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For doctoral students, dissertation writing is an important stage in their completion of the degree. They might face several problems during this stage. The aim of the current qualitative study was to explore doctoral students' perceptions of dissertation writing. Ten participants were selected through a purposive sampling technique from the education department of a private university in Lahore, Pakistan. An interview guide was constructed in light of the research objectives and literature review. Data were collected through semi-structured interviews and analyzed through qualitative content analysis. The findings of the study revealed language barriers, insufficient academic writing skills, inadequate supervisory support, and personal factors as problems faced by doctoral students during their dissertation writing. It is recommended that an academic writing course should be offered during coursework. Moreover, effective supervisory support should be ensured at the dissertation writing stage. The concerned department should facilitate and solve the problems of doctoral students during their write-up stage.

One of the major biomedical problems facing worldwide is the diagnosis and treatment of tumor. This disease may lead to severe incidence with increased mortality rates. Therefore, it is the need of present era to develop advanced tools/methods for timely diagnosis of tumor. Aim of the present study is to evaluate the cytotoxicity and biodistribution of iron-oxide-stabilized zirconia (IOZH) nanoparticles with honey as a capping agent. In vivo-targeted diagnostic applications of stabilized ZrO2 nanoparticles are investigated through biodistribution of nanoparticles in rabbits. Nanoparticles (NPs) are synthesized using the microwave-assisted sol–gel method. Powers of microwave energy (100–900 W) are varied to synthesize stabilized zirconia NPs. Honey, as an organic capping agent, is added during synthesis. Structural results demonstrate the appearance of stabilized tetragonal phase of zirconia at 700 and 900 W without any further heat treatments. Smaller crystallite size of ~20 nm is observed for stabilized zirconia samples. Higher X-ray density is observed for pure tetragonal phase at 700 and 900 W. High dielectric constant (~55.8 at log f = 4) along with low tan loss is observed for zirconia prepared at 900 W. Magnetic results show superparamagnetic nature of the samples synthesized at 700 and 900 W. Radiolabeling along with biodistribution of iron-oxide-stabilized zirconia nanoparticles with technetium-99m is studied in normal rabbits. It is worth mentioning here that high-yield efficacy and stability along with its biodistribution and scintigraphy studies have been investigated. High uptake of radiotracer in bladder of rabbit is found to be potential candidate for its use in tumor therapies. Urination and physical properties of rabbit, after the post injection of nanoparticles, are checked periodically for many months and found normal.

Zirconia ceramics have attained much consideration owing to the amazing mechanical strength and white color. These properties provide an opportunity for the use in biomedical applications. In the present study, an application oriented sol-gel route was adapted for synthesis of zirconia nanoparticles. ZrOCl2·8H2O was used as a precursor, iron oxide (Fe3O4) nanoparticles (pH 2 & pH 9) as a stabilizer and de-ionized water was used as a solvent. Sol-gel synthesized iron oxide stabilized zirconia nanoparticles were prepared by varying concentrations of iron oxide nanoparticles in the range of 2–10 wt%. X-ray diffraction results showed mixed phases at all wt% with acidic pH value, while pure tetragonal phase of zirconia was observed for stabilization with 6 wt% basic iron oxide. Maximum value of dielectric constant (~80 at log f = 4) and minimum value of tangent loss (~0.66 at log f = 4) were observed for zirconia stabilized with basic 6 wt% iron oxide. Maximum value of hardness (1410 ± 10 HV) along with high fracture toughness were observed with optimized stabilization. Very weak hemolytic activity and maximum scavenging (~76) antioxidant activity was observed under optimized conditions. Thus, it can be suggested that optimized nanoparticles, i.e. tetragonal zirconia stabilized with 6 wt% of basic Fe3O4, can be further useful for therapeutical and pharmaceutical applications.

Background Changing climate enhances the survival of pests and pathogens, which eventually affects crop yield and reduces its economic value. Novel approaches should be employed to ensure sustainable food security. Nano-based agri-chemicals provide a distinctive mechanism to increase productivity and manage phytopathogens, with minimal environmental distress. In vitro and in greenhouse studies were conducted to evaluate the potential of green-synthesized iron-oxide nanoparticles (IONPs) in suppressing wilt infection caused by Fusarium oxysporum f. sp. lycospersici, and improving tomato growth (Solanum lycopersicum) and fruit quality. Results Various microwave powers (100–1000 W) were used to modulate the properties of the green-synthesized IONPs, using spinach as a starting material. The IONPs stabilized with black coffee extract were substantively characterized using X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy, dielectric and impedance spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning and transmission electron microscopy (SEM and TEM, respectively), and magnetization analysis. XRD revealed a cubic magnetite (Fe3O4) phase with super-paramagnetic nature, detected at all microwave powers. The binding energies of Fe 2p3/2 (710.9 eV) and Fe 2p1/2 (724.5 eV) of Fe3O4 NPs were confirmed using XPS analysis at a microwave power of 1000 W. Uniform, spherical/cubical-shaped particles with an average diameter of 4 nm were confirmed using SEM and TEM analysis. A significant reduction in mycelial growth and spore germination was observed upon exposure to different IONP treatments. Malformed mycelium, DNA fragmentation, alternation in the cell membrane, and ROS production in F. oxysporum indicated the anti-microbial potential of the IONPs. The particles were applied both through the root (before transplantation) and by means of foliar application (after two weeks) to the infected seedlings. IONPs significantly reduced disease severity by an average of 47.8%, resulting in increased plant growth variables after exposure to 12.5 µg/mL of IONPs. Analysis of photosynthetic pigments, phenolic compounds, and anti-oxidant enzymes in the roots and shoots showed an increasing trend after exposure to various concentrations of IONPs. Correspondingly, lycopene, vitamin C, total flavonoids, and protein content were substantially improved in tomato fruits after treatment with IONPs. Conclusion The findings of the current investigation suggested that the synthesized IONPs display anti-fungal and nutritional properties that can help to manage Fusarium wilt disease, resulting in enhanced plant growth and fruit quality. Graphical Abstract

Tomato plants are prone to various biotic and abiotic stresses. Fusarium wilt is one of the most devasting diseases of tomatoes caused by

Background: Changing climate enhances the survival of pests and pathogens which eventually affects the crop yield and reduces its economic value. To attain the sustainable food security, novel approaches should be employed. Nanobased agri-chemicals provide a distinctive mechanism to increase productivity and manage phytopathogens with minimum environmental distress. In-vitro and greenhouse studies were conducted to evaluate the potential of green synthesized iron oxide nanoparticles (IONPs) in suppressing the wilt infection caused by Fusarium oxysporum f.sp. lycospersici and to improve tomato growth (Solanum lycopersicum) and fruit quality. Results: Various microwave powers (100 W- 1000 W) were used to modulate the properties of green synthesize IONPs by using spinach as a starting material. The IONPs stabilized with black coffee extract were substantively characterized by X-ray diffraction analysis, fourier transform infrared spectroscopy, dielectric and impedance spectroscopy, X-ray photoelectron spectroscopy, Scanning and transmission electron microscopy and magnetization-analysis. XRD revealed cubic magnetite (Fe3O4) phase with superparamagnetic nature, detected at all microwave powers. Binding energies of Fe 2p3/2 (712.05 eV) and Fe 2p1/2 (723.9 eV) of Fe3O4 NPs was confirmed by XPS analysis observed at microwave power of 1000 W. Uniform, spherical shaped particles with an average diameter of 4 nm were confirmed by SEM and TEM analysis. Significant reduction in mycelial growth and spore germination was perceived after exposure to different treatments of IONPs. Malformed mycelium, DNA fragmentation, alternation in cell membrane and ROS production in F. oxysporum indicates antimicrobial affinity of iron oxide NPs. The particles were applied both through root (before transplantation) and foliar application (after two weeks) to infected seedlings. The IONPs significantly reduced the disease severity by an average of 47.8% resulting in increased plant growth variables at exposure to 10 µg/mL of IONPs. Analysis of photosynthetic pigment, phenolic compounds and antioxidant enzymes in root and shoots signifies an increasing trend after exposure to various concentrations of IONPs. Correspondingly, lycopene, vitamin C, total flavonoids and protein content was substantially improved in tomato fruits after treatment of IONPs. Conclusion: These findings of current investigation suggests that IONPs owned antifungal properties to subdue Fusarium wilt disease by boosting plant growth and fruit quality.

Use of ceramic coatings has increased dramatically in orthopedics by improving their wear resistance and consequent long-term stability. Such stability involves not only the strength of material but also its resistance toward bacterial attacks. Amongst all ceramics, zirconia is selected in the present study due to its white color and high value of hardness making it a potential candidate to be used as implants and their coatings. In the present study effect of varying microwave powers (i.e. 100W, 200W, 300W, 400W, 500W, 600W, 700W, 800W, 900W and 1000W) on sol–gel synthesized glucose and fructose added zirconia coatings has been investigated. Formation of mixed tetragonal – monoclinic phases has been observed at relatively low microwave powers, i.e. 100–500W. However, at 600–1000W phase pure tetragonal zirconia is observed without any post heat treatment. FTIR analysis confirms formation of tetragonal phase of zirconia at 600–1000W microwave power. XPS results confirm the binding energies of Zr 3d and O 1s of microwave assisted zirconia coatings. High value of transmittance, i.e. ~90%, is observed at higher microwave powers. Variation in microwave powers is observed to tune the energy band gap of zirconia coatings in the range of 4.2–5.1 eV. Dielectric constant of 8–10 at log f = 4 is observed. High value of hardness and fracture toughness i.e. 1231 HV and 24.85 MPam−1/2, respectively, is observed for stabilized tetragonal zirconia coatings. Stabilized glucose fructose added zirconia shows strong antioxidant activity. Zirconia coatings are tested against Staphylococcus aureus bacteria for their potential application to treat bone infection. Results suggest that stabilized tetragonal zirconia can be successfully employed for orthopedic coatings.

Demand of bioactive materials that may create a bacteria-free environment while healing and regenerating the defect area is increasing day by day. Zirconia is a very interesting material because of its biocompatibility and high fracture toughness. In this research work, zirconia nanoparticles (NPs) have been synthesized using sol-gel method. Molarity of sols is varied in the range of 25 to 125 mM. The effect of acidic and basic nature of sols is studied by maintaining acidic (2) and basic (9) pH. As-synthesized NPs are made soluble in deionized (DI) water using tangerine drops. Dissolved NPs are spin coated onto glass substrate prior to characterization. Pure tetragonal phase, observed under all conditions using basic medium (pH 9), is accompanied by smaller crystallite size and unit cell volume. Presence of stabilized zirconia phase leads to higher value of density and higher mechanical strength. Nanodendrites with distinct features are observed for the sample prepared with high molarity using basic medium. Whereas, soft agglomerated nanodendrites are observed using acidic medium. Optical properties show transmission of 60–80% in the visible and infrared regions for acidic based samples and ~84% for basic samples. Direct energy band gap is varied from 4.96 eV to 5.1 eV in acidic (pH 2) and 4.91 eV to 4.97 eV in basic (pH 9) media. FTIR spectra show the formation of fundamental tetragonal band at 490 cm−1 for basic samples. Antibacterial response of zirconia is tested against E. coli, Streptococcus and Bacillus bacteria. Human teeth, bare and zirconia coated, are tested for their possible weight loss after dipping in various beverages. Zirconia coated tooth shows negligible degradation in hardness and weight after 24 hr dipping period. Thus, coatings prepared using water soluble zirconia (WSZ) nanoparticles, without the use of toxic solvents/reagents, are promising material to be used as protective coatings in biomedical applications.

It is well known that long term stability in zirconia has been a problem because of the structural alteration from stabilized tetragonal zirconia to monoclinic that leads to fracture in implants. Microwave (MW) assisted sol-gel synthesis is employed in the present work to prepare stabilize zirconia nanoparticles. ZrOCl2.8H2O is used as a precursor whereas de-ionized water is used as a solvent. Power of microwave radiations is varied in the range of 100–1000W. Zirconia nanoparticles have been characterized under as-synthesized, 6- and 12-months’ room temperature (RT) aged conditions. Metastable phase (MP) of zirconia, appearing under as-synthesized conditions, transforms to phase pure tetragonal zirconia (t-ZrO2) after RT aging that was prepared with MW powers of 100, 200 and 700–1000W. Whereas, MP transforms to mixed tetragonal-monoclinic phases at microwave powers of 300–600W after RT aging. XPS results show presence of oxygen-deficient state of ZrO2 lattice along with surface defects contributing towards the tetragonal zirconia phase under all conditions. Value of dielectric constant (i.e. ∼11–12 at log f = 4.0), hardness (∼1376 HV) and fracture toughness observed under all conditions are well in agreement to be used for biological implants. Disks of aged t-ZrO2 nanoparticles are checked for their biodegradation test by dipping in simulated body fluid for several weeks. ZrO2, with 26 weeks of immersion, shows small loss in hardness and weight. Stabilized tetragonal zirconia shows strong anti-oxidant activity. Stabilized ZrO2 nanoparticles presented strong antibacterial activity against both gram positive (S. aureus, Bacillus) and gram negative (E. coli) bacteria. Thus, structural and mechanical stability of zirconia (checked after 6 and 12 months) make this material highly beneficial for long term use in biomedical applications.