Ranjha N.M.,Bz University |
Qureshi U.F.,Bz University
International Journal of Pharmacy and Pharmaceutical Sciences | Year: 2014
Objective: Hydrogels are high-water content materials prepared from cross-linked polymers that are able to provide sustained, local delivery of a variety of therapeutic agents. Use of the natural polymer, such as HPMC, in hydrogels has been highly pursued thanks to the polymer's hydrophilicity, low toxicity, and biodegradability. The advanced development of these hydrogels has led to new drug delivery systems that release their payloads under varying environmental stimuli. Method: In the present work, series of pH sensitive acrylic acid/hydroxypropyl methylcellulose (AA/HPMC) hydrogels have been prepared by free radical polymerization in the presence of ethylene glycol dimethacrylate (EGDMA) as a crosslinking agent and benzyl peroxide as initiator. Dynamic and equilibrium swelling studies of prepared hydrogels were investigated in USP phosphate buffer solutions of pH 1.2, 5.5, 6.5 and 7.5 with constant ionic strength. Results: Swelling coefficient was significantly higher at higher pH as compared to low pH. Increased in swelling of hydrogel was observed due to increase in concentration of AA and HPMC. On the other hand, swelling of hydrogel was decreased by increasing the concentration of EGDMA due to presence of more physical entanglements between hydrogels. Swelling and structural parameters of AA/HPMC hydrogel were investigated by measuring diffusion coefficient, volume fraction of polymer, solvent interaction parameters, molecular weight between crosslinks and crosslinked density. Sol-gel analysis was investigated to calculate the sol fraction and gel fraction of hydrogel. Gel fraction was increased by increasing the concentration of AA and EGDMA and decreased by increasing the concentration of HPMC. Porosity of hydrogels was also calculated. Increased in porosity was observed by increasing the concentration of AA and HPMC due to formation of concentrated solution that prevents the bubble from escaping. Decreased in porosity was observed with increase of crosslinking agent due to physical entanglements between AA/HPMC hydrogels. Isosorbide mononitrate was loaded as model drug and release study was carried out in USP phosphate buffer solutions of pH 1.2, 6.5 and 7.5. The drug release data was fitted into various kinetic models i.e. zero order, first order, Higuchi and Peppas model. Results showed that increased drug release at higher pH and was strongly influenced by swelling behavior of hydrogels. The structure of AA/HPMC hydrogel was characterized by fourier transform infrared spectroscopy (FTIR). Conclusion: The result confirms that AA/HPMC hydrogels can be effectively used in pH sensitive controlled released vehicle for drug delivery due to rate controlling and swellability nature of hydrophilic HPMC.
Ahmad I.,Bz University |
Davies H.A.,University of Sheffield |
Kanwal M.,Bz University
Journal of Magnetism and Magnetic Materials | Year: 2012
The base alloys of nominal composition (Nd 0.75Pr 0.25) yFe balanceB x (y=10-9.2 and x=6-19.2) were chosen to study the influence of RE/B ratio, smaller than stochiometric composition on magnetic properties of over quenched and annealed ribbons. From X-ray diffraction analysis of these ribbons, the α-Fe and Fe 3B phases were observed along with (Nd,Pr) 2Fe 14B major phase. The average grain size was calculated using these patterns as: 35 nm for α-Fe, 45 nm for (Nd,Pr) 2Fe 14B and 22 nm for Fe 3B particles. TEM analysis also supported the nano distribution of the above phases. These X-ray graphs support the idea of exchange coupling between hard and soft phases responsible for the observed magnetic properties. In these ribbons the saturation magnetization J s and remnant magnetization J r increases from 1.19 T to 1.66 T and from 0.65 T to 0.91 T, respectively as RE/B ratio increases. The increase in J s and J r may be attributed to the presence of exchange coupling between these phases. The corresponding coercivity jH c decreases from 673.33 to 271.33 k Am -1. The maximum energy product (BH) max initially increases from 72.42 kJ m -3to 109.85 kJ m -3 up to RE/B≈1 and then decreases to 58.5 kJ m -3, depending on the shape of second quadrant B-H loop. The coercivity mechanism observed from initial hysteresis curve was considered to be nucleation of domain wall. © 2012 Elsevier B.V. All rights reserved.
Ranjha N.M.,Bz University |
Ayub G.,Drug Testing Laboratory |
Naseem S.,University of Punjab |
Ansari M.T.,Bz University
Journal of Materials Science: Materials in Medicine | Year: 2010
In the present work crosslinked hydrogels based on chitosan (CS) and acrylic acid (AA) were prepared by free radical polymerization with various feed compositions using N,N methylenebisacrylamide (MBA) as crosslinking agent. Benzoyl peroxide was used as catalyst. Fourier transform infrared spectra (FTIR) confirmed the formation of the crosslinked hydrogels. This hydrogel is formed due to electrostatic interaction between cationic groups in CS and anionic groups in AA. Prepared hydrogels were used for dynamic and equilibrium swelling studies. For swelling behavior, effect of pH, polymeric and monomeric compositions and degree of crosslinking were investigated. Swelling studies were performed in USP phosphate buffer solutions of varying pH 1.2, 5.5, 6.5 and 7.5. Results showed that swelling increased by increasing AA contents in structure of hydrogels in solutions of higher pH values. This is due to the presence of more carboxylic groups available for ionization. On the other hand by increasing the chitosan content swelling increased in a solution of acidic pH, but this swelling was not significant and it is due to ionization of amine groups present in the structure of hydrogel. Swelling decreased with increase in crosslinking ratio owing to tighter hydrogel structure. Porosity and sol-gel fraction were also measured. With increase in CS and AA contents porosity and gel fraction increased, whereas by increasing MBA content porosity decreased and gel fraction increased. Furthermore, diffusion coefficient (D) and the network parameters i.e., the average molecular weight between crosslinks (M c), polymer volume fraction in swollen state (V2s), number of repeating units between crosslinks (Mr) and crosslinking density (q) were calculated using Flory-Rehner theory. Selected samples were loaded with a model drug verapamil. Release of verapamil depends on the ratios of CS/AA, degree of crosslinking and pH of the medium. The release mechanisms were studied by fitting experimental data to model equations and calculating the corresponding parameters. The result showed that the kinetics of drug release from the hydrogels in both pH 1.2 and 7.5 buffer solutions was mainly non-Fickian diffusion. © 2010 Springer Science+Business Media, LLC.
Ahmad M.,The University of Lahore |
Wahid A.,BZ University |
Sheikh S.A.,Fatima Jinnah Women University |
Butt Z.A.,The University of Lahore |
Tariq M.,The University of Lahore
Pakistan Journal of Botany | Year: 2011
The effects of hexavalent chromium (Cr) were studied in rice plants by applying its different concentrations ranging from 50-500 mg/kg of soil. Cr significantly altered growth of rice plants and reduced dry weights of shoot (7-58%) and roots (7-73%) in different treatments. Cr impact was remarkably high on photosynthetic rate (21-62%), transpiration rate (5-59%), and stomatal conductance (21-66%). Chlorophyll a and b and carotenoid contents were also reduced in Cr-treatment plants by 17-47%, 12-43%, 31-50%, respectively. Highly pronounced reductions were recorded in nitrogen (23-82%), phosphorous (4-37%), and potassium (6-42%) content of treated plant leaves. Cr accumulation was extremely higher in shoots (3575-19150%), roots (1023-5869%), and seeds (21-249%) of treated plants compared with control. Present investigation has reported injurious effects of Cr6+ on different aspect of rice plants. Cr accumulation in threshold amounts in plant parts and seeds is a matter of serious concern to human health as it causes cardiovascular diseases, kidney failure and cancer.
Shakoor A.,Bz University |
Rizvi T.Z.,Quaid-i-Azam University |
Nawaz A.,Quaid-i-Azam University
Journal of Materials Science: Materials in Electronics | Year: 2011
A series of polyaniline/montmorillonite clay (PANI-MMT) nanocomposites were synthesised by in situ polymerisation of aniline in acidic medium in the presence of varying amounts (from 1 to 30 wt%) of MMT and a substoichiometric amount of ammonium persulfate (APS). For a preferred molar ratio of monomer to oxidant of 2:1, the aniline was polymerised and largely incorporated into the MMT. The PANI-MMT nanocomposites were characterised and compared by wide-angle powder X-ray diffraction and UV-Vis spectroscopy. Raman spectroscopy was used to investigate the interaction between clay layers and the intercalated polymer chains. Room temperature AC conductivity was measured in the frequency range 30 Hz to 1 MHz. Pure PANI and all the composites exhibited a low frequency region of frequency independent AC conductivity followed by a high frequency dispersive region where the AC conductivity obeyed a fractional power law of frequency dependence. The fractional exponent n for all the nanocomposites is significantly high as compared to that of pure PANI; n = 0.9 for all the composites whereas for pure PANI n = 0.2. In pristine PANI the onset of the dispersive region ω c is at a much higher frequency (at 300 kHz) as compared to the nanocomposites in which ω c is about 10 kHz. © 2010 Springer Science+Business Media, LLC.
Abrar M.,BZ University |
Gui X.,Massey University
Proceedings of 2016 SAI Computing Conference, SAI 2016 | Year: 2016
In this paper, we consider a cellular network with overlay device-to-device (D2D) communication where same radio resources are available for conventional cellular users and D2D users. The optimization objective is to maximize the sum-rate of the system while maintaining proportional fairness among both cellular and D2D users. Minimum Rate Proportional Fairness (MRPF) algorithm is investigated and performance is compared with fixed allocation algorithm. The simulation results show the effectiveness of the proposed algorithm. © 2016 IEEE.
Ahmad S.S.,Fatima Jinnah Women University |
Abdul W.,BZ University |
Khalid F.A.,Government College University at Faisalabad
Pakistan Journal of Botany | Year: 2010
A survey of motorway (M-2) roadside vegetation and soils was undertaken. In this study, phytosociological survey using Braun-Blanquet's approach was undertaken. The floristic data were analyzed by the TWINSPAN and DECORANA, computer programs in order to classify and provide baseline information about the study area. Two major and 16 sub-communities were recognized along 358 km long motorway. Floristic data was collected from 397 quadrats and 227 vascular plants species belonging to 75 families were recorded. TWINSPAN divided the vegetation of whole study area into 2 major communities, which are further divided into 16 sub-communities. The study also provides basic information for the implementation of conservation oriented planning and management to preserve and improve the road verges of M-2.
Kakar S.-U.-R.,University of Balochistan |
Wahid A.,BZ University |
Tareen R.B.,University of Balochistan |
Kakar S.A.,Government of Pakistan |
And 2 more authors.
Pakistan Journal of Botany | Year: 2010
The present study was carried out in order to investigate the impact of municipal wastewater effluents of Quetta city on the biomass, physiology, and productivity of two canola (Brassica napus L.) cultivars viz., Oscar and Rainbow. Plants were grown in pots from seed to maturity during 2005-2006 growth season. Different concentrations of effluents (T1: 20%; T2: 40%; T3: 60%; T4: 80; T5: 100%) were supplied to plants as a soil drench compared to control plants (T0) receiving normal tap water. The wastewater effluents were highly alkaline in nature along with very high Electrical Conductivity, Biological Oxygen Demand; Chemical Oxygen Demand; Sodium Adsorption Ratio, Total Suspended Solids and minerals concentrations have found well above threshold limits set for the usage of municipal wastewater for irrigation purposes. Growth performance of both canola cultivars showed statistically significant effects on some physiological attributes. All treated plants showed reductions in growth and yield parameters, but T5 treated plants were most affected compared to control. There were significantly higher reductions in stomatal conductance (49% in Oscar; 53% in Rainbow), transpiration rate (62% Oscar; 67% in Rainbow), and photosynthetic rate (62% in Oscar; 69% in Rainbow) of T5 treatment plants compared with control. Both pigments of chlorophyll (a and b) responded efficiently to the applied stress of wastewater effluents showing reductions in chlorophyll a and b by 68-82% in cv. Oscar and 74-86% in cv. Rainbow. Similarly, fresh and dry biomass also showed reductions in different effluents treated plants (T1 to T5) ranging from 2-78% in both the cultivars of canola. Drastic reductions were recorded in the number of siliqua per plant (70-72%), seeds per plant (84-85%), seed weight per plant (87-90), and in the harvest index (72-74%) in cultivars Oscar and Rainbow, respectively than that of control. The overall result of the municipal wastewater impacts on canola cultivars are alarming, as Pakistan is an agrarian country and the agriculture sector bears the brunt of country's economy. This study urged the vital significance of recycling the liquid wastewater effluents before discharge otherwise these could seriously affect the growth and productivity of plants.
Alam M.A.,University of Veterinary and Animal Sciences |
Maqbool A.,University of Veterinary and Animal Sciences |
Nazir M.M.,Bz University |
Lateef M.,University of Veterinary and Animal Sciences |
And 2 more authors.
Veterinary Parasitology | Year: 2015
Entamoeba histolytica, a protozoan parasite that affects humans and other primates all over the world. It is a common waterborne pathogen in endemic areas that have fecal oral transmission cycle. The aim of the present study was to examine the prevalence of E. histolytica and other Entamoeba species cysts in three different dog populations. Fecal samples from 600 dogs were collected and processed to detect Entamoeba cysts using the triple fecal test (light microscopy) and fecal antigens of E. histolytica were detected using a fecal antigen ELISA (TechLab E. histolytica II). Because it is impossible to differentiate E. histolytica from Entamoeba dispar and E. moshkovskii, using light microscopy we referred to all cysts morphologically consistent with E. histolytica as E. histolytica/. dispar/. moskovskii to reflect this uncertainty. Samples from 197 household dogs without clinical signs, 122 samples from household dogs exhibiting clinical signs of diarrhea, dysentery and vomiting and 281 stray dogs with no specific clinical signs were examined. Entamoeba histolytica-like cysts were observed in 94 (15.6%, 95% CI. =. ±3.88) by triple fecal test microscopy and E. histolytica antigens were demonstrated in 66 (11%, 95% CI. =. ±4.41) by fecal antigen ELISA in 600 fecal samples. Significant differences (. P≤. 0.05) in prevalence were found between the three populations. Twenty (10.1%, 95% CI. =. ±7.86) and 11 (5.6%, 95% CI. =. ±7.70) of 197 fecal samples from household dogs without clinical signs were positive by microscopy and by antigen ELISA, respectively. Twenty-nine (23.8%, 95% CI. =. ±6.58) and 23 (18.8%, 95% CI. =. ±7.81) of 122 the fecal samples from household dogs with clinical signs were positive by microscopy and by antigen ELISA, respectively. Forty-five (16.01%, 95% CI. =. ±5.62) and 32 (11.3%, 95% CI. =. ±6.38) of 281 fecal samples from stray dogs were positive by microscopy and by fecal antigen ELISA, respectively. Dogs from the youngest age group (6 months to 1 year) were more likely to be E. histolytica antigen positive than were dogs from the other two older age groups, with a significant difference (. P≤. 0.05) between all age groups. Statistically, no significant (. P≥. 0.05) difference of prevalence was seen in male and female dogs. The local dogs had the highest prevalence rate of E. histolytica antigens (36 of 246, 14.2%, 95% CI. =. ±6.32) followed by imported breeds (11 of 115, 9.5%, 95% CI. =. ±10.4) and crossbred (19 of 239, 8.3%, 95% CI. =. ±7.47), indicating a significant (P≤. 0.05) trend of positivity between various breeds of dogs. These findings suggest that dogs may play an important role in the epidemiology of this pathogen. © 2014 Elsevier B.V.
PubMed | Veterinary Research Institute, Shifa International Hospital, Virginia Polytechnic Institute and State University, Bz University and 2 more.
Type: | Journal: Zoonoses and public health | Year: 2017
Toxoplasma gondii infections are prevalent in humans and warm-blooded animals. Maternal infections during pregnancy may have devastating consequences for transplacentally infected neonates. This study was conducted to examine the seroprevalence of antibodies to T.gondii in pregnant women of childbearing age and determine risk factors associated with pregnancy history, pet ownership, social and cultural factors at Nishtar Hospital, Multan. Samples were collected from 403 women and examined using a commercially available enzyme-linked immunosorbent assay (ELISA). The overall prevalence of antibodies to T.gondii was 17.6% (71) in the 403 samples collected from women. Antibodies to T.gondii were present in 19.4% (45) of 232 pregnant women and 15.2% (26) of the samples from 171 non-pregnant women. This study identified miscarriage history, pet ownership, type of residence, marital status, source of drinking water and eating habits as significant (P<0.05) risk factors associated with the presence of antibodies to T.gondii infection. Seroprevalence was not significantly different (P>0.05) in women from different ethnic groups based upon lifestyle and culture.