A thrombus or blood clot is a solid mass, made up of a network of fibrin, platelets and other blood components. Blood clots can form through various pathways, for example as a result of exposed ...tissue factor from vascular injury, as a result of low flow/stasis, or in very high shear flow conditions. Embolization of cardiac or vascular originating blood clots, causing an occlusion of the neurovasculature, is the major cause of stroke and accounts for 85% of all stroke. With mechanical thrombectomy emerging as the new standard of care in the treatment of acute ischemic stroke (AIS), the need to generate a better understanding of the biomechanical properties and material behaviour of thrombus material has never been greater, as it could have many potential benefits for the analysis and performance of these treatment devices. Defining the material properties of a thrombus has obvious implications for the development of these treatment devices. However, to-date this definition has not been adequately established. While some experimentation has been performed, model development has been extremely limited. This paper reviews the previous literature on mechanical testing of thrombus material. It also explores the use of various constitutive and computational models to model thrombus formation and material behaviour.
About 20% of patients with acute ischemic stroke due to large-artery occlusion do not achieve recanalization with mechanical thrombectomy. We aimed to determine whether the speed of retrieval of the ...stent retriever influences the efficacy in removing different clot types.
Sixty mechanical thrombectomies were performed using an in vitro pulsatile cerebrovascular circulation model with controlled pressure and flow rate. Experiments were dichotomized into fast and slow retrieval using a wedging technique, in which the stent retriever and distal catheter are retrieved together. We used 3 different clot types: erythrocyte-rich, fibrin-rich, and friable clots. Primary end points were complete (TICI 3) and successful (TICI 2b-3) recanalizations. Secondary measures were distal and new territory embolizations.
Fast retrieval was more frequently associated with complete (RR = 1.83; 95% CI, 1.12-2.99) and successful recanalization (RR = 1.50; 95% CI, 1.03-2.19) than slow retrieval, without a difference in distal embolization (RR = 0.75; 95% CI, 0.29-1.90). There were no emboli in a new territory. The advantage of fast retrieval over slow retrieval differed according to the clot composition, with a stronger effect with fibrin-rich clots with regard to complete (RR = 4.00; 95% CI, 1.11-14.35;
int
.04) and successful (
int
.10) recanalization.
In our experimental model, a fast removal improved recanalization rates of mechanical thrombectomy, especially in the case of fibrin-rich clots. An in vivo confirmation is warranted to see whether our findings can have an impact in clinical practice.
Long term outdoor radon measurements were recorded in Ireland using CR-39 track etch detectors. A measurement protocol was designed for this study, which was optimized for the relatively low radon ...concentrations expected outdoors. This protocol included pre-etching the detectors before exposure to allow radon tracks to be more easily distinguished from background. The average outdoor radon concentration for the Republic of Ireland was found to be 5.6 ± 0.7 Bq m(-3). A statistically significant difference between inland and coastal radon concentrations was evident but no difference between mean radon concentrations on the east coast and those on the west coast was observed.
Objective: To examine the clinical outcome of percutaneous coronary intervention where the procedure was complicated by vessel perforation. Setting: Tertiary referral centre. Methods: The procedural ...records of 6245 patients undergoing coronary intervention were reviewed. In 52 patients (0.8%) the procedure was complicated by vessel perforation, ranging from wire exit to free flow of contrast into the pericardial space. The majority of lesions treated were complex (37% type B, 59% type C) and 9 of 52 (17%) were chronic occlusions. Ten patients (19%) received abciximab. Four underwent rotational atherectomy (8%). Results: In 28 of 52 patients (54%) the perforation was benign and managed conservatively without the development of haemodynamically significant sequelae. In 24 of 52 (46%) a significant pericardial effusion ensued requiring drainage. Of these 24 procedures 6 had involved the treatment of a chronic occlusion (25%). Eight of the 24 patients were referred for emergency bypass surgery (33%), 3 of whom died. Of the remaining 16 not referred for surgery, 3 died. Of the 10 procedures complicated by vessel perforation where abciximab had been administered, 9 (90%) led to pericardial tamponade. Latterly 2 vessel perforations were successfully treated by the deployment of a covered stent. Conclusions: Coronary artery perforation with sequelae during intervention is rare—26 of 6245 (0.4%). This complication was seen in the treatment of chronic occlusions, which are therefore not risk-free procedures. The development of pericardial tamponade carries a high mortality. While prompt surgical intervention may be life saving, expertise in the use of covered stents may provide a valuable rescue option for this serious complication. Caution should be exercised where coronary perforation occurs and abciximab has been used.
Construction quality defects are a widespread and recurrent industry problem; the ISO 9001 Quality Management System (QMS) has been proposed as a tool to improve construction quality. It is one of ...the most widely adopted management systems worldwide and is a prerequisite for many construction tenders. Institutional theory uses the concept of regulatory decoupling to probe "performative" implementation of a standard or regulation; this theory has not to date been applied to ISO 9001 QMS implementation in the construction industry. In this context, the aim of this research is to investigate the extent of regulatory decoupling and its impact on the effectiveness of implementation of the ISO 9001 QMS in 3 case study construction organizations. 34 interviews are undertaken across three case study organizations and analyzed using an abductive grounded theory approach. In all three case study organizations, regulatory decoupling between the operation of the companies and their ISO 9001 system is taking place. Disconnection of the QMS to quality "on the ground" is evident. A model showing factors that foster regulatory decoupling is produced. The picture of compliance is complex and continually evolving. The study concludes with recommendations for industry to reconnect QMS systems to site operation and management.
Seven different types of radon detectors (Atmos 12 dpx, RAD7, RStone, Sun Nuclear 1028, Ramon 2.2, Canary and CR-39) were compared for exposure periods of 1, 2, 3 and 4 weeks. The comparison was ...conducted under two conditions: (a) in a purpose-built radon chamber with an average radon concentration of 2560 Bq m(-3) (b) in a home environment with a radon concentration of 57 Bq m(-3), in both cases measured by the reference detector (Atmos 12 dpx) with a ±10% uncertainty range. In (a) 5 out of 8 detectors recorded radon concentrations within the Atmos uncertainty range and all detectors recorded within ±15%; in (b) 3 out of 9 detectors recorded within the Atmos uncertainty range and 6 out of 9 measured within ±20%, for a 4 week measurement. The results from this study show that radon surveys can be conducted for shorter periods than the recommended 3 months where a rapid indication is needed of whether the radon concentration is above the reference level, such as when assessing the concentration during and after remediation work.
Help for reading teachers in continuous monitoring, assessment and instruction that targets students' problem areas This vital resource offers classroom teachers and literacy coaches practical ...assessments that can be used to evaluate key areas in students' reading performance. These assessments will provide information that can be directly used for planning instruction. Specific instructional techniques and activities are linked to each of the assessments so that teachers know exactly how to teach necessary skills. Tests and other evaluative devices are aligned with Common Core State Standards and state frameworks.Offers a proven model for monitoring and assessing studentsAssessments and instructional strategies are easy to implement as part of any curriculumPractical strategies are modeled on a tested approach for helping students work through their problem areas
The dynamic characteristics of a discrete mode laser diode fabricated in the InGaAs/InP multiple quantum well material system and emitting single mode at λ ≃ 2.0 μm are reported. Results are ...presented on the electro-optical bandwidth, direct modulation and gain switched performance.
Balloon aortic valvuloplasty in contemporary practice Sandhu, Kully; Krishnamoorthy, Suresh; Afif, Ashari ...
Journal of interventional cardiology,
June 2017, 2017-Jun, 2017-06-00, 20170601, Volume:
30, Issue:
3
Journal Article
Peer reviewed
Background
There has been a revival of balloon aortic valvuloplasty (BAV) for severe aortic stenosis, as a result of an increasing number of patients undergoing trans‐catheter aortic valve ...implantation (TAVI). However, there has not been universal adoption of BAV as a standalone, nor bridging therapy.
Methods
A retrospective analysis of the practice at our institution between June 2009 and May 2016 was performed. Demographic, clinical, procedural, and follow‐up data on all patients were collected.
Results
A total of 200 patients with a median age of 82 years and severe symptomatic aortic stenosis underwent BAV from June 2009 to May 2016. All patients had appreciable comorbidity with a mean logistic Euro SCORE of 48 ± 11 and mean standard Euro SCORE 15 ± 4. BAV was performed for palliation in 118 (59%), as a bridging therapy for TAVI in 55 (27.5%) and bridging to surgical AVR in 27 patients (13.5%), respectively. Major complications occurred in 14 patients (7%) including 2 in‐patient deaths (1%). A statistically significant improvement in symptoms and a decrease in trans‐valvular gradient were observed.
Conclusion
BAV is an effective treatment strategy, either as a bridge to definitive therapy or as a palliative procedure, with an acceptable mortality. BAV is associated with a significant improvement in symptoms and is valuable as a palliative treatment in high‐risk patients, where no other invasive option is available.
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