Ultrasound-assisted efficient and convenient method of extracting valuable metals (Ni, Co, and Cd) from waste Ni-Cd batteries using DL-malic acid.

Recycling waste Ni-Cd batteries has received much attention recently because of the serious environmental pollution they cause and to avoid the dissipation of valuable metals. Despite significant research, it is still difficult to efficiently recycle valuable and hazardous metals from waste Ni-Cd batteries in an economical and environmentally friendly manner. This study employed a novel process utilizing ultrasound-assisted leaching to recover Ni, Cd, and Co from waste nickel-cadmium (Ni-Cd) batteries. Organic DL-malic acid served as the leaching agent and H2O2 was employed as an oxidizing agent. The effects of various factors on the recovery efficiency of Ni, Cd, and Co, such as leaching temperature, time, DL-malic acid concentration, pulp density, H2O2 concentration, and ultrasound frequency, were also examined. To predict the chemical compounds present before and after the recycling experiments, the solid residues from the metal extraction were analyzed using XRD, XPS, FE-SEM, and EDS element mapping. Concurrently, ICP-OES was utilized to determine the metal content in the leachate. Under optimized conditions of 90 °C, 90 min, 2M DL-malic acid, 160 mL/g pulp density, and 20% ultrasound frequency, over 83% of Ni, 94% of Cd, and 98% of Co were effectively leached from the waste Ni-Cd battery powder. The leaching kinetics of Ni, Cd, and Co followed the surface chemical reaction control model. The activation energies (Ea) for Ni, Cd, and Co leaching were 21.34, 20.47, and 18.38 kJ/mol, respectively. The findings suggest that ultrasound-assisted leaching is an efficient, cost-effective, environmentally friendly, and sustainable alternative for extracting precious and hazardous metals from waste Ni-Cd batteries. Additionally, it reduces industrial chemical usage and enhances waste management sustainability.

A finite element study and mathematical modeling of lumbar pedicle screw along with various design parameters.

BACKGROUND: Lumbar pedicle screw is one of the most common and important elements in the field of lumbar surgery. It plays a great role in rectifying the spinal alignment and stabilization providing strength and stability to the affected area of spine. In spinal surgery, minimally invasive techniques and minor incisions are made which makes it less painful for the patients than the traditional methods. Moreover, the screws are not needed to be removed after the surgery which is yet another great advantage of the pedicle screw. METHOD: In this study, 3D Finite Element (FE) model of human L4 vertebrae is taken for analysis using image processing tool. Pedicle screw design with varying mechanical and geometrical properties has been carried out at different applied loads on it along with considering the effect of frictional forces between all contact surfaces. RESULT: Mathematical relationship among stress, strain, pitch of the screw and diameter have been developed for different thread profiles which will be beneficial for researchers for further development of pedicle screw implants. CONCLUSION: Results from the different analysis shows that bending stress on the screw for different loads at triangular pitch is higher than the trapezoidal. Hence, trapezoidal thread is efficacious than triangular thread. In case of vertebral bone, the magnitude of stress is less for trapezoidal screw than triangular and stress has a linear relationship with pitch length. In term of strain, triangular thread develops more strain than trapezoidal thread. A set of mathematical relation has been developed for different thread profile based on pitch length, stress and strain which gives the idea about von Mises stress and strain.

Mathematical Modelling and Optimization for Facile Synthesis of Structured Activated Carbon (ACs) from Adansonia kilima (Baobab) Wood Chips Integrating Microwave-Assisted Pyrolysis for the Elimination of Lead (II) Cations from Wastewater Effluents.

In this research, activated carbon (AC) was synthesized from ligno-cellulosic residues of Adansonia kilima (Baobab) wood chips (AKTW) using two-step semi-carbonization and subsequent pyrolysis using microwave-induced heating (MWP) in the presence of a mild activating agent of K2CO3. The influence of process input variables of microwave power (x1), residence time (y1), and amount of K2CO3 (z1) were analysed to yield superior quality carbon having maximum removal efficiencies (R1) for lead (II) cations from waste effluents, fixed carbon percentages (R2), and carbon yield percentages (R3). Analysis of variance (ANOVA) was used to develop relevant mathematical models, with an appropriate statistical assessment of errors. Level factorial response surface methodology (RSM) relying on the Box-Behnken design (BBD) was implemented for the experimental design. The surface area and porous texture of the samples were determined using Brunauer, Emmett, and Teller (BET) adsorption/desorption curves based on the N2 isotherm. Surface morphological structure was observed using field emission scanning electron microscopic (FESEM) analysis. Thermogravimetric analysis (TGA) was carried out to observe the thermal stability of the sample. Change in the carbon content of the samples was determined using ultimate analysis. X-ray diffraction (XRD) analysis was performed to observe the crystalline and amorphous texture of the samples. The retention of a higher proportion of fixed carbon (80.01%) ensures that the synthesized adsorbent (AKTWAC) will have a greater adsorption capacity while avoiding unwanted catalytic activity for our synthesized final sample.

Assessing the implementation processes of a large-scale, multi-year quality improvement initiative: survey of health care providers.

BACKGROUND: Beginning in 2012, Lean was introduced to improve health care quality and promote patient-centredness throughout the province of Saskatchewan, Canada with the aim of producing coordinated, system-wide change. Significant investments have been made in training and implementation, although limited evaluation of the outcomes have been reported. In order to better understand the complex influences that make innovations such as Lean "workable" in practice, Normalization Process Theory guided this study. The objectives of the study were to: a) evaluate the implementation processes associated with Lean implementation in the Saskatchewan health care system from the perspectives of health care professionals; and b) identify demographic, training and role variables associated with normalization of Lean. METHODS: Licensed health care professionals were invited through their professional associations to complete a cross-sectional, modified, online version of the NoMAD questionnaire in March, 2016. Analysis was based on 1032 completed surveys. Descriptive and univariate analyses were conducted. Multivariate multinomial regressions were used to quantify the associations between five NoMAD items representing the four Normalization Process Theory constructs (coherence, cognitive participation, collective action and reflexive monitoring). RESULTS: More than 75% of respondents indicated that neither sufficient training nor resources (collective action) had been made available to them for the implementation of Lean. Compared to other providers, nurses were more likely to report that Lean increased their workload. Significant differences in responses were evident between: leaders vs. direct care providers; nurses vs. other health professionals; and providers who reported increased workload as a result of Lean vs. those who did not. There were no associations between responses to normalization construct proxy items and: completion of introductory Lean training; participation in Lean activities; age group; years of professional experience; or employment status (full-time or part-time). Lean leader training was positively associated with proxy items reflecting coherence, cognitive participation and reflexive monitoring. CONCLUSIONS: From the perspectives of the cross-section of health care professionals responding to this survey, major gaps remain in embedding Lean into healthcare. Strategies that address the challenges faced by nurses and direct care providers, in particular, are needed if intended goals are to be achieved.

Effect of two-level pedicle-screw fixation with different rod materials on lumbar spine: A finite element study.

BACKGROUND: Pedicle-screw-rod fixation system is very popular surgical remedy for degenerative disc disease. It is important to observe load vs. spinal motion characteristic for better understanding of clinical problems and treatment of spinal instability associated with low-back pain. OBJECTIVE: The objective of this study is to understand the effect [range of motion (ROM) and intervertebral foramen height] of pedicle-screw fixation with three rod materials on lumbar spine under three physiological loading conditions. METHOD: A three-dimensional finite element (FE) model of lumbar to sacrum (L1-S) vertebrae with pedicle-screw-rod fixation at L3-L5 level is developed. Three rod materials [titanium alloy (Ti6Al4V), ultra-high molecular weight poly ethylene (UHMWPE) and poly-ether-ether-ketone (PEEK)] are used for two-level fixation and the FE models are simulated for axial rotation, lateral bending and flexion-extension under ±10 Nm moment and 500 N compressive load and compared with the intact (natural) model. RESULT & DISCUSSION: For axial rotation, lateral bending and flexion, ROM increased 2.8, 4.5 and 1.83 times respectively for UHMWPE, and 3.7, 7.2 and 2.15 times respectively for PEEK in comparison to Ti6Al4V. As ROM is 49, 29 and 31% of the intact model during axial rotation, lateral bending and flexion respectively, PEEK rod produced better motion flexibility than Ti6Al4V and UHMWPE rod. Foramen height increased insignificantly by 2.21% for the PEEK rod with respect to the intact spine during flexion. For the PEEK rod, maximum stress of 40 MPa during axial rotation is much below the yield stress of 98 MPa. CONCLUSION: Ti6Al4V pedicle-screw-rod fixation system highly restricted the ROM of the spine, which is improved by using UHMWPE and PEEK, having lower stiffness. The foramen height did not vary significantly for any implant materials. In terms of ROM and maximum stress, PEEK rod may be considered for a better implant design to get better ROM and thus mobility.

Assessment of knowledge regarding tuberculosis among non-medical university students in Bangladesh: a cross-sectional study.

BACKGROUND: Tuberculosis (TB) is the second leading cause of human death and TB is one of the major public health problems in Bangladesh. The aim of the present study was to assess the Knowledge about TB among non-medical university students in Bangladesh. METHODS: A cross-sectional survey was performed on 839 non-medical university students. Data were collected from University of Rajshahi from March to August 2013 using a standard semi-structured questionnaire. Chi-square test was utilized to find the factors which are associated with students' knowledge about TB. RESULTS: Among 839 students, male and female were 68.2 % and 31.8 % respectively. Most of the students (94.4 %) were informed about the term TB, among them 50 % got information from electronic media. More than 50 % students believed that TB is a communicable disease, 42.8 % students agreed that bacteria is an agent for TB, most of the subjects (93 %) had the knowledge about the vaccination against TB and 97.6 % students believed that TB is curable. However, students had poor knowledge about latent TB (13.7 %) and DOTs program (28.5 %). χ (2)-test demonstrated that gender, residence, type of family and parents education were associated with students' knowledge of TB. CONCLUSION: In the present study demonstrated that the level of general knowledge about TB was insufficient among non-medical university students. Consequently, health education program is needed to improve the knowledge among university students regarding TB.

Positive-pressure ventilation during transport: a randomized crossover study of self-inflating and flow-inflating resuscitators in a simulation model.

BACKGROUND: Positive-pressure ventilation during transport of intubated patients is generally delivered via a hand-pressurized device. Of these devices, self-inflating resuscitators (SIR) and flow-inflating resuscitators (FIR) constitute the two major types used. Selection of a particular device for transport, however, remains largely an institutional practice. OBJECTIVE: To evaluate the hypothesis that transport ventilation goals of intubated pediatric patients are better achieved using an FIR compared to an SIR. METHODS: This randomized crossover simulation study compared the performance of SIR and FIR among anesthesia providers in a pediatric transport scenario. Subjects hand-ventilated a test lung while simultaneously maneuvering a stretcher bed to simulate patient transport. Hand ventilation was carried out using a Jackson-Rees circuit (FIR) and a Laerdal pediatric silicone resuscitator (SIR). The primary outcome was the proportion of total breaths delivered within the predefined target PIP/PEEP range (30+/- 3, 10+/- 3 cm H2O). Secondary outcomes included proportion of total breaths delivered with operationally defined unacceptable breath variables (PIP > 35 cm H2O or PEEP < 5 cm H2O). RESULTS: Overall, participants were four times more likely to deliver target breaths and one-third less likely to deliver unacceptable breaths using the FIR compared to the SIR. When comparing device performance, a 44% increase in the proportions of target breaths and a 40.4% decrease in unacceptable breaths using the FIR were observed (P < 0.0001 for both). CONCLUSIONS: Hand ventilation during patient transport is superior using the FIR compared to the SIR to achieve target ventilatory goals and avoid unacceptable ventilatory cycles.

Design and manufacturing of patient-specific Ti6Al4V implants with inhomogeneous porosity.

Stress shielding remains a challenge in orthopaedic implants, including total hip arthroplasty. Recent development in printable porous implants offers improved patient-specific solutions by providing adequate stability and reducing stress shielding possibilities. This work presents an approach for designing patient-specific implants with inhomogeneous porosity. A novel group of orthotropic auxetic structures is introduced, and their mechanical properties are computed. These auxetic structure units were distributed at different locations on the implant along with optimized pore distribution to achieve optimum performance. A computer tomography (CT) based finite element (FE) model was used to evaluate the performance of the proposed implant. The optimized implant and the auxetic structures were manufactured using laser powder bed-based laser metal additive manufacturing. Validation was done by comparing FE results with experimentally measured directional stiffness and Poisson's ratio of the auxetic structures and strain on the optimized implant. The correlation coefficient for the strain values was within a range of 0.9633-0.9844. Stress shielding was mainly observed in Gruen zones 1, 2, 6, and 7. The average stress shielding on the solid implant model was 56%, reduced to 18% when the optimized implant was used. This significant reduction in stress shielding can decrease the risk of implant loosening and create an osseointegration-friendly mechanical environment on the surrounding bone. The proposed approach can be effectively applied to the design of other orthopaedic implants to minimize stress shielding.

Catalytic depolymerization of Kraft lignin to high yield alkylated-phenols over CoMo/SBA-15 catalyst in supercritical ethanol.

Lignin is generally considered to be a renewable and sustainable resource of aromatic chemicals. However, the depolymerization of Kraft lignin (KL) for the production of selective phenolic monomers presents a significant challenge due to its highly recalcitrant nature. Therefore, in this work, we investigated the effect of metal sites and acid active sites on Mo/SBA-15, Co/SBA-15 and CoMo/SBA-15 catalysts in supercritical ethanol for the depolymerization of KL to produce phenolic monomers. Ethanol was used as a hydrogen donor solvent instead of using external hydrogen. Results showed that the bimetallic CoMo/SBA-15 catalyst exhibited significantly higher catalytic activity compared to the monometallic, Co/SBA-15, Mo/SBA-15 or bare SBA-15. The highest phenolic monomers yield of 27.04 wt% was achieved at 290 °C for 4 h over CoMo/SBA-15 catalyst. The inter-unit linkages such as ß-O-4', ß-ß and α-O-4' in lignin were considerably cleaved during the catalytic depolymerization in supercritical ethanol. Meanwhile, higher functionality of carbonyl compounds was present in the non-catalytic bio-oil, while more alkylated phenols were produced over CoMo/SBA-15 catalyst. The major phenolic monomers identified in the catalytic bio-oil were 4-ethylguaiacol (9.15 wt%), 4-methylguaiacol (6.80 wt%), and 4-propylguaiacol (2.85 wt%). These findings suggest that the metal sites and abundant acid active sites of CoMo/SBA-15 had a synergistic effect toward the degradation of different linkages of lignin and production of selective phenolic monomers in bio-oils.

In-silico study of type 'B' condylar head fractures and evaluating the influence of two positional screw distance in two-screw osteosynthesis construct.

Clinical fixation screws are common in clinical practices to fix mandibular condyle fractures. Evidence suggests significance of 'working length' that is, distance between proximal and distal fixation screws in proximity to the fracture in orthopaedic implant design. In pursuit of stable implant-bone construct, this study aims to investigate the biomechanical performance of each configuration considered in the study and provide an optimal working length between the screws for clinical reference. Finite element models of virtually designed broken condyle as type 'B' were simulated and analysed in ANSYS Workbench. Screws are implanted according to previous literature at five varied distances 'd' maintaining five different ratios with the fracture length 'D'. Based on a literature review, boundary conditions, muscle traction forces and non-linear contacts were assigned to obtain precise results. Each case is considered an individual configuration and von Mises distribution, microstrain in bone, screw-bone interface micromotion and fracture dislocation were evaluated for all these configurations. Stress-shielding phenomenon is observed for maximum von Mises stresses in bone. Microstrain concentration was significant in cancellous bone in the vicinity of the screw around the fracture line. Configurations were compared based on the stress-strain along with micromotion to support the required amount of osseointegration between implant and bone. Presented data from all five conditions supported the assumption that under physiological loading conditions, the D3 configuration provided stability for fracture healing. Further research on screw shapes, diameters and material properties, or investigating the direction of forces within the screws could provide further insight into this topic.

Development and performance evaluation of an improved electric baking oven for baked products.

An improved electric baking oven was designed and fabricated using locally available materials for baking cakes and biscuits. Provisions of necessary adjustments were employed for ensuring uniform distribution of heat in all trays of the baking chamber. Its baking characteristics in terms of baking time, specific volume, and product quality in terms of sensory attributes were evaluated. The oven was found to be quite satisfactory in functioning for baking cakes and biscuits. Total time was only 15-28 min for baking the cake samples in the oven. On the other hand, comparatively, a bit longer time 18-35 min required for baking the biscuit samples. Baking cost was lesser in baking small-sized cakes and biscuits than those of large sized. The quality of baked products was better in terms of taste, color, flavor, texture, and appearance than ordinary market products. Loaf volume of each cake (with 4 × 5 × 8 cm3) was 100%, which gave specific volume of 652.8 cm3/kg. Similarly, the specific volume of biscuits was 810 cm3/kg. The electric baking oven is quite efficient in baking quality cakes and biscuits uniformly, which can be provided to rural small entrepreneurs for commercial manufacturing of biscuits and cakes.

Patient-specific femoral implant design using metamaterials for improving load transfer at proximal-lateral region of the femur.

Loading configuration of hip joint creates resultant bending effect on femoral implants. So, the lateral side of femoral implant which is under tension retracts from peri­implant bone due to positive Poisson's ratio. This retraction of implant leads to load shielding and gap opening in proximal-lateral region, thereby allowing entry of wear particle to implant-bone interface. Retraction of femoral implant can be avoided by introducing auxetic metamaterial to the retracting side. This allows the implant to push peri­implant bone under tensile condition by virtue of their auxetic (negative Poisson's ratio) nature. To develop such implants, a patient-specific conventional solid implant was first designed based on computed-tomography scan of a patient's femur. Two types of metamaterials (2D: type-1) and (3D: type-2) were employed to design femoral meta-implants. Type-1 and type-2 meta-implants were fabricated using metallic 3D printing method and mechanical compression testing was conducted. Three finite element (FE) models of the femur implanted with solid implant, type-1 meta-implant and type-2 meta-implant were developed and analysed under compression loading. Significant correlation (R2 = 0.9821 and R2 = 0.9977) was found between the experimental and FE predicted strains of the two meta-implants. In proximal-lateral region of the femur, an increase of 7.1% and 44.1% von-Mises strain was observed when implanted with type-1 and type-2 meta-implant over the solid implant. In this region, bone remodelling analysis revealed 2.5% bone resorption in case of solid implant. While bone apposition of 0.5% and 7.7% was observed in case of type-1 and type-2 meta-implants, respectively. The results of this study indicates that concept of introduction of metamaterial to the lateral side of femoral implant can prove to provide higher osseointegration-friendly environment in the proximal-lateral region of femur.

Zinc-Bromine Rechargeable Batteries: From Device Configuration, Electrochemistry, Material to Performance Evaluation.

Zinc-bromine rechargeable batteries (ZBRBs) are one of the most powerful candidates for next-generation energy storage due to their potentially lower material cost, deep discharge capability, non-flammable electrolytes, relatively long lifetime and good reversibility. However, many opportunities remain to improve the efficiency and stability of these batteries for long-life operation. Here, we discuss the device configurations, working mechanisms and performance evaluation of ZBRBs. Both non-flow (static) and flow-type cells are highlighted in detail in this review. The fundamental electrochemical aspects, including the key challenges and promising solutions, are discussed, with particular attention paid to zinc and bromine half-cells, as their performance plays a critical role in determining the electrochemical performance of the battery system. The following sections examine the key performance metrics of ZBRBs and assessment methods using various ex situ and in situ/operando techniques. The review concludes with insights into future developments and prospects for high-performance ZBRBs.

Scientific issues of zinc-bromine flow batteries and mitigation strategies.

Zinc-bromine flow batteries (ZBFBs) are promising candidates for the large-scale stationary energy storage application due to their inherent scalability and flexibility, low cost, green, and environmentally friendly characteristics. ZBFBs have been commercially available for several years in both grid scale and residential energy storage applications. Nevertheless, their continued development still presents challenges associated with electrodes, separators, electrolyte, as well as their operational chemistry. Therefore, rational design of these components in ZBFBs is of utmost importance to further improve the overall device performance. In this review, the focus is on the scientific understanding of the fundamental electrochemistry and functional components of ZBFBs, with an emphasis on the technical challenges of reaction chemistry, development of functional materials, and their application in ZBFBs. Current limitations of ZBFBs with future research directions in the development of high performance ZBFBs are suggested.

Prevalence of hepatitis B and C, and syphilis among aspirant migrant workers of Bangladesh.

Background: In Bangladesh, labour migration is a source of employment and workers' remittances are critical to poverty mitigation. The aim of this study was to assess the prevalence of hepatitis B, C, HIV, tuberculosis, syphilis, kidney and liver diseases along with presence of infections among aspirant migrant workers of Bangladesh. Method: This study was carried out from September-December 2019. We analysed data collected on screening tests of specific diseases of aspirant workers. For each test, the prevalence was computed with 95% confidence interval. Association between categorical data was determined by the Chi-square test. Results: A total of 2385 aspirants, 1988 (83.35%) males, aged between 18 and 65 years (29.76±6.578) were studied. Positive results for screening tests of HBsAg were 38 (1.6%,), anti-HCV were 2 (0.08%), TPHA were 25 (1.05%) and VDRL were 5 (0.21%) though no individual was positive for HIV and TB. Elevated level of SGOT (n=99, 4.2%), SGPT (n=322, 13.5%), RBS (n=57, 2.4%), bilirubin (n=46, 1.92%), creatinine (n=7, 0.3%) and ESR (n=19, 0.8%) were found in the workers. Conclusion: Diagnosis of diseases of workers is obligatory before going abroad to safeguard the health of the workers and residents of destination country. Consequently, it will contribute to reducing the global burden of infectious diseases.

Endosulfan affects embryonic development synergistically under elevated ambient temperature.

In the present study, we determined the developmental toxicity of endosulfan at an elevated ambient temperature using the zebrafish animal model. Zebrafish embryos of various developmental stages were exposed to endosulfan through E3 medium, raised under two selected temperature conditions (28.5 °C and an elevated temperature of 35 °C), and monitored under the microscope. Zebrafish embryos of very early developmental stages (cellular cleavage stages, such as the 64-cell stage) were highly sensitive to the elevated temperature as 37.5% died and 47.5% developed into amorphous type, while only 15.0% of embryos developed as normal embryos without malformation. Zebrafish embryos that were exposed concurrently to endosulfan and an elevated temperature showed stronger developmental defects (arrested epiboly progress, shortened body length, curved trunk) compared to the embryos exposed to either endosulfan or an elevated temperature. The brain structure of the embryos that concurrently were exposed to the elevated temperature and endosulfan was either incompletely developed or malformed. Furthermore, the stress-implicated genes hsp70, p16, and smp30 regulations were synergistically affected by endosulfan treatment under the elevated thermal condition. Overall, the elevated ambient temperature synergistically enhanced the developmental toxicity of endosulfan in zebrafish embryos.

A comparative finite element analysis of artificial intervertebral disc replacement and pedicle screw fixation of the lumbar spine.

Titanium alloy-based Pedicle screw-rod fusion is a very common technique to provide higher fusion regularity than other methods. In recent times, Carbon-fibre-reinforced (CFR)-PEEK rod is used to better reduce the fusion rate. Alternatively, total disc replacement (TDR) is also very common for the non-fusion treatment method for degenerative disc disease (DDD). This study aims to investigate flexibility (ROM), stability, stress condition in implant, implant adjacent bone of the implanted lumbar spine during different physiological movements and loading environments. The finite element (FE) intact model of the lumbar spine (L2-L5) with two-level pedicle screw-rod fusion at L3-L4-L5 and two-level artificial disc replacement was developed. CFR-PEEK was taken for rod for semi-rigid fusion. UHMWPE was taken as core part of the artificial disc. The FE models were simulated under 6, 8 and 10 Nm moments in left right lateral bending, flexion and extension movements. The total ROM was reduced for two-level pedicle screw fixation and increased for the artificial disc replacement model during flexion extension compared to the intact spine. The total ROM was reduced by around 54% and 25% for two-level fixation and increased by 30% and 19.5% for artificial disc replacement spine, under flexion-extension and left-right lateral bending respectively. For screw fixation, the ROM increased by 15% and 18% reduced by 4.5% and 14% for disc replacement at the adjacent segments for flexion-extension and left-right lateral bending.

Hepatic Histoplasmosis: An Update.

Histoplasma capsulatum is the most common cause of endemic mycosis in developing countries. It is a self-limited and asymptomatic disease in immunocompetent individuals but remains a frequent cause of opportunistic infection in patients with compromised immune status. Liver involvement as a part of disseminated histoplasmosis is well known. However, liver infection as a primary manifestation of histoplasmosis without evidence of primary lung involvement is rare. In conclusion, clinicians should be aware of isolated histoplasmosis affecting the hepatobiliary system, and careful evaluation is warranted to confirm the diagnosis. Given the appropriate clinical context, histoplasmosis should be considered in both immunocompetent and immunocompromised patients, regardless of pulmonary symptoms, in non endemic as well as endemic areas.

Design of patient specific basal dental implant using Finite Element method and Artificial Neural Network technique.

The bone conditions of mandibular bone vary from patient to patient, and as a result, a patient-specific dental implant needs to be designed. The basal dental implant is implanted in the cortical region of the bone since the top surface of the bone narrows down because of aging. Taguchi designs of experiments technique are used in which 25 optimum solid models of basal dental implants are modeled with variable geometrical parameters, viz. thread length, diameter, and pitch. In the solid models the implants are placed in the cortical part of the 3D models of cadaveric mandibles, that are prepared from CT data using image processing software. Patient-specific bone conditions are varied according to the strong, weak, and normal basal bone. A compressive force of 200 N is applied on the top surface of these implants and using finite element analysis software, the microstrain on the peri-implant bone ranges from 1000 to 4000 depending on the various bone conditions. According to the finite element data, it can be concluded that weak bone microstrain is comparatively high compared with normal and strong bone conditions. A surrogate artificial neural network model is prepared from the finite element analysis data. Surrogate model assisted genetic algorithm is used to find the optimum patient-specific basal dental implant for a better osseointegration-friendly mechanical environment.

Influence of implant parameters on biomechanical stability of TMJ replacement: A finite element analysis.

The articular disc reduces the stress distribution from the mandible to fossa. In total temporomandibular joint (TMJ) replacement, the implant is required to reduce the stress on fossa implant. Current studies lack standard and optimized parameters for the cylindrical dome on Christensen TMJ implant collar. This study briefed a novel TMJ implant head design and investigates the biomechanical behaviour by considering the articular disc. The radius of the head was varied with the height of the cylinder height to obtain the design of the experiment and the stress distribution was compared with an intact mandible-articular disc model by considering the viscoelastic property of the TMJ disc. The model was simulated at three different angles: 20°, 0° and -20° in the mediolateral direction to simulate the manducation. FEA analysis showed high stresses at the circular heads, and high strength is achieved with increased implant cylinder length and diameter. The results also showed a stress reduction of 50% on the fossa from the mandible. Hence, the newly designed head and suggested modifications may be used as a reference for further clinical improvement of Christensen TMJ as well as other TMJ implants.