Search Results (22)

Temperature is a critical abiotic factor regulating the physiology, growth, and reproduction of ectothermic aquatic animals. In China, the rapid expansion of the red swamp crayfish Procambarus clarkii) industry faces significant challenges due to seasonal temperature fluctuations (optimal growth at 20–25 °C and reproduction favored at 18–22 °C). This review focuses specifically on TRP channels, particularly TRPA1 as a key thermosensor in crayfish, and on downstream signaling pathways involving heat shock proteins (HSPs) and antioxidant defenses. We further link these biological mechanisms to aquaculture applications by evaluating best management practices for mitigating thermal stress, including integrated rice–crayfish co-culture, recirculating aquaculture systems (RAS), molecular marker-assisted breeding for thermal tolerance, and nutritional modulation (e.g., probiotics and immunostimulants). By maintaining thermal stability within the optimal range and directly enhancing physiological resilience through genetic and nutritional interventions, these practices provide a foundation for more sustainable and climate-resilient crayfish aquaculture. Full article

Photoluminescent liquid crystals with photoluminescence (PL) and liquid-crystalline (LC) properties have attracted attention as PL-switching materials owing to their thermally induced phase transitions, such as crystal → smectic A/nematic → isotropic phase transitions. Our group previously developed tetrafluorinated tolane mesogenic dimers linked by flexible alkylene-1,n-dioxy spacers, demonstrating that the position of the tetrafluorinated aromatic ring critically influences the LC behavior. However, these compounds exhibited very weak fluorescence owing to an insufficient D–π–A character of the π-conjugated mesogens, which facilitated internal conversion from emissive ππ* to non-emissive πσ* states. We designed and synthesized derivatives in which the mesogen–spacer linkage was modified from ether to ester, thereby enhancing the D–π–A character. Thermal and structural analyses revealed spacer-length parity effects: even-numbered spacers induced nematic phases, whereas odd-numbered spacers stabilized smectic A phases. Photophysical studies revealed multi-state PL across solution, crystal, and LC phases. Strong blue PL (Φ_PL = 0.39–0.48) was observed in solution, while crystals exhibited aggregation-induced emission enhancement (Φ_PL = 0.48–0.77) with spectral diversity. In LC states, Φ_PL values up to 0.36 were maintained, showing reversible intensity and spectral shifts with phase transitions. These findings establish design principles that correlate spacer parity, phase behavior, and PL properties, enabling potential applications in PL thermosensors and responsive optoelectronic devices. Full article

Temperature homeostasis is controlled by the vagus nerve. Thermal information is collected by thermoreceptors present in the viscera and driven across sensory neurons of the nodose ganglia (NG), which in turn send it to the hypothalamus. While transient receptor potential channels (TRPs) are traditionally considered for thermal transduction, TREK channels belonging to the two-pore domain K⁺ channels family are emerging as thermosensors, but their role in the NG remains understudied. Patch-clamp recordings revealed that increasing the temperature to physiological levels causes a hyperpolarization of the membrane potential followed by a depolarization and, despite physiological temperature increased the firing rate, we have demonstrated that TREK channels might be taking part in the excitability control by counteracting TRPs’ effects. In fact, single-channel experiments revealed an increase in TREK channel open probability and a subsequent rise in their activity in NG neurons. All this indicates that TREK channels, mainly TREK1, may be responsible along with TRPs for the maintenance of the membrane potential at physiological temperature in NG neurons. Full article

Plants respond to higher ambient temperatures by modifying their growth rate and habitus. This review aims to summarize the accumulated knowledge obtained with Arabidopsis seedlings grown at normal and elevated ambient temperatures. Thermomorphogenesis in the shoot and the root is overviewed separately, since the experiments indicate differences in key aspects of thermomorphogenesis in the two organs. This includes the variances in thermosensors and key transcription factors, as well as the predominance of cell elongation or cell division, respectively, even though auxin plays a key role in regulating this process in both organs. Recent findings also highlight the role of the root and shoot meristems in thermomorphogenesis and suggest that the cell cycle inhibitor RETINOBLASTOMA-RELATED protein may balance cell division and elongation at increased temperatures. Full article

Temperature is an essential physical characteristic that influences all biological processes. Building on previous research on dialkylamino-functionalized rhodamine-based thermo-sensors, we investigate herein the thermosensitive properties of triamino-phenazinium dyes. Through a simple five-step synthetic route, we synthesized amino-phenazinium chromophores 6 and 7, featuring diethylamine substituents at different positions. A comparative analysis of optical properties and thermosensitivity was conducted on these compounds and an isomer, 5, in which butylamine moiety replaced the diethylamine group. The different emissive behaviors of the three fluorophores emphasize that not only the chemical nature but also the specific position of the alkylamine substituent play fundamental roles in the synthesis of highly emissive thermo-probes. Full article

Photomorphogenic development in seedlings may be diagnostic of future plant performance. In this report, we characterize the Thai Oakleaf lettuce genotype, as it exhibited abnormalities in photomorphogenic development that were the most conspicuous under red light, including defects in hypocotyl growth inhibition, decreased cotyledon expansion, and constitutive shade avoidance tendencies. These observations are consistent with defects in red light sensing through the phytochrome B (phyB) photoreceptor system. This genotype is sold commercially as a heat-tolerant variety, which aligns with the evidence that phyB acts as a thermosensor. Full article

Stenotrophomonas maltophilia is a major threat to the food industry and human health owing to its strong protease production and biofilm formation abilities. However, information regarding regulatory factors or potential mechanisms is limited. Herein, we observed that temperature differentially regulates biofilm formation and protease production, and a cAMP receptor-like protein (Clp) negatively regulates thermosensor biofilm formation, in contrast to protease synthesis. Among four c-di-GMP-related two-component systems (TCSs), promoter fusion analysis revealed that clp transcription levels were predominantly controlled by LotS/LotR, partially controlled by both RpfC/RpfG and a novel TCS Sm0738/Sm0737, with no obvious effect caused by Sm1912/Sm1911. Biofilm formation in Δclp and ΔTCSs strains suggested that LotS/LotR controlled biofilm formation in a Clp-mediated manner, whereas both RpfC/RpfG and Sm0738/Sm0737 may occur in a distinct pathway. Furthermore, enzymatic activity analysis combined with c-di-GMP level indicated that the enzymatic activity of c-di-GMP-related metabolism proteins may not be a vital contributor to changes in c-di-GMP level, thus influencing physiological functions. Our findings elucidate that the regulatory pathway of c-di-GMP-related TCSs and Clp in controlling spoilage or the formation of potentially pathogenic factors in Stenotrophomonas expand the understanding of c-di-GMP metabolism and provide clues to control risk factors of S. maltophilia in food safety. Full article

Infrared thermography is an advanced technique usually applied for the assessment of thermal losses through different elements of the building envelope, or as a method for detection of damage (cracks) in reinforced concrete elements, such as bridges. Use of this method for the investigation of temperature development during early cement hydration is still an evolving area of research. For the purpose of verifying the reliability of the method, two types of cubic samples of different heights were prepared using a cement-based paste, with 20% of cement (by mass) replaced with fly ash. Temperature development was measured in two ways: using infrared thermography and thermo-sensors embedded in the samples. Additionally, the obtained results were modeled using the asymmetric Gaussian function. Peak temperatures in the middle of each sample were higher than the peak temperatures measured on the sample surface, with differences ranging between 2 °C and 4 °C. Differences between the temperature measurements of the thermo-sensors placed on the surface of the sample and thermal camera were lower than 2 °C. Very good compliance of the results was obtained for both the camera and the surface sensors measurements, as well as for the modeling coefficients. Full article

Photoluminescent liquid-crystalline (PLLC) molecules, which can easily tune the PL behavior through the crystal (Cry)–LC phase transition, have attracted significant attention. Previously, we have demonstrated that the incorporation of a semifluoroalkoxy chain into π-conjugated mesogen is a promising approach for developing PLLC molecules with PL and SmA LC characteristics. We focused on the LC and PL characteristics of the molecules induced by the semifluoroalkoxy chain and fluorinated tolanes in the condensed phase. In this study, we developed cyano- or ethoxycarbonyl-terminated donor-π-acceptor-type fluorinated tolanes containing a semifluoroalkoxy flexible chain. The cyano-terminated fluorinated tolanes exhibited intense light-blue photoluminescence in the crystalline phase and did not exhibit any LC phase. In contrast, blue photoluminescence in the ethoxycarbonyl-terminated analogs was slightly weak; however, they exhibited Cry–SmA phase transition during the heating and cooling processes. The PL intensity of the ethoxycarbonyl-terminated fluorinated tolanes significantly decreased in the SmA phase; however, their PL colors changed during the Cry–SmA phase transition. This indicates that the developed tolanes are promising temperature-dependent PL materials, such as PL thermosensors or PL thermometers. Full article

Functional molecules possessing photoluminescence (PL) and liquid-crystalline (LC) behaviors, known as photoluminescent liquid crystals, along with a small molecular structure, have attracted significant attention. Fluorinated tolane skeletons are small π-conjugated structures, which are promising candidates for such functional molecules. These structures were revealed to exhibit strong PL in solid state but no LC behavior. Based on a report on hydrogen-bonded dimer-type LC molecules of carboxylic acid, in this study, we designed and synthesized a series of fluorinated tolanecarboxylic acids (2,3,5,6-tetrafluoro-4-[2-(4-alkoxyphenyl)ethyn-1-yl]benzoic acids) as promising PLLC molecules. Evaluation of the LC behavior revealed that fluorinated tolanecarboxylic acids with a longer alkoxy chain than a butoxy chain exhibited nematic LC behavior. Additionally, fluorinated tolanecarboxylic acids showed intense PL in the solution and crystalline states. Notably, fluorinated tolanecarboxylic acid with an aggregated structure in the nematic LC phase also exhibited PL with a slight blue shift in PL maximum wavelength compared to the crystalline state. The present fluorinated tolanecarboxylic acid exhibiting PL and LC characteristics in a single molecule can be applied to thermoresponsive PL materials, such as a PL thermosensor. Full article

This work reports fabrication of polylactide (PLA) films doped with various additives of an amorphous Eu(III) complex. We study the temperature behavior of the luminescence intensity and lifetime of the PLA-Eu(III) composites in the range of 298–353 K and investigate the mechanism of luminescence temperature quenching. The peak relative sensitivity of the films reaches 20.1 %×K⁻¹ and exceeds the respective characteristics of all known lanthanide-containing thermosensors designed for the range of physiological temperatures. The produced films can be potential novel materials for luminescent thermosensors. Full article

The expression of genes of interest (GOI) can be initiated by providing external stimuli such as temperature shifts and light irradiation. The application of thermal or light stimuli triggers structural changes in stimuli-sensitive biomolecules within the cell, thereby inducing or repressing gene expression. Over the past two decades, several groups have reported genetic circuits that use natural or engineered stimuli-sensitive modules to manipulate gene expression. Here, we summarize versatile strategies of thermosensors and light-driven systems for the conditional expression of GOI in bacterial hosts. Full article

Luminescent temperature sensors are of great interest because they allow remote determination of temperature in transparent media, such as living tissues, as well as on scattering or transparent surfaces of materials. This study analyzes the luminescent properties of copper(II) etioporphyrinate (Cu-EtioP) in a polystyrene film upon variation of temperature from −195 °C to +65 °C in a cryostat. It is shown that the ratio of intensities of phosphorescence transitions in the red spectral region of such a material varies significantly, that is, the material has thermosensory properties. The phosphorescence decay curves of copper(II) etioporphyrinate in a polystyrene film are analyzed. The quantum yield of phosphorescence of copper(II) etioporphyrinate determined by the absolute method was 3.15%. It was also found that the electroluminescence (EL) spectra of copper(II) etioporphyrinate in a poly(9-vinylcarbazole) (PVK) matrix demonstrated a similar change in the spectra in the temperature range −3 °C to +80 °C. That is, copper(II) etioporphyrinate can also be used as a luminescent temperature sensor as part of an active OLED layer. Full article

¹H NMR measurements are reported for the CD₂Cl₂/CDCl₃ solutions of the Co(II) calix[4]arenetetraphosphineoxide complex (I). Temperature dependences of the ¹H NMR spectra of I have been analyzed using the line shape analysis, taking into account the temperature variation of paramagnetic chemical shifts, within the frame of the dynamic NMR method. Conformational dynamics of the 2:1 Co(II) calix[4]arene complexes was conditioned by the pinched cone ↔pinched cone interconversion of I (with activation Gibbs energy ΔG^≠(298K) = 40 ± 3 kJ/mol. Due to substantial temperature dependence of paramagnetic shifts, complex I can be used as model compound for designing an NMR thermosensor reagent for local temperature monitoring. Full article

The heat-shock response, a universal protective mechanism consisting of a transcriptional reprogramming of the cellular transcriptome, results in the accumulation of proteins which counteract the deleterious effects of heat-stress on cellular polypeptides. To quickly respond to thermal stress and trigger the heat-shock response, bacteria rely on different mechanisms to detect temperature variations, which can involve nearly all classes of biological molecules. In Campylobacter jejuni the response to heat-shock is transcriptionally controlled by a regulatory circuit involving two repressors, HspR and HrcA. In the present work we show that the heat-shock repressor HrcA acts as an intrinsic protein thermometer. We report that a temperature upshift up to 42 °C negatively affects HrcA DNA-binding activity to a target promoter, a condition required for de-repression of regulated genes. Furthermore, we show that this impairment of HrcA binding at 42 °C is irreversible in vitro, as DNA-binding was still not restored by reversing the incubation temperature to 37 °C. On the other hand, we demonstrate that the DNA-binding activity of HspR, which controls, in combination with HrcA, the transcription of chaperones’ genes, is unaffected by heat-stress up to 45 °C, portraying this master repressor as a rather stable protein. Additionally, we show that HrcA binding activity is enhanced by the chaperonin GroE, upon direct protein–protein interaction. In conclusion, the results presented in this work establish HrcA as a novel example of intrinsic heat-sensing transcriptional regulator, whose DNA-binding activity is positively modulated by the GroE chaperonin. Full article