Power generation from ambient humidity using protein nanowires.

Harvesting energy from the environment offers the promise of clean power for self-sustained systems1,2. Known technologies-such as solar cells, thermoelectric devices and mechanical generators-have specific environmental requirements that restrict where they can be deployed and limit their potential for continuous energy production3-5. The ubiquity of atmospheric moisture offers an alternative. However, existing moisture-based energy-harvesting technologies can produce only intermittent, brief (shorter than 50 seconds) bursts of power in the ambient environment, owing to the lack of a sustained conversion mechanism6-12. Here we show that thin-film devices made from nanometre-scale protein wires harvested from the microbe Geobacter sulfurreducens can generate continuous electric power in the ambient environment. The devices produce a sustained voltage of around 0.5 volts across a 7-micrometre-thick film, with a current density of around 17 microamperes per square centimetre. We find the driving force behind this energy generation to be a self-maintained moisture gradient that forms within the film when the film is exposed to the humidity that is naturally present in air. Connecting several devices linearly scales up the voltage and current to power electronics. Our results demonstrate the feasibility of a continuous energy-harvesting strategy that is less restricted by location or environmental conditions than other sustainable approaches.

Identification and validation of ferroptosis-related hub genes and immune infiltration in liver ischemia-reperfusion injury.

Ischemia-reperfusion injury (IRI) is a cumulation of pathophysiological processes that involves cell and organelle damage upon blood flow constraint and subsequent restoration. However, studies on overall immune infiltration and ferroptosis in liver ischemia-reperfusion injury (LIRI) are limited. This study explored immune cell infiltration and ferroptosis in LIRI using bioinformatics and experimental validation. The GSE151648 dataset, including 40 matched pairs of pre- and post- transplant liver samples was downloaded for bioinformatic analysis. Eleven hub genes were identified by overlapping differentially expressed genes (DEGs), iron genes, and genes identified through weighted gene co-expression network analysis (WGCNA). Subsequently, the pathway enrichment, transcription factor-target, microRNA-mRNA and protein-protein interaction networks were investigated. The diagnostic model was established by logistic regression, which was validated in the GSE23649 and GSE100155 datasets and verified using cytological experiments. Moreover, several drugs targeting these genes were found in DrugBank, providing a more effective treatment for LIRI. In addition, the expression of 11 hub genes was validated using quantitative real-time polymerase chain reaction (qRT-PCR) in liver transplantation samples and animal models. The expression of the 11 hub genes increased in LIRI compared with the control. Five genes were significantly enriched in six biological process terms, six genes showed high enrichment for LIRI-related signaling pathways. There were 56 relevant transcriptional factors and two central modules in the protein-protein interaction network. Further immune infiltration analysis indicated that immune cells including neutrophils and natural killer cells were differentially accumulated in the pre- and post-transplant groups, and this was accompanied by changes in immune-related factors. Finally, 10 targeted drugs were screened. Through bioinformatics and further experimental verification, we identified hub genes related to ferroptosis that could be used as potential targets to alleviate LIRI.

IRG1 restrains M2 macrophage polarization and suppresses intrahepatic cholangiocarcinoma progression via the CCL18/STAT3 pathway.

Intrahepatic cholangiocarcinoma (ICC) is a highly malignant and aggressive cancer whose incidence and mortality continue to increase, whereas its prognosis remains dismal. Tumor-associated macrophages (TAMs) promote malignant progression and immune microenvironment remodeling through direct contact and secreted mediators. Targeting TAMs has emerged as a promising strategy for ICC treatment. Here, we revealed the potential regulatory function of immune responsive gene 1 (IRG1) in macrophage polarization. We found that IRG1 expression remained at a low level in M2 macrophages. IRG1 overexpression can restrain macrophages from polarizing to the M2 type, which results in inhibition of the proliferation, invasion, and migration of ICC, whereas IRG1 knockdown exerts the opposite effects. Mechanistically, IRG1 inhibited the tumor-promoting chemokine CCL18 and thus suppressed ICC progression by regulating STAT3 phosphorylation. The intervention of IRG1 expression in TAMs may serve as a potential therapeutic target for delaying ICC progression.

Difunctional Microelectrode Arrays for Single-Cell Electrical Stimulation and pH Detection.

Due to its direct effect on biomolecules and cells, electrical stimulation (ES) is now widely used to regulate cell proliferation, differentiation, and neurostimulation and is even used in the clinic for pain relief, treatment of nerve damage, and muscle rehabilitation. Conventional ES is mostly studied on cell populations, but the heterogeneity of cancer cells results in the inability to access the response of individual cells to ES. Therefore, detecting the extracellular pH change (ΔpHe) after ES at the single-cell level is important for the application of ES in tumor therapy. In this study, cellular ΔpHe after periodic impulse electrostimulation (IES) was monitored in situ by using a polyaniline (PANI)-modified gold microelectrode array. The PANI sensor had excellent sensitivity (53.68 mV/pH) and linear correlation coefficient (R2 = 0.999) over the pH range of 5.55-7.41. The cells showed different degrees of ΔpHe after the IES with different intervals and stimulation potential. A shorter pulse interval and a higher stimulation potential could effectively enhance stimulation and increase cellular ΔpHe. At 0.5 V potential stimulation, the cellular ΔpHe increased with decreasing pulse interval. However, if the pulse interval was long enough, even at a higher potential of 0.7 V, there was no significant additional ΔpHe due to the insufficient stimulus strength. Based on the above conclusions, the prepared PANI microelectrode arrays (MEAs) were capable of stimulating and detecting single cells, which contributed to the deeper application of ES in tumor therapy.

FGF21 protects against ischaemia reperfusion injury in normal and fatty livers.

BACKGROUND: Liver ischaemia/reperfusion (I/R) injury, which is an inevitable clinical problem of liver resection, liver transplantation and haemorrhagic shock. Fibroblast growth factor 21 (FGF21) was intimately coupled with multiple metabolic processes and proved to protect against apoptosis and inflammatory response in hepatocytes during hepatic I/R injury. However, the regulatory mechanisms of FGF21 in hepatic I/R injury remains unknown. Therefore, we hypothesize that FGF21 protects hepatic tissues from I/R injury. METHODS: Blood samples were available from haemangiomas patients undergoing hepatectomy and murine liver I/R model and used to further evaluate the serum levels of FGF21 both in humans and mice. We further explored the regulatory mechanisms of FGF21 in murine liver I/R model by using FGF21-knockout mice (FGF21-KO mice) and FGF21-overexpression transgenic mice (FGF21-OE mice) fed a high-fat or ketogenic diet. RESULTS: Our results show that the circulating levels of FGF21 were robustly decreased after liver I/R in both humans and mice. Silencing FGF21 expression with FGF21-KO mice aggravates liver injury at 6 h after 75 min of partial liver ischaemia, while FGF21-OE mice display alleviated hepatic I/R injury and inflammatory response. Compared with chow diet mice, exogenous FGF21 decreases the levels of aminotransferase, histological changes, apoptosis and inflammatory response in hepatic I/R injury treatment mice with a high-fat diet. Meanwhile, ketogenic diet mice are not sensitive to hepatic I/R injury. CONCLUSIONS: The circulating contents of FGF21 are decreased during liver warm I/R injury and exogenous FGF21 exerts hepatoprotective effects on hepatic I/R injury. Thus, FGF21 regulates hepatic I/R injury and may be a key therapeutic target.

Unraveling the molecular freezing behavior of water on a calcium silicate hydrate matrix.

The hydration process of cement-based materials primarily results in the formation of calcium silicate hydrate (CSH), which is crucial in deciding how long concrete will last. This study utilizes molecular dynamics simulation technology to explore the freezing behavior of pure water solutions within various calcium silicate hydrate (CSH) matrices. The investigated matrices encompass four different Ca/Si ratios. According to the simulation, as ice crystals develop close to the surface of CSH, the CSH matrix strengthens its hydrogen and ionic interactions with water molecules, which effectively prevents water molecules from crystallizing and nucleating. Consequently, these molecules compose an unfrozen water film structure that bridges between ice crystals and the CSH matrix. The research also reveals an intriguing relationship between silica chain behavior on the Ca/Si ratio and the CSH surface. Surface flaws arise as a result of the silica chains of CSH breaking into shorter segments as the Ca/Si ratio increases. These surface defects manifest as grooves on the matrix's surface, effectively capturing and retaining specific water molecules. The CSH matrix's hydrogen bonds with water molecules are weakened as a result of this process, facilitating their participation in the crystallization process, and leading to a thinner unfrozen water film thickness with an increased Ca/Si ratio. This study contributes to a greater knowledge of the performance and dependability of cement-based products by offering molecular-level insights into the freezing actions of liquids in gel pores.

Auxiliary Rather Than Dominant. The Role of Direct Dy-S Coordination in Single-Molecule Magnet Unveiled via ab initio Study.

The role of Dy-S coordination in a single-molecule magnet (SMM) is investigated via an ab initio study in a group of mononuclear structures. The SMM performance of this group is well interpreted via a concise criterion consisting of long quantum tunneling of magnetization (QTM) time τQTM and high effective barrier for magnetic reversal Ueff. The best SMMs in the selected group, i.e., 1Dy (CCDC refcode: PUKFAF) and 2Dy (CCDC refcode: NIKSEJ), are just those holding the longest τQTM and the highest Ueff simultaneously. Further analysis based on the crystal field model and ab initio magneto-structural exploration indicates that the influence of Dy-S coordination on the SMM performance of 1Dy is weaker than that of axial Dy-O coordination. Thus, Dy-S coordination is more likely to play an auxiliary role rather than a dominant one. However, if placed at the suitable equatorial position, Dy-S coordination could provide important support for good SMM performance. Consequently, starting from 1Dy, we built two new structures where Dy-S coordination only exists at the equatorial position and two axial positions are occupied by strong Dy-O/Dy-F coordination. Compared to 1Dy and 2Dy, these new ones are predicted to have significantly longer τQTM and higher Ueff, as well as a nearly doubled blocking temperature TB. Thus, they are probable candidates of SMM having clearly improved performance.

[Research progress in raw and processed Raphani Semen and prediction of quality markers].

Raphani Semen, with both edible and medicinal values, is a typical Chinese herbal medicine with different effects before and after processing. The raw helps ascending and the cooked helps descending. This paper comprehensively summarizes the differences in chemical constituents and pharmacological effects between raw and processed Raphani Semen that are reported in recent years. Based on the principle of quality markers(Q-markers) of traditional Chinese medicines, the chemical constituent sources, chemical constituent detection techniques, and correlation between bidirectional regulatory efficacy and chemical constituents are compared between raw and processed Raphani Semen. The results suggest that sulforaphene and glucoraphanin could be used as candidate Q-markers of raw and processed Raphani Semen, respectively. This review is expected to provide a reference for further research on the processing, new drug development, and improvement of safety and effectiveness of Raphani Semen in clinical application.

Enhancing electrochemical properties of a two-dimensional zeolitic imidazole framework by incorporating a conductive polymer for dopamine detection.

The zeolitic imidazole framework with a leaf-shaped morphology (ZIF-L) has a wide range of promising applications in gas storage, battery materials, catalytic reactions, and optoelectronic devices due to its planar leaf-like structure and large surface area. However, the low conductivity, weak catalytic activity, and poor stability in the water dielectric medium of ZIF-L limit its further practical application. To solve these problems, we added the conductive polymer heterocyclic poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) to ZIF-L for the sensitive detection of dopamine (DA). The synthesized composite ZIF-L/PEDOT:PSS (ZIF-L/PEDOT) not only retained the surface morphology of ZIF-L but also exhibited excellent electrochemical properties. The higher electrical conductivity of ZIF-L/PEDOT than that of ZIF-L was due to the enhanced electron transfer at the interface between ZIF-L and PEDOT:PSS. As a result, we developed an electrochemical biosensor based on the ZIF-L/PEDOT composite, which has a limit of detection of 7 nM for DA and a wide linear range from 25 nM to 500 µM. Furthermore, the current drop was negligible after 28 days, proving that the biosensor has excellent stability. Based on the above-mentioned outstanding performance, the ZIF-L/PEDOT-based biosensor was successfully used to detect DA in human serum samples. These results demonstrated that ZIF-L/PEDOT is expected to play an essential role in disease detection.

Unveiling the correlation between the catalytic efficiency and acidity of a metal-free catalyst in a hydrogenation reaction. A theoretical case study of the hydrogenation of ethene catalyzed by a superacid arising from a superhalogen.

A systematic quantum-chemical study of the hydrogenation of ethene, catalyzed by strong acids HX (X = F, Cl, Br) and superacids HA (A = MgX3, Mg2X5; X = F, Cl, Br) arising from octet superhalogens is explored. Two possible paths are proposed, concerted and stepwise, and the calculated results show that the concerted path is more favorable than the stepwise path. Compared to the hydrogenation reaction without any catalyst, the improvement of the catalytic efficiency of the superacid HA (A = MgX3, Mg2X5) is high, up to 38.8 to 59.4%. Compared to the strong acid HX (X = F, Cl, Br), the barrier energy is significantly reduced and the improvement of the catalytic efficiency of the superacid HA reaches 23.1 to 31.7%. In particular, for HMg2Br5, the barrier energy of the hydrogenation of ethene is only 36 kcal mol-1, which shows that the reaction could proceed under experimental conditions. In addition, the results show that the catalytic efficiency of the superacid HA is related to the acidity of the superacid. In general, the greater the acidity, the lower the barrier energy and the easier the hydrogenation reaction. From the analysis of the bond order, the newly formed C-H bond of the transition state (TS3) in the concerted path, in which the H atom comes from the superacid catalyst, directly affects the barrier energy of the entire reaction. For the more acidic catalyst, this H atom is provided more easily, and then the formed C-H bond in the transition state is stronger. Consequently, this stronger bond leads to a more stable transition state, and hence to a lower energy barrier as well as a higher efficiency of the superacid catalyst. Therefore, a positive correlation between the acidity of the metal-free catalyst and its catalytic efficiency is expected in the hydrogenation reaction.