Recurrent Metastatic Chordoma to the Liver: A Case Report and Review of the Literature

Chordoma is a rare malignant neoplasm derived from notochordal tissue that primarily affects the axial skeleton. Almost 40% of patients have non-cranial chordoma metastases. The most common metastatic sites are the lungs, bones, lymph nodes, and subcutaneous tissue. We present a 52-year female with a history of sacral chordoma presenting with abdominal fullness, early satiety, and a palpable abdominal mass. Abdominal magnetic resonance imaging (MRI) revealed an isolated, highly vascularized, and multilobed liver mass in the left lateral segment. The mass was surgically removed using a clean surgical margin. A histological examination and immunohistochemical staining were consistent with a metastatic chordoma. Two years later, follow-up imaging studies showed a 6.5 × 4.0 × 2.0 cm right liver lesion with multiple lungs, chest wall, pleural, and diaphragmatic lesions. Microscopic- and immunohistochemical staining revealed a recurrent metastatic chordoma. Herein, we present a unique case of metastatic recurrent chordoma in the liver with the involvement of other sites. To the best of our knowledge, no other case of recurrent liver metastasis has been reported.     

Non-edible plant seeds of Acacia farnesiana as a new and effective source for biofuel production

Currently, the energy crisis is a hot topic for researchers because we are facing serious problems due to overpopulation and natural energy sources are vanishing day-by-day. To overcome the energy crisis, biofuel production from non-edible plant seeds is the best solution for the present era. In the present study, we select the non-edible seeds of Acacia farnesiana for biofuel production from different areas of Pakistan with better oil production results. Different kinds of analytical method, like the American Standard for Testing and Materials and techniques like Fourier transform infra-red spectroscopy, nuclear magnetic resonance spectroscopy, gas chromatography, and inductively coupled plasma optical emission spectrometry, were used to evaluate the chemical compositions. The maximum oil extraction rate (23%) was produced by petroleum ether. Potassium hydroxide exhibited the best conversion result of 96% fatty acid methyl ester. The transesterification method was used for the preparation of fatty acid methyl ester (96%) using potassium hydroxide and methanol. The viscosity and density of Acacia farnesiana seed oil biodiesel was comparable to American Standard for Testing Material biodiesel standards. By using gas chromatography-mass spectrometry, five fatty acids were detected comprising palmitic acid (6.85%), stearic acid (2.36%), oleic acid (12.13%), linoleic acid (46.85%), and α-linolenic acid (1.23%). This study concludes that Acacia farnesiana seed oil biodiesel could be an intriguing raw material for yielding Acacia farnesiana seed oil methyl ester as an alternative fuel source.

Currently, the energy crisis is a hot topic for researchers because we are facing serious problems due to overpopulation and natural energy sources are vanishing day-by-day.     

Prediction of Compressive Strength of Sustainable Foam Concrete Using Individual and Ensemble Machine Learning Approaches

The entraining and distribution of air voids in the concrete matrix is a complex process that makes the mechanical properties of lightweight foamed concrete (LFC) highly unpredictable. To study the complex nature of aerated concrete, a reliable and robust prediction model is required, employing different machine learning (ML) techniques. This study aims to predict the compressive strength of LFC by using a support vector machine (SVM) as an individual learner along with bagging, boosting, and random forest (RF) as a modified ensemble learner. For that purpose, a database of 191 data points was collected from published literature, where the mix design ingredients, i.e., cement content, sand content, water to cement ratio, and foam volume, were chosen to predict the compressive strength of LFC. The 10-K fold cross-validation method and different statistical error and regression tools, i.e., mean absolute error (MAE), root means square error (RMSE), and coefficient of determinant (R²), were used to evaluate the performance of the developed ML models. The modified ensemble learner (RF) outperforms all models by yielding a strong correlation of R² = 0.96 along with the lowest statistical error values of MAE = 1.84 MPa and RMSE = 2.52 MPa. Overall, the result suggests that the ensemble learners would significantly enhance the performance and robustness of ML models.     

Enhancement of Confinement in Scaled RC Columns using Steel Fibers Extracted from Scrap Tyres

Steel fibers are widely extracted from scrap tyres, causing environmental concerns. This paper presents the use of steel fibers in variable proportions extracted from scrap tyres. The enhancement of the confinement was envisaged through the addition of steel fibers obtained from scrap tyres. The study included an experimental program for the development of constitutive material models for ordinary Portland cement (OPC) concrete and concrete with added steel fibers. A mix design was carried out for OPC, targeting a compressive strength of 3000 psi. Steel fibers were added to OPC in ratios of 1.0% to 3.0%, with an increment of 0.5%. Concrete columns, with cross-sectional dimensions of 6 × 6 inches and a length of 30 inches, were cast with both OPC and fiber-reinforced concrete. The column confinement was evaluated with a different spacing of ties (3- and 4-inch center-to-center). Compression tests on the concrete columns indicate that the addition of steel fibers to a concrete matrix results in an appreciable increase in strength and ductility. Overall, increasing the percentage of steel fibers increased the compression strength and the ductility of concrete. The maximum strain in the concrete containing 2.5% steel fibers increased by 285% as compared to the concrete containing 1% of steel fibers. An optimum percentage of 2.5% steel fibers added to the concrete resulted in a 39% increase in compressive strength, accompanied by a significant improvement in ductility. The optimum content of steel fibers, when used in confined columns, showed that confined compression strength increased with the addition of steel fibers. However, it is recommended that additional columns on the basis of the optimum steel fiber content shall be tested to evaluate their effectiveness in reducing the stirrup spacing.     

A Review of Tags Anti-collision and Localization Protocols in RFID Networks

Radio Frequency IDentification (RFID) has allowed the realization of ubiquitous tracking and monitoring of physical objects wirelessly with minimum human interactions. It plays a key role in a wide range of applications including asset tracking, contactless payment, access control, transportation and logistics, and other industrial applications. On the other side, RFID systems face several technical challenges that need to be overcome in order to achieve their potential benefits; tags collisions and localization of tagged objects are two important challenges. Numerous anti-collision and localization protocols have been proposed to address these challenges. This paper reviews the state-of-art tags?? anti-collision and localization protocols, and provides a deep insight into technical issues of these protocols. The probabilistic and deterministic anti-collision protocols are critically studied and compared in terms of different parameters. We further review distance estimation, scene analysis, and proximity localization schemes and provide useful suggestions. We also introduce a new hybrid direction that utilizes power control to spatially partition the interrogation range of a reader for more efficient anti-collision and localization. Finally, we present the applications of RFID systems in healthcare sectors.     

Totally extra-peritoneal repair of inguinal hernia by a glove-balloon: technical innovation.

Totally extra-peritoneal (TEP) laparoscopic repair of an inguinalhernia involves the creation of an extra-peritoneal space by blunt dissection or the use of commercial balloons. This new technique demonstrates the use of a device to create this extra-peritoneal space, without the need for any commercial balloons. The extra-peritoneal space was created using a glove-balloon. A total of 107 consecutive TEP repairs were carried out using the glove-balloon technique, these included ten bilateral and 17 recurrent inguinal hernias. This method is simple, cost-effective and easy to teach.     

Assessing the complications and effectiveness of open carpal tunnel release in a tertiary care centre in a developing country

INTRODUCTION

Open surgical release for carpal tunnel syndrome is not devoid of complications and its quantitative assessment with the Boston questionnaire in a developing country had not been conducted, where, lack of facilities and surgical technique can influence the outcome.

PRESENTATION OF CASE

This was a prospective study in which all cases of carpal tunnel syndrome undergoing open release between June 2007 and June 2012 and who returned for follow up were included. Each patient was requested to fill out the Boston questionnaire twice both pre and post op at 3 months. All complications were recorded as well as bio-data of patients and co morbidities. Follow up was at 2 weeks and at 3 months. Those reporting complications at 3 months were further followed up until 6 months. 373 patients were included in the study. Twenty four patients developed complications. Of these, 12 experienced pain resulting from reflex sympathetic dystrophy. Three patients developed wound dehiscence, 2 cases acquired infections, 4 patients developed immediate post-operative haemorrhage and in 3 patients there was late recurrence of median nerve compression. The symptom severity score pre-operatively was 3.30 (±0.60) and it improved to 1.65 (±0.75) post-operatively indicating a significant change (p < 0.0001). The preoperative functional status score was 2.58 (±0.75) and post-op it became 1.60 (±0.80) again implying a good improvement with an effect size of 1.3.

DISCUSSION

All of the complications produced were well managed. The complication incidence was low. The open release procedure produced good improvement in hand function and in decreasing the symptom severity.

CONCLUSION

Conducting open release for carpal tunnel syndrome in a tertiary referral centre in a developing country offers a good outcome.     

Surgical management of contiguous multilevel thoracolumbar tuberculous spondylitis

Introduction

Tuberculous spondylitis (TBS) is the most common form of extra-pulmonary tuberculosis. The mainstay of TBS management is anti-tuberculous chemotherapy. Most of the patients with TBS are treated conservatively; however in some patients surgery is indicated. Most common indications for surgery include neurological deficit, deformity, instability, large abscesses and necrotic tissue mass or inadequate response to anti-tuberculous chemotherapy. The most common form of TBS involves a single motion segment of spine (two adjoining vertebrae and their intervening disc). Sometimes TBS involves more than two adjoining vertebrae, when it is called multilevel TBS. Indications for correct surgical management of multilevel TBS is not clear from literature.

Materials and methods

We have retrospectively reviewed 87 patients operated in 10 years for multilevel TBS involving the thoracolumbar spine at our spine unit. Two types of surgeries were performed on these patients. In 57 patients, modified Hong Kong operation was performed with radical debridement, strut grafting and anterior instrumentation. In 30 patients this operation was combined with pedicle screw fixation with or without correction of kyphosis by osteotomy. Patients were followed up for correction of kyphosis, improvement in neurological deficit, pain and function. Complications were noted. On long-term follow-up (average 64 months), there was 9.34 % improvement in kyphosis angle in the modified Hong Kong group and 47.58 % improvement in the group with pedicle screw fixation and osteotomy in addition to anterior surgery (p < 0.001). Seven patients had implant failures and revision surgeries in the modified Hong Kong group. Neurological improvement, pain relief and functional outcome were the same in both groups.

Conclusion

We conclude that pedicle screw fixation with or without a correcting osteotomy should be added in all patients with multilevel thoracolumbar tuberculous spondylitis undergoing radical debridement and anterior column reconstruction.