17 research outputs found

    Internal Finishing of Aluminium Tube with Sintered Magnetic Abrasive

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    There has been a rapid growth in the development of harder and complex shapes to machine metals and alloys during the last few years. Conventional edged tool machining is difficult and uneconomical for such materials and degree of surface finish attainable is poor. In view of the seriousness of this problem, recently new non-conventional fine machining processes like Magnetic Abrasive Polishing, Magnetic Abrasive Flow Machining (MAFM), Magnetic Float Machining (MFM) and Magnetic Abrasive Machining (MAM), Magneto ndashRheological Machining (MRM), Chemo-Mechanical Polishing (CMP) have been developed. Among these processes lsquoMagnetic Abrasive Finishing processes are widely used for obtaining quality finish on metallic (ferrous and non ferrous) as well as non metallic (ceramics) components. MAF process has been recently used in its variant forms such as Magnetic float polishing, Magneto-rheological machining, Electrolytic magnetic polishing but the problem of development of magnetic abrasive powders is still present and efforts are in continuous progress at global to remove this problem.nbspIn the MAF method, a magnetic field is used to generate cutting force to treat the surface of a machined part. The magnetic field helps to form a flexible magnetic abrasives brush for finishing of surface.nbsp Finishing force can be controlled with magnetic field and a low surface temperature is generated during finishing operations. Magnetic abrasives are not easily available. Very few studies have been reported till date on the development of alternative magnetic abrasives. The aim of study is to evaluate the performance of developed sintered magnetic abrasives for internal finishing of aluminium tubes using MAF process. PISF is calculated nbspconsidering different variables like speed (rpm) , quantity of abrasive and gap of magnetic pole and work piece.nbsp Preparation of sintered magnetic abrasive was difficult and time consuming. The best result came at 425 rpm and quantity of abrasive used 6 gm. PISF value obtained in present case was 84 % . nbs

    The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study

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    Background: Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy. Methods: Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored. Results: A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays. Conclusions: IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients

    The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

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    AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

    Effectiveness of a national quality improvement programme to improve survival after emergency abdominal surgery (EPOCH): a stepped-wedge cluster-randomised trial

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    Background: Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. Methods: We did a stepped-wedge cluster-randomised trial of patients aged 40 years or older undergoing emergency open major abdominal surgery. Eligible UK National Health Service (NHS) hospitals (those that had an emergency general surgical service, a substantial volume of emergency abdominal surgery cases, and contributed data to the National Emergency Laparotomy Audit) were organised into 15 geographical clusters and commenced the QI programme in a random order, based on a computer-generated random sequence, over an 85-week period with one geographical cluster commencing the intervention every 5 weeks from the second to the 16th time period. Patients were masked to the study group, but it was not possible to mask hospital staff or investigators. The primary outcome measure was mortality within 90 days of surgery. Analyses were done on an intention-to-treat basis. This study is registered with the ISRCTN registry, number ISRCTN80682973. Findings: Treatment took place between March 3, 2014, and Oct 19, 2015. 22 754 patients were assessed for elegibility. Of 15 873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 patients in the usual care group and 7374 in the QI group. Eight patients in the usual care group and nine patients in the QI group were not included in the analysis because of missing primary outcome data. The primary outcome of 90-day mortality occurred in 1210 (16%) patients in the QI group compared with 1393 (16%) patients in the usual care group (HR 1·11, 0·96–1·28). Interpretation: No survival benefit was observed from this QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. Future QI programmes should ensure that teams have both the time and resources needed to improve patient care. Funding: National Institute for Health Research Health Services and Delivery Research Programme

    Effectiveness of a national quality improvement programme to improve survival after emergency abdominal surgery (EPOCH): a stepped-wedge cluster-randomised trial

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    BACKGROUND: Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. METHODS: We did a stepped-wedge cluster-randomised trial of patients aged 40 years or older undergoing emergency open major abdominal surgery. Eligible UK National Health Service (NHS) hospitals (those that had an emergency general surgical service, a substantial volume of emergency abdominal surgery cases, and contributed data to the National Emergency Laparotomy Audit) were organised into 15 geographical clusters and commenced the QI programme in a random order, based on a computer-generated random sequence, over an 85-week period with one geographical cluster commencing the intervention every 5 weeks from the second to the 16th time period. Patients were masked to the study group, but it was not possible to mask hospital staff or investigators. The primary outcome measure was mortality within 90 days of surgery. Analyses were done on an intention-to-treat basis. This study is registered with the ISRCTN registry, number ISRCTN80682973. FINDINGS: Treatment took place between March 3, 2014, and Oct 19, 2015. 22 754 patients were assessed for elegibility. Of 15 873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 patients in the usual care group and 7374 in the QI group. Eight patients in the usual care group and nine patients in the QI group were not included in the analysis because of missing primary outcome data. The primary outcome of 90-day mortality occurred in 1210 (16%) patients in the QI group compared with 1393 (16%) patients in the usual care group (HR 1·11, 0·96-1·28). INTERPRETATION: No survival benefit was observed from this QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. Future QI programmes should ensure that teams have both the time and resources needed to improve patient care. FUNDING: National Institute for Health Research Health Services and Delivery Research Programme

    Investigation of the impact of the language used for instruction on high school students' identity formation in Punjab, India

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    Existing research suggests that the force and flow of globalisation and the consequent use of English as the global lingua franca has a significant impact on people’s identity formation. Many postcolonial countries use English as a second or foreign language and thus have adopted it as the language for instruction in schools. The use of English as the medium of instruction (EMI) has been widely studied and it has been found that this has an impact on people's identity formation. Although extensive research on EMI and identity formation has been conducted, this remains an under-researched area in many multilingual contexts, for example, in the Punjab in India. Moreover, research that does exist has not focused on high school students’ views and experiences. To begin to address this gap in the existing published literature, this qualitative study set out to investigate whether, and to what extent, the language used as the MOI in Punjab in India affects high school students’ perceptions of their identity formation. Two schools were involved: one where English was used as the medium of instruction, and one where Punjabi was used as the medium of instruction. Data were gathered using documentary analysis; four focus group discussions with pupils (two in each of the two schools, involving a total of twenty four students); and semi-structured interviews with two headteachers, four English language teachers (two from each school) and twelve high school students in 9th and 10th grades (six from each school). Participants’ views and perceptions concerning the language of instruction and its impact on students’ opportunities to access higher education programmes, their future careers, and their social positions in Punjabi society were sought. The conceptual framing of the study draws on Norton's concept of investment (Norton, 1995; Norton, 2016b) which includes ideology, agency and identity. In addition, significant concepts such as Bourdieu's (1986) forms of capital and Markus and Nurius's (1986) notion of ‘possible selves’ have also been used. The data were analysed using Charmaz’s (1995, 2006, 2014) account of constructivist grounded theory, and a constant comparative analysis approach was employed to identify similarities and differences in participants’ accounts and to locate dominant themes within and across the data sets. Key findings revealed that the use of English as the medium of instruction was seen by each participant group to have a significant positive impact on students’ identity formation and of their perceptions of their future possible selves; on their opportunities to embark on higher education degrees, particularly in areas such as medicine and science; on their future employment opportunities; and on their social positions in Punjab. This research contributes geographically, theoretically, as well as methodologically to the research in the area of EMI and identity and may help to raise awareness about learning and teaching in different languages and its impact on students’ identity formation. This study concludes with a discussion of the implications of findings from the study for policymakers in Punjab, for language teachers, for the education and training of teachers, for parents, and above all for the students

    Fine Mapping of the Wheat Leaf Rust Resistance Gene <i>Lr42</i>

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    Leaf rust caused by Puccinia triticina Eriks is one of the most problematic diseases of wheat throughout the world. The gene Lr42 confers effective resistance against leaf rust at both seedling and adult plant stages. Previous studies had reported Lr42 to be both recessive and dominant in hexaploid wheat; however, in diploid Aegilops tauschii (TA2450), we found Lr42 to be dominant by studying segregation in two independent F2 and their F2:3 populations. We further fine-mapped Lr42 in hexaploid wheat using a KS93U50/Morocco F5 recombinant inbred line (RIL) population to a 3.7 cM genetic interval flanked by markers TC387992 and WMC432. The 3.7 cM Lr42 region physically corresponds to a 3.16 Mb genomic region on chromosome 1DS based on the Chinese Spring reference genome (RefSeq v.1.1) and a 3.5 Mb genomic interval on chromosome 1 in the Ae. tauschii reference genome. This region includes nine nucleotide-binding domain leucine-rich repeat (NLR) genes in wheat and seven in Ae. tauschii, respectively, and these are the likely candidates for Lr42. Furthermore, we developed two kompetitive allele-specific polymorphism (KASP) markers (SNP113325 and TC387992) flanking Lr42 to facilitate marker-assisted selection for rust resistance in wheat breeding programs
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