Transitions/relaxations in polyester adhesive/PET system

The correlations between the transitions and the dielectric relaxation processes of the oriented poly(ethylene terephthalate) (PET) pre-impregnated of the polyester thermoplastic adhesive have been investigated by differential scanning calorimetry (DSC) and dynamic dielectric spectroscopy (DDS). The thermoplastic polyester adhesive and the oriented PET films have been studied as reference samples. This study evidences that the adhesive chain segments is responsible for the physical structure evolution in the PET-oriented film. The transitions and dielectric relaxation modes’ evolutions in the glass transition region appear characteristic of the interphase between adhesive and PET film, which is discussed in terms of molecular mobility. The storage at room temperature of the adhesive tape involves the heterogeneity of the physical structure, characterized by glass transition dissociation. Thus, the correlation between the transitions and the dielectric relaxation processes evidences a segregation of the amorphous phases. Therefore, the physical structure and the properties of the material have been linked to the chemical characteristics

Assessment of trace metal contamination in a historical freshwater canal (Buckingham Canal), Chennai, India

The present study was done to assess the sources and the major processes controlling the trace metal distribution in sediments of Buckingham Canal. Based on the observed geochemical variations, the sediments are grouped as South Buckingham Canal and North Buckingham Canal sediments (SBC and NBC, respectively). SBC sediments show enrichment in Fe, Ti, Mn, Cr, V, Mo, and As concentrations, while NBC sediments show enrichment in Sn, Cu, Pb, Zn, Ni, and Hg. The calculated Chemical Index of Alteration and Chemical Index of Weathering values for all the sediments are relatively higher than the North American Shale Composite and Upper Continental Crust but similar to Post-Archaean Average Shale, and suggest a source area with moderate weathering. Overall, SBC sediments are highly enriched in Mo, Zn, Cu, and Hg (geoaccumulation index (Igeo) class 4– 6), whereas NBC sediments are enriched in Sn, Cu,Zn, and Hg (Igeo class 4–6). Cu, Ni, and Cr show higher than Effects-Range Median values and hence the biological adverse effect of these metals is 20%; Zn, which accounts for 50%, in the NBC sediments, has a more biological adverse effect than other metalsfound in these sediments. The calculated Igeo, Enrichment Factor, and Contamination Factor values indicate that Mo, Hg, Sn, Cu, and Zn are highly enriched in the Buckingham Canal sediments, suggesting the rapid urban and industrial development of Chennai MetropolitanCity have negatively influenced on the surrounding aquatic ecosystem

Ground Water Pollution and Emerging Environmental Challenges of Industrial Effluent Irrigation: A Case Study of Mettupalayam Taluk, Tamilnadu

Industrial disposal of effluents on land and the subsequent pollution of groundwater and soil of surrounding farmlands – is a relatively new area of research. The environmental and socioeconomic aspects of industrial effluent irrigation have not been studied as extensively as domestic sewage based irrigation practices, at least for a developing country like India. The disposal of effluents on land has become a regular practice for some industries. Industries located in Mettupalayam Taluk, Tamil Nadu, dispose their effluents on land, and the farmers of the adjacent farmlands have complained that their shallow open wells get polluted and also the salt content of the soil has started building up slowly. This study attempts to capture the environmental and socioeconomic impacts of industrial effluent irrigation in different industrial locations at Mettupalayam Taluk, Tamil Nadu, through primary surveys and secondary information. This study found that the continuous disposal of industrial effluents on land, which has limited capacity to assimilate the pollution load, has led to groundwater pollution. The quality of groundwater in shallow open wells surrounding the industrial locations has deteriorated, and the application of polluted groundwater for irrigation has resulted in increased salt content of soils. In some locations drinking water wells (deep bore wells) also have a high concentration of salts. Since the farmers had already shifted their cropping pattern to salt-tolerant crops (like jasmine, curry leaf, tobacco, etc.) and substituted their irrigation source from shallow open wells to deep bore wells and/or river water, the impact of pollution on livelihoods was minimized. Since the local administration is supplying drinking water to households, the impact in the domestic sector has been minimized. It has also been noticed that in some locations industries are supplying drinking water to the affected households. However, if the pollution continues unabated it could pose serious problems in the future

Surgical Treatment of Insufficiency Fractures of the Knee

Bone marrow lesions (BMLs) in the knee represent focal edema caused by subchondral bone attrition and microfractures to the trabecular bone. These lesions are poor prognostic indicators for several orthopaedic procedures but also have been associated with the progression of osteoarthritis. Current research is aimed at treating BMLs with the intent to improve the overall structural integrity of the subchondral bone and delay the need for arthroplasty. The injection of calcium phosphate bone substitute has been proposed to treat BMLs because animal models have shown its potential to stimulate bone repair. This technical note describes the key steps involved in performing percutaneous fixation of BMLs with a hard-setting bone substitute, as well as associated pearls and pitfalls. Although continued research with prospective comparative cohorts and long-term follow-up is needed to determine the efficacy of this procedure, this intervention holds promise in delaying the need for total knee replacement in the arthritic patient with a focal lesion

Arthroscopic Massive Rotator Cuff Repair and Techniques for Mobilization

Massive rotator cuff tears, as classified by size or tendon involvement, are challenging to repair due to scarring, retraction of the tendons, and difficult visualization. Left untreated, these injuries can lead to fatty infiltration and reduced acromiohumeral distance that precludes future repair. The high rate of failure in these patients often impedes an anatomical repair. However, advanced mobilization techniques of the supraspinatus help facilitate a reduction of an otherwise irreparable tear. By performing this repair, more costly procedures may be avoided, such as a superior capsular reconstruction and reverse total shoulder arthroplasty. This Technical Note presents our preferred technique of an all-arthroscopic, medialized repair with double interval slides for the treatment of a massive rotator cuff tear

Return to Work After Shoulder Replacement for Glenohumeral Osteoarthritis Is Similar When Hemiarthroplasty Is Compared to Total Shoulder Arthroplasty

© 2019, Hospital for Special Surgery. Background: Return to work after shoulder arthroplasty for glenohumeral osteoarthritis (OA) is an important consideration for an aging workforce. Questions/Purposes: The aim of this study was to compare the shoulder function, pain levels, and rate of return to work in patients treated with anatomic total shoulder arthroplasty (aTSA) versus humeral hemiarthroplasty (HHA). Methods: A retrospective review of consecutive HHA patients was performed of our institution’s shoulder arthroplasty registry. Inclusion criteria were pre-operative diagnosis of end-stage OA and more than 2 years’ follow-up. HHA patients were statistically matched to aTSA patients and then screened for pre-operative work status; 26 HHA and 23 aTSA patients worked before surgery. There was no difference in average age (HHA, 62.4 years; aTSA, 61.7 years) or follow-up (HHA, 67.5 months; aTSA, 66.9 months). Results: Average American Shoulder and Elbow Surgeons (ASES) scores (HHA, 37.6 to 70.3; aTSA, 35.6 to 80.1) and visual analogue scale (VAS) for pain scores (HHA, 6.1 to 2.3; aTSA, 6.5 to 0.6) improved in both groups. However, HHA patients had worse final VAS scores, and aTSA patients were more satisfied (100% vs 77%); 61.5% of HHA patients returned to work post-operatively versus 87.0% of aTSA patients. There was no difference in time to return to work (HHA, 1.9 ± 2.3 months; aTSA, 1.3 ± 1.0 months). Conclusion: Patients with shoulder OA undergoing aTSA have higher rates of return to work, function, and satisfaction than those undergoing HHA

A 15-Minute Incremental Increase in Operative Duration Is Associated With an Additional Risk of Complications Within 30 Days After Arthroscopic Rotator Cuff Repair

Background: Operative time is a risk factor for short-term complications after orthopaedic procedures; however, it has yet to be investigated as an independent risk factor for postoperative complications after arthroscopic rotator cuff repair. Purpose: To determine whether operative time is an independent risk factor for complications, readmissions, and extended hospital stays within 30 days after arthroscopic rotator cuff repair. Study Design: Descriptive epidemiology study. Methods: The American College of Surgeons National Surgical Quality Improvement Program was queried for all hospital-based inpatient and outpatient arthroscopic rotator cuff repairs (Current Procedural Terminology code 29827) from 2005 to 2016. Concomitant procedures such as subacromial decompression, biceps tenodesis, superior labrum anterior and posterior (SLAP) repair, labral repair, and distal clavicle excision were also included, whereas patients undergoing arthroplasty were excluded from the study. Operative time was correlated with patient demographics, comorbidities, and concomitant procedures. All adverse events were correlated with operative time, while controlling for the above preoperative variables, using multivariate Poisson regression with a robust error variance. Results: A total of 27,524 procedures met inclusion and exclusion criteria. The mean age of patients was 58.4 +/- 10.9 years, the mean operative time was 86.9 +/- 37.4 minutes, and the mean body mass index was 30.4 +/- 7.0 kg/m(2). Concomitant biceps tenodesis, glenohumeral debridement, SLAP repair, labral repair, and distal clavicle excision significantly increased operative time (P .05). The overall rate of adverse events was 0.88%. After adjusting for demographic and procedural characteristics, a 15-minute increase in operative duration was associated with an increased risk of anemia requiring transfusion (relative risk [RR], 1.27 [95% CI, 1.14-1.42]; P \u3c .001), venous thromboembolism (RR, 1.17 [95% CI, 1.02-1.35]; P = .029), surgical site infection (RR, 1.13 [95% CI, 1.03-1.24]; P = .011), and extended length of hospital stay (RR, 1.07 [95% CI, 1.00-1.14]; P = .036). Conclusion: Although the rate of short-term complications after arthroscopic rotator cuff repair is low, incremental increases in operative time are associated with an increased risk of adverse events such as surgical site infection, pulmonary embolism, transfusion, and extended length of hospital stay. Efforts should be made to maximize surgical efficiency in the operating room through optimal coordination of the staff or increased preoperative planning