Arifa Tahir

Chitosan extracted from Labeo rohita fish scales via chemical demineralization, deproteinization, and deacetylation yields 25% overall from raw scales. The chitosan has 88%–90% deacetylation, a molecular weight (MW) of 109.5 kDa, and low residual ash (0.1%) and protein (0.29%). Composite films (CGP) with fixed gelatin: polyvinylpyrrolidone (PVP, 10:5) and varying chitosan (1%–7% w/v) are prepared. FTIR confirms cross‑linking; SEM shows smooth surfaces for CGP 3% and CGP 5%, but rougher texture for CGP 7%. Water uptake decreases with higher chitosan content (160% for CGP 1% vs. 22% for CGP 7%). PBS buffer uptake is highest for CGP 1%–5% (80%–120%), and lowest for CGP 7% (∼40%). Lower chitosan content slows degradation. Tensile strength increases with chitosan concentration (27 MPa for CGP 1% to 32.8 MPa for CGP 7%), while elongation at break decreases (13% to 4%). Antibacterial activity against Escherichia coli and Staphylococcus aureus is strongest for CGP 3% and CGP 5% (inhibition zones 13–14 mm), outperforming pure chitosan. In the hen's egg test on the chorioallantoic membrane (HET‑CAM) assay, CGP 3% induces the highest angiogenic response (27.2 ± 0.3 vs. 12.9 ± 0.6 vessels in control), with no toxicity. CGP 3% and CGP 5% are optimal for wound‑healing applications.

Cement production is highly carbon-intensive and contributes significantly to carbon emissions. The study aimed to estimate the carbon footprint of sawdust combustion compared to coal, highlighting the ecological benefits of sawdust as an alternative energy source. Refuse-derived fuel energy was produced by converting waste into alternative fuels to replace coal. This process can reduce the carbon footprint and provide additional environmental credentials. For this, we used one year of data to compare the carbon footprints of coal and sawdust sourced from furniture factories, which were burned in the local cement industry. The carbon footprint was evaluated by identifying the key emission categories, collecting relevant data, and calculating greenhouse gas emissions. The calorific value of coal was found to be 24 MJ/kg, while that of sawdust was 17.5 MJ/kg. An average of 586.116 tons of sawdust was used monthly, peaking at 1,302.60 tons in October 2023 and dropping to 34.735 tons in May 2024. Monthly, 974.08 tCO₂e emissions were generated from sawdust, with October 2023 recording the highest release at 2,164.83 tCO₂e. In contrast, coal combustion in the same month released 2931.12 tCO₂e, resulting in a 766.29 tCO₂e difference. In May 2024, sawdust usage was minimal, resulting in a release of only 57.73 tCO₂e, with a difference of 11.97 tCO₂e. By increasing the mass of the sawdust-to-coal ratio, its heating value can be matched to that of coal. The study found that while sawdust has a lower calorific value than coal, it produces significantly less CO₂ emissions per unit of energy generated, making it a cleaner alternative in terms of greenhouse gas output. The research highlighted sawdust as a sustainable energy source. Graphical Abstract

In the present study, an iron(II)-nanoscale organic complex (Fe-NO) was used as an enhancement factor by two different Rhodopseudomonas species of purple non-sulphur bacteria (PNSB) to produce hydrogen (H₂). The Fe-NO complex was synthesised using FeSO₄·7H₂O and Eucalyptus viminalis—a native Australian plant leaf extract—in a 1:2 and 2:1 concentration ratio. Besides, FeSO₄·7H₂O was also used as a source of iron(II) for comparison with the Fe-NO complex. The photo-fermentative bacterial cultures were isolated from a fishpond, and only two strains, MP3 and SP6, were found viable after several attempts of quadrate streaking. After phylogenetic analysis, these strains were designated as R. palustris MP3 and R. harwoodiae SP6. After comparison with the control, the results showed that the PNSBs manifested an approximately 50% higher H₂ yield when the 1:2 Fe-NO complex was used in the fermentation broth at 10 mg/L concentration, where 10.7 ± 0.54 and 10.0 ± 0.49 mL H₂/L were obtained by R. palustris MP3 and R. harwoodiae SP6, respectively. The study revealed that the 1:2 Fe-NO complex could be an important material for efficient H₂ production.

Recent technological advances in nanoscience and material designing have led to the development of point-of-care devices for biomolecule sensing and cancer diagnosis. In situ and portable sensing devices for bedside, diagnosis can effectively improve the patient’s clinical outcomes and reduce the mortality rate. Detection of exosomal RNAs by immuno-biochip with increased sensitivity and specificity to diagnose cancer has raised the understanding of the tumor microenvironment and many other technology-based biosensing devices hold great promise for clinical innovations to conquer the unbeatable fort of cancer metastasis. Electrochemical biosensors are the most sensitive category of biomolecule detection sensors with significantly low concentrations down to the atomic level. In this sense, this review addresses the recent advances in cancer detection and diagnosis by developing significant biological sensing devices that are believed to have better sensing potential than existing facilities.

This study aims to quantify heavy metals (Ni, Pb, Zn, Mn, Cr, Cu and Se) in eggs obtained from poultry farms and backyard raised hens by comparing the concentration of metals in their feed intake. Overall, 90 samples of egg and 12 samples of poultry feed (6 each with food and water) were collected from 3 different poultry farms and backyards located in peri-urban areas of Lahore. A di-acid digestion method was adopted for digestion, after which digested samples were analyzed under atomic absorption spectrophotometer. Results showed that the concentration of Pb, Cr and Se in egg white (Pb = 0.6578, Cr = 0.18 and Se = 0.2161), egg yolk (Pb = 0.7011, Cr = 0.2617 and Se = 0.2656), feed (Pb = 2.585, Cr = 1.3039 and Se = 0.9411) and water (Pb = 0.5483, Cr = 0.1006 and Se = 0.3461) were above permissible limits in both poultry farms (study group 1) and backyards (study group 2). The concentration of metals such as Pb, Mn, Cr, Cu and Se in poultry farms eggs were higher than backyard hen eggs, which may be due to the intake of contaminated feed. So, the current study concluded that the higher concentration of metals in eggs has a positive correlation with the intake of feed contaminated with heavy metals.

Climatic changes pose serious risks to the rural community’s livelihoods of many developing countries whereas people in mountainous regions are exposed to multiple hazards with limited livelihood resources and heavy dependence on natural resources. The objective of the current study is to assess the livelihood practices and adaptive capacity of a mountainous region of Pakistan, the Balakot, where people are highly vulnerable to climatic changes. The study uses a triangulation method to explore various issues and options of climate change risks sand adaptation and impact of well-being on resilience capacity and livelihood strategies. For this purpose, ten focus group discussions (FGDs) with carefully selected key informants and structured interviews with randomly selected 200 local households are conducted to evaluate different hazards and their associated livelihood effects. It is observed that the changing climate has significantly influenced livelihoods of the local community in the recent past through resource degradation, gradual unavailability of sufficient basic services (quantity and quality of drinking water, crop food diversity, fuel wood, and non-timber forest products), low agricultural productivity, and social inequity viz. income distribution, health, education, and food storage. Such a brunt is felt disproportionately more by poor households due to their low adaptive capacity to climate change with constrained livelihood resources. The study emphasizes the need for targeted efforts to move from coping strategies to adaptations among people considering their social inequalities. Timely information sharing, livelihood diversification and preservation of livelihood resources such as crop and forest production, livestock grazing, creating awareness on the pace, and pattern of climate change in the region and subsequent role of adaptation options are major interventions that should be emphasized by the public bodies.