Medulloblastoma

Among the pediatric brain tumors, medulloblastoma (MB) is the most common solid variety and entirely occur in the posterior fossa with tendency to seed into CSF spaces. Despite innovations in technological developments and understanding of tumor biology, modern imaging facilities, advances in surgical practices, and newer chemotherapeutic and radiation techniques, this malignant type of tumor continues to be a formidable entity. Even though, the outcome in terms of survival rate is better than any time before, the overall result is still disappointing. With advances in management strategy, chances of survival with good quality of life have been amplified, where newer targeted therapies and rehabilitation plays an immense role. While the adverse effects of surgery and adjuvant therapies are still on play, researchers are trying ceaselessly to minimize those to give maximum wellbeing to these unfortunate children

“Stealth Cranioplasty” for Adult Chiari Malformation Type 1: A Philosophical Journey of Innovation, Adaptation, and Evolution

Chiari malformation (CM) and its management are long debated enigmas for neurosurgeons. Many surgical procedures have been innovated and are in practice for this perplexing and daunting entity to give the patients a satisfactory remedy. But, a unanimously accepted surgical procedure is still lacking to achieve gratifying result. We tried to develop a novel technique, which we call the “stealth cranioplasty (SCP),” to help the adult Chiari malformation type 1 (CM1) patients. In this chapter, the philosophy behind developing the technique of “stealth cranioplasty” by reconstruction of posterior fossa (PF) by cranioplasty with pre-shaped titanium mesh is described. Different stages, difficulties, and modifications of the journey toward the present day status are also elaborated graphically

Role of Cranioplasty in Management of Chiari Malformation

Chiari malformations (CM) are a set of enigmatic congenital anomalies, owing to their complex pathology, varied presentations and management dilemma. Because of the daunting nature of this disease, a universal definitive treatment protocol is yet to be established. Diverse surgical procedures are in practice with various philosophies, aiming to resolve different sections of the pathologies of this disorder, either singly or in combination. However, outcomes are quite variable. Though not a well-recognized and commonly practiced paradigm of managing CM, different techniques of cranioplasty for CM has been described by many authors with variable rates of success. Cranioplasty for Chiari has been found to be helpful in different circumstances with the objective to address different predicaments. Initially, it has been exercised as one of the modalities to manage some particular situations, mostly in cases to solve complications following surgery. Now in some centers, different types of methods of cranioplasty are practiced routinely to treat particular set of Chiari patients with specifically set criteria and some have shown success in those certain scenarios. In this chapter, different methods of cranioplasty for Chiari malformation by different authors, strategies behind the techniques and their results are described in brief. “Stealth cranioplasty”, a technique devised by our team is also portrayed

METAL REACTIVITY IN LABORATORY BURNED WOOD FROM A WATERSHED AFFECTED BY WILDFIRES

Massive amounts of wood ash are deposited into nearby streams as a result of runoff from storm events after increasing frequency of wildfire events that negatively affect water quality. Ash and debris from burned vegetation can alter the pH, turbidity and dissolved oxygen (DO) in water and can release heavy metals, organic matter, and nutrients. We investigated interfacial processes affecting metal mobility in wood ash burned under laboratory-controlled conditions using aqueous chemistry, microscopy and spectroscopy analyses. Wood was collected from the Valles Caldera National Preserve in New Mexico which has experienced two wildfires since 2011 that have caused devastating effects. Wood samples (e.g. Ponderosa Pine, Quaking Aspen, and Colorado Blue Spruce) collected from this site were exposed to temperatures of 60°C, 350°C and 550°C. Pine ashes burned at 350°C and 550°C were associated with high concentrations of metals (i.e., Cu, Cr, Si, Ni, Fe, K and Mg). Pine ash burned at 350°C had the highest content of Cu (4997 +/- 262 mg kg-1), Cr (543 +/- 124 mg kg-1), and labile dissolved organic carbon (DOC, 11.3 +/- 0.28 mg L-1). Metal sorption experiments were conducted by reacting 350°C Pine ash separately with 10μM solutions of Cu(II) and Cr(VI), as examples of a cation and an oxyanion found in high concentrations in water following wildfire events near VALL. High decrease in Cu(II) concentration (up to 92%) was observed in solution while Cr(VI) showed limited decrease (up to 13%) in concentration after 180 mins of reaction. X-ray photoelectron spectroscopy (XPS) v analyses detected increased association of Cu(II) on the near surface region of the reacted ash from the sorption experiments compared to the unreacted ash. The results from this investigation suggest that dissolution and sorption processes are essential to understand the transport of metals in water following wildfires. This study provides relevant insights about the potential effects of metals transported by wood ash on water quality that have important implications for post-fire recovery and response strategies

Comparison of Compressive Strength and Flexural Capacity between Engineered Cementitious Composites (Bendable Concrete) and Conventional Concrete used in Bangladesh

The Engineered Cementitious Composites (ECC) is made of the same ingredients as in regular concrete. The coarse aggregate is replaced with tiny Polyvinyl Alcohol fibres. This structure offers maximum flexibility and it is expected to cost less. It looks exactly like normal concrete, but under excessive strain, the ECC concrete allows, the specially coated network of fibre in the cement to slide within the cement, thus avoiding the inflexibility that causes brittleness and breakage. As this is a special type of concrete there are no defined codes for it, thus for these reasons, the parameters needed are to be obtained using trial and error method. During the composite preparation, sieve analysis was carried out. Composites were reinforced with Polyvinyl Alcohol (PVA) at the following ratios: 0 % (control), 0.5 %, 1 % and 1.5 %. The cylindrical specimens were subjected to compression and the slab specimens were subjected to flexural test using a Universal Testing Machine, while acquiring data with GOM Correlation Software. Test results reveal that fibre ratio 1% is most acceptable for attaining best compressive strength along with high flexural value. Even though 1% fibre content concrete in the flexural strength test showed 33% less strength of what 1.5% fibre content concrete gained, in the long run, for having the highest compressive strength value (almost 62% more than of 0% fibre content concrete and 15% more than of 1.5% fibre content concrete), 1% fibre content concrete is most suited for constructions

Inconsistent using FLOOD and Flooding Development of EPA SWMM for Assessing Flood Occurrences in Vulnerable Urban Watershed Considering Extreme Rainfall Events

Urban flood, commonly known as urban water congestion, is a type of water hazard that poses significant challenges for urban residents and water management experts. Chittagong, an essential economic hub in Bangladesh, renowned for its role as a port city, comprises a diverse range of land use, including residential, industrial, and commercial sectors. The Chaktai canal, an important element of Chittagong drainage system, is connected to the Karnaphuli river, playing a vital role in managing drainage by handling a substantial portion of the city water. Therefore, this research evaluated the operational efficiency of a specific drainage network under the influence of altered rainfall events using the Storm Water Management Model (SWMM). Using ArcGIS 10.4, the land use pattern of the area was researched, incorporating data from field surveys and secondary sources. SWMM 5.1 integrated watershed data, and further simulation was carried out to estimate runoff in various sub-catchments and drainage network limitations during heavy rain. During the intense monsoon period, the tool determined the average runoff depth, considering backwater effects and robust tidal surges, resulting in a depth of 3.3m compared to 2.6m in the dry season. This research evaluated the influence of impervious land use changes on urban drainage systems. While meteorological factors alone render drainage network sufficient in dry periods, the outfall shows vulnerability during the rainy season, with an allowance of only 0.7m, jeopardizing the catchment through flood. It contributed a schematic sub-catchment representation, emphasizing that flood events depend on volume runoff and peak flow in urban drainage system. SWMM model was used to illustrate the catchment surface runoff and interconnected node depths via conduits, as well as the current catchment scenario comprehensively

Bio-Engineered Concrete: A Critical Review on The Next Generation of Durable Concrete

Concrete is a prerequisite material for infrastructural development, which is required to be sufficiently strong and durable. It consists of fine, coarse, and aggregate particles bonded with a fluid cement that hardens over time. However, micro cracks development in concrete is a significant threat to its durability. To overcome this issue, several treatments and maintenance methods are adopted after construction, to ensure the durability of the structure. These include the use of bio-engineered concrete, which involved the biochemical reaction of non-reacted limestone and a calcium-based nutrient with the help of bacteria. These bio-cultures (bacteria) act as spores, which have the ability to survive up to 200 years, as they are also found to start the mineralization process and the filling of cracks or pores when in contact with moisture. Previous research proved that bio-engineered concrete is a self-healing technology, which developed the mechanical strength properties of the composite materials. The mechanism and healing process of the concrete is also natural and eco-friendly. Therefore, this study aims to critically analyze bio-engineered concrete and its future potentials in the Structural Engineering field, through the use of literature review. The data analysis was conducted in order to provide gradual and informative ideas on the historical background, present situation, and main mechanism process of the materials. According to the literature review, bio-engineered concrete has a promising outcome in the case of strength increment and crack healing. However, the only disadvantage was its less application in the practical fields. The results concluded that bio-engineered concrete is a new method for ensuring sustainable infrastructural development. And also, it indicated that more practical outcome-based analysis with extensive application in various aspects should be conducted, in order to assess the overall durability

Comparison of Compressive Strength and Flexural Capacity between Engineered Cementitious Composites (Bendable Concrete) and Conventional Concrete used in Bangladesh

The Engineered Cementitious Composites (ECC) is made of the same ingredients as in regular concrete. The coarse aggregate is replaced with tiny Polyvinyl Alcohol fibres. This structure offers maximum flexibility and it is expected to cost less. It looks exactly like normal concrete, but under excessive strain, the ECC concrete allows, the specially coated network of fibre in the cement to slide within the cement, thus avoiding the inflexibility that causes brittleness and breakage. As this is a special type of concrete there are no defined codes for it, thus for these reasons, the parameters needed are to be obtained using trial and error method. During the composite preparation, sieve analysis was carried out. Composites were reinforced with Polyvinyl Alcohol (PVA) at the following ratios: 0 % (control), 0.5 %, 1 % and 1.5 %. The cylindrical specimens were subjected to compression and the slab specimens were subjected to flexural test using a Universal Testing Machine, while acquiring data with GOM Correlation Software. Test results reveal that fibre ratio 1% is most acceptable for attaining best compressive strength along with high flexural value. Even though 1% fibre content concrete in the flexural strength test showed 33% less strength of what 1.5% fibre content concrete gained, in the long run, for having the highest compressive strength value (almost 62% more than of 0% fibre content concrete and 15% more than of 1.5% fibre content concrete), 1% fibre content concrete is most suited for constructions

Comparing laboratory dynamic modulus values with long term pavement performance predictions

This study compares laboratory dynamic modulus value of Superpave mixes with the dynamic modulus obtained from Long Term Pavement Performance (LTPP) database. The comparison shows that the dynamic modulus from LTPP database, which were determined by using different types of artificial neural network (ANN) models, differs from the laboratory tested dynamic modulus. The dynamic modulus data of five LTPP test sections are considered. Mixes similar to those five sections were collected from the field and tested in the laboratory. Based on the findings of this study, it can be said that dynamic modulus from ANN models are less than the laboratory dynamic modulus for New Mexico Superpave mixes. Therefore, as an important design parameter, the use of dynamic modulus predicted from Neural Network models can result in outcomes different from those using laboratory dynamic modulus

An Experimental Study of the Physio-Mechanical and Microstructural Performances of Escherichia Coli Bacteria-Based Bio-Concrete

A balanced mixture of cement, sand, stone or brick chips, and water is carefully allowed to form concrete, a man-made building material. These elements can be adjusted appropriately to produce concrete with a variety of qualities. Although concrete may endure compressive forces, like natural stone, tensile forces can cause it to crack. As a result, crack formation is a frequent occurrence in concrete, allowing various foreign chemicals and water to enter the structures and shortening their life span. The likelihood of cracking grows with time due to variations in humidity and temperature. It can be exceedingly expensive to maintain or repair concrete construction items. The use of bio-concrete for the construction of durable structures has shown to be quite advantageous in this perspective. It is beneficial for improving the properties of concrete as well as lowering maintenance costs. In this investigation, concrete samples measuring 100×100×100 mm were made and periodically tested for compressive and split tensile strength testing. Following a 28-day curing period, the concrete treated with Escherichia coli bacteria had compressive and split tensile strengths that were 10% and 23% higher than identical bacteria-free. The non-destructive test on cylindrical samples was then conducted to evaluate the material qualities. The mortar samples of crystalline structures were also validated by SEM examination. In order to properly and reliably anticipate the strength of concrete, the RSM model was also formulated