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Fulltext Predicting compressive strength of eco-friendly plastic sand paver blocks using gene expression and artificial intelligence programming

Iftikhar B, Alih SC, Vafaei M, Javed MF, Rehman MF, Abdullaev SS, et al.

Sci Rep, 2023 Jul 27;13(1):12149.
PMID: 37500697 DOI: 10.1038/s41598-023-39349-2

Plastic sand paver blocks provide a sustainable alternative by using plastic waste and reducing the need for cement. This innovative approach leads to a more sustainable construction sector by promoting environmental preservation. No model or Equation has been devised that can predict the compressive strength of these blocks. This study utilized gene expression programming (GEP) and multi-expression programming (MEP) to develop empirical models to forecast the compressive strength of plastic sand paver blocks (PSPB) comprised of plastic, sand, and fibre in an effort to advance the field. The database contains 135 results for compressive strength with seven input parameters. The R2 values of 0.87 for GEP and 0.91 for MEP for compressive strength reveal a relatively significant relationship between predicted and actual values. MEP outperformed GEP by displaying a higher R2 and lower values for statistical evaluations. In addition, a sensitivity analysis was conducted, which revealed that the sand grain size and percentage of fibres play an essential part in compressive strength. It was estimated that they contributed almost 50% of the total. The outcomes of this research have the potential to promote the reuse of PSPB in the building of green environments, hence boosting environmental protection and economic advantage.
Fulltext Pre-grafting histological studies of skin grafts cryopreserved in α helix antarctic yeast oriented antifreeze peptide (Afp1m)

Khan MS, Ibrahim SM, Adamu AA, Rahman MBA, Bakar MZA, Noordin MM, et al.

Cryobiology, 2020 02 01;92:26-33.
PMID: 31580830 DOI: 10.1016/j.cryobiol.2019.09.012

A number of living creatures in the Antarctic region have developed characteristic adaptation of cold weather by producing antifreeze proteins (AFP). Antifreeze peptide (Afp1m) fragment have been designed in the sequence of strings from native proteins. The objectives of this study were to assess the properties of Afp1m to cryopreserve skin graft at the temperature of -10 °C and -20 °C and to assess sub-zero injuries in Afp1m cryopreserved skin graft using light microscopic techniques. In the present study, a process was developed to cryopreserve Sprague-Dawley (SD) rat skin grafts with antifreeze peptide, Afp1m, α-helix peptide fragment derived from Glaciozyma antractica yeast. Its viability assessed by different microscopic techniques. This study also described the damages caused by subzero temperatures (-10 and -20 °C) on tissue cryopreserved in different concentrations of Afp1m (0.5, 1, 2, 5 and 10 mg/mL) for 72 h. Histological scores of epidermis, dermis and hypodermis of cryopreserved skin grafts showed highly significant difference (p 
Fulltext Population structure of a global agricultural invasive pest, Bactrocera dorsalis (Diptera: Tephritidae)

Qin YJ, Krosch MN, Schutze MK, Zhang Y, Wang XX, Prabhakar CS, et al.

Evol Appl, 2018 Dec;11(10):1990-2003.
PMID: 30459843 DOI: 10.1111/eva.12701

Bactrocera dorsalis, the Oriental fruit fly, is one of the world's most destructive agricultural insect pests and a major impediment to international fresh commodity trade. The genetic structuring of the species across its entire geographic range has never been undertaken, because under a former taxonomy B. dorsalis was divided into four distinct taxonomic entities, each with their own, largely non-overlapping, distributions. Based on the extensive sampling of six a priori groups from 63 locations, genetic and geometric morphometric datasets were generated to detect macrogeographic population structure, and to determine prior and current invasion pathways of this species. Weak population structure and high genetic diversity were detected among Asian populations. Invasive populations in Africa and Hawaii are inferred to be the result of separate, single invasions from South Asia, while South Asia is also the likely source of other Asian populations. The current northward invasion of B. dorsalis into Central China is the result of multiple, repeated dispersal events, most likely related to fruit trade. Results are discussed in the context of global quarantine, trade, and management of this pest. The recent expansion of the fly into temperate China, with very few associated genetic changes, clearly demonstrates the threat posed by this pest to ecologically similar areas in Europe and North America.
Fulltext Pomegranate peels waste hydrolyzate optimization by Response Surface Methodology for Bioethanol production

Chaudhary A, Hussain Z, Aihetasham A, El-Sharnouby M, Abdul Rehman R, Azmat Ullah Khan M, et al.

Saudi J Biol Sci, 2021 Sep;28(9):4867-4875.
PMID: 34466060 DOI: 10.1016/j.sjbs.2021.06.081

Unwanted agricultural waste is largely comprised of lignocellulosic substrate which could be transformed into sugars. The production of bioethanol from garbage manifested an agreeable proposal towards waste management as well as energy causation. The goal of this work is to optimize parameters for generation of bioethanol through fermentation by different yeast strains while Saccharomyces cerevisiae used as standard strain. The low cost fermentable sugars from pomegranate peels waste (PPW) were obtained by hydrolysis with HNO3 (1 to 5%). The optimum levels of hydrolysis time and temperature were elucidated via RSM (CCD) ranging from 30 to 60 min and 50 to 100 °C respectively. The result shows that optimum values (g/L) for reducing sugars was 61.45 ± 0.01 while for total carbohydrates was 236 ± 0.01. These values were found when PPW was hydrolyzed with 3% HNO3, at 75 °C for one hour. The hydrolyzates obtained from the dilute HNO3 pretreated PPW yielded a maximum of 0.43 ± 0.04, 0.41 ± 0.03 g ethanol per g of reducing sugars by both Metchnikowia sp. Y31 and M. cibodasensis Y34 at day 7 of ethanologenic experiment. The current study exhibited that by fermentation of dilute HNO3 hydrolyzates of PPW could develop copious amount of ethanol by optimized conditions.
Fulltext Platelet-Rich Fibrin Used in Regenerative Endodontics and Dentistry: Current Uses, Limitations, and Future Recommendations for Application

Arshad S, Tehreem F, Rehab Khan M, Ahmed F, Marya A, Karobari MI

Int J Dent, 2021;2021:4514598.
PMID: 34956367 DOI: 10.1155/2021/4514598

Regenerative endodontics has introduced numerous procedures such as pulp implantation, revascularization, and postnatal stem cell therapy. Revascularization has been successfully implemented clinically nowadays, thus providing dentists with outrageous results. Platelet-rich fibrin (PRF) used either alone or along with bone graft promotes bone growth and vascularization. This matrix promotes migration, cell attachment, and proliferation of osteoblast that leads to bone formation. PRF consists of a packed fibrin complex consisting of leukocytes, cytokines, and glycoproteins such as thrombospondin. The usage of PRF has reported high success rates in surgical cases such as sinus lift procedures, healing of extraction sockets, and management of periapical abscesses. Compared to platelet-rich plasma, PRF is more economical, easy to prepare, and feasible to use in daily clinical practices. Revascularization compromised the induction of a blood clot into the root canal space, which emerged as a clinical triumph. This further led to platelet concentrates as an autologous scaffold on which revascularization could occur. The applications of PRF in regenerative endodontics are numerous, such as an agent for repairing iatrogenic perforation of the pulpal floor and for the revascularization of immature permanent teeth with necrotic pulps. It acts as a matrix for tissue ingrowth. Evidence of progressive thickening of dentinal walls, root lengthening, regression in the periapical lesion, and apical closure was reported. Further studies are needed to clarify the precise mechanism of action of PRF for dental pulp regeneration both in vitro and in vivo. The current review aims at the present uses of PRF in regenerative endodontics dentistry and its application with future recommendations and limitations.
Ongoing efforts to improve the management of patients with diabetes in Bangladesh and the implications

Haque M, Islam S, Kamal ZM, Akter F, Jahan I, Rahim MSA, et al.

Hosp Pract (1995), 2021 Oct;49(4):266-272.
PMID: 33734004 DOI: 10.1080/21548331.2021.1906083

BACKGROUND: Prevalence rates of patients with diabetes are growing across countries, and Bangladesh is no exception. Associated costs are also increasing, driven by costs associated with the complications of diabetes including hypoglycemia. Long-acting insulin analogues were developed to reduce hypoglycemia as well as improve patient comfort and adherence. However, they have been appreciably more expensive, reducing their affordability and use. Biosimilars offer a way forward. Consequently, there is a need to document current prescribing and dispensing rates for long-acting insulin analogues across Bangladesh, including current prices and differences, as a result of affordability and other issues.
METHODS: Mixed method approach including surveying prescribing practices in hospitals coupled with dispensing practices and prices among community pharmacies and drug stores across Bangladesh. This method was adopted since public hospitals only dispense insulins such as soluble insulins free-of-charge until funds run out and all long-acting insulin analogues have to be purchased from community stores.
RESULTS: There has been growing prescribing and dispensing of long-acting insulins in Bangladesh in recent years, now accounting for over 80% of all insulins dispensed in a minority of stores. This increase has been helped by growing prescribing and dispensing of biosimilar insulin glargine at lower costs than the originator, with this trend likely to continue with envisaged growth in the number of patients. Consequently, Bangladesh can serve as an exemplar to other low- and middle-income countries struggling to fund long-acting insulin analogues for their patients.
CONCLUSIONS: It was encouraging to see continued growth in the prescribing and dispensing of long-acting insulin analogues in Bangladesh via the increasing availability of biosimilars. This is likely to continue benefitting all key stakeholder groups.
Fulltext Ongoing declines for the world's amphibians in the face of emerging threats

Luedtke JA, Chanson J, Neam K, Hobin L, Maciel AO, Catenazzi A, et al.

Nature, 2023 Oct;622(7982):308-314.
PMID: 37794184 DOI: 10.1038/s41586-023-06578-4

Systematic assessments of species extinction risk at regular intervals are necessary for informing conservation action1,2. Ongoing developments in taxonomy, threatening processes and research further underscore the need for reassessment3,4. Here we report the findings of the second Global Amphibian Assessment, evaluating 8,011 species for the International Union for Conservation of Nature Red List of Threatened Species. We find that amphibians are the most threatened vertebrate class (40.7% of species are globally threatened). The updated Red List Index shows that the status of amphibians is deteriorating globally, particularly for salamanders and in the Neotropics. Disease and habitat loss drove 91% of status deteriorations between 1980 and 2004. Ongoing and projected climate change effects are now of increasing concern, driving 39% of status deteriorations since 2004, followed by habitat loss (37%). Although signs of species recoveries incentivize immediate conservation action, scaled-up investment is urgently needed to reverse the current trends.
Occurrence and health risk assessment of arsenic and heavy metals in groundwater of three industrial areas in Delhi, India

Alsubih M, El Morabet R, Khan RA, Khan NA, Ul Haq Khan M, Ahmed S, et al.

Environ Sci Pollut Res Int, 2021 Nov;28(44):63017-63031.
PMID: 34218378 DOI: 10.1007/s11356-021-15062-3

Groundwater is a primary natural water source in the absence of surface water bodies. Groundwater in urban environments experiences unprecedented stress from urban growth, population increase, and industrial activities. This study assessed groundwater quality in terms of arsenic and heavy metal contamination in three industrial areas (Shahdara, Jhilmil, and Patparganj), Delhi, India. The water quality was assessed over a 3-year time interval (i.e., 2015 and 2018). The groundwater constituents investigated were As, Fe, Cr, Cd, Ni, Zn, Mn, Cu, and Pb. Metal index and heavy metal pollution indexes were estimated to assess groundwater pollution. The health risk was evaluated in terms of non-carcinogenic and carcinogenic risk assessment. Patparganj industrial area saw increment in concentration for Cu 0.23 mg/L (2015)-0.85 mg/L (2018), Zn 0.51 mg/L (2015)-7.2 mg/L (2018), Fe 0.32 mg/L (2015)-0.9 mg/L (2018), Cr 0.21 mg/L (2015)-0.26 mg/L (2018), Mn 0.14 mg/L (2015)-0.25 mg/L (2018), Ni 0.04 mg/L (2015)-0.34 mg/L (2018), and As 0.01 mg/L (2015)-0.18 mg/L (2018). Cd and Pb concentrations were observed to decrease by 40-90 % and 85-99% for all the three industrial areas. Metal index and heavy metal index values were found to be >1 for all locations. The risk quotient value > 1 was observed for all locations in the year 2015 but was found to increase further to a range of RQ 10-62 in the year 2018, inferring increased non-carcinogenic risk to consumers. The carcinogenic risk was significant with respect to Fe (0.2-0.7), Zn (0.001-0.007), and As (0.002-0.003) for all locations in the year 2015. This study concludes that groundwater in the three industrial areas is highly polluted and is not fit for human consumption. Further studies are required to explore possible control measures and develop methods to mitigate groundwater pollution, sustainable management, and optimized use to conserve it for future generations.
Nurses should be empowered to be proactively involved in family decision meetings on intensive care unit patient care decisions

Khan M

Evid Based Nurs, 2020 10;23(4):114.
PMID: 31511244 DOI: 10.1136/ebnurs-2019-103089
Fulltext Nipah virus dynamics in bats and implications for spillover to humans

Epstein JH, Anthony SJ, Islam A, Kilpatrick AM, Ali Khan S, Balkey MD, et al.

Proc Natl Acad Sci U S A, 2020 11 17;117(46):29190-29201.
PMID: 33139552 DOI: 10.1073/pnas.2000429117

Nipah virus (NiV) is an emerging bat-borne zoonotic virus that causes near-annual outbreaks of fatal encephalitis in South Asia-one of the most populous regions on Earth. In Bangladesh, infection occurs when people drink date-palm sap contaminated with bat excreta. Outbreaks are sporadic, and the influence of viral dynamics in bats on their temporal and spatial distribution is poorly understood. We analyzed data on host ecology, molecular epidemiology, serological dynamics, and viral genetics to characterize spatiotemporal patterns of NiV dynamics in its wildlife reservoir, Pteropus medius bats, in Bangladesh. We found that NiV transmission occurred throughout the country and throughout the year. Model results indicated that local transmission dynamics were modulated by density-dependent transmission, acquired immunity that is lost over time, and recrudescence. Increased transmission followed multiyear periods of declining seroprevalence due to bat-population turnover and individual loss of humoral immunity. Individual bats had smaller host ranges than other Pteropus species (spp.), although movement data and the discovery of a Malaysia-clade NiV strain in eastern Bangladesh suggest connectivity with bats east of Bangladesh. These data suggest that discrete multiannual local epizootics in bat populations contribute to the sporadic nature of NiV outbreaks in South Asia. At the same time, the broad spatial and temporal extent of NiV transmission, including the recent outbreak in Kerala, India, highlights the continued risk of spillover to humans wherever they may interact with pteropid bats and the importance of limiting opportunities for spillover throughout Pteropus's range.
Fulltext Multiphasic Reaction Modeling for Polypropylene Production in a Pilot-Scale Catalytic Reactor

Jakir Hossain Khan M, Azlan Hussain M, Mujtaba IM

Polymers (Basel), 2016 Jun 14;8(6).
PMID: 30979325 DOI: 10.3390/polym8060220

In this study, a novel multiphasic model for the calculation of the polypropylene production in a complicated hydrodynamic and the physiochemical environments has been formulated, confirmed and validated. This is a first research attempt that describes the development of the dual-phasic phenomena, the impact of the optimal process conditions on the production rate of polypropylene and the fluidized bed dynamic details which could be concurrently obtained after solving the model coupled with the CFD (computational fluid dynamics) model, the basic mathematical model and the moment equations. Furthermore, we have established the quantitative relationship between the operational condition and the dynamic gas⁻solid behavior in actual reaction environments. Our results state that the proposed model could be applied for generalizing the production rate of the polymer from a chemical procedure to pilot-scale chemical reaction engineering. However, it was assumed that the solids present in the bubble phase and the reactant gas present in the emulsion phase improved the multiphasic model, thus taking into account that the polymerization took place mutually in the emulsion besides the bubble phase. It was observed that with respect to the experimental extent of the superficial gas velocity and the Ziegler-Natta feed rate, the ratio of the polymer produced as compared to the overall rate of production was approximately in the range of 9%⁻11%. This is a significant amount and it should not be ignored. We also carried out the simulation studies for comparing the data of the CFD-dependent dual-phasic model, the emulsion phase model, the dynamic bubble model and the experimental results. It was noted that the improved dual-phasic model and the CFD model were able to predict more constricted and safer windows at similar conditions as compared to the experimental results. Our work is unique, as the integrated developed model is able to offer clearer ideas related to the dynamic bed parameters for the separate phases and is also capable of computing the chemical reaction rate for every phase in the reaction. Our improved mutiphasic model revealed similar dynamic behaviour as the conventional model in the initial stages of the polymerization reaction; however, it diverged as time progressed.
Fulltext Multifaceted Pharmacological Potentials of Curcumin, Genistein, and Tanshinone IIA through Proteomic Approaches: An In-Depth Review

Khan FB, Singh P, Jamous YF, Ali SA, Abdullah, Uddin S, et al.

Cancers (Basel), 2022 Dec 30;15(1).
PMID: 36612248 DOI: 10.3390/cancers15010249

Phytochemicals possess various intriguing pharmacological properties against diverse pathological conditions. Extensive studies are on-going to understand the structural/functional properties of phytochemicals as well as the molecular mechanisms of their therapeutic function against various disease conditions. Phytochemicals such as curcumin (Cur), genistein (Gen), and tanshinone-IIA (Tan IIA) have multifaceted therapeutic potentials and various efforts are in progress to understand the molecular dynamics of their function with different tools and technologies. Cur is an active lipophilic polyphenol with pleiotropic function, and it has been shown to possess various intriguing properties including antioxidant, anti-inflammatory, anti-microbial, anticancer, and anti-genotoxic properties besides others beneficial properties. Similarly, Gen (an isoflavone) exhibits a wide range of vital functions including antioxidant, anti-inflammatory, pro-apoptotic, anti-proliferative, anti-angiogenic activities etc. In addition, Tan IIA, a lipophilic compound, possesses antioxidant, anti-angiogenic, anti-inflammatory, anticancer activities, and so on. Over the last few decades, the field of proteomics has garnered great momentum mainly attributed to the recent advancement in mass spectrometry (MS) techniques. It is envisaged that the proteomics technology has considerably contributed to the biomedical research endeavors lately. Interestingly, they have also been explored as a reliable approach to understand the molecular intricacies related to phytochemical-based therapeutic interventions. The present review provides an overview of the proteomics studies performed to unravel the underlying molecular intricacies of various phytochemicals such as Cur, Gen, and Tan IIA. This in-depth study will help the researchers in better understanding of the pharmacological potential of the phytochemicals at the proteomics level. Certainly, this review will be highly instrumental in catalyzing the translational shift from phytochemical-based biomedical research to clinical practice in the near future.
Fulltext Misfolded N-CoR is Linked to the Ectopic Reactivation of CD34/Flt3-Based Stem-Cell Phenotype in Promyelocytic and Monocytic Acute Myeloid Leukemia

Nin DS, Li F, Visvanathan S, Khan M

Front Oncol, 2015;5:210.
PMID: 26500885 DOI: 10.3389/fonc.2015.00210

Nuclear receptor co-repressor (N-CoR) is the key component of generic co-repressor complex essential for the transcriptional control of genes involved in cellular hemostasis. We have recently reported that N-CoR actively represses Flt3, a key factor of hematopoietic stem cells (HSC) self-renewal and growth, and that de-repression of Flt3 by the misfolded N-CoR plays an important role in the pathogenesis of promyelocytic and monocytic acute myeloid leukemia (AML). The leukemic cells derived from the promyelocytic and monocytic AML are distinctly characterized by the ectopic reactivation of stem cell phenotypes in relatively committed myeloid compartment. However, the molecular mechanism underlying this phenomenon is not known. Here, we report that N-CoR function is essential for the commitment of primitive hematopoietic cells to the cells of myeloid lineage and that loss of N-CoR function due to misfolding is linked to the ectopic reactivation of generic stem cell phenotypes in promyelocytic and monocytic AML. Analysis of N-CoR and Flt3 transcripts in mouse hematopoietic cells revealed a positive correlation between N-CoR level and the commitment of myeloid cells and an inverse correlation between N-CoR and Flt3 levels in primitive as well as committed myeloid cells. Enforced N-CoR expression in mouse HSCs inhibited their growth and self-renewal potentials and promoted maturation toward cells of myeloid lineage, suggesting a role of N-CoR in the commitment of cells of myeloid lineage. In contrast to AML cells with natively folded N-CoR, primary and secondary promyelocytic and monocytic AML cells harboring the misfolded N-CoR were highly positive for Flt3 and myeloid antigen-based HSC marker CD34. Genetic and therapeutic restoration of N-CoR conformation significantly down-regulated the CD34 levels in monocytic AML cells, suggesting an important role of N-CoR in the suppression of CD34-based HSC phenotypes. These findings collectively suggest that N-CoR is crucial for the commitment of primitive hematopoietic cells to cells of myeloid lineage and that misfolded N-CoR may contribute to transformation of committed myeloid cells through the ectopic reactivation of Flt3/CD34-based stem cell phenotypes in promyelocytic and monocytic AML. Moreover, these findings provide novel mechanistic insights into the formation of leukemic stem cells in subsets of AML and identify the misfolded N-CoR as a subtype-specific biomarker of AML.
Fulltext Micro computed tomography (Micro-CT) characterization of root and root canal morphology of mandibular first premolars: a systematic review and meta-analysis

Karobari MI, Batul R, Khan M, Patil SR, Basheer SN, Rezallah NNF, et al.

BMC Oral Health, 2024 Jan 02;24(1):1.
PMID: 38167114 DOI: 10.1186/s12903-023-03624-5

INTRODUCTION: Mandibular first premolars are familiar with their varied root canal morphology, causing difficulties and challenges for successful endodontic procedures. This systematic review and meta-analysis aim to study the characterization of root and canal morphology of the first mandibular premolar using micro-computed tomography.
METHODOLOGY: The literature search was conducted using electronic web databases like PubMed, Scopus, ScienceDirect and Cochrane with the chosen MeSH key words and data was retrieved until May 2023. Further to perform the statistical analysis, R v 4.3.1 software with "meta", 'metafor" "metaviz" " ggplot2" package was used, and results were represented by odds ratios (OR) and the percentage of forest plots along a 95 per cent confidence interval (CI).
RESULTS: The total number of studies meeting the inclusion criteria was 13; these studies were conducted on mandibular first premolar using Micro-CT; the total sample size was 1817. To scan the sample, an X-ray micro-focus CT system (Siemens Inveon CT, Erlangen, Germany) was used in four studies and seven different machines were used in the respective studies. Mimics 10.01 software (Materialize, Leuven, Belgium) and NRecon v.1.6.9 software (Bruker, Kontich, Belgium) were commonly operated. The minimum and maximum voxel size ranges between 11.94 and 50 μm. Vertucci's classification was frequently used (9), while one study applied Ahmed et al. and Vertucci's classification.
CONCLUSION: This systematic review provides essential information about the root and canal configurations, radicular grooves, accessory canals, and apical foramina through Micro-CT, aiming to improve the accuracy of endodontic treatment and help practitioners.
Mercury in dental amalgam: Are our health care workers at risk?

Sahani M, Sulaiman NS, Tan BS, Yahya NA, Anual ZF, Mahiyuddin WR, et al.

J Air Waste Manag Assoc, 2016 Nov;66(11):1077-1083.
PMID: 27192328 DOI: 10.1080/10962247.2016.1188866

Dental amalgam in fillings exposes workers to mercury. The exposure to mercury was investigated among 1871 dental health care workers. The aim of the study was to evaluate the risk of mercury exposure among dental compared to nondental health care workers and to determine other risk factors for mercury exposure. Respondents answered questionnaires to obtain demographic, personal, professional, and workplace information and were examined for their own amalgam fillings. Chronic mercury exposure was assessed through urinary mercury levels. In total, 1409 dental and 462 nondental health care workers participated in the study. Median urine mercury levels for dental and nondental health care workers were 2.75 μg/L (interquartile range [IQR] = 3.0175) and 2.66 μg/L (IQR = 3.04) respectively. For mercury exposure, there were no significant risk factor found among the workers involved within the dental care. The Mann-Whitney test showed that urine mercury levels were significantly different between respondents who eat seafood more than 5 times per week compared to those who eat it less frequently or not at all (p = 0.003). The urinary mercury levels indicated significant difference between dental workers in their practice using squeeze cloths (Mann-Whitney test, p = 0.03). Multiple logistic regression showed that only the usage of cosmetic products that might contain mercury was found to be significantly associated with the urinary mercury levels (odds ratio [OR] = 15.237; CI: 3.612-64.276). Therefore, mean urinary mercury levels of health care workers were low. Exposure to dental amalgam is not associated with high mercury exposure. However, usage of cosmetic products containing mercury and high seafood consumption may lead to the increase of exposure to mercury.

IMPLICATIONS: Exposure to the high levels of mercury from dental amalgam can lead to serious health effects among the dental health care workers. Nationwide chronic mercury exposure among dental personnel was assessed through urinary mercury levels. Findings suggest low urinary mercury levels of these health care workers. Exposure to dental amalgam is not associated with high mercury exposure. However, the usage of cosmetic products containing mercury and high seafood consumption may lead to the increase of exposure to mercury.
Management and treatment outcomes of MDR-TB: results from a setting with high rates of drug resistance

Ahmad N, Javaid A, Basit A, Afridi AK, Khan MA, Ahmad I, et al.

Int J Tuberc Lung Dis, 2015 Sep;19(9):1109-14, i-ii.
PMID: 26260834 DOI: 10.5588/ijtld.15.0167

Although Pakistan has a high burden of multidrug-resistant tuberculosis (MDR-TB), little is known about the management and treatment outcomes of MDR-TB patients in Pakistan.
Lignin nanoparticles-reduced graphene oxide based hydrogel: A novel strategy for environmental applications

Sohni S, Hassan T, Khan SB, Akhtar K, Bakhsh EM, Hashim R, et al.

Int J Biol Macromol, 2023 Jan 15;225:1426-1436.
PMID: 36436599 DOI: 10.1016/j.ijbiomac.2022.11.200

In this work, facile fabrication of lignin nanoparticles (LNP)-based three-dimensional reduced graphene oxide hydrogel (rGO@LNP) has been demonstrated as a novel strategy for environmental applications. Herein, LNP were facilely synthesized from walnut shell waste through a direct chemical route. These LNP were incorporated into the continuous porous network of rGO network to fabricate rGO@LNP hydrogel. Characterization studies were carried out using various analytical techniques viz. scanning electron microscopy, Fourier transform IR spectroscopy, X-ray diffraction and thermogravimetric analysis. The efficiency of rGO@LNP hydrogel as adsorptive platform was evaluated by employing methylene blue and Pb2+ as model pollutants, whilst the effect of various experimental parameters was ascertained for optimal performance. Furthermore, Agar well diffusion method was used to check the antibacterial activities of the hydrogel using two bacterial pathogenic strains, i.e. Klebsiella pneumoniae (gram negative) and Enterococcus faecalis (gram positive). Results showed that after the inclusion of LNP into rGO hydrogel, there was a marked improvement in pollutant's uptake ability and compared to bare LNP and rGO, the composite hydrogel showed enhanced bactericidal effect. Overall, this approach is outstanding because of the synergy of functional properties of nano-lignin and rGO due to multi-interaction sites in the resulting hydrogel. The results presented herein support the application of rGO@LNP as innovative water filter material for scavenging broad spectrum pollutants and bactericidal properties.
Kinetics and mechanism of the cleavage of phthalic anhydride in glacial acetic acid solvent containing aniline

Damit EF, Ariffin A, Khan MN

J Org Chem, 2008 Dec 5;73(23):9303-13.
PMID: 18954113 DOI: 10.1021/jo8011072

Apparent second-order rate constants (k(n)(app)) for the nucleophilic reaction of aniline (Ani) with phthalic anhydride (PAn) vary from 6.30 to 7.56 M(-1) s(-1) with the increase of temperature from 30 to 50 degrees C in pure glacial acetic acid (AcOH). However, the values of pseudo-first-order rate constants (k(s)) for the acetolysis of PAn in pure AcOH increase from 16.5 x 10(-4) to 10.7 x 10(-3) s(-1) with the increase of temperature from 30 to 50 degrees C. The values of k(n)(app) and k(s) vary from 5.84 to 7.56 M(-1) s(-1) and from 35.1 x 10(-4) to 12.4 x 10(-4) s(-1), respectively, with the increase of CH(3)CN content from 1% to 80% v/v in mixed AcOH solvents at 35 degrees C. The plot of k(s) versus CH(3)CN content shows a minimum (with 10(4) k(s) = 4.40 s(-1)) at 50% v/v CH(3)CN. Similarly, the variations of k(n)(app) and k(s) with the increasing content of tetrahydrofuran (THF) in mixed AcOH solvent reveal respective a maximum (with k(n)(app) = 17.5-15.6 M(-1) s(-1)) at 40-60% v/v THF and a minimum (with k(s) = approximately 0-1.2 x 10(-4) s (-1)) at 60-70% v/v THF. The respective values of DeltaH* and DeltaS* are 15.3 +/- 1.2 kcal mol(-1) and -20.1 +/- 3.8 cal K(-1) mol(-1) for k(s) and 1.1 +/- 0.5 kcal mol(-1) and -51.2 +/- 1.7 cal K(-1) mol(-1) for k(n)(app), while the values of k(n) (= k(n)(app)/f(b) with f(b) representing the fraction of free aniline base) are almost independent of temperature within the range 30-50 degrees C. A spectrophotometric approach has been described to determine f(b) in AcOH as well as mixed AcOH-CH(3)CN and AcOH-THF solvents. Thus, the observed data, obtained under different reaction conditions, have been explained quantitatively. An optimum reaction condition, within the domain of present reaction conditions, has been suggested for the maximum yield of the desired product, N-phenylphthalamic acid.
Kinetics and mechanism of the alkaline hydrolysis of securinine

Lajis NH, Noor HM, Khan MN

J Pharm Sci, 1995 Jan;84(1):126-30.
PMID: 7714735

The hydroxide ion-catalyzed hydrolysis of securinine involves the ring opening of the lactone moiety. The rate of hydrolysis is insensitive to the ionic strength. The observed pseudo-first-order rate constants reveal a decrease of approximately 4-fold due to the increase in the MeCN content from 4 to 50% (v/v) in mixed aqueous solvent. The temperature dependence of the rate of hydrolysis follows the Eyring equation, which yields delta H* and delta S* as 11.0 kcal mol-1 and -34.5 cal deg-1 mol-1, respectively. The hydroxyl carboxylate product of the alkaline hydrolysis of securinine is shown to undergo cyclization in acidic medium to yield securinine. The observed pseudo-first-order rate constants for cyclization increase linearly with an increase in [H+]. The change in the content of MeCN from 3.8 to 47.2% (v/v) in mixed aqueous solvents does not show an effect on the rate of the cyclization reaction. The most plausible mechanisms for alkaline hydrolysis and acid cyclization reactions are also discussed.
Fulltext Kinetics and mechanism of nanoparticles-catalyzed piperidinolysis of anionic phenyl salicylate

Razak NA, Khan MN

ScientificWorldJournal, 2014;2014:604139.
PMID: 25478597 DOI: 10.1155/2014/604139

The values of the relative counterion (X) binding constant R(X)(Br) (=K(X)/K(Br), where K(X) and K(Br) represent cetyltrimethylammonium bromide, CTABr, micellar binding constants of X(v-) (in non-spherical micelles), v = 1,2, and Br(-) (in spherical micelles)) are 58, 68, 127, and 125 for X(v-) = 1(-), 1(2-), 2(-), and 2(2-), respectively. The values of 15 mM CTABr/[Na(v)X] nanoparticles-catalyzed apparent second-order rate constants for piperidinolysis of ionized phenyl salicylate at 35 °C are 0.417, 0.488, 0.926, and 0.891 M(-1) s(-1) for Na(v)X = Na1, Na2 1, Na2, and Na2 2, respectively. Almost entire catalytic effect of nanoparticles catalyst is due to the ability of nonreactive counterions, X(v-), to expel reactive counterions, 3(-), from nanoparticles to the bulk water phase.

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