Muhammad Rafiq

Influence of plasma-activated compounds on melanogenesis and tyrosinase activity

Many organic chemists around the world synthesize medicinal compounds or extract multiple compounds from plants in order to increase the activity and quality of medicines. In this work, we synthesized new eugenol derivatives (ED) and then treated them with an N2 feeding gas atmospheric pressure plasma jet (APPJ) to increase their utility. We studied the tyrosinase-inhibition activity (activity test) and structural changes (circular dichroism) of tyrosinase with ED and plasma activated eugenol derivatives (PAED) in a cell-free environment. Later, we used docking studies to determine the possible interaction sites of ED and PAED compounds with tyrosinase enzyme. Moreover, we studied the possible effect of ED and PAED on melanin synthesis and its mechanism in melanoma (B16F10) cells. Additionally, we investigated the structural changes that occurred in activated ED after plasma treatment using nuclear magnetic resonance (NMR). Hence, this study provides a new perspective on PAED for the field of plasma medicine.

Anti-microbial efficacy and biochemical analysis from different parts of Acacia nilotica L. and Ricinus communis L. extracts

The present study was under taken to explore the potential of Acacia nilotica L and Ricinus communis L as antimicrobial agents in relation with various important bio-molecules and to check their correlation as antimicrobial agent. In present study water and methanol extract (20%) of different parts of A. nilotica and R. communis showed good inhibition against Gram positive ( Staphylococcus aureus and Streptococcus pneumoniae ), and Gram negative bacteria ( Pseudomonas aeruginosa , Escherichia coli, Klebsiella pneumoniae) and some fungi (Aspergillus niger , Penicillium expansum and Aspergillus fumigatus ). The presence of significant concentration of total protein, total sugar, reducing sugar, some identified free amino acids and sugars provided good correlation among antimicrobial compounds which are present in both plants extracts and have capability to kill the pathogens or inhibit the growth of microbes. Key words:

Identification of a homozygous missense mutation in LRP2 and a hemizygous missense mutation in TSPYL2 in a family with mild intellectual disability.

Non-syndromic autosomal recessive intellectual disability (ID) is a genetically heterogeneous disorder with more than 50 mutated genes to date. ID is characterized by deficits in memory skills and language development with difficulty in learning, problem solving, and adaptive behaviors, and affects ∼1% of the population. For detection of disease-causing mutations in such a heterogeneous disorder, homozygosity mapping together with exome sequencing is a powerful approach, as almost all known genes can be assessed simultaneously in a high-throughput manner. In this study, a hemizygous c.786C>G:p.Ile262Met in the testis specific protein Y-encoded-like 2 (TSPYL2) gene and a homozygous c.11335G>A:p.Asp3779Asn in the low-density lipoprotein receptor-related protein 2 (LRP2) gene were detected after genome-wide genotyping and exome sequencing in a consanguineous Pakistani family with two boys with mild ID. Mutations in the LRP2 gene have previously been reported in patients with Donnai–Barrow and Stickler syndromes. LRP2 has also been associated with a 2q locus for autism (AUTS5). The TSPYL2 variant is not listed in any single-nucleotide polymorphism databases, and the LRP2 variant was absent in 400 ethnically matched healthy control chromosomes, and is not listed in single-nucleotide polymorphism databases as a common polymorphism. The LRP2 mutation identified here is located in one of the low-density lipoprotein-receptor class A domains, which is a cysteine-rich repeat that plays a central role in mammalian cholesterol metabolism, suggesting that alteration of cholesterol processing pathway can contribute to ID.

Mutations in the genes for thyroglobulin and thyroid peroxidase cause thyroid dyshormonogenesis and autosomal-recessive intellectual disability

We have used single-nucleotide polymorphism microarray genotyping and homozygosity-by-descent (HBD) mapping followed by Sanger sequencing or whole-exome sequencing (WES) to identify causative mutations in three consanguineous families with intellectual disability (ID) related to thyroid dyshormonogenesis (TDH). One family was found to have a shared HBD region of 12.1 Mb on 8q24.21-q24.23 containing 36 coding genes, including the thyroglobulin gene, TG. Sanger sequencing of TG identified a homozygous nonsense mutation Arg2336*, which segregated with the phenotype in the family. A second family showed several HBD regions, including 6.0 Mb on 2p25.3-p25.2. WES identified a homozygous nonsense mutation, Glu596*, in the thyroid peroxidase gene, TPO. WES of a mother/father/proband trio from a third family revealed a homozygous missense mutation, Arg412His, in TPO. Mutations in TG and TPO are very rarely associated with ID, mainly because TDH is generally detectable and treatable. However, in populations where resources for screening and detection are limited, and especially where consanguineous marriages are common, mutations in genes involved in thyroid function may also be causes of ID, and as TPO and TG mutations are the most common genetic causes of TDH, these are also likely to be relatively common causes of ID.

Synthesis, Crystallization Behavior and Surface Modification of Ni-Cr-Si-Fe Amorphous Alloy

A quaternary Ni86Cr7Si4Fe3 amorphous alloy was synthesized by melt spinning technique. Surface modification was done by electron beam melting (EBM), neutron irradiation and γ-rays. Microstructure of as cast, annealed and modified samples was examined by scanning electron microscope. Crystallization behavior was studied by annealing the samples in vacuum at different temperatures in the range 773-1073 K. Techniques of X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used for characterization. Differential scanning calorimetry (DSC) was conducted at various heating rates in the range 10-40 K/min. Thermal parameters like glass transition temperature Tg, crystallization temperature Tx, supercooled liquid region ΔTx and reduced glass transition temperature Trg were measured. The Ni86Cr7Si4Fe3 alloy exhibits wide supercooled liquid region of 60 K indicating good thermal stability. The activation energy was calculated to be 160±4 kJ/mol using Kissinger and Ozawa equations respectively which indicates high resistance against crystallization. The XRD results of the samples annealed at 773 K, 923 K, 973 K and 1073 K/20 min show nucleation of Ni2Cr3 and NiCrFe crystalline phases. Vickers microhardness of the as cast ribbon was measured to be 680.. About 30-50 % increase in hardness was achieved by applying EBM technique.

Production and characterization of extracellular lipase secreted by Mucor geophillus

Nowadays, the growing interest in microbial lipase production by using the cheapest sources of carbon source, and its potential applications in biotechnological field has shown a remarkable place of prominence among the enzymes, owing to their significant ability to catalyze a wide variety of reactions in aqueous and non aqueous media. The purpose of this study was to enhance the production of lipase by Mucor geophillus in submerged culture condition, using molasses mineral medium as a low cost substrate and to increase the economical feasibility attractiveness. M. geophillus lipase was also assessed and characterized on the basis of some kinetic parameters. M. geophillus secreted higher yield of lipase at approximately 44.56 U.ml -1 at 72 h cultivation time. The optimal assay conditions were found at 60 min incubation of 2.0 and 8% enzyme and substrate concentration, respectively. However, lipase was active at 35°C and pH 6.5, but enzyme was found to be stable at about 70°C. From the range of pH 4.0 to 8.0, KCl enhanced the lipase activity, and had higher specific lipase activity towards the olive oil than other substrates. Key words : Lipase, Mucor geophillus , submerged fermentation, characterization.

Surface Modification and Characterization of Bulk Amorphous Materials

Bulk metallic glasses (BMGs) are well known for their promising properties. Surface properties can be further improved by using certain techniques such as electron beam melting (EBM), laser beam melting (LBM), ion irradiation, ion implantation and neutron irradiation. BMGs especially Zr-based BMGs have numerous applications as structural materials. In this manuscript, the results are presented on microstructural investigations and phase formations in Zr-based BMGs modified by using above mentioned techniques. Microstructure was studied by scanning electron microscopy (SEM). Phase analysis was done by X-ray diffraction (XRD) and confirmed by energy dispersive spectroscopy (EDS). Vickers hardness was measured and correlated with the microstructure. The phases identified in Zr-Cu-Al-Ni alloy samples modified by EBM, LBM and ion irradiation are Ni-Zr, NiZr2, CuZr2, Cu10Zr7 and Al2NiZr6. ZrSi2 phase was detected in Zr55Cu30Al10Ni5 and Zr65Cu17Ni10Al8 BMGs irradiated with Si+ (ions). About 20-35 % increase in hardness and elastic moduli was achieved by surface modification. Modifications of BMGs by electron and laser beams melted the materials surfaces while ion irradiation improved the mechanical properties of localized zones without melting.

Shocks in Macroeconomic Variables and Stock Market Stability: Case Study of KSE-100 Index

This study was conducted to quantify the stability impacts of shocks in leading macroeconomic variables on Karachi Stock Exchange (KSE)-100 index using annual data from 2000-2010. Four macroeconomic variables, Average annual exchange rate (EXR), inflation rate CPI based (INFR), real GDP growth rate (RGDP) and unemployment rate (UEMR), have been used. Dynamic Distributed lag (DDL) model was selected after experimenting on different forms and specifications. Selections were based on recent advance measure of co-integration i.e. “Bonds Testing” proposed by (Pesaran, Shin, & Smith, 2001) which can be applied even on small number of observations. Based on empirical analysis, inflation rate (CPI based) and unemployment rate (UMER) were dropped due to its insignificance in the present context. Major findings of this study includes that shocks in current index of Karachi stock exchange are due to, other factors constant, one period lag shocks in its own index, real GDP and average annual exchange rate. Whereas current GDP growth has strong significant impact compared to one period lag GDP. So our main conclusion is that, shocks in KSE-index to some extent can be controlled by stabilizing main macroeconomic variables such as Real growth rate of GDP, exchange rate even its own stability (i.e. stability of KSE-100 index) have also significant lesson for its future stability

Facile synthesis, crystal structure, DFT calculation and biological activities of 4-(2-fluorophenyl)-3-(3-methoxybenzyl)-1H-1,2,4-triazol-5(4H)-one (5)

BACKGROUND In the past few decades, design, synthesis, and characterization of novel heterocyclic compounds with auspicious biological profile received the considerable attention of the scientific community. Among them, the small and simple organic molecular backbone like triazole moiety have a broad spectrum of applications in the medicinal as well as diagnostic areas. OBJECTIVE The objective of present study was synthesis, characterization, and exploration of biological profile of 4-(2-fluorophenyl)-3-(3-methoxybenzyl)-1H-1,2,4-triazole-5(4H)-one (5). The tautomeric interconversion of the molecule was observed by the single crystal XRD and DFT analysis. METHODS N-(2-fluorophenyl)-2-[2-(3-methoxyphenyl)acetyl]hydrazine carboxamide (4) was synthesized by the condensation of 2-(3-methoxyphenyl)acetohydrazide (3) with 1-fluoro-2- isocyanatobenzene. The dehydrocyclization of compound (4) yielded target compound (5) by refluxing in 2 N aqueous sodium hydroxide solutions. The target molecule was characterized by FTIR, 1H NMR, 13C NMR, single crystal X-ray diffraction analysis and DFT calculation. The enzymatic assay measurements were carried out by using a microplate reader (OPTI Max, Tunable Microplate Reader; Wavelength range: 340-850 nm; for 96-well plates) while DFT calculation was performed by Gaussian 09 package. RESULTS The XRD result and DFT calculations showed that molecule 5 predominantly exists in thione conformation and crystallized in the triclinic system of P-1 space group. Furthermore, for the practical applicability of synthesized compound 5, the in vitro acetylcholinesterase as well as α-glucosidase inhibition activities were performed and found moderate enzyme inhibition potential comparable with that of reference inhibitors. CONCLUSION This study might be helpful for future design and development of potent enzyme inhibitor to control Alzheimers as well as diabetic disease. The DFT and single crystal XRD analysis data might be helpful for understanding the mechanism of drug binding and its mode of action.

Compositional Changes in Public Expenditure and Economic Growth: Time Series Evidence from Pakistan

The role of government in achieving economic growth through its fiscal policy, particularly spending policy cannot be overlooked. Investigation of public spending policy and its transmission mechanism to sustainable growth is imperative to the ultimate objective of welfare maximization. This study aims to identify the growth-oriented components of public expenditure as it seems useful to know the contribution of each component of spending towards the objective of economic growth. The study adopts the Kocherlakota and Yi’s (1997) model as modified by Colombier (2008) to carry out the empirical analysis. To this end, ARDL is employed on annual data that ranges from 1973 to 2014 to estimate both the long-run and short-run dynamics between public expenditure composition and economic growth in Pakistan. The results indicate that public development expenditures are growth-oriented, while current expenditures reduce economic growth. Thus sustainable economic growth and sustainable development can only be materialized by changing the composition of public spending in favor of development expenditure. Since Pakistan is in the dire need of infrastructure and energy, therefore, allocation of more funds to Public Sector Development Programs (PSDP) are expected to add directly to growth on one hand and set a crowding-in effect for private investments—thereby enhancing growth indirectly—on the other hand