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Defect-mediated electron–phonon coupling in halide double perovskite
No full textOptically active defects often play a crucial role in governing the light emission as well as the electronic properties of materials. Moreover, defect-mediated states in the midgap region can trap electrons, thus opening a path for the recombination of electrons and holes in lower energy states that may require phonons in the process. Considering this, we have probed electron–phonon interaction in halide perovskite systems with the introduction of defects and investigated the thermal effect on this interaction. Here, we report Raman spectroscopic study of the thermal evolution of electron–phonon coupling, which is tunable with the crystal growth conditions, in the halide perovskite systems Cs2AgInCl6 and Cs2NaInCl6. The signature of electron–phonon coupling is observed as a Fano anomaly in the lowest frequency phonon mode (51 cm-1), which evolves with temperature. In addition, we observe a broad band in the photoluminescence (PL) measurements for the defect-mediated systems, which is otherwise absent in defect-free halide perovskite. The simultaneous observation of the Fano anomaly in the Raman spectrum and the emergence of the PL band suggests the defect-mediated midgap states and the consequent existence of electron–phonon coupling in the double perovskite
Reservoir storage flash droughts in India are driven by human interventions
No full textReservoir storage flash droughts (RFDs), characterized by the rapid decline in reservoir storage, and conventional (long-term) reservoir storage droughts (RDs) impact water availability, hydropower generation, and agricultural activities. However, the mechanism and drivers of flash and conventional reservoir storage droughts in India remain unexplored. Using daily observations of reservoir storage, we identify RFDs and RDs in 81 major reservoirs in India during the 2000–2023 period. 46 out of 81 reservoirs are dominated by upstream climate as reservoir storage trends are driven by changes and variability in upstream precipitation, while the remaining 35 reservoirs are identified as human-dominating reservoirs. RFDs occur more frequently in human-dominating reservoirs than climate-dominating, especially in small reservoirs. About 70 % of RFDs in climate and human-dominating reservoirs are caused by sudden release to meet increased water demands in the downstream regions. Additionally, upstream precipitation deficit and downstream water demand control RDs, while downstream water demands can solely drive RFDs. Unlike reservoir storage trends, reservoir storage droughts are mostly linked with downstream water demands. We highlight the role of climate and human interventions in reservoir storage/droughts in India
Tropical cyclones as a possible source of lower ionosphere (thermosphere) perturbation: a case study of Amphan Super Cyclone (SuCS) over Bay of Bengal
No full textThe study investigates Super Cyclone (SuCS) Amphan, which occurred over the Bay of Bengal (BoB) during 16–21 May 2020 as a possible source of lower ionospheric perturbations. INSAT-3D satellite observations confirmed intense convective activity through low Cloud Top Brightness Temperature (∼–80 °C) and suppressed Outgoing Longwave Radiation (below 100 W/m2). Lightning analysis indicated an increase in activity within 500 km of the cyclone center, with cloud-to-cloud (CC) lightning intensifying in the eyewall during the cyclone's peak. Over 60 % of positive CC flashes exceeded 10 kA, highlighting strong convective electrical dynamics. Temperature perturbations observed by the AIRS instrument onboard NASA's Aqua satellite appeared as concentric wave patterns at stratospheric altitudes, indicating atmospheric gravity waves (AGWs) activity in the northeast of the storm center. SABER temperature profiles further revealed enhanced wave amplitudes from May 17–20, confirming AGW propagation into the mesosphere-lower thermosphere (MLT) region. Nightglow emissions observed by the Suomi-NPP/DNB sensor provided additional evidence of concentric gravity waves at the MLT heights. This enhanced AGW activity coincided with Amphan's intensification. This multi-altitude observational analysis highlights the role of intense convection and lightning in AGW generation and their subsequent influence on upper atmospheric dynamics. The observations confirm that tropical cyclones serve as a source of lower ionospheric disturbances through AGW-driven energy and momentum deposition
Compound weather and climate extremes in the Asian region: science-informed recommendations for policy
No full textAnthropogenic climate change has led to rapid and widespread changes in the atmosphere, land, ocean, cryosphere, and biosphere, leading to more pronounced weather and climate extremes globally. Recent IPCC reports have highlighted that the probability of compound extreme events, which can amplify risk, has risen in multiple regions. However, significant gaps remain in our understanding of the drivers and mechanisms behind these events. This concept paper discusses compound events in the Asian region in the context of its unique and diverse geographical settings, and regional climatic features including the seasonal monsoons. Notably, Asia is the world’s most disaster-affected region due to weather, climate, and water-related hazards. Therefore, an integrated understanding of how climate change will impact compound events in this region is essential for effective forewarning and risk mitigation. This paper analyzes three typologies of compound events in the Asian region, illustrating their regional complexity and potential linkages to climate change. The first typology pertains to compound floods, for example, the devastating floods in the Indus River Basin and adjoining Western Himalayas during 2022 caused by the combined effects of heavy monsoon rainfall, intense pre-monsoon heatwaves, glacier melt, and modes of climate variability. The second typology relates to compound heatwave-drought events that have prominently manifested in East and South Asia, and are linked to large-scale drivers of the land-atmosphere–ocean coupled system and local feedbacks. The third typology relates to marine extremes involving the compounding effects of ocean warming, sea-level rise, marine heatwaves, and intensifying tropical cyclones. We identify key knowledge gaps in understanding and predicting compound events over the Asian region and discuss advances required in science and technology to address these gaps. We also provide recommendations for the effective utilization of climate information towards improving early warning systems and disaster risk reduction
Optical, dielectric and electroconvection studies of a five-ring ester-difluoromethoxy linked ferroelectric nematic liquid crystal with a lateral methoxy group
No full textThere has been a surge of interest in the synthesis and characterisation of new ferroelectric nematic liquid crystals in recent times, focussing on understanding and optimising their properties for fundamental and practical applications. Here, we report experimental studies of a five-ring ester-difluoromethoxy linked ferroelectric nematic liquid crystal with a lateral methoxy group. We measure temperature-dependent electric polarisation, investigate the critical behaviour of the birefringence across the nematic to ferroelectric nematic phase transition and discuss the dielectric properties in view of the two physical models proposed recently. We study electrohydrodynamic instability and show that the phase diagram above the N–NF transition in the voltage–frequency plane is much richer than the NF phase
Survival differences of patients with treatment-naive CLL between the chemoimmunotherapy and BTKi eras: An eric study.
No full textIntroduction: Several randomized controlled trials have demonstrated superiority of BTK inhibitors (BTKis) over chemoimmunotherapy (CIT) in patients with treatment naïve (TN) CLL. In some of these trials, BTKis have also led to a statistically significant improvement in overall survival (OS). However, it is largely unknown if the adoption of BTKis in TN CLL has improved OS of patients with CLL in the real world (RW).
Methods: This is a retrospective, observational study that aimed to explore differences in the OS of patients with TN CLL treated a) in different eras [CIT-era group vs BTKi-era] and b) with BTKis vs fludarabine-cyclophosphamide-rituximab (FCR) in a RW setting. In the latter comparison, we excluded patients >70 years at first-line (1L) treatment and patients with TP53 aberrations.
Patients who received 1L treatment for CLL between 2010 and 2020 in 14 countries were included in the study. Patients were allocated to two different groups (CIT-era and BTKi-era groups) according to the actual use of BTKis in each country.
The year when the use of BTKis surpassed 25% was defined as the cutoff year for each country. Cases treated before the cutoff year were allocated to the CIT-era group, and cases treated after the cutoff year were allocated to the BTKi-era group. OS was defined as the time from CLL-directed treatment to death (event) or last follow-up date (censoring). For the propensity score matching (PSM), we matched patients based on age at 1L initiation, biological sex, and TP53 aberrations for the group comparison and on age at 1L initiation and biological sex for the BTKis vs FCR comparison.
Results: A total of 5642 patients (CIT-era group: 4321 and BTKi-era group: 1321) from 37 centers were eligible for the study. The cutoff year was 2020 for the Czech Republic and Russia, 2019 for Brazil, Croatia, Germany, Greece, 2018 for Israel and Turkey, 2017 for Italy and Spain, and 2016 for Switzerland and the United Kingdom. Cases treated in India and Serbia did not reach the 25% cut-off and were allocated to the CIT-era group.
BTKis represented the most common treatment in 1L for the BTKi-era group [484 (37%), ibrutinib-based: 443 (91.5%), acalabrutinib-based: 34 (7%), and zanubrutinib-based: 7 (1.5%)], while only 67 (5.1%) cases were treated with venetoclax-based regimens, reflecting the later approval of these regimens in 1L. In the CIT-era group, FCR (1478, 34.1%) chlorambucil-based (1131, 26.2%) and bendamustine plus anti-CD20 antibody (549, 12.7%) were the most common treatments. The use of BTKis in 1L in the CIT-era group was minimal (141, 3.3%).
In both groups, most patients were males [2755 (64%) in the CIT-era group and 836 (63%) in the BTKi-era group, p=0.8]. Patients in the CIT group were younger at the start of 1L treatment [67 years (IQR=59-74) vs 69 (IQR=62, 76) p=0.001 for the CIT and BTKi-era groups, respectively].
TP53 mutations and del(17p) were similarly distributed among the two groups [del(17q): 304 (11%) vs. 130 (13%), p=0.09 | TP53 mutations: 202 (15%) vs. 100 (12%), p=0.09]. Unmutated immunoglobulin heavy variable (IGHV) gene status and del(11q) were more frequent in the CIT-era group [449 (19%) vs 126 (15%), p= 0.02 | 1.209 (65%) vs 532 (59%), p= 0.003, respectively]. The follow-up time from 1L treatment was longer for the CIT group [64 months (IQR: 31-98) vs 48 (IQR: 22- 63)] for CIT and BTKi groups, respectively.
OS was similar between the two groups [HR: 0.98 (95%CI: 0.88-1.10), p=0.8), median OS: CIT-era group: 7.8 years (95% CI: 7.5, 8) vs BTKi-era group: not reached (7.5, not estimable (NE)]. However, the OS difference was statistically significantly better for the BTKi-era group when we compared OS with PSM for age at 1L initiation and biological sex (HR=0.88 (95%CI: 0.79-0.99), p= 0.04) and for age at 1L initiation, biological sex, and TP53 aberrations [HR:0.73 (95%CI: 0.61-0.88), p< 0.001].
Finally, in the PMS analysis, the OS of patients treated with BTKis was not statistically significantly different compared to cases treated with FCR in 1L (HR: 0.80 (95%CI: 0.56, 1.15), p= 0.2). The median OS for patients treated with BTKis (n=211) and FCR (n=1259) was 10 years (95% CI: 10, NE) and 10.8 years (95% CI: 9.8-11.9), respectively.
Conclusion: Our findings show that the availability of BTKis has improved the OS of patients with TN CLL. Patients treated with BTKis had a similar OS with cases treated with FCR in the RW setting
MM-588: Prevalence of plasma cell dyscrasia at the All India Institute of Medical Sciences, New Delhi, India
No full textContext:
Plasma cell dyscrasias (PCDs) represent a diverse set of disorders defined by the malignant proliferation of monoclonal plasma cells in the bone marrow, which produce monoclonal immunoglobulins commonly known as M protein.
Objective:
To assess the frequency and distribution of different PCDs diagnosed at the largest tertiary care centre in India.
Design, Setting, and Participants
This study involved a retrospective analysis of all newly diagnosed patients with PCDs who underwent a complete baseline workup at the All India Institute of Medical Sciences, New Delhi, India, from June 2023 to February 2025.
Results:
A total of 140 patients were diagnosed with PCD at our center during this period, with a median age of 59 years and a male-to-female ratio of 2:1. Multiple myeloma (MM) represents the predominant type, accounting for 70% of all cases (IgG Kappa: 61%; ISS stage 3: 40.1%; high-risk patients: 21.6%; extramedullary disease [EMD]: 19.2%; light chain myeloma: 18.1%). In our cohort, additional PCDs identified included AL amyloidosis: 9.3%; solitary plasmacytoma: 6.42%; POEMS syndrome: 5.71%; Waldenstrom macroglobulinemia: 2.8%; monoclonal gammopathy of undetermined significance (MGUS): 2.14%; smouldering myeloma: 1.42%; plasma cell leukaemia: 1.42%; others: 0.71%.
Conclusions:
Multiple myeloma is the most prevalent plasma cell disorder, followed by AL amyloidosis and solitary plasmacytoma. The prevalence of EMD is elevated relative to published literature, potentially attributable to disease biology or the frequent utilization of PET-CT scans during initial staging assessments. The prevalence of MGUS in our population is lower than in Western countries, underscoring the necessity for a screening method that promotes early detection, suitable risk classification, and timely treatment for high-risk MGUS cases to avert progression to multiple myeloma
Delphi survey on measurable residual disease in multiple myeloma: Prevailing practices and the way forward in India
No full textBackground:
Measurable residual disease (MRD) is becoming a cornerstone in the multiple myeloma (MM) management; however, its implementation in India faces several challenges. This Delphi survey aimed to gather expert consensus on the current practices, and barriers in MRD monitoring in MM in India.
Methods:
A 3-round Delphi process (2 e-surveys and 1 in-person meeting) was conducted with hematologists, pathologists, and oncologists managing MM in India. Consensus (≥ 75% agreement) led to recommendations for standardized MRD practices.
Results:
Twenty-five experts participated, agreeing on key protocols: processing first-pull bone marrow aspirates within 24 hours, using a single tube with at least a 10-color panel, acquiring at least 3 million events for 10-5 sensitivity under proper environmental control, and by adequately trained staff. At least 4 monoclonal antibodies for gating of plasma cells and at least 3 parameters among mast cells, myeloid precursors, hematogones, normal plasma cells, should be used to assess hemodilution. Guidance on modulation of treatment decisions, including maintenance therapy based on MRD status remains inconclusive. Though, there is an agreement that MRD negativity in MM improves survival and lowers relapse risk but currently it does not influence maintenance therapy decisions. MRD testing was advised at postinduction, pre/post-transplant, and annually during maintenance.
Challenges identified included protocol variability, interpretation issues, and lack of an external quality assessment program. Experts emphasized the need for advanced flow cytometry training.
Conclusions:
The findings of this study will guide clinical adoption and future research, particularly for high-risk populations and novel therapies
Synthesis of sulfonated metal-substituted hydroxyapatite and its polymeric composite for sequestration of lead and cadmium from water: Batch and column study.
No full textAluminium substituted hydroxyapatite (aHAp) was functionalized with sulfonate moieties employing an in-situ co-precipitation method using thioglycolic acid (TGA). Polymeric composite beads (denoted as aHAp-TGA PAN) were synthesized by immobilizing the modified aHAp (aHAp-TGA) nanoparticles in polyacrylonitrile (PAN) matrix for removal of toxic heavy metals, lead (Pb) and cadmium (Cd), from water. The adsorbents (both nanoparticles and composite) were characterized using state-of the art techniques. aHAp-TGA demonstrated a maximum saturation capacity of 1131 mg/g and 177 mg/g for Pb and Cd, respectively, evidencing significant increase in capacity (nearly 40 % for Pb and over 60 % for Cd) compared to aHAp due to the inclusion of sulfur-functionalities into the structure (through chelation and electrostatic interaction). The influence of adsorbent dose, pH, feed concentration, temperature and contact time were explored in detail along with the associated kinetic and thermodynamic parameters. High affinity of aHAp-TGA for Pb and Cd was indicated by the distribution coefficient (Kd:3.66 × 105 mL/g and 1.25 × 104 mL/g, respectively). The selectivity in presence of interfering ionic species and the regeneration of the materials (for 5 cycles) were also observed. Dynamic uptake studies were conducted in adsorption column with aHAp-TGA PAN beads to study the breakthrough performance that was simulated using an available diffusion-adsorption-convection model. This work focuses on the efficient wastewater treatment using the macrobeads showcasing a sustainable and scalable media in real-field application
Degradable theranostic polyurethane for macrophage-targeted antileishmanial drug delivery.
No full textThe present investigation aims to develop a reactive oxygen species (ROS) and esterase-responsive biodegradable mannosylated polyurethane to effectively deliver the encapsulated antileishmanial drug amphotericin B (AmB) selectively to infected macrophage cells. Owing to suitable amphiphilic balance, the as-synthesized glycosylated polyurethane (PU2M) with aryl boronic ester-based diol (M2) moiety as ROS-trigger, water-soluble mannose pendants, and fluorescent 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) chain ends for bioimaging formed nanoaggregates in an aqueous medium as confirmed by 1H NMR spectroscopy, dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and critical aggregation concentration (CAC) measurements. Aided by two endogenous stimuli present in phagolysosome, ROS and esterase, AmB-encapsulated polymeric nanoaggregates as drug delivery vehicles achieved an efficient reduction of both L. donovani and L. major intracellular amastigote burden compared to the free AmB. Overall, this work illustrated a promising therapeutic application of dual endogenous stimuli-triggered degradable theranostic polyurethane for target-specific drug delivery of AmB, to mitigate leishmaniasis