Heteroatom Doping in Pollutant Diesel Soot-Derived Nanocarbon for Enhanced Zn-Ion Storage Performance.

Herein, we have isolated onion-like nanocarbon (ONC) from the exhaust soot of diesel engines and further doped it with nitrogen (N) and sulfur (S) to fabricate N,S-co-doped ONC (N-S-ONC). To explore its application feasibility, we have assembled an aqueous Zn-ion hybrid supercapacitor (ZIHSC) with a N-S-ONC cathode, which attains high specific capacitance with good rate capability. In-depth analyses suggest that the mechanism of charge storage in the ONC is governed by both capacitive-controlled and diffusion-controlled processes, with the capacitive processes leading at all sweep rates. The ZIHSC demonstrated a good energy density of 50 Wh/kg, a maximum power density of 3.6 kW/kg, and an impressive cycle life with 73% capacitance retention after 50,000 charge-discharge cycles. The study suggests the potential possibly for the long-term application of BC derived nanocarbon in electrochemical energy storage systems (EESSs).

Energy-Dense Zinc Ion Hybrid Supercapacitors with S, N Dual-Doped Porous Carbon Nanocube Based Cathodes.

Zinc ion hybrid supercapacitors (ZIHSCs) are truly promising as next-generation high-performance energy storage systems because they could offer high energy density like batteries while exhibiting high power output and long cycle life traits of supercapacitors. The key point of constructing a high-performance ZIHSC is to couple the Zn anode with an appropriate cathode material, which has high theoretical capacity, cost-effectiveness, and intrinsic safety features. In this work, we have demonstrated the potentiality of S, N co-doped porous carbon nanocubes (S, N-CNCs) as a cathode material for devising a ZIHSC with excellent energy density and cycle life. The S, N-CNCs are prepared from a zeolitic imidazolate framework (ZIF)-8 precursor via a simultaneous pyrolyzing-doping strategy in an inert atmosphere. Resultant CNCs are monodisperse with an average size of around 65 nm and porous in nature, with uniform N and S doping throughout the structure. Benefitted from such hierarchical porous architecture and the presence of abundant heteroatoms, the assembled ZIHSC with S, N-CNC as the cathode and Zn-foil as the anode in a ZnSO4 aqueous electrolyte could reach a specific capacity as high as 165.5 mA h g-1 (331 F g-1) at 1 A g-1, which corresponds to a satisfactory energy density of 148.9 W h kg-1 at the power density of 900 W kg-1. The ZIHSC has displayed a good cycle stability with more than 70% capacity retention after 10,000 charge-discharge cycles. Furthermore, to verify the practical feasibility of such a cathode material, an aqueous 3D Zn@Cu//S, N-CNC full-cell device is fabricated, which has demonstrated a satisfactory specific capacity (49.6 mAh g-1 at 0.25 A g-1) and an impressive energy density (42.2 Wh kg-1 with 212.2 W kg-1). Full ZIHSC devices are also found to be efficient in powering light-emitting diodes, further substantiating their feasibility in next-generation energy storage applications.

Crystal water intercalated interlayer expanded MoS2 nanosheets as a cathode for efficient zinc-ion storage.

Zinc-ion batteries (ZIBs) have attracted tremendous interest from the scientific community in recent years due to their extreme safety, cost-effectiveness, environmental benignity and the unique properties of the Zn anode. However, more suitable cathode materials are needed to achieve their potential widespread applications. MoS2, a 2D layered material with fascinating properties, could also serve as a cathode in ZIBs but is rarely studied due to its limited interlayer spacing, poor ionic/electronic conductivity and hydrophobicity. In this work, we report a facile hydrothermal method for synthesizing crystal water-intercalated MoS2 nanosheets and their application in efficient Zn-ion storage. Morphological characterization reveals the average thickness of the nanosheets to be 15.2 nm. With a large interlayer spacing (0.79 nm), high 1T content (49.7%) and high defects, MoS2·nH2O achieves a high discharge capacity of 197 mA h g-1 at 0.1 A g-1 in an aqueous 2 M ZnSO4 electrolyte. Moreover, it exhibits modest cyclic stability with 55% capacity retention after 1000 charge/discharge cycles. Furthermore, we evaluated the charge storage kinetics of crystal water-intercalated MoS2 nanosheets and realized that the electrochemical reaction is diffusion dominated with a diffusion coefficient of 10-10 to 10-13 cm2 s-1 in a 0.3 to 1.3 V potential window. This simple and cost-effective strategy for improving the performance of ZIBs by crystal water intercalation in 2D cathode materials will pave the way for their commercial-level grid-scale applications.

Characterization and Classification of ADHD Subtypes: An Approach Based on the Nodal Distribution of Eigenvector Centrality and Classification Tree Model.

In recent times, the complex network theory is increasingly applied to characterize, classify, and diagnose a broad spectrum of neuropathological conditions, including attention deficit hyperactivity disorder (ADHD), Alzheimer's disease, bipolar disorder, and many others. Nevertheless, the diagnosis and associated subtype identification majorly rely on the baseline correlation matrix obtained from the functional MRI scan. Thus, the existing protocols are either full of personalized bias or computationally expensive as network complexity-based simple but deterministic protocols are yet to be developed and formalized. This article proposes a deterministic method to identify and differentiate the common ADHD subtypes, which is based on a single complexity measure, namely the eigenvector centrality. The node-wise centrality differences were explored using a classification tree model (p < 0.05) to diagnose the subtypes. Identification of marker nodes from default mode, visual, frontoparietal, limbic, and cerebellar networks strongly vouch for the involvement of multiple brain regions in ADHD neuropathology.

Structural and information-theoretic complexity measures of brain networks: Evolutionary aspects and implications.

The evolutionary lineage of neuronal phenotype is notably complex even within a limited number of species. One of the approaches resides in the realm of complex network theory. The theory reduces the connectomic data into a hallmarked set of few parameters, some of which might be correlated with a suitably chosen phylogenetic marker. In this first-of-its-kind attempt, interspecific variations of two structural complexity measures (i.e., clustering coefficient and centrality) along with two independent information-theoretic measures (i.e., von Neumann entropy and multifractality) are investigated to decipher any hidden evolutionary signature considering four mammalian connectomes (i.e., felis catus, mus musculus, macaca mulatta, and homo sapiens). All network complexity measures partially corroborate with the phylogenetic order. Nevertheless, monotonicity of the measures with the chosen phylogenetic marker of genome size has been majorly violated because of the mus musculus data point. On the other hand, von Neumann entropy was found to exhibit an allometric scaling behavior with the community structure of all connectomes (p<0.0001, and R2>0.95). The respective scaling exponent was noted to be monotonic with the genome size. Singularities of the real connectomes were also investigated upon carrying out a similar analysis in three equivalent synthetic network models.

Charge storage mechanism in vanadium telluride/carbon nanobelts as electroactive material in an aqueous asymmetric supercapacitor.

A novel one-step method for fabricating vanadium telluride nanobelt composites for high-performance supercapacitor applications is reported. The nanobelts are realized by direct tellurization of vanadium oxide in-situ formed via decomposition of ammonium metavanadate in argon atmosphere. Use of melamine as precursor helps in forming graphitic carbon layers during pyrolization on which the nanobelts are grafted. Morphological analysis suggests interconnected nanobelts of ∼23.0 nm width coming out of carbon structure. As pseudocapacitive electrode, vanadium telluride/carbon (C) composite exhibits interesting electrochemical performance within a potential window of 0-1.0 V in 1.0 M sodium sulfate electrolyte along with excellent capacitance retention during 5000 cycles. In-depth analysis suggests that the charge storage mechanism in the composite is governed by both diffusion-controlled and diffusion-independent processes with the former dominating at slower scan rates and later at faster scan rates. The asymmetric supercapacitor assembled using vanadium telluride/C and activated charcoal (AC) as respective positive and negative electrodes exhibited an energy/power combination of 19.3 Wh/kg and 1.8 kW/kg within a potential window of 0-1.8 V in aqueous electrolyte. This strategy to improve capacitance along with potential window in an aqueous electrolyte would facilitate development of high-performance energy storage devices with metal chalcogenides.

Effect of defect-rich Co-CeOx OER cocatalyst on the photocarrier dynamics and electronic structure of Sb-doped TiO2 nanorods photoanode.

This work demonstrates the in-depth mechanism of enhanced photoelectrochemical (PEC) water oxidation of Sb-doped rutile TiO2 nanorods (NRs) photoanode coupled with oxygen vacancy defect-rich Co-doped CeOx (Co-CeOx) oxygen evolution reaction (OER) cocatalyst. The defect-rich Co-CeOx cocatalyst modification improves the conductivity, light absorption, charge transfer efficiency, and surface photovoltage generation of the Co-CeOx/Sb-TiO2 hybrid NRs photoanode. The Co-CeOx cocatalyst also serves as the surface passivating overlayer for the Sb-TiO2 photoanode, which suppresses the surface states mediated recombination of electron-hole pairs in the NRs. The PEC studies further indicate that Co-CeOx cocatalyst induces remarkably large band bending at the semiconductor/electrolyte interface and shortens the carrier diffusion length and depletion layer width, facilitating the rapid separation and transportation of the photocarriers for the surface PEC reactions. The experimental and theoretical studies confirm that the Co-doping in CeOx cocatalyst enhances the surface oxygen vacancy defects, which provides active catalytic sites for OH- adsorption and charge transportation for enhanced OER kinetics. The density functional theory (DFT) calculations demonstrate a higher conductivity of the Co-CeOx cocatalyst, advantageous for rapid charge transfer capability during PEC reactions. The synergy between all these merits helps the optimized Co-CeOx/Sb-TiO2 photoanode to deliver a maximum photocurrent density of 1.41 mA cm-2 at 1.23 V vs. reversible hydrogen electrode (VRHE) and an ultra-low turn on potential (Von) of 0.1 VRHE under AM 1.5G solar illumination compared to the Sb-TiO2 NRs (0.96 mA cm-2 at 1.23 VRHE and Von = 0.42 VRHE). This work demonstrates the design of an efficient defect-rich cocatalyst modified photoanode for solar energy harvesting.

Mediator dynamics during heat shock in budding yeast.

The Mediator complex is central to transcription by RNA polymerase II (Pol II) in eukaryotes. In budding yeast (Saccharomyces cerevisiae), Mediator is recruited by activators and associates with core promoter regions, where it facilitates preinitiation complex (PIC) assembly, only transiently before Pol II escape. Interruption of the transcription cycle by inactivation or depletion of Kin28 inhibits Pol II escape and stabilizes this association. However, Mediator occupancy and dynamics have not been examined on a genome-wide scale in yeast grown in nonstandard conditions. Here we investigate Mediator occupancy following heat shock or CdCl2 exposure, with and without depletion of Kin28. We find that Pol II occupancy shows similar dependence on Mediator under normal and heat shock conditions. However, although Mediator association increases at many genes upon Kin28 depletion under standard growth conditions, little or no increase is observed at most genes upon heat shock, indicating a more stable association of Mediator after heat shock. Unexpectedly, Mediator remains associated upstream of the core promoter at genes repressed by heat shock or CdCl2 exposure whether or not Kin28 is depleted, suggesting that Mediator is recruited by activators but is unable to engage PIC components at these repressed targets. This persistent association is strongest at promoters that bind the HMGB family member Hmo1, and is reduced but not eliminated in hmo1Δ yeast. Finally, we show a reduced dependence on PIC components for Mediator occupancy at promoters after heat shock, further supporting altered dynamics or stronger engagement with activators under these conditions.

Tailor-made design, fabrication and validation of SrO doped nanostructured ZTA ceramic Femoral head - Acetabular socket liner assembly.

An established commercial grade SrO doped ZTA composition has been considered to design, fabrication through uniaxial pressing followed by sintering and polishing, validation of dimension, 3D surface profile, 3D microstructure, and compressive load bearing capacity of femoral head - acetabular socket liner prototypes for the hip prosthesis. While design and dimensions are concerned, both the steel (HRC60) molds were designed and machined to achieve precious dimensions of femoral head (FH; OD - 30 ± 0.01 mm) and acetabular socket liner (ASL; ID - 30.15 ± 0.01 mm). A close variation in the range of ±0.01 mm was confirmed the precision geometry of polished FH and ASL with consideration of 22 points coordinate measuring method (CMM). 3D surface profile ensures the surface characteristics of Ra = 0.2 ± 0.01 µm and Rq = 0.5 ± 0.01 µm for outer surface of FH and an inner surface of ASL, respectively. Structure integrity and fabrication defects including cracks and pores free bulk structures were confirmed by Micro CT. The compressive load resistance known as burst strength for independent FH and FH-ASL assembly were measured 16.2 KN and 17.6 KN, respectively. The developed ceramic prototypes have an economic advantage and can be adopted as artificial hip prosthesis after extensive in-vitro and in-vivo analysis.

Cobalt phosphide (Co2P) encapsulated in nitrogen-rich hollow carbon nanocages with fast rate potassium ion storage.

We synthesized Co2P nanoparticle encapsulated N-doped carbon nanocages through one-step carbonization-phosphidation of ZIF-67. As potassium ion battery (KIB, PIB) anodes, the Co2P@NCCs display state-of-the-art electrochemical performance, including the most favorable fast charge characteristics reported. The single-nanometer thick carbon cage yields rapid solid-state K-ion diffusion and prevents aggregation/pulverization of 40 nm cobalt phosphide.

Interfacial energy driven distinctive pattern formation during the drying of blood droplets.

HYPOTHESIS: Dried blood droplet morphology may potentially serve as an alternative biomarker for several patho-physiological conditions. The deviant properties of the red blood cells and the abnormal composition of diseased samples are hypothesized to manifest through unique cell-cell and cell-substrate interactions leading to different morphological patterns. Identifying distinctive morphological trait from a large sample size and proposing confirmatory explanations are necessary to establish the signatory pattern as a potential biomarker to differentiate healthy and diseased samples. EXPERIMENTS: Comprehensive experimental investigation was undertaken to identify the signatory dried blood droplet patterns. The corresponding image based analysis was in turn used to differentiate the blood samples with a specific haematological disorder "Thalassaemia" from healthy ones. Relevant theoretical analysis explored the role of cell-surface and cell-cell interactions pertinent to the formation of the distinct dried patterns. FINDINGS: The differences observed in the dried blood patterns, specifically the radial crack lengths, were found to eventuate from the differences in the overall interaction energies of the system. A first-generation theoretical analysis, with the mean field approximation, also confirmed similar outcome and justified the role of the different physico-chemical properties of red blood cells in diseased samples resulting in shorter radial cracks.

Kin28 depletion increases association of TFIID subunits Taf1 and Taf4 with promoters in Saccharomyces cerevisiae.

Transcription of eukaryotic mRNA-encoding genes by RNA polymerase II (Pol II) begins with assembly of the pre-initiation complex (PIC), comprising Pol II and the general transcription factors. Although the pathway of PIC assembly is well established, the mechanism of assembly and the dynamics of PIC components are not fully understood. For example, only recently has it been shown that in yeast, the Mediator complex normally occupies promoters only transiently, but shows increased association when Pol II promoter escape is inhibited. Here we show that two subunits of TFIID, Taf1 and Taf4, similarly show increased occupancy as measured by ChIP upon depletion or inactivation of Kin28. In contrast, TBP occupancy is unaffected by depletion of Kin28, thus revealing an uncoupling of Taf and TBP occupancy during the transcription cycle. Increased Taf1 occupancy upon Kin28 depletion is suppressed by depletion of TBP, while depletion of TBP in the presence of Kin28 has little effect on Taf1 occupancy. The increase in Taf occupancy upon depletion of Kin28 is more pronounced at TFIID-dominated promoters compared to SAGA-dominated promoters. Our results support the suggestion, based on recent structural studies, that TFIID may not remain bound to gene promoters through the transcription initiation cycle.

Role of the pre-initiation complex in Mediator recruitment and dynamics.

The Mediator complex stimulates the cooperative assembly of a pre-initiation complex (PIC) and recruitment of RNA Polymerase II (Pol II) for gene activation. The core Mediator complex is organized into head, middle, and tail modules, and in budding yeast (Saccharomyces cerevisiae), Mediator recruitment has generally been ascribed to sequence-specific activators engaging the tail module triad of Med2-Med3-Med15 at upstream activating sequences (UASs). We show that yeast lacking Med2-Med3-Med15 are viable and that Mediator and PolII are recruited to promoters genome-wide in these cells, albeit at reduced levels. To test whether Mediator might alternatively be recruited via interactions with the PIC, we examined Mediator association genome-wide after depleting PIC components. We found that depletion of Taf1, Rpb3, and TBP profoundly affected Mediator association at active gene promoters, with TBP being critical for transit of Mediator from UAS to promoter, while Pol II and Taf1 stabilize Mediator association at proximal promoters.

Realizing an Asymmetric Supercapacitor Employing Carbon Nanotubes Anchored to Mn3O4 Cathode and Fe3O4 Anode.

A facile route to anchor pseudocapacitive materials on multiwalled carbon nanotubes (CNTs) to realize high-performance electrode materials for asymmetric supercapacitors (ASCs) is reported. The anchoring process is developed after direct decomposition of metal-hexacyanoferrate complex on the CNT surface. Transmission electron microscopy (TEM) analysis reveals that the nanoparticles (NPs) are discretely attached over the CNT surface without forming a uniform layer, thus making most of the entire NP surface available for electrochemical reactions. Accordingly, CNT-Mn3O4 nanocomposite cathode shows significantly improved capacitive performance as compared to pristine CNT electrode, validating the efficacy of designing the composite electrode. With CNT-Fe3O4 nanocomposite as the paired anode, the hybrid ASC delivers a specific capacitance of 135.2 F/g at a scan rate of 10 mV/s within a potential window of 0-1.8 V in the aqueous electrolyte and retains almost 100% of its initial capacitance after 15,000 cycles. The serially connected ASCs can power commercial light-emitting diodes (LEDs) and mobile phones, reflecting their potential in next-generation storage applications.

A facile approach for preparing densely-packed individual p-NiO/n-Fe2O3 heterojunction nanowires for photoelectrochemical water splitting.

Innovative design of electrode materials is crucial for efficient conversion of solar energy into chemical fuel through photoelectrochemical (PEC) water splitting. Herein, we report the development of a p-n heterojunction nanowire (NW) based photoanode made of low cost earth-abundant materials. Densely-packed and freestanding individual p-NiO/n-Fe2O3 heterojunction NWs are fabricated through consecutive electrodeposition of Fe and Ni NWs inside the pores of the anodic alumina template followed by controlled oxidation. Heterojunction formation in individual NWs is confirmed through energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM), along with elemental mapping on individual NWs through electron energy loss spectroscopy (EELS). An inverted 'V' shape nature of the Mott-Schottky curve suggests p-n diode like characteristics of the heterojunction NWs. These p-n heterojunction NWs demonstrate a significantly enhanced photocurrent density (∼24 times at a potential of 1.23 V vs. RHE) and a cathodic shift (∼0.4 V) of the photocurrent onset potential compared to the pristine Fe2O3 NW electrode, which can be attributed to the synergistic combination of n-Fe2O3 with the co-catalyst p-NiO facilitating the generation and transfer of photogenerated holes into the electrolyte for water oxidation. This study validates the feasibility of developing Fe2O3 based heterojunction photoelectrodes for efficient PEC water splitting.

Surface property induced morphological alterations of human erythrocytes.

Microscopic investigations of any abnormality associated with erythrocyte/red blood cell morphology constitute an important segment of the age-old peripheral smear test. Though the test is conducted on a glass slide, the effect of glass and similar other solid substrates on erythrocyte morphology remained majorly unexplored. In the first of its kind investigation, we have outlined the effect of varying the substrate surface potential on erythrocyte morphology. Such a substrate induced phenomenon has been quantified for two distinctly different drying configurations (droplets and film) upon systematically varying the cell concentration. Experimental results and supporting theoretical analysis unambiguously show the surface potential of the solid substrate to be the most influential parameter in the process of morphological alteration. The findings of the present investigation may be utilized to formulate an error-free protocol for the baseline peripheral smear test of hematological diagnosis.

Fractal Dimension of Erythrocyte Membranes: A Highly Useful Precursor for Rapid Morphological Assay.

Morphology of erythrocyte membrane has been recognized as an alternative biomarker of several patho-physiological states. Numerous attempts have been made to upgrade the existing method of primitive manual counting, particularly exploring the light scattering properties of erythrocyte. All the techniques are at best semi-empirical and heavily rely on the effectiveness of the statistical correlations. Precisely, this is due to the lack of a non-empirical scale of the so-called "morphological scores". In this article, fractal dimension of erythrocyte membrane has been used to formulate a suitable scoring scale. Subsequently, the rapid experimental output of flow-cytometry has been functionally related to the mean morphological quantifier of the whole cell population via an optimum neural network model (R2 = 0.98). Moreover, the fractal dimension has been further demonstrated to be an important parameter in early detection of an abnormal patho-physiological state, even without any noticeable poikilocytic transformation in micrometric domain.

Probing Cytocompatibility, Hemocompatibility, and Quantitative Inflammatory Response in Mus musculus toward Oxide Bioceramic Wear Particulates and a Comparison with CoCr.

Peri-prosthetic bone resorption and loosening of artificial joints have been widely recognized to limit the performance of the load-bearing implants. Therefore, the present study probes into the cyto-, hemo-, and histocompatibility of the small sized wear particulates of ZrO2-toughened Al2O3 (ZTA). In order to develop a comprehensive, yet clinically relevant understanding, a comparison is made with two baseline ceramics (Al2O3 and ZrO2) and metallic material (CoCr), all in particulate forms. While in vitro cytotoxicity assessment was carried out with mouse osteoblast cells, preclinical testing of intra-articularly injected particulates up to the concentration 25 wt % in PBS over the period of 12 weeks was performed in mouse model. Interestingly, mouse osteoblast cells, cultured in media with ZTA, Al2O3, and ZrO2 particulates of three different concentrations (0.25, 2.5, and 25 mg/mL) exhibited uncompromised cell viability and considerable cell spreading, up to the time frame of 72 h. In contrast, similar experiments with CoCr particulates demonstrated significant decrease in cellular growth with drastic change in osteoblast proliferation behavior. Furthermore, the decrease in RBC damage after contact with ZTA, Al2O3, and ZrO2 particulates at 25 mg/mL of dose level illustrated 4.4, 5.8, and 1.25% hemolysis, respectively, confirming clinically acceptable hemocompatibility. However, hematic activity of CoCr particles was reflected with 15.6% of hemolysis. In vivo, the absence of any significant effect of intra-articularly injected ceramic (Al2O3, ZrO2, ZTA) as well as metallic (CoCr) particulates on complete hemogram and serum biochemistry of Balb/C mice was recorded at all the time points up to 12 weeks. The extensive histological analysis confirmed the absence of any signature of the tissue-level toxicity at all time points. The pro-inflammatory cytokine analysis using TNF-α and IL-1ß markers provided complementary evidence toward nongranulomatous and nonimmunogenic response of synovial membrane of knee joint and other vital organs of mice that were exposed to Al2O3, ZrO2, ZTA, and CoCr particulates. Taken together, our results establish the nontoxic nature of oxide ceramic particulates to bone cells, in vitro, as well as to periprosthetic tissue, in vivo.

ZrO2-toughened Al2O3 composites with better fracture and wear resistance properties.

In view of the importance of the fracture resistance and wear properties on the performance and durability in a number of engineering applications, we have analysed such properties of sintered zirconia toughened alumina with varying zirconia content of 5 and 15 wt.%. Using micro-computed tomography, homogenous particulate distribution of zirconia is established through 3D volume rendering of the sintered pellet and by 2D orthoslice view. Depending on zirconia content and MgO addition (sintering additive), an interesting combination of strength and toughness properties was recorded with the investigated materials. While explaining the origin of cracking on worn surfaces of optimized zirconia toughened alumina, theoretical calculations revealed that the maximum tensile stress at the trailing edge of sliding contact is higher than critical damage stress. Such analysis incorporates the effect of factors such as the internal stresses due to thermal expansion anisotropy of non-cubic Al2O3 matrix, mismatch in elastic modulus/thermal expansion and athermal ZrO2 phase transformation.

Nuclear mRNA degradation tunes the gain of the unfolded protein response in Saccharomyces cerevisiae.

Unfolded protein response (UPR) is triggered by the accumulation of unfolded proteins in the endoplasmic reticulum (ER), which is accomplished by a dramatic induction of genes encoding ER chaperones. Activation of these genes involves their rapid transcription by Hac1p, encoded by the HAC1 precursor transcript harboring an intron and a bipartite element (3'-BE) in the 3'-UTR. ER stress facilitates intracellular targeting and recruitment of HAC1 pre-mRNA to Ire1p foci (requiring 3'-BE), leading to its non-spliceosomal splicing mediated by Ire1p/Rlg1p. A critical concentration of the pre-HAC1 harboring a functional 3'-BE element is governed by its 3'→5' decay by the nuclear exosome/DRN. In the absence of stress, pre-HAC1 mRNA undergoes a rapid and kinetic 3'→5' decay leading to a precursor pool, the majority of which lack the BE element. Stress, in contrast, causes a diminished decay, thus resulting in the production of a population with an increased abundance of pre-HAC1 mRNA carrying an intact BE, which facilitates its more efficient recruitment to Ire1p foci. This mechanism plays a crucial role in the timely activation of UPR and its prompt attenuation following the accomplishment of homeostasis. Thus, a kinetic mRNA decay provides a novel paradigm for mRNA targeting and regulation of gene expression.