ISMAIL SHAIKH - Academia.edu (original) (raw)

Papers by ISMAIL SHAIKH

Annals of Phytomedicine: An International Journal

Curcumin (1,7-bis(4-hydroxy 3-methoxy phenyl)-1,6-heptadione-3,5-dione), also known as diferuloyl... more Curcumin (1,7-bis(4-hydroxy 3-methoxy phenyl)-1,6-heptadione-3,5-dione), also known as diferuloyl methane, is a polyphenolic compound with a 1,3-diketo moiety at its core. Natural curcumin's therapeutic application is limited due to its low bioavailability and instability. Many chemical modifications to the curcumin framework have been documented, either to improve bioavailability or to develop novel therapeutic candidates. The modification of curcumin's 1,3-diketone group by heterocycles such as pyrazole, isoxazole, pyrimidine, and other heterocycles is the subject of current review. Overall, the current review focus on the modification of curcumin's chemical structure, which resulted in important derivatives with enhanced pharmacokinetic characteristics and biological activities.

N-Acetylation of aniline by using clay as catalyst gives good yield acetic anhydride is commonly ... more N-Acetylation of aniline by using clay as catalyst gives good yield acetic anhydride is commonly used as reagent for acylation of aniline but use of acetic anhydride is banned in Countries due to its utility in narcotics business. In the present investigation, we used acetic acid and novel clay

The present paper gives the application of Novel Clay material obtained from Bashir farm Jatadeva... more The present paper gives the application of Novel Clay material obtained from Bashir farm Jatadevale, Tq Pathardi; Dist. Ahmednagar for the synthesis bis indolyl methane derivatives from 1, 3-diphenyl-1-H-pyrazole-4-carboxaldehyde was reacted with indole to form a new species of biologically active moiety to gives very clean and good product. Additionally keeping the view of biological and medicinal properties of pyrazoles and the potential chemistry of indole hence the chemistry of both moieties are synthesized by condensation of these two in search of designing biological active compounds that could aggressively work against bacterial species and cancer cell.

International journal of scientific research in science, engineering and technology, 2018

The novel clay material was found to catalyze electrophilic substitution reaction of 2-phenyl-1-H... more The novel clay material was found to catalyze electrophilic substitution reaction of 2-phenyl-1-H-indole with a variety of aromatic aldehydes to excellent yields of bis (indolyl)methanes at room temperature. The compound 3((4-chlorophenyl)(2-phenyl-1H-indol-3-yl)methyl)-2-phenyl-1H-indole shows more antibacterial activity towards S. aureus and E. coli than standard drug Amplicillin.

Engineered Science, 2020

As there is no specified drug available to fight COVID-19, it is essential to have a different st... more As there is no specified drug available to fight COVID-19, it is essential to have a different strategy to fight this virus. In the present study, using molecular docking, we have identified possible protease inhibitors of COVID-19 by the molecules present in Nigella sativa L. (black cumin), which is a reputed healing herb extensively used for processing Ayurvedic and Unani remedies. Herein, we perform molecular docking and study of various physical properties/descriptors of four derivatives of thymoquinone found in the essential oil of the said seeds and they are compared with the docking results of chloroquine to determine its potential against COVID-19 infection.

INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY, 2017

Facebook occupies an important part of people's time and life due to the recent developments ... more Facebook occupies an important part of people's time and life due to the recent developments in the field of communication technologies (CT). This paper aims at investigating the Facebook impact (FI) on undergraduate students at Charmo University. Moreover, Facebook also has a great impact on students' life studies at universities. However, in addition to its benefits, Facebook also has some side effects on students' life study. In regard to data collection, an online survey was used in which 15 questions were answered by 100 participants from different faculties at Charmo University. The data collection process was conducted from First of March to 30 of April 2016. The program of SPSS was used to analyze the results of the survey. The results of the current study shows that students spend a significant amount of their times on using Facebook.

INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY, 2017

Over the last twenty years face recognition has made immense progress based on statistical learni... more Over the last twenty years face recognition has made immense progress based on statistical learning or subspace discriminant analysis. This paper investigates a technique to reduce features necessary for face recognition based on local binary pattern, which is constructed by applying wavelet transform into local binary pattern. The approach is evaluated in two ways: wavelet transform applied to the LBP features and wavelet transform applied twice on the original image and LBP features. The resultant data are compared to the results obtained without applying wavelet transform, revealing that the reduction base one wavelet achieves the same or sometimes improved accuracy. The proposed algorithm is experimented on the Cambridge ORL Face database.

Qatar Foundation Annual Research Conference Proceedings Volume 2016 Issue 1, 2016

The Arabian Gulf is a semi-enclosed sea with very high evaporation and low discharge rates result... more The Arabian Gulf is a semi-enclosed sea with very high evaporation and low discharge rates resulting in extreme saline and thermal conditions. Additionally the system is characterized by a weak hydrodynamic flushing resulting in pollutant build-up over time. As a result, compared to open marine systems, added stress imposed by pollutants is likely to have severe consequences.Qatar has witnessed a rapid expansion in coastal development, linked to its industrial and population growth in recent decades. While economically and socially valuable, the growth comes with an associated environmental cost and Qatar's marine environment now faces many pressures including eutrophication, inputs of domestic sewage, discharge of industrial waste and the resuspension of sediment due to coastal construction. Although the threats pose to biota inhabiting Qatar's marine environment are evident, their extent has yet to be fully assessed.A large percentage of contaminants in the aquatic environ...

Indian Journal of Research in Homoeopathy, 2019

Infantile haemangioma is a benign vascular tumour of childhood, characterised by endothelial cell... more Infantile haemangioma is a benign vascular tumour of childhood, characterised by endothelial cell proliferation. It usually develops shortly after birth and grows most rapidly over the first 6 months. However, it may keep growing for up to 12–18 months. After that, it undergoes regression or involution, and 50% of all infantile haemangiomas have completed involution by the age of 5 years, 70% by the age of 7 years and 90% by the age of 9–12 years. However, in a small percentage of patients in whom haemangioma is not disappearing completely, residual fatty tissue or superficial skin telangiectasias remains. These patients may require drug therapy (propranolol/timolol/steroids/vincristine), surgery and/or laser therapy often during childhood involving certain risks or side effects. However, homoeopathic medicine can quickly, safely and effectively diminish proliferative growth and hasten resolution without any side effects. Two children with infantile haemangioma were treated with homoeopathic medicines, selected on the basis of their totality of symptoms and repertorisation. Each child was followed up every 2–4 weeks’ interval, and photographs were taken to assess/compare the vascularity, height (thickness), pliability and pigmentation according to the Vancouver Scar Scale chart. In the 1st case, the score reduced from 9 to 1 in about 10 months of follow-up and showed 88.8% improvement. In the 2nd case, the score reduced from 9 to 0 in about 10 months of follow-up and showed 100% improvement. These case reports show that early treatment of infantile haemangioma with Homoeopathy medicine can diminish proliferative growth and hasten resolution as early as possible without any side effects.

Indian Journal of Research in Homoeopathy, 2016

Warts are the growth of skin resulting from human papillomavirus infection. In general, three typ... more Warts are the growth of skin resulting from human papillomavirus infection. In general, three types of warts are found. (a) common warts appear on any part of the body, (b) plantar warts appear on the sole of feet, and (c) genital and anal warts appear on the genitalia and anal region. Various types of treatment procedures are available for removing warts. Some of these are (a) applying salicylic acid, liquid nitrogen, and podophyllin; (b) loop electrosurgical excision procedure; (c) CO 2 laser surgery; and (d) interferon injections. [1] Dr. Christian Fredrick Samuel Hahnemann laid down the foundation of Homoeopathy in the year 1796 and prescribed medicines in centesimal potencies in his early practice and got results. [2] However, he observed severe aggravations when repeated the medicine in cases with gross pathological changes and with high potencies. Therefore, Dr. Hahnemann started working to prepare medicine in new scale and finally in the year 1837 he introduced a new principle of fifty millesimal potencies in the 6 th edition of Organon of Medicine. [3] In this scale, he repeated medicine frequently, prescribed medicines with higher potencies even in diseases with gross pathological changes without any significant homoeopathic aggravation. [4] Aim and Objectives The primary objective was to identify usefulness of homoeopathic medicines used in centisimal scale and fifty millesimal potencies in the treatment of warts.

ICES Journal of Marine Science, 2017

As with many other regions in the world, more complete information on the distribution of marine ... more As with many other regions in the world, more complete information on the distribution of marine habitats in the Gulf is required to inform environmental policy, and spatial management of fisheries resources will require better understanding of the relationships between habitat and fish communities. Towed cameras and sediment grabs were used to investigate benthic habitats and associated epifauna, infauna and fish communities in the central Gulf, offshore from the east coast of Qatar, in water depths of between 12 and 52 m. Six different habitats were identified: (i) soft sediment habitats of mud and (ii) sand, and structured habitats of (iii) macro-algal reef, (iv) coral reef, (v) mixed reef, and (vi) oyster bed. The epibenthic community assemblage of the mud habitat was significantly different to that of sand, which in turn differed from the structured habitats of coral reef, mixed reef and oyster bed, with the macroalgal assemblage having similarities to both sand and the other s...

Marine pollution bulletin, Jan 10, 2017

Surface sediment samples from the coastal zone of Qatar were collected and analyzed to determine ... more Surface sediment samples from the coastal zone of Qatar were collected and analyzed to determine the characteristics, and sources of anthropogenic and biogenic hydrocarbons. The main compounds in these surface sediments included n-alkanes, methyl n-alkanoates, diterpenoids, hopanes, steranes, phthalate esters, polycyclic aromatic hydrocarbons (PAHs) and unresolved complex mixture (UCM). Their total concentrations ranged from 18.7±3.7-81.1±7.5ng/g (3.7±0.6-10.4±4.8%) for n-alkanes, 8.3±2.3-51±3.4ng/g (3.0±2.0-5.6±2.0%) for methyl n-alkanoates, 1.8±0.1-10.5±1.0ng/g (1.0±0.5-0.4±0.1%) for diterpenoids, 0.0-79.3±7.4ng/g (0.0-7.9±0.6%) for hopanes, 0.0-32.9±7.9ng/g (0.0-6.5±1.0%) for steranes, 0.7±0.1-36.3±3.4ng/g (0.1±0.1-1.9±3.4%) for phthalates, 0.30±0.2-7.8±0.7ng/g (0.02±0.04-0.42±0.72%) for PAHs, and 38±9-609±57ng/g (38.5±13.4-56.5±13.4%) for UCM. The major sources of these lipids were anthropogenic petroleum residues and plasticizers (80-89%), with lesser amounts from natural highe...

Journal of Ultra Chemistry, 2017

In this study, we report that the novel clay material was found to catalyze electrophilic substit... more In this study, we report that the novel clay material was found to catalyze electrophilic substitution reaction of 2-phenyl-1-H-indoles with a variety of aromatic aldehydes to excellent yields of bis (indolyl) methanes at room temperature. The efficient synthesis of 2-phenyl-1-H-indoles was achieved by Fischer indole synthesis with addition of phenyl hydrazine and acetophenone.

Environmental Monitoring and Assessment, 2016

The study aimed to examine the residues of organochlorines pesticides (OCPs) in vegetables and fr... more The study aimed to examine the residues of organochlorines pesticides (OCPs) in vegetables and fruits in Qatar. A total of 127 samples was studied. Ninety percent of the imported samples recorded residues above the maximum residue levels (MRLs). The most frequently detected OCP in the samples was heptachlor (found in 75 samples). In the comparisons between the washed and unwashed samples, no significant differences were observed (P > 0.05). However, the effect of washing process with tap water depended on the type of vegetables and fruits.

QScience Proceedings, 2015

QScience Proceedings, 2015

We present data on elemental concentrations of plankton net tow samples from the Exclusive Econom... more We present data on elemental concentrations of plankton net tow samples from the Exclusive Economic Zone (EEZ) of Qatar in the Arabian Gulf as part of a broader study of biogenic and lithogenic influences on particulate trace metal concentrations in the surface ocean. There are relatively few analyses of planktonic trace metals and their associated role in the biogeochemical system. We had the opportunity to investigate the composition of plankton in a region heavily affected by dust, a significant factor for phytoplankton growth. Our samples were collected from 2012 to 2015 using trace metal clean net tows with mesh sizes of 50 and 200 microns for measurements of phytoplankton and zooplankton, respectively. Samples were totally digested and analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS). The biogenic portion was determined by subtracting the lithogenic portion from the total concentration. The lithogenic fraction was defined as the concentration of aluminum in th...

Environmental Monitoring and Assessment, 2015

Concentrations of 25 heavy metals (Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo,... more Concentrations of 25 heavy metals (Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Sr, V, Zn and Hg) in surface sediments along the Doha Bay from 10 transects each with five stations were studied. Significant differences were observed in metal concentrations between the sampling locations and durations. Higher concentrations were observed in areas where there are a lot of anthropological activities. The distribution of selected metals was presented in contour maps showing the variation between the two periods. In order to further study particle size effect on metal uptake, two different grinding times were administered on four randomly selected samples and the results showed no significant difference on the analysis in the inductively coupled plasma-optical emission spectrometry (ICP-OES) instrument. The overall results of metal analyses were within the international standards criteria, and the results were comparable to the previous studies conducted around Qatar.

PLoS ONE, 2014

The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below ... more The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below as it is surrounded by sand dunes. We investigated the chemical composition, the microbial activity and biodiversity of the four main layers (L1-L4) in the photosynthetic mats. Chlorophyll a (Chl a) concentration and distribution (measured by HPLC and hyperspectral imaging, respectively), the phycocyanin distribution (scanned with hyperspectral imaging), oxygenic photosynthesis (determined by microsensor), and the abundance of photosynthetic microorganisms (from 16S and 18S rRNA sequencing) decreased with depth in the euphotic layer (L1). Incident irradiance exponentially attenuated in the same zone reaching 1% at 1.7-mm depth. Proteobacteria dominated all layers of the mat (24%-42% of the identified bacteria). Anoxygenic photosynthetic bacteria (dominated by Chloroflexus) were most abundant in the third red layer of the mat (L3), evidenced by the spectral signature of Bacteriochlorophyll as well as by sequencing. The deep, black layer (L4) was dominated by sulfate reducing bacteria belonging to the Deltaproteobacteria, which were responsible for high sulfate reduction rates (measured using 35 S tracer). Members of Halobacteria were the dominant Archaea in all layers of the mat (92%-97%), whereas Nematodes were the main Eukaryotes (up to 87%). Primary productivity rates of Um Alhool mat were similar to those of other hypersaline microbial mats. However, sulfate reduction rates were relatively low, indicating that oxygenic respiration contributes more to organic material degradation than sulfate reduction, because of bioturbation. Although Um Alhool hypersaline mat is a nutrient-limited ecosystem, it is interestingly dynamic and phylogenetically highly diverse. All its components work in a highly efficient and synchronized way to compensate for the lack of nutrient supply provided during regular inundation periods.

Dermatopathology, Apr 20, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Annals of Phytomedicine: An International Journal

Curcumin (1,7-bis(4-hydroxy 3-methoxy phenyl)-1,6-heptadione-3,5-dione), also known as diferuloyl... more Curcumin (1,7-bis(4-hydroxy 3-methoxy phenyl)-1,6-heptadione-3,5-dione), also known as diferuloyl methane, is a polyphenolic compound with a 1,3-diketo moiety at its core. Natural curcumin's therapeutic application is limited due to its low bioavailability and instability. Many chemical modifications to the curcumin framework have been documented, either to improve bioavailability or to develop novel therapeutic candidates. The modification of curcumin's 1,3-diketone group by heterocycles such as pyrazole, isoxazole, pyrimidine, and other heterocycles is the subject of current review. Overall, the current review focus on the modification of curcumin's chemical structure, which resulted in important derivatives with enhanced pharmacokinetic characteristics and biological activities.

N-Acetylation of aniline by using clay as catalyst gives good yield acetic anhydride is commonly ... more N-Acetylation of aniline by using clay as catalyst gives good yield acetic anhydride is commonly used as reagent for acylation of aniline but use of acetic anhydride is banned in Countries due to its utility in narcotics business. In the present investigation, we used acetic acid and novel clay

The present paper gives the application of Novel Clay material obtained from Bashir farm Jatadeva... more The present paper gives the application of Novel Clay material obtained from Bashir farm Jatadevale, Tq Pathardi; Dist. Ahmednagar for the synthesis bis indolyl methane derivatives from 1, 3-diphenyl-1-H-pyrazole-4-carboxaldehyde was reacted with indole to form a new species of biologically active moiety to gives very clean and good product. Additionally keeping the view of biological and medicinal properties of pyrazoles and the potential chemistry of indole hence the chemistry of both moieties are synthesized by condensation of these two in search of designing biological active compounds that could aggressively work against bacterial species and cancer cell.

International journal of scientific research in science, engineering and technology, 2018

The novel clay material was found to catalyze electrophilic substitution reaction of 2-phenyl-1-H... more The novel clay material was found to catalyze electrophilic substitution reaction of 2-phenyl-1-H-indole with a variety of aromatic aldehydes to excellent yields of bis (indolyl)methanes at room temperature. The compound 3((4-chlorophenyl)(2-phenyl-1H-indol-3-yl)methyl)-2-phenyl-1H-indole shows more antibacterial activity towards S. aureus and E. coli than standard drug Amplicillin.

Engineered Science, 2020

As there is no specified drug available to fight COVID-19, it is essential to have a different st... more As there is no specified drug available to fight COVID-19, it is essential to have a different strategy to fight this virus. In the present study, using molecular docking, we have identified possible protease inhibitors of COVID-19 by the molecules present in Nigella sativa L. (black cumin), which is a reputed healing herb extensively used for processing Ayurvedic and Unani remedies. Herein, we perform molecular docking and study of various physical properties/descriptors of four derivatives of thymoquinone found in the essential oil of the said seeds and they are compared with the docking results of chloroquine to determine its potential against COVID-19 infection.

INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY, 2017

Facebook occupies an important part of people's time and life due to the recent developments ... more Facebook occupies an important part of people's time and life due to the recent developments in the field of communication technologies (CT). This paper aims at investigating the Facebook impact (FI) on undergraduate students at Charmo University. Moreover, Facebook also has a great impact on students' life studies at universities. However, in addition to its benefits, Facebook also has some side effects on students' life study. In regard to data collection, an online survey was used in which 15 questions were answered by 100 participants from different faculties at Charmo University. The data collection process was conducted from First of March to 30 of April 2016. The program of SPSS was used to analyze the results of the survey. The results of the current study shows that students spend a significant amount of their times on using Facebook.

INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY, 2017

Over the last twenty years face recognition has made immense progress based on statistical learni... more Over the last twenty years face recognition has made immense progress based on statistical learning or subspace discriminant analysis. This paper investigates a technique to reduce features necessary for face recognition based on local binary pattern, which is constructed by applying wavelet transform into local binary pattern. The approach is evaluated in two ways: wavelet transform applied to the LBP features and wavelet transform applied twice on the original image and LBP features. The resultant data are compared to the results obtained without applying wavelet transform, revealing that the reduction base one wavelet achieves the same or sometimes improved accuracy. The proposed algorithm is experimented on the Cambridge ORL Face database.

Qatar Foundation Annual Research Conference Proceedings Volume 2016 Issue 1, 2016

The Arabian Gulf is a semi-enclosed sea with very high evaporation and low discharge rates result... more The Arabian Gulf is a semi-enclosed sea with very high evaporation and low discharge rates resulting in extreme saline and thermal conditions. Additionally the system is characterized by a weak hydrodynamic flushing resulting in pollutant build-up over time. As a result, compared to open marine systems, added stress imposed by pollutants is likely to have severe consequences.Qatar has witnessed a rapid expansion in coastal development, linked to its industrial and population growth in recent decades. While economically and socially valuable, the growth comes with an associated environmental cost and Qatar's marine environment now faces many pressures including eutrophication, inputs of domestic sewage, discharge of industrial waste and the resuspension of sediment due to coastal construction. Although the threats pose to biota inhabiting Qatar's marine environment are evident, their extent has yet to be fully assessed.A large percentage of contaminants in the aquatic environ...

Indian Journal of Research in Homoeopathy, 2019

Infantile haemangioma is a benign vascular tumour of childhood, characterised by endothelial cell... more Infantile haemangioma is a benign vascular tumour of childhood, characterised by endothelial cell proliferation. It usually develops shortly after birth and grows most rapidly over the first 6 months. However, it may keep growing for up to 12–18 months. After that, it undergoes regression or involution, and 50% of all infantile haemangiomas have completed involution by the age of 5 years, 70% by the age of 7 years and 90% by the age of 9–12 years. However, in a small percentage of patients in whom haemangioma is not disappearing completely, residual fatty tissue or superficial skin telangiectasias remains. These patients may require drug therapy (propranolol/timolol/steroids/vincristine), surgery and/or laser therapy often during childhood involving certain risks or side effects. However, homoeopathic medicine can quickly, safely and effectively diminish proliferative growth and hasten resolution without any side effects. Two children with infantile haemangioma were treated with homoeopathic medicines, selected on the basis of their totality of symptoms and repertorisation. Each child was followed up every 2–4 weeks’ interval, and photographs were taken to assess/compare the vascularity, height (thickness), pliability and pigmentation according to the Vancouver Scar Scale chart. In the 1st case, the score reduced from 9 to 1 in about 10 months of follow-up and showed 88.8% improvement. In the 2nd case, the score reduced from 9 to 0 in about 10 months of follow-up and showed 100% improvement. These case reports show that early treatment of infantile haemangioma with Homoeopathy medicine can diminish proliferative growth and hasten resolution as early as possible without any side effects.

Indian Journal of Research in Homoeopathy, 2016

Warts are the growth of skin resulting from human papillomavirus infection. In general, three typ... more Warts are the growth of skin resulting from human papillomavirus infection. In general, three types of warts are found. (a) common warts appear on any part of the body, (b) plantar warts appear on the sole of feet, and (c) genital and anal warts appear on the genitalia and anal region. Various types of treatment procedures are available for removing warts. Some of these are (a) applying salicylic acid, liquid nitrogen, and podophyllin; (b) loop electrosurgical excision procedure; (c) CO 2 laser surgery; and (d) interferon injections. [1] Dr. Christian Fredrick Samuel Hahnemann laid down the foundation of Homoeopathy in the year 1796 and prescribed medicines in centesimal potencies in his early practice and got results. [2] However, he observed severe aggravations when repeated the medicine in cases with gross pathological changes and with high potencies. Therefore, Dr. Hahnemann started working to prepare medicine in new scale and finally in the year 1837 he introduced a new principle of fifty millesimal potencies in the 6 th edition of Organon of Medicine. [3] In this scale, he repeated medicine frequently, prescribed medicines with higher potencies even in diseases with gross pathological changes without any significant homoeopathic aggravation. [4] Aim and Objectives The primary objective was to identify usefulness of homoeopathic medicines used in centisimal scale and fifty millesimal potencies in the treatment of warts.

ICES Journal of Marine Science, 2017

As with many other regions in the world, more complete information on the distribution of marine ... more As with many other regions in the world, more complete information on the distribution of marine habitats in the Gulf is required to inform environmental policy, and spatial management of fisheries resources will require better understanding of the relationships between habitat and fish communities. Towed cameras and sediment grabs were used to investigate benthic habitats and associated epifauna, infauna and fish communities in the central Gulf, offshore from the east coast of Qatar, in water depths of between 12 and 52 m. Six different habitats were identified: (i) soft sediment habitats of mud and (ii) sand, and structured habitats of (iii) macro-algal reef, (iv) coral reef, (v) mixed reef, and (vi) oyster bed. The epibenthic community assemblage of the mud habitat was significantly different to that of sand, which in turn differed from the structured habitats of coral reef, mixed reef and oyster bed, with the macroalgal assemblage having similarities to both sand and the other s...

Marine pollution bulletin, Jan 10, 2017

Surface sediment samples from the coastal zone of Qatar were collected and analyzed to determine ... more Surface sediment samples from the coastal zone of Qatar were collected and analyzed to determine the characteristics, and sources of anthropogenic and biogenic hydrocarbons. The main compounds in these surface sediments included n-alkanes, methyl n-alkanoates, diterpenoids, hopanes, steranes, phthalate esters, polycyclic aromatic hydrocarbons (PAHs) and unresolved complex mixture (UCM). Their total concentrations ranged from 18.7±3.7-81.1±7.5ng/g (3.7±0.6-10.4±4.8%) for n-alkanes, 8.3±2.3-51±3.4ng/g (3.0±2.0-5.6±2.0%) for methyl n-alkanoates, 1.8±0.1-10.5±1.0ng/g (1.0±0.5-0.4±0.1%) for diterpenoids, 0.0-79.3±7.4ng/g (0.0-7.9±0.6%) for hopanes, 0.0-32.9±7.9ng/g (0.0-6.5±1.0%) for steranes, 0.7±0.1-36.3±3.4ng/g (0.1±0.1-1.9±3.4%) for phthalates, 0.30±0.2-7.8±0.7ng/g (0.02±0.04-0.42±0.72%) for PAHs, and 38±9-609±57ng/g (38.5±13.4-56.5±13.4%) for UCM. The major sources of these lipids were anthropogenic petroleum residues and plasticizers (80-89%), with lesser amounts from natural highe...

Journal of Ultra Chemistry, 2017

In this study, we report that the novel clay material was found to catalyze electrophilic substit... more In this study, we report that the novel clay material was found to catalyze electrophilic substitution reaction of 2-phenyl-1-H-indoles with a variety of aromatic aldehydes to excellent yields of bis (indolyl) methanes at room temperature. The efficient synthesis of 2-phenyl-1-H-indoles was achieved by Fischer indole synthesis with addition of phenyl hydrazine and acetophenone.

Environmental Monitoring and Assessment, 2016

The study aimed to examine the residues of organochlorines pesticides (OCPs) in vegetables and fr... more The study aimed to examine the residues of organochlorines pesticides (OCPs) in vegetables and fruits in Qatar. A total of 127 samples was studied. Ninety percent of the imported samples recorded residues above the maximum residue levels (MRLs). The most frequently detected OCP in the samples was heptachlor (found in 75 samples). In the comparisons between the washed and unwashed samples, no significant differences were observed (P > 0.05). However, the effect of washing process with tap water depended on the type of vegetables and fruits.

QScience Proceedings, 2015

QScience Proceedings, 2015

We present data on elemental concentrations of plankton net tow samples from the Exclusive Econom... more We present data on elemental concentrations of plankton net tow samples from the Exclusive Economic Zone (EEZ) of Qatar in the Arabian Gulf as part of a broader study of biogenic and lithogenic influences on particulate trace metal concentrations in the surface ocean. There are relatively few analyses of planktonic trace metals and their associated role in the biogeochemical system. We had the opportunity to investigate the composition of plankton in a region heavily affected by dust, a significant factor for phytoplankton growth. Our samples were collected from 2012 to 2015 using trace metal clean net tows with mesh sizes of 50 and 200 microns for measurements of phytoplankton and zooplankton, respectively. Samples were totally digested and analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS). The biogenic portion was determined by subtracting the lithogenic portion from the total concentration. The lithogenic fraction was defined as the concentration of aluminum in th...

Environmental Monitoring and Assessment, 2015

Concentrations of 25 heavy metals (Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo,... more Concentrations of 25 heavy metals (Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Sr, V, Zn and Hg) in surface sediments along the Doha Bay from 10 transects each with five stations were studied. Significant differences were observed in metal concentrations between the sampling locations and durations. Higher concentrations were observed in areas where there are a lot of anthropological activities. The distribution of selected metals was presented in contour maps showing the variation between the two periods. In order to further study particle size effect on metal uptake, two different grinding times were administered on four randomly selected samples and the results showed no significant difference on the analysis in the inductively coupled plasma-optical emission spectrometry (ICP-OES) instrument. The overall results of metal analyses were within the international standards criteria, and the results were comparable to the previous studies conducted around Qatar.

PLoS ONE, 2014

The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below ... more The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below as it is surrounded by sand dunes. We investigated the chemical composition, the microbial activity and biodiversity of the four main layers (L1-L4) in the photosynthetic mats. Chlorophyll a (Chl a) concentration and distribution (measured by HPLC and hyperspectral imaging, respectively), the phycocyanin distribution (scanned with hyperspectral imaging), oxygenic photosynthesis (determined by microsensor), and the abundance of photosynthetic microorganisms (from 16S and 18S rRNA sequencing) decreased with depth in the euphotic layer (L1). Incident irradiance exponentially attenuated in the same zone reaching 1% at 1.7-mm depth. Proteobacteria dominated all layers of the mat (24%-42% of the identified bacteria). Anoxygenic photosynthetic bacteria (dominated by Chloroflexus) were most abundant in the third red layer of the mat (L3), evidenced by the spectral signature of Bacteriochlorophyll as well as by sequencing. The deep, black layer (L4) was dominated by sulfate reducing bacteria belonging to the Deltaproteobacteria, which were responsible for high sulfate reduction rates (measured using 35 S tracer). Members of Halobacteria were the dominant Archaea in all layers of the mat (92%-97%), whereas Nematodes were the main Eukaryotes (up to 87%). Primary productivity rates of Um Alhool mat were similar to those of other hypersaline microbial mats. However, sulfate reduction rates were relatively low, indicating that oxygenic respiration contributes more to organic material degradation than sulfate reduction, because of bioturbation. Although Um Alhool hypersaline mat is a nutrient-limited ecosystem, it is interestingly dynamic and phylogenetically highly diverse. All its components work in a highly efficient and synchronized way to compensate for the lack of nutrient supply provided during regular inundation periods.

Dermatopathology, Apr 20, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY