Performance of Microchannel Heat Sink Made of Silicon Material with the Two-Sided Wedge

New designs of the microchannel with a two-sided wedge shape at the base were studied numerically. Five different wedge angles ranging from 3° to 15° were incorporated into the microchannel design. Simulation of this novel microchannel was carried out using Computational Fluid Dynamics (CFD). Three-dimensional models of the microchannel heat sink were created, discretized, and based on Navier–Stokes and energy equations; laminar numerical solutions were obtained for heat transfer and pressure drop. Flow characteristics of water as coolant in a microchannel were studied. It was observed that numerical results are in good agreement with experimental results. It was found that the Nusselt number and friction factor are significantly varied with the increase in Reynolds number. The Nusselt number varies in the following ranges of 5.963–8.521, 5.986–8.550, 6.009–8.568, 6.040–8.609, and 6.078–8.644 at 3°, 6°, 9°, 12°, and 15°, respectively. The microchannel with a wedge angle of 15° was found to be better in terms of Nusselt number and thermo-hydraulic performance. The enhancement in the Nusselt number is found as 1.017–1.036 for a wedge angle of 15°; however, friction factors do not show the perceptible values at distinct values of wedge angle. Moreover, the thermo-hydraulic performance parameters (THPP) were evaluated and found to be maximum in the range of 1.027–1.045 for a wedge angle of 15°. However, minimum THPP was found in the range of 1.005–1.0185 for a wedge angle of 3°.     

Evolution of a Systematic Approach to Smoking Cessation in Ontario’s Regional Cancer Centres

Smoking cessation after a cancer diagnosis can significantly improve a person’s prognosis, treatment efficacy and safety, and quality of life. In 2012, Cancer Care Ontario (now part of Ontario Health) introduced a Framework for Smoking Cessation, to be implemented for new ambulatory cancer patients at the province’s 14 Regional Cancer Centres (RCCs). Over time, the program has evolved to become more efficient, use data for robust performance management, and broaden its focus to include new patient populations and additional data collection. In 2017, the framework was revised from a 5As to a 3As brief intervention model, along with an opt-out approach to referrals. The revised model was based on emerging evidence, feedback from stakeholders, and an interim program evaluation. Results showed an initial increase in referrals to cessation services. Two indicators (tobacco use screening and acceptance of a referral) are routinely monitored as part of Ontario Health’s system-wide performance management approach, which has been identified as a key driver of change among RCCs. Due to the COVID-19 pandemic, many RCCs reported a decrease in these indicators. RCCs that were able to maintain a high level of smoking cessation activities during the pandemic offer valuable lessons, including the opportunity to swiftly leverage virtual care. Future directions for the program include capturing data on cessation outcomes and expanding the intervention to new populations. A focus on system recovery from COVID-19 will be paramount. Smoking cessation must remain a core element of high-quality cancer care, so that patients achieve the best possible health benefits from their treatments.     

Solitary sacral osteochondroma without neurological symptoms: a case report and review of the literature

Purpose

To report a case of solitary sacral osteochondroma without neurological symptoms and describe the en bloc excision of the tumour, as well as review the literature on osteochondroma involving the sacrum.

Methods

Summary of the background data: although osteochondromas are among the most common benign tumours of the bone, they uncommonly involve the spine. Its occurence in the sacrum is rare, accounting for only 0.5 % of the osteochondromas involving spine. All previous cases of sacral osteochondroma have reported neurological symptoms on presentation.

Case report

A 21-year-old male presented with a palpable, painless mass in the left side of the sacral region of 1 year duration, without neurological symptoms. Radiological studies showed a well-circumscribed lesion with bony osteoid within arising from the sacrum at S3–S4 level left to midline, with features suggestive of osteochondroma. The tumour was excised en bloc through posterior approach. A literature review of sacral osteochondroma was conducted using MEDLINE search of English Literature and bibliographies.

Results

Histopathological studies showed the lesion to consist mature bone trabeculae with active enchondral ossification with cap of normal hyaline cartilage. Literature review yielded only 8 cases of sacral osteochondroma reported earlier.

Conclusion

This is the 9th case of solitary osteochondroma of the sacrum to be reported, the first to be reported without any neurological symptoms, and third case reported for which en bloc excision was performed.

     

Treatment of variola major with cytosine arabinoside.

A controlled study of the efficacy of cytosine arabinoside in the treatment of patients with variola major was performed. Cytosine aravinoside was given intravenously at a dose approximating 3 mg/kg of body weight every 24 hr for up to seven days. All nine patients receiving cytosine arabinoside and four of the 11 patients receiving placebo died. In three of the patients receiving cytosine aravinoside, death occurred late in the illness at a time when the patient's lesions began to dry up, the patient's temperature became normal, and the patient's general condition appeared to improve. The virus could be isolated from the blood at day 7 from three of four patients treated with cytosine arabinoside as compared with zero of six control patients. Hematologic data showed a depression in the number of circulating granulocytes. It is possible that the drug lowered the resistance to infection either through direct suppression of granulocytes or through interference with other immune mechanisms. Cytosine arabinside administered in the doses used in this study is not effective in the treatment of variola major.     

Occurrence of virulence genes, 16S rRNA methylases,and plasmid-mediated quinolone resistance genes in CTX-M-producing Escherichia coli from Pakistan

The aim of the study was to conduct a comprehensive molecular characterization of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli collected from Pakistan. Genetic relatedness among 98 ESBL-producing E. coli was measured by pulsed-field gel electrophoresis (PFGE). The presence of genes encoding ESBLs, virulence factors (VFs), 16S rRNA methylases, plasmid-mediated quinolone resistance (PMQR) encoding elements, plasmid replicon types, phylogenetic groups of E. coli, prevalence of the worldwide disseminated clone E. coli ST131, and phylogrouping of CTX-M enzymes was investigated by polymerase chain reaction (PCR). All isolates carried bla _CTX-M genes and, except for one isolate from CTX-M phylogroup 9, they all belonged to CTX-M phylogroup 1. The isolates were genetically diverse with PFGE. Phylogenetic group D (36 %) was most abundant in this collection of E. coli, whereas isolates belonging to B2 (22 %) had the highest content of virulence genes. PMQR genes were found in 84.6 % of the isolates; among them, 93 % isolates were positive for variants of acetyltransferases (aac(6′)-lb-cr), whereas qnrB, qepA, and qnrS were present in 11 %, 5 %, and 4 % of the isolates, respectively. Only 3 % of the isolates contained genes encoding 16S rRNA methylases. The most abundant replicon type was IncF (96 %), and 18 % of the isolates belonged to the ST131 clone. Out of 34 investigated VFs, 24 genes encoding different types of adhesins, protectins, toxins, siderophores, and other VFs were found. Although the isolates in this collection were highly resistant to many antimicrobials, susceptibility to amikacin and meropenem was retained.     

Emblica officinalis improves glycemic status and oxidative stress in STZ induced type 2 diabetic model rats

Objective:To evaluate the antidiabetic and antioxidant potential of Emblica officinalis(E.officinalis)fruit on normal and type 2 diabetic rats.Methods:Type 2 diabetes was induced into the male Long-Evans rats.The rats were divided into nine groups including control groups receiving water,type 2 diabetic controls,type 2 diabetic rats treated with glibenclamide(T2GT)and type 2diabetic rats treated with aqueous extract of fruit pulp of E.officinalis.They were fed orally for8 weeks with a single feeding.Blood was collected by cutting the tail tip on 0 and 28 days and by decapitation on 56 day.Packed red blood cells and serum were used for evaluating different biochemical parameters.Results:Four weeks administration of aqueous extract of E.officinalis improved oral glucose tolerance in type 2 rats and after 8 weeks it caused significant(P0.007)reduction in fasting serum glucose level compared to 0 day.Triglycerides decreased by 14%but there was no significant change in serum ALT,creatinine,cholesterol and insulin level in any group.Furthermore,reduced erythrocyte malondialdehyde level showed no significant change(P0.07)but reduced glutathione content was found to be increased significantly(P0.05).Conclusions:The aqueous extract of E.officinalis has a promising antidiabetic and antioxidant properties and may be considered for further clinical studies in drug development.     

A Simple Technique of Laparoscopic Port Closure

Background:

Laparoscopic and robotic surgery is widely practiced in modern medicine. The operative procedure is not complete until the port sites are closed with a fascial suture. We report a simple new technique that is easy, cost-effective, and quick to apply using 2 S-retractors for suture placement under direct visualization to secure the abdominal wall fascia and peritoneum.

Materials and Methods:

As a prospective consecutive case series, this technique was used for fascial closure after laparoscopy ports > 8 mm using 2 S-retractors. One S-retractor is used as a barrier protecting the contents of the abdominal cavity, reducing the risk of visceral injuries. The second S-retractor allows us to directly visualize the different layers, exposing the needle tip during its course through the fascia.

Results:

This method was used in 100 patients with no intraoperative incidents, additional operative time, or need to access costly instruments. Currently, this technique is also used by many surgeons in our institution without any difficulty. No bowel injuries or port-site hernias were reported during a mean follow-up of 6 wk postoperation and 12-mo annual follow-up.

Conclusion:

The procedure is simple, easy, cost-effective, and quick to apply.