Towards reuse and recycling of lithium-ion batteries: tele-robotics for disassembly of electric vehicle batteries.

Disassembly of electric vehicle batteries is a critical stage in recovery, recycling and re-use of high-value battery materials, but is complicated by limited standardisation, design complexity, compounded by uncertainty and safety issues from varying end-of-life condition. Telerobotics presents an avenue for semi-autonomous robotic disassembly that addresses these challenges. However, it is suggested that quality and realism of the user's haptic interactions with the environment is important for precise, contact-rich and safety-critical tasks. To investigate this proposition, we demonstrate the disassembly of a Nissan Leaf 2011 module stack as a basis for a comparative study between a traditional asymmetric haptic-"cobot" master-slave framework and identical master and slave cobots based on task completion time and success rate metrics. We demonstrate across a range of disassembly tasks a time reduction of 22%-57% is achieved using identical cobots, yet this improvement arises chiefly from an expanded workspace and 1:1 positional mapping, and suffers a 10%-30% reduction in first attempt success rate. For unbolting and grasping, the realism of force feedback was comparatively less important than directional information encoded in the interaction, however, 1:1 force mapping strengthened environmental tactile cues for vacuum pick-and-place and contact cutting tasks.

Post-operative N-terminal pro-brain natriuretic peptide predicts in-hospital mortality after living donor liver transplantation.

OBJECTIVE: The post-operative serum level of N-terminal pro-brain natriuretic peptide (NT-proBNP) has been found to be associated with post-operative cardiovascular complications and mortality in high-risk surgeries. The usefulness of the post-operative NT-proBNP level as a predictor of mortality after liver transplantation (LT) is unknown. METHODS: The records of patients at a single, tertiary university hospital who had undergone adult living donor liver transplantation (LDLT) with data of post-operative NT-proBNP level values were retrospectively analyzed for in-hospital mortality. The highest post-operative NT-proBNP level from the first 3 days after surgery was included in the study. Receiver operating characteristic curve analysis was performed to assess the best cut-off value of post-operative NT-proBNP, and Cox regression analysis was performed to investigate the effect of NT-proBNP on mortality. RESULTS: A total of 114 LT recipients with a mean Model for End-Stage Liver Disease score of 15.8 were included in the study. In-hospital mortality occurred in 11 (9.6%) of the patients. A history of diabetes mellitus and the post-operative NT-proBNP level were found to be associated with mortality (p=0.011 for diabetes mellitus and p<0.001 for NT-proBNP). The best cut-off value of post-operative NT-proBNP was 1009 ng/L. Cox regression analysis indicated that the NT-proBNP level was a strong predictor of in-hospital mortality (hazard ratio: 24.467, 95% confidence interval: 3.120-191.750; p=0.002). CONCLUSION: The post-operative NT-proBNP serum level independently predicted in-hospital mortality in patients who underwent LDLT. Post-operative NT-proBNP-guided management of LT recipients should be pursued.

The effects of CYP2C9 and VKORC1 gene polymorphisms on warfarin maintenance dose in Turkish cardiac patients.

Aim: Our aim was to examine the effect of CYP2C9 and VKORC1 polymorphisms on warfarin dose requirements in Turkish patients. Materials & methods: 24 warfarin prescribed patients were included and analyzed for eight VKORC1 and 6 CYP2C9 polymorphisms in the study. Results: Patients with CYP2C9 *1/*1 and VKORC1 -1639 GG and GA genotypes required higher warfarin doses in comparison to wild type VKORC1 genotype. Patients with CYP2C9 *1/*3 and VKORC1 -1639 GG genotypes simultaneously, required the lowest dose of warfarin (4.64 mg/day). Patients with CYP2C9 *1/*1 and VKORC1 9041 AA genotype were found to require higher warfarin doses. Conclusion: Our results provide additional evidence to support the hypothesis that CYP2C9 *2, *3, VKORC1 9041 G > A polymorphisms explain considerable proportion of inter-individual variability in warfarin dose requirement.

Postoperative Myocardial Injury Does Not Predict Early and 1-Year Mortality After Living Donor Liver Transplantation.

BACKGROUND: Preoperative cardiac troponin-I (cTnI) elevation has been shown to be a predictor of mortality after liver transplantation. Myocardial injury after non-cardiac surgery (MINS) has been defined as elevation of serum cardiac troponin levels in the perioperative period that does not fulfill the criteria for myocardial infarction. MINS has been shown to be a prognostic factor for in-hospital and long-term mortality, but there is limited data in patients undergoing living-donor liver transplantation (LDLT). In this study, we aimed to evaluate the relationship between MINS and postoperative mortality. MATERIAL AND METHODS: Patients who had undergone adult LDLT at Florence Nightingale Hospital Liver Transplantation Unit between December 2012 and December 2015 were retrospectively analyzed for 30-day in-hospital and 1-year mortality. Myocardial injury was defined as cTnI level above 0.04 ng/mL. Patients (N = 214) were divided into 2 groups according to postoperative cTnI levels. The following were the exclusion criteria: 1. patients under 18 years old, 2. patients undergoing deceased-donor liver transplantation or dual liver-kidney transplantation, 3. cTnI elevation due to other causes (sepsis, renal failure, pulmonary embolism, myocardial infarction), and 4. patients without postoperative troponin levels. RESULTS: MINS occurred in 123 (57.4%) patients after LDLT. There was no difference between the groups according to age, sex, creatinine levels, presence of ischemic heart disease, hypertension, diabetes mellitus, and tobacco use. The presence of MINS did not predict 30-day and 1-year mortality in the study population. CONCLUSION: Myocardial injury detected by serum cTnI elevation was frequent after LDLT; however, it was not associated with 30-day in-hospital and 1-year mortality.

Glycoprotein Ibα Kozak polymorphism in patients presenting with early-onset acute coronary syndrome.

INTRODUCTION: Glycoprotein Ibα (GPIbα) receptor is the chief molecule responsible for initial platelet adhesion to the subendothelium. A thymidine to cytosine single nucleotide substitution at position -5 from the ATG start codon characterizes the Kozak sequence polymorphism. The Kozak sequence polymorphism may increase the surface expression of GPIbα and contribute to thrombogenesis. We evaluated the allele frequencies of GPIbα Kozak sequence polymorphism in the Turkish population and examined the relationship between GPIbα Kozak sequence polymorphism and early-onset acute coronary syndrome (ACS). MATERIAL AND METHODS: This study enrolled 200 patients (122 male, 78 female, mean age: 39 ±5 years) and 200 healthy control subjects (110 male, 90 female, 41 ±4 years). The patient group was composed of patients admitted to our coronary care unit with early-onset ACS and patients who attended to our cardiology outpatient clinic after hospital discharge with a diagnosis of early-onset ACS. RESULTS: Kozak polymorphism frequencies in patients and control subjects did not differ significantly (23% versus 22.5%, p = 0.812, respectively). In patients who presented with non-ST elevation myocardial infarction (NSTEMI), the frequency of GPIbα Kozak polymorphism was borderline significantly higher when compared with patients who presented with ST elevation myocardial infarction (STEMI) (35% vs. 20%, p = 0.05, respectively). Allele frequencies of T and C were calculated to be 0.873 and 0.128. CONCLUSIONS: Although the frequency of GPIbα Kozak polymorphism did not differ significantly in early-onset ACS patients versus control subjects, Kozak polymorphism frequency was borderline significantly higher in patients who presented with NSTEMI when compared to patients with STEMI.

Influence of coronary calcification patterns on hemodynamic outcome of coronary stenoses and remodeling.

OBJECTIVE: The histological characteristics of plaque may affect the hemodynamic outcome of a given coronary stenosis. In particular, the potential effect of volumetric calcium content and the topographical distribution in the lesion segment on physiological outcome has not yet been investigated. The aim of this study was to identify any potential correlation between patterns of calcification and the fractional flow reserve (FFR) and the coronary remodeling index (RMI). METHODS: A total of 26 stable angina pectoris and 34 acute coronary syndrome patients without persistent ST-segment elevation constituted the study population. FFR was used to assess 70 intermediate coronary stenosis lesions. After obtaining hemodynamic measurements, quantitative grayscale and virtual histology-intravascular ultrasound analyses were performed. The depth, length, and circumferential distribution of calcification of the lesions were also recorded. RESULTS: Within the analyzed segment (area of interest, lesion segment), FFR was correlated with maximal thickness of deep calcification (r=-0.285; p=0.021) and calcification angle (r=-0.396; p=0.001). In lesions with a calcification angle >180°, the mean FFR value was significantly lower compared with those <180° (0.64±0.17 vs. 0.78±0.08; p=0.024). RMI was correlated with maximal angle of superficial (r=-0.437; p<0.001) and deep (r=0.425; p<0.001) calcification. RMI was correlated with maximal thickness of superficial (r=-0.357; p=0.003) and deep (r=0.417; p<0.001) calcification. RMI was also correlated with FFR (r=-0.477; p<0.001). CONCLUSION: This study demonstrated that the geometry, location, and amount of calcification of a plaque could affect hemodynamic and anatomical outcome measures in functionally significant stenoses by affecting vessel wall compliance.

Comparison of different cardiovascular magnetic resonance sequences for native myocardial T1 mapping at 3T.

BACKGROUND: T1 mapping based on cardiovascular magnetic resonance (CMR) is a novel approach using the magnetic relaxation T1 time as a quantitative marker for myocardial tissue composition. Various T1 mapping sequences are being used, with different strengths and weaknesses. Data comparing different sequences head to head however are sparse. METHODS: We compared three T1 mapping sequences, ShMOLLI, MOLLI and SASHA in phantoms and in a mid-ventricular slice of 40 healthy individuals (mean age 59 ± 7 years, 45 % male) with low (68 %) or moderate cardiovascular risk. We calculated global and segmental T1 in vivo through exponential curve fitting and subsequent parametric mapping. We also analyzed image quality and inter-observer reproducibility. RESULTS: There was no association of T1 with cardiovascular risk groups. T1 however differed significantly depending on the sequence, with SASHA providing consistently higher mean values than ShMOLLI and MOLLI (1487 ± 36 ms vs. 1174 ± 37 ms and 1199 ± 28 ms, respectively; p < 0.001). This difference between sequences was much smaller in phantom measurements. In patients, segmental values were lower in the anterior wall for all sequences. Image quality, in general good for the steady-state-free-precession readouts in all sequences, was lower for SASHA parametric maps. On multivariate regression analysis, a longer T1 measured by MOLLI was correlated with lower ejection fraction and female gender. Inter-observer variability as assessed by intra-class correlation coefficients was excellent for all sequences (ShMOLLI: 0.995; MOLLI: 0.991; SASHA: 0.961; all p < 0.001). CONCLUSION: In a cross-sectional population with low to moderate cardiovascular risk, we observed a variation in T1 mapping results between inversion-recovery vs. saturation-recovery sequences in vivo, which were less evident in phantom images, despite a small interobserver variability. Thus, physiological factors, most likely related to B1 inhomogeneities, and tissue-specific properties, like magnetization transfer, that impact T1 values in vivo, render phantom validation insufficient, and have to be further investigated for a better understanding of the clinical utility of different T1 mapping approaches. TRIAL REGISTRATION: "Canadian Alliance For Healthy Hearts and Minds" - ClinicalTrials.gov NCT02220582 ; registered August 18, 2014.

The Relationship between Left Atrial Volume and Ventricular Arrhythmias in the Patients with Dilated Cardiomyopathy.

BACKGROUND: The present study aimed to investigate the relationship between Left Atrial Volume (LAV), a marker of diastolic dysfunction, and the frequency of malignant ventricular arrhythmia in the patients with left ventricular dysfunction and a previously implanted Implantable Cardioverter Defibrillator (ICD) device. METHODS: This cross-sectional study was conducted on 32 patients with ischemic or idiopathic dilated cardiomyopathy, each having had an ICD device implanted at least 1 year beforehand. The ventricular arrhythmia episodes which were detected and stored by the device were retrieved and evaluated. In addition to routine echocardiographic measurements, all the patients had their LAV and LAV indexes calculated. After all, student's t-test, Mann-Whitney U test, and Pearson correlation were used to analyze the data. Besides, P value < 0.05 was considered as statistically significant. RESULTS: This study was conducted on 4 female and 28 male patients with the mean age of 58.41 ± 9.97 years. Among the study patients, 21 had at least one previous myocardial infarction. In addition, 17 patients had experienced sustained VT or VF within the last year. No significant difference was found between the patients with and without malignant ventricular arrhythmias (sustained VT or VF) regarding LAV (17 patients with arrhythmia (68 + 23.39 mL) vs. 15 patients without arrhythmia (55.13 ± 20.41 mL); P = 0.100). However, the LAV index was significantly higher in the patients with arrhythmia compared to those without arrhythmia (39.27 ± 12.19 mL / m2 vs. 25.18 ± 7.45 mL / m2; P = 0.004). Both LAV (73.33 ± 17.64 mL and 57.52 ± 23.15 mL, respectively; P = 0.040) and LAV index (40.86 ± 8.47 mL / m2 and 28.20 ± 11.77 mL / m2, respectively; P = 0.010) were significantly greater in the patients with ICD shock therapy within the last year compared to the others. However, both groups were similar regarding Left Ventricular Volume (LVV), LVV index, and ejection fraction. CONCLUSIONS: The study findings demonstrated that LAV and LAV index could be used in detecting the patients who are at high risk of malignant ventricular arrhythmias.

Role of C-reactive protein in determining microvascular function in patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention.

The extent of coronary microvascular dysfunction might be related, not only to patient characteristics and procedural factors, but also to the inflammatory status. The aim of the present study was to examine a possible association between inflammation, as reflected by the serum C-reactive protein (CRP) levels, and the extent of baseline and post-percutaneous coronary intervention (PCI) coronary microvascular dysfunction in patients with non-ST-segment elevation acute coronary syndrome undergoing PCI. A total of 42 patients undergoing PCI for non-ST-segment elevation acute coronary syndrome were enrolled. Coronary microvascular resistance (MR) was determined in the territory of culprit artery using a Doppler probe- and a pressure sensor-equipped guidewire both before (taking the collateral blood into account) and after PCI. The periprocedural changes in MR were calculated. The CRP levels at admission were correlated with the pre-PCI MR (r = 0.498, p = 0.001), post-PCI MR (r = 0.429, p = 0.005), and periprocedural changes in MR (r = 0.785, p <0.001). On multivariate regression analysis, the only predictor of the pre-PCI (ß = 0.531, p = 0.002) and post-PCI (ß = 0.471, p = 0.012) MR was the serum CRP concentration. Likewise, the periprocedural changes in MR was predicted by the serum CRP levels (ß = 0.677, p = 0.001) and the presence of angiographic thrombus (ß = -0.275, p = 0.02). In conclusion, these results have shown that the CRP level is related to increased coronary MR in the territory of the culprit lesion. This suggests that inflammatory processes might play a role in microvascular impairment in patients with non-ST-segment elevation acute coronary syndrome.

Percutaneous coronary intervention increases microvascular resistance in patients with non-ST-elevation acute coronary syndrome.

AIMS: In the acute coronary syndrome setting, the interaction between epicardial coronary artery stenosis and microcirculation subtended by the culprit vessel is poorly understood. The purpose of the present study was to assess the immediate impact of percutaneous coronary intervention (PCI) on microvascular resistance (MR) in patients with non-ST-elevation myocardial infarction (NSTEMI). METHODS AND RESULTS: Thirty-eight patients undergoing PCI for NSTEMI were recruited consecutively. Culprit lesions were stented over a Doppler and pressure-sensor-equipped guidewire. In the presence of epicardial stenosis, MR was calculated by taking collateral flow, as measured by the coronary wedge pressure, into consideration. After removal of epicardial stenosis, MR was calculated simply as distal coronary pressure divided by average peak velocity. When collateral flow was incorporated into the calculation, MR increased significantly from 1.70 ± 0.76 to 2.05 ± 0.72 (p=0.001) after PCI in the whole population. Periprocedural changes (Δ) in absolute values of MR and troponin T correlated significantly (r=0.629, p=0.0001). In patients who developed periprocedural myocardial infarction, MR increased significantly after PCI (1.48 ± 0.73 versus 2.28 ± 0.71, p<0.001). Nevertheless, removal of the epicardial lesion did not change MR in patients without periprocedural MI (1.91±0.73 versus 1.81±0.67, p=0.1). CONCLUSIONS: When collateral flow is accounted for, removal of epicardial stenosis increases MR in patients with NSTEMI undergoing PCI.

Intrarenal application of N-acetylcysteine for the prevention of contrast medium-induced nephropathy in primary angioplasty.

OBJECTIVE: Contrast medium-induced nephropathy (CIN) is a well-known complication of coronary angiographic procedures, especially in patients treated with primary angioplasty. To prevent CIN, we examined using a local application of N-acetylcysteine (NAC) for the prevention of CIN during primary angioplasty. We hypothesized that a local application of NAC into the renal arteries would provide the benefit of a higher local concentration, lower first-pass metabolism, and faster efficacy. To evaluate the effects of NAC by the intrarenal route, we performed a prospective, randomized clinical study in patients with acute myocardial infarction treated with primary angioplasty. METHODS: Participants were 312 patients with ST-segment elevation myocardial infarction undergoing primary angiography. Eligible patients were randomly assigned to receive intravenous NAC, intrarenal NAC, or placebo. RESULTS: Overall, CIN occurred in 74 (23.7%) of the 312 patients. The rate of CIN was 25% in the intravenous NAC group, 22.9% in the intrarenal NAC group, and 23.2% in the placebo group, with no significant effect seen for either treatment (P=0.64). We did find a significant correlation between CIN and ejection fraction (P=0.05) and baseline renal function (P=0.01). CONCLUSION: Both intrarenal and intravenous applications of NAC failed to show any benefit over placebo in the prevention of CIN. This result shows that NAC application does not have any prophylactic effect, dose dependent or otherwise, on CIN, as previously reported. Our results suggest that more attention should be paid to optimize hemodynamic variables for the prevention of CIN.