Intermediate Duration Research Articles

Echocardiographic assessment of CRT candidates. Does it work equally well in intermediate QRS duration?

Abstract Background The presence of mechanical dyssynchrony – such as apical rocking (ApRock) and septal flash (SF) – on echocardiography is associated with favourable outcome after cardiac resynchronization therapy (CRT). Myocardial scar on the other hand, has a considerable negative impact on CRT response. There is growing evidence that a visual echocardiographic assessment of mechanical dyssynchrony by ApRock, SF and scar predicts CRT response. Little is known however if this works equally well in patients with intermediate QRS duration (120–150ms), where guideline recommendation for CRT is weaker. Methods A total of 400 unselected patients referred for CRT, who fulfil the contemporary guidelines, were enrolled in this multicentre study. Echocardiographic images were visually assessed before CRT implantation, focussing on the presence of ApRock, SF and location and extent of scar segments in the left ventricle (LV), resulting in a CRT response prediction (i.e. Reader Interpretation). Readers were blinded to all patient information other than ischaemic aetiology of heart failure. CRT response was defined as ≥15% reduction in LV end-systolic volume on echocardiography, on average 15 months after device implantation. Results Overall, 321 (80%) patients had a left bundle branch block (LBBB), with an average QRS duration of 166±25ms. Ischemic aetiology of heart failure was found in 131 (33%) patients. Before CRT, ApRock and SF were present in 254 (64%) and 244 (61%) patients, respectively. ApRock and SF alone predicted CRT response with an area under the curve (AUC) of 0.79 (95% CI: 0.74–0.84) and 0.78 (95% CI: 0.73–0.83) (Figure A), while the echocardiographic Reader Interpretation had an AUC of 0.85 (95% CI: 0.81–0.89), with a sensitivity of 89% and a specificity of 82% for the prediction of CRT response (Figure B) (p<0.0001 vs. ApRock and SF alone). A total of 92 patients had a QRS duration of 120–150ms, and 48 of them responded to CRT. In these patients, the AUC of Reader Interpretation was comparable to that of the entire study cohort [0.83 (95% CI: 0.75–0.92)], as was sensitivity and specificity (90% and 79%, respectively, p=0.717 vs. the AUC of the entire cohort) (Figure C). Conclusions A visual assessment of LV function, by means of mechanical dyssynchrony and scar, has an excellent predictive value for CRT response, and requires only apical echocardiographic images. Responders were identified equally well in the challenging subgroup of patients with a QRS duration of 120–150 ms. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): KU Leuven

Sexual reproductive strategies ofPuya nitida(Bromeliaceae) in a Colombian paramo, a tropical high-elevation ecosystem

AbstractThe low availability of pollinators in high-elevation ecosystems can lead to flowering plants showing different adaptive responses in order to assure their reproductive success. Shifts toward autogamy and asexual reproductive rates (the reproductive assurance hypothesis) and the compensatory measures to maintain outcrossing such as flower longevity and more prolonged pistil receptivity (the increased pollination probability hypothesis) are some of these responses. Several studies have tested both hypotheses, but investigations of plants of tropical alpine environments such as paramos that support these assumptions are still scarce.Puya nitida, an endemic Colombian plant species distributed in the paramo and subparamo in the Eastern Cordillera of Cundinamarca department, was used as a case study to test its reproductive characteristics that assure its sexual reproduction. We analysed the species’ floral morphology and development, its phenological patterns and its plant mating-system. We found thatPuya nitidashowed floral characteristics that promote pollination by birds, herkogamy and dichogamy, flowers and receptive stigmas with 9 and 12 days of longevity, respectively and an index of self-incompatibility that shows that it is mostly self-incompatible. We found a synchronic phenological pattern with an annual frequency and an intermediate duration with a peak in the period of lowest rainfall. Our results suggested that longer floral development, prolonged stigma receptivity, herkogamy and dichogamy and self-incompatibility might assure reproductive success, since the cross-pollination might be favoured when few pollinators are in attendance. Overall, these reproductive mechanisms add evidence to the increased pollination probability hypothesis, specifically for a plant species of a tropical high-elevation ecosystem where pollinators are scarce.

Short or Long Sleep Duration and CKD: A Mendelian Randomization Study.

Studies have found sleeping behaviors, such as sleep duration, to be associated with kidney function and cardiovascular disease risk. However, whether short or long sleep duration is a causative factor for kidney function impairment has been rarely studied. We studied data from participants aged 40-69 years in the UK Biobank prospective cohort, including 25,605 self-reporting short-duration sleep (<6 hours per 24 hours), 404,550 reporting intermediate-duration sleep (6-8 hours), and 35,659 reporting long-duration sleep (≥9 hours) in the clinical analysis. Using logistic regression analysis, we investigated the observational association between the sleep duration group and prevalent CKD stages 3-5, analyzed by logistic regression analysis. We performed Mendelian randomization (MR) analysis involving 321,260 White British individuals using genetic instruments (genetic variants linked with short- or long-duration sleep behavior as instrumental variables). We performed genetic risk score analysis as a one-sample MR and extended the finding with a two-sample MR analysis with CKD outcome information from the independent CKDGen Consortium genome-wide association study meta-analysis. Short or long sleep duration clinically associated with higher prevalence of CKD compared with intermediate duration. The genetic risk score for short (but not long) sleep was significantly related to CKD (per unit reflecting a two-fold increase in the odds of the phenotype; adjusted odds ratio, 1.80; 95% confidence interval, 1.25 to 2.60). Two-sample MR analysis demonstrated causal effects of short sleep duration on CKD by the inverse variance weighted method, supported by causal estimates from MR-Egger regression. These findings support an adverse effect of a short sleep duration on kidney function. Clinicians may encourage patients to avoid short-duration sleeping behavior to reduce CKD risk.

Time contraction caused by a distractor in children and adults: The influence of inhibition capacities

The aim of this study was to examine the cognitive processes involved in time contraction caused by a non-temporal distractor during the presentation of a temporal stimulus. To this aim 95 children aged 5 to 8 years old as well as 25 adults were first trained to discriminate, on two visual temporal bisection tasks, a short standard duration (400 or 600 ms) from a long one (1500 or 2400 ms). They had then to decide whether intermediate stimulus duration was more similar to the short or to the long standard duration. Furthermore, a 40 ms distractor taking the form of a 4 cm diameter rosette, either did or did not appear during the temporal stimulus. Participants' task was to report whether they had been exposed to the short or long standard duration. Subsequently, each subject's capacities in terms of memory skills (short term and working memory), as well as attention (selective attention and inhibition), were assessed using different neuropsychological tests. The results showed a shortening effect of the perceived time from non-distractor to distractor trials, which also turned out to attenuate with the age increase. Interestingly, inhibition was found to mediate this effect while the other cognitive variables were found to be of no significance. We therefore discussed the importance of categorizing two attentional interferences: one related to attention control and the other to attentional resources.

Key Evidence Supporting Prescription Opioids Approved by the U.S. Food and Drug Administration, 1997 to 2018.

Little is known about the evidence required by the U.S. Food and Drug Administration (FDA) for new approvals of opioid analgesics. To characterize the quality of safety and efficacy data in new drug applications (NDAs) for opioid analgesics approved by the FDA between 1997 and 2018. Cross-sectional analysis. Data from ClinicalTrials.gov, FDA reviews, and peer-reviewed publications. Patients with pain who participated in phase 3 pivotal trials. FDA-approved opioid analgesics. Key characteristics of each NDA, including the number, size, and duration of pivotal trials; trial control groups; the use of enriched trial populations; and systematically measured safety outcomes. Most of the 48 NDAs evaluated were for new dosage forms (n= 25 [52.1%]) or new formulations (n= 9 [18.8%]); only 1 (2.1%) was for a new molecular entity. Of 39 NDAs approved for treating chronic pain, only 21 products were supported by at least 1 pivotal trial; these trials (n= 28) had a median duration of 84 days (interquartile range [IQR], 25 to 84 days) and enrolled a median of 299 patients (IQR, 174 to 525 patients). Seventeen (81%) of these products were approved on the basis of designs that excluded patients who could not tolerate the drugs, had early adverse effects, or reported few immediate benefits. Among NDAs for chronic pain, 8 (20.5%) included pooled safety reviews that reported systematic assessment of diversion, 7 (17.9%) reported systematic measurement of nonmedical use, and 15 (38.5%) assessed development of tolerance. Eight of 9 products for acute pain were supported by at least 1 pivotal trial; the pivotal trials (n= 19) had a median duration of 1 day (IQR, 1 to 2 days) and enrolled a median of 329 patients (IQR, 199 to 456 patients). Although all but 1 of the 48 approved NDAs were for previously approved moieties, analysis of available NDAs for referent products yielded similar findings. The analysis was limited to approved opioids. Animal studies and nonpivotal trials were excluded. Evidence for safety in NDAs was presented for chronic pain only. Between 1997 and 2018, the FDA approved opioids on the basis of pivotal trials of short or intermediate duration, often in narrowly defined pain populations of patients who could tolerate the drug. Systematic collation of certain important safety outcomes was rare. None.

Identification of a Novel Retrieval-dependent Memory Process in the Crab Neohelice granulata

Fully consolidated associative memories may be altered by alternative retrieval dependent memory processes. While a brief exposure to the conditioned stimulus (CS) can trigger reconsolidation of the original memory, a prolonged CS exposure will trigger memory extinction. The conditioned response is maintained after reconsolidation, but is inhibited after extinction, presumably by the formation of a new inhibitory memory trace. In rats and humans, it has been shown that CS exposure of intermediate duration leave the memory in an insensitive or limbo state. Limbo is characterised by the absence of reconsolidation or extinction. Here we investigated the evolutionary conserved nature of limbo using a contextual Pavlovian conditioning (CPC) memory paradigm in the crab Neohelice granulata. In animals with fully consolidated CPC memory, systemic administration of the protein synthesis inhibitor cycloheximide after 1 CS presentation disrupted the memory, presumably by interfering with memory reconsolidation. The same intervention given after 320 CSs prevented CPC memory extinction. Cycloheximide had no behavioural effect when administered after 80 CS presentations, a protocol that failed to extinguish CPC memory. Also, we observed that a stronger CPC memory engaged reconsolidation after 80 CS instead of limbo, indicating that memory strength affects the parametrical conditions to engage either reconsolidation or limbo. Altogether, these results indicate that limbo is an evolutionary conserved memory process segregating reconsolidation from extinction in the number of CSs space. Limbo appears as an intrinsic component of retrieval dependent memory processing, with a key function in the transition from memory maintenance to inhibition.

Preference of individuals in the treatment strategies of acute myocardial infarction in China: a discrete choice experiment

BackgroundAcute myocardial infarction (AMI) is a significant cause of mortality and morbidity worldwide. Today, with increasing life quality and social economy, people pay much attention to the cost-effectiveness of a treatment strategy. This study investigated the preferences of individuals who would be potential caregivers or patients for AMI treatment in order to provide liable and instructive information for cardiologists and other related physicians.MethodsA discrete choice experiment was conducted among people to assess preferences for hypothetical AMI treatment scenarios characterized by the attributes of treatment method, mortality within 5 years, complication rate within 1 year, treatment duration and expense. A conditional logit regression model and latent class analysis were used to interpret the collected data systematically. The relative importance of each attribute and willingness to pay of people on the trade-offs between different treatment strategies were estimated.ResultsParticipants valued mortality within 5 years most highly (average importance: 40.9, 95%CI 0.447–0.530). Three classes of participants were identified: Class 1 placed the most importance on treatment duration, class 2 corresponded with the overall result while expense was regarded as the most important attribute in class 3. Individuals favored an intermediate treatment duration of about 10 days instead of the shortest (95% CI 1.044–1.248, P < 0.001). People’s characteristics (sex, age, marriage, education and income) affected their preferences (P < 0.01).ConclusionPeople considered a mortality rate within 5 years as the most crucial attribute in the MI treatment and preferred an intermediate treatment duration of about 10 days. Furthermore, the findings estimated the trade-offs acceptable to patients and heterogeneity in preferences for AMI treatment.

Preferencias de formación continua entre los Titulados Universitarios en Ciencias de la Actividad Física y el Deporte en activo en Galicia

La formación continua es una oportunidad de estar actualizado a los rápidos cambios en la adquisición de competencias que requiere el mercado laboral. Sin embargo, muchas veces la oferta no está acorde con las necesidades. Este artículo analiza los intereses formativos que tienen los profesionales Titulados Universitarios en Ciencias de la Actividad Física y el Deporte, y su relación con los ámbitos y salidas profesionales en el sector del deporte. Se utilizó una encuesta on-line en la que participaron 80 sujetos que actualmente ejercen en la Comunidad Autónoma de Galicia. El diseño del cuestionario fu encargado un grupo de expertos. En Galicia los Titulados Universitarios en Ciencias de la Actividad Física y el Deporte en activo tienen mayor inclinación hacia la formación en los ámbitos de la Actividad Física y Salud, Entrenamiento, y Gestión Deportiva. Así mismo, prefieren formaciones específicas de duración intermedia y de carácter presencial. Lifelong learning is an opportunity to be updated to the rapid changes in the acquisition of skills required by the labor market. However, the supply is often not in line with the needs. This article analyzes the training interests of University Graduates in Physical Activity and Sport Sciences and their relationship with the professional fields and exits of the sports sector. An online survey was passed to 80 subjects who currently work in the Autonomous Community of Galicia. The design of the questionnaire was commissioned by a group of experts. In Galicia, University Graduates in Physical Activity and Sports Sciences are more inclined to training in the areas of Physical Activity and Health, Training, and Management of Sport. Likewise, they prefer specific formations of intermediate duration and face to face.

S223. DETERMINANTS OF SUSTAINED UNEMPLOYMENT IN FORMERLY EMPLOYED SCHIZOPHRENIA PATIENTS

BackgroundVocational drift, or the suggestion that severe mental illness leads to reductions in occupational attainment, has been repeatedly observed in schizophrenia. Neurocognition, social functioning, education, environment, and previous work experience have been implicated in patients’ ability to acquire and maintain a job. Interestingly, some patients with successful prior work histories can develop chronic unemployment. In this study, we analyzed a sample of schizophrenic individuals with varying histories of obtaining and sustaining employment to examine vocational drift through the lens of vocational deterioration. We hypothesized that 1) social cognitive variables would be more impaired in patients with a long duration of unemployment and 2) neurocognitive deficits would be more prominent in patients who were never employed.Methods396 patients between 18 and 70 years old with a diagnosis of Schizophrenia, Schizoaffective Disorder, or First Episode Spectrum Disorder were included in this analysis. Measures included comprehensive clinical, neurocognitive, social cognitive, and functional assessments. Samples were divided into groups based on their employment history.Although our original sample included currently employed patients, the following groups were examined as a function of vocational drift: a) Never (n=150), individuals who have never had a job and b) Formerly employed (n=138), individuals who had a job for at least two years in the past but are currently unemployed. Among unemployed patients, we identified those with Short (less than 2 years; n=65), Intermediate (2 to 5 years; n=87), and Extended (more than 5 years; n=136) unemployment.ResultsIn the overall comparison of Formerly employed patients, those with Short and Intermediate duration of unemployment did not differ from each other on any variables and performed better than Extended duration unemployment patients on measures of premorbid intelligence (WRAT, p<.01), processing speed (Symbol coding, p<.01), emotion recognition (BLERT, p<.01 and ER-40, p<.01), theory of mind (Hinting test, p<.05) and hostile cognitive bias (AIHQ Blame, p<.01). Interestingly, patients with Extended unemployment had less depression (BDI total, p<.01) compared to patients who Never worked. The Extended unemployment patients performed worse than the Never employed patients on premorbid intelligence (WRAT, p<.01), processing speed (Symbol coding, p<.05), emotion recognition (BLERT, p<.01 and ER-40, p<.01), theory of mind (Hinting test, p<.05), social inference (TASIT, p<.01), hostile cognitive bias (AIHQ Blame, p<.01), and had higher clinical ratings on PANSS Blunted affect (P<.01) and Poor Rapport (p<.01).DiscussionThe development of long-term unemployment in patients with schizophrenia is associated with multiple neurocognitive and social cognitive deficits, particularly when compared to patients who have never been employed. These deficits were also notable when compared to patients with a shorter duration of unemployment. It is not possible to determine if these long-term unemployed patients always exhibited these deficits, suggesting additional support for vocational drift among patients with schizophrenia. The possible deterioration in neurocognitive and social cognitive performance over time may be driving the development of long-term unemployment in previously employed patients, who in many ways, underperformed compared to patients who had never worked.

Pet shop mice are infected with a novel lymphocytic choriomeningitis virus strain that sustains an abundance of stem-like PD-1+ CD8 T cells

Abstract Lymphocytic choriomeningitis virus (LCMV) is a natural mouse pathogen. LCMV Armstrong, an acutely resolved strain, and LCMV Clone13, a mutant that establishes chronic infection, have provided contrasting infection models that continue to inform the fundamental biology of T cell differentiation, regulation of exhaustion, and response to checkpoint blockade. Here, we describe LCMV Minnesota (LCMV-MN), which was transmitted to laboratory mice upon cohousing with pet shop mice and shares 80–95% amino acid homology with previously characterized LCMV strains. Infection of laboratory mice with purified LCMV-MN resulted in widely disseminated viral replication and viremia that was controlled within 15–30 days; which is of intermediate duration between LCMV Armstrong and Clone13. The magnitude of the LCMV-MN specific CD8+ T cell was maintained at much higher levels than that observed after LCMV Armstrong or Clone13 infections. LCMV-MN responding CD8+ T cells were further associated with significantly biased differentiation towards the recently described PD1+ CXCR5+ Tim-3lo stem-like CD8+ T cell population that was previously shown to be largely responsible for responsiveness to PD-1 inhibitory checkpoint blockade. In contrast to LCMV Clone13-induced responses, this subset persisted after resolution of LCMV-MN viremia, yet transcriptionally, phenotypically and functionally resembled PD1+ TCF1+ stem-like CD8+ T cells maintained by LCMV Clone13 infection. Together with existing models, LCMV-MN may contribute to a better understanding of the breadth of immune response in different chronic infections or tumor settings as well as the regulation of responsiveness to PD-1 blockade.

Subjective time estimation in Antarctica: The impact of extreme environments and isolation on a time production task

Interval timing measures time estimation in the seconds-to-minutes range. Antarctica provides a real-world context to study the effect of extreme photoperiods and isolation on time perception. The aim of this study was to explore interval timing as a cognitive measure in the crew of Belgrano II Argentine Antarctic Station. A total of 13 subjects were assessed for interval timing in short (3 s), intermediate (6 s) and long (12 s) duration stimuli. Measures were taken during the morning and evening, five times along the year. Significant variations were found for 3 s and 6 s during the morning and 6 s during the evening. Results suggest an impact of isolation on morning performances and an effect of the polar night on evening measures. These findings shed some light on the use of interval timing as a cognitive test to assess performance in extreme environments.

Outcomes of transcatheter closure of patent ductus arteriosus with the off-label use of large occluders (≥16 mm)

ObjectiveTranscatheter closure is the first-choice strategy for the management of appropriate patients with patent ductus arteriosus (PDA). The management of large PDAs is challenging due to the limited available sizes of approved devices and the inherent risks of surgical ligation, especially in adults with calcified PDAs. This study aimed to assess the outcomes of the off-label use of large occluders at a tertiary center. MethodsThis retrospective review included patients who underwent transcatheter PDA closure with large occluders (≥16 mm) over 16 years. The baseline patient data, procedural details, angiograms, and immediate outcomes were recorded and patients were followed up at 3, 6, 12 months after the intervention and annually thereafter. ResultsOf the 685 patients who underwent transcatheter PDA closure, 36 patients (mean age 16.6 ± 12.5 years) needed occluders ≥ 16 mm in size. Cocoon duct occluder, Cera duct occluder, Amplatzer atrial septal occluder (ASO), and Cera muscular ventricular septal defect occluders were used for PDA closure. There was no device embolization, one patient in whom ASO was used had residual shunt with intravascular hemolysis requiring surgery, and one patient had mild left pulmonary artery narrowing after the intervention, which was managed conservatively. No patient had residual shunt and one patient had persistent pulmonary hypertension at an intermediate duration of follow-up. ConclusionTranscatheter PDA closure with the use of large devices, which are available in Asia and Europe, is an effective and safe method, especially in adolescents and adults. However, a close follow-up of these patients is mandatory.

Temperature-Dominated Driving Mechanisms of the Plant Diversity in Temperate Forests, Northeast China

Climate, topography, and tree structure have different effects on plant diversity that vary with spatial scale. In this study, we assessed the contribution of these drivers and how they affect the vascular plant richness of different functional groups in a temperate forest ecosystem in Northeast China. We investigated about 0.986 million plants from 3160 sites to quantify the impact of annual mean temperature, sunshine duration, annual precipitation, standard deviation of diameter at breast height, and forest type on richness of vascular plants (total species, tree, treelet, shrub, and herb, separately) using the gradient boosting model. The results show that annual mean temperature had the strongest impact on plant richness. The tree richness peaked at intermediate annual mean temperature and sunshine duration and increased with annual precipitation. The Shannon diversity index and Simpson dominance index increased with annual precipitation and standard deviation of diameter at breast height, decreased with sunshine duration, and peaked at intermediate annual mean temperature and forest type. The total richness and understory richness increased with annual mean temperature and standard deviation of diameter at breast height and peaked at intermediate sunshine duration and annual precipitation. A comprehensive mechanism was found to regulate the plant diversity in forest ecosystems. The relationship between tree richness and annual mean temperature with latitudinal effect could be affected by the differences in number and size of tree individuals, indicating that plant diversity varies with the utilization of energy. The force driving plant richness varied with the functional group due to the different environmental resource requirements and the life history strategies of plants layers.

A comparative study of activated platelet rich plasma versus local corticosteroid injection for the treatment of lateral epicondylitis: A randomised study

Background: Lateral epicondylitis (Tennis elbow) is due to degeneration in common origin of extensor group of muscles of forearm. The objective of our study was assessment of efficacy of activated platelet rich plasma and local corticosteroid injection for the treatment of lateral epicondylitis. Methods: 50 patients with chronic lateral epicondylitis were included in the study and randomised into 2 groups. Group 1 was treated with a single injection of 2 ml of autologous platelet rich plasma (4.8 times of plasma) with 1 ml of calcium chloride as activator and group 2 patients were infiltrated with 2 ml of local corticosteroid (methylprednisolone acetate 80 mg) mixed with 1 ml of 2 % lignocaine, followed by elbow strap, stretching and strengthening exercises along with oral non-steroidal anti-inflammatory drugs for both groups. Pain and functional outcomes were assessed using visual analogue scale (VAS) and NIRSCHL staging at 0, 1, 3, 6, weeks and 4 months and 8 months. Results: Pain variables including VAS and NIRSCHL scores improved significantly in both groups at short and intermediate duration, but long-term activated platelet rich plasma showed better improvement in regard to pain severity, functional outcome and recurrence rates. Conclusion: Both platelet rich plasma and local corticosteroid injection are effective to treat chronic lateral epicondylitis., But platelet rich plasma is better in both short-term and long-term follow-up in tennis elbow with no post injection exacerbation of pain in PRP cases.

Characterization of Optimal Strain, Frequency and Duration of Mechanical Loading on Skeletal Myotubes' Biological Responses.

Mechanical loading of differentiated myoblasts in vitro may mimic loading patterns of skeletal muscle in vivo. However, it is still uncharacterized the loading conditions that can produce the most effective muscle cells' biological responses, in vitro. This study investigated the effects of different loading protocols on the expression of myogenic regulatory factors, anabolic, atrophy and pro-apoptotic factors in skeletal myotubes. C2C12 myoblasts were differentiated and underwent various stretching protocols by altering their elongation, frequency and duration, utilizing an in vitro cell tension system. The loading-induced expression changes of MyoD, Myogenin, MRF4, IGF-1 isoforms, Murf1, Atrogin, Myostatin, Foxo and Fuca were measured by Real Time-PCR. Stretching by 2% elongation at 0.25 Hz for 12 h was overall the most effective in inducing beneficial responses. A low strain, low frequency intermediate duration stretching can most effectively up-regulate myogenic/anabolic factors and down-regulate pro-apoptotic and atrophy genes in myotubes.

A clinical comparative study of different doses of cisatracurium for intubation in patients undergoing general anaesthesia

Cisatracurium is a new non-depolarizing, benzylisoquinolinium neuromuscular blocking drug with intermediate duration of action .It is a stereoisomer of atracurium with a potency of approximately 3 to 4 times greater than that of atracurium. Despite the higher potency, cisatracurium is associated with more stable hemodynamics than atracurium and does not cause histamine release even at doses of upto 0.4mg/kg (8×ED95). The recommended intubating dose is 0.15mg/kg (3×ED95) & High Most of the previous clinical studies have compared equipotent doses of atracurium and cisatracurium and concluded that atracurium is more effective than cisatracurium at same dose (2×ED95). However, few studies have shown that increasing the dose of cisatracurium to 4×ED95 (0.2mg/kg) and 6×ED95 (0.3mg/kg) provided more effective neuromuscular blockade and excellent cardiovascular stability with no marked histamine release clinically. Hence the present study was done in order to test the intubating conditions and hemodynamic stability of cisatracurium at 2 ×ED95 and 4×ED95 doses.Methods: Randomised controlled trial conducted, after ethical committee clearance and informed written consent from patient. Sixty patients of ASA 1 and 2 aged 20 -60 yrs of both sexes coming for elective surgeries under general anaesthesia. Patients were divided into two groups, so each, group A received 0.1mg/kg (2*ED95) and group B received 0.2mg/kg(4*ED95) loading dose of cisatracurium.Results: Intubating conditions were satisfactory with group B compared to group A and was statistically significant. Better hemodynamic stability with respect to mean pulse rate, systolic blood pressure and mean arterial pressure in group B compared to group A and was statistically significant. Conclusion: 4*ED95 doses of cisatracurium provides better intubating conditions and more stable hemodynamic status than 2*ED95. There was no untoward effects noted clinically.

Phototransferred thermoluminescence of annealed synthetic quartz: Analysis of illumination-time profiles, kinetics and competition effects

Phototransferred thermoluminescence (PTTL) induced from annealed synthetic quartz using 470 nm blue light is reported. The quartz was annealed at 900 °C for 10, 30 and 60 min prior to use. A glow curve of conventional TL measured at 1 °C s−1 following irradiation to 200 Gy for the sample annealed for 10 min shows six peaks at 90, 122, 176, 210, 240 and 340 °C. The sample annealed for 30 min has peaks at 80, 110, 136, 196, 240 and 330 °C. Similarly, the sample annealed for 60 min also has six peaks at 80, 120, 134, 188, 235 and 340 °C. For ease of reference, these are labelled I-VI respectively. Peaks observed under PTTL are referred to as A1 onwards. Of the six peaks, only the first three are reproduced under phototransfer for the sample annealed for 60 min. When the duration of annealing is reduced to 10 min, PTTL is induced only at peaks A1 and A3. Interestingly, for the intermediate duration of annealing of 30 min, the only peak that appears under phototransfer is the first one, A1. For quartz annealed for 10 min, the PTTL appears as long as the preheating temperature does not exceed 560 °C. On the other hand, in the quartz annealed for 30 and 60 min, PTTL only appears for preheating to and below 450 °C. This shows that the occupancy of deep electron traps at temperatures beyond 450 or 560 °C is low in the said samples. The activation energy for peaks A1 and A3 was found to be about 0.68 eV. The PTTL peaks were studied for thermal quenching and peaks A1 and A3 were determined to be subject to this effect. The activation energy for thermal quenching was determined as 0.62±0.04 eV in analysis using peak A1. In all cases, the PTTL intensity goes through a peak as a function of illumination time. The experimental dependence of PTTL intensity on illumination time is modelled using sets of coupled linear differential equations based on systems of donors and acceptors whose number is determined by preheating temperature. Competition effects involved in the PTTL have been discussed.

P602Septal function and viability determine response to cardiac resynchronization therapy

Abstract Introduction Cardiac resynchronization therapy (CRT) has evolved as an important treatment in patients with symptomatic heart failure, reduced left ventricular (LV) ejection fraction and wide QRS. However, as one third of patients do not benefit from the therapy, there is need for better selection criteria. Previous studies have shown an association between recovery of septal function and response to CRT. Purpose To test the hypothesis that septal dysfunction in the absence of scar predicts response to CRT. Methods In 121 patients undergoing CRT implantation according to current European Society of Cardiology guidelines, we performed speckle-tracking echocardiography and estimated LV pressure non-invasively based on a method recently innovated in our lab. Pressure-strain analysis was used to calculate myocardial work. Septal dysfunction with asymmetric LV workload was calculated as the difference between LV lateral wall and septal work. Late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR) was performed to assess septal scar. CRT response was defined as ≥15% reduction of LV end systolic volume by echocardiography at 6 months follow-up. Results Eighty-eight patients (73%) responded to CRT at 6 months follow-up. Multivariate logistic regression analysis including lateral-to-septal work difference, septal scar, QRS duration and QRS morphology found that only lateral-to-septal work difference and septal scar were significant predictors of CRT response (both p&lt;0.005). Using logistic regression and receiver operating characteristic (ROC) curve analysis, we found that the combined approach of these two parameters identified CRT responders with a sensitivity of 86% and a specificity of 82%. The area under the curve (AUC) for CRT response prediction was 0.85 (95% CI: 0.76–0.94) (Figure). In comparison, the AUC value for QRS duration was 0.63 (95% CI: 0.52–0.75). Furthermore, for the subgroup of patients with QRS duration 120–150 ms (n=27), the AUC value for lateral-to-septal work difference in combination with septal scar was 0.90 (95% CI: 0.78–1.00). Conclusions A multimodality approach with strain echocardiography and LGE-CMR was able to detect CRT responders with high accuracy, also in the subset of patients with intermediate QRS duration. A dysfunctional but viable septum appears to be an ideal target for CRT.

An experimental study on occurrence of intermediate peaks in ice load signals

The purpose of this study is to analyze the relationship between the occurrence of intermediate peak and time duration, and to conduct a review for the causes of the intermediate peak. In this test, ice impact tests were conducted using a bow side shell frame and ice specimen. A total of 70 samples were manufactured. Two types of ice specimen with relatively different surface conditions were used. The criterion for dividing the two types of ice specimen was the different exposure times to room temperature after freezing. This experiment was conducted for each parameter in order to reproduce the actual icebreaking situation.As a result of the analysis, the intermediate peak in the ice load signal have been found to be caused by mechanisms by which the inner surface of broken ice contact with hull immediately after the initial hitting point of ice has been broken.

West African mixed farming systems as meta-ecosystems: A source-sink modelling approach

Nutrient availability is a major limitation of the production of West African mixed farming systems. The fertility of these systems was traditionally sustained by fallowing, and nutrient transfers by livestock from savanna to croplands. However, demographic growth and socio-economic constraints require the agro-ecological intensification of these systems. To understand how agricultural practices and landscape management affect crop production, we built a meta-ecosystem model of nitrogen stocks and fluxes, and we examined different scenarios of fallow management with or without livestock.Our results suggest that crop production is highly dependent on the source-sink dynamics of nitrogen. Without livestock, maximum crop production is obtained for an intermediate duration of fallowing, highlighting a trade-off between space devoted to production (cropland) and space devoted to fertility restoration (fallow). In presence of livestock, crop production is maximum for a shorter duration of fallowing; it is markedly higher with than without livestock. This result highlights the positive roles of livestock and fallows as pumps (vectors) of nitrogen from savanna rangeland to cropland, and from fallow land to cropland, respectively. However, it also highlights the negative relationship between livestock presence and fallowing, suggesting that the optimal configuration of livestock and fallow management is highly context-dependent.Overall, we argue that the meta-ecosystem approach is particularly relevant for the study of agro-ecosystems characterized by high spatial heterogeneity. This work can be seen as a first step toward an alternative approach, integrating tools from theoretical ecology for the study of agro-ecosystems which functioning strongly depends on spatial organisation.