Unique Property Research Articles

Rapid Characterization of Phospholipids from Biological Matrix Enabled by Indium Tin Oxide (ITO) Coated Slide Assisted Enrichment MALDI Mass Spectrometry

AbstractLipidomic analysis of human serum is essential to monitor the individual's health status. Herein, we develop a facile strategy for rapid characterization of phospholipids in human serum via indium tin oxide (ITO) coated glass slide solid phase extraction MALDI mass spectrometry (ITO‐SPE‐MALDI‐MS). Phospholipid species are retained on ITO slide via solid phase extraction owing to the unique property of the ITO material; the measurement of phospholipid species from 1 μl human serum within 2 min is achievable. A comparison of ITO‐SPE strategy with conventional extraction methods was further carried out using liquid chromatography‐mass spectrometry (LC‐MS) and ion‐mobility mass spectrometry (IM‐MS), resulting in a comparable enrichment performance for the phospholipid analysis. Furthermore, rapid lipidomic profiling of serum samples from human colorectal cancer patients and cell lines was demonstrated. Our results indicate that ITO‐SPE‐MALDI‐MS provides a higher throughput strategy for the analysis of phospholipid species in complex biological mixtures, showcasing its potential for applications in the analysis of clinical biofluids.

β-NaBiF4:Yb3+,Er3+:Novel green synthesis, crystal structure, upconversion luminescence and optical thermometry

Non-lanthanide based NaBiF4 host have evoked remarkable interest due to unique luminescent property and potential applications. Current synthetic methods are not environment friendly and causes pollution. This is the first report mentioning green synthetic innovative route to develop upconversion, crystalline, and temperature sensing material. Here, we deigned ultrasonic assisted green approach for successful synthesis of β-NaBiF4:Yb3+, Er3+ (size ∼25–100 nm) using Tabernaemontana divaricata leaves extract without any surfactant. Characterization techniques such as XRD, SEM, TEM, XPS, EDX, and PL unveiled its properties. Green and red upconversion emissions (λex = 980 nm) were two-photon absorption process. The possible energy transfer and thermal quenching mechanism is discussed. Using thermally coupled levels (2H11/2 and 4S3/2) of Er3+, FIR based temperature sensing revealed ΔE ∼841 cm−1, linear response (R2 ∼0.99), outstanding relative sensitivity (Sr max∼ 1.4 % K−1 @294 K), good absolute sensitivity (Sa max∼ 0.29 %K−1 @ 398 K) and a low temperature resolution (δTmin = 0.35 K) over temperature range 294–398 K.

Evaluation of Kappa-carrageenan supplementation in extender for post-thaw Kajli ram sperm quality.

Cryopreservation is one of the reliable techniques for long-term storage of sperm. The success of this technique depends on the choice of cryoprotectant; therefore, a plethora of literature has reported the effects of different cryoprotective agents so far. Kappa-carrageenan (κ-carrageenan) is a hydrocolloid polysaccharide extracted from red marine seaweed. Its unique property makes it a promising option as a non-colligative cryoprotectant. The current study aims to evaluate the cryoprotective effect of k-carrageenan along with glycerol on ram sperm quality both after equilibration and freezing. Nine Kajli rams were utilized in this experiment for semen collection through an artificial vagina maintained at 42°C. Qualified samples were diluted in tris egg yolk glycerol (TEYG) extender containing different concentrations of k-carrageenan as 0 mg/mL (control), 0.2, 0.5, 0.8 and 1 mg/mL. Post-thaw assessment was done at 37°C after 24 h of storage, which showed a significant improvement (p < .05) in sperm viability, motility, membrane and acrosome integrity in an extender containing k-carrageenan at a concentration of 0.5 mg/mL compared to control. It is concluded from the current study that the combination of glycerol and 0.5 mg/mL concentration of k-carrageenan improved the sperm post-thaw quality.

Carbon Ion Irradiation Activates Anti-Cancer Immunity.

Carbon ion beams have the unique property of higher linear energy transfer, which causes clustered damage of DNA, impacting the cell repair system. This sometimes triggers apoptosis and the release in the cytoplasm of damaged DNA, leading to type I interferon (IFN) secretion via the activation of the cyclic GMP-AMP synthase-stimulator of interferon genes pathway. Dendritic cells phagocytize dead cancer cells and damaged DNA derived from injured cancer cells, which together activate dendritic cells to present cancer-derived antigens to antigen-specific T cells in the lymph nodes. Thus, carbon ion radiation therapy (CIRT) activates anti-cancer immunity. However, cancer is protected by the tumor microenvironment (TME), which consists of pro-cancerous immune cells, such as regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages. The TME is too robust to be destroyed by the CIRT-mediated anti-cancer immunity. Various modalities targeting regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages have been developed. Preclinical studies have shown that CIRT-mediated anti-cancer immunity exerts its effects in the presence of these modalities. In this review article, we provide an overview of CIRT-mediated anti-cancer immunity, with a particular focus on recently identified means of targeting the TME.

Upconversion Nanoparticles Based Sensing: From Design to Point-of-Care Testing.

Rare earth-doped upconversion nanoparticles (UCNPs) have achieved a wide range of applications in the sensing field due to their unique anti-Stokes luminescence property, minimized background interference, excellent biocompatibility, and stable physicochemical properties. However, UCNPs-based sensing platforms still face several challenges, including inherent limitations from UCNPs such as low quantum yields and narrow absorption cross-sections, as well as constraints related to energy transfer efficiencies in sensing systems. Therefore, the construction of high-performance UCNPs-based sensing platforms is an important cornerstone for conducting relevant research. This work begins by providing a brief overview of the upconversion luminescence mechanism in UCNPs. Subsequently, it offers a comprehensive summary of the sensors' types, design principles, and optimized design strategies for UCNPs sensing platforms. More cost-effective and promising point-of-care testing applications implemented based on UCNPs sensing systems are also summarized. Finally, this work addresses the future challenges and prospects for UCNPs-based sensing platforms.

Probability of stability calculation of MIMOn cascade non-linear systems with random parameters

Abstract The stability problem of Multiple n Inputs and Multiple n Outputs (MIMOn) cascade non-linear systems with random parameters is considered in this paper using the probability of stability estimation method. MIMOn cascade non-linear systems, particularly when the number of inputs and outputs exceeds three (n &amp;gt; 3), exhibit a unique property: the appearance of spatial hyperchaos that can lead to system instability. To achieve desired spatial dynamics and prevent the occurrence of spatial hyperchaos, it is necessary to select the appropriate parameter values for these systems. Moreover, the optimal parameter values enable the attainment of the highest probability of stability for stochastic MIMOn systems. The research presents the results of stability analysis using tools such as bifurcation diagram, Lyapunov diagram and spatial phase portraits, generated through MATLAB M-files, with a specific focus on a stochastic MIMO5 system (five inputs and five outputs).

Enhancement of the Visible Light Photodetection of Inorganic Photodiodes via Additional Quantum Dots Layers.

Visible light photodetectors are extensively researched with transparent metal oxide holes/electron layers for various applications. Among the metal oxide transporting layers, nickel oxide (NiO) and zinc oxide (ZnO) are commonly adopted due to their wide band gap and high transparency. The objective of this study was to improve the visible light detection of NiO/ZnO photodiodes by introducing an additional quantum dot (QD) layer between the NiO and ZnO layers. Utilizing the unique property of QDs, we could select different sizes of QDs and responsive light wavelength ranges. The resulting red QDs utilized device that could detect light starting at 635 nm to UV (Ultra-violet) light wavelength and exhibited a photoresponsivity and external quantum efficiency (EQE) of 14.99 mA/W and 2.92% under 635 nm wavelength light illumination, respectively. Additionally, the green QDs, which utilized a device that could detect light starting at 520 nm, demonstrated photoresponsivity values of 8.34 mA/W and an EQE of 1.99% under 520 nm wavelength light illumination, respectively. In addition, we used X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) to investigate the origin of the photocurrents and the enhancement of the device's performance. This study suggests that incorporating QDs with metal oxide semiconductors is an effective approach for detecting visible light wavelengths in transparent optoelectronic devices.

Insights into interfacial S-scheme/bulk type II dual charge transfer mechanism enabling silver oxide/N-rich carbon nitride anti-photocorrosion and enhanced photoactivity

Infectious diseases, such as COVID-19, continue to pose a significant threat to global public health and economics. This study establishes a one-of-a-kind heterojunction catalyst with a built-in electric field and enhanced structural defects, allowing for the formation of interfacial S-scheme and bulk type-II dual charge transfer channels, as demonstrated by extensive experimental investigation and density functional theory calculations. This unique property greatly enhances the photogenerated electron/hole pair separation and transfer, producing more active species in Ag2O/C3N5 for water disinfection, which inactivation efficiency of E. coli is around 7.0 folds for pure C3N5 and 1.5 folds for Ag2O. The spatial separation of photogenerated e-/h+ pairs and the tendency of O2/H2O molecules to be reduced or oxidized at the interface enable excellent anti-photocorrosion. Exceptional disinfection of real lake and river water, along with exceptional stability and reusability, demonstrate the practical application potential. This work is pivotal for the theoretical development of sophisticated photocatalytic systems.

Structure of mavacamten-free human cardiac thick filaments within the sarcomere by cryoelectron tomography

Heart muscle has the unique property that it can never rest; all cardiomyocytes contract with each heartbeat which requires a complex control mechanism to regulate cardiac output to physiological requirements. Changes in calcium concentration regulate the thin filament activation. A separate but linked mechanism regulates the thick filament activation, which frees sufficient myosin heads to bind the thin filament, thereby producing the required force. Thick filaments contain additional nonmyosin proteins, myosin-binding protein C and titin, the latter being the protein that transmits applied tension to the thick filament. How these three proteins interact to control thick filament activation is poorly understood. Here, we show using 3-D image reconstruction of frozen-hydrated human cardiac muscle myofibrils lacking exogenous drugs that the thick filament is structured to provide three levels of myosin activation corresponding to the three crowns of myosin heads in each 429Å repeat. In one crown, the myosin heads are almost completely activated and disordered. In another crown, many myosin heads are inactive, ordered into a structure called the interacting heads motif. At the third crown, the myosin heads are ordered into the interacting heads motif, but the stability of that motif is affected by myosin-binding protein C. We think that this hierarchy of control explains many of the effects of length-dependent activation as well as stretch activation in cardiac muscle control.

Green composite colorimetric and “Turn-on” fluorescent material for the detection of Al3+ ion in blood serum and herbal tea

In the present investigation, we fabricated an ecologically sustainable green composite material derived from green raw materials, including cellulose nanomaterials and Morin. This innovative material underscores its commitment to environmental friendliness and boasts distinctive surface properties that render it an ideal substrate. The selection of this material was motivated by its intricate network structure and inherent capacity for surface modifications. The crux of our methodology involved the integration of the organic probe 2-(2,4-dihydroxyphenyl)-3,5,7-trihydroxychromen-4-one, commonly known as Morin, onto the surface of the cellulose nanocomposite. This strategic embedding of Morin conferred the composite material with exceptional attributes, enabling preconcentration, spectrophotometric determination, and fluorometric turn-on sensing of Al3+ ions. This unique property facilitated the ion-sensing of Al3+ ions in diverse samples, including blood serum and herbal tea.The resultant Morin green composite material exhibited remarkable sensitivity toward Al3+ ions in aqueous solutions, accomplishing extraordinary LOD as low as 0.26 ppb. This heightened sensitivity permits for precise and efficient ion-sensing and enables the detection to be perceptible to the naked eye. Notably, the Morin green composite material displayed a rapid and distinct color change within a brief span of less than two minutes when exposed to varying concentrations of Al3+ ions. Beyond its analytical prowess, the developed Morin green composite material demonstrated significant efficacy in practical applications. Specifically, it showcased remarkable performance in detecting Al3+ ions in serum samples and herbal tea samples.

Elastic Buckling Behavior of Functionally Graded Material Thin Skew Plates with Circular Openings

This study investigates the elastic buckling behavior of Functionally Graded Material (FGM) thin skew plates featuring a circular opening. FGMs, known for their unique property gradients, have gained prominence in structural engineering due to their mechanical performance and durability. Including a circular opening introduces a critical geometric consideration, influencing the structural stability and load-carrying capacity of FGM plates. The study examines the effects of the skew angle, plate’s aspect ratio, opening position, and size on the critical buckling load, normalized buckling load, and various buckling failure modes through computer modeling and finite element analysis. The results offer valuable insights into the interplay between material heterogeneity, geometric configuration, and structural stability. For instance, the critical buckling load increases by 29%, 82%, and 194% with an increment in skew angle from 0° to 30°, 45°, and 60°, respectively. Moreover, as the opening shifts from the plate’s edge closer to the center, the critical buckling load decreases by 26%. The critical buckling load is also dependent on the power index, as an increase in the power index from 0.2 to 5 reduced the buckling load by 1698 kN. This research contributes to the advancement of our understanding of FGM thin plates’ behavior under skew loading conditions, with implications for the design and optimization of innovative structures. The findings presented provide a foundation for further exploration of advanced composite materials and their applications in structural engineering.

Cathepsin B-Activated PET Tracer for In Vivo Tumor Imaging.

Cathepsin B, a lysosomal protease, is considered as a crucial biomarker for tumor diagnosis and treatment as it is overexpressed in numerous cancers. A stimulus-responsive SF scaffold has been reported to detect the activity of a variety of tumor-associated enzymes. In this work, a small-molecule PET tracer ([68Ga]NOTA-SF-CV) was developed by combining an SF scaffold with a cathepsin B-specific recognition substrate Cit-Val. Upon activation by cathepsin B, [68Ga]NOTA-SF-CV could form the cyclization product in a reduction environment, resulting in reduced hydrophilicity. This unique property could effectively prevent exocytosis of the tracer in cathepsin B-overexpressing tumor cells, leading to prolonged retention and amplified PET imaging signal. Moreover, [68Ga]NOTA-SF-CV had great targeting specificity to cathepsin B. In vivo microPET imaging results showed that [68Ga]NOTA-SF-CV was able to effectively visualize the expression level of cathepsin B in various tumors. Hence, [68Ga]NOTA-SF-CV may be served as a potential tracer for diagnosing cathepsin B-related diseases.

Quasispecies productivity.

The quasispecies theory is a helpful concept in the explanation of RNA virus evolution and behaviour, with a relevant impact on methods used to fight viral diseases. It has undergone some adaptations to integrate new empirical data, especially the non-deterministic nature of mutagenesis, and the variety of behavioural motifs in cooperation, competition, communication, innovation, integration, and exaptation. Also, the consortial structure of quasispecies with complementary roles of memory genomes of minority populations better fits the empirical data than did the original concept of a master sequence and its mutant spectra. The high productivity of quasispecies variants generates unique sequences that never existed before and will never exist again. In the present essay, we underline that such sequences represent really new ontological entities, not just error copies of previous ones. Their primary unique property, the incredible variant production, is suggested here as quasispecies productivity, which replaces the error-replication narrative to better fit into a new relationship between mankind and living nature in the twenty-first century.

Ultrasensitive cancer cell sensing based on tapered optical fiber operating near the dispersion turning point

Cancer cell screening is very important for its treatment and prognosis. The screening techniques are required with high sensitivity and specific recognition. Here, an ultrasensitive tapered optical fiber (TOF) biosensor for cancer cell sensing is proposed. The unique property of the dispersion turning point (DTP) in the TOF is utilized to greatly improve the sensing sensitivity. Combined with numerical calculations, the TOF with the extremely high refractive index (RI) sensitivity (close to 18390 nm/RIU) near the DTP is achieved by precisely controlling the diameter of the TOF. In addition, biotin is used to functionalize the TOF for specific recognition of the biotin-overexpressing cancer cells. The sensitivity and selectivity of the TOF were demonstrated by the detection of the biotin receptor protein (streptavidin) and overexpressed cancer cells (lung epithelial adenocarcinoma cells, A549). The experiment results show that the TOF has a low limit of detection (LOD) for streptavidin and cancer cells, which are 28.73 pM and 49 cells/mL respectively. At the same time, the TOF showed the obvious response to another biotin-overexpressed cancer cell (breast cancer cells, 4T1), but is insensitive to normal cells (gastric mucosa cells, GES-1 and mouse epithelioid fibroblasts cells, L929). We believe that the proposed biosensor which exhibited extremely high sensitivity and good selectivity, will have potential application prospects in the field of chemical and biological detection.

Unique continuation problem on RCD Spaces. I

In this note we establish the weak unique continuation theorem for caloric functions on compact RCD(K, 2) spaces and show that there exists an RCD(K, 4) space on which there exist non-trivial eigenfunctions of the Laplacian and non-stationary solutions of the heat equation which vanish up to infinite order at one point . We also establish frequency estimates for eigenfunctions and caloric functions on the metric horn. In particular, this gives a strong unique continuation type result on the metric horn for harmonic functions with a high rate of decay at the horn tip, where it is known that the standard strong unique continuation property fails.

Transition‐Metal‐Catalyzed α,β‐Dehydrogenation of Carbonyl Compounds

Abstractα,β‐Unsaturated compounds are one of the most important functional compounds. Due to their unique property and versatile utility, they usually occur as the key intermediates for the synthesis of pharmaceuticals and biological materials. Thus, their synthesis has attracted more attentions than before. The early approaches to α,β‐unsaturated compounds are mainly about transition‐metal‐free methods, such as halogenation‐dehydrohalogenation methods and strong oxidants methods (organosulfur, organoselenium, benzoquinone). Subsequently, palladium and the other transition‐metals catalyzed dehydrogenation of carbonyl compounds appeared respectively. In this review, transition‐metal‐catalyzed α,β‐dehydrogenation is discussed, which is categorized by functional groups.

Pressure‐Induced Inversion of Chiroptical Properties in Cholesteric Assembled Cellulose Nanocrystals

AbstractDynamic manipulation of the chiroptical effect, particularly the inversion of chiral signal, has attracted broad attention, but still remains challenging, Here, stepwise tuning of the helicoidal assembly and chiroptical properties of the cellulose nanocrystal (CNC) films utilizing high pressure are demonstrated. With in situ monitoring, the changes of Fourier‐transform infrared (FTIR) spectra and evaluating the corresponding applied energy, three distinctive stages of chiroptical properties are clearly identified. In these stages, the photonic bandgap of the CNC film exhibits a fast‐slow–fast alteration over different energy imposed. The three stages are associated sequentially with interlayer space reduction, hydrogen bonding reconfiguration, and covalent bands changing. A switch of chiral signal from left‐ to right‐handedness is observed in the third stage, and the handedness of CD spectra can be recovered upon release, which is barely observed. This unique property is suspected to be the change in CNCs assembly induced by molecular‐level conformational change. This work sheds light on the fundamental understanding of how pressure can trigger the change from molecular‐level to hierarchical assembly and corresponding chiroptical performance, facilitating the design of chiral assembly with pre‐programmed triggering chiroptical properties of bio‐photonic materials.

Characterization of Acinetobacter baumannii core oligosaccharide synthesis reveals novel aspects of lipooligosaccharide assembly.

Acinetobacter baumannii is a multidrug-resistant pathogen that produces lipooligosaccharide (LOS), a glycolipid that confers protective asymmetry to the bacterial outer membrane. The core oligosaccharide is a ubiquitous component of LOS that typically follows a well-established model of synthesis. In addition to providing an extensive analysis of the genes involved in the synthesis of the core region, we demonstrate that this organism has evidently diverged from the long-held archetype of core synthesis. Moreover, our data suggest that A. baumannii LOS assembly is important for cell division and likely intersects with the synthesis of the peptidoglycan cell wall, another essential component of the Gram-negative cell envelope. This connection between LOS and cell wall synthesis provides an intriguing foundation for a unique method of outer membrane biogenesis and cell envelope coordination.

Beyond the classical strong maximum principle: Sign-changing forcing term and flat solutions

Abstract We show that the classical strong maximum principle, concerning positive supersolutions of linear elliptic equations vanishing on the boundary of the domain can be extended, under suitable conditions, to the case in which the forcing term is sign-changing. In addition, for the case of solutions, the normal derivative on the boundary may also vanish on the boundary (definition of flat solution). This leads to examples in which the unique continuation property fails. As a first application, we show the existence of positive solutions for a sublinear semilinear elliptic problem of indefinite sign. A second application, concerning the positivity of solutions of the linear heat equation, for some large values of time, with forcing and/or initial datum changing sign, is also given.

Flashlight treatment for instantaneous structuring of dense MXene film into porous MXene/TiO2 nanocomposite for lithium-ion battery anodes

MXenes, the two-dimensional metal carbides and nitrides, have been considered a new class of electrode materials with their noticeable performance in various energy storage systems. Furthermore, the unique property and morphology allow MXenes to be assembled into freestanding films, which can be applied in energy storage devices with lightweight and high energy density. However, their tendency to restack and aggregate remains a challenge to enhance the electrochemical performance of MXenes. In this study, we propose a facile method to fabricate a porous MXene-TiO2 freestanding anode with the help of a flashlight. Simply heating the MXene films with a flashlight in milliseconds increases the interlayer spacing of the MXenes and simultaneously forms TiO2 on the MXene surface. Along with the widened interlayer and formation of TiO2, improved wettability, easy electrolyte penetration, and reduced electrode resistance were achieved. As a result, this freestanding anode exhibits nearly 50 times higher Li+ storage capacity (148 mAh/g) than pristine MXene film (3 mAh/g) at 0.05 A/g and excellent cycle stability up to 1500 cycles without degradation.