Low Cost Research Articles

Fe-loaded two-dimensional nitrogen-doped carbon for electromagnetic wave absorption

Abstract Electromagnetic wave absorbing materials are particularly important in modern electronics, especially in the fields of stealth and communications. Carbon-based materials show great promise in the production and application of efficient wave-absorbing materials due to their rich structure, ultra-light weight, good corrosion resistance, and low cost. Among them, nitrogen-doped carbon-based two-dimensional materials have a stronger depletion effect on electromagnetic waves due to their higher specific surface area and abundant polarization states. In this article, nitrogen-doped carbon 2D flakes (NC) were successfully synthesized by a hydrothermal method. Furthermore, Fe single atoms were successfully loaded onto their surfaces, creating Fe@NC. The wave-absorbing properties of Fe@NC samples were significantly enhanced, with the minimum reflection loss (RLmin) reaching -69.22 dB at 11.48 GHz and the effective absorption bandwidth (EAB) extending to 5.79 GHz. The enhancement of electromagnetic wave absorption is attributed to the synergistic effects of magnetic loss, relaxation processes, dipole polarization, and electrical conduction loss. The successful preparation of Fe@NC offers new possibilities for the development of atomically dispersed wave-absorbing materials.

SURG-35. NEURONAVIGATED INTRAOPERATIVE ULTRASSOUND X SODIUM FLUORESCEIN FOR BRAIN METASTASIS: WHICH IS BETTER?

Abstract BACKGROUND Improve quality of life with a maximum surgical resection is the main goal of neurosurgeons. Brain metastasis are even more prevalent because of patients are living more. The grade of resection and the maintenance of a good performance are fundamental for these patients perform adjuvant radiotherapy. There are several technologies that may help. Considering two of them that have an easier access and are cheaper, we compared a high definition ultrasound (BK 3000) coupled to neuronavigation system (Brainlab) and sodium fluorescein (SF). METHODS Adult patients with main radiological hypothesis of brain metastasis were included in a PhD study previously approved by ethics committee. 3-5mg/kg of SF was administered by intravenous infusion during anesthetic induction. An specific craniotomy transducer was used in all cases with shift correction in real time by neuronavigator. All procedures were guided by the same neurosurgeon. RESULTS High definition ultrasound allows an excellent tumor delimitation. SF helped to increase grade of resection however made confusion about what is infiltration and what is tumor and for this ultrasound were superior. Increased fluorescence is easily detected when compared to ultrasound information’s.. For both technologies, when the surgical site had blood, the evaluation about grade of resection is not accurate because in ultrasound appears a posterior shadow and considering SF it seems that there are not further tumor because blood does not have increased fluorescence. CONCLUSIONS US and SF are different tools which improve brain metastasis resection. In each moment of surgery one technology was superior or not. We used an specific probe for neurosurgery that has high quality and allowed detailed evaluations. These technologies helps surgeons take quick decision and optimized brain tumor removal. The neurosurgeon should be more familiar to US images because provide a real time evaluation with low cost.

Evaluation of training models for intraventricular neuroendoscopy.

Structured surgical education has become increasingly important in recent years. Intraventricular neuroendoscopic procedures have been widely established. However, training surgical skills with these techniques is crucial for young residents due to the potential harm to adjacent tissue. Therefore, we evaluated two different training models.Participants in two different international workshops were trained on a prefixed cadaver model and on a living murine intraabdominal model. Crucial neuroendoscopic techniques such as membrane perforation and tissue biopsy were performed. A blinded questionnaire evaluated both models.Sixty-three participants were trained on the animal model. Forty of these were trained on the cadaver model. The training effect was evaluated almost equally, with 8.5/10 for the animal model and 8.9/10 for the cadaver model. The tissue properties were rated higher regarding realism in the animal model, whereas the anatomic realism was rated higher in the cadaver model.The animal model is a valid alternative to cadaver models for teaching endoscopic neurosurgical skills. This model benefits from the simulation of real surgical tissue properties, including bleeding. The low costs and availability of this technique make it more ubiquitous and can help train further generations of neurosurgeons.

Advancing the Commercialization of Perovskite‐Based Radiation Detectors for High‐Resolution Imaging

AbstractRadiation detectors play an indispensable role in medical diagnostics, industrial non‐destructive inspection and national security. Recently, halide perovskites are considered as the new generation of radiation active materials due to excellent optoelectronic properties such as adjustable bandgap, high absorption coefficient, high carrier mobility and low cost. The radiation detectors based on perovskite show high sensitivity and low detection limit, contributing to excellent spatial resolution for imaging. However, the commercialization of perovskite radiation detectors for high quality imaging still faces many challenges, including ion migration in perovskite, fermi level pinning and electrochemical reaction at the interface of perovskite/electrode, and difficulties of integration with readout circuit. All the issues hinder the further improvement of device performance. This review summarizes the material forms and the optimized growth methods of perovskite for radiation imaging detectors. Further, this work focuses on challenges and improvements of the interface between perovskites and electrodes. Meanwhile, this work outlines the technical routes used to realize array detectors for radiation imaging. The comprehensive review would guide the commercialization of perovskite radiation detectors for high‐quality imaging.

THIN FILM METHANE SENSOR BASED ON CARBON COMPOSITE

Today, with the oil and gas industry playing a key role in the global energy sector, issues related to the effective control and detection of methane leaks are becoming an integral part of the strategic tasks of the industry. The article is devoted to the research and development of a thin-film sensor for detecting methane in the air using a carbon composite. The technical result of this study is the creation of a highly sensitive and energy efficient sensor for measuring methane concentration. The basis for the sensitive element is a thin film of a carbon composite, consisting of a polymer, single-wall carbon nanotubes and graphene oxide, with aluminum electrodes. The sensor has a number of advantages, including responding to the presence of methane without the need for heating, the simplicity of the sensitive material preparation process, and low cost. The ability to quickly start small-scale production, simplified manufacturing due to the use of only one pair of electrodes, as well as increased energy efficiency due to the absence of the need for heating are also positive characteristics of this device. The study presents the results of manufacturing the sensor, including the steps of cleaning the surface of the substrate, creating a shadow mask, spraying electrodes, forming a thin film of the composite by centrifugation, as well as analyzing the microstructure of the sensor using an atomic force microscope. Also presented are data on obtaining multilayer structures of thin-film resistive sensors based on a polymer matrix nanocomposite, single-wall carbon nanotubes and graphene oxide, including the process of creating electrodes. This study is important for the development of methane monitoring methods in the oil and gas industry and other industrial areas, offering promising technical solutions to ensure environmental and economic sustainability of production.

Rational design of MoS2/CNT heterostructure with rich S-vacancy for enhanced HER performance.

Molybdenum disulfide (MoS2) is a promising electrocatalyst for the hydrogen evolution reaction (HER) due to excellent stability and low cost. However, the utilization in electrocatalytic hydrogen evolution is constrained by inherent shortcomings, including fewer edge active sites, poor dispersion, and electrical conductivity. In this work, MoS2 was compounded with carbon nanotubes (CNTs), which are known for their high specific surface area and excellent electrical conductivity. These CNTs, laden with oxygen-containing functional groups, provided nucleation sites that facilitated the rapid assembly of MoS2 nanoflowers under hydrothermal conditions within 3h. Due to their diminutive size (∼300nm), these nanoflowers possess a large specific surface area and numerous active sites at their edges. Furthermore, MoS2 nanoflowers exhibited a high concentration of intrinsic S-vacancies. This heterojunction material exhibited superior HER properties. In addition, density functional theory simulation further confirmed that the MoS2 with S vacancy and CNT heterojunction electrocatalysts (VS-M/C) provided a fast charge transfer pathway for water electrolysis, and analysis showed that the conduction band minimum and valence band maximum were mainly contributed by the d orbits of Mo and the p orbits of C. This study proffered a novel approach for the engineering of high-performance MoS2-based HER electrocatalysts.

Activated charcoal application in gastric ulceration areas in horses: preliminary experimental study

Gastric ulceration is frequent in adult horses, bringing significant economic and welfare implications to these animals. Treatment may employ several drugs, but adsorbents, such as activated charcoal, are not mentioned. Activated charcoal may be a valuable therapeutic option mainly because of its few adverse effects, fecal elimination, and low cost. This study aimed to evaluate the use of activated charcoal in experimentally induced gastric ulceration in horses and perform the microscopic characterization of charcoal particles in the injured epithelium. Five adult, undefined breed horses underwent a gastric ulcer induction protocol based on alternating fasting and free food access periods. Next, we performed a gastroscopic examination and applied activated charcoal diluted in water at the ulcers through a probe passed through the working channel of the gastroscope. The gastric mucosa was washed with water after a contact period of 5 min until the complete lack of macroscopic product visualization. Then, we performed a biopsy of the aglandular mucosa in erosive to ulcerative injury sites and a microscopic assessment of the fragments. Macroscopically, all animals presented ulcerative lesions in the greater or lesser gastric curvature along the margo plicatus and hyperkeratosis in the aglandular portion. Microscopically, all animals had hyperplasia, hyperkeratosis, epithelial erosion, desquamated epithelial cells, inflammatory cells, and variable amounts of charcoal particles, either free or adhered to the epithelium. We concluded that activated charcoal remains adhered to aglandular gastric lesions in horses even after lavage with water and histological processing, allowing its microscopic visualization. Therefore, activated charcoal’s effectiveness as a therapy for equine gastric lesions warrants evaluation.

Implementasi dan Pengaruh Time Division Multiplexing (TDM) terhadap Kualitas Transmisi Sinyal

Time Division Multiplexing (TDM) is a multiplexing technique that enables the transmission of multiple signals over a single communication channel by allocating separate time slots for each signal stream. This study aims to analyze the working principles of TDM, examples of its implementation, as well as the benefits and drawbacks of TDM in communication networks. The findings show that TDM can enhance data transmission efficiency through flexible bandwidth allocation, minimizing signal interference and thereby improving signal quality. Due to these advantages, TDM is widely used in fiber optic communication systems, such as telephone and internet networks. Additionally, all data processing is conducted within integrated circuits utilizing Plastic Optical Fiber (POF), allowing TDM to be implemented at a low cost.

Optimizing Charge Separation and Transport: Enhanced Photoelectrochemical Water Splitting in α-Fe2O3/CZTS Nanorod Arrays

This study explores the enhancement of α-Fe2O3 (hematite) nanorod arrays for photoelec-trochemical applications by constructing a Cu2ZnSnS4 (CZTS) heterojunction. While α-Fe2O3 offers good stability, a low cost, and environmental benefits, its efficiency is limited by slow oxygen evolution kinetics, high carrier recombination rates, and low conductivity. By introducing CZTS, a material with strong light absorption and charge transport properties, we enhance the separation of photogenerated charge carriers, reduce charge transfer resistance, and increase the carrier concentration, thereby boosting the overall photoelectrochemical performance. The experimental results show that a modified FC-15 photoanode achieves a photocurrent density of 3.40 mA/cm2 at 1.60 V vs. RHE, a substantial increase compared to 0.40 mA/cm2 for unmodified α-Fe2O3. Band gap analysis reveals a reduced band gap in the FC-15 material, enhancing light absorption and boosting the photoelectrocatalytic performance. In photoelectrochemical water-splitting tests, the FC-15 photoanode achieves a hydrogen production rate of 41.6 μmol/cm2/h, which is significantly improved over the unmodified sample at 5.64 μmol/cm2/h. These findings indicate that the CZTS/α-Fe2O3 heterojunction effectively promotes charge separation, enhances charge transport, and improves light absorption, substantially increasing photocatalytic efficiency. This heterojunction approach offers new insights and technical strategies for developing photocatalytic materials with potential applications in renewable energy.

Differences in Models of Traumatic Brain Injury and the Subsequent Behavior Assessment in Rats and Mice

Traumatic brain injury (TBI) is associated with varied and unpredictable consequences, which can be manifested during both acute and long-term periods. Such consequences may lead to the development of neurodegenerative diseases years and even decades after the injury. Given the heterogeneous nature of TBI in humans, preclinical studies need to be conducted using different test systems. Currently, preference is given to rodents due to their availability and low cost. However, the choice of test systems for research should be based not only on economic and logistical components, but also on their specific physiological characteristics.

Synthesis of TiO2-ZnO n-n Heterojunction with Excellent Visible Light-Driven Photodegradation of Tetracycline

Zinc oxide-based photocatalysts with non-toxicity and low cost are promising candidates for the degradation of tetracycline. Despite the great success achieved in constructing n-n-type ZnO-based heterojunctions for the degradation of tetracycline under full-spectrum conditions, it is still challenging to realize rapid and efficient degradation of tetracycline under visible light using n-n-type ZnO-based heterojunctions, as they are constrained by the quick recombination of electron–hole pairs in ZnO. Here, we report highly efficient and stable n-n-type ZnO-TiO2 heterojunctions under visible light conditions, with a degradation efficiency reaching 97% at 1 h under visible light, which is 1.2 times higher than that of pure zinc oxide, enabled by constructing an n-n-type heterojunction between ZnO and TiO2 to form a built-in electric field. The photocatalytic degradation mechanism of n-n TiO2-ZnO to tetracycline is also proposed in detail. The demonstration of efficient and stable heterojunction-type ZnO photocatalysts under visible light is an important step toward commercialization and opens up new opportunities beyond conventional ZnO technologies, such as composite ZnO catalysts.

Effect of Mechanically Exfoliated Graphite Flakes on Morphological, Mechanical, and Thermal Properties of Epoxy

Carbon-reinforced polymer composites form an important category of advanced materials, and there is an increasing demand to enhance their performance using more convenient and scalable processes at low costs. In the present study, graphitic flakes were prepared by the mechanical exfoliation of synthetic graphite electrodes and utilized as an abundant and potentially low-cost filler to fabricate epoxy-based composites with different additive ratios of 1–10 wt.%. The morphological, structural, thermal, and mechanical properties of these composites were investigated. It was found that the thermal conductivity of the composites increases by adding graphite, and this increase mainly depends on the ratio of the graphite additive. The addition of graphite was found to have a diverse effect on the mechanical properties of the composites: the tensile strength of the composites decreases with the addition of graphite, whilst their compressive strength and elastic modulus are enhanced. The results demonstrate that incorporating 5 wt% of commercially available graphite into epoxy not only raises the thermal conductivity of the material from 0.223 to 0.485 W/m·K, but also enhances its compressive strength from 66 MPa to 72 MPa. The diverse influence of graphite provides opportunities to prepare epoxy composites with desirable properties for different applications.

SURG-33. INTRAOPERATIVE ULTRASSOUND X SODIUM FLUORESCEIN FOR GLIOMA SURGERY: WHICH IS BETTER?

Abstract BACKGROUND Improve quality of life with a maximum surgical resection is the main goal of neurosurgeons. A better delimitation of intrinsic brain tumors are required for achieving a maximum tumor removal. There are several technologies that may help. Considering two of them that have an easier access and are cheaper, we compared a high definition ultrasound (BK 3000) and sodium fluorescein (SF) during glioma surgeries. METHODS Adult patients with main radiological hypothesis of low or high grade glioma were included in a PhD study previously approved by ethics committee. 3-5mg/kg of SF was administered by intravenous infusion during anesthetic induction. An specific craniotomy transducer was used in all cases. All procedures were guided by the same neurosurgeon. RESULTS High definition ultrasound allows an excellent tumor delimitation in high and low grade tumors. However the gray scale and distinction of brain structures and residual lesion was difficult for surgeons who are not habituated to ultrasound use. SF did not help low grade glioma removal, and in these cases ultrasound were superior. Increased fluorescence is easily detected when compared to ultrasound information’s. For small residual tumor, SF helps more than US. For both technologies, when the surgical site had blood, the evaluation about grade of resection is not accurate because in ultrasound appears a posterior shadow and considering SF it seems that there are not further tumor because blood does not have increased fluorescence. CONCLUSIONS US showed superiority for low grade gliomas resection. Considering high grade, both technologies helps in different moments during the surgery and are complimentary. We used an specific probe for neurosurgery that has high quality and allowed detailed evaluations. These technologies helps surgeons take quick decision and optimized brain tumor removal. The neurosurgeon should be more familiar to US images because provide a real time evaluation with low cost. KEY WORDS: ultrasound; fluorescein; gliomas; brain tumors

Compact Defected Ground Structure Microstrip Patch Antenna for Wi-Fi Applications

In recent years microstrip patch antennas having minute size is an exciting topic for many researchers and design engineers. In this paper a novel miniaturized microstrip patch antenna for Wi-Fi applications is proposed. The concept of defected ground plane (DGS) is used for achieving miniaturization. The prototype is designed and analyzed by CST Microwave Studio. Low cost FR-4 substrate having thickness of 0.8 mm is used for the design of the antenna. The antenna is having compact size of 16 × 17 mm2. The simulated results demonstrate that the antenna has bandwidth of 2.02% (49 MHz) with -41.46 dB reflection coefficient at resonating frequency. The antenna has bidirectional radiation pattern. The proposed design provides a size reduction of 75.46% in comparison to conventional patch. The proposed antenna is having compact size and is low cost which makes it a suitable candidate for 2.4 GHz Wi-Fi band.

The Degradation of Furfural from Petroleum Refinery Wastewater Employing a Packed Bubble Column Reactor Using O3 and a CuO Nanocatalyst

Furfural is one of the main pollutant materials in petroleum refinery wastewater. This work used an ozonized bubble column reactor to remove furfural from wastewater. The reactor applied two shapes of packing materials and two dosages of CuO nanocatalyst (0.05 and 0.1 ppm) to enhance the degradation process. The results indicated that adding 0.1 ppm of nanocatalyst provided an efficient rate of furfural degradation compared to that of 0.05 ppm. Also, the packing materials enhanced the furfural degradation significantly. As a result, the contact area between the gas and liquid phases increased, and a high furfural removal efficiency was achieved. It was found that the CuO nanocatalyst generated more (OH•) radicals. At a treatment time of 120 min and an ozone flow of 40 L/h, the furfural degradation recorded values of 80.66 and 78.6% at 10 and 20 ppm of initial concentration, respectively. At 60 ppm, the degradation efficiency did not exceed 74.16%. Furthermore, the kinetic study indicated that the first-order mechanism is more favorable than the second-order mechanism, representing the furfural degradation with a correlation factor of 0.9837. Finally, the furfural reaction can be achieved successfully in a shorter time and at low cost.

Switching to reusable operating theatre equipment: lessons learnt from sterile light handle projects in two Australian hospitals.

Replacing single-use operating theatre equipment with reusables might be one strategy for reducing the carbon footprint of operating theatres. However, in Australia, where the energy mix is predominantly fossil-fuel-based, the re-sterilization of reusables may increase the carbon footprint. We analyzed the financial and environmental impacts of introducing reusable operating theatre light handles in two NSW hospitals. The effects on cost, waste, and carbon footprint of replacing disposable light handle covers with reusable handles in each hospital were analyzed over 12 months using procurement, waste and sterilization data, and life cycle assessment. Energy requirement for sterilization of reusable handles, increasing alongside weight of the handle, resulted in higher carbon footprint than using disposable covers. At one hospital, using a heavy handle increased carbon emissions sixfold, while the cost of handle sterilization exceeded the cost of disposable covers, resulting in 11% higher cost per use. At the other hospital, using a lighter handle increased carbon emissions by 40% per use, while sterilization cost was less than the cost of disposable covers, resulting in 14.8% lower cost per use. Scenario modelling indicated that sterilizing handles as part of a hollowware set rather than as individual items would significantly reduce cost and carbon footprint. At both hospitals, associated clinical waste was essentially eliminated. Judicious replacement of disposable covers with lightweight yet durable reusable handles can reduce costs, but increases carbon footprint in the current Australian energy context. Adopting predominantly renewable energy and more efficient sterilization practice would mitigate this.

A Comprehensive Survey of Studies on Predicting Anatomical Therapeutic Chemical Classes of Drugs

Drug classification plays a crucial role in contemporary drug discovery, design, and development. Determining the Anatomical Therapeutic Chemical (ATC) classes for new drugs is a laborious, costly, and intricate process, often requiring multiple clinical trial phases. Computational models offer significant benefits by accelerating drug evaluation, reducing complexity, and lowering costs; however, challenges persist in the drug classification system. To address this, a literature survey of computational models used for predicting ATC classes was conducted, covering research from 2008 to 2024. This study reviews numerous research articles on drug classification, focusing on drug descriptors, data sources, tasks, computational methods, model performance, and challenges in predicting ATC classes. It also examines the evolution of computational techniques and their application in identifying ATC classes. Finally, the study highlights open problems and research gaps, suggesting areas for further investigation in ATC class prediction.

Matching excellence: Oxford Nanopore Technologies' rise to parity with Pacific Biosciences in genome reconstruction of non-model bacterium with high G+C content.

The reconstruction of complete bacterial genomes is essential for microbial research, offering insights into genetic content, ontology and regulation. While Pacific Biosciences (PacBio) provides high-quality genomes, its cost remains a limitation. Oxford Nanopore Technologies (ONT) offers long reads at a lower cost, yet its error rate raises scepticism. Recent ONT advancements, such as new Flow cells (R10.4.1), chemistry (V14) and duplex mode, improve data quality. Our study compares ONT with PacBio and Illumina, including hybrid data. We used Propionibacterium freudenreichii, a bacterium with a genome known for being difficult to reconstruct. By combining data from ONT's Native Barcoding and a custom-developed BARSEQ method, we achieved high-quality, near-perfect genome assemblies. Our findings demonstrate, for the first time, that the combination of nanopore-only long-native with shorter PCR DNA reads (~3 kb) results in high-quality genome reconstruction, comparable to hybrid data assembly from two sequencing platforms. This endorses ONT as a cost-effective, stand-alone strategy for bacterial genome reconstruction. Additionally, we compared methylated motif detection between PacBio and ONT R10.4.1 data, showing that results comparable to PacBio are achievable using ONT, especially when utilizing the advanced Nanomotif tool.

Simplifying acquisition of essential diagnostics: A comprehensive costing tool for anatomic pathology.

Histopathology is the core diagnostic tool for cancer in pathology laboratories around the world, but there are disparities in access to diagnostics globally. As recognition of the need for cancer care and treatment grows, especially in the wake of World Health Organization programs for cervical, breast, and pediatric cancers, policymakers and health care funders are seeking tools and processes that allow for the largest number of patients to receive a diagnosis at the lowest cost. As histopathology represents the most cost-effective diagnostic method by sheer number of tumor types and volume, understanding the detailed logistics and costs for histology as well as the impactful benefits of economies of scale (ie, larger volumes are less expensive per patient) and scope (ie, the multiple stains available after basic histology sectioning) is paramount to planning an effective publicly funded or government laboratory. Understanding the economic structure of a country's population along with the financial model of a histology laboratory also leads to a market understanding of private laboratories, which can provide services at a profit as well as pro bono services more cost-effectively than purely public laboratories. We have developed a comprehensive, scalable costing tool of a functioning histology laboratory that accounts for all feasible costs and variations in models of service. The tool allows for a standardized approach to selecting goods needed to provide histology services and serves as a guide for implementation of pathology services. Using the tool, laboratories can achieve self-sustainment and long-term financial health while incorporating a proportion of impoverished patients who cannot afford out-of-pocket expenses.

Carbon Asset Management Mode Selection for Capital-Constrained Enterprises

Carbon asset management has become an important way to reduce carbon costs. There are three main carbon asset management modes, including carbon quota compliance, carbon asset autonomous management, and custody. A key challenge faced by capital-constrained enterprises is how to scientifically select a carbon asset management mode based on actual needs. This paper considers the impacts of setup costs of carbon asset management departments, carbon asset appreciation, custody costs, and revenue sharing, maximizes the enterprises’ profits, develops optimization models for three modes, and provides the optimal low-carbon production strategies. This paper provides evidence for enterprises to choose optimal modes under different capital levels and carbon emissions by comparing modes. The conclusions are as follows. When setup costs are low, the carbon asset autonomous management mode is suggested for the optimal profit. With higher setup costs, either carbon asset compliance or custody mode is recommended. Under abundant capital, the carbon asset custody mode is suggested. Given a certain amount of capital and low setup costs, high-emission enterprises are encouraged to adopt the carbon asset autonomous management mode for a win–win of profits and carbon emissions. The carbon asset custody and compliance modes are suggested for medium-emission and low-emission enterprises, respectively.