14 research outputs found
Heat induction in two-dimensional graphene–Fe3O4 nanohybrids for magnetic hyperthermia applications with artificial neural network modeling
We report the synthesis and characterization of graphene functionalized with iron (Fe3+) oxide (G-Fe3O4) nanohybrids for radio-frequency magnetic hyperthermia application. We adopted the wet chemical procedure, using various contents of Fe3O4 (magnetite) from 0–100% for making two-dimensional graphene–Fe3O4 nanohybrids. The homogeneous dispersal of Fe3O4 nanoparticles decorated on the graphene surface combined with their biocompatibility and high thermal conductivity make them an excellent material for magnetic hyperthermia. The morphological and magnetic properties of the nanohybrids were studied using scanning electron microscopy (SEM) and a vibrating sample magnetometer (VSM), respectively. The smart magnetic platforms were exposed to an alternating current (AC) magnetic field of 633 kHz and of strength 9.1 mT for studying their hyperthermic performance. The localized antitumor effects were investigated with artificial neural network modeling. A neural net time-series model was developed for the assessment of the best nanohybrid composition to serve the purpose with an accuracy close to 100%. Six Nonlinear Autoregressive with External Input (NARX) models were obtained, one for each of the components. The assessment of the accuracy of the predicted results has been done on the basis of Mean Squared Error (MSE). The highest Mean Squared Error value was obtained for the nanohybrid containing 45% magnetite and 55% graphene (F45G55) in the training phase i.e., 0.44703, which is where the model achieved optimal results after 71 epochs. The F45G55 nanohybrid was found to be the best for hyperthermia applications in low dosage with the highest specific absorption rate (SAR) and mean squared error values
Maternal anaemia and the risk of postpartum haemorrhage: a cohort analysis of data from the WOMAN-2 trial
Background: Worldwide, more than half a billion women of reproductive age are anaemic. Each year, about 70 000 women who give birth die from postpartum haemorrhage. Almost all deaths are in low-income or middle-income countries. We examined the association between anaemia and the risk of postpartum haemorrhage. Methods: We did a prospective cohort analysis of data from the World Maternal Antifibrinolytic-2 (WOMAN-2) trial. This trial enrols women with moderate or severe anaemia giving birth vaginally in hospitals in Pakistan, Nigeria, Tanzania, and Zambia. Hospitals in each country where anaemia in pregnancy is common were identified from a network established during previous obstetric trials. Women who were younger than 18 years without permission provided by a guardian, had a known tranexamic acid allergy, or developed postpartum haemorrhage before the umbilical cord was cut or clamped were excluded from the study. Prebirth haemoglobin, the exposure, was measured after hospital arrival and just before giving birth. Postpartum haemorrhage, the outcome, was defined in three ways: (1) clinical postpartum haemorrhage (estimated blood loss ≥500 mL or any blood loss sufficient to compromise haemodynamic stability); (2) WHO-defined postpartum haemorrhage (estimated blood loss of at least 500 mL); and (3) calculated postpartum haemorrhage (calculated estimated blood loss of ≥1000 mL). Calculated postpartum haemorrhage was estimated from the peripartum change in haemoglobin concentration and bodyweight. We used multivariable logistic regression to examine the association between haemoglobin and postpartum haemorrhage, adjusting for confounding factors. Findings: Of the 10 620 women recruited to the WOMAN-2 trial between Aug 24, 2019, and Nov 1, 2022, 10 561 (99·4%) had complete outcome data. 8751 (82·9%) of 10 561 women were recruited from hospitals in Pakistan, 837 (7·9%) from hospitals in Nigeria, 525 (5·0%) from hospitals in Tanzania, and 448 (4·2%) from hospitals in Zambia. The mean age was 27·1 years (SD 5·5) and mean prebirth haemoglobin was 80·7 g/L (11·8). Mean estimated blood loss was 301 mL (SD 183) for the 8791 (83·2%) women with moderate anaemia and 340 mL (288) for the 1770 (16·8%) women with severe anaemia. 742 (7·0%) women had clinical postpartum haemorrhage. The risk of clinical postpartum haemorrhage was 6·2% in women with moderate anaemia and 11·2% in women with severe anaemia. A 10 g/L reduction in prebirth haemoglobin increased the odds of clinical postpartum haemorrhage (adjusted odds ratio [aOR] 1·29 [95% CI 1·21–1·38]), WHO-defined postpartum haemorrhage (aOR 1·25 [1·16–1·36]), and calculated postpartum haemorrhage (aOR 1·23 [1·14–1·32]). 14 women died and 68 either died or had a near miss. Severe anaemia was associated with seven times higher odds of death or near miss (OR 7·25 [95% CI 4·45–11·80]) than was moderate anaemia. Interpretation: Anaemia is strongly associated with postpartum haemorrhage and the risk of death or near miss. Attention should be given to the prevention and treatment of anaemia in women of reproductive age. Funding: The WOMAN-2 trial is funded by Wellcome and the Bill & Melinda Gates Foundation
Electroanalysis of Ibuprofen and Its Interaction with Bovine Serum Albumin
The current work presents a sensitive, selective, cost-effective, and environmentally benign protocol for the detection of ibuprofen (IBP) by an electrochemical probe made of a glassy carbon electrode modified with Ag-ZnO and MWCNTs. Under optimized conditions, the designed sensing platform was found to sense IBP up to a 28 nM limit of detection. The interaction of IBP with bovine serum albumin (BSA) was investigated by differential pulse voltammetry. IBP−BSA binding parameters such as the binding constant and the stoichiometry of complexation were calculated. The results revealed that IBP and BSA form a single strong complex with a binding constant value of 8.7 × 1013. To the best of our knowledge, this is the first example that reports not only IBP detection but also its BSA complexation
Investigation of Electron Transfer Mechanistic Pathways of Ferrocene Derivatives in Droplet at Carbon Electrode
The results of cyclic, differential pulse and square wave voltammetric studies of four ferrocene derivatives, i.e., 4-ferrocenyl-3-methyl aniline (FMA), 3-Chloro-4-ferrocenyl aniline (CFA), 4-ferrocenyl aniline (FA) and ferrocenyl benzoic acid (FBA) on carbon electrode, revealed that the redox behavior of these compounds is sensitive to pH, concentration, scan number and scan rate. One electron, diffusion controlled, with a quasi-reversible redox signal displaying ferrocene/ferrocenium couple was observed for each of the studied ferrocenyl derivatives. Quasi-reversibility of this signal is evidenced by ∆Ep, Ia/Ic current ratio and ksh values. Another one electron and one proton irreversible oxidation signal was noticed in the voltammograms of these compounds except FBA. This signal corresponds to the electro-oxidation of the amine group and its irreversibility, as supported by ∆Ep, Ia/Ic current ratio and ksh values, is due to the influence of the electron donating nature of the amine group. A number of electrochemical parameters such as D, ksh, LOD and LOQ were evaluated for the targeted ferrocene derivatives. The obtained parameters are expected to provide insights into the redox mechanism for understanding their biochemical actions. The electrochemistry presented in this work is done using a unique environmentally benign and cost-effective droplet electrochemical approach
Investigation of Electron Transfer Mechanistic Pathways of Ferrocene Derivatives in Droplet at Carbon Electrode
The results of cyclic, differential pulse and square wave voltammetric studies of four ferrocene derivatives, i.e., 4-ferrocenyl-3-methyl aniline (FMA), 3-Chloro-4-ferrocenyl aniline (CFA), 4-ferrocenyl aniline (FA) and ferrocenyl benzoic acid (FBA) on carbon electrode, revealed that the redox behavior of these compounds is sensitive to pH, concentration, scan number and scan rate. One electron, diffusion controlled, with a quasi-reversible redox signal displaying ferrocene/ferrocenium couple was observed for each of the studied ferrocenyl derivatives. Quasi-reversibility of this signal is evidenced by ∆Ep, Ia/Ic current ratio and ksh values. Another one electron and one proton irreversible oxidation signal was noticed in the voltammograms of these compounds except FBA. This signal corresponds to the electro-oxidation of the amine group and its irreversibility, as supported by ∆Ep, Ia/Ic current ratio and ksh values, is due to the influence of the electron donating nature of the amine group. A number of electrochemical parameters such as D, ksh, LOD and LOQ were evaluated for the targeted ferrocene derivatives. The obtained parameters are expected to provide insights into the redox mechanism for understanding their biochemical actions. The electrochemistry presented in this work is done using a unique environmentally benign and cost-effective droplet electrochemical approach
Laparoscopy in Gynaecological Problems
and findings observed on laparoscopy in gynaecological conditions to assess the role of laparoscopy. Methods: In this cross sectional study 57 patients were included. Patients were in their reproductive age with history of lower abdominal pain for longer than six months. Laparoscopy was performed under general anesthesia. The uterine cannula was secured to the cervix after holding it by means of single toothed tenaculum. After induction of proper pneumo-peritoneum, laparoscopy was performed using an intra-umbilical or sub-umbilical entry. In subfertile patients 10 to 15ml of methylene blue dye solution was instilled and dye was inspected entering in the tubes and free spill through fimbrial end. Results: Major indication for laparoscopy was subfertility(75.43%). Majority (52.63%) belonged to primary subfertility. Six women(10.52%) were with chronic pelvic pain. Chronic ectopic pregnancy was suspected in 7.01% and lost IUCD in 7.01%. Mean age of the women was 31 years. Majority (52.63%) were nullipara.In primary subfertility group, tubal factor was found in 46.6% and ovarian factor in 16(53.33%). Normal pelvic findings were observed in 46.6%. Lost IUCD was found in four cases. No major complications were observed postoperatively. Patients were discharged on the next day of operation. Conclusion: Laparoscopy circumvents unnecessary surgeries and helps in making early diagnosi
Multiwalled Carbon Nanotube/Fe-Doped ZnO-Based Sensors for Droplet Electrochemical Detection and Degradation Monitoring of Brilliant Green
The
present research work aims to contribute toward the sustainable
development goal of water cleanliness by monitoring and removing toxic
effluents from wastewater. Herein, we present an electrochemical sensing
platform made of a glassy carbon electrode modified with Fe-doped
ZnO nanoparticles (NPs) and multiwalled carbon nanotubes (MWCNTs)
for the detection of brilliant green (BG) using a smart droplet analysis
approach. The Fe–ZnO NPs were synthesized via a hydrothermal
method and characterized by various analytical techniques such as
UV–visible spectroscopy, XRD, SEM, EDX, and FTIR spectroscopy.
Fe–ZnO NPs were found to act as a mediator between the transducer
and BG for efficient electron transport, while MWCNTs led to the enhanced
current response of BG at the electrode surface owing to their conductive
and adsorptive characteristics. Under optimized conditions of pH 6,
0.1 V deposition potential, and 40 s deposition time, a 0.40 nM limit
of detection was achieved at the designed nanosensor. Photocatalytic
degradation of the dye with NPs was also investigated in different
pH media using UV–visible spectroscopy. The dye was found to
photocatalytically degrade up to 99% in just 30 min, following first-order
kinetics with a rate constant of 0.14 min–1. The
photocatalytic degradation was also monitored electrochemically at
the designed sensing platform, and the findings were found to be in
good agreement with the results of UV–visible spectroscopy.
The developed electrochemical droplet analysis approach is not only
economical but also efficient, ultra-sensitive, and environmentally
friendly
A case of congenital methaemoglobinaemia with secondary polycythemia
Haemoglobin contains iron in a ferrous form. When the iron is oxidized, it is called Methaemoglobin (MetHb). MetHb leads to tissue hypoxia, cyanosis, and secondary polycythemia. Methaemoglobinaemia is acquired or congenital. In this case, a 22-years-old male patient presented with cyanosis, headache, and lack of concentration. Cyanosis was present since birth. His previous investigations showed polycythemia. He was misdiagnosed on multiple occasions and was undergoing venesections for polycythemia. On evaluation at a private clinic, an Oxygen saturation gap was noted between the results of the pulse oximeter and arterial blood gas analyzer. This raised suspicion on the presence of MetHb. He was referred to Air Force Institute of Pathology, Rawalpindi for further workup.The sample obtained for MetHb was chocolate brown in colour. Analysis was done via co-oximetry. A high level of MetHb (45.6%) was obtained.
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Production of Fuel Range Hydrocarbons from Pyrolysis of Lignin over Zeolite Y, Hydrogen
In the current study, plain and lignin loaded with Zeolite Y, hydrogen was decomposed in a pyrolysis chamber. The reaction parameters were optimized and 390 °C, 3% catalyst with a reaction time of 40 min were observed as the most suitable conditions for better oil yield. The bio-oil collected from the catalyzed and non-catalyzed pyrolytic reactions was analyzed by gas chromatography mass spectrometry (GCMS). Catalytic pyrolysis resulted in the production of bio-oil consisting of 15 components ranging from C3 to C18 with a high percentage of fuel range benzene derivatives. Non-catalytic pyrolysis produced bio-oil that consists of 58 components ranging from C3 to C24; however, the number and quantity of fuel range hydrocarbons were lower than in the catalyzed products. The pyrolysis reaction was studied kinetically for both samples using thermogravimetry at heating rates of 5, 10, 15 and 20 °C/min in the temperature range 20–600 °C. The activation energies and pre-exponential factors were calculated using the Kissinger equation for both non-catalytic and catalytic decomposition and found to be 157.96 kJ/mol, 141.33 kJ/mol, 2.66 × 1013 min−1 and 2.17 × 1010 min−1, respectively. It was concluded that Zeolite Y, hydrogen worked well as a catalyst to decrease activation energy and enhance the quality of the bio-oil generated