ESTIMATION OF ANISOTROPIC ELASTIC PROPERTIES OF CARBON FIBERS USING NANOINDENTATION

Understanding the mechanical behavior of carbon fiber reinforced polymers requires knowledge on the deformation behavior of carbon fibers, they are highly anisotropic and heterogeneous. Nanoindentation is an efficient method for determining the mechanical properties in small volumes of materials. For isotropic materials, a single nanoindentation test can evaluate an elastic properties of the material. But for anisotropic material, the difficulty increases since measured indentation modulus depends on five elastic parameters (El,Et,Glt, νlt,and νtt) of the material. Nanoindentation experiments are performed on carbon fibers orientated between 0° to 90° at ten different orientations to the fiber axis. From theoretical models given by Vlassak et al. and Delafargue and Ulm, the elastic constants are predicted numerically by comparing the results of indentation modulus versus orientation angle with the experiments

Solitary Pancreatic Metastasis from Renal Cell Carcinoma: A Case Report from India with a Review of Literature

ABSTRACT: Metastatic cancer to the pancreas accounts for less than 2% of all pancreatic malignancies, with renal cell carcinoma being the predominant type. We report the case of an elderly patient detected with a solitary lesion in the head of the pancreas, 6 years after a nephrectomy for renal cell carcinoma. The patient underwent a pancreaticoduodenectomy for the same. A review of literature showed isolated pancreatic metastasis to be rare, ranging from 0.5 to 3%. Patients are usually asymptomatic, unless the tumor enlarges. Spread usually takes place by the hematogenous route or via lymphatics, direct spread being very unusual. Surgical resection seems to be the standard of care for isolated metastasis from renal cell carcinoma as the other modalities of treatment seem unresponsive. Typically, patients undergo a pancreaticoduodenectomy or distal pancreatectomy depending on the location of the tumor. Atypical resections are done in certain situations. Surgery is carried out in favourable candidates and a thorough evaluation needs to be done intraoperatively for multiple metastases. Histology revealed a metastatic renal cell carcinoma confirmed on immunohistochemistry. All margins were free of tumor without lymphnodal involvement. Eight months after the surgery the patient is doing well. As compared to primary pancreatic cancer, metastasis from renal cell carcinoma has a higher resectability rate. Solitary metastasis to the pancreas has a good prognosis especially in renal cell carcinoma, with a 5 years survival rate of 43 to 88%.KEYWORDS: Renal Cell Carcinoma; Pancreatic Metastasis; PancreaticoduodenectomyInternet Journal of Medical Update 2012 January;7(1):62-

Custom Design & Fabrication of 3D printed cast for ankle immobilisation

Management of bone and joint injuries is commonly done by immobilisation using plaster/fibreglass casts. This study describes design and fabrication of patient specific cast using 3D printing.  The 3D printed cast while being patient friendly is superior to earlier casts in healing efficacy and hence redefines the joint immobilisation practice. We present here a case of “walk on brace” design and fabrication using 3D printing. The custom design of ankle immobilisation cast was done for an 18-year-old boy having tibia bone fracture during gymnastic activity. The workflow comprises of anatomical data acquisition, CAD, 3D printing, post processing and clinical approval for use. Additional features such as straps, anti-slip inner surface and tread for floor grip were incorporated in the design.

Complications as indicators of quality assurance after 401 consecutive colorectal cancer resections: the importance of surgeon volume in developing colorectal cancer units in India

<p>Abstract</p> <p>Background</p> <p>The low incidence of colorectal cancer in India, coupled with absence of specialized units, contribute to lack of relevant data arising from the subcontinent. We evaluated the data of the senior author to better define the requirements that would enable development of specialized units in a country where colorectal cancer burden is increasing.</p> <p>Methods</p> <p>We retrospectively analyzed data of 401 consecutive colorectal resections from a prospective database of the senior author. In addition to patient demographics and types of resections, perioperative data like intraoperative blood loss, duration of surgery, complications, re-operation rates and hospital stay were recorded and analyzed.</p> <p>Results</p> <p>The median age was 52 years (10-86 years). 279 were males and 122 were females. The average duration of surgery was 220.32 minutes (range 50 - 480 min). The overall complication rate was 12.2% (49/401) with a 1.2% (5/401) mortality rate. The patients having complications had an increase in their median hospital stay (from 10.5 days to 23.4 days) and the re-operation rate in them was 51%. The major complications were anastomotic leaks (2.5%) and stoma related complications (2.7%).</p> <p>Conclusions</p> <p>This largest ever series from India compares favorably with global standards. In a nation where colorectal cancer is on the rise, it is imperative that high volume centers develop specialized units to train future specialist colorectal surgeons. This would ensure improved quality assurance and delivery of health care even to outreach, low volume centers.</p

Is early feeding after major gastrointestinal surgery a fashion or an advance? Evidence-based review of literature

Early enteral nutrition (EN) after major digestive surgery has been receiving increasing attention. Supporting evidence has not been clear. This evidence-based review traces the development of early EN and analyses whether it is indeed an advance. We performed a PubMed search in October 2009 with the key words enteral nutrition, early feeding, and gastrointestinal surgery. Our emphasis was on earliest studies documenting the benefits or adverse effects of EN, comparative studies, documenting the benefits or adverse effects of EN, comparative studies, and randomized controlled trials. Thirty-one results were returned from which 17 were included for evaluation (1979-2009). Fifteen papers concluded that early EN was beneficial. In general, patients put on early EN and immunonutrition postoperatively seemed to have decreased hospital stay, decreased complication rates, decreased treatment and hospital costs, and even decreased morbidity and mortality; however, judicious use has been suggested. One study did not recommend early enteral feeding in well-nourished patients at low risk of nutrition-related complications and another suggested that immunonutrition is not beneficial and should not be used routinely. Early EN has been safely given after major digestive surgery since 1979. It benefits patients undergoing major gastrointestinal (GI) surgeries, with reduction in perioperative infection, better maintainance of nitrogen balance, and shorter hospital stay. Early EN may be superior to total parenteral nutrition (TPN). However, TPN is perhaps better tolerated in the immediate postoperative period. Early enteral immunonutrition should be used only in malnourished and in transfused patients. Early EN after major digestive surgery is an old advance that is now in fashion

Anesthetic management of a child with homocystinuria

Homocystinuria is a disorder of methionine metabolism, leading to an abnormal accumulation of homocysteine and its metabolites in blood and urine. It is most often diagnosed in childhood and has variable expressions. We report a case of a 7-year-old male child with diminished vision since birth diagnosed as bilateral congenital cataract and superomedial subluxation of lens posted for cataract excision under general anesthesia. The key points of perioperative management included prevention of hypoglycemia, optimal hydration, prevention of thromboembolic episodes, and total intravenous anesthesia