Radiomics Combined with ACR TI-RADS for Thyroid Nodules: Diagnostic Performance, Unnecessary Biopsy Rate, and Nomogram Construction.

RATIONALE AND OBJECTIVES: To develop a radiomics model with enhanced diagnostic performance, reduced unnecessary fine needle aspiration biopsy (FNA) rate, and improved clinical net benefit for thyroid nodules. METHODS: We conducted a retrospective study of 217 thyroid nodules. Lesions were divided into training (n = 152) and verification (n = 65) cohorts. Three radiomics scores were derived from B-mode ultrasound (B-US) and strain elastography (SE) images, alone and in combination. A radiomics nomogram was constructed by combining high-frequency ultrasonic features and the best-performing radiomics score. The area under the receiver operating characteristic curve (AUC), unnecessary FNA rate, and decision curve analysis (DCA) results for the nomogram were compared to those obtained with the American College of Radiology Thyroid Imaging, Reporting and Data System (ACR TI-RADS) score and the combined TI-RADS+SE+ contrast-enhanced ultrasound (CEUS) advanced clinical score. RESULTS: The three radiomics scores (B-US, SE, B-US+SE) achieved training AUCs of 0.753 (0.668-0.825), 0.761 (0.674-0.838), and 0.795 (0.715-0.871), and validation AUCs of 0.732 (0.579-0.867), 0.753 (0.609-0.892), and 0.752 (0.592-0.899) respectively. The AUC of the nomogram for the entire patient cohort was 0.909 (0.864-0.954), which was higher than that of the ACR TI-RADS score (P < 0.001) and equivalent to the TI-RADS+SE+CEUS score (P = 0.753). Similarly, the unnecessary FNA rate of the radiomics nomogram was significantly lower than that of the ACR TI-RADS score (P = 0.007) and equivalent to the TI-RADS+SE+CEUS score (P = 0.457). DCA also showed that the radiomics nomogram brought more net clinical benefit than the ACR TI-RADS score but was similar to that of the TI-RADS+SE+CEUS score. CONCLUSION: The radiomics nomogram developed in this study can be used as an objective, accurate, cost-effective, and noninvasive method for the characterization of thyroid nodules.

Multi-modal ultrasound multistage classification of PTC cervical lymph node metastasis via DualSwinThyroid.

Objective: This study aims to predict cervical lymph node metastasis in papillary thyroid carcinoma (PTC) patients with high accuracy. To achieve this, we introduce a novel deep learning model, DualSwinThyroid, leveraging multi-modal ultrasound imaging data for prediction. Materials and methods: We assembled a substantial dataset consisting of 3652 multi-modal ultrasound images from 299 PTC patients in this retrospective study. The newly developed DualSwinThyroid model integrates various ultrasound modalities and clinical data. Following its creation, we rigorously assessed the model's performance against a separate testing set, comparing it with established machine learning models and previous deep learning approaches. Results: Demonstrating remarkable precision, DualSwinThyroid achieved an AUC of 0.924 and an 96.3% accuracy on the test set. The model efficiently processed multi-modal data, pinpointing features indicative of lymph node metastasis in thyroid nodule ultrasound images. It offers a three-tier classification that aligns each level with a specific surgical strategy for PTC treatment. Conclusion: DualSwinThyroid, a deep learning model designed with multi-modal ultrasound radiomics, effectively estimates the degree of cervical lymph node metastasis in PTC patients. In addition, it also provides early, precise identification and facilitation of interventions for high-risk groups, thereby enhancing the strategic selection of surgical approaches in managing PTC patients.

Correlation and Performance of three Ultrasound Techniques to Stage Hepatic Steatosis in Nonalcoholic Fatty Liver Disease.

AIMS: There is a need to assess the severity of steatosis caused by Nonalcoholic Fatty Liver Disease (NAFLD). We explored new techniques in which Ultrasound-Guided Attenuation Parameter (UGAP), Liver Steatosis Analysis (LiSA) and Hepatorenal Index (HRI) can be applied to the grading of steatosis. MATERIALS AND METHODS: We enrolled 120 patients with or without NAFLD in this study who underwent UGAP, LiSA, HRI and controlled attenuation parameter (CAP) measurements in our hospital from September 2022 to April 2023. Spearman correlation coefficient was used to calculate the correlation between UGAP, LiSA, HRI and CAP values, and the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic accuracy of UGAP, LiSA, and HRI for different grades of steatosis. RESULTS: The cohort was classified into four groups based on means of CAP: S0 (no steatosis): 30/120, S1 (mild): 30/120, S2 (moderate): 15/120, and S3 (severe): 45/120. The cut-off values and areas under the receiver operating characteristic curve (AUC) of UGAP, LiSA and HRI for predicting different grades of steatosis were: S≥S1:227dB/m (AUC=0.904), 241dB/m (AUC=0.873), 1.19 (AUC=0.696); S≥S2:251dB/m (AUC=0.978), 264dB/m (AUC=0.913), 1.37 (AUC=0.770); S=S3:263dB/m (AUC=0.962), 289dB/m (AUC=0.923), 1.45 (AUC=0.809). The diagnostic efficacy of UGAP and LiSA was significantly better than HRI, and there were statistically significant differences (all p<0.05). A strong correlation was found between UGAP, LiSA and CAP values (UGAP: r=0.865; LiSA: r=0.810), moderate correlation between HRI and CAP values (r=0.476). CONCLUSION: Both UGAP and LiSA have a strong correlation with CAP and are more accurate than HRI in diagnosing different grades of hepatic steatosis, which can be widely used in the diagnosis of liver steatosis.

Association between dietary antioxidant quality score and periodontitis: A cross-sectional study.

Background/purpose: Evidence to date linking relation between dietary antioxidant quality score (DAQS) and periodontitis is limited. This study aimed to investigate the relationship between DAQS and periodontitis. Materials and methods: In total, 9457 participants from the National Health and Nutrition Examination Survey 2009-2014 were enrolled in this cross-sectional study. The outcome was defined as periodontitis. DAQS was calculated by comparing the daily dietary intake of six micronutrients (vitamin A, C, E, selenium, magnesium and zinc) to the recommended daily intake, which was divided into three groups: low quality (1-2 points), medium quality (3-4 points) and high quality (5-6 points). Weighted logistic regression models were carried out to examine the association of DAQS and periodontitis. Meanwhile, this study investigated the effects of DAQS and periodontitis by stratified specific analyses based on diabetes and dyslipidemia. Results: There were 4951 participants with periodontitis and 4506 non-periodontitis subjects. Compared with periodontitis group, mean DAQS score in participants with non-periodontitis was higher. After adjusting for all possible confounding factors, the results showed that high quality group of DAQS was related to the decreased risk of periodontitis [odds ratio (OR) = 0.80, 95% confidence interval (CI): 0.67-0.95, P = 0.012]. Subgroup analysis showed that the association between high quality group of DAQS and periodontitis was significant in participants without diabetes nor dyslipidemia (OR = 0.58, 95%CI: 0.39-0.87, P = 0.009). Conclusion: Based on data from nationally representative data from the US population, DAQS is found to be associated with periodontitis risk.

4D-diaXLMS: Proteome-wide Four-Dimensional Data-Independent Acquisition Workflow for Cross-Linking Mass Spectrometry.

Cross-linking mass spectrometry (XL-MS) is a powerful tool for examining protein structures and interactions. Nevertheless, analysis of low-abundance cross-linked peptides is often limited in the data-dependent acquisition (DDA) mode due to its semistochastic nature. To address this issue, we introduced a workflow called 4D-diaXLMS, representing the first-ever application of four-dimensional data-independent acquisition for proteome-wide cross-linking analysis. Cross-linking studies of the HeLa cell proteome were evaluated using the classical cross-linker disuccinimidyl suberate as an example. Compared with the DDA analysis, 4D-diaXLMS exhibited marked improvement in the identification coverage of cross-linked peptides, with a total increase of 36% in single-shot analysis across all 16 SCX fractions. This advantage was further amplified when reducing the fraction number to 8 and 4, resulting in 125 and 149% improvements, respectively. Using 4D-diaXLMS, up to 83% of the cross-linked peptides were repeatedly identified in three replicates, more than twice the 38% in the DDA mode. Furthermore, 4D-diaXLMS showed good performance in the quantitative analysis of yeast cross-linked peptides even in a 15-fold excess amount of HeLa cell matrix, with a low coefficient of variation and high quantitative accuracies in all concentrations. Overall, 4D-diaXLMS was proven to have high coverage, good reproducibility, and accurate quantification for in-depth XL-MS analysis in complex samples, demonstrating its immense potential for advances in the field.

Enhanced bone regeneration by low-intensity pulsed ultrasound and lipid microbubbles on PLGA/TCP 3D-printed scaffolds.

BACKGROUND: To investigate the effect of low-intensity pulsed ultrasound (LIPUS) combined with lipid microbubbles on the proliferation and bone regeneration of bone marrow mesenchymal stem cells (BMSCs) in poly (lactic-glycolic acid copolymer) (PLGA)/α-tricalcium phosphate (TCP) 3D-printed scaffolds. METHODS: BMSCs were irradiated with different LIPUS parameters and microbubble concentrations, and the best acoustic excitation parameters were selected. The expression of type I collagen and the activity of alkaline phosphatase were detected. Alizarin red staining was used to evaluate the calcium salt production during osteogenic differentiation. RESULTS: BMSCs proliferation was the most significant under the condition of 0.5% (v/v) lipid microbubble concentration, 2.0 MHz frequency, 0.3 W/cm2 sound intensity and 20% duty cycle. After 14 days, the type I collagen expression and alkaline phosphatase activity in the scaffold increased significantly compared to those in the control group, and alizarin red staining showed more calcium salt production during osteogenic differentiation. After 21 days, scanning electron microscopy experiments showed that osteogenesis was obvious in the PLGA/TCP scaffolds. CONCLUSION: LIPUS combined with lipid microbubbles on PLGA/TCP scaffolds can promote BMSCs growth and bone differentiation, which is expected to provide a new and effective method for the treatment of bone regeneration in tissue engineering.

High-Coverage Four-Dimensional Data-Independent Acquisition Proteomics and Phosphoproteomics Enabled by Deep Learning-Driven Multidimensional Predictions.

Four-dimensional (4D) data-independent acquisition (DIA)-based proteomics is a promising technology. However, its full performance is restricted by the time-consuming building and limited coverage of a project-specific experimental library. Herein, we developed a versatile multifunctional deep learning model Deep4D based on self-attention that could predict the collisional cross section, retention time, fragment ion intensity, and charge state with high accuracies for both the unmodified and phosphorylated peptides and thus established the complete workflows for high-coverage 4D DIA proteomics and phosphoproteomics based on multidimensional predictions. A 4D predicted library containing ∼2 million peptides was established that could realize experimental library-free DIA analysis, and 33% more proteins were identified than using an experimental library of single-shot measurement in the example of HeLa cells. These results show the great values of the convenient high-coverage 4D DIA proteomics methods.

Selective versus stepwise removal of deep carious lesions: A meta-analysis of randomized controlled trials.

Background/purpose: Stepwise removal (SWR) and selective removal (SCR) are proposed techniques to treat deep carious lesions, but it is currently uncertain which technique is better. This meta-analysis aimed to compare the therapeutic effects of SCR and SWR for deep carious lesions in both primary and permanent teeth. Materials and methods: PubMed, Embase, Cochrane Library, Web of Science, CNKI, WanFang, and VIP databases were searched until June 9, 2021. Success was the primary outcome. Secondary outcomes included pulp exposure, tooth extraction, pulp necrosis, pulpitis, and endodontic treatment. The effect size of each outcome was tested for heterogeneity. The source of heterogeneity was explored by meta regression analysis. Subgroup analysis and sensitivity analysis were conducted for the outcomes. Results: Nine studies of 1550 patients with 1929 deep carious teeth were included. SCR had a significantly higher success rate than SWR (pooled relative risk [RR] = 1.123, 95% confidence interval [CI] = 1.056-1.194, I2 = 52.3%, P < 0.001). The incidence of pulp exposure was significantly lower in the SCR group than that in the SWR group (pooled RR = 0.266, 95%CI = 0.096-0.740, I2 = 0.0%, P = 0.011). The incidence of pulp necrosis in the SCR group was approximately 14.2% of that in the SWR group (pooled RR = 0.142, 95%CI = 0.026-0.789, I2 = 0.0%, P = 0.026). Compared with SWR, SCR reduced the incidence of pulpitis by about 76.3% (pooled RR = 0.237, 95%CI = 0.090-0.623, I2 = 0.0%, P = 0.003). Conclusion: SCR may be a better treatment for deep caries to achieve better outcomes than SWR. Future research on comparing SCR and SWR for different outcomes in deep carious lesions is warranted to confirm our findings.

Uncovering the interference from lipid fragments on the qualification and quantification of serum metabolites in matrix-assisted laser desorption/ionization time-of-flight mass spectrometric analysis.

RATIONALE: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has exhibited great advantages in rapid analysis of metabolites. However, the influence of lipid fragments generated by in-source fragmentation (ISD) and/or post-source fragmentation (PSD) on the accurate qualification and quantification of metabolites has not been fully demonstrated. METHODS: Phospholipid standards and serum extract were analyzed by MALDI MS with both TiO2 nanoparticle (TiO2 NP) and 2,5-DHB matrices to illustrate the structures of lipid fragments and their influence on the qualitative and quantitative analysis of metabolites in biological samples. Monophasic and biphasic extraction methods were also compared for their efficiency in removing potential interferents. RESULTS: The fragment ions derived from the phosphocholine head group of phosphatidylcholines (PC) interfere with peaks of low molecular weight (LMW) metabolites at both the MS and MS2 levels. The biphasic extraction system with methanol/chloroform very efficiently removed the interference from PC fragments, and the metabolites choline and carnitine in serum were directly and accurately quantified by MALDI MS by using this biphasic extraction. CONCLUSIONS: The phospholipids could produce fragment ions through ISD and PSD in MALDI MS with both nanoparticle and organic matrices. The fragments exerted influence on the qualification and qualification of metabolites in serum. By choosing the proper extraction method, the interference from lipid fragments could be efficiently alleviated.

A protocol for investigating lipidomic dysregulation and discovering lipid biomarkers from human serums.

Lipids play important roles in various human diseases. Disease-associated lipid dysregulation and biomarkers could provide molecular clues for diagnosis, pathogenesis, and therapy. This protocol provides a step-by-step workflow to investigate lipid dysregulation and discover biomarkers in human serum samples by liquid chromatography-mass spectrometry (LC-MS)-based lipidomics and machine learning analysis. The workflow includes project design, serum collection, sample preparation, data acquisition, data processing, and machine learning analysis. For complete details on the use and execution of this profile, please refer to Hao et al. (2021).

High-Throughput Nano-Electrostatic-Spray Ionization/Photoreaction Mass Spectrometric Platform for the Discovery of Visible-Light-Activated Photocatalytic Reactions in the Picomole Scale.

Visible-light-activated photocatalysis has emerged as a green and powerful tool for the synthesis of various organic compounds under mild conditions. However, the expeditious discovery of novel photocatalysts and synthetic pathways remains challenging. Here, we developed a bifunctional platform that enabled the high-throughput discovery and optimization of new photochemical reactions down to the picomole scale. This platform was designed based on a contactless nano-electrostatic-spray ionization technique, which allows synchronized photoreactions and high-throughput in situ mass spectrometric analysis with a near-100% duty cycle. Using this platform, we realized the rapid screening of photocatalytic reactions in ambient conditions with a high speed of less than 1.5 min/reaction using picomolar materials. The versatility was validated by multiple visible-light-induced photocatalytic reactions, especially the discovery of aerobic C-H thiolation with low-cost organic photocatalysts without any other additives. This study provided a new paradigm for the integration of ambient ionization techniques and new insights into photocatalytic reaction screening, which will have broad applications in the development of new visible-light-promoted reactions.

Machine Learning of Serum Metabolic Patterns Encodes Asymptomatic SARS-CoV-2 Infection.

Asymptomatic COVID-19 has become one of the biggest challenges for controlling the spread of the SARS-CoV-2. Diagnosis of asymptomatic COVID-19 mainly depends on quantitative reverse transcription PCR (qRT-PCR), which is typically time-consuming and requires expensive reagents. The application is limited in countries that lack sufficient resources to handle large-scale assay during the COVID-19 outbreak. Here, we demonstrated a new approach to detect the asymptomatic SARS-CoV-2 infection using serum metabolic patterns combined with ensemble learning. The direct patterns of metabolites and lipids were extracted by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) within 1 s with simple sample preparation. A new ensemble learning model was developed using stacking strategy with a new voting algorithm. This approach was validated in a large cohort of 274 samples (92 asymptomatic COVID-19 and 182 healthy control), and provided the high accuracy of 93.4%, with only 5% false negative and 7% false positive rates. We also identified a biomarker panel of ten metabolites and lipids, as well as the altered metabolic pathways during asymptomatic SARS-CoV-2 Infection. The proposed rapid and low-cost approach holds promise to apply in the large-scale asymptomatic COVID-19 screening.

Hsa_circ_0060937 accelerates non-small cell lung cancer progression via modulating miR-195-5p/HMGB3 pathway.

Circular RNAs (circRNAs) exert a critical effect on tumorigenesis and development. Our research aimed to clarify the function and underlying mechanism of circ_0060937 inNSCLC. The concentrations of circ_0060937, miR-195-5p and high-mobility group box 3 (HMGB3) were monitored via qRT-PCR and western blot assays. Additionally, cell proliferation, apoptosis, migration and invasion were assessed using CCK-8, colony formation, flow cytometry and transwell assays. Glycolysis was evaluated via detecting glucose uptake and lactate product. The association between miR-195-5p and circ_0060937/HMGB3 were validated using dual-luciferase reporter, RNA pull-down and RIP assays. Furthermore,in vivo experiment was performed to analyze tumorigenesis.Circ_0060937 and HMGB3 levels were elevated, whereas miR-195-5p level was dropped in NSCLC. Circ_0060937 down-regulation restrainedNSCLC cell proliferation, migration, invasion and glycolysis, and triggered apoptosis. Knockdown of circ_0060937 restrained NSCLC development via absorbing miR-195-5p. Circ_0060937 silencing inhibited NSCLC progression by mediating HMGB3. Besides, circ_0060937 depletion suppressed tumor growth in vivo.Circ_0060937 knockdown hindered NSCLC development and glycolysis via regulating miR-195-5p/HMGB3 pathway.

Distinct lipid metabolic dysregulation in asymptomatic COVID-19.

Asymptomatic infection is a big challenge in curbing the spread of COVID-19. However, its identification and pathogenesis elucidation remain issues. Here, by performing comprehensive lipidomic characterization of serum samples from 89 asymptomatic COVID-19 patients and 178 healthy controls, we screened out a panel of 15 key lipids that could accurately identify asymptomatic patients using a new ensemble learning model based on stacking strategy with a voting algorithm. This strategy provided a high accuracy of 96.0% with only 3.6% false positive rate and 4.8% false negative rate. More importantly, the unique lipid metabolic dysregulation was revealed, especially the enhanced synthesis of membrane phospholipids, altered sphingolipids homeostasis, and differential fatty acids metabolic pattern, implicating the specific host immune, inflammatory, and antiviral responses in asymptomatic COVID-19. This study provides a potential prediagnostic method for asymptomatic COVID-19 and molecular clues for the pathogenesis and therapy of this disease.

Analysis of the Relevance of the Ultrasonographic Features of Papillary Thyroid Carcinoma and Cervical Lymph Node Metastasis on Conventional and Contrast-Enhanced Ultrasonography.

BACKGROUND: Preoperative prediction of lymph node metastases has a major impact on prognosis and recurrence for patients with papillary thyroid carcinoma (PTC). Thyroid ultrasonography is the preferred inspection to guide the appropriate diagnostic procedure. PURPOSE: To investigate the relationship between PTC and cervical lymph node metastasis (CLNM, including central and lateral LNM) using both conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS). MATERIAL AND METHODS: Our study retrospectively analyzed 379 patients diagnosed with PTC confirmed by surgical pathology at our hospital who underwent US and CEUS examinations from October 2016 to March 2021. Individuals were divided into two groups: the lymph node metastasis group and the nonmetastasis group. The relationship between US and CEUS characteristics of PTC and CLNM was analyzed. Univariate and multivariable logistic regression methods were used to identify the high-risk factors and established a nomogram to predict CLNM in PTC. Furthermore, we explore the frequency of CLNM at each nodal level in PTC patients. RESULTS: Univariate analysis indicated that there were significant differences in gender, age, tumor size, microcalcification, contact with the adjacent capsule, multifocality, capsule integrity and enhancement patterns in CEUS between the lymph node metastasis group and the nonmetastasis group (all P<0.05). Multivariate regression analysis showed that tumor size ≥1 cm, age ≤45 years, multifocality, and contact range of the adjacent capsule >50% were independent risk factors for CLNM in PTC, which determined the nomogram. The diagnostic model had an area under the curve (AUC) of 0.756 (95% confidence interval, 0.707-0.805). And calibration plot analysis shown that clinical utility of the nomogram. In 162 PTC patients, the metastatic rates of cervical lymph nodes at levels I-VI were 1.9%, 15.4%, 35.2%, 34.6%, 15.4%, 82.1%, and the difference was statistically significant (P<0.001). CONCLUSION: Our study indicated that the characteristics of PTC on ultrasonography and CEUS can be used to predict CLNM as a useful tool. Preoperative analysis of ultrasonographical features has important value for predicting CLNM in PTCs. The risk of CLNM is greater when tumor size ≥1 cm, age ≤45 years, multifocality, contact range of the adjacent capsule >50% are present.

Circular RNA Circ_0016760 Modulates Non-Small-Cell Lung Cancer Growth Through the miR-577/ZBTB7A Axis.

BACKGROUND: Patients with locally advanced or metastatic non-small-cell lung cancer (NSCLC) have a poor prognosis. Circular RNA circ_0016760 (circ_0016760) is associated with the development of NSCLC. At present, the role and regulatory mechanism of circ_0016760 in NSCLC have not been well explained. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was executed to detect the expression of circ_0016760, miR-577, and Zinc finger and BTB domain containing 7A (ZBTB7A) mRNA in NSCLC tissues and cells. The colony formation, migration, invasion, and extracellular acidification rate (ECAR) of NSCLC cells were determined through colony formation, transwell, or ECAR assays. The relationship between circ_0016760 or ZBTB7A and miR-577 was analyzed via dual-luciferase reporter and RNA pull-down or RNA immunoprecipitation (RIP) assays. Protein level of ZBTB7A was evaluated with Western blot analysis. Xenograft assay was conducted to confirm the role of circ_0016760 in vivo. RESULTS: Circ_0016760 and ZBTB7A were upregulated and miR-577 was downregulated in NSCLC tissues and cells. Circ_0016760 exhaustion curbed the colony formation, migration, invasion, and ECAR of NSCLC cells in vitro and impeded tumor growth in vivo. Mechanically, circ_0016760 modulated ZBTB7A expression via sponging miR-577 in NSCLC cells. MiR-577 downregulation abolished the repressive effects of circ_0016760 silencing on colony formation, migration, invasion, and ECAR of NSCLC cells. Also, ZBTB7A upregulation overturned the repressive impacts of miR-577 elevation on colony formation, migration, invasion, and ECAR of NSCLC cells. CONCLUSION: Circ_0016760 silencing impeded NSCLC advancement through regulation of the miR-577/ZBTB7A axis.

A visible-light activated [2 + 2] cycloaddition reaction enables pinpointing carbon-carbon double bonds in lipids.

The precise location of C[double bond, length as m-dash]C bonds in bioactive molecules is critical for a deep understanding of the relationship between their structures and biological roles. However, the traditional ultraviolet light-based approaches exhibited great limitations. Here, we discovered a new type of visible-light activated [2 + 2] cycloaddition of carbonyl with C[double bond, length as m-dash]C bonds. We found that carbonyl in anthraquinone showed great reactivities towards C[double bond, length as m-dash]C bonds in lipids to form oxetanes under the irradiation of visible-light. Combined with tandem mass spectrometry, this site-specific dissociation of oxetane enabled precisely locating the C[double bond, length as m-dash]C bonds in various kinds of monounsaturated and polyunsaturated lipids. The proof-of-concept applicability of this new type of [2 + 2] photocycloaddition was validated in the global identification of unsaturated lipids in a complex human serum sample. 86 monounsaturated and polyunsaturated lipids were identified with definitive positions of C[double bond, length as m-dash]C bonds, including phospholipids and fatty acids even with up to 6 C[double bond, length as m-dash]C bonds. This study provides new insights into both the photocycloaddition reactions and the structural lipidomics.

[Investigation of aflatoxins,mycobiota,and toxigenic fungi during post-harvest handling of Ziziphi Spinosae Semen].

Ziziphi Spinosae Semen is one of the Chinese herbal medicine being susceptible to aflatoxins contamination. To investigate the sources of aflatoxins contamination and toxigenic fungi species on Ziziphi Spinosae Semen,32 samples were collected from multiple steps during the post-harvest processing in this study. Aflatoxins in these samples were determined by immunoaffinity column and HPLC coupled with post-column photochemical derivatization. The dilution-plate method was applied to the fungi isolation. The isolated fungi strains were identified by morphological characterization and molecular approaches. The results showed that aflatoxins were detected in 28 samples from every step during the processing of Ziziphi Spinosae Semen. Three samples were detected with aflatoxin B_1 and 2 samples with both aflatoxin B_1 and total aflatoxin exceeding the limit of Chinese Pharmacopoeia. Especially the samples from the washing step,with the highest detected amounts of AFB_1 and AFs were reached 94. 79,121. 43 µg·kg~(-1),respectively. All 32 samples were contaminated by fungi. The fungal counts on the newly harvested samples were 2. 20 × 10~2 CFU·g~(-1). Moreover,it increased as tphreocessing progresses,and achieved 1. 16×10~6 CFU·g~(-1) after washing. A total of 321 isolates were identified to 17 genera. Aspergillus flavus was the main source of aflatoxins during the processing and storage of Ziziphi Spinosae Semen. One isolate of A. flavus was confirmed producing AFB_1 and AFB_2. The fungal count was significantly increased by composting,and Aspergillus was the predominant genus after shell breaking. The contamination level of aflatoxins was increased by composting and washing.

Directing-Group-Free C7-Alkylations of N-Alkylindoles Mediated by Cationic Zirconium Complexes: Role of Brønsted Acid for Catalytic Manifold.

Highly position selective alkylations of N-alkylindoles at C7-positions have been enabled by cationic zirconium complexes. The strategy provides a straightforward access to install alkyl groups at C7-positions of indoles without a complex directing group. Mechanistic studies provided support for the importance of Brønsted acids in the catalytic manifold.

BIG regulates stomatal immunity and jasmonate production in Arabidopsis.

Plants have evolved an array of responses that provide them with protection from attack by microorganisms and other predators. Many of these mechanisms depend upon interactions between the plant hormones jasmonate (JA) and ethylene (ET). However, the molecular basis of these interactions is insufficiently understood. Gene expression and physiological assays with mutants were performed to investigate the role of Arabidopsis BIG gene in stress responses. BIG transcription is downregulated by methyl JA (MeJA), necrotrophic infection or mechanical injury. BIG deficiency promotes JA-dependent gene induction, increases JA production but restricts the accumulation of both ET and salicylic acid. JA-induced anthocyanin accumulation and chlorophyll degradation are enhanced and stomatal immunity is impaired by BIG disruption. Bacteria- and lipopolysaccaride (LPS)-induced stomatal closure is reduced in BIG gene mutants, which are hyper-susceptible to microbial pathogens with different lifestyles, but these mutants are less attractive to phytophagous insects. Our results indicate that BIG negatively and positively regulate the MYC2 and ERF1 arms of the JA signalling pathway. BIG warrants recognition as a new and distinct regulator that regulates JA responses, the synergistic interactions of JA and ET, and other hormonal interactions that reconcile the growth and defense dilemma in Arabidopsis.