A patient had undergone surgical resection twice for primary and metastatic dedifferentiated liposarcomas. Follow-up computed tomography revealed a new tumor mass located at the cavoatrial junction. Prompt surgical resection of the tumor with thrombectomy was successfully performed using cardiopulmonary bypass with hypothermic circulatory arrest. We report a rare case of a patient surviving for 8 years after the first tumor resection despite the poor prognosis of metastatic or recurrent liposarcoma.

Background: This study evaluated the impact of various sizing metrics on outcomes of female donor to male recipient orthotopic heart transplantation (OHT). Methods: We queried the United Network of Organ Sharing database to analyze all isolated, primary adult OHTs from 1/12010-3/20/2020. Patients were stratified by donor-recipient sex pairing. Logistic regression was used to investigate risk-adjusted effects of current size matching criteria (weight ratio, body mass index (BMI) ratio, predicted heart mass (pHM) ratio) on one-year post-transplant mortality. Kaplan-Meier analysis was used to compare posttransplant survival among cohorts. Results: A total of 22,450 patients were analyzed, of which 3,019 (13.4%) underwent female-to-male transplantation. Of sex-matched pairs, female-to-male donation had the lowest proportion of undersized hearts using weight and BMI ratio metrics (10.5% and 5.2%) but had the highest proportion of undersizing using pHM metrics (48.1%) (all P<0.001). Female-to-male recipients had the lowest rate of unadjusted one-year survival (90.0%, P = 0.0169), and increased hazards of mortality after risk adjustment (OR 1.17, 95% CI 1.01-1.36, P=0.034)). Undersizing using pHM (donor-recipient ratio < 0.85) was the only metric found to be associated in increased mortality after risk adjustment (OR 1.32, 95% CI 1.02 to 1.71, P=0.035). Conclusions: Female-to-male heart transplantation has the worst survival of all sex-matching combinations. Although female donors in this cohort are appropriately sized using traditional metrics, half are under-sized using pHM. This, combined with its strong association with mortality, underscores the importance of routine pHM assessment when evaluating female donors for male recipients.

A 75 years old man with previous aortic abdominal aneurysm surgery through a transverse laparotomy underwent bilateral internal mammary artery (BIMA) to coronary artery bypass grafting (CABG). He immediately thereafter developed a severe chest and upper abdominal walls ischemia with metabolic acidosis, and finally deep sternum wound infection and upper abdominal wall necrosis. He benefitted from sternal reconstruction and vaccum assisted treatment, with delayed pectus major flap reconstruction. Chest and abdominal wall infarction following BIMA harvesting is a very rare but life-threatening complication. Caution use of BIMA should be in order in patients with inferior epigastric artery flow impairment.

Here we describe two clinical prenatal cases with rare de novo RIT1 variants which showed more severe clinical manifestations than other Noonan Syndrome genotypes, resulting in fetal death. It is recommended that extra attention would be exercised when these variants are detected, and an appropriate patient counselling would be provided.

Drooping wildryegrass (Elymus nutans) has been widely planted together with other perennial grasses for rebuilding degraded alpine meadow atop the Tibetan Plateau. However, the rebuilt sown pastures begin to decline a few years after establishing. One of the possible causes for degradation of sown grassland may come from allelopathy of planted grasses. The purpose of this study was to examine allelopathic potential of drooping wildryegrass. Three types aqueous extracts from drooping wildryegrass and its root zone soil were prepared and 5 highland crops and 5 perennial grasses were used as recipient plants. Drooping wildryegrass exhibited strong allelopathic potential on germination and seedling growth of 5 crops germination and growth, but different crops or perennial grasses respond to the extracts differently. The pieces extract has stronger inhibition than others. Hulless barley, oat and Chinese fescue were the most affected, while quinoa and Siberian wildryegrass were the least affected. Drooping wildryegrass presented less influence on Kentucky bluegrass and crymophylla bluegrass than on Chinese fescue. It is recommended that the species combination of mixture for restoration should consider allopathic effects of the co-seeding and decrease the seeding rate ratio of drooping wildryegrass. The annual dicot crop quinoa and rape seeds can be used as alternative subsequent crop for seed field of drooping wildryegrass monoculture.

Telomere DNA length is a complex trait controlled both by multiple loci and environmental factors. Even though the use of telomere DNA length measurement, as a method of assessing stress accumulation and predicting how this will influence survival, is currently being studied in numerous human cohort studies, the importance of telomere length for stress response in ecological studies remains at its infancy. Here, we investigated the telomere changes occurring in the symbiotic coral Stylophora pistillata that has experienced a continuous darkness over six months. This stress condition led to the loss of its symbionts, as what is also observed when bleaching occurs in the field at a large-scale due to climate changes and anthropogenic activities, threatening the worldwide reef ecosystem. We found that the continuous darkness condition was associated with telomere DNA length shortening and a downregulation of the expression of the telomere-associated protein Pot2. These results pave the way for future studies on the role of telomere in coral stress response and the importance of telomere dysregulation in endangered coral species.

A document by Marguerite Lawler, written on Authorea.

Background: Inflammatory markers such as C-reactive protein and Albumin have previously been associated with poor prognosis in ST-elevation myocardial infarction (STEMI). Objective: The present study aims to investigate the relationship between the infarct-related arteries (IRA) patency and C-reactive protein/Albumin ratio (CAR) before primary percutaneous intervention (p-PCI) in patients with STEMI. Methods A total of 822 patients who underwent primary PCI (p-PCI) for acute STEMI were included in this study. Patients were divided into two groups according to IRA patency as TIMI flow 0-1 (n = 551) and TIMI flow 2-3 (n = 271). CAR ratio measured at admission was compared with IRA patency. Results: The average age of 822 patients was 55±12, and 84.3% (693) of the patients were male. The mean CAR level of the patients was determined as 0.26 (0.08-0.48). CAR level was statistically significantly higher in TIMI flow 0-1 group when compared to TIMI flow 2-3 group [0.31 (0.09-0.51) vs 0.23 (0.06-0.42); p<0.001]. In the multivariate logistic regression analysis a significant relation was found between CAR (odds ratio [OR]:1.56, 95% confidence interval [CI]:1.22-1.97, p<0.001), and neutrophil count (OR:1.72, 95% CI:1.33-2.25, p<0.001) in patients with TIMI flow 0-1 Conclusion: An inflammation-based risk index, CAR measured at admission in patients with anterior STEMI has been found to be a useful prognostic tool for predicting adverse cardiovascular outcomes. However, this finding needs to be confirmed in future prospective studies.

Thoracic endovascular aortic repair has been preferred over surgery for aortic lesions owing to its minimal invasiveness. Here we report the successful endovascular repair of a thoracic aortic pseudoaneurysm after esophageal perforation induced by accidental ingestion of a fishbone.

Statins are widely prescribed and well tolerated with most side effects now considered a nocebo effect. Occasionally, statins can be associated with immune mediated necrotizing myositis that is both difficult to diagnose and treat. Aggressive immunosuppressive therapy is the best recognized method of treatment of this complication.

Desertified land reclamation for the purposes of winegrape cultivation can profoundly alter the properties of the underlying soil and the microbial communities therein. Herein, we assessed the effects of such reclamation of non-productive desert land on the soil microbial communities associated with the resultant vineyards, and to identify key soil properties related to these changes. Soil was collected from natural desert land (DL) and from different reclaimed vineyard types: Cabernet Sauvignon (CS), Merlot (M), Chardonnay (C), and Italian Riesling (IR). High-throughput sequencing was used to assess microbial community composition and diversity in these samples. Significant differences in soil organic carbon (SOC), total nitrogen, available nitrogen, available phosphorus, and pH were detected when comparing soil from DL and reclaimed lands. CS, M, C, and IR soils exhibited higher relative Actinobacteria, Proteobacteria, and Ascomycota abundance, while DL soil exhibited higher relative Acidobacteria and Mortierellomycota abundance. In total, 165 and 55 bacterial and fungal amplicon sequence variants or operational taxonomic units (ASVs/OTUs) were shared across land use types. Following reclamation, soil bacteria ASVs/OTUs in CS, M, C, and IR soils rose to 2846, 3191, 7630, and 6373, respectively. Biomarkers of these different land use types were successfully identified via an LDA Effect Size (LEfSe) approach, while key soil properties including pH, SOC, and available nitrogen were found to be associated with these changes in microbial community structural composition following reclamation. As such, our data indicate that viticulture in desertified regions can enhance soil properties and microbial diversity, thereby supporting sustainable land use.

Background: Pulmonary embolism (PE) patients with right ventricular (RV) involvement are a heterogenous group who mandate further risk stratification. Our objective was to evaluate the efficacy of the PE severity index (PESI) for predicting adverse clinical outcomes among PE patients with RV involvement. Methods and Results: Consecutive normotensive PE patients with RV involvement were allocated according to admission PESI score (PESI <4 vs. PESI ≥4). The primary outcome included hemodynamic instability and in-hospital mortality. Secondary outcomes included each component of the primary outcome as well as mechanical ventilation, thrombolytic therapy, acute kidney injury, and major bleeding. Multivariable logistic regression model was performed to assess the independent association between the PESI score and primary outcome. C-Statistic was used to compare the PESI with the BOVA score. A total of 253 patients were evaluated: 95 (38%) with a PESI of ≥4. Of them, 82 (32%) patients were classified as intermediate-low risk and 171 (68%) as intermediate-high risk. Fifty (20%) patients had at least 1 adverse event. Multivariate analysis demonstrated the PESI to be an independent predictor for the primary outcome (HR 4.81, CI 95%, 1.15-20.09, P=0.031), which was increased with a concomitant increase of the PESI score (PESI 1:4.2%, PESI 2: 3.4%, PESI 3:12%, PESI 4: 16.3%, PESI 5:23.1%, P for trend <0.001). C-Statistic analysis for the PESI score yielded an AUC-0.746 (0.637-0.854), P=0.001, compared to the BOVA score: AUC-0.679 (0.584-0.775), P=0.011. Conclusion: PESI score was found to predict adverse outcomes among normotensive PE patients with RV involvement.

Background and aim of the study: Patients with severe coronavirus disease 2019 (COVID-19) develop a profound cytokine-mediated pro-inflammatory response. This study reports outcomes in 10 patients with COVID-19 supported on veno-venous extracorporeal membrane oxygenation (VV-ECMO) who were selected for the emergency use of a hemoadsorption column integrated in the ECMO circuit. Materials and Methods: Pre and post treatment, clinical data and inflammatory markers were assessed to determine the safety and feasibility of using this system, and to evaluate the clinical effect. Results: During hemoadsorption, median levels of interleukin (IL)-2R, IL-6, and IL-10 decreased by 54%, 86%, and 64% respectively. Reductions in other markers were observed for LDH (-49%), ferritin (-46%), D-dimer (-7%), C-reactive protein (-55%), procalcitonin (-76%) and lactate (-44%). Vasoactive-inotrope scores decreased significantly over the treatment interval (-80%). The median hospital length of stay was 53 days (36-85) and at 90-days post cannulation, survival was 90% which was similar to a group of patients without the use of hemoadsorption. Conclusions: Addition of hemoadsorption to VV-ECMO in patients with severe COVID-19 is feasible and reduces measured cytokine levels. However, in this small series, the precise impact on the overall clinical course and survival benefit still remains unknown.

Background Food protein-induced enterocolitis syndrome (FPIES) is a non IgE-mediated food allergy, with potential dehydration secondary to vomiting. Differences exist regarding culprit foods, onset symptoms, and age of tolerance depending on the country of origin. We aimed to describe the characteristics of a French population of children with FPIES. Methods Data from 179 children who were referred for acute or chronic FPIES in two pediatric tertiary centers between 2014 and 2020 were retrospectively collected. The diagnosis of FPIES was based on international consensus guidelines. Clinical characteristics, culprit food and age at resolution were assessed. Results In the 192 described FPIES, the age at first symptoms was 5.8 months old. The main offending foods were cow’s milk (60.3%), hen’s egg (16.2%), and fish (11.7%). Single FPIES was observed in 94.4% and multiple FPIES in 5.6% of cases. The age at resolution of FPIES was 2.2 years old, and resolution occurred later for fish than for milk (2.9 years versus 2.0, p=0.01). Severe acute FPIES was a risk factor for delayed resolution (relative risk: 3.3 [1.2-9.2]), but not IgE sensitization. Performing an oral food challenge within 12 months after the first reaction increased the risk of failure (RR: 2.0 [1.2-3.5]). Conclusion In this French cohort of children with FPIES, the main culprit foods were ubiquitous. Rice, oat and soy were rarely or not involved. Multiple FPIES was infrequent. Our data confirmed the overall good prognosis of FPIES, the later resolution of FPIES to fish and in the case of severe acute FPIES.

Aims: This study sought to describe originating from the spontaneous scarring of left atrial anterior wall (LAAW) left atrial macroreentry tachycardia (LAMRT) clinical and electrophysiological characteristics, mechanisms, the formation of substrates. Methods and Results: 9 of 123 patients (89% female, age 79.78±5.59 years) had LAMRT originating from the LAAW and no cardiac surgery or prior left atrial (LA) ablation. The mean tachycardia cycle length (TCL) was 241.67±38.00 milliseconds. Spontaneous scars areas and low voltage areas (LVAs) in the LAAW were found in all patients. Successful ablation of the critical isthmus caused terminated of the LAMRT and was not inducible in all patients. Arrhythmogenic substrates of LAMRT were the spontaneous scars of LAAW, which matched with the aorta or/and pulmonary artery contact area. The area under the curve (AUC) of age and combination of gender and age for predicting the LAMRT originating from the LAAW were 0.918 and 0.951, respectively, with a cutoff value of ≥73.5 years of age and gender (female) predicting LAMRT with 88.9% sensitivity and 89% specificity. Conclusion: Combination of gender and age provides a simple and useful criterion to distinguish LAMRT from cavo-tricuspid isthmus (CTI) -dependent atrial tachycardia in macroreentry atrial tachycardia (MRAT) in patients without a history of surgery or ablation. Aorta or/and pulmonary artery contacting LA may be related to spontaneous scars. Ablation the isthmus eliminated LAMRT in all patients.

The characterization of fluid dynamics and mass transfer is often influenced by phase maldistribution. An existing cell model approach for fluid distribution is extended for gas distribution and mass transfer. The model differentiates wall and bulk zones, allowing a detailed evaluation of local fluid dynamics and mass transfer, which is based on a state-of-the-art literature correlation. Distribution parameters are determined experimentally. The model allows scale-up by considering the phase distribution at constant computational effort. A scale-up strategy to adapt the distribution parameters to different geometries is presented. Results for fluid dynamics and liquid distribution are in good agreement with experimental data of columns with diameters of 0.288, 0.5 and 0.6 m. Mass transfer is in good qualitative agreement with own experiments in a 0.288 diameter column. While maldistribution consequently reduces the gas side mass transfer, the reduced liquid bulk flow weakens the effect of liquid side mass transfer.

In this article, we consider the following p-q-Laplacian system with singular and critical nonlinearity \begin{equation*} \left \{ \begin{array}{lllll} -\Delta_{p}u-\Delta_{q}u=\frac{h_{1}(x)}{u^{r}}+\lambda\frac{\alpha}{\alpha+\beta}u^{\alpha-1}v^{\beta} \ \ in\ \Omega ,\\ -\Delta_{p}v-\Delta_{q}v=\frac{h_{2}(x)}{v^{r}}+\lambda\frac{\beta}{\alpha+\beta}u^{\alpha}v^{\beta-1} \ \ in\ \Omega, \\ u,v>0 \ \ \ \ \ \ in \ \Omega, \ \ \ \ \ u=v=0 \ \ \ \ \ \ \ on \ \partial\Omega, \end{array} \right. \end{equation*} where Ω is a bounded domain in $\mathbb {R}^{n}$ with smooth boundary $\partial\Omega$. $11,\lambda\in(0,\Lambda_{*})$ is parameter with $\Lambda _{*}$ is a positive constant and $h_{1}(x),h_{2}(x)\in L^{\infty},h_{1}(x),h_{2}(x)>0$. We show the existence and multiplicity of weak solution of equation above for suitable range of $\lambda$.

Identification of phenotypic characteristics in reproductively successful individuals provides important insights into the evolutionary processes that cause range shifts due to environmental change. Female beluga whales (Delphinapterus leucas) from the Baffin Bay region (BB) of the Canadian Arctic in the core area of the species’ geographic range have larger body size than their conspecifics at the southern range periphery in Hudson Bay (HB). We investigated the mechanism for this north and south divergence as it relates to reproductive activity (RA = total corpora) that combines morphometric data with ovarian corpora counted from female reproductive tracts. Based on the previous finding of reproductive senescence in older HB females, but not for BB whales, we compared RA patterns the of the two populations’ with age and body length. Female beluga whale RA increased more quickly with age (63% partial variation explained) in BB than in HB (41%). In contrast, body length in HB female beluga whale accounted for considerably more of the total variation (12 vs 1%) in RA compared to BB whales. We speculate that female HB beluga whale RA was more strongly linked with body length due to higher population density resulting in food competition that favors the energetic advantages of larger body size during seasonal food limitations. Understanding the evolutionary mechanism of how RA, and potentially fitness, varies across a species’ range will assist conservation efforts in anticipating and mitigating future challenges associated with a warming planet.

Background: The known primary radiological diagnosis of Chiari Malformation-I (CM-I) is based on the degree of tonsillar herniation ( TH) below the Foramen Magnum (FM). However, recent data also shows the association of such malformation with smaller posterior cranial fossa (PCF) volume and the anatomical issues regarding the Odontoid. This study presents the achieved result regarding some detected potential radiological findings that may aid CM-I diagnosis using several machine learning (ML) algorithms. Materials and Methods: Between 2011 and 2020, radiological examinations of 100 clinically/radiologically proved symptomatic CM-I cases and 100 control were evaluated by matching age and gender. A team of Neuroradiologists had reviewed the MR images of the study population. A total of 11 different radiological parameters were assessed for CM-I diagnosis. The parameters were defined and examined in 5 designed different ML algorithms. Statistical analysis was conducted for data analysis. Results: The mean age of patients was 29.92 ± 15.03 years. The primary presenting symptoms were headaches (62%). Syringomyelia and retrocurved-odontoid were detected in 34% and 8% of patients, respectively. All of the morphometric measures were significantly different between the groups, except for the distance from the dens axis to the posterior margin of FM. The Radom Forest model is found to have the best 1.0 (14 of 14) ratio of accuracy in regard to 14 different combinations of morphometric features. Conclusion: This study indicates the potential usefulness of ML-guided PCF measurements, other than TH, that may be used to predict and diagnose CM-I accurately. Our results support the view of TH as a single radiological parameter may fail during the diagnosis of CM-I. Combining two or three preferable osseous structure-based parameters may increase the accuracy of radiological diagnosis of CM-I.

Premature ventricular complexes (PVC) ablation has increased over the past decades. The morphology of PVCs arising from left anterior fascicle (LAF) is typically a right bundle branch block-like morphology with an inferior axis showing a qR or qRs complex in the inferior leads and an rS or RS complex in leads I and aVL. We describe the case of a 38 years old woman with symptomatic, high burden PVCs, despite of beta blockers treatment. The PVC’s ECG morphology suggested an origin in the LAF. This case illustrates how ablation from the right coronary cusp for PVC arising from the LAF could be accurately guided by pace-mapping. At this location, pacing at different outputs can result in both a selective and a non-selective capture of the left anterior fascicle.

A 42-year-old woman presented with myalgia, which ameliorated a week after treatment. She was diagnosed with Basedow's disease. The presence of concomitant autoimmune diseases are important considerations for patients with Basedow's disease presenting with myalgia. Thyrotoxicosis should be included as a rare differential diagnosis for myalgia.

Leadless Pacing with Mechanical Atrial Sensing and Variable AV ConductionJason Cook, MDTravis D. Richardson, MDFrom Vanderbilt University Medical Center. Nashville, TennesseeCorresponding author:Travis D. Richardson, MDAssistant Professor Cardiac ElectrophysiologyVanderbilt Heart and Vascular Institute1215 21st Ave S. Nashville, TNMedical Center East, South Tower, Suite 5209ph (615) 936-7537fax (615) 936-5064travis.d.richardson@vanderbilt.eduWord Count:1331Disclosures: The authors report no relevant financial disclosures.Funding: NoneThe MicraTM leadless transcatheter pacing system (Medtronic Inc., Mounds View, MN) has been shown to be an effective alternative to transvenous pacing with excellent implantation success rates and durable long-term performance.1–3 The first generation device provided single chamber right ventricular pacing with rate responsiveness enabled by a 3-axis accelerometer.Recently, the MARVEL 2 study (Micra Atrial tRacking using a Ventricular accELerometer 2) reported the ability of software enhancements to allow a leadless pacemaker to deliver single chamber atrioventricular (AV) synchronized pacing.4 In contrast to dual-chamber transvenous pacemakers which sense atrial electrograms, the MARVEL 2 algorithm adjudicates atrial events using mechanically sensed atrial activity from the 3-axis accelerometer. During initial programming, the relative timing of mechanical events to the ventricular electrogram allows for identification of A3 (passive ventricular filling) and A4 (atrial contraction). Atrial-sensed events are then defined by the A4 signal, and tracking may occur. MARVEL 2 reported VDD pacing was achieved at rest in an impressive 89.2% of patients.The Micra AVTM system’s unique programming includes three basic pacing modes: VDD, VVI and VDIR (Figure 1). Additionally, two mode switch algorithms are available and by default programmed on: the AV conduction mode switch and the activity mode switch. Unlike mode switch algorithms in dual chamber pacing systems, which are intended to avoid inappropriate tracking of atrial arrhythmias, these algorithms are intended to 1) minimize ventricular pacing, and 2) to improve rate support during patient activity respectively.When the AV conduction mode switch algorithm is enabled, the device periodically switches from VDD to VVI at 40 bpm to allow for intrinsic AV conduction. If ventricular sensing occurs above a rate of 40 bpm, in order to reduce right ventricular pacing, VVI 40 programming will continue regardless of the programmed lower rate limit. However, if two of any window of four beats are paced at VVI 40, the device reverts to VDD. Thereafter, reassessments of AV conduction are performed at increasing intervals starting at 2 minutes until either AV conduction is detected or 8 hours is reached at which point subsequent testing occurs at regular 8 hour intervals.The activity mode switch algorithm utilizes the sensor indicated rate in an attempt to ensure adequate ventricular rate support during patient activity regardless of AV conduction. The sensor in the MicraTM is always running. If at any time 1) the sensor indicated rate is above the device programmed ADL rate, and 2) the current ventricular rate is >20 BPM below the sensor rate, the activity mode switch will change the device to VDIR mode with heart rates determined by the sensor. This switch may occur from either the VDD mode or VVI in the setting of AV conduction. The device will revert to VDD mode when the sensor rate drops below the ADL rate.With the added functionality of atrial sensing and the incorporation of the MARVEL 2 algorithms described above, in this issue of the Journal of Cardiovascular Electrophysiology, Garweg et al. examined the pacing behavior of the Micra AVTM in the presence of variable AV conduction, atrial arrhythmias, sinus bradycardia (< 40 bpm), sinus arrhythmia, and periods of atrial and ventricular ectopy (Reference). During the data collection period in MARVEL 2, ECG, electrogram, accelerometer waveforms, and device marker data were obtained; this was collected either after initial implant and follow-up or, for patients with previously placed devices, during a single encounter. The average monitoring period was 153 minutes. The study included 73 patients with normal sinus node function and varying degrees of AV block.While the number of patients with variable AV conduction was small (5), the investigators found that the rhythm checks allowed for appropriate mode adjustments during the study period. During periods of AV block, as expected, 99.9% ventricular pacing was observed while during 1:1 AV conduction only 0.2% pacing was observed. Ventricular pacing was monitored in patients with 1:1 AV conduction using conventional VVI pacing and MARVEL 2 programming. MARVEL 2 programming using the AV conduction mode switch algorithm resulted in a reduction in ventricular pacing from 22.8% to 0.2% (n=18). Reducing the burden of ventricular pacing is an important enhancement to the system with the potential to minimize pacing-induced cardiomyopathy.5One potential pitfall of atrial sensing addressed by this study is tracking of atrial arrhythmias. While the sample size was small (n=7), tracking of atrial fibrillation resulting in pacing at the upper tracking rate was not observed in any of the patients. In one patient with atrial flutter, intermittent atrial tracking did occur but did not result in tachycardia. In contrast to atrial rate based mode switching used in conventional dual-chamber pacemakers, the behavior of the MARVEL 2 algorithm during atrial fibrillation is dictated by the sensed ventricular rate. With the AV conduction mode switch enabled, if the ventricular rate is above 40 bpm, the pacing mode will be VVI at 40 bpm. If rates are less than 40 bpm, the pacing mode will be VDD. In the context of atrial fibrillation, reduced atrial contractility results in lack of mechanical sensing, and pacing at the lower rate is observed. In this small sample size, atrial arrhythmias did not result in device tracking resulting in tachycardia. Further investigation in a larger number of patients is warranted to better characterize these findings and to assess pacing behavior during more organized atrial arrhythmias which could result in mechanical sensing (atrial tachycardia and atrial flutter, for example).While the MARVEL 2 programming seems to perform well in the setting of atrial fibrillation or intermittent complete AV block, there are some potential pitfalls. AV conduction mode switch behavior is based on sensed ventricular rates with a threshold of 40 bpm; this cutoff is not currently programmable. Any ventricular sensed rhythm with a rate greater than 40 bpm will result in the device continuing at VVI 40. For example, in a patient with sinus rhythm at 90 bpm and 2:1 AV conduction, the device would not track the atrium and pace at 90 bpm, but rather remain VVI 40 because the ventricular sensed rate is above 40 bpm. The same would be observed in patients with junctional or ventricular escape rhythms >40 bpm. In this sense, pacing could be inappropriately inhibited during a potentially hemodynamically significant rhythm. For this reason, in our opinion, the AV conduction mode switch algorithm should be disabled in the majority of patients with AV block as this physiology is dynamic and sudden loss of rate support can have deleterious consequences. While the activity mode switch algorithm may address some of these concerns real world data are needed for validation.There is no question that the functionality and indications for leadless pacemakers will continue to expand. In current guidelines, which predate the development of the Micra AVTM, single chamber ventricular pacing is only recommended in patients with AV block and permanent atrial fibrillation, a low burden of anticipated pacing, or substantial comorbidities.6 Given the potential for lower complication rates compared with transvenous systems, Micra AV may be a superior option in some patients with complete heart block and preserved ventricular function. However, with the advent of conduction system pacing, the decreased risks of a leadless system have to be balanced with the relative risk of long term right ventricular pacing. Although the results will need to be validated with larger, longer-term studies, which are underway (Clinical trials.gov NCT04245345), these data indicate that Micra AVTM is likely to perform well in the setting of atrial arrhythmias. In patients with variable AV conduction, there are certainly pitfalls to the AV conduction mode switch algorithm, many of which could be avoided by the ability to program the mode switch VVI rate. While leadless pacing is often considered in patients with multiple comorbidities at high risk of complications from a transvenous system, we may be on the cusp of a dramatic paradigm shift. The technological developments and success of leadless pacing to date prompt the question of when, and not if, leadless dual chamber pacing and potentially even cardiac resynchronization will be available.References:1. Reynolds D, Duray GZ, Omar R, et al. A Leadless Intracardiac Transcatheter Pacing System. https://doi.org/10.1056/NEJMoa1511643. doi:10.1056/NEJMoa15116432. El-Chami MF, Al-Samadi F, Clementy N, et al. Updated performance of the Micra transcatheter pacemaker in the real-world setting: A comparison to the investigational study and a transvenous historical control. Heart Rhythm . 2018;15(12):1800-1807. doi:10.1016/j.hrthm.2018.08.0053. Duray GZ, Ritter P, El-Chami M, et al. Long-term performance of a transcatheter pacing system: 12-Month results from the Micra Transcatheter Pacing Study. Heart Rhythm . 2017;14(5):702-709. doi:10.1016/j.hrthm.2017.01.0354. Steinwender C, Khelae SK, Garweg C, et al. Atrioventricular Synchronous Pacing Using a Leadless Ventricular Pacemaker: Results From the MARVEL 2 Study. JACC Clin Electrophysiol . 2020;6(1):94-106. doi:10.1016/j.jacep.2019.10.0175. Merchant FM, Mittal S. Pacing induced cardiomyopathy. J Cardiovasc Electrophysiol . 2020;31(1):286-292. doi:10.1111/jce.142776. Kusumoto Fred M., Schoenfeld Mark H., Barrett Coletta, et al. 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation . 2019;140(8):e382-e482. doi:10.1161/CIR.0000000000000628

Objectives: The treatment of COVID-19 infection remains a challenge because till now, there is no approved therapy for it. This study aimed to estimate the difference in the therapeutic efficacy and safety between remdesivir as monotherapy and its use in combination with lopinavir/ritonavir provided with standard supportive care. Methods: This is a prospective randomized cohort study included 1043 adult patients with confirmed moderate and severe COVID-19 infection. Treatment of all patients followed Egyptian Ministry of Health COVID-19 protocol as the first group received IV remdesivir 200 mg on day 1, followed by 100 mg once daily, for 5 days while the second group received lopinavir/ritonavir 400/100 mg twice daily, for 5 days with the same remdesivir regimen in the first group. All laboratory and clinical parameters were assessed before and after treatment duration. Results: There was no significant difference related to improvement parameters such as laboratory data and improvement time between the two groups. On the other hand, hepatotoxicity of the second group (combination) was significantly higher compared with that of the first one. The elevation on liver enzymes was affected by the severity of the disease, the severe cases showed a high enzyme elevation rate. Conclusion: Remdesivir as monotherapy and its use in combination with lopinavir/ritonavir is effective in the management of moderate COVID 19 subjects than severe cases. The combination of remdesivir with lopinavir/ritonavir is not recommended due to the increased hepatotoxicity effect.

In the light of the current climate crisis, one of the most serious ecological threats is the increase of desertification. In this context, restoration projects are necessary for reverting land degradation, and nature-based solutions could help them. The Cocoon™ has been designed as a new ecotechnology for improving seedling establishment. The Cocoon consists of a donut-shaped container made out of recycled cardboard that provides water and shelter to the seedling, at least during its first year, which is the most critical for plant establishment. The Cocoon was tested on a variety of soils, Mediterranean mesoclimates, vegetation and land uses that allowed testing the effectiveness of this ecotechnology under different conditions. Six planting trials, five of them in Spain (Canary Islands, Almería, Catalonia and two in Valencia), and one in Ptolemais (Greece), were performed. With the objective of studying its functionality, the survival of the seedlings, their vigor and growth were monitored along two years. In general, the Cocoon has proven its effectiveness by increasing seedling survival compared to the conventional planting system, especially under dry growing conditions (low rainfall, soils with low water holding capacity). The Cocoon also allowed for higher growth of some species (olive trees, olm oaks and Aleppo pines). Moreover, a positive correlation between the rainfall on the site and the degradation degree of the Cocoon device was observed. Overall, the Cocoon becomes more efficient the more arid the climate or the more difficult the growing conditions are.