Search

Proton exchange membrane water electrolyser (PEMWE) possesses great significance for the production of high purity of hydrogen. To expedite the anodic oxygen evolution reaction (OER) that involved multiple electron–proton‐coupled process, efficient and stable electrocatalysts are highly desired. Currently, noble‐metal Ir‐based materials are the benchmark anode due to its corrosion‐resistant property and favourable combination of activity/stability. However, the large‐scale deployment of PEMWE is usually constrained due to the use of the scarcest element iridium. In this review, we disclose the current research progress towards the non‐iridium‐based electrocatalysts for OER in acidic media, and then summarize some typical oxides that possesses good catalytic performance. Besides, we also present the unresolved problems and challenges in an attempt to enhance the activity/stability of these catalysts. [ABSTRACT FROM AUTHOR]

The detection of acetone in human exhaled breath is crucial for the noninvasive diagnosis of diabetes. However, the direct and reliable detection of acetone in exhaled breath with high humidity at the parts per billion level remains a great challenge. Here, an ultrasensitive acetone gas sensor based on a K/Sn-Co 3 O 4 porous microsphere was reported. The sensor demonstrates a detection limit of up to 100 ppb, along with excellent repeatability and selectivity. Remarkably, without the removal of water vapor from exhaled breath, the sensor can accurately distinguish diabetic patients and healthy individuals according to the difference in acetone concentrations, demonstrating its great potential for diabetes diagnosis. The enhanced sensitivity of the sensor is attributed to the increased oxygen adsorption on the material surface due to K/Sn codoping and the stronger coadsorption of Sn-K atoms to acetone molecules. These findings shed light on the mechanisms underlying the sensor's improved performance.

Aconitum vilmorinianum is an authentic and superior medicinal herbal in Yunnan, which is rich in yunaconitine and other diterpene alkaloids. Diterpene alkaloids are its main active components. Farnesyl pyrophosphate synthase(FPS) is a key enzyme in the terpene biosynthetic pathway and plays an important role in diterpene alkaloid biosynthesis. Functional studies of FPS help to reveal the molecular mechanism of diterpene alkaloid biosynthesis. In this study, one FPS gene(AvFPS) was selected based on the transcriptome data of A. vilmorinianum. Its full-length sequence was cloned, and bioinformatic analysis, functional verification, and gene expression analysis were performed. The open reading frame(ORF) of AvFPS was 1 056 bp, encoding 351 amino acids. Its molecular weight was 41 kDa. AvFPS had two typical conserved functional domains of isopentenyl transferase, " DDIMD" and " DDYXD". The recombinant protein of AvFPS was expressed in Escherichia coli, and purified recombinant protein was used for in vitro enzymatic reaction. The results revealed that AvFPS was able to catalyze the synthesis of farnesyl pyrophosphate(FPP). The results of qRT-PCR analysis showed that AvFPS was expressed in the roots, stems, leaves, and flowers of A. vilmorinianum, with the highest expression level in the roots. The expression level of AvFPS was significantly up-regulated by MeJA induction. This study clarified the catalytic function of AvFPS, revealed the expression pattern of AvFPS in different tissue, as well as at different time induced by MeJA, and provided a reference for a deeper understanding of the function of FPS in the biosynthesis of diterpenoid components.

Accurate assessment of material and energy exchange between land and atmosphere is essential for water resources management and sustainable development of agriculture. To understand the characteristics of energy distribution and the dynamic change process of water and heat fluxes within the maize farmland ecosystem in the old course of Yellow River and their response to meteorological factors, we utilized the eddy covariance measurements and the full-element automatic weather station to continuously observe energy fluxes and conventional meteorological elements of summer maize farmland in the old course of Yellow River during 2019-2020. We analyzed the variation of energy fluxes and the effects of environmental factors, such as temperature, precipitation, and wind speed. Additionally, we calculated the energy closure rate and the proportion of energy distribution during the growth stage. The results showed that the peaks of net radiation, sensible heat flux, and latent heat flux occurred between 11:00 and 14:00, and the peak of soil heat flux occurred between 14:00 and 15:00. In terms of energy distribution, energy consumption of summer maize farmland during the whole growth period was dominated by latent heat flux and sensible heat flux. Energy was mainly consumed by sensible heat flux at sowing-emergence stage, accounting for 37.1% of net radiation, respectively. Energy in the rest of growth stages was dominated by latent heat flux. The energy closure rate during the whole growth period was better, with a coefficient of determination of 0.83, and the closure rate was higher in day and lower at night. Precipitation affected latent heat flux and sensible heat flux, and latent heat flux was more sensitive to precipitation. The increase of latent heat flux after rainfall was lower in late growth stage than in early growth stage. During the whole growth period of summer maize, solar radiation was the most significant meteorological factor affecting both sensible heat flux and latent heat flux, followed by vapor pressure deficit. The contribution of temperature and vapor pressure deficit to latent heat flux was significantly higher than sensible heat flux, while the relative contribution of wind speed, relative humidity, and solar radiation to latent heat flux was lower than sensible heat flux. Leaf area index and fractional vegetation cover had a significant positive correlation with latent heat flux and a significant negative correlation with sensible heat flux. Our results could deepen the understanding of water and heat transfer law of summer maize farmland in the old course of Yellow River, providing a theoretical basis for efficient water use of crops.

Understanding the sensing mechanism of metal oxide semiconductors is imperative to the development of high-performance sensors. The traditional sensing mechanism only recognizes the effect of surface chemisorbed oxygen from the air but ignores surface lattice oxygen. Herein, using in-situ characterizations, we provide direct experimental evidence that the surface chemisorbed oxygen participated in the sensing process can come from lattice oxygen of the oxides. Further density functional theory (DFT) calculations prove that the p-band center of O serves as a state of art for regulating the participation of lattice oxygen in gas-sensing reactions. Based on our experimental data and theoretical calculations, we discuss mechanisms that are fundamentally different from the conventional mechanism and show that the easily participation of lattice oxygen is helpful for the high response value of the materials., (© 2024. The Author(s).)

Purpose: Colorectal cancer (CRC) is a highly heterogeneous malignancy with an unfavorable prognosis. The purpose of this study was to address the heterogeneity of CRC by categorizing it into ion channel subtypes, and to develop a predictive modeling based on ion channel genes to predict the survival and immunological states of patients with CRC. The model will provide guidance for personalized immunotherapy and drug treatment., Methods: A consistent clustering method was used to classify 619 CRC samples based on the expression of 279 ion channel genes. Such a method was allowed to investigate the relationship between molecular subtypes, prognosis, and immune infiltration. Furthermore, a predictive modeling was constructed for ion channels to evaluate the ion channel properties of individual tumors using the least absolute shrinkage and selection operator. The expression patterns of the characteristic genes were validated through molecular biology experiments. The effect of potassium channel tetramerization domain containing 9 (KCTD9) on CRC was verified by cellular functional experiments., Results: Four distinct ion channel subtypes were identified in CRC, each characterized by unique prognosis and immune infiltration patterns. Notably, Ion Cluster3 exhibited high levels of immune infiltration and a favorable prognosis, while Ion Cluster4 showed relatively lower levels of immune infiltration and a poorer prognosis. The ion channel score could predict overall survival, with lower scores correlated with longer survival. This score served as an independent prognostic factor and presented an excellent predictive efficacy in the nomogram. In addition, the score was closely related to immune infiltration, immunotherapy response, and chemotherapy sensitivity. Experimental evidence further confirmed that low expression of KCTD9 in tumor tissues was associated with an unfavorable prognosis in patients with CRC. The cellular functional experiments demonstrated that KCTD9 inhibited the proliferation, migration and invasion capabilities of LOVO cells., Conclusions: Ion channel subtyping and scoring can effectively predict the prognosis and evaluate the immune microenvironment, immunotherapy response, and drug sensitivity in patients with CRC., (© 2024. The Author(s).)

Background: Pneumothorax is a common complication induced by computed tomography (CT)-guided percutaneous needle biopsy, with a frequency of 17-40.4%. It remains debatable how to predict and prevent the occurrence of post-biopsy pneumothorax. In a real-world setting, we investigated the characteristics associated with pneumothorax in primary lung nodule biopsy., Methods: This clinical registry cohort study recorded patients with newly diagnosed pulmonary nodules from 10 medical centers from April 2021 to April 2022, and the data were input into the electronic data capture (EDC) system. The eligibility criteria for participants included being within the age range of 18 to 80 years and expressing a willingness to undergo percutaneous puncture biopsy, among other requirements. Conversely, the exclusion criteria included an inability to cooperate throughout the biopsy process and the emergence of new health issues during the study duration resulting in attendance delays, among other factors. This study collected data from 924 patients, out of which 593 were included after exclusion. The essential characteristics, imaging features of pulmonary nodules, and technical factors associated with percutaneous biopsy were recorded. T -tests or one-way analysis of variance (ANOVA) were performed for continuous variables and Pearson's χ 2 test, likelihood ratio, or Fisher's exact test were applied for categorical variables for comparison as appropriate, followed by multivariate logistic regression., Results: The overall incidence of pneumothorax was 13.0% (77/593), among which timely pneumothorax was 10.3% (61/593), delayed pneumothorax was 2.7% (16/593), and the rate of chest tube placement was 3.4% (20/593). There was no significant difference in the incidence of pneumothorax in a needle size range of 16-19 G (P=0.129), but the incidence of pneumothorax was lower with 17 G needles than with 18 G. An increased morbidity of pneumothorax was correlated with age (P=0.003), emphysema (P=0.006), and operation time (P=0.002). There was no significant increase in the incidence of pneumothorax between 1 or 2 passes through the pleura (P=0.062). However, multiple pleural passes (3 times) increased the chances of pneumothorax significantly (P=0.022). These risk factors have a certain clinical value in predicting the incidence of post-biopsy pneumothorax, and the area under the curve (AUC) was 0.749., Conclusions: The most common post-biopsy complication, pneumothorax, was managed conservatively in most cases. A maximum of two pleural passes does not increase the incidence of pneumothorax, and the 17 G needle is more suitable for percutaneous biopsy of pulmonary nodules in the real world., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-23-891/coif). The authors have no conflicts of interest to declare., (2024 Quantitative Imaging in Medicine and Surgery. All rights reserved.)