Prospects and challenges of environmental DNA (eDNA) monitoring in freshwater ponds

Environmental DNA (eDNA) analysis is a rapid, non-invasive, cost-efficient biodiversity monitoring tool with enormous potential to inform aquatic conservation and management. Development is ongoing, with strong commercial interest, and new uses are continually being discovered. General applications of eDNA and guidelines for best practice in freshwater systems have been established, but habitat-specific assessments are lacking. Ponds are highly diverse, yet understudied systems that could benefit from eDNA monitoring. However, eDNA applications in ponds and methodological constraints specific to these environments remain unaddressed. Following a stakeholder workshop in 2017, researchers combined knowledge and expertise to review these applications and challenges that must be addressed for the future and consistency of eDNA monitoring in ponds. The greatest challenges for pond eDNA surveys are representative sampling, eDNA capture, and potential PCR inhibition. We provide recommendations for sampling, eDNA capture, inhibition testing, and laboratory practice, which should aid new and ongoing eDNA projects in ponds. If implemented, these recommendations will contribute towards an eventual broad standardisation of eDNA research and practice, with room to tailor workflows for optimal analysis and different applications. Such standardisation will provide more robust, comparable, and ecologically meaningful data to enable effective conservation and management of pond biodiversity

Minimal access median sternotomy for aortic valve replacement in elderly patients

BACKGROUND: We report our clinical experience with a approach for aortic valve replacement (AVR) via minimal access skin incision and complete median sternotomy. This approach was used in patients with higher age and multiple co-morbidities, facilitating an easy access with short bypass and cross clamp times. It was especially performed in patients asking for an excellent cosmetic result, who did not qualifying for minimally-invasive AVR via partial upper sternotomy. METHODS: AVR via minimal-access median sternotomy, was performed in 58 patients between 01/2009 and 11/2011. Intra- and postoperative data including cross clamp time, cardiopulmonary bypass time, mortality, stroke, pacemaker implantation, re-operation for bleeding, ventilation time, ICU and hospital stay, wound infection, sternal dehiscence or fracture and 30 day mortality were collected. RESULTS: Mean patients age was 76.1 +/−9.4 years, 72% were female. Minimal-access AVR could be performed with a mean length of midline skin incision of 7.8 cm. Aortic cross-clamping time was 54.6 +/−6.3 min, cardiopulmonary bypass time 71.2+/−11.3 min and time of surgery 154.1 +/−26.8 min. Re-operation for bleeding had to be performed in 1 case (1.7%). There were no strokes or pacemaker implantations needed. Mean ventilation time was 4.5 h, ICU stay was 2 days and mean length of hospital stay was 6 days. 6 months follow up showed mortality of 0% and no sternal dehiscence or wound infection was observed. CONCLUSION: Minimal-access AVR via complete median sternotomy can be performed safely,in this elderly patient cohort without adding additional operative risk compared to conventional AVR. By avoidiance of large skin incisions this approach combines excellent cosmetic results with fast surgery time and excellent postoperative recovery

Combinations of QT-prolonging drugs: towards disentangling pharmacokinetic and pharmaco-dynamic effects in their potentially additive nature.

Background: Whether arrhythmia risks will increase if drugs with electrocardiographic (ECG) QT-prolonging properties are combined is generally supposed but not well studied. Based on available evidence, the Arizona Center for Education and Research on Therapeutics (AZCERT) classification defines the risk of QT prolongation for exposure to single drugs. We aimed to investigate how combining AZCERT drug categories impacts QT duration and how relative drug exposure affects the extent of pharmacodynamic drug–drug interactions. Methods: In a cohort of 2558 psychiatric inpatients and outpatients, we modeled whether AZCERT class and number of coprescribed QT-prolonging drugs correlates with observed rate-corrected QT duration (QTc) while also considering age, sex, inpatient status, and other QTc-prolonging risk factors. We concurrently considered administered drug doses and pharmacokinetic interactions modulating drug clearance to calculate individual weights of relative exposure with AZCERT drugs. Because QTc duration is concentration-dependent, we estimated individual drug exposure with these drugs and included this information as weights in weighted regression analyses. Results: Drugs attributing a ‘known’ risk for clinical consequences were associated with the largest QTc prolongations. However, the presence of at least two versus one QTc-prolonging drug yielded nonsignificant prolongations [exposure-weighted parameter estimates with 95% confidence intervals for ‘known’ risk drugs + 0.93 ms (–8.88;10.75)]. Estimates for the ‘conditional’ risk class increased upon refinement with relative drug exposure and coadministration of a ‘known’ risk drug as a further risk factor. Conclusions: These observations indicate that indiscriminate combinations of QTc-prolonging drugs do not necessarily result in additive QTc prolongation and suggest that QT prolongation caused by drug combinations strongly depends on the nature of the combination partners and individual drug exposure. Concurrently, it stresses the value of the AZCERT classification also for the risk prediction of combination therapies with QT-prolonging drugs

Hybrid QRS detector based on dynamic reconfigurable field programmable analog array

W artykule zaprezentowano nową koncepcję układu detekcji w czasie rzeczywistym zespołu QRS z przebiegu elektrokardiograficzngo. W detektorze wykorzystano programowalną matrycę analogową AN221E04 firmy Anadigm. Parametry wybranych bloków są na bieżąco zmieniane w zależności od zmian parametrów przebiegu EKG dzięki dynamicznej rekonfigurowalności układu. Uzyskano bardzo krótki czas reakcji detektora na wykryty zespół QRS przy zadowalającej skuteczności detekcji. Opracowany detektor może znaleźć zastosowanie w aplikacjach biomedycznych wymagających wykrywania zespołu QRS w przebiegu EKG z małym opóźnieniem czasowym.In many applications it is important to detect the QRS complex in the ECG waveform with possibly low time delay. Traditional software detectors of the QRS complex implement algorithms, usually based on cascades of digital filters, introduce delays up to parts of a second. Hardware QRS detectors (Fig. 1) fulfill the low delay requirements, but have worse adaptive features for the changing ECG shape. In this paper a new approach to QRS detection is presented. The proposed solution implements a classical detector structure in a Field Programmable Analog Array (FPAA) i.e. AN221E04 circuit from the AnadigmŽ company - Fig. 3. The most interesting feature of the FPAA is the dynamic reconfigurability. This solution makes it possible to modify the parameters of particular blocks of the detector or even the whole structure during runtime, without any changes in hardware and disturbance of the system functionality. Important parameters of particular blocks of the QRS detector are modified on-the-fly according to changes observed in the ECG signal. New data are calculated by the AD7020 microcontroller and downloaded to the FPAA using dynamic reconfigurability after each QRS detection. The prototype QRS detector was tested using a real ECG signal taken from Mit-Bih Arrythmia Database. The results obtained in the prototype circuit (Table 1) show that the detection delay is really small. The error rate of the QRS detection is low and can be acceptable in most real time applications

The Induction of Mild Hypothermia Prevents Acute Respiratory Failure During Endotoxemia in Pigs

Cardiac Dysfunction and Arrhythmia

The Induction of Mild Hypothermia Prevents Sympathetic Activation but Preserves Systemic Vascular Resistance During Endotoxemia in Pigs

Cardiac Dysfunction and Arrhythmia