MyMedR

Displaying all 7 publications

Abstract:

Sort:

Fulltext Effects of Modified Metakaolin Using Nano-Silica on the Mechanical Properties and Durability of Concrete

Shafiq N, Kumar R, Zahid M, Tufail RF

Materials (Basel), 2019 Jul 17;12(14).
PMID: 31319615 DOI: 10.3390/ma12142291

This paper discussed the effects of modified metakaolin (MK) with nano-silica (NS) on the mechanical properties and durability of concrete. In the first phase, trial mixes of concrete were prepared for achieving the desired value of the 28 days compressive strength, and the charge passed in rapid chloride permeability test (RCPT). In the second phase, statistical analysis was performed on the experimental results using the response surface method (RSM). The RSM was applied for optimizing the mix proportions for the required performance by exploiting the relationship between the mix characteristics and the corresponding test results. A blend of 10% MK + 1% NS as part of cement replacement exhibited the highest mechanical properties and durability characteristics of concrete; concrete mix showed that the 28-days compressive strength (CS) was 103 MPa, which was 15% greater than the CS of the control mix without MK or NS. The same mix showed more than 40% higher flexural and split-tensile strength than the control mix; also it resulted in a reduction of 73% in the rapid chloride permeability value. ANOVA technique was used for optimizing the nano-silica and metakaolin content for achieving maximum compressive strength and minimum RCPT value. Statistical analysis using ANOVA technique showed that the maximum compressive strength and lowest RCPT value could be achieved with a blend of 10% MK and 1.55% NS.
Isolation and characterization of arsenic resistant bacteria from wastewater

Abbas SZ, Riaz M, Ramzan N, Zahid MT, Shakoori FR, Rafatullah M

Braz J Microbiol, 2014;45(4):1309-15.
PMID: 25763035

The present study proposed the isolation of arsenic resistant bacteria from wastewater. Only three bacterial isolates (MNZ1, MNZ4 and MNZ6) were able to grow in high concentrations of arsenic. The minimum inhibitory concentrations of arsenic against MNZ1, MNZ4 and MNZ6 were 300 mg/L, 300 mg/L and 370 mg/L respectively. The isolated strains showed maximum growth at 37 °C and at 7.0 pH in control but in arsenite stress Luria Bertani broth the bacterial growth is lower than control. All strains were arsenite oxidizing. All strains were biochemically characterized and ribotyping (16S rRNA) was done for the purpose of identification which confirmed that MNZ1 was homologous to Enterobacter sp. while MNZ4 and MNZ6 showed their maximum homology with Klebsiella pneumoniae. The protein profiling of these strains showed in arsenic stressed and non stressed conditions, so no bands of induced proteins appeared in stressed conditions. The bacterial isolates can be exploited for bioremediation of arsenic containing wastes, since they seem to have the potential to oxidize the arsenite (more toxic) into arsenate (less toxic) form.
Incidence and management of cleft lip and palate in Pakistan

Sharif F, Mahmood F, Azhar MJ, Asif A, Zahid M, Muhammad N, et al.

J Pak Med Assoc, 2019 May;69(5):632-639.
PMID: 31105281

OBJECTIVE: To compare the occurrence, distribution and management of clefts of lip and palate in local patients with the available data from India and China.
METHODS: The retrospective study was conducted at the Interdisciplinary Research Centre in Biomedical Materials, COMSATS University Islamabad, Lahore Campus, Lahore, Pakistan, and comprised data related to a three-month period from January to March 2015 at two medical centres in Lahore. Data from Pakistani centres was analysed based on province, gender, age and clefts of lip and palate conditions and Spearman's correlation matrix.
RESULTS: Of the 1574 cases, 1061(67.4%) were from Punjab, 361(23%) Khyber Pakhtunkhwa, 85(5%) Sindh and 67(4.2%) were from Azad Jammu and Kashmir. The incidence of clefts of lip and palate was higher in males than females. There was higher awareness of the need for timely management in new borns with clefts of lip and palate. Some patients seeking secondary treatment were also being surgically corrected. There is no national registry of children born with cleft defect, making it difficult to assess the full scale of the problem..
CONCLUSIONS: Based on available data, it is likely that there are many adults who have not been treated when younger..
Inherited metabolic disorders presenting as hypoxic ischaemic encephalopathy: A case series of patients presenting at a tertiary care hospital in Pakistan

Zahid M, Khan AH, Yunus ZM, Chen BC, Steinmann B, Johannes H, et al.

J Pak Med Assoc, 2019 Mar;69(3):432-436.
PMID: 30890842

In spite of the efforts and interventions by the Government of Pakistan and The World Health Organization, the neonatal mortality in Pakistan has declined by only 0.9% as compared to the global average decline of 2.1% between 2000 and 2010. This has resulted in failure to achieve the global Millennium Development Goal 4. Hypoxic-ischaemic encephalopathy, still birth, sepsis, pneumonia, diarrhoea and birth defects are commonly attributed as leading causes of neonatal mortality in Pakistan. Inherited metabolic disorders often present at the time of birth or the first few days of life. The clinical presentation of the inherited metabolic disorders including hypotonia, seizure and lactic acidosis overlap with clinical features of hypoxic-ischaemic encephalopathy and sepsis. Thus, these disorders are often either missed or wrongly diagnosed as hypoxicischaemic encephalopathy or sepsis unless the physicians actively investigate for the underlying inherited metabolic disorders. We present 4 neonates who had received the diagnosis of hypoxic-ischaemic encephalopathy and eventually were diagnosed to have various inherited metabolic disorders. Neonates with sepsis and hypoxic-ischaemic encephalopathy-like clinical presentation should be evaluated for inherited metabolic disorders.
A walk of corporate sustainability towards sustainable development: a bibliometric analysis of literature from 2005 to 2021

Jan AA, Lai FW, Siddique J, Zahid M, Ali SEA

Environ Sci Pollut Res Int, 2023 Mar;30(13):36521-36532.
PMID: 36547839 DOI: 10.1007/s11356-022-24842-4

Recent years have seen a burgeoning interest in the involvement of corporate sustainability (CS) in sustainable development (SD), yet both concepts are fewer and newer in the academic field. This study aims to present a thorough bibliometric analysis that provides fresh new insights on the subject. Using VOSviewer software, this study analyzed and visualized 1214 documents for the period 2005-2021 in the Web of Science (WoS) database. The findings of the study indicate that the co-theme CS and SD are lasting but thriving research subjects. The findings also revealed that authors from the USA published the highest number of articles followed by the UK, Spain, Italy, and Germany. The co-authorship network showed strong links between these countries. Three main clusters are identified based on research titles frequently co-cited and have significant co-citation connections. In general, this study provides valuable insight into the current status and future trends for research on SDGs. The outcome of the study could be useful to policymakers, regulators, sustainability practitioners, and researchers in understanding the key research areas, influential authors, institutions, and countries actively involved in the field. Considering the involvement of corporate sustainability in sustainable development is a useful and informative endeavor for all community actors. To the best of the authors' knowledge, this is the first comprehensive study that presents the holistic picture of CS and SD-related research to identify the knowledge map between the two subjects.
Microwave assisted synthesis and characterization of magnesium substituted calcium phosphate bioceramics

Khan NI, Ijaz K, Zahid M, Khan AS, Abdul Kadir MR, Hussain R, et al.

Mater Sci Eng C Mater Biol Appl, 2015 Nov 1;56:286-93.
PMID: 26249592 DOI: 10.1016/j.msec.2015.05.025

Hydroxyapatite is used extensively in hard tissue repair due to its biocompatibility and similarity to biological apatite, the mineral component of bone. It differs subtly in composition from biological apatite which contains other ions such as magnesium, zinc, carbonate and silicon (believed to play biological roles). Traditional methods of hydroxyapatite synthesis are time consuming and require strict reaction parameter control. This paper outlines synthesis of magnesium substituted hydroxyapatite using simple microwave irradiation of precipitated suspensions. Microwave irradiation resulted in a drastic decrease in ageing times of amorphous apatitic phases. Time taken to synthesize hydroxyapatite (which remained stable upon heat treatment at 900°C for 1h) reduced twelve folds (to 2h) as compared to traditionally required times. The effects of increasing magnesium concentration in the precursors on particle size, surface area, phase-purity, agglomeration and thermal stability, were observed using scanning electron microscopy, BET surface area analysis, X-ray diffraction and photo acoustic Fourier transform infra-red spectroscopy. Porous agglomerates were obtained after a brief heat-treatment (1h) at 900°C.
Fulltext Malay Validation of Copenhagen Psychosocial Work Environment Questionnaire in Context of Second Generation Statistical Techniques

Isha ASN, Javaid MU, Zaib Abbasi A, Bano S, Zahid M, Memon MA, et al.

Biomed Res Int, 2020;2020:7680960.
PMID: 32090111 DOI: 10.1155/2020/7680960

Psychosocial hazards present in workplaces are being actively investigated by researchers from multiple domains. More research and resources are required to investigate the debilitating consequences of these hazards in the developing and underdeveloped countries where this issue remains one of grave concern. This study aims at investigating the psychometric properties of Malaysian version of Copenhagen Psychosocial Questionnaire for reliability and validity purpose. The Malaysian version of COPSOQ is a multidimensional questionnaire; it comprises of 7 major formative constructs and 28 variables with an additional inclusion of two variables which are organizational loyalty and physiological health biomarkers (blood pressure and body mass index) that explicate a reflective construct which has 93 items all catering to assess psychosocial determinants present in workplace environments. Each formative second-order construct is further categorized into different reflective first-order constructs. The focus of this study was only on first-order reflective constructs. Probability sampling was used for data collection from 300 respondents working in industries with a response rate of 100%; structural equation modeling technique was applied for data analysis. All psychometric analysis performed on reflective constructs gave reliable results which demonstrate the validity of Bahasa Melayu (BM-COPSOQ) and its comprehensiveness of including relevant dimensions particularly in context to Asian region. The BM-COPSOQ will fill up the knowledge gap and provide a bridge between researchers, work professionals and practitioners, and many other workplaces for the best understanding of psychosocial work environment.