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An inherently stable boundary-condition-transfer algorithm for muffler analysis
No full textWave coupling exists in the wave propagation in multiple interacting ducts within a waveguide. One may use the segmentation approach, decoupling approach, eigenvalue approach, or the matrizant approach to derive the overall transfer matrix for the muffler section with interacting ducts, and then apply the terminal boundary conditions to obtain a two-by-two transfer matrix. In such instances, a boundary condition applied to a vector is given as a linear combination of its components. Spatial dimensions along with parameters like impedance of the perforated interface may yield numerical instability during computation leading to inaccurate prediction of the acoustic performance of mufflers. Here, an inherently stable boundary-condition-transfer approach is discussed to analyze the plane wave propagation in suchlike mufflers and applied to waveguides of variable cross-sectional area. The concept of pseudo boundary conditions applied to the state vector at an intermediate point is outlined. The method is checked for self-consistency and shown to be stable even for extreme geometries
Structure and stabilities of the isomers of SiB<SUB>2</SUB>H<SUB>4</SUB>
No full textAb initio quantum-mechanical methods at the HF/6-31G∗, MP2/6-31G∗ and MP2/6-31G∗ levels are used to study the relative stabilities of the isomers of SiB2H4. Isomers obtained using the analogy between trivalent boron and divalent silicon are calculated to be more stable compared to isomers where carbon is replaced by the isovalent silicon. 2π aromaticity and the preference of silicon for lower valency control the relative stabilities of SiB2H4 isomers
The secular variation of the magnetic field and its cyclic components
No full textThe application of effective digital filters to separate and compute the amplitude of cyclic components of the observed secular variation (Bhargava and Yacob, 1968) has been extended to a series of mean annual values of horizontal force at Alibag derived from night-time field on magnetically quiet days as well as to series of mean annual values, one for every month. It is shown that the 11-yr cyclic component of secular variation is not associated with the greater incidence of Dst during high solar activity and that the amplitude of this component is largest in Winter and smallest in Summer. The method has also been applied to a long series of data from Oslo, Norway. Amplitudes of 11-yr cyclic component at Oslo have been computed both from power density in the autospectra as well as by application of a band-pass filter. Cross spectra of the computed 11-yr cyclic components ΔH, ΔX, ΔY, ΔZ and ΔF with sunspot numbers show that at Oslo the minima of ΔH, ΔX, ΔZ and ΔF precede the maxima of solar activity by an interval of 0.3 to 1.4 yr. In the case of ΔY the maximum in this component precedes the solar activity maximum by 0.6 yr. The coherence between these components and sunspot numbers is found to vary from 0.70 for ΔZ to 0.89 for ΔH
Effect of pressure on the resistivity of lead oxide-lead halide glasses
No full textResistivity behaviour of PbO---PbX2 (X=F,Cl) glasses has been investigated as a function of pressure at laboratory temperature. All PbO---PbX2 glasses undergo crystallization under pressure and the resistivities of crystallized samples are lower than the corresponding glasses. Transitions in PbO---PbF2 glasses exhibit a first order behaviour while transitions in PbO---PbCl2 glasses possess features of a continuous transition. The differences in the pressure behaviour of the two glass systems have been attributed to the differences in the ionic sizes of F- and Cl- ions and also to pressure induced modifications of Pb---O bonding
Impact of Rituximab maintenance on outcomes in Follicular lymphoma: An Indian experience
No full textBackground:
Follicular lymphoma (FL) is the second most common subtype of non-Hodgkin lymphoma (NHL) and comprises 9 % of total NHL in India. Rituximab maintenance (RM) after induction immunochemotherapy improves PFS. However, currently, no data exists from the Indian continent regarding the impact of Rituximab maintenance (RM) on overall survival (OS) & progression-free survival (PFS). Our study aims to assess if RM improves the outcomes in FL patients.
Methods:
This retrospective study included 95 patients diagnosed with FL meeting GELF criteria and registered at our institute All India Institute of Medical Sciences Delhi between January 2012 -December 2023. Among these, forty -four (46 %) patients received 2 years of RM every 2 months after induction immunochemotherapy. The primary outcome were overall survival (OS) and progression-free survival. Secondary outcomes were factors affecting OS & PFS.
Results:
Out of the 95 patients who met GELF criteria, 52 were male and 43 were female, with a median age of 53 years (range: 27–81). Advanced Ann Arbor stage III/IV comprises 82 (86 %) patients. Bone marrow involvement and bulky disease were observed in 36 (38 %) and 29 (31 %) patients respectively. Based on the Follicular Lymphoma International Prognostic Index (FLIPI-1), 27 (28 %) were low risk, 9 (10 %) intermediate risk, and 59 (62 %) were high risk. The complete remission (CR) was achieved in 71 % of patients. During follow-up, 27 (28 %) patients experienced relapsed and 8 patients transformed to diffuse large B-cell lymphoma (DLBCL). At a median follow-up of 63 months, the median OS was not reached. The median PFS was 122 months in the RM group and 94 months in the non-RM group, with 5-year PFS of 91.6 % vs 59.3 %, respectively (log-rank p = 0.017). Rituximab maintenance was independently associated with improved PFS (adjusted HR 0.28, 95 % CI: 0.12–0.65, p = 0.003). Failure to attain CR (aHR 2.49, 95 % CI: 1.20–5.19, p = 0.015) and bone marrow involvement (aHR 2.92, 95 % CI: 0.99–8.63, p = 0.05) were independently associated with inferior PFS.
Conclusions:
Rituximab maintenance after induction immunochemotherapy significantly improved PFS. This is the first study from India demonstrating the impact of rituximab maintenance in FL
Regional responses to oceanic variability constrain global drought synchrony
No full textSynchronized droughts threaten global food security, with concerns about increased frequency and duration under climate change. However, their long-term evolution and physical limits remain unknown. We analyze 61 drought networks over 120 years (1901–2020) of Self Calibrating palmer drought severity index (sc-PDSI) data, employing a suite of network synchronization measures and empirical orthogonal functions to unravel the physical drivers and limiters of drought synchrony. Our results show that, contrary to claims that synchronized droughts could affect up to one sixth of the global land mass, the maximum synchronized area fluctuates between 1.84% and 6.5% of the total land mass. Although we observe a strong dependence between drought onset and local crop failures, global drought synchrony is shaped by a dichotomy: temperature trends exacerbate it, while precipitation variability, modulated by sea surface temperature oscillations, limits it. This suggests that although drought hubs are increasing, large-scale synchronization across multiple agricultural regions is less widespread than expected, affecting global food security strategies
Copper-sensitive OsSPL9 TF regulates expression of indica rice domestication-associated miRNAs and phenotypes
No full textDomestication of indica rice facilitated better harvest and yield, however the molecular mechanisms that drove multitude of the associated phenotypes is poorly understood. A few genetic and epigenetic mechanisms have been attributed to indica rice domestication; however, upstream regulators of these variations are unknown. Here, we identified a copper (Cu)-dependent regulatory module, involved in the regulation of OsSPL9 TF and two classes of RNAs under its control. Differential accumulation of Cu-associated micro(mi)RNAs and Cu-associated protein-coding RNAs were a major portion of the differences between wild (Oryza nivara) and cultivated rice lines. We identified OsSPL9 as an upstream regulator of these changes through genetic and molecular analysis as well as by using Cu stressed conditions. OsSPL9 bound to the promoters of these genes through a conserved GTAC enriched motif. OsSPL9, Cu-associated miRNAs and their targets acted as a regulatory loop, since mis-expression of SPL9 alone, or any individual Cu-associated miRNA, also altered levels of other Cu-miRNAs and their cognate targets. OsSPL9-mediated regulation was closely linked to Cu accumulation and metabolism, indicating previously unappreciated roles of metal ions in mediating domestication-associated phenotypes. Our study facilitates a better understanding of the crosstalk between genetic and epigenetic regulation that contributed to indica rice domestication
Influence of magnesium ions and crowding agents on structure and stability of rna aptamers
No full textAptamers bind to their targets with exceptional affinity and specificity. However, their intracellular application is hampered by the lack of knowledge about the effect of the cellular milieu on the RNA structure/stability. In this study, cellular crowding was mimicked using polyethylene glycol (PEG), and the crucial role of Mg2+ ions in stabilizing the structure of an RNA aptamer was investigated. Increasing the concentration of Mg2+ or PEG increased the thermal stability of the aptamer. The crowding effect lowered the requirement of the Mg2+ ion to form the binding-competent conformer of the aptamer. This suggests that crowding and other factors may compensate for a lower concentration of Mg2+ for proper folding of aptamers inside cells. Selective 2′-hydroxyl acylation and primer extension (SHAPE) probing permitted residue-level analysis of the aptamer. Mg2+ and/or PEG were shown to be involved in increasing the rigidity or flexibility of different regions of the aptamer. Fluorescence correlation spectroscopy showed a significantly low hydrodynamic radius (RH) in the presence of molecular crowders and Mg2+ ions. We believe that the decreased water activity due to crowding may be responsible for reduced RH. Our results show that in a crowded environment, the RNA aptamer was exposed to conformers that were not available to it in simple buffer solutions or solely in the presence of lower concentrations of Mg2+
Treatment of leather industry effluents by membrane-based technologies.
No full textMembrane processes represent useful approaches for the treatment of industrial wastewater due to their advantages over conventional separation processes that include mild operating conditions of temperature and pressure, high selectivity towards target solutes, non-use of additives and consequently reduced risk of contamination, ease scale-up and low energy consumption.
This chapter provides an overview of membrane-based technologies of practical and potential interest for the treatment of spent effluents from beamhouse, tanning and post-tanning operations as well of global effluents of the leather industry. Typical advantages over conventional methodologies and process designs in agreement with zero discharge approaches and circular economy principles are highlighted and discussed