On a set of strips of ultraoriented polyethylene of ultrahigh molecular weight the thermal diffusivity has been measured at room temperature. The draw ratio was between 12 and 250. The diffusivity increases with draw ratio and begins to level off at about X = 50. The maximum diffusivity a ~1.9 X 10~5 m2/s corresponding to a thermal conductivity of k = 37.5 W/mK obtained in the stretching direction is 4 times that of steel. In the perpendicular direction the diffusivity decreased to a = 10'7 m2/s (i.e., half its initial value). The plot of conductivity versus modulus enables an extrapolation to the ultimate modulus (300 GPa), yielding k" < 80 W/mK. This value being higher than that of many metals corresponds to a crystal in the impurity-governed range, i.e., the lower limit of crystal thermal conductivity.
Objective.Rheumatoid arthritis (RA) is associated with significant impairments in health-related quality of life (HRQOL). We evaluated patient-reported outcomes including HRQOL outcomes following adalimumab plus methotrexate (MTX) therapy in patients with early RA.Methods.PREMIER was a phase III, multicenter, randomized, double-blind, active-comparator clinical trial in early RA. Patients aged ≥ 18 years were randomly assigned to receive adalimumab 40 mg every other week (eow) plus weekly MTX, weekly MTX, or adalimumab 40 mg eow for 104 weeks. American College of Rheumatology (ACR) criteria were used to evaluate clinical efficacy and response. Outcomes were assessed using the Health Assessment Questionnaire Disability Index (HAQ-DI), Short-Form 36 Health Survey (SF-36), Short-Form 6 Dimension (SF-6D), visual analog scale (VAS) assessments of global disease activity (patient’s global assessment; PtGA) and pain, Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), and Health Utility Index Mark 3 (HUI-3).Results.Of 799 patients enrolled, 268 received adalimumab plus MTX, 257 received MTX monotherapy, and 274 received adalimumab monotherapy. Patients treated with adalimumab plus MTX demonstrated significant baseline to Week 104 improvements in HAQ-DI (p < 0.0001), SF-36 Physical Component Summary (p < 0.0001), 4 SF-36 domains [physical function (p < 0.0001), bodily pain (p <0.0001), vitality (p = 0.0139), role limitations-physical (p = 0.0005)], SF-6D (p = 0.0152), VAS-PtGA (p < 0.0001), VAS-pain (p < 0.0001), FACIT-F (p < 0.0001), and HUI-3 (p = 0.0034) scores versus patients treated with MTX monotherapy. Both SF-6D and HUI-3 were found to be sensitive preference-based measures for assessing the effects of treatment on multidimensional function. No clinically meaningful differences between adalimumab and MTX monotherapy groups were observed for most measures. For each measure, there was significant association between HRQOL improvement and ACR clinical response.Conclusion.Adalimumab plus MTX significantly improved physical functioning and HRQOL in patients with early RA over 2 years of treatment. (ClinicalTrials.gov identifier NCT00195663).
Blends of ethylene methyl acrylate (EMA) and polfidimethylsiloxane) rubber (PDMS) are demonstrated to be miscible. The miscibility results in a single and composition-dependent glass transition temperature. IR spectra of the blends provide direct evidence of chemical reaction between EMA and PDMS rubber.
Background This was a retrospective, matching-adjusted indirect comparison of clinical outcomes between patients from a single-arm trial of the ECHELON CIRCULAR™ Powered Stapler (ECP) and those from a historical cohort of patients who underwent left-sided colorectal resection using conventional manual circular staplers, extracted from the Premier Healthcare Database. Methods Patients in the ECP trial cohort were propensity score matched to those in the historical cohort through nearest neighbor matching. Outcomes included 30-day readmission rates; length of stay (LOS) for the index admission; rates of anastomotic leak, pelvic abscess, ileus/small bowel obstruction, infection, bleeding, and stoma creation. Results The study included 168 patients in the ECP trial cohort and 4544 patients in the historical cohort; 165 ECP trial patients were matched to 1348 historical cohort patients. After matching, conversions were more prevalent in the historical cohort than the ECP trial cohort (4.2% ECP vs. 10.2% historical, p = 0.001). Relative to the historical cohort, the ECP trial cohort had statistically significant lower rates of 30-day inpatient readmission (6.1% vs. 10.8%, p = 0.019), anastomotic leak (1.8% vs. 6.9%, p < 0.001), ileus/small bowel obstruction (4.8% vs. 14.7%, p < 0.001), infection (1.8% vs. 5.7%, p = 0.001), and bleeding (1.8% vs. 9.2%, p < 0.001) during the index admission or within 30 days thereafter. No statistically significant differences in rates of pelvic abscess, stoma creation, or LOS were found between the two cohorts. Three sensitivity analyses to address the difference in conversion rates yielded largely consistent results, with loss of statistical significance for inpatient admission in some cases. This study is limited by its potential for differences in unmeasurable factors between the ECP trial and historical cohorts. Conclusions In this study, the ECP trial cohort had lower incidence proportions of several surgical complications as compared with the historical cohort. Further controlled prospective clinical studies are needed to confirm the validity of this finding.
IntroductionVideo-assisted thoracic surgery (VATS) lung resections are complex procedures with a critical role played by endoscopic staplers in the transection of vessels, bronchi, and lung tissue. This retrospective, observational study compared hospital resource use, costs, and complications of VATS lobectomy procedures for whom powered versus manual endoscopic surgical staplers were used.MethodsPatients ≥ 18 years of age undergoing elective VATS lobectomy during an inpatient admission from January 1, 2012 to September 30, 2016 were identified from the Premier Healthcare Database (first admission = index admission). Use of either powered or manual endoscopic staplers during the index admission was identified from hospital administrative records. Multivariable regression analyses adjusting for patient, hospital, and provider characteristics and hospital-level clustering were carried out to compare the following outcomes between the powered and manual stapler groups: hospital length of stay (LOS), operating room time (ORT), hospital costs, complications (bleeding and/or transfusions, air leak complications, pneumonia, and infection), discharge status, and 30-, 60-, and 90-day all-cause readmissions.ResultsThe powered and manual stapler groups comprised 659 patients (mean age 66.1 years; 53.6% female) and 3100 patients (mean age 66.7 years; 54.8% female), respectively. In the multivariable analyses, the powered stapler group had shorter LOS (4.9 vs. 5.9 days, P < 0.001), lower total hospital costs ($23,841 vs. $26,052, P = 0.009), and lower rates of combined hemostasis complications (bleeding and/or transfusions; 8.5% vs. 16.0%, P < 0.001) and transfusions (5.4% vs. 10.9%, P = 0.002), compared with the manual stapler group. Other outcomes did not differ significantly between the study groups. Similar trends were observed in subanalyses comparing devices across predominant manufacturers in each group, and in subanalyses of patients with comorbid chronic obstructive pulmonary disease.ConclusionIn this analysis of VATS lobectomy procedures, powered staplers were associated with significant benefits with respect to selected types of hospital resource use, costs, and clinical outcomes when compared with manual staplers.FundingJohnson & Johnson.Electronic supplementary materialThe online version of this article (10.1007/s12325-018-0679-z) contains supplementary material, which is available to authorized users.
Background:Laparoscopic surgery is increasingly replacing the open procedure because of its many patient-related benefits that are well aligned with policies and programs that seek to optimize health system performance. However, widespread adoption of laparoscopic surgery has been slow, in part, because of the complexity of laparoscopic suturing. The objective of this study was to review the clinical and economic impacts of laparoscopic suturing in key procedures and to assess its role as a barrier to the broader adoption of laparoscopic surgery.Database:A medical literature search of MEDLINE, EMBASE, and BIOSIS from January 2010 through June 2016 identified 47 relevant articles.Conclusion:Laparoscopic suturing and intracorporeal knot tying may result in extended surgical time, complications, and surgeon errors, while improving patient quality of life through improved cosmesis, diet toleration, and better bowel movements. Despite advancement in surgical techniques and the availability of newer surgical tools, the complexity of laparoscopic suturing continues to be a barrier to greater adoption of MIS. The results of the study underscore the need for development of proficiency in laparoscopic suturing, which may help improve patient outcomes and reduce healthcare costs.
Aims: To compare economic and clinical outcomes between patients undergoing laparoscopic Rouxen-Y gastric bypass (LRY) or laparoscopic sleeve gastrectomy (LSG) with use of powered vs manual endoscopic surgical staplers. Materials and methods: Patients (aged !21 years) who underwent LRY or LSG during a hospital admission (January 1, 2012-September 30, 2015 were identified from the Premier Perspective Hospital Database. Use of powered vs manual staplers was identified from hospital administrative billing records. Multivariable analyses were used to compare the following outcomes between the powered and manual stapler groups, adjusting for patient and hospital characteristics and hospital-level clustering: hospital length of stay (LOS), total hospital costs, medical/surgical supply costs, room and board costs, operating room costs, operating room time, discharge status, bleeding/transfusion during the hospital admission, and 30, 60, and 90-day all-cause readmissions. Results: The powered and manual stapler groups comprised 9,851 patients (mean age ¼ 44.6 years; 79.3% female) and 21,558 patients (mean age ¼ 45.0 years; 78.0% female), respectively. In the multivariable analyses, adjusted mean hospital LOS was 2.1 days for both the powered and manual stapler groups (p ¼ .981). Adjusted mean total hospital costs ($12,415 vs $13,547, p ¼ .003), adjusted mean supply costs ($4,629 vs $5,217, p ¼ .011), and adjusted mean operating room costs ($4,126 vs $4,413, p ¼ .009) were significantly lower in the powered vs manual stapler group. The adjusted rate of bleeding and/or transfusion during the hospital admission (2.46% vs 3.22%, p ¼ .025) was significantly lower in the powered vs manual stapler group. The adjusted rates of 30, 60, and 90-day all-cause readmissions were similar between the groups (all p > .05). Sub-analysis by manufacturer showed similar results. Limitations: This observational study cannot establish causal linkages. Conclusions: In this analysis of patients who underwent LRY or LSG, the use of powered staplers was associated with better economic outcomes, and a lower rate of bleeding/transfusion vs manual staplers in the real-world setting.ARTICLE HISTORY
SUMMARYPolyethylene (PE, 100 parts by weight) was mixed with methyl methacrylate (MMA, up to 5 parts by weight) at 120°C and subsequently exposed to electron radiation of different doses (up to 20 Mrad) to prepare PE/MMA graft copolymers. Successful grafting was verified by IR spectroscopy. Gel formation indicated crosslinking. Grafting increased with increasing MMA concentration and increasing irradiation dose. Crystalline melting temperature and percent crystallinity were lower than those of untreated PE. Tensile strength, elongation at break and dielectric constant of grafted samples were measured and discussed. ZUSAMMENFASSUNG:Polyethylen (PE, 100 Gew.-Teile) wurde mit Methylmethacrylat (MMA, bis zu 5 Gew.-Teilen) gemischt und anschlieljend mit Elektronen (bis zu 20 Mrad) bestrahlt, um PE/MMA-Pfropfcopolymere herzustellen, deren Bildung mittels IR-Spektroskopie nachgewiesen wurde. Gelbildung wies auf eine Vernetzung wahrend der Bestrahlung hin. Zunehmende MMA-Konzentration und hohere Bestrahlungsdosen verringerten die Kristallit-Schmelztemperatur und den Kristallisationsgrad des PE. Zugfestigkeit, Bruchdehnung und Dielektrizitatskonstante wurden gemessen und diskutiert.
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