Emission characteristics of biogenic volatile organic compounds in a subtropical pristine forest of southern China.

Emission characteristics of biogenic volatile organic compounds (BVOCs) from dominant tree species in the subtropical pristine forests of China are extremely limited. Here we conducted in situ field measurements of BVOCs emissions from representative mature evergreen trees by using dynamic branch enclosures at four altitude gradients (600-1690 m a.s.l.) in the Nanling Mountains of southern China. Composition characteristics as well as seasonal and altitudinal variations were analyzed. Standardized emission rates and canopy-scale emission factors were then calculated. Results showed that BVOCs emission intensities in the wet season were generally higher than those in the dry season. Monoterpenes were the dominant BVOCs emitted from most broad-leaved trees, accounting for over 70% of the total. Schima superba, Yushania basihirsuta and Altingia chinensis had relatively high emission intensities and secondary pollutant formation potentials. The localized emission factors of isoprene were comparable to the defaults in the Model of Emissions of Gases and Aerosols from Nature (MEGAN), while emission factors of monoterpenes and sesquiterpenes were 2 to 58 times of those in the model. Our results can be used to update the current BVOCs emission inventory in MEGAN, thereby reducing the uncertainties of BVOCs emission estimations in forested regions of southern China.

Development of a coupled model to simulate and assess arsenic contamination and impact factors in the Jinsha River Basin, China.

With the increasing severity of arsenic (As) pollution, quantifying the environmental behavior of pollutant based on numerical model has become an important approach to determine the potential impacts and finalize the precise control strategies. Taking the industrial-intensive Jinsha River Basin as typical area, a two-dimensional hydrodynamic water quality model coupled with Soil and Water Assessment Tool (SWAT) model was developed to accurately simulate the watershed-scale distribution and transport of As in the terrestrial and aquatic environment at high spatial and temporal resolution. The effects of hydro-climate change, hydropower station construction and non-point source emissions on As were quantified based on the coupled model. The result indicated that higher As concentration areas mainly centralized in urban districts and concentration slowly decreased from upstream to downstream. Due to the enhanced rainfall, the As concentration was significantly higher during the rainy season than the dry season. Hydro-climate change and the construction of hydropower station not only affected the dissolved As concentration, but also affected the adsorption and desorption of As in sediment. Furthermore, As concentration increased with the input of non-point source pollution, with the maximum increase about 30%, resulting that non-point sources contributed important pollutant impacts to waterways. The coupled model used in pollutant behavior analysis is general with high potential application to predict and mitigate water pollution.

A novel gelatin composite film with melt extrusion for walnut oil packaging.

Gelatin have excellent film-forming and barrier properties, but its lack of biological activity limits its application in packaging. In this study, fish gelatin incorporated with apple polyphenol/cumin essential oil composite films were successfully prepared by melt extrusion. The cross-linking existed in gelatin and apple polyphenol improved the thermal stability and oxidation resistance of the film. The synergistic effect of apple polyphenols and cumin essential oil decreased the sensitivity of the film to water, especially the water solubility decreased from 41.60 % to 26.07 %. The plasticization of essential oil nearly doubled the elongation at break while maintaining the tensile strength of the film (11.45 MPa). Furthermore, the FG-CEO-AP film can inhibit peroxide value to extend the shelf life about 20 days in the walnut oil preservation. In summary, the apple polyphenol/cumin essential oil of FG film exhibits excellent comprehensive properties and high preparation efficiency for utilization as an active packaging material.

AB042. Combined anti-PD-L1 and anti-VEGFR2 therapy promotes the antitumor immune response in glioblastoma multiforme by reprogramming tumor microenvironment.

BACKGROUND: Inhibitors of programmed cell death ligand 1 (PD-L1) and vascular endothelial growth factor receptor 2 (VEGFR2) are commonly used in the clinic, but they are beneficial for only a minority of glioblastoma multiforme (GBM) patients. GBM has significant immunosuppressive properties, and there are many immunosuppressive cells and dysfunctional effector T-cell in the tumor microenvironment (TME), which is one of the important reasons for the failure of clinical treatment of GBM. P21-activated kinase 4 (PAK4) is a threonine protein kinase, and as a pivotal immune suppressor in the TME. PAK4 knockdown attenuates vascular abnormalities and promotes T-cell infiltration. METHODS: Using RNA sequencing (RNA-seq) technology, western blotting, and immunofluorescence, we identified changes in genes expression following VEGFR2 knockdown. The impact of anti-PD-L1 and anti-VEGFR2 on GBM cells apoptosis was assessed using coculture assays, western blotting, and flow cytometry. Additionally, the therapeutic efficacy of anti-PD-L1 and anti-VEGFR2 therapy was evaluated through in vivo experiments, immunohistochemistry, and immunofluorescence. RESULTS: Our studies revealed that VEGFR2 binds and phosphorylates signal transducer and activator of transcription 3 (p-STAT3), thereby regulating the expression of PAK4. Anti-PD-L1 and anti-VEGFR2 therapy can increase the secretion of interferon-gamma (IFN-γ), granzyme B, and perforin by immune cells and promoting the cytotoxic effects of cytotoxic cluster of differentiation 8 (CD8)+ T cells, and overexpression of PAK4 could reverse this effect. We also demonstrated that combination therapy with anti-PD-L1 and anti-VEGFR2 agents prevents tumor growth in an intracranial tumor model. CONCLUSIONS: Our results support that anti-VEGFR2 therapy can downregulate PAK4, reprogram the TME by increasing CD8+ T cells infiltration and activation, and enhance the therapeutic effect of anti-PD-L1 therapy on GBM cells.

AB046. Dual role of POSTN in maintaining glioblastoma stem cells and immune-suppressive microglia in glioblastoma.

BACKGROUND: Glioblastoma (GBM) is an immunosuppressive, universally lethal cancer driven by GBM stem cells (GSCs). The interplay between GSCs and the immunosuppressive microglia plays crucial roles in promoting malignant growth of GBM, however, the molecular mechanisms underlying this crosstalk are incompletely understood. METHODS: We performed RNA sequencing to explore the mechanism by which periostin (POSTN) regulates GSCs and microglia. The biological function of POSTN in GBM development was confirmed in vitro and in vivo. Specifically, tumorsphere formation assay, proliferation analysis, migration assays, enzyme-linked immunosorbent assay, immunoblotting, and intracranial mouse model were performed. RESULTS: We identified POSTN secreted from GSCs promotes GSC self-renewal and tumor growth via activation of the αVß3/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/ß-catenin/FOS like antigen 1 (FOSL1) pathway. In addition to its GSC intrinsic effects, POSTN is able to recruit microglia and upregulate cluster of differentiation 70 (CD70) expression through PI3K/AKT/nuclear factor-kappa B (NFκB) pathway in microglial cells, which in turn promotes the Treg development and functionality, and generates an immunosuppressive tumor microenvironment. Inhibition POSTN disrupts the GSC maintenance, inhibits recruitment of immunosuppressive microglial, reduces Treg development and function, and suppresses GBM growth, suggesting that targeting POSTN may effectively improve GBM treatment. CONCLUSIONS: In conclusion, our study defined POSTN as a key regulator in mediating the molecular crosstalk between GSCs and immune-suppressive Microglia in the tumor microenvironment in GBM. POSTN activates the PI3K/AKT/ß-catenin/FOSL1 pathway in an autocrine manner to promote GSC self-renewal and tumor growth. At the same time, POSTN recruits microglia in a paracrine manner and upregulates the expression of CD70 in microglia through the PI3K/AKT/NFκB pathway, thereby promoting the development and function of Treg and generating an immunosuppressive tumor microenvironment. Our findings indicate that targeting the POSTN gene may be a promising approach to ablating GSCs, breaking the immunosuppressive environment and overcoming treatment resistance in GBM.

Plasma cell-free RNA signatures of inflammatory syndromes in children.

Inflammatory syndromes, including those caused by infection, are a major cause of hospital admissions among children and are often misdiagnosed because of a lack of advanced molecular diagnostic tools. In this study, we explored the utility of circulating cell-free RNA (cfRNA) in plasma as an analyte for the differential diagnosis and characterization of pediatric inflammatory syndromes. We profiled cfRNA in 370 plasma samples from pediatric patients with a range of inflammatory conditions, including Kawasaki disease (KD), multisystem inflammatory syndrome in children (MIS-C), viral infections, and bacterial infections. We developed machine learning models based on these cfRNA profiles, which effectively differentiated KD from MIS-C-two conditions presenting with overlapping symptoms-with high performance [test area under the curve = 0.98]. We further extended this methodology into a multiclass machine learning framework that achieved 80% accuracy in distinguishing among KD, MIS-C, viral, and bacterial infections. We further demonstrated that cfRNA profiles can be used to quantify injury to specific tissues and organs, including the liver, heart, endothelium, nervous system, and the upper respiratory tract. Overall, this study identified cfRNA as a versatile analyte for the differential diagnosis and characterization of a wide range of pediatric inflammatory syndromes.

Structure and evolution of alanine/serine decarboxylases and the engineering of theanine production.

Ethylamine (EA), the precursor of theanine biosynthesis, is synthesized from alanine decarboxylation by alanine decarboxylase (AlaDC) in tea plants. AlaDC evolves from serine decarboxylase (SerDC) through neofunctionalization and has lower catalytic activity. However, lacking structure information hinders the understanding of the evolution of substrate specificity and catalytic activity. In this study, we solved the X-ray crystal structures of AlaDC from Camellia sinensis (CsAlaDC) and SerDC from Arabidopsis thaliana (AtSerDC). Tyr341 of AtSerDC or the corresponding Tyr336 of CsAlaDC is essential for their enzymatic activity. Tyr111 of AtSerDC and the corresponding Phe106 of CsAlaDC determine their substrate specificity. Both CsAlaDC and AtSerDC have a distinctive zinc finger and have not been identified in any other Group II PLP-dependent amino acid decarboxylases. Based on the structural comparisons, we conducted a mutation screen of CsAlaDC. The results indicated that the mutation of L110F or P114A in the CsAlaDC dimerization interface significantly improved the catalytic activity by 110% and 59%, respectively. Combining a double mutant of CsAlaDCL110F/P114A with theanine synthetase increased theanine production 672% in an in vitro system. This study provides the structural basis for the substrate selectivity and catalytic activity of CsAlaDC and AtSerDC and provides a route to more efficient biosynthesis of theanine.

A Randomized, Double-Blind, Parallel-Group Phase I Study Comparing the Pharmacokinetics, Safety, and Immunogenicity of CMAB015, a Candidate Secukinumab Biosimilar, with Its Reference Product Cosentyx® in Healthy Chinese Male Subjects.

Purpose: Secukinumab, a monoclonal antibody targeting interleukin (IL)-17A, is approved for the treatment of psoriasis, psoriatic arthritis, ankylosing spondylitis, non-radiographic axial spondyloarthritis, enthesitis-related arthritis, and hidradenitis suppurativa. This study compared the pharmacokinetics (PK), safety, and immunogenicity of CMAB015, a candidate secukinumab biosimilar, with the reference product secukinumab (Cosentyx®) in healthy Chinese male subjects. Patients and methods: This double-blind, parallel-group study randomized healthy Chinese male subjects (N=130) to receive either a single dose of 150 mg CMAB015 or secukinumab subcutaneously. Primary study endpoints were PK parameters such as the maximum concentration (Cmax) and area under the curve from zero to infinity (AUC0-inf), while safety and immunogenicity were secondary endpoints. Results: The 90% confidence intervals (CIs) of the geometric mean ratios (GMRs) of Cmax and AUC0-inf for CMAB015 to secukinumab were all within the bioequivalence limits (80.00-125.00%). Other PK parameters were comparable between the groups. The safety profile of CMAB015 was similar to that of secukinumab, with no serious adverse events related to treatment. The incidence of TEAEs was slightly higher in the CMAB015 group, but these events were mild to moderate in severity and did not lead to any withdrawals from the study. Immunogenicity analysis revealed low rates of anti-drug antibody (ADA) positivity, with similar rates between CMAB015 and secukinumab. Conclusion: This study demonstrated equivalent PK, comparable safety, and immunogenicity of CMAB015 to secukinumab in healthy Chinese male subjects. These findings support further clinical evaluation of CMAB015 as a secukinumab biosimilar. Trial Registration: The trial was registered on Clinicaltrials.gov (Identifier No. NCT05734482) and Chinadrugtrials.org.cn (Identifier No. CTR20230105).

AtML: An Arabidopsis thaliana root cell identity recognition tool for medicinal ingredient accumulation.

Arabidopsis thaliana synthesizes various medicinal compounds, and serves as a model plant for medicinal plant research. Single-cell transcriptomics technologies are essential for understanding the developmental trajectory of plant roots, facilitating the analysis of synthesis and accumulation patterns of medicinal compounds in different cell subpopulations. Although methods for interpreting single-cell transcriptomics data are rapidly advancing in Arabidopsis, challenges remain in precisely annotating cell identity due to the lack of marker genes for certain cell types. In this work, we trained a machine learning system, AtML, using sequencing datasets from six cell subpopulations, comprising a total of 6000 cells, to predict Arabidopsis root cell stages and identify biomarkers through complete model interpretability. Performance testing using an external dataset revealed that AtML achieved 96.50% accuracy and 96.51% recall. Through the interpretability provided by AtML, our model identified 160 important marker genes, contributing to the understanding of cell type annotations. In conclusion, we trained AtML to efficiently identify Arabidopsis root cell stages, providing a new tool for elucidating the mechanisms of medicinal compound accumulation in Arabidopsis roots.

Acute Aerobic Exercise Intensity on Working Memory and Vigilance After Nap Deprivation: Effects of Low-Intensity Deserve Attention.

Background: Napping deprivation in habitual nappers leads to cognitive impairment. The ameliorative effect of acute aerobic exercise has been demonstrated for this post-cognitive impairment. However, it is still unclear which intensity of aerobic exercise is the most effective and how long this improvement can be sustained. Methods: Fifty-eight healthy adults with a chronic napping habit were randomly assigned to four intervention groups after undergoing nap deprivation: a sedentary control group, a low-intensity exercise group (50-59% maximum heart rate, HRmax), a moderate-intensity exercise group (60-69% HRmax), and a high-intensity exercise group (70-79% HRmax). Working memory (N-back task), vigilance (Psychomotor Vigilance Task, PVT), and response inhibitory capacity (Go/NoGo task) were measured. Results: Regression analyses showed a quadratic trend between exercise intensity and working memory reaction time and accuracy (F =3.297-5.769, p < 0.05, R2 =10.7-18.9%). The effects of exercise were optimal at low-intensity. There was a significant quadratic trend between exercise intensity and PVT lapse (F =4.314, p =0.042, R² =7.2%). The effect of exercise increased with higher intensity. Prolonged observation found that the effect of low-intensity exercise on working memory was maintained for 2 hours. Conclusion: The effect of low-intensity exercise might be underestimated. Low-intensity exercise significantly improved working memory performance, and the effects could be maintained throughout the afternoon. In contrast, the effects of high-intensity exercise were unlikely to be maintained and might even have negative effects. Future researchers can broaden the categories of participants to enhance the external validity and collect diverse physiological indicators to explore related physiological mechanisms.

Retracted: Long Non-Coding RNA Plasmacytoma Variant Translocation 1 (PVT1) Enhances Proliferation, Migration, and Epithelial-Mesenchymal Transition (EMT) of Pituitary Adenoma Cells by Activating ß-Catenin, c-Myc, and Cyclin D1 Expression.

The Editors of Medical Science Monitor wish to inform you that the above manuscript has been retracted from publication due to concerns with the credibility and originality of the study, the manuscript content, and the Figure images. Reference: Yihua Zhang, Yang Tan, Hao Wang, Minhui Xu, Lunshan Xu. Long Non-Coding RNA Plasmacytoma Variant Translocation 1 (PVT1) Enhances Proliferation, Migration, and Epithelial-Mesenchymal Transition (EMT) of Pituitary Adenoma Cells by Activating ß-Catenin, c-Myc, and Cyclin D1 Expression. Med Sci Monit, 2019; 25: 7652-7659. DOI: 10.12659/MSM.917110.

Roles of small GTPases in cardiac hypertrophy (Review).

Cardiac hypertrophy results from the heart reacting and adapting to various pathological stimuli and its persistent development is a major contributing factor to heart failure. However, the molecular mechanisms of cardiac hypertrophy remain unclear. Small GTPases in the Ras, Rho, Rab, Arf and Ran subfamilies exhibit GTPase activity and play crucial roles in regulating various cellular responses. Previous studies have shown that Ras, Rho and Rab are closely linked to cardiac hypertrophy and that their overexpression can induce cardiac hypertrophy. Here, we review the functions of small GTPases in cardiac hypertrophy and provide additional insights and references for the prevention and treatment of cardiac hypertrophy.

Predicting leaf nitrogen content in wolfberry trees by hyperspectral transformation and machine learning for precision agriculture.

Leaf nitrogen content (LNC) is an important indicator for scientific diagnosis of the nutrition status of crops. It plays an important role in the growth, yield and quality of wolfberry. This study aimed to develop new spectral indices (NSIs) and constructed machine learning regression (MLR) models for predicting wolfberry tree LNC. By utilizing four smoothing methods and five mathematic transformation methods, we obtained the original spectral dataset and five spectral transformation datasets for quantitative analysis and model establishment. Subsequently, published vegetation indices (PVIs) were acquired, sensitive wavelengths (SWs) were screened and NSIs were calculated based on SWs. Then MLR models were constructed by combining NSIs from six spectral datasets with three machine learning algorithms. Finally, a comparison was made among the MLR models. The study indicated that the application of mathematical transformation highlighted the differences in spectra, the square root, first-derivative and second-derivative transformation improved the prediction accuracy of MLR models constructed based on NSIs (MLR-NSIs models). However, these transformations had little impact on improving the prediction ability of MLR models constructed based on PVIs (MLR-PVIs models). Additionally, The optimal model for predicting the LNC of wolfberry tree was obtained by using the Random Forest (RF) algorithm combined with NSIs developed by first-derivative transformation spectra. The determination coefficient of validation (Rv2) and ratio of percentage deviation (RPD) was 0.71 and 1.90, respectively. In conclusion, this study has demonstrated that the combination of hyperspectral transformation and machine learning is useful for improving the accuracy of LNC estimation in wolfberry trees.

Identification of cellular senescence-related genes and immune cell infiltration characteristics in intervertebral disc degeneration.

Background: Intervertebral disc degeneration (IDD) progression involves multiple factors, including loss of nucleus pulposus cells and extracellular matrix as the basic pathological mechanism of degeneration, and is closely related to cellular senescence and immune cell infiltration. The aim of study was to identify critical cellular senescence-related genes and immune cell infiltration characteristics in IDD. Methods: Four datasets, including GSE70362, GSE112216, GSE114169, and GSE150408, were downloaded from the Gene Expression Omnibus database. The senescence-related genes were acquired from the CellAge Database and intersected with differentially expressed genes (DEGs) between IDD and control samples for senescence-related DEGs (SRDEGs). Protein-protein interaction (PPI) network analysis was performed to obtain ten hub SRDEGs. A consensus cluster analysis based on these hub genes was performed to divide the patients into clusters. The functional enrichment, and immune infiltration statuses of the clusters were compared. Weighted gene co-expression network analysis was used to identified key gene modules. The overlapping genes from key modules, DEGs of clusters and hub SRDEGs were intersected to obtain potential biomarkers. To verify the expression of potential biomarkers, quantitative polymerase chain reaction (qPCR) and immunohistochemistry were performed by using human intervertebral disc tissues. Results: In the GSE70362 dataset, a total of 364 DEGs were identified, of which 150 were upregulated and 214 were downregulated, and 35 genes were selected as SRDEGs. PPI analysis revealed ten hub SRDEGs and consensus cluster analysis divided the patients into two clusters. Compared to Cluster 2, Cluster 1 was highly enriched in extracellular matrix organization and various metabolic process. The level of Follicular T helper cells in the Cluster 1 was significantly higher than that in the Cluster 2. IGFBP3 and NQO1 were identified as potential biomarkers. The remaining 3 datasets, and the result of qPCR and immunohistochemistry showed that the expression levels of NQO1 and IGFBP3 in the degenerated group were higher than those in the control or treatment groups. Conclusion: Senescence-related genes play a key role in the development and occurrence of IDD. IGFBP3 and NQO1 are strongly correlated with immune infiltration in the IDD and could become novel therapeutic targets that prevent the progression of IDD.

Infrared Spectrum of the Adduct 2-Chloro-2-hydroperoxybut-3-ene [(C2H3)CCl(CH3)OOH] of the Reaction between the Criegee Intermediate Methyl Vinyl Ketone Oxide [C2H3C(CH3)OO] and HCl.

Methyl vinyl ketone oxide (MVKO, C2H3C(CH3)OO) is an important Criegee intermediate produced from ozonolysis of isoprene, which is the most abundant nonmethane hydrocarbon emitted into the atmosphere. Reactions between Criegee intermediate and hydrogen chloride (HCl) are important because of their large rate coefficients. In this work, we photolyzed a mixture of (Z)-(CH2I)HC═C(CH3)I/HCl/O2 at 248 nm to produce MVKO to carry out the reaction MVKO + HCl and recorded infrared spectra of transient species with a step-scan Fourier-transform infrared absorption spectrometer. Eleven bands near 1415, 1381, 1350, 1249, 1178, 1118, 1103, 1065, 978, 931, and 895 cm-1 were observed and assigned to the hydrogen-transferred adduct (C2H3)CCl(CH3)OOH (2-chloro-2-hydroperoxybut-3-ene, CHPB) according to the predicted IR spectrum using the B3LYP/aug-cc-pVTZ method; the conformation could not be definitively determined. According to calculations, most low-energy conformers can interconvert, and the most stable conformers anti-trans-CHPB and syn-trans-CHPB might have the major contributions. Four bands near 1423, 1360, 1220, and 1080 cm-1 were observed and tentatively assigned to the OH-decomposition products (C2H3)CCl(CH3)O (1-chloro-1-methyl-2-propenyloxy, CMP); both trans-CMP and cis-CMP might contribute. Unlike in the case of CH2OO + HCl and CH3CHOO + HCl, in which secondary reactions of the OH-decomposition products reacted readily with O2 to produce the dehydrated products HC(O)Cl and CH3C(O)Cl, respectively, the secondary reaction of CMP with O2 was not observed because there is no feasible H atom in CMP for O2 to abstract.

Soluble sugar, organic acid and phenolic composition and flavor evaluation of plum fruits.

Plums (Prunus salicina and Prunus domestica) are prevalent in southwestern China, and have attracted interest owing to their delectable taste and exceptional nutritional properties. Therefore, this study aimed to investigate the nutritional and flavor properties of plum to improve its nutritional utilization. Specifically, we determined the soluble sugars, organic acids, and phenolic components in 86 accessions using high-performance liquid chromatography. Notably, glucose, fructose, malic, and quinic acids were the predominant sweetness and acidity in plums, with sucrose contributing more to the sweetness of the flesh than the peel. Moreover, The peel contains 5.5 fold more phenolics than flesh, epicatechin, gallic acid, and proanthocyanidins C1 and B2 were the primary sources of astringency. Correlation and principal component analyses showed eight core factors for plum flavor rating, and a specific rating criterion was established. Conclusively, these findings provide information on the integrated flavor evaluation criteria and for enhancing optimal breeding of plums.

Intracorporeal urinary diversion offers the advantage of delaying postoperative renal function injury in patients undergoing robot-assisted radical cystectomy.

Objective: To analyze changes in renal function and associated risk factors in patients with bladder cancer undergoing robot-assisted radical cystectomy (RARC) with intracorporeal or extracorporeal urinary diversion (ICUD or ECUD). Methods: Clinical-pathological data was extracted from electronic medical records of 266 patients with bladder cancer who underwent RARC at our institution between August 2015 and August 2022. Postoperative renal function was assessed using the estimated glomerular filtration rate (eGFR). Result: Patients were classified into ECUD and ICUD groups based on the surgical approach. Significant differences in eGFR were observed between the two groups at 1, 2, and 3 years postoperatively. Moreover, 112 patients (42.1%) experienced long-term renal function injury. Independent risk factors for long-term renal function injury included the type of surgical approach, ureteroenteric anastomotic strictures, and pathological stage T3 or above. In terms of short-term renal function, 30 cases of acute kidney injury (AKI) were observed, with an incidence rate of 11.3%. No difference in AKI incidence was found between the groups. Conclusions: Postoperative AKI and chronic kidney injury are prevalent complications following RC. This study highlights that pathological stage, ureteroenteric anastomotic strictures, and ECUD significantly impact long-term renal function, but the type of urinary diversion (ileal conduit or orthotopic neobladder) had no effect on renal function, and ICUD was superior in terms of long-term renal injury rate. Therefore, precise preoperative assessment and the selection of appropriate surgical approach are crucial for preserving renal function in patients with bladder cancer.

Sugar/sugar alcohol with glycerol as co-plasticizers for high-content starch/PBAT blown films: from fine structure to physicochemical properties.

BACKGROUND: Glycerol is a well-known plasticizer for starch-based materials, but it easily migrates during starch retrogradation, thereby deteriorating the films' properties. We hypothesized that the performance of high-content starch/poly(butylene adipate-co-terephthalate) (PBAT) films could be enhanced by using sugar/sugar alcohol (glucose, sucrose and sorbitol) as natural, green and edible co-plasticizers with glycerol. RESULTS: The employment of co-plasticizers reduced the melt fluidity of the blends, established intermolecular hydrogen bonds with starch and resulted in a brittle film structure. The presence of sucrose contributed to the formation of more B-type starch crystals. Glucose and sucrose promoted the conversion of bound water to entrapped water, while sorbitol contributed to more bound water. The co-plasticizers enhanced films' thermal stability, moisture permeability (from 3.61 to 3.72 × 10-11 g m m-2 s-1 Pa-1), and oxygen barrier (from 12.84 to 8.74 × 10-13 cm3 cm cm-2 s-1 Pa-1). Glucose/glycerol co-plasticized film had the maximum tensile strength (10.12 MPa), and sucrose/glycerol co-plasticized film showed the highest Young's modulus (380.31 MPa). CONCLUSION: Sorbitol with linear structure and the lowest melting point exhibited a plasticizing capacity similar to glycerol. The molecular structure (linear or cyclic), hydroxyl group proportion and melting point of the sugar/sugar alcohol were the key factors to regulate the fine structure and properties of starch/PBAT films. © 2024 Society of Chemical Industry.

Sodium Ion-Induced Structural Transition on the Surface of a DNA-Interacting Protein.

Protein surfaces have pivotal roles in interactions between proteins and other biological molecules. However, the structural dynamics of protein surfaces have rarely been explored and are poorly understood. Here, the surface of a single-stranded DNA (ssDNA) binding protein (SSB) with four DNA binding domains that bind ssDNA in binding site sizes of 35, 56, and 65 nucleotides per tetramer is investigated. Using oligonucleotides as probes to sense the charged surface, NaCl induces a two-state structural transition on the SSB surface even at moderate concentrations. Chelation of sodium ions with charged amino acids alters the network of hydrogen bonds and/or salt bridges on the surface. Such changes are associated with changes in the electrostatic potential landscape and interaction mode. These findings advance the understanding of the molecular mechanism underlying the enigmatic salt-induced transitions between different DNA binding site sizes of SSBs. This work demonstrates that monovalent salt is a key regulator of biomolecular interactions that not only play roles in non-specific electrostatic screening effects as usually assumed but also may configure the surface of proteins to contribute to the effective regulation of biomolecular recognition and other downstream events.

Homogenizing Energy Landscape for Efficient and Spectrally Stable Blue Perovskite Light-Emitting Diodes.

Blue perovskite light-emitting diodes (PeLEDs) have attracted enormous attention; however, their unsatisfactory device efficiency and spectral stability still remain great challenges. Unfavorable low-dimensional phase distribution and defects with deeper energy levels usually cause energy disorder, substantially limiting the device's performance. Here, an additive-interface optimization strategy is reported to tackle these issues, thus realizing efficient and spectrally stable blue PeLEDs. A new type of additive-formamidinium tetrafluorosuccinate (FATFSA) is introduced into the quasi-2D mixed halide perovskite accompanied by interface engineering, which effectively impedes the formation of undesired low-dimensional phases with various bandgaps throughout the entire film, thereby boosting energy transfer process for accelerating radiative recombination; this strategy also diminishes the halide vacancies especially chloride-related defects with deep energy level, thus reducing nonradiative energy loss for efficient radiative recombination. Benefitting from homogenized energy landscape throughout the entire perovskite emitting layer, PeLEDs with spectrally-stable blue emission (478 nm) and champion external quantum efficiency (EQE) of 21.9% are realized, which represents a record value among this type of PeLEDs in the pure blue region.