Study of the role of dysprosium substitution in tuning structural, optical, electrical, dielectric, ferroelectric, and magnetic properties of bismuth ferrite multiferroic

Magnetoelectric multiferroics, which combine ferroelectric and magnetic characteristics, have potential use in a variety of electronic devices. In this work, Dy3+ substituted bismuth ferrites with the chemical formula Bi1−xDyxFeO3 (x = 0.0, 0.15, 0.30, 0.45, and 0.60) were synthesized using the sol-gel auto combustion process. The effect of Dysprosium substitution in BiFeO3 (BFO), on its structural, surface morphology, optical, electrical, dielectric, ferroelectric, and magnetic properties were studied. The rhombohedral perovskite structure of the space group (R3c) was confirmed via X-ray diffraction (XRD) analysis. Moreover, the crystallite size had a maximum value of 59.57 nm for x = 0.30. XRD and FTIR confirmed the substitution of Dy3+ into BFO ferrite. Further, the structural change and absorption bands confirmed the substitution of Dy3+ ions into the lattice. For x = 0.30, the energy bandgap of 2.81 eV was found. The resistivity and activation energy were minimum and drift mobility was maximum at x = 0.30 as compared to Dy3+ doped BFO samples. At low frequency, the dielectric loss was reduced, while at high frequency, the dielectric loss increased with increasing frequency. The saturated polarization (PS), electric polarization (EC), and remnant polarization (Pr) have values of 6.95 µC/cm2, 3.49 µC/cm2, and 1.53 kV/cm for x = 0.30, respectively. The maximum saturation magnetization and microwave frequencies were 10.89 emu/g and 2.41 GHz, respectively at Dy3+ concentration x = 0.30. These materials are suitable for electronic and microwave devices

Synthesis and characterizations of nickel doped Co-Zn-Y ferrites

The Nickel substituted Cu-Co-Zn-Ce nano ferrites, Zn0.15Co0.45Cu0.40-xNix Fe1.85Ce0.15O4 with x=0, 0.1, 0.20, 0.30, 0.40, were synthesized using the coprecipitation technique. The sample were sintered at 900 ℃ for 5h. The structural, electrical, dielectric and magnetic properties of all the prepared samples were characterized by XRD, SMU2401, UV-Vis and FTIR. The powder X-ray diffraction patterns of all the prepared samples confirmed the formation of single-phase cubic spinel structures. These samples further characterized for the electrical properties by using two-probe type method. The DC resistivity of all the ferrite composition decreased as the temperature increased, showing their semiconductor nature. UV-Vis and FTIR confirmed the substitution of nickel in Cu-Co-Zn-Ce ferrites. From UV-Vis it is observed that the optical band gap changes from 3.9 eV to 5.3 eV with addition of Ni. FTIR analysis revealed that a strong variation on tetrahedral absorption frequency band is present which is due to the replacement of Ni on Cu. All these results suggested that these materials can be used for wastewater treatment

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

Households willingness to pay for improved solid waste management

Waste is a byproduct of human life. Nowadays, municipal solid waste is being produced in excessive amounts and in this way, both developing and developed countries are facing challenges regarding generation of waste. Economic development, urbanization and improved living standards in cities have contributed to increase in the amount and complexity of solid waste produced. The present study was conducted in the residential area of main Boulevard Gulberg, Lahore to determine the present methods and efficiency of current solid waste management facility and to estimate the willingness of the selected households to pay for the improvement of solid waste management through questionnaire survey. It was found that current Solid waste management system in the area is fair but needs more improvement in terms of improved collection efficiency and rates, recycling bins, and segregation of waste at storage. According to the questionnaire survey, majority of the respondents despite belonging to middle class incomes are willing to pay an amount less than USD 4.8 for the improvement of waste management facility in the area. The area lacks frequent collection of waste containers. Therefore, there is a need for upgradation of storage and collection facilities in terms of increase in collection efficiency and rates, introduction of recycling facility and segregation of waste at source. Waste storage and collection sites of the area should be monitored periodically and waste should be disposed of in a scientific manner in sanitary landfills

Identification of a novel FBN1 gene mutation in a large Pakistani family with Marfan syndrome

Contains fulltext : 108198.pdf (publisher's version ) (Open Access)PURPOSE: To describe a novel mutation in the fibrillin-1 (FBN1) gene in a large Pakistani family with autosomal dominant Marfan syndrome (MFS). METHODS: Blood samples were collected of 11 family members affected with Marfan syndrome, and DNA was isolated by phenol-extraction. The coding exons of FBN1 were analyzed by polymerase chain reaction (PCR) and direct sequencing. One hundred-thirty controls were screened for a mutation in the FBN1 gene that was identified in this family by restriction fragment length polymorphism (RFLP) analysis. RESULTS: A novel heterozygous missense mutation c.2368T>A; p.Cys790Ser was observed in exon 19. This mutation substitutes a highly conserved cysteine residue by serine in a calcium binding epidermal growth factor-like domain (cbEGF) of FBN1. This mutation was present in all affected members and absent from unaffected individuals of the family in addition to 130 healthy Pakistani controls. Interestingly all affected family members presented with ectopia lentis, myopia and glaucoma, but lacked the cardinal cardiovascular features of MFS. CONCLUSIONS: This is a first report of a mutation in FBN1 in MFS patients of Pakistani origin. The identification of a FBN1 mutation in this family confirms the diagnosis of MFS patients and expands the worldwide spectrum of FBN1 mutations

Polymorphisms in matrix metalloproteinases MMP1 and MMP9 are associated with primary open-angle and angle closure glaucoma in a Pakistani population

Contains fulltext : 117444.pdf (publisher's version ) (Open Access)PURPOSE: Matrix metalloproteinases (MMPs) play an important role in remodeling of the extracellular matrix during development and growth of various tissues including the eye. Various functional polymorphisms in MMPs have been implicated in the pathogenesis of different types of glaucoma. The aim of the present study was to investigate the role of various polymorphisms in Pakistani patients with glaucoma. METHODS: The present case-control study included 112 patients with primary open-angle glaucoma (POAG), 82 patients with primary angle closure glaucoma (PACG), and 118 control subjects. Genotyping of polymorphisms was done using PCR followed by restriction fragment length polymorphism analysis. RESULTS: A significant difference in the genotype frequencies of MMP1 rs1799750 (-1607 1G/2G) was observed between the patients with POAG and the control subjects (p = 0.001). This was attributed to the female subjects (p 0.47). In addition, a significant difference was observed in genotype frequencies of MMP9 rs17576 (c.836A>G) in patients with PACG compared to the control subjects (p C) and MMP9 (c.-1562C>T) polymorphisms. CONCLUSIONS: Our data suggest that the MMP1 rs1799750 (-1607 1G/2G) and MMP9 rs17576 polymorphisms might be of value for further study as potential gender-dependent risk factors for developing POAG and PACG, respectively, in Pakistan

Tuning structural, electrical, dielectric and magnetic properties of Mg–Cu–Co ferrites via dysprosium (Dy3+) doping

In current research work, Dy3+ substituted Mg0.5Cu0.25Co0.25Fe2‒xDyxO4 (0.0 ≤ x ≤ 0.04 with the step interval of 0.01) soft ferrites were synthesized by the sol–gel auto combustion method. The prepared samples were characterized by the techniques using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, current–voltage (I–V) measurement, LCR meter, vibrating sample magnetometer (VSM) and Raman. XRD data reveal that the average crystallite size is 49.71 nm and the lattice constant is 0.83703 nm for sample x = 0.03. The non-uniform grain growth was demonstrated by micrographs and impurity-free elemental composition was observed from EDX analysis. The DC resistivity has an increasing and decreasing trend in ferromagnetic and paramagnetic regions with an increase in temperature. Moreover, the high resistivity is observed with the order of 1010 Ω·cm, and the activation energy is 0.944 eV for samples x = 0.03. The dielectric parameters including dielectric constant, dielectric losses, and impedance gradually decrease with the increase in frequency from 8 Hz–8 MHz. The minimum dielectric loss at high frequency is found for sample x = 0.03. The coercivity (Hc) and saturation magnetization (Ms) are found in the ranges of 520.82–544.02 Oe and 20.5841–21.1473 emu/g, respectively. These observations confirm that dysprosium (x = 0.03) doped MCC-soft ferrites may be applicable in transformer cores, microwave absorbance, and telecommunication devices

Association of eNOS and HSP70 gene polymorphisms with glaucoma in Pakistani cohorts.

Contains fulltext : 88359.pdf (publisher's version ) (Open Access)PURPOSE: To investigate the involvement of stress-regulating genes, endothelial nitric oxide synthase (eNOS) and heat shock protein 70 (HSP70) with primary open angle glaucoma (POAG) and primary closed angle glaucoma (PCAG). METHODS: POAG and PCAG patients recruited from different areas of Pakistan were diagnosed on the basis of clinical history, raised intraocular pressure (IOP), cup-to-disc ratio (CDR) and visual field defects. Their blood was collected and genomic DNA was extracted from it, followed by PCR amplification and VNTR typing of the eNOS gene, while the HSP70 SNP was analyzed with PCR-RFLP. For both of the polymorphisms, the genotype distribution of the POAG and PCAG patients was compared with unaffected controls. RESULTS: HSP70 polymorphism was found to be significantly associated with PCAG (chi(2)=15.29 [p0.05]). As opposed to this significant eNOS association, was seen with PCAG (chi(2)=6.33 [p<0.05], OR=2.09 [95% CI=1.12-3.89]), with p<0.01 for the dominant model, as well as with POAG (chi(2)=8.89 [p<0.05], OR=2.23 [95% CI=1.26-3.39]), with p<0.01 for dominant model. For the eNOS case, we found a significant association with the risk allele "a" for POAG patients (chi(2)=9.29 [p<0.01], OR=2.02 [95% CI=1.25-3.28, p=0.001]) and PCAG patients (chi(2)=7.59 [p<0.01], OR=1.99 [95% CI=1.18-3.37, p<0.01]). Similarly, in the HSP70 case, there was a significant association with the risk allele "C" for POAG patients (chi(2)=3.57 [p=0.05], OR=1.38 [95% CI=0.97-1.94, p<0.05]) and PCAG patients (chi(2)=18.32 (p<0.001), OR=2.16 [95% CI=1.49-3.13, p<0.001]). CONCLUSIONS: The intron 4 polymorphism of eNOS is associated with POAG, as well as PCAG, while the G+190C polymorphism in HSP70 is associated with PCAG, but not with POAG in the Pakistani population

Association of known common genetic variants with primary open angle, primary angle closure, and pseudoexfoliation glaucoma in Pakistani cohorts

Contains fulltext : 138859.pdf (publisher's version ) (Open Access)PURPOSE: Despite the different etiology of primary open angle glaucoma (POAG), primary angle closure glaucoma (PACG), and pseudoexfoliative glaucoma (PEXG), several studies have suggested that these forms of glaucoma have overlapping genetic risk factors. Therefore, the aim of this study was to evaluate the role of genetic variants recently associated with POAG in different types of glaucoma in Pakistani POAG, PACG, and PEXG patient cohorts. METHODS: Six variants in CDKN2B-AS1 (rs4977756), CDKN2B (rs1063192), ATOH7 (rs1900004), CAV1 (rs4236601), TMCO1 (rs4656461), and SIX1 (rs10483727) were genotyped using TaqMan assays. A total of 513 unrelated patients with glaucoma (268 with POAG, 125 with PACG, and 120 with PEXG) and 233 healthy controls were included in the study. Genotypic and allelic associations were analyzed with a chi-square test. RESULTS: The frequency of the G allele of TMCO1 rs4656461 was significantly lower in the patients with POAG (p=0.003; OR [odds ratio]=0.57), PACG (p=0.009; OR=0.52), and PEXG (p=0.01; OR=0.54) compared to the control individuals. The T allele of ATOH7 rs1900004 was observed less frequently in the patients with PACG (p=0.03; OR=0.69) compared to the control individuals. The A allele of CAV1 rs4236601 was found more frequently in the patients with POAG (p=0.008; OR=1.49) compared to the control individuals. This study demonstrates that the TMCO1 rs4656461 variant is associated with POAG, PACG and PEXG in the Pakistani population. Our study was unable to confirm previous associations reported for variants in CDKN2B-AS1, CDKN2B, and SIX1 with any type of glaucoma. CONCLUSIONS: In conclusion, we found consistent evidence of the significant association of three common variants in TMCO1, ATOH7, and CAV1