Development and characterization of alginate-chitosan-hyaluronic acid (ACH) composite fibers for medical applications

Natural materials and plants have a long history of medical applications due to their broad range of favorable biological functions including biocompatibility, anti-bacterial, anti-oxidant and anti-inflammatory properties. Main objective of this study was to develop alginate-chitosan-hyaluronic acid (ACH) composite fibers with controlled drug release, and liquid retention properties for better moist wound healing. The dope comprising sodium alginate was extruded into calcium chloride (CaC1₂) coagulation bath. The developed calcium alginate fibers were then passed through a bath containing hydrolyzed chitosan and dip coated with hyaluronic acid for 24 hours. The resulting ACH composite fibers were then rinsed with deionized water and dried using acetone. These fibers were tested for tensile properties, % swelling, liquid absorption (g/g) and controlled drug release. The results concluded that ACH composite fibers can be produced by wet spinning and have adequate tensile properties, high % swelling, liquid absorption (g/g) and controlled release of hyaluronic acid for improved wound healing.     

Effect of diet on preweaning performance of Sahiwal calves

The objective was to study the growth potential of Sahiwal calves given milk or milk replacer with or without concentrates. For this purpose, forty-eight Sahiwal calves were divided into four groups of 12 animals each with equal sex ratio. In each group, the calves were offered either milk or a milk replacer (MR) at a rate of 10% of their body weight adjusted weekly. In addition to this, calves were fed either a starter ration plus Egyptian clover hay (SR + H) or hay only (H) until the end of trial. The milk or MR was withdrawn gradually from day 56 until animals were weaned completely by day 84. Calves offered milk grew faster than those offered MR (357 ± 9 vs. 162 ± 9 g/day; p < 0.05) and displayed higher weaning weights (51.6 ± 0.8 vs. 35.2 ± 0.8 kg; p < 0.05). The calves offered SR + H grew faster (311 ± 9 vs. 208 ± 9 g/day; p < 0.05) and displayed higher weaning weights (48.7 ± 0.8 vs. 38.1 ± 0.8 kg; p < 0.05) than those fed H alone. Calves offered milk plus SR + H showed the highest growth rate and weaning weights (401 ± 13 g/day and 56.3 ± 1 kg, respectively). The lowest growth rate and weaning weights were observed in calves offered MR and H only (115 ± 13 g/day and 30.3 ± 1 kg, respectively). Calves offered the MR had higher number of scour days than those offered milk (13.5 vs. 3.3). The feeding of whole milk in combination with the starter ration and hay resulted in superior growth rates, higher weaning weights, and healthier calves than the other feeding regimens.     

Integrated Weed Management Through Tillage and Herbicides for Wheat Production in Rice-Wheat Cropping System in Northwestern Pakistan

Conservational tillage (CT) in combination with broad spectrum herbicide may be more efficient and economical in controlling weeds,reducing cost of cultivation,and enhancing wheat yield.Field experimen...     

The Promotive Effects of Nephthyl Acetic Acid on Maize Cultivars Grown Under Saline Conditions

Soil salinity is becoming a major problem due to a variety of natural and man-caused factors particularly in arid areas. The present study documented on the effect of nephthyl acetic acid (NAA) foliar spray on physiological attributes of maize including growth responses, osmolites, and antioxidant enzymatic activities of the selected maize varieties PSEV3-2(ES) and Sarhad yellow at vegetative stage exposed to different sodium chloride (NaCl) concentrations of 20mM to 100mM, through pot experiments. Osmolites and antioxidant enzymes serve as physiological markers for selected maize varieties under saline conditions. The maximum increase in osmolites and protein contents, Peroxidases (EC 1.11.1.x), Superoxide dismutase (EC 1.15.1.1), Catalse (EC 1.11.1.6) and Ascorbate peroxidase (EC 1.11.1.11) activities in Sarhad yellow indicating the tolerance level of this variety as compare to PSEV3-2(ES). It has been concluded that the reduction in growth responses due to salinity has been improved by the exogenous application of nephthyl acetic acid.     

Citrus leafminer Phyllocnistis citrella and its parasitoids in Sargodha region of Pakistan

In order to identify the parasitoids of Phyllocnistis citrella, an important pest of Citrus, the larvae and pupae of this pest were collected from Citrus reticulata Blanco orchards in the Sargodha region of Pakistan. The parasitoid species were identified, and their abundance was recorded. A total of two species were identified: Citrostichus phyllocnistoides (Narayan) (Hymenoptera: Eulophidae) and Cirrospilus ingenuus Gahan (Hymenoptera: Eulophidae). Out of a total of 409 P. citrella larvae and pupae collected, 73 C. phyllocnistoides and 39 C. ingenuus adults emerged. This paper documents the species and the abundance of the parasitoids associated with P. citrella in the Sargodha region of Pakistan.     

Kinetic characterization of O-phospho-L-tyrosine phosphohydrolase activity of two fungal phytases

Fungal phytases belonging to "histidine acid phosphatase" or HAP class of phosphohydrolases that catalyze the hydrolysis of phytic acid could also hydrolyze O-phospho-L-tyrosine, which is also called phosphotyrosine. Two phytases from Aspergillus niger and Aspergillus awamori with pH optima 2.5 were tested for phosphotyrosine hydrolase activity; both enzymes cleaved the phosphomonoester bond of phosphotyrosine efficiently at acidic pH. The Km for phosphotyrosine ranged from 465 to 590 microM as opposed to 135 to 160 microM for phytate. The Vmax, however, is 2-4 times higher for phosphotyrosine than it is for phytate. The catalytic efficiency of phytase for phosphotyrosine is on the same order as it is for phytate (3.5 x 10(6) to 1.6 x 10(7) M(-1) s(-1)); the pH versus activity profile for phosphotyrosine is, however, different from what it is for phytate. The temperature optima shifted 5 degrees C higher to 70 degrees C when phosphotyrosine was used as the substrate. Taken together, the kinetic data show that fungal HAPs that are known as PhyB are capable of cleaving the phosphomonoester bond in phosphotyrosine. This is the first time that phosphotyrosine phosphatase (PTPase) activity has been reported for the subgroup of HAP known as phytase.     

Growth and yield of lowland rice as affected by integrated nutrient management and cultivation method under alternate wetting and drying water regime

The effects of integrated nutrient management, cultivation method, and variety on root and shoot growth, grain yield and its components of lowland rice under alternate wetting and drying (AWD) irrigation were evaluated. Treatments included were three varieties (Pathumthani 1, RD57, and RD41), three cultivation methods [dry direct seeding, wet direct seeding, and transplanting], and three nutrient combinations [100% NPK (160?kg ha^?1), 50% NPK (80?kg ha^?1) + 50% FYM (5 t ha^?1), and 100% FYM (10 t ha^?1)] under AWD. Root dry matter of RD41 and RD57 was reduced by 12–25% at the 100% NPK and 100% FYM compared with the 50% NPK + 50% FYM. Panicle number, panicle length, and 1000-grain weight were higher at the 50% NPK + 50% FYM. Application of the 50% NPK + 50% FYM could be a feasible option under AWD irrigation; however, benefits may vary with varieties and cultivation methods.     

Studies on Plant Population and Stand Establishment Techniques for Increasing Productivity of Rice in Dera Ismail Khan, Pakistan

Rice production in Pakistan is constraint by many factors pertaining to prevalent planting techniques. A research on the feasibility of new planting techniques (direct seeding on flat, transplanting on flat, direct seeding on ridges, transplanting on ridges and parachute planting) in transplanted and direct wet-seeded rice was undertaken at Dera Ismail Khan region of Pakistan’s North West Frontier Province during 2002 and 2003. Among the planting techniques, the best performance for the yield formation and economic evaluation was noted for transplanting on flat during both years. Chinese parachute planting technology also showed very promising results in most of the parameters. Direct seeding on ridges could not excel transplanting on flat and parachute planting during both cropping seasons. The findings concluded the feasibility of parachute planting technology along with traditional rice transplanting on flat over all other planting techniques being practiced in the area.     

60Co-γ Radiation Alters Developmental Stages of Zeugodacus cucurbitae (Diptera: Tephritidae) Through Apoptosis Pathways Gene Expression

Radiation is considered as a promising insect pest control strategy for minimizing postharvest yield losses. Among various techniques, irradiation is a method of choice as it induces lethal biochemical or molecular changes that cause a downstream cascade of abrupt physiological abnormalities at the cellular level. In this study, we evaluated the effect of ⁶⁰Co-γ radiation on various developmental stages of Zeugodacus cucurbitae Coquillett and subsequent carry-over effects on the progeny. For this purpose, we treated eggs with 30- and 50-Gy radiation doses of ⁶⁰Co-γ. We found that radiation significantly affected cellular antioxidants, insect morphology, and gene expression profiles. Our results indicate that in response to various doses of irradiation reactive oxygen species, catalase, peroxidase, and superoxide dismutase activities were increased along with a significant increase in the malondialdehyde (MDA) content. We observed higher mortality rates during the pupal stage of the insects that hatched from irradiated eggs (50 Gy). Furthermore, the life span of the adults was reduced in response to 50 Gy radiation. The negative effects carried over to the next generation were marked by significantly lower fecundity in the F₁ generation of the irradiation groups as compared to control. The radiation induced morphological abnormalities at the pupal, as well as the adult, stages. Furthermore, variations in the gene expression following irradiation are discussed. Taken together, our results signify the utility of ⁶⁰Co-γ radiation for fruit fly postharvest management.     

A strategy of ideotype development for heat-tolerant wheat

Heat stress significantly limits yield in many wheat-growing areas globally including north-western NSW. While various traits linked to high-temperature tolerance have been identified, the combination of traits that optimize the heat tolerance of wheat has not been established in most environments. A total of 554 genotypes were evaluated in the field at different times of sowing in north-western NSW for three consecutive years to develop a heat-tolerant wheat ideotype for this environment. The later sown experiments were exposed to higher temperatures at the critical reproductive and grain-filling stages of development. The impact of high temperature was greatest at anthesis, and eventual grain yield was reduced by between 4% and 7% with every 1°C rise in average maximum temperature above the optimum of 25°C. High temperature reduced yield, plant height, grain weight and days to anthesis and maturity, and increased the percentage of screenings and grain protein content. Genotypes that produced higher yield under heat stress had shorter days to flowering and maturity, higher NDVI during grain filling, greater chlorophyll content at the milk stage of grain fill, taller plants, greater grain weight and number, and lower screenings compared with the benchmark cultivar Suntop. The genotype closest to the predicted heat-tolerant wheat ideotype identified from trait ranges had 79.6% similarity.