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Synergistic effect of multimodal γ' precipitates tuned through Ti addition on phase stability and strength of Co-Ni based superalloy
No full textThe paper explores the role of multimodal γ' distribution in a CoNi-based superalloy on their thermophysical and mechanical properties. Three categories of γ' size distribution as primary, secondary type-1, and secondary type-2 were obtained by varying Ti composition (2, 4, and 6 at.%) in a Co-30Ni-7Al-2Nb (at.%) alloy. The study reveals an anomaly in primary γ' solvus with an increase in Ti composition that influences the microstructure. The anomaly can be related to the interplay between Nb and Ti composition in the γ'. We report a direct correlation among the nature of γ' distribution, its composition, and the yield strength of the alloys at room and high temperatures
Search and routing in large area hierarchical IoT networks
No full textThe world wide use of the public internet has opened up the possibility of applying similar technology for automated functioning of physical objects equipped with micro electronic devices. The perception is to apply that kind of technology to various areas of human activity for enhancing the quality and scale of performance. Starting from automated homes, the possibility of application are projected to be in efficient transport systems, energy management, smart cities, industrial automation, environmental monitoring, business management, defense operations etc. Such activities require huge network support, deployed over vast areas of the globe with suitable taxonomy for fast connectivity and operation. In this paper, it is suggested that the network is hierarchical having hybrid tree graph architecture, with the root node as the overall controlling headquarter. The hierarchy of the nodal stations is assumed to be based on the geographical distance from the root node, in which the nodes having the same hierarchy are also linked by collateral bus connectivity. The search of a node and routing data to the destination is carried out along a path which is as close as possible along the geographical direction of the location of that destination. Such a procedure was earlier developed by this author [19], [20], accounting fully for the sphericity of the globe. Accordingly, an algorithm for the search and routing in the envisaged network is presented in conclusion
Pressure-induced superconductivity in the weak topological insulator BiSe
No full textQuasi-two-dimensional layered BiSe, a natural super-lattice with Bi2Se3-Bi2-Bi2Se3 units, has recently been predicted to be a dual topological insulator, simultaneously weak topological insulator as well as topological crystalline insulator. Here using structural, transport, spectroscopic measurements and density functional theory calculations, we show that BiSe exhibits rich phase diagram with the emergence of superconductivity with Tc ~8K under pressure. Sequential structural transitions into SnSe-type energetically tangled orthorhombic and CsCl-type cubic structures having distinct superconducting properties are identified at 8 GPa and 13 GPa respectively. Our observation of weak-antilocalization in magneto-conductivity suggests that spin-orbit coupling (SOC) plays a significant role in retaining non-trivial band topology in the trigonal phase with possible realization of 2D topological superconductivity. Theoretical analysis reveals that SOC significantly enhances superconducting Tc of the high-pressure cubic phase through an increase in electron-phonon coupling strength. Simultaneous emergence of Dirac-like surface states suggests cubic BiSe as a suitable candidate for the 3D-topological superconductor
Design of porphyrin-based frameworks for efficient visible light-promoted reduction of CO<sub>2</sub> from dilute gas: Combined experimental and theoretical investigation
No full textThe photocatalytic carbon dioxide reduction (CO2R) coupled with hydrogen evolution reaction (HER) constitutes a promising step for a sustainable generation of syngas (CO + H2), an essential feedstock for the preparation of several commodity chemicals. Herein, visible light/sunlight-promoted catalytic reduction of CO2 and protons to syngas using rationally designed porphyrin-based 2D porous organic frameworks, POF(Co/Zn) is demonstrated. Indeed, POF(Co) showed superior catalytic performance over the Zn counterpart with CO and H2 generation rates of 1104 and 3981 μmol g−1h−1, respectively. The excellent catalytic performance of Co-based POF is aided by the favorable transfer of photo-excited electrons from Ru-sensitizer to the CoII catalytic site, which is not feasible in the case of POF(Zn), revealed from the theoretical investigation. More importantly, the POF(Co) catalyzes the reduction of CO2 even from dilute gas (13% CO2), surpassing most reported framework-based photocatalytic systems. Significantly, the catalytic performance of POF(Co) was increased under natural sunlight conditions suggesting sunlight-promoted enhancement in syngas generation. The in-depth theoretical investigation further unveiled the comprehensive mechanistic pathway of the light-promoted concurrent CO and H2 generation. This work showcases the advantages of porphyrin-based frameworks for visible light/sunlight-promoted syngas generation by utilizing greenhouse gas (CO2) and protons under mild eco-friendly conditions
Quality assessment of adhesive joints using third harmonics of fundamental shear horizontal wave mode
No full textThis study aims to investigate the bond quality of aluminum–epoxy–aluminum tri-layer bonds using nonlinear ultrasonics. An experimental methodology was developed in which the tri-layer bonds with different interface qualities were inspected using the fundamental shear horizontal guided wave mode (SH0). An in-house developed magnetostrictive transducer assembly was used to excite the SH0 wave mode in the bonded samples. The harmonic generation of the SH0 wave mode was confirmed using dispersion curves overlaid on short-time Fourier transform (STFT) and frequency–wavenumber plots. The sensitivity of the third harmonics to the interface quality of the bonds was estimated using a relative nonlinearity parameter (δ*). In this work, the mean δ* for the non-sandblasted bond is found to be 70% more than that of the sandblasted sample, which shows the sensitivity of the third-harmonic generation to the interfacial degradation. The analysis shows that the technique can be implemented for a quick and early inspection of the bonded samples for their bond quality
A Hybrid High-Order Method for a Class of Strongly Nonlinear Elliptic Boundary Value Problems
No full textIn this article, we design and analyze a hybrid high-order (HHO) finite element approximation for a class of strongly nonlinear boundary value problems. We consider an HHO discretization for a suitable linearized problem and show its well-posedness using the Garding type inequality. The essential ingredients for the HHO approximation involve local reconstruction and high-order stabilization. We establish the existence of a unique solution for the HHO approximation using the Brouwer fixed point theorem and contraction principle. We derive an optimal order a priori error estimate in the discrete energy norm. Numerical experiments are performed to illustrate the convergence histories
Pyrazine derivative as supramolecular host for immobilization of palladium nanoparticles for efficient Suzuki coupling
No full textPalladium nanoparticles (NPs) have been extensively explored as unique catalyst for carbon-carbon coupling reactions. Nonetheless, because of extreme tendency of nanoparticles to undergo agglomeration, the immobilization of these metal NPs on organic frameworks is an important area of research. The present investigation demonstrates the synthesis of pyrazine derivative PYZ-TA as a supramolecular host for holding co-released Pd NPs derived from the original catalyst (Pd(II)) under standard Suzuki coupling. Unprecedent, physical bars are not required to capture Pd NPs within the pores of supramolecular host. The as obtained catalyst PYZ-TA@Pd exhibits high potential to undergo self-assembly in solid as well as in liquid state. The PYZ-TA@Pd ensemble shows high catalytic activity and recyclability (up to seven cycles) in Suzuki-Miyaura coupling reactions using low palladium loading and provides the corresponding products in excellent yields (up to 98 %). Therefore, this study provides an efficient strategy to develop an easy to synthesize palladium centered solid catalyst through coordination between organic host and Pd NPs
ALL-544 exploring the genetic landscape of B-ALL: A comparative analysis of copy number alterations in adult and pediatric B-ALL patients
No full textContext:
B-cell acute lymphoblastic leukemia (B-ALL) primarily affects the pediatric and young adult populations. Generally, pediatric patients have better prognostic outcomes compared to adults. However, there is a lack of comparative data on copy number alterations (CNAs) in adult and pediatric B-ALL patients.
Objective:
To study the genetic landscape or CNAs of B-ALL in adult and pediatric B-ALL patients.
Study Design:
Overall, 214 B-ALL patients were enrolled and divided into pediatric (≤18 years) and adult (≥19 years) cohorts for comparison. Genomic DNA from bone marrow/peripheral blood samples underwent multiplex ligation-dependent probe amplification (MLPA) for CNAs using P335 kit (MRC, Holland). The CNAs of key genes were detected, namely EBF1, IKZF1, JAK2, CDKN2A, CDKN2B, PAX5, ETV6, BTG1, RB1 and the Xp22.33/Yp11.31 region (PAR1), comprising CRLF2, CSF2RA, and IL3RA.
Results:
The analysis incorporated a cohort of 214 patients comprising 126 (58.8%) pediatric and 88 (41.2%) adult cases diagnosed with B-ALL. Patients in the adult cohort had a median age of 33.5 years (range 19–61 years), and patients in the pediatric cohort had a median age of 7 years (range 8mths–18 years). CNAs were identified in a total of 148 cases (69.1%) in our study. The most frequently affected genes associated with CNAs were CDKN2A/B, observed in 71 cases (33.1%), IKZF1–68 cases (31.7%), and PAX5–65 cases (30.3%). Among the patients in the pediatric cohort, the most affected genes were CDKN2A/B–37 cases (29.3%), PAX5–30 cases (23.8%), and IKZF1–21 cases (16.6%). In the adult group, the most frequently affected genes were IKZF1–47 cases (53.4%), CDKN2A/B–34 cases (38.4%), and PAX5–35 cases (39.7%). The pediatric cohort had 35 (28%), 20 (16%), 20 (16%) cases with 1, 2, and ≥3 CNAs, respectively, and the adult cohort had 22(25%), 17(19%), and 34 (39%) cases, respectively.
Conclusion
Our findings indicate an overall higher proportion of >3CNAs (39% vs 16%) in the adult B-ALL patients as well as much higher prevalence of IKZF1 deletions (53.4% vs 16.6%)
Analytical appraisal of hematogones in B-ALL MRD assessment using multidimensional dot-plots by multiparametric flow cytometry: A critical review and update
No full textThe spectrum of benign B-cell precursors, known as hematogones (HGs), shows a significant morphological and immunophenotypic overlap with their malignant counterpart i.e. B-lymphoid blasts (BLBs). This results in a diagnostic dilemma in assessment of cases wherein there is a physiological preponderance of HGs and also poses a significant challenge in measurable residual disease assessment in B-cell acute lymphoblastic leukaemia. Consequently, expression patterns of various immunophenotypic markers are considered the most important tool in identification and delineation of HGs from BLBs. However, certain aspects of B-cell compartment evaluation by flow cytometric immunophenotyping and its relevance in clinical scenarios is yet to be defined precisely. This review summarizes current flowcytometric data on HGs and its discrimination from BLBs based on thorough review of literature and evaluation of in-house data. Furthermore, it focuses on the utility of an additional analytical tool i.e., radar plot for a comprehensive representation of various subsets of the B-cell compartment and their differentiation from BLBs
IBCL-188 hairy cell leukemia: A single center analysis from India
No full textContext:
Hairy cell leukemia (HCL) is a rare chronic lymphoproliferative disorder of small mature B lymphoid cells constituting 2% of all leukemias. The published literature on HCL from the Indian sub-continent is scarce.
Objective:
We analyzed the clinico-demographic parameters at the time of presentation, treatment patterns, and outcomes after first-line and subsequent treatment of HCL patients at a tertiary care center in India.
Design and Participants
This is a retrospective analysis of 20 consecutive cases of HCL diagnosed and treated at the Department of Medical Oncology, All India Institute of Medical Sciences (AIIMS) in New Delhi between May 1, 2013, and April 30, 2023.
Results:
The median age at presentation was 50 years (range, 32–70 years), 15 males and 5 females. The median symptom duration was 3 months (range, 1–24 months). Common presenting symptoms were fatigue (80%), fever (40%), abdominal discomfort (20%), weight loss (20%), bleeding (15%), infection (15%), and bone pain (10%). At presentation, 18 patients (90%) had splenomegaly, 12 (60%) had hepatomegaly, and lymphadenopathy was present in 3 (15%) patients. Bicytopenia or pancytopenia was present in 90%, and bone marrow fibrosis in 75% of cases. Eighteen patients were treated with cladribine (2-CdA) with a response rate of 95% (complete remission rate, 90%). The median time for normalization of blood counts after 2-CdA was 36 days, and the median time to spleen regression was 60 days. The median follow-up period was 42 months. Three patients relapsed but attained complete remission; two received cladribine, and one received single-agent rituximab due to active infection. Minimal residual disease (MRD) was documented in three cases, and one patient received maintenance rituximab due to persistent MRD positivity. One patient died of disseminated tuberculosis during the induction phase. During follow-up, 3 patients developed pulmonary tuberculosis, and 2 had herpes zoster.
Conclusion:
In patients with HCL, cladribine treatment results in long-lasting disease remission, making it the treatment of choice. Tuberculosis (pulmonary/disseminated) is a major concern, especially in India, where subclinical tuberculosis rates are high