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The RNA programmed non-specific (trans) nuclease activity of CRISPR-Cas Type V and VI systems has opened a new era in the field of nucleic acid-based detection. Here, we report on the enhancement of trans-cleavage activity of Cas12a enzymes using hairpin DNA sequences as FRET-based reporters. We discover faster rate of trans-cleavage activity of Cas12a due to its improved affinity (Km) for hairpin DNA structures, and provide mechanistic insights of our findings through Molecular Dynamics simulations. Using hairpin DNA probes we significantly enhance FRET-based signal transduction compared to the widely used linear single stranded DNA reporters. Our signal transduction enables faster detection of clinically relevant double stranded DNA targets with improved sensitivity and specificity either in the presence or in the absence of an upstream pre-amplification step.

Offshore wind energy has seen a steady increase in the latest years as it serves as an ideal alternative energy source to meet our renewable energy goals. Due to this increase in interest and in installations of offshore wind farms a better understanding of the impact of waves on the power production of wind farms in necessary. This wave-wind farm power production interaction has scarcely been examined, however, some exceptions of small scale large-eddy-simulations exist. Unfortunately, these studies are not able to take multiple wind farms under real weather conditions into account. Here, we show the power production and wake lengths of 1250 offshore wind turbines located in the German Bight simulated by a stand-alone atmospheric (WRF) model and a coupled atmosphere-wave (WRF-SWAN) model. The coupled atmosphere-wave model estimates larger (smaller) power production in case of waves and wind traveling in the same (opposed) direction compared to the stand-alone atmospheric model. The relative difference between the two models can be as much as 20% for the two-week averaged grid power production, while the difference in total power over this two-week period is equal to 9%. Moreover, the wind farm wake lengths of waves and wind traveling in the same (opposed) direction are longer (shorter) for the coupled atmosphere-wave model compared to the stand-alone atmospheric model. Here, the relative difference of the mean wake length between the two models can be up to 25%. This shows the importance of waves as a part of the offshore wind environment and can be an important factor in future wind assessment or power production estimation studies.

We present a new class of DNA-based nanoswitches that, upon enzymatic repair, could undergo a conformational change mechanism leading to a change in fluorescent signal. Such folding-upon-repair DNA nanoswitches are synthetic DNA sequences containing O(6)-methyl-guanine (O(6)-MeG) nucleobases and labelled with a fluorophore/quencher optical pair. The nanoswitches are rationally designed so that only upon enzymatic demethylation of the O(6)-MeG nucleobases they can form stable intramolecular Hoogsteen interactions and fold into an optically active triplex DNA structure. We have first characterized the folding mechanism induced by the enzymatic repair activity through fluorescent experiments and Molecular Dynamics simulations. We then demonstrated that the folding-upon-repair DNA nanoswitches are suitable and specific substrates for different methyltransferase enzymes including the human homologue (hMGMT) and they allow the screening of novel potential methyltransferase inhibitors.

BACKGROUND: The DyeVert™ system (Osprey Medical Inc., Minnesota, MN) may reduce contrast media (CM) volume during coronary procedures while maintaining fluoroscopic image quality. Here, we assessed whether the use of the DyeVert system reduces acute kidney injury (AKI) rate in patients with acute coronary syndrome (ACS) undergoing invasive coronary procedures. METHODS: ACS patients scheduled for coronary procedure from January 2017 to December 2019 were included. Two groups were identified: (a) Control group (n= 339), including patients in which a conventional manual injection syringe was used; and (b) DyeVert group (n= 112), in which CM injection was handled by the DyeVert™ system. A propensity score matching was performed to reduce the effect of treatment selection bias and potential confounders. In all cases, a low-osmolar, nonionic CM was administered. The primary objective was the rate of AKI, defined as a serum creatinine increase ≥0.3mg/dl within 72 hr after CM exposure. RESULTS: CM volume was higher in the Control group than in the DyeVert group (130 [120–188] ml vs. 99 [69–136] ml; p&nbsp

Plaque prolapse (PP) is commonly defined as tissue extrusion through the stent strut. It is not a rare event, frequently detected by intravascular ultrasound, and it is associated with stent thrombosis and adverse outcomes. We present a case of PP after stenting of the left anterior descending coronary artery.

ispartof: QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY vol:147 issue:735 pages:825-846 status: published

Coronary artery fistula (CAF) is defined as anomalous communication between coronary arteries and cardiac chamber or a major thoracic vessel. CAF are a rare coronary anomaly, mostly congenital, first described by Krause in 1856. In literature the incidence in general population is approximately 0,002%. Detection of CAF during coronary angiography is usually accidental. In 50% of cases CAF originate from right coronary artery, in 30% they originate from LAD, while in the rest of the percentage CAF originate from left circumflex artery. CAF drain into low–pressure chamber (right ventricle or right atrium, superior Vena Cava or pulmonary artery). We can distinguish CAF into little or medium sized, usually with silent clinical course, and large sized CAF, with variable clinical signs, depending on the extent of the shunt and on the hemodynamic overload of the receiving chamber. We describe the case of a 57 y.o woman with hypertension, admitted for femur fracture. ECG showed bifasic T waves in the anterior leads, already described in a previous ECG. Normal systolic function and no valvular defect were found on the echocardiogram. Patient was asymptomatic. Coronary angiography documented normal coronary arteries, with a double coronary fistula: the first from a septal branch of posterior descending and the second one from distal branches of the first diagonal. Even if CAF have often a favorable clinical course with no relevant consequences for the patient, it’s crucial to obtain more information about their functional implication and their anatomic connections. Indeed, rare cases of sudden cardiac death have been described in patients with CAF involved in myocardial ischemia based on the theft syndrome mechanism. Echocardiographic evaluation of the patient to detect associated congenital abnormalities, pressure overload of the receiving chambers and the extent of the shunt on the coronary angiography are crucial for the proper management of CAF. In the case described above we decided to optimize therapy adding beta–blocker (to reduce the overload caused by the two coronary fistula).

Coronary artery kink is a variant of anomalous coronary artery, not related to vessel disease. Often it is associated with coronary artery tortuosity (CAT) and fibromuscular dysplasia. The pathogenesis and clinical implications are not fully understood. Kinks are hypothesized to cause coronary blood flow alterations that can results in ischemia and even in acute coronary syndrome. It is speculated that coronary artery kinks are most often caused by guide wire straightening and seen after wiring the artery, but that is not always the case. We describe the case of a 55 years old woman, with familiar history of CAD. In 2019 she had percutaneous Patent Foramen Ovale closure intervention. She presented to the Emergency Department complaining chest pain radiating into the neck. The ECG was normal, but Troponin I levels were mildly elevated (2,1 ng/ml) and ipokinesia of basal and mid segment of the anterior intraventricular spetum was found at the ecoscopy. The patient was admitted to Cardiology department with diagnosis of unstable angina and urgent coronary angiography was performed. At a first glance the coronary arteries did not exhibit significant arteriosclerotic or thrombotic changes. However, upon a closer review, a focal kink of the mid left descending coronary artery was found. This coronary kink folded the LAD during systole causing a transient stenosis that resolved during diastole. Management of coronary kinks is controversial. In the past, literature suggested treatment with coronary stenting as one of the management options. However there are reported cases of adverse outcomes, such as shifting of kink proximally, requiring an additional stenting. We decided to treat patient with medical approach: beta–blockers at the tolerated doses was initiated, in addition to ACE–Inibithor, Aspirin and statin. Stenting of the coronary artery was not a choice, due to the possibility of shifting (as described in literature) and stent fracture. At a one month follow up the patient presented asymptomatic for angina, palpitation or dyspnea. Even if rarely coronary artery kink is a potential cause of myocardial ischemia and its treatment is often challenging to improve patient quality of life and to prevent adverse cardiac event.

The infective endocarditis (IE) has a significant impact on mortality rate in the first year after diagnosis, despite the improvements in early diagnosis and therapy. Embolic complications cause worsening of patient’s prognosis and they occur in the 20–50% of cases, with a risk of new embolic events after the initiation of antibiotic therapy rated between 6 and 12%. Echocardiographic characterization of vegetation has an important role in the definition of the embolization risk, it is documented that vegetation with dimension more than 10 mm are at higher risk. Several characteristic of the patient (diabetes, previous embolization, atrial fibrillation) determine the increase of the embolization risk, as well as the initiation of antibiotic therapy. We describe the case of a 64 y.o. man with chronic coronary syndrome (previous PCI) and previous Bentall–De Bono intervention for ascending aorta aneurysm. Patient was under anticoagulant therapy with DOAC due to atrial fibrillation. He was admitted to the emergency department for intermittent fever during the last three months, dyspnea and fatigue. Blood test showed neutrophilic leukocytosis and increased value of inflammatory markers. Transthoracic echography revealed an hyperechoic image on the ventricular side of the aortic prosthesis. The diagnosis of infective endocarditis was confirmed with transesophageal echocardiography, and empiric antibiotic therapy was initiated. Cardiac surgeon suggested follow up and new evaluation after three weeks of therapy. Clinical course was complicated by acute abdomen. The CT exam revealed dilation of a distal tract of superior mesenteric artery (maximum axial diameter was 10 mm) associated with distal thrombosis extended for 6 mm. The transthoracic echocardiogram showed absence of the vegetation on aortic prosthesis previous documented. Therapy with intravenous infusion of unfractionated heparin was administrated for three weeks, but the control TC showed persistence of the thrombotic occlusion of superior mesenteric artery so the case was discussed with Vascular Surgery team. They decided to treat patient with embolization and aneurysmectomy surgery (cultures were negative). This clinical case demonstrates that embolic complication of infective endocarditis, even on proper antbiotic therapy and close monitorization, are unpredictable and can cause the worsening of patient’s clinical course.

We report here the development of a cell-free

Carbon nanotube (CNT)-based electrodes are cheap, highly performing, and robust platforms for the fabrication of electrochemical sensors. Engineering programmable DNA nanotechnologies on the CNT surface can support the construction of new electrochemical DNA sensors providing an amperometric output in response to biomolecular recognition. This is a significant challenge, since it requires gaining control of specific hybridization processes and functional DNA systems at the interface, while limiting DNA physisorption on the electrode surface, which contributes to nonspecific signal. In this study, we provide design rules to program dynamic DNA structures at the surface of single-walled carbon nanotubes electrodes, showing that specific DNA interactions can be monitored through measurement of the current signal provided by redox-tagged DNA strands. We propose the use of pyrene as a backfilling agent to reduce nonspecific adsorption of reporter DNA strands and demonstrate the controlled formation of DNA duplexes on the electrode surface, which we then apply in the design and conduction of programmable DNA strand displacement reactions. Expanding on this aspect, we report the development of novel amperometric hybridization platforms based on artificial DNA structures templated by the small molecule melamine. These platforms enable dynamic strand exchange reactions orthogonal to conventional toehold-mediated strand displacement and may support new strategies in electrochemical sensing of biomolecular targets, combining the physicochemical properties of nanostructured carbon-based materials with programmable nucleic acid hybridization.