Symptomatic aneurysms of the innominate and subclavian arteries are rare and pose unique challeng... more Symptomatic aneurysms of the innominate and subclavian arteries are rare and pose unique challenges for endovascular repair particularly in a patient with a “bovine” arch. Previous publications have described back table modifications of standard iliac endografts to conform to the innominate artery for exclusion of the lesion. Others have proposed extra-anatomic bypass or carotid-subclavian transposition with occlusion of the innominate artery. We were unable to find a report of repair when aneurysms of the innominate and subclavian arteries were in continuity. We present such a case of endovascular repair using commercially available endografts without compromise of the left common carotid artery origin as this patient had a “bovine” arch. Surgeons will benefit from adding this endovascular option to their “tool box” when confronted with such a challenging clinical scenario.
Objectives Early infarct expansion promotes adverse remodeling and is associated with poor long-t... more Objectives Early infarct expansion promotes adverse remodeling and is associated with poor long-term prognosis. We hypothesized that thickening the infarcted territory of the LV wall by means of intramyocardial injection of a clinically available acellular hydroxyapatite-based dermal filler would attenuate infarct expansion and improve long-term remodeling after myocardial infarction. Methods Twenty-five adult male sheep underwent coronary ligations that create an anteroapical MI. Fifteen animals subsequently underwent injection of 1.3 mL of a viscous hydroxyapatite based preparation into the infarcted territory - 10 served as controls. Rt-3DE was performed at baseline, 30 minutes post-MI, 30 minutes post-injection and then at 2, 4 and 8 weeks post-MI. LV volumes and EF were calculated in each case. Cardiac output was measured at 8 weeks with no inotropic stimulation and then during infusions of 2.5 and 5.0 mcg/kg/min of dobutamine after which all animals were sacrificed. Finally, L...
We work through a scenario of an observation of multiple images when two parallel mirrors are fac... more We work through a scenario of an observation of multiple images when two parallel mirrors are facing each other, with an omnidirectional light source situated between them. We find that a typical conventional light bulb as a source shall initiate approximately 83 images perceivable by human eye.
This paper analyses the effects due to special and general relativity on a GPS satellite orbiting... more This paper analyses the effects due to special and general relativity on a GPS satellite orbiting at an altitude of 3 Mars radii. It was found that in order to keep both the ground station and the satellite in synchronisation the clock on the satellite would have to be 1.56 μs per Martian day faster than the one on the ground
In this article we investigate whether large angle shots in cue ball games, like Pool or Snooker,... more In this article we investigate whether large angle shots in cue ball games, like Pool or Snooker, have an effect on accuracy. It was concluded that 0 to 40 shots introduce smallest uncertainty, and that shots over 70 have asymptotically large uncertainty.
Background— Although localized delivery of biocomposite materials, such as calcium hydroxyapatite... more Background— Although localized delivery of biocomposite materials, such as calcium hydroxyapatite (CHAM), have been demonstrated to potentially attenuate adverse left ventricular (LV) remodeling after myocardial infarction (MI), the underlying biological mechanisms for this effect remain unclear. This study tested the hypothesis that targeted CHAM injections would alter proteolytic pathways (matrix metalloproteinases [MMPs] and tissue inhibitors of MMPs [TIMPs]) and would be associated with parameters of post-MI LV remodeling. Methods and Results— MI was induced in adult sheep followed by 20 targeted injections of a total volume of 1.3 mL (n=6) or 2.6 mL of CHAM (n=5) or saline (n=13) and LV end-diastolic volume (EDV) and MMP/TIMP profiles in the MI region were measured at 8 weeks after MI. LV EDV decreased with 2.6 mL CHAM versus MI only (105.4±7.5 versus 80.6±4.2 respectively, P <0.05) but not with 1.3 mL CHAM (94.5±5.0, P =0.32). However, MI thickness increased by 2-fold in bo...
Background The asymmetry and complex shape of the right ventricle have made it difficult to deter... more Background The asymmetry and complex shape of the right ventricle have made it difficult to determine right ventricular (RV) volume with 2-dimensional echocardiography. Three-dimensional cardiac imaging improves visualization of cardiac anatomy but is also complex and time consuming. A newly developed volumetric scanning system holds promise of obviating past limitations. Methods Real-time, transthoracic 3-dimensional echocardiographic images of the right ventricle
Symptomatic aneurysms of the innominate and subclavian arteries are rare and pose unique challeng... more Symptomatic aneurysms of the innominate and subclavian arteries are rare and pose unique challenges for endovascular repair particularly in a patient with a “bovine” arch. Previous publications have described back table modifications of standard iliac endografts to conform to the innominate artery for exclusion of the lesion. Others have proposed extra-anatomic bypass or carotid-subclavian transposition with occlusion of the innominate artery. We were unable to find a report of repair when aneurysms of the innominate and subclavian arteries were in continuity. We present such a case of endovascular repair using commercially available endografts without compromise of the left common carotid artery origin as this patient had a “bovine” arch. Surgeons will benefit from adding this endovascular option to their “tool box” when confronted with such a challenging clinical scenario.
Objectives Early infarct expansion promotes adverse remodeling and is associated with poor long-t... more Objectives Early infarct expansion promotes adverse remodeling and is associated with poor long-term prognosis. We hypothesized that thickening the infarcted territory of the LV wall by means of intramyocardial injection of a clinically available acellular hydroxyapatite-based dermal filler would attenuate infarct expansion and improve long-term remodeling after myocardial infarction. Methods Twenty-five adult male sheep underwent coronary ligations that create an anteroapical MI. Fifteen animals subsequently underwent injection of 1.3 mL of a viscous hydroxyapatite based preparation into the infarcted territory - 10 served as controls. Rt-3DE was performed at baseline, 30 minutes post-MI, 30 minutes post-injection and then at 2, 4 and 8 weeks post-MI. LV volumes and EF were calculated in each case. Cardiac output was measured at 8 weeks with no inotropic stimulation and then during infusions of 2.5 and 5.0 mcg/kg/min of dobutamine after which all animals were sacrificed. Finally, L...
We work through a scenario of an observation of multiple images when two parallel mirrors are fac... more We work through a scenario of an observation of multiple images when two parallel mirrors are facing each other, with an omnidirectional light source situated between them. We find that a typical conventional light bulb as a source shall initiate approximately 83 images perceivable by human eye.
This paper analyses the effects due to special and general relativity on a GPS satellite orbiting... more This paper analyses the effects due to special and general relativity on a GPS satellite orbiting at an altitude of 3 Mars radii. It was found that in order to keep both the ground station and the satellite in synchronisation the clock on the satellite would have to be 1.56 μs per Martian day faster than the one on the ground
In this article we investigate whether large angle shots in cue ball games, like Pool or Snooker,... more In this article we investigate whether large angle shots in cue ball games, like Pool or Snooker, have an effect on accuracy. It was concluded that 0 to 40 shots introduce smallest uncertainty, and that shots over 70 have asymptotically large uncertainty.
Background— Although localized delivery of biocomposite materials, such as calcium hydroxyapatite... more Background— Although localized delivery of biocomposite materials, such as calcium hydroxyapatite (CHAM), have been demonstrated to potentially attenuate adverse left ventricular (LV) remodeling after myocardial infarction (MI), the underlying biological mechanisms for this effect remain unclear. This study tested the hypothesis that targeted CHAM injections would alter proteolytic pathways (matrix metalloproteinases [MMPs] and tissue inhibitors of MMPs [TIMPs]) and would be associated with parameters of post-MI LV remodeling. Methods and Results— MI was induced in adult sheep followed by 20 targeted injections of a total volume of 1.3 mL (n=6) or 2.6 mL of CHAM (n=5) or saline (n=13) and LV end-diastolic volume (EDV) and MMP/TIMP profiles in the MI region were measured at 8 weeks after MI. LV EDV decreased with 2.6 mL CHAM versus MI only (105.4±7.5 versus 80.6±4.2 respectively, P <0.05) but not with 1.3 mL CHAM (94.5±5.0, P =0.32). However, MI thickness increased by 2-fold in bo...
Background The asymmetry and complex shape of the right ventricle have made it difficult to deter... more Background The asymmetry and complex shape of the right ventricle have made it difficult to determine right ventricular (RV) volume with 2-dimensional echocardiography. Three-dimensional cardiac imaging improves visualization of cardiac anatomy but is also complex and time consuming. A newly developed volumetric scanning system holds promise of obviating past limitations. Methods Real-time, transthoracic 3-dimensional echocardiographic images of the right ventricle
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Papers by Liam Ryan