Friction Stir Processing of SSM356 Aluminium Alloy

AbstractThe aim of this experiment was to improve the mechanical properties of SSM 356 aluminum alloys by friction stir processing, a solid-state technique for microstructural modification using the heat from a friction and stirring. The parameters of friction stir processing for SSM 356 aluminum alloys were studied at three different travelling speeds: 80, 120 and 160mm/min under three different rotation speeds 1320, 1480 and 1750rpm. The hardness and tensile strength properties were increased by friction stir processing. The hardness of friction stir processing was 64.55 HV which was higher than the base metal (40.58 HV). The tensile strengths of friction stir processing were increased about 11.8% compared to the base metal. The optimal processing parameter was rotation speed at 1750rpm with the travelling speed at 160mm/min. Consequently, the application of the friction stir processing is a very effective method for the mechanical improvement of semi-solid metal aluminum alloys

Globalization: Its Effects

A global culture is now increasingly emerging.  The process of globalization is facilitated by technology.  This technology comes from but one place – education.  The primary way to accept (or fight it) globalization is through knowledge.  Education is the main way to facilitate interaction and increase the quality of life for people everywhere

Should cable television channels be offered à la carte?

Why do cable TV companies force people to purchase channels they don’t even like? Wouldn’t consumers be better off if they could purchase channels individually rather than only as part of large packages? Not necessarily. This research shows that channel prices would be higher on average if they were offered individually, and if the increase in prices is large enough it can more than offset the benefits of unbundling

Lazard-style CAD and Equational Constraints

McCallum-style Cylindrical Algebra Decomposition (CAD) is a major improvement on the original Collins version, and has had many subsequent advances, notably for total or partial equational constraints. But it suffers from a problem with nullification. The recently-justified Lazard-style CAD does not have this problem. However, transporting the equational constraints work to Lazard-style does reintroduce nullification issues. This paper explains the problem, and the solutions to it, based on the second author's Ph.D. thesis and the Brown--McCallum improvement to Lazard. With a single equational constraint, we can gain the same improvements in Lazard-style as in McCallum-style CAD . Moreover, our approach does not fail where McCallum would due to nullification. Unsurprisingly, it does not achieve the same level of improvement as it does in the non-nullified cases. We also consider the case of multiple equational constraints.Comment: 9 page

Applying Occupation-Centered Coaching for Caregivers of Children with Disabilities

Statement of the problem: Caregivers of children with disabilities (CWD) experience stress, mental health conditions, sleep disruption, and fatigue leading to decreased occupational engagement and family community participation. Purpose Statement: This project applied Occupation-Centered Coaching with a family-centered approach to promote caregiver empowerment, advocacy for mental health services, and family community participation.https://soar.usa.edu/otdcapstonesfall2023/1000/thumbnail.jp

Dynamical Behavior of the BTZ Black Hole

We study the dynamical behavior of the BTZ (Banados-Teitelboim-Zanelli) black hole with the low-energy string effective action. The perturbation analysis around the BTZ black hole reveals a mixing between the dilaton and other fields. Introducing the new gauge (dilaton gauge), we disentangle this mixing completely and obtain one decoupled dilaton equation. We obtain the decay rate $\Gamma$ of BTZ black hole.Comment: minor typhographical corrections, ReVTeX, 9 pages with no figure

Direct cost variance analysis of peroral endoscopic myotomy vs Heller myotomy for management of achalasia: A tertiary referral center experience

BACKGROUND: Laparoscopic Heller myotomy (LHM) has been the traditional surgical treatment for achalasia. Recently, peroral endoscopic myotomy (POEM) has demonstrated similar clinical outcomes with shorter procedure times. Studies comparing the direct cost-effectiveness of POEM AIM: To compare costs of POEM METHODS: This retrospective chart review aimed to compare the outcomes and cost of clinical care between patients who underwent POEM and LHM procedures for achalasia. The study was conducted at a tertiary academic center from January 2019 to December 2020. Clinical outcomes, including post-operative Eckardt scores and adverse events, were assessed and compared between the two groups. Direct cost variance analysis was utilized to evaluate the cost of clinical care incurred by patients undergoing POEM in the year preceding the procedure, during the index admission, and one year post-procedure, in comparison to patients undergoing LHM. RESULTS: Of 30 patients were included (15 POEM and 15 LHM) in the study. Patients in the POEM group had a mean Eckardt score of 0.5 ± 0.5 post-procedure, which was no different from patients in the LHM group (0.7 ± 0.6, CONCLUSION: Despite similar clinical outcomes, the cost of the index procedure admission for POEM was significantly lower than for LHM. The difference was primarily related to shorter time increments utilized in the operating room during the index procedure, and shorter length of hospital stay following POEM

Impact of the 2016 American College of Surgeons Guideline Revision on Overlapping Lumbar Fusion Cases at a Large Academic Medical Center

OBJECTIVE: The American College of Surgeons (ACS) u pdated its guidelines on overlapping surgery in 2016. The objective was to examine differences in postoperative outcomes after overlapping surgery either pre-ACS guide-line revision or post-guideline revision, in a coarsened exact matching sample. -METHODS: A total of 3327 consecutive adult patients u ndergoing single-level posterior lumbar fusion from 2013 to 2019 were retrospectively analyzed. Patients were separated into a pre-ACS guideline revision cohort (surgery before April 2016) or a post-guideline revision cohort (surgery after October 2016) for comparison. The primary outcomes were proportion of cases performed with any degree of overlap, and adverse events including 30-day and 90-day rates of readmission, reoperation, emergency department visit, morbidity, and mortality. Subsequently, coarsened exact matching was used among overlapping surgery patients only to assess the impact of the ACS guideline revision on overlapping outcomes, and control-ling for attending surgeon and key patient characteristics known to affect surgical outcomes. -RESULTS: After the implementation of the ACS guide-lines, fewer cases were performed with overlap (22.0% vs. 53.7%; P \u3c 0.001). Patients in the post-ACS guideline revi-sion cohort experienced improved rates of readmission and reoperation within 30 and 90 days. However, when limited to overlapping cases only, no differences were observed in overlap outcomes pre-ACS versus post-ACS guideline revision. Similarly, when exact matched on risk-associated patient characteristics and attending surgeon, overlapping surgery patients pre-ACS and post-ACS guideline revision experienced similar rates of 30-day and 90-day outcomes. -CONCLUSIONS: After the ACS guideline revision, no discernable impact was observed on postoperative out-comes after lumbar fusion performed with overlap

Mipomersen, an Apolipoprotein B Synthesis Inhibitor, Reduces Atherogenic Lipoproteins in Patients With Severe Hypercholesterolemia at High Cardiovascular Risk A Randomized, Double-Blind, Placebo-Controlled Trial

ObjectivesThis study sought to examine the efficacy and safety of mipomersen for reducing atherogenic lipids and lipoproteins in patients with hypercholesterolemia.BackgroundMany patients on lipid-lowering therapies remain unable to achieve target low-density lipoprotein (LDL) cholesterol levels. Mipomersen, an antisense oligonucleotide inhibitor of apolipoprotein B, reduces LDL cholesterol and atherogenic lipoproteins.MethodsThis randomized, double-blind, multicenter study enrolled 158 patients with baseline LDL cholesterol levels ≥100 mg/dl with, or at high risk for, coronary heart disease who were receiving maximally tolerated lipid-lowering therapy. Patients received weekly subcutaneous mipomersen 200 mg (n = 105) or placebo (n = 52) for 26 weeks, with a 24-week follow-up period. Randomization was stratified by type 2 diabetes status.ResultsSixty mipomersen and 44 placebo patients completed treatment. Mean baseline LDL cholesterol levels were 122.7 and 122.6 mg/dl in the placebo and mipomersen patients, respectively. Mipomersen reduced LDL cholesterol by −36.9% compared with placebo at −4.5% (p < 0.001). Target LDL cholesterol <100 mg/dl was attained in 76% of mipomersen and 38% of placebo patients. Mipomersen also significantly reduced apolipoprotein B (−38%) and lipoprotein(a) (−24%) (p < 0.001). Common adverse events included injection site reactions (78% with mipomersen, 31% with placebo) and flu-like symptoms (34% with mipomersen, 21% with placebo). Elevations in transaminases and liver fat also occurred in some patients, and these levels returned toward baseline after treatment cessation.ConclusionsMipomersen significantly reduced LDL cholesterol, apolipoprotein B, and lipoprotein(a) in patients with hypercholesterolemia with, or at risk for, coronary heart disease not controlled by existing therapies. (Safety and Efficacy of Mipomersen [ISIS 301012] as Add-On Therapy in High Risk Hypercholesterolemic Patients; NCT00770146

The Utility of Cervical Spine Bracing As a Postoperative Adjunct to Multilevel Anterior Cervical Spine Surgery

Background: Use of cervical bracing/collar subsequent to anterior cervical spine discectomy and fusion (ACDF) is variable. Outcomes data regarding bracing after ACDF are limited. Here, we study the impact of bracing on short-term outcomes related to safety, quality of care, and direct costs in multilevel ACDF.Methods: Retrospective cohort analyses of all consecutive patients undergoing multilevel ACDF with or without bracing from 2013 to 2017 was undertaken (n = 616). Patient demographics and comorbidities were analyzed. Tests of independence and logistic regressions were used to assess differences in length of stay (LOS), discharge disposition (home, assisted rehabilitation facility [ARF], or skilled nursing facility [SNF]), quality-adjusted life year (QALY), direct cost, readmission within 30 days, and emergency room (ER) visits within 30 days.Results: Amongst the study population, 553 were braced and 63 were not braced. There was no difference in comorbidities (P \u3e .05) such as obesity, smoking, chronic obstructive pulmonary disease, hypertension, coronary artery disease, congestive heart failure, and problem list number. A significant difference in American Society of Anesthesiologists (ASA) score was found, with more ASA 2 patients in the braced cohort and more ASA 3 patients in the unbraced cohort (P = .007). LOS was extended for the unbraced group (median 156.9 +/- 211.4 versus 86.67 +/- 130.6 h, P = .003), and ER visits within 30 days were 0.21 times less likely in the braced group (P = .006). There was no difference in readmission (P = .181), QALY gain (P = .968), and direct costs (P = .689).Conclusion: Bracing following multilevel cervical fixation does not alter short-term postoperative course or reduce the risk for early adverse outcomes in a significant manner