AbstractNatural polymers (biopolymers) are discussed as environmentally friendly and sustainable grouting chemicals. This paper presents guidelines for selecting potentially useful biopolymers for ...strengthening cohesionless soil. Agar and six modified starches were identified for further study over a range of concentrations (1–4% agar and 0.5–1% starch). Experimental results demonstrated the compatibility of agar and starch. Depending on the biopolymer concentration, the unconfined compressive strength of the sand treated with agar and starch biopolymers ranged from 158 to 487 kPa. Triaxial compression tests over a range of confining pressures also indicated that the biopolymers effectively increased the cohesion intercept and stiffness of the treated sand.
Beyond conventional risk factors for cardiovascular disease, women face an additional burden of sex-specific risk factors. Key stages of a woman's reproductive history may influence or reveal short- ...and long-term cardiometabolic and cardiovascular trajectories. Early and late menarche, polycystic ovary syndrome, infertility, adverse pregnancy outcomes (eg, hypertensive disorders of pregnancy, gestational diabetes, preterm delivery, and intrauterine growth restriction), and absence of breastfeeding are all associated with increased future cardiovascular disease risk. The menopause transition additionally represents a period of accelerated cardiovascular disease risk, with timing (eg, premature menopause), mechanism, and symptoms of menopause, as well as treatment of menopause symptoms, each contributing to this risk. Differences in conventional cardiovascular disease risk factors appear to explain some, but not all, of the observed associations between reproductive history and later-life cardiovascular disease; further research is needed to elucidate hormonal effects and unique sex-specific disease mechanisms. A history of reproductive risk factors represents an opportunity for comprehensive risk factor screening, refinement of cardiovascular disease risk assessment, and implementation of primordial and primary prevention to optimize long-term cardiometabolic health in women.
This study investigates the combined performance of ground rubber (GR), the additive, and polyacrylamide (PAM), the binder, as a sustainable solution towards ameliorating the inferior geotechnical ...attributes of an expansive clay. The first phase of the experimental program examined the effects of PAM concentration on the soil’s mechanical properties—consistency, sediment volume attributes, compactability, unconfined compressive strength (UCS), reactivity and microstructure features. The second phase investigated the effects of GR content, with and without the optimum PAM concentration. An increase in PAM beyond 0.2 g/L, the identified optimum concentration, caused the excess PAM to act as a lubricant rather than a flocculant. This feature facilitated reduced overall resistance to sliding of soil particles relative to each other, thereby adversely influencing the improvement in stress–strain–strength response achieved for ≤0.2 g/L PAM. This transitional mechanism was further verified by the consistency limits and sediment volume properties, both of which exhibited only minor variations beyond 0.2 g/L PAM. The greater the GR content, the higher the mobilized UCS up to 10% GR, beyond which the dominant GR-to-GR interaction (i.e., rubber-clustering) adversely influenced the stress–strain–strength response. Reduction in the soil’s swell–shrink capacity, however, was consistently in favor of higher GR contents. Addition of PAM to the GR-blended samples amended the soil aggregate–GR connection interface, thereby achieving further improvements in the soil’s UCS and volume change behaviors. A maximum GR content of 20%, paired with 0.2 g/L PAM, managed to satisfy a major decrease in the swell–shrink capacity while improving the strength-related features, and thus was deemed as the optimum choice.
In this study, the potential of pulverized waste tires (PWTs), either on their own or mixed with soil (well graded sand), to act as adsorptive fill materials was evaluated by conducting laboratory ...tests for accessing their adsorption and geotechnical properties. PWT (0, 5, 10, 15, 25, and 100 wt%) was mixed with soil to evaluate the removal of benzene, toluene, ethylbenzene, and xylene (BTEX) components and two heavy metal ions (Pb2+ and Cu2+). Adsorption batch tests were performed to determine the equilibrium sorption capacity of each mixture. Subsequently, compaction, direct shear, and consolidation tests were performed to establish their geotechnical properties. The results showed that BTEX had the strongest affinity based on the uptake capacity by the soil–PWT mixtures. The adsorption of BTEX increased for greater PWT content, with pure PWT having the highest adsorption capacity toward BTEX removal: uptake capacities for xylene, ethylbenzene, toluene, and benzene were 526, 377, 207 and 127 μg/g sorbent, respectively. Heavy metal removal was increased by increasing the amount of PWT up to 10 wt%, and then decreased beyond this ratio. Compacted soil–PWT mixtures comprising 5–25 wt% PWT have relatively low dry unit weight, low compressibility, adequate shear capacity for many load-bearing field applications, and satisfactory adsorption of organic/inorganic contaminants, such that they could also be used as adsorptive fill materials.
•Promising potential to reuse Pulverized Waste Tire (PWT) against removing BTEX.•Satisfactory adsorption capacity of PWT for removal of heavy metals.•Acceptable performances of PWT-soil mixture in terms of geotechnical properties.•Mitigation the waste tire disposal problems by reusing them as adsorptive fill materials.
Flow-diverting stents, such as the PED, have emerged as a novel means of treating complex intracranial aneurysms. This retrospective analysis of the initial Canadian experience provides insight into ...technical challenges, clinical and radiographic outcomes, and complication rates after the use of flow-diverting stents for unruptured aneurysms.
Cases were compiled from 7 Canadian centers between July 2008 and December 2010. Each center prospectively tracked their initial experience; these data were retrospectively updated and pooled for analysis.
During the defined study period, 97 cases of unruptured aneurysm were treated with the PED, with successful stent deployment in 94 cases. The overall complete or near-complete occlusion rate was 83%, with a median follow-up at 1.25 years (range 0.25-2.5 years). Progressive occlusion was witnessed over time, with complete or near-complete occlusion in 65% of aneurysms followed through 6 months, and 90% of aneurysms followed through 1 year. Multivariate analysis found previous aneurysm treatment and female sex predictive of persistent aneurysm filling. Most patients were stable or improved (88%), with the most favorable outcomes observed in patients with cavernous carotid aneurysms. The overall mortality rate was 6%. Postprocedural aneurysm hemorrhage occurred in 3 patients (3%), while ipsilateral distal territory hemorrhage was observed in 4 patients (3.4%).
Flow-diverting stents represent an important tool in the treatment of complex intracranial aneurysms. The relative efficacy and morbidity of this treatment must be considered in the context of available alternate interventions.
The PED is a flow-diverting stent designed for the treatment of cerebral aneurysms. We report 4 cases of delayed ipsilateral IPH following the technically successful treatment of anterior circulation ...aneurysms with the PED.
Clinical and imaging data from all patients undergoing aneurysm treatment with the PED at 2 institutions were analyzed to assess the incidence of delayed IPH after treatment with the PED.
A total of 66 patients (47 anterior circulation) with cerebral aneurysms underwent treatment with a PED between January 2008 and November 2010. Four patients experienced delayed periprocedural IPH, all after the treatment of anterior circulation aneurysms (8.5%, 4/47). The aneurysm size ranged from 5 to 21 mm. All IPHs occurred within the cerebral hemisphere, ipsilateral to the treated aneurysm, and were anatomically remote from the treated aneurysms. All procedures were uncomplicated, and patients emerged from general anesthesia at neurologic baseline. The hemorrhages became clinically evident between 1 and 6 days after the procedure. Two patients had unfavorable outcomes (mRS scores, 4 and 6).
Delayed IPH may occur after the treatment of anterior circulation aneurysms with flow diverters. This complication does not seem to be restricted to a specific aneurysm subtype and does not seem to be related to an intraprocedural complication or solely attributable to DAT.
The 2018 update of the Canadian Stroke Best Practice Recommendations for Acute Stroke Management, 6th edition, is a comprehensive summary of current evidence-based recommendations, appropriate for ...use by healthcare providers and system planners caring for persons with very recent symptoms of acute stroke or transient ischemic attack. The recommendations are intended for use by a interdisciplinary team of clinicians across a wide range of settings and highlight key elements involved in prehospital and Emergency Department care, acute treatments for ischemic stroke, and acute inpatient care. The most notable changes included in this 6th edition are the renaming of the module and its integration of the formerly separate modules on prehospital and emergency care and acute inpatient stroke care. The new module, Acute Stroke Management: Prehospital, Emergency Department, and Acute Inpatient Stroke Care is now a single, comprehensive module addressing the most important aspects of acute stroke care delivery. Other notable changes include the removal of two sections related to the emergency management of intracerebral hemorrhage and subarachnoid hemorrhage. These topics are covered in a new, dedicated module, to be released later this year. The most significant recommendation updates are for neuroimaging; the extension of the time window for endovascular thrombectomy treatment out to 24 h; considerations for treating a highly selected group of people with stroke of unknown time of onset; and recommendations for dual antiplatelet therapy for a limited duration after acute minor ischemic stroke and transient ischemic attack. This module also emphasizes the need for increased public and healthcare provider’s recognition of the signs of stroke and immediate actions to take; the important expanding role of paramedics and all emergency medical services personnel; arriving at a stroke-enabled Emergency Department without delay; and launching local healthcare institution code stroke protocols. Revisions have also been made to the recommendations for the triage and assessment of risk of recurrent stroke after transient ischemic attack/minor stroke and suggested urgency levels for investigations and initiation of management strategies. The goal of this updated guideline is to optimize stroke care across Canada, by reducing practice variations and reducing the gap between current knowledge and clinical practice.
Flow diverting stents are emerging as a treatment option for difficult intracranial aneurysms. Current grading scales for assessment of angiographic outcomes following aneurysm treatment do not apply ...to aneurysms treated by flow diversion. We propose a novel grading scale based on the degree of angiographic filling and contrast stasis. This scale will facilitate communication and standardize reporting of outcomes following flow diversion treatments.
Maternal mortality rates are rising in the United States, a trend which is in contrast to that seen in other high-income nations. Cardiovascular disease and hypertensive disorders of pregnancy are ...consistently the leading causes of maternal mortality both in the United States and globally, accounting for about one-quarter to one-third of maternal and peripartum deaths. A large proportion of cardiovascular morbidity and mortality stems from acquired disease in the context of cardiovascular risk factors, which include obesity, pre-existing diabetes and hypertension, and inequities in care from maternal care deserts and structural racism. Patients may also become pregnant with preexisting structural heart disease, or acquire disease throughout pregnancy (ex: spontaneous coronary artery dissection, peripartum cardiomyopathy), and be at higher risk of pregnancy-related cardiovascular complications. While risk-stratification tools including the modified World Health Organization (mWHO) classification, Cardiac Disease in Pregnancy (CARPREG II) and Zwangerschap bij Aangeboren HARtAfwijking/Pregnancy in Women with Congenital Heart Disease (ZAHARA) have been designed to help physicians identify patients at increased risk for adverse pregnancy outcomes and who may therefore benefit from referral to a tertiary care center, the limitation of these scores is their predominant focus on patients with known preexisting heart disease. As such, identifying patients at risk for pregnancy complications presents a significant challenge, and it is often patients with high-risk cardiovascular substrates prior to or during pregnancy who are at a highest risk for adverse pregnancy outcomes including cardiogenic shock.
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