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Ruwai galena ore contains a high amount of lead (Pb) and a higher silver (Ag) content than similar ores. It indicates that Ruwai galena ore has excellent potential to be utilized as a prospective source of Ag . However, recovery of Ag from the galena ore is quite challenging due to the very high iron (Fe) and zinc (Zn) content. For this reason, separating both elements from the main galena ore needs to be performed. This study examines the performance of the froth flotation process using agitation to obtain ore (or tailings) rich in Ag so that the Ag leaching process becomes more efficient. The flotation process was conducted by varying the flotation time, the concentration of KEX (potassium ethyl xanthate, as a collector), and MIBC (methyl isobutyl carbinol, as a frother). The flotation results showed that 85% Pb was successfully floated at 120 minutes, the KEX concentration of 80 ppm, and the MIBC concentration of 30 ppm. In this condition, Zn was 48%, Fe was 38% recovered, while 49% of Ag was detected.

Halmahera Island in Indonesia holds great potential for nickel laterite due to its geological setting. As the product of chemical weathering, nickel laterite can be divided into saprolite and limonite. Despite containing invaluable elements like nickel and cobalt, limonite ore is seldom used in metal production. This study evaluates these two elements’ leaching behavior and kinetics from the Halmahera deposit. Limonite ore was leached using 50 mL of 0.5 M sulfuric acid at an S/L ratio of 10% and 20%. The leaching process was conducted at 30°C, 50°C, and 80°C. The experimental results showed that the highest recovery for cobalt and nickel was 100% in the adequate presence of H+ ions. The result shows that sulfuric acid is more selective to cobalt than a nickel. The shrinking core ash diffusion model represents the leaching kinetics of cobalt, while nickel recovery follows the Kröger-Ziegler kinetics model.

Abstract Currently, Magnetic Resonance arthrography procedures require two rooms and two imaging modalities: fluoroscopically guided needle insertion in a fluoroscopy suite, followed by diagnostic MRI in a separate MRI suite. The use of fluoroscopy for needle placement exposes patients to ionizing radiation, which is an important concern, especially in pediatrics. The need for two different rooms and coordinating times for these rooms complicates hospital resource scheduling and logistics. In addition, the added delays could expose younger children to additional risks associated with the use of general anesthesia. To address these issues, we propose a new technique to streamline the arthrography procedure. Our proposed technology aims to eliminate exposure to ionizing radiation and to streamline arthrography procedures that are conducted solely under MRI. This toolkit consists of a 3D slicer-based user interface, a spatially unique silicone grid template, and a hand-held needle guidance device. Together, these tools are intended to simplify and shorten the procedure while maintaining accuracy and precision comparable to the current gold standard procedure. In our cadaver study, we evaluated the feasibility and accuracy of our novel MRI-safe Needle Guidance Toolkit for MRI arthrography procedures, achieving an average targeting accuracy of 3.2 ± 1.0 mm. The results presented in this study showed the feasibility and promise of our novel MRI-safe needle guidance toolkit for arthrography procedures.

This review systematically examines the recent research from the past decade on diverse path-planning algorithms tailored for stereotactic neurosurgery applications. Our comprehensive investigation involved a thorough search of scholarly papers from Google Scholar, PubMed, IEEE Xplore, and Scopus, utilizing stringent inclusion and exclusion criteria. The screening and selection process was meticulously conducted by a multidisciplinary team comprising three medical students, robotic experts with specialized knowledge in path-planning techniques and medical robotics, and a board-certified neurosurgeon. Each selected paper was reviewed in detail, and the findings were synthesized and reported in this review. The paper is organized around three different types of intervention tools: straight needles, steerable needles, and concentric tube robots. We provide an in-depth analysis of various path-planning algorithms applicable to both single and multi-target scenarios. Multi-target planning techniques are only discussed for straight tools as there is no published work on multi-target planning for steerable needles and concentric tube robots. Additionally, we discuss the imaging modalities employed, the critical anatomical structures considered during path planning, and the current status of research regarding its translation to clinical human studies. To the best of our knowledge and as a conclusion from this systematic review, this is the first review paper published in the last decade that reports various path-planning techniques for different types of tools for minimally invasive neurosurgical applications. Furthermore, this review outlines future trends and identifies existing technology gaps within the field. By highlighting these aspects, we aim to provide a comprehensive overview that can guide future research and development in path planning for stereotactic neurosurgery, ultimately contributing to the advancement of safer and more effective neurosurgical procedures.

This study examines the potential use of the spent catalyst as a raw material for rechargeable batteries. The spent catalyst Ni/γ-Al2O3 still contains relatively high amounts of nickel. This indicates the potential use of the spent catalyst to be leached and purified for synthesizing nickel-based compounds so that it can be applied to rechargeable battery cathodes. In this study, the spent catalyst leaching process employed four types of organic acids: citric acid, lactic acid, oxalic acid, and acetic acid. The spent catalyst was leached under atmospheric conditions and room temperature. Organic acid concentrations were also varied at 0.1, 0.5, 1, and 2 M. The leaching process took place for 240 minutes, where sampling was conducted periodically at 30, 60, 120, 180, and 240 minutes. Experimental results showed that Ni (II) and Al (III) ions were successfully leached to the maximum when using 2M citric acids at a leaching time of 240 minutes. The conditions succeeded in leaching Ni (II) and Al (III) ions of 357.8 and 1,975.4 ppm, respectively. Organic acid, notably citric acid, has excellent potential for further development. Citric acid, as a solvent, has the ability to leach metal ions with high recovery. In addition, this acid is categorized as an eco-friendly and green solvent compared to inorganic acid. Thus, the leaching process can take place without harming the environment.

Chemical industry wastewater containing metals must be treated so as not to threaten the environment or human life. One of the wastewater treatments is the biosorption process using living microalgae. Although living microalgae can provide better results as a biosorbent, the mechanism of this biosorption process is complex because it involves two steps of the process, active and passive uptake, which run simultaneously. In addition, several process parameters need to be adjusted for the biosorption process to operate optimally. This study aims to investigate the effect of several parameters such as microalgae concentration, salinity, and light color. Synthetic CuSO4 solution at a concentration of 40 mg/L and pH 5 is used as artificial waste, while microalgae Chlorella sp. is used as biosorbent. The biosorption process was operated in a batch system at room temperature for 6 days. The experimental results show that 96.83% of the Cu(II) ions could be removed when the microalgae concentration, salinity, and light color were conditioned at 1.5 x 106 cells/mL, 3,000 mg/L, and red light, respectively.

This work studies the leaching kinetics of nickel laterite in a citric acid solution. A new kinetics model that considers a reversible chemical reaction and internal diffusion of a product is proposed. The experiment was conducted at various temperatures (303, 333, and 358 K) and particle sizes (< 70 to 250 ?m). Whereas acid concentration, pulp density, and leaching time were constant at 0.1 M, 20% w/v, and 120 min, respectively. The experimental results showed that the leaching process was dependent on temperature and particle size. In the case of Ni, Al, and Fe leachings, the formation of complex molecules might lead to a steric hindrance of product diffusion; however, this was not observable for Mg. The proposed model was found to be much better than the conventional shrinking core models (SCM). Using the proposed model, the activation energy for nickel was found to be 121.38 ± 0.0324 kJ/mol, 78.98 ± 0.4157 kJ/mol, 1,022.62 ± 9.6507 J/mol for forward reaction, backward reaction, and diffusion, respectively.

As one of the hazardous and toxic solid wastes, spent catalysts need to be treated before the waste is discharged into the environment. One of the substances that need to be removed from the spent catalysts is the heavy metal ions and/or compounds contained therein. The method that can be applied is the extraction method using an acid solvent. In this study, the extraction process was carried out on spent catalysts samples from PT. Petrokimia Gresik. The focus of the study is on nickel extraction by varying the temperature in the range of 30–85 oC. A 1 M hydrochloric acid (HCl) solution was used as a solvent while the extraction process was 120 minutes. The experimental results show that the maximum nickel recovery of 14.70% can be achieved at a temperature of 85 oC. Kinetic studies were carried out using two kinetic models. The results of both models evaluation on the research data show that the lump model gives better results than the shrinking core model. The average error percentage of the lump model is smaller than the shrinking core model. It indicates that the extraction process was controlled by the diffusion step through the ash layer in the solid and chemical reactions simultaneously.

This paper presents an intraoperative MRI-guided, patient-mounted robotic system for shoulder arthrography procedures in pediatric patients. The robot is designed to be compact and lightweight and is constructed with nonmagnetic materials for MRI safety. Our goal is to transform the current two-step arthrography procedure (CT/x-ray-guided needle insertion followed by diagnostic MRI) into a streamlined single-step ionizing radiation-free procedure under MRI guidance. The MR-conditional robot was evaluated in a Thiel embalmed cadaver study and healthy volunteer studies. The robot was attached to the shoulder using straps and ten locations in the shoulder joint space were selected as targets. For the first target, contrast agent (saline) was injected to complete the clinical workflow. After each targeting attempt, a confirmation scan was acquired to analyze the needle placement accuracy. During the volunteer studies, a more comfortable and ergonomic shoulder brace was used, and the complete clinical workflow was followed to measure the total procedure time. In the cadaver study, the needle was successfully placed in the shoulder joint space in all the targeting attempts with translational and rotational accuracy of 2.07 ± 1.22 mm and 1.46 ± 1.06 degrees, respectively. The total time for the entire procedure was 94 min and the average time for each targeting attempt was 20 min in the cadaver study, while the average time for the entire workflow for the volunteer studies was 36 min. No image quality degradation due to the presence of the robot was detected. This Thiel-embalmed cadaver study along with the clinical workflow studies on human volunteers demonstrated the feasibility of using an MR-conditional, patient-mounted robotic system for MRI-guided shoulder arthrography procedure. Future work will be focused on moving the technology to clinical practice.

The overall prevalence of chronic kidney disease in the general population is ∼14% with more than 661,000 Americans having a kidney failure. Ultrasound (US)-guided renal biopsy is a critically important tool in the evaluation and management of renal pathologies. This Letter presents KBVTrainer, a virtual simulator that the authors developed to train clinicians to improve procedural skill competence in US-guided renal biopsy. The simulator was built using low-cost hardware components and open source software libraries. They conducted a face validation study with five experts who were either adult/pediatric nephrologists or interventional/diagnostic radiologists. The trainer was rated very highly (>4.4) for the usefulness of the real US images (highest at 4.8), potential usefulness of the trainer in training for needle visualization, tracking, steadiness and hand-eye coordination, and overall promise of the trainer to be useful for training US-guided needle biopsies. The lowest score of 2.4 was received for the look and feel of the US probe and needle compared to clinical practice. The force feedback received a moderate score of 3.0. The clinical experts provided abundant verbal and written subjective feedback and were highly enthusiastic about using the trainer as a valuable tool for future trainees.

Technological advances in game-mediated robotics provide an opportunity to engage children with cerebral palsy (CP) and other neuromotor disabilities in more frequent and intensive therapy by making personalized, programmed interventions available 24/7 in children’s homes. Though shown to be clinically effective and feasible to produce, little is known of the subjective factors impacting acceptance of what we term assistive/rehabilitative (A/R) gamebots by their target populations. This research describes the conceptualization phase of an effort to develop a valid and reliable instrument to guide the design of A/R gamebots. We conducted in-depth interviews with 8 children with CP and their families who had trialed an exemplar A/R gamebot, PedBotHome, for 28 days in their homes. The goal was to understand how existing theories and instruments were either appropriate or inappropriate for measuring the subjective experience of A/R gamebots. Key findings were the importance of differentiating the use case of therapy from that of assistance in rehabilitative technology assessment, the need to incorporate the differing perspectives of children with CP and those of their parents into A/R gamebot evaluation, and the potential conflict between the goals of preserving the quality of the experience of game play for the child while also optimizing the intensity and duration of therapy provided during play.

The kinetics study has an essential role in the scale-up process because it illustrates the real phenomena of a process. This study aims to develop a mathematical model that can explain the mechanism of the leaching process of laterite ore using a low concentration of the citric acid solution and evaluate that model using the experimental data. As a raw material, this process used powder-shaped limonite laterite ores with a size of 125–150 µm. The leaching process is carried out using 0.1 M citric acid solution, F:S ratio of 1:20, and a leaching time of 2 h. The temperature parameter was varied at 303, 333, and 358 K. The experimental results showed that the higher the operating temperature, the higher the extracted nickel. The results of this experiment were used to evaluate the shrinking core kinetics model and the lumped model. The simulation results for both models show that the lumped model can provide better simulation results. Quantitatively, the percentage of errors from the shrinking core model is around 3.5 times greater than the percentage of errors from using the lumped model. This result shows that in this leaching process, the process mechanism that occurs involves the reactant diffusion step and the chemical reactions step; those steps run simultaneously.

Angiosarcomas are malignant endothelial cell tumors with few effective systemic treatments. Despite a unique endothelial origin, molecular candidates for targeted therapeutic intervention have been elusive. In this study, we explored the tunica internal endothelial cell kinase 2 (Tie2) receptor as a potential therapeutic target in angiosarcoma. Human angiosarcomas from diverse sites were shown to be universally immunoreactive for Tie2. Tie2 and vascular endothelial growth factor receptor (VEGFR) antagonists inhibited SVR and MS1-VEGF angiosarcoma cell survival in vitro. In the high-grade SVR cell line, Tie2 and VEGF antagonists inhibited cell survival synergistically, whereas effects were largely additive in the low-grade MS1-VEGF cell line. Xenograft modeling using these cell lines closely recapitulated the human disease. In vivo, Tie2 and VEGFR inhibition resulted in significant angiosarcoma growth delay. The combination proved more effective than either agent alone. Tie2 inhibition seemed to elicit tumor growth delay through increased tumor cell apoptosis, whereas VEGFR inhibition reduced tumor growth by lowering tumor cell proliferation. These data identify Tie2 antagonism as a potential novel, targeted therapy for angiosarcomas and provide a foundation for further investigation of Tie2 inhibition, alone and in combinations, in the management of this disease.

Chitin, a versatile biopolymer with applications in biomedicine, antimicrobial agents, and cosmetics, can be sustainably sourced from the black soldier fly (BSF). This alternative is gaining popularity because it not only provides a sustainable supply of raw materials but also possesses chitin properties. Consequently, this broadens the potential applications of chitin in the development of derivative products with varied characteristics. The BSF undergoes complete metamorphosis, consisting of four stages: egg, larva, pupa, and fly. While the extraction method is commonly used to isolate chitin from other sources, a modified approach is necessary for the BSF due to the unique chitin-binding elements present in its biological structures. Given the high fat content in BSF and its metamorphosis stages, separating the fat prior to the extraction process is crucial. Co-fermentation, a biologically driven extraction technique, offers a cost-effective, environmentally friendly alternative with potential for high chitin yields. These findings underscore the potential of BSF as a sustainable chitin source and emphasize the significance of optimizing extraction processes to produce high-quality chitin and chitosan products. There remains considerable scope for future research, particularly in areas such as the identification of effective bleaching agents, optimizing conditions for maximum chitin extraction from BSF, and refining the extraction process to enhance cost-effectiveness. [ABSTRACT FROM AUTHOR]

Halmahera Island in Indonesia holds great potential for nickel laterite due to its geological setting. As the product of chemical weathering, nickel laterite can be divided into saprolite and limonite. Despite containing invaluable elements like nickel and cobalt, limonite ore is seldom used in metal production. This study evaluates these two elements' leaching behavior and kinetics from the Halmahera deposit. Limonite ore was leached using 50 mL of 0.5 M sulfuric acid at an S/L ratio of 10% and 20%. The leaching process was conducted at 30°C, 50°C, and 80°C. The experimental results showed that the highest recovery for cobalt and nickel was 100% in the adequate presence of H+ ions. The result shows that sulfuric acid is more selective to cobalt than a nickel. The shrinking core ash diffusion model represents the leaching kinetics of cobalt, while nickel recovery follows the Kröger-Ziegler kinetics model. [ABSTRACT FROM AUTHOR]