High Sensitive Fiber Optic Temperature Sensor Based on a Side-polished Single-mode Fiber Coupled to a Tapered Multimode Overlay Waveguide

Prerana,Ravendra Kumar Varshney,Bishnu Pada Pal,Bezwada Nagaraju 한국광학회 2010 Current Optics and Photonics Vol.14 No.4

A high sensitivity fiber optic temperature sensor based on a side-polished fiber (SPF) coupled to a tapered multimode overlay waveguide (MMOW) is proposed and studied. Both tapered and non-tapered MMOW were considered to study the effect of tapering of MMOW on the characteristics of the device and to investigate the criticality of the uniformity of the multimode overlay waveguide over the SPF. Present study shows that tapering of the MMOW can be used to tune the desired wavelength range without any loss in the sensitivity. Sensitivity up to 9 nm/℃ within the temperature range of 25 to 100℃ can be achieved with the proposed sensor, almost 6 times higher compared even to state-of-the-art high-sensitivity grating-based fiber optic temperature sensors.

Current Status of Marine Pollution and Mitigation Strategies in Arid Region: A Detailed Review

Prerana Chitrakar,Mahad Said Baawain,Ahmad Sana,Abdullah Al-Mamun 한국해양과학기술원 2019 Ocean science journal Vol.54 No.3

Coastal pollution is becoming a significant threat for both marine ecosystems and humans. Marine pollution and coastal degradation are severely exacerbated by anthropogenic activities involving the discharge of industrial and domestic effluents, ballast water and brine wastes, accidental spillage of oil and radioactive wastes, and the modification of coastal structures. Understanding the sources of marine pollution and their possible impacts allows us to measure the current mitigation and conservation strategies aimed at protecting marine ecosystems from further deterioration. This review assessed the status of marine pollution based on the literature with a focus on the sea in arid regions over the last four decades. The review also summarized the degree of contamination of heavy metals and petroleum hydrocarbons that accumulated in marine water, sediments and living organisms. In addition, the review critically suggested several mitigation strategies to alleviate the impacts of such pollutions. The key findings indicated that the oil and gas production and processing industries, desalination industries, sea traffic, urban development, and discharge of treated wastewater and ballast water along with seasonal upwelling, and climate change were the main contributors of marine pollution in these regions including the Sea of Oman. The major identified pollutants were heavy metals, petroleum hydrocarbons, organochlorine, tar, harmful algal blooms, marine debris, non-native species, and sediment that are posing severe threats to marine biodiversity and ecosystems. The occurrence of radionuclides in these regions seems to be smaller compared to the World Ocean because of the insignificant disposal of nuclear waste due to strict law enforcement and monitoring. However, marine litter, micro-plastic, radionuclides, greenhouse gases, and non-point pollutant sources have not been investigated properly. Therefore, efforts to identify the possible sources of pollution, estimate their impacts based on field data and numerical modeling, and understand ocean dynamics with regard to the transportation and deposition of sediments and pollutants need to be undertaken in order to protect the coastal and marine environment and ecosystems. Furthermore, integration of robotic aircraft along with satellite surveillance can be an additional measure deployed for the purposes of monitoring oil spillage, illegal ballast water discharge, harmful algal blooms, and beach utilization.

Association of Genetic Variants in ARID5B, IKZF1 and CEBPE with Risk of Childhood de novo B-Lineage Acute Lymphoblastic Leukemia in India

Bhandari, Prerana,Ahmad, Firoz,Mandava, Swarna,Das, Bibhu Ranjan Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.8

Background: Childhood acute lymphoblastic leukemia (ALL) is a heterogeneous genetic disease and its etiology remains poorly understood. Recent genome wide association and replication studies have highlighted specific polymorphisms contributing to childhood ALL predispositions mostly in European populations. It is unclear if these observations generalize to other populations with a lower incidence of ALL. The current case-control study evaluated variants in ARID5B (rs7089424, rs10821936), IKZF1 (rs4132601) and CEBPE (rs2239633) genes, which appear most significantly associated with risk of developing childhood B-lineage ALL. Materials and Methods: Using TaqMan assays, genotyping was conducted for 162 de novo B-lineage ALL cases and 150 unrelated healthy controls in India. Appropriate statistical methods were applied. Results: Genotypic and allelic frequencies differed significantly between cases and controls at IKZF1-rs4132601 (p=0.039, p=0.015) and ARID5B-rs10821936 (p=0.028, p=0.026). Both rs10821936 (p=0.019; OR 0.67; 95% CI=0.47-0.94) and rs4132601 (p=0.018; OR 0.67; 95%CI 0.48-0.94) were associated with reduced disease risk. Moreover, gender-analysis revealed male-specific risk associations for rs10821936 (p=0.041 CT+CC) and rs4132601 (p=0.005 G allele). Further, ARID5B-rs7089424 and CEBPE-rs2239633 showed a trend towards decreased disease risk but without significance (p=0.073; p=0.73). Conclusions: Our findings provide the first evidence that SNPs ARID5B-rs10821936 and IKZF1-rs4132601 are associated with decreased B-lineage ALL susceptibility in Indian children. Understanding the effects of these variants in different ethnic groups is crucial as they may confer different risk of ALL within different populations.

Cytogenetic Profile of De Novo B lineage Acute Lymphoblastic Leukemia: Determination of Frequency, Distribution Pattern and Identification of Rare and Novel Chromosomal Aberrations in Indian Patients

Bhandari, Prerana,Ahmad, Firoz,Dalvi, Rupa,Koppaka, Neeraja,Kokate, Prajakta,Das, Bibhu Ranjan,Mandava, Swarna Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.16

Background: Chromosomal aberrations identified in acute lymphoblastic leukemia (ALL) have an important role in disease diagnosis, prognosis and management. Information on karyotype and associated clinical parameters are essential to physicians for planning cancer control interventions in different geographical regions. Materials and Methods: In this study, we present the overall frequency and distribution patterns of chromosomal aberrations in both children and adult de novo B lineage ALL Indian patients using conventional cytogenetics, interphase FISH and multiplex RT-PCR. Results: Among the 215 subjects, cytogenetic results were achieved in 172 (80%) patients; normal karyotype represented 37.2% and abnormal 62.8% with a distribution as follows: 15.3% hypodiploidy; 10.3% hyperdiploidy; 15.8% t(9;22); 9.8% t(1;19); 3.7% t(12;21); 2.8% t(4;11); 2.8% complex karyotypes. Apart from these, we observed several novel, rare and common chromosomal rearrangements. Also, FISH studies using LSI extra-signal dual-color probes revealed additional structural or numerical changes. Conclusions: These results demonstrate cytogenetic heterogeneity of ALL and confirm that the incidence of chromosomal abnormalities varies considerably. To the best of our knowledge, this is one of the largest reported series of cytogenetic investigations in Indian B-lineage ALL cases. In addition, ongoing cytogenetic studies are warranted in larger groups of B-lineage ALL cases to identify newly acquired chromosomal abnormalities that may contribute to disease diagnosis and management.

Clinical Presentation and Management of Eyes with Globe Perforation during Peribulbar and Retrobulbar Anesthesia: A Retrospective Case Series

Naresh Babu,Jayant Kumar,Piyush Kohli,Ashish Ahuja,Prerana Shah,Kim Ramasamy 대한안과학회 2022 Korean Journal of Ophthalmology Vol.36 No.1

Purpose: To evaluate the clinical presentation, management, and outcome of eyes with an inadvertent globe perforationduring peribulbar or retrobulbar block. Methods: This retrospective study evaluated the eyes which had an accidental globe perforation during local ocular anesthesiafrom 2012 to 2020. The patients were divided into three groups: group 1, Clear media with no rhegmatogenous retinaldetachment (RRD); group 2, significant vitreous hemorrhage (VH) precluding the retinal view without RRD; and group 3, RRDwith/without VH. Results: Twenty-five patients were included in the study. The mean axial length (AL) was 24.7 ± 2.7 mm (range, 20.9–31.2mm). The most common presenting feature was VH (n = 14). The treatment included retinal laser barrage (n = 7) and vitrectomy(n = 17). Retinal breaks were identified in all the eyes (total breaks = 37). The mean presenting best-corrected visual acuityin groups 1, 2, and 3 were logarithm of the minimum angle of resolution 0.79 ± 0.73, 1.82 ± 0.78, and 2.13 ± 0.59 respectively. All the treated patients had an attached retina at the last follow-up. The mean final best-corrected visual acuity for eachgroup was logarithm of the minimum angle of resolution 0.59 ± 0.79, 0.48 ± 0.26, and 1.25 ± 0.64, respectively (p = 0.006). The development of RRD was associated with a larger AL (p = 0.015); while the development of significant VH associated withthe superior location of the perforation (p = 0.015), late recognition of the perforation (p = 0.004), and multiple perforations (p= 0.015). Conclusions: Early recognition and intervention in eyes with an inadvertent perforation can lead to a good outcome. Eyeswith a longer AL, superior, and multiple perforations are at higher risk of developing complications like RRD and VH. Complicationslike RRD, macular injury, and vascular occlusion are risk factors for poor prognosis.