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Papers by arifa tahir

Journal of Heterocyclic Chemistry, Sep 2, 2010

A series of new N-Substituted-N′-(4,6-dimethylpyrimidin-2-yl)-thiourea derivatives (3a, 3b, 3c, 3... more A series of new N-Substituted-N′-(4,6-dimethylpyrimidin-2-yl)-thiourea derivatives (3a, 3b, 3c, 3d) and related fused heterocyclic compounds (4a, 4b, 4c, 4d) were synthesized using tetrabutylammonium bromide as phase transfer catalyst (PTC). N-[(2E)-5,7-dimethyl-2H-[1,2,4] thiadiazolo [2,3-a] pyrimidin-2-ylidene] derivatives (4a, 4b, 4c, 4d) were prepared by oxidative cyclization of 3a, 3b, 3c, 3d. The structures of these novel compounds were characterized by IR, 1H NMR, 13C NMR, mass spectrometry, and the elemental analysis. The crystal structures were determined from single crystal X-ray diffraction data. The results indicated that the compounds possessed a broad spectrum of activity against the tested microorganisms and showed higher activity against fungi than bacteria. Compounds 3d and 3a exhibited the greatest antimicrobial activity. J. Heterocyclic Chem., 2011.

ChemInform, May 19, 2011

Title compounds (IV) and their intramolecular cyclization products (V) are prepared and tested fo... more Title compounds (IV) and their intramolecular cyclization products (V) are prepared and tested for their antifungal and antibacterial activities.

Journal of Applied Pharmacy

Energies

In the present study, an iron(II)-nanoscale organic complex (Fe-NO) was used as an enhancement fa... more 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...

Journal of Plant Nutrition

International Journal of Phytoremediation

Cancer Cell International

Recent technological advances in nanoscience and material designing have led to the development o... more 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 faci...

Cellulose Chemistry and Technology

The present study focuses on testing the potential of starch from two different sources: corn and... more The present study focuses on testing the potential of starch from two different sources: corn and rice, to produce bioplastics, and the impact of natural agricultural waste materials (eggshells and rice hulls) as fillers. Bioplastic samples with different starches, plasticizers and amounts of fillers, in varying combinations, were prepared to determine the feasibility of the produced bioplastics. The physico-chemical properties of the bioplastics, such as moisture content, water absorption, water and alcohol solubility, biodegradability, tensile strength and Young’s modulus, were investigated. FT-IR analysis was also performed. The RTV silicone coating of the samples was tested to induce hydrophobic properties to water-soluble bioplastics. This study demonstrated that the utilization of starches from different sources, various types of plasticizers, as well as filler types and amounts, can have a significant impact on the physico-chemical properties of the bioplastics. Moreover, the...

Advances in Eco-Fuels for a Sustainable Environment

Abstract Sustainable energy sources empower change of ecological protection and are an imperative... more Abstract Sustainable energy sources empower change of ecological protection and are an imperative component of sustainable improvement. Utilizing ecofuel positively affects nature the reasons being it provides the energy safety, improve transport facilities and decreases the emission of exhaust gases. The most encouraging future ecofuels are biofuel (ethanol, biodiesel, and biogas) and heat recovery. In this book chapter, the environmental sustainability and socioeconomic impacts of ecofuel has been explored. Many indicators come in the category of social, environment and economic goodness have important part in sustainability aspect of ecofuel. These indicators are based on practicality of community benefits and picked with precaution to be practiced, sympathetic, clear, proactive and prognostic. Key socioeconomic impacts of for ecofuel production system including feedstock are investigated in perspectives of climate changes. Overall by desired socio-economic and environmental means, it is analyzed that the ecofuel is highly valuable due to its economically beneficial indicators and will help in environmental sustainability.

Proceedings of the Pakistan Academy of Sciences: B. Life and Environmental Sciences, Feb 15, 2022

Biophilic urbanism as an emerging paradigm in the design field has initiated various patterns of ... more Biophilic urbanism as an emerging paradigm in the design field has initiated various patterns of naturebased mutation. One of the most associated environmental benefits of this amalgamation of nature in urban design is carbon sequestration [CS]. The main focus of this research was to quantify the potential of trees to act as carbon reservoirs. It was investigated by assessing the roles of several tree parameters, such as diameter at breast height [DBH], height, biomass, and age in CS. A comparison of native and exotic trees was also done for this. In a field survey at Jilani Park, Lahore, 16 different families of trees (N = 115) were measured through a non-destructive method and CS was calculated. The results revealed that sample trees sequestered 588452.9 kg of carbon with an annual rate of 19998.92 kg and Combretaceae (M = 11813.65, SD = 6492.38) and Moraceae (M = 9909.93, SD = 12695.26) were the dominant families in doing so. The Pearson's correlation and linear regression analyses indicated that biomass and DBH have a significant positive relationship with CS, r = 0.100, R 2 = 0.99, and r = 0.943, R 2 = 0.89, respectively. The independent-sample t-test revealed a significant difference in CS capacity between native and exotic trees, with t (67.626) = 3.016, p =.004, and the greater biomass and DBH of native trees were the distinguishable factors. To conclude, trees are the most efficient source of carbon attenuation in the urban environment, and native species have an advantage in this process. This study will inspire new endeavours in research related to the benefits of biophilic cities.

Microscopy Research and Technique

Heavy metal toxicity due to industrial wastewater has been a threat to the environment for the pa... more Heavy metal toxicity due to industrial wastewater has been a threat to the environment for the past many decades, especially in developing countries. Electroplating Industry wastewater containing heavy metals can become a serious environmental pollutant if not treated appropriately. Present study investigated the removal of nickel and chromium ions from electroplating wastewater using calcined hen eggshells because of it high removal capability, little cost and easy approachability. Characterization of the adsorbent such as proximate analysis, surface charge, X‐ray diffraction, and surface area was done prior to adsorption process. Batch adsorption experiment was performed to study the effect of different parameters such as adsorbent dose, contact time, temperature, and pH for adsorbent. Removal percentage of both heavy metals was checked by using calcined eggshell as adsorbent. Comparison was made between nickel and chromium to identify the most effective removal efficacy. It was c...

Journal of microbiology, biotechnology and food sciences

In this study, carboxymethyl cellulase was produced in submerged fermentation characterized and s... more In this study, carboxymethyl cellulase was produced in submerged fermentation characterized and saccharification was optimized through Box-Behnken design. The optima pH and temperature of enzyme produced by Trichoderma viride were 5 and 50 oC, respectively. The crude enzyme had Km and Vmax values of 1.5143 µM and 0.9253µM/min, respectively, using carboxymethyl cellulose as substrate respectively. Three variables including pH (X1), incubation temperature (X2) and substrate concentration (X3) with three levels were used to optimize saccharification of wheat straw having 83% cellulose content using Box Behnken design and Artificial Neural Network (ANN). Results reveal that the proposed model was significant and quadratic effect of these parameters significantly affects the sugar production. Maximum sugar production (28.87 mg/ml) was predicted at RSM predicted levels of pH (6.6), incubation temperature (50 ºC) and (6.2%) substrate concentration, while the levels predicted for pH, temper...

International Journal of Botany Studies, 2020

Simple method to study the mechanism of thermal and non thermal bactericidal action of microwave ... more Simple method to study the mechanism of thermal and non thermal bactericidal action of microwave radiations on different bacterial species

Environmental Earth Sciences, 2021

Pakistan is known to be a climate vulnerable country in the world. Being an agrarian country, flo... more Pakistan is known to be a climate vulnerable country in the world. Being an agrarian country, floods poses higher threat to rural livelihood. The study assessed the underline causes of livelihood vulnerability in a flood prone rural area surrounded by riverine Jhok Reserve forest of Punjab Province. Using Livelihood Vulnerability Index (LVI), eight potential components were inquired from two hundred natural-resource dependent households. Two approaches of LVI were customized to incorporate indigenous knowledge into 42 sub-components. The findings of the study showed that local people had poor socio-economic conditions, which led to have a wide networking gap in the community. People have become highly vulnerable to climatic changes because of higher environmental degradation in form of riverbank erosion, deforestation, etc. It was revealed that community in Jhok Reserve Forest had low adaptive capacities mainly due to higher poverty, low education level and lack of awareness about future disasters. And this has exposed them being unable to adapt to environmental changes. The findings of the study are significant for the policy makers to analyze the root causes of livelihood vulnerability and formulate agricultural adaptations for other rural communities. Overall, it is suggested that a reliable vulnerability assessment approach is presented in the study which can be replicated in other settings and regions of the world.

This study explores the applicability of internationally prescribed nutrient recipes to greenhous... more This study explores the applicability of internationally prescribed nutrient recipes to greenhouse hydroponic production in Lahore. Lactuca sativa was hydroponically grown at different nutrient concentrations to uncover optimum nutrition for maximum foliage cover. Conclusions were based on visual analysis of foliage cover, as laboratory analysis of trial plants was beyond the scope of this environmental study. Nutrient levels that displayed the best foliage cover in Lahore-based greenhouse during spring weather were different from concentrations kept in US- or Europe-based hydroponic greenhouses. Plant trials conducted for this article explain the adjustments that must be made to hydroponic recipes discussed in international literature; if they are to be used in polyhouse hydroponic production in Lahore’s warmer climate.

Cholera is pandemic and food and water borne disease caused by bacteria named Vibrio cholera. It ... more Cholera is pandemic and food and water borne disease caused by bacteria named Vibrio cholera. It is an intestinal disease which is mainly identified by severe diarrhea and vomiting. It is transmitted through food and water contaminated with Vibrio cholera. Vibrio cholera is found on crustaceans, copepods, plants surfaces etc. which spread from waters for the search of food and leave the organism there. Here it causes disease by contaminating the food and water. This bacterium has many serotypes but O1 and O139 is mainly known to be the causing agents of cholera disease. The disease is simply treated with ORS (Oral Rehydration Solution), a solution or may be powder form to mix in specific amount, recommended by WHO. The disease can also be treated by antibiotics. The origin of cholera is thought to be Ganges Delta region (in Asia). Vibrio bacteria attack on the small intestinal wall and secrete its toxin ‘CTX’ also called as Cholera toxin. This toxin is the virulence factor of chole...

Brazilian Journal of Biology, 2023

Dengue fever vectored by the mosquito Aedes aegypti is one of the most rapidly spreading insect-b... more Dengue fever vectored by the mosquito Aedes aegypti is one of the most rapidly spreading insect-borne diseases. Current reliance of dengue vector control is mostly on chemical insecticides. Growing insecticide resistance in the primary mosquito vector, Aedes aegypti, limits the effectiveness of vector control through chemical insecticides. These chemical insecticides also have negative environmental impacts on animals, plants and human health. Myco-biocontrol agents are naturally occurring organisms and are found to be less damaging to the environment as compared to chemical insecticides. In the present study, entomopathogenic potential of local strains of fungi isolated from soil was assessed for the control of dengue vector. Local fungal isolates presents better alternative to introducing a foreign biocontrol strain, as they may be better adapted to environmental conditions of the area to survive and may have more entomopathogenic efficacy against target organism. Larvicidal effic...