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result(s) for
"Das, Dipankar"
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Diluting quark flavor hierarchies using dihedral symmetry
by
Das Dipankar
,
Srivastava Ayushi
,
Levy, Miguel
in
Flavor (particle physics)
,
Hierarchies
,
Quarks
2022
We present a D4 flavored extension of the SM which provides an intuitive reasoning for the masses and mixing patterns in the quark sector. In our model, the Cabibbo mixing angle becomes related to the ratio of two vacuum expectation values. In fact, the orders of magnitude of the CKM matrix elements are readily obtained from the hierarchical nature of the vacuum expectation values. Moreover, we also show that the smallness of the off-Cabibbo elements in the CKM matrix is strongly connected to the heaviness of the third generation of quarks.
Journal Article
Validation of urinary reproductive hormone measurements using a novel smartphone connected reader
by
Das, Dipankar
,
Pattnaik, Siddharth
,
Venkatesan, Varun Akur
in
692/163/2743
,
692/700/139
,
Accuracy
2023
Home use tests to monitor hormone trends during the menstrual cycle have been available over-the-counter for a long time. However, these tests often depend upon manual readouts and hence may lead to false analysis. Furthermore, a lot of these tests are also not quantitative. The aim of this study was to evaluate the accuracy of the quantitative home-based fertility monitor, Inito Fertility Monitor (IFM) and to use it to identify novel hormone trends in natural menstrual cycles. There were two aspects to our analysis: (i) Evaluating the efficacy of Inito Fertility Monitor in the measurement of urinary Estrone-3-glucuronide (E3G), Pregnanediol glucuronide (PdG) and Luteinizing hormone (LH), and (ii) A retrospective study of patients' hormone profiles using IFM. To evaluate the efficacy, the recovery percentage of the three hormones from IFM was evaluated using standard spiked solutions, the accuracy of measurement was calculated and the correlation between reproducible values from IFM and ELISA was established. During the validation of IFM, novel hormone trends were also observed. In order to reinforce the observations, a second group of 52 women was recruited. Assessment of the accuracy of IFM and evaluation of the volunteer urine samples was performed in a laboratory. Home assessment of hormone analysis was carried out using IFM. For the validation study, 100 women aged 21–45 years with cycle lengths ranging from 21 to 42 days were recruited. The participants had no previously diagnosed infertility conditions and their cycle lengths did not vary for more than 3 days from the expected cycle length. Daily first morning urine samples were collected from these 100 women. For the second group, 52 women were selected meeting the same criteria set for the validation study and IFM was provided to these women for testing at home. Coefficient of variation and recovery percentage of IFM with respect to laboratory based ELISA. Percentage occurrence of novel hormone trends and AUC analysis of a novel criteria identified for confirming ovulation. We observed that with all three hormones, IFM had an accurate recovery percentage. We found that the assay has an average CV of 5.05% in PdG measurement, 4.95% in E3G measurement and 5.57% in LH measurement. Furthermore, in predicting the concentration of E3G, PdG and LH in urine samples, we show that IFM has a high correlation with ELISA. In this study, we could also reproduce hormones trends across the menstrual cycle that have been observed by previous studies. We also identified a novel criterion for earlier confirmation of ovulation which could accurately distinguish ovulatory from anovulatory cycles with 100% specificity and had an area under the ROC curve of 0.98. In addition, we identified a new hormone trend which could be observed in 94.5% of the ovulatory cycles. The Inito Fertility Monitor is an effective tool for calculating the urinary concentrations of E3G, PdG and LH and can also be used to provide accurate fertility scores and confirm ovulation. We show that certain hormone trends associated with urinary E3G, PdG and LH could be accurately captured using IFM. In addition, we report a novel criterion for earlier confirmation of ovulation compared to existing criteria. Finally, we present a novel hormone pattern associated with most of the menstrual cycles by examining hormone profiles from the volunteers recruited for the clinical trial.
Trial registration
: The trial is registered at the current controlled trials ISRCTN registry #ISRCTN15534557.
Journal Article
A three Higgs doublet model with symmetry-suppressed flavour changing neutral currents
by
Das, Dipankar
,
Rodrigues, J. Pedro
,
Padilla-Gay, Ian
in
Beyond Standard Model
,
Bosons
,
Classical and Quantum Gravitation
2021
A
bstract
We construct a three-Higgs doublet model with a flavour non-universal U(1) × ℤ
2
symmetry. That symmetry induces suppressed flavour-changing interactions mediated by neutral scalars. New scalars with masses below the TeV scale can still successfully negotiate the constraints arising from flavour data. Such a model can thus encourage direct searches for extra Higgs bosons in the future collider experiments, and includes a non-trivial flavour structure.
Journal Article
A model of neutrino mass and dark matter with large neutrinoless double beta decay
by
Das, Dipankar
,
Santamaria, Arcadi
,
Alcaide, Julien
in
Beta decay
,
Beyond Standard Model
,
Classical and Quantum Gravitation
2017
A
bstract
We propose a model where neutrino masses are generated at three loop order but neutrinoless double beta decay occurs at one loop. Thus we can have large neutrinoless double beta decay observable in the future experiments even when the neutrino masses are very small. The model receives strong constraints from the neutrino data and lepton flavor violating decays, which substantially reduces the number of free parameters. Our model also opens up the possibility of having several new scalars below the TeV regime, which can be explored at the collider experiments. Additionally, our model also has an unbroken
Z
2
symmetry which allows us to identify a viable Dark Matter candidate.
Journal Article
Surfactant based synthesis and magnetic studies of cobalt ferrite
by
Das, Dipankar
,
Das, Anusree
,
Datta, Anindya
in
Applied physics
,
Cetyltrimethylammonium bromide
,
Characterization and Evaluation of Materials
2020
Nanoparticles of cobalt ferrite were synthesized by two different surfactants cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulphate (SDS) by the microemulsion method. Formation of cobalt ferrite was confirmed by structural characterization techniques XRD and TEM. The magnetic properties of these systems were studied using Mössbauer spectroscopy and SQUID magnetometry. The study determined the impact of the synthetic procedure and surfactant composition on the nanomaterial characteristics. The overall magnetic response for the material was different compared to the bulk with a major decrease in room temperature magnetic saturation. Magnetic properties were affected by the type of surfactant template due to its impact on the geometry of the synthesized cobalt ferrite nanoparticles.
Graphic abstract
Journal Article
Thermoelectric composite material of CuBO2 incorporated PANI powders with enhanced Seebeck coefficient
by
Das, Dipankar
,
Bhagade, Sagarika
,
Saha, Biswajit
in
Characterization and Evaluation of Materials
,
Chemistry
,
Chemistry and Materials Science
2022
A Composite of PANI with CuBO
2
has been prepared by a solid-state synthesis method and its thermoelectric performance has been studied. The PANI/CuBO
2
composite mixture shows p-type conduction with exceptionally improved Seebeck coefficient (S) and electrical conductivity (σ) as well as thermoelectric power factor (P = S
2
σ). The outstanding enhancement in TE properties of the composite mixture is attributed to the reduction of π-π conjugated defects in the polymer chain matrix. The highest values of electrical conductivity and Seebeck coefficient for the prepared composite mixture reach 0.34 S/cm and 0.43 mV/°C, respectively, and the maximum TE power factor as recorded is 6.28 μW/mK
2
, which is about 107-fold larger in magnitude than that of pure PANI. The power factor as achieved at a comparatively lower temperature difference below 100 °C indicates that these powder mixtures of PANI/CuBO
2
can be an effective material for better performance in thermoelectric energy harvesting from waste heat.
Journal Article
Groundwater arsenic contamination and its health effects in India
by
Das, Dipankar
,
Biswas, Bhajan Kumar
,
Chowdhury, Uttam Kumar
in
Aquatic Pollution
,
Arsenic
,
Bioaccumulation
2017
During a 28-year field survey in India (1988–2016), groundwater arsenic contamination and its health effects were registered in the states of West Bengal, Jharkhand, Bihar and Uttar Pradesh in the Ganga River flood plain, and the states of Assam and Manipur in the flood plain of Brahamaputra and Imphal rivers. Groundwater of Rajnandgaon village in Chhattisgarh state, which is not in a flood plain, is also arsenic contaminated. More than 170,000 tubewell water samples from the affected states were analyzed and half of the samples had arsenic >10 μg/L (maximum concentration 3,700 μg/L). Chronic exposure to arsenic through drinking water causes various health problems, like dermal, neurological, reproductive and pregnancy effects, cardiovascular effects, diabetes mellitus, diseases of the respiratory and gastrointestinal systems, and cancers, typically involving the skin, lungs, liver, bladder, etc. About 4.5% of the 8,000 children from arsenic-affected villages of affected states were registered with mild to moderate arsenical skin lesions. In the preliminary survey, more than 10,000 patients were registered with different types of arsenic-related signs and symptoms, out of more than 100,000 people screened from affected states. Elevated levels of arsenic were also found in biological samples (urine, hair, nails) of the people living in affected states. The study reveals that the population who had severe arsenical skin lesions may suffer from multiple Bowens/cancers in the long term. Some unusual symptoms, such as burning sensation, skin itching and watering of eyes in the presence of sun light, were also noticed in arsenicosis patients.
Journal Article
Transmittance characteristics of transparent hydrophobic acrylic foldable intraocular lenses that were in vivo for a prolonged period of time: A UV visible spectrophotometric study
by
Das, Dipankar
,
Javeri, Henal
,
Bhattacharjee, Kasturi
in
Care and treatment
,
Cataract
,
delayed dislocation
2023
Purpose:
To record experimental data on the spectral transmittance characteristics of transparent hydrophobic acrylic foldable IOLs, which were in vivo for a prolonged period of time and explanted under clinical indications and also to compare the data with that of corresponding control and crystalline lens along with review of the relevant literature.
Method:
Material and make of each of the explanted intraocular lenses (IOLs) as well as pre-explantation clinical status of the eyes were confirmed from the medical record. The transmittance of wavelength from 185 to 900 nm of each of the selected IOLs was measured using Shimadzu UV 2600 UV visible (UV-Vis) spectrophotometer in double-beam configuration and probe version 2.16 software. The data obtained were statistically analyzed.
Results:
The mean transmittance of 12 clinically explanted IOLs at spectral range 300-700 nm was 49.5% ± SD 6.9%. This value was 10% and 38% less than the corresponding clear (59% ± SD 0.4%) and yellow (87.5% ± SD 0.4%) control, respectively. The mean transmittance of the analytes in the UV range was 43.3 ± SD 6.9%, and it was almost similar to the control. The data showed wide variations without good correlation, and it matches with the human crystalline lens at the age range of 50-60 years. All eyes were otherwise healthy, and none had age-related macular degeneration.
Conclusion:
In comparison with fresh IOL with a yellow filter, light transmittance at the spectral range 300-700 nm was found decreased in all the IOLs, which were in vivo for an average period of 12.25 ± 4.4 years. All IOLs transmitted variable amounts of UV radiation. More data are required for further analysis on the subject.
Journal Article