Stress Shift Research Articles

P‐4.4: Multifunctional Laminated Organic Passivation Layer on InSnZnO Thin‐Film Transistors for Enhanced Reliability

To improve the stability of the ZnO‐based thin‐film transistors (TFTs) in multiple environments, we propose a new multifunctional laminated organic passivation layer (MLO PVL) structure for ITZO TFTs. This MLO PVL structure is composed of a self‐assembled monolayer (SAM) and an ultraviolet (UV) absorber‐modified polydimethylsiloxane (PDMS) layer, which provides the functionality of both passivation layers at the same time. The SAM film could be prepared by vapor‐phase treatment, while the UV‐absorber‐modified PDMS layer could be fabricated using the spin‐coating method. Thus, the MLO PVL could be manufactured through a low‐temperature and low‐cost process. Compared to the unpassivated devices, the MLO‐passivated ITZO TFTs exhibit better properties, such as an on‐off current ratio (Ion/Ioff) of up to 8.99×109, a field‐effect mobility of 19.55 cm2V−1s−1, and a subthreshold swing (SS) down to 100 mV/dec. Furthermore, the MLO‐passivated ITZO TFTs showed an outstanding improvement in the bias stress stability and UV light illumination stress stability with negligible threshold voltage shifts in both positive bias stress (PBS) and positive bias illumination stress (PBIS) tests. This new passivation structure provides a potential strategy for improving the stability of ZnO‐based TFTs.

Effect of intermetallic compounds distribution on bonding strength of steel–aluminum laminates

In this study, steel–Al laminates are prepared via hot-roll bonding and annealed for various durations to generate intermetallic compounds (IMCs) with different distributions at the interface. The fracture forms of the laminates with different IMCs distributions are analyzed via in-situ tensile–shear experiments, and the shear stress distribution in the regions adjacent to the bonding interface during the tensile–shear process is investigated via finite element modeling using Abaqus. Results show that granular IMCs can change the direction of cracks and limit crack expansion during the tensile–shear process. The location of the maximum shear stress shifts from the interface to the aluminum matrix, causing fracture to be generated in the Al matrix. When an approximate IMC layer is formed at the bonding interface, the maximum shear stress occurs at the IMC–Al interface. Additionally, Kirkendall voids, which are the source of cracks, are observed at the IMCs–Al interface. They expand along the IMC–Al interface during the tensile–shear process, thus reducing the bonding strength. This study shows that granular IMCs are beneficial for improving the bonding strength, and that the bonding strength begins to deteriorate when the IMCs accumulate to form a layer.

Socially Transferred Stress Experience Modulates Social Affective Behaviors in Rats

Social communication of affective states between individuals, as well as actual experiences, influences their internal states and behaviors. Although prior stress experiences promote empathy-like behaviors, it remains unclear whether the social transmission of stress events modulates these behaviors. Here, we provide evidence that transferred stress experiences from cage mates modulate socioaffective approach-avoidance behaviors in rats. Male Wistar-Imamichi rats were assigned to one of five experimental groups (Control (n = 15); no shock with shocked cage mates (n = 15); low (0.1 mA, n = 15), middle (0.5 mA, n = 14), and high shock (1.0 mA, n = 14)). Except for the naïve and housed with stressed mate groups, rats received two foot-shocks (5 s for each). The next day, the subjects were allowed to explore two unfamiliar conspecifics; one was a naïve, while the other was a distressed conspecific that received two foot-shocks (1.0 mA, 5 s) immediately before the test. Rats that were housed with stressed mates, as well as those that experienced a higher intensity of foot-shocks, were more likely to approach, while naïve rats avoided, a distressed conspecific. These results suggest that socially transferred stress shifts socioaffective response styles from avoidance to approach toward a stressed conspecific in rats.

Stochastic Modeling of the Al Hoceima (Morocco) Aftershock Sequences of 1994, 2004 and 2016

The three aftershock sequences that occurred in Al Hoceima, Morocco, in May 1994 (Mw 6.0), February 2004 (Mw 6.4) and January 2016 (Mw 6.3) were stochastically modeled to investigate their temporal and energetic behavior. A form of the restricted trigger model known as the restricted epidemic type aftershock sequence (RETAS) was used for the temporal analysis of the selected series. The best-determined fit models for each sequence differ based on the Akaike information criteria. The revealed discrepancies suggest that, although the activated fault systems are close (within 10 to 20 km), their stress regimes change and shift across each series. In addition, a stochastic model was presented to study the strain release following a specific strong earthquake. This model was constructed using a compound Poisson process and depicted the progression of the strain release during the aftershock sequence. The proposed model was then applied to the data. After the RETAS model was used to evaluate the behavior of the aftershock decay rate, the best-fit model was obtained and integrated into the strain-release stochastic analysis. By detecting the potential disparities between the observed data and model, the applied stochastic model of strain release allows for a more comprehensive examination. Furthermore, comparing the observed and expected cumulative energy release numbers revealed some variations at the start of all three sequences. This demonstrates that significant aftershock clusters occur more frequently shortly after the mainshock at the start of the sequence rather than if they are assumed to occur randomly.

ACCENTUATIONAL PECULIARITIES OF VERBATIVES WITH DISPOSABLE SEMANTICS IN THE SOUTH-WESTERN PATOIS OF UKRAINIAN LANGUAGE

Introduction. The paper focuses on the accentual specifics of the VIIth Structural Class verbs with disposable semantics in the south-western patois in correlation with those in late pre-Slavic language community and Ukrainian literary language.Purpose. The paper aims at tracing back the process of root accentuation formation in the verbs under investigation, finding their stress tendencies; defining the role and place of the patois in the process of establishing accent norms in variants of the Ukrainian literary language, and thus in present day Ukrainian language; explaining the causes of stressincompatibility of the verbatives in the patois under analysis as well as in south-western variants of the literary language and present day literary Ukrainian.Methods. To achieve the aim of the work the following methods of investigation have been applied: comparative-historic and that of internal reconstruction, inductive and deductive, synchronic and diachronic.Results. It has been revealed that the process derivatives, performing as the bearers of process semantics of influence on the object (subject) and movement in space, mainly accompanied by sound, are characterized by usage and derivation productivity, completeness of the grammatical paradigm, perfective aspect grammeme, morphological, phonetical and stress variance with the root one prevailing. It has also been found out that the majority of the verbatives belong to the derivative possessions of the Ukrainian language proper, root accentuation of which having been caused by the analogy to the derivatives of the mentioned paradigms.The stress shift from the root to the stem class suffix in the infinitive, and more rarely to the flexion in presence in the group of the verbative analyzed are motivated by rhythmic organizing of song lyrics, stress specifics of Lemcovian dialects, technical omissions of the compilers of thecorresponding lexicographic sources and functional load of the stress.Conclusion. The sporadicity of variance accentuation (root and suffix-flexional) of some verbs is motivated by crossing two (South-western and South-eastern) stress tendencies of the Ukrainian language. Suffix-flexional accentuation of the part of the defined derivatives in south-eastern variant of the Ukrainian literary language and present day Ukrainian is explained by the influence of the Russian language lexicographic tradition.

Reconstructing non-contrastive stress in Austronesian and the role of the mora in stress shift, gemination and vowel shift

Abstract Competing schools of thought on the reconstruction of Proto-Austronesian stress contend that primary stress was either regular (falling on the penultimate syllable with possible phonetic conditions that triggered stress shift to the final syllable) or lexical (falling unpredictably either on the penult or ultima). In this study, I argue that the comparative evidence supports the first position: that primary stress fell regularly on the penultimate syllable and was not lexical. Further, primary stress was repelled to the final syllable if the penultimate syllable was open and contained a schwa nucleus. Three Austronesian first-order subgroups, Malayo-Polynesian, Western Formosan, and Paiwan, are shown to directly continue the reconstructed stress system of Proto-Austronesian, with stress falling regularly on the penultimate syllable but shifting to the final syllable after a schwa. I also argue that the inability of schwa to hold stress is a result not of quality, but rather of quantity, as it is shown that schwa was a zero-weight vowel in Proto-Austronesian. Words with a schwa in the penultimate syllable, CəCVC, are shown to be sub-minimal, containing only a single mora. Daughter languages in Malayo-Polynesian underwent multiple cases of phonologically motivated drift, including consonant gemination, the deletion of penultimate schwa in three-syllable words, and vowel shift. These sound changes are argued to be part of a phonological conspiracy whose outcome is the addition of a mora to sub-minimal words. This study therefore offers both a reconstruction of Proto-Austronesian stress as well as a phonological explanation for these various sound changes in Malayo-Polynesian.

Magnetic and structural entropy contributions to the multicaloric effects in Ni-Mn-Ga-Cu

We have studied the multicaloric properties of a Ni-Mn-Ga-Cu alloy. In this alloy, application of magnetic field and uniaxial stress shift its martensitic transition towards higher temperatures which results in synergic magnetocaloric and elastocaloric effects. By a proper numerical treatment of the calorimetric curves obtained under applied magnetic field and uniaxial stress we have obtained the entropy $S(T,{\ensuremath{\mu}}_{0}H,\ensuremath{\sigma})$ as a function of the magnetic field, uniaxial stress, and temperature over the whole phase space under study. We have determined the different entropy contributions to the multicaloric effect in this alloy, and noticeably we have evidenced the role played by the interplay between magnetic and vibrational degrees of freedom. A comparison between single caloric and multicaloric effects shows that appropriate combinations of magnetic field and stress reduce the magnitude of the specific field required to obtain a given value of the isothermal entropy and adiabatic temperature changes. For example, at 299 K, to achieve an entropy change ($\mathrm{\ensuremath{\Delta}}S$) of $\ensuremath{-}14$ J ${\mathrm{kg}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}1}$, a magnetic field of $\ensuremath{\sim}2.5$ T or a uniaxial stress of 19 MPa are required, while a combination of dual fields of (1 T, 12 MPa) yields to the same value of $\mathrm{\ensuremath{\Delta}}S$. Moreover, the maximum adiabatic temperature change is enlarged up to 9.4 K by the dual fields, higher than the value obtained by a single field ($\ensuremath{\sim}7$ K). The advantage of multicaloric effect is particularly relevant at low magnetic fields which are achievable by permanent magnets. Our findings open new avenues for using multicaloric materials in novel refrigeration technologies.

Between- and within-person effects of stress on emotional eating in women: a longitudinal study over 49 days.

Stress is associated with binge eating and emotional eating (EE) cross-sectionally. However, few studies have examined stress longitudinally, limiting understanding of how within-person fluctuations in stress influence EE over time and whether stress is a risk factor or consequence of EE. Additionally, little is known regarding how the biological stress response relates to EE. We used an intensive, longitudinal design to examine between-person and within-person effects of major life stress, daily stress, and cortisol on EE in a population-based sample of women (N = 477; ages 15-30; M = 21.8; s.d. = 3.0) from the Michigan State University Twin Registry. Participants reported past year major life stress, then provided daily ratings of EE and stress for 49 consecutive days. Hair cortisol concentration (HCC) was collected as a longitudinal biological stress measure. Women reported greater EE when they experienced greater mean stress across days (between-person effects) or greater stress relative to their own average on a given day (within-person effects). Daily stress was more strongly associated with EE than major life stress. However, the impact of daily stress on EE was amplified in women with greater past year major life stress. Finally, participants with lower HCC had increased EE. Findings confirm longitudinal associations between stress and EE in women, and highlight the importance of within-person shifts in stress in EE risk. Results also highlight HCC as a novel biological stress measure that is significantly associated with EE and may overcome limitations of prior physiological stress response indicators.

Triaxial Contact Stresses of the Green Bus Tire Including Complex Rubber Materials and Rim

The primary purpose of the research is to explore triaxial contact stresses of the green bus tire including complex rubber materials and rim. An accurate finite element model of the bus tire is constructed using ABAQUS software after verification. The measured and calculated values have good consistency under different tire loads and inflation pressures. The finite element model is applied for quantitative research by changing tire loads, inflation pressures, and rolling conditions. The analysis results show that higher inflation pressure increases vertical contact stress, which requires a reasonable balance between high load and high inflation pressure. When the inflation pressure increases, the position of the maximum longitudinal contact stress shifts forward, and the maximum transverse contact stress shifts inboard in the transverse direction. When the tire load becomes larger at the free rolling condition, the position of the maximum vertical contact stress moves forward, and the position at the full braking condition is more advanced under the same load conditions. Overload not only causes great damage to the tire during the braking condition but also accelerates the appearance of the rutting and shoving of the road.

(Invited) Operando Measurement of Redox-Originated Stress in Anode Supported SOFC

Mechanical failures of an anode supported SOFC implies crack formation in the electrolyte, delamination of the electrode/electrolyte interfaces, and contact loss caused by cell deformation. To find the risk of those failures, it is essential to know the complicated behavior of stress state which is affected not only by thermal expansion mismatch but also by chemical change of the components. Structural analyses have been made by various groups by using mechanical property data accumulated in these decades. However, effects of chemical strain are not always taken into consideration, and even when it is properly included in the calculation, actually observed behavior does not always follow the expectation. It is thus important to make in-situ or operando measurement of the stress in cell components. Several in-situ measurement methods were tested, and cosα method of X-ray diffraction was chosen as the best suited method for the operando application [1]. With cosα method, focused X-ray beam irradiates the sample surface with a certain angle to the normal, and the Debye ring is monitored with a co-axially aligned imaging plate. The stress of the sample is estimated from the deformation of the Debye ring from the stress-free state. A specially designed one- or two-chamber cell holder was developed to be used with a portable X-ray stress analyzer (μ-X360s, Pulstec Industrial. Co. Ltd.). Anode-supported cells purchased from multiple sources were analyzed. Measurements were made focusing on the initial reduction of the nickel oxide support, re-oxidation at operation temperatures, and re-oxidation at medium temperature ranges. In the initial reduction at 700˚C, highly compressive stress of about -300 MPa appeared on the electrolyte. It, however, was gradually mitigated down to around -100 MPa in 3 hours. This behavior was explained with the reduction contraction of NiO to Ni and subsequent softening of the support layer. Similarly, as is expected, reoxidation at 700˚C caused the shift of the residual stress to the tensile direction. The transient behavior, however, was different with the cells from different manufacturers. This could be due to the difference of the microstructure of the anode support layer which causes different bending behavior. Another interesting behavior was on the reoxidation of the support at intermediate temperature range. As reported elsewhere [2,3], nickel metal shows oxidation “contraction” when it is oxidized at temperatures around 400˚C to 500˚C, which is accompanied by enhancement of creep deformation rate. The mechanism is interpreted as the formation of slightly oxidized layer which promotes mass transport at the particle surfaces and grain boundaries. It is coupled with the driving force of oxidation that makes the nickel ions move from the inside to the outside. Consequently, neck growth takes place and the separation of the particles are reduced. The same mechanism can work with Ni-YSZ cermet anode and can cause compressive stress on the electrolyte. With this expectation, the reduced cell without cathode was re-oxidized at 400˚C. Actually, increase in the compressive stress was found on the electrolyte. The magnitude of the stress, however, was unexpectedly large as -600 MPa. It is even larger than that on the initial reduction, and the stress mitigation did not work despite the enhanced creep rate. This is probably because the driving force for the contraction is the oxidation that continues to exist before all nickel is re-oxidized. In an actual cell, this large compressive stress may cause buckling delamination of the electrolyte. Reoxidation during shutdown operation must be carefully avoided. As was found in several experiments, unexpected stress state may appear in an actual SOFC operation, which emphasizes the importance of operando analyses.AcknowledgementThis study was supported by the New Energy and Industrial Technology Development Organization (NEDO) .Acknowledgement[1] K. Oshima et al.,ECS Trans. 103(1), 1251-1260 (2021)[2] K. Yashiro et al., 12th European SOFC&SOE Forum, Lucerne, Switzerland, 05-08 July (2016)[3] Y. Morishita et al. , ECS Trans., 91(1) 1979 (2019).

Projected future changes in the contribution of Indo-Pacific sea surface height variability to the Indonesian throughflow

The Indonesian throughflow (ITF) transports a significant amount of warm freshwater from the Pacific to the Indian Ocean, making it critical to the global climate system. This study examines decadal ITF variations using ocean reanalysis data as well as climate model simulations from the Coupled Model Inter-comparison Project Phase 5 (CMIP5). While the observed annual cycle of ITF transport is known to be correlated with the annual cycle of sea surface height (SSH) difference between the Pacific and Indian Oceans, ocean reanalysis data (1959–2015) show that the Pacific Ocean SSH variability controls more than 85% of ITF variation on decadal timescales. In contrast, the Indian Ocean SSH variability contributes less than 15%. While those observed contributions are mostly reproduced in the CMIP5 historical simulations, an analysis of future climate projections shows a 25–30% increase in the Indian Ocean SSH variability to decadal ITF variations and a corresponding decrease in the Pacific contribution. These projected changes in the Indian Ocean SSH variability are associated with a 23% increase in the amplitudes of negative zonal wind stress anomalies over the equatorial Indian Ocean, along with a 12º eastward shift in the center of action in these anomalies. This combined effect of the increased amplitude and eastward shift in the zonal wind stress increases the SSHA variance over the Indian Ocean, increasing its contribution to the ITF variation. The decadal ITF changes discussed in this study will be crucial in understanding the future global climate variability, strongly coupled to Indo-Pacific interactions.

Metrical exceptionality and stress shift in Romanian nouns and adjectives

This paper proposes a reanalysis of stress in Romanian nouns and adjectives. We will argue that an analysis in Strict CV Metrics produces a simple account of the stress facts of Romanian without arbitrarily dividing the lexicon into regular and irregular words. The result is a system, which, although entirely lexically marked, always has accent falling within a determined metrical window; one that is not defined by syllables or feet, but CV syllabification. In this reanalysis, all forms share precisely the same conditions on stress. Moreover, the fact that the window is defined in CVs rather than syllables uniquely makes the correct prediction that nouns/adjectives of the shape CV́.CV.CVC are impossible. Previous accounts that split the lexicon into “regular” and “irregular” forms have no obvious way to exclude this particular shape, despite it being truly unattested in the language, unlike the stated “exceptional” patterns, all of which are attested. We further use the Strict CV metrical window to correctly predict a pattern of stress shift observed with the adjectival suffix -ik. The implications for diphthong structures in Romanian are also discussed.

강세 충돌 해소의 음성학적 실태 연구

The present study examines the phonetic realization of vowels in the avoidance of stress clash. This study compares a 5 syllable phrase which shows stress movement, with a 4 syllable word which has stress on the right foot. 5 male native speakers and 5 female native speakers read 16 sentences with words and phrases. Pitch declined in the third syllable compared to the first syllable in phrases (σ1σ3). Correspondingly, pitch in the third syllable of a phrase was lower than that of a word. Intensity in the first and the third syllable of a phrase was similar (σ1≒σ3) and there was no significant intensity change in the third syllables between a word and a phrase. As a result, pitch reflected the effect of stress clash and showed stress shift and stress deletion in the manner of an acoustic value decrease, achieving the goal of avoiding stress clash. Intensity, on the other hand, maintained the periodical alternation (sw sw) and did not show the grid lowering in the manner of an acoustic value decrease.

The Impact of the Cut-Out Shape on the Dynamic Behavior of Composite Thin Circular Plates

This study measures the impact of the cut-out shape on the fundamental frequency and the harmonic response of thin composite circular plates under fixed boundary conditions. For this purpose, the Finite Element Method has been employed using the SHELL181 element of ANSYS Workbench 18.2 software. Nine different circular plates having central equilateral triangle, square, regular pentagon, regular hexagon, regular heptagon, regular octagon, regular nonagon, regular decagon, and circular cut-outs have been designed to understand the changes in the vibrational behavior of a structure as the cut-out geometry approximates to circular. Additionally, a solid circular plate has been modelled for comparison purposes. To investigate the effect of the cut-out shape more deeply, all structures have been designed as cross-ply and angle-ply composites. The free vibration analysis has been performed to obtain the fundamental frequency of each structure. The harmonic response analysis problem has been solved by employing the Mode Superposition Method and considering a constant damping ratio. The results of the study have been interpreted by considering the displacement response, stress, and phase shifts at a certain frequency range. The results indicate that the shape of the cut-out considerably affects the fundamental frequency and harmonic response of the circular structure regardless of its fiber orientation.

Optimized integration of metabolomics and lipidomics reveals brain region-specific changes of oxidative stress and neuroinflammation in type 1 diabetic mice with cognitive decline

IntroductionType 1 diabetes (T1D) causes cognitive decline and has been associated with brain metabolic disorders, but its potential molecular mechanisms remain unclear. ObjectivesThe purpose of this study was to explore the molecular mechanisms underlying T1D-induced cognitive impairment using metabolomics and lipidomics. MethodsWe developed an optimized integration approach of metabolomics and lipidomics for brain tissue based on UPLC-Q-TOF-MS and analyzed a comprehensive characterization of metabolite and lipid profiles in the hippocampus and frontal cortex of T1D male mice with cognitive decline (T1DCD) and age-matched control (CONT) mice. ResultsThe results show that T1DCD mice had brain metabolic disorders in a region-specific manner relative to CONT mice, and the frontal cortex exhibited a higher lipid peroxidation than the hippocampus in T1DCD mice. Based on metabolic changes, we found that microglia was activated under diabetic condition and thereby promoted oxidative stress and neuroinflammation, leading to neuronal injury, and this event was more pronounced in the frontal cortex than the hippocampus. ConclusionOur results suggest that brain region-specific shifts in oxidative stress and neuroinflammation may contribute to diabetic cognitive decline, and the frontal cortex could be the more vulnerable brain region than the hippocampus.

Canopy Temperature Is Regulated by Ecosystem Structural Traits and Captures the Ecohydrologic Dynamics of a Semiarid Mixed Conifer Forest Site

AbstractPlant canopy temperature (Tc) is partly regulated by evaporation and transpiration from the canopy surface and can be used to infer changes in stomatal regulation and vegetation water stress. In this study, we used a thermal Unmanned Aircraft Systems in conjunction with eddy covariance, sap flow, and spectral reflectance data to assess the diurnal characteristics of Tc and water stress status over a semiarid mixed conifer forest in Arizona, USA. Diurnal Tc dynamics were closely related to tree sap flow and changes in spectral reflectance associated with stomatal regulation. Consistent with previously reported deviations, we found that on average Tc was 1.8°C lower than the above canopy air temperature (Ta). However, the relationship between Tc and Ta varied significantly according to tree density and tree height classes, with taller and denser trees exhibiting relatively low |Tc‐Ta| (2.4 and 2.1°C cooler canopies, respectively) compared to shorter and less‐dense tree stands (1.7 and 1.5°C cooler canopies, respectively). We used these data to evaluate space‐borne diurnal measurements of Tc and water stress from the ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) mission. We found that ECOSTRESS observations of Tc accurately tracked seasonal shifts in diurnal surface temperatures and vegetation water stress, and that site‐level observations of heterogeneity in forest composition and structure could be applied to separate the processes of canopy transpiration and soil evaporation within the ECOSTRESS footprint. This study demonstrates how proximal and satellite remote sensing approaches can be combined to reveal the diurnal and seasonally dynamic nature of Tc and water stress.

Некоторые лексические закономерности переноса ударения на предлог в сочетаниях «предлог плюс существительное»

The paper addresses lexical factors of stress shift from nouns to prepositions in the modern Russian literary language. The purpose of the study is to determine the conditions that promote or hinder accentuation of functional lexemes in live spoken speech. Scientific novelty of the research lies in the fact that the author for the first time conducts a comprehensive sociolinguistic study on accentuation of prepositional phrases “preposition + noun” and compares codified and usual norms of accentuation of these phrases. As a result of the research, the linguistic and sociolinguistic factors that affect stress shift have been determined and described in detail and trends in the development of the considered norms have been identified.

Numerical Simulation of Integrated Mechanics of Drilling and Mechanical Cavitation in Coal Seam.

For coal and gas outburst and difficult extraction in soft, low-permeability, and high-gas seam, the integration technology of drilling and mechanical cavitation is put forward to relieve pressure and improve permeability of coal seam. Through the test of mechanical parameters of the coal body, the physical model of drilling and cave-making in coal seam is established, and the mechanical characteristics of drilling and mechanical cavitation are simulated numerically. The results show that the peak strength of coal increases linearly with confining pressure. When the drill bit just touches the coal, the maximum stress occurs at the center of the coal sample. With the increase in the drilling depth of the drill bit, the maximum stress point shifts to the depth. When the coal at the center of the sample is broken, the position of the maximum stress shifts to the surrounding. With the increase of drilling depth, the maximum contact number between the drill bit and coal body increases sharply. When the bit body basically enters the coal body, the maximum contact number between the drill bit and coal body remains unchanged. When the drill pipe rotates, the reaming tool collides with the hole wall at the reaming position on the axis. In general, the contact area increases with the opening of the reaming tool, but the contact between the reaming tool and the hole wall is random. As time increases, the contact force begins to increase and then basically stabilizes; at this time the reaming tool has been fully opened.

Identification of an integrated stress and growth response signaling switch that directs vertebrate intestinal regeneration

BackgroundSnakes exhibit extreme intestinal regeneration following months-long fasts that involves unparalleled increases in metabolism, function, and tissue growth, but the specific molecular control of this process is unknown. Understanding the mechanisms that coordinate these regenerative phenotypes provides valuable opportunities to understand critical pathways that may control vertebrate regeneration and novel perspectives on vertebrate regenerative capacities.ResultsHere, we integrate a comprehensive set of phenotypic, transcriptomic, proteomic, and phosphoproteomic data from boa constrictors to identify the mechanisms that orchestrate shifts in metabolism, nutrient uptake, and cellular stress to direct phases of the regenerative response. We identify specific temporal patterns of metabolic, stress response, and growth pathway activation that direct regeneration and provide evidence for multiple key central regulatory molecules kinases that integrate these signals, including major conserved pathways like mTOR signaling and the unfolded protein response.ConclusionCollectively, our results identify a novel switch-like role of stress responses in intestinal regeneration that forms a primary regulatory hub facilitating organ regeneration and could point to potential pathways to understand regenerative capacity in vertebrates.

Shaping the stress field in cell monolayers via intercellular water flows

As open systems, cells significantly change their volumes under mechanical forces. Mechanical forces are ubiquitous in cell monolayers due to cell–cell interactions, cell–substrate interactions, and external mechanical perturbations. Thus, cells in the monolayer will dramatically change their volumes. How cellular volume regulation (i.e. water and ion flows) affects the stress profile of cell monolayer, however, remains elusive. In this work, we develop a theoretical framework to systematically study the coupling mechanism between intercellular water flows and cell stress. Consistently with experimental observations, this model can recapitulate prominent distribution features of internal stress and cell–matrix traction, including the localization of traction force, the build-up of internal cell stress, and the scaling relation between traction force and the size of cell monolayer. More importantly, the model can also predict how intercellular water flow field dictates the profiles of traction and internal stress. We find that a bigger water flow field leads to bigger maximum stress and traction. Likewise, as the water flow field increases, the position corresponding to the maximum stress shifts from monolayer center to monolayer periphery. Together, our study establishes a direct link between intercellular water flows and stress profile in the cell monolayers, which will provide a new strategy to modulate the stress field and stress-related physiological processes in living tissues.