Physiological Range Research Articles

An Evaluation of the Systemic Impact and Clinical Efficacy of Sequential Vincristine Sulfate Versus Doxorubicin in the Post-operative Management of Canine Mammary Tumours (CMT)

The present study was conducted to evaluate the systemic impact and clinical efficacy of sequential vincristine sulfate compared to doxorubicin in the post-operative management of Canine Mammary Tumours (CMT) on 18 clinical cases of mammary tumour of various breed, irrespective of their age, sex and divided into three groups consisting of 6 animals in each. Group Surgery was treated with surgical removal of tumouronly while animals of Group Surg Dox and Group Surg Vin were treated with surgical excision followed by administration of Doxorubicin (30mg/m2) BSA and Vincristine sulfate (0.025 mg/kg) intravenously along with DNS at 7th and 14th post-operative days respectively. The haemato-biochemical parameters and wound evaluation were done at different time intervals. Systemic impact on haematological and biochemical parameters were briefly altered and chemotherapeutic medications does not induce any adverse reactions or detrimental effects on vital organs, but these changes remained within the normal physiological range. Doxorubicin and vincristine sulfate therapy showed minimum to no reoccurrence of tumour with few adverse reactions such as inappetance, vomition, anaemia and alopecia. However, these conditions were managed by supportive therapy. Therefore, it could be concluded that sequential vincristine therapy is best for the post-operative management of canine mammary tumours as it effectively regressed the tumour without relapse.

A Pilot Study of a Simulation-Based Mastery Learning Procedural Curriculum for Pediatric Emergency Medicine Fellows.

Pediatric emergency medicine (PEM) fellows are expected to perform high-risk procedures across a wide range of patient age, size, and physiology including procedures that are no longer required during pediatric residency training. Examples include central venous catheter (CVC) placement, endotracheal intubation of children and adolescents, and tube thoracostomy placement. Simulation-based mastery learning has demonstrated decreased patient morbidity. In this study, we describe implementation of a simulation-based mastery learning (SBML) procedural curriculum for PEM fellows. Our PEM fellows underwent an SBML procedural curriculum for lumbar puncture (LP), CVC placement, endotracheal intubation, and tube thoracostomy placement. These procedures are mandatory for fellows to learn, have known association with potential iatrogenic injury, and are widely available commercial task trainers. Fellows underwent baseline assessments, group demonstration, deliberate practice, and then postassessments. For both pre- and postassessments, we used internally developed checklists with minimum passing scores (MPSs) calculated by the Mastery-Angoff technique. Nineteen pediatrics residency-trained PEM fellows underwent this curriculum over a 2-year period. Six fellows (31.58%) achieved the MPS on all four procedures during their first posttest attempt. All fellows achieved the MPS on all four procedures by the second posttest attempt. Most fellows (17/19 or 89.47%) did not achieve the MPS on baseline LP assessments, despite inclusion of this procedure as an Accreditation Council of Graduate Medical Education (ACGME) requirement during their pediatric residency training. All participating PEM fellows demonstrated competency after training on four procedures associated with iatrogenic injuries. Using an SBML framework is a feasible method to teach procedural skills to PEM fellows, allowing them to demonstrate objective measures of competency in the simulation laboratory.

Enhanced upconversion luminescence of Er/Tm for highly sensitive multi-mode optical nanothermometer

A novel class of Er3+/Tm3+/Yb3+ co-doped Sc4Zr3O12 nanocrystals have been successfully synthesized via a hydrothermal method. The enhanced green and red emissions of Er3+are achieved through the mediation of Tm3+. Decay curves and DFT calculations indicate this enhancement is due to the cross relaxation processes and narrowed bandgap. Based on the temperature-dependent upconversion characteristics, a multi-mode optical thermometer is developed using the fluorescence intensity ratio (FIR) technique of thermally coupled levels (TCLs) and non-thermally coupled levels (NTCLs), as well as the valley to peak ratio (VPR) technique. The absolute sensitivity (Sa) and relative sensitivity (Sr) derived from 1G4(b)/2H11/2 NTCLs reach as high as 11.84% K−1 and 1.89% K−1, respectively. Additionally, the optimal sensitivities occur at 303 K, perfectly aligning with the physiological temperature range. A comparison of different fitting models for NTCLs reveals that the exponential model offers the best performance for this system, with a correlation coefficient of 99.9%. This work provides new insights into upconversion enhancement of multi-emission centers and lays the theoretical and experimental foundation for developing high-sensitivity and high-precision optical nanothermometers.

Transcatheter bicuspid venous valve prostheses: fluid mechanical performance testing of artificial nonwoven leaflets

BackgroundChronic venous insufficiency (CVI) is a common disease with a high prevalence. Incompetent venous valves are considered as one of the main causes. Besides compression therapy, various surgical therapies are practiced, whereby the reconstruction of valves is of central importance. There is an unmet clinical need, no valve prosthesis is commercially available to date. This work introduces two versions of a patented prosthetic bicuspid valve design made of electrospun thermoplastic silicone polycarbonate polyurethane (TSPCU) nanofiber leaflets attached in a nitinol stent, and their performance in static and pulsatile operation.ResultsThe valves mainly fulfill the requirements widely accepted in literature. Valves of both versions were functional in the physiological pressure range up to 50 mmHg with design specific differences.ConclusionsThe here introduced design versions act as a platform technology and can be tailored for an intended implantation site. Evaluation of the original and modified valve concept demonstrated efficacy, with limitations at higher loads for original design. At the current state, the modification is preferable for fabrication, as one processing step is eliminated. Moreover, specific design recommendations could be drawn for valves of similar basic structure. Future work will focus on long-term performance and biocompatibility prior to the initiation of preclinical in vivo studies.

Chloride removal and bicarbonate replacement by isotonic sodium bicarbonate-based continuous hemodiafiltration: a novel method to correct severe metabolic acidosis.

Previous reports highlighted the efficacy of hemofiltration utilizing isotonic sodium bicarbonate solution as replacement fluid for severe metabolic acidosis. This approach corrects metabolic acidosis by eliminating chloride and supplementing bicarbonate. Here, we present the results of an in vitro study aimed at determining the effect of Isotonic sodium bicarbonate-based Continuous HemoDiafiltration (IBB-CHDF). Conventional Continuous HemoDiaFiltration (CHDF) and IBB-CHDF utilized aqueous solutions mimicking blood's electrolyte composition. To assess the efficacy and safety, we compared serial changes in pH, HCO3-, Na+, and K+ concentrations. Blood flow rate was 100mL/min, and the dialysis fluid flow rate maintained 1.0 L/h for both CHDF and IBB-CHDF. Replacement flow rates ranged from 0.5 to 1.5 L/h for CHDF and 0.1 to 1.5 L/h for IBB-CHDF. At a replacement flow rate of 0.5 L/h with IBB-CHDF, bicarbonate increased from 14.7 mEq/L to within the physiological range (25.9mEq/L), whereas in conventional CHDF, the post-treatment bicarbonate concentration did not increase (16.5mEq/L). The maximum bicarbonate concentration achieved was 22.0mEq/L at a replacement flow rate of 1.5 L/h in conventional CHDF. Notably, in IBB-CHDF, the sodium concentration remained constant at 150mEq/L, 10mEq/L higher than conventional CHDF, and did not escalate despite increasing the replacement flow rate. IBB-CHDF effectively corrects metabolic acidosis without inducing sodium and water overload by eliminating excess chloride while providing bicarbonate.

Taste preference and conditioned taste aversion of the metallothionein-1/2 null mice

To investigate the effects of metallothionein (MT)-1/2 gene knockout on the taste preference and the conditioned taste aversion (CTA), we performed an experiment comparing the behavior of wild type (WT) mice and MT-1/2 null (KO) mice. The taste preference ratio of saccharin solutions (0.1 or 0.2 %) was significantly greater in KO mice than WT mice. The preference ratio of salt and bitter solutions was not different between KO mice and WT mice. After feeding with a low zinc diet, the average saccharin preference ratio was not significantly different between WT and KO mice at any concentration of saccharin. Concentrations of zinc in plasma in KO mice was slightly higher than WT mice, but both were within the physiological range. When conditioning for saccharin using intraperitoneal injection of LiCl, a marked CTA was produced in both WT and KO mice. These results suggest that MT may be involved in the regulation of sweet taste preferences and indicate that the brain function that mediates sweet taste-induced CTA acquisition is maintained in KO mice. In addition, it was suggested that MT was not actively involved in the regulation of plasma zinc concentration in either mice fed a normal diet or mice fed a low zinc diet for a week. The relation between the malfunction of MT-1/2 and signal transduction of intracellular zinc remained to be determined.

Excitation-Dependent pKa Extends the Sensing Range of Fluorescence Lifetime pH Sensors

Biological activity is strongly dependent on pH, which fluctuates within a variety of neutral, alkaline, and acidic local environments. The heterogeneity of tissue and subcellular pH has driven the development of sensors with different pKa values, and a huge assortment of fluorescent sensors have been created to measure and visualize pH in living cells and tissues. In particular, sensors that report based on fluorescence lifetime are advantageous for quantitation. Here, we apply a theoretical framework to derive how the apparent pKa of lifetime-based pH sensors depends on fluorescence excitation wavelength. We demonstrate that theory predicts the behavior of two different fluorescent protein-based pH sensors in solution as proofs-of-concept. Furthermore, we show that this behavior has great practical value in living cells because it extends the sensing range of a single sensor by simply choosing appropriate detection parameters to match the physiological pH range of interest. More broadly, our results show that the versatility of a single lifetime-based sensor has been significantly underappreciated, and our approach provides a means to use a single sensor across a range of pH environments.

A Comprehensive Review of Advanced Diagnostic Techniques for Endometriosis: New Approaches to Improving Women's Well-Being.

According to the World Health Organization (WHO), endometriosis affects roughly 10% (190 million) of reproductive-age women and girls in the world (2023). The diagnostic challenge in endometriosis lies in the limited value of clinical tools, making it crucial to address diagnostic complexities in patients with suggestive symptoms and inconclusive clinical or imaging findings. Saliva micro ribonucleic acid (miRNA) signature, nanotechnologies, and artificial intelligence (AI) have opened up new perspectives on endometriosis diagnosis. The aim of this article is to review innovations at the intersection of new technology and AI when diagnosing endometriosis. Aberrant epigenetic regulation, such as DNA methylation in endometriotic cells (ECs), is associated with the pathogenesis and development of endometriosis. By leveraging nano-sized sensors, biomarkers specific to endometriosis can be detected with high sensitivity and specificity. A chemotherapeutic agent with an LDL-like nano-emulsion targets rapidly dividing cells in patients with endometriosis. The developed sensor demonstrated effective carbohydrate antigen 19-9 detection within the normal physiological range. Researchers have developed magnetic iron oxide nanoparticles composed of iron oxide. As novel methods continue to emerge at the forefront of endometriosis diagnostic research, it becomes imperative to explore the impact of nanotechnology and AI on the development of innovative diagnostic solutions.

Thermal behavior of polymers and copolymers based on plant oils with differing saturated and monounsaturated content

AbstractPlant oil‐based acrylic monomers from hydrogenated sunflower (HFM), palm (PMM) and castor (CSM) oils were polymerized to investigate the effect of chemical composition on polymer phase transitions at temperatures relevant to physiological range. While HFM and PMM possess a highly differing content of saturated palmitic and stearic acids combined with unsaturated fatty acids, CSM contains primarily fragments based on monounsaturated ricinoleic hydroxy acid (up to 90%). Differential scanning calorimetry (DSC) measurements indicate that polymers from PMM and HFM are both semicrystalline (with Tm = −6 and −13 °C, respectively), while poly(CSM) appears to be amorphous (Tg = −49 °C). Considering the similarity in polymers' molar mass (Mn = 16 000–20 000 g mol−1), the observed thermal transitions can be explained by the formation of ordered morphological domains due to the presence of saturated palmitic and stearic acid fractions in poly(PMM) and poly(HFM). For copolymers of CSM, PMM and HFM (80 wt% of monomer feed) with styrene, DSC data show two transitions corresponding to the mobility of long alkyl fatty acid side fragments and the macromolecular backbone. For copolymers of PMM and HFM, comparable values (−52.8 and −55.5 °C, respectively) were obtained, while the second transition for poly(CSM‐co‐styrene) appears at 35 °C. We attribute this higher value to the presence of hydroxyl groups in ricinoleic acid fragments of CSM serving as additional chain transfer sites and the formation of macromolecular fractions enriched with polystyrene fragments. We expect that the temperature transitions obtained can be relevant to the future use of these polymers for biomedical applications, including the synthesis of polymer brushes. © 2024 Society of Chemical Industry.

Computational Model-Assisted Development of a Nonenzymatic Fluorescent Glucose-Sensing Assay.

Deep-red fluorescence was implemented in this fully injectable, nonenzymatic glucose biosensor design to allow for better light penetration through the skin, particularly for darker skin tones. In this work, a novel method was developed to synthesize Cy5.5 labeled mannose conjugates (Cy5.5-mannobiose, Cy5.5-mannotriose, and Cy5.5-mannotetraose) to act as the fluorescent competing ligand in a competitive binding assay with the protein Concanavalin A acting as the recognition molecule. Using fluorescence anisotropy (FA) data, a computational model was developed to determine optimal concentration ratios of the assay components to allow for sensitive glucose measurements within the physiological range. The model was experimentally validated by measuring the glucose response via FA of the three Cy5.5-labeled mannose conjugates synthesized with Cy5.5-mannotetraose demonstrating the most sensitive response to glucose across the physiological range. The developed method may be broadly applied to a vast range of commercially available fluorescent dyes and opens up opportunities for glucose measurements using nonenzymatic assays.

Novel Mn5+-activated Ba2TiO4 phosphor emitting in the second near-infrared biological window

In recent years, second near-infrared window emitting phosphors have gained widespread research interest due to their excellent tissue penetration and high imaging accuracy. In this work, a new type of Ba2Ti1-xMnxO4+x/2 (0.02 ≤ x ≤ 0.10) phosphors were successfully prepared by high-temperature solid-phase method and their potential in luminescence thermometry is evaluated. PL and PLE spectral analysis prove that the optimal Mn doping concentration is x = 0.03. The as-synthesized phosphors exhibit a broad excitation band of 550–1000 nm and a narrow emission band of 1170–1220 nm. The electronic structures of the original Ba2TiO4 and Mn-doped Ba2TiO4 were calculated and analyzed using the DFT + U method, which facilitates a better understanding of the impact of Mn doping on the luminescent properties of Ba2TiO4. The luminescence decay lifetime is measured to be 101.44 μs at room temperature, which is a giant enhancement compared to conventional nanosecond lifetime phosphor, indicating a progress in imaging accuracy. In addition, the as-synthesized phosphors maintain over 75 % of the maximum luminescence intensity within the physiological temperature range. The potential applications in luminescence temperature measurement were also analyzed by the LIR ratio method, and the relative sensitivity could reach 2.31 %K−1 at 283 K, which is a relatively high value in the second near-infrared window. Therefore, the as-synthesized Ba2Ti1-xMnxO4+x/2 (0.02 ≤ x ≤ 0.10) phosphors demonstrate great potential in NIR applications such as biological imaging and luminescent thermometry.

Insertable Biomaterial-Based Multianalyte Barcode Sensor toward Continuous Monitoring of Glucose and Oxygen.

Chronic diseases, including diabetes, cardiovascular diseases, and microvascular complications, contribute significantly to global morbidity and mortality. Current monitoring tools such as glucometers and continuous glucose monitors only measure one analyte; multiplexing technologies offer a promising approach for monitoring multiple biomarkers, enabling the management of comorbidities and providing more comprehensive disease insights. In this work, we describe a miniaturized optical "barcode" sensor with high biocompatibility for the continuous monitoring of glucose and oxygen. This enzymatic sensor relies on oxygen consumption in proportion to local glucose levels and the phosphorescence reporting of tissue oxygen with a lifetime-based probe. The sensor was specifically designed to operate in a tissue environment with low levels of dissolved oxygen. The barcode sensor consists of a poly(ethylene glycol) diacrylate (PEGDA) hydrogel with four discrete compartments separately filled with glucose- or oxygen-sensing phosphorescent microparticles. We evaluated the response of the barcode hydrogels to fluctuating glucose levels over the physiological range under low oxygen conditions, demonstrating the controlled tuning of dynamic range and sensitivity. Moreover, the barcode sensor exhibited remarkable storage stability over 12 weeks, along with full reversibility and excellent reproducibility (∼6% variability in the phosphorescence lifetime) over nearly 50 devices. Electron beam sterilization had a negligible effect on the glucose response of the barcode sensors. Furthermore, our investigation revealed minimal phosphorescence lifetime changes in oxygen compartments while exhibiting increased lifetime in glucose-responsive compartments when subjected to alternating glucose concentrations (0 and 200 mg/dL), showcasing the sensor's multianalyte sensing capabilities without crosstalk between compartments. Additionally, the evaluation of chronic tissue response to sensors inserted in pigs revealed the appropriate biocompatibility of the barcodes as well as excellent material stability over many months. These findings support further development of similar technologies for introducing optical assays for multiple biomarkers that can provide continuous or on-demand feedback to individuals to manage chronic conditions.

Water-soluble lanthanide complexes with bispidine-substituted benzoic acid for luminescent thermometry in a physiological range

A novel material based on europium and terbium complexes with a bispidine-substituted benzoate anion for luminescent thermometry in the physiological temperature range was obtained. The obtained complexes demonstrated intense visible luminescence with quantum yields up to 75%, high water solubility, and high luminescence sensitivity toward temperature (Sr = 2.1% K–1).

Highly selective and sensitive N-amidothiourea-based fluorescence chemosensor for detecting Zn2+ ions and cell Imaging: Potential applications for plasma membrane detection

A “turn-on” fluorescent sensor L was developed for the selective detection of Zn2+ ions in biological settings. This sensor exhibited a specific response to Zn2+ ions, with a detection limit of 39 nM. Analyses through titration and Job’s plot confirmed that the formed complex has a 2:1 stoichiometry (L: Zn2+). The sensor displayed strong selectivity for Zn2+ over other metal ions, demonstrating a robust binding affinity while effectively reducing interference from heavy metals. The identification process was validated by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H NMR) titrations, mass spectrometry (MS), and Density Functional Theory (DFT) calculations. Maximum fluorescence intensity was achieved upon interaction with Zn2+ ions within a physiological pH range of 7.0–7.5. Moreover, successful imaging experiments in HEK293 cells highlighted the sensor’s potential as a powerful tool for monitoring interactions at the plasma membrane.

In silico analysis of ventricular action potential with a current-voltage-time representation: Thresholds, membrane resistance, repolarization reserve.

The waveform of ventricular action potential (AP) is a key determinant of the cardiac cycle, a marker of beating pathophysiology, and a target for anti-arrhythmic drug design. The information contained in the waveform, though, is limited to the actual dynamics of the AP under consideration. By measuring quasi-instantaneous current-voltage relationships during repolarization, I propose a three-dimensional representation of the ventricular AP which includes potential dynamic responses that the beat can show when electrically perturbed. This representation is described in the case of a numerically reconstructed ventricular AP, but it can be, at least partially, derived in real cardiomyocytes. Simulation allows to disclose the potentialities and the limitations of the approach, that can be extended to any non-cardiac AP. By reporting, at any AP time, the ion current available within the physiological membrane potential range at that time, the representation makes all together available: (1) refractory period, (2) thresholds for eliciting full or calcium-driven APs, (3) threshold for all-or-none repolarization, (4) membrane resistance during repolarization, (5) the safety of membrane repolarization. It provides further evidence of a negative membrane resistance during the late phase of ventricular AP and a quantitative estimate of repolarization reserve (RR), key determinants of repolarization dynamics.

An Isoniazid-Based reversible Schiff base chemosensor for Multi-Analyte (Cu2+, Ni2+, Hg2+) detection

Isoniazid-based Schiff base N’-(furan-2-ylmethylene)isonicotinohydrazide (FINH) has been synthesized. FINH has proven its ability to selectively sense and respond to Cu2+, Ni2+, and Hg2+, which shows its potential as a chemosensor. UV–visible experiments, the absorption band (at 360 nm) of FINH shifted with the gradual addition of Cu2+, Ni2+, and Hg2+. A significant quenching in the emission band of FINH in fluorescence spectra has been observed with the addition of analytes at the physiological pH range. Cyclic voltammetric experiments have been conducted to determine the electron transfer process that occurs during the complexation of FINH with analytes. Moreover, the interactions of FINH-metal ions are reversible, and their reversible behavior has been demonstrated with the Na2EDTA solution. The binding insights among FINH and Cu2+, Ni2+, and Hg2+ are explained by IR spectral study. Additionally, the FINH works within the appreciable detection limit of 9.472 x 10−7 M (for Cu2+), 7.685 x 10−7 M (for Ni2+) and 2.411 x 10−7 M (for Hg2+), limit of quantitation of 3.15 x 10−6 M (for Cu2+), 2.561 x 10−6 M (for Ni2+) and 8.036 x 10−7 M (for Hg2+). Applying this isoniazid-based reversible chemosensor in analyzing real samples demonstrates its practicality and effectiveness for multi-analyte detection. This sensor could consistently measure metal ion concentrations in various environmental and biological samples, providing a valuable tool for monitoring pollutants and evaluating exposure risks.

Dialectics of perisomatic inhibition-The unity and conflict of opposites.

Over the past three decades, a great deal of attention has been paid to the study of perisomatic inhibition and perisomatic inhibitory basket cells. A growing body of experimental evidence points to the leading role of perisomatic inhibitory cells in the generation of oscillatory activity in various frequency ranges. Recently the link between the activity of basket cells and complex behavior has been demonstrated in several laboratories. However, all this is true only for one type of perisomatic inhibitory interneuron-parvalbumin-positive basket cells. Nevertheless, where parvalbumin-positive basket cells are found, there is another type of basket cell, cholecystokinin-positive interneurons. These two types of interneurons share a number of common features: they innervate the same compartments of target neurons and they often receive excitation from the same sources, but they also differ from each other in the synchrony of their GABA release and expression of receptors. The functional role of cholecystokinin-positive basket cells in oscillatory activity is not so obvious. They were thought to be involved in theta oscillations, however recent measurements in free moving animals have put some doubts on this hypothesis. Therefore, an important question is, whether these two types of basket cells work synergistically or perform opposing actions in functional networks? In this mini-review, we attempt to answer this question by putting forward the idea that these two types of basket cells are functionally united as two entities of the same network, and their opposing actions are necessary to maintain rhythmogenesis in a "healthy", physiological range.

Cardiovascular (reverse) remodelling induced by pregnancy: looking at the right side of the heart

Abstract Introduction Many studies have focused on pregnancy-induced left ventricular remodelling, overlooking the changes in right cardiac chambers. Purpose To characterize the right cardiovascular (CV) remodelling and reverse remodelling (RR) induced by pregnancy and postpartum, respectively, and the impact of CV risk (CVR) factors on these processes. Methods This prospective cohort was recruited at two tertiary centers from 2019 to 2022, including 51 healthy and 79 obese and/or hypertensive and/or with gestational diabetes and/or smoking habits pregnant women (cardiovascular risk [CVR] group). Women were evaluated by transthoracic echocardiography at the 1st trimester (1T) and 3rd trimester (3T) of pregnancy, as well as one-month (PP1), six-months (PP2), and one-year postpartum (PP3). Generalized linear mixed-effects models were used for the analysis of right CV remodelling and RR and to evaluate the impact of CVR factors on these processes. Results This study included 130 pregnant women, 60.8% primiparous, with a median age of 33 years. Despite all echocardiographic results being within the normality range, we describe the progression of right heart adaptations throughout pregnancy and postpartum (Table 1), namely: 1) Similar enlargement of the right atrium (RA) and right ventricle (RV) dimensions throughout pregnancy, recovering at PP2 except for RA in the CVR group; 2) Preserved RV systolic function throughout pregnancy in both groups, while the postpartum hemodynamic normalization triggers a reduction of (TAPSE) and tricuspid S' wave velocity; 3) Reduced RA strain in both groups during pregnancy, more evident in CVR group, which had a slower postpartum recovery; 4) Preserved RV global longitudinal strain (GLS) throughout follow-up time, being significantly reduced in 3T of CVR group and recovering at PP2; 5) Reduction of tricuspid E/A ratio from 1T to 3T in both groups with an early recovery at PP1, being these values significantly higher in the healthy group, and 6) Steady pulmonary artery systolic pressure (PASP) values throughout follow-up time, showing consistently higher values in the CVR group. Conclusion This study describes the subclinical right cardiac functional and structural changes within the physiological range, which recover 6 months after delivery. CVR factors impact the magnitude of the subclinical RV diastolic function changes, PASP and myocardial deformation (strain) without any impact on classic RV systolic function.

A Flexible Organomagnetic Single-Layer Composite Film with Built-In Multistimuli Responsivity.

Materials possessing multiple properties and functionalities, that can be controlled or modulated by external stimuli, are a central focus of current research in materials sciences due to their potential to significantly enhance various future technological applications. Herein, we report a significant advancement in this field through the development of a smart, multifunctional organomagnetic composite material. By utilizing a thin layer of polydimethylsiloxane (PDMS) and polypyrrole (PPy) precursors, doped with nickel nanoparticles (NiNPs), we have created an innovative organomagnetic, PDMS/PPy/NiNPs (PPN), single-layer composite film that displays multistimuli responsivity. The study presents the first demonstration of a multifunctional flexible, three-component film structure integrating the structural and flexible PDMS component, together with a conductive polymer component and metal-based nanoparticles into a single-layer design, which displays enhanced and unprecedented responsivity properties against multiple different stimuli. Unlike typical stacked multilayered structures, that exhibit one or two functionalities at most, this novel configuration exhibits multiple functionalities, including magnetoresistance, mechanical stress response, piezoresistivity, and temperature change sensitivity. The as-prepared film demonstrates notable magnetoresistance responsivity, with a relative electrical resistance, ΔR/R0, changing under a weak magnetic field and under ambient conditions. The significance of our study lies in the film's versatility, stability, and sensitivity, especially within the physiological temperature range, making it highly relevant for future biomedical applications. Furthemore, the film's sensitivity to mechanical deformation reveals an impressive piezoresistance behavior. Unlike existing multilayer architectures of higher complexity, our single-layer thin film offers a simpler, more flexible, and reliable solution with a broad range of stimuli-sensing capabilities. The significance of this novel multiresponsive composite material is underscored by the growing demand for advanced materials in biomedical devices, magnetic switches, sensors, electronic skin, transistors, and organic spintronic devices. These promising organomagnetic self-standing layers provide a robust platform for future technological innovations.

Characterization of the calmodulin-like protein family in Chara braunii and their conserved interaction with the calmodulin-binding transcription activator family.

Calcium sensor proteins play important roles by detecting changes in intracellular calcium and relaying that information onto downstream targets through protein-protein interaction. Very little is known about calcium sensors from plant species that predate land colonization and the evolution of embryophytes. Here, we examined the genome of the multicellular algae, Chara braunii, for orthologs to the evolutionarily-conserved calcium sensor calmodulin (CaM), and for CaM-like proteins (CMLs). We identified one CaM and eight CML isoforms which range in size from 16.4 to 21.3 kDa and are predicted to have between two to four calcium-binding (EF-hand) domains. Using recombinant protein, we tested whether CbCaM and CbCMLs1-7 possess biochemical properties of typical calcium sensors. CbCaM and the CbCMLs all displayed high-affinity calcium binding with estimated global KD,app values in the physiological µM range. In response to calcium binding, CbCaM and the CbCMLs exhibited varying degrees of increase in exposed hydrophobicity, suggesting different calcium-induced conformational changes occur among isoforms. We found many examples of putative CaM targets encoded in the C. braunii genome and explored the ability of CbCaM and CbCMLs to interact in planta with a representative putative target, a C. braunii CaM-binding transcription factor (CbCAMTA1). CbCaM, CbCML2, and CbCML4 associated with the C-terminal region of CbCAMTA1. Collectively, our data support the hypothesis that complex calcium signaling and sensing networks involving CaM and CMLs evolved early in the green lineage. Similarly, it seems likely that calcium-mediated regulation of transcription occurs in C. braunii via CAMTAs and is an ancient trait predating embryophytic emergence.