Yolk sac tumor in an antenatal patient: a challenging case

Pregnancy complicated with adnexal masses is a very common occurrence. However, most of these adnexal masses encountered in pregnancy are benign in nature and are found incidentally during routine antenatal ultrasound. Malignant ovarian neoplasms account for 1%-8% of all persistent adnexal masses diagnosed during pregnancy. Yolk sac tumor (YST) complicating pregnancy is very rare and has no proper guidelines for its diagnosis and management hence causing a therapeutic dilemma for the clinicians. Therefore, an individualised approach is preferred in such cases. It is very important to report such cases for better understanding and management of these cases. Here we present a case report of a 23-year-old primigravida at 30 weeks gestation with yolk sac tumor of right ovary, surgical stage IIIc who responded well to fertility sparing surgery with cisplatin-based combination chemotherapy. She has no evidence of disease post treatment and has been put on regular follow up

Recent advances in hydrothermal carbonisation:from tailored carbon materials and biochemicals to applications and bioenergy

Introduced in the literature in 1913 by Bergius, who at the time was studying biomass coalification, hydrothermal carbonisation, as many other technologies based on renewables, was forgotten during the "industrial revolution". It was rediscovered back in 2005, on the one hand, to follow the trend set by Bergius of biomass to coal conversion for decentralised energy generation, and on the other hand as a novel green method to prepare advanced carbon materials and chemicals from biomass in water, at mild temperature, for energy storage and conversion and environmental protection. In this review, we will present an overview on the latest trends in hydrothermal carbonisation including biomass to bioenergy conversion, upgrading of hydrothermal carbons to fuels over heterogeneous catalysts, advanced carbon materials and their applications in batteries, electrocatalysis and heterogeneous catalysis and finally an analysis of the chemicals in the liquid phase as well as a new family of fluorescent nanomaterials formed at the interface between the liquid and solid phases, known as hydrothermal carbon nanodots

Sustainable Synthesis of Multifunctional Nanomaterials for Sensing and Catalytic Applications

Nanotechnology has enable us to develop various novel and advanced materials with unique optical, catalytic, magnetic, electrical and, structural properties for various exciting applications. With the progress of nanoscience and technology, emphasis of the materials are changed from simple nanomaterials to the multi-functional nanomaterials (MFNMs) because of their improved as well as multiple activities. In general, the MFNMs are made with the combination of different components in the same structure, which in turn not only show the additive properties of individual components but also new properties because of the synergistic effect. Multifunctionality in nanomaterials can be achieved in two ways, either by changing the morphology (anisotropic, hollow), or the composition (doped, QDs, heterostructures, core/shell, and yolk/shell). Over the years, continuously growing research interest on this area is mainly because of unique advantages in various applications such as catalysis, sensors, environmental remediation, photovoltaics, energy storage, biomedical, and so on. In recent years, the sustainable routes of nanomaterials are preferred over the conventional chemical routes, which is also applicable for the MFNMs. In view of the importance of MFNMs, the overall aim of this thesis is to develop novel MFNMs via green synthesis route with improved properties for sensing and catalytic applications. In this study following materials were developed: the hollow and doped nanostructures (TiO2, -Fe2O3) synthesized using natural fibers templates. The metallic (Au, Ag, Pd), alloy (Au-Pd), and metal oxides/hydroxide (-Fe2O3, β-FeOOH) NPs were synthesized using the renewable resources (green tea extract and glucose) in aqueous medium. The carbon dots (C-dots) and graphitic carbon were synthesized from tender coconut water and glucose under hydrothermal condition, respectively. The Ag NPs were deposited on semiconductor (AgBr, TiO2) and polymer (PVP) materials by photo-mediated and dissolution approach for the development of plasmonic catalyst, respectively. The C-dots were used for fluorometric thiamine sensor with ultra-low level detection (280 nM) and bio-imaging of fungus cells. β-FeOOH nanorods were used for sulfide ions and thiamine detection with ultra-low level detection limits of 2.19 μM and 44 nM, respectively. The Ag deposited PVP structures showed enhanced SERS activity for the sensing and detection of very low level (nM) organic molecules. Metal NPs (Au, Ag, Pd) decorated -Fe2O3 magnetic hollow tubes showed excellent recyclable catalytic reduction of 4-nitrophenol to 4-aminophenol. Carbon-doped high surface area TiO2 multi-tubes showed visible light induced photo-reduction activity for Cr(VI) reduction to Cr(III). Graphitic carbon coated Au-Pd alloy showed stable, durable, and enhanced electro-catalytic activity for ethanol oxidation. The Au/AgBr–Ag and TiO2/Ag core/shell heterostructures were also showed very good visible-light driven photocatalytic and photo-electrochemical activity. The present research work addresses a new perspective for green synthesis of distinct novel MFNMs and provide valuable insight into the role of the multi-functional properties to stimulate the outstanding sensing and catalytic applications

Carbon-Doped Mesoporous Anatase TiO₂ Multi-Tubes Nanostructures for Highly Improved Visible Light Photocatalytic Activity

Development of a high surface area and efficient visible light induced photocatalyst on a large scale is a promising task from the practical perspective. In this study, visible light active C-doped anatase TiO₂ multi-tubes were synthesized using banana (<i>Musa acuminata</i>) stem fiber as a sacrificial template, removed by calcination at 450 °C. During the calcination process, the lattice of anatase TiO₂ phase was doped with C, and obtained multi-tubes showed high surface area (∼99 m²/g) with a mesoporous structure made of ∼15 ± 3 nm nanoparticles. The synthesized TiO₂ multi-tubes showed an enhanced light absorption property in the whole visible light region and good thermal stability of the anatase phase up to 750 °C. The synthesized C-doped TiO₂ multi-tubes manifest an excellent photocatalytic activity for the reduction of Cr (VI) to Cr­(III) under the visible light exposure. This process may have lots of practical importance as the method of synthesis of the catalyst is novel and the multi-tubes structure can be synthesized on a large scale through a quick and economical way with excellent photocatalytic activity. This novel multi-tubes structure may also be useful for photovoltaics, antimicrobial, and Li-batteries applications in the future

Effect of Calcination Time on the Catalytic Activity of Ni/γ-Al2O3 Cordierite Monolith for Dry Reforming of Biogas

Ni/γ-Al2O3 wash coated cordierite monolith catalysts are calcined in air at 800 °C for 4, 10, and 20 h in order to study the effect of calcination time on the activity of the catalysts for dry reforming of model biogas. Catalytic activity studies are performed at 800 °C with three different CH4/CO2 ratios of 1.0, 1.5, and 2.0. The catalyst calcined for the longest time (C-20) displays higher stability and activity in terms of CH4 and CO2 conversion compared to those calcined for 4 h (C-4) and 10 h (C-10). XRD data and TPR analysis detect the maximum amount of NiAl2O4/MgAl2O4 phases and strongest metal-support interaction, respectively, for the C-20 sample. FESEM reveals the particle size of the calcined and reduced C-20 sample to be smaller than that of the C-4 and C-10 samples. Whereas, H2 pulse-chemisorption characterization demonstrates the highest metal surface area, metal dispersion, and smallest Ni particle size for the C-20 catalyst. While, no carbon deposition on any catalyst occurs for the CH4/CO2 ratio of one, lowest amount of carbon nanotubes is formed on the C-20 sample for the CH4/CO2 ratio of 1.5 and 2.0, as observe by DTA-TGA. EDX reveals concentration variation of Mg and Si from the cordierite monolith wall along the thickness of the coating for all the samples. In addition, the maximum amount of these elements is observed for the calcined C-20 catalyst coating. These implies that the diffusion of Mg and Si from the cordierite monolith to the catalyst coating during calcination contribute significantly in controlling the physicochemical properties of the catalysts. As a result, the higher stability and activity of the C-20 could be attributed to the formation of higher amount of the Ni– Mg- alumina spinel complex in the catalyst coating during longer calcination time, which leads to the improved metal-support interaction and higher nickel dispersion over monolith

Zero-dimensional heterostructures: N-doped graphene dots/SnO(2)for ultrasensitive and selective NO(2)gas sensing at low temperatures

To enable the sensitive and selective monitoring of NO(2)gas at low ppb concentrations, zero-dimensional N-doped graphene dot/SnO(2)quantum dot (N-GD-SnO2) heterostructures are preparedviaa simple wet-chemical method. In comparison with pristine-SnO2, our fabricated device exhibits an enhanced response (R-g/R-a= 292) with a short response (181 s) and recovery time (81 s) toward 100 ppb NO(2)gas at 150 degrees C; furthermore, the response increases to 4336 as the temperature decreases to 50 degrees C. The sensor also exhibits the distinct capability to detect NO(2)with an ultralow concentration of 20 ppb with high response. This dramatic enhancement is attributed to enhanced electron transfer from SnO(2)to N-GDs and stronger adsorption of NO(2)molecules onto the N-GDs&apos; surface. Additionally, zero-dimensional morphology also helped to enhanced sensing performance due to large surface area, more active sites, and better nanoscale interface. Finally, the sensor exhibits the characteristics of excellent selectivity toward NO(2)over other gases (SO2, H2S, CO, and NH3). Thus, our research provides a new approach toward zero-dimensional heterostructures for gas-sensing applications

Environment-Adaptable Edge-Computing Gas Sensor Device with Analog-Assisted Continual Learning Scheme

This paper presents a multi-gas sensor device whose structure is optimized for edge computing capability under internet of things (IoT) environments. Considering inherent sensor device characteristics susceptible to environmental factors like temperature and humidity, edge-computing capability for the on-site sensor calibration and pattern recognition (PR) is facilitated through a proposed analog-assisted continual learning scheme. An environment-adaptable continual learning (EACL) is proposed to combine multiple learning processes under different environments including chamber and on-site. Its computation burden is much relieved to be integrated into the edge device by adopting the analog-assisted structure, where a designed readout integrated circuit (ROIC) for automatic calibration normalizes gas-sensor data. For functional feasibility, an edge-computing IoT device prototype is manufactured with a fabricated ROIC and an in-house semiconductor-type sensor array, supporting wireless on-site monitoring platform interfaces. The environment-adaptable edge-computing capability is functionally verified through EACL-PR experiments on hazardous gases such as NO 2 and CO under environmental factor variations. The average PR accuracy of 97% is achieved on several kinds of mixture gas patterns. The analog-assisted operation is verified to reduce the training cycles by 3 times while the EACL itself achieves 25% better efficiency