Adaptive GPU-accelerated force calculation for interactive rigid molecular docking using haptics

Molecular docking systems model and simulate in silico the interactions of intermolecular binding. Haptics-assisted docking enables the user to interact with the simulation via their sense of touch but a stringent time constraint on the computation of forces is imposed due to the sensitivity of the human haptic system. To simulate high fidelity smooth and stable feedback the haptic feedback loop should run at rates of 500 Hz to 1 kHz. We present an adaptive force calculation approach that can be executed in parallel on a wide range of Graphics Processing Units (GPUs) for interactive haptics-assisted docking with wider applicability to molecular simulations. Prior to the interactive session either a regular grid or an octree is selected according to the available GPU memory to determine the set of interatomic interactions within a cutoff distance. The total force is then calculated from this set. The approach can achieve force updates in less than 2 ms for molecular structures comprising hundreds of thousands of atoms each, with performance improvements of up to 90 times the speed of current CPU-based force calculation approaches used in interactive docking. Furthermore, it overcomes several computational limitations of previous approaches such as pre-computed force grids, and could potentially be used to model receptor flexibility at haptic refresh rates

Severe accordion effect: Myocardial ischemia due to wire complication during percutaneous coronary intervention: A case report

A mechanical alteration during manoeuvring of stiff guidewires in tortuous coronary arteries frequently induces vessel wall shortening and coronary psedostenosis, referred as accordion phenomenon. Subtraction of the guidewires normally leads to the entire resolution of the lesions. A case of this transient angiographic finding, during percutaneous coronary intervention in a tortuous right coronary artery, which resulted in a flow limiting effect and myocardial ischemia, is described in the present report. Differential diagnosis from potential procedure complications and interventional methodology issues are discussed, while similar reports are reviewed

Water stable molecular n-doping produces organic electrochemical transistors with high transconductance and record stability.

From established to emergent technologies, doping plays a crucial role in all semiconducting devices. Doping could, theoretically, be an excellent technique for improving repressively low transconductances in n-type organic electrochemical transistors - critical for advancing logic circuits for bioelectronic and neuromorphic technologies. However, the technical challenge is extreme: n-doped polymers are unstable in electrochemical transistor operating environments, air and water (electrolyte). Here, the first demonstration of doping in electron transporting organic electrochemical transistors is reported. The ammonium salt tetra-n-butylammonium fluoride is simply admixed with the conjugated polymer poly(N,N'-bis(7-glycol)-naphthalene-1,4,5,8-bis(dicarboximide)-co-2,2'-bithiophene-co-N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide), and found to act as a simultaneous molecular dopant and morphology-additive. The combined effects enhance the n-type transconductance with improved channel capacitance and mobility. Furthermore, operational and shelf-life stability measurements showcase the first example of water-stable n-doping in a polymer. Overall, the results set a precedent for doping/additives to impact organic electrochemical transistors as powerfully as they have in other semiconducting devices

Primary Percutaneous Coronary Intervention in Acute ST-Elevation Myocardial Infarction: The Experience of "Evagelismos" General Hospital of Athens

BACKROUND: Primary percutaneous coronary intervention (PCI) has been shown to be a better reperfusion strategy in patients with ST-elevation myocardial infarction (STEMI) compared with thrombolysis, particularly when applied early. The objective of the present study was to report our experience from treating patients presenting to the emergency room of our hospital with STEMI with primary PCI. PATIENTS AND METHODS: The population of the study included 100 patients who presented to our hospital with STEMI and underwent primary PCI over a 12-month period. Patients’ clinical and angiographic data were retrospectively collected and patients were followed up for 9 months. Technical details of the primary PCI, including stent implantation, and use of drug eluting stents, thrombus aspiration catheter, or platelet glycoprotein IIb/ΙΙΙa inhibitors were recorded and correlated to clinical and angiographic patient data. RESULTS: Of 196 patients who presented o the emergency room with STEMI during the study period, 100 (51%) patients (85 men and 15 women) underwent primary PCI. PCI was successful with TIMI 3 flow of the infarct-related coronary artery in 79 (79%) patients. Six (6%) patients died during hospitalization and another 4 (4.3%) patients died during the 9-month follow up period. Twenty one (22%) patients required rehospitalization for acute coronary syndrome, of whom 17 needed a repeat PCI and 4 patients were submitted to coronary artery bypass grafting. Left ventricular ejection fraction (LVEF) was <50% in 54 (54%) patients. In 52 patients primary PCI was performed in less than 4 hours from onset of symptoms. In his cohort, 19 patients were thrombolyzed before arriving to the catheterization laboratory. Antithrombotic therapy with platelet glycoprotein IIb/IIIa inhibitors was used in 48 (48%) patients. Univariate analysis showed that the odds of achieving TIMI 3 flow were higher after using IIb/ΙΙΙa inhibitors (odds ratio-OR 6.4) or if the LVEF ≥50% (vs LVEF < 50%) at the beginning of the PCI (OR 6.4). If the time from the onset of symptoms to PCI was >4 hours, the odds of achieving TIMI 3 flow were reduced by 23.4% compared to time from symptoms to PCI <4 hours. The presence of TIMI 3 flow of the infarct-related artery reduced the odds of death by 10.2% compared to the absence of TIMI 3 flow of the infarct-related coronary artery. CONCLUSION: Our results are in keeping with those published by other groups performing primary PCI. We demonstrated the importance of time interval from onset of symptoms until PCI is started. We found that the use of GP IIb/IIIa inhibitors was beneficial and emphasized the predictive value of LVEF >50% and the importance of achieving TIMI 3 flow in the IRA at the end of the procedure

Doping-induced decomposition of organic semiconductors: a caveat to the use of Lewis acid p-dopants

Solution-processable molecular dopants are popular wet-lab mediators to engineer the electronic properties of organic semiconductors and to optimize the level performance of their corresponding devices. Nonetheless, the exact doping mechanism that is operative during the interaction of organic semiconductors with Lewis acid species is not fully elaborated. The products of the doping reactions between Lewis acids and organic semiconductors have not been studied in detail. Here we focus on the macromolecular poly[bis(4-phenyl)(2,4-dimethylphenyl)]amine (PTAA) and molecular fluorinated anthradithiophene (diF-TES-ADT) organic semiconductors for addressing their chemical integrity after p-doping by the tris(pentafluorophenyl) borane [B(C6F5)3] Lewis acid agent. The PTAA and diF-TES-ADT organic substrates are studied in mixtures with B(C6F5)3 at three discrete concentration regimes. In the dilute solution regime, UV-Vis absorption spectroscopy verifies the effectiveness of p-doping by the changes observed in the absorption spectra of the solutions at increased B(C6F5)3 content. In the concentrated solution regime, the reactivity of B(C6F5)3 with PTAA and diF-TES-ADT is monitored by proton nuclear magnetic resonance (1H-NMR) and electrospray ionization mass spectroscopy (ES-MS), as well as thin-layer chromatography (TLC). Finally, in the solid-state the photophysical properties of spin-coated PTAA:B(C6F5)3 and diF-TES-ADT:B(C6F5)3 films are examined as a function of their B(C6F5)3 content. Density functional theory (DFT) calculations corroborate the experimental findings. Both theoretical and experimental results exclude the formation of Lewis adduct species in the PTAA:B(C6F5)3 and diF-TES-ADT:B(C6F5)3 systems. In agreement with recent literature, the B(C6F5)3 reactivity is attributed to the Brønsted-type acidity of the hydrated B(C6F5)3-OH2 complex that induces p-doping via the protonation of the organic substrates. The formation of the B(C6F5)3-OH2 acidic agent is identified experimentally by its characteristic 1H-NMR signal at 4.7 ppm. All results for the three concentration regimes provide evidence for the occurrence of PTAA and diF-TES-ADT decomposition in the presence of B(C6F5)3. At high B(C6F5)3 loadings, ES-MS spectroscopy and TLC analysis suggest that B(C6F5)3 remains unreacted, revealing the catalytic role in the decomposition process of PTAA and diF-TES-ADT. The results suggest that after interacting with Lewis acids, organic semiconductors may undergo detrimental decomposition reactions. This potentially undesired chemical reactivity should be considered for evaluating the operation stability of the p-doped electronic devices

Primary Percutaneous Coronary Intervention in Acute ST-Elevation Myocardial Infarction: The Experience of "Evagelismos" General Hospital of Athens

We report our experience from treating a large number of patients who presented to the Emergency Department of our Hospital with ST-elevation acute myocardial infarction (AMI) with primary percutaneous coronary intervention (PCI). Of the 196 patients who presented with ST elevation AMI over a period of 12 months, 100 (51%) patients underwent primary PCI. Clinical and angiographic data were collected and patients were followed up for 9 months. Technical details of the primary PCI, including use of balloon, use of thrombus aspiration catheter, stent implantation, use of drug eluting stents, and use of GP IIb/IIIa inhibitors were recorded and correlated to clinical and angiographic patient data. Our results are in keeping with those published by other groups performing primary PCI. We demonstrated the importance of time interval from onset of symptoms until PCI is started. We found that the use of GP IIb/IIIa inhibitors was beneficial and emphasized the predictive value of left ventricular ejection fraction >50% and the importance of achieving TIMI 3 flow in the AMI related artery at the end of the procedure

Water stable molecular n-doping produces organic electrochemical transistors with high transconductance and record stability

Improving electron transport and stability of n-type organic electrochemical transistors (OECTs) is required to realize a commercially-viable technology for bioelectronics applications. Here, the authors report water-stable doped n-type OECTs with enhanced transconductance and record stability

Endovascular Treatment of Aneurysm With Side Branches - A Simple Method. Myth or Reality?

PURPOSE: The aim of this study is to present performance data on the use of the multilayer stent which is a 3-dimensional (3D) braided mesh made of interconnected layers, particularly in patients with side branches within the aneurysm. METHODS:  A study protocol was designed to examine the safety and efficacy of the multilayer stent in patients with aneurysms in different target vessels. Between December 2006 and November 2009, 19 patients were enrolled in the study. Four patients had a renal aneurysm (1 male / 3 females) (mean diameter: 18 mm), while the other 15 patients (all males) had iliac artery (n=12, mean diameter: 25 mm),  popliteal artery (n=1, diameter: 55 mm), thoracic aorta (n=1, diameter: 57mm) and abdominal aorta (n=1, diameter: 97.3 mm) aneurysms. RESULTS: The multilayer stent was successfully deployed in all patients (100% technical success); Mean follow-up for the peripheral aneurysms was 28 months (range 12 to 36) and for the aortic aneurysms was 3 months. The occlusion rate of the aneurysm at the peripheral arteries was 100% and all the side branches remained patent. For the thoracic and the abdominal aneurysms, the 3 months computed tomography angiography (CTA) showed patent artery side branches and reduced blood flow inside the sac. CONCLUSION: The multilayer stent seems to be efficient with regard to the side branches which remain patent and the aneurysm is excluded. The question remains about the time needed to achieve the exclusion of the aneurysm in large arteries such as the thoracic and abdominal aorta; we believe this is related to the number and size of the branches within the aneurysm as well as the size of the target vessel itself. A larger multi center study is needed to confirm the suitability of the multilayer stent for the large thoracic, abdominal and thoracoabdominal aneurysms