by ventriculography. The left ventricular contour was divided into five segments and contractility scores for the residual myocardium and the segments adjacent to the aneurysm were allocated along with assessment of the EF. A normal adjacent segment was considered present when at least one segment adjacent to the aneurysm exhibited normokinesia. Presence of ventricular tachycardia was documented by Holter recording.Results:At a 5.2‐year median follow‐up, there were 12 NSCD and 8 SCD. The EF was lower among patients who died vs. survivors (31.5% vs. 39.7%, P‐0.01). Patients with NSCD and SCD, exhibited similar EF but disparate residual contractility scores (3.0 vs. 4.1, P<0.004). Among cardiac deaths, a decreasing residual contractility score differentially predicted NSCD (odds ratio‐17.06, P<0.03), while a normokinetic adjacent segment differentially predicted SCD (odds ratio‐21, P<0.02). Albeit a predictor of both NSCD and SCD, ventricular tachycardia increased markedly the model significance (P<0.004) only when tested with a normokinetic adjacent segment vis‐à‐vis SCD.Conclusions:In the presence of LVA, the contractility of the non‐aneurysmal myocardium is a differential predictor of death from pump failure. In contrast, a normal segment adjacent to LVA constitutes an independent and discriminate predictor of SCD, possibly through an arrhythmic substrate linked to the motion discordance between the expanding aneurysm and a normokinetic adjacent myocardium.
Identification and validation of selective upregulation of ventricular myosin light chain type 2 mRNA in idiopathic dilated cardiomyopathy
Authors: Haase Daniela , Lehmann Michael H. , Körner Michael M. , Körfer Reiner , Sigusch Holger H. , Figulla Hans R. 
Published: October 2002

AbstractBackground and aims:the etiology of idiopathic dilated cardiomyopathy (IDCM) is unknown, methods such as suppression subtractive hybridization (SSH) and DNA microarray technology can help to identify genes which might be involved in the pathogenesis of this disease.Methods and results:we used SSH which compared mRNA populations extracted from the left ventricular tissue of IDCM hearts and from the control tissue to identify sequences which correspond to genes up‐regulated in IDCM. We identified ventricular myosin light chain type 2 (MLC2V), skeletal α‐actin, long‐chain‐acyl‐CoA‐synthetase and mRNA for the protein KIAA0465 as differentially up‐regulated genes. Expression of MLC2V mRNA was determined by RT‐PCR in patients with end‐stage heart failure caused by IDCM (n‐11) or coronary artery disease (CAD, n‐9) who underwent heart transplantation as well as the controls (n‐6). MLC2V/GAPDH ratios were 2.95±0.32, 0.69±0.03 and 0.28±0.08 (arbitrary unit) for the IDCM group, the CAD group and controls, respectively (P<0.05). DNA microarray analysis confirmed the finding of MLC2V upregulation in IDCM (3.7‐ and 1.8‐fold increase in MLC2V mRNA).Conclusions:we have demonstrated that SSH is a useful method to identify differential myocardial upregulation of genes. Upregulation of MLC2V can be judged as a specific IDCM related feature, which might be clinically helpful.
Angiotensin II subtype 1 (AT1) receptors contribute to ischemic contracture and regulate chemomechanical energy transduction in isolated transgenic rat (αMHC‐hAT1)594–17 hearts
Authors: Han Hong , Hoffmann Sigrid , Hu Kai , Ertl Georg 
Published: October 2002

AbstractBackground:The role of AT1 receptors in myocardial ischemia/reperfusion injury is unclear. We, therefore, investigated the effects of the AT1 receptor antagonist irbesartan (Irb) in isolated hearts of selective myocardial AT1 overexpressing transgenic [transgenic(αMHC‐hAT1)594–17] and Sprague–Dawley rats (SD) subjected to ischemia/reperfusion injury.Methods and results:Hearts of 4‐week‐old male SD or transgenic rats were isolated and perfused with Krebs–Henseleit buffer with or without 10 μM Irb in Langendorff mode. After 15 min of stabilization, pressure–volume curves were obtained and the hearts subjected to 20 min ischemia followed by 30 min reperfusion. A second set of pressure–volume curves was obtained thereafter. Left ventricular developed pressure (LVDP), end‐diastolic pressure (LVEDP), total coronary flow (CF) and oxygen consumption (MVO2) were recorded continuously. Myocardial efficiency was derived from the slope of relations of MVO2 to pressure/volume area. After 20 min ischemia, LVEDP was significantly higher in transgenic than in SD (35.7±1.8 vs. 29.2±1.0 mmHg, P<0.05) or Irb treated transgenic hearts (24.3±1.6 mmHg, P<0.05). Myocardial efficiency was increased by Irb before ischemia. Ischemia increased efficiency in SD but not in transgenic rats, Irb increased efficiency in transgenic hearts post‐ischemia.Conclusion:Transgenic hearts developed ischemic contracture more rapidly than SD hearts as indicated by higher LVEDP during ischemia. This response was antagonized by Irb, indicating a role of AT1 receptors in ischemic contracture, AT1‐receptors also appear to be involved in the control of myocardial efficiency.
Lactic acidosis following heart transplantation: a common phenomenon?
Authors: Mohacsi Paul , Pedrazzini Giovanni , Tanner Hildegard , Tschanz Hans‐Ueli , Hullin Roger , Carrel Thierry 
Published: October 2002

AbstractBackground:Lactic acidosis (LAc) is a common form of metabolic acidosis early after heart transplantation (HTX). The mechanism remains unclear. This study analyzed 13 patients who developed severe LAc after HTX.Methods:From a series of 60 consecutive heart transplant patients, we identified 13 patients with LAc in the first hours following HTX. Nine patients with normal or mildly elevated lactate levels (<5.0 mmol/l) were investigated as controls.Results:Thirteen patients developed a moderate or severe LAc (up to 14.6 mmol/l) after HTX. Serum lactate levels increased immediately following surgery with a peak after 6.3±1.4 h, spontaneously returning to normal values within 24 h. In contrast to the control group, a significant correlation was found between the maximal serum lactate level and the maximal dosage of inotropic drugs (r‐0.93, P<0.02), administered during the reperfusion phase and continued for 12–24 h postoperatively. No correlation was found between LAc and blood gas analysis during extracorporeal perfusion period.Conclusion:LAc can occur after HTX and seems to be related to the inotropic support of the graft. In contrast to other forms, LAc after HTX has an excellent prognosis and resolves rapidly and spontaneously without treatment. The fact that inotropic support during and immediately after cardiac transplantation can enhance preexisting severe peripheral metabolic cellular dysfunction remains hypothetical.
Effects of Geometric Distortions on Face-Recognition Performance
Authors: Hole Graham J , George Patricia A , Eaves Karen , Rasek Ayman 
Published: October 2002

The importance of ‘configural’ processing for face recognition is now well established, but it remains unclear precisely what it entails. Through four experiments we attempted to clarify the nature of configural processing by investigating the effects of various affine transformations on the recognition of familiar faces. Experiment 1 showed that recognition was markedly impaired by inversion of faces, somewhat impaired by shearing or horizontally stretching them, but unaffected by vertical stretching of faces to twice their normal height. In experiment 2 we investigated vertical and horizontal stretching in more detail, and found no effects of either transformation. Two further experiments were performed to determine whether participants were recognising stretched faces by using configural information. Experiment 3 showed that nonglobal vertical stretching of faces (stretching either the top or the bottom half while leaving the remainder undistorted) impaired recognition, implying that configural information from the stretched part of the face was influencing the process of recognition — ie that configural processing involves global facial properties. In experiment 4 we examined the effects of Gaussian blurring on recognition of undistorted and vertically stretched faces. Faces remained recognisable even when they were both stretched and blurred, implying that participants were basing their judgments on configural information from these stimuli, rather than resorting to some strategy based on local featural details. The tolerance of spatial distortions in human face recognition suggests that the configural information used as a basis for face recognition is unlikely to involve information about the absolute position of facial features relative to each other, at least not in any simple way
Stroke patients entering nursing home care: a content analysis of discharge letters
Authors: Sackley Catherine M , Pound Kate 
Published: October 2002

Objective: To examine the information contained in medical and nursing staff hospital discharge letters for stroke patients entering nursing home care. Design: A retrospective content analysis comparing case notes with discharge letters. Setting: Nottingham (UK) hospitals. Subjects: Thirty-eight stroke patients with a Barthel Activities of Daily Living Index score of less than 11/20 at three months post stroke who were discharged into a nursing home. Method: Patients' medical case notes and medical and nursing discharge letters were subjected to the same structured content analysis. The three key areas were: self-care ability (i.e. washing, dressing), nursing needs (i.e. diet, continence) and risk assessment (i.e. falls, pressure sores). Results: Discharge letters were least likely to provide information on risk assessments, for example only 14 (37%) documented the risk of pressure sores and 7 (18%) falls. Thirty discharge letters (79%) had information relating to self-care ability and nursing care, although a blanket term ‘needs all care’ was used to describe patient ability in 20 (66%) of these. Conclusion: The results demonstrate that the completeness and accuracy of information is often poor, doing little to enhance the continuity of care for patients who are transferred from hospital to nursing homes.
Short-term effectiveness of intensive multidisciplinary rehabilitation for people with Parkinson's disease and their carers
Authors: Trend Patrick , Kaye Julie , Gage Heather , Owen Charles , Wade Derick 
Published: October 2002

Objective: To evaluate the short-term effectiveness of an intensive multidisciplinary rehabilitation programme for people with Parkinson's disease and their carers. Design: Observational, with assessments before and after intervention. Setting: An elderly care day unit in a district general hospital in south-east England. Subjects: One hundred and eighteen people with Parkinson's disease and no cognitive impairment, and their carers. Intervention: Participants attended the day hospital in groups of six patients with their carers for one day per week over six consecutive weeks. After assessment, they received individual treatment from a specialist team. Weekly group activities included relaxation and talks from experts. Outcome measures: Patients and carers were assessed for: health-related quality of life, psychological well-being, social services need, perceptions of the programme. Patients were additionally assessed for mobility, gait and speech. Carers were assessed for strain. Results: After treatment significant improvements were recorded in patients' mobility and gait ( p < 0.05), speech ( p < 0.001), depression ( p = 0.029), health-related quality of life ( p = 0.001). People with more advanced disease at baseline gained significantly more from treatment ( p £ 0.04). Carers were less depressed and had higher health-related quality of life than patients at baseline ( p < 0.001) and no improvements in these indicators were recorded after treatment. A high unmet need for social services was identified in 31% of participants, and 10% of carers were found in danger of being unable to continue caring. Participants reported knowledge gains and high levels of satisfaction with both individual therapies and group activities. Conclusions: This intensive co-ordinated programme provided immediate benefits to people with Parkinson's disease and their carers.
The influence of preparedness on rapid stepping in young and older adults
Authors: Brauer Sandra G , Burns Yvonne R 
Published: October 2002

Objective: To investigate the influence of age and preparation level on postural muscle activation and step completion time during a rapid step task. Design: Postural muscle onset times (EMG) and ground reaction forces were recorded from healthy young ( n = 20, age 21 ± 3 years) and older ( n = 25, age 71 ± 5 years) female adults during a choice reaction-time stepping paradigm. Main outcome measures: Onset times of six trunk and hip muscles, reaction time and components of the step (weight shift time, step time and task time) were recorded. Results: Muscle activation was delayed and movement time was lengthened in both young and older adults when poorly prepared for a stepping task. While reduced preparation did not influence older adults to a greater extent than young adults, the slowest step response and completion time was evident in older adults when poorly prepared to move. Conclusions: A late postural response when poorly prepared to move may be a contributing factor to an increased risk of overbalancing in older adults. Future assessment of and intervention to improve postural stability in older adults should be expanded to incorporate tasks performed at various levels of preparation.
New Approach for Enhancing Sensitivity in Liquid‐Gated Nanowire FET Biosensors Under Optical Excitation
Authors: Petrychuk Mykhailo , Pustovyi Denys , Boichuk Nazarii , Zhang Yongqiang , Long Hanlin , Vitusevich Svetlana 
Published: January 2024

AbstractThe results obtained for liquid‐gated (LG) nanowire (NW) field‐effect transistor (FET) sensors analyzed in divalent ion (MgCl2) solutions, which play a crucial role in the human body, are reported. Liquid‐gated NW FET sensors fabricated in‐house are investigated using I–V characteristics and noise spectroscopy in a wide range of voltages and different intensities of optical infrared irradiation. A new effect is revealed under the influence of external optical excitation. The effect allows for the control of characteristic times of single‐trap phenomena: capture time to a single trap, emission time from the trap, and its ratio represented by the dimensionless ratio parameter (R‐factor). These parameters enabled an improvement in sensor sensitivity. The findings open prospects for controlling charge states in LG NW FET structures to optimize new parameters for achieving ultrahigh sensitivity in biosensors.
Bio‐Disintegrable Elastic Polymers for Stretchable Piezoresistive Strain Sensors
Authors: Vahdani Mostafa , Mirjalali Sheyda , Razbin Milad , Moshizi Sajad Abolpour , Payne David , Kim Jincheol , Huang Shujuan , Asadnia Mohsen , Peng Shuhua , Wu Shuying 
Published: January 2024

AbstractThe fast‐growing usage of electronics is creating large amounts of e‐waste (electronic waste), most of which are directly sent into landfills or incinerated as recycling is either impractical or too costly. Therefore, it is believed that degradable, environmentally friendly materials are the solution to this pressing issue. Herein, disintegrable, durable, and highly stretchable strain sensors are developed based on elastic thin films made of sodium carboxymethyl cellulose, glycerol, and polyvinyl alcohol. The polymer thin films show a failure strain up to ≈ 330% and low hysteresis (5.74% at the second cycle) when subjected to 50% cyclic strain, due to the formation of inter or intramolecular hydrogen bonds. Carbon nanofibers with Au thin film are deposited on the elastic thin film, resulting in highly stretchable piezoresistive strain sensors with a maximum gauge factor of 1.7. More interestingly, the as‐developed sensors can be completely broken down in hot water (at ≈ 95 °C) within ≈ 25 min, indicating their remarkable disintegrability. This unique characteristic is expected to contribute to environmental sustainability. The applications of the sensor for joint bending recognition as well as physiological sign measurement have been demonstrated.
Investigating the influence of particle distribution on force and torque statistics using hierarchical machine learning
Authors: Siddani B. , Balachandar S. , Zhou Jiazhong , Subramaniam Shankar 
Published: January 2024

AbstractAn accurate representation of hydrodynamic force and torque experienced by every particle in a distribution can be obtained from particle resolved (PR) simulations. These unique quantities are influenced by the deterministic position of surrounding particles. However, systems simulated with this methodology are typically limited to particles due to the involved computational cost. This resource requirement is a major bottleneck in analyzing the effect of variations in particle distribution. This article attempts to address this bottleneck by availing relatively inexpensive deep learning models. The surrogate models that we employ in this article use a physics‐based hierarchical framework and symmetry‐preserving neural networks to achieve robustness with limited training data. This article first performs additional generalizability tests on PR data of distinct distributions that are not involved in the training process. The models are then deployed on several different particle distributions. Impact of clustering and structure on the observed statistics are investigated.
Enhanced azeotropic C2ClF5/C3F8 separation by TMA+ exchanged MFI zeolites for ultrapure fluorine electronic gas
Authors: Zhou Xiaoying , Wu Ying , Liu Zewei , Wang Xingjie , Yang Cuiting , Yu Jian , Xiao Jing 
Published: January 2024

AbstractThe demand for the azeotropic C2ClF5/C3F8 separation continues to rise owing to the significance of ultrapure fluoride gases for the electronic industry. With a boiling point differential of 1.1 K, separating an azeotropic mixture of C2ClF5/C3F8 through sorption‐based processes under ambient conditions is a preferable alternative to the current energy‐intensive cryogenic separation method. Here, we report the highly efficient C2ClF5/C3F8 adsorption separation in quaternary alkylammonium ions modified MFI type zeolites with interlaced channels which provide a cooperative effect conferred by specific interaction sites and optimal pore size. A path‐regulatory mechanism was proposed, whereby TMA+ cations located at intersections resembling “train turnouts” force gas molecules to switch traffic channels to confined sinusoidal channels affecting the C2ClF5/C3F8 recognition sites and diffusion behavior. Molecular simulations were conducted to reveal the separation mechanism, and the breakthrough experiment validated the effectiveness of this adsorbent at 298 K outperforming conventional adsorbents for the challenging azeotropic separation.
Anisotropic electro‐driven phase change materials inspired by biological structure
Authors: Jia Zhaoying , Li Zaichao , Wang Xuan , Hu Caishuo , Tang Bingtao , Zhang Shufen , Zhang Yuang 
Published: January 2024

AbstractElectro‐driven phase change materials (PCMs) can effectively realize electrothermal conversion and storage and have attracted much attention in the fields of electrothermal therapy and thermal management of electronic devices. How to effectively reduce the leakage current risk of it is a core problem in the application process. In this work, we used carbon fibers and boron nitride to mimic the microstructure of Greta oto butterfly's wing, and composite it with a form‐stable PCM‐PPEGMA to obtain a thermally conductive enhanced anisotropic electro‐driven PCM. The material exhibits high electrothermal conversion and storage efficiency (86.76%, 5 V), high thermal conductivity, excellent electrical anisotropy, and thermal stability because of the well‐designed spatial arrangement. The unique bionic structure effectively inhibits the conductive isotropy phenomenon of traditional electro‐driven PCMs and significantly reduces the risk of leakage current. On the basis of this situation, the system shows great application potential in the field of electrothermal therapy.