AIM:To evaluate the efficacy of telomerase activity assay and peritoneal lavage cytology (PLC) examination in peritoneal lavage fluid for the prediction of peritoneal metastasis in gastric cancer patients, and to explore the relationship between telomerase activity and proliferating cell nuclear antigen expression. METHODS:Telomeric repeated amplification protocol (TRAP)-enzyme-linked immunosorbent assay (ELISA) was performed to measure the telomerase activity in 60 patients with gastric cancer and 50 with peptic ulcer.PLC analysis of the 60 patients with gastric cancer was used for comparison.The proliferating cell nuclear antigen (PCNA) in gastric carcinoma was immunohistochemically examined. RESULTS:The telomerase activity and PLC positive rate in peritoneal lavage fluid from patients with gastric cancer was 41.7% (25/60), and 25.0% (15/60), respectively.The positive rate of telomerase activity was significantly higher than that of PLC in the group of pT4 (15/16 vs 9/16, P < 0.05), P1-3 (13/13 vs 9/13, P < 0.05) and diffuse type (22/42 vs 13/42, P < 0.05).The patients with positive telomerase activity, peritoneal metastasis, and serosal invasion had significantly higher levels of average PCNA proliferation index (PI), (55.00 ± 6.59 vs 27.43 ± 7.72, 57.26 ± 10.18 vs 29.15 ± 8.31, and 49.82 ± 6.74 vs 24.65 ± 7.33, respectively, P < 0.05). CONCLUSION:The TRAP assay for telomerase activity is a useful adjunct for cytologic method in the diagnosis of peritoneal micrometastasis and well related to higher proliferating activity of gastric cancer.The results of this study also suggest a promising future therapeutic strategy for treating peritoneal dissemination based on telomerase inhibition.
Conventional solid ion channel systems relying on single one- or two-dimensional confined nanochannels enabled selective and ultrafast convective ion transport. However, due to intrinsic solid channel stacking, these systems often face pore-pore polarization and ion concentration blockage, thereby restricting their efficiency in macroscale ion transport. Here, we constructed a soft heterolayer-gel system that integrated an ion-selective hydrogel layer with a water-barrier organogel layer, achieving ultrahigh cation selectivity and flux and effectively providing high-efficiency gradient energy conversion on a macroscale order of magnitude. Specifically, the hydrogel layer featured an unconfined 3D network, where the fluctuations of highly hydrated polyelectrolyte chains driven by thermal dynamics enhanced cation selectivity and mitigated transfer energy barriers. Such chain fluctuation mechanisms facilitated ion-cluster internal transmission, thereby enhancing ion concentration hopping for more efficient ion-selective transport. Compared to the existing rigid nanochannel-based gradient energy conversion systems, such a heterogel-based power generator exhibited a record power density of 192.90 and 1.07 W/m
Abstract Many biological organisms with exceptional freezing tolerance can resist the damages to cells from extra-/intracellular ice crystals and thus maintain their mechanical stability at subzero temperatures. Inspired by the freezing tolerance mechanisms found in nature, here we report a strategy of combining hydrophilic/oleophilic heteronetworks to produce self-adaptive, freeze-tolerant and mechanically stable organohydrogels. The organohydrogels can simultaneously use water and oil as a dispersion medium, and quickly switch between hydrogel- and organogel-like behaviours in response to the nature of the surrounding phase. Accordingly, their surfaces display unusual adaptive dual superlyophobic in oil/water system (that is, they are superhydrophobic under oil and superoleophobic under water). Moreover, the organogel component can inhibit the ice crystallization of the hydrogel component, thus enhancing the mechanical stability of organohydrogel over a wide temperature range (−78 to 80 °C). The organohydrogels may have promising applications in complex and harsh environments.
Shape memory effect in polymer materials has attracted considerable attention due to its promising applications in a variety of fields. However, shape memory polymers prepared by conventional strategy suffer from a common problem, in which high strain capacity and excellent shape memory behavior cannot be simultaneously achieved. This study reports a general and synergistic strategy to fabricate high‐strain and tough shape memory organohydrogels that feature binary cooperative phase. The phase‐ transition micro‐organogels and elastic hydrogel framework act synergistically to provide excellent thermomechanical performance and shape memory effect. During shape memory process, the organohydrogels exhibit high strain capacity, featuring fully recoverable stretching deformation by up to 2600% and compression by up to 85% beneath a load ≈20 times the organohydrogel's weight. Furthermore, owing to the micro‐organogel and hydrogel heterostructures, the interfacial tension derived from heterophases dominates the shape recovery of the organohydrogel material. Simple processing and smart surface patterning of the shape memory behavior and multiple shape memory effects can also be realized. Meanwhile, these organohydrogels are also nonswellable in water and oil, which is important for multimedia applications.
Currently, electronics and iontronics in abiotic-biotic systems can only use electrons and single-species ions as unitary signal carriers. Thus, a mechanism of gating transmission for multiple biosignals in such devices is needed to match and modulate complex aqueous-phase biological systems. Here we report the use of cascade-heterogated biphasic gel iontronics to achieve diverse electronic-to-multi-ionic signal transmission. The cascade-heterogated property determined the transfer free energy barriers experienced by ions and ionic hydration-dehydration states under an electric potential field, fundamentally enhancing the distinction of cross-interface transmission between different ions by several orders of magnitude. Such heterogated or chemical-heterogated iontronics with programmable features can be coupled with multi-ion cross-interface mobilities for hierarchical and selective cross-stage signal transmission. We expect that such iontronics would be ideal candidates for a variety of biotechnology applications.
Vortex induced vibrations (VIV) of long flexible risers subjected to ocean currents are of vital interest to the offshore industry. Although significant efforts have been seen during the last decades, reliable prediction of this complicated fluid structure interaction phenomenon is still a challenge. The primary objective of this paper is to characterize the frequency components of VIV measured in flexible beams subjected to sheared current, and try to establish a general model for frequency participation for use in semi-empirical models for calculation of fatigue damage from VIV. Experimental data from the well known Hanøytangen tests and the Norwegian Deep-water Programme (NDP) high mode experiments have been used in this study. The present paper is mainly based on results from Ziguang Zhao (2011). Wavelet analyses are applied to reveal the frequency components in the measured signals. These analyses give information on the time-varying intensity of each active frequency at a specific position on the beam. The dominating frequency and range of other active frequencies are two key parameters from the wavelet analyses that are further used in this work. By comparing synchronic measurements from various positions along the beam, we can see that neighbor locations often will display the same time-varying peak frequency. However, the response at two positions apart form each other may be dominated by different frequencies. Hence, the time sharing concept needs to be reformulated from describing a frequency variation valid for the total length of a riser, to consider different zones separately. Based on the observation above, a combined time sharing and space sharing model is proposed. The controlling parameters in this model are an energy based parameter that ranks the participating frequencies, a threshold for a frequency candidate to become active, and the length of the excitation zone for each frequency. All parameters can easily be found for cases of practical interest.
Currently, it remains challenging to balance intrinsic stiffness with programmability in most vitrimers. Simultaneously, coordinating materials with gel-like iontronic properties for intrinsic ion transmission while maintaining vitrimer programmable features remains underexplored. Here, we introduce a phase-engineering strategy to fabricate bicontinuous vitrimer heterogel (VHG) materials. Such VHGs exhibited high mechanical strength, with an elastic modulus of up to 116 MPa, a high strain performance exceeding 1000%, and a switchable stiffness ratio surpassing 5 × 10 3 . Moreover, highly programmable reprocessing and shape memory morphing were realized owing to the ion liquid–enhanced VHG network reconfiguration. Derived from the ion transmission pathway in the ILgel, which responded to the wide-span switchable mechanics, the VHG iontronics had a unique bidirectional stiffness-gated piezoresistivity, coordinating both positive and negative piezoresistive properties. Our findings indicate that the VHG system can act as a foundational material in various promising applications, including smart sensors, soft machines, and bioelectronics.
Abstract In bioneuronal systems, the synergistic interaction between mechanosensitive piezo channels and neuronal synapses can convert and transmit pressure signals into complex temporal plastic pulses with excitatory and inhibitory features. However, existing artificial tactile neuromorphic systems struggle to replicate the elaborate temporal plasticity observed between excitatory and inhibitory features in biological systems, which is critical for the biomimetic processing and memorizing of tactile information. Here we demonstrate a mechano-gated iontronic piezomemristor with programmable temporal-tactile plasticity. This system utilizes a bicontinuous phase-transition heterogel as a stiffness-governed iontronic mechanogate to achieve bidirectional piezoresistive signals, resulting in wide-span dynamic tactile sensing. By micro-integrating the mechanogate with an oscillatory iontronic memristor, it exhibits stiffness-induced bipolarized excitatory and inhibitory neuromorphics, thereby enabling the activation of temporal-tactile memory and learning functions (e.g., Bienenstock–Cooper–Munro and Hebbian learning rules). Owing to dynamic covalent bond network and iontronic features, reconfigurable tactile plasticity can be achieved. Importantly, bridging to bioneuronal interfaces, these systems possess the capacity to construct a biohybrid perception-actuation circuit. We anticipate that such temporal plastic piezomemristor devices for abiotic-biotic interfaces can serve as promising hardware systems for interfacing dynamic tactile behaviors into diverse neuromodulations.
Abstract Current hydrogel actuators mostly suffer from weak actuation strength and low responsive speed owing to their solvent diffusion‐induced volume change mechanism. Here a skeletal muscle‐inspired organohydrogel actuator is reported in which solvents are confined in hydrophobic microdomains. Organohydrogel actuator is driven by compartmentalized directional network deformation instead of volume change, avoiding the limitations that originate from solvent diffusion. Organohydrogel actuator has an actuation frequency of 0.11 Hz, 110 times that of traditional solvent diffusion‐driven hydrogel actuators (<10 −3 Hz), and can lift more than 85 times their own weight. This design achieves the combination of high responsive speed, high actuation strength, and large material size, proposing a strategy to fabricate hydrogel actuators comparable with skeletal muscle performance.
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