Calcutta Research Group

Precise control of the Fermi level in two-dimensional materials is critical for modulating their electronic structure, thereby facilitating their effective implementation in advanced electronic and optoelectronic applications. Here, we report on the role of cobalt doping in modulating the Fermi level of MoS2 synthesized by the chemical vapor deposition process. Raman spectroscopic results confirmed the presence of p-type dopants and tensile strain in the system through characteristic peak shifts. Photoluminescence studies reinforced the Raman findings by showing progressive quenching of excitonic emission and defect state evolution, consistent with Co-induced p-type doping. X-ray photoelectron spectroscopy validated Co substitution in the MoS2 lattice and provided quantitative insights into bonding states and dopant concentration. Furthermore, Kelvin probe force microscopy measurements demonstrated a clear increase in work function with increasing Co concentration, reflecting a Fermi level shift toward the valence band. These findings highlight the dual role of cobalt doping in inducing strain and charge transfer, thereby offering a tunable strategy for engineering the electronic properties of MoS2 for next-generation nanoelectronics and catalytic applications.

Ageing has been recognized as the leading risk factor for Alzheimer's disease (AD), with an intricate interplay of oxidative stress, neuroinflammation, and cellular senescence implicated in its pathogenesis. Mitochondrial dysfunction has been linked to redox imbalance and excessive production of reactive oxygen species (ROS), which disrupt homeostasis and damage both mitochondrial and nuclear DNA, thereby promoting amyloid-β accumulation and cognitive decline. Chronic activation of inflammasome signaling in microglia and astrocytes, characterized by the upregulation of NLRP3 and NF-κB, has been linked to the establishment of a neuroinflammatory environment, leading to synaptic loss and exacerbating tau pathology. Additionally, the accumulation of senescent glial and neuronal cells has been shown to drive the senescence-associated secretory phenotype (SASP), further amplifying inflammation and oxidative damage. Promising therapeutic interventions, including mitochondria-targeted antioxidants and senolytics, have been evaluated; however, translational challenges persist, such as the heterogeneity of biomarker measures and the insufficient delivery of antioxidants. A proposed roadmap emphasizes the importance of monitoring oxidative and inflammatory biomarkers, implementing combinatorial therapies, and personalizing interventions to enhance resilience in the ageing brain and delay the onset of AD.

In soils, microorganisms interact with biotic and abiotic components to drive rock-to-soil transformations and imbue soil with its characteristics. We studied the bacterial and fungal communities using total DNA extracted from a soil sample collected from the active weathering zone of a landscape covered by ferruginous duricrust in the Gangani area of Garbeta, Eastern India. The XRF analysis revealed a compositionally matured nature of the ferricrete, whereas poorly sorted grain size indicates a texturally immature character. Molecular characterisation of bacterial and fungal communities through partial sequencing of the 16S and ITS rRNA genes, respectively, revealed a diverse presence of chromium (Cr) and vanadium (V)-tolerant bacterial (Bacillus, Pseudomonas and Serratia) and fungal (Aspergillus, Inocybe, Penicillium, and Pisolithus) genera in the studied sample. Such a microbiome can influence weathering, biomineralisation and nutrient cycling in lateritic/ferricrete landscapes and soils. The presence of Mn-oxidisers (Serratia sp.) and acidophilic iron-oxidisers (Acidithiobacillus sp.), along with Bacillus sp., in combination with mycorrhizal fungi Pisolithus sp., can increase weathering fluxes. The presence of ectomycorrhizal fungi, Inocybe, may have a possible role in stabilising laterite soils. This study is likely the first report of such geomicrobial interactions from eastern India, especially from its lateritic/ferricrete landscapes. Total DNA reveals the presence of bacteria and fungi in ferruginous duricrust. Microbiome can influence biomineralisation and nutrient cycling. XRF analysis reveals compositionally matured but texturally immature ferricrete. Increase weathering flux and stabilise lateritic soil in the active weathering zone.

In today's fast-paced world, emergencies such as train accidents, road accidents, heart attacks, brain strokes, or situations involving lost children and abandoned elderly individuals pose significant challenges in providing timely assistance. To address these critical situations effectively, we propose an innovative solution: an integrated system designed to quickly identify individuals in distress and provide necessary information to their guardians and emergency responders. Our proposed system leverages advanced technologies, including QR code scanning and biometric recognition, integrated with India's Aadhaar database. The system consists of a face and fingerprint scanner that, when deployed in an emergency, can quickly identify a person by matching their biometric data with the Aadhaar database. This match provides crucial information such as the individual's address, emergency contact numbers, and medical history.

The present study aims to examine the age-wise occupational disparity in West Bengal using National Classification of Occupation (NCO) classifications between working age male and female workers by different occupation status using the latest Periodic Labour Force Survey (PLFS) data 2022–2023 separately for the rural and urban sectors. Three different age cohorts that are (15–24) as young, (25–44) as middle and (45–65) as old are considered here to examine the age-wise contribution in each occupation of both the workers. The substantial differences in occupations have been observed by not only gender but also sectors. Occupations in urban West Bengal are mainly semi-skilled and high-skilled types, whereas in the rural sector, the predominance of agricultural activity and elementary occupations led the workers to perform mainly low-skilled occupations. The contribution of youth female workers in professional occupations is notable in both the sectors. An ordered logit model is performed to determine the possible personal and household factors for the participation of different ranks of occupations for separate gender of both the sectors where marital status, number of children and dependency ratio are found to be potential obstacles for the females to engage in high-rank occupations. Finally, this chapter concludes with some policy suggestions.

The resurgence of Visceral Leishmaniasis (VL) is a natural cyclical phenomenon with an inter-epidemic period of 10-15 years. It might be due to the persistence of a silent parasite pool amongst post kala-azar dermal leishmaniasis (PKDL) and asymptomatic leishmanial infection (ALI). The present study targeted to find out the obstacles for unearthing and proper management of the hidden parasite pool for prevention of the resurgence of VL in erstwhile endemic districts of West Bengal, India. Two strategies were employed to identify the latent parasite reservoirs: follow-up of individuals having a previous history of VL and/or PKDL and limited mass sero-surveillance within a 500-m radius of recently treated VL and PKDL. Diagnosed PKDL and VL cases were treated and ALI were followed up. A total of 95 new PKDL and 70 relapse PKDL were diagnosed during the entire study period; those remained undiagnosed in spite of ongoing case searching methods recommended by the national VL elimination programme. 'Relapse PKDL'-a new challenge for VL elimination has been identified. The incidence of PKDL declined steadily during successive study years. Limited mass survey revealed 17 VL, 2 PKDL and 124 ALI. Most of the ALI sero-reverted during the follow up period and 2 of them converted to disease VL. The present work revealed three major obstacles. First, identification of the occult parasite pool may be resolved by applying the searching methods used in this study. Second, case confirmation of 'relapse PKDL' may be achieved by examining slit skin samples at the local level by existing staff with proper training. Alternative short duration treatment strategy for the treatment of new and relapse PKDL is needed. Third, considering the long inter-epidemic period and observed declining trend of incident PKDL, such surveillance should be continued for 10-15 years for the prolonged post-elimination phase and finally to achieve eradication.

ABSTRACT This research presents a wearable radiator with dual‐band and quad‐terminal that is compact and made on polyimide substrate. Dual metallic rings integrated with the feed line create the band notch in between 2.66 and 3.28 GHz and convert the wideband into dual band feature. By taking use of spatial and polarization diversity, the separation level among various terminals is more than 25 dB. A single‐negative (SNG) metamaterial‐based metasurface (MS) reflector‐cum‐absorber surface located just below the radiator reduces the specific absorption rate (SAR) for the 1‐ and 10‐g tissue models by more than 90%, while also increasing the radiator gain to 5.65 and 4.55 dBi. ANSYS HFSS 2023 R2 was used for full‐wave simulations, and a Keysight E5071C VNA in both flat and bending configurations was used for experimental validation. Using a three‐layer human tissue phantom (skin, fat, and muscle) with 1‐ and 10‐g averages, SAR assessment was conducted in accordance with IEEE/IEC 62209‐1 and ICNIRP recommendations. Its performance in two frequency bands, 2.3–2.65 and 3.3–3.65 GHz, is confirmed by measurement findings. All these features make the radiator applicable for WBAN application.

BackgroundBlood eosinophils have become an invaluable tool in the assessment, management, and prognostication of patients with asthma and chronic obstructive pulmonary disease (COPD). Historically, the understanding and application of blood eosinophil counts (BEC) have been primarily based on data from high-income countries, with limited information available from developing regions, including the Indian subcontinent.Research QuestionThis study aims to assess the distribution and clinical relevance of BEC among patients with asthma and COPD as well as healthy volunteers across India, to determine if patterns observed in Western studies hold true in an Indian setting.Study Design and MethodsA multi-centre cross-sectional study was conducted at 16 clinics across India. Participants included patients diagnosed with asthma or COPD and healthy volunteers who were identified from referrals to these clinics. Comprehensive data collection involved demographics, medication use, smoking status, and pre- and post-bronchodilator spirometry. All participants underwent a laboratory full blood count.ResultsThe study comprised 4782 adults, including 1,332 patients with asthma (571 males, 761 females), 1,001 patients with COPD (691 males, 310 females), and 2,449 healthy volunteers (1,399 males, 1,050 females). Among patients with asthma, the mean BEC was higher at geometric mean 173.9 [156.2, 193.6]; patients with COPD had a mean BEC of 198.4 [178.6, 220.4] which was significantly higher than that of healthy volunteers (144.7 [134.5, 155.5]).InterpretationThe range of eosinophils in the contemporary Indian population aligns with data from Europe, affirming the validity of using BEC as a biomarker in obstructive lung disease within the Indian demographic. This insight challenges the prevailing assumption of distinct eosinophil count profiles in different geographical regions and underscores the global applicability of eosinophil-based management strategies for asthma and COPD.