TCOD: an integrated resource for tropical crops.

Tropical crops are vital for tropical agriculture, with resource scarcity, functional diversity and extensive market demand, providing considerable economic benefits for the world's tropical agriculture-producing countries. The rapid development of sequencing technology has promoted a milestone in tropical crop research, resulting in the generation of massive amount of data, which urgently needs an effective platform for data integration and sharing. However, the existing databases cannot fully satisfy researchers' requirements due to the relatively limited integration level and untimely update. Here, we present the Tropical Crop Omics Database (TCOD, https://ngdc.cncb.ac.cn/tcod), a comprehensive multi-omics data platform for tropical crops. TCOD integrates diverse omics data from 15 species, encompassing 34 chromosome-level de novo assemblies, 1 255 004 genes with functional annotations, 282 436 992 unique variants from 2048 WGS samples, 88 transcriptomic profiles from 1997 RNA-Seq samples and 13 381 germplasm items. Additionally, TCOD not only employs genes as a bridge to interconnect multi-omics data, enabling cross-species comparisons based on homology relationships, but also offers user-friendly online tools for efficient data mining and visualization. In short, TCOD integrates multi-species, multi-omics data and online tools, which will facilitate the research on genomic selective breeding and trait biology of tropical crops.

Local Mechanical Modulation-Driven Evagination in Invaginated Epithelia.

Local cells can actively create reverse bending (evagination) in invaginated epithelia, which plays a crucial role in the formation of elaborate organisms. However, the precise physical mechanism driving the evagination remains elusive. Here, we present a three-dimensional vertex model, incorporating the intrinsic cell polarity, to explore the complex morphogenesis induced by local mechanical modulations. We find that invaginated tissues can spontaneously generate local reverse bending due to the shift of the apicobasal polarity. Their exact shapes can be analytically determined by the local apicobasal differential tension and the internal stress. Our continuum theory exhibits three regions in a phase diagram controlled by these two parameters, showing curvature transitions from ordered to disordered states. Additionally, we delve into epithelial curvature transition induced by the nucleus repositioning, revealing its active contribution to the apicobasal force generation. The uncovered mechanical principles could potentially guide more studies on epithelial folding in diverse systems.

Targeting type H vessels in bone-related diseases.

Blood vessels are essential for bone development and metabolism. Type H vessels in bone, named after their high expression of CD31 and Endomucin (Emcn), have recently been reported to locate mainly in the metaphysis, exhibit different molecular properties and couple osteogenesis and angiogenesis. A strong correlation between type H vessels and bone metabolism is now well-recognized. The crosstalk between type H vessels and osteoprogenitor cells is also involved in bone metabolism-related diseases such as osteoporosis, osteoarthritis, fracture healing and bone defects. Targeting the type H vessel formation may become a new approach for managing a variety of bone diseases. This review highlighted the roles of type H vessels in bone-related diseases and summarized the research attempts to develop targeted intervention, which will help us gain a better understanding of their potential value in clinical application.

Study on the characteristics of genetic diversity of different populations of Guizhou endemic plant Rhododendron pudingense based on microsatellite markers.

BACKGROUND: Rhododendron pudingense, firstly discovered in Puding county of Guizhou province in 2020, have adapted to living in rocky fissure habitat, which has important ornamental and economic values. However, the genetic diversity and population structure of this species have been rarely described, which seriously affects the collection and protection of wild germplasm resources. RESULTS: In the present study, 13 pairs of primers for polymorphic microsatellite were used to investigate the genetic diversity of 65 R. pudingense accessions from six different geographic populations. A total of 254 alleles (Na) were obtained with an average of 19.5 alleles per locus. The average values of polymorphic information content (PIC), observed heterozygosity (Ho), and expected heterozygosity (He) were 0.8826, 0.4501, and 0.8993, respectively, These results indicate that the microsatellite primers adopted demonstrate good polymorphism, and the R. pudingense exhibits a high level of genetic diversity at the species level. The average genetic differentiation coefficient (Fst) was 0.1325, suggested that moderate divergence occurred in R. pudingense populations. The average values of genetic differentiation coefficient and gene flow among populations were 0.1165 and 3.1281, respectively. The analysis of molecular variance (AMOVA) indicated that most of the population differences (88%) were attributed to within-population variation. The PCoA results are consistent with the findings of the UPGMA clustering analysis, supporting the conclusion that the six populations of R. pudingense can be clearly grouped into two separate clusters. Based on Mantel analysis, we speculate that the PD population may have migrated from WM-1 and WM-2. Therefore, it is advised to protect the natural habitat of R. pudingense in situ as much as possible, in order to maximize the preservation of its genetic diversity. CONCLUSIONS: This is the first comprehensive analysis of genetic diversity and population structure of R. pudingense in Guizhou province. The research results revealed the high genetic diversity and moderate population diferentiation in this horticulture plant. This study provide a theoretical basis for the conservation of wild resources of the R. pudingense and lay the foundation for the breeding or cultivation of this new species.

Membrane vesicles derived from Enterococcus faecalis promote the co-transfer of important antibiotic resistance genes located on both plasmids and chromosomes.

BACKGROUND: Bacterial membrane vesicles (BMVs) are novel vehicles of antibiotic resistance gene (ARG) transfer in Gram-negative bacteria, but their role in the spread of ARGs in Gram-positive bacteria has not been defined. The purpose of this study was to evaluate the role of MVs in the transmission of antimicrobial resistance in Gram-positive bacteria. METHODS: A linezolid-resistant Enterococcus faecalis CQ20 of swine origin was selected as the donor strain. Linezolid-susceptible E. faecalis SC032 of human origin, Enterococcus faecium BM4105 and Escherichia coli were selected as recipient strains. The presence of plasmids (pCQ20-1 and pCQ20-2) and an optrA-carrying transposon Tn6674 in CQ20, MVs and vesiculants was verified by WGS or PCR. MVs were isolated with density gradient centrifugation, and MV-mediated transformation was performed to assess the horizontal transferability of MVs. The MICs for CQ20 and its vesiculants were determined by the broth microdilution method. RESULTS: CQ20-derived MVs (CQ20-MV) were isolated, and PCR identified the presence of two plasmids and the optrA gene in the CQ20-MVs. MV-mediated transformation to E. faecalis SC032 and E. faecium BM4105 was successfully performed, and the WGS data also showed that both plasmids pCQ20-1 and pCQ20-2 and optrA-carrying transposon Tn6674 were transferred to E. faecalis SC032 and E. faecium BM4105, but failed for E. coli. Additionally, vesiculants that had acquired ARGs still had the ability to spread these genes via MVs. CONCLUSIONS: To our knowledge, this is the first report of MV-mediated co-transfer of ARG-carrying plasmids and transposons in the Gram-positive bacterium E. faecium.

The m6 A modification of Il17a in CD4+ T cells promotes inflammation in psoriasis.

Psoriasis is a chronic inflammatory skin disorder. The mechanism of psoriasis pathogenesis is not entirely clear. Here, we reported that the level of the N6-methyladenosine (m6 A) modification was increased in psoriatic CD4+ T cells compared with healthy controls. In the psoriasis mouse model, depletion of the RNA demethylase, Alkbh5, from CD4+ T cells promoted the psoriasis-like phenotype and inflammation. Intriguingly, this phenotype and inflammation were alleviated by the ablation of the m6 A methyltransferase Mettl3 in CD4+ T cells. Mechanistically, we found that the m6 A modification of IL17A mRNA increased the expression of IL-17A (an important pro-inflammatory factor in psoriasis) and promoted psoriasis. Thus, our study provided evidence that the m6 A modification of IL17A in CD4+ T cells regulates inflammation in psoriasis.

Protective effect of apelin-13 on ventilator-induced acute lung injury.

BACKGROUND: Mechanical Ventilation (MV) is an essential mechanism of life support in the clinic. It may also lead to ventilator-induced acute lung injury (VILI) due to local alveolar overstretching and/or repeated alveolar collapse. However, the pathogenesis of VILI is not completely understood, and its occurrence and development may be related to physiological processes such as the inflammatory response, oxidative stress, and apoptosis. Some studies have found that the the apelin/APJ axis is an endogenous antagonistic mechanism activated during acute respiratory distress syndrome(ARDS), that can counteract the injury response and prevent uncontrolled lung injury. To indicate that apelin-13 plays a protective role in VILI, an animal model of VILI was established in this study to explore whether apelin-13 can alleviate VILI in rats by inhibiting inflammation, apoptosis and oxidative stress. METHODS: SD rats were divided into four groups: control, high tidal volume, high tidal volume + normal saline and high tidal volume + apelin-13. After tracheotomy, the rats in control maintained spontaneous breathing, and the other rats were connected to the small animal ventilator for 4 h to establish the rat VILI model. The mRNA expression of apelin was measured by real-time quantitative polymerase chain reaction(qRT-PCR), immunofluorescence and Western blotting(WB) were used to detect the expression level of APJ, and WB was used to detect the expression of the apoptotic proteins Bax and bcl-2. The degree of lung injury was evaluated by pathological staining of lung tissue,W/D ratio, and BALF total protein concentration. The expression of inflammatory factors(IL-1ß, IL-6, TNF-α) in alveolar lavage fluid was measured using ELISA. The activities of MPO and cat and the content of MDA, an oxidative product, in lung tissue were measured to evaluate the degree of oxidative stress in the lung. RESULTS: After treatment with apelin-13, the apelin/APJ axis in the lung tissue of VILI model rats was activated, and the effect was further enhanced. The pathological damage of lung tissue was alleviated, the expression of the antiapoptotic protein Bcl-2 and the proapoptotic protein Bax was reversed, and the levels of the inflammatory cytokines IL-1ß, IL-6, TNF-α levels were all decreased. MPO activity and MDA content decreased, while CAT activity increased. CONCLUSION: The apelin/apj axis is activated in VILI. Overexpression of apelin-13 further plays a protective role in VILI, mainly by including reducing pathological damage, the inflammatory response, apoptosis and antioxidant stress in lung tissue, thus delaying the occurrence and development of VILI.

Structurally diverse stilbenes from Gnetum parvifolium and their anti-neuroinflammatory activities.

Phytochemical investigation on the aerial parts of Gnetum parvifolium led to the isolation of 15 new and eight known structurally diverse stilbenes. The isolated compounds comprised (E)- or (Z)-stilbene (1-6, 15-20), dihydrostilbene (21), phenylbenzofuran (7, 8, 22), benzylated stilbene (9-11), benzylated stilbene dimer (12), and nitrogen-containing stilbene (13a, 13b, 14) types. The structures of the new compounds (1-12, 13a, 13b, 14) were established through spectroscopic analyses and experimental and calculated ECD data. Compound 12 is the first stilbene dimer connected through a benzyl group. In the anti-neuroinflammatory activity assay, compounds 4, 5, 9-11, 13b, and 16-21 displayed significant inhibitory effects against LPS-induced NO release in BV-2 microglial cells, with IC50 values of 0.35-16.1 µM. Compound 10 had the most potent activity (IC50 = 0.35 µM), and the further research indicated that it could decrease the mRNA levels of iNOS, IL-1ß, IL-6, and TNF-α in a dose-dependent manner.

Performance evaluation and comparative research of underwater wireless optical communication system by using different structured beams.

Structured beams have attracted increasing interest in free-space and fiber-based optical communications. Underwater wireless optical communication (UWOC) is becoming a prospective technique in marine exploration. We investigated UWOC performance using different representative structured beams. The transmission performances of the Gaussian, Bessel-Gaussian (BG), Ince-Gaussian (IG), and radially polarized Gaussian (RPG) beams were experimentally demonstrated and evaluated in underwater channels subjected to thermal gradient. The experimental results show that the BG, IG, and RPG perform better against the thermal gradient. Compared with the Gaussian beams, the beam wanders of BG, IG, and RPG beams under the thermal gradient have been reduced by 56.9%, 8.2%, and 59%, the scintillation indices have been decreased by 12.8%, 17.3%, and 28.9%, and the BER performance of the BG, IG, and RPG beams have been improved by ∼5.5, ∼3.7, and ∼5.2d B at the forward error correction threshold (FEC threshold). Based on the above results, the RPG beam is a more promising light source for UWOC. The experimental results provide a promising beam choice for UWOC.

Two new cases with the UBQLN2 gene mutation in Han Chinese.

Variations in the UBQLN2 gene are associated with a group of diseases with X-linked dominant inheritance and clinical phenotypes of amyotrophic lateral sclerosis (ALS) and/or frontal temporal lobe dementia (FTD). Cases with UBQLN2 variations have been rarely reported worldwide. The reported cases exhibit strong clinical heterogeneity. Here, we report two adult-onset cases with UBQLN2 variations in Han Chinese. Whole exome sequencing revealed the hemizygous P506S (c.1516C > T) and the heterozygous P509S variation (c.1525C > T), both of which were located within the hotspot mutation region. The patient with the P506S variation was a 24-year-old male. The clinical feature was spastic paraplegia without lower motor neuron damage. The patient's mother was an asymptomatic heterozygote carrier with skewed X-chromosome inactivation. The patient with the P509S variation was a 63-year-old female. Clinical features included ALS and parkinsonism. 18F-fluorodopa PET-CT revealed presynaptic dopaminergic deficits in bilateral posterior putamen. These cases further highlight the clinical heterogeneity of UBQLN2 cases.

UV irradiation enhanced removal of colloidal phosphorus in agricultural runoff.

Colloidal phosphorus (P) is an important P form in agricultural runoff and can threaten water quality. However, up to date, there are few effective approaches to mitigate colloidal P pollution. This study investigated the effect of ultraviolet (UV) irradiation on medium-colloidal (MC; 220 nm-450 nm) and fine-colloidal (FC; 3 kDa-220 nm) P in agricultural runoff. Under 24 h of UV irradiation, as the most abundant colloidal P fraction, concentration of total P (TP) in FC consistently decreased by 81.0%, while TP concentration in MC first increased by 74.4% after 3 h and then decreased with irradiation time. At the same time, particulate TP (>450 nm) concentration was found to be increased from 0 to 14.7 µM. However, there were no obvious variations in TP concentrations in FC and MC fractions under dark conditions. In FC fraction, with the decrease of TP, the corresponding concentrations of iron (Fe), aluminum (Al), silicon (Si) declined synchronously, and ferric iron/ferrous iron (Fe(III)/Fe(II)) ratio and organic matter (OM) concentration were reduced as well. These results suggested that P in FC fraction was gradually transformed into particulate P during photoreduction of Fe(III) and photodegradation of OM under UV irradiation. Our study helps to understand the mechanism of the phototransformation of colloidal P, and propose an UV irradiation-based approach to remove colloidal P in agricultural runoff.

Optical noise-resistant nonreciprocal phonon blockade in a spinning optomechanical resonator.

A scheme of nonreciprocal conventional phonon blockade (PB) is proposed in a spinning optomechanical resonator coupled with a two-level atom. The coherent coupling between the atom and breathing mode is mediated by the optical mode with a large detuning. Due to the Fizeau shift caused by the spinning resonator, the PB can be implemented in a nonreciprocal way. Specifically, when the spinning resonator is driven from one direction, the single-phonon (1PB) and two-phonon blockade (2PB) can be achieved by adjusting both the amplitude and frequency of the mechanical drive field, while phonon-induced tunneling (PIT) occurs when the spinning resonator is driven from the opposite direction. The PB effects are insensitive to cavity decay because of the adiabatic elimination of the optical mode, thus making the scheme more robust to the optical noise and still feasible even in a low-Q cavity. Our scheme provides a flexible method for engineering a unidirectional phonon source with external control, which is expected to be used as a chiral quantum device in quantum computing networks.

Average capacity of an underwater wireless communication link with the quasi-Airy hypergeometric-Gaussian vortex beam based on a modified channel model.

Prompted by alleviating the random perturbation of underwater channel and enhancing the performance for the orbital angular momentum (OAM) -based underwater wireless optical communication (UWOC), the quasi-Airy Hypergeometric-Gaussian (QAHyGG) vortex beam is first proposed and demonstrated. Moreover, an underwater channel model is first modified for more accurate simulated results of the propagation property of various beams. Based on the modified model, the transmission and communication performance of three different OAM-carrying beams (the Gauss vortex (GV) beam, the Hypergeometric-Gaussian (HyGG) vortex beam, and the QAHyGG vortex beam) are comparatively studied. In addition, the parameters optimization of the QAHyGG vortex beam is made for further enhancing the average capacity. The results show that the QAHyGG vortex beam exhibits higher received power and lower crosstalk probability under different channel conditions. The average capacity of the QAHyGG vortex beam has enhanced by ∼8% and ∼27% compared with the HyGG vortex beam and the GV beam at 100m, respectively. The QAHyGG vortex beam is more suitable in an OAM-based UWOC system with a limited-size receiving aperture or lower transmit power. Besides, the average capacity will improve effectively at longer distances with the optimized beam parameters. These research results can provide advances in designing the practical OAM-based UWOC system.

Selective and controllable amination and defluoroamidation of α-trifluoromethylstyrene.

We present a blueprint for the amination and defluoroamidation of α-trifluoromethylstyrene. This practical protocol presents a general method for the diversity-oriented synthesis of vicinal trifluoromethyl amines and gem-difluoro alkenes from α-trifluoromethylstyrene maintaining excellent chemoselectivity. The synthetic strategy features outstanding atom economy and wide functional group tolerance under mild reaction conditions.

Prognosis and immunotherapy significances of a cancer-associated fibroblasts-related gene signature in lung adenocarcinoma.

Cells associated with cancer (CAFs) contribute significantly to the stroma of a tumor microenvironment (TME), which is related to the occurrence, treatment, and prognosis of lung adenocarcinoma (LUAD). Therefore, this study investigated the function of CAF-associated genes in the microenvironment of LUAD. The Cancer Genome Atlas (TCGA) database was used to download RNA-seq data from the TCGA Lung Adenocarcinoma cohort (TCGA-LUAD). The GSE68465 dataset, as the external validation set, was from the Gene Expression Omnibus (GEO) database. Besides, CAF-associated genes were sourced from the GeneCards and Molecular Signatures Database (MsigDB). For LUAD, differentially expressed CAF-related genes were selected from overlapping CAF and LUAD patient and control samples. Next, LASSO and Univariate Cox analyses were used to construct the risk model. Additionally, an analysis of Cox regression was used to construct a nomogram. Next, the immune infiltration in malignant tumour tissues was compared between high- and low-risk groups using Estimation of STromal and Immune cells in MAlignant Tumours (ESTIMATE) tissues and Cell-type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT). The sensitivity differences of immunotherapy between the two risk groups were estimated by Tumor Immune Dysfunction and Exclusion (TIDE), and compared by rank-sum test. Finally, the model genes were detected by fluorescent real-time quantitative polymerase chain reaction (qRT-PCR). A total of 57 DE-CAFGs were acquired, and 9 of them (SHCBP1, CCNA2, AKAP12, CCNB1, GALNT3, SCGB1A1, CPS1, CDC6, and CXCL13) were selected as prognostic biomarkers. The Cox independent prognosis revealed the RiskScore and Stage were the two LUAD independent prognosis factors Moreover, 11 types of immune cells (memory B cells, resting natural killer cells (NK cells), Eosinophils, Macrophages M0, CD4 memory resting T cells, CD4 memory activated T cells, resting Mast cells, naive B cells, T cells regulatory (Tregs), neutrophils, and plasma cell), and 18 human leukocyte antigen (HLA) genes were different with the two risk groups. Lastly, the TIDE analysis showed differences between the two risk groups for TIDE, T cell dysfunction, and T cell exclusion, PD-L1 treatment scores. Lastly, Both LUAD and normal samples expressed the 9 model genes differently. A CAF-related prognostic model was constructed, which may have potential immunotherapy guiding significance for LUAD patients.

Prediction of nano, fine, and medium colloidal phosphorus in agricultural soils with machine learning.

Soil colloids have been shown to play a critical role in soil phosphorus (P) mobility and transport. However, identifying the potential mechanisms behind colloidal P (Pcoll) release and the key influencing factors remains a blind spot. Herein, a machine learning approach (random forest (RF) coupled with partial dependence plot analyses) was applied to determine the effects of different soil physicochemical parameters on Pcoll content in three colloidal subfractions (i.e., nano- (NC): 1-20 nm, fine- (FC): 20-220 nm and medium-sized colloids (MC): 220-450 nm) based on a regional dataset of 12 farmlands in Zhejiang Province, China. RF successfully predicted Pcoll content (R2 = 0.98). Results showed that colloidal- organic carbon (OCcoll) and minerals were the major determinants of total Pcoll content (1-450 nm); their critical values for increasing Pcoll release were 87.0 mg L-1 for OCcoll, 11.0 mg L-1 for iron (Fecoll) or aluminium (Alcoll), 2.6 mg L-1 for calcium (Cacoll), 9.0 mg L-1 for magnesium (Mgcoll), 2.5 mg L-1 for silicon (Sicoll), and 1.4 mg L-1 for manganese (Mncoll). Among three colloidal subfractions, the major factors determining Pcoll were soil Olsen-P (POlsen; 125.0 mg kg-1), Cacoll (2.5 mg L-1), and colloidal P saturation (21.0%) in NC; Mncoll (1.5 mg L-1), Mgcoll (6.8 mg L-1), and POlsen (135.0 mg kg-1) in FC; while Mncoll (1.5 mg L-1), Alcoll (2.5 mg L-1), and Fecoll (3.8 mg L-1) in MC, respectively. OCcoll had a considerable effect in the three fractions, with critical values of 80.0 mg L-1 in NC or FC, and 50.0 mg L-1 in MC. Our study concluded that the information gleaned using the RF model can be used as crucial evidence to identify the key determinants of different size fractionated Pcoll contents. However, we still need to discover one or more easy-to-measure parameters that can help us better predict Pcoll.

Effect and mechanical mechanism of spontaneous breathing on oxygenation and lung injury in mild or moderate animal ARDS.

OBJECTIVE: The present study aimed to determine the effect and mechanical mechanism of spontaneous breathing during mechanical ventilation on oxygenation and lung injury using Beagles dogs mild or moderate acute respiratory distress syndrome (ARDS) model. METHODS: After inducing mild or moderate ARDS by infusion of oleic acid, Eighteen Beagles dogs were randomly split into Spontaneous breathing group (BIPAPSB, n = 6), and Complete muscle paralysis group (BIPAPPC, n = 6),Six Beagles without ventilator support comprised the control group. Both groups were ventilated for 8 h under BIPAP mode. High-pressure was titrated TV to 6 ml/kg. A multi-pair esophageal balloon electrode catheter was used to measure respiratory mechanics and electromyogram. End-expiratory lung volume (EELV), gas exchange and respiratory variables were recorded in the process of mechanical ventilation. The contents of Interleukin (IL)-6 and IL-8 in lung tissue were measure using qRT-PCR. Besides, lung injury score was calculated in the end of mechanical ventilation. RESULTS: Based on the comparable setting of ventilator, BIPAPSB group exhibited higher safety peak transpulmonary pressure, abdominal pressure, EELV and P/F(PaO2/FiO2) than BIPAPPC group, whereas mean transpulmonary pressure, the mRNA levels of the IL-6 and IL-8 in the lung tissues and lung injury score in BIPAPSB group were lower than those in BIPAPPC group. CONCLUSION: In mild to moderate ARDS animal models, during mechanical ventilation, SB may improve respiratory function and reduce ventilator-induced lung injury. The mechanism may be that spontaneous inspiration up-regulates peak transpulmonary pressure and EELV; Spontaneous expiration decreases mean transpulmonary pressure by up-regulating intra-abdominal pressure, thereby reducing stress and strain.

Aptasensor-based assay for dual-readout determination of aflatoxin B1 in corn and wheat via an electrostatic force-mediated FRET strategy.

A rapid and sensitive aptasensor was established for the dual-readout determination of aflatoxin B1 (AFB1) utilizing an electrostatically mediated fluorescence resonance energy transfer (FRET) signal amplification strategy. In the presence of AFB1, the aptamer preferentially bound to AFB1, resulting in the aggregation of bare gold nanoparticles (AuNPs) induced by NaCl, accompanied by a change of AuNP solution from wine-red to purple. This color change was used for colorimetric channel analysis. Then, the positively charged quantum dots were introduced into reaction system and interacted with negatively charged AuNPs, which successfully converted the color signal into a more sensitive fluorescence signal through FRET. The fluorescence quenching efficiency decreased with increasing concentrations of AFB1, and the fluorescence of aptasensor gradually recovered. The variation of fluorescence intensity was employed for fluorometric channel analysis. Under the optimal conditions, the color and fluorescence signals exhibited excellent response to AFB1 concentration within the ranges 10-320 ng·mL-1 and 3-320 ng·mL-1, respectively, and the limit of detection was as low as 7.32 ng·mL-1 and 1.48 ng·mL-1, respectively. The proposed aptasensor exhibited favorable selectivity, good recovery (85.3-113.4% in spiked corn and wheat samples), stable reproducibility (RSD<13.3%), and satisfactory correlation with commercial kits (R2=0.998). The aptasensor developed integrates advantages of modification-free, dual-readout, self-calibration, easy operation, and cost-effectiveness, while providing a simple and universal strategy for rapid and sensitive detection of mycotoxins in foodstuffs.

Improving the Thermostability of Thermomyces lanuginosus Lipase by Restricting the Flexibility of N-Terminus and C-Terminus Simultaneously via the 25-Loop Substitutions.

(1) Lipases are catalysts widely applied in industrial fields. To sustain the harsh treatments in industries, optimizing lipase activities and thermal stability is necessary to reduce production loss. (2) The thermostability of Thermomyces lanuginosus lipase (TLL) was evaluated via B-factor analysis and consensus-sequence substitutions. Five single-point variants (K24S, D27N, D27R, P29S, and A30P) with improved thermostability were constructed via site-directed mutagenesis. (3) The optimal reaction temperatures of all the five variants displayed 5 °C improvement compared with TLL. Four variants, except D27N, showed enhanced residual activities at 80 °C. The melting temperatures of three variants (D27R, P29S, and A30P) were significantly increased. The molecular dynamics simulations indicated that the 25-loop (residues 24-30) in the N-terminus of the five variants generated more hydrogen bonds with surrounding amino acids; hydrogen bond pair D254-I255 preserved in the C-terminus of the variants also contributes to the improved thermostability. Furthermore, the newly formed salt-bridge interaction (R27…E56) in D27R was identified as a crucial determinant for thermostability. (4) Our study discovered that substituting residues from the 25-loop will enhance the stability of the N-terminus and C-terminus simultaneously, restrict the most flexible regions of TLL, and result in improved thermostability.

Foegraecumoside O and P, a Pair of Triterpenoid Saponins with a 4/5/6 Fused Tricyclic Oleanane Carbon Skeleton from Lysimachia foenum-graecum Hance.

Lysimachia foenum-graecum Hance (Primulaceae) is a medicinal plant used for cold, pain, ascariasis, etc., in China. Triterpenoid saponins have been found to be the main components of this genus. In this work, a pair of oleanane-type triterpenoid saponins with an unprecedented 4/5/6 fused tricyclic skeleton, foegraecumoside O (1) and foegraecumoside P (2) were isolated from the butanol fraction of the aerial parts of L. foenum-graecum. Their structures were determined using chemical methods and extensive spectroscopic analyses, along with quantum chemical calculations. Compound 2 displayed moderate cytotoxicity against HepG2, MGC-803, T24, NCI-H460, A549, and A549/CDDP (drug-resistant lung-cancer cell line) with IC50 at 12.4-19.2 µM in an MTT assay, comparing with the positive control doxorubicin, which had IC50 at 0.53-4.92 µM, but was inactive for A549/CDDP. Furthermore, a possible biosynthetic pathway for forming compounds 1 and 2 was proposed.